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Publisher: John Wiley and Sons   (Total: 1577 journals)

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Showing 1 - 200 of 1577 Journals sorted alphabetically
Abacus     Hybrid Journal   (Followers: 12, SJR: 0.48, h-index: 22)
About Campus     Hybrid Journal   (Followers: 5)
Academic Emergency Medicine     Hybrid Journal   (Followers: 61, SJR: 1.385, h-index: 91)
Accounting & Finance     Hybrid Journal   (Followers: 46, SJR: 0.547, h-index: 30)
ACEP NOW     Free   (Followers: 1)
Acta Anaesthesiologica Scandinavica     Hybrid Journal   (Followers: 49, SJR: 1.02, h-index: 88)
Acta Archaeologica     Hybrid Journal   (Followers: 144, SJR: 0.101, h-index: 9)
Acta Geologica Sinica (English Edition)     Hybrid Journal   (Followers: 3, SJR: 0.552, h-index: 41)
Acta Neurologica Scandinavica     Hybrid Journal   (Followers: 5, SJR: 1.203, h-index: 74)
Acta Obstetricia et Gynecologica Scandinavica     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 81)
Acta Ophthalmologica     Hybrid Journal   (Followers: 5, SJR: 0.112, h-index: 1)
Acta Paediatrica     Hybrid Journal   (Followers: 56, SJR: 0.794, h-index: 88)
Acta Physiologica     Hybrid Journal   (Followers: 6, SJR: 1.69, h-index: 88)
Acta Polymerica     Hybrid Journal   (Followers: 9)
Acta Psychiatrica Scandinavica     Hybrid Journal   (Followers: 35, SJR: 2.518, h-index: 113)
Acta Zoologica     Hybrid Journal   (Followers: 6, SJR: 0.459, h-index: 29)
Acute Medicine & Surgery     Hybrid Journal   (Followers: 3)
Addiction     Hybrid Journal   (Followers: 33, SJR: 2.086, h-index: 143)
Addiction Biology     Hybrid Journal   (Followers: 12, SJR: 2.091, h-index: 57)
Adultspan J.     Hybrid Journal   (SJR: 0.127, h-index: 4)
Advanced Energy Materials     Hybrid Journal   (Followers: 24, SJR: 6.411, h-index: 86)
Advanced Engineering Materials     Hybrid Journal   (Followers: 26, SJR: 0.81, h-index: 81)
Advanced Functional Materials     Hybrid Journal   (Followers: 50, SJR: 5.21, h-index: 203)
Advanced Healthcare Materials     Hybrid Journal   (Followers: 13, SJR: 0.232, h-index: 7)
Advanced Materials     Hybrid Journal   (Followers: 251, SJR: 9.021, h-index: 345)
Advanced Materials Interfaces     Hybrid Journal   (Followers: 6, SJR: 1.177, h-index: 10)
Advanced Optical Materials     Hybrid Journal   (Followers: 5, SJR: 2.488, h-index: 21)
Advanced Science     Open Access   (Followers: 5)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17, SJR: 2.729, h-index: 121)
Advances in Polymer Technology     Hybrid Journal   (Followers: 13, SJR: 0.344, h-index: 31)
Africa Confidential     Hybrid Journal   (Followers: 19)
Africa Research Bulletin: Economic, Financial and Technical Series     Hybrid Journal   (Followers: 12)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 9)
African Development Review     Hybrid Journal   (Followers: 35, SJR: 0.275, h-index: 17)
African J. of Ecology     Hybrid Journal   (Followers: 15, SJR: 0.477, h-index: 39)
Aggressive Behavior     Hybrid Journal   (Followers: 15, SJR: 1.391, h-index: 66)
Aging Cell     Open Access   (Followers: 10, SJR: 4.374, h-index: 95)
Agribusiness : an Intl. J.     Hybrid Journal   (Followers: 6, SJR: 0.627, h-index: 14)
Agricultural and Forest Entomology     Hybrid Journal   (Followers: 14, SJR: 0.925, h-index: 43)
Agricultural Economics     Hybrid Journal   (Followers: 44, SJR: 1.099, h-index: 51)
AIChE J.     Hybrid Journal   (Followers: 30, SJR: 1.122, h-index: 120)
Alcoholism and Drug Abuse Weekly     Hybrid Journal   (Followers: 7)
Alcoholism Clinical and Experimental Research     Hybrid Journal   (Followers: 7, SJR: 1.416, h-index: 125)
Alimentary Pharmacology & Therapeutics     Hybrid Journal   (Followers: 34, SJR: 2.833, h-index: 138)
Alimentary Pharmacology & Therapeutics Symposium Series     Hybrid Journal   (Followers: 3)
Allergy     Hybrid Journal   (Followers: 49, SJR: 3.048, h-index: 129)
Alternatives to the High Cost of Litigation     Hybrid Journal   (Followers: 3)
American Anthropologist     Hybrid Journal   (Followers: 133, SJR: 0.951, h-index: 61)
American Business Law J.     Hybrid Journal   (Followers: 24, SJR: 0.205, h-index: 17)
American Ethnologist     Hybrid Journal   (Followers: 91, SJR: 2.325, h-index: 51)
American J. of Economics and Sociology     Hybrid Journal   (Followers: 27, SJR: 0.211, h-index: 26)
American J. of Hematology     Hybrid Journal   (Followers: 31, SJR: 1.761, h-index: 77)
American J. of Human Biology     Hybrid Journal   (Followers: 12, SJR: 1.018, h-index: 58)
American J. of Industrial Medicine     Hybrid Journal   (Followers: 16, SJR: 0.993, h-index: 85)
American J. of Medical Genetics Part A     Hybrid Journal   (Followers: 15, SJR: 1.115, h-index: 61)
American J. of Medical Genetics Part B: Neuropsychiatric Genetics     Hybrid Journal   (Followers: 3, SJR: 1.771, h-index: 107)
American J. of Medical Genetics Part C: Seminars in Medical Genetics     Partially Free   (Followers: 5, SJR: 2.315, h-index: 79)
American J. of Physical Anthropology     Hybrid Journal   (Followers: 36, SJR: 1.41, h-index: 88)
American J. of Political Science     Hybrid Journal   (Followers: 254, SJR: 5.101, h-index: 114)
American J. of Primatology     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 63)
American J. of Reproductive Immunology     Hybrid Journal   (Followers: 3, SJR: 1.347, h-index: 75)
American J. of Transplantation     Hybrid Journal   (Followers: 16, SJR: 2.792, h-index: 140)
American J. on Addictions     Hybrid Journal   (Followers: 9, SJR: 0.843, h-index: 57)
Anaesthesia     Hybrid Journal   (Followers: 126, SJR: 1.404, h-index: 88)
Analyses of Social Issues and Public Policy     Hybrid Journal   (Followers: 10, SJR: 0.397, h-index: 18)
Analytic Philosophy     Hybrid Journal   (Followers: 16)
Anatomia, Histologia, Embryologia: J. of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3, SJR: 0.295, h-index: 27)
Anatomical Sciences Education     Hybrid Journal   (Followers: 1, SJR: 0.633, h-index: 24)
Andrologia     Hybrid Journal   (Followers: 2, SJR: 0.528, h-index: 45)
Andrology     Hybrid Journal   (Followers: 2, SJR: 0.979, h-index: 14)
Angewandte Chemie     Hybrid Journal   (Followers: 159)
Angewandte Chemie Intl. Edition     Hybrid Journal   (Followers: 211, SJR: 6.229, h-index: 397)
Animal Conservation     Hybrid Journal   (Followers: 36, SJR: 1.576, h-index: 62)
Animal Genetics     Hybrid Journal   (Followers: 8, SJR: 0.957, h-index: 67)
Animal Science J.     Hybrid Journal   (Followers: 6, SJR: 0.569, h-index: 24)
Annalen der Physik     Hybrid Journal   (Followers: 5, SJR: 1.46, h-index: 40)
Annals of Anthropological Practice     Partially Free   (Followers: 2, SJR: 0.187, h-index: 5)
Annals of Applied Biology     Hybrid Journal   (Followers: 8, SJR: 0.816, h-index: 56)
Annals of Clinical and Translational Neurology     Open Access   (Followers: 1)
Annals of Human Genetics     Hybrid Journal   (Followers: 9, SJR: 1.191, h-index: 67)
Annals of Neurology     Hybrid Journal   (Followers: 44, SJR: 5.584, h-index: 241)
Annals of Noninvasive Electrocardiology     Hybrid Journal   (Followers: 2, SJR: 0.531, h-index: 38)
Annals of Public and Cooperative Economics     Hybrid Journal   (Followers: 9, SJR: 0.336, h-index: 23)
Annals of the New York Academy of Sciences     Hybrid Journal   (Followers: 5, SJR: 2.389, h-index: 189)
Annual Bulletin of Historical Literature     Hybrid Journal   (Followers: 12)
Annual Review of Information Science and Technology     Hybrid Journal   (Followers: 14)
Anthropology & Education Quarterly     Hybrid Journal   (Followers: 24, SJR: 0.72, h-index: 31)
Anthropology & Humanism     Hybrid Journal   (Followers: 17, SJR: 0.137, h-index: 3)
Anthropology News     Hybrid Journal   (Followers: 15)
Anthropology of Consciousness     Hybrid Journal   (Followers: 11, SJR: 0.172, h-index: 5)
Anthropology of Work Review     Hybrid Journal   (Followers: 11, SJR: 0.256, h-index: 5)
Anthropology Today     Hybrid Journal   (Followers: 92, SJR: 0.545, h-index: 15)
Antipode     Hybrid Journal   (Followers: 45, SJR: 2.212, h-index: 69)
Anz J. of Surgery     Hybrid Journal   (Followers: 6, SJR: 0.432, h-index: 59)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apmis     Hybrid Journal   (Followers: 1, SJR: 0.855, h-index: 73)
Applied Cognitive Psychology     Hybrid Journal   (Followers: 69, SJR: 0.754, h-index: 69)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7, SJR: 0.632, h-index: 58)
Applied Psychology     Hybrid Journal   (Followers: 140, SJR: 1.023, h-index: 64)
Applied Psychology: Health and Well-Being     Hybrid Journal   (Followers: 48, SJR: 0.868, h-index: 13)
Applied Stochastic Models in Business and Industry     Hybrid Journal   (Followers: 5, SJR: 0.613, h-index: 24)
Aquaculture Nutrition     Hybrid Journal   (Followers: 14, SJR: 1.025, h-index: 55)
Aquaculture Research     Hybrid Journal   (Followers: 31, SJR: 0.807, h-index: 60)
Aquatic Conservation Marine and Freshwater Ecosystems     Hybrid Journal   (Followers: 34, SJR: 1.047, h-index: 57)
Arabian Archaeology and Epigraphy     Hybrid Journal   (Followers: 11, SJR: 0.453, h-index: 11)
Archaeological Prospection     Hybrid Journal   (Followers: 12, SJR: 0.922, h-index: 21)
Archaeology in Oceania     Hybrid Journal   (Followers: 13, SJR: 0.745, h-index: 18)
Archaeometry     Hybrid Journal   (Followers: 27, SJR: 0.809, h-index: 48)
Archeological Papers of The American Anthropological Association     Hybrid Journal   (Followers: 14, SJR: 0.156, h-index: 2)
Architectural Design     Hybrid Journal   (Followers: 25, SJR: 0.261, h-index: 9)
Archiv der Pharmazie     Hybrid Journal   (Followers: 4, SJR: 0.628, h-index: 43)
Archives of Drug Information     Hybrid Journal   (Followers: 4)
Archives of Insect Biochemistry and Physiology     Hybrid Journal   (SJR: 0.768, h-index: 54)
Area     Hybrid Journal   (Followers: 12, SJR: 0.938, h-index: 57)
Art History     Hybrid Journal   (Followers: 224, SJR: 0.153, h-index: 13)
Arthritis & Rheumatology     Hybrid Journal   (Followers: 50, SJR: 1.984, h-index: 20)
Arthritis Care & Research     Hybrid Journal   (Followers: 28, SJR: 2.256, h-index: 114)
Artificial Organs     Hybrid Journal   (Followers: 1, SJR: 0.872, h-index: 60)
ASHE Higher Education Reports     Hybrid Journal   (Followers: 14)
Asia & the Pacific Policy Studies     Open Access   (Followers: 14)
Asia Pacific J. of Human Resources     Hybrid Journal   (Followers: 315, SJR: 0.494, h-index: 19)
Asia Pacific Viewpoint     Hybrid Journal   (SJR: 0.616, h-index: 26)
Asia-Pacific J. of Chemical Engineering     Hybrid Journal   (Followers: 7, SJR: 0.345, h-index: 20)
Asia-pacific J. of Clinical Oncology     Hybrid Journal   (Followers: 6, SJR: 0.554, h-index: 14)
Asia-Pacific J. of Financial Studies     Hybrid Journal   (SJR: 0.241, h-index: 7)
Asia-Pacific Psychiatry     Hybrid Journal   (Followers: 3, SJR: 0.377, h-index: 7)
Asian Economic J.     Hybrid Journal   (Followers: 8, SJR: 0.234, h-index: 21)
Asian Economic Policy Review     Hybrid Journal   (Followers: 4, SJR: 0.196, h-index: 12)
Asian J. of Control     Hybrid Journal   (SJR: 0.862, h-index: 34)
Asian J. of Endoscopic Surgery     Hybrid Journal   (SJR: 0.394, h-index: 7)
Asian J. of Organic Chemistry     Hybrid Journal   (Followers: 4, SJR: 1.443, h-index: 19)
Asian J. of Social Psychology     Hybrid Journal   (Followers: 5, SJR: 0.665, h-index: 37)
Asian Politics and Policy     Hybrid Journal   (Followers: 12, SJR: 0.207, h-index: 7)
Asian Social Work and Policy Review     Hybrid Journal   (Followers: 5, SJR: 0.318, h-index: 5)
Asian-pacific Economic Literature     Hybrid Journal   (Followers: 5, SJR: 0.168, h-index: 15)
Assessment Update     Hybrid Journal   (Followers: 4)
Astronomische Nachrichten     Hybrid Journal   (Followers: 2, SJR: 0.701, h-index: 40)
Atmospheric Science Letters     Open Access   (Followers: 29, SJR: 1.332, h-index: 27)
Austral Ecology     Hybrid Journal   (Followers: 13, SJR: 1.095, h-index: 66)
Austral Entomology     Hybrid Journal   (Followers: 10, SJR: 0.524, h-index: 28)
Australasian J. of Dermatology     Hybrid Journal   (Followers: 8, SJR: 0.714, h-index: 40)
Australasian J. On Ageing     Hybrid Journal   (Followers: 7, SJR: 0.39, h-index: 22)
Australian & New Zealand J. of Statistics     Hybrid Journal   (Followers: 13, SJR: 0.275, h-index: 28)
Australian Accounting Review     Hybrid Journal   (Followers: 4, SJR: 0.709, h-index: 14)
Australian and New Zealand J. of Family Therapy (ANZJFT)     Hybrid Journal   (Followers: 3, SJR: 0.382, h-index: 12)
Australian and New Zealand J. of Obstetrics and Gynaecology     Hybrid Journal   (Followers: 43, SJR: 0.814, h-index: 49)
Australian and New Zealand J. of Public Health     Hybrid Journal   (Followers: 11, SJR: 0.82, h-index: 62)
Australian Dental J.     Hybrid Journal   (Followers: 7, SJR: 0.482, h-index: 46)
Australian Economic History Review     Hybrid Journal   (Followers: 4, SJR: 0.171, h-index: 12)
Australian Economic Papers     Hybrid Journal   (Followers: 25, SJR: 0.23, h-index: 9)
Australian Economic Review     Hybrid Journal   (Followers: 6, SJR: 0.357, h-index: 21)
Australian Endodontic J.     Hybrid Journal   (Followers: 3, SJR: 0.513, h-index: 24)
Australian J. of Agricultural and Resource Economics     Hybrid Journal   (Followers: 3, SJR: 0.765, h-index: 36)
Australian J. of Grape and Wine Research     Hybrid Journal   (Followers: 5, SJR: 0.879, h-index: 56)
Australian J. of Politics & History     Hybrid Journal   (Followers: 13, SJR: 0.203, h-index: 14)
Australian J. of Psychology     Hybrid Journal   (Followers: 18, SJR: 0.384, h-index: 30)
Australian J. of Public Administration     Hybrid Journal   (Followers: 398, SJR: 0.418, h-index: 29)
Australian J. of Rural Health     Hybrid Journal   (Followers: 4, SJR: 0.43, h-index: 34)
Australian Occupational Therapy J.     Hybrid Journal   (Followers: 68, SJR: 0.59, h-index: 29)
Australian Psychologist     Hybrid Journal   (Followers: 11, SJR: 0.331, h-index: 31)
Australian Veterinary J.     Hybrid Journal   (Followers: 19, SJR: 0.459, h-index: 45)
Autism Research     Hybrid Journal   (Followers: 31, SJR: 2.126, h-index: 39)
Autonomic & Autacoid Pharmacology     Hybrid Journal   (SJR: 0.371, h-index: 29)
Banks in Insurance Report     Hybrid Journal   (Followers: 1)
Basic & Clinical Pharmacology & Toxicology     Hybrid Journal   (Followers: 10, SJR: 0.539, h-index: 70)
Basic and Applied Pathology     Open Access   (Followers: 2, SJR: 0.113, h-index: 4)
Basin Research     Hybrid Journal   (Followers: 5, SJR: 1.54, h-index: 60)
Bauphysik     Hybrid Journal   (Followers: 2, SJR: 0.194, h-index: 5)
Bauregelliste A, Bauregelliste B Und Liste C     Hybrid Journal  
Bautechnik     Hybrid Journal   (Followers: 1, SJR: 0.321, h-index: 11)
Behavioral Interventions     Hybrid Journal   (Followers: 9, SJR: 0.297, h-index: 23)
Behavioral Sciences & the Law     Hybrid Journal   (Followers: 23, SJR: 0.736, h-index: 57)
Berichte Zur Wissenschaftsgeschichte     Hybrid Journal   (Followers: 9, SJR: 0.11, h-index: 5)
Beton- und Stahlbetonbau     Hybrid Journal   (Followers: 2, SJR: 0.493, h-index: 14)
Biochemistry and Molecular Biology Education     Hybrid Journal   (Followers: 6, SJR: 0.311, h-index: 26)
Bioelectromagnetics     Hybrid Journal   (Followers: 1, SJR: 0.568, h-index: 64)
Bioengineering & Translational Medicine     Open Access  
BioEssays     Hybrid Journal   (Followers: 10, SJR: 3.104, h-index: 155)
Bioethics     Hybrid Journal   (Followers: 14, SJR: 0.686, h-index: 39)
Biofuels, Bioproducts and Biorefining     Hybrid Journal   (Followers: 1, SJR: 1.725, h-index: 56)
Biological J. of the Linnean Society     Hybrid Journal   (Followers: 15, SJR: 1.172, h-index: 90)
Biological Reviews     Hybrid Journal   (Followers: 3, SJR: 6.469, h-index: 114)
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 42, SJR: 0.12, h-index: 1)
Biology of the Cell     Full-text available via subscription   (Followers: 9, SJR: 1.812, h-index: 69)
Biomedical Chromatography     Hybrid Journal   (Followers: 6, SJR: 0.572, h-index: 49)
Biometrical J.     Hybrid Journal   (Followers: 5, SJR: 0.784, h-index: 44)
Biometrics     Hybrid Journal   (Followers: 37, SJR: 1.906, h-index: 96)
Biopharmaceutics and Drug Disposition     Hybrid Journal   (Followers: 10, SJR: 0.715, h-index: 44)
Biopolymers     Hybrid Journal   (Followers: 18, SJR: 1.199, h-index: 104)
Biotechnology and Applied Biochemistry     Hybrid Journal   (Followers: 45, SJR: 0.415, h-index: 55)
Biotechnology and Bioengineering     Hybrid Journal   (Followers: 136, SJR: 1.633, h-index: 146)
Biotechnology J.     Hybrid Journal   (Followers: 13, SJR: 1.185, h-index: 51)
Biotechnology Progress     Hybrid Journal   (Followers: 39, SJR: 0.736, h-index: 101)
Biotropica     Hybrid Journal   (Followers: 18, SJR: 1.374, h-index: 71)
Bipolar Disorders     Hybrid Journal   (Followers: 9, SJR: 2.592, h-index: 100)
Birth     Hybrid Journal   (Followers: 35, SJR: 0.763, h-index: 64)
Birth Defects Research Part A : Clinical and Molecular Teratology     Hybrid Journal   (Followers: 2, SJR: 0.727, h-index: 77)
Birth Defects Research Part B: Developmental and Reproductive Toxicology     Hybrid Journal   (Followers: 5, SJR: 0.468, h-index: 47)
Birth Defects Research Part C : Embryo Today : Reviews     Hybrid Journal   (SJR: 1.513, h-index: 55)
BJOG : An Intl. J. of Obstetrics and Gynaecology     Partially Free   (Followers: 222, SJR: 2.083, h-index: 125)

