for Journals by Title or ISSN
for Articles by Keywords
help

Publisher: John Wiley and Sons   (Total: 1592 journals)

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

        1 2 3 4 5 6 7 8 | Last   [Sort by number of followers]   [Restore default list]

Showing 1 - 200 of 1592 Journals sorted alphabetically
Abacus     Hybrid Journal   (Followers: 13, SJR: 0.48, h-index: 22)
About Campus     Hybrid Journal   (Followers: 5)
Academic Emergency Medicine     Hybrid Journal   (Followers: 66, SJR: 1.385, h-index: 91)
Accounting & Finance     Hybrid Journal   (Followers: 47, SJR: 0.547, h-index: 30)
ACEP NOW     Free   (Followers: 1)
Acta Anaesthesiologica Scandinavica     Hybrid Journal   (Followers: 54, SJR: 1.02, h-index: 88)
Acta Archaeologica     Hybrid Journal   (Followers: 175, 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: 14, SJR: 1.197, h-index: 81)
Acta Ophthalmologica     Hybrid Journal   (Followers: 6, 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: 37, SJR: 2.518, h-index: 113)
Acta Zoologica     Hybrid Journal   (Followers: 7, SJR: 0.459, h-index: 29)
Acute Medicine & Surgery     Hybrid Journal   (Followers: 5)
Addiction     Hybrid Journal   (Followers: 36, SJR: 2.086, h-index: 143)
Addiction Biology     Hybrid Journal   (Followers: 15, SJR: 2.091, h-index: 57)
Adultspan J.     Hybrid Journal   (SJR: 0.127, h-index: 4)
Advanced Energy Materials     Hybrid Journal   (Followers: 26, 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: 51, SJR: 5.21, h-index: 203)
Advanced Healthcare Materials     Hybrid Journal   (Followers: 14, SJR: 0.232, h-index: 7)
Advanced Materials     Hybrid Journal   (Followers: 283, 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: 7, SJR: 2.488, h-index: 21)
Advanced Science     Open Access   (Followers: 5)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 18, 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: 21)
Africa Research Bulletin: Economic, Financial and Technical Series     Hybrid Journal   (Followers: 13)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 11)
African Development Review     Hybrid Journal   (Followers: 33, SJR: 0.275, h-index: 17)
African J. of Ecology     Hybrid Journal   (Followers: 16, SJR: 0.477, h-index: 39)
Aggressive Behavior     Hybrid Journal   (Followers: 16, SJR: 1.391, h-index: 66)
Aging Cell     Open Access   (Followers: 11, SJR: 4.374, h-index: 95)
Agribusiness : an Intl. J.     Hybrid Journal   (Followers: 3, SJR: 0.627, h-index: 14)
Agricultural and Forest Entomology     Hybrid Journal   (Followers: 16, SJR: 0.925, h-index: 43)
Agricultural Economics     Hybrid Journal   (Followers: 45, SJR: 1.099, h-index: 51)
AIChE J.     Hybrid Journal   (Followers: 32, 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: 51, SJR: 3.048, h-index: 129)
Alternatives to the High Cost of Litigation     Hybrid Journal   (Followers: 3)
American Anthropologist     Hybrid Journal   (Followers: 155, 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: 93, SJR: 2.325, h-index: 51)
American J. of Economics and Sociology     Hybrid Journal   (Followers: 29, SJR: 0.211, h-index: 26)
American J. of Hematology     Hybrid Journal   (Followers: 35, SJR: 1.761, h-index: 77)
American J. of Human Biology     Hybrid Journal   (Followers: 13, 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: 17, SJR: 1.115, h-index: 61)
American J. of Medical Genetics Part B: Neuropsychiatric Genetics     Hybrid Journal   (Followers: 4, SJR: 1.771, h-index: 107)
American J. of Medical Genetics Part C: Seminars in Medical Genetics     Partially Free   (Followers: 6, SJR: 2.315, h-index: 79)
American J. of Physical Anthropology     Hybrid Journal   (Followers: 38, SJR: 1.41, h-index: 88)
American J. of Political Science     Hybrid Journal   (Followers: 300, 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: 4, SJR: 1.347, h-index: 75)
American J. of Transplantation     Hybrid Journal   (Followers: 18, SJR: 2.792, h-index: 140)
American J. on Addictions     Hybrid Journal   (Followers: 10, SJR: 0.843, h-index: 57)
Anaesthesia     Hybrid Journal   (Followers: 143, 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: 20)
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: 169)
Angewandte Chemie Intl. Edition     Hybrid Journal   (Followers: 236, SJR: 6.229, h-index: 397)
Animal Conservation     Hybrid Journal   (Followers: 41, 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: 7, 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: 49, SJR: 5.584, h-index: 241)
Annals of Noninvasive Electrocardiology     Hybrid Journal   (Followers: 1, SJR: 0.531, h-index: 38)
Annals of Public and Cooperative Economics     Hybrid Journal   (Followers: 8, 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: 26, SJR: 0.72, h-index: 31)
Anthropology & Humanism     Hybrid Journal   (Followers: 18, 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: 93, SJR: 0.545, h-index: 15)
Antipode     Hybrid Journal   (Followers: 52, SJR: 2.212, h-index: 69)
Anz J. of Surgery     Hybrid Journal   (Followers: 8, 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: 73, SJR: 0.754, h-index: 69)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7, SJR: 0.632, h-index: 58)
Applied Psychology     Hybrid Journal   (Followers: 183, SJR: 1.023, h-index: 64)
Applied Psychology: Health and Well-Being     Hybrid Journal   (Followers: 51, 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: 32, SJR: 0.807, h-index: 60)
Aquatic Conservation Marine and Freshwater Ecosystems     Hybrid Journal   (Followers: 36, 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: 30, SJR: 0.809, h-index: 48)
Archeological Papers of The American Anthropological Association     Hybrid Journal   (Followers: 15, SJR: 0.156, h-index: 2)
Architectural Design     Hybrid Journal   (Followers: 27, SJR: 0.261, h-index: 9)
Archiv der Pharmazie     Hybrid Journal   (Followers: 3, SJR: 0.628, h-index: 43)
Archives of Drug Information     Hybrid Journal   (Followers: 5)
Archives of Insect Biochemistry and Physiology     Hybrid Journal   (SJR: 0.768, h-index: 54)
Area     Hybrid Journal   (Followers: 13, SJR: 0.938, h-index: 57)
Art History     Hybrid Journal   (Followers: 270, SJR: 0.153, h-index: 13)
Arthritis & Rheumatology     Hybrid Journal   (Followers: 55, SJR: 1.984, h-index: 20)
Arthritis Care & Research     Hybrid Journal   (Followers: 27, 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: 15)
Asia & the Pacific Policy Studies     Open Access   (Followers: 16)
Asia Pacific J. of Human Resources     Hybrid Journal   (Followers: 330, SJR: 0.494, h-index: 19)
Asia Pacific Viewpoint     Hybrid Journal   (Followers: 1, SJR: 0.616, h-index: 26)
Asia-Pacific J. of Chemical Engineering     Hybrid Journal   (Followers: 8, 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: 4, 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   (Followers: 1, SJR: 0.394, h-index: 7)
Asian J. of Organic Chemistry     Hybrid Journal   (Followers: 6, 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: 3, SJR: 0.701, h-index: 40)
Atmospheric Science Letters     Open Access   (Followers: 29, SJR: 1.332, h-index: 27)
Austral Ecology     Hybrid Journal   (Followers: 15, SJR: 1.095, h-index: 66)
Austral Entomology     Hybrid Journal   (Followers: 9, 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: 6, SJR: 0.39, h-index: 22)
Australian & New Zealand J. of Statistics     Hybrid Journal   (Followers: 14, SJR: 0.275, h-index: 28)
Australian Accounting Review     Hybrid Journal   (Followers: 3, 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: 47, SJR: 0.814, h-index: 49)
Australian and New Zealand J. of Public Health     Hybrid Journal   (Followers: 13, SJR: 0.82, h-index: 62)
Australian Dental J.     Hybrid Journal   (Followers: 6, SJR: 0.482, h-index: 46)
Australian Economic History Review     Hybrid Journal   (Followers: 6, SJR: 0.171, h-index: 12)
Australian Economic Papers     Hybrid Journal   (Followers: 31, 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: 15, 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: 433, SJR: 0.418, h-index: 29)
Australian J. of Rural Health     Hybrid Journal   (Followers: 6, SJR: 0.43, h-index: 34)
Australian Occupational Therapy J.     Hybrid Journal   (Followers: 74, SJR: 0.59, h-index: 29)
Australian Psychologist     Hybrid Journal   (Followers: 12, SJR: 0.331, h-index: 31)
Australian Veterinary J.     Hybrid Journal   (Followers: 23, SJR: 0.459, h-index: 45)
Autism Research     Hybrid Journal   (Followers: 37, 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: 11, 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: 10, 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: 18, SJR: 1.172, h-index: 90)
Biological Reviews     Hybrid Journal   (Followers: 5, SJR: 6.469, h-index: 114)
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 41, 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: 44, SJR: 0.415, h-index: 55)
Biotechnology and Bioengineering     Hybrid Journal   (Followers: 160, SJR: 1.633, h-index: 146)
Biotechnology J.     Hybrid Journal   (Followers: 14, SJR: 1.185, h-index: 51)
Biotechnology Progress     Hybrid Journal   (Followers: 39, SJR: 0.736, h-index: 101)
Biotropica     Hybrid Journal   (Followers: 20, SJR: 1.374, h-index: 71)
Bipolar Disorders     Hybrid Journal   (Followers: 9, SJR: 2.592, h-index: 100)
Birth     Hybrid Journal   (Followers: 38, 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: 7, 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: 250, SJR: 2.083, h-index: 125)

        1 2 3 4 5 6 7 8 | Last   [Sort by number of followers]   [Restore default list]

Journal Cover AIChE Journal
  [SJR: 1.122]   [H-I: 120]   [32 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  [1592 journals]
  • Hydrodynamics in a Pilot-Scale Cocurrent Trickle-Bed Reactor at Low Gas
           Velocities
    • Authors: Puneet Kawatra; Srikanth Panyaram, Benjamin A. Wilhite
      Abstract: Hydrodynamic data obtained from laboratory-scale trickle-beds often fail to accurately represent industrial-scale systems with high packing aspect ratios and column-to-particle diameter ratios. In this study, pressure drop, liquid holdup, and flow regime transition were investigated in a pilot-scale trickle-bed column of 33 cm ID and 2.45 m bed height packed with 1.6mm x 8.4 +/- 1.4mm cylindrical extrudates for air-water mass superficial velocities of 0.0023 - .094 kg/m2s and 4.5 – 45 kg/m2s, respectively, at atmospheric pressure. Significant deviation was observed from pressure drop and liquid holdup correlations at low liquid flows rates, corresponding to gravity-driven flow limit. Likewise, liquid saturation is overestimated by correlations at high liquid flowrates, owing to significantly reduced wall effects. Lastly, trickle-to-dispersed bubble flow and trickle-to-pulsing flow regime transitions are reported using a combination of visual observations and analysis of the magnitude of local pressure fluctuations within the column. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-14T13:19:26.260602-05:
      DOI: 10.1002/aic.16126
       
  • Experimental Data for Code Validation: Horizontal Air Jets in a
           Semicircular Fluidized Bed of Geldart Group D Particles
    • Authors: William D. Fullmer; Casey Q. LaMarche, Allan Issangya, Peiyuan Liu, Ray Cocco, Christine M. Hrenya
      Abstract: Experiments were conducted with 6 mm plastic beads (Geldart Group D) in a semi-circular, gas-fluidized bed with side jets. Attention was paid to particle characterization and bed measurements, making the resulting dataset ideal for CFD-DEM validation and uncertainty quantification. The bed was operated slightly above and below the minimum fluidization velocity, with additional fluidization provided by one of two pairs of opposing jets located above the distributor near the flat, front face of the unit. Care is taken to report material properties and bed conditions with either measured distribution functions or uncertainty bounds. High-speed video imaging and particle tracking velocimetry are used to extract bin-averaged velocity profiles, which are used to extract jet penetration depths. The time-averaged mean and standard deviation of the bed pressure drop is also reported. Finally, the lower jets are also inserted into the bed until the opposing jets merge to form a spout-like pattern. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-14T11:40:50.212041-05:
      DOI: 10.1002/aic.16128
       
  • Framework for Work-Heat Exchange Network Synthesis (WHENS)
    • Authors: Sajitha K Nair; Harsha Nagesh Rao, I A Karimi
      Abstract: Work and heat are the two predominant forms of energy in the process industry. Considerable savings can be achieved by synergizing the work and heat requirements of process streams. In this work, a generalized framework for integrating heat and work simultaneously is proposed based on a mixed-integer nonlinear programming (MINLP) model for work-heat exchange network synthesis (WHENS). Starting with a set of streams with known flows, temperatures, and pressures, a network of single-shaft-turbine-compressors (SSTCs) with motors/generators, valves, heat exchangers, and utility heaters/coolers is synthesized for minimized total annualized cost. In contrast to existing works, we (1) do not pre-classify streams as hot/cold or high/low-pressure, (2) allow pressure changes for streams with no net pressure change, (3) allow liquid-vapor phase changes, and (4) use phase-based property correlations. Successful application of our approach to C3 splitting yields a non-intuitive configuration. We also study another application of an offshore natural gas liquefaction process. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-14T11:40:36.128707-05:
      DOI: 10.1002/aic.16129
       
  • Relative time-averaged gain array (RTAGA) for distributed control-oriented
           network decomposition
    • Authors: Wentao Tang; Davood Babaei Pourkargar, Prodromos Daoutidis
      Abstract: Input-output partitioning for decentralized control has been studied extensively using various methods, including those based on relative gains and those based on relative degrees and sensitivities. These two concepts are characterizations of long-time and short-time input-output response, respectively. This work proposes a unifying new input-output interaction measure, called relative time-averaged gain, which characterizes the input-output interactions during a time scale of interest for linear time-invariant systems. This measure is used as a basis for community detection in the input-output bipartite graph of a process network to produce subnetworks whose responses are weakly coupled in the time scale of interest. As such, the resulting decomposition accounts for both response characteristics and the network topology, and can be used efficiently for distributed control architecture design. In a case study, the proposed decomposition is applied to the distributed model predictive control of a reactor-separator benchmark process. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-14T11:40:22.836026-05:
      DOI: 10.1002/aic.16130
       
  • Experimental and numerical investigation of structure and hydrodynamics in
           packed beds of spherical particles
    • Authors: P. Lovreglio; S. Das, K.A. Buist, E.A.J.F. Peters, L. Pel, J.A.M. Kuipers
      Abstract: In chemical industry, flows often occur in non-transparent equipment, for example in steel pipelines and vessels. MRI is a suitable approach to visualize the flow, which cannot be performed with classical optical techniques, and obtain quantitative data in such cases. It is therefore a unique tool to non-invasively study whole-field porosity and velocity distributions in opaque single-phase porous media flow. In this paper, experimental results obtained with this technique, applied to the study of structure and hydrodynamics in packed beds of spherical particles, are shown and compared with detailed CFD simulations performed with an in-house numerical code based on an IBM-DNS approach. Pressure drop and the radial profiles of porosity and axial velocity of the fluid for three packed beds of spheres with different sizes were evaluated, both experimentally and numerically, in order to compare the two approaches. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-14T11:35:47.018689-05:
      DOI: 10.1002/aic.16127
       
  • Continuous Manufacturing: Is the Process Mean Stationary'
    • Authors: Levente L. Simon
      Abstract: This paper describes the statistical framework to systematically detect mean stationarity in the context of continuous manufacturing. The methods presented in this paper use econometric and financial time-series analysis concepts in the form of unit-root and stationarity hypothesis tests. The tests under discussion are the augmented Dickey-Fuller, Philips-Perron, Leybourne-McCabe and Kwiatkowski-Phillips-Schmidt-Shin. These hypothesis tests are evaluated on data generated by a focused-beam reflectance measurement sensor implemented on-line in a continuous plug-flow crystallizer.This contribution has shown that the hypothesis tests can be used to detect steady-state conditions on-line in a plug-flow crystallizer. Furthermore, this econometric framework can be used as a mean stationarity “certificate” of collected samples to document that the process was mean stationary during the sampling.The statistical framework described in this paper can be applied to any continuously operated unit operation or sensor measurement. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-14T11:30:24.719796-05:
      DOI: 10.1002/aic.16125
       
  • Heat/Mass Transfer from a Neutrally Buoyant Sphere by Mixed Natural and
           Forced Convection in a Simple Shear Flow
    • Authors: Bing Yuan; Chao Yang, Zai-Sha Mao, Xiaolong Yin, Donald L. Koch
      Abstract: Building on the work of Yang et al. in 2011, the finite difference method and the Boussinesq approximation were applied to solve the time-dependent Navier-Stokes, convection diffusion and continuity equations in spherical coordinates. An idealized condition, the mass transfer from a neutrally buoyant sphere in a horizontal simple shear flow with natural convection was numerically simulated for the first time in this work. In the hybrid transfer case, the outwardly spiraling streamlines enhanced the transfer process, but the counter-gravity spiraling streamlines near the sphere hindered the natural convection and the spatial dilution action weakened the natural convection transfer process. These competing effects led to non-monotonic behavior of the Nusselt number with Reynolds number. Results from these previously undocumented cases were summarized into correlations for predicting Nusselt numbers at finite Reynolds numbers for various Grashof and Prandtl numbers. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-12T07:40:32.71646-05:0
      DOI: 10.1002/aic.16122
       
