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Publisher: John Wiley and Sons   (Total: 1589 journals)

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Showing 1 - 200 of 1589 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: 47, SJR: 0.547, h-index: 30)
ACEP NOW     Free   (Followers: 1)
Acta Anaesthesiologica Scandinavica     Hybrid Journal   (Followers: 52, SJR: 1.02, h-index: 88)
Acta Archaeologica     Hybrid Journal   (Followers: 165, 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: 6, SJR: 0.112, h-index: 1)
Acta Paediatrica     Hybrid Journal   (Followers: 56, SJR: 0.794, h-index: 88)
Acta Physiologica     Hybrid Journal   (Followers: 6, SJR: 1.69, h-index: 88)
Acta Polymerica     Hybrid Journal   (Followers: 9)
Acta Psychiatrica Scandinavica     Hybrid Journal   (Followers: 35, SJR: 2.518, h-index: 113)
Acta Zoologica     Hybrid Journal   (Followers: 7, 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: 14, SJR: 2.091, h-index: 57)
Adultspan J.     Hybrid Journal   (SJR: 0.127, h-index: 4)
Advanced Energy Materials     Hybrid Journal   (Followers: 27, SJR: 6.411, h-index: 86)
Advanced Engineering Materials     Hybrid Journal   (Followers: 26, SJR: 0.81, h-index: 81)
Advanced Functional Materials     Hybrid Journal   (Followers: 51, SJR: 5.21, h-index: 203)
Advanced Healthcare Materials     Hybrid Journal   (Followers: 14, SJR: 0.232, h-index: 7)
Advanced Materials     Hybrid Journal   (Followers: 268, SJR: 9.021, h-index: 345)
Advanced Materials Interfaces     Hybrid Journal   (Followers: 6, SJR: 1.177, h-index: 10)
Advanced Optical Materials     Hybrid Journal   (Followers: 7, SJR: 2.488, h-index: 21)
Advanced Science     Open Access   (Followers: 5)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 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: 21)
Africa Research Bulletin: Economic, Financial and Technical Series     Hybrid Journal   (Followers: 13)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 10)
African Development Review     Hybrid Journal   (Followers: 33, SJR: 0.275, h-index: 17)
African J. of Ecology     Hybrid Journal   (Followers: 16, SJR: 0.477, h-index: 39)
Aggressive Behavior     Hybrid Journal   (Followers: 15, SJR: 1.391, h-index: 66)
Aging Cell     Open Access   (Followers: 11, SJR: 4.374, h-index: 95)
Agribusiness : an Intl. J.     Hybrid Journal   (Followers: 3, SJR: 0.627, h-index: 14)
Agricultural and Forest Entomology     Hybrid Journal   (Followers: 16, SJR: 0.925, h-index: 43)
Agricultural Economics     Hybrid Journal   (Followers: 45, SJR: 1.099, h-index: 51)
AIChE J.     Hybrid Journal   (Followers: 32, SJR: 1.122, h-index: 120)
Alcoholism and Drug Abuse Weekly     Hybrid Journal   (Followers: 7)
Alcoholism Clinical and Experimental Research     Hybrid Journal   (Followers: 7, SJR: 1.416, h-index: 125)
Alimentary Pharmacology & Therapeutics     Hybrid Journal   (Followers: 33, SJR: 2.833, h-index: 138)
Alimentary Pharmacology & Therapeutics Symposium Series     Hybrid Journal   (Followers: 3)
Allergy     Hybrid Journal   (Followers: 51, SJR: 3.048, h-index: 129)
Alternatives to the High Cost of Litigation     Hybrid Journal   (Followers: 3)
American Anthropologist     Hybrid Journal   (Followers: 148, 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: 92, SJR: 2.325, h-index: 51)
American J. of Economics and Sociology     Hybrid Journal   (Followers: 29, SJR: 0.211, h-index: 26)
American J. of Hematology     Hybrid Journal   (Followers: 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: 276, 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: 137, SJR: 1.404, h-index: 88)
Analyses of Social Issues and Public Policy     Hybrid Journal   (Followers: 9, SJR: 0.397, h-index: 18)
Analytic Philosophy     Hybrid Journal   (Followers: 18)
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: 225)
Angewandte Chemie Intl. Edition     Hybrid Journal   (Followers: 222, SJR: 6.229, h-index: 397)
Animal Conservation     Hybrid Journal   (Followers: 41, SJR: 1.576, h-index: 62)
Animal Genetics     Hybrid Journal   (Followers: 8, SJR: 0.957, h-index: 67)
Animal Science J.     Hybrid Journal   (Followers: 6, SJR: 0.569, h-index: 24)
Annalen der Physik     Hybrid Journal   (Followers: 5, SJR: 1.46, h-index: 40)
Annals of Anthropological Practice     Partially Free   (Followers: 2, SJR: 0.187, h-index: 5)
Annals of Applied Biology     Hybrid Journal   (Followers: 7, SJR: 0.816, h-index: 56)
Annals of Clinical and Translational Neurology     Open Access   (Followers: 1)
Annals of Human Genetics     Hybrid Journal   (Followers: 9, SJR: 1.191, h-index: 67)
Annals of Neurology     Hybrid Journal   (Followers: 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: 8, SJR: 0.336, h-index: 23)
Annals of the New York Academy of Sciences     Hybrid Journal   (Followers: 5, SJR: 2.389, h-index: 189)
Annual Bulletin of Historical Literature     Hybrid Journal   (Followers: 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: 89, SJR: 0.545, h-index: 15)
Antipode     Hybrid Journal   (Followers: 49, SJR: 2.212, h-index: 69)
Anz J. of Surgery     Hybrid Journal   (Followers: 8, SJR: 0.432, h-index: 59)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apmis     Hybrid Journal   (Followers: 1, SJR: 0.855, h-index: 73)
Applied Cognitive Psychology     Hybrid Journal   (Followers: 70, SJR: 0.754, h-index: 69)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7, SJR: 0.632, h-index: 58)
Applied Psychology     Hybrid Journal   (Followers: 207, 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: 5)
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: 245, SJR: 0.153, h-index: 13)
Arthritis & Rheumatology     Hybrid Journal   (Followers: 52, SJR: 1.984, h-index: 20)
Arthritis Care & Research     Hybrid Journal   (Followers: 27, SJR: 2.256, h-index: 114)
Artificial Organs     Hybrid Journal   (Followers: 1, SJR: 0.872, h-index: 60)
ASHE Higher Education Reports     Hybrid Journal   (Followers: 15)
Asia & the Pacific Policy Studies     Open Access   (Followers: 16)
Asia Pacific J. of Human Resources     Hybrid Journal   (Followers: 319, 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: 6, SJR: 1.443, h-index: 19)
Asian J. of Social Psychology     Hybrid Journal   (Followers: 5, SJR: 0.665, h-index: 37)
Asian Politics and Policy     Hybrid Journal   (Followers: 12, SJR: 0.207, h-index: 7)
Asian Social Work and Policy Review     Hybrid Journal   (Followers: 5, SJR: 0.318, h-index: 5)
Asian-pacific Economic Literature     Hybrid Journal   (Followers: 5, SJR: 0.168, h-index: 15)
Assessment Update     Hybrid Journal   (Followers: 4)
Astronomische Nachrichten     Hybrid Journal   (Followers: 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: 15, SJR: 1.095, h-index: 66)
Austral Entomology     Hybrid Journal   (Followers: 9, SJR: 0.524, h-index: 28)
Australasian J. of Dermatology     Hybrid Journal   (Followers: 8, SJR: 0.714, h-index: 40)
Australasian J. On Ageing     Hybrid Journal   (Followers: 6, SJR: 0.39, h-index: 22)
Australian & New Zealand J. of Statistics     Hybrid Journal   (Followers: 14, SJR: 0.275, h-index: 28)
Australian Accounting Review     Hybrid Journal   (Followers: 3, SJR: 0.709, h-index: 14)
Australian and New Zealand J. of Family Therapy (ANZJFT)     Hybrid Journal   (Followers: 3, SJR: 0.382, h-index: 12)
Australian and New Zealand J. of Obstetrics and Gynaecology     Hybrid Journal   (Followers: 47, SJR: 0.814, h-index: 49)
Australian and New Zealand J. of Public Health     Hybrid Journal   (Followers: 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: 5, SJR: 0.171, h-index: 12)
Australian Economic Papers     Hybrid Journal   (Followers: 31, SJR: 0.23, h-index: 9)
Australian Economic Review     Hybrid Journal   (Followers: 6, SJR: 0.357, h-index: 21)
Australian Endodontic J.     Hybrid Journal   (Followers: 3, SJR: 0.513, h-index: 24)
Australian J. of Agricultural and Resource Economics     Hybrid Journal   (Followers: 3, SJR: 0.765, h-index: 36)
Australian J. of Grape and Wine Research     Hybrid Journal   (Followers: 5, SJR: 0.879, h-index: 56)
Australian J. of Politics & History     Hybrid Journal   (Followers: 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: 72, SJR: 0.59, h-index: 29)
Australian Psychologist     Hybrid Journal   (Followers: 12, SJR: 0.331, h-index: 31)
Australian Veterinary J.     Hybrid Journal   (Followers: 21, SJR: 0.459, h-index: 45)
Autism Research     Hybrid Journal   (Followers: 36, SJR: 2.126, h-index: 39)
Autonomic & Autacoid Pharmacology     Hybrid Journal   (SJR: 0.371, h-index: 29)
Banks in Insurance Report     Hybrid Journal   (Followers: 1)
Basic & Clinical Pharmacology & Toxicology     Hybrid Journal   (Followers: 11, SJR: 0.539, h-index: 70)
Basic and Applied Pathology     Open Access   (Followers: 2, SJR: 0.113, h-index: 4)
Basin Research     Hybrid Journal   (Followers: 5, SJR: 1.54, h-index: 60)
Bauphysik     Hybrid Journal   (Followers: 2, SJR: 0.194, h-index: 5)
Bauregelliste A, Bauregelliste B Und Liste C     Hybrid Journal  
Bautechnik     Hybrid Journal   (Followers: 1, SJR: 0.321, h-index: 11)
Behavioral Interventions     Hybrid Journal   (Followers: 9, SJR: 0.297, h-index: 23)
Behavioral Sciences & the Law     Hybrid Journal   (Followers: 24, SJR: 0.736, h-index: 57)
Berichte Zur Wissenschaftsgeschichte     Hybrid Journal   (Followers: 10, SJR: 0.11, h-index: 5)
Beton- und Stahlbetonbau     Hybrid Journal   (Followers: 2, SJR: 0.493, h-index: 14)
Biochemistry and Molecular Biology Education     Hybrid Journal   (Followers: 6, SJR: 0.311, h-index: 26)
Bioelectromagnetics     Hybrid Journal   (Followers: 1, SJR: 0.568, h-index: 64)
Bioengineering & Translational Medicine     Open Access  
BioEssays     Hybrid Journal   (Followers: 10, SJR: 3.104, h-index: 155)
Bioethics     Hybrid Journal   (Followers: 14, SJR: 0.686, h-index: 39)
Biofuels, Bioproducts and Biorefining     Hybrid Journal   (Followers: 1, SJR: 1.725, h-index: 56)
Biological J. of the Linnean Society     Hybrid Journal   (Followers: 16, SJR: 1.172, h-index: 90)
Biological Reviews     Hybrid Journal   (Followers: 4, SJR: 6.469, h-index: 114)
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 42, SJR: 0.12, h-index: 1)
Biology of the Cell     Full-text available via subscription   (Followers: 9, SJR: 1.812, h-index: 69)
Biomedical Chromatography     Hybrid Journal   (Followers: 6, SJR: 0.572, h-index: 49)
Biometrical J.     Hybrid Journal   (Followers: 5, SJR: 0.784, h-index: 44)
Biometrics     Hybrid Journal   (Followers: 37, SJR: 1.906, h-index: 96)
Biopharmaceutics and Drug Disposition     Hybrid Journal   (Followers: 10, SJR: 0.715, h-index: 44)
Biopolymers     Hybrid Journal   (Followers: 18, SJR: 1.199, h-index: 104)
Biotechnology and Applied Biochemistry     Hybrid Journal   (Followers: 45, SJR: 0.415, h-index: 55)
Biotechnology and Bioengineering     Hybrid Journal   (Followers: 142, SJR: 1.633, h-index: 146)
Biotechnology J.     Hybrid Journal   (Followers: 14, SJR: 1.185, h-index: 51)
Biotechnology Progress     Hybrid Journal   (Followers: 39, SJR: 0.736, h-index: 101)
Biotropica     Hybrid Journal   (Followers: 20, SJR: 1.374, h-index: 71)
Bipolar Disorders     Hybrid Journal   (Followers: 9, SJR: 2.592, h-index: 100)
Birth     Hybrid Journal   (Followers: 38, SJR: 0.763, h-index: 64)
Birth Defects Research Part A : Clinical and Molecular Teratology     Hybrid Journal   (Followers: 2, SJR: 0.727, h-index: 77)
Birth Defects Research Part B: Developmental and Reproductive Toxicology     Hybrid Journal   (Followers: 6, 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: 243, SJR: 2.083, h-index: 125)

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Journal Cover AIChE Journal
  [SJR: 1.122]   [H-I: 120]   [32 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0001-1541 - ISSN (Online) 1547-5905
   Published by John Wiley and Sons Homepage  [1589 journals]
  • Limiting Flux in Microfiltration of Colloidal Suspensions by Focusing on
           Hydrodynamic Forces in Viscous Sublayer
    • Authors: Ryo Makabe; Kazuki Akamatsu, Shin-ichi Nakao
      Abstract: Cross-flow microfiltration tests were performed on colloidal suspensions under turbulence conditions. By changing the particle diameter, flow rate, and channel height in the membrane housing to measure limiting fluxes, the influence of each parameter on the limiting flux was assessed from the viewpoint of hydrodynamic forces exerted on a particle in the viscous sublayer. In analyzing all the data taken, we found that the particle Reynolds number calculated from the limiting flux is proportional to the 1.5-power of that calculated from the flow rate at the boundary between the viscous sublayer and the intermediate layer. This fact indicates that the limiting flux can be determined in situations where the drag force exerted by the flux is balanced by the lift force in the viscous sublayer. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-08T13:10:55.882106-05:
      DOI: 10.1002/aic.16050
       
  • Model fitting of sorption kinetics data: Rectification of misapplications
           overlooked
    • Authors: Yifeng Huang; Muhammad U. Farooq, Shuixiu Lai, Panida Sampranpiboon, Xiaodong Wang, Wei Huang, Xianshe Feng
      Abstract: When the model fitting of sorption kinetics data was carried out using linearized pseudo second order rate equations based on constant Qe corresponding to equilibrium sorption, the instantaneous driving force for sorption was underestimated, resulting in an erroneous overestimation of the rate constant. To resolve the issue, a rectification of the model fitting was proposed by accounting for the concentration dependence of Qe in the model equation based on the fact that Qe in the equation represents the sorption capacity at that instant as sorption proceeded with time. The rectified approach was validated with experimental data for various sorption systems reported in the literature. It was shown that the rectification yielded true sorption rate constant that characterizes the relationship between sorption rate and solute concentration, thereby resolving the issues associated with the original approach where the specific rate constant was found to depend on solute concentration and sorption time. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-08T13:10:51.887542-05:
      DOI: 10.1002/aic.16051
       
  • Heat Transfer Characteristics of Polymer Hollow Fiber Heat Exchanger for
           Vaporization Application
    • Authors: Jun Liu; Hong Guo, Xingxing Zhi, Lei Han, Kai Xu, Hailei Li, Baoan Li
      Abstract: The heat transfer characteristics of polymer hollow fiber heat exchanger were investigated by analysing the heat transfer coefficient (HTC) and the heat transfer resistance (HTR) distributions of both the lumen side and the shell side. The influences of the fiber wall thickness and the polymer thermal conductivity on the heat transfer performance were studied numerically based on the experimental validated simulation model. It is found that the original overall HTC value is below 1032 W/m2·K and the HTR is focus on the fiber wall. However, if enhancing the polymer thermal conductivity to be higher than 1.0 W/m·K and/or lowering the fiber wall thickness to be less than 0.1 mm, the overall HTC could be improved to over 2000 W/m2·K, which indicates that the fiber wall HTR is no longer the limiting factor of the polymer hollow fiber heat exchanger applications. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-08T13:10:37.500975-05:
      DOI: 10.1002/aic.16049
       
  • Mass Transfer Coefficient of Tubular Ultrafiltration Membranes under
           High-Flux Conditions
    • Authors: Kazuki Akamatsu; Keita Ishizaki, Shotaro Yoshinaga, Shin-ichi Nakao
      Abstract: The effect of suction flow on the mass transfer coefficient of tubular ultrafiltration membranes, in particular that under a high flux condition, was studied. We pointed out that Nsh is proportional to NRe 0.875 NSc 0.25 under turbulent conditions, and that the proportional constant, b, exceeds 0.023 when the effect of suction flow is not negligible. We conducted the velocity variation method using ultrafiltration membranes with MWCOs of 20k and 100k and dextrans having molecular weights of 40,000 and 70,000 at the conditions where NRe exceeded 3.6 × 103. We demonstrated that the effect of suction flow includes not only flux but also the diffusion coefficient of solute, and that the ratio of the flux to the diffusion coefficient, expressed as NPew, is an important index. Finally, we concluded that b = 0.023 when NPew is smaller than 2.23 × 103, giving the Deissler equation itself, and that b=2.04×10-6×NPew1.21 when NPew exceeds 2.23 × 103. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-08T13:05:23.128217-05:
      DOI: 10.1002/aic.16052
       
  • A Full-condition Monitoring Method for Nonstationary Dynamic Chemical
           Processes with Cointegration and Slow Feature Analysis
    • Authors: Chunhui Zhao; Biao Huang
      Abstract: Chemical processes are in general subject to time variant conditions because of load changes, product grade transitions, or other causes, resulting in typical nonstationary dynamic characteristic. It is of a considerable challenge for process monitoring to consider all possible operation conditions simultaneously including multifarious steady states and dynamic switchings. In the present work, a novel full-condition monitoring strategy is proposed based on both cointegration analysis (CA) and slow feature analysis (SFA) with the following considerations: (1) Despite that the operation conditions may vary over time, they may follow certain equilibrium relations that extend beyond the current time; (2) there may exist certain dynamic relations that stay invariant under normal process operation despite process may operate at different operating conditions. To monitor both equilibrium and dynamic relations, in the proposed method, nonstationary variables are separated from stationary variables first. Then by CA and SFA, the long-term equilibrium relation is distinguished from the specific relation held by the current conditions from both static and dynamic aspects. Various monitoring statistics are designed with clear physical interpretation. It can distinguish between the changes of operation conditions and real faults by checking deviations from equilibrium relation and deviations from the specific relation. Case study on a chemical industrial scale multiphase flow experimental rig shows the validity of the proposed full-condition monitoring method. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-06T15:25:32.357672-05:
      DOI: 10.1002/aic.16048
       
  • Combined Effects of Soot Load and Catalyst Activity on the Regeneration
           Dynamics of Catalytic Diesel Particulate Filters
    • Authors: Valeria Di Sarli; Almerinda Di Benedetto
      Abstract: The combined effects of soot load and catalyst activity on the regeneration dynamics of a catalytic diesel particulate filter have been investigated through transient CFD-based simulations of soot combustion in a single-channel configuration. The soot load was changed by varying the amount of soot accumulated as cake layer, while keeping the amount of soot trapped inside the catalytic wall constant.Substantially uniform soot combustion that allows reasonably fast regeneration of the filter under controlled temperature conditions has been simulated only in the absence of cake and at relatively low catalyst activity. Conversely, in the presence of cake, numerical predictions have shown that, regardless of both soot load and catalyst activity, fast regeneration always occurs by propagation of sharp reaction fronts that result in high temperature rises.These findings highlight the importance of avoiding the cake formation, while properly optimizing the catalyst activity, to conduct an effective regeneration of catalytic filters. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-05T07:55:41.670631-05:
      DOI: 10.1002/aic.16047
       
  • Influence of Mixing Performance on Polymerization of Acrylamide in
           Capillary Microreactors
    • Authors: Yang Song; Minjing Shang, Guangxiao Li, Luo Zheng-Hong, Yuanhai Su
      Abstract: Non-living free radical polymerization of acrylamide was chosen as a model reaction to investigate the effect of mixing performance on the polymerization in capillary microreactors. The polymerization rate was enhanced by increasing the volumetric flow rate and the reaction temperature at a constant residence time. However, higher temperatures led to lower Mn and larger PDI. The reaction mixture viscosity increased significantly during the polymerization. Both diffusion and dispersion coefficients were calculated in order to evaluate the mixing performance in microreactors. The capillary microreactor with a larger inner diameter led to higher monomer conversions, lower Mn and larger PDI compared to the capillary microreactor with a smaller inner diameter, which could be explained through a heat balance analysis for the polymerization and the dispersion effect. Moreover, it was found that the addition of a pre-mixing stage minimized the effect of insufficient mixing between the initiators and the monomers on the polymerization. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-04T10:31:21.040339-05:
      DOI: 10.1002/aic.16046
       
  • Multilevel Monte Carlo Applied to Chemical Engineering Systems Subject to
           Uncertainty
    • Authors: Grigoriy Kimaev; Luis A. Ricardez-Sandoval
      Abstract: The aim of this study is to evaluate the performance of Multilevel Monte Carlo (MLMC) sampling technique for uncertainty quantification in chemical engineering systems. Three systems (a mixing tank, a wastewater treatment plant and a ternary distillation column, all subject to uncertainty) were considered. The expected values of the systems' observables were estimated using MLMC, Power Series and Polynomial Chaos expansions, and standard Monte Carlo (MC) sampling. The MLMC technique achieved results of significantly greater accuracy than other methods at a lower computational cost than standard MC. This study highlights the nuances of adapting the MLMC technique to chemical engineering systems and the advantages of using MLMC for uncertainty quantification. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-04T10:31:11.300659-05:
      DOI: 10.1002/aic.16045
       
  • Simulation of Gas Separation Using Partial Element Stage Cut Modeling of
           Hollow Fiber Membrane Modules
    • Authors: Sina Gilassi; Seyed Mohammad Taghavi, Denis Rodrigue, Serge Kaliaguine
      Abstract: A mathematical model is developed to simulate a gas separation process using a hollow fiber membrane module. In particular, a new numerical technique is introduced based on flash calculation. Such analysis allows identifying the required membrane properties needed to reach module performance of interest. This model is validated for six different gas separation cases taken from literature. Then, the validated model is used to investigate the effect of O2 and N2 permeances on O2 recovery and O2 mole fraction in the permeate stream. A realistic two-stage air enrichment process is also proposed for O2 production using an industrial module with different fibers numbers. Moreover, this model is used to simulate a natural gas purification process using a single unit to determine the required membrane separation area and CH4 loss. Finally, a two-stage process is proposed to equally enhance CH4 retentate mole fraction and decrease CH4 loss. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-04T10:30:41.921538-05:
      DOI: 10.1002/aic.16044
       
  • Extending the Range of COSMO-SAC to High Temperatures and High Pressures
    • Authors: Christian L. Silveira; Stanley I. Sandler
      Abstract: In this paper we extend the range of the predictive Gibbs energy of solvation model, COSMO-SAC, to large ranges of density, pressure and temperature for very nonideal mixtures by combining it with an equation of state using the Wong-Sandler mixing rule. We compare the accuracy of isothermal vapor-liquid equilibria (VLE) calculations based on using the predictive COSMO-SAC model and separately the correlative NRTL model, each combined with three different forms of the Peng-Robinson equation of state (PREOS). All the models considered require the value of the EOS mixing rule binary parameter kij. The NRTL model also requires three other parameters obtained from correlation low pressure VLE data. We show that the PRSV + COSMO-SAC model, with its one adjustable parameter obtained from low temperature data leads good predictions at much higher temperatures and pressures. This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-01T11:06:26.182402-05:
      DOI: 10.1002/aic.16043
       
  • Enhanced CO2 Separation Performance for Tertiary Amine-silica Membranes
           via Thermally Induced Local Liberation of CH3Cl
    • Authors: Liang Yu; Masakoto Kanezashi, Hiroki Nagasawa, Norihiro Moriyama, Henji Ito, Toshinori Tsuru
      Abstract: A facile method for the fabrication of amine-silica membranes with enhanced CO2 separation performance was proposed via the thermally induced liberation of small molecules from quaternary ammonium salt. Quaternary ammonium-silica (QA-SiO1.5) xerogel powders/films were fabricated via sol-gel processing and their thermal stability was systematically studied using TG-MS, FTIR, EDS, and PALS analysis. CO2 sorption performances of QA-SiO1.5 derived xerogel powders were quantitatively compared after assigning their relevant parameters to a dual-mode sorption model. The gas permeation performances of membranes derived from QA-SiO1.5 were evaluated in terms of kinetic diameter and temperature dependence of gas permeance, and activation energy (Ep) required for gas permeation. The results indicate that liberation of the CH3Cl molecules from these membranes significantly improved both CO2 permeation and CO2/N2 separation capabilities. Therefore, the present study provides insight that should be useful in the development of high-performance CO2 separation membranes via the effect of the thermally induced liberation of small molecules. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-28T10:40:55.024476-05:
      DOI: 10.1002/aic.16040
       
  • Stem Cell Biomanufacturing under Uncertainty: A Case Study in Optimizing
           Red Blood Cell Production
    • Authors: Ruth Misener; Mark C. Allenby, María Fuentes-Garí, Karan Gupta, Thomas Wiggins, Nicki Panoskaltsis, Efstratios N. Pistikopoulos, Athanasios Mantalaris
      Abstract: As breakthrough cellular therapy discoveries are translated into reliable, commercializable applications, effective stem cell biomanufacturing requires systematically developing and optimizing bioprocess design and operation. This manuscript proposes a rigorous computational framework for stem cell biomanufacturing under uncertainty. Our mathematical tool kit incorporates: high-fidelity modeling; single- and multivariate sensitivity analysis; global topological superstructure optimization; robust optimization. We quantitatively demonstrate the advantages of the proposed bioprocess optimization framework using, as a case study, a dual hollow fiber bioreactor producing red blood cells from progenitor cells. The optimization phase reduces the cost by a factor of 4 and the price of insuring process performance against uncertainty is approximately 15% over the nominal optimal solution. Mathematical modeling and optimization can guide decision making; we quantitatively evaluate the possible commercial impact of this cellular therapy using the disruptive technology paradigm. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-28T10:40:33.501778-05:
      DOI: 10.1002/aic.16042
       
  • Hydrodynamics in a Jet Bubbling Reactor: Experimental Research and
           Mathematical Modeling
    • Authors: Zhengliang Huang; Haotong Wang, Yun Shuai, Tianqi Guo, Musango Lungu, Yao Yang, Jingdai Wang, Yongrong Yang
      Abstract: The radial distribution of liquid velocity in the axial direction of a jet bubbling reactor has been measured by experimentation. Three different typical flow structures controlled by liquid jet, gas bubbling and liquid jet coupled with bubbling are observed. A tank in series model is established on this basis. Calculated values in each region are in good agreement with measured values in jet, bubbling and wall effect controlled areas. Axial flow rate, radial exchange rate and jet controlled volume η are analyzed from energy input aspect under different ug and uj. Simulation results indicate that under the synergetic action of the liquid jet and gas bubbling effect, jet controlled area exhibits a “spindle” structure, and its size decreases with the increase of ug. When gas input power occupies about 67% of total energy consumption, the best synergy of liquid jet and gas bubbling is obtained. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-28T10:35:36.521727-05:
      DOI: 10.1002/aic.16041
       
  • An Innovative Unit Operation of Particle Separation/Classification by
           Irradiating Low-Frequency Ultrasound into Water
    • Authors: Hiroya Muramatsu; Takayuki Saito
      Abstract: By irradiating kHz-band ultrasound, submillimeter- or millimeter-size particles that were dispersed in water with dissolved gases flocculated into a spherically flocculated particle swarm (SFPS). Acoustic cavitation-oriented bubbles caused by the irradiation played essential roles in the formation of the SFPS. Unprecedented and promising phenomena were observed: the particles were separated based on their diameters through the precise control of the ultrasound irradiation, and the SFPS was easily manipulated by using a motion-controlled stick. We discuss the relationship between the sound-pressure profiles and the manipulable range of the SFPS; i.e., the effectively manipulable range was limited by the sound-pressure profile. By means of manipulation control, we demonstrate the particle classification by particle diameters. On the basis of these findings, we propose an example of a practical application of this technique. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-24T10:40:40.100345-05:
      DOI: 10.1002/aic.16039
       
  • Numerical and Experimental Evaluation of Heat Transfer in Helically
           Corrugated Tubes
    • Authors: David J. Van Cauwenberge; Jens N. Dedeyne, Jens Floré, Kevin M. Van Geem, Guy B. Marin
      Abstract: The enhancement of convective heat transfer in single-phase heat transfer through the use of helicoidally corrugated tubes has been studied numerically. By comparing the large eddy simulation (LES) results with detailed Stereo-PIV and Liquid Crystal Thermography measurements obtained at the von Karman Institute for Fluid Dynamics (VKI), a validated numerical framework was obtained. Heat transfer enhancements of 83-119% were seen, at the cost of pressure losses that were approximately 5.6 to 6.7 times higher than for a bare tube. In order to extrapolate the results to industrial Reynolds numbers at which experimental data is scarce, the simulation data was used to develop an improved near-wall Reynolds stress transport model (RSTM) that more accurately describes the heat flux vector. Comparison of both global and local flow characteristics at different Reynolds numbers confirms that the approach allows more accurate predictions over a wider range of design and operating parameters than using two-equation turbulence models, while the computational cost is still significantly lower than LES. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-24T10:40:37.154999-05:
      DOI: 10.1002/aic.16038
       
  • Catalytic Partial Oxidation of CH4 over Bimetallic Ni-Re/Al2O3: Kinetic
           determination for Application in Microreactor
    • Authors: Kuson Bawornruttanaboonya; Navadol Laosiripojana, Arun S. Mujumdar, Sakamon Devahastin
      Abstract: The activity of a novel Ni-Re/Al2O3 catalyst toward partial oxidation of methane was investigated in comparison with a precious-metal Rh/Al2O3 catalyst. Reactions involving CH4/O2/Ar, CH4/H2O/Ar, CH4/CO2/Ar, CO/O2/Ar and H2/O2/Ar were performed to determine the kinetic expressions based on indirect partial oxidation scheme. A mathematical model comprising of Ergun equation as well as mass and energy balances with lumped indirect partial oxidation network was applied to obtain the kinetic parameters and then used to predict the reactant and product concentrations as well as temperature profiles within a fixed-bed microreactor. H2 and CO production as well as H2/CO2 and CO/CO2 ratios from the reaction over Ni-Re/Al2O3 catalyst were higher than those over Rh/Al2O3 catalyst. Simulation revealed that much smoother temperature profiles along the microreactor length were obtained when using Ni-Re/Al2O3 catalyst. Steep hot-spot temperature gradients, particularly at the entrance of the reactor, were, on the other hand, noted when using Rh/Al2O3 catalyst. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-24T10:40:22.472597-05:
      DOI: 10.1002/aic.16037
       
  • Magnetic Resonance Imaging of Gas-Solid Fluidization with Liquid Bridging
    • Authors: C. M. Boyce; A. Penn, K. P. Pruessmann, C. R. Müller
      Abstract: Magnetic resonance imaging is used to generate snapshots of particle concentration and velocity fields in gas-solid fluidized beds into which small amounts of liquid are injected. Three regimes of bed behavior (stationary, channeling and bubbling) are mapped based on superficial velocity and liquid loading. Images are analyzed to determine quantitatively the number of bubbles, the bubble diameter, bed height and the distribution of particle speeds under different wetting conditions. The cohesion and dissipation provided by liquid bridges cause an increase in the minimum fluidization velocity and a decrease in the number of bubbles and fast particles in the bed. Changes in liquid loading alter hydrodynamics to a greater extent than changes in surface tension or viscosity. Keeping U/Umf at a constant value of 1.5 produced fairly similar hydrodynamics across different wetting conditions. The detailed results presented provide an important dataset for assessment of the validity of assumptions in computational models. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-21T10:06:04.060573-05:
      DOI: 10.1002/aic.16036
       
  • Analysis of North-American Tight Oil Production
    • Authors: Raul Velascoa; Palash Panja, Manas Pathak, Milind Deo
      Abstract: North-American tight oil production has been on the rise due to the introduction of new drilling and hydraulic fracturing technologies. Such advances have dramatically changed the conventional understanding of the hydrocarbon recovery process. A dimensionless study of tight oil production across the United Sates in plays such as the Bakken, Niobrara, Eagle Ford, Woodford, Bone Spring, and Wolfcamp shed light on some of these recovery processes. Production from any well, regardless of geologic attributes and operating conditions, fits into a universal curve during its initial productive period. Subsequently, production becomes a strong function of hydrocarbon thermodynamics and multiphase flow. Results from this analysis help rank important parameters that affect oil recovery in terms of how wells are operated and the reservoir's intrinsic geological and fluid properties. Furthermore, production results are combined with a simple dimensionless economic analysis to determine optimal fracture configurations independent of oil price environment. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-21T10:00:56.000202-05:
      DOI: 10.1002/aic.16034
       
  • Simulation and Modeling of Segregating Rods in Quasi-2D Bounded Heap Flow
    • Authors: Yongzhi Zhao; Hongyi Xiao, Paul B. Umbanhowar, Richard M. Lueptow
      Abstract: Many products in the chemical and agricultural industries are pelletized in the form of rod-like particles that often have different aspect ratios. However, the flow, mixing, and segregation of non-spherical particles such as rod-like particles are poorly understood. Here, we use the discrete element method (DEM) utilizing super-ellipsoid particles to simulate the flow and segregation of rod-like particles differing in length but with the same diameter in a quasi-2D one-sided bounded heap. The DEM simulations accurately reproduce the segregation of size bidisperse rod-like particles in a bounded heap based on comparison with experiments. Rod-like particles orient themselves along the direction of flow, though bounding walls influence the orientation of the smaller aspect ratio particles. The flow kinematics and segregation of bidisperse rods having identical diameters but different lengths are similar to spherical particles. The segregation velocity of one rod species relative to the mean velocity depends linearly on the concentration of the other species, the shear rate, and a parameter based on the relative lengths of the rods. A continuum model developed for spherical particles that includes advection, diffusion, and segregation effects accurately predicts the segregation of rods in the flowing layer for a range of physical control parameters and particle species concentrations. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-21T10:00:31.548838-05:
      DOI: 10.1002/aic.16035
       
  • Robust Stabilization of a Two-Stage Continuous Anaerobic Bioreactor System
    • Authors: Zhaoyang Duan; Costas Kravaris
      Abstract: This paper studies the problem of stabilizing a two-stage continuous bioreactor system. A simple dynamic model of the system is first introduced based on a detailed mass balance model, and then used to derive a constant-yield controller to stabilize the system at given design steady state conditions. Using Lyapunov stability analysis, this control law is proved to guarantee stability of the closed loop system over the entire positive orthant. Simulation results show the successful performance of the controller. The control law is proved to be robust with respect to errors in the kinetic parameters and in the inlet feed concentration, in the sense of preserving its stability region. Performance of the control system can be enhanced if a feedforward measurement of the inlet feed concentration can be incorporated in the control law. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-14T10:55:41.235266-05:
      DOI: 10.1002/aic.16033
       
  • Mixed-Cation LiCa-LSX Zeolite with Minimum Lithium for Air Separation
    • Authors: Franklin E. Epiepang; Xiong Yang, Jianbo Li, Yingshu Liu, Ralph T. Yang
      Abstract: The aim of this work was to reduce/minimize Li in Li-LSX by replacing the 70% Li+ cations in Li-LSX that are bonded to the interior or inaccessible sites which are not used for adsorption. Thus, mixed-cation LiCa-LSX containing minimum lithium were prepared by exchanging small fractions of Li+ into Ca-LSX, followed by dehydration under mild conditions to avoid migration/equilibration of Li+ cations. Comparisons of adsorption isotherms of N2/O2 and heats of adsorption for the LiCa-LSX samples with that for pure-cation Li-LSX and Ca-LSX provided strong evidence that significant amounts of these Li+ cations indeed remained on the exposed sites (SIII). The mixed-cation LiCa-LSX samples were compared against the pure-cation Ca-LSX and Li-LSX based on their performance for oxygen production by PSA, via model simulation. The results showed that the mixed-cation LiCa-LSX samples yielded significantly higher O2 product productivities at the same product purity and recovery than their pure-cation precursor (Ca-LSX). This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-14T10:55:36.79446-05:0
      DOI: 10.1002/aic.16032
       
  • Modeling of Circulating Fluidized Beds systems for post-combustion CO2
           capture via Temperature Swing Adsorption
    • Authors: Stefano E. Zanco; Matteo Gazzani, Matteo C. Romano, Isabel Martínez, Marco Mazzotti
      Abstract: The technology of circulating uidized beds (CFB) is applied to temperature swing adsorption (TSA) processes for post-combustion CO2 capture employing a commercial zeolite sorbent. Steady state operation is simulated through a one-dimensional model, which combines binary adsorption with the CFB dynamics. Both single step and multi-step arrangements are investigated. Extensive sensitivity analyses are performed varying the operating conditions, in order to assess the inuence of the main operational parameters. The results reveal a neat superiority of multi-step configurations over the standard one, in terms of both separation performance and efficiency. Compared to fixed-bed TSA systems, CFB TSA features a high compactness degree. However, product purity levels are limited compared to the best performing fixed-bed processes, and heat management within the system appears to be a major issue. As regards energy efficiency, CFB systems place themselves in between the most established absorption-based technologies and the fixed-bed TSA. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-14T10:50:38.062582-05:
      DOI: 10.1002/aic.16029
       
  • Feedback control of proppant bank heights during hydraulic fracturing for
           enhanced productivity in shale formations
    • Authors: Prashanth Siddhamshetty; Joseph Sang-II Kwon, Shuai Liu, Peter P. Valkó
      Abstract: In hydraulic fracturing of shale formations, compared to conventional reservoirs, the fracturing fluid injected is of low-viscosity and hence during pumping the proppant settles significantly, forming a proppant bank. Motivated by this consideration, we initially develop a high-fidelity process model of hydraulic fracturing to describe the dominant proppant settling behavior during hydraulic fracturing. Second, a novel remeshing strategy is developed to handle the high computational requirement due to moving boundaries. Third, a section-based optimization method is employed to obtain key fracture design parameters for enhanced productivity in shale formations subject to given fracturing resources. Fourth, a reduced-order model is constructed to design a Kalman filter and to synthesize a real-time model-based feedback control system by explicitly taking into account actuator limitations, process safety and economic considerations. We demonstrate that the proposed control scheme can regulate the uniformity of proppant bank heights along the fracture at the end of pumping. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-14T10:50:30.307892-05:
      DOI: 10.1002/aic.16031
       
  • Optimal PID Controller Tuning using Stochastic Programming Techniques
    • Authors: Jose A. Renteria; Yankai Cao, Alexander W. Dowling, Victor M. Zavala
      Abstract: We argue that stochastic programming provides a powerful framework to tune and analyze the performance limits of controllers. In particular, stochastic programming formulations can be used to identify controller settings that remain robust across diverse scenarios (disturbances, set-points, and modeling errors) observed in real-time operations. We also discuss how to use historical data and sampling techniques to construct operational scenarios and inference analysis techniques to provide statistical guarantees on limiting controller performance. Under the proposed framework, it is also possible to use risk metrics to handle extreme (rare) events and stochastic dominance concepts to conduct systematic benchmarking studies. We provide numerical studies to illustrate the concepts and to demonstrate that modern modeling and local/global optimization tools can tackle large-scale applications. The proposed work also opens the door to data-based controller tuning strategies that can be implemented in real-time operations. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-11T09:50:21.698851-05:
      DOI: 10.1002/aic.16030
       
  • Optimal Operation of Batch Enantiomer Crystallization: From Ternary
           Diagrams to Predictive Control
    • Authors: Caio Felippe Curitiba Marcellos; Helen Durand, Joseph Sang-II Kwon, Amaro Gomes Barreto, Paulo Laranjeira da Cunha Lage, Maurício Bezerra de Souza, Argimiro Resende Secchi, Panagiotis D. Christofides
      Abstract: In this work, the modeling and control of batch crystallization for racemic compound forming systems is addressed in a systematic fashion. Specifically, a batch crystallization process is considered for which the initial solution has been pre-enriched in the desired enantiomer to enable crystallization of only the preferred enantiomer. A method for determining desired operating conditions (composition of the initial pre-enriched solution and temperature to which the mixture must be cooled for maximum yield) for the batch crystallizer based on a ternary diagram for the enantiomer mixture in a solvent is described. Subsequently, it is shown that the information obtained from the ternary diagram, such as the maximum yield attainable from the process due to thermodynamics, can be used to formulate constraints for an optimization-based control method to achieve desired product characteristics such as a desired yield. The proposed method is demonstrated for the batch crystallization of mandelic acid in a crystallizer with a fines trap that is seeded with crystals of the desired enantiomer. The process is controlled with an optimization-based controller to minimize the ratio of the mass of crystals obtained from nuclei to the mass obtained from seeds while maintaining the desired enantioseparation. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-10T11:05:24.444146-05:
      DOI: 10.1002/aic.16028
       
  • More Comprehensive 3D Modeling of Clay-like Material Drying
    • Authors: M. Heydari; K. Khalili, S. Y. Ahmadi-Brooghani
      Abstract: Drying process plays an important role in the manufacturing of many products such as ceramic, kitchenware and building materials, some of which have complex 3D geometry. To deal with many restrictions found in literatures, a 3D numerical approach was used to describe the drying process of a porous Clay-like material. The problem investigated involves highly coupled equations considering heat, mass and mechanical aspects. The model is validated through the comparison of experimental measurements with simulation result. Simulation results show that increasing the initial moisture content and reducing the initial temperature have the same privilege and without significant increase in drying time, it reduces slightly the amount of maximum stress but delays the occurrence time of maximum stress. The non-uniform heat expansion induced stresses are very small in comparison to non-uniform moisture shrinkage induced stresses and can be neglected in drying simulation. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-10T10:10:20.229176-05:
      DOI: 10.1002/aic.16027
       
  • Numerical Simulation on Flow Behaviour of Twin-liquid Films over a
           Vertical Plate with an Open Window
    • Authors: Hanguang Xie; Jianguang Hu, Gance Dai
      Abstract: A novel element for gas–liquid contact, a plate with rectangular windows was designed to enhance absorption process. Coexistence and interaction of wall-bounded films and confined free films named as “twin-liquid films” were observed on the plate. VOF method was used to simulate its flow behavior. Flow phenomena such as flow around a step-in, jet impingement, varicose waves, and sinuous waves were observed. Different from thin films flow on an unperforated plate, larger mean velocity, thinner film thickness, more intensive capillary waves, and stronger vorticity on the free surfaces were detected inside the window, and the disturbances could propagate over the whole plate. Three-dimensional simulation results generally agreed with our experimental observations and further demonstrated complex wavy structures both inside and outside the window. The results would broaden traditional knowledge of liquid films flow and clarify the mechanism of mass transfer intensification for the plate with windows. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-08T11:20:42.379766-05:
      DOI: 10.1002/aic.16021
       
  • Materials Genomics-Guided Ab Initio Screening of MOFs with Open Copper
           Sites for Acetylene Storage
    • Authors: Ce Zhang; Youshi Lan, Xiangyu Guo, Qingyuan Yang, Chongli Zhong
      Abstract: Discovering high-performance metal-organic frameworks (MOFs) with open metal sites has become an increasingly hot research topic in the field of safe storage and transportation of acetylene. Following the concept of Materials Genomics proposed recently, a database of 502 experimental MOFs was built by searching the structures deposited in the CSD with the dicopper paddle-wheel node Cu2(COO)4 as the characteristic materials gene. On the basis of the developed ab initio force field, a high-throughput computational screening was conducted to examine the property-performance relationships of MOFs containing Cu-OMS for C2H2 storage at ambient conditions. The optimal ranges of the structural and energetic features for the design of such MOFs were suggested. From our computational screening, three potentially promising MOFs were identified which exhibit a performance outperforming those MOFs reported experimentally so far with record high gravimetric C2H2 uptakes, both in the total and deliverable adsorption capacities. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-08T11:20:34.030147-05:
      DOI: 10.1002/aic.16025
       
  • DEM Study on the Discharge Characteristics of Lognormal Particle Size
           Distributions from a Conical Hopper
    • Authors: Ya Zhao; Shiliang Yang, Liangqi Zhang, Jia Wei Chew
      Abstract: This study employs the discrete element method (DEM) to investigate the impact of the widths of lognormal particle size distributions (PSDs) with the same mean particle diameter on hopper discharge behaviors, namely, discharge rate, particle velocities and size-segregation. Results reveal that (i) the hopper discharge rate decreases as PSD width increases; (ii) the mean discharge rates are constant with time, but the fluctuations increase as the PSD width increases; (iii) the overall size-segregation increases with PSD width; (iv) the overall mean particle diameters of the narrower PSDs do not exceed the initial mean of 5 mm, whereas that of wider ones do; (v) the relationship between PSD width and particle velocities is non-monotonic with no consistent trends; and (vi) no direct correlation exists between particle velocity and size-segregation. The results here provide valuable insights on the behavior of the prevalent polydisperse mixtures in hoppers. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-08T11:20:30.637498-05:
      DOI: 10.1002/aic.16026
       
  • Studies on Mild Catalytic Synthesis of Methyl Acrylate via One-Step Aldol
           Reaction
    • Authors: Gang Wang; Chidchon Sararuk, Zeng-xi Li, Chun-shan Li, Hui Wang, Suo-jiang Zhang
      Abstract: One-step catalytic synthesis of methyl acrylate from methyl acetate and trioxane, with 90.7% yield and 91.8% selectivity, was realized at 10°C-25°C. NMR analysis confirmed the ester enolization with generation of [i-Pr2EtN-H]+[TfO]- in the presence of i-Pr2EtN and Bu2BOTf, which was affected by solvent and base. The depolymerization of trioxane into formaldehyde was catalyzed by Bu2BOTf. The in-situ catalytic mechanism and efficiency of [i-Pr2EtN-H]+[TfO]- was determined and analyzed. Mechanism-based kinetic and thermodynamic studies were conducted for better understanding of this route. Also the primary process design and product separation simulation were carried out. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-08T01:15:52.329623-05:
      DOI: 10.1002/aic.16022
       
  • Synthesis of Ternary Distillation Process Structures Featuring Minimum
           Utility Cost Using the IDEAS Approach
    • Authors: Hiroshi Takase; Shinji Hasebe
      Abstract: A synthesis method for ternary distillation process structures is proposed on the basis of the infinite-dimensional state-space (IDEAS) approach. The proposed synthesis procedure consists of two steps. At the first step, the utility cost is minimized. The result of the first step contains many tiny flows among the modules because the number of flows is not included in the objective function. Then, at the second step, an evolutionary procedure for process simplification is executed. In this step, the weighted sum of flow rates is minimized recursively while updating the weights at each iteration. The practical process structure is finally determined from the result of the second simplification step. The developed synthesis procedure was applied to the separation problem of a ternary mixture consisting of benzene, toluene, and o-xylene. It demonstrated that the proposed procedure provides a process whose liquid composition profile is quite similar to that of a Petlyuk column. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-08T01:15:39.984478-05:
      DOI: 10.1002/aic.16023
       
  • A Comparative Kinetics Study of CO2 Absorption into Aqueous DEEA/MEA and
           DMEA/MEA Blended Solutions
    • Authors: Wusan Jiang; Xiayi Hu, Xiao Luo, Hongxia Gao, Zhiwu Liang, Bin Liu, Paitoon Tontiwachwuthikul
      Abstract: The kinetics of CO2 absorption into aqueous solutions of N,N-diethylethanolamine (DEEA), and N,N-dimethylethanolamine (DMEA), and their blends with monoethanolamine (MEA) have been studied in a stopped-flow apparatus. The kinetics experiments were carried out at the concentrations of DEEA and DMEA varying from 0.075 to 0.175 kmol/m3 respectively, and that of MEA ranging between 0.0075 and 0.0175 kmol/m3, over the temperature range of 293K to 313K. Two kinetics models are proposed to interpret the reaction in the blended amine systems and the results show that the model which incorporates the base-catalyzed hydration mechanism and termolecular mechanism resulted in a better prediction. Furthermore, the kinetics behaviors of CO2 absorption into two blended systems are comprehensively discussed according to their molecular structures. It can be concluded that the interaction between tertiary amines and primary amines as well as the alkyl chain length of tertiary amines have a significant influence on the kinetics. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-07T17:38:46.095241-05:
      DOI: 10.1002/aic.16024
       
  • Uncertainty-Conscious Methodology for Process Performance Assessment in
           Biopharmaceutical Drug Product Manufacturing
    • Authors: Gioele Casola; Christian Siegmund, Markus Mattern, Hirokazu Sugiyama
      Abstract: This work presents an uncertainty-conscious methodology for the assessment of process performance—e.g., run time—in the manufacturing of biopharmaceutical drug products. The methodology is presented as an activity model using the type 0 integrated definition (IDEF0) functional modelling method, which systematically interconnects information, tools, and activities. In executing the methodology, a hybrid stochastic–deterministic model that can reflect operational uncertainty in the assessment result is developed using Monte Carlo simulation. This model is used in a stochastic global sensitivity analysis to identify tasks that had large impacts on process performance under the existing operational uncertainty. Other factors are considered, such as the feasibility of process modification based on Good Manufacturing Practice, and tasks to be improved is identified as the overall output. In a case study on cleaning and sterilization processes, suggestions were produced that could reduce the mean total run time of the processes by up to 40%. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-06T17:21:56.05222-05:0
      DOI: 10.1002/aic.16020
       
  • A Branch and Bound Algorithm to Solve Large-Scale Multi-Stage Stochastic
           Programs with Endogenous Uncertainty
    • Authors: Brianna Christian; Selen Cremaschi
      Abstract: The growth in computation complexity of multistage stochastic programs (MSSPs) with problem size often prevents its application to real-world size problems. We present two variants of branch-and-bound algorithm, which reduce the resource requirements for the generation and solution of large-scale MSSPs with endogenous uncertainty. Both variants use Knapsack-problem based Decomposition Algorithm12 to generate feasible solutions and primal bounds. First variant (PH-KDA) uses a progressive hedging dual-bounding approach; the second (OSS-KDA) solves the MSSP removing all non-anticipativity constraints. Both variants were employed to solve several instances of the pharmaceutical clinical trial planning problem. The first iteration of both algorithms provide a feasible solution, and a primal bound and a dual bound for the problem. Although the dual-bounds of OSS-KDA were generally weaker than PH-KDA, they are generated considerably faster. For the seven-product case the OSS-KDA generated a solution with a gap of 9.92% in 115 CPU seconds. This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-06T17:21:53.693542-05:
      DOI: 10.1002/aic.16019
       
  • Issue information
    • Abstract: Cover illustration. Photo of Roy Jackson taken around the time of his retirement from rinceton University; Eqs. 67 and 68 from his foundational paper in 1967, coauthored with Anderson, describing the momentumbalances for two-fluid model; image showing visualization of interaction of particles with boundary and the deduced momentum boundary condition (Eq. 2.10 from Johnson & Jackson, 1987); circulating flow inside a rising bubble (Anderson et al., 1994); his 2000 monograph; and title credit of his 1972 paper with Horn on mass action kinetics. Please see Introductory Retrospective for further details. 10.1002/aic.15981
      PubDate: 2017-11-02T11:29:41.317027-05:
      DOI: 10.1002/aic.15485
       
  • Food engineering into the XXI century
    • Authors: José Miguel Aguilera
      PubDate: 2017-10-30T10:30:21.799741-05:
      DOI: 10.1002/aic.16018
       
  • Insight in Kinetics from Pre-edge Features using Time Resolved in situ XAS
    • Authors: N.V.R.A. Dharanipragada; Vladimir V. Galvita, Hilde Poelman, Lukas C. Buelens, Alessandro Longo, Guy B. Marin
      Abstract: The kinetics of reduction of a 10wt%Fe2O3-MgAl2O4 spinel were investigated using XRD and time resolved Fe-K QXANES. The Rietveld refinement of the XRD pattern showed the replacement of Al with Fe in the spinel structure and the formation of MgFeAlOx. The XANES pre-edge feature was employed to study the reduction kinetics during H2-TPR (Temperature Programmed Reduction) up to 730°C. About 55% of the Fe3+ in MgFeAlOx was reduced to Fe2+. A shrinking core model, which takes into account both solid-state diffusion via an oxygen diffusion coefficient, and gas-solid reaction through a reaction rate coefficient, was applied. The activation energy for chemical reaction showed a linear dependence on the conversion, increasing from 104 kJ/mol to 126 kJ/mol over the course of material reduction. The good accordance between the shrinking core model description and the experimental data indicates that XANES pre-edge features can be used to correlate changes in material structure and reaction kinetics. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-27T10:35:26.233322-05:
      DOI: 10.1002/aic.16017
       
  • Effect of Viscosity on Liquid Curtain Stability
    • Authors: Alireza Mohammad Karim; Wieslaw J. Suszynski, Lorraine F. Francis, Marcio S. Carvalho
      Abstract: The effect of viscosity on liquid curtain stability was explored by high-speed visualization. Measurements of the velocity within the curtain revealed the presence of a viscous boundary layer along the edge guides. The critical condition at the onset of curtain breakup was determined by identifying the flow rate below which the curtain broke for two different edge guide geometries: parallel and convergent. Curtain breakup was initiated by the expansion of a hole within the curtain. For low viscosity liquid, the measured hole retraction speed is independent of the viscosity and equal to the Taylor-Culick speed. For high viscosity liquids, the retraction speed is lower than the Taylor-Culick speed due to viscous forces that resist the flow. The results also show the effect of liquid viscosity on the curtain stability is a strong function of the edge guide design. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-24T11:06:24.441319-05:
      DOI: 10.1002/aic.16015
       
  • 3D-Foam-Structured Nitrogen-Doped Graphene-Ni Catalyst for Highly
           Efficient Nitrobenzene Reduction
    • Authors: Zhiyong Wang; Yuan Pu, Dan Wang, Jie Shi, Jie-Xin Wang, Jian-Feng Chen
      Abstract: We report the preparation of a porous 3D-foam-structured nitrogen-doped graphene-Ni (NG/NF) catalyst and the evaluation of its performance in the reduction of nitrobenzene (NB) through detailed studies of the kinetics. The NG/NF catalyst showed a significantly higher reaction rate than pure Ni foam (NF). Moreover, the separation of the 3D-foam-structured catalyst from the products was more convenient than that of NG powdered catalysts. The obtained kinetics data fit well to the Langmuir-Hinshelwood model, with an error ratio below 10%. Density functional theory (DFT) calculations indicated that the adsorption of sodium borohydride (NaBH4) on the NG/NF surface was stronger than that of NB, which strongly agreed with the kinetic parameters determined from the Langmuir-Hinshelwood model. The excellent catalytic efficiency of the 3D-foam-structured catalyst combined with the knowledge of the kinetics data make this catalyst promising for application in larger scale nitrobenzene reduction. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-24T11:05:10.257711-05:
      DOI: 10.1002/aic.16016
       
  • Highly Efficient Separation of Strongly Hydrophilic Structurally-Related
           Compounds by Hydrophobic Ionic Solutions
    • Authors: Qiwei Yang; Shaocong Guo, Xianxian Liu, Zhiguo Zhang, Zongbi Bao, Huabin Xing, Qilong Ren
      Abstract: The selective separation of strongly hydrophilic structurally-related compounds in aqueous solutions is a long-standing challenge due to a trade-off between separation selectivity and capacity. This work shows a new method to separate strongly hydrophilic structurally-related compounds through hydrophobic ionic solution-based liquid-liquid extraction, with L-ascorbic acid 2-glucoside (AA-2G) and L-ascorbic acid as model compounds. Extraordinary distribution coefficient, superb molecular selectivity, large extraction capacity and good recyclability without using strong acids and salts were all achieved, with a small consumption of phosphonium bromide ionic liquid and aprotic molecular diluent. The essence of this method is the successful combination of both strong hydrogen-bond basicity and good hydrophobicity along with significant preferential solvation phenomena of the constructed ionic solutions. Even if at a high feed concentration of 100 mg/ml, the purity of AA-2G could be greatly elevated from 50% to 96.2% with an ultrahigh yield of almost 100% after five-stage countercurrent extraction. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-22T05:55:31.803455-05:
      DOI: 10.1002/aic.16013
       
  • Joint Capacity Planning and Distribution Network Optimization of Coal
           Supply Chains under Uncertainty
    • Authors: Rui-Jie Zhou; Li-Juan Li
      Abstract: A two-stage stochastic integer programming model is developed to address the joint capacity planning and distribution network optimization of multi-echelon coal supply chains (CSCs) under uncertainty. The proposed model not only introduces the uses of compound real options in sequential capacity planning, but also considers uncertainty induced by both risks and ambiguities. Both strategic decisions (i.e., facility locations and initial investment, service assignment across the entire CSC, and option holding status) and scenario-based operational decisions (i.e., facility operations and capacity expansions, outsourcing policy, and transportation and inventory strategies) can be simultaneously determined using the model. By exploiting the nested decomposable structure of the model, we develop a new distributed parallel optimization algorithm based on non-convex generalized Bender decomposition and Lagrangean relaxation to mitigate the computation resource limitation. One of the main CSCs in China is studied to demonstrate the applicability of the proposed model and the performance of the algorithm. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-22T05:55:25.758985-05:
      DOI: 10.1002/aic.16012
       
  • Enhancing CO2 Absorption Efficiency using a Novel PTFE Hollow Fiber
           Membrane Contactor at Elevated Pressure
    • Authors: Fushan Wang; Guodong Kang, Dandan Liu, Meng Li, Yiming Cao
      Abstract: The internal structure design of membrane module is very important for gas removal performance using membrane contactor via physical absorption. In this study, a novel membrane contactor developed by weaving polytetrafluoroethylene (PTFE) hollow fibers was applied to remove CO2 from 60% N2 + 40% CO2 mixture (with CO2 concentration similar to that of biogas) at elevated pressure (0.8 MPa) using water as absorbent. Compared with the conventional module with randomly packed straight fibers, the module with woven PTFE fibers exhibited much better CO2 absorption performance. The weaving configuration facilitated the meandering flow or Dean vortices and renewing speed of water around hollow fibers. Meanwhile, the undesired influences such as channeling and bypassing were also eliminated. Consequently, the mass transfer of liquid phase was greatly improved and the CO2 removal efficiency was significantly enhanced. The effects of operation pressure, module arrangement, feed gas and water flow rate on CO2 removal were systematically investigated as well. The overall mass transfer coefficient (KOV) varied from 1.96 × 10−5 to 4.39 × 10−5 m/s (the volumetric mass transfer coefficient KLa = 0.034 – 0.075 s−1) under the experimental conditions. The CO2 removal performance of novel woven fiber membrane contactor matched well with the simulation results. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-22T05:50:24.492818-05:
      DOI: 10.1002/aic.16014
       
  • Two-Step Continuous Production of Monodisperse Colloidal Ellipsoids at
           Rates of One Gram per Day
    • Authors: