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Publisher: John Wiley and Sons   (Total: 1579 journals)

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Showing 1 - 200 of 1579 Journals sorted alphabetically
Abacus     Hybrid Journal   (Followers: 12, SJR: 0.48, h-index: 22)
About Campus     Hybrid Journal   (Followers: 5)
Academic Emergency Medicine     Hybrid Journal   (Followers: 65, SJR: 1.385, h-index: 91)
Accounting & Finance     Hybrid Journal   (Followers: 46, SJR: 0.547, h-index: 30)
ACEP NOW     Free   (Followers: 1)
Acta Anaesthesiologica Scandinavica     Hybrid Journal   (Followers: 51, SJR: 1.02, h-index: 88)
Acta Archaeologica     Hybrid Journal   (Followers: 153, SJR: 0.101, h-index: 9)
Acta Geologica Sinica (English Edition)     Hybrid Journal   (Followers: 3, SJR: 0.552, h-index: 41)
Acta Neurologica Scandinavica     Hybrid Journal   (Followers: 5, SJR: 1.203, h-index: 74)
Acta Obstetricia et Gynecologica Scandinavica     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 81)
Acta Ophthalmologica     Hybrid Journal   (Followers: 5, SJR: 0.112, h-index: 1)
Acta Paediatrica     Hybrid Journal   (Followers: 56, SJR: 0.794, h-index: 88)
Acta Physiologica     Hybrid Journal   (Followers: 6, SJR: 1.69, h-index: 88)
Acta Polymerica     Hybrid Journal   (Followers: 9)
Acta Psychiatrica Scandinavica     Hybrid Journal   (Followers: 35, SJR: 2.518, h-index: 113)
Acta Zoologica     Hybrid Journal   (Followers: 6, SJR: 0.459, h-index: 29)
Acute Medicine & Surgery     Hybrid Journal   (Followers: 4)
Addiction     Hybrid Journal   (Followers: 35, SJR: 2.086, h-index: 143)
Addiction Biology     Hybrid Journal   (Followers: 13, 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: 50, SJR: 5.21, h-index: 203)
Advanced Healthcare Materials     Hybrid Journal   (Followers: 13, SJR: 0.232, h-index: 7)
Advanced Materials     Hybrid Journal   (Followers: 258, SJR: 9.021, h-index: 345)
Advanced Materials Interfaces     Hybrid Journal   (Followers: 6, SJR: 1.177, h-index: 10)
Advanced Optical Materials     Hybrid Journal   (Followers: 5, SJR: 2.488, h-index: 21)
Advanced Science     Open Access   (Followers: 5)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17, SJR: 2.729, h-index: 121)
Advances in Polymer Technology     Hybrid Journal   (Followers: 13, SJR: 0.344, h-index: 31)
Africa Confidential     Hybrid Journal   (Followers: 19)
Africa Research Bulletin: Economic, Financial and Technical Series     Hybrid Journal   (Followers: 12)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 9)
African Development Review     Hybrid Journal   (Followers: 34, SJR: 0.275, h-index: 17)
African J. of Ecology     Hybrid Journal   (Followers: 15, SJR: 0.477, h-index: 39)
Aggressive Behavior     Hybrid Journal   (Followers: 15, SJR: 1.391, h-index: 66)
Aging Cell     Open Access   (Followers: 10, SJR: 4.374, h-index: 95)
Agribusiness : an Intl. J.     Hybrid Journal   (Followers: 6, SJR: 0.627, h-index: 14)
Agricultural and Forest Entomology     Hybrid Journal   (Followers: 15, SJR: 0.925, h-index: 43)
Agricultural Economics     Hybrid Journal   (Followers: 45, SJR: 1.099, h-index: 51)
AIChE J.     Hybrid Journal   (Followers: 30, SJR: 1.122, h-index: 120)
Alcoholism and Drug Abuse Weekly     Hybrid Journal   (Followers: 7)
Alcoholism Clinical and Experimental Research     Hybrid Journal   (Followers: 7, SJR: 1.416, h-index: 125)
Alimentary Pharmacology & Therapeutics     Hybrid Journal   (Followers: 33, SJR: 2.833, h-index: 138)
Alimentary Pharmacology & Therapeutics Symposium Series     Hybrid Journal   (Followers: 3)
Allergy     Hybrid Journal   (Followers: 50, SJR: 3.048, h-index: 129)
Alternatives to the High Cost of Litigation     Hybrid Journal   (Followers: 3)
American Anthropologist     Hybrid Journal   (Followers: 140, 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: 90, SJR: 2.325, h-index: 51)
American J. of Economics and Sociology     Hybrid Journal   (Followers: 28, SJR: 0.211, h-index: 26)
American J. of Hematology     Hybrid Journal   (Followers: 33, SJR: 1.761, h-index: 77)
American J. of Human Biology     Hybrid Journal   (Followers: 12, SJR: 1.018, h-index: 58)
American J. of Industrial Medicine     Hybrid Journal   (Followers: 16, SJR: 0.993, h-index: 85)
American J. of Medical Genetics Part A     Hybrid Journal   (Followers: 16, 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: 37, SJR: 1.41, h-index: 88)
American J. of Political Science     Hybrid Journal   (Followers: 271, SJR: 5.101, h-index: 114)
American J. of Primatology     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 63)
American J. of Reproductive Immunology     Hybrid Journal   (Followers: 3, SJR: 1.347, h-index: 75)
American J. of Transplantation     Hybrid Journal   (Followers: 17, SJR: 2.792, h-index: 140)
American J. on Addictions     Hybrid Journal   (Followers: 9, SJR: 0.843, h-index: 57)
Anaesthesia     Hybrid Journal   (Followers: 131, SJR: 1.404, h-index: 88)
Analyses of Social Issues and Public Policy     Hybrid Journal   (Followers: 10, SJR: 0.397, h-index: 18)
Analytic Philosophy     Hybrid Journal   (Followers: 16)
Anatomia, Histologia, Embryologia: J. of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3, SJR: 0.295, h-index: 27)
Anatomical Sciences Education     Hybrid Journal   (Followers: 1, SJR: 0.633, h-index: 24)
Andrologia     Hybrid Journal   (Followers: 2, SJR: 0.528, h-index: 45)
Andrology     Hybrid Journal   (Followers: 2, SJR: 0.979, h-index: 14)
Angewandte Chemie     Hybrid Journal   (Followers: 169)
Angewandte Chemie Intl. Edition     Hybrid Journal   (Followers: 216, SJR: 6.229, h-index: 397)
Animal Conservation     Hybrid Journal   (Followers: 38, 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: 47, SJR: 5.584, h-index: 241)
Annals of Noninvasive Electrocardiology     Hybrid Journal   (Followers: 2, SJR: 0.531, h-index: 38)
Annals of Public and Cooperative Economics     Hybrid Journal   (Followers: 9, SJR: 0.336, h-index: 23)
Annals of the New York Academy of Sciences     Hybrid Journal   (Followers: 5, SJR: 2.389, h-index: 189)
Annual Bulletin of Historical Literature     Hybrid Journal   (Followers: 13)
Annual Review of Information Science and Technology     Hybrid Journal   (Followers: 14)
Anthropology & Education Quarterly     Hybrid Journal   (Followers: 25, SJR: 0.72, h-index: 31)
Anthropology & Humanism     Hybrid Journal   (Followers: 17, SJR: 0.137, h-index: 3)
Anthropology News     Hybrid Journal   (Followers: 15)
Anthropology of Consciousness     Hybrid Journal   (Followers: 11, SJR: 0.172, h-index: 5)
Anthropology of Work Review     Hybrid Journal   (Followers: 11, SJR: 0.256, h-index: 5)
Anthropology Today     Hybrid Journal   (Followers: 91, SJR: 0.545, h-index: 15)
Antipode     Hybrid Journal   (Followers: 47, SJR: 2.212, h-index: 69)
Anz J. of Surgery     Hybrid Journal   (Followers: 7, SJR: 0.432, h-index: 59)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apmis     Hybrid Journal   (Followers: 1, SJR: 0.855, h-index: 73)
Applied Cognitive Psychology     Hybrid Journal   (Followers: 69, SJR: 0.754, h-index: 69)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7, SJR: 0.632, h-index: 58)
Applied Psychology     Hybrid Journal   (Followers: 176, SJR: 1.023, h-index: 64)
Applied Psychology: Health and Well-Being     Hybrid Journal   (Followers: 49, SJR: 0.868, h-index: 13)
Applied Stochastic Models in Business and Industry     Hybrid Journal   (Followers: 5, SJR: 0.613, h-index: 24)
Aquaculture Nutrition     Hybrid Journal   (Followers: 14, SJR: 1.025, h-index: 55)
Aquaculture Research     Hybrid Journal   (Followers: 31, SJR: 0.807, h-index: 60)
Aquatic Conservation Marine and Freshwater Ecosystems     Hybrid Journal   (Followers: 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: 27, 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: 25, SJR: 0.261, h-index: 9)
Archiv der Pharmazie     Hybrid Journal   (Followers: 4, SJR: 0.628, h-index: 43)
Archives of Drug Information     Hybrid Journal   (Followers: 4)
Archives of Insect Biochemistry and Physiology     Hybrid Journal   (SJR: 0.768, h-index: 54)
Area     Hybrid Journal   (Followers: 12, SJR: 0.938, h-index: 57)
Art History     Hybrid Journal   (Followers: 238, SJR: 0.153, h-index: 13)
Arthritis & Rheumatology     Hybrid Journal   (Followers: 51, 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: 14)
Asia & the Pacific Policy Studies     Open Access   (Followers: 15)
Asia Pacific J. of Human Resources     Hybrid Journal   (Followers: 314, 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   (SJR: 0.394, h-index: 7)
Asian J. of Organic Chemistry     Hybrid Journal   (Followers: 5, SJR: 1.443, h-index: 19)
Asian J. of Social Psychology     Hybrid Journal   (Followers: 5, SJR: 0.665, h-index: 37)
Asian Politics and Policy     Hybrid Journal   (Followers: 12, SJR: 0.207, h-index: 7)
Asian Social Work and Policy Review     Hybrid Journal   (Followers: 5, SJR: 0.318, h-index: 5)
Asian-pacific Economic Literature     Hybrid Journal   (Followers: 5, SJR: 0.168, h-index: 15)
Assessment Update     Hybrid Journal   (Followers: 4)
Astronomische Nachrichten     Hybrid Journal   (Followers: 2, SJR: 0.701, h-index: 40)
Atmospheric Science Letters     Open Access   (Followers: 29, SJR: 1.332, h-index: 27)
Austral Ecology     Hybrid Journal   (Followers: 14, 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: 7, SJR: 0.39, h-index: 22)
Australian & New Zealand J. of Statistics     Hybrid Journal   (Followers: 13, SJR: 0.275, h-index: 28)
Australian Accounting Review     Hybrid Journal   (Followers: 4, SJR: 0.709, h-index: 14)
Australian and New Zealand J. of Family Therapy (ANZJFT)     Hybrid Journal   (Followers: 3, SJR: 0.382, h-index: 12)
Australian and New Zealand J. of Obstetrics and Gynaecology     Hybrid Journal   (Followers: 46, SJR: 0.814, h-index: 49)
Australian and New Zealand J. of Public Health     Hybrid Journal   (Followers: 11, SJR: 0.82, h-index: 62)
Australian Dental J.     Hybrid Journal   (Followers: 7, SJR: 0.482, h-index: 46)
Australian Economic History Review     Hybrid Journal   (Followers: 4, SJR: 0.171, h-index: 12)
Australian Economic Papers     Hybrid Journal   (Followers: 29, 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: 14, 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: 406, SJR: 0.418, h-index: 29)
Australian J. of Rural Health     Hybrid Journal   (Followers: 5, SJR: 0.43, h-index: 34)
Australian Occupational Therapy J.     Hybrid Journal   (Followers: 71, SJR: 0.59, h-index: 29)
Australian Psychologist     Hybrid Journal   (Followers: 12, SJR: 0.331, h-index: 31)
Australian Veterinary J.     Hybrid Journal   (Followers: 19, SJR: 0.459, h-index: 45)
Autism Research     Hybrid Journal   (Followers: 32, SJR: 2.126, h-index: 39)
Autonomic & Autacoid Pharmacology     Hybrid Journal   (SJR: 0.371, h-index: 29)
Banks in Insurance Report     Hybrid Journal   (Followers: 1)
Basic & Clinical Pharmacology & Toxicology     Hybrid Journal   (Followers: 10, SJR: 0.539, h-index: 70)
Basic and Applied Pathology     Open Access   (Followers: 2, SJR: 0.113, h-index: 4)
Basin Research     Hybrid Journal   (Followers: 5, SJR: 1.54, h-index: 60)
Bauphysik     Hybrid Journal   (Followers: 2, SJR: 0.194, h-index: 5)
Bauregelliste A, Bauregelliste B Und Liste C     Hybrid Journal  
Bautechnik     Hybrid Journal   (Followers: 1, SJR: 0.321, h-index: 11)
Behavioral Interventions     Hybrid Journal   (Followers: 9, SJR: 0.297, h-index: 23)
Behavioral Sciences & the Law     Hybrid Journal   (Followers: 24, SJR: 0.736, h-index: 57)
Berichte Zur Wissenschaftsgeschichte     Hybrid Journal   (Followers: 9, SJR: 0.11, h-index: 5)
Beton- und Stahlbetonbau     Hybrid Journal   (Followers: 2, SJR: 0.493, h-index: 14)
Biochemistry and Molecular Biology Education     Hybrid Journal   (Followers: 6, SJR: 0.311, h-index: 26)
Bioelectromagnetics     Hybrid Journal   (Followers: 1, SJR: 0.568, h-index: 64)
Bioengineering & Translational Medicine     Open Access  
BioEssays     Hybrid Journal   (Followers: 10, SJR: 3.104, h-index: 155)
Bioethics     Hybrid Journal   (Followers: 14, SJR: 0.686, h-index: 39)
Biofuels, Bioproducts and Biorefining     Hybrid Journal   (Followers: 1, SJR: 1.725, h-index: 56)
Biological J. of the Linnean Society     Hybrid Journal   (Followers: 16, SJR: 1.172, h-index: 90)
Biological Reviews     Hybrid Journal   (Followers: 3, SJR: 6.469, h-index: 114)
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 42, SJR: 0.12, h-index: 1)
Biology of the Cell     Full-text available via subscription   (Followers: 9, SJR: 1.812, h-index: 69)
Biomedical Chromatography     Hybrid Journal   (Followers: 6, SJR: 0.572, h-index: 49)
Biometrical J.     Hybrid Journal   (Followers: 5, SJR: 0.784, h-index: 44)
Biometrics     Hybrid Journal   (Followers: 36, SJR: 1.906, h-index: 96)
Biopharmaceutics and Drug Disposition     Hybrid Journal   (Followers: 10, SJR: 0.715, h-index: 44)
Biopolymers     Hybrid Journal   (Followers: 18, SJR: 1.199, h-index: 104)
Biotechnology and Applied Biochemistry     Hybrid Journal   (Followers: 45, SJR: 0.415, h-index: 55)
Biotechnology and Bioengineering     Hybrid Journal   (Followers: 179, 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: 37, SJR: 0.763, h-index: 64)
Birth Defects Research Part A : Clinical and Molecular Teratology     Hybrid Journal   (Followers: 2, SJR: 0.727, h-index: 77)
Birth Defects Research Part B: Developmental and Reproductive Toxicology     Hybrid Journal   (Followers: 5, SJR: 0.468, h-index: 47)
Birth Defects Research Part C : Embryo Today : Reviews     Hybrid Journal   (SJR: 1.513, h-index: 55)
BJOG : An Intl. J. of Obstetrics and Gynaecology     Partially Free   (Followers: 234, SJR: 2.083, h-index: 125)

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Journal Cover AIChE Journal
  [SJR: 1.122]   [H-I: 120]   [30 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0001-1541 - ISSN (Online) 1547-5905
   Published by John Wiley and Sons Homepage  [1579 journals]
  • Low Reynolds number isotope transient kinetic modeling in isothermal
           differential tubular catalytic reactors
    • Authors: Masood Otarod; Ronald M. Supkowski
      Abstract: A novel method is presented for modeling steady state isotope transient kinetics of heterogeneous catalytic reactions when the flow regime is laminar and conversion is differential. It is based on a factorization theorem which is deduced from the observation that transport functions fluctuate radially in porous beds. Factorization separates the radial from axial and temporal coordinates of the flow rate and concentration functions. It is shown that in transient tracing with a differential conversion, the radial components of the transport functions in the material conservation equations can be integrated into constant parameters to be determined from experimental data. The method is in particular useful since the knowledge of the radial profile of velocity and other transport functions and parameters are not prerequisites for data correlation. The methodology was successfully applied to the adsorption of carbon monoxide in Boudouard reaction on an alumina supported palladium catalyst. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-16T01:15:28.033637-05:
      DOI: 10.1002/aic.16006
       
  • A Pore Network Study of Evaporation from the Surface of a Drying
           Non-Hygroscopic Porous Medium
    • Authors: Alireza Attari Moghaddam; Abdolreza Kharaghani, Evangelos Tsotsas, Marc Prat
      Abstract: The phenomena occurring at the surface of a porous medium during drying in the capillary regime are investigated by pore network simulations. The impact of the formation of wet and dry patches at the surface on the drying rate is studied. The simulations indicate an edge effect characterized by a noticeable variation of saturation in a thin layer adjacent to the porous surface. Also, the results indicate a significant non-local equilibrium effect at the surface. The simulation results are exploited to test Schlünder's classical model which offers a simple closure relationship between the evaporation rate and the degree of occupancy of the surface by the liquid. In addition to new insights into the surface phenomena, the results open up new prospects for improving the continuum models of the drying process. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-13T10:55:37.309147-05:
      DOI: 10.1002/aic.16004
       
  • DEM-PBM modeling of abrasion dominated ribbon breakage
    • Authors: Simone Loreti; Chuan-Yu Wu, Gavin Reynolds, Jonathan Seville
      Abstract: In dry granulation, fine cohesive powders are compacted into large multi-particle entities, i.e., briquettes, flakes or ribbons. The powder compaction is generally followed by milling, a size reduction process, which is crucial to obtain the desired granule size or properties. Abrasion and impact are two primary mechanisms of comminution in ribbon milling, but they are not completely understood. The aim of this paper was hence to investigate numerically the fragmentation process induced by abrasion during ribbon milling. The discrete element method (DEM) was employed to simulate abrasion tests, for which three-dimensional parallelepiped ribbons were generated using auto-adhesive elastic spheres. The fragmentation rate, and the fragments size and number were determined for various surface energies and abrasive velocities. The DEM results showed that the mass-equivalent fragment size distributions were bi-modal, similar to the experimental observations and the numerical results for impact-dominated ribbon milling reported in the literature. In addition, two quantities were determined from the DEM analysis, i.e. the number of large fragments and the fraction of fines, which was then integrated into the population balance models (PBM) so that a DEM-PBM multiscale modeling framework was developed to predict the granule size distribution during ribbon milling. The DEM-PBM results were compared with the experimental results reported in the literature, and a broad agreement was obtained, implying the proposed DEM-PBM can be used to analyse the ribbon milling behavior. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-13T10:55:31.869796-05:
      DOI: 10.1002/aic.16005
       
  • Improving mixing characteristics with a pitched tip in kneading elements
           in twin-screw extrusion
    • Authors: Yasuya Nakayama; Hiroki Takemitsu, Toshihisa Kajiwara, Koichi Kimura, Takahide Takeuchi, Hideki Tomiyama
      Abstract: In twin-screw extrusion, the geometry of a mixing element mainly determines the basic ow pattern, which eventually affects the mixing ability as well as the dispersive ability of the mixing element. We discuss the effects of geometrical modification, with both forward and backward pitched tips, of a conventional forwarding kneading discs element (FKD) in the pitched-tip kneading discs element (ptKD) on the ow pattern and mixing characteristics. Numerical simulations of fully-filled, non-isothermal polymer melt ow in the melt-mixing zone were performed, and the flow pattern structure and the tracer trajectories were investigated. The pitched tips largely affects the inter-disc fluid transport, which is mainly responsible for mixing. These changes in the local ow pattern are analyzed by the distribution of the strain-rate state. The distribution of the finite-time Lyapunov exponent reveals a large inhomogeneity of the mixing in FKD is suppressed both by the forward and backward tips. By the forward tips on FKD, the mixing ability is relatively suppressed compared to FKD, whereas for the backward tips on FKD, the mixing ability is enhanced while maintaining the same level of dispersion efficiency as FKD. From these results, the pitched tips on the conventional KD turns out to be effective at reducing the inhomogeneity of the mixing and tuning the overall mixing performance. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-13T10:46:06.039922-05:
      DOI: 10.1002/aic.16003
       
  • Chemical Hydrodynamics of a Downward Microbubble Flow for Intensification
           of Gas-Fed Bioreactors
    • Authors: Manizheh Ansari; D.E. Turney, R. Yakobov, D.V. Kalaga, S. Kleinbart, Sanjoy Banerjee, J.B. Joshi
      Abstract: Bioreactors are of interest for value-upgrading of stranded or waste industrial gases. Reactor intensification requires development of low cost bioreactors with fast gas-liquid mass transfer rate. Here we assess published reactor technology in comparison with a novel downward bubble flow created by a micro-jet array. Compared to known technology, the advanced design achieves higher volumetric gas transfer efficiency (kLa per power density) while operating at higher kLa. We measure the effect of four reactor heights (height-to-diameter ratios of 12, 9, 6 and 3) on the gas transfer coefficient kL, total interfacial area a, liquid residence time distribution, energy consumption, and turbulent hydrodynamics. Leading models for predicting kL and a are appraised with experimental data. The results show kL is governed by “entrance effects” due to Higbie penetration dominate at short distances below the micro-jet array, while turbulence dominates at intermediate distances, and finally terminal rise velocity dominates at large distances. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-13T10:45:25.454122-05:
      DOI: 10.1002/aic.16002
       
  • Pressure Drop through Platinized Titanium Porous Electrodes for
           Cerium-based Redox Flow Batteries
    • Authors: Luis F. Arenas; Carlos Ponce de León, Frank C. Walsh
      Abstract: The pressure drop, ΔP, across a redox flow battery is linked to pumping costs and energy efficiency, making fluid properties of electrodes important in scale-up. In this work, 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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-12T11:30:36.188909-05:
      DOI: 10.1002/aic.16000
       
  • Modeling the Deposition of Fluorescent Whitening Agents (FWAs) on Cotton
           Fabrics
    • Authors: L. Bueno; C. Amador, S. Bakalis
      Abstract: The adsorption of two widely used Fluorescent Whitening Agents (FWAs) on un-brightened cotton fabrics has been investigated as a function of temperature, hardness of the wash liquor, initial concentration of FWA in solution and fabric to wash liquor ratio. Sorption efficiencies of FWAs have been studied using a UV spectrophotometry technique. A mechanistic model has been developed to describe the dissolution process of FWAs, convective mass transport into the fabrics, diffusion in the stagnant layer to the fabrics' surface and adsorption of FWAs on cotton fabrics. Dual porosity of the fabrics (inter-yarn and intra-yarn porosity) has been considered by allowing two different regions (outer and inner areas of the cotton fabrics) where FWAs molecules can diffusive and adsorb. Good agreement between experimental and predicted whiteness benefit by the proposed mathematical model has been observed for the range of variables considered. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-12T11:15:27.922426-05:
      DOI: 10.1002/aic.16001
       
  • Computer-Aided Design of Ionic Liquids as Solvents for Extractive
           Desulfurization
    • Authors: Zhen Song; Chenyue Zhang, Zhiwen Qi, Teng Zhou, Kai Sundmacher
      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. In this work, 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 multi-component model EDS system, under consideration of constraints regarding the IL structure, thermodynamic and physical properties. The top five IL candidates pre-identified 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 extractive desulfurization. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-10T18:40:34.375093-05:
      DOI: 10.1002/aic.15994
       
  • 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
      Abstract: Poisoning effects of sulfur compounds on the performances of solid oxide fuel cells (SOFCs) 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 ε/τ is detrimental, especially for low-temperature operations with a high H2S concentration and a low current density. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-10T18:40:31.827109-05:
      DOI: 10.1002/aic.15997
       
  • The Promotion of Argon and Water Molecule on Direct Synthesis of H2O2 from
           H2 and O2
    • Authors: Yanhui Yi; Li Wang, Juan Yu, Changgong Meng, Jialiang Zhang, Hongchen Guo
      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 paper 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 towards 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%. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-10T18:40:28.540728-05:
      DOI: 10.1002/aic.15999
       
  • Integrated Solvent and Process Design for Continuous Crystallization and
           Solvent Recycling using PC-SAFT
    • Authors: Jiayuan Wang; Richard Lakerveld
      Abstract: Solvent usage is a major source of environmental waste in pharmaceutical industry. The current paradigm shift towards continuous manufacturing in pharmaceutical industry has renewed the interest in continuous crystallization, which offers the prospect of easy solvent recycling. However, the selection of solvents for an integrated crystallization processes is nontrivial due to the likely trade-off between optimal solvent properties for crystallization and solvent separation and recycling. A systematic approach for the simultaneous optimization of process conditions and solvent selection for continuous crystallization including solvent recycling is presented. A unified PC-SAFT model framework is applied to predict thermodynamic properties related to solubility and vapor-liquid equilibrium, which is integrated with a process model. A continuous mapping procedure is adopted to solve the optimization problem effectively. A case study based on continuous anti-solvent crystallization of paracetamol with solvent separation via flash demonstrates the approach. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-10T18:40:21.501415-05:
      DOI: 10.1002/aic.15998
       
  • Issue information
    • Abstract: Cover illustration. A molecular-level view of the gas absorption process in which an ionic liquid is used to separate carbon dioxide from methane. Image courtesy: Kristina Davis, University of Notre Dame Center for Research Computing. 10.1002/aic.15957
      PubDate: 2017-10-10T18:38:25.333311-05:
      DOI: 10.1002/aic.15483
       
  • A Tribute to Roy Jackson
    • Authors: Sankaran Sundaresan; Christine M. Hrenya, Michael P. Harold, Jennifer Sinclair Curtis
      PubDate: 2017-10-10T18:35:26.503596-05:
      DOI: 10.1002/aic.15993
       
  • A Dynamic Game Theoretic Framework for Process Plant Competitive Upgrade
           and Production Planning
    • Authors: Philip Tominac; Vladimir Mahalec
      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 multi-market 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 in order to become competitive and escape the threat, or alternatively in which the threat of elimination will never be carried out and the refiner is effectively safe in the given market configuration. Globally optimal dynamic Nash equilibrium production trajectories are presented for each case. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-10T18:35:24.932878-05:
      DOI: 10.1002/aic.15995
       
  • A Thermodynamic Investigation of Adsorbate-Adsorbate Interactions of
           Carbon Dioxide on Nanostructured Carbons
    • Authors: Maxwell Murialdo; Channing C. Ahn, Brent Fultz
      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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-10T18:35:22.8165-05:00
      DOI: 10.1002/aic.15996
       
  • 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
       
  • The lift on a disc immersed in a rotating granular bed
    • Authors: Bhanjan Debnath; K. Kesava Rao, Prabhu R. Nott
      Abstract: The discrete element method has been used to study the lift FL on a stationary disc immersed coaxially in a slowly rotating cylinder containing a granular material. In a tall granular column, FL rises with the immersion depth h, but reaches a roughly constant asymptote at large h, in agreement with previous studies. Our results indicate that the argument in some earlier studies that FL is proportional to the static stress gradient is incorrect. Instead, our results show that the lift is caused by an asymmetry in the dilation and shear rate between the regions above and below the disc. We argue that the cause of the lift is similar to that in fluids, namely that it arises as a result of the disturbance in the velocity and density fields around the body due to its motion relative to the granular bed. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-05T06:55:24.428784-05:
      DOI: 10.1002/aic.15991
       
  • Model Based Analysis of Lithium Batteries Considering Particle Size
           Distribution
    • Authors: E. R. Henquín; P. A. Aguirre
      Abstract: Performance of lithium ion batteries whose electrodes are composed of particles of different sizes is studied. Simplified model developed in 7 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 carried out 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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-05T04:20:21.195117-05:
      DOI: 10.1002/aic.15990
       
  • Packaging of Yield Stress Fluids: Flow Patterns
    • Authors: Fanny Rasschaert; Emeline Talansier, Didier Blésès, Maud Lambert, Albert Magnin
      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 by using an experimental laboratory plant able to reproduce the industrial transitory packaging conditions. Firstly, a Newtonian validation was conducted in order to compare and to confirm our set-up results with available literature data. Secondly 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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-04T10:56:05.754901-05:
      DOI: 10.1002/aic.15989
       
  • Enhanced Solubility of Hydrogen and Carbon Monoxide in Propane- and
           Propylene-Expanded Liquids
    • Authors: Dupeng Liu; Raghunath V. Chaudhari, Bala Subramaniam
      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 66% 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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-04T10:25:33.770979-05:
      DOI: 10.1002/aic.15988
       
  • A Pseudo-Transient Optimization Framework for Periodic Processes: Pressure
           Swing Adsorption and Simulated Moving Bed Chr
    • Authors: Calvin Tsay; Richard C. Pattison, Michael Baldea
      Abstract: Πeriodic systems are widely used in separation processes and in reaction engineering. They are designed for and operated at a cyclic steady state (CSS). Identifying and optimizing the CSS has proven to be computationally challenging. In this paper, we introduce a novel framework for equation-oriented simulation and optimization of cyclic processes. We propose a two-step reformulation of the process model, comprising, i) a full discretization of the time and spatial domains and ii) re-casting the discretized model as a differential-algebraic equation (DAE) system, for which we provide theoretical stability guarantees. Additionally, we establish a mathematical, structural connection between the CSS constraints and material recycling, which allows us to deal with these conditions via a “tearing” procedure. We integrate these developments in a pseudo-transient design optimization framework and present two extensive case studies: a simulated moving bed chromatography system and a pressure swing adsorption process. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-03T10:25:30.192562-05:
      DOI: 10.1002/aic.15987
       
  • Mixing Processes in the Cavity Transfer Mixer: a Thorough Study
    • Authors: Giovanna Grosso; Martien A. Hulsen, Arash Sarhangi Fard, Andrew Overend, Patrick D. Anderson
      Abstract: In many industrial applications, the quality of mixing between different materials is fundamental to guarantee the desired properties of products. However, properly modelling 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, in order 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 in order 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 in order to guarantee good mixing quality. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-29T11:44:51.410537-05:
      DOI: 10.1002/aic.15986
       
  • Detailed Thermodynamics for Analysis and Design of Ranque-Hilsch Vortex
           Tubes
    • Authors: John P. O'Connell
      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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-29T11:44:15.594323-05:
      DOI: 10.1002/aic.15985
       
  • 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
      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 could 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 reactants phase, which is in good agreement with the van der Waals energy between the reactants and cations of the ILs. The longer chains on cations could promote the interfacial width and facilitate the dissolution of isobutane in catalyst phase, and thus exhibits a better catalytic performance, which agrees well with alkylation experiments in this work. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-29T11:44:10.083427-05:
      DOI: 10.1002/aic.15984
       
  • 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
      Abstract: In order to address the problem of insufficient available modelling data for glucose prediction, as well as modelling burden, a model migration method was developed in a previous work to quickly transfer an old model to a new subject by 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 modelling samples, including glucose and two exogenous inputs (meal and insulin), the optimal modelling method may be different, and therefore must be properly determined for each modelling 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 modelling 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 modelling 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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-28T10:25:21.449536-05:
      DOI: 10.1002/aic.15983
       
  • A Tribute to Professor Roy Jackson: Intellectual Leader, Scholar, Mentor
    • Authors: Sankaran Sundaresan; Martin Feinberg, Kesava Rao Kaza, Prabhu R. Nott
      Abstract: This article, and this entire issue of the AIChE Journal, are meant to honor Professor Roy Jackson, whose contributions to chemical engineering have been profound and exceptionally broad. It is often said of Roy Jackson that few, if any, scholars have so deep a command of the full range of highly varied subjects that comprise the chemical engineering discipline. We have attempted a hardly-complete description of Professor Jackson's wide-ranging academic journey, both geographic (Cambridge, London, Edinburgh, Houston, Pasadena, Princeton) and intellectual (fluidization, mechanics of granular flows, process optimization, chemical reaction network theory, diffusion and reaction in porous catalyst pellets). The contributions of friends and colleagues appearing elsewhere in this issue are a testament to the broad range of subjects in which Professor Jackson had interest. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-26T11:15:36.321605-05:
      DOI: 10.1002/aic.15981
       
  • A Mesoscale Model for Diffusion and Permeation of Shale Gas at Geological
           Depth
    • Authors: Tiexin Tong; Dapeng Cao
      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 (DCV-GCMD) 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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-26T11:15:19.247051-05:
      DOI: 10.1002/aic.15982
       
  • Numerical Prediction of Dust Capture Efficiency of a Centrifugal Wet
           Scrubber
    • Authors: Hassan Ali; Floren Plaza, Anthony Mann
      Abstract: The gas, liquid and dust particle behaviour inside a centrifugal wet scrubber was simulated and a sub-model 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 modelling results. Ideal operating parameters for maximum scrubbing efficiency and minimum droplet carryover were identified. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-26T11:10:33.477652-05:
      DOI: 10.1002/aic.15979
       
  • 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
      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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-26T11:10:29.600618-05:
      DOI: 10.1002/aic.15980
       
  • Iron-based Electrochemically Mediated Atom Transfer Radical Polymerization
           with Tunable Catalytic Activity
    • Authors: Jun-Kang Guo; Zhou Yin-Ning, Luo Zheng-Hong
      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: 2017-09-26T11:10:26.703103-05:
      DOI: 10.1002/aic.15978
       
  • 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
      Abstract: In a recent article, Gonçalves et al.,11,12 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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-25T11:35:21.95513-05:0
      DOI: 10.1002/aic.15977
       
  • Flow Dynamics in Taylor–Couette Flow Reactor with Axial Distribution
           of Temperature
    • Authors: Hayato Masuda; Saho Yoshida, Takafumi Horie, Makoto Shimoyamada, Naoto Ohmura
      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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-21T11:20:57.584634-05:
      DOI: 10.1002/aic.15972
       
  • Characterization of Liquid-Liquid Mass Transfer Performance in a Capillary
           Microreactor System
    • Authors: Guangxiao Li; Minjing Shang, Yang Song, Yuanhai Su
      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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-21T11:20:54.627313-05:
      DOI: 10.1002/aic.15973
       
  • 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
      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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-21T11:15:52.463262-05:
      DOI: 10.1002/aic.15976
       
  • 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
      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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-21T11:15:46.302932-05:
      DOI: 10.1002/aic.15974
       
  • 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, Bart van der Bruggen, Jiangnan Shen
      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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-21T11:15:29.696738-05:
      DOI: 10.1002/aic.15975
       
  • A Theory of Ultra-Deep Hydrodesulfurization of Diesel in Stacked-Bed
           Reactors
    • Authors: Teh C. Ho
      Abstract: Hydrodesulfurization catalysts have two types of active sites for hydrogenation and hydrogenolysis reactions. While hydrogenation sites are more active for desulfurizing refractory sulfur species, they are more susceptible to organonitrogen inhibition than hydrogenolysis sites. In contrast, hydrogenolysis sites are more resistant to organonitrogen inhibition but are less active for desulfurizing refractory sulfur species. This dichotomy is exploited to develop an ultra-deep hydrodesulfurization stacked-bed reactor comprising two catalysts of different characteristics. The performance of such a catalyst system can be superior or inferior to that of either catalyst alone. A mathematical model is constructed to predict the optimum stacking configuration for maximum synergies between the two catalysts. The best configuration provides the precise environment for the catalysts to reach their full potentials, resulting in the smallest reactor and minimum hydrogen consumption. Model predictions are consistent with experimental results. A selectivity-activity diagram is developed for guiding the development of stacked-bed catalyst systems. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-16T10:55:28.438511-05:
      DOI: 10.1002/aic.15969
       
  • 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
      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 multi-continuum 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 multi-continuum 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 are likewise obtained. These information are then lumped to calculate the rejection capacity of membranes. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-16T10:55:25.689633-05:
      DOI: 10.1002/aic.15970
       
  • A pinch-like targeting framework for systematic thermal process
           intensification
    • Authors: Michael Baldea
      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 paper 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 (MILP). An extensive case study illustrating its application is presented. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-16T10:55:21.254673-05:
      DOI: 10.1002/aic.15971
       
  • 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
      Abstract: Dissipative particle dynamics (DPD) 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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-11T11:21:19.364479-05:
      DOI: 10.1002/aic.15961
       
  • A flowsheet model for the development of a continuous process for
           pharmaceutical tablets – an industrial perspective
    • Authors: Salvador García-Muñoz; David Slade, Adam Butterbaugh, Ian Leavesley, Leo Francis Manley, Sean Bermingham
      Abstract: A dynamic model of a continuous direct compression process for pharmaceutical tablets is presented. The objective is to assess the impact of the variability from the feeder system on the concentration of drug in the powder in the feed frame of a tablet press. The model is based on principles of dispersed flow from the reaction engineering field. An estimability analysis was performed to understand the impact of the available measurements on the estimated parameters and suggest better ways to approach the parametrization. Predictions are successfully contrasted with experimental data. The model is used to produce residence time distributions at different process conditions and a graphical representation of the allowable range of disturbances in the feeders that can be mitigated by the process. The model was used in support of the method development for an on-line near infra-red sensor. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-11T11:15:49.984299-05:
      DOI: 10.1002/aic.15967
       
  • Target Bounds on Reaction Selectivity via Feinberg's CFSTR Equivalence
           Principle
    • Authors: Jeffrey A. Frumkin; Michael F. Doherty
      Abstract: In this work, we show that the Continuous Flow Stirred Tank Reactor (CFSTR) Equivalence Principle, developed by Feinberg and Ellison,1 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. [1, 2] 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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-11T11:15:42.2626-05:00
      DOI: 10.1002/aic.15968
       
  • Reversible Cluster Aggregation and Growth Model for Graphene Suspensions
    • Authors: Michail Alifierakis; Kevin S. Sallah, Jean H. Prévost, Ilhan A. Aksay
      Abstract: We present a reversible cluster aggregation model for 2-dimensional macromolecules represented by line segments in 2-dimensions; and, we use it to describe the aggregation process of functionalized graphene particles in an aqueous SDS surfactant solution. The model produces clusters with similar sizes and structures as a function of SDS concentration in agreement with experiments and predicts the existence of a critical surfactant concentration (Ccrit) beyond which thermodynamically stable graphene suspensions form. Around Ccrit, particles form dense clusters rapidly and sediment. At C ≪ Ccrit, a contiguous ramified network of graphene gel forms which also densifies, but at a slower rate, and sediments with time. The deaggregation-reaggregation mechanism of our model captures the restructuring of the large aggregates towards a graphite-like structure for the low SDS concentrations. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-11T11:11:05.074495-05:
      DOI: 10.1002/aic.15962
       
  • A Systematic Method to Synthesize All Dividing Wall Columns for
           n-component Separation - Part II
    • Authors: Gautham Madenoor Ramapriya; Mohit Tawarmalani, Rakesh Agrawal
      Abstract: We present a simple rule that, for the first time, enables exhaustive enumeration of dividing wall columns (DWCs) corresponding to any given thermally coupled distillation column-configuration. With the successive application of our rule, every partition in a DWC can be extended all the way to the top and/or to the bottom of a column without losing thermodynamic equivalence to the original thermally coupled configuration. This leads to easy-to-operate DWCs with possible control/regulation of each and every vapor split by external means. As a result, we conclude that any given DWC can be transformed into a thermodynamically equivalent form that is easy-to-operate, and hence, there always exists at least one easy-to-operate DWC for any given thermally coupled distillation. Our method of enumerating and identifying easy-to-operate DWCs for an attractive thermally coupled configuration will contribute towards process intensification by providing ways to implement efficient and low-cost multicomponent distillations. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-09T10:45:25.110804-05:
      DOI: 10.1002/aic.15963
       
  • Spontaneous Imbibition of Liquids in Glass-Fiber Wicks. Part I: Usefulness
           of a Sharp-Front Approach
    • Authors: M. Amin F. Zarandi; Krishna M Pillai, Adam S. Kimmel
      Abstract: Spontaneous imbibition of a liquid into glass-fiber wicks is modeled using the single-phase Darcy's law after assuming a sharp flow-front marked by full saturation behind the front occurring in a transversely-isotropic porous medium. An analytical expression for the height of the wicking flow-front as a function of time is tested through comprehensive experiments involving using eight different wicks and one oil as the wicking liquid. A good fit with experimental data is obtained without using any fitting parameter. The contact-angle is observed to be important for the success of the model—lower contact angle cases marked by higher capillary pressures were predicted the best. The proposed model provides a nice upper bound for all the wicks, thereby establishing its potential as a good tool to predict liquid absorption in glass-fiber wicks. However, the sharp-front model is unable to explain region of partial saturation, thereby necessitating the development of part II of this paper series 1 using Richard's equation This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-09T10:35:37.036253-05:
      DOI: 10.1002/aic.15965
       
  • Co-Production of Acetic Acid and Hydrogen/Power from Natural Gas with Zero
           Carbon Dioxide Emissions
    • Authors: Ibubeleye Somiari; Vasilios Manousiouthakis
      Abstract: In this work, a process plant flowsheet that co-produces 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 co-produces 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 flowsheet 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. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-09T10:35:31.074333-05:
      DOI: 10.1002/aic.15966
       
  • A Systematic Method to Synthesize All Dividing Wall Columns for
           n-Component Separation - Part I
    • Authors: Gautham Madenoor Ramapriya; Mohit Tawarmalani, Rakesh Agrawal
      Abstract: We present an easy-to-use stepwise procedure to synthesize an initial-dividing wall column (i-DWC) from any given n-component basic distillation column-sequence or its thermally coupled derivative. The procedure to be used is dependent on the nature of the distillation column-sequence that is to be converted into a DWC, and comprises of an intuitive set of steps that we demonstrate through examples. It is noteworthy that, even for a ternary distillation, fifteen potentially useful DWCs, some of which had been missing from the literature, have now been identified. This work significantly expands the search space of useful DWCs to separate any given multicomponent mixture. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-09T10:35:22.976856-05:
      DOI: 10.1002/aic.15964
       
  • Flow of Viscoelastic Surfactants through Porous Media
    • Authors: S. De; M. Golombok, S.P. Koesen, R.V. Maitri, J.T. Padding, J.F.M. van Santvoort
      Abstract: We compare the flow behavior of viscoelastic surfactant (VES) solutions and Newtonian fluids through two different model porous media having similar permeability: (a) a 3D random packed bed and (b) a microchannel with a periodically spaced pillars. The former provides much larger flow resistance at the same apparent shear rate compared to the latter. The flow profile in the 3D packed bed cannot be observed since it is a closed system. However, visualization of the flow profile in the microchannel shows strong spatial and temporal flow instabilities in VES fluids appear above a critical shear rate. The onset of such elastic instabilities correlates to the flow rate where increased flow resistance is observed. The elastic instabilities are attributed to the formation of transient shear induced structures. The experiments provide a detailed insight into the complex interplay between the pore scale geometry and rheology of VES in the creeping flow regime. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-09T10:30:26.413062-05:
      DOI: 10.1002/aic.15960
       
  • Flow Field Design and Optimization of High Power Density Vanadium Flow
           Batteries: a Novel Trapezoid Flow Battery
    • Authors: Meng Yue; Qiong Zheng, Feng Xing, Huamin Zhang, Xianfeng Li, Xiangkun Ma
      Abstract: Vanadium flow battery (VFB) is one of the preferred techniques for efficient large-scale energy storage applications. The key issue for its commercialization is cost reduction, which can be achieved by developing high power density VFB stacks. One of the effective strategies for developing high power density stacks is to enhance the mass transport by performing flow field design. Based on the maldistribution characteristics of concentration polarization inside a conventional rectangular flow battery (RFB), a novel trapezoid flow battery (TFB) was firstly proposed. Furthermore, a practical and general strategy, consisting of a stepping optimization method and an arithmetic progression model, has been developed for the TFB's structure optimization. By combining numerical simulation with charge-discharge test of the magnified stacks, it was verified that mass transport enhancement and performance improvement of the optimized TFB, with significant increments in voltage efficiency and electrolyte utilization, allowed it to possess great superiority over the RFB. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-09T10:30:21.929485-05:
      DOI: 10.1002/aic.15959
       
  • Modular Methanol Manufacturing from Shale Gas: Techno-economic and
           Environmental Analyses of Conventional Large-scale Production versus
           Small-scale Distributed, Modular Processing
    • Authors: Minbo Yang; Fengqi You
      Abstract: This paper presents comparative techno-economic and environmental analyses of four representative shale gas monetization options, namely, conventional shale gas processing, large-scale methanol manufacturing, modular methanol manufacturing with shale gas supplied by pipelines, and modular methanol manufacturing with consideration of plant relocation. We first present shale gas supply models for the four gas monetization options. Next, the process designs for shale gas processing and methanol manufacturing from shale gas are described. We develop detailed process simulation models for shale gas processing and methanol manufacturing with different scales using raw shale gas extracted from the Marcellus, Eagle Ford, and Bakken shale plays. On this basis, techno-economic analyses and environmental impact analyses are conducted for the four shale gas monetization options to systematically compare their economic and environmental performances based on the same conditions. The results show that modular methanol manufacturing is more economically competitive than conventional shale gas processing, although it leads to higher environmental impacts. Besides, modular methanol manufacturing is better than large-scale methanol manufacturing for raw shale gas produced from distributed, remote wells from both economic and environmental perspectives. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-07T10:40:29.957529-05:
      DOI: 10.1002/aic.15958
       
  • Novel Semi-interpenetrating Network Structural Phase Change Composites
           with High Phase Change Enthalpy
    • Authors: Yuang Zhang; Jinghai Xiu, Bingtao Tang, Rongwen Lu, Shufen Zhang
      Abstract: High phase change enthalpy, controllable temperature, and stable shape can expand the application of phase change materials (PCMs) in energy storage. In this study, a series of novel form-stable PCMs with high phase change enthalpy (169–195 J/g) and controllable temperature (45.3–61.4°C) were prepared. The PCMs exhibited a semi-interpenetrating polymer network (semi-IPN) structure resulting from the combination of polyethylene glycol and a 3D network gel. The gel itself featured an inherent phase change characteristic and a 3D network structure. Thus, it improved the phase transition enthalpy of the materials and facilitated the formation of a semi-IPN that endowed the materials with excellent form-stable properties. In addition, the latent heat of the composites (169–195 J/g) is much higher than most of the previously reported composites using PEG as phase change component (68–132 J/g). This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-07T01:45:41.598328-05:
      DOI: 10.1002/aic.15956
       
  • The Solubility of Gases in Ionic Liquids
    • Authors: Mark B. Shiflett; Edward J. Maginn, Mark B. Shiflett, Edward J. Maginn
      PubDate: 2017-09-06T16:35:27.546367-05:
      DOI: 10.1002/aic.15957
       
  • Adsorption Separation of R134a, R125 and R143a Fluorocarbon Mixtures Using
           13X and Surface Modified 5A Zeolites
    • Authors: Darshika K. J. A. Wanigarathna; Jiajian Gao, Bin Liu
      Abstract: We report a facile method for the adsorption separation of fluorocarbon blends containing tetrafluoroethane (R134a), pentafluoroethane (R125) and trifluoroethane (R143a) refrigerants into their pure components using commercial 13X zeolite and pore size modified 5A zeolite under ambient condition. Based on the measured R134a, R125 and R143a pure gas equilibrium adsorption isotherms, the adsorption capacity varies in the order of R134a > R143a > R125 on 13X zeolite. The mixed gas breakthrough experiments reveal that 13X zeolite selectively adsorbs R134a over R125 and R143a. By running two adsorption cycles, it is possible to obtain R134a with ultrahigh purity. Furthermore, through chemical modification of tetraethyl orthosilicate (TEOS), the pore size of 5A zeolite could be successfully narrowed to the extent to just adsorb R125 while excluding R143a. The modified 5A zeolite was utilized to separate refrigerant mixtures containing R125 and R143a into their pure components. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-02T10:41:40.716377-05:
      DOI: 10.1002/aic.15955
       
  • Gravitational Discharge of Fine Dry Powders with Asperities from a Conical
           Hopper
    • Authors: Hui Lu; Jia Zhong, Gui-Ping Cao, Hai-Feng Liu
      Abstract: The effects of particle properties, especially the surface roughness and particle type, on the gravity discharge rate and flow behavior of fine dry powders from a conical hopper are studied in detail. The van der Waals force is considered to dominate the discharge of small particles, while the empty annulus effect dominates the discharge of large particles. To predict the van der Waals force between two rough spherical particles, a model based on Rumpf theory is adopted. The effect of surface roughness can be reflected by Bond number Bog which is correlated with discharge rate. By modifying the powder bed porosity and Beverloo constant, the discharge rates of fine dry powders can be well predicted by an empirical correlation. Finally, not only the ratio of hopper outlet size to particle size D0/dp, but also the Bond number Bog is found to be an important indicator to determine the powder flowability. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-01T10:45:52.469286-05:
      DOI: 10.1002/aic.15954
       
  • 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
       
  • Chemical Solvent in Chemical Solvent: A Class of Hybrid Materials for
           Effective Capture of CO2
    • Authors: Feng-Feng Chen; Kuan Huang, Jie-Ping Fan, Duan-Jian Tao
      Abstract: Amino acid ionic liquids (AAILs) are chemical solvents with high reactivity to CO2. However, they suffer from drastic increase in viscosity upon the reaction with CO2, which significantly limits their application in the industrial capture of CO2. In this work, 1-ethyl-3-methylimidazolium acetate ([emim][Ac]) which also exhibits chemical affinity to CO2 but low viscosity, and its viscosity does not increase drastically after CO2 absorption, was proposed as the diluent for AAILs to fabricate hybrid materials. The AAIL+[emim][Ac] hybrids were found to display enhanced kinetics for CO2 absorption, and their viscosity increase after CO2 absorption are much less significant than pure AAILs. More importantly, owing to the fact that [emim][Ac] itself can absorb large amount of CO2, the AAIL+[emim][Ac] hybrids still have high absolute capacities of CO2. Such hybrid materials consisting of a chemical solvent plus another chemical solvent are believed to be a class of effective absorbents for CO2 capture. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-01T10:42:09.223407-05:
      DOI: 10.1002/aic.15952
       
  • Multi-scale modeling of methane catalytic partial oxidation: From the
           meso-pore to the full-scale reactor operation
    • Authors: Jorge E. P. Navalho; José M. C. Pereira, José C. F. Pereira
      Abstract: A multi-scale methodology combining three different reactor length-scales is presented to investigate the role of the catalyst internal pore structure and metal loading and dispersion on the catalyst layer and full-scale reactor performances. At the catalyst level, the methodology involves pore-scale simulations in the 3D meso- and macro-pore space. The information gathered at the catalyst level is delivered to the full-scale reactor model. The methodology is applied to a honeycomb reactor performing methane partial oxidation considering reaction kinetics described through a detailed multi-step reaction mechanism. Realistic meso- and macro-pore structures were reconstructed and combined to form specific bidisperse porous washcoat layers. The study shows that species effective diffusivities vary significantly but not in the same proportion for different structures. For structures featuring poor transport characteristics, the integral methane conversion and hydrogen selectivity are strongly affected while the reactor temperatures increase substantially. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-01T10:42:02.690345-05:
      DOI: 10.1002/aic.15945
       
  • Verification of Eulerian–Eulerian and Eulerian–Lagrangian simulations
           for turbulent fluid–particle flows
    • Authors: Ravi G. Patel; Bo Kong, Jesse Capecelatro, Olivier Desjardins, Rodney O. Fox
      Abstract: We present a verification study of three simulation techniques for fluid–particle flows, including an Euler–Lagrange approach (EL) inspired by Jackson's seminal work on fluidized particles, a quadrature–based moment method based on the anisotropic Gaussian closure (AG), and the traditional two-fluid model. We perform simulations of two problems: particles in frozen homogeneous isotropic turbulence (HIT) and cluster-induced turbulence (CIT). For verification, we evaluate various techniques for extracting statistics from EL and study the convergence properties of the three methods under grid refinement. The convergence is found to depend on the simulation method and on the problem, with CIT simulations posing fewer difficulties than HIT. Specifically, EL converges under refinement for both HIT and CIT, but statistics exhibit dependence on the post-processing parameters. For CIT, AG produces similar results to EL. For HIT, converging both TFM and AG poses challenges. Overall, extracting converged, parameter-independent Eulerian statistics remains a challenge for all methods. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-01T10:41:57.27573-05:0
      DOI: 10.1002/aic.15949
       
  • The Effect of Liquid Bridge Model Details on the Dynamics of Wet Fluidized
           Beds
    • Authors: Mingqiu Wu; Johannes G. Khinast, Stefan Radl
      Abstract: Wet fluidized beds of particles in small periodic domains are simulated using the CFD-DEM approach. A liquid bridge is formed upon particle-particle collisions, which then ruptures when the particle separation exceeds a critical distance. The simulations take into account both surface tension and viscous forces due to the liquid bridge. We perform a series of simulations based on different liquid bridge formation models: (i) the static bridge model of Shi and McCarthy, (ii) a simple static version of the mode of Wu et al., as well as (iii) the full dynamic bridge model of Wu et al. We systematically compare the differences caused by different liquid bridge formation models, as well as their sensitivity to system parameters. Finally, we provide recommendations for which systems a dynamic liquid bridge model must be used, and for which application this appears to be less important. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-01T10:41:48.752007-05:
      DOI: 10.1002/aic.15947
       
  • Organocatalyzed Beckmann Rearrangement of Cyclohexanone Oxime in a
           Microreactor: Kinetic Model and Product Inhibition
    • Authors: Chencan Du; Jisong Zhang, Guangsheng Luo
      Abstract: This paper presents the kinetic study of Beckmann rearrangement of cyclohexanone oxime catalyzed by trifluoroacetic acid and acetonitrile in a microreactor. Parametric studies are conducted varying temperature, ratio of trifluoroacetic acid to acetonitrile, and concentration of cyclohexanone oxime. The inhibition effect of ε-caprolactam in this reaction system is firstly reported. A comprehensive mathematic kinetic model considering the product inhibition effect of caprolactam has been developed in the temperature range of 368-391 K, which agrees well with the experimental results across a broad experimental parameter space. In addition, kinetic study indicates that the esterification of cyclohexanone oxime and transposition reaction of the intermediate are both supposed to be the rate-determining steps, and in this catalyst system, the ratio of trifluoroacetic acid and acetonitrile mainly influences the reaction rate and the activation energy of the transposition step. The developed model could provide much reliable knowledge for industrial application. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-01T10:41:42.500704-05:
      DOI: 10.1002/aic.15946
       
  • Model of inertial spreading and imbibition of a liquid drop on a capillary
           plate
    • Authors: Michel Y. Louge; Shilpa Sahoo
      Abstract: We outline a low-order Lagrangian model for the inertial dynamics of spreading and imbibition of a spherical liquid cap on a plane featuring independent cylindrical capillaries without gravity. The analysis predicts the relative roles of radial and axial kinetic energy, reveals the critical Laplace number beyond which the drop oscillates, and attributes the exponent of the initial power-law for contact patch radius vs time to the form of capillary potential energy just after the liquid sphere touches the plate. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-01T10:41:01.40578-05:0
      DOI: 10.1002/aic.15953
       
  • Settling and Re-Entrainment of Wax Particles in Near-Gelling Systems
    • Authors: Seetharaman Navaneetha Kannan; Nagu Daraboina, Rama Venkatesan, Cem Sarica
      Abstract: Under near-gelling conditions, the precipitated wax particles can settle down due to gravity and form a bed at the bottom of pipeline. During the restart, the settled waxy bed can increase the pressure drop significantly, and the necessity for pigging and/or addition of chemicals has to be determined to re-entrain settled wax particles. A laboratory scale flow loop, first of its kind, has been built and used to understand the settling and re-entrainment behavior. The experimental results confirmed the settling of precipitated wax in a pipe under quiescent conditions when the oil temperature falls between Wax Appearance Temperature (WAT) and Pour Point (PP). During restart, complete re-entrainment was attained after reaching a critical flow rate. Solid transport models were able to predict reasonably good results in agreement with experiments. This work emphasizes the importance of understanding the behavior of waxy crude oil during production shut down and design appropriate startup strategies. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-01T10:35:44.786598-05:
      DOI: 10.1002/aic.15948
       
  • Confinement of a Polymer Chain: an Entropic Study by Monte Carlo Method
    • Authors: Flavia Ruggiero; Rosaria Aruta, Paolo Antonio Netti, Enza Torino
      Abstract: The properties of macromolecules in presence of an interface could be considerably modified due to confinement effects. When phase separations are performed in nanoconfined domains, the concurrent presence of high-energy interfaces and conformational entropy constraints of the macromolecules causes profound differences in polymer aggregation behavior. Here, thermodynamics of a polymer chain in solution, confined by a three-dimensional cubic interface, is studied by means of Monte Carlo method, focusing on the chain conformational entropy penalty arising from the excluded volume effects. The presented method might become a general tool for a preliminary evaluation of the thermodynamic effects due to the confinement of a polymer system. Further, the interface effects on Thermally Induced Phase Separation (TIPS) of polymer solutions, confined by High-Pressure Homogenization, are experimentally studied, regarding final morphologies. It is confirmed how peculiar polymer morphologies are obtained only when the TIPS develops under nanoconfinement degrees above a threshold one. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-01T10:35:40.961338-05:
      DOI: 10.1002/aic.15951
       
  • Nonlinear Robust Optimization for Process Design
    • Authors: Yuan Yuan; Zukui Li, Biao Huang
      Abstract: A novel robust optimization framework is proposed to address general nonlinear problems in process design. Local linearization is taken with respect to the uncertain parameters around multiple realizations of the uncertainty, and an iterative algorithm is implemented to solve the problem. Furthermore, the proposed methodology can handle different categories of problems according to the complexity of the problems. First, inequality-only optimization problem as in most existing robust optimization methods can be addressed. Second, the proposed framework can deal with problems with equality constraint associated with uncertain parameters. In the final case, we investigate problems with operation variables which can be adjusted according to the realizations of uncertainty. A local affinely adjustable decision rule is adopted for the operation variables (i.e., an affine function of the uncertain parameter). Different applications corresponding to different classes of problems are used to demonstrate the effectiveness of the proposed nonlinear robust optimization framework. This article is protected by copyright. All rights reserved.
      PubDate: 2017-09-01T10:35:34.793741-05:
      DOI: 10.1002/aic.15950
       
  • Sorption Enhanced Reaction for High Purity Products in Reversible
           Reactions
    • Authors: Fan Ni; Hugo S. Caram
      Abstract: Reversible reactions (A + B = C + D) can be carried out to near completion using an admixture of catalyst and sorbent that will selectively adsorb one of the reaction products. For an initially clean sorbent and a favorable adsorption isotherm and a long reactor, the adsorbed product, C, will propagate as a sharp, shock-like front. While the adsorbed product will not move faster than this front, the second, non-adsorbed product, D, will, in principle, leave the reactor, uncontaminated. However, a parametric analysis of the two examples presented in this work, the water gas shift and the cracking of hydrogen sulfide, reveals an unexpectedly complex behavior. While assuming adsorption equilibrium the effect of the equilibrium constant, the reaction kinetics and adsorption isotherm on the reactant and product concentration profiles are simulated. It is found that desired behavior is favored by large equilibrium constants, rapid kinetics and strong nonlinear adsorption. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-26T09:25:25.801144-05:
      DOI: 10.1002/aic.15943
       
  • La-hexaaluminate for Synthesis Gas Generation by Chemical Looping Partial
           Oxidation of Methane using CO2 as Sole Oxidant
    • Authors: Yanyan Zhu; Weiwei liu, Yu Kang, Xueyan Sun, Xiaodong Wang, Xiaoxun Ma, Junhu Wang
      Abstract: Chemical looping partial oxidation of methane using a sole CO2 oxidant (CL-POM-CO2) is an emerging technology for synthesis gas generation and CO2 utilization, which is highly dependent on an oxygen carrier (OC). In this work, Fe-substituted La-hexaaluminate as the OC was found to exhibit good reactivity and stability during 50 periodic CH4/CO2 redox cycles due to the formation of magnetoplumbite La-hexaaluminate structure with the introduction of La. Deeper reduction for synthesis gas generation did not destroy the La-hexaaluminate structure via a charge compensation mechanism, which increased CH4 reactivity and further improved CO2 utilization under subsequent re-oxidation. In the La-hexaaluminate structure, O6-Fe3+(Oh) was highly active for the total oxidation of methane, while O5-Fe3+(Tr) and O4-Fe3+(Th) selectively oxidized CH4 to synthesis gas. The sole CO2 oxidant only selectively recovered O5-Fe3+(Tr) and O4-Fe3+(Th), and thus is more favorable for improving synthesis gas selectivity than O2/air, which offers an attractive opportunity for CO2 utilization. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-24T11:20:34.905167-05:
      DOI: 10.1002/aic.15942
       
  • Automated Measurements of Gas-Liquid Mass Transfer in Micro-Packed Bed
           Reactors
    • Authors: Jisong Zhang; Andrew R. Teixeira, Klavs F. Jensen
      Abstract: Gas-liquid mass transfer in micro-packed bed reactors is characterized with an automated platform integrated with in-line Fourier transform infrared spectroscopy. This setup enables screening of a multidimensional parameter space underlying absorption and with chemical reaction. Volumetric gas-liquid mass transfer coefficients (kLa) are determined for the model reaction of CO2 absorption in a methyl diethanolamine/water solution. Parametric studies are conducted varying gas and liquid superficial velocities, packed bed dimensions and packing particle sizes. The results show that kLa values are in the range of 0.24∼0.64 s−1, which is about one-to-two orders of magnitude larger than those of conventional trickle beds. An empirical correlation predicts kLa in micro-packed bed reactors in good agreement with experimental data. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-24T11:20:29.607571-05:
      DOI: 10.1002/aic.15941
       
  • On Facilitated Computation of Mesoscopic Behavior of Reaction-Diffusion
           Systems
    • Authors: Vu Tran; Doraiswami Ramkrishna
      Abstract: Various cellular and subcellular biological systems occur in the conditions where both reactions and diffusion take place. Since the concentration of species varies spatially, application of reaction-diffusion master equation (RDME) has served as an effective method to handle these complicated systems; yet solving these equation incurs a large CPU time penalty. Counter to the traditional technique of generating many sample paths, this paper introduces a method which combines Grima's effective rate equation approach1with a linear operator formalism for diffusion to capture averaged species behaviors. The formulation also shows correct results at various choices of compartment sizes, which have been found to be an important factor that can affect accuracy of the final predictions.2 It is shown that the method presented allows the computation of the mesoscopic average of reaction-diffusion systems at considerably accelerated rates (exceeding a thousand fold) over those based on sample path averages. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-24T11:20:27.542766-05:
      DOI: 10.1002/aic.15940
       
  • Nanoparticles@rGO Membrane Enabling Highly-enhanced Water Permeability and
           Structural Stability with Preserved Selectivity
    • Authors: Mengchen Zhang; Kecheng Guan, Jie Shen, Gongping Liu, Yiqun Fan, Wanqin Jin
      Abstract: Developing advanced membranes with high separation performance and robust mechanical properties is critical to the current water crisis. Herein, we report a general and scalable fabrication of nanoparticles (NPs)@reduced graphene oxide (rGO) membranes with significantly expanded nanochannels meanwhile ordered laminar structures using in situ synthesized NPs@rGO nanosheets as building blocks. Size- and density-controllable NPs were uniformly grown on the regularly stacked rGO nanosheets through coordination, followed by filtration-deposition on inner surface of porous ceramic tubes. The NPs bonded rGO building blocks enabled the as-prepared membranes 1-2 orders of magnitudes higher water permeance than the counterparts while keeping excellent rejections for various organic matters and ions. Moreover, the industrially preferred GO-based tubular membrane exhibited an extraordinary structural stability under high-pressure and cross-flow process of water purification, which is considered as a notable step toward realizing scalable GO-based membranes. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-24T11:20:25.109807-05:
      DOI: 10.1002/aic.15939
       
  • Effects of Compositional Variations on CO2 Foam under Miscible Conditions
    • Authors: S. Kahrobaei; K. Li, S. Vincent-Bonnieu, R. Farajzadeh
      Abstract: Foam can mitigate the associated problems with the gas injection by reducing the mobility of the injected gas. The presence of an immiscible oleic phase can adversely affect the foam stability. Nevertheless, under miscible conditions gas and oil mix in different proportions forming a phase with a varying composition at the proximity of the displacement front. Therefore, it is important to understand how the compositional variations of the front affect the foam behavior. In this study through several core-flood experiments under miscible condition, three different regimes were identified based on the effects of the mixed-phase composition on CO2 foam-flow behavior: In Regime 1 the apparent viscosity of the in-situ fluid was the highest and increased with increasing xCO2. In Regime 2 the apparent viscosity increased with decreasing xCO2. In Regime 3 the apparent viscosity of the fluid remained relatively low and insensitive to the value of xCO2. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-22T10:35:24.252442-05:
      DOI: 10.1002/aic.15938
       
  • Fenton-Like Degradation of Rhodamine B over Highly Durable Cu-Embedded
           Alumina: Kinetics and Mechanism
    • Authors: Yiyi Sheng; Yang Sun, Jing Xu, Jie Zhang, Yi-Fan Han
      Abstract: Cu-embedded mesoporous alumina, as a Fenton-like catalyst prepared via a sol-gel method, showed excellent activity and durability for the degradation of refectory compounds. The origin of active sites for the generation of hydroxyl radicals (•OH) were thoroughly studied using multi techniques. Cu, as the only active element, could be penetrated into the bulk of alumina and some Cu atoms were embedded into the framework. The dynamic structure of surface Cu species (the variety of Cu+/Cu2+ ratio) during the reaction were determined as well. Furthermore, the structure plasticity of catalyst has proved by optimizing preparation and reaction conditions. A 98.53% degradation of RhB was recorded within 30 min, following a pseudo-first-order reaction rate expression. Electron spin resonance spectra and •OH scavenging experiments have confirmed that •OH is the main reactive oxidant for the elimination of RhB. By the surface-enhanced Raman spectroscopy and gas chromatography-mass spectrometer results, plausible pathways of RhB degradation were elaborated. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-21T10:20:29.175322-05:
      DOI: 10.1002/aic.15937
       
  • Protic Ionic Liquid as Excellent Shuttle of MDEA for Fast Capture of CO2
    • Authors: Wen-Tao Zheng; Kuan Huang, You-Ting Wu, Xing-Bang Hu
      Abstract: A cheap protic ionic liquid (PIL), 3-(Dimethylamino)-1-propylamine acetate (abbreviated as [DMAPAH][Ac]), is investigated in this work as the activator of N-methyldiethanolamine (MDEA) for fast capture of CO2. The PIL-activated MDEA solutions show excellent performance in absorption rate and capacity (≥ 2.5 mol·kg−1). A novel absorption mechanism is proposed to account for the phenomenon, where the shuttling role of the PIL is described in detail. Additionally, the enthalpy change ΔHSOL (-45 ∼ -52 kJ·mol−1), the turnover number of the PIL and the regeneration efficiency (> 92%) are also measured. All these data show that the PIL-mediated MDEA solutions may be used as a kind of promising absorbents for fast capture of CO2. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-21T04:59:21.175095-05:
      DOI: 10.1002/aic.15921
       
  • On the use of a powder rheometer to characterize the powder flowability at
           low consolidation with torque resistances
    • Authors: Hamid Salehi; Denis Schütz, Richard Romirer, Diego Barletta, Massimo Poletto
      Abstract: The Anton Paar Powder Cell was used to measure the torque necessary to rotate an impeller in beds of glass beads, sand and alumina powders aerated between no aeration to the minimum for fluidization. Measured torque values depend on the material tested, on the air flow rate applied, on the impeller depth and on the height of the impeller blade. The effect of the impeller depth is linear for low impeller depth and is less than linear at high depth values. A model was developed for the interpretation of the experimental results based on the idea that the material is shearing on the surface described by the impeller rotation. The model allows to estimate an effectiveness of the impeller in the torque determination and also to predict the torque for the impeller at the at deepest positions at which the wall effects have to be considered. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-17T10:45:45.750695-05:
      DOI: 10.1002/aic.15934
       
  • Experiments on Breakup of Bubbles in a Turbulent Flow
    • Authors: Jiří Vejražka; Mária Zedníková, Petr Stanovský
      Abstract: The breakup of air bubbles in a turbulent water flow is studied experimentally. Water flows from a nozzle array, generating intense turbulence, and then flows downward through a cell. The velocity field is measured by PIV, and the local dissipation rate is estimated using a large-eddy PIV technique. Bubbles (1.8 to 5 mm) are injected in the bottom of the cell and rise toward the region of intense turbulence, where they break. The time spent by bubbles in various zones without breaking and the number of breakups are evaluated, providing information about the breakup frequency. The number of daughter bubbles and their size distribution are determined. The number of daughters depends on a Weber number 2ρε2/3 D'5/3/σ, where ε is the turbulent energy dissipation rate, D' is the mother particle size, ρ and σ are the liquid density and surface tension. The daughter size distribution is a function of their number. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-17T10:45:43.520383-05:
      DOI: 10.1002/aic.15935
       
  • Ultrasound–Assisted Synthesis and Characterization of Polymethyl
           Methacrylate/Reduced Graphene Oxide Nanocomposites
    • Authors: Maneesh Kumar Poddar; Mohammad Arjamand, Uttandaraman Sundararaj, Sushobhan Pradhan, Vijayanand S. Moholkar
      Abstract: This paper reports ultrasound–assisted synthesis of polymethyl methacrylate (PMMA)/reduced graphene oxide (RGO) nanocomposites by in–situ emulsion polymerization coupled with in–situ reduction of graphene oxide. The thermal degradation kinetics of the nanocomposites was also assessed with Criado and Coats-Redfern methods. Intense micro-convection generated by ultrasound and cavitation results in uniform dispersion of RGO in the polymer matrix, which imparts markedly higher physical properties to resulting nanocomposites at low (≤ 1.0 wt%) RGO loadings, as compared to nanocomposites synthesized with mechanical stirring. Some important properties of the PMMA/RGO nanocomposites synthesized with sonication (with various RGO loadings) are: glass transition temperature (0.4 wt%) = 124.5°C, tensile strength (0.4 wt%) = 40.4 MPa, electrical conductivity (1.0 wt%) = 2 × 10−7 S/cm, electromagnetic interference shielding effectiveness (1.0 wt%) = 3.3 dB. Predominant thermal degradation mechanism of nanocomposites (1.0 wt% RGO) is 1-D diffusion with activation energy of 111.3 kJ/mol. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-17T10:45:30.613722-05:
      DOI: 10.1002/aic.15936
       
  • Gas Drying with Ionic Liquids
    • Authors: Jingli Han; Chengna Dai, Lei Zhigang, Biaohua Chen
      Abstract: The gas drying technology with ionic liquids (ILs) was systematically studied ranging from the molecular level to industrial scale. The COSMO-RS model was first used to screen the suitable IL and provide theoretical insights at the molecular level. Towards CO2 gas dehydration, we measured the CO2 solubility in single [EMIM][Tf2N] and in the [EMIM][Tf2N] + H2O mixture, as well as the vapor-liquid equilibrium (VLE) of [EMIM][Tf2N] + H2O system, to justify the applicability of UNIFAC model. Based on the thermodynamic study, the rigorous equilibrium (EQ) stage mathematical model was established for process simulation. The gas drying experiment with IL was also carried out, and the water content in gas product can be reduced to 375 ppm. It was confirmed that a less flow rate of absorbent, a higher CO2 recovery ratio and a much lower energy consumption can be achieved with IL than with the conventional triethylene glycol (TEG). This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:06:00.956979-05:
      DOI: 10.1002/aic.15926
       
  • Chaotic Mixing in a Barrier-Embedded Partitioned Pipe Mixer
    • Authors: Seon Yeop Jung; Kyung Hyun Ahn, Tae Gon Kang, Gi Taek Park, Sang Ug Kim
      Abstract: Inspired by the partitioned-pipe mixer (PPM), a barrier-embedded partitioned pipe mixer (BPPM) is designed and analyzed using a numerical simulation scheme. The BPPM is a static mixer, composed of orthogonally connected rectangular plates with a pair of barriers, which divide, stretch, and fold fluid elements, leading to chaotic mixing via the baker's transformation. The aspect ratio of the plate (α) and the dimensionless height of the barrier (β) are chosen as design parameters to conduct a parameter study on the mixing performance. The flow characteristics and mixing performance are analyzed using the cross-sectional velocity vectors, Poincaré section, interface tracking, and the intensity of segregation. The results indicate that several designs of the BPPM significantly enhance the PPM's mixing performance. The best BPPMs are identified with regard to compactness and energy consumption. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:05:57.928475-05:
      DOI: 10.1002/aic.15929
       
  • CFD Simulation of the Effect of Rain on the Performance of Horizontal Wind
           Turbines
    • Authors: Hamid Arastoopour; Aiden Cohan
      Abstract: Wind turbine power output is influenced by environmental conditions, including rain. Therefore, a better understanding of the effect of rain on the performance of wind turbines is necessary. Our coupled Lagrangian-Eulerian multiphase computational fluid dynamics model was modified to more accurately simulate the momentum transfer during water film formation on the airfoils of a horizontal-axis turbine and the performance loss caused by the rainwater film on the National Renewable Energy Laboratory (NREL) turbine performance. To obtain three-dimensional numerical simulation of the wind turbine in manageable computational time, we made simplifying assumptions and verified the validity of these assumptions by simulating the flow over the S809 airfoil of the NREL turbine. In a dry environment, simulation of turbine power output agreed well with NREL experimental data. Our multiphase model showed that the rain film accumulation and flow on the surface of the turbine airfoil reduces the power output of the turbine. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:05:29.911494-05:
      DOI: 10.1002/aic.15928
       
  • Using the Discrete Element Method to develop Collisional Dissipation Rate
           Models that Incorporate Particle Shape
    • Authors: Kevin E. Buettner; Yu Guo, Jennifer S. Curtis
      Abstract: Discrete Element Method (DEM) simulations of Homogeneous Cooling Systems (HCS) are used to develop a collisional dissipation rate model for non-spherical particle systems that can be incorporated in a two-fluid multiphase flow framework. Two types of frictionless, elongated particle models are compared in the HCS simulations: glued-sphere and true cylinder. Simulation results show that the ratio of translational to rotational granular temperatures is equal to one for the true cylindrical particles with particle aspect ratios (AR) greater than one and glued-sphere particles with AR > 1.5, while the temperature ratio is less than one for glued-sphere particles with 1 
      PubDate: 2017-08-14T11:05:24.559378-05:
      DOI: 10.1002/aic.15933
       
  • Plasma Assisted Nitrogen Oxide Production from Air: Using Pulsed Powered
           Gliding Arc Reactor for a Containerized Plant
    • Authors: B. S. Patil; F. J. J. Peeters, J. A. Medrano, G. J. van Rooij, F. Gallucci, J. Lang, Q. Wang, V. Hessel
      Abstract: The production of NOx from air and air+O2 is investigated in a pulsed powered milli-scale gliding arc (GA) reactor, aiming at a containerized process for fertilizer production. Influence of feed mixture, flowrate, temperature, and Ar and O2 content are investigated at varying specific energy input. The findings are correlated with high-speed imaging of the GA dynamics. An O2 content of 40-48% was optimum, with an enhancement of 11% in NOx production. Addition of Ar and preheating of the feed resulted in lower NOx production. Lower flowrates produced higher NO concentrations due to longer residence time in the GA. The volume covered by GA depends strongly on the gas flowrate, emphasizing that the gas flowrate has a major impact on the GA dynamics and the reaction kinetics. For 0.5 L/min, 1.4 vol% of NOx concentration was realized, which is promising for a containerized process plant to produce fertilizer in remote locations. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:01:37.642803-05:
      DOI: 10.1002/aic.15922
       
  • Quantitative and Qualitative Studies of Microorganisms involved in
           Full-scale Autotrophic Nitrogen Removal Performance
    • Authors: Barbara Muñoz-Palazon; Alejandro Rodriguez-Sanchez, Antonio Castellano-Hinojosa, Jesus Gonzalez-Lopez, Mark C.M. van Loosdrecth, Riku Vahala, Alejandro Gonzalez-Martinez
      Abstract: Autotrophic nitrogen removal systems have been implemented at full-scale and provide an efficient way for nitrogen removal from industrial and urban wastewaters. Our study present qualitative and quantitative analysis of archaeal and bacterial amoA genes and Candidatus Brocadiales bacteria analyzed in six full-scale autotrophic nitrogen removal bioreactors. The results showed that Ammonium Oxidizing Bacteria (AOB) were detected in all bioreactors. However, Ammonium Oxidizing Archaea (AOA) were detected only in the non-aerated technologies. On the other hand, different Candidatus Brocadiales phylotypes appeared due to differences in influent wastewater composition and hydraulic retention time (HRT). In the same terms multivariate redundancy analysis confirmed that AOA was positively correlated with temperature, ammonium concentration and low HRT. However, AOB population was positively correlated with pH, temperature and dissolved oxygen concentration. Our data suggested a correlation between the microorganisms involved in the nitrogen removal performance and the operational conditions in the different full-scale bioreactors. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:00:37.857253-05:
      DOI: 10.1002/aic.15925
       
  • Model for the Outer Cavity of a Dual-Cavity Die with Parameters Determined
           by Two-Dimensional Finite-Element Analysis
    • Authors: Kenneth J. Ruschak; Steven J. Weinstein
      Abstract: A coating die forms liquid layers of uniform thickness for application to a substrate. In a dual-cavity coating die an outer cavity and slot improves flow distribution from an inner cavity and slot. A model for axial flow in the outer cavity must consider the ever present cross flow. A one-dimensional equation for the pressure gradient for a power-law liquid is obtained as a small departure from a uniform flow distribution and no axial flow. The equation contains a shape factor dependent on cavity shape, Reynolds number, and power-law index. The shape factor for five triangular cavity shapes is obtained by finite-element analysis and correlated for application to die design up to the onset of flow recirculation which arises at the junction of the cavity and outer slot. The performance of the combined cavity and slot is considered and the most effective design determined. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:00:33.45287-05:0
      DOI: 10.1002/aic.15927
       
  • Particle-Resolved PIV Experiments of Solid-Liquid Mixing in a Turbulent
           Stirred Tank
    • Authors: Genghong Li; Zhengming Gao, Zhipeng Li, Jiawei Wang, J.J. Derksen
      Abstract: Particle Image Velocimetry (PIV) experiments on turbulent solid-liquid stirred tank flow with careful refractive index matching of the two phases have been performed. The spatial resolution of the PIV data is finer than the size of the spherical, uniformly sized solid particles, thereby providing insight in the flow around individual particles. The impeller is a down-pumping pitch-blade turbine. The impeller-based Reynolds number has been fixed to Re=104. Overall solids volume fractions up to 8% have been investigated. The PIV experiments are impeller-angle resolved, i.e. conditioned on the angular position of the impeller. The two-phase systems are in partially suspended states with an inhomogeneous distribution of solids: high solids loadings near the bottom and near the outer walls of the tank, much less solids in the bulk of the tank. The liquid velocity fields show very strong phase coupling effects with the particles increasingly attenuating the overall circulation patterns as well as the liquid velocity fluctuation levels when the solids volume fraction is increased. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:00:30.294146-05:
      DOI: 10.1002/aic.15924
       
  • Kinetics of Glycerol Conversion to Hydrocarbon Fuels over Pd/H-ZSM-5
           Catalyst
    • Authors: Yang Xiao; Arvind Varma
      Abstract: The utilization of glycerol, primary byproduct of biodiesel production, is important to enhance process economics. In our recent prior work, it was shown that glycerol can be converted to hydrocarbon fuels over bifunctional catalysts, containing a noble metal supported on H-ZSM-5. Over Pd/H-ZSM-5 catalyst, an optimal ∼60% yield of hydrocarbon fuels was obtained. In the present work, based on experimental data over Pd/H-ZSM-5 catalyst, a lumped reaction network and kinetic model are developed. Using differential kinetic experiments over the temperature range 300-450°C, the rate constants, reaction orders and activation energies are obtained for each reaction step. The predicted values match well with experimental data for glycerol conversion up to ∼90%. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T11:00:19.259015-05:
      DOI: 10.1002/aic.15931
       
  • Bubble Splitting under Gas-Liquid-Liquid Three-Phase Flow in a Double
           T-junction Microchannel
    • Authors: Yanyan Liu; Jun Yue, Shuainan Zhao, Chaoqun Yao, Guangwen Chen
      Abstract: Gas-aqueous liquid-oil three-phase flow was generated in a microchannel with a double T-junction. Under the squeezing of the dispersed aqueous phase at the second T-junction (T2), the splitting of bubbles generated from the first T-junction (T1) was investigated. During the bubble splitting process, the upstream gas-oil two-phase flow and the aqueous phase flow at T2 fluctuate in opposite phases, resulting in either independent or synchronous relationship between the instantaneous downstream and upstream bubble velocities depending on the operating conditions. Compared with two-phase flow, the modified capillary number and the ratio of the upstream velocity to the aqueous phase velocity were introduced to predict the bubble breakup time. The critical bubble breakup length and size laws of daughter bubbles/slugs were thereby proposed. These results provide an important guideline for designing microchannel structures for a precise manipulation of gas-liquid-liquid three-phase flow which finds potential applications among others in chemical synthesis. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T10:55:28.484738-05:
      DOI: 10.1002/aic.15920
       
  • Adiabatic Time to Maximum Rate Evaluation using an Analytical Approach
    • Authors: Roberto Sanchirico
      Abstract: This article presents an analytical method for the calculation of the adiabatic time to maximum rate. The procedure is developed considering a thermal decomposition process described by a simple n-order kinetic and is based on the introduction of a special function that is possible by integrating analytically. The application of the method requires the knowledge of the thermokinetic parameters of the process under study and allows the calculation of the adiabatic time to maximum rate without the numerical integration of the heat and mass balance equations or the use of relationships based on particular simplifying hypotheses. Its validity has been demonstrated considering numerical and real experiments (thermal decomposition of trityl azide) providing in both cases times to maximum rate values which are very close to the real ones. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T10:55:26.272667-05:
      DOI: 10.1002/aic.15923
       
  • Economic Assessment of Carbon Capture by Minichannel Absorbers
    • Authors: Ziqiang Yang; Tariq S. Khan, Mohamed Alshehhi, Yasser F. AlWahedi
      Abstract: In this work we present a physio-economic model supported by lab scale experiments assessing the economic viability of minichannel based carbon capture units. The Net Present Value of capital and operating Costs (NPVC) ensued throughout the plant life is selected as the benchmarking parameter. An optimization problem is formulated and solved with the objective of minimizing the NPVC of the unit subject to constraints imposed by the physics of absorption and pressure drop limits; both of which are captured via experimentally deduced empirical correlations. The results show that the minichannel absorbers are economically competitive to conventional systems for low capacity CO2 capture achieving savings ranging from ∼50% to 3% for plant capacities ranging from 5 to 50 MMSCFD respectively primarily due to their lower capital costs. At higher plant capacities, the higher operating costs of the minichannel units dominate their NPVC and as such lead them to lose their competitiveness. This article is protected by copyright. All rights reserved.
      PubDate: 2017-08-14T10:55:24.026502-05:
      DOI: 10.1002/aic.15919
       
  • Dynamic Modeling and Simulations of the Behavior of a Fixed-Bed
           Reactor-Exchanger used for CO2 Methanation
    • Authors: Rasmey Try; Alain Bengaouer, Pierre Baurens, Christian Jallut
      Abstract: A multidimensional heterogeneous and dynamic model of a fixed-bed heat exchanger reactor used for CO2 methanation has been developed in this work that is based on mass, energy and momentum balances in the gas phase and mass and energy balances for the catalyst phase. The dynamic behavior of this reactor is simulated for transient variations in inlet gas temperature, cooling temperature, gas inlet flow rate and outlet pressure. Simulation results showed that wrong-way behaviors can occur for any abrupt temperature changes. Conversely, temperature ramp changes enable to attenuate and even fade the wrong-way behavior. Traveling hot spots appear only when the change of an operating condition shifts the reactor from an ignited steady state to a non-ignited one. Inlet gas flow rate variations reveal overshoots and undershoots of the reactor maximum temperature. This article is protected by copyright. All rights reserved.
      PubDate: 2017-07-20T10:10:25.956822-05:
      DOI: 10.1002/aic.15874
       
  • Issue information - table of contents
    • Pages: 4721 - 4721
      PubDate: 2017-10-10T18:38:23.941843-05:
      DOI: 10.1002/aic.15482
       
  • Optimization and control of bio-conversion of polymeric substrate in the
           chemostat
    • Authors: Jacques Alexandre Sepulchre; Francis Mairet, Jean-Luc Gouzé
      Pages: 4738 - 4747
      Abstract: In this article, a simple model of the growth of polymer-decomposing bacteria in a continuous stirred tank reactor is proposed. The dilution rate is controlled to optimize the output of monomers. This model is studied to find the optimum at the stationary state. However, the optimal stationary state is not robust against perturbations, leading to washout in the bioreactor. A control that makes the closed system globally stable around the optimal equilibrium is proposed. Then, a more complex model for polymers and oligomers of any lengths is studied. It is shown that the same technics also lead to a globally stable optimal point for the controlled system. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-18T11:30:45.583953-05:
      DOI: 10.1002/aic.15853
       
  • Heat assisted twin screw dry granulation
    • Authors: Y. Liu; M. R. Thompson, K. P. O'Donnell, S. Ali
      Pages: 4748 - 4760
      Abstract: A new “assisted” dry granulation method has been devised for the twin-screw granulator. The method may be beneficial to drug preparation as it limits heat exposure to only one barrel zone, much shorter than melt granulation. Its mechanism was investigated using four placebo formulations, each containing a polymer binder with a glass transition temperature lower than 130°C. Variables of study included screw configuration, screw speed, barrel zone temperature, and moisture content. Granulated samples were characterized for size and porosity while feed powders were examined for their thermal transitions, interparticle friction, cohesion, and sintering rate. Results indicated that granule coalescence relied on melting of polymer binder in the kneading blocks by a combination of heat conducted from barrel and generated from screw speed friction. Successful granulation was possible with minimal addition of water, although varying the moisture content showed the relevance of the polymer's glass transition temperature and sintering progress. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-21T18:50:47.1639-05:00
      DOI: 10.1002/aic.15820
       
  • Integrating the physics with data analytics for the hybrid modeling of the
           granulation process
    • Authors: Wafa' H. AlAlaween; Mahdi Mahfouf, Agba D. Salman
      Pages: 4761 - 4773
      Abstract: A hybrid model based on physical and data interpretations to investigate the high shear granulation (HSG) process is proposed. This model integrates three separate component models, namely, a computational fluid dynamics model, a population balance model, and a radial basis function model, through an iterative procedure. The proposed hybrid model is shown to provide the required understanding of the HSG process, and to also accurately predict the properties of the granules. Furthermore, a new fusion model based on integrating fuzzy logic theory and the Dempster-Shafer theory is also developed. The motivation for such a new modeling framework stems from the fact that integrating predictions from models which are elicited using different paradigms can lead to a more robust and accurate topology. As a result, significant improvements in prediction performance have been achieved by applying the proposed framework when compared to single models. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-23T12:55:35.374115-05:
      DOI: 10.1002/aic.15831
       
  • Interface-resolved simulations of normal collisions of spheres on a wet
           surface
    • Authors: Yali Tang; J. A. M. (Hans) Kuipers, Britta Buck, Stefan Heinrich, Niels G. Deen
      Pages: 4774 - 4787
      Abstract: Detailed knowledge of micromechanics of individual particle collisions with the presence of liquid is crucial for modelling/understanding of wet granular flows that are omnipresent in nature and industrial applications. Despite many reported studies, very limited detailed interface-resolved modeling of such collision problems has been conducted. This article presents an improved model for direct numerical simulations of normal impacts of spheres on wet surfaces. This model combines the immersed boundary method and the volume-of-fluid method supplemented with a model describing gas-liquid-solid contact line. It is demonstrated that our model not only correctly describes the collision dynamics of wet particles, but also well captures the dynamics of the liquid bridge formed during the collision. Quantitative agreement is obtained between the simulation results and the experimental data. It is concluded that the developed model constitutes a powerful tool to complement experimental studies, which are challenging for more complex wet collision systems in practice. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-11T12:35:37.460015-05:
      DOI: 10.1002/aic.15847
       
  • Stochastic programming models for optimal shale well development and
           refracturing planning under uncertainty
    • Authors: Markus G. Drouven; Ignacio E. Grossmann, Diego C. Cafaro
      Pages: 4799 - 4813
      Abstract: In this work we present an optimization framework for shale gas well development and refracturing planning. This problem is concerned with if and when a new shale gas well should be drilled at a prospective location, and whether or not it should be refractured over its lifespan. We account for exogenous gas price uncertainty and endogenous well performance uncertainty. We propose a mixed-integer linear, two-stage stochastic programming model embedded in a moving horizon strategy to dynamically solve the planning problem. A generalized production estimate function is described that predicts the gas production over time depending on how often a well has been refractured, and when exactly it was restimulated last. From a detailed case study, we conclude that early in the life of an active shale well, refracturing makes economic sense even in low-price environments, whereas additional restimulations only appear to be justified if prices are high. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-15T13:45:48.623833-05:
      DOI: 10.1002/aic.15804
       
  • Prediction of maximum recoverable mechanical energy via work integration:
           A thermodynamic modeling and analysis approach
    • Authors: Aida Amini-Rankouhi; Yinlun Huang
      Pages: 4814 - 4826
      Abstract: Thermal energy and mechanical energy are two common forms of energy consumed significantly in the process industries. While thermal energy can be effectively recovered using matured heat integration technologies, recovery of mechanical energy through work integration has not been fully explored. It is shown that work integration can be achieved through synthesizing work exchange networks (WENs), where work exchangers are operated in a batch mode, and compressors and expanders are operated in a continuous mode; this renders network synthesis a very sophisticated design task. It is greatly beneficial if the maximum amount of mechanical energy recoverable by a WEN can be determined prior to network design. In this article, we introduce a thermodynamic modeling and analysis method to identify accurately the maximum amount of recoverable mechanical energy of any process system of interest. The method is rigorous and general for target setting of mechanical energy recovery prior to WEN synthesis. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-15T13:40:27.617466-05:
      DOI: 10.1002/aic.15813
       
  • Process design and control optimization: A simultaneous approach by
           multi-parametric programming
    • Authors: Nikolaos A. Diangelakis; Baris Burnak, Justin Katz, Efstratios N. Pistikopoulos
      Pages: 4827 - 4846
      Abstract: We present a framework for the application of design and control optimization via multi-parametric programming through four case studies. We develop design dependent multi-parametric model predictive controllers that are able to provide the optimal control actions as functions of the system state and the design of the process at hand, via our recently introduced PAROC framework (Pistikopoulos et al, Chem Eng Sci. 2015;136:115–138). The process and the design dependent explicit controllers undergo a mixed integer dynamic optimization (MIDO) step for the determination of the optimal design. The result of the MIDO is the optimal design of the process under optimal operation. We demonstrate the framework through case studies of a tank, a continuously stirred tank reactor, a binary distillation column and a residential cogeneration unit. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-25T15:47:39.501806-05:
      DOI: 10.1002/aic.15825
       
  • Feasible separation regions for distillation I: Structure
    • Authors: Lechoslaw J. Krolikowski
      Pages: 4847 - 4861
      Abstract: A feasible separation region is determined for only four special combinations of a saturated vapor/liquid feed and total/partial condenser or reboiler. This work addresses the construction of a feasible separation region for a general case where the feed is a mixture of vapor and liquid in equilibrium and where the column is equipped with a partial/total condenser and reboiler. The analysis reveals that the product composition sets (which are defined for various reflux and reboil ratios and a fixed number of stages in each column section) are the main elements of the feasible separation region. The application of the geometric model of the column in combination with the shape of the distillation line led to the conclusion that the feasible separation region is the union of two product composition sets for both enriching and stripping columns both with an infinite number of stages. The boundary of the feasible separation region consists of several curves related to specific types of operating modes in the column. Some of these curves create a well-known product composition multitude, whereas other curves form a generalized distillation limit. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-29T08:15:27.977066-05:
      DOI: 10.1002/aic.15839
       
  • Feasible separation regions for distillation II: A generalized
           distillation limit
    • Authors: Lechoslaw J. Krolikowski
      Pages: 4862 - 4869
      Abstract: The boundary of the feasible separation region consists of several curves that are related to specific types of operating modes of the column. Some of these curves create a well-known product composition multitude, whereas other curves form a generalized distillation limit. The generalized distillation limit demarcates the sloppy splits (i.e., separations in which the composition of at least one product lies inside the composition space) from regions not accessible by distillation and depends on the thermodynamic state of the feed (a mixture of vapor and liquid in equilibrium or saturated vapor/liquid) and column equipment (total/partial condenser and total/partial reboiler). The mathematical equations describing the generalized distillation limit are obtained based on the relationships between the curves (which form the generalized distillation limit) and specific types of operating modes of the column as well as the material balances for the enriching and stripping columns. Furthermore, the vapor and liquid pinch-point curves, which go through the feed composition point, are not dependent on the thermodynamic state of the feed and column equipment. In addition, an algorithm for determining the generalized distillation limit is obtained. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-04T15:10:26.277978-05:
      DOI: 10.1002/aic.15845
       
  • How graphical analysis helps interpreting optimal experimental designs for
           nonlinear enzyme kinetic models
    • Authors: Rüdiger Ohs; Jan Wendlandt, Antje C. Spiess
      Pages: 4870 - 4880
      Abstract: Progress curve experiments combined with optimal experimental design (OED) are an efficient approach to determine enzyme kinetics. However, it is hardly possible to verify why specific experiments are suggested for nonlinear enzyme kinetic model identification. Therefore, we systematically investigated the surface and contour plots of the sensitivities and of the OED criteria which are based on sensitivities. The model reaction was an enzyme catalyzed self-ligation of aldehydes to chiral 2-hydroxyketones. The visualization improved the understanding of OED and allowed for deducing and confirming five suggestions for kinetic identification: (1) Avoid experiments vicinal to the reaction equilibrium, (2) Choose the design space as large as possible, (3) Prefer D(eterminant)- and E(igenvalue)-criteria over the A(verage)-criterion, (4) Apply enzyme concentrations such that the reaction does not complete too fast, and (5) Few optimal experiments result in significantly improved parameter estimations. The graphical analysis also provides information about selecting appropriate optimization algorithms. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-21T19:16:17.377599-05:
      DOI: 10.1002/aic.15814
       
  • Investigation of hydrodynamics in bubble column with internals using
           radioactive particle tracking (RPT)
    • Authors: Dinesh V. Kalaga; H. J. Pant, Sameer V. Dalvi, Jyeshtharaj B. Joshi, Shantanu Roy
      Pages: 4881 - 4894
      Abstract: Even though many experimental investigations are reported on this subject of liquid velocity patterns in bubble columns, most of the reported work is restricted to measurements at the near wall regions, columns without internals, and in low dispersed phase hold-ups. In the present work, a non-invasive radioactive particle tracking technique was employed to quantify the hydrodynamic parameters in 120 mm diameter bubble column with, and without vertical rod internals, using air/water system as the working fluids. The superficial air velocities cover a wide range of flow regimes: from 14 to 265 mm/s. Experiments were performed for two internals configurations with percentage obstruction area varied from 0 (without internals) to 11.7%. We report that the liquid phase hydrodynamics depends strongly on superficial gas velocity and internals. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-23T12:50:37.941432-05:
      DOI: 10.1002/aic.15829
       
  • Inhomogeneous distribution of platinum and ionomer in the porous cathode
           to maximize the performance of a PEM fuel cell
    • Authors: Lei Xing; Weidong Shi, Prodip K. Das, Keith Scott
      Pages: 4895 - 4910
      Abstract: A proton exchange membrane (PEM) fuel cell model, accounting for the combined water transport mechanism, ionomer swelling, water phase-transfer, two-phase flow and transport processes, is developed. The inhomogeneous distributions of Pt and ionomer inside the catalyst layer (CL) are numerically studied to achieve an optimal cell performance for two types of oxygen reduction reaction catalysts at different loadings. Results indicate that the optimal variation in loading through the thickness of the electrode (slopes) of Pt catalyst and ionomer vary with conditions of operation. An optimal platinum slope increases the agglomerate effectiveness factor and decreases the second Damköhler number near the CL-membrane interface. An optimal ionomer slope increases the CL porosity near the GDL-CL interface and decreases the mass transport resistance of reactant through the ionomer film. Their interaction shows that the optimal platinum slope is a tradeoff between the electrochemical active surface area and porosity at high current densities. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-25T15:37:49.708716-05:
      DOI: 10.1002/aic.15826
       
  • Structure and catalytic consequence of Mg-modified VOx/Al2O3 catalysts for
           propane dehydrogenation
    • Authors: Tengfang Wu; Gang Liu, Liang Zeng, Guodong Sun, Sai Chen, Rentao Mu, Sika Agbotse Gbonfoun, Zhi-Jian Zhao, Jinlong Gong
      Pages: 4911 - 4919
      Abstract: Supported VOx catalysts are promising nonoxidative propane dehydrogenation (PDH) materials for their commercially attractive activity and propylene selectivity. However, they frequently suffer from rapid deactivation caused by coke deposition. This article describes the promoting role of magnesium on the stability of VOx/Al2O3 catalysts for PDH. A series of VOx/Al2O3 and Mg-modified VOx/Al2O3 catalysts were synthesized by an incipient wetness impregnation method. The catalysts were carefully characterized by Raman spectra, UV-Vis spectra, STEM, TGA and in situ DRIFTS. We showed that the stability of a 12V/Al2O3 catalyst was significantly improved on addition of small amounts of MgO. Experimental evidences indicate that V2O5 nanoparticles emerge in the 12V/Al2O3 samples, and appropriate Mg addition helps dispersing the V2O5 nanoparticles into 2D VOx species thus decreasing coke formation and improving stability in nonoxidative dehydrogenation of propane. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-29T08:35:44.41716-05:0
      DOI: 10.1002/aic.15836
       
  • A novel route for green conversion of cellulose to HMF by cascading
           enzymatic and chemical reactions
    • Authors: Yunlei Zhang; Pei Jin, Meng Liu, Jianming Pan, Yongsheng Yan, Yao Chen, Qingang Xiong
      Pages: 4920 - 4932
      Abstract: In this work, a novel route to deconstruct cellulose into 5-hydroxymethylfurfural (HMF) by cascading enzymatic and chemical reactions is reported. For biocatalyst preparation, Fe3O4 nanoparticles encapsulated SBA-15 with appropriate pore size was synthesized and utilized as magnetic scaffolds for the immobilization of cellulase. For chemical catalyst preparation, sulfated zirconium dioxide conformed monolayers were grafted on SBA-15 template to create thermally robust mesoporous catalysts with tunable solid basic/Lewis acid and Brønsted acid sites. Catalytic performance of biocatalyst and chemical catalyst was explored in the aqueous phase conversion of IL pretreated cellulose to glucose, and in the iPrOH/water solvent conversion of glucose to HMF conversion, respectively. After the optimization of reaction conditions, a sequential conversion of pretreated cellulose to glucose and glucose to HMF was performed, and 43.6% HMF yield can be obtained. The cascaded enzymatic and chemocatalytic reaction system demonstrates an effective and economically friendly process for biomass energy conservation. A novel route for green conversion of IL pretreated cellulose to 5-hydroxymethylfurfural (HMF) by cascading an enzymatic catalysis in an aqueous system with chemocatalysis in an iPrOH/water solvent mixture is reported. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-02T06:45:39.131231-05:
      DOI: 10.1002/aic.15841
       
  • The development of kinetics model for CO2 absorption into tertiary amines
           containing carbonic anhydrase
    • Authors: Bin Liu; Xiao Luo, Zhiwu Liang, Wilfred Olson, Helei Liu, Raphael Idem, Paitoon Tontiwachwuthikul
      Pages: 4933 - 4943
      Abstract: CO2 absorption into aqueous solutions of two tertiary alkanolamines, namely, MDEA and DMEA with and without carbonic anhydrase (CA) was investigated with the use of the stopped-flow technique at temperatures in the range of 293–313 K, CA concentration varying from 0 to 100 g/m3 in aqueous MDEA solution with the amine concentration ranging from 0.1 to 0.5 kmol/m3, and CA concentration varying from 0 to 40 g/m3 in aqueous DMEA solution with the amine concentration ranging from 0.05 to 0.25 kmol/m3. The results show that the pseudofirst-order reaction rate (k0, amine; s−1) is significantly enhanced in the presence of CA as compared with that without CA. The enhanced values of the kinetic constant in the presence of CA has been calculated and a new kinetics model for reaction of CO2 absorption into aqueous tertiary alkanolamine solutions catalyzed by CA has been established and used to make comparisons of experimental and calculated pseudo first-order reaction rate constant (k0, with CA) in CO2-MDEA-H2O and CO2-DMEA-H2O solutions. The AADs were 15.21 and 15.17%, respectively. The effect of pKa on the CA activities has also been studied by comparison of CA activities in different tertiary amine solutions, namely, TEA, MDEA, DMEA, and DEEA. The pKa trend for amines were: DEEA > DMEA > MDEA > TEA. In contrast, the catalyst enhancement in amines was in the order: TEA> MDEA> DMEA> DEEA. Therefore, it can be seen that the catalyst enhancement in the amines decreased with their increasing pKa values. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-03T12:58:20.739157-05:
      DOI: 10.1002/aic.15833
       
  • Modeling the reaction event history and microstructure of individual
           macrospecies in postpolymerization modification
    • Authors: Julio C. Hernández-Ortiz; Paul H. M. Van Steenberge, Marie-Françoise Reyniers, Guy B. Marin, Dagmar R. D'hooge, Jan N. E. Duchateau, Klaas Remerie, Carolina Toloza, Ana Luisa Vaz, Fons Schreurs
      Pages: 4944 - 4961
      Abstract: For postpolymerization modification, a novel kinetic Monte Carlo (kMC) modeling strategy for the description of the reaction event history and the evolution of the microstructure of individual macrospecies with a complex topology is presented. The kMC model allows the kinetic analysis of free radical induced grafting of vinyl monomers onto polyethylene (PE) chains, assuming isothermal conditions and perfect macromixing and accounting for diffusional limitations on the microscale. Not only average characteristics such as the monomer conversion, grafting selectivity and yield, but also the chain length distribution (CLD) of all macromolecular species types, the average “from/to” grafting and cross-linking density, the number of grafts and cross-links per individual macromolecule, the chain length of every graft, and the CLD of the grafted chains are calculated. Under typical grafting conditions, depropagation and diffusional limitations cannot be ignored. The functionalization occurs mainly on those macrospecies in the PE-CLD with a high mass concentration. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-06T14:40:35.776393-05:
      DOI: 10.1002/aic.15842
       
  • Dehydrogenation kinetic model of heavy paraffins
    • Authors: Hongbo Jiang; Yilong Zhou, Liqun Zhou, Yu Wang, Jing Cao
      Pages: 4962 - 4970
      Abstract: Based on the dehydrogenation mechanism of heavy paraffins under industrial conditions, the intrinsic reaction kinetic model and catalyst deactivation model were established considering the influence of side reactions with different carbon-number heavy paraffins. Based on the experimental data of dehydrogenation reactions with different carbon-number paraffins in an axial continuous-flow isothermal fixed-bed microreactor, Powell optimization method was used to estimate the model parameters. The results show that there is a liner relationship between the activation energies and pre-exponential factors of homologous reactions and carbon number of paraffins. A correlation model about the deactivation rate constants under different conditions was established. The validation of kinetic model showed that the model could be used to predict detailed product distribution with different feedstocks under different reaction conditions. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-06T14:45:21.630645-05:
      DOI: 10.1002/aic.15848
       
  • How penultimate monomer unit effects and initiator influence ICAR ATRP of
           n-butyl acrylate and methyl methacrylate
    • Authors: Stijn K. Fierens; Paul H. M. Van Steenberge, Marie-Françoise Reyniers, Guy B. Marin, Dagmar R. D'hooge
      Pages: 4971 - 4986
      Abstract: The relevance of penultimate monomer unit (PMU) effects and the selection of the correct initiator species under typical reversible deactivation radical copolymerization conditions is illustrated, using matrix-based kinetic Monte Carlo simulations allowing the visualization of all monomer sequences along individual chains. Initiators for continuous activator regeneration atom transfer radical polymerization (ICAR ATRP) is selected as illustrative polymerization technique with n-butyl acrylate and methyl methacrylate as comonomers, aiming at the synthesis of well-defined gradient copolymers. Using literature based model parameters, in particular temperature dependent monomer and radical reactivity ratios, it is demonstrated that PMU effects on propagation and ATRP (de)activation cannot be ignored to identify the most suited ICAR ATRP reactants (e.g., tertiary ATRP initiator) and reaction conditions (e.g., feeding rates under fed-batch conditions). The formulated insights highlight the need for further research on PMU effects on all reaction steps in radical polymerization. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-09T09:45:32.103617-05:
      DOI: 10.1002/aic.15851
       
  • Assessment of kinetics of photoinduced Fe-based atom transfer radical
           polymerization under conditions using modeling approach
    • Authors: Yin-Ning Zhou; Zheng-Hong Luo
      Pages: 4987 - 4997
      Abstract: Kinetic insight into photoinduced Fe-based atom transfer radical polymerization (ATRP) involving monomer-mediated photoreduction was performed by modeling approach for the first time. Preliminary numerical analysis of number-average molar mass (Mn) derivation in this specific system was given. Simulation results provided a full picture of reactant concentration and reaction rate throughout the entire polymerization. Methyl 2,3-dibromoisobutyrate (MibBr2) generated from methyl methacrylate (MMA)-mediated photoreduction as the leading factor for the deviation of Mn from theoretical value was confirmed by reaction contributions in α-bromophenylacetate (EBPA) containing system. Reasonable predictions were made with respect to the polymerizations under a variety of initial conditions. Results show that increasing light intensity will shorten transition period and increase steady state polymerization rate; decreasing catalyst loading will cause the decrease in polymerization rate and Mn deviation; varying initiation activity will slightly increase the time to attain steady state of dispersity (Mw/Mn) evolution and enormously change the fraction of reaction contributions; increasing targeted chain length will extend transition period, decrease steady state polymerization rate, increase Mn deviation degree with same reaction contributions, and decrease the time to attain the steady state of Mw/Mn. The numerical analysis presented in this work clearly demonstrates the unique ability of our modeling approach in describing the kinetics of photoinduced Fe-based ATRP of MMA. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-17T09:45:38.326879-05:
      DOI: 10.1002/aic.15850
       
  • Oxidation of caffeine by acid-activated ferrate(VI): Effect of ions and
           natural organic matter
    • Authors: Kyriakos Manoli; George Nakhla, Ajay K. Ray, Virender K. Sharma
      Pages: 4998 - 5006
      Abstract: Caffeine (CAF) is the most commonly consumed stimulant and frequently detected emerging pollutant in influents and effluents of wastewater treatment plants (WWTP) and surface waters. Acid-activated ferrate(VI) (FeVIO42−, Fe(VI)) oxidizes CAF in water in seconds to minutes at three times lower molar ratio of Fe(VI) to CAF than oxidative transformation observed in hours by nonactivated Fe(VI) (8.0 vs. 25.0). CAF oxidation by acid-activated Fe(VI) is not affected by ionic constituents of water. Organic components of natural organic matter (NOM) and secondary effluent wastewater (SE) decrease efficiency of CAF transformation. However, acid-activated Fe(VI) could mineralize other organics present in both NOM and SE as indicated by the dissolved organic carbon (DOC) removal. Comparatively, no mineralization was seen without activation of Fe(VI). Four oxidized products of CAF were identified by a liquid chromatography high resolution mass spectrometry technique. The reaction pathways of the oxidation of CAF by activated Fe(VI) have been proposed. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-08-02T13:50:28.185732-05:
      DOI: 10.1002/aic.15878
       
  • Integrated B2B-NMPC control strategy for batch/semibatch crystallization
           processes
    • Authors: Qinglin Su; Min-Sen Chiu, Richard D. Braatz
      Pages: 5007 - 5018
      Abstract: The uncertainty in crystallization kinetics is of major concern in manufacturing processes, which can result in deterioration of most model-based control strategies. In this study, uncertainties in crystallization kinetic parameters were characterized by Bayesian probability distributions. An integrated B2B-NMPC control strategy was proposed to first update the kinetic parameters from batch to batch using a multiway partial least-squares (MPLS) model, which described the variances of kinetic parameters from that of process variables and batch-end product qualities. The process model with updated kinetic parameters was then incorporated into an NMPC design, the extended prediction self-adaptive control (EPSAC), for online control of the final product qualities. Promising performance of the proposed integrated strategy was demonstrated in a simulated semibatch pH-shift reactive crystallization process to handle major crystallization kinetic uncertainties of L-glutamic acid, wherein smoother and faster convergences than the conventional B2B control were observed when process dynamics were shifted among three scenarios of kinetic uncertainties. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-15T13:45:37.16142-05:0
      DOI: 10.1002/aic.15810
       
  • The effect of the size of square microchannels on hydrodynamics and mass
           transfer during liquid-liquid slug flow
    • Authors: Mehdi Sattari-Najafabadi; Mohsen Nasr Esfahany, Zan Wu, Bengt Sundén
      Pages: 5019 - 5028
      Abstract: The present study investigated the influence of square microchannel (MC) size on hydrodynamics and mass transfer in the liquid-liquid slug flow regime. Three square MCs with the hydraulic diameters of 200, 400, and 600 μm were used. The employed method for estimating mass-transfer coefficients remarkably increased the accuracy of the results. The findings revealed that decreasing the MC size improved the interfacial area due to plug length enlargement and deteriorated mass-transfer resistances because of augmented internal circulations, leading to the considerable enhancement of mass-transfer coefficients. The increasing effect on the overall mass-transfer coefficient became greater with flow velocity, showing that size effect on mass-transfer resistances was more profound at higher flow velocities. The influence of size on the interfacial area was significantly greater than that on mass-transfer resistances due to the significant increment of wall film length with the decrease in channel size. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-21T18:51:01.260467-05:
      DOI: 10.1002/aic.15822
       
  • A mechanistic modeling framework for gas-phase adsorption kinetics and
           fixed-bed transport
    • Authors: Austin P. Ladshaw; Sotira Yiacoumi, Ronghong Lin, Yue Nan, Lawrence L. Tavlarides, Costas Tsouris
      Pages: 5029 - 5043
      Abstract: Adsorption is a complex physicochemical process involving interparticle transport, interphase mass-transfer, intraparticle diffusion, and surface reactions. Although the exact description of the adsorption process will inevitably vary from system to system, it will always be governed by those primary mechanisms. Therefore, by devising a model framework that can inherently include those mechanisms, it would be possible to create a modeling platform on which many different adsorption problems could be solved numerically. To accomplish this task, a generalized 1-D conservation law model was created to include the necessary mechanisms of adsorption on several different geometrical domains. Specific model applications for adsorption were developed under that framework and validated using experimental data available in literature or obtained in this work. This modeling platform makes it easier to model various adsorption problems and develop new adsorption models because of the common treatment of the mathematics governing the physical processes. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-12T13:40:28.242002-05:
      DOI: 10.1002/aic.15855
       
  • Adsorptive removal of refractory sulfur compounds by tantalum oxide
           modified activated carbons
    • Authors: Amir A Iravani; Kamalakar Gunda, Flora T.T. Ng
      Pages: 5044 - 5053
      Abstract: Adsorptive desulfurization of a model diesel fuel consisting of dibenzothiophene (DBT) or 4,6-dimethyldibenzothiophene(4,6-DMDBT) in hexadecane was performed over activated carbons and tantalum oxide modified (Ta-x/ACC, x= 2, 5 or 10 wt % Ta, Activated Carbon Centaur) activated carbons at 50°C. The adsorption isotherm for ACC followed the Langmuir model while the adsorption on Ta-5/ACC fitted the Sips equation indicating more than one type of adsorption sites. Characterization studies indicated new types of adsorption site resulting from the incorporation of Ta oxide into the porous structure of the ACC. XPS data suggested interaction of Ta with the S atom in DBT. The heats of adsorption in the liquid phase determined from micro flow calorimetry for DBT in C16 confirmed the interaction of Ta with DBT. Ta-5/ACC exhibited the highest adsorption capacity for 4,6-DMDBT compared to literature reports. Competitive adsorption experiments showed the adsorption capacity as follows: quinoline> DBT≫ naphthalene. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-17T09:50:40.92988-05:0
      DOI: 10.1002/aic.15852
       
  • Predicting phase behavior in aqueous systems without fitting binary
           parameters II: Gases and non-aromatic hydrocarbons
    • Authors: Ilya Polishuk; Helena Lubarsky, Dong NguyenHuynh
      Pages: 5064 - 5075
      Abstract: This investigation continues a series of studies evaluating the capability of the recently proposed CP-PC-SAFT and sPC-SAFT of Liang et al. to estimate the thermodynamic properties of aqueous systems in the entirely predictive manner. Similarly to the previously considered systems, CP-PC-SAFT remains a realistic estimator of the available data on critical loci, high pressure-high temperature phase equilibria and volumetric properties also in the cases of non-polar gases and non-aromatic hydrocarbons from argon and nitrogen till n-eicosane and squalene while keeping zero values of binary parameters. Nevertheless, such application of the model poses certain unavoidable compromises on its accuracy. Inter alia, CP-PC-SAFT is a particularly inaccurate estimator of the water-rich liquid phases away from the critical points. sPC-SAFT predicts these data in a more reliable manner. Moreover, its predictive capability goes beyond the liquid phases and it exhibits a remarkable accuracy in forecasting various phase equilibria below the critical point of water. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-14T09:30:28.47589-05:0
      DOI: 10.1002/aic.15815
       
  • A molecular-thermodynamic approach to predict the micellization of binary
           surfactant mixtures containing amino sulfonate amphoteric surfactant and
           nonionic surfactant
    • Authors: Zhao Hua Ren
      Pages: 5076 - 5082
      Abstract: A molecular-thermodynamic approach was adopted to predict the value of mixed critical micelle concentration (cmc) for the binary surfactant mixtures constituted by an amino sulfonate amphoteric surfactant, sodium 3-(N-dodecyl ethylenediamino)-2-hydropropyl sulfonate (abbr. C12AS), and a nonionic surfactant, octylphenol polyethylene ether (OP-n, where n denotes the average number of oxyethylene glycol ether). In this investigation, considering two positive charges on the hydrophilic group of C12AS, which is unlike to conventional zwitterionic surfactants having one positive charge (such as, alkylbetaine, etc.), three schemes were designed to obtain the geometric parameter describing the dipole structure of C12AS. According to the selected optimum scheme, four cases corresponding to the different conformations of both the headgroup and the hydrocarbon chain of surfactant were discussed. The results show that the predicted value of mixed cmc for the C12AS/OP-n mixtures agrees well with the experiment value. The deviation of the predicted value from the experimental value can be explained by the effect of the hydrophilicity of OP-n on the process of micellization. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-19T18:24:07.868702-05:
      DOI: 10.1002/aic.15817
       
  • Prediction of thermodynamic properties of aqueous electrolyte solutions
           using equation of state
    • Authors: Reza Shahriari; Mohammad Reza Dehghani
      Pages: 5083 - 5097
      Abstract: In this study, a predictive model is presented for estimation of second order thermodynamic properties of electrolyte solutions. In order to provide a comprehensive understanding, the capability of modified electrolyte PC-SAFT up to high pressure and temperature has been studied. In addition to the first order derivative thermodynamic properties, the Gibbs free energy, enthalpy and heat capacity of aqueous electrolyte solutions at infinite dilution are predicted. Using new methodology, the dielectric constant is modified to keep the pressure, temperature, and ionic strength dependency. Our results show that the Born term has a significant contribution on prediction of second order derivative properties. Meanwhile the impact of temperature-dependent solution dielectric constant on standard state heat capacity is studied. Finally, the isobaric heat capacity at various salt concentrations is predicted without any adjustable parameters. The results of this work indicate an acceptable agreement with experimental data especially at high pressure and temperature. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-21T19:04:57.851925-05:
      DOI: 10.1002/aic.15827
       
  • Transferable potentials for phase equilibria. Improved united-atom
           description of ethane and ethylene
    • Authors: Mansi S. Shah; J. Ilja Siepmann, Michael Tsapatsis
      Pages: 5098 - 5110
      Abstract: A more accurate version of the Transferable Potentials for Phase Equilibria—United Atom force field, called TraPPE–UA2, for ethane and ethylene is presented. Very similar molecular volumes, shapes, and self- and cross-interaction strengths of ethane and ethylene make their separation fundamentally interesting and industrially challenging. Separation factors as low as 1.5–3.0 necessitate very accurate molecular models in order to be able to computationally design potential separation processes. Additional force field parameters, namely the distance between the Lennard-Jones sites for both compounds and partial charges only for ethylene, are introduced in the parameterization and different combining rules for the Lennard-Jones interaction are considered. In addition to the liquid densities and critical temperature, the training set also includes saturation vapor pressures to yield an accurate two-site ethane model. Binary ethane/ethylene, CO2/ethylene, and H2O/ethylene vapor–liquid equilibria and H2O/ethylene dimer calculations are used for further optimization of a four-site ethylene model. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-29T08:05:53.448802-05:
      DOI: 10.1002/aic.15816
       
  • Universal correlation for gas hydrates suppression temperature of
           inhibited systems: I. Single salts
    • Authors: Yue Hu; Bo Ram Lee, Amadeu K. Sum
      Pages: 5111 - 5124
      Abstract: Reliable prediction of hydrate suppression temperature in presence of inhibitors, such as salts, over a wide range of pressures (up to 200 MPa) is critically important, especially in the area of deepwater oil and gas production. However, the existing models and correlations that account for salts have severe limitations and deficiencies in estimating the hydrate suppression temperature. Herein, we propose a new correlation, to be called Hu-Lee-Sum correlation, that significantly improves the predictions of the hydrate suppression temperature by considering the salt species and concentrations, system temperature and pressure, and hydrate structure. This article represents part I of this work and it will detail the development of the correlation and demonstrate the generality and universality of the correlation to predict the hydrate suppression temperature for any single salt system. Specifically, we show accurate predictions for the hydrate suppression temperature for a number of chloride and bromide salt brine systems. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-11T12:35:47.101303-05:
      DOI: 10.1002/aic.15846
       
  • A rigorous method to evaluate the consistency of experimental data in
           phase equilibria. Application to VLE and VLLE
    • Authors: Luís J. Fernández; Juan Ortega, Jaime Wisniak
      Pages: 5125 - 5148
      Abstract: This work forms part of a broader study that describes a methodology to validate experimental data of phase equilibria for multicomponent systems from a thermodynamic-mathematical perspective. The goal of this article is to present and justify this method and to study its application to vapor–liquid equilibria (VLE) and vapor–liquid–liquid equilibria (VLLE), obtained under isobaric/isothermal conditions. A procedure based on the Gibbs-Duhem equation is established which presents two independent calculation paths for its resolution: (a) an integral method and (b) a differential method. Functions are generated for both cases that establish the verification or consistency of data, δψ for the integral test and δζ for the differential approach, which are statistically evaluated by their corresponding average values [δψ¯,δζ¯], and the standard deviations [s(δψ),s(δζ)]. The evaluation of these parameters for application to real cases is carried out using a set of hypothetical systems (with data generated artificially), for which the values are adequately changed to determine their influence on the method. In this way, the requirements of the proposed method for the data are evaluated and their behavior in response to any disruption in the canonical variables (p,T, phase compositions). The conditions for thermodynamic consistency of data are: δψ¯
      PubDate: 2017-08-09T22:11:04.621855-05:
      DOI: 10.1002/aic.15876
       
  • Magnetohydrodynamics thin film fluid flow under the effect of
           thermophoresis and variable fluid properties
    • Authors: Liaqat Ali; Saeed Islam, Taza Gul, Ali Saleh Alshomrani, Ilyas Khan, Aurangzeb Khan
      Pages: 5149 - 5158
      Abstract: The thin film flow of fluid over a stretching sheet with variable fluid properties under the effect of thermophoresis has been investigated. A transverse magnetic field is also applied to the fluid flow in the presence of thermal radiation. The governing equations have been transformed through suitable similarity variables into nonlinear coupled differential equations with physical conditions. The solution of the coupled problem has been obtained by using the second alternative of OHAM (OHAM-2). The solution of the coupled problem through this new method and its fast convergence is mainly focused in this work. The effect of physical parameters appears in the problem are shown graphically and discussed. Finally, the obtained results are compared with a numerical (ND-Solve) method to authenticate the code of the OHAM-2. The physical and numerical agreement of these two methods has been shown. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-14T13:46:01.671274-05:
      DOI: 10.1002/aic.15794
       
  • Quantitative dependence of CH4-CO2 dispersion on immobile water fraction
    • Authors: Marco Zecca; Sarah J. Vogt, Abdolvahab Honari, Gongkui Xiao, Einar O. Fridjonsson, Eric F. May, Michael L. Johns
      Pages: 5159 - 5168
      Abstract: Enhanced Gas Recovery (EGR) involves CO2 injection into natural gas reservoirs to both increase gas recovery and trap CO2. EGR viability can be determined by reservoir simulations; however, these require a description of fluid dispersion (mixing) between the supercritical CO2 and natural gas. Here, this dispersivity (α) in sandstone rock plugs as a function of residual water fraction is quantified. To ensure the accuracy of such data, a novel core flooding experimental protocol that ensured an even spatial distribution of water was designed, minimized erroneous entry/exit contributions to mixing, and minimized dissolution of the CO2 into the water phase. Dispersivity was found to increase significantly with water content, although the differences in α between sandstones were eliminated upon the inclusion of residual water. This enabled development of a correlation between α and water content and, hence, between the dispersion coefficient and Peclet number that is readily incorporable into reservoir simulations. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-23T12:55:26.480599-05:
      DOI: 10.1002/aic.15824
       
  • On air entrainment in a water pool by impingement of a jet
    • Authors: Vatsal Sanjay; Arup Kumar Das
      Pages: 5169 - 5181
      Abstract: Air entrainment due to impingement of a water jet on a pool is studied extensively to understand the physics of the initiation and the cluster of bubbles formed below the free surface. Possible outcomes due to the jet impingement in a pool have been identified as smooth free surface without entrainment or formation of rigorous bubble cluster below the jet-pool contact. Triangular entrained region is found to be a three-dimensional association of disconnected bubble population continuously breaking and making with the neighbors. A correlation for prediction of maximum entrained height for a range of jet diameters and lengths is proposed. The trajectory of a single bubble is also studied to understand the kinematics of the bubble cluster. Alongside, an electrical conductivity probe has been used to examine the probabilistic presence of the bubble at a given depth in the liquid pool. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-25T15:27:54.815303-05:
      DOI: 10.1002/aic.15828
       
  • Pipe flow of a dense emulsion: Homogeneous shear-thinning or shear-induced
           migration'
    • Authors: Micheline Abbas; Amélie Pouplin, Olivier Masbernat, Alain Liné, Sandrine Décarre
      Pages: 5182 - 5195
      Abstract: The flow field of a 70% concentrated noncolloidal o/w emulsion in a pipe has been investigated by means of Particle Image Velocimetry in a matched refractive index medium. At steady state and in laminar regime, the shape of axial velocity profiles is not parabolic and exhibits a shear-thinning behavior of the dense emulsion, with a flow index of 0.5 and a negligible yield stress (less than 1 Pa). However, instead of a square root law, the pressure drop increases linearly with Um. To explain this apparent inconsistency, two mechanisms of different nature are considered. The first originates from a possible relation between the consistency factor and the drop mean diameter. The second mechanism is shear-induced migration and leads to the development of a concentration gradient in the pipe cross section. Both mechanisms considered reconcile the experimental data, the apparent local shear-thinning behavior and the linear evolution of the pressure drop with the flow rate. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-27T11:55:30.670176-05:
      DOI: 10.1002/aic.15811
       
  • Self-similar breakup of viscoelastic thread for droplet formation in
           flow-focusing devices
    • Authors: Wei Du; Taotao Fu, Qindan Zhang, Chunying Zhu, Youguang Ma, Huai Z. Li
      Pages: 5196 - 5206
      Abstract: The self-similarity of the breakup of viscoelastic dispersed thread for droplet formation in flow-focusing devices is investigated experimentally. A high-speed camera is used to capture the evolution and angles of the cone-shaped liquid-liquid interface. The self-similar profiles for the liquid-liquid interface are obtained by normalizing the interface with the minimum width of the dispersed thread. The breakup of the dispersed thread transfers from a self-similar power law scaling stage with an exponent of 0.36 to a self-similar exponential scaling stage. The asymptotic cone angles prior to final breakup are consistent with the value of 125.5° and 151°, respectively. The viscoelasticity inhibits the development of finite-time singularity for the breakup of the liquid-liquid interface at microscale, similar to the capillary breakup at macroscale. The results demonstrate that the breakup of the viscoelastic dispersed thread for droplet formation exhibits self-similarity at microscale. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-06-28T08:25:52.458914-05:
      DOI: 10.1002/aic.15834
       
  • Darcy's law for two-dimensional flows: Singularities at corners and a new
           class of models
    • Authors: Yulii D. Shikhmurzaev
      Pages: 5207 - 5214
      Abstract: As is known, Darcy's model for fluid flows in isotropic homogeneous porous media gives rise to singularities in the velocity field for essentially two-dimensional flow configuration, like flows over corners. Considering this problem from the modeling viewpoint, this study aims at removing this singularity, which cannot be regularized via conventional generalizations of the Darcy model, like Brinkman's equation, without sacrificing Darcy's law itself for unidirectional flows where its validity is well established experimentally. The key idea is that as confirmed by a simple analogy, the permeability of a porous matrix with respect to flow is not a constant independent of the flow but a function of the flow field (its scalar invariants), decreasing as the curvature of the streamlines increases. This introduces a completely new class of models where the flow field and the permeability field are linked and, in particular problems, have to be found simultaneously. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-12T13:30:25.395453-05:
      DOI: 10.1002/aic.15840
       
  • Oxygen transfer in co-extruded multilayer active films for food packaging
    • Authors: Luciano Di Maio; Francesco Marra, Tesfaye F. Bedane, Loredana Incarnato, Sam Saguy
      Pages: 5215 - 5221
      Abstract: Oxygen scavenger applications in flexible food packaging are still limited due to the difficulty to ensure scavenging activity during storage and throughout the product shelf life. To avoid fast inactivation of the scavenger, multilayer active structures can be realized by inserting the active layer between two or more inert layers. In this work, an unsteady-state 1D reaction-diffusion mass transfer model was developed for predicting and optimizing the barrier-to-oxygen performance and the physical configurations of the co-extruded multilayer active films. The film configuration was a three-layers structure composed of polyethylene terephthalate (PET) as external inert layers, and PET with a polymeric oxygen scavenger as the core reactive layer. Scavenging activity of the multilayer film increased with the reactive layer thickness. Oxygen absorption reaction at short times decreased proportionally with the thickness of the external layers. The most appropriate combinations of inert-to-active film thickness were studied and analyzed. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-12T13:30:21.486438-05:
      DOI: 10.1002/aic.15844
       
  • Oil jet with dispersant: Macro-scale hydrodynamics and tip streaming
    • Authors: Lin Zhao; Feng Gao, Michel C. Boufadel, Thomas King, Brian Robinson, Kenneth Lee, Robyn Conmy
      Pages: 5222 - 5234
      Abstract: Modeling the movement of oil released underwater is a challenging task due to limitations in measuring the hydrodynamics in an oil-water system. In this work, we conducted an experiment of horizontal release of oil without and with dispersant. The model VDROP-J was used and compared to the model JETLAG, a miscible plume trajectory model. Both models were found to reproduce the oil jet hydrodynamics for oil without and with dispersant. The predicted DSD from VDROP-J matched closely observation for untreated oil. For oil with dispersant, experimental results have shown evidence that tip streaming occurred. For this purpose, a new conceptual module was developed in VDROP-J to capture the tip streaming phenomenon and an excellent match was achieved with observation. This study is the first to report tip streaming occurring in underwater oil jets, which should have consequences on predicting the DSD when dispersant are used on an underwater oil release. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-07-18T11:40:34.815324-05:
      DOI: 10.1002/aic.15864
       
 
 
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