  • Concentrated Slurry Formation via Drawdown and Incorporation of Wettable
           Solids in a Mechanically Agitated Vessel
    • Authors: Thomas Wood; Mark J. H. Simmons, Richard W. Greenwood, E. Hugh Stitt
      Abstract: This paper describes the effect of vessel configurations upon the drawdown and incorporation of floating solids to prepare concentrated alumina slurries in stirred tanks. The impeller speed and power draw required to incorporate all dry powder within four seconds, NJI and PJI, are used to evaluate incorporation performance. The effect of impeller type is assessed, with pitched blade impellers proving to be the most effective across the full range of solid contents considered.At higher solids content the energy demand is shown to increase dramatically, with a 100-fold increase in energy required to add 1% w/w more solid at 50% by weight compared to 1% by weight. Analysis of impeller power numbers show this coincides with a transition from constant power number to a region where power number increases linearly with decreasing Reynolds number. Contrary to studies at low solids content, the presence of baffles is shown to inhibit drawdown. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-12T07:40:22.789403-05:
      DOI: 10.1002/aic.16121
       
  • Theoretical and Computational Comparison of Continuous-Time Process
           Scheduling Models for Adjustable Robust Optimization
    • Authors: Nikolaos H. Lappas; Chrysanthos E. Gounaris
      Abstract: Coping with uncertainty in system parameters is a prominent hurdle when scheduling multi-purpose batch plants. To that end, we previously introduced a multi-stage adjustable robust optimization framework that was shown to be able to obtain more profitable solutions, while maintaining the same level of immunity against risk, as compared to traditional robust optimization approaches. In this paper, we investigate the amenability of existing deterministic continuous-time scheduling models to serve as the basis of this adjustable robust optimization framework. We conduct a comprehensive computational study that compares the numerical tractability of various models across a suite of literature benchmark instances and a wide range of uncertainty sets. As part of this study, we also provide for the first time in the open literature robust optimal solutions to process scheduling instances involving uncertainty in production yields. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-12T07:31:07.982939-05:
      DOI: 10.1002/aic.16124
       
  • The impact of hydrodynamics on viscosity evolution in colloidal
           dispersions: Transient, nonlinear microrheology
    • Authors: Ritesh P. Mohanty; Roseanna N. Zia
      Abstract: Evolution of microstructure and rheology during flow startup, and its connection to microscopic transport processes, is studied theoretically via active microrheology. At steady state, the balance between entropic, hydrodynamic, and other forces changes with flow strength, producing sustained microstructural asymmetry and non-Newtonian rheology. However, the transition from equilibrium to steady flow is sometimes marked by overshoots in viscosity that suggests a temporally evolving competition between these rate processes. Here we formulate and solve a Smoluchowski equation for the time-dependent evolution of particle microstructure induced by the motion of a colloidal probe driven through a bath of colloidal spheres. The structure is then utilized to compute the time-dependent microviscosity. Brownian diffusion always sets short-time particle dynamics, which hinders maturation of the boundary layer. The disparity in Brownian and advective transport rates produces a reversal from flow thinning to flow thickening during startup, revealing that non-Newtonian flow phenomenology is not instantaneously established. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-12T07:25:28.274154-05:
      DOI: 10.1002/aic.16123
       
  • Issue Information
    • Abstract: Cover illustration. Achieving chemical safety requires commitment to a broad awareness of past events, regulations, and evolving methods for avoiding future incidents. Word cloud prepared using tools from Zygomatic at https://www.wordclouds.com/.
      DOI 10.1002/aic.16099
      PubDate: 2018-02-10T20:40:57.356245-05:
       
  • Reduction in Greenhouse Water usage through Inlet CO2 Enrichment
    • Authors: Neil Stacey; James Fox, Diane Hildebrandt
      Abstract: Agriculture is mankind's single largest usage of water, comprising 70% of all water usage. Optimizing water usage in agriculture is therefore crucial to ensuring global water security. In this paper, a greenhouse is quantitatively modelled as a bio-reactor and it is shown the bulk of the water supplied to a conventionally-aspirated greenhouse is lost in the form of humidity. This implies that evaporative losses in agriculture comprise a clear majority of mankind's total water consumption. This article demonstrates that inlet CO2 enrichment using existing membrane materials can minimize the air feed rate required to supply adequate CO2 for photosynthesis, thereby mitigating evaporative losses. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-07T18:40:31.829241-05:
      DOI: 10.1002/aic.16120
       
  • Manufactured Chemistry: Rethinking unit operation design in the age of
           additive manufacturing
    • Authors: Addison Killean Stark
      Abstract: Additive manufacturing enables new approaches to chemical reactor design due to the ability to build complex geometries and topologies unaccessible to traditional manufacturing technologies. These benefits have been demonstratedinthedesignandmanufactureofnovelheatexchangersandfluidicdevices. However,duetoprevailingheuristics in chemical reactor design, many of the benefits of additive manufacturing have yet to be realized by the chemical engineer. In order to reap these benefits, a formalized design methodology such as topology optimization should be employed for the development of high-efficiency small scale modular reactors capable of being manufactured at large volumes. In this way we may be able to start to descend fast manufacturing learning curves and unleash a new wave of innovation in the chemical engineering sciences. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-07T18:30:29.632699-05:
      DOI: 10.1002/aic.16118
       
  • Microfluidic Synthesis of Elastomeric Microparticles: A Case Study in
           Catalysis of Palladium-Mediated Cross-Coupling
    • Authors: Jeffrey Bennett; Andrew Kristof, Vishal Vasudevan, Jan Genzer, Jiri Srogl, Milad Abolhasani
      Abstract: Palladium (Pd)-loaded poly-hydromethylsiloxane (PHMS) microparticles of tunable size and elasticity are prepared in a capillary-based coaxial flow-focusing microfluidic device constructed using off-the-shelf components. Simultaneous droplet formation and chemical cross-linking processes are performed by tuning the dilution of the cross-linking catalyst in the annular flow of the microreactor, resulting in PHMS microparticles synthesized in a single step. The size of the elastomeric microparticles can be tuned by adjusting the flow rate ratio of the polymer and cross-linker mixture to water, while the elasticity can be tuned by the polymer to cross-linker ratio as well as the flow rate ratio of the polymer mixture to cross-linking catalyst mixture. Microparticle elasticity is characterized by the degree of solvent uptake. Application of the synthesized PHMS microparticles in organic synthesis is demonstrated by producing monodispersed Pd-loaded microparticles and utilizing them as microreaction vessels for continuous Suzuki-Miyaura cross-coupling in a Pd-loaded microparticle-packed bed reactor (µ-PBR). This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-07T18:26:23.902702-05:
      DOI: 10.1002/aic.16119
       
  • Hydrothermal Pretreatment for Deconstruction of Plant Cell Wall: Part I.
           Effect on Lignin-Carbohydrate Complex
    • Authors: Kun Yao; Qinfeng Wu, Ran An, Wei Meng, Mingzhu Ding, Bingzhi Li, Yingjin Yuan
      Abstract: Hydrothermal pretreatment with characteristic of green chemistry is considered as promising technology in the biorefineries. In this study, using material balance and multi-scale characterization techniques, the effects of process severity factor and pH on chemical behaviors of lignin-carbohydrate complex (LCC) were systematically studied. During pretreatment, spatial relocation of lignin with covalently linked xylan facilitated local cell wall collapse. A kinetic model was established to describe the behaviors of LCC components changing with severity factor. It was found that cleavage of LCC linkage was strongly pH-dependent. Low pH dominated cleavage of coumarate/ferulate esters which cross-linking lignin with xylan and repolymerization of aromatics either from furfural or lignin into polymers such as pseudo lignin, while high pH which allowed the existence of soluble LCC dominated the aldol condensations from xylose to aromatics and depolymerizaton of lignin to phenols. Detailed reaction pathways concerned with LCC were finally established to elucidate the underlying mechanism. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-05T11:00:37.263672-05:
      DOI: 10.1002/aic.16114
       
  • Bilevel and Parallel Programming-based Operability Approaches for Process
           Intensification and Modularity
    • Authors: Juan C. Carrasco; Fernando V. Lima
      Abstract: Process operability emerged in the last decades as a powerful tool for the design and control of chemical processes. Recent efforts in operability have been focused on the calculation of the desired input set for process design and intensification of natural gas utilization applications described by nonlinear models. However, there is still a gap in terms of problem dimensionality that nonlinear operability methods can handle. To fill this gap, in this paper, the incorporation of bilevel and parallel programming approaches into classical process operability concepts is discussed. Results on the implementation of the proposed method show a reduction in computational time up to 2 orders of magnitude, when compared to the original results without parallelization. These results could be extrapolated for use in a supercomputer as presented in the computational time analysis performed. In terms of intensification, the proposed approach can produce a natural gas combined cycle plant modular design with a dramatic reduction in size, from the original 400 to 0.11 [MW], while still keeping the high net plant efficiency. This approach thus provides a computationally efficient framework for process intensification of high-dimensional nonlinear energy systems towards modularity. The proposed approach also enables the verification of a modular design and conditions that can be obtained according to economic and physical constraints associated with a specific natural gas well production. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-05T11:00:31.014225-05:
      DOI: 10.1002/aic.16113
       
  • Universal Correlation for Gas Hydrates Suppression Temperature of
           Inhibited Systems: II. Mixed Salts and Structure Type
    • Authors: Yue Hu; Bo Ram Lee, Amadeu K. Sum
      Abstract: The first paper of this study discussed the development of the Hu-Lee-Sum (HLS) correlation and demonstrated the generality and universality of the correlation to predict structure I hydrates suppression temperature for any single salt system. However, natural gas commonly forms structure II hydrates, and mixed salts naturally occur in oil and gas production. Therefore, reliable prediction of structure II hydrates suppression temperature in presence of mixed salts over a wide range of pressure is considerably important. The contribution for each salt in salt mixtures is accounted for in the effective mole fraction to extend the HLS correlation for mixed salts systems. Moreover, a parameter (α) is introduced to account for the effect of hydrate structure on the hydrate suppression temperature. Herein, the HLS correlation is further shown to be universal and reliable to predict the hydrate suppression temperature for more complicated systems for mixed gases and mixed salts. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-05T11:00:27.417595-05:
      DOI: 10.1002/aic.16116
       
  • Bubble-separation dynamics in a planar cyclone: Experiments and CFD
           simulations
    • Authors: Xiao Xu; Xiao-ling Ge, Yun-dong Qian, Hua-lin Wang, Qiang Yang
      Abstract: A planar cyclone is designed for visualizing bubbles in the cross-section of a degassing hydrocyclone. The pressure distribution is studied through a series of experiments and Reynolds stress model simulations. The velocity distribution of the planar cyclone mostly exhibits the quasi-forced vortex zone and boundary layer zone. The bubble dynamics are simulated using both Euler–Euler and Euler–Lagrange approaches, and the output is compared with the imaging results. The Euler–Euler simulation provides more accurate predictions of the bubble trajectory. The histograms of residence time and traveling distance given by the Euler–Lagrange approach exhibit a reasonably regular pattern. With higher values of the inlet Reynolds number, stronger forces acting on the bubbles lead to a decreased but more uniform residence time. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-05T10:55:56.558427-05:
      DOI: 10.1002/aic.16115
       
  • Predicting NRTL Binary Interaction Parameters from Molecular Simulations
    • Authors: Ashwin Ravichandran; Rajesh Khare, Chau-Chyun Chen
      Abstract: A predictive approach for calculating the binary interaction parameters (τij) of the nonrandom two liquid (NRTL) local composition model is developed, combining molecular simulations with the two-fluid theory. The binary interaction parameters are determined for the following three sets of model binary mixtures: water + methanol, methanol + methyl acrylate, and water + methyl acrylate. For each binary mixture, the interaction parameters are expressed in terms of molecular size and strength of interactions, which are in turn, calculated from molecular simulations. We show that the binary interaction parameters determined from simulations are in qualitative agreement with those estimated from regressing experimental data. The major factors that determine the binary interaction parameters are outlined based on simple thermodynamic arguments for each mixture. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-05T10:55:41.504496-05:
      DOI: 10.1002/aic.16117
       
  • Supra-Monolayer Coverages on Small Metal Clusters and Their Effects on H2
           Chemisorption Particle Size Estimates
    • Authors: Abdulrahman S. Almithn; David D. Hibbitts
      Abstract: H2 chemisorption measurements are used to estimate the size of supported metal particles, often using a hydrogen-to-surface-metal stoichiometry of unity. This technique is most useful for small particles whose sizes are difficult to estimate through electron microscopy or X-ray diffraction. Undercoordinated metal atoms at the edges and corners of particles, however, make up large fractions of small metal clusters, and can accommodate multiple hydrogen atoms leading to coverages which exceed 1 ML (supra-monolayer). Density functional theory was used to calculate hydrogen adsorption energies on Pt and Ir particles (38–586 atoms, 0.8–2.4 nm) at high coverages (≤ 3.63 ML). Calculated differential binding energies confirm that Pt and Ir (111) single-crystal surfaces saturate at 1 ML; however, Pt and Ir clusters saturate at supra-monolayer coverages as large as 2.9 ML. Correlations between particle size and saturation coverage are provided that improve particle size estimates from H2 chemisorption for Pt-group metals. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-02T17:53:06.076574-05:
      DOI: 10.1002/aic.16110
       
  • Dynamics of Pristine Graphite and Graphene at an Air-Water Interface
    • Authors: David M. Goggin; Joseph R. Samaniuk
      Abstract: We examine the dynamics and morphology of graphitic films at an air-water interface in a Langmuir trough by varying interfacial surface coverage, observing in situ interfacial structure, and by characterizing interfacial structure of depositions on mica substrates. In situ interfacial structure is visualized with Brewster angle microscopy, and depositions of the interface are characterized with atomic force microscopy and field-emission scanning electron microscopy. Compression/expansion curves exhibit a monotonically decreasing surface pressure between consecutive compressions, but demonstrate a “rebound” of hysteretic behavior when the interface is allowed to relax between consecutive compressions. This dynamic results from a competition between consolidation of the interface via agglomeration of particles or the stacking of graphene sheets, and a thermally driven relaxation where nanometer-thick particles are able to overcome capillary interactions. These results are especially relevant to applications where functional films with controlled conductivity and transparency may be produced via liquid-phase deposition methods. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-02T17:47:00.466695-05:
      DOI: 10.1002/aic.16112
       
  • Characterization of PVC-soy Protein Nonwoven Mats prepared by
           Electrospinning
    • Authors: HeeRan Hong; Zachary T. Tronstad, Yi Yang, Matthew D. Green
      Abstract: Poly(vinyl chloride) (PVC) is one of the most common polymers used in the water treatment industry due to outstanding hydrophobicity and mechanical strength. Generating eco-friendly membranes derived from natural polymers has gained attention, particularly for water purification and producing potable water. In this study, nonwoven mats were prepared by electrospinning polymer solutions. Mats with a tailorable hydrophilicity were prepared by electrospinning solution mixtures containing PVC and an eco-friendly, hydrophilic natural polymer: soy protein. As the viscosity of the solution decreased, the average fiber diameter and average pore surface area reduced. However, when the PVC concentration remained constant and the soy protein concentration increased, the viscosity decreased and average fiber diameter became reduced, while the average pore diameter remained relatively constant. The mats with volumetric ratios of PVC:soy protein of 85:15 and 80:20 displayed optimal characteristics suitable for mat fabrication based on the fiber diameter and average pore surface area. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-02T17:42:19.428434-05:
      DOI: 10.1002/aic.16109
       
  • An Evaluation of the Impact of SG1 Disproportionation and the Addition of
           Styrene in NMP of Methyl methacrylate
    • Authors: S.K. Fierens; P.H.M. Van Steenberge, F. Vermeire, Marie-Françoise Reyniers, Dagmar R. D'hooge, Guy B. Marin
      Abstract: A kinetic modeling study is presented for batch nitroxide mediated polymerization (NMP) of methyl methacrylate (MMA; nitroxide: N-tert-butyl-N-[1-diethylphosphono-(2,2-dimethylpropyl)] (SG1)). Arrhenius parameters for SG1 disproportionation (A = 1.4 107 L mol−1 s−1; Ea = 23 kJ mol−1) are reported, based on homopolymerization data accounting for unavoidable temperature variations with increasing time, i.e. non-isothermicity. For low targeted chain lengths (TCLs ≤ 300), this non-isothermicity is also relevant for NMP of MMA with a small amount of styrene. Parameter tuning to copolymerization data confirms a penultimate monomer unit effect for activation (sa2 = ka12/ka22=6.7; 363 K; 1: MMA; 2: styrene). To obtain, for a broad TCL range (up to 800), a dispersity well below 1.3 an initial styrene mass fraction of ca. 10% is required. An interpretation of the comonomer incorporation is performed by calculating the fractions of activation-growth-deactivation cycles with a given amount of monomer units and the copolymer composition distribution. This article is protected by copyright. All rights reserved.
      PubDate: 2018-02-02T17:41:10.038237-05:
      DOI: 10.1002/aic.16111
       
  • A Numerical Model of Exchange Chromatography Through 3D Lattice Structures
    • Authors: Maher Salloum; David B. Robinson
      Abstract: Rapid progress in the development of additive manufacturing technologies is opening new opportunities to fabricate structures that control mass transport in three dimensions across a broad range of length scales. We describe a structure that can be fabricated by newly available commercial 3D printers. It contains an array of regular three-dimensional flow paths that are in intimate contact with a solid phase, and thoroughly shuffle material among the paths. We implement a chemically reacting flow model to study its behavior as an exchange chromatography column, and compare it to an array of one-dimensional flow paths that resemble more traditional honeycomb monoliths. A reaction front moves through the columns and then elutes. The front is sharper at all flow rates for the structure with three-dimensional flow paths, and this structure is more robust to channel width defects than the one-dimensional array. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-30T13:00:55.872934-05:
      DOI: 10.1002/aic.16108
       
  • Scalar Mixing in Anisotropic Turbulent Flow
    • Authors: Quoc Nguyen; Dimitrios V. Papavassiliou
      Abstract: While turbulent mixing has been studied extensively in homogeneous turbulence, chemical engineering processes where mixing is important are anisotropic. In anisotropic turbulence, the interplay between convection and diffusion is critical. Flow in an infinite channel is utilized here with clouds of scalars released instantaneously at different distances from the wall and at Schmidt numbers between 0.7 and 2,400. Qualitative and quantitative measures of mixing efficiency and intensity are defined and the dynamics of mixing are explored. It is found that molecular diffusivity can even hinder mixing in some instances, because it affects the development of the cloud of the released scalars from regions within the viscous wall layer. Another finding is that while one would expect mixing to occur mostly in the space between two points of release, considerable amount of mixing could take place outside of this region and closer to the wall. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-29T10:55:43.669066-05:
      DOI: 10.1002/aic.16104
       
  • Hydrothermal Pretreatment for Deconstruction of Plant Cell Wall:Part II.
           Effect on Cellulose Structure and Bioconversion
    • Authors: Kun Yao; Qinfeng Wu, Ran An, Wei Meng, Mingzhu Ding, Bingzhi Li, Yingjin Yuan
      Abstract: Influences of both ultrastructural modification of cellulose after hydrothermal pretreatment and products derived from lignin-carbohydrate complex (LCC) on the subsequent enzymatic digestibility and fermentation were studied in this study. Under hydrothermal conditions, it was found that the rearrangement of hydrogen bonding pattern in cellulose via allomorph and conformational changes which was mainly severity-dependent increased the numbers of water-exposed glycosidic bond and the formation of “amorphous-like” cellulose fibril facilitated enzymatic hydrolysis. Pseudo lignin, soluble xylo-oligomers, phenols and degradation products from high severity impeded enzymatic digestion. LCC and phenols which were rich in pH-controlled prehydrolyzate did not sufficiently inhibit yeast while furans and some aromatics which were rich in high-severity prehydrolyzate might be potential inhibitors. Trade-off phenomenon was solved by pH-controlled operation and high yields in both glucose (83-93%) and xylose (75-80%) were simultaneously obtained. The final ethanol yield from cellulose to ethanol reached as high as 84-93%. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-29T10:55:37.778212-05:
      DOI: 10.1002/aic.16106
       
  • Removal of Yield-Stress Fluids from Pipework using Water
    • Authors: I. Palabiyik; E. Lopez-Quiroga, P.T. Robbins, K.R. Goode, P.J. Fryer
      Abstract: The emptying of product from process plant is a significant multiphase flow problem in food and personal care industries, controlling both product recovery and cleaning time. Product and operational losses can be significant, especially with viscous products. It is necessary to maximize product recovery whilst minimizing cleaning time and effluent volume. The removal of a range of products from fully filled pipework by using water has been characterised and monitored by weighing pipes at intervals and by inline turbidity probe. Data is presented for a range of products (toothpaste, hand cream, apple sauce, yoghurt and shower gel) that have been cleaned from two pipe systems. The data can be fitted by a linear relationship between a dimensionless cleaning time, and the ratio of the product yield stress to the surface shear stress. The effect of pipe fittings is to reduce cleaning times, reflecting increased shear/energy dissipation in the pipe. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-29T10:55:29.520375-05:
      DOI: 10.1002/aic.16105
       
  • Preparation of High-Performance zeolite NaA Membranes in Clear Solution by
           Adding SiO2 into Al2O3 Hollow-Fiber Precursor
    • Authors: Nanke Ma; Rui Wang, Gaohong He, Zhengbao Wang
      Abstract: Zeolite NaA membranes were prepared in a clear synthesis solution without the aid of nanoseeds. To improve the properties of the membranes formed in a clear solution, alumina hollow fibers were fabricated by adding silica powder to the conventional spinning slurry, resulting in hollow fibers with a mullite phase. Prior to the membrane synthesis, the hollow fibers were pretreated by dipping in an aged synthesis solution diluted with isopropanol. Dense zeolite NaA membranes on mullite-containing alumina hollow fibers were successfully obtained at 100°C for 2 h without the aid of nanoseeds. The membranes have a good pervaporation performance with a high flux of 10.8 kg m−2 h−1 and a separation factor of over 10,000. The abundant mullite-phase hydroxyl groups on the support surface promote the nucleation and growth of zeolite crystals on the support, resulting in dense membranes. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-29T10:46:21.812335-05:
      DOI: 10.1002/aic.16107
       
  • A Decomposition Algorithm for Simultaneous Scheduling and Control of CSP
           Systems
    • Authors: Alexander W. Dowling; Tian Zheng, Victor M. Zavala
      Abstract: We present a decomposition algorithm to perform simultaneous scheduling and control decisions in concentrated solar power (CSP) systems. Our algorithm is motivated by the need to determine optimal market participation strategies at multiple timescales. The decomposition scheme uses physical insights to create surrogate linear models that are embedded within a mixed-integer linear scheduling layer to perform discrete (operational mode) decisions. The schedules are then validated for physical feasibility in a dynamic optimization layer that uses a continuous full-resolution dynamic CSP model. The dynamic optimization layer updates the physical variables of the surrogate models to refine schedules. We demonstrate that performing this procedure recursively provides high-quality solutions of the simultaneous scheduling and control problem. We exploit these capabilities to analyze different market participation strategies and to explore the influence of key design variables on revenue. Our results also indicate that using scheduling algorithms that neglect detailed dynamics significantly decreases market revenues. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-25T11:51:04.853432-05:
      DOI: 10.1002/aic.16101
       
  • Metal Nanoparticles in Ionic Liquid - Cosolvent Biphasic Systems as Active
           Catalysts for Acetylene Hydrochlorination
    • Authors: Lifeng Yang; Qiwei Yang, Jingyi Hu, Zongbi Bao, Baogen Su, Zhiguo Zhang, Qilong Ren, Huabin Xing
      Abstract: Ionic liquid (IL)-stabilized metal nanoparticles (NPs) have attracted increased attention as novel catalysts for various reactions due to their excellent stability and high activity. However, the high viscosity of ILs limits their applications. Here, for the first time, we reported an NPs@IL-cosolvent liquid-liquid biphasic system for metal NPs catalysis. The NPs were successfully confined to IL phase, and abundant IL droplets containing NPs were generated under the reactant flow. The NPs@IL droplets served as microreactors for the catalysis; while the low viscosity organic phase enabled the rapid mass transfer of substances. The biphasic system exhibited improved performance for acetylene hydrochlorination than that of the pure IL system. An acetylene conversion of 98% and a selectivity of 99.5% were achieved along with a 90% decrease on IL usage. The tolerable gas hourly space velocity in the biphasic system for a satisfactory conversion was almost double that of the pure IL system. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-25T11:50:54.384231-05:
      DOI: 10.1002/aic.16103
       
  • Method to Estimate Uncertainty Associated with Parcel Size in Coarse
           Discrete Particle Simulation
    • Authors: Liqiang Lu; Sofiane Benyahia
      Abstract: Coarse grained particle methods significantly reduce the computation cost of large-scale fluidized bed simulation by lumping many real particles into a computation parcel. This research provides a method to estimate the errors associated with parcel size in large-scale fluidized bed simulations. This uncertainty is first quantified in small scale domains by comparing results of discrete particle method with that employing coarse parcels of different sizes. Then, this uncertainty is correlated with parcel size and simulation domains consisting of a simple homogeneous cooling system and more complex bubbling and circulating fluidized beds. These correlations allow us to accurately estimate the uncertainty in large-scale fluidized beds based solely on data obtained in smaller systems. The ability to estimate model-related uncertainty in larger systems makes this method relevant for industrial applications. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-25T11:40:23.237862-05:
      DOI: 10.1002/aic.16100
       
  • Optimal design of batch-storage network considering ownership
    • Authors: Gyeongbeom Yi; Gintaras V. Reklaitis
      Abstract: This paper develops a model of multi-national supply chain activities, which incorporates currency storage units to manage currency flows associated with activities such as raw material procurement, processing, inventory control, transportation and finished product sales. The core contribution of this model is that it facilitates the quantitative investigation of the influence of macroscopic economic factors such as ownership on supply chain operational decisions. The supply chain system is modeled as a batch-storage network with recycle streams. The supply chain optimization problem is posed with the objective of minimizing the opportunity costs of annualized capital investments and currency/material inventories, while taking into account the benefit to stockholders in the numeraire currency. The major constraints on the optimization are that the material and currency storage units must not be depleted. A production and inventory analysis formulation (the periodic square wave model) provides useful expressions for the upper and lower bounds and for the average levels of the currency and material inventory holdings. The expressions for the Kuhn-Tucker conditions of the optimization problem are reduced to a subproblem that allows development of analytical lot-sizing equations. The lot sizes of procurement, production, transportation and financial transactions can be determined in closed form once the average flow rates are known. The key result we obtain is that optimal value of the economic order quantity changes substantially with variation in ownership, thus showing quantitatively that ownership structure does impact plant operation. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-25T11:20:33.845228-05:
      DOI: 10.1002/aic.16102
       
  • Atomic Layer Deposition Fabricating of Ceramic Nanofiltration Membranes
           for Efficient Separation of Dyes from Water
    • Authors: He Chen; Shanshan Wu, Xiaojuan Jia, Sen Xiong, Yong Wang
      Abstract: To meet the strong need for highly efficient and controllable manufacturing methods to ceramic nanofiltration (NF) membranes, we use atomic layer deposition (ALD) to prepare NF membranes by tightening ultrafiltration (UF) membranes. We confine the ALD deposition of TiO2 to the near-surface region of substrate UF membranes. The pores (∼ 5 nm) in the selective layers are progressively reduced, thus transforming the original UF membranes to NF ones at acceptable expense of permeability. A molecular-weight-cut-off (MWCO) down to 890 Da is obtained after merely 40 cycles and the water permeability remains as high as 32 L·m−2·h−1·bar−1. MWCOs can be flexibly tuned by altering ALD cycles, which is lowered down to 410 Da with 60 ALD cycles. The deposited membranes are used to remove dyes from water and they show significantly enhanced rejection to negatively charged dyes. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-21T05:16:00.017186-05:
      DOI: 10.1002/aic.16097
       
  • Safety Awareness – A Chemical Engineering Imperative
    • Authors: Robert S. Davidson
      PubDate: 2018-01-21T05:15:48.971249-05:
      DOI: 10.1002/aic.16099
       
  • Real-time Multi-Variable Model Predictive Control (MPC) for Steam-Assisted
           Gravity Drainage (SAGD)
    • Authors: Sagar N Purkayastha; Ian D. Gates, Milana Trifkovic
      Abstract: Thermal recovery techniques, such as Steam-Assisted Gravity Drainage (SAGD), is used to recover the majority of the crude bitumen, in Western Canada. However, suboptimal production techniques have led to a large carbon footprint and a subsequent search for more efficient extraction techniques, than open loop manual control. This paper summarizes research on the comparison of performance of a novel Multi Input Multi Output (MIMO) Model Predictive Controller (MPC) with steam trap and oil rate controls with a Multi Input Single Output (MISO) MPC with only steam trap control. An appropriate system identification technique was also used for periodic model update in compliance with changing system behavior. The real time control study was made possible by establishing a bidirectional communication between Computer Modeling Group (CMG) STARSTM (virtual reservoir) and MATLAB (onsite controller) software. The results show a 171% improvement in oil recovery for the novel MIMO MPC over the MISO MPC. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-21T05:15:46.463946-05:
      DOI: 10.1002/aic.16098
       
  • Reduced power consumption in stirred vessels by means of fractal impellers
    • Authors: S. Başbuğ; G. Papadakis, J. C. Vassilicos
      Abstract: Earlier studies1,2 have shown that the power consumption of an unbaffled stirred vessel decreases significantly when the regular blades are replaced by fractal ones. In this paper, the physical explanation for this reduction is investigated using Direct Numerical Simulations at Re = 1600. The gaps around the fractal blade perimeter create jets that penetrate inside the recirculation zone in the wake and break up the trailing vortices into smaller ones. This affects the time-average recirculation pattern on the suction side. The volume of the separation region is 7% smaller in the wake of the fractal blades. The lower torque of the fractal impeller is equivalent to a decreased transport of angular momentum; this difference stems from the reduced turbulent transport induced by the smaller trailing vortices. The major difference in the turbulent dissipation is seen in the vicinity of trailing vortices, due to fluctuations of velocity gradients at relatively low frequencies. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-18T12:50:25.823794-05:
      DOI: 10.1002/aic.16096
       
  • Stochastic Back-off Algorithm for Simultaneous Design, Control and
           Scheduling of Multi-product Systems under Uncertainty
    • Authors: Robert W. Koller; Luis A. Ricardez-Sandoval, Lorenz T. Biegler
      Abstract: An algorithm that employs the back-off method to provide optimal solutions for integration of design, control, and scheduling for multi-product systems is presented, featuring a flexibility and feasibility analysis. The algorithm employs Monte Carlo (MC) sampling to generate a large number of random realizations, and simulate the system to determine feasibility. Back-off terms are determined and incorporated into a new flexibility analysis to approximate the effect of stochastic uncertainty and disturbances. Through successive iterations, the algorithm converges, terminating on a solution that is robust to a specified level of process variability due to stochastic realizations in the disturbances and uncertain parameters. The proposed algorithm has been successfully applied to a multi-product continuous stirred tank reactor for which optimal design, control, and scheduling decisions are identified, subject to stochastic uncertainty and disturbance. The present approach has been compared to a critical-set (multi-scenario) method showing the benefits and limitations of both approaches. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-17T11:45:41.009039-05:
      DOI: 10.1002/aic.16092
       
  • Ecosystems as Unit Operations for Local Techno-Ecological Synergy:
           Integrated Process Design with Treatment Wetlands
    • Authors: Varsha Gopalakrishnan; Bhavik R. Bakshi
      Abstract: Despite the critical importance of ecological systems for sustaining all chemical and manufacturing processes, process design has kept nature outside its system boundary. Recent efforts for sustainable process design aim to reduce environmental impact, but no design method considers the capacity of ecosystems to supply the goods and services that are needed to sustain a process. Overcoming this deficiency of conventional process design is essential to transform the chemical industry into an activity that respects ecological constraints and results in a net positive societal impact. As an important step toward meeting this goal, this work expands the boundary of process design to include ecosystems as unit operations in traditional design. Similar to tasks performed by conventional unit operations, ecological processes perform ecosystem functions resulting in goods and services required by the technological system. The goal behind designing integrated techno-ecological process flowsheets is to balance the ecosystem service demand of technological systems with the ecosystem service supply of ecological systems. Systems are optimized to balance the demand and supply subject to unit operation level constraints of technological and ecological systems, and interactions between detailed process level variables and ecological variables are explored. The Techno-Ecological Synergy (TES) Design method is developed and applied to a biofuel production system, considering ecosystem services like water provisioning and water quality regulation provided by wetland ecosystems. Comparing the integrated TES design with conventional techno-centric design shows that TES design can result in net positive impact manufacturing: a case where the ecosystem service supply is equal to or exceeds the demand, with little or no compromises in process profitability. These results should encourage close integration between technological and ecological systems while designing sustainable processes, and identify many challenges for developing TES of individual processes and across the life cycle. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-17T11:43:42.742612-05:
      DOI: 10.1002/aic.16093
       
  • Highly Efficient Methane Reforming over a Low-loading Ru/γ-Al2O3 Catalyst
           in a Pd-Ag Membrane Reactor
    • Authors: David S. A. Simakov; Yuriy Román-Leshkov
      Abstract: Natural gas can be reformed to syngas (CH4 + H2O = CO + 3H2), at temperatures above 850 °C. Membrane catalytic reformers can provide high CH4 conversions at temperatures below 650 °C, by separating H2 from the reactive mixture. Traditional Ni-based catalysts suffer from low activity at low temperatures and deactivate rapidly by coking, particularly at low steam/carbon ratios. In this study, an ultra-low loading (0.15 wt%) Ru/γ-Al2O3 catalyst was implemented in a lab-scale membrane reformer, using a supported 5μm Pd-Ag film membrane. Methane conversions above 90% were achieved at 650 °C, 8 bar, and H2O/CH4 = 2, 3 with contact times of ca. 10 s. The system generated up to 3.5 mol of ultra-pure H2 per mol of CH4 fed, with a maximum power density of 0.9 kW/L. No significant deactivation was observed after 200 h time on stream, even when using low H2O:CH4 ratios. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-17T11:43:05.959442-05:
      DOI: 10.1002/aic.16094
       
  • Continuous-Time Formulations for the Optimal Planning of Multiple
           Refracture Treatments in a Shale Gas Well
    • Authors: Diego C. Cafaro; Markus G. Drouven, Ignacio E. Grossmann
      Abstract: This work presents a continuous-time optimization model for planning multiple refracture treatments over the lifespan of a shale gas well. We demonstrate that continuous-time models can handle multiple restimulations very efficiently, increasing the net present value of the well development and refracturing plan. Well productivity is represented by a piecewise hyperbolic function, which accounts for when and how often the well has been refractured. We illustrate the application and effectiveness of the proposed approach for both the maximization of the total gas recovered and the maximization of the net present value. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-17T11:41:41.24767-05:0
      DOI: 10.1002/aic.16095
       
  • Impact of Diversity of Morphological Characteristics and Reynolds number
           on Local Hemodynamics in Basilar Aneurysms
    • Authors: Marjan Rafat; Mahsa Dabagh, Martin Heller, James D. Rabinov, Howard A. Stone, Amanda Randles, Debra T. Auguste
      Abstract: Morphological and hemodynamic parameters have been suggested to affect the rupture of cerebral aneurysms, but detailed mechanisms of rupture are poorly understood. The purpose of our study is to determine criteria for predicting the risk of aneurysm rupture, which is critical for improved patient management. Existing aneurysm hemodynamics studies generally evaluate limited geometries or Reynolds numbers (Re), which are difficult to apply to a wide range of patient-specific cases. We focused on the association between hemodynamic characteristics and morphology. We assessed several two-dimensional (2D) and three-dimensional (3D) idealized and physiological geometries to characterize the hemodynamic landscape between flow patterns. The impact of morphology on velocity and wall shear stress (WSS) profiles were evaluated. We found that slight changes in aneurysm geometry or Re result in significant changes in the hemodynamic and WSS profiles. Our systematic mapping and non-dimensional analysis qualitatively identify hemodynamic conditions that may predispose aneurysms to rupture. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-12T11:05:22.297615-05:
      DOI: 10.1002/aic.16091
       
  • A Square-Force Cohesion Model and its Extraction from Bulk Measurements
    • Authors: Peiyuan Liu; Casey Q. LaMarche, Kevin M. Kellogg, Christine M. Hrenya
      Abstract: Accurate modeling of interparticle forces in DEM is critical to predicting the rheology of cohesive particles. Rigorous cohesion models usually include parameters associated with particle surface roughness. However, both roughness measurement and its distillation into appropriate model parameters remain challenging. We propose a square-force cohesion model, where cohesive force remains constant until a cut-off separation, above which cohesion vanishes. We demonstrate the square-force model is a valid surrogate of more rigorous models. Specifically, when two parameters of square-force model are chosen to match the two key quantities governing dense and dilute flows, namely maximum cohesive force and critical cohesive energy31, respectively, DEM results using square-force and more rigorous models show good agreement. For practical application of the square-force model to lightly cohesive systems, a method is established to extract its parameters via defluidization, enabling determination of particle-particle cohesion from simpler bulk measurements than complicated and expensive scans on individual grains. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-11T11:21:07.514719-05:
      DOI: 10.1002/aic.16089
       
  • Globally Optimal Linear Approach to the Design of Heat Exchangers Using
           Threshold Fouling Modeling
    • Authors: Julia C. Lemos; André L. H. Costa, Miguel J. Bagajewicz
      Abstract: This article presents a method for the mathematical optimization of the design of heat exchangers including fouling rate modeling for the tube-side. The description of the fouling rate in crude preheat trains of petroleum distillation units is commonly based on threshold models (Ebert-Panchal model and its variants). Our formulation of the design problem employs a mixed integer linear programing approach; therefore the solution is the global optimum and common nonconvergence drawbacks of mixed-integer nonlinear programming models are totally avoided. Three different examples are employed to compare the proposed approach with an optimization procedure using fixed fouling resistances. The results indicate that in two problems was possible to obtain design solutions associated to smaller heat exchangers. Additionally, three case studies are also explored to discuss how fouling is related to crude types, pressure drop manipulation, and energy integration. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-11T11:20:59.068084-05:
      DOI: 10.1002/aic.16083
       
  • Experimental Investigation of Particle Migration in Suspension Flow
           through Bifurcating Microchannels
    • Authors: Bhaskar Jyoti Medhi; Vipin Agrawal, Anugrah Singh
      Abstract: Experimental measurements of velocity and concentration profiles were carried out to study transport of non-colloidal suspension in bifurcating micro channels for both diverging and converging flow conditions using a combination of Mirco Particle Image Velocimetry (PIV) and Particle Tracking Velicimetry (PTV) techniques. Migration of particles across the streamline was observed and symmetric velocity and concentration profile in the inlet branch becomes asymmetric in the daughter branches. Further migration of particles towards the center of the channel in the outlet branch make the profiles again symmetric. The evolution of velocity and concentration profiles was observed to be different in the symmetric and asymmetric bifurcation channels. The comparison of the streamlines for the fluid and the particles showed significant deviation near the bifurcation region. This may explain why there is unequal flow and particle partitioning during flow of suspension in asymmetric bifurcating channels as reported in many previous studies. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-11T11:20:57.069458-05:
      DOI: 10.1002/aic.16084
       
  • 3D Simulation of the Time-dependent Fluid Flow and Fouling Behavior in an
           Industrial Hollow Fiber Membrane Module
    • Authors: Liwei Zhuang; Gance Dai, Zhen-liang Xu
      Abstract: A novel three-dimensional CFD model has been developed on the basis of fluid flow in the shell and lumen sides, and permeation and fouling behavior in the porous membrane zone. The simulated 25-minute dead-end outside-in filtration process showed that the energy consumed by the inlet manifold decreases during the constant pressure filtration. The velocity and pressure distributions in the module change with time. Flux distribution both in the axial and radial directions becomes increasingly more uniform, so does the cake distribution. Flux distribution and cake distribution inter-adjust each other in different modes. A correlation equation has been developed to describe the relationship between the volumetric flow rate and accumulated water production. The correlation equation with simple experiment enables the dynamic evolution of energy consumed by shell inlet manifold to be presented, which can be the criterion of how well the shell inlet manifold or module has been designed. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-11T11:20:53.190384-05:
      DOI: 10.1002/aic.16090
       
  • A Study of Film Thickness and Hydrodynamic Entrance Length in Liquid
           Laminar Film Flow along a Vertical Tube
    • Authors: Hongxia Gao; Xiao Luo, Ding Cui, Xiayi Hu, Ardi Hartono, Hallvard F. Svendsen, Zhiwu Liang
      Abstract: The liquid film thickness and hydrodynamic entrance length in a vertical tube was studied experimentally and numerically. Measurements using distilled water, 30 wt% MEA and 40 wt% sugar solutions were carried out to investigate the effects of liquid flow rate on the formation of the liquid film. The experimental results validate the new Navier-Stokes based equation in cylindrical coordinates (Eq.16) and the volume of fluid (VOF) model giving a competitively high prediction of the liquid film thickness especially in the low Reynolds number region. In addition, a new empirical model and an improved minimal surface model have been firstly proposed for calculation of the hydrodynamic entrance length, with a relatively reasonable average absolute relative deviation (AARD) of 3.03% and 6.83%, respectively. Furthermore, the effects of the hydrodynamic entry length on the gas-liquid interfacial area calculated by the improved minimal surface model were comprehensively studied, and can be ignored if the ratio of the liquid film length (y) and the hydrodynamic entrance length (λE) is lower than 10. However, it should be noted that the hydrodynamic entrance length cannot be ignored in packed columns in which the liquid flow is very complex due to the packings with different structures and materials. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-11T11:20:46.94143-05:0
      DOI: 10.1002/aic.16081
       
  • Influence of Normal Contact Force Model on Simulations of
           Sphero-cylindrical Particles
    • Authors: Rohit Kumar; Avik Sarkar, William Ketterhagen, Bruno Hancock, Jennifer Curtis, Carl Wassgren
      Abstract: This paper investigates how the choice of elastic normal contact force model affects predictions from DEM simulations of sphero-cylindrical particles. Three force models were investigated: (1) a Hertzian force model (HFM) which assumes a circular contact area; (2) a linear force model (LFM) with a constant stiffness; and (3) a modified Hertzian force model (MFM) that accounts for various contact areas and contact transitions. With the MFM, transitions between contact area types must be accounted for otherwise discontinuities in the contact force can occur. It is found that simple force models (HFM, LFM) can be substituted for more accurate force models if only force data and bulk properties are of interest. However, if more detailed contact information, such as contact area, contact overlap, contact duration, or collision frequency are needed, for example in population balance models and transient liquid bridge modeling, then a more accurate force model should be used. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-11T11:20:39.716576-05:
      DOI: 10.1002/aic.16082
       
  • Liquid-Liquid-Solid Mass Transfer and Phase Behavior of Heterogeneous
           Etherification of Glycerol with Isobutene
    • Authors: Jingjun Liu; Bolun Yang
      Abstract: Previous experiments observed auto-acceleration in the etherification of glycerol with isobutene. This paper engaged to uncover the reason for this phenomenon via investigating the heterogenicity, including liquid-liquid phase equilibrium and liquid-liquid-solid mass transfer, of the reaction system. Phase behavior analysis showed that the reaction mixture separates into two liquid phases during the whole course of the reaction. The produced mono ethers of glycerol thermodynamically promote the homogenization of the two liquid phases. The modeling results of liquid-liquid-solid mass transfer indicated that the resistance of mass transfer is insignificant during the reaction. The bulk compositions of the two liquid phases are very close to their corresponding equilibrium compositions. An increase of isobutene concentration in the reaction phase is believed to lead all reactions speeding up. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-11T11:20:34.597975-05:
      DOI: 10.1002/aic.16080
       
  • On the Mechanisms of Secondary Flows in a Gas Vortex Unit
    • Authors: Kaustav Niyogi; Maria M. Torregrosa, Vladimir N. Shtern, Guy B. Marin, Geraldine J. Heynderickx
      Abstract: The hydrodynamics of secondary flow phenomena in a disc-shaped gas vortex unit (GVU) is investigated using experimentally validated numerical simulations. The simulation using ANSYS FLUENT® v.14a reveals the development of a backflow region along the core of the central gas exhaust, and of a counterflow multi-vortex region in the bulk of the disc part of the unit. Under the tested conditions, the GVU flow is found to be highly spiraling in nature. Secondary flow phenomena develop as swirl becomes stronger. The backflow region develops first via the swirl-decay mechanism in the exhaust line. Near-wall jet formation in the boundary layers near the GVU end-walls eventually results in flow reversal in the bulk of the unit. When the jets grow stronger the counterflow becomes multi-vortex. The simulation results are validated with experimental data obtained from Stereoscopic Particle Image Velocimetry and surface oil visualization measurements. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-11T11:17:01.37428-05:0
      DOI: 10.1002/aic.16087
       
  • Lattice Boltzmann Simulation of Asymptotic Longitudinal Mass Dispersion in
           Reconstructed Random Porous Media
    • Authors: Chen Yang; Yixiong Lin, Gérald Debenest, Akira Nakayama, Ting Qiu
      Abstract: In order to research macroscopic mass transport characteristics of porous media, a lattice Boltzmann method (LBM) approach was utilized to calculate asymptotic longitudinal mass dispersion. In this study, a D2Q9 model with multi-relaxation-time (MRT) collision operator, which is appropriate for incompressible flow with a high Péclet number without refining the lattice, was chosen. With respect to the microstructure of porous media, random placement (RP) method was applied to obtain randomly positioned particles. Based on the exhausted numerical results presented in the study, a new correlation of longitudinal mass dispersion was established. By comparing with available experimental data in the literature, reasonable agreements are observed in a wide porosity range from 0.3 to 0.7, indicating the validity of the proposed correlation. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-11T11:16:14.217384-05:
      DOI: 10.1002/aic.16088
       
  • Experimental investigation of the morphology of salt deposits from drying
           sessile droplets by white-light interferometry
    • Authors: F. Sondej; M. Peglow, A. Bück, E. Tsotsas
      Abstract: This study presents a new approach to investigate the drying behavior and the structure of deposit resulting from drying of solid containing micro droplets. It is shown that deposit structure (porosity and “footprint”) depends on drying conditions. This dependency may contribute to better understanding of particle-forming processes, such as fluidized bed coating. In the framework of this study, sessile droplets containing sodium benzoate dissolved in water were dried on thin glass plates in a small drying chamber. The drying conditions (temperature, moisture content and flow rate of drying gas) and material parameters (solid content of solution) were systematically varied. The drying rate of droplets was determined from the moisture balance of the drying gas. The final 3D shape of dried sessile droplets was measured using white-light interferometry and transformed into a 2D profile using a Monte Carlo method. Moreover the mean porosity of dried droplets was calculated. By comparison of structural information and process conditions it is shown that the drying process may have a large influence on deposit structure. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-11T11:15:34.490529-05:
      DOI: 10.1002/aic.16085
       
  • Flow Distribution of Hydrocarbon Fuel in Parallel Mini-Channels Heat
           Exchanger
    • Authors: Yu Chen; Zhiliang Lei, Tianhao Zhang, Quan Zhu, Zewei Bao, Qiyi Zhang, Xiang-Yuan Li
      Abstract: In this paper, the flow distribution of the Chinese No. 3 jet fuel in parallel mini-channels heat exchanger under high temperature condition was investigated. The models of PFR and choked flow were established based on the real fluid model. The formation mechanism of flow maldistribution of the fuel in the freely-distributed channels was studied. It was found that: under low heat flux, the slight flow rate deviation will be spontaneously eliminated; under high heat flux, the slight deviation of flow rate and heat flux will be enlarged and result in the channel with smaller flow rate entering the coking region. The feasibility and influence factors of the control method of flow distribution based on choked flow were discussed. The experimental results indicated that the mini-channels fuel-cooled plate with choked flow could maintain uniform flow distribution when the total fuel outlet temperature reached 1035 K. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-11T11:10:30.909323-05:
      DOI: 10.1002/aic.16086
       
  • Non-homogeneous flow of micellar solutions: A kinetic - network theory
           approach
    • Authors: J. Paulo García-Sandoval; A. Martín del Campo, F. Bautista, O. Manero, Jorge E. Puig
      Abstract: The rheological behavior of micellar solutions is analyzed under non-homogeneous velocity and stress flow conditions. The framework is based on the extended irreversible thermodynamics and the transient network formulation coupled to the underlying kinetics embodying two relevant processes: formation of wormlike chains from a free micellar solution through a thermally activated process and their flow induced degradation. The second kinetic process consists in the formation of entanglements from the free wormlike chains and their flow-induced breakage. These processes are modeled in a coupled kinetic scheme constituted by a set of reversible kinetic equations describing the evolution in average of the three microstates (free short rod-like micelles, free wormlike chains and entangled wormlike chains) that reflect the complexity of macromolecular interactions. The predictions of the shear stress and first normal stress difference as a function of shear-rate under banded flow are in good agreement with experimental data. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-06T10:40:26.871744-05:
      DOI: 10.1002/aic.16079
       
  • Non-spherical particles in a pseudo-2D fluidized bed: Experimental study
    • Authors: Vinay V. Mahajan; Tim M.J. Nijssen, Kay A. Buist, J. A. M. Kuipers, Johan T. Padding
      Abstract: Fluidization is widely used in industries and has been extensively studied, both experimentally and theoretically, in the past. However, most of these studies focus on spherical particles while in practice granules are rarely spherical. Particle shape can have a significant effect on fluidization characteristics. It is therefore important to study the effect of particle shape on fluidization behaviour in detail. In this study, experiments in pseudo-2D fluidized beds are used to characterize the fluidization of spherocylindrical (rod-like) Geldart D particles of aspect ratio 4. Pressure drop and optical measurement methods (DIA, PIV, PTV) are employed to measure bed height, particle orientation, particle circulation, stacking and coordination number. The commonly used correlations to determine the pressure drop across a bed of non-spherical particles are compared to experiments. Experimental observations and measurements have shown that rod-like particles are prone to interlocking and channelling behaviour. Well above the minimum fluidization velocity, vigorous bubbling fluidization is observed, with groups of interlocked particles moving upwards, breaking up, being thrown high in the freeboard region and slowly raining down as dispersed phase. At high flowrates, a circulation pattern develops with particles moving up through the center and down at the walls. Particles tend to orient themselves along the flow direction. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-05T10:50:43.158868-05:
      DOI: 10.1002/aic.16078
       
  • The pH, Temperature and Protein Structure Effect on β-Lactoglobulin A and
           B Separation in Anion-Exchange Chromatography
    • Authors: Gorgi Pavlova; James T. Hsua
      Abstract: The effect of pH and temperature on separating a mixture of similar proteins, namely β-lactoglobulin A (LGA) and β-lactoglobulin B (LGB) in anion-exchange chromatography is explored. The proteins carry a slight difference in negative charge at basic pH, providing a separation basis on an Q Sepharose Fast Flow anion-exchange resin. They were separated at different temperatures and pH values, and the separation factor was evaluated. The experimental results were matched to a theoretical model to compute the equilibrium constant KA. The data shows that an increase in temperature and pH leads to an increase in the retention time of the proteins. The results were correlated with the net charge of the molecule for the separation so that the elution can be simulated for any condition that was studied. The tertiary structures of LGA and LGB are analyzed to illustrate the structure effect on the separation. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-05T10:50:20.515597-05:
      DOI: 10.1002/aic.16077
       
  • A Regime Map for the Normal Surface Impact of Wet and Dry Agglomerates
    • Authors: Mohammad Khalilitehrani; Joakim Olsson, Farin Daryosh, Anders Rasmuson
      Abstract: The normal surface impacts of wet and dry agglomerates are simulated in a DEM framework. While the impact behavior of dry agglomerates has been addressed previously, similar studies on wet agglomerate impact are missing. We show that by adding a small amount of liquid the impact behavior changes significantly.The impact behavior of the agglomerates at different moisture contents and impact energies are analyzed through post-impact parameters and coupled to their microscopic and macroscopic properties. While increasing the impact energy breaks more inter-particle bonds and intensifies damage and fragmentation, increasing the moisture content is found to provide the agglomerates with higher deformability and resistance against breakage. It is shown that the interplay of the two latter parameters together with the agglomerate structural strength creates various impact scenarios, which are classified into different regimes and addressed with a regime map. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-03T10:42:01.559243-05:
      DOI: 10.1002/aic.16072
       
  • Revealing Low Temperature Microwave-assisted Pyrolysis Kinetic Behaviors
           and Dielectric Properties of Biomass Components
    • Authors: Hu Luo; Li-Wei Bao, Ling-Zhao Kong, Yu-Han Sun
      Abstract: The kinetic characteristics of microwave-assisted pyrolysis of biomass components were investigated in a self-designed microwave TGA using the KAS model and the master plot method. Compared with conventional pyrolysis, the initial decomposition temperatures of biomass components were reduced by 50-100°C and the fastest weight loss regions were shifted to lower temperatures. The average apparent activation energies of cellulose, hemicellulose and lignin were 47.82, 44.81 and 51.54 kJ/mol, respectively. Analysis with master plot method suggested the MAP of cellulose followed the 2-D diffusion reaction model, while hemicellulose and lignin could be interpreted by 3rd order-based and 3-D diffusion model. The change of dielectric properties was consistent with the weight loss behaviors of biomass components during the pyrolysis process. The increase of dielectric properties with temperature can lead to a thermal gradient and “hot spots” within biomass, which accelerated the pyrolysis process at low temperatures and reduced the apparent activation energy. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-03T10:41:54.278231-05:
      DOI: 10.1002/aic.16073
       
  • Heat Transfer Intensification for Retrofitting Heat Exchanger Networks
           with Considering Exchanger Detailed Performances
    • Authors: Ming Pan; Igor Bulatov, Robin Smith
      Abstract: The challenging of this work is to present a thorough study of implementing heat transfer intensification in heat exchanger network (HEN) retrofitting, including all details of exchanger geometry, stream bypassing and splitting, temperature-variation of properties, LMTD and its correction, and pressure drops. This leads to very complex mixed integer nonlinear programming (MINLP) problems rarely reported before. By adopting the MILP-based iterative approach proposed in the earlier work (Pan et al. in 2013), temperature-variation of properties, LMTD and its correction are initialised to parameters at first, and the rest nonlinear terms are then linearized and expressed as first order Taylor series expansions. Finally, two iteration loops are executed to find optimal solutions. A small-scale motivating problem and an industrial scale problem are presented to demonstrate the validity and efficiency of the proposed methods. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-03T10:41:40.632147-05:
      DOI: 10.1002/aic.16075
       
  • On the construction of binary mixture p-x and T-x diagrams from isochoric
           thermodynamics∗
    • Authors: Ian H. Bell; Ulrich K. Deiters
      Abstract: In this work we describe how to efficiently and reliably calculate p-x and T-x diagrams for binary mixtures of fluids. The method is based on the use of the Helmholtz energy density as the fundamental thermodynamic potential. Through the use of temperature and molar concentrations of the components as the independent variables, differential relationships can be constructed along the phase envelope surface, and this system of differential equations is then integrated to construct isotherms and isobars cutting through the phase envelope.The use of the Helmholtz energy density as the fundamental potential allows several models to be considered in this formalism, including cubic equations of state (Peng-Robinson, GC-VTPR, etc.) as well as high-accuracy multifluid equations of state (the so-called GERG mixture model). Examples of each class are presented, demonstrating the flexibility of this method. Source code, examples, and comprehensive analytic derivatives are provided in the supplemental material. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-03T10:41:32.191932-05:
      DOI: 10.1002/aic.16074
       
  • Enhanced Water Flux through Graphitic Carbon Nitride Nanosheets Membrane
           by Incorporating Polyacrylic Acid
    • Authors: Yanjie Wang; Lingfei Liu, Jian Xue, Jiamin Hou, Li Ding, Haihui Wang
      Abstract: Membranes assembled from two-dimensional (2D) layered materials have shown potential use in water purification. Recently, a 2D graphitic carbon nitride (g-C3N4) nanosheets membrane exhibit considerable separation performance in water purification. In this study, to further improve this water separation performance, polyacrylic acid (PAA) was introduced to tune the nanochannels formed between the g-C3N4 nanosheets. The fabricated g-C3N4-PAA hybrid membranes possessed higher water flux without sacrificing much rejection rate compared with that of the g-C3N4 membrane; however noticeable fouling was observed upon addition of the PAA into the membrane composite structure. In addition, the effect of PAA on the morphology, surface hydrophilicity, separation performance, and antifouling properties of the g-C3N4 membrane were examined in detail. Overall, incorporating PAA into the g-C3N4 nanosheets membrane was an effective and convenient method to improve the water separation performance, which could promote the application of the 2D g-C3N4 nanosheets membrane in practical ultrafiltration processes. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-03T10:41:04.62055-05:0
      DOI: 10.1002/aic.16076
       
  • CO2 Capture by Methanol, Ionic Liquid, and Their Binary Mixtures:
           Experiments, Modeling, and Process Simulation
    • Authors: Mohsen Taheri; Chengna Dai, Lei Zhigang
      Abstract: The CO2 solubility data in the ionic liquid (IL) 1-allyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide, methanol (MeOH), and their mixture with different combinations at temperatures of (313.2, 333.2, and 353.2 K) and pressures up to 6.50 MPa were measured experimentally. New group binary interaction parameters of the predictive UNIFAC-Lei model, which has been continually advanced by our group, were introduced by correlating the experimental data of this work and the literature. The consistency between experimental data and predicted results proves the reliability of UNIFAC-Lei model for CO2-IL-organic solvent systems. The newly obtained parameters were incorporated into the UNIFAC property model of Aspen Plus software to optimize a conceptual process developed for the purification of a CO2-containing gas stream. The simulation results indicate that the use of IL either mixed with MeOH or purely considerably lowers the process power consumption, and improves the process performance in terms of CO2 capture rate and solvent loss. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-02T10:10:41.785233-05:
      DOI: 10.1002/aic.16070
       
  • Solubilities of Solid n-Alkanes in Methane: Data Analysis and Models
           Assessment
    • Authors: Marco Campestrini; Paolo Stringari
      Abstract: This paper reviews the results of experiments underway since 1950 studying the solid solubility of n-alkanes (from ethane up to n-triacontane) in methane and the factors influencing the global phase equilibrium behavior of the related binary mixtures.The methodology used consists of a series of comparisons of data in the composition-temperature and pressure-temperature diagrams. The kind of global phase diagram of the binary mixtures of methane referred to in the present article is found to be dependent of the ratio between the triple-point temperature of the generic n-alkane and the critical-point temperature of methane.The Peng-Robinson (1976), Predictive Soave-Redlich-Kwong, and Predictive Peng-Robinson (1978) equations of state have been applied and compared with respect to the calculation of bivariant, univariant, and invariant equilibrium data involving solid n-alkanes in binary mixture with methane. The fugacities of the solid n-alkanes have been calculated by means of the so-called classic approach. This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-02T10:10:37.398384-05:
      DOI: 10.1002/aic.16071
       
  • Issue Information – Table of Contents
    • Pages: 797 - 797
      PubDate: 2018-02-10T20:40:52.501881-05:
      DOI: 10.1002/aic.15899
       
  • Experimental Measurement and Thermodynamic Modeling of Cyclopentane
           Hydrates with NaCl, KCl, CaCl2 or NaCl-KCl Present
    • Authors: S. Ho-Van; B. Bouillot, J. Douzet, S. Maghsoodloo, J.M. Herri
      Abstract: Consistent phase equilibrium data for cyclopentane hydrates in presence of salts are vitally important to many industries, with particular interest to the field of hydrate-based water separation via cyclopentane hydrate crystallization such as desalination. However, there are very little experimental equilibrium data, and no thermodynamic prediction tools. Hence, we set up a method to generate a great deal of much needed equilibrium data for cyclopentane hydrates in diverse saline solutions with a wide range of salt concentrations. Our method does furnish verified, reliable and accurate equilibrium data. Plus, three thermodynamic approaches are developed to predict equilibrium, and provide tools for simulations, by considering the kind of salt and concentrations. All three models are in very good accordance with experimental data. One method, using a new correlation between occupancy factor and water activity, might be the best way to obtain consistent, quick and accurate dissociation temperatures of cyclopentane hydrate in brine. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-28T10:30:46.662499-05:
      DOI: 10.1002/aic.16067
       
  • On reduced modeling of mass transport in wavy falling films
    • Authors: P. Bandi; S. Groß, Y. Heng, W. Marquardt, A. Mhamdi, M. Modigell, A. Reusken, L. Zhang
      Abstract: In many industrial units such as packing columns, falling film reactors, etc., the liquid phase is designed as a falling film. It is well known that the mass and heat transfer in laminar wavy film flows is significantly enhanced compared to flat films. The kinetic phenomena underlying the increase in mass and heat transfer are, however, still not fully understood. For an efficient design of falling film units, computational models that account for these enhanced transport mechanisms are of key importance. In this paper, we present a reduced modeling approach based on a long-wave approximation to the fluid dynamics of the film. Furthermore, we introduce a new 2D high-resolution laser-induced luminescence measurement technique. Both in the numerical simulation results and in the high-resolution 2D-concentration measurements obtained in the experiments we observe similar patterns of high concentrations locally, especially in the areas close to the wave hump. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-28T10:30:43.927612-05:
      DOI: 10.1002/aic.16065
       
  • Nanospace-Confined Synthesis of Coconut-like SnS/C Nanospheres for
           High-Rate and Stable Lithium-Ion Batteries
    • Authors: Zongnan Deng; Hao Jiang, Yanjie Hu, Chunzhong Li, Yu Liu, Honglai Liu
      Abstract: Coconut-like monocrystalline SnS/C nanospheres are developed as anode materials for lithium-ion batteries (LIBs) by a micro-evaporation-plating strategy in confined nanospaces, achieving reversible capacities as high as 936 mAh g−1 at 0.1 A g−1 after 50 cycles and 830 mAh g−1 at 0.5 A g−1 for another 250 cycles. The remarkably improved electrochemical performances can be mainly attributed to their unique structural features, which can perfectly combine the advantages of the face-to-face contact of core/shell nanostructure and enough internal void space of yolk/shell nanostructure, and therefore well-addressing the pivotal issues related to SnS low conductivity, sluggish reaction kinetics and serious structure pulverization during the lithiation/delithiation process. The evolutionary process of the nanospheres is clearly elucidated based on experimental results and a multiscale kinetic simulation combining the microscopic reaction-diffusion equation and the mesoscopic theory of crystal growth. Furthermore, a LiMn2O4//SnS/C full cell is assembled, likewise exhibiting excellent electrochemical performance. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-28T10:30:40.251797-05:
      DOI: 10.1002/aic.16068
       
  • Determination of Crystalline Thermodynamics and behavior of Anthracene in
           different Solvents
    • Authors: Cui-ping Ye; Xiao-xiao Ding, Wen-ying Li, Hai Mu, Wei Wang, Jie Feng
      Abstract: To screen suitable solvents for anthracene crystallization, the solubilities of anthracene and metastable zone width were determined in four different solvents, N,N-dimethyl formamide (DMF), xylene, tetrachloroethylene, and diethylene glycol dimethyl ether from 30 to 80°C at atmospheric pressure using a self-made crystallizer. The cooling modes, solvents, and the effects of carbazole on the solvent crystallization process of anthracene were also investigated. The composition of mother liquors and solid products were measured by gas chromatography, the solids were analyzed by scanning electron microscope, X-ray diffractometer, differential scanning calorimetry, granulometer, and fluorescence spectrometer. The results showed that a uniform anthracene crystal was obtained when using DMF under the forced circulation cooling mode. Solid solution of anthracene and carbazole was initially detected in solvent crystallization. The existence of carbazole in solution has an obvious effect on the crystal morphology of anthracene, to some extent, is beneficial to the crystal growth of anthracene. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-28T10:30:36.40887-05:0
      DOI: 10.1002/aic.16069
       
  • Solvent-free polymer emulsification inside a twin screw extruder
    • Authors: A. Goger; M.R. Thompson, J.L. Pawlak, M.A. Arnould, D.J.W. Lawton
      Abstract: Solvent-free extrusion emulsification (SFEE) is new technique for a twin screw extruder to prepare sub-micron sized particles (100-500 nm) without using hazardous solvents. The particle size is reliant upon the thickness of striated lamellae, which can be monitored rheologically based on the viscosity change occurring at the SFEE process. The lamellae coarsening rate is predominantly affected by the interfacial energy of the system when a surfactant is added but shows stronger dependency on viscosity change when interfacial growth between the polymer and water phases is solely determined by the end-groups conversion into carboxylate species. For this latter case, the dissolution of the sodium hydroxide species and the kinetics of end-groups conversion prove to be rate-limiting phenomena to generating thinner striated lamellae. Additionally, the ionic strength of the system is notably important to the viscosity response and particle size produced, particularly when surfactant is not added. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-22T10:10:30.019902-05:
      DOI: 10.1002/aic.16066
       
  • Convex Relaxations for Global Optimization Under Uncertainty Described by
           Continuous Random Variables
    • Authors: Yuanxun Shao; Joseph K. Scott
      Abstract: This article considers nonconvex global optimization problems subject to uncertainties described by continuous random variables. Such problems arise in chemical process design, renewable energy systems, stochastic model predictive control, etc. Here, we restrict our attention to problems with expected-value objectives and no recourse decisions. In principle, such problems can be solved globally using spatial branch-and-bound. However, branch-and-bound requires the ability to bound the optimal objective value on subintervals of the search space, and existing techniques are not generally applicable because expected-value objectives often cannot be written in closed-form. To address this, this article presents a new method for computing convex and concave relaxations of nonconvex expected-value functions, which can be used to obtain rigorous bounds for use in branch-and-bound. Furthermore, these relaxations obey a second-order pointwise convergence property, which is sufficient for finite termination of branch-and-bound under standard assumptions. Empirical results are shown for three simple examples. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-21T10:46:48.450981-05:
      DOI: 10.1002/aic.16064
       
  • Dynamics and Scaling of Explosion Cratering in Granular Media
    • Authors: Ming Gao; Xiao Liu, Luana Pasetti Vanin, Ting-Pi Sun, Leonardo Gordillo, Xiang Cheng
      Abstract: Granular cratering is a ubiquitous phenomenon occurring in various natural and industrial contexts. Although impact-induced granular cratering has been extensively studied, fewer experiments have been conducted on granular cratering via low-energy explosions. Here, we study the dynamics and scaling of explosion granular cratering by injecting short pulses of pressurized air in quasi-two-dimensional granular media. Through an analysis of the dynamics of explosion processes at different explosion pressures, explosion durations and burial depths, we identify two regimes, the bubbling and the eruption regimes, in explosion granular cratering. Our experiments explore the distinctive dynamics and crater morphologies of these regimes and show the energy scaling of the size of explosion craters. We compare high-energy and low-energy explosion cratering as well as explosion and impact cratering in terms of their energy scalings. Our work illustrates complex granular flows in explosion cratering and provides new insights into the general scaling of granular cratering processes. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-19T08:27:00.634136-05:
      DOI: 10.1002/aic.16063
       
  • Rheological properties and structure of step- and chain-growth gels
           concentrated above the overlap concentration
    • Authors: Matthew D. Wehrman; Andrew Leduc, Holly E. Callahan, Michelle S. Mazzeo, Mark Schumm, Kelly M. Schultz
      Abstract: Cross-linked polymeric gels are widely used in applications ranging from biomaterial scaffolds to additives in enhanced oil recovery. Despite this, fundamental understanding of the effect of polymer concentration and reaction mechanism on the scaffold structure is lacking. We measure scaffold properties and structure during gelation using multiple particle tracking microrheology. To determine the effect of concentration, we measure gelation as polymer interactions are increased in the backbone precursor solution: below, at and above the overlap concentration, c*. To determine structural changes due to the gelation mechanism, we measure gelation between the same polymers undergoing both step- and chain-growth reactions using self-assembling maleimide:thiol and photo-initiated acrylate:thiol chemistries, respectively. We determine the critical relaxation exponent, n, a measure of structure. n decreases with increasing concentration, indicating a change from a percolated (c 
      PubDate: 2017-12-18T10:30:21.502207-05:
      DOI: 10.1002/aic.16062
       
  • Eulerian-Lagrangian Simulations of Settling and Agitated Dense
           Solid-Liquid Suspensions – Achieving Grid Convergence
    • Authors: J.J. Derksen
      Abstract: Eulerian-Lagrangian simulations of solid-liquid flow have been performed. The volume-averaged Navier-Stokes equations have been solved by a variant of the lattice-Boltzmann method; the solids dynamics by integrating Newton's second law for each individual particle. Solids and liquid are coupled via mapping functions. The application is solids suspension in a mixing tank operating in the transitional regime (the impeller-based Reynolds number is 4,000), an overall solids volume fraction of 10% and a particle-liquid combination with an Archimedes number of 30. In this application, the required grid resolution is dictated by the liquid flow and we thus need freedom to choose the particle size independent of the grid spacing. Preliminary hindered settling simulations show that the proposed Eulerian-Lagrangian mapping strategy indeed offers this independence. The subsequent mixing tank simulations generate grid-independent results. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-15T11:20:32.511175-05:
      DOI: 10.1002/aic.16061
       
  • Simulation of Shale Gas Transport and Production with Complex Fractures
           using Embedded Discrete Fracture Model
    • Authors: Wei Yu; Yifei Xu, Malin Liu, Kan Wu, Kamy Sepehrnoori
      Abstract: The goal of this study is to develop a new model to simulate gas and water transport in shale nanopores and complex fractures. We first derive a new gas diffusivity equation to consider multiple important physical mechanisms such as gas desorption, gas slippage and diffusion, and non-Darcy flow. For complex fractures, we implement a state-of-the-art embedded discrete fracture model (EDFM). We verify this numerical model against a commercial reservoir simulator for shale gas simulation with multiple planar fractures. After that, we perform a series of simulation studies to investigate the impacts of complex gas transport mechanisms and various fracture geometries on well performance. The critical parameters controlling well performance are identified. The simulation results reveal that modeling of gas production from complex fractures as well as modeling important gas transport mechanisms in shale gas reservoirs is extremely significant. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-15T11:20:28.910288-05:
      DOI: 10.1002/aic.16060
       
  • Monetizing Shale Gas to Polymers under Mixed Uncertainty: Stochastic
           Modeling and Likelihood Analysis
    • Authors: Chang He; Ming Pan, Bingjian Zhang, Qinglin Chen, Fengqi You, Jingzheng Ren
      Abstract: This paper presents a novel framework based on stochastic modeling methods and likelihood analysis to address large-scale monetization processes of converting shale gas to polymers under the mixed uncertainties of feedstock compositions, estimated ultimate recovery, and economic parameters. A new stochastic data processing strategy is developed to quantify the feedstock variability through generating the appropriate number of scenarios. This strategy includes the Kriging-based surrogate model, sample average approximation and the integrated decline-stimulate analysis curve. The feedstock variability is then propagated through performing a detailed techno-economic modeling method on distributed-centralized conversion network systems. Uncertain economic parameters are incorporated into the stochastic model to estimate the maximum likelihood of performance objectives. The proposed strategy and models are illustrated in four case studies with different plant locations and pathway designs. The results highlight the benefits of the hybrid pathway as it is more amenable to reducing the economic risk of the projects. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-15T11:16:27.67898-05:0
      DOI: 10.1002/aic.16058
       
  • Extracting Dynamic Features with Switching Models for Process Data
           Analytics and Application in Soft Sensing
    • Authors: Yanjun Ma; Biao Huang
      Abstract: In recent decades, soft sensors have been profoundly studied and successfully applied to predict critical process variables in real-time. While dealing with various application scenarios, data-driven methods with representation learning possess great potentials. Latent features are formulated in these approaches to predict outputs from correlated input variables. In this study, a probabilistic framework of feature extraction is proposed in the context of process data analysis. To address switching behaviours in industrial processes, multiple emission models are utilized to construct latent space. To address temporal correlations from continuously operating processes, a dynamic model is implemented in latent space. Bayesian learning strategy is then developed for parameters estimation, where modelling preferences and uncertainties from multiple models are considered. The effectiveness and practicability of the proposed feature extraction algorithm are illustrated through numerical simulations, as well as an industrial case study. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-15T11:16:01.49727-05:0
      DOI: 10.1002/aic.16059
       
  • Dynamic Catalytic Adsorptive Desulfurization of Real Diesel over
           Ultra-Stable and Low-Cost Silica Gel supported TiO2
    • Authors: Xiaoling Ren; Zewei Liu, Lei Dong, Guang Miao, Neng Liao, Zhong Li, Jing Xiao
      Abstract: The work aims to develop dynamic ultra-deep catalytic adsorptive desulfurization of real diesel using ultra-stable and low-cost silica gel supported TiO2. A two-stage dynamic breakthrough model was built to describe the CADS process, varied with H/R ratio and O/S ratio. The desulfurization capacity reached 1.3 mg-S/g-A at the breakthrough concentration of 5 ppm-S. Various types of silica gel were screened as the substrate for TiO2, and the textural/acidic properties and CADS capacity were correlated in high relevancy. The effectiveness of diverse oxidants on CADS and the oxidation path were elucidated via combined experiment/simulation. Adsorption enthalpy derived from fitted isotherm data was calculated as 33.4 kJ/mol. The TiO2/silica gel-based sorbent demonstrated remarkable recyclability/stability in 10 cycles. This work provides an effective and economic route to eliminate the trace amount of stubborn sulfur compounds in low-sulfur diesel, which can be potentially implemented as the final polishing step for ultra-clean diesel production. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-14T10:35:44.823274-05:
      DOI: 10.1002/aic.16055
       
  • Towards a continuous synthesis of porous carbon xerogel beads
    • Authors: David Eskenazi; Patrick Kreit, Jean-Paul Pirard, Philippe Compère, Nathalie Job
      Abstract: A continuous process for producing porous carbon xerogel beads has been developed. It consists in injecting a pre-cured aqueous solution of resorcinol and formaldehyde on top of a column filled with hot oleic acid. The latter is pumped on the top of the column and fed at the bottom, generating an upward flow that can be adjusted to match the terminal velocity of the settling beads. Thus, the bead residence time in the column can be adjusted to match the gelation time, allowing the beads to solidify before reaching the bottom of the vessel. The obtained beads are subsequently dried and pyrolyzed.The developed experimental setup proved the continuous synthesis of porous carbon beads is possible. Nevertheless, the shaping process caused various texture changes of the porous carbon, which mainly yields macropores instead of micro and mesopores. This process also leads to the build-up of a denser skin around the beads. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-14T10:35:40.993442-05:
      DOI: 10.1002/aic.16056
       
  • Surface Nonuniformities in Latex Paints due to Evaporative Mechanisms
    • Authors: K.B. Sutton; C.B. Clemons, K.L. Kreider, J.P. Wilber, G.W. Young
      Abstract: A model is developed for predicting long-wavelength nonuniformities in the thickness of drying latex paint films. The model includes the effects of temperature, latex particle volume fraction, surface surfactant density, bulk surfactant density, and several material and environmental factors. After the model is simplified by applying the lubrication approximation, equations for spatially independent base state solutions are derived. The base state solutions describe a drying latex paint film of uniform thickness. The equations for the base states are solved numerically and a linear stability analysis is conducted. This analysis indicates that evaporation, slow surfactant kinetics, low initial surface tension, substrate permeability, and high initial latex particle volume fractions destabilize the uniform film, while fast surfactant kinetics, high initial surface tension, and high viscosity are stabilizing. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-14T10:35:33.285414-05:
      DOI: 10.1002/aic.16057
       
  • Multi-Dimensional Modeling of a Microfibrous Entrapped Cobalt Catalyst
           Fischer-Tropsch Reactor Bed
    • Authors: M. S. Challiwala; B. A. Wilhite, M. M. Ghouri, N. O. Elbashir
      Abstract: Thermal management of highly-exothermic Fischer-Tropsch-Synthesis has been a challenging bottleneck limiting the radial dimension of the Packed-Bed (PB) reactor tube to 1.5”-ID. In this work, a computational demonstration of a novel Microfibrous-Entrapped-Cobalt-Catalyst (MFECC) in mitigating hotspot formation has been evaluated. Specifically, a 2-D model was developed in COMSOL®, validated with experimental data and subsequently employed to demonstrate scale-up of the FTS bed from 0.59” – 4”ID. Significant hot-spot of 102.39 K in PB was reduced to 9.4 K in MFECC bed under gas-phase at 528.15 K and 2 MPa. Improvement in heat-transfer within the MFECC bed facilitates higher productivities at low space velocities (≥1000 1/h) corresponding to high CO-conversion (≥90%). Additionally, the MFECC reactor provides an 8-fold increase in the reactor ID at hotspots≤30 K with CO% conversions≥90%. This model was developed for a typical FTS cobalt-based catalyst where CO2 production is negligible. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-12T15:41:18.867483-05:
      DOI: 10.1002/aic.16053
       
  • Synthesis of Ni Nanoparticles with Controllable Magnetic Properties by
           Atmospheric Pressure Microplasma Assisted Process
    • Authors: Liangliang Lin; Sergey A. Starostin, R. Lavrijsen, Wei Zhang, Sirui Li, Volker Hessel
      Abstract: An atmospheric pressure microplasma technique is demonstrated for the gas phase synthesis of Ni nanoparticles by plasma-assisted nickelocene dissociation at different conditions. The dissociation process and the products are characterized by complementary analytical methods to establish the relationship between operational conditions and product properties. The innovation is to show proof-of-principle of a new synthesis route which offers access to less costly and less poisonous reactant, a higher quality product, and a simple, continuous and pre/post treatment-free manner with chance for fine-tuning “in-flight”. Results show that Ni nanoparticles with controllable magnetic properties are obtained, in which flexible adjustment of product properties can be achieved by tuning operational parameters. At the optimized condition only fcc Ni nanoparticles are formed, with saturation magnetization value of 44.4 mAm2/g. The upper limit of production rate for Ni nanoparticles is calculated as 4.65 × 10−3 g/h using a single plasma jet, but the process can be scaled-up through a microplasma array design. In addition, possible mechanisms for plasma-assisted nickelocene dissociation process are discussed. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-12T15:41:06.40549-05:0
      DOI: 10.1002/aic.16054
       
  • Model fitting of sorption kinetics data: Rectification of misapplications
           overlooked
    • Authors: Yifeng Huang; Muhammad U. Farooq, Shuixiu Lai, Panida Sampranpiboon, Xiaodong Wang, Wei Huang, Xianshe Feng
      Abstract: When the model fitting of sorption kinetics data was carried out using linearized pseudo second order rate equations based on constant Qe corresponding to equilibrium sorption, the instantaneous driving force for sorption was underestimated, resulting in an erroneous overestimation of the rate constant. To resolve the issue, a rectification of the model fitting was proposed by accounting for the concentration dependence of Qe in the model equation based on the fact that Qe in the equation represents the sorption capacity at that instant as sorption proceeded with time. The rectified approach was validated with experimental data for various sorption systems reported in the literature. It was shown that the rectification yielded true sorption rate constant that characterizes the relationship between sorption rate and solute concentration, thereby resolving the issues associated with the original approach where the specific rate constant was found to depend on solute concentration and sorption time. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-08T13:10:51.887542-05:
      DOI: 10.1002/aic.16051
       
  • Heat Transfer Characteristics of Polymer Hollow Fiber Heat Exchanger for
           Vaporization Application
    • Authors: Jun Liu; Hong Guo, Xingxing Zhi, Lei Han, Kai Xu, Hailei Li, Baoan Li
      Abstract: The heat transfer characteristics of polymer hollow fiber heat exchanger were investigated by analysing the heat transfer coefficient (HTC) and the heat transfer resistance (HTR) distributions of both the lumen side and the shell side. The influences of the fiber wall thickness and the polymer thermal conductivity on the heat transfer performance were studied numerically based on the experimental validated simulation model. It is found that the original overall HTC value is below 1032 W/m2·K and the HTR is focus on the fiber wall. However, if enhancing the polymer thermal conductivity to be higher than 1.0 W/m·K and/or lowering the fiber wall thickness to be less than 0.1 mm, the overall HTC could be improved to over 2000 W/m2·K, which indicates that the fiber wall HTR is no longer the limiting factor of the polymer hollow fiber heat exchanger applications. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-08T13:10:37.500975-05:
      DOI: 10.1002/aic.16049
       
  • Combined Effects of Soot Load and Catalyst Activity on the Regeneration
           Dynamics of Catalytic Diesel Particulate Filters
    • Authors: Valeria Di Sarli; Almerinda Di Benedetto
      Abstract: The combined effects of soot load and catalyst activity on the regeneration dynamics of a catalytic diesel particulate filter have been investigated through transient CFD-based simulations of soot combustion in a single-channel configuration. The soot load was changed by varying the amount of soot accumulated as cake layer, while keeping the amount of soot trapped inside the catalytic wall constant.Substantially uniform soot combustion that allows reasonably fast regeneration of the filter under controlled temperature conditions has been simulated only in the absence of cake and at relatively low catalyst activity. Conversely, in the presence of cake, numerical predictions have shown that, regardless of both soot load and catalyst activity, fast regeneration always occurs by propagation of sharp reaction fronts that result in high temperature rises.These findings highlight the importance of avoiding the cake formation, while properly optimizing the catalyst activity, to conduct an effective regeneration of catalytic filters. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-05T07:55:41.670631-05:
      DOI: 10.1002/aic.16047
       
  • An interfacial curvature distribution model and phase inversion
    • Authors: A. Vikhansky
      Abstract: The state of the two-phase system is described by the interfacial curvature distribution. A phenomenological closure model is proposed for the exact (unclosed) equations. Parameters of the model are related to the existing correlations for drop size in stirred flows. If water is dispersed in oil, the curvature has a uni-modal distribution with a positive mode. When a control parameter, e.g., water volume fraction is increasing, the distribution becomes bi-modal with both negative and positive values. After a while, the phase inversion occurs, and the distribution becomes uni-modal with a negative mode. Going in the other direction the phase inversion happens at lower volume fraction of water, i.e., there is an ambivalent region, where both phases might be in the dispersed state. The model implies, that even if the conditions for phase inversion are met, there might be a significant delay before the new morphology is established. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-06T17:50:21.172204-05:
      DOI: 10.1002/aic.15992
       
  • Modeling and Prediction of Protein Solubility using the Second Osmotic
           Virial Coefficient
    • Authors: Marcel Herhut; Christoph Brandenbusch, Gabriele Sadowski
      Abstract: The development of a precipitation or crystallization step requires knowing the solubility of the target protein and its crystallization behavior in aqueous solutions at different pH, temperatures and in the presence of precipitating agents, especially salts. Within this work, a solubility model for proteins based on the second osmotic virial coefficient B22 is developed. For this, a relation between protein solubility and B22 was combined with the extended DLVO model. This solubility model was then used to model and also predict the protein solubility of lysozyme and monoclonal antibody for different salts, salt concentrations, and pH. The modeled as well predicted B22 and protein solubility data of lysozyme in the presence of sodium chloride and sodium p-toluenesulfonate and of a monoclonal antibody in the presence of ammonium sulfate at different pH shows good agreement with experimental data. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-01T10:42:19.405106-05:
      DOI: 10.1002/aic.15944
       
  • Dissipative particle dynamic simulation on the assembly and release of
           siRNA/polymer/gold nanoparticles based polyplex
    • Authors: Xiaona Xie; Shouping Xu, Pihui Pi, Jiang Cheng, Xiufang Wen, Xuan Liu, Shengnian Wang
      Pages: 810 - 821
      Abstract: Dissipative particle dynamics simulation is used to reveal the loading/release of small interfering RNA (siRNA) in pH-sensitive polymers/gold nanoparticles (AuNPs) polyplex. The conformation dynamics of these polyplex at various Au/siRNA mass ratios, the original AuNPs sizes, polymer types, and pH values are simulated and compared to experimental results. At neutral conditions (pH = 7.4), spherical micelles with a multilayer structure are formed in siRNA/polyethyleneimine/cis-aconitic anhydride functionalized poly(allylamine)/polyethyleneimine/11-mercaptoundecanoic acid-gold nanoparticle (siRNA/PEI/PAH-Cit/PEI/MUA-AuNP) polyplex. Large polyplex are obtained with high Au/siRNA mass ratio and/or small original AuNPs size. The release dynamics of siRNA from AuNPs-polyplex systems were also simulated in the intracellular environment (pH = 5.0). A swelling-demicellization-releasing mechanism is followed while the release of siRNA is found much faster for polyplex involving charge-reversal PAH-Cit. These findings are qualitatively consistent with the experimental results and may provide valuable guidance in later design and optimization of delivery carriers for siRNA or other molecule probes. © 2017 American Institute of Chemical Engineers AIChE J, 64: 810–821, 2018
      PubDate: 2017-09-27T10:50:49.347443-05:
      DOI: 10.1002/aic.15961
       
  • Multiple order model migration and optimal model selection for online
           glucose prediction in Type 1 diabetes
    • Authors: Hong Zhao; Chunhui Zhao, Chengxia Yu, Eyal Dassau
      Pages: 822 - 834
      Abstract: To address the problem of insufficient available modeling data for glucose prediction, as well as modeling burden, a model migration method was developed in a previous work to quickly transfer an old model to a new subject using a simple parameter adjustment. However, this method, which is referred to as first-order model migration (FOMM), only considers a single order for each exogenous input, and may not produce an optimal model structure for accurate prediction. To overcome this problem, a multiple order model migration (MOMM) algorithm is proposed in this study. For different numbers of modeling samples, including glucose and two exogenous inputs (meal and insulin), the optimal modeling method may be different, and therefore, must be properly determined for each modeling scenario. First, the optimal model order is determined for each input and a multiple order prediction model is used. Then, a MOMM algorithm is developed based on particle swarm optimization (PSO) to simultaneously revise multiple parameters. The multiple order parameters of each input in the old model are quickly customized so that the revised model can be used for new subjects with desirable prediction accuracy. In particular, the influence of the number of modeling samples is analysed to check the applicability of different methods; this analysis determines the appropriate selection guidelines for the optimal model in response to different data sizes. The proposed method was evaluated using thirty in silico subjects and clinical data from seven individuals with Type 1 diabetes mellitus (DM). Overall, the MOMM algorithm presented superior results when the time period for collecting the samples was larger than 10 h (50 samples). In particular, the size of the modeling samples was separated into three different regions by evaluating the glucose prediction performance and the comparison between different algorithms for both in silico and clinical subjects. In Region I, the FOMM method achieves the best performance. In Region II, the MOMM method should be used and the prediction accuracy is superior in Region II in general. With enough samples (Region III), the subject-dependent model (SM) algorithm can be chosen. The MOMM algorithm is demonstrated to be able to transfer models for new subjects with improved model structure. © 2017 American Institute of Chemical Engineers AIChE J, 64: 822–834, 2018
      PubDate: 2017-10-06T13:25:25.566088-05:
      DOI: 10.1002/aic.15983
       
  • Anticancer drug delivery systems based on inorganic nanocarriers with
           fluorescent tracers
    • Authors: Jiangli Fan; Suzhen Wang, Wen Sun, Shigang Guo, Yao Kang, Jianjun Du, Xiaojun Peng
      Pages: 835 - 859
      Abstract: In recent years, anticancer nanomedicines have mainly been developed for chemotherapy and combination therapy in which the main contributing anticancer drugs are delivered by deliberately designed nano drug delivery systems (nano-DDSs). Inorganic nanocarriers equipped with fluorescent tracers have become attractive tools to monitor the whole drug delivery and release processes. The fluorescence signal of tracers could be observed concomitantly with drug release, and thus, this strategy is of great benefit to evaluate the therapeutic effects of the nano-DDSs. This review provides a brief overview about three inorganic nanocarriers for drug delivery, including mesoporous silica, Fe3O4, and hydroxyapatite. We mainly discussed about their preparation processes, drug loading capacities, and the development of different fluorescent materials (fluorescent dyes, quantum dots, fluorescent macromolecules, and rare earth metals) hybridized to nanocarriers for real-time monitoring of drug release both in vitro and in vivo. This review also provides some recommendations for more in-depth research in future. © 2017 American Institute of Chemical Engineers AIChE J, 64: 835–859, 2018
      PubDate: 2017-10-04T11:52:40.093992-05:
      DOI: 10.1002/aic.15976
       
  • Coproduction of acetic acid and hydrogen/power from natural gas with zero
           carbon dioxide emissions
    • Authors: Ibubeleye Somiari; Vasilios Manousiouthakis
      Pages: 860 - 876
      Abstract: A process plant flow sheet that coproduces acetic acid and hydrogen/power from natural gas with zero carbon dioxide emissions is developed. Two cases are explored: the production of acetic acid and hydrogen (Case 1) and the production of acetic acid and power (Case 2). This is realized by the selection of an appropriate reaction cluster whose sum results in the overall reaction that coproduces acetic acid and hydrogen/power. The concept of energetic self-sufficiency is introduced and it imposes constraints on the system defined in terms of the ratio of oxygen feed to acetic acid produced. Heat and power integration of the converged flow sheet reveals an operating range for each case that guarantees energetic self-sufficiency. Operating points are chosen to conduct a preliminary economic analysis and a carbon dioxide cost and performance metric calculation to quantify profitability and carbon capture potential of the overall process. © 2017 American Institute of Chemical Engineers AIChE J, 64: 860–876, 2018
      PubDate: 2017-09-26T12:20:28.987705-05:
      DOI: 10.1002/aic.15966
       
  • A pinch-like targeting framework for systematic thermal process
           intensification
    • Authors: Michael Baldea
      Pages: 877 - 885
      Abstract: The design of intensified systems remains an “Edisonian” effort, whereby new intensification schemes are the product of creativity rather than the result of applying systematic procedures. Under this motivation, this article presents a novel and systematic approach for identifying targets for thermal process intensification, defined as combining two or more heat sources and sinks present in a process flowsheet, possibly along with a thermal utility stream, in a single intensified device where heat exchange takes place. The targeting problem is formulated as a mixed-integer linear program. An extensive case study illustrating its application is presented. © 2017 American Institute of Chemical Engineers AIChE J, 64: 877–885, 2018
      PubDate: 2017-09-28T13:55:23.871585-05:
      DOI: 10.1002/aic.15971
       
  • Globally optimal linear approach for the design of process equipment: The
           case of air coolers
    • Authors: Priscila A. Souza; André L. H. Costa, Miguel J. Bagajewicz
      Pages: 886 - 903
      Abstract: In a recent article, Gonçalves et al., introduced a linear and rigorous methodology for equipment design, in particular shell-and-tube heat exchanger. Here, we explore its application to air coolers, a problem that we solve globally for the first time. Because the approach is linear, results are globally optimal. The objective function is the total annualized cost. The constraints include the thermal and hydraulic modeling of the process stream flow in the tube bundle and the air flow through the finned surface. In addition, we worked on reducing computing time, through an analysis of different alternatives for the description of the original discrete variables organized in sets of binary variables. The performance of the proposed approach is illustrated through its comparison with an air cooler described in the literature. © 2017 American Institute of Chemical Engineers AIChE J, 64: 886–903, 2018
      PubDate: 2017-10-20T13:35:41.608118-05:
      DOI: 10.1002/aic.15977
       
  • Model based analysis of lithium batteries considering particle-size
           distribution
    • Authors: E. R. Henquín; P. A. Aguirre
      Pages: 904 - 915
      Abstract: Performance of lithium ion batteries whose electrodes are composed of particles of different sizes is studied. Simplified model developed in (Henquín and Aguirre, AIChE J. 2015; 61:90–102) is extended and the simulations are compared with experiments from the literature so as to validate this new model. The differences in current density observed in particles of different sizes, which are in contact, depend on particle size and state of charge. Internal particle to particle discharge currents are observed during relaxation times. A parametric study of the applied current and particle sizes of electrodes is performed to evaluate cell performance, with emphasis on cell voltage and final capacity measurement. The evolution of reaction rates on the surface of electrode particles and their corresponding states of charge are depicted. An analysis of relaxation times in terms of cell voltage, current density, equilibrium potentials, and overpotentials is included. © 2017 American Institute of Chemical Engineers AIChE J, 64: 904–915, 2018
      PubDate: 2017-10-20T13:45:32.516852-05:
      DOI: 10.1002/aic.15990
       
  • A dynamic game theoretic framework for process plant competitive upgrade
           and production planning
    • Authors: Philip Tominac; Vladimir Mahalec
      Pages: 916 - 925
      Abstract: A dynamic potential game theoretic production planning framework is presented in which production plants are treated as individual competing entities and competition occurs dynamically over a discrete finite time horizon. A modified Cournot oligopoly with sticky prices provides the basis for dynamic game theoretic competition in a multimarket nonlinear and nonconvex production planning model wherein market price adapts to a value that clears cumulative market supply. The framework is used to investigate a petrochemical refining scenario in which a single inefficient refiner faces elimination by its competitors; we demonstrate that there exist conditions under which the threatened refiner may upgrade itself to become competitive and escape the threat, or alternatively in which the threat of elimination is illegitimate and the refiner is effectively safe in the given market configuration. Globally optimal dynamic Nash equilibrium production trajectories are presented for each case. © 2017 American Institute of Chemical Engineers AIChE J, 64: 916–925, 2018
      PubDate: 2017-10-26T10:06:42.559088-05:
      DOI: 10.1002/aic.15995
       
  • Target bounds on reaction selectivity via Feinberg's CFSTR equivalence
           principle
    • Authors: Jeffrey A. Frumkin; Michael F. Doherty
      Pages: 926 - 939
      Abstract: In this work, we show that the continuous flow stirred tank reactor (CFSTR) equivalence principle, developed by Feinberg and Ellison, can be used to obtain practical upper bounds on reaction selectivity for any chemistry of interest. The CFSTR equivalence principle allows one to explore the attainable reaction region by decomposing any arbitrary, steady-state reactor-mixer-separator system with total reaction volume V > 0 into a new system comprising R+1 CFSTRs (where R is the number of linearly independent chemical reactions) with the same total reaction volume and a perfect separator system. This work further refines the allowable selectivities by incorporating capacity constraints into the CFSTR equivalence principle to prevent arbitrarily large recycle streams between the CFSTRs and the separators and infinitesimally small CFSTR conversions. These constraints provide practical upper bounds on reaction selectivities of chemistries completely independent of reactor design. We present the methodology and the results for a selection of realistic chemistries. © 2017 American Institute of Chemical Engineers AIChE J, 64: 926–939, 2018
      PubDate: 2017-09-28T13:50:37.40773-05:0
      DOI: 10.1002/aic.15968
       
  • Catalytic combustion of SOFC stack flue gas over CuO and Mn2O3 supported
           by La0.8Sr0.2Mn0.67Cu0.33O3 perovskite
    • Authors: Jae Gi Sung; Taewook Kim, Han Kyu Jung, Hwan Kim, Jong Shik Chung
      Pages: 940 - 949
      Abstract: An efficient oxidation catalyst was developed to increase the combustion efficiency of unreacted CO, H2, and CH4 in flue gas of solid oxide fuel cell (SOFC) stack. Amorphous Cu-Mn oxide catalyst (CuMnLa/Alumina) showed high catalytic activity, but significant degradation occurred due to phase transition to spinel structure at high temperatures (T > 650°C). La0.8Sr0.2Mn0.67Cu0.33O3 perovskite (LSMC(p)) supported CuO or Mn2O3 exhibited improved thermal stability than CuMnLa/Alumina catalyst. Especially in case of 50Mn/LSMC(p), after the catalyst was exposed to 800°C for 24 h, T50 of CO, H2 and CH4 was achieved at 170, 230, and 600°C, respectively. This result is much lower than that of CuMnLa/Alumina, which was exposed to the same condition. The high combustion efficiency is due to retention of the Cu2+-Mn3+ redox couple, and supply of lattice oxygen from LSMC(p), especially at high temperature. © 2017 American Institute of Chemical Engineers AIChE J, 64: 940–949, 2018
      PubDate: 2017-10-06T13:20:28.604687-05:
      DOI: 10.1002/aic.15980
       
  • Understanding interfacial behaviors of isobutane alkylation with C4 olefin
           catalyzed by sulfuric acid or ionic liquids
    • Authors: Weizhong Zheng; Huanying Wang, Wenxiu Xie, Ling Zhao, Weizhen Sun
      Pages: 950 - 960
      Abstract: The interfacial properties between the hydrocarbon phase including isobutane and 2-butene and the catalyst phase including H2SO4 or ionic liquids (ILs) with various alkyl chain length on their imidazolium cations have been investigated using molecular dynamics (MD) simulations. Compared to H2SO4, ILs can obviously improve the interfacial width, solubility and diffusion of reactants at the interface. The ILs with longer chains on cations exhibit a significant density enrichment of alkyl chains at the interface and tend to orient themselves with alkyl chains perpendicular to the interface and protruding into the reactant phase, which is in good agreement with the van der Waals energy between the reactants and cations of the ILs. The ILs with longer chains can improve the interfacial width and facilitate the dissolution of isobutane in catalyst phase, and thus exhibit a better catalytic performance, which agrees well with alkylation experiments in this work. © 2017 American Institute of Chemical Engineers AIChE J, 64: 950–960, 2018
      PubDate: 2017-10-10T10:25:47.954127-05:
      DOI: 10.1002/aic.15984
       
  • Iron-based electrochemically mediated atom transfer radical polymerization
           with tunable catalytic activity
    • Authors: Jun-Kang Guo; Yin-Ning Zhou, Zheng-Hong Luo
      Pages: 961 - 969
      Abstract: An iron-based electrochemically mediated atom transfer radical polymerization (eATRP) system with tunable catalytic activity was developed by adjusting the supporting electrolyte formula. Kinetic behaviors of the systems using four typical supporting electrolytes (namely, TBABr, TBAPF6, TBACl, and TBABF4) were investigated. The type of anions was found to significantly affect the polymerization kinetics. TBAPF6 system proceeded with a considerable polymerization rate, whereas TBABr system showed better controllability. Importantly, the effect of supporting electrolyte on eATRP kinetics (mainly on ATRP equilibrium) was confirmed through kinetic modeling. Furthermore, the effect of catalyst loading using TBAPF6 as supporting electrolyte was also studied, and the results showed an uncontrolled polymerization for catalyst loading lower than 500 ppm. When hybrid supporting electrolyte (TBAPF6/TBABr) was used to tune catalytic activity, the polymerization slows down and the dispersity decreases with the increase in TBABr ratio. Polymers with a narrow molecular weight distribution (dispersity index
      PubDate: 2017-10-12T17:00:24.347221-05:
      DOI: 10.1002/aic.15978
       
  • Enhanced solubility of hydrogen and carbon monoxide in propane- and
           propylene-expanded liquids
    • Authors: Dupeng Liu; Raghunath V. Chaudhari, Bala Subramaniam
      Pages: 970 - 980
      Abstract: Conventional propylene hydroformylation occurs in a gas-expanded liquid phase. Reliable knowledge of the phase equilibria of such systems, including the solubilities of CO and H2 in propylene-expanded solvents, is essential for rational process design and development. Herein, we report the vapor–liquid equilibrium (VLE) data of the following ternary systems involving CO, H2, propane, propylene, toluene and NX-795 at temperatures from 70 to 90°C and pressures up to 1.5 MPa: propane/H2/toluene, propane/CO/toluene, propylene/H2/toluene, propylene/CO/toluene, propane/H2/NX-795, propane/CO/NX-795, propylene/H2/NX-795 and propylene/CO/NX-795. The solubilities of H2 and CO in either propane-expanded or propylene-expanded phases are observed to be greater than those in the neat organic solvents, by as high as 78% at 70°C and 1.5 MPa. By modeling the vapor and the liquid phases as pseudo-binary systems, the Peng-Robinson equation of state (PR-EoS) with van der Waals’ mixing rules and binary interaction parameters is shown to satisfactorily predict the experimental VLE data. © 2017 American Institute of Chemical Engineers AIChE J, 64: 970–980, 2018
      PubDate: 2017-10-16T19:55:47.073684-05:
      DOI: 10.1002/aic.15988
       
  • The promotion of Argon and water molecule on direct synthesis of H2O2 from
           H2 and O2
    • Authors: Yanhui Yi; Li Wang, Juan Yu, Hongchen Guo, Jialiang Zhang, Changgong Meng
      Pages: 981 - 992
      Abstract: Direct synthesis of hydrogen peroxide (H2O2) from H2 and O2 is an ideal route. H2/O2 plasma has a great potential for direct synthesis of high purity H2O2 without purification operations. However, low yield and high energy consumption limits the application of H2/O2 plasma in industry. This article reports that gas state Ar and H2O molecule serving as molecular catalysts promoted the synthesis of H2O2 from H2/O2/Ar/H2O plasma dramatically: the H2O2 yield was enhanced by 244% and the energy consumption was reduced by 70.9%. Ar not only increased the electron density, but also selectively accelerated the dissociation of H2 toward the formation of •HO2, a key intermediate species in H2O2 synthesis. While H2O facilitated the formation of •HO2 radical and stabilized it by forming a HO2•H2O complex, resulting in enhancing the H2O2 production. This single molecular catalysis reduced the cost of H2O2 synthesis more than 50%. © 2017 American Institute of Chemical Engineers AIChE J, 64: 981–992, 2018
      PubDate: 2017-10-23T09:26:29.880094-05:
      DOI: 10.1002/aic.15999
       
  • Surface layer modification of AEMs by infiltration and photo-cross-linking
           to induce monovalent selectivity
    • Authors: Huimin Liu; Yuliang Jiang, Jincheng Ding, Wenhui Shi, Jiefeng Pan, Congjie Gao, Jiangnan Shen, Bart van der Bruggen
      Pages: 993 - 1000
      Abstract: Surface modification of anion exchange membranes (AEMs) by attaching a negatively charged layer is the main method for preparing monovalent anion selective membranes. However, tremendous increase of membrane resistance and poor long-term stability of the modified membranes face great challenges. In this work, a photosensitive molecule (4,4-diazostilbene-2,2-disulfonic acid disodium salt [DAS]) was infiltrated into the membrane surface and immobilized in the structure by cross-linking under UV irradiation. This method introduced negative charge to the surface layer of the AEMs without increasing membrane thickness, leading to high performance membrane with high monovalent anion selectivity. The optimized membrane (D-5) shows the highest perm-selectivity of 11.21, which is superior to the commercial selective membrane Selemion® ASV and previously reported monovalent anion selective AEMs. Furthermore, the newly developed membrane exhibits excellent long-term stability, which can maintain constant selectivity during the 80 h ED experiment. © 2017 American Institute of Chemical Engineers AIChE J, 64: 993–1000, 2018
      PubDate: 2017-09-28T13:50:25.492116-05:
      DOI: 10.1002/aic.15975
       
  • Numerical prediction of dust capture efficiency of a centrifugal wet
           scrubber
    • Authors: Hassan Ali; Floren Plaza, Anthony Mann
      Pages: 1001 - 1012
      Abstract: The gas, liquid, and dust particle behavior inside a centrifugal wet scrubber was simulated and a submodel for predicting its collection efficiency was developed that also takes in account the reduction in collection efficiency due to droplet carryover. Centrifugal wet scrubbers are used in many industries and deliver a high scrubbing efficiency at relatively low capital and operational costs. However, they often experience problems such as droplet carryover at high gas flows and reduced collection efficiency at low gas flows. An improved understanding of flow processes inside the scrubbers is needed to develop a better scrubber design. An experimental test facility was setup for this purpose which also served to validate the CFD modeling results. Ideal operating parameters for maximum scrubbing efficiency and minimum droplet carryover were identified. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1001–1012, 2018
      PubDate: 2017-10-05T13:50:37.417819-05:
      DOI: 10.1002/aic.15979
       
  • Computer-aided design of ionic liquids as solvents for extractive
           desulfurization
    • Authors: Zhen Song; Chenyue Zhang, Zhiwen Qi, Teng Zhou, Kai Sundmacher
      Pages: 1013 - 1025
      Abstract: Although ionic liquids (ILs) have been widely explored as solvents for extractive desulfurization (EDS) of fuel oils, systematic studying of the optimal design of ILs for this process is still scarce. The UNIFAC-IL model is extended first to describe the EDS system based on exhaustive experimental data. Then, based on the obtained UNIFAC-IL model and group contribution models for predicting the melting point and viscosity of ILs, a mixed-integer nonlinear programming (MINLP) problem is formulated for the purpose of computer-aided ionic liquid design (CAILD). The MINLP problem is solved to optimize the liquid-liquid extraction performance of ILs in a given multicomponent model EDS system, under consideration of constraints regarding the IL structure, thermodynamic and physical properties. The top five IL candidates preidentified from CAILD are further evaluated by means of process simulation using ASPEN Plus. Thereby, [C5MPy][C(CN)3] is identified as the most suitable solvent for EDS. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1013–1025, 2018
      PubDate: 2017-10-19T10:20:28.675272-05:
      DOI: 10.1002/aic.15994
       
  • A thermodynamic investigation of adsorbate-adsorbate interactions of
           carbon dioxide on nanostructured carbons
    • Authors: Maxwell Murialdo; Channing C. Ahn, Brent Fultz
      Pages: 1026 - 1033
      Abstract: A thermodynamic study of carbon dioxide adsorption on a zeolite-templated carbon (ZTC), a superactivated carbon (MSC-30), and an activated carbon (CNS-201) was carried out at temperatures from 241 to 478 K and pressures up to 5.5•106 Pa. Excess adsorption isotherms were fitted with generalized Langmuir-type equations, allowing the isosteric heats of adsorption and adsorbed-phase heat capacities to be obtained as a function of absolute adsorption. On MSC-30, a superactivated carbon, the isosteric heat of carbon dioxide adsorption increases with occupancy from 19 to 21 kJ•mol−1, before decreasing at high loading. This increase is attributed to attractive adsorbate–adsorbate intermolecular interactions as evidenced by the slope and magnitude of the increase in isosteric heat and the adsorbed-phase heat capacities. An analysis of carbon dioxide adsorption on ZTC indicates a high degree of binding-site homogeneity. A generalized Law of Corresponding States analysis indicates lower carbon dioxide adsorption than expected. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1026–1033, 2018
      PubDate: 2017-10-19T10:15:23.922823-05:
      DOI: 10.1002/aic.15996
       
  • Mixing processes in the cavity transfer mixer: A thorough study
    • Authors: Giovanna Grosso; Martien A. Hulsen, Arash Sarhangi Fard, Andrew Overend, Patrick D. Anderson
      Pages: 1034 - 1048
      Abstract: In many industrial applications, the quality of mixing between different materials is fundamental to guarantee the desired properties of products. However, properly modeling and understanding polymer mixing presents noticeable difficulties, because of the variety and complexity of the phenomena involved. This is also the case with the Cavity Transfer Mixer (CTM), an add-on to be mounted downstream of existing extruders, to improve distributive mixing. The present work proposes a fully three-dimensional model of the CTM: a finite element solver provides the transient velocity field, which is used in the mapping method implementation to compute the concentration field evolution and quantify mixing. Several simulations are run assessing the impact on mixing of geometrical and functioning parameters. In general, the number of cavities per row should be limited and the cavity size rather big to guarantee good mixing quality. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1034–1048, 2018
      PubDate: 2017-10-11T09:56:46.702496-05:
      DOI: 10.1002/aic.15986
       
  • A mesoscale model for diffusion and permeation of shale gas at geological
           depth
    • Authors: Tiexin Tong; Dapeng Cao
      Pages: 1059 - 1066
      Abstract: The demand on energy is rising and shale gas as an important unconventional energy resource has received worldwide attention. It has shown a significant effect on the world's energy structure after the commercial exploitation of shale gas in the United States. Understanding diffusion and permeation of shale gas at geological depths is quite essential, but it cannot be described by traditional Fick or Knudsen diffusion models. In this work, we use dual control volume–grand canonical molecular dynamics method to systematically investigate the permeation process of shale gas in montmorillonite (i.e., a clay mineral of shale) at different geological depths. Results indicate that temperature, pressure, and pore size have an important effect on the permeability, and Knudsen equation cannot describe the permeability of shale gas. Accordingly, on the basis of these simulated data, we propose a new mesoscale model to describe the permeability of shale gas at geological depths. The new mesoscale model shows extensive applicability and can excellently reproduce the extrapolation testing data, and it satisfactorily bridges the gap between Knudsen diffusion and Fick diffusion, which provides important fundamentals for exploitation of shale gas. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1059–1066, 2018
      PubDate: 2017-10-10T10:25:26.61166-05:0
      DOI: 10.1002/aic.15982
       
  • Detailed thermodynamics for analysis and design of Ranque-Hilsch vortex
           tubes
    • Authors: John P. O'Connell
      Pages: 1067 - 1074
      Abstract: The Ranque-Hilsch vortex tube is a device for continuously separating an inlet pressurized fluid stream into two outlet streams of warmer and cooler temperatures at lower pressures, with no moving parts and without any heat or work effects. It has been applied to cool or heat small systems where refrigeration is impractical. Studies of the fluid mechanics inside the tube have not fully established the flow structure that provides the separation. Thermodynamic energy and entropy balances giving relations among properties and the relative amounts of the three fluid streams have been examined to determine consistency among measured data along with sensitivity of the phenomena to tube configuration, measurement error, and properties. The strong response of the temperature separation to small variations in entropy generation is shown to limit the possibilities for generalized prediction of vortex tube behavior. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1067–1074, 2018
      PubDate: 2017-10-20T13:50:56.51523-05:0
      DOI: 10.1002/aic.15985
       
  • Flow dynamics in Taylor–Couette flow reactor with axial distribution
           of temperature
    • Authors: Hayato Masuda; Saho Yoshida, Takafumi Horie, Naoto Ohmura, Makoto Shimoyamada
      Pages: 1075 - 1082
      Abstract: In this study, the flow dynamics of a Taylor–Couette flow with an axial distribution of temperature was experimentally investigated. The flow can be classified into three patterns based on the balance between the centrifugal force and the buoyancy. If the buoyancy is dominant, global heat convection is observed instead of Taylor vortices (Case I). When the buoyancy is comparable to the centrifugal force, the Taylor vortices and global heat convection appear alternately (Case II). If the centrifugal force is sufficiently high to suppress the buoyancy, stable Taylor vortices are observed (Case III). The characteristics of the mixing/diffusion are investigated by conducting a decolorization experiment on a passive tracer. In Case II, the tracer is rapidly decolorized in the presence of the global heat convection instead of the Taylor vortices. This result implies that the interaction between the centrifugal force and the buoyancy would induce an anomalous transport. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1075–1082, 2018
      PubDate: 2017-09-28T14:20:40.131346-05:
      DOI: 10.1002/aic.15972
       
  • A new insight into the stability of variable viscosity diffusive boundary
           layers in porous media under gravity field
    • Authors: Nasser Sabet; Hassan Hassanzadeh, Jalal Abedi
      Pages: 1083 - 1094
      Abstract: We study the stability of gravitationally unstable transient diffusive boundary layers with variable viscosity in porous media. The previous studies characterize the effect of viscosity variation only in terms of viscosity contrast and generalize their findings. However, conclusions of different studies seem contradictory. Our results demonstrate that stability of diffusive fronts is governed by the boundary layer viscosity and not solely by the viscosity contrast. In other words, the use of viscosity contrast to ascertain the stability of the system cannot be generalized. Nonlinear simulations are conducted based on a finite difference scheme to validate the results of linear stability analysis for which the amplification theory is adopted. We also revisit other available scaling approaches used to characterize the effect of viscosity variation on the onset of convective dissolution and explain why previously made conclusions are not inclusive and sometimes appeared to be contradictory. A critical Rayleigh number is found to predict stability of Rayleigh-Darcy convection in a porous layer with variable viscosity. The results reveal that this critical value can differ highly from the conventional value of 4π2. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1083–1094, 2018
      PubDate: 2017-09-28T14:20:33.458717-05:
      DOI: 10.1002/aic.15974
       
  • A multicontinuum approach for the problem of filtration of oily-water
           systems across thin flat membranes: II. Validation and examples
    • Authors: Amgad Salama; Mohamed Zoubeik, Amr Henni
      Pages: 1095 - 1105
      Abstract: In this second part, a validation exercise is conducted to investigate the accuracy of the multicontinuum approach in estimating the permeation capacity of membranes used for the filtration of oily-water systems. Comparisons with the experimental works found in the literature reveals that the multicontinuum approach is quite accurate and show excellent match. Although the comparisons with the experimental data have been with respect to macroscopic integral variables, like the rejection capacity of membranes, the multicontinuum approach provides myriad information about the permeation process that have neither been presented nor even measured. Such detailed information has been highlighted in two examples. Details about which of the oil continua is going to be rejected or permeated through which porous membrane continuum are obtained. Furthermore, the flux of each oil continuum through every porous membrane continua is likewise obtained. These informations are then lumped to calculate the rejection capacity of membranes. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1095–1105, 2018
      PubDate: 2017-10-05T09:46:04.574854-05:
      DOI: 10.1002/aic.15970
       
  • Characterization of liquid–liquid mass transfer performance in a
           capillary microreactor system
    • Authors: Guangxiao Li; Minjing Shang, Yang Song, Yuanhai Su
      Pages: 1106 - 1116
      Abstract: Liquid–liquid mass transfer performance in a capillary microreactor system was studied with an improved experimental method. Proper sampling modes were chosen to eliminate the effect of the sampling zone on the mass transfer characterization in capillary microreactor systems. The overall volumetric mass transfer coefficients in the T-micromixer and the capillary microreactor system were found to smoothly increase and then significantly increase with increasing the Reynolds number of two immiscible liquid phases. Other factors such as the inlet mode and inner diameter of T-micromixer, the capillary length, and the volumetric flux ratio of the aqueous phase to the organic phase affected the mass transfer performance in the T-micromixer and the capillary microreactor system. Furthermore, the contribution of the mass transfer in the T-micromixer zone to the capillary microreactor system was found to be in a range of 34–78% under the involved experimental conditions, which was emphasized in the proposed empirical correlations. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1106–1116, 2018
      PubDate: 2017-10-10T10:21:05.15097-05:0
      DOI: 10.1002/aic.15973
       
  • Packaging of yield stress fluids: Flow patterns
    • Authors: Fanny Rasschaert; Emeline Talansier, Didier Blésès, Albert Magnin, Maud Lambert
      Pages: 1117 - 1126
      Abstract: The packaging or filling of a container with a non-Newtonian fluid without quality failures is a current issue encountered at the final step of industrial product processes. In this work, the container filling of viscoplastic fluids is studied using an experimental laboratory plant able to reproduce the industrial transitory packaging conditions. First, a Newtonian validation was conducted to compare and to confirm our setup results with available literature data. Second five flow patterns including dripping, jet buckling, mounding, planar filling, and air entrainment were observed and characterized for the viscoplastic container filling. Most of them present different types of instabilities during the filling, except the planar filling, which seems to be ideal according to industrial specifications. A flow pattern distribution depending on relevant dimensionless numbers was developed. Finally, flow pattern transition criteria are determined highlighting the influence of rheological and process parameters on container filling. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1117–1126, 2018
      PubDate: 2017-10-16T19:25:56.086479-05:
      DOI: 10.1002/aic.15989
       
  • Synergistic effects of sulfur poisoning and gas diffusion on polarization
           loss in anodes of solid oxide fuel cells
    • Authors: Yinghua Niu; Weiqiang Lv, Zhaohuan Wei, Weirong Huo, Weidong He
      Pages: 1127 - 1134
      Abstract: Poisoning effects of sulfur compounds on the performances of solid oxide fuel cells are non-trivial. However, the synergistic effects of gas diffusion, adsorption, desorption and reaction in anodes are typically neglected. In this work, an analytical model is derived to quantitatively evaluate the poisoning effects of H2S. The results show that sulfur poisoning correlates closely with inefficient gas diffusion for small anode pore size, small porosity/tortuosity, and low working temperatures. As compared with concentration polarization, H2S-diffusion-induced activation polarization in thin anodes with a large ɛτ is detrimental, especially for low-temperature operations with a high H2S concentration and a low current density. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1127–1134, 2018
      PubDate: 2017-10-23T09:25:32.1428-05:00
      DOI: 10.1002/aic.15997
       
  • Pressure drop through platinized titanium porous electrodes for
           cerium-based redox flow batteries
    • Authors: Luis F. Arenas; Carlos Ponce de León, Frank C. Walsh
      Pages: 1135 - 1146
      Abstract: The pressure drop, ΔP, across a redox flow battery is linked to pumping costs and energy efficiency, making fluid properties of the electrolyte important in scale-up operations. The ΔP at diverse platinized titanium electrodes in Ce-based redox flow batteries is reported as a function of mean linear electrolyte velocity measured in a rectangular channel flow cell. Darcy's friction factor and permeability vs. Reynolds number are calculated. Average permeability values are: 7.10 × 10−4 cm2 for Pt/Ti mesh, 4.45 × 10−4 cm2 for Pt/Ti plate + turbulence promoters, 1.67 × 10−5 cm2 for Pt/Ti micromesh, and 1.31 × 10−6 cm2 for Pt/Ti felt. The electrochemical volumetric mass transport coefficient, kmAe, is provided as a function of ΔP. In the flow-by configuration, Pt/Ti felt combines high kmAe values with a relatively high ΔP, followed by Pt/Ti micromesh. Pt/Ti mesh and Pt/Ti plate gave a lower ΔP but poorer electrochemical performance. Implications for cell design are discussed. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1135–1146, 2018
      PubDate: 2017-10-25T08:05:46.053125-05:
      DOI: 10.1002/aic.16000
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-