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Journal Cover AIChE Journal
  [SJR: 1.122]   [H-I: 120]   [30 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0001-1541 - ISSN (Online) 1547-5905
   Published by John Wiley and Sons Homepage  [1577 journals]
  • On the use of a powder rheometer to characterize the powder flowability at
           low consolidation with torque resistances
    • Authors: Hamid Salehi; Denis Schütz, Richard Romirer, Diego Barletta, Massimo Poletto
      Abstract: The Anton Paar Powder Cell was used to measure the torque necessary to rotate an impeller in beds of glass beads, sand and alumina powders aerated between no aeration to the minimum for fluidization. Measured torque values depend on the material tested, on the air flow rate applied, on the impeller depth and on the height of the impeller blade. The effect of the impeller depth is linear for low impeller depth and is less than linear at high depth values. A model was developed for the interpretation of the experimental results based on the idea that the material is shearing on the surface described by the impeller rotation. The model allows to estimate an effectiveness of the impeller in the torque determination and also to predict the torque for the impeller at the at deepest positions at which the wall effects have to be considered. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-17T10:45:45.750695-05:
      DOI: 10.1002/aic.15934
       
  • Experiments on Breakup of Bubbles in a Turbulent Flow
    • Authors: Jiří Vejražka; Mária Zedníková, Petr Stanovský
      Abstract: The breakup of air bubbles in a turbulent water flow is studied experimentally. Water flows from a nozzle array, generating intense turbulence, and then flows downward through a cell. The velocity field is measured by PIV, and the local dissipation rate is estimated using a large-eddy PIV technique. Bubbles (1.8 to 5 mm) are injected in the bottom of the cell and rise toward the region of intense turbulence, where they break. The time spent by bubbles in various zones without breaking and the number of breakups are evaluated, providing information about the breakup frequency. The number of daughter bubbles and their size distribution are determined. The number of daughters depends on a Weber number 2ρε2/3 D'5/3/σ, where ε is the turbulent energy dissipation rate, D' is the mother particle size, ρ and σ are the liquid density and surface tension. The daughter size distribution is a function of their number. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-17T10:45:43.520383-05:
      DOI: 10.1002/aic.15935
       
  • Ultrasound–Assisted Synthesis and Characterization of Polymethyl
           Methacrylate/Reduced Graphene Oxide Nanocomposites
    • Authors: Maneesh Kumar Poddar; Mohammad Arjamand, Uttandaraman Sundararaj, Sushobhan Pradhan, Vijayanand S. Moholkar
      Abstract: This paper reports ultrasound–assisted synthesis of polymethyl methacrylate (PMMA)/reduced graphene oxide (RGO) nanocomposites by in–situ emulsion polymerization coupled with in–situ reduction of graphene oxide. The thermal degradation kinetics of the nanocomposites was also assessed with Criado and Coats-Redfern methods. Intense micro-convection generated by ultrasound and cavitation results in uniform dispersion of RGO in the polymer matrix, which imparts markedly higher physical properties to resulting nanocomposites at low (≤ 1.0 wt%) RGO loadings, as compared to nanocomposites synthesized with mechanical stirring. Some important properties of the PMMA/RGO nanocomposites synthesized with sonication (with various RGO loadings) are: glass transition temperature (0.4 wt%) = 124.5°C, tensile strength (0.4 wt%) = 40.4 MPa, electrical conductivity (1.0 wt%) = 2 × 10−7 S/cm, electromagnetic interference shielding effectiveness (1.0 wt%) = 3.3 dB. Predominant thermal degradation mechanism of nanocomposites (1.0 wt% RGO) is 1-D diffusion with activation energy of 111.3 kJ/mol. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-17T10:45:30.613722-05:
      DOI: 10.1002/aic.15936
       
  • Gas Drying with Ionic Liquids
    • Authors: Jingli Han; Chengna Dai, Lei Zhigang, Biaohua Chen
      Abstract: The gas drying technology with ionic liquids (ILs) was systematically studied ranging from the molecular level to industrial scale. The COSMO-RS model was first used to screen the suitable IL and provide theoretical insights at the molecular level. Towards CO2 gas dehydration, we measured the CO2 solubility in single [EMIM][Tf2N] and in the [EMIM][Tf2N] + H2O mixture, as well as the vapor-liquid equilibrium (VLE) of [EMIM][Tf2N] + H2O system, to justify the applicability of UNIFAC model. Based on the thermodynamic study, the rigorous equilibrium (EQ) stage mathematical model was established for process simulation. The gas drying experiment with IL was also carried out, and the water content in gas product can be reduced to 375 ppm. It was confirmed that a less flow rate of absorbent, a higher CO2 recovery ratio and a much lower energy consumption can be achieved with IL than with the conventional triethylene glycol (TEG). This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:06:00.956979-05:
      DOI: 10.1002/aic.15926
       
  • Chaotic Mixing in a Barrier-Embedded Partitioned Pipe Mixer
    • Authors: Seon Yeop Jung; Kyung Hyun Ahn, Tae Gon Kang, Gi Taek Park, Sang Ug Kim
      Abstract: Inspired by the partitioned-pipe mixer (PPM), a barrier-embedded partitioned pipe mixer (BPPM) is designed and analyzed using a numerical simulation scheme. The BPPM is a static mixer, composed of orthogonally connected rectangular plates with a pair of barriers, which divide, stretch, and fold fluid elements, leading to chaotic mixing via the baker's transformation. The aspect ratio of the plate (α) and the dimensionless height of the barrier (β) are chosen as design parameters to conduct a parameter study on the mixing performance. The flow characteristics and mixing performance are analyzed using the cross-sectional velocity vectors, Poincaré section, interface tracking, and the intensity of segregation. The results indicate that several designs of the BPPM significantly enhance the PPM's mixing performance. The best BPPMs are identified with regard to compactness and energy consumption. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:05:57.928475-05:
      DOI: 10.1002/aic.15929
       
  • CFD Simulation of the Effect of Rain on the Performance of Horizontal Wind
           Turbines
    • Authors: Hamid Arastoopour; Aiden Cohan
      Abstract: Wind turbine power output is influenced by environmental conditions, including rain. Therefore, a better understanding of the effect of rain on the performance of wind turbines is necessary. Our coupled Lagrangian-Eulerian multiphase computational fluid dynamics model was modified to more accurately simulate the momentum transfer during water film formation on the airfoils of a horizontal-axis turbine and the performance loss caused by the rainwater film on the National Renewable Energy Laboratory (NREL) turbine performance. To obtain three-dimensional numerical simulation of the wind turbine in manageable computational time, we made simplifying assumptions and verified the validity of these assumptions by simulating the flow over the S809 airfoil of the NREL turbine. In a dry environment, simulation of turbine power output agreed well with NREL experimental data. Our multiphase model showed that the rain film accumulation and flow on the surface of the turbine airfoil reduces the power output of the turbine. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:05:29.911494-05:
      DOI: 10.1002/aic.15928
       
  • Using the Discrete Element Method to develop Collisional Dissipation Rate
           Models that Incorporate Particle Shape
    • Authors: Kevin E. Buettner; Yu Guo, Jennifer S. Curtis
      Abstract: Discrete Element Method (DEM) simulations of Homogeneous Cooling Systems (HCS) are used to develop a collisional dissipation rate model for non-spherical particle systems that can be incorporated in a two-fluid multiphase flow framework. Two types of frictionless, elongated particle models are compared in the HCS simulations: glued-sphere and true cylinder. Simulation results show that the ratio of translational to rotational granular temperatures is equal to one for the true cylindrical particles with particle aspect ratios (AR) greater than one and glued-sphere particles with AR > 1.5, while the temperature ratio is less than one for glued-sphere particles with 1 
      PubDate: 2017-08-14T11:05:24.559378-05:
      DOI: 10.1002/aic.15933
       
  • Plasma Assisted Nitrogen Oxide Production from Air: Using Pulsed Powered
           Gliding Arc Reactor for a Containerized Plant
    • Authors: B. S. Patil; F. J. J. Peeters, J. A. Medrano, G. J. van Rooij, F. Gallucci, J. Lang, Q. Wang, V. Hessel
      Abstract: The production of NOx from air and air+O2 is investigated in a pulsed powered milli-scale gliding arc (GA) reactor, aiming at a containerized process for fertilizer production. Influence of feed mixture, flowrate, temperature, and Ar and O2 content are investigated at varying specific energy input. The findings are correlated with high-speed imaging of the GA dynamics. An O2 content of 40-48% was optimum, with an enhancement of 11% in NOx production. Addition of Ar and preheating of the feed resulted in lower NOx production. Lower flowrates produced higher NO concentrations due to longer residence time in the GA. The volume covered by GA depends strongly on the gas flowrate, emphasizing that the gas flowrate has a major impact on the GA dynamics and the reaction kinetics. For 0.5 L/min, 1.4 vol% of NOx concentration was realized, which is promising for a containerized process plant to produce fertilizer in remote locations. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:01:37.642803-05:
      DOI: 10.1002/aic.15922
       
  • Quantitative and Qualitative Studies of Microorganisms involved in
           Full-scale Autotrophic Nitrogen Removal Performance
    • Authors: Barbara Muñoz-Palazon; Alejandro Rodriguez-Sanchez, Antonio Castellano-Hinojosa, Jesus Gonzalez-Lopez, Mark C.M. van Loosdrecth, Riku Vahala, Alejandro Gonzalez-Martinez
      Abstract: Autotrophic nitrogen removal systems have been implemented at full-scale and provide an efficient way for nitrogen removal from industrial and urban wastewaters. Our study present qualitative and quantitative analysis of archaeal and bacterial amoA genes and Candidatus Brocadiales bacteria analyzed in six full-scale autotrophic nitrogen removal bioreactors. The results showed that Ammonium Oxidizing Bacteria (AOB) were detected in all bioreactors. However, Ammonium Oxidizing Archaea (AOA) were detected only in the non-aerated technologies. On the other hand, different Candidatus Brocadiales phylotypes appeared due to differences in influent wastewater composition and hydraulic retention time (HRT). In the same terms multivariate redundancy analysis confirmed that AOA was positively correlated with temperature, ammonium concentration and low HRT. However, AOB population was positively correlated with pH, temperature and dissolved oxygen concentration. Our data suggested a correlation between the microorganisms involved in the nitrogen removal performance and the operational conditions in the different full-scale bioreactors. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:00:37.857253-05:
      DOI: 10.1002/aic.15925
       
  • Model for the Outer Cavity of a Dual-Cavity Die with Parameters Determined
           by Two-Dimensional Finite-Element Analysis
    • Authors: Kenneth J. Ruschak; Steven J. Weinstein
      Abstract: A coating die forms liquid layers of uniform thickness for application to a substrate. In a dual-cavity coating die an outer cavity and slot improves flow distribution from an inner cavity and slot. A model for axial flow in the outer cavity must consider the ever present cross flow. A one-dimensional equation for the pressure gradient for a power-law liquid is obtained as a small departure from a uniform flow distribution and no axial flow. The equation contains a shape factor dependent on cavity shape, Reynolds number, and power-law index. The shape factor for five triangular cavity shapes is obtained by finite-element analysis and correlated for application to die design up to the onset of flow recirculation which arises at the junction of the cavity and outer slot. The performance of the combined cavity and slot is considered and the most effective design determined. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:00:33.45287-05:0
      DOI: 10.1002/aic.15927
       
  • Particle-Resolved PIV Experiments of Solid-Liquid Mixing in a Turbulent
           Stirred Tank
    • Authors: Genghong Li; Zhengming Gao, Zhipeng Li, Jiawei Wang, J.J. Derksen
      Abstract: Particle Image Velocimetry (PIV) experiments on turbulent solid-liquid stirred tank flow with careful refractive index matching of the two phases have been performed. The spatial resolution of the PIV data is finer than the size of the spherical, uniformly sized solid particles, thereby providing insight in the flow around individual particles. The impeller is a down-pumping pitch-blade turbine. The impeller-based Reynolds number has been fixed to Re=104. Overall solids volume fractions up to 8% have been investigated. The PIV experiments are impeller-angle resolved, i.e. conditioned on the angular position of the impeller. The two-phase systems are in partially suspended states with an inhomogeneous distribution of solids: high solids loadings near the bottom and near the outer walls of the tank, much less solids in the bulk of the tank. The liquid velocity fields show very strong phase coupling effects with the particles increasingly attenuating the overall circulation patterns as well as the liquid velocity fluctuation levels when the solids volume fraction is increased. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:00:30.294146-05:
      DOI: 10.1002/aic.15924
       
  • Dynamic Formation and Scaling Law of Hollow Droplet with Gas/Oil/Water
           System in Dual-Coaxial Microfluidic Devices
    • Authors: Fu-Ning Sang; Zhuo Chen, Yun-Dong Wang, Jian-Hong Xu
      Abstract: Based on the one-step microfluidic method of producing hollow droplet with thin film, this article studies the effect of water and oil flow rate, gas pressure and viscosity of aqueous phase on the dynamic formation and size of hollow droplet by analyzing large amounts of data acquired automatically. The results show that the filling stage of hollow droplet is similar to that of microbubble formation, while the necking stage is similar to that of droplet formation process. Furthermore, based on the data and mathematical model describing droplet formation mechanism, a filling stage model including Capillary number of continuous phase is developed. Considering the dynamic interface breakup and displacement of droplet in necking stage, a necking stage model is developed. The results show that the model results considering filling and necking stage fit well with the experimental data, and the relative error is less than 5%. Finally, the same model with parameters is used to predict the size of hollow droplet with other systems and devices, and the model is proved to be relative precise in our experimental conditions. The results presented in this work provide a more in-depth understanding of the dynamic formation and scaling law of hollow droplet with G/L/L systems in microfluidic devices. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:00:23.947198-05:
      DOI: 10.1002/aic.15930
       
  • Kinetics of Glycerol Conversion to Hydrocarbon Fuels over Pd/H-ZSM-5
           Catalyst
    • Authors: Yang Xiao; Arvind Varma
      Abstract: The utilization of glycerol, primary byproduct of biodiesel production, is important to enhance process economics. In our recent prior work, it was shown that glycerol can be converted to hydrocarbon fuels over bifunctional catalysts, containing a noble metal supported on H-ZSM-5. Over Pd/H-ZSM-5 catalyst, an optimal ∼60% yield of hydrocarbon fuels was obtained. In the present work, based on experimental data over Pd/H-ZSM-5 catalyst, a lumped reaction network and kinetic model are developed. Using differential kinetic experiments over the temperature range 300-450°C, the rate constants, reaction orders and activation energies are obtained for each reaction step. The predicted values match well with experimental data for glycerol conversion up to ∼90%. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:00:19.259015-05:
      DOI: 10.1002/aic.15931
       
  • Interface-Shrinkage-driven Breakup of Droplets in Micro-devices with
           different Dispersed Fluid Channel Shape
    • Authors: Wenjie Lan; Zhihui Wang, Yinjie Du, Xuqiang Guo, Shaowei Li
      Abstract: We previously proposed a new droplet breakup mechanism — interface-shrinkage-driven breakup. In co-axial microdevices, when the contact angle between the continuous phase and dispersed fluid channel is sufficiently low, the new mechanism instead of the classic shear-driven mechanism dominates the breakup. The present study further investigated the new mechanism in microdevices with dispersed fluid channels of different shape. Critical contact angles in different devices were determined by theoretical analysis and verified by experiments. It was found that the critical contact angle for the new mechanism depends on the shape of the dispersed fluid channel. The droplet size was measured for different devices when the new mechanism dominated the breakup. In contrast to the case for the shear-driven mechanism, the droplet size is little affected by the capillary number. Mathematical models were established to predict the droplet size in different devices and results were found to agree well with experimental results. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T10:55:31.273356-05:
      DOI: 10.1002/aic.15932
       
  • Bubble Splitting under Gas-Liquid-Liquid Three-Phase Flow in a Double
           T-junction Microchannel
    • Authors: Yanyan Liu; Jun Yue, Shuainan Zhao, Chaoqun Yao, Guangwen Chen
      Abstract: Gas-aqueous liquid-oil three-phase flow was generated in a microchannel with a double T-junction. Under the squeezing of the dispersed aqueous phase at the second T-junction (T2), the splitting of bubbles generated from the first T-junction (T1) was investigated. During the bubble splitting process, the upstream gas-oil two-phase flow and the aqueous phase flow at T2 fluctuate in opposite phases, resulting in either independent or synchronous relationship between the instantaneous downstream and upstream bubble velocities depending on the operating conditions. Compared with two-phase flow, the modified capillary number and the ratio of the upstream velocity to the aqueous phase velocity were introduced to predict the bubble breakup time. The critical bubble breakup length and size laws of daughter bubbles/slugs were thereby proposed. These results provide an important guideline for designing microchannel structures for a precise manipulation of gas-liquid-liquid three-phase flow which finds potential applications among others in chemical synthesis. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T10:55:28.484738-05:
      DOI: 10.1002/aic.15920
       
  • Adiabatic Time to Maximum Rate Evaluation using an Analytical Approach
    • Authors: Roberto Sanchirico
      Abstract: This article presents an analytical method for the calculation of the adiabatic time to maximum rate. The procedure is developed considering a thermal decomposition process described by a simple n-order kinetic and is based on the introduction of a special function that is possible by integrating analytically. The application of the method requires the knowledge of the thermokinetic parameters of the process under study and allows the calculation of the adiabatic time to maximum rate without the numerical integration of the heat and mass balance equations or the use of relationships based on particular simplifying hypotheses. Its validity has been demonstrated considering numerical and real experiments (thermal decomposition of trityl azide) providing in both cases times to maximum rate values which are very close to the real ones. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T10:55:26.272667-05:
      DOI: 10.1002/aic.15923
       
  • Economic Assessment of Carbon Capture by Minichannel Absorbers
    • Authors: Ziqiang Yang; Tariq S. Khan, Mohamed Alshehhi, Yasser F. AlWahedi
      Abstract: In this work we present a physio-economic model supported by lab scale experiments assessing the economic viability of minichannel based carbon capture units. The Net Present Value of capital and operating Costs (NPVC) ensued throughout the plant life is selected as the benchmarking parameter. An optimization problem is formulated and solved with the objective of minimizing the NPVC of the unit subject to constraints imposed by the physics of absorption and pressure drop limits; both of which are captured via experimentally deduced empirical correlations. The results show that the minichannel absorbers are economically competitive to conventional systems for low capacity CO2 capture achieving savings ranging from ∼50% to 3% for plant capacities ranging from 5 to 50 MMSCFD respectively primarily due to their lower capital costs. At higher plant capacities, the higher operating costs of the minichannel units dominate their NPVC and as such lead them to lose their competitiveness. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T10:55:24.026502-05:
      DOI: 10.1002/aic.15919
       
  • Kinetic and Transport Effects on Enzymatic Biocatalysis Resulting from the
           PEGylation of Cofactors
    • Authors: Harun F. Ozbakir; Scott Banta
      Abstract: The utilization of cofactor-dependent redox enzymes in bioprocess technologies requires low cost cofactor regeneration methods. PEGylated NAD(H) (PEG-NAD(H)) has been utilized in enzyme membrane reactors as a means to recover the cofactor; however, there is a lack of understanding of the effect of PEGylation on enzymatic activity, especially on the relationship between biocatalysis and transport phenomena. To explore this further, two redox enzymes (formate dehydrogenase (FDH) from S. cerevisiae and NAD(H)-dependent D-lactate dehydrogenase (nLDH) from E.coli) have been chosen and the kinetic effects caused by cofactor modifications (with PEG of three different chain lengths) have been investigated. The PEGylation did not impact the cofactor dissociation constants and mass transfer was not the rate-limiting step in biocatalysis for either enzyme. However, the PEG chain length had different impacts on the formation of enzyme/cofactor and/or enzyme/cofactor/substrate ternary complexes for the enzymes. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-09T03:05:22.150096-05:
      DOI: 10.1002/aic.15893
       
  • Issue information
    • Abstract: Cover illustration. A description of the evolution of a research program at the interface of chemical engineering and chemistry is provided as an example to illustrate key factors for consideration by young and aspiring independent researchers. As an example, a laboratory based on a foundation of synthetic materials chemistry applied to problems in catalysis and gas separations is highlighted. Image by Mr. Bradley E. Dixon based on the concept of Dr. Michele L. Sarazen.10.1002/aic.15835
      PubDate: 2017-08-03T09:33:20.400664-05:
      DOI: 10.1002/aic.15479
       
  • Systematic Analysis and Optimization of Power Generation in Pressure
           Retarded Osmosis: Effect of Multi-Stage Design
    • Authors: Mingheng Li
      Abstract: This work presents a systematic method for analysis and optimization of specific energy production (SEP) of PRO systems employing single-stage configuration as well as multi-stage design with inter-stage hydro-turbines. It is shown that the SEP nor- malized by the draw solution feed osmotic pressure increases with the number of stages as well as a dimensionless parameter γtot = AtotLpπ0 = Q0. As compared to the single- stage PRO, the multi-stage arrangement not only increases ux and volume gain, but also allows a stage-dependent, progressively decreasing hydraulic pressure, both of which contribute to enhanced SEP and power density. At the thermodynamic limit where tot goes to infinity, the theoretical maximum SEP by an N-stage PRO system is N *******, where qtot is the ratio of the draw solution ow rate at the outlet to the inlet on the system level. For single-stage PRO, it is no more than π0. For infinite number of stages, the theoretical limit becomes (ln qtot)π0. SEP under realistic conditions and practical constraints on multi-stage design are discussed. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-31T11:10:28.525393-05:
      DOI: 10.1002/aic.15894
       
  • Intrusive Probes in Riser Applications
    • Authors: Ray A. Cocco; S.B. Reddy Karri, Ted M. Knowlton, John Findlay, Thierry Gauthier, Jia Wei Chew, Christine M. Hrenya
      Abstract: Many of the probes used to understand hydrodynamics in circulating fluidized bed risers intrude into the environment they are measuring, although assumptions are typically asserted that the intrusive probes do not affect the data collected. This could be a poor assumption in some cases and conditions. We found that intrusive fiber optic probe measurements consistently mis-predicted the solids concentration compared to the non-intrusive pressure drop measurements outside the fully developed flow region of a riser containing fluid catalytic cracking catalyst or glass bead particles. The discrepancy was sensitive to superficial gas velocity, solid circulation rate, probe position and flow direction. Barracuda VR™ computational fluid dynamics simulations confirmed this, and indicated that particle momentum was lost at the leading edge of the probe and particles were spilling over to the probe tip. Accordingly, new probe designs were proposed to mitigate the intrusiveness of a fiber optical probe for more accurate characterization. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-28T06:45:42.075365-05:
      DOI: 10.1002/aic.15892
       
  • Tensile Modulus of Polymer/CNT Nanocomposites containing Networked and
           dispersed Nanoparticles
    • Authors: Yasser Zare; Kyong Yop Rhee
      Abstract: The properties of three-dimensional networks of nanoparticles in polymer/CNT nanocomposites (PCNT) are particularly interesting from fundamental and application views. In this paper, a new model is suggested for predicting the tensile modulus of PCNT using the Ouali and Paul models. The Ouali model considers the network of CNT in a polymer matrix, while the Paul model predicts the tensile modulus of samples containing dispersed nanoparticles. The predictions of the suggested approach are compared with experimental data from several samples. Also, the roles of the main parameters in the tensile modulus of PCNT are evaluated. The predictions agree with the experimental results at different filler concentrations. The roles of these parameters on the tensile modulus of PCNT are discussed based on the properties of CNT networks. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-28T06:45:26.170362-05:
      DOI: 10.1002/aic.15891
       
  • Steady Microfluidic Measurements of Mutual Diffusion Coefficients of
           Liquid Binary Mixtures
    • Authors: Anne Bouchaudy; Charles Loussert, Jean-Baptiste Salmon
      Abstract: We present a microfluidic method leading to accurate measurements of the mutual diffusion coefficient of a liquid binary mixture over the whole solute concentration range in a single experiment. This method fully exploits solvent pervaporation through a poly(dimethylsiloxane) (PDMS) membrane to obtain a steady concentration gradient within a microfluidic channel. Our method is applicable for solutes which cannot permeate through PDMS, and requires the activity and the density over the full concentration range as input parameters. We demonstrate the accuracy of our methodology by measuring the mutual diffusion coefficient of the water (1) + glycerol (2) mixture, from measurements of the concentration gradient using Raman confocal spectroscopy and the pervaporation-induced flow using particle tracking velocimetry. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-27T10:20:27.247365-05:
      DOI: 10.1002/aic.15890
       
  • Formation of Liquid-Liquid Slug Flow in a Microfluidic T-junction: Effects
           of Fluid Properties and Leakage Flow
    • Authors: Chaoqun Yao; Yanyan Liu, Chao Xu, Shuainan Zhao, Guangwen Chen
      Abstract: Characteristics of liquid-liquid slug flow are investigated in a microchannel with focus on the leakage flow that bypasses droplets through channel gutters. The results show that the leakage flow rate varies in a range of 10.7 ∼ 53.5% and 8.3 ∼ 30.9% of the feed flow rate, during the droplet formation (i.e., at T-junction) and downstream flow (i.e., in the main channel), respectively, which highly depends on Ca number and wetting condition. Empirical correlations are proposed to predict them for perfectly and partially wetting conditions. Leakage flow contribution is further used to improve the Garstecki model for size scaling in order to extend its suitability for both squeezing and shearing regimes. The instantaneous flow rates of the immiscible phases are found to fluctuate periodically with the formation cycles, but in opposite behavior. The effect of the presence of leakage flow on such fluctuation are investigated and compared with gas-liquid systems. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-26T10:10:26.141307-05:
      DOI: 10.1002/aic.15889
       
  • Complete Carbon Analysis of Sulfur-Containing Mixtures using Post-Column
           Reaction and Flame Ionization Detection
    • Authors: Connor A. Beach; Kristeen E. Joseph, Charles S. Spanjers, Andrew J. Jones, Triantafillos J. Mountziaris, Paul J. Dauenhauer
      Abstract: Quantitative analysis of complex mixtures containing hundreds-to-thousands of organic compounds rich in heteroatoms, including oxygen, sulfur, and nitrogen, is a major challenge in the fuel, food, and chemical industries. In this work, a two-stage (oxidation and methanation) catalytic process in a 3D-printed metal microreactor was evaluated for its capability to convert sulfur-containing organic compounds to methane. The microreactor was inserted into a gas chromatograph between the capillary column and flame ionization detector. Catalytic conversion of all sulfur-containing analytes to methane enabled carbon quantification without calibration, by the method identified as “quantitative carbon detection” or QCD. Quantification of tetrahydrothiophene, dimethyl sulfoxide, diethyl sulfide, and thiophene indicated complete conversion to methane at 450°C. Long-term performance of a commercial microreactor was evaluated for 2,000 consecutive injections of sulfur-containing organic analytes. The sulfur processing capacity of the microreactor was identified experimentally, after which reduced conversion to methane was observed. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-26T10:05:23.015485-05:
      DOI: 10.1002/aic.15888
       
  • Kinetic Monte Carlo Simulation for Homogeneous Nucleation of Metal
           Nanoparticles during Vapor Phase Synthesis
    • Authors: Seyyed Ali Davari; Dibyendu Mukherjee
      Abstract: We present a free-energy driven kinetic Monte Carlo model to simulate homogeneous nucleation of metal nanoparticles (NPs) from vapor phase. The model accounts for monomer-cluster condensations, cluster-cluster collisions, and cluster evaporations simultaneously. Specifically, we investigate the homogeneous nucleation of Al NPs starting with different initial background temperatures. Our results indicate good agreement with earlier phenomenological studies using the Gibbs' free energy formulation from Classical Nucleation Theory (CNT). Furthermore, nucleation rates for various clusters are calculated through direct cluster observations. The steady state nucleation rate estimated using two different approaches namely, the Yasuoka-Matsumoto (YM) and mean first passage time (MFPT) methods indicate excellent agreement with each. Finally, our simulation results depict the expected increase in the entropy of mixing as clusters approach the nucleation barrier, followed by its subsequent drastic loss after the critical cluster formation resulting from first-order phase transitions. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-24T17:06:12.989891-05:
      DOI: 10.1002/aic.15887
       
  • Influence and CFD Analysis of Cooling Air Velocity on the Purification of
           Aqueous Nickel Sulfate Solutions by Freezing
    • Authors: M. Hasan; Roman Filimonov, Miia John, Joonas Sorvari, M. Louhi-Kultanen
      Abstract: Finite energy resources and their rapidly waning imprint necessitate a sustainable wastewater treatment method. Nature could be exploited to freeze wastewater in locations which experience subzero temperatures during winter. The two most vital components that influence the efficiency of natural freezing are the ambient temperature and air velocity. The turbulent and unsteady air-cooled natural freezing is simulated for ice crystallization from 0.1 wt-% and 1 wt-% NiSO4 (aq) solutions. The efficiency of natural freezing is tested for different air velocities (2 ms−1, 5 ms−1) and levels of undercooling (ΔT=0.5˚C, 1˚C) from the freezing temperature of the corresponding solution. The airflow in the winter simulator is modeled by computational fluid dynamics (CFD) to investigate its behavior and to assess its effect on freezing. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-22T11:05:38.368865-05:
      DOI: 10.1002/aic.15885
       
  • Molecular Simulation Study of Aluminum – Noble Gas Interfacial Thermal
           Accommodation Coefficients
    • Authors: Haoyan Sha; Gulcin Tetiker, Peter Woytowitz, Roland Faller
      Abstract: Thermal accommodation coefficients (TAC) between aluminum and noble gases were studied with molecular dynamics (MD) simulations. Gases interacting with aluminum substrates were modeled by MD with gas velocities sampled from the Maxwell – Boltzmann distribution to give accumulated TAC results. Different implementations of the equation to calculate the TAC, which differ in the amount of information gleaned from MD and the corresponding simulation results, were carefully discussed. The best formula for molecular dynamics modeling in finite simulation time was determined. Additionally, the influence of the combining rules applied on aluminum – noble gas interatomic potential was characterized with the well-known Lennard – Jones 12 – 6 potential combined with Lorentz – Berthelot and Fender – Halsey mixing rules. The results were compared with experimental values and previous analytical model. TACs simulated with Fender – Halsey rules present excellent agreement with the experimental values. Detailed TAC distributions and accumulated TAC convergence are also included. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-22T11:05:32.622228-05:
      DOI: 10.1002/aic.15886
       
  • Considerations on film reactivity in the aqueous biphasic hydroformylation
    • Authors: H. Warmeling; A.-C. Schneider, A. J. Vorholt
      Abstract: In experiments and kinetic models it was shown that the reaction rate of the biphasic aqueous hydroformylation of 1-octene is linear dependent on the created interfacial area. This phenomenon is directly linked to the question whether the reaction takes place in the bulk phase and is mass transfer limitation or at the surface which would mean an increase of reaction space. To evaluate the place of reaction a mass transfer analysis has been carried out. No mass transfer limitation for the gaseous components carbon monoxide and hydrogen as well as the olefin 1-octene was determined for the aqueous catalyst phase by calculating the Hatta numbers. With this observation it is possible to exclude the mass transfer as a potential influence and hence the aqueous bulk as the place of reaction. Thus the reaction is most probably surface active. This can be either explained the increase in film volume fraction where non-polar substrate as well as polar catalyst complex is present or through an increased catalyst concentration at the surface through dipole moment fluctuations. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-22T11:00:24.330841-05:
      DOI: 10.1002/aic.15884
       
  • A Comprehensive Analysis of the BET Area for Nanoporous Materials
    • Authors: Yun Tian; Jianzhong Wu
      Abstract: The Brunauer-Emmett-Teller (BET) method has been used extensively to characterize the surface areas of porous materials by semi-empirical fitting of gas-adsorption isotherms. However, questions arise recently concerning the applicability and the exact meaning of the BET areas. In particular, there has been much debate about whether the BET method provides a faithful description of the geometrical areas of porous materials if the atomic structures are exactly known. In this work, we provide a comprehensive analysis of the BET areas for both model slit pores and crystalline porous materials using the grand canonical Monte Carlo simulation. Based on extensive simulation data for nitrogen adsorption at 77 K and the conventional models of materials characterization, we find no simple correlation between the BET and geometrical surface areas. For materials with the same BET area, their geometric surface areas may vary over one order of magnitude. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-21T11:16:04.000004-05:
      DOI: 10.1002/aic.15880
       
  • A Semi-analytical Model for Simulating Real Gas Transport in Nanopores and
           Complex Fractures of Shale Gas Reservoirs
    • Authors: Weihong Wang; Wei Yu, Xiaohu Hu, Hua Liu, Youguang Chen, Kan Wu, Biyi Wu
      Abstract: An efficient gridless semi-analytical model was developed to simulate real gas transport in shale formation with nanopores and complex fracture geometry. This model incorporates multiple physics such as gas desorption, adsorbed gas porosity, gas slippage and diffusion, residual water saturation, non-Darcy flow, choke skin, and pressure-dependent matrix permeability and fracture conductivity. Additionally, this model is easy to handle complex fracture geometry through dividing fractures into a number of segments and nodes. We verified the model against a numerical model and an analytical model for bi-wing hydraulic fractures. After validation, the impacts of all these physics on well performance were evaluated in detail through a series of case studies. The simulation results confirm that modeling of gas production from complex fracture geometry as well as modeling important physics in shale gas reservoirs is significant. This study improves our understanding of critical physics affecting gas recovery in shale gas reservoirs. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-21T11:16:01.831887-05:
      DOI: 10.1002/aic.15881
       
  • A New Superstructure Optimization Paradigm for Process Synthesis with
           Product Distribution Optimization: Application to An Integrated Shale Gas
           Processing and Chemical Manufacturing Process
    • Authors: Jian Gong; Fengqi You
      Abstract: We propose a novel process synthesis framework that combines product distribution optimization of chemical reactions and superstructure optimization of the process flowsheet. A superstructure with a set of technology/process alternatives is first developed. Next, the product distributions of the involved chemical reactions are optimized to maximize the profits of the effluent products. Extensive process simulations are then performed to collect high-fidelity process data tailored to the optimal product distributions. Based on the simulation results, a superstructure optimization model is formulated as a mixed-integer nonlinear program (MINLP) to determine the optimal process design. A tailored global optimization algorithm is employed to efficiently solve the large-scale nonconvex MINLP problem. The resulting optimal process design is further validated by a whole-process simulation. The proposed framework is applied to a comprehensive superstructure of an integrated shale gas processing and chemical manufacturing process, which involves steam cracking of ethane, propane, n-butane, and i-butane. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-21T11:15:45.027113-05:
      DOI: 10.1002/aic.15882
       
  • CFD as an approach to understand flammable dust 20 L standard test: effect
           of the ignition time on the fluid flow
    • Authors: Daniel Vizcaya; Carlos Murillo, Andrés Pinilla, Mariangel Amín, Nicolás Ratkovich, Felipe Munoz, Nathalie Bardin-Monnier, Olivier Dufaud
      Abstract: A computational study based on the Euler-Lagrange approach was developed for the characterization of flammable dusts in the 20 L sphere standard test. The aim of the study was to analyze some parameters that might affect the experimental data (e.g. cold turbulence and particle size). The turbulence of a wheat starch cloud was described with the Detached Eddy Simulation model. Both the pressure of the system and the RMS velocity were compared with the flow patterns established with a particle image velocimetry analysis. It was concluded that the rebound nozzle forms a cloud that is composed by clumps. This fact implies dissimilarities between the local concentrations and the nominal value. Finally, a granulometric analysis established that the mean diameter of the particle size distribution (PSD) decreased by 69% during the dispersion. Thus, it is suggested to consider the PSD at the ignition zone rather than the PSD of the sample. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-21T11:15:26.161092-05:
      DOI: 10.1002/aic.15883
       
  • Investigation of Gas-Solid Bubbling Fluidized Beds using ECT with a
           Modified Tikhonov Regularization Technique
    • Authors: Qiang Guo; Shuanghe Meng, Dehu Wang, Yinfeng Zhao, Mao Ye, Wuqiang Yang, Zhongmin Liu
      Abstract: Electrical Capacitance Tomography (ECT) provides a non-intrusive means to visualize cross-sectional material distribution of gas-solid bubbling fluidized beds. Successful application of ECT strongly depends on the image reconstruction algorithm used. For on-line measurements of bubbling fluidized beds, employing an algorithm that can produce high-quality images without extensive computation is necessary. Using the conventional Tikhonov regularization algorithm, image quality in the central area is basically satisfied but suffers from artifacts in the near-wall region. To solve this problem, a similar division operation learned from linear back projection was introduced to modify the conventional Tikhonov algorithm. Both numerical simulations and experiments were performed to evaluate the modified technique. The results indicate that the artifacts can be effectively removed and the reconstructed image quality is similar to Landweber method with dozens of iterations. Furthermore, the modified Tikhonov technique shows high accuracy when obtaining important hydrodynamic parameters in gas-solid bubbling fluidized beds. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-20T10:25:45.362589-05:
      DOI: 10.1002/aic.15879
       
  • Development of a COSMO-RS based model for the calculation of phase
           equilibria in electrolyte systems
    • Authors: Thomas Gerlach; Simon Müller, Irina Smirnova
      Abstract: A new electrolyte model, which is based on the predictive thermodynamic model COSMO-RS, is presented. For this purpose, an implementation of COSMO-RS that allows the integration of multiple segment descriptors was developed. To aid in the development of the electrolyte model, a new technique is presented that allows the evaluation of the different contributions of the interaction terms of COSMO-RS to the partial molar enthalpies. General empirical interaction energy equations are introduced into the electrolyte model. They are parameterized based on a large training set of mean ionic activity coefficients as well as liquid-liquid equilibrium data close to ambient conditions. The model is shown to be capable of predicting properties of systems containing anions that were not part of the training set of the model. Furthermore, it is demonstrated that the model can also lead to satisfying predictions if compared to vapor-liquid equilibrium data. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-20T10:15:51.376791-05:
      DOI: 10.1002/aic.15875
       
  • A Rigorous Method to Evaluate the Consistency of Experimental Data in
           Phase Equilibria. Application to VLE and VLLE
    • Authors: Luís J. Fernández; Juan Ortega, Jaime Wisniak
      Abstract: This work forms part of a broader study that describes a methodology to validate experimental data of phase equilibria for multicomponent systems from a thermodynamic-mathematical perspective. The goal of this paper is to present and justify this method and to study its application to vapor-liquid equilibria (VLE) and vapor-liquid-liquid equilibria (VLLE), obtained under isobaric/isothermal conditions. A procedure based on the Gibbs-Duhem equation is established which presents two independent calculation paths for its resolution: (a) an integral method and (b) a differential method. Functions are generated for both cases that establish the verification or consistency of data, δψ for the integral test and δζ for the differential approach, which are statistically evaluated by their corresponding average values [δψ¯, δζ¯], and the standard deviations [s(δψ), s(δϛ)]. The evaluation of these parameters for application to real cases is carried out using a set of hypothetical systems (with data generated artificially), for which the values are adequately changed to determine their influence on the method. In this way, the requirements of the proposed method for the data are evaluated and their behavior in response to any disruption in the canonical variables (p,T, phase compositions). The conditions for thermodynamic consistency of data are: δψ¯
      PubDate: 2017-07-20T10:15:46.321288-05:
      DOI: 10.1002/aic.15876
       
  • Sustainable Biopolymer Synthesis via Superstructure and Multi-Objective
           Optimization
    • Authors: Ehecatl Antonio del Rio-Chanona; Dongda Zhang, Nilay Shah
      Abstract: Sustainable polymers derived from biomass have great potential to replace petrochemical based polymers and fulfill the ever-increasing market demand. To facilitate their industrialization, in this research, a comprehensive superstructure reaction network comprising a large number of reaction pathways from biomass to both commercialized and newly proposed polymers is constructed. To consider economic performance and environmental impact simultaneously, both process profit and green chemistry metrics are embedded into the multi-objective optimization framework, and MINLP is employed to enable the effective selection of promising biopolymer candidates. Through this proposed approach, the current study identifies the best biopolymer candidates and their most profitable and environmentally-friendly synthesis routes under different scenarios. Moreover, the stability of optimization results regarding the price of raw materials and polymers and the effect of process scale on the investment cost are discussed in detail. These results, therefore, pave the way for future research on the production of sustainable biopolymers. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-20T10:15:37.212697-05:
      DOI: 10.1002/aic.15877
       
  • Oxidation of Caffeine by Acid-activated Ferrate(VI): Effect of Ions and
           Natural Organic Matter
    • Authors: Kyriakos Manoli; George Nakhla, Ajay K. Ray, Virender K. Sharma
      Abstract: Caffeine (CAF) is the most commonly consumed stimulant and frequently detected emerging pollutant in influents and effluents of wastewater treatment plants (WWTP) and surface waters. Acid-activated ferrate(VI) (FeVIO42-, Fe(VI)) oxidizes CAF in water in seconds to minutes at three times lower molar ratio of Fe(VI) to CAF than oxidative transformation observed in hours by non-activated Fe(VI) (8.0 versus 25.0). CAF oxidation by acid-activated Fe(VI) is not affected by ionic constituents of water. Organic components of natural organic matter (NOM) and secondary effluent wastewater (SE) decrease efficiency of CAF transformation. However, acid-activated Fe(VI) could mineralize other organics present in both NOM and SE as indicated by the dissolved organic carbon (DOC) removal. Comparatively, no mineralization was seen without activation of Fe(VI). Four oxidized products of CAF were identified by a liquid chromatography high resolution mass spectrometry technique. The reaction pathways of the oxidation of CAF by activated Fe(VI) have been proposed. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-20T10:15:31.534913-05:
      DOI: 10.1002/aic.15878
       
  • Some mechanistic insights into the action of facilitating agents on gas
           permeation through glassy polymeric membranes
    • Authors: Md Oayes Midda; Akkihebbal K Suresh
      Abstract: Incorporation of facilitating agents is one of the promising strategies being researched in recent years to cross the Robeson bounds for gas separations using polymeric membranes. The ways in which such inclusions modify the performance of membranes are not always clear. Here, we study the performance of two glassy membranes, Polyfurfuryl alcohol and Polysulfone, in O2/N2 and CO2/N2 separations, with Cobalt phthalocyanin in insoluble and solubilized forms as the facilitating agent. The results show that in general, three effects are important: (i) a barrier effect, (ii) a facilitation effect and (iii) morphological effects on the polymer matrix due to an incompatibility between the particles and the polymer. These results provide some insight into the action of facilitating agents in soluble and insoluble form, when used as membrane additives. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-20T10:10:35.9034-05:00
      DOI: 10.1002/aic.15873
       
  • Dynamic Modeling and Simulations of the Behavior of a Fixed-Bed
           Reactor-Exchanger used for CO2 Methanation
    • Authors: Rasmey Try; Alain Bengaouer, Pierre Baurens, Christian Jallut
      Abstract: A multidimensional heterogeneous and dynamic model of a fixed-bed heat exchanger reactor used for CO2 methanation has been developed in this work that is based on mass, energy and momentum balances in the gas phase and mass and energy balances for the catalyst phase. The dynamic behavior of this reactor is simulated for transient variations in inlet gas temperature, cooling temperature, gas inlet flow rate and outlet pressure. Simulation results showed that wrong-way behaviors can occur for any abrupt temperature changes. Conversely, temperature ramp changes enable to attenuate and even fade the wrong-way behavior. Traveling hot spots appear only when the change of an operating condition shifts the reactor from an ignited steady state to a non-ignited one. Inlet gas flow rate variations reveal overshoots and undershoots of the reactor maximum temperature. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-20T10:10:25.956822-05:
      DOI: 10.1002/aic.15874
       
  • Modular Manufacturing Processes: Status, Challenges and Opportunities
    • Authors: Michael Baldea; Thomas F. Edgar, Bill L. Stanley, Anton A. Kiss
      Abstract: Chemical companies are constantly seeking new, high-margin growth opportunities, the majority of which lie in high-grade, specialty chemicals, rather than in the bulk sector. In order to realize these opportunities, manufacturers are increasingly considering decentralized, flexible production facilities: large-scale production units are uneconomical for innovative products with a short lifespan and volatile markets. Small modular plants have low financial risks, are flexible and can respond rapidly to changes in demand. Logistics costs can be also reduced by moving production closer to customers and/or sources of raw materials. Moreover, stricter safety regulations can in many cases be more easily met using smaller distributed facilities.Modularization of chemical production can thus have potentially significant economic and safety ben- efits. In this article, we review several drivers for modular production, and evaluate modular production architectures based on the value density of feedstock resources and markets for the products of a process. We also discuss the links between modularization and process intensification. We illustrate the discussion with an array of industrial examples, which we also use to motivate a summary of challenges and future directions for this area. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-18T10:55:37.449298-05:
      DOI: 10.1002/aic.15872
       
  • COSMO-based computer-aided molecular/mixture design: A focus on reaction
           solvents
    • Authors: Nick D. Austin; Nikolaos V. Sahinidis, Ivan A. Konstantinov, Daniel W. Trahan
      Abstract: In this article, we investigate reaction solvent design using COSMO-RS thermodynamics in conjunction with computer-aided molecular design (CAMD) techniques. CAMD using COSMO-RS has the distinct advantage of being a method based in quantum chemistry, which allows for the incorporation of quantum-level information about transition states, reactive intermediates, and other important species directly into CAMD problems. This work encompasses three main additions to our previous framework for solvent design1: (1) altering the group contribution method to estimate hydrogen-bonding and non-hydrogen-bonding σ-profiles; (2) ab initio modeling of strong solute/solvent interactions such as H-bonding or coordinate bonding; and (3) solving mixture design problems limited to common laboratory and industrial solvents. We apply this methodology to three diverse case studies: accelerating the reaction rate of a Menschutkin reaction, controlling the chemoselectivity of a lithiation reaction, and controlling the chemoselectivity of a nucleophilic aromatic substitution reaction. We report improved solvents/mixtures in all cases. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-13T03:30:21.889893-05:
      DOI: 10.1002/aic.15871
       
  • The Maximum Flammable Content for Binary Aqueous–Organic Mixtures Not to
           Flash and their Maximum Flash Points
    • Authors: Horng-Jang Liaw
      Abstract: Aqueous–organic solutions can flash only over a limited composition range. This manuscript proposes a model to estimate the two critical parameters, maximum flammable content not to flash and the maximum flash point temperature, in judging whether an aqueous–organic solution is flammable or not. The results are applicable to flammability elimination and flammability hazard assessment of liquid solutions. Validation of this model was performed with measurements for 14 aqueous–organic miscible and partially miscible mixtures. Various mixtures were tested including alcohols, ketones, and esters in aqueous solutions. Overall, the estimation of the maximum flash point value and maximum flammable content not to flash were acceptable when using the proposed model. The termination of the flash for aqueous solutions was clarified to be the non-flammability of the vapor phase resulting from the high steam concentration when the temperature of such solutions is greater than the maximum flash point. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-12T13:10:32.304053-05:
      DOI: 10.1002/aic.15867
       
  • Design of Mixed Energy-integrated Batch Process Networks by Pseudo-direct
           Approach
    • Authors: Parikshit S. Shahane; Channamallikarjun S. Mathpati, Sujit S. Jogwar
      Abstract: In this paper, a novel framework for the design of mixed (combined direct and indirect) integration for batch process systems is presented. The framework is based on the concept of pseudo-direct energy integration (PDEI) which reformulates indirect integration as direct integration using pseudo-process streams. Two algorithms are presented to achieve energy integration for batch processes operating cyclically (in a campaign mode). The first algorithm targets maximization of energy recovery and overcomes the limitations of some of the existing contributions for design of mixed integrated systems. The second algorithm provides a network reduction methodology to generate a cadre of integrated designs while exploring the trade off between capital (number of heat exchangers and storage units) and operating costs (utility consumption). The proposed framework is illustrated using a benchmark example of two hot and two cold streams. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-12T13:10:30.51338-05:0
      DOI: 10.1002/aic.15869
       
  • Quantifying the Uncertainty Introduced by Discretization and
           Time-Averaging in Two-Fluid Model Predictions
    • Authors: Madhava Syamlal; Ismail Celik, Sofiane Benyahia
      Abstract: The two-fluid model (TFM) has become a tool for the design and troubleshooting of industrial fluidized bed reactors. To use TFM for scale up with confidence, the uncertainty in its predictions must be quantified. Here we study two sources of uncertainty: discretization and time-averaging. First, we show that successive grid refinement may not yield grid-independent transient quantities, including cross-section-averaged quantities. Successive grid refinement would yield grid-independent time-averaged quantities on sufficiently fine grids. Then a Richardson extrapolation can be used to estimate the discretization error, and the grid convergence index gives an estimate of the uncertainty. Richardson extrapolation may not work for industrial-scale simulations that use coarse grids. We present an alternative method for coarse grids and assess its ability to estimate the discretization error. Second, we assess two methods (autocorrelation and binning) and find that the autocorrelation method is more reliable for estimating the uncertainty introduced by time-averaging TFM data. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-12T13:10:27.598574-05:
      DOI: 10.1002/aic.15868
       
  • Biochar Soil Amendments for Increased Crop Yields: How to design a
           “designer” biochar
    • Authors: Kyriacos Zygourakis
      Abstract: This study presents the development and testing of a transient adsorption/desorption model that describes the response of biochar particles to nutrient pulses simulating the application of fertilizer. Intraparticle nutrient transfer occurs both by diffusion through liquid-filled pores and by surface diffusion, and nutrient adsorption is described by Langmuir-Freundlich (Sips) isotherms. Simulation results show that the ability of a biochar to adsorb and then slowly release the nutrient is modulated by a complex interplay of external mass transfer, intraparticle diffusion (both pore and surface diffusion), and adsorption dynamics. The nutrient retention potential of biochar-amended soils is quantified and is shown to depend on multiple factors that include chemical and physical biochar properties, soil permeability, water flow and the method of fertilizer application. These findings may explain why biochars with similar properties can potentially have widely different impacts on crop yields, as has been repeatedly reported in the literature. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-12T13:10:21.010583-05:
      DOI: 10.1002/aic.15870
       
  • Improving the Design of Depth Filters: A Model-Based Method Using Optimal
           Control Theory
    • Authors: Michael Kuhn; Christoph Kirse, Heiko Briesen
      Abstract: Because there is no general design method for depth filters, especially for layered configurations, we here address this methodological gap. Using optimal control theory, paths of the filter coefficient, a measure for local filtration performance, are determined along the filter depth. An analytical optimal control solution is derived and used to validate the numerical algorithm. Two optimal control scenarios are solved numerically: In the first scenario, the goal of constant deposition along the filter depth is addressed. The second scenario aims at maximizing the time until some maximal pressure drop is reached. Furthermore, we present a computational strategy to derive discrete layers suitable for practical design from the continuous optimal control solutions. All optimized scenarios are compared to one-layered filter designs and significant improvements are found. As this work is based on strongly validated and widely used filtration models, the presented methods are expected to have broad applicability. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-12T13:05:21.372076-05:
      DOI: 10.1002/aic.15866
       
  • Next generation of low global warming potential refrigerants:
           Thermodynamic properties molecular modeling
    • Authors: Wael A. Fouad; Lourdes F. Vega
      Abstract: The recent global agreement signed in Kigali to limit the use of hydrofluorocarbons (HFCs) as refrigerants, starting by 2019, has promoted an active area of research towards the development of low Global Warming Potential (GWP) new refrigerants. Hydrofluoroolefins (HFOs) have been proposed as a low GWP alternative to third generation HFC refrigerants, but further work on fully characterizing them and their blends with other compounds is still required to fully assess their performance to replace the ones in current use. In this work, the polar and perturbed chain statistical associating fluid theory (Polar PC-SAFT) coupled with the density gradient theory is used to predict the vapor-liquid equilibrium, isobaric heat capacity, speed of sound and surface tension of selected HFC and HFO based commercial azeotropic blends as fourth generation low GWP refrigerants, seeking for a predictive tool for these properties. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-10T11:05:50.869683-05:
      DOI: 10.1002/aic.15859
       
  • Design and Assessment of Delay Timer Alarm Systems for Nonlinear Chemical
           Processes*
    • Authors: Aditya Tulsyan; Feras Alrowaie, R. Bhushan Gopaluni
      Abstract: In process and manufacturing industries, alarm systems play a critical role in ensuring safe and efficient operations. The objective of a standard industrial alarm system is to detect undesirable deviations in process variables as soon as they occur. Fault detection and diagnosis (FDD) systems often need to be alerted by an industrial alarm system; however, poorly designed alarms often lead to alarm flooding and other undesirable events. In this paper, we consider the problem of industrial alarm design for processes represented by stochastic nonlinear time-series models. The alarm design for such complex processes faces three important challenges: 1) industrial processes exhibit highly nonlinear behavior; 2) state variables are not precisely known (modeling error); and 3) process signals are not necessarily Gaussian, stationary or uncorrelated. In this paper, a procedure for designing a delay timer alarm configuration is proposed for the process states. The proposed design is based on minimization of the rate of false and missed alarm rates – two common performance measures for alarm systems. To ensure the alarm design is robust to any non-stationary process behavior, an expected-case and a worst-case alarm designs are proposed. Finally, the efficacy of the proposed alarm design is illustrated on a non-stationary chemical reactor problem. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-10T11:05:08.150056-05:
      DOI: 10.1002/aic.15860
       
  • Numerical and Experimental Investigation on Surface Air Entrainment
           mechanisms of a Novel Long-Short Blades Agitator
    • Authors: Yueqiao Zhang; Xiang Pan, Yaohua Wang, Peicheng Luo, Hua Wu
      Abstract: We investigate numerically and experimentally the mechanisms of surface air entrainment in the vessels equipped with the long-short blades agitator. VOF method coupled with LES model is used to visualize the surface air entrainment process. In the case of partial submergence of the long blades (LBs), the interaction of the LBs with the liquid free surface creates a depression behind the LBs. Backfilling of the liquid into the depression leads to gas separation and entrapping into the liquid. The critical tip velocity of the LBs, utip,c, for the onset of gas entrainment is measured in vessels with diameters, T = 200∼600mm. It is found that when H/T≥1.0, utip,c is determined by the LBs, independent of the liquid level. utip,c is also affected by the size of the vessel through the diameter of the sweeping circle of the LBs, but for substantially large vessels, it approaches a constant value. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-10T11:05:06.161132-05:
      DOI: 10.1002/aic.15865
       
  • Generalized Gibbs Free Energy of Confined Nanoparticles
    • Authors: Nanhua Wu; Xiaoyan Ji, Rong An, Chang Liu, Xiaohua Lu
      Abstract: The nanoparticles generally show abnormal properties compared to those in the bulk phase, and they exhibit significant potential in various applications such as catalysis and energy conversion. However, the theoretical work for describing the properties of nanoparticles is limited with poor prediction capacity. In this work, the Gibbs free energy was studied, from both macroscope and microscope, predictive models were proposed to study the thermodynamic properties of nanoparticles with a generalized description of the Gibbs free energy considering the effects of surface-energy and the substrate contacted. The proposed model from the microscope was based on the corresponding states theory to describe the effect of the substrate on the Gibbs free energy of nanoparticles, in which the molecular parameter with a generalized constant was obtained from the melting point of metals due to sufficient experimental information. The comparison with the new measured experimental results proves the reliability of the model prediction. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-10T10:41:50.101726-05:
      DOI: 10.1002/aic.15861
       
  • Flame Stabilization in a Planar Micro-Combustor Partially Filled with
           Anisotropic Porous Medium
    • Authors: Long Meng; Jun Li, Qingqing Li, Junrui Shi
      Abstract: Heat recirculation through the combustor walls is responsible in sustaining flames in micro-combustors. Incorporating porous medium into micro-combustors helps further enhance heat recirculation via the solid matrix. However, the problem of anisotropy arises when the pore size is comparable to the characteristic length of micro-combustors. To quantitatively address the problem, an experimental study on the flame stability limits of premixed H2/air in a planar micro-combustor partially filled with porous medium is undertaken. Three folding schemes, namely, parallel sheets, streamwise flow passage and streamwise flow blocking, are employed to realize the anisotropic properties. By varying the width (W) and position (Lout) of the porous medium, the effects of folding schemes on the critical flashback (Ф2) and breaking-through (Ф3) conditions are examined. The experimental results indicate that the disturbance to flow velocity in the transverse direction mainly influences Ф2, while Ф3 is greatly affected by the blocking normal to the flow direction. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-10T10:41:19.263964-05:
      DOI: 10.1002/aic.15862
       
  • Pressure drop and saturation of non-wettable coalescing filters at
           different loading rates
    • Authors: Cheng Chang; Zhongli Ji, Jialin Liu
      Abstract: The effect of layers on the pressure drop and saturation of non-wettable filters at different loading rates were investigated. It was found that both the jump and channel pressure drop depended on the loading rate. The total channel pressure drop of different filters seemed independent of the number of layers. At the same loading rate, more layers led to fewer channels per layer and larger size of each channel. Moreover, according to the evolution of channel number and size, there was a reorganization of channel structure in the filters. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-10T10:41:12.627436-05:
      DOI: 10.1002/aic.15863
       
  • Oil Jet with Dispersant: Macro-Scale Hydrodynamics and Tip Streaming
    • Authors: Lin Zhao; Feng Gao, Michel C. Boufadel, Thomas King, Brian Robinson, Robyn Conmy, Kenneth Lee
      Abstract: Modeling the movement of oil released underwater is a challenging task due to limitations in measuring hydrodynamics in an oil-water system. In this work, we conducted an experiment of horizontal release of oil without and with dispersant. The model VDROP-J was used and compared to the model JETLAG, a miscible plume trajectory model. Both models were found to reproduce the oil jet hydrodynamics for oil without and with dispersant. The predicted DSD from VDROP-J matched closely observation for untreated oil. For oil with dispersant, experimental results have shown evidence that tip streaming occurred. For this purpose, a new conceptual module was developed in VDROP-J to capture the tip streaming phenomenon and an excellent match was achieved with observation. This study is the first to report tip streaming occurring in underwater oil jets, which should have consequences on predicting the DSD when dispersant are used on an underwater oil release. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-10T10:41:07.214771-05:
      DOI: 10.1002/aic.15864
       
  • Development of 3D Polymer DFT and Its Application to Molecular Transport
           through a Surfactant-Covered Interface
    • Authors: Yu Liu; Honglai Liu
      Abstract: We have developed a 3-dimensional polymer density functional theory (DFT) and applied it to predict the thermodynamic and structural information of molecular transport through a surfactant-covered interface. The Green recursive function (GRF) method has been employed to consider the chain conformation effect. The reference ideal gas (RIG) method has been developed, extending it from molecular DFT to polymer DFT, with a universal form to calculate thermodynamic properties such as the grand potential and free energy. We have demonstrated the accuracy of the theory by comparing it to available simulations. Furthermore, we have applied the theory to predict the free energy barrier and density profile of molecular transport through a surfactant-covered interface. The free energy profile provides reasonable predictions of the transition velocity, while the density profile gives insight into the microstructural information of the transport process, which is consistent with the available molecular simulations. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-10T10:36:38.44232-05:0
      DOI: 10.1002/aic.15858
       
  • Spontaneous Imbibition of Liquid in Glass fiber Wicks, Part II: Validation
           of a Diffuse-front Model
    • Authors: M. Amin F. Zarandi; Krishna M Pillai
      Abstract: In Part I 1, we proposed a model based on sharp liquid-front where a good match with the experimental data was achieved. However the model failed to account for partial saturations in the wicks. Here we try Richard's equation to predict liquid saturation where the equation is solved numerically in 3-D using COMSOL and analytically in 1-D using Mathematica for glass-fiber wicks after treating them as transversely-isotropic porous media. As a novel contribution, relative permeability and capillary pressure are determined directly from pore-scale simulations in wick microstructure using the state-of-the-art software GeoDict. The saturation along the wick length is determined experimentally through a new liquid-N2 based freezing technique. After including the gravity effect, good agreements between the numerical/analytical predictions and experimental results are achieved in saturation distributions. We also validated the Richard's equation based model while predicting absorbed liquid-mass into the wick as function of time. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-10T10:36:00.867287-05:
      DOI: 10.1002/aic.15856
       
  • Multi-criteria optimization for parametrization of SAFT-type equations of
           state for water
    • Authors: Esther Forte; Jakob Burger, Kai Langenbach, Michael Bortz, Hans Hasse
      Abstract: Finding appropriate parameter sets for a given equation of state to describe different properties of a certain substance is an optimization problem with conflicting objectives. Such problem is commonly addressed by single-criteria optimization in which the different objectives are lumped into a single goal function. We show how multi-criteria optimization (MCO) can be beneficially used for parameterizing equations of state. The Pareto set which comprises a set of optimal solutions of the multi-criteria optimization problem is determined. As an example, the perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state (EoS) is used and applied to the description of the thermodynamic properties of water, focusing on saturated liquid density and vapor pressure. Different options to describe the molecular nature of water by the PC-SAFT EoS are studied and for all variants, the Pareto sets are determined, enabling a comprehensive assessment. When compared to literature models, Pareto optimization yields improved models. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-10T10:35:28.012935-05:
      DOI: 10.1002/aic.15857
       
  • A Mechanistic Modeling Framework for Gas-Phase Adsorption Kinetics and
           Fixed-Bed Transport
    • Authors: Austin P. Ladshaw; Sotira Yiacoumi, Ronghong Lin, Yue Nan, Lawrence L. Tavlarides, Costas Tsouris
      Abstract: Adsorption is a complex physicochemical process involving interparticle transport, interphase mass-transfer, intraparticle diffusion, and surface reactions. Although the exact description of the adsorption process will inevitably vary from system to system, it will always be governed by those primary mechanisms. Therefore, by devising a model framework that can inherently include those mechanisms, it would be possible to create a modeling platform on which many different adsorption problems could be solved numerically. To accomplish this task, a generalized 1-D conservation law model was created to include the necessary mechanisms of adsorption on several different geometrical domains. Specific model applications for adsorption were developed under that framework and validated using experimental data available in literature or obtained in this work. This modeling platform makes it easier to model various adsorption problems and develop new adsorption models because of the common treatment of the mathematics governing the physical processes. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-06T00:25:30.230112-05:
      DOI: 10.1002/aic.15855
       
  • Magnetic Particle Tracking for non-spherical particles in a cylindrical
           fluidized bed
    • Authors: K.A. Buist; P. Jayaprakash, N.G. Deen, J.T. Padding, J.A.M. Kuipers
      Abstract: In granular flow operations often particles are non-spherical. This has inspired a vast amount of research in understanding the behaviour of these particles. Various models are being developed to study the hydrodynamics involving non-spherical particles. Experiments however are often limited to obtain data on the translational motion only. This paper focusses on the unique capability of Magnetic Particle Tracking to track the orientation of a marker in a full 3D cylindrical fluidized bed. Stainless steel particles with the same volume and different aspect ratios are fluidized at a range of superficial gas velocities. Spherical and rod-like particles show distinctly different fluidization behaviour. Also the distribution of angles for rod-like particles changes with position in the fluidized bed as well as with the superficial velocity. Magnetic Particle Tracking shows its unique capability to study both spatial distribution and orientation of the particles allowing more in depth validation of Discrete Particle Models. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-06T00:25:24.925116-05:
      DOI: 10.1002/aic.15854
       
  • Optimization and control of bio-conversion of polymeric substrate in the
           chemostat
    • Authors: J-A. Sepulchre; F. Mairet, J-L. Gouzé
      Abstract: In this paper, a simple model of the growth of polymer-decomposing bacteria in a continuous stirred tank reactor is proposed. The dilution rate is controlled to optimize the output of monomers. This model is studied in order to find the optimum at the stationary state. However, the optimal stationary state is not robust against perturbations, leading to washout in the bioreactor. A control that makes the closed system globally stable around the optimal equilibrium is proposed. Then, a more complex model for polymers and oligomers of any lengths is studied. It is shown that the same technics also lead to a globally stable optimal point for the controlled system. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-01T02:35:37.297214-05:
      DOI: 10.1002/aic.15853
       
  • Adsorptive Removal of Refractory Sulphur Compounds by Tantalum Oxide
           Modified Activated Carbons
    • Authors: Amir A Iravani; Kamalakar Gunda, Flora T.T. Ng
      Abstract: Adsorptive desulphurization of a model diesel fuel consisting of dibenzothiophene (DBT) or 4,6-dimethyldibenzothiophene(4,6-DMDBT) in hexadecane was carried out over activated carbons and tantalum oxide modified (Ta-x/ACC, x= 2, 5 or 10wt% Ta, Activated Carbon Centaur) activated carbons at 50 °C. The adsorption isotherm for ACC followed the Langmuir model while the adsorption on Ta-5/ACC fitted the Sips equation indicating more than one type of adsorption sites. Characterization studies indicated new types of adsorption site resulting from the incorporation of Ta oxide into the porous structure of the ACC. XPS data suggested interaction of Ta with the S atom in DBT. The heats of adsorption in the liquid phase determined from micro flow calorimetry for DBT in C16 confirmed the interaction of Ta with DBT. Ta-5/ACC exhibited the highest adsorption capacity for 4,6-DMDBT compared to literature reports. Competitive adsorption experiments showed the adsorption capacity as follows: quinoline> DBT≫ naphthalene. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-01T02:35:35.526519-05:
      DOI: 10.1002/aic.15852
       
  • How penultimate monomer unit effects and initiator influence ICAR ATRP of
           n-butyl acrylate and methyl methacrylate
    • Authors: Stijn K. Fierens; Paul H. M. Van Steenberge, Marie-Françoise Reyniers, Dagmar R. D'hooge, Guy B. Marin
      Abstract: The relevance of penultimate monomer unit (PMU) effects and the selection of the correct initiator species under typical reversible deactivation radical copolymerization conditions is illustrated, using matrix-based kinetic Monte Carlo simulations allowing the visualization of all monomer sequences along individual chains. Initiators for continuous activator regeneration atom transfer radical polymerization (ICAR ATRP) is selected as illustrative polymerization technique with n-butyl acrylate and methyl methacrylate as comonomers, aiming at the synthesis of well-defined gradient copolymers. Using literature based model parameters, in particular temperature dependent monomer and radical reactivity ratios, it is demonstrated that PMU effects on propagation and ATRP (de)activation cannot be ignored to identify the most suited ICAR ATRP reactants (e.g. tertiary ATRP initiator) and reaction conditions (e.g. feeding rates under fed-batch conditions). The formulated insights highlight the need for further research on PMU effects on all reaction steps in radical polymerization. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-29T13:20:35.544449-05:
      DOI: 10.1002/aic.15851
       
  • Assessment of Kinetics of Photoinduced Fe-based Atom Transfer Radical
           Polymerization under Conditions Using Modeling Approach
    • Authors: Zhou Yin-Ning; Luo Zheng-Hong
      Abstract: Kinetic insight into photoinduced Fe-based atom transfer radical polymerization (ATRP) involving monomer-mediated photoreduction was carried out by modeling approach for the first time. Preliminary numerical analysis of number-average molar mass (Mn) derivation in this specific system was given. Simulation results provide a full picture of reactant concentration and reaction rate throughout the entire polymerization. Methyl 2,3-dibromoisobutyrate (MibBr2) generated from methyl methacrylate (MMA)-mediated photoreduction as the leading factor for the deviation of Mn from theoretical value was confirmed by reaction contributions in α-bromophenylacetate (EBPA) containing system. Reasonable predictions were made with respect to the polymerizations under a variety of initial conditions. Results show that increasing light intensity will shorten transition period and increase steady state polymerization rate; decreasing catalyst loading will cause the decrease in polymerization rate and Mn deviation; varying initiation activity will slightly increase the time to attain steady state of dispersity (Mw/Mn) evolution and enormously change the fraction of reaction contributions; increasing targeted chain length will extend transition period, decrease steady state polymerization rate, increase Mn deviation degree with same reaction contributions, and decrease the time to attain the steady state of Mw/Mn. The numerical analysis presented in this work clearly demonstrates the unique ability of our modeling approach in describing the kinetics of photoinduced Fe-based ATRP of MMA. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-29T13:20:23.651277-05:
      DOI: 10.1002/aic.15850
       
  • Enhancing Oxygen Permeation via Multiple Types of Oxygen Transport Paths
           in Hepta-bore Perovskite Hollow Fibers
    • Authors: Jiawei Zhu; Tianlei Wang, Zhe Song, Zhengkun Liu, Guangru Zhang, Wanqin Jin
      Abstract: The multiple types of efficient oxygen transport paths were demonstrated in high-mechanical-strength hepta-bore Ba0.5Sr0.5Co0.8Fe0.2O3-δ hollow fiber membranes. These types of paths play a prominent role in enhancing oxygen permeation fluxes (17.6 mL min−1 cm−2 at 1223 K) which greatly transcend the performance of state-of-the-art Ba0.5Sr0.5Co0.8Fe0.2O3-δ hollow fiber membranes, showing a good commercialization prospect. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-28T10:55:20.810451-05:
      DOI: 10.1002/aic.15849
       
  • Dehydrogenation Kinetic Model of Heavy Paraffins
    • Authors: Hongbo Jiang; Yilong Zhou, Liqun Zhou, Yu Wang, Jing Cao
      Abstract: Based on the dehydrogenation mechanism of heavy paraffins under industrial conditions, the intrinsic reaction kinetic model and catalyst deactivation model were established considering the influence of side reactions with different carbon-number heavy paraffins. Based on the experimental data of dehydrogenation reactions with different carbon-number paraffins in an axial continuous-flow isothermal fixed-bed microreactor, Powell optimization method was used to estimate the model parameters. The results show that there is a liner relationship between the activation energies and pre-exponential factors of homologous reactions and carbon number of paraffins. And a correlation model about the deactivation rate constants under different conditions was established. The validation of kinetic model showed that the model could be used to predict detailed product distribution with different feedstocks under different reaction conditions. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-26T06:52:44.285205-05:
      DOI: 10.1002/aic.15848
       
  • Interface-Resolved Simulations of Normal Collisions of Spheres on a Wet
           Surface
    • Authors: Y. (Yali) Tang; B. (Britta) Buck, S. (Stefan) Heinrich, N.G. (Niels) Deen, J.A.M. (Hans) Kuipers
      Abstract: Detailed knowledge of micro-mechanics of individual particle collisions in the presence of liquid is crucial for modelling/understanding of wet granular flows that are omnipresent in nature and industrial applications. Despite many reported studies, very limited detailed interface-resolved modelling of such collision problems has been conducted. This paper presents an improved model for direct numerical simulations of normal impacts of spheres on wet surfaces. This model combines the immersed boundary method and the volume-of-fluid method supplemented with a model describing gas-liquid-solid contact line. It is demonstrated that our model not only correctly describes the collision dynamics of wet particles, but also well captures the dynamics of the liquid bridge formed during the collision. Quantitative agreement is obtained between the simulation results and the experimental data. It is concluded that the developed model constitutes a powerful tool to complement experimental studies, which are challenging for more complex wet collision systems in practice. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-26T06:52:42.349078-05:
      DOI: 10.1002/aic.15847
       
  • Rapid Development of Thickness-controllable Superamphiphobic Coating on
           the Inner Wall of Long Narrow Pipes
    • Authors: Ziyi Hu; Huaiyuan Wang, Yixing Zhu, Yanji Zhu
      Abstract: A novel electrochemical technique had been introduced to prepare nanocrystalline superamphiphobic coatings inside of narrow pipes of significant length. The axially propagated ultrasound was utilized to ensure the scaling-up potential of this technique. The coating had strong mechanical strength, durability in low/high pH solutions and the potential of controlling its thickness while preserving a stable nonwetting performance. In addition, the properties of anti-scaling and drag reduction under the flowing circumstance had been demonstrated. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-23T20:55:32.779806-05:
      DOI: 10.1002/aic.15843
       
  • Feasible Separation Regions for Distillation II: A Generalized
           Distillation Limit
    • Authors: Lechoslaw J. Krolikowski
      Abstract: The boundary of the feasible separation region consists of several curves that are related to specific types of operating modes of the column. Some of these curves create a well-known product composition multitude, whereas other curves form a generalized distillation limit. The generalized distillation limit demarcates the sloppy splits (i.e., separations in which the composition of at least one product lies inside the composition space) from regions not accessible by distillation and depends on the thermodynamic state of the feed (a mixture of vapor and liquid in equilibrium or saturated vapor/liquid) and column equipment (total/partial condenser and total/partial reboiler). The mathematical equations describing the generalized distillation limit are obtained based on the relationships between the curves (which form the generalized distillation limit) and specific types of operating modes of the column as well as the material balances for the enriching and stripping columns. Furthermore, the vapor and liquid pinch-point curves, which go through the feed composition point, are not dependent on the thermodynamic state of the feed and column equipment. In addition, an algorithm for determining the generalized distillation limit is obtained. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-23T20:50:40.765616-05:
      DOI: 10.1002/aic.15845
       
  • Universal Correlation for Gas Hydrates Suppression Temperature of
           Inhibited Systems: I. Single Salts
    • Authors: Yue Hu; Bo Ram Lee, Amadeu K. Sum
      Abstract: Reliable prediction of hydrate suppression temperature in presence of inhibitors, such as salts, over a wide range of pressures (up to 200 MPa) is critically important, especially in the area of deepwater oil and gas production. However, the existing models and correlations that account for salts have severe limitations and deficiencies in estimating the hydrate suppression temperature. Herein, we propose a new correlation, to be called Hu-Lee-Sum correlation, that significantly improves the predictions of the hydrate suppression temperature by considering the salt species and concentrations, system temperature and pressure, and hydrate structure. This paper represents part I of this work and it will detail the development of the correlation and demonstrate the generality and universality of the correlation to predict the hydrate suppression temperature for any single salt system. Specifically, we show accurate predictions for the hydrate suppression temperature for a number of chloride and bromide salt brine systems. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-23T20:50:37.552754-05:
      DOI: 10.1002/aic.15846
       
  • Oxygen transfer in co-extruded multilayer active films for food packaging
    • Authors: Luciano Di Maio; Francesco Marra, Tesfaye F. Bedane, Sam Saguy, Loredana Incarnato
      Abstract: Oxygen scavenger applications in flexible food packaging are still limited due to the difficulty to ensure scavenging activity during storage and throughout the product shelf life. To avoid fast inactivation of the scavenger, multilayer active structures can be realized by inserting the active layer between two or more inert layers. In this work, an unsteady-state 1D reaction-diffusion mass transfer model was developed for predicting and optimizing the barrier-to-oxygen performance and the physical configurations of the co-extruded multilayer active films. The film configuration was a 3-layers structure composed of polyethylene terephthalate (PET) as external inert layers, and PET with a polymeric oxygen scavenger as the core reactive layer. Scavenging activity of the multilayer film increased with the reactive layer thickness. Oxygen absorption reaction at short times decreased proportionally with the thickness of the external layers. The most appropriate combinations of inert-to-active film thickness were studied and analyzed. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-23T20:45:30.529482-05:
      DOI: 10.1002/aic.15844
       
  • A Novel Route for Green Conversion of Cellulose to HMF by Cascading
           Enzymatic and Chemical Reactions
    • Authors: Yunlei Zhang; Yao Chen, Pei Jin, Meng Liu, Jianming Pan, Yongsheng Yan, Qingang Xiong
      Abstract: In this work, a novel route to deconstruct cellulose into 5-hydroxymethylfurfural (HMF) by cascading enzymatic and chemical reactions is reported. For biocatalyst preparation, Fe3O4 nanoparticles encapsulated SBA-15 with appropriate pore size was synthesized and utilized as magnetic scaffolds for the immobilization of cellulase. For chemical catalyst preparation, sulfated zirconium dioxide conformed monolayers were grafted on SBA-15 template to create thermally robust mesoporous catalysts with tunable solid basic/Lewis acid and Brønsted acid sites. Catalytic performance of biocatalyst and chemical catalyst was explored in the aqueous phase conversion of IL pre-treated cellulose to glucose, and in the iPrOH/water solvent conversion of glucose to HMF conversion, respectively. After the optimization of reaction conditions, a sequential conversion of pre-treated cellulose to glucose and glucose to HMF was carried out, and 43.6% HMF yield can be obtained. The cascaded enzymatic and chemocatalytic reaction system demonstrates an effective and economically friendly process for biomass energy conservation. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-22T18:35:46.710151-05:
      DOI: 10.1002/aic.15841
       
  • Modeling the Reaction Event History and Microstructure of Individual
           Species in Post-Polymerization Modification
    • Authors: Julio C. Hernández-Ortiz; Paul Van Steenberge, Jan N. E. Duchateau, Klaas Remerie, Carolina Toloza, Ana Luisa Vaz, Fons Schreurs, Marie-Françoise Reyniers, Guy B. Marin, Dagmar R. D'hooge
      Abstract: For post-polymerization modification, a novel kinetic Monte Carlo (kMC) modeling strategy for the description of the reaction event history and the evolution of the microstructure of individual macrospecies with a complex topology is presented. The kMC model allows the kinetic analysis of free radical induced grafting of vinyl monomers onto polyethylene (PE) chains, assuming isothermal conditions and perfect macromixing and accounting for diffusional limitations on the micro-scale. Not only average characteristics such as the monomer conversion, grafting selectivity and yield, but also the chain length distribution (CLD) of all macromolecular species types, the average “from/to” grafting and crosslinking density, the number of (dead) grafts and crosslinks per individual macromolecule, the chain length of every graft, and the CLD of the grafted chains are calculated. Under typical grafting conditions, depropagation and diffusional limitations cannot be ignored. The functionalization occurs mainly on those macrospecies in the PE-CLD with a high mass concentration. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-22T18:35:31.920707-05:
      DOI: 10.1002/aic.15842
       
  • Darcy's law for two-dimensional ows: Singularities at corners and a new
           class of models
    • Authors: Yulii D. Shikhmurzaev
      Abstract: As is known, Darcy's model for fluid flows in isotropic homogeneous porous media gives rise to singularities in the velocity field for essentially two-dimensional flow configuration, like flows over corners. Considering this problem from the modelling viewpoint, the present study aims at removing this singularity, which cannot be regularized via conventional generalizations of the Darcy model, like Brinkman's equation, without sacrificing Darcy's law itself for unidirectional flows where its validity is well established experimentally. The key idea is that, as confirmed by a simple analogy, the permeability of a porous matrix with respect to flow is not a constant independent of the flow but a function of the flow field (its scalar invariants), decreasing as the curvature of the streamlines increases. This introduces a completely new class of models where the flow field and the permeability field are linked and, in particular problems, have to be found simultaneously. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-22T18:12:50.506215-05:
      DOI: 10.1002/aic.15840
       
  • Feasible Separation Regions for Distillation I: Structure
    • Authors: Lechoslaw J. Krolikowski
      Abstract: A feasible separation region is determined for only four special combinations of a saturated vapor/liquid feed and total/partial condenser or reboiler. The present work addresses the construction of a feasible separation region for a general case where the feed is a mixture of vapor and liquid in equilibrium and where the column is equipped with a partial/total condenser and reboiler. The analysis reveals that the product composition sets (which are defined for various reflux and reboil ratios and a fixed number of stages in each column section) are the main elements of the feasible separation region. The application of the geometric model of the column in combination with the shape of the distillation line led to the conclusion that the feasible separation region is the union of two product composition sets for both enriching and stripping columns both with an infinite number of stages. The boundary of the feasible separation region consists of several curves related to specific types of operating modes in the column. Some of these curves create a well-known product composition multitude, whereas other curves form a generalized distillation limit. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-19T10:31:02.506929-05:
      DOI: 10.1002/aic.15839
       
  • Structure and Catalytic Consequence of Mg-modified VOx/Al2O3 Catalysts for
           Propane Dehydrogenation
    • Authors: Tengfang Wu; Gang Liu, Liang Zeng, Guodong Sun, Sai Chen, Rentao Mu, Sika Agbotse Gbonfoun, Zhi-Jian Zhao, Jinlong Gong
      Abstract: Supported VOx catalysts are promising non-oxidative propane dehydrogenation (PDH) materials for their commercially attractive activity and propylene selectivity. However, they frequently suffer from rapid deactivation caused by coke deposition. This paper describes the promoting role of magnesium on the stability of VOx/Al2O3 catalysts for PDH. A series of VOx/Al2O3 and Mg-modified VOx/Al2O3 catalysts were synthesized by an incipient wetness impregnation method. The catalysts were carefully characterized by Raman spectra, UV-Vis spectra, STEM, TGA and in situ DRIFTS. We showed that the stability of a 12V/Al2O3 catalyst was significantly improved upon addition of small amounts of MgO. Experimental evidences indicate that V2O5 nanoparticles emerge in the 12V/Al2O3 samples, and appropriate Mg addition helps dispersing the V2O5 nanoparticles into 2D VOx species thus decreasing coke formation and improving stability in non-oxidative dehydrogenation of propane. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-16T11:20:52.05908-05:0
      DOI: 10.1002/aic.15836
       
  • A Highly Stable Metal-Organic Framework with Optimum Aperture Size for CO2
           Capture
    • Authors: Zhigang Hu; Yuxiang Wang, Shamsuzzaman Farooq, Dan Zhao
      Abstract: We herein report an optimal modulated hydrothermal (MHT) synthesis of a highly-stable zirconium metal-organic framework (MOF) with an optimum aperture size of 3.93 Å that is favorable for CO2 adsorption. It exhibits excellent CO2 uptake capacities of 2.50 and 5.63 mmol g−1 under 0.15 bar and 1 bar at 298 K, respectively, which are among the highest of all the pristine water-stable MOFs reported so far. In addition, we have designed a lab-scale breakthrough set-up to study its CO2 capture performance under both dry and wet conditions. The velocity at the exit of breakthrough column for mass balance accuracy is carefully measured using argon with a fixed flow rate as the internal reference. Other factors that may affect the breakthrough dynamics, such as pressure drop and its impact on the roll-up of the weaker component have been studied in details. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-16T11:20:50.948084-05:
      DOI: 10.1002/aic.15837
       
  • A framework for ammonia supply chain optimization incorporating
           conventional and renewable generation
    • Authors: Andrew Allman; Douglas Tiffany, Stephen Kelley, Prodromos Daoutidis
      Abstract: Ammonia is an essential nutrient for global food production brought to farmers by a well established supply chain. This paper introduces a supply chain optimization framework which incorporates new renewable ammonia plants which produce hydrogen from wind-powered electrolysis into the conventional ammonia supply chain. Both economic and environmental objectives are considered. The framework is then applied to two separate case studies analyzing the supply chains of Minnesota and Iowa, respectively. The base case results present an expected tradeoff between cost, which favors purchasing ammonia from conventional plants, and emissions, which favor building distributed renewable ammonia plants. Further analysis of this tradeoff shows that a carbon tax above $25/t will reduce emissions in the optimal supply chain through building large renewable plants. The importance of scale is emphasized through a Monte Carlo sensitivity analysis, as the largest scale renewable plants are selected most often in the optimal supply chain. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-16T11:20:23.663565-05:
      DOI: 10.1002/aic.15838
       
  • Advice for Emerging Researchers on Research Program Development: A
           Personal Case Study
    • Authors: Christopher W. Jones
      PubDate: 2017-06-15T17:15:30.012427-05:
      DOI: 10.1002/aic.15835
       
  • How Nano-Scale Roughness Impacts the Flow of Grains influenced by
           Capillary Cohesion
    • Authors: Casey Q. LaMarche; Andrew W. Miller, Peiyuan Liu, Stuart Leadley, Christine M. Hrenya
      Abstract: We show that nano-scale changes in surface roughness affect the macro-scale (many-particle) behavior of granular materials influenced by cohesion. Macro-scale effects of roughness are investigated for conditions where cohesion is dominated by either humidity-induced or van der Waals-induced forces. Surface-topography measurements are used to calculate the relevant inter-particle cohesive forces. The (force-dominated) macro-scale cohesion measurements are explained via the ratio of the predicted inter-particle cohesive force to gravity, thus reinforcing the importance of roughness to cohesion. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-13T10:46:24.016806-05:
      DOI: 10.1002/aic.15830
       
  • An Efficient and Reliable Predictive Method for Fluidized Bed Simulation
    • Authors: Liqiang Lu; Tingwen Li, Sofiane Benyahia
      Abstract: In past decades, the continuum approach was the only practical technique to simulate large-scale fluidized bed reactors because discrete approaches suffer from the cost of tracking huge numbers of particles and their collisions. This study significantly improved the computation speed of discrete particle methods in two steps: First, the time-driven hard-sphere (TDHS) algorithm with a larger time-step is proposed allowing a speedup of 20-60 times; second, the number of tracked particles is reduced by adopting the coarse-graining technique gaining an additional 2-3 orders of magnitude speedup of the simulations. A new velocity correction term was introduced and validated in TDHS to solve the over-packing issue in dense granular flow. The TDHS was then coupled with the coarse-graining technique to simulate a pilot-scale riser. The simulation results compared well with experiment data and proved that this new approach can be used for efficient and reliable simulations of large-scale fluidized bed systems. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-13T10:46:20.017741-05:
      DOI: 10.1002/aic.15832
       
  • The Development of Kinetics Model for CO2 Absorption into Tertiary Amines
           containing Carbonic Anhydrase
    • Authors: Bin Liu; Xiao Luo, Zhiwu Liang, Wilfred Olson, Helei Liu, Raphael Idem, Paitoon Tontiwachwuthikul
      Abstract: CO2 absorption into aqueous solutions of two tertiary alkanolamines, namely, MDEA and DMEA with and without carbonic anhydrase (CA) was investigated with the use of the stopped-flow technique at temperatures in the range of 293-313 K, CA concentration varying from 0-100 g/m3 in aqueous MDEA solution with the amine concentration ranging from 0.1-0.5 kmol/m3, and CA concentration varying from 0-40 g/m3 in aqueous DMEA solution with the amine concentration ranging from 0.05-0.25 kmol/m3. The results show that the pseudo first-order reaction rate (k0, amine; s−1) is significantly enhanced in the presence of CA as compared with that without CA. The enhanced values of the kinetic constant in the presence of CA has been calculated and a new kinetics model for reaction of CO2 absorption into aqueous tertiary alkanolamine solutions catalyzed by CA has been established and used to make comparisons of experimental and calculated pseudo first-order reaction rate constant (k0, with CA) in CO2-MDEA-H2O and CO2-DMEA-H2O solutions. The AADs were 15.21% and 15.17% respectively. The effect of pKa on the CA activities has also been studied by comparison of CA activities in different tertiary amine solutions, namely, TEA, MDEA, DMEA and DEEA. The pKa trend for amines were: DEEA>DMEA>MDEA>TEA. In contrast the catalyst enhancement in amines was in the order: TEA> MDEA> DMEA> DEEA. Therefore, it can be seen that the catalyst enhancement in the amines decreased with their increasing pKa values. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-13T10:46:15.564291-05:
      DOI: 10.1002/aic.15833
       
  • Coaxial Electrohydrodynamic Atomization towards Large Scale Production of
           Core-shell Structured Microparticles
    • Authors: Wei-Cheng Yan; Yen Wah Tong, Chi-Hwa Wang
      Abstract: In this work, a double-nozzle coaxial electrohydrodynamic atomization (CEHDA) system was designed as an instructive case towards large-scale production of core-shell microspheres. The effect of nozzle-to-nozzle distance was investigated to reveal that the interference between neighboring nozzles significantly affect the product quality in terms of morphology and core-shell structure. Optimal spacing indicated that ∼3000 nozzle/m2 packing density may be achieved with minimum interference of electric field from neighboring nozzle by adjusting the nozzle-to-nozzle distance greater than 0.018m. The proposed multi-scale model also showed that the X-component of electric field strength (Ex) at the region near side nozzles increases with increasing nozzle number, and the bending of jets/sprays at the side may be reduced by using dummy nozzle at the edge side. The model could guide the design of multi-nozzle CEHDA system for production of core-shell microparticles in large-scale. This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-07T10:30:27.034469-05:
      DOI: 10.1002/aic.15821
       
  • Issue information - table of contents
    • Pages: 3625 - 3626
      PubDate: 2017-08-03T09:33:14.790876-05:
      DOI: 10.1002/aic.15478
       
  • Theoretical analysis of natural gas recovery from marginal wells with a
           deep well reactor
    • Authors: David Frederic Emerson; Amir Al Ghatta, Benjamin M. Woolston, Adrian Fay, Amit Kumar, Gregory Stephanopoulos
      Pages: 3642 - 3650
      Abstract: Current natural gas harvesting technologies are only economically viable at high gas flow rates. Subsequently, a significant quantity of gas remains unused in abandoned wells. Methanotrophic organisms are under development to capitalize on this resource given their preference for ambient conditions, however capital and methane mass transfer costs must be minimized. We propose using the well as the bioreactor negating capital costs, and leveraging the gas pressure for mass transfer. We evaluate the Deep Well Reactor's feasibility by developing mathematical models to simulate mass transfer and explore how operating parameters impact ethanol production. The results show sufficient mass transfer for 100% conversion, despite minimal complexity. Current aerobic methanotrophs and inorganic catalysts provide sufficient reaction rates. Conversely, anaerobic methanotrophs rates must be improved by a factor of 1200. With an appropriate catalyst, this technology allows the recovery of methane at flow rates an order of magnitude lower than current technologies. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3642–3650, 2017
      PubDate: 2017-04-14T08:50:51.096582-05:
      DOI: 10.1002/aic.15738
       
  • Modeling the dynamics of tamponade multicomponent gases during retina
           reattachment surgery
    • Authors: Sheldon K. Hall; Thomas H. Williamson, Jean-Yves Guillemaut, Tony Goddard, Andrew P. Baumann, Joseph C. Hutter
      Pages: 3651 - 3662
      Abstract: Vitrectomy and pneumatic retinopexy are common surgical procedures used to treat retinal detachment. To reattach the retina, gases are used to inflate the vitreous space allowing the retina to attach by surface tension and buoyancy forces that are superior to the location of the bubble. These procedures require the injection of either a pure tamponade gas, such as C3F8 or SF6, or mixtures of these gases with air. The location of the retinal detachment, the anatomical spread of the retinal defect, and the length of time the defect has persisted, will determine the suggested volume and duration of the gas bubble to allow reattachment. After inflation, the gases are slowly absorbed by the blood allowing the vitreous to be refilled by aqueous. We have developed a model of the mass transfer dynamics of tamponade gases during pneumatic retinopexy or pars plana vitrectomy procedures. The model predicts the expansion and persistence of intraocular gases (C3F8, SF6), oxygen, nitrogen, and carbon dioxide, as well as the intraocular pressure. The model was validated using published literature in rabbits and humans. In addition to correlating the mass transfer dynamics by surface area, permeability, and partial pressure driving forces, the mass transfer dynamics are affected by the percentage of the tamponade gases. Rates were also correlated with the physical properties of the tamponade and blood gases. The model gave accurate predictions in humans. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3651–3662, 2017
      PubDate: 2017-04-16T18:25:26.329631-05:
      DOI: 10.1002/aic.15739
       
  • Synthesis of transparent oil dispersion of monodispersed calcium carbonate
           nanoparticles with high concentration
    • Authors: Yuan Pu; Fang Kang, Xiao-Fei Zeng, Jian-Feng Chen, Jie-Xin Wang
      Pages: 3663 - 3669
      Abstract: The preparation of monodispersed inorganic nanoparticles is of great interest for many applications. In this article, transparent oil dispersion of monodispersed amorphous CaCO3 nanoparticles with high concentration and long-term stability were controllably prepared by a reverse microemulsion method. The effects of the addition amount of extra minute water and (NH4)2CO3 as novel assistant promoter, reaction temperature, Ca(OH)2/CaO mole ratio were explored. The optimum synthesis conditions were achieved. The as-prepared transparent oil nanodispersion had a good monodispersity, a uniform particle size of 8–10 nm, a high stability of over 12 months, a high solid content of 38 wt% (Ca content of about 15.5 wt%) and a high total base number of 416 mgKOH/g. The preparation process was further investigated by polarized optical microscope and Fourier transform infrared. This nanodispersion will find a promising applicability as an excellent nanodetergent in the fields of automobile and marine lubricants. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3663–3669, 2017
      PubDate: 2017-04-12T10:34:27.650312-05:
      DOI: 10.1002/aic.15729
       
  • A promising technique of Aegle marmelos leaf extract mediated
           self-assembly for silver nanoprism formation
    • Authors: K. Jagajjanani. Rao; N. V. S. Praneeth, Santanu Paria
      Pages: 3670 - 3680
      Abstract: The Aegle marmelos leaf extract (LE) mediated synthesis of prismatic and spherical Ag nanoparticles (NPs) has been studied. The formation of prismatic structures from spherical NPs was observed microscopically using scanning electron microscope, transmission electron microscope, and atomic force microscope. The shape transformation from spherical NPs to prismatic nanostructures was studied by simply changing LE concentration, keeping constant AgNO3 concentration (1 mM). The role of pH toward prism formation and the effect of sonication on the formed structures were also investigated. The antimicrobial activity of the synthesized Ag spherical/prismatic NPs was evaluated against gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa) and on a phytopathogen Fusarium solani. This green synthesis approach for the synthesis of prismatic Ag nanostructures may be useful for surface-enhanced Raman spectroscopy application for the detection of low concentration organic molecules, apart from the studied antimicrobial activity. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3670–3680, 2017
      PubDate: 2017-05-02T09:53:53.593548-05:
      DOI: 10.1002/aic.15766
       
  • Dynamic multiscale method for gas-solid flow via spatiotemporal coupling
           of two-fluid model and discrete particle model
    • Authors: Xizhong Chen; Junwu Wang
      Pages: 3681 - 3691
      Abstract: Various computational fluid dynamics methods have been developed to study the hydrodynamics of gas-solid flows, however, none of those methods is suitable for all the problems encountered due to the inherent multiscale characteristics of gas-solid flows. Both discrete particle model (DPM) and two-fluid model (TFM) have been widely used to study gas-solid flows, DPM is accurate but computationally expensive, whereas TFM is computationally efficient but its deficiency is the lack of reliable constitutive relationships in many situations. Here, we propose a hybrid multiscale method (HMM) or dynamic multiscale method to make full use of the advantages of both DPM and TFM, which is an extension of our previous publication from rapid granular flow (Chen et al., Powder Technol. 2016;304:177–185) to gas-solid two-phase flow. TFM is used in the regions where it is valid and DPM is used in the regions where continuum description fails, they are coupled via dynamical exchange of parameters in the overlap regions. Simulations of gas-solid channel flow and fluidized bed demonstrate the feasibility of the proposed HMM. The Knudsen number distributions are also reported and analyzed to explain the differences. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3681–3691, 2017
      PubDate: 2017-04-12T10:34:24.647228-05:
      DOI: 10.1002/aic.15723
       
  • DEM–PBM modeling of impact dominated ribbon milling
    • Authors: Simone Loreti; Chuan-Yu Wu, Gavin Reynolds, Andreja Mirtič, Jonathan Seville
      Pages: 3692 - 3705
      Abstract: Ribbon milling is a critical step in dry granulation using roll compaction as it determines the properties of granules, and subsequently the properties of final products. During ribbon milling, fragmentation of ribbons or flakes (i.e., compressed agglomerates from dry powders) are induced by either impact or abrasion. Understanding these fragmentation mechanisms is critical in optimizing ribbon milling processes. In the current study, the discrete element method (DEM) was used to model fragmentation at the microscopic level, providing a detailed insight into the underlying breakage mechanism. In DEM modeling, virtual ribbons were created by introducing an appropriate interfacial energy using the cohesive particle model based on the JKR theory. A set of three-dimensional parallelepiped ribbons with solid fraction φ=0.7422 and surface energies ranging from γ=0.03J/m2 and γ=2 J/m2 were created and then fractured during impacts with a plane at various impact velocities, to model impact dominated milling. The fragmentation rate, and the number and size of fragments (i.e., granules) resulting from the breakage of a ribbon during the impact were determined. The DEM simulations showed that the granules size distribution had a bimodal pattern and there was a strong correlation between the size of fines generated from fragmentation during impact and the size of the feed powder (i.e., the size of the primary particles in this study), which was consistent with the observation from physical experiments. Two quantities were calculated from the DEM simulations: the number of fragments p and the fraction of fines z for each breakage event which were then used as input parameters for population balance models (PBM) to develop a DEM–PBM modeling framework. Comparision with published experimental data shows that the developed DEM-PBM model is a promising tool for analysing ribbon milling, but all breakage mechanisms involved need to to considered in order to achieve an accurate prediction. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3692–3705, 2017
      PubDate: 2017-04-14T08:55:43.885858-05:
      DOI: 10.1002/aic.15721
       
  • Morphological properties of flocs under turbulent break-up and
           restructuring processes
    • Authors: M. Vlieghe; C. Frances, C. Coufort-Saudejaud, A. Liné
      Pages: 3706 - 3716
      Abstract: Bentonite flocculation was performed in a Taylor–Couette reactor coupled with an in situ method of image acquisition and analysis. A hydrodynamic sequencing is imposed to perform successive cycles of flocculation and breakage. Depending on the shear rate applied during the breakage step, one or two cycles are needed after the first flocculation step to recover a full reversibility on both size and shape factors. The breakup step produces flocculi that are the building blocks for the next. The re-flocculation steps produce smaller sizes and more regular shapes than the initial growth step. The floc size is calibrated by the turbulence as the radius of gyration is close to the Kolmogorov microscale whereas the floc structure is determined by flocculi aggregates. An analysis of the change of the flocs morphology, despite of their diversity, can also be achieved thanks to some relevant moments of the distributions. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3706–3716, 2017
      PubDate: 2017-04-14T08:50:43.402179-05:
      DOI: 10.1002/aic.15745
       
  • Passive rate-based separation in collisional flows
    • Authors: Diana Lievano Bartlow; Tathagata Bhattacharya, J. J. McCarthy
      Pages: 3717 - 3727
      Abstract: The passive separation of a binary mixture of spherical particles is accomplished using a laboratory scale quasi-two-dimensional inclined board such that gravity alone drives the flow of the mixture through a static array of obstacles. Experimental results compare well with simulations both qualitatively and quantitatively. An increase in separation is observed for increasing board length, whereas a decrease in separation is observed as the solid fraction (area coverage) of particles increases. The possibility of designing green technology for solid-solid separations by taking advantage of particle properties that aid naturally occurring segregation is demonstrated. A probability-based model is suggested as a way to predict the viability of separation between particle types as a function of particle size and coefficient of restitution. It should be noted that size separation is achieved despite peg spacings that are larger than both particles in a mixture. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3717–3727, 2017
      PubDate: 2017-04-20T18:37:20.640058-05:
      DOI: 10.1002/aic.15744
       
  • Yield stress dependency on the evolution of bubble populations generated
           in consolidated soft sediments
    • Authors: Michael Johnson; Michael Fairweather, David Harbottle, Timothy N. Hunter, Jeffrey Peakall, Simon Biggs
      Pages: 3728 - 3742
      Abstract: Retention of hydrogen bubbles within consolidated soft sediments represents an important safety consideration for the management of legacy nuclear wastes due to the potential for acute gas release. Gas retention sufficiently reduced the bulk density of intermediate yield stress (
      PubDate: 2017-05-02T09:53:48.272108-05:
      DOI: 10.1002/aic.15731
       
  • Scaling inter-tablet coating variability in a horizontal rotating drum
    • Authors: J. Ban; R. Kumar, S. Agarwal, C. Wassgren
      Pages: 3743 - 3755
      Abstract: This study investigates how the drum-to-particle diameter ratio (D/d) affects the surface speed and interparticle coating variability in geometrically similar coaters. Discrete element method simulations were used to model particle movement in different-sized, cylindrical drums with identical particle diameters, Froude numbers, fill volume fractions, and spray characteristics. The dimensionless streamwise surface speed profiles become increasingly symmetric as D/d increases, with the maximum speed increasing with D/d. The relationship between the maximum dimensionless speed and D/d is fit well with a power-law expression. Interparticle coating variability decreases with the square root of the number of drum revolutions after a sufficiently large number of drum revolutions. Increasing D/d increases, in a logarithmic manner, the number of drum revolutions required to reach a given degree of coating variability. A similar logarithmic coating variability trend was observed in simulations using almond-shaped pharmaceutical tablets, suggesting that the trend is independent of tablet shape. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3743–3755, 2017
      PubDate: 2017-05-05T12:16:22.817484-05:
      DOI: 10.1002/aic.15758
       
  • Validating granular segregation rate models
    • Authors: Siying Liu; Joseph J. McCarthy
      Pages: 3756 - 3763
      Abstract: One significant hindrance to the development of granular segregation rate models is the inherent difficulty of performing the dynamic experiments required for validation. Here, we seek to overcome this experimental hurdle by establishing an “equilibrium” between segregation and flow perturbation in free surface granular flows and use steady-state—rather than dynamic—measurements for validation. That is, we combine the segregation rate expressions to be tested with a segregation control framework such that the perturbation rate enables us to infer the segregation rate by measuring simply the steady state extent of segregation. We use periodic flow inversions via an axially located baffle in a tumbler-type mixer to provide the perturbations that ultimately alter the steady-state distribution of particles. This work examines the efficacy of existing models for binary segregation driven by either size or density differences. For completeness, we test our model validation framework both computationally and experimentally. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3756–3763, 2017
      PubDate: 2017-05-10T04:45:50.28458-05:0
      DOI: 10.1002/aic.15770
       
  • A superstructure-based model for multistream heat exchanger design within
           flow sheet optimization
    • Authors: Harsha Nagesh Rao; Iftekhar A. Karimi
      Pages: 3764 - 3777
      Abstract: Multistream heat exchangers (MHEXs) are often used in energy-intensive cryogenic processes. Modeling them within a process optimization formulation has been a challenge due to the needs to accommodate phase changes and ensure temperature approach. In this work, we present a nonlinear model for MHEXs based on a novel single-stage superstructure of two-stream exchangers. Our formulation guarantees a minimum temperature approach for all heat exchanges, estimates heat exchange areas for individual stream matches, requires no prior knowledge of phase changes, uses no Boolean variables, and enables seamless optimization of a process with multiple MHEXs. Furthermore, it facilitates dedicated constant-phase intervals that allow accurate estimation of heat-transfer parameters for various stream matches. We optimize two natural gas liquefaction processes involving MHEXs, and report better solutions than the existing literature. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3764–3777, 2017
      PubDate: 2017-04-05T09:06:17.906776-05:
      DOI: 10.1002/aic.15714
       
  • Equation-oriented simulation and optimization of process flowsheets
           incorporating detailed spiral-wound multistream heat exchanger models
    • Authors: Calvin Tsay; Richard C. Pattison, Michael Baldea
      Pages: 3778 - 3789
      Abstract: Multiple chemical processes rely on multistream heat exchangers (MHEXs) for heat integration, particularly at cryogenic temperatures. Owing to their geometric complexity, the detailed design of MHEXs is typically iterative: the exchanger geometric parameters are selected to match process specifications resulting from a flowsheet optimization step; then, the flowsheet is reoptimized with the predictions of the MHEX model, and these steps are repeated until a convergence criterion is met. This paper presents a novel framework that allows—for the first time, to our knowledge—for the simultaneous optimization of the process flowsheet and the detailed MHEX design. Focusing on spiral-wound MHEXs, we develop an equation-oriented exchanger model using industry-accepted heat transfer and pressure drop correlations for single-phase and multiphase streams. We embed this model in our previously developed pseudo-transient equation-oriented process simulation and optimization framework. We demonstrate our approach on an industrial case study, the PRICO® natural gas liquefaction process. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3778–3789, 2017
      PubDate: 2017-04-07T09:35:48.483306-05:
      DOI: 10.1002/aic.15705
       
  • Data-driven adaptive nested robust optimization: General modeling
           framework and efficient computational algorithm for decision making under
           uncertainty
    • Authors: Chao Ning; Fengqi You
      Pages: 3790 - 3817
      Abstract: A novel data-driven adaptive robust optimization framework that leverages big data in process industries is proposed. A Bayesian nonparametric model—the Dirichlet process mixture model—is adopted and combined with a variational inference algorithm to extract the information embedded within uncertainty data. Further a data-driven approach for defining uncertainty set is proposed. This machine-learning model is seamlessly integrated with adaptive robust optimization approach through a novel four-level optimization framework. This framework explicitly accounts for the correlation, asymmetry and multimode of uncertainty data, so it generates less conservative solutions. Additionally, the proposed framework is robust not only to parameter variations, but also to anomalous measurements. Because the resulting multilevel optimization problem cannot be solved directly by any off-the-shelf solvers, an efficient column-and-constraint generation algorithm is proposed to address the computational challenge. Two industrial applications on batch process scheduling and on process network planning are presented to demonstrate the advantages of the proposed modeling framework and effectiveness of the solution algorithm. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3790–3817, 2017
      PubDate: 2017-04-07T09:41:11.467319-05:
      DOI: 10.1002/aic.15717
       
  • Temporal clustering for order reduction of nonlinear parabolic PDE systems
           with time-dependent spatial domains: Application to a hydraulic fracturing
           process
    • Authors: Abhinav Narasingam; Prashanth Siddhamshetty, Joseph Sang-Il Kwon
      Pages: 3818 - 3831
      Abstract: A temporally-local model order-reduction technique for nonlinear parabolic partial differential equation (PDE) systems with time-dependent spatial domains is presented. In lieu of approximating the solution of interest using global (with respect to the time domain) empirical eigenfunctions, low-dimensional models are derived by constructing appropriate temporally-local eigenfunctions. Within this context, first of all, the time domain is partitioned into multiple clusters (i.e., subdomains) by using the framework known as global optimum search. This approach, a variant of Generalized Benders Decomposition, formulates clustering as a Mixed-Integer Nonlinear Programming problem and involves the iterative solution of a Linear Programming problem (primal problem) and a Mixed-Integer Linear Programming problem (master problem). Following the cluster generation, local (with respect to time) eigenfunctions are constructed by applying the proper orthogonal decomposition method to the snapshots contained within each cluster. Then, the Galerkin's projection method is employed to derive low-dimensional ordinary differential equation (ODE) systems for each cluster. The local ODE systems are subsequently used to compute approximate solutions to the original PDE system. The proposed local model order-reduction technique is applied to a hydraulic fracturing process described by a nonlinear parabolic PDE system with the time-dependent spatial domain. It is shown to be more accurate and computationally efficient in approximating the original nonlinear system with fewer eigenfunctions, compared to the model order-reduction technique with temporally-global eigenfunctions. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3818–3831, 2017
      PubDate: 2017-04-16T18:30:29.405944-05:
      DOI: 10.1002/aic.15733
       
  • Adaptive POD–DEIM basis construction and its application to a nonlinear
           population balance system
    • Authors: Lihong Feng; Michael Mangold, Peter Benner
      Pages: 3832 - 3844
      Abstract: We propose an adaptive algorithm for constructing reduced-order models (ROMs) of nonlinear systems based on proper orthogonal decomposition (POD) combined with the discrete empirical interpolation method (DEIM). Using an efficient output error estimation, the reduced basis and the DEIM interpolation basis are adaptively adjusted to derive a small, yet accurate ROM. The adaptive algorithm is further explored for a population balance system of a crystallization process. Simulation results show that much smaller and reliable ROMs can be adaptively obtained using the algorithm with ignorable extra computational load as compared with the standard POD–DEIM method. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3832–3844, 2017
      PubDate: 2017-04-22T18:43:44.216023-05:
      DOI: 10.1002/aic.15749
       
  • Preemptive dynamic operation of cryogenic air separation units
    • Authors: Yanan Cao; Christopher L.E. Swartz, Jesus Flores-Cerrillo
      Pages: 3845 - 3859
      Abstract: As markets become more competitive and dynamic, manufacturing plants are undergoing transitions toward flexible, agile, and low costs operations. Appropriate coordination within the supply chain is an important factor in manufacturing systems' performance. In this study, the impact of preemptive control action in advance of an upcoming demand change on the economic performance of a cryogenic air separation unit is investigated. The effects of various factors are explored through optimization formulations utilizing a high-fidelity collocation based dynamic process model. This includes the amount of lead time, choice of manipulated inputs, direction of demand change, and liquid product market conditions. Plant performance is evaluated and analyzed through a comprehensive multipart case study. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3845–3859, 2017
      PubDate: 2017-05-02T17:31:35.499532-05:
      DOI: 10.1002/aic.15753
       
  • Consensus algorithm-based approach to fundamental modeling of water pipe
           networks
    • Authors: Shin Je Lee; Jong Min Lee, Jingbo Wu, Frank Allgöwer, Jung Chul Suh, Gibaek Lee
      Pages: 3860 - 3870
      Abstract: Modeling the flow dynamics of leaks in water pipe networks is an extremely difficult problem due to the complex entangled network structure and hydraulic phenomenon. A mathematical model for leak dynamics in water pipe networks based on consensus algorithm and water hammer theory is proposed. The resulting model is a simple and linearly interconnected system even though the dynamics of water pipe networks has considerable complexity. The model is then validated using experimental data obtained from real pipe network. A comparative study demonstrates the proposed model can describe the real system with high qualitative and quantitative accuracy and it can be used to develop model-based leak detection and location algorithm based on state estimation. To show applicability of the proposed model, we apply cooperative H∞ estimation to the developed model. The results demonstrate the consensus-based pipe model can be potentially used for leak detection and location with state estimation. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3860–3870, 2017
      PubDate: 2017-05-02T17:37:23.465136-05:
      DOI: 10.1002/aic.15760
       
  • Multi-parametric linear programming under global uncertainty
    • Authors: Vassilis M. Charitopoulos; Lazaros G. Papageorgiou, Vivek Dua
      Pages: 3871 - 3895
      Abstract: Multi-parametric programming has proven to be an invaluable tool for optimisation under uncertainty. Despite the theoretical developments in this area, the ability to handle uncertain parameters on the left-hand side remains limited and as a result, hybrid, or approximate solution strategies have been proposed in the literature. In this work, a new algorithm is introduced for the exact solution of multi-parametric linear programming problems with simultaneous variations in the objective function's coefficients, the right-hand side and the left-hand side of the constraints. The proposed methodology is based on the analytical solution of the system of equations derived from the first order Karush–Kuhn–Tucker conditions for general linear programming problems using symbolic manipulation. Emphasis is given on the ability of the proposed methodology to handle efficiently the LHS uncertainty by computing exactly the corresponding nonconvex critical regions while numerical studies underline further the advantages of the proposed methodology, when compared to existing algorithms. © 2017 The
      Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 63: 3871–3895, 2017
      PubDate: 2017-05-04T03:38:51.721922-05:
      DOI: 10.1002/aic.15755
       
  • Dynamic real-time optimization with closed-loop prediction
    • Authors: Mohammad Zamry Jamaludin; Christopher L. E. Swartz
      Pages: 3896 - 3911
      Abstract: Process plants are operating in an increasingly global and dynamic environment, motivating the development of dynamic real-time optimization (DRTO) systems to account for transient behavior in the determination of economically optimal operating policies. This article considers optimization of closed-loop response dynamics at the DRTO level in a two-layer architecture, with constrained model predictive control (MPC) applied at the regulatory control level. A simultaneous solution approach is applied to the multilevel DRTO optimization problem, in which the convex MPC optimization subproblems are replaced by their necessary and sufficient Karush–Kuhn–Tucker optimality conditions, resulting in a single-level mathematical program with complementarity constraints. The performance of the closed-loop DRTO strategy is compared to that of the open-loop prediction counterpart through a multi-part case study that considers linear dynamic systems with different characteristics. The performance of the proposed strategy is further demonstrated through application to a nonlinear polymerization reactor grade transition problem. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3896–3911, 2017
      PubDate: 2017-05-10T04:55:40.599191-05:
      DOI: 10.1002/aic.15752
       
  • Numerical prediction of a nusselt number equation for stirred tanks with
           helical coils
    • Authors: Ronald Jaimes Prada; José Roberto Nunhez
      Pages: 3912 - 3924
      Abstract: A methodology to obtain a Nusselt correlation for stirred tank reactors is presented. The novelty of the approach is the use of a validated computational model to obtain the heat-transfer coefficients. The advantages of this new approach are many, including the possibility of testing different heat-transfer configurations to obtain their Nusselt correlation without performing experimental runs. Physical phenomena involved was represented both qualitatively and quantitatively. The classical experimental work of (Oldshue and Gretton, Chem Eng Prog. 1954;50(12):615–621) illustrates the procedure. A sufficient number of virtual points in the whole range of the Reynolds number should be obtained. Results strongly depend on mesh refinement in the boundary layer, so a procedure is suggested to guarantee heat-transfer coefficients are accurately estimated. The final Nusselt correlation was compared against all the 107 experimental points of the work by (Oldshue and Gretton, Chem Eng Prog. 1954;50(12):615–621), and an average deviation on the results of 10.7%. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3912–3924, 2017
      PubDate: 2017-05-10T05:00:28.907145-05:
      DOI: 10.1002/aic.15765
       
  • A mathematical model for optimal compression costs in the hydrogen
           networks for the petroleum refineries
    • Authors: Anoop Jagannath; Ali Almansoori
      Pages: 3925 - 3943
      Abstract: Hydrogen network design is an important step in hydrogen management of a petroleum refinery that manages the hydrogen distribution and consumption in a cost-effective manner. While most works in this area have primarily focused on minimization of fresh hydrogen requirement and hydrogen purification aspects, very few works have dealt the issue of compression costs in hydrogen network designs. This work proposes a new mathematical model for synthesizing a hydrogen network with minimum compression costs. In contrast to the existing literature, this model uses stream-dependent properties and realistic compressor cost correlations to determine the compression duty and costs, respectively. Tests on literature examples show that our model is flexible and gives reasonably favorable solutions than the previous models. Furthermore, the usefulness of understanding the trade-offs between the number of compressors and compression duty and the importance of using stream-dependent conditions in estimating compression costs are also highlighted in this work. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3925–3943, 2017
      PubDate: 2017-05-10T05:05:31.829898-05:
      DOI: 10.1002/aic.15771
       
  • Brick by brick computation of the gibbs free energy of reaction in
           solution using quantum chemistry and COSMO-RS
    • Authors: Arnim Hellweg; Frank Eckert
      Pages: 3944 - 3954
      Abstract: The computational modeling of reactions is simple in theory but can be quite tricky in practice. This article aims at the purpose of providing an assistance to a proper way of describing reactions theoretically and provides rough guidelines to the computational methods involved. Reactions in liquid phase chemical equilibrium can be described theoretically in terms of the Gibbs free energy of reaction. This property can be divided into a sum of three disjunct terms, namely the gas phase reaction energy, the finite temperature contribution to the Gibbs free energy, and the Gibbs free energy of solvation. The three contributions to the Gibbs free energy of reaction can be computed separately, using different theoretico-chemical calculation methods. While some of these terms can be obtained reliably by computationally cheap methods, for others a high level of theory is required to obtain predictions of quantitative quality. To propose workflows which can strike the balance between accuracy and computational cost, a number of benchmarks assessing the precision of different levels of theory is given. As an illustrative example, the low-temperature hydrogenation reaction of acetaldehyde to ethanol in solvent toluene is shown. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3944–3954, 2017
      PubDate: 2017-04-05T08:50:45.091223-05:
      DOI: 10.1002/aic.15716
       
  • Fabrication of supported Pd–Ir/Al2O3 bimetallic catalysts for
           2-ethylanthraquinone hydrogenation
    • Authors: Runrun Hong; Yufei He, Junting Feng, Dianqing Li
      Pages: 3955 - 3965
      Abstract: A series of χ wt % Pd-(1-χ) wt % Ir (χ = 0.75, 0.50, and 0.25) catalysts supported on γ-Al2O3 have been prepared by co-impregnation and calcination-reduction, and subsequently employed in the hydrogenation of 2-ethylanthraquinone—a key step in the manufacture of hydrogen peroxide. Detailed studies showed that the size and structure of the bimetallic Pd–Ir particles vary as a function of Pd/Ir ratio. By virtue of its small metal particle size and the strong interaction between Pd and Ir, the 0.75 wt % Pd–0.25 wt % Ir/Al2O3 catalyst afforded the highest yield of H2O2, some 25.4% higher than that obtained with the monometallic 1 wt % Pd catalyst. Moreover, the concentration of the undesired byproduct 2-ethyl-5,6,7,8-tetrahydroanthraquinone (H4eAQ) formed using the Pd–Ir bimetallic catalysts was much lower than that observed with the pure Pd catalyst, which can be assigned to the geometric and electronic effects caused by the introduction of Ir. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3955–3965, 2017
      PubDate: 2017-04-16T18:45:28.189574-05:
      DOI: 10.1002/aic.15748
       
  • Kinetics of the liquid phase dehydration of 1-octanol to di-n-octyl ether
           on Amberlyst 70
    • Authors: Carlos Casas; Roger Bringué, Carles Fité, Montserrat Iborra, Javier Tejero
      Pages: 3966 - 3978
      Abstract: The kinetics of the liquid phase dehydration of 1-octanol to di-n-octyl ether (DNOE) over Amberlyst 70 was studied at 413–453 K. Mechanistic rate models assuming water and 1-octanol adsorbed on the resin, and the free sites fraction negligible, were selected from 1-octanol dehydration experiments. Next, the influence of DNOE, water, and 1,4-dioxane (solvent) concentration was evaluated. DNOE and 1,4-dioxane do not affect significantly the reaction rate, while water inhibits it strongly. Water effect was quantified by splitting the rate constant into a “true one” and a correction factor related to the fraction of active sites blocked by water. The best kinetic model stemmed from an Eley-Rideal mechanism with water adsorbed onto the resin and DNOE released directly to the liquid phase, with a correction factor for water inhibitory effect based on a Freundlich isotherm-like function; activation energy being 110 ± 5 kJ·mol−1, in line with literature data on homologous reactions. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3966–3978, 2017
      PubDate: 2017-04-17T09:45:33.335108-05:
      DOI: 10.1002/aic.15741
       
  • The critical condition for thermal explosion in an isoperibolic system
    • Authors: Daniel Sánchez-Rodriguez; Jordi Farjas, Pere Roura
      Pages: 3979 - 3993
      Abstract: Knowing the conditions for a system to undergo thermal explosion is of utmost importance for many applications. A critical condition that accounts for reactant consumption and covers most practical situations, including low activation energy reactions is presented. Our solution applies to cylindrical reactors of any radius to height ratio. In the case of films, it is shown that thermal explosion is virtually impossible. A new criterion to define the boundary of thermal runaway based on heat balance is introduced. This new definition of criticality allows us to check the accuracy of the nonstationary model to describe the critical condition. The nonstationary model is the base of most approaches. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3979–3993, 2017
      PubDate: 2017-04-18T11:32:07.554927-05:
      DOI: 10.1002/aic.15727
       
  • In-line monitoring of hydrogen peroxide in two-phase reactions using raman
           spectroscopy
    • Authors: Fatemeh Ebrahimi; Jörn Viell, Alexander Mitsos, Adel Mhamdi, Markus Brandhorst
      Pages: 3994 - 4002
      Abstract: Hydrogen peroxide is an environment-friendly oxidizer, which is used in several chemical processes. However, safety necessitates the determination and control of the concentration of hydrogen peroxide during oxidation reactions. We propose a methodology to monitor hydrogen peroxide in disperse two-phase reaction mixtures based on in-line Raman spectroscopy. We compare indirect hard modeling (IHM), peak integration (PI), and partial least squares (PLS). Building predictive PLS and PI calibration models is challenging, whereas the IHM calibration is easy to develop. These methods show good accuracy for known samples (root mean square error of cross validation [RMSECV] of 0.3–0.7 wt %) compared to the classic titration method (RMSECV of 0.4 wt %). After calibration, inline monitoring during reaction is performed demonstrating that the concentration of hydrogen peroxide can be successfully monitored in a fast and reliable way by Raman spectroscopy. The IHM seems to give slightly better inline predictions. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3994–4002, 2017
      PubDate: 2017-04-18T12:20:38.949282-05:
      DOI: 10.1002/aic.15754
       
  • More active Ir subnanometer clusters than single-atoms for catalytic
           oxidation of CO at low temperature
    • Authors: Jian Lin; Yang Chen, Yanliang Zhou, Lin Li, Botao Qiao, Aiqin Wang, Jingyue Liu, Xiaodong Wang, Tao Zhang
      Pages: 4003 - 4012
      Abstract: This work reported the adsorption and reaction performance of FeOx supported subnanometer cluster and single-atom Ir catalysts for the oxidation of CO at low temperature. By varying the pretreatment temperature and Ir loading, the single-atom and subnanometer cluster Ir catalysts were obtained. The Ir subnanometer clusters exhibited higher activity for the oxidation of CO with or without the presence of H2 than the single-atom counterpart. By using adsorption microcalorimetry and in situ infrared spectroscopy measurements, it was found that the Ir subnanometer clusters not only promoted the adsorption and reaction of CO and O2 but also facilitated the formation of OH species from reaction between H2 and O2, thus opening a new reaction pathway between CO and OH species to produce CO2 compared with that between CO and O species on the single-atom counterpart. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4003–4012, 2017
      PubDate: 2017-04-24T21:06:21.134042-05:
      DOI: 10.1002/aic.15756
       
  • Acceleration of kinetic monte carlo simulations of free radical
           copolymerization: A hybrid approach with scaling
    • Authors: Hanyu Gao; Linda J. Broadbelt, Ivan A. Konstantinov, Steven G. Arturo
      Pages: 4013 - 4021
      Abstract: Kinetic Monte Carlo (KMC) has been widely used in the simulation of polymeric reactions. The power of KMC is highlighted by its ability to keep track of the length and sequence of every radical or polymer chain, while it is computationally more expensive than deterministic kinetic models. This paper introduces an acceleration method that significantly reduces the computational cost of KMC simulations, while keeping the same features as the full kinetic Monte Carlo simulations. Case studies are used to demonstrate the general applicability of this method to free radical copolymerization. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4013–4021, 2017
      PubDate: 2017-04-25T11:45:32.472687-05:
      DOI: 10.1002/aic.15751
       
  • FeOx supported single-atom Pd bifunctional catalyst for water gas shift
           reaction
    • Authors: Xiucheng Sun; Jian Lin, Yanliang Zhou, Lin Li, Yang Su, Xiaodong Wang, Tao Zhang
      Pages: 4022 - 4031
      Abstract: Water gas shift reaction on supported noble metal catalysts is an essential process for upgrading hydrogen source industrially. Here a series of Pd/FeOx catalysts were detected for this reaction with Pd/Al2O3 as reference. It was found that Pd/FeOx exhibited higher CO conversion than Pd/Al2O3 with a good stability even in the presence of CO2 and H2. Along the loading decreasing, the turnover frequency of exposed Pd atoms increased with the dispersion from subnanometer (∼1 nm) to single atoms. Various characterizations suggested that Pd single atoms greatly enhanced the reducibility of FeOx and facilitated the formation of oxygen vacancies, which served as sites to promote the dissociation of H2O to form H2 and atomic O. The atomic O was ready to react with the linear adsorbed CO species on Pd single-atom sites through a redox mechanism, which resulted in low activation energy of ∼30 kJ mol−1. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4022–4031, 2017
      PubDate: 2017-05-02T09:53:44.961284-05:
      DOI: 10.1002/aic.15759
       
  • Selective removal of 1,2-propanediol and 1,2-butanediol from bio-ethylene
           glycol by catalytic reaction
    • Authors: Shuo Ai; Mingyuan Zheng, Yu Jiang, Xiaofeng Yang, Xinsheng Li, Jifeng Pang, Joby Sebastian, Weizhen Li, Aiqin Wang, Xiaodong Wang, Tao Zhang
      Pages: 4032 - 4042
      Abstract: Ethylene glycol (EG), synthesized from biomass, frequently contains refractory 1,2-propanediol (PDO) and 1,2-butanediol (BDO). Selective removal of PDO and BDO was realized herein by catalytic dehydration to form volatile aldehydes, ketones, and acetals. Various acidic and basic catalysts were screened under a range of conditions for the conversion of a mixture containing 73 wt % EG, 20 wt % PDO, and 7 wt % BDO. Over H-Beta 26 zeolite, the most selective catalyst among tested, PDO and BDO conversions reached 99.1 and 99.3%, respectively, after 4 h reaction at 453 K, with separation factors over 2. The activation energies for EG, PDO, and BDO dehydration were ca. 99.3, 69.9, and 54.0 kJ/mol, respectively, accounting for the high reactivity of PDO and BDO. The dehydration largely proceeded in the micropores of H-Beta and depended on the number of strong Brønsted acid sites, but excessively strong acid sites enhanced the polymerization of EG. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4032–4042, 2017
      PubDate: 2017-05-10T04:50:31.219352-05:
      DOI: 10.1002/aic.15764
       
  • Selection of oxygen permeation models for different mixed ionic-electronic
           conducting membranes
    • Authors: Yue Zhu; Wenping Li, Yan Liu, Xuefeng Zhu, Weishen Yang
      Pages: 4043 - 4053
      Abstract: Permeation data of several mixed ionic-electronic conducting (MIEC) membranes were analyzed by two oxygen permeation models (i.e., Zhu's model and Xu–Thomson's model), respectively, to find a concise method to guide the choice of permeation models. We found that Zhu's model can well fit the permeation data of perovskite-type membranes, like Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) and BaCe0.05Fe0.95O3-δ (BCF), and dual-phase membranes, like 75 wt % Ce0.85Sm0.15O1.925–25 wt % Sm0.6Sr0.4Al0.3Fe0.7O3-δ (SDC-SSAF), whose oxygen vacancy concentrations are almost independent of the oxygen partial pressure at elevated temperatures. However, Zhu's model was not appropriate for membranes whose oxygen vacancy concentration changed obviously with oxygen partial pressure at elevated temperatures, such as La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) and La0.7Sr0.3CoO3-δ (LSC). On the contrary, Xu–Thomson's model can fit the data of LSCF and LSC well, but it is inapplicable for BSCF, BCF, and SDC-SSAF. Therefore, the dependence of oxygen vacancy concentration on oxygen partial pressure was suggested as an index for the selection of the permeation models. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4043–4053, 2017
      PubDate: 2017-04-08T23:10:46.65019-05:0
      DOI: 10.1002/aic.15718
       
  • Dearomatization of pyrolysis gasoline with an ionic liquid mixture:
           Experimental study and process simulation
    • Authors: Marcos Larriba; Pablo Navarro, Noemí Delgado-Mellado, Carlos González, Julián García, Francisco Rodríguez
      Pages: 4054 - 4065
      Abstract: The pyrolysis gasoline is the main source of benzene, toluene, and xylenes. The dearomatization of this stream is currently performed by liquid–liquid extraction using sulfolane. However, the sulfolane process has high operating costs that could be minimized by employing ionic liquids as solvents because of their non-volatile character. In this work, we proposed a novel process to perform the dearomatization of pyrolysis gasoline using a binary mixture of 1-ethyl-3-methylimidazolium tricyanomethanide ([emim][TCM]) and 1-ethyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide ([4empy][Tf2N]) ILs. The composition in the IL mixture was optimized considering their extractive and thermophysical properties. The Kremser method was applied using the experimental data to determine the number of equilibrium stages in the liquid–liquid extractor which provides the same extraction yields of aromatics using the IL mixture that those of the sulfolane process. The recovery section was designed and simulated from the experimental vapor–liquid equilibrium between the hydrocarbons and the IL mixture. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4054–4065, 2017
      PubDate: 2017-04-13T12:07:41.45007-05:0
      DOI: 10.1002/aic.15735
       
  • Comparative performance of an adiabatic and a nonadiabatic PSA process for
           bulk gas separation—a numerical simulation
    • Authors: Rama Rao Vemula; Shivaji Sircar
      Pages: 4066 - 4078
      Abstract: A detailed numerical model of a Skarstrom-like PSA process is used to investigate the separation performance of an adiabatic and a nonadiabatic process for removal of bulk CO2 impurity from inert He. The complexity of the gas phase adsorbate composition, adsorbate loading, and the adsorbent temperature profiles as functions of positions inside an adsorber at the start and end of each step of the PSA process are discussed. The separation performance of a nonadiabatic PSA process is generally inferior to that of the corresponding adiabatic process. Smaller adsorbent column diameter accentuates nonadiabatic operation and hence lower separation efficiency. Furthermore, the separation efficiency decreases more rapidly at short cycle times and smaller column diameters. Insulation of PSA columns of a process development unit operated under these conditions is recommended for reliable data analysis. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4066–4078, 2017
      PubDate: 2017-04-18T12:06:25.599595-05:
      DOI: 10.1002/aic.15740
       
  • Expeditious modeling of vapor transport and reactions in polymeric
           materials
    • Authors: Yunwei Sun; Charles Tong, Stephen J. Harley, Elizabeth A. Glascoe
      Pages: 4079 - 4089
      Abstract: We present a methodology for approximating dynamic adsorption of vapor coupled with diffusion in polymeric materials. In previous publications, the dynamic adsorption was represented by ordinary differential equations (ODEs) and solved in concentration and parameter space. To accelerate the calculation, we have developed a statistical approximation method using computationally cheap surrogate models (e.g., algebraic polynomials) that replace the ODE solutions of adsorption and are coupled with the diffusion equations. Since the polynomial presentation of the adsorption term is obtained in a standard format prior to modeling coupled sorption-diffusion, the adsorption operator can be expressed as input data in the transport code. Compared to conventional operator-splitting methods, the polynomial approximation of adsorption offers better computational efficiency. The methodology is demonstrated and validated using a dynamic Langmuir adsorption model that is coupled to diffusion and absorption models and applied to a water vapor sorption-diffusion process in polydimethylsiloxane polymers. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4079–4089, 2017
      PubDate: 2017-05-02T09:53:57.834074-05:
      DOI: 10.1002/aic.15746
       
  • Hydrophobic surface modification of FMSS and its application as effective
           sorbents for oil spill clean-ups and recovery
    • Authors: Oluwasola Oribayo; Qinmin Pan, Xianshe Feng, Garry L. Rempel
      Pages: 4090 - 4102
      Abstract: Superhydrophobic sponge-like materials are attracting more attention in recent years as potential sorbent materials for oil spill clean-up. In this work, the authors report the incorporation of hydrophobic structural features into a superhydrophilic pristine formaldehyde-melamine-sodium bisulfite copolymer sponge (FMSS) by N-acylation with a fatty acid derivative, for use as an oil sorbent in oil spill clean-ups. This resulted in our ability to transform the surface properties of the sponge skeleton to superhydrophobic with a contact angle of 143°. The acylated FMSS (a-FMSS) was shown to retain the interconnected porous structure, and was characterized with microscopic and spectroscopic analyses. Sorption experiments with engine oil and chloroform showed that a-FMSS had a very high oil sorption capacity (amounting to 99 and 168.2 times its own weight respectively) than commercial nonwoven polypropylene sorbent. In this view, a-FMSS is considered to be a promising oil sorbent for potential applications in large-scale oil spill clean-ups. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4090–4102, 2017
      PubDate: 2017-05-07T07:05:50.454649-05:
      DOI: 10.1002/aic.15767
       
  • Magnetic ionic liquid-water Janus droplets: Preparation, structure and
           morphology adjustment and magnetic manipulation
    • Authors: Peng Guo; Changfeng Zeng, Chongqing Wang, Lixiong Zhang
      Pages: 4115 - 4123
      Abstract: Surfactant-free magnetic ionic liquid (MIL)-water Janus microdroplets with adjustable structures and morphologies are prepared in capillary-based microfluidic devices. Their morphologies (e.g., sizes, curvatures of the interfaces, and structures from Janus to core/shell) can be adjusted in a wide range by changing the flow rate ratio of water to MIL, adding different mass fractions of polyethylene glycol in water, and using soybean oil rather than liquid paraffin as the continuous phase. MIL-water-MIL ternary Janus magnetic microdroplets with adjustable symmetric and asymmetric structures are also prepared. These Janus microdroplets can be manipulated by magnetic attraction, leading to easy formation of water-MIL-water, MIL-water-oil, necklace-structured MIL-water alternative Janus droplets as well as more complex Janus droplets, such as MIL-CO2-in-water and MIL-water-water droplets. Such preparation strategy is simple and can be applied in fields like pharmaceuticals, multi-drug chemotherapies, and catalysis with expensive materials. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4115–4123, 2017
      PubDate: 2017-04-07T09:41:16.629549-05:
      DOI: 10.1002/aic.15672
       
  • Predicting phase behavior in aqueous systems without fitting binary
           parameters I: CP-PC-SAFT EOS, aromatic compounds
    • Authors: Ilya Polishuk; Yulia Sidik, Dong NguyenHuynh
      Pages: 4124 - 4135
      Abstract: This study examines an accuracy of CP-PC-SAFT attached by the 4C cross-association scheme and zero values of binary parameters in predicting the high temperature-high pressure phase behavior in aqueous systems of aromatic compounds containing one and two benzoic rings, CO2 and cis-decalin. In spite of the noteworthy complexity of these systems and the entirely predictive nature of the current approach, it correctly predicts the topology of phase behavior and typically yields the quantitatively accurate estimations of critical loci and the hydrocarbon–rich liquid phases in wide range of conditions. The available single phase volumetric data are also predicted accurately. Unfortunately, it is not a case of the water–rich phases exhibiting very small hydrocarbon concentrations. Nevertheless, the model is still capable of capturing the solubility minima characteristic for these phases around the room temperature. Predictions of the recent version of Simplified PC-SAFT proposed by Liang et al. (2014) are also discussed. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4124–4135, 2017
      PubDate: 2017-04-07T09:35:53.571139-05:
      DOI: 10.1002/aic.15715
       
  • Dynamics of hydrate formation and deposition under pseudo multiphase flow
    • Authors: Jiafei Zhao; Bin Wang, Amadeu K. Sum
      Pages: 4136 - 4146
      Abstract: Gas hydrate formation is considered one of the major challenges in the flow assurance of deepwater oil and gas pipelines, as their blockage by hydrate can lead to significant production/economic loss and safety risk. Understanding the hydrate formation and deposition processes can improve the management methods in field development and production. This study used a high-pressure rocking cell to simulate multiphase flow conditions to visually investigate the hydrate formation and deposition from an oil-gas-water system. The changing hydrate morphologies, flow pattern and particle distribution during hydrate formation were studied and a conceptual model was proposed. The relative motion of hydrates to the cell wall and the final morphology of the hydrate chunks are found to be two critical parameters for evaluating hydrate deposition characteristics in the flow system. Five types of hydrate deposition morphologies are observed and these are correlated to the hydrate porosity. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4136–4146, 2017
      PubDate: 2017-04-05T09:00:57.497982-05:
      DOI: 10.1002/aic.15722
       
  • Algebraic modeling of the liquid film dynamics in a centrifugal separator
    • Authors: H. E. M. Ninahuanca; H. Stel, R. E. M. Morales
      Pages: 4147 - 4160
      Abstract: This work presents an algebraic model to estimate liquid film flow variables in a centrifugal separator. A mechanistic approach is employed to evaluate operating quantities such as the film thickness and velocity components. The model is based on a force balance on a fluid element of an idealized mean streamline. Additional terms account for the sudden spread of the inflowing stream at the entrance of the cylindrical chamber. A previously validated computational fluid dynamics (CFD) model is used to provide some constants for constitutive equations required by the algebraic model. Results from the algebraic and CFD models agree well for a wide range of Reynolds and Froude numbers. The proposed model can be useful to obtain fast and accurate predictions of the behavior of the liquid flow in the type of separators studied and to help designing more reliable and efficient concepts. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4147–4160, 2017
      PubDate: 2017-04-13T12:08:00.012128-05:
      DOI: 10.1002/aic.15724
       
  • Hydrodynamics of inclined packed beds under flow modulation - CFD
           simulation and experimental validation
    • Authors: Amir Motamed Dashliborun; Mohsen Hamidipour, Faïçal Larachi
      Pages: 4161 - 4176
      Abstract: A three-dimensional unsteady-state Eulerian multi-fluid CFD model was developed to simulate the hydrodynamic behavior of inclined gas-liquid cocurrent downflow packed beds under ON-OFF liquid, ON-OFF gas, and gas/liquid alternating cyclic operations. Validation of the CFD simulation results was performed with experimental data provided by electrical capacitance tomography imaging. Incorporation in the Eulerian multifluid CFD model of capillary pressure and mechanical dispersion force was essential to accurately capture the transient spatial heterogeneities arising in tilted packed beds under different cyclic modulation strategies. The applied CFD model was able to satisfactorily predict the values of liquid holdup and pressure drop as well as the morphological characteristics of the traveling waves inside the bed for the examined flow modulations. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4161–4176, 2017
      PubDate: 2017-04-16T18:40:28.623626-05:
      DOI: 10.1002/aic.15732
       
  • Fluid dynamic characterization of a laboratory scale rocked bag bioreactor
    • Authors: Douglas T. J. Marsh; Gary J. Lye, Martina Micheletti, Akinlolu O. O. Odeleye, Andrea Ducci, Matthew D. Osborne
      Pages: 4177 - 4187
      Abstract: Single-use technology is being widely adopted for the manufacture of biotherapeutics and cell therapy products. Rocked single-use bioreactors in particular have been commonly used, however, the hydrodynamics have rarely been characterized and are poorly understood. In this work, phase-resolved Particle Image Velocimetry and high frequency visual fluid tracking were used to investigate the flow pattern and velocity characteristics for the first time. The studies were performed on an optically accessible mimic of a Sartorius 2L CultiBag at different conditions. Wave formation was observed and higher rocking speeds caused the fluid to move proportionately out of phase with respect to the platform. Dimensional comparisons of fluid velocities with conventional bioreactors suggest that similar fluid dynamics characteristics can be achieved between rocked and stirred configurations. These results provide a first insight into the fluid dynamics of a novel bioreactor type at relevant process conditions supporting the generation of scale translation laws. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4177–4187, 2017
      PubDate: 2017-04-16T18:15:31.590737-05:
      DOI: 10.1002/aic.15734
       
  • Direct measurement of droplet breakage in a pulsed disc and doughnut
           column
    • Authors: Hao Zhou; Shan Jing, Qi Fang, Shaowei Li, Wenjie Lan
      Pages: 4188 - 4200
      Abstract: The lack of experimental data for the droplet breakup has been one of the limitations for the application of population balance model (PBM). In this work, a high-speed camera was used to directly measure the droplet breakup frequency and daughter size distribution in a pulsed disc and doughnut column. It was found from the captured video that multiple breakup events were more frequently observed than binary breakup. The multiple breakup was treated as an original breakup and several intermediate breakups to characterize the process quantitatively. The effects of pulsation intensity, dispersed phase flow rates, and the spatial locations were investigated in detail. Empirical correlations were finally established for both the breakup frequency function and the daughter droplet size distribution function and fitted well with the experimental data. The correlation equations were then used in a simplified PBM to calculate the droplet number density, which further proved the feasibility of the correlations. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4188–4200, 2017
      PubDate: 2017-04-20T18:32:23.775505-05:
      DOI: 10.1002/aic.15742
       
  • A fundamental wax deposition model for water-in-oil dispersed flows in
           subsea pipelines
    • Authors: Sheng Zheng; H. Scott Fogler, Amir Haji-Akbari
      Pages: 4201 - 4213
      Abstract: Water-in-oil dispersions frequently form in subsea oil pipeline transportation and their presence affects the wax deposition rate in subsea pipelines. A fundamental model for wax deposition on the wall of water-in-oil dispersed phase flow pipelines has not been developed. Dispersed water droplets can affect the heat and mass transfer characteristics of wax deposition and alter the deposit growth rate. In this study, wax deposition from water-in-oil dispersed flows is comprehensively modeled using first principles of heat and mass transfer. The role of the dispersed water phase on the heat and mass transfer aspects of wax deposition is analyzed. The developed model predicts different effects of the water volume fraction and droplet size on the wax deposition rates in laboratory flow loop experiments and in field scale wax deposition processes. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4201–4213, 2017
      PubDate: 2017-04-22T19:06:18.436666-05:
      DOI: 10.1002/aic.15750
       
  • Phase distribution in dispersed liquid–liquid flow in vertical pipe:
           Mean and turbulent contributions of interfacial force
    • Authors: Mariem Rezig; Ghazi Bellakhal, Jamel Chahed
      Pages: 4214 - 4223
      Abstract: We applied an Eulerian–Eulerian two-fluid model on an upward dispersed oil–water flow in vertical pipe with 80 mm diameter and 2.5 m length. The numerical profiles of the radial distribution of the oil drops at 1.5 m from the inflow are compared to the experimental data of Lucas and Panagiotopoulos (Flow Meas Instrum. 2009;20:127–135) This article analyzes the roles of turbulence and interfacial forces on the phase distribution phenomenon. In liquid–liquid flow the relative velocity is low and the distribution of the dispersed phase is mainly governed by the turbulence. This work highlights the important role of the turbulent contribution obtained by averaging the added mass force on the radial distribution profiles of the oil drops. The numerical results present improved profiles of the dispersed phase comparing to the experimental data when this turbulent contribution is taken into account in the momentum balance. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4214–4223, 2017
      PubDate: 2017-04-25T11:25:41.697336-05:
      DOI: 10.1002/aic.15736
       
  • Big data for microstructure-property relationships: A case study of
           predicting effective conductivities
    • Authors: Ole Stenzel; Omar Pecho, Lorenz Holzer, Matthias Neumann, Volker Schmidt
      Pages: 4224 - 4232
      Abstract: The analysis of big data is changing industries, businesses and research as large amounts of data are available nowadays. In the area of microstructures, acquisition of (3-D tomographic image) data is difficult and time-consuming. It is shown that large amounts of data representing the geometry of virtual, but realistic 3-D microstructures can be generated using stochastic microstructure modeling. Combining the model output with physical simulations and data mining techniques, microstructure-property relationships can be quantitatively characterized. Exemplarily, we aim to predict effective conductivities given the microstructure characteristics volume fraction, mean geodesic tortuosity, and constrictivity. Therefore, we analyze 8119 microstructures generated by two different stochastic 3-D microstructure models. This is—to the best of our knowledge—by far the largest set of microstructures that has ever been analyzed. Fitting artificial neural networks, random forests and classical equations, the prediction of effective conductivities based on geometric microstructure characteristics is possible. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4224–4232, 2017
      PubDate: 2017-05-03T09:20:43.768252-05:
      DOI: 10.1002/aic.15757
       
  • Validation of a CFD model of an orbiting culture dish with PIV and
           analytical solutions
    • Authors: Jonathan Michael D. Thomas; Amlan Chakraborty, R. Eric Berson, Mostafa Shakeri, M. Keith Sharp
      Pages: 4233 - 4242
      Abstract: Particle image velocimetry (PIV) and an extended solution of Stokes’ second problem were used to validate a computational fluid dynamics (CFD) model of flow in an orbiting dish. Velocity vector components throughout one complete orbit differed between CFD and PIV by less than 5%. Computational velocity magnitudes averaged over the interior 20% radius, the region where the analytical solution is most applicable, were 0.3% higher than the analytical values, while the experimental values in the same region were 2.4% higher. Velocity profiles in the center of the dish across normalized heights that most influence wall shear stress varied on average by ∼–0.00046 for the normalized radial component and by ∼0.0038 for the normalized tangential component compared to the analytical solution. These results represent the most comprehensive validation to date for computational models of the orbiting dish system. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4233–4242, 2017
      PubDate: 2017-05-03T09:30:47.682305-05:
      DOI: 10.1002/aic.15762
       
  • Numerical simulation of solvent and water assisted electrical heating of
           oil sands including aquathermolysis and thermal cracking reactions
    • Authors: Hassan Hassanzadeh; Moosa Rabiei Faradonbeh, Thomas Harding
      Pages: 4243 - 4258
      Abstract: Simulations of bitumen recovery using solvent- and water-assisted electrical heating of oil sands are presented to evaluate the process and to study gas generation. Aquathermolysis and thermal cracking and dissolution of acid-gases in water are included. Steam-assisted gravity drainage (SAGD) is also simulated for comparison. Results show that gas generation negatively impacts SAGD. However, in electrical heating dissolution of gases into solvent weakens their negative impact. Results indicate that SAGD generates a larger gas volume than electrical heating. In both processes, methane is found to be the major species in the produced gas and H2S concentration can reach high values. While the effect of acid–gas solubility in water on oil recovery is not evident its effect on generated gas volume is significant. Simulation results demonstrate that electrical heating is more energy efficient than SAGD. These results find application in design of experiments and pilot and field-scale implementation of the process. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4243–4258, 2017
      PubDate: 2017-05-10T04:40:29.903319-05:
      DOI: 10.1002/aic.15774
       
 
 
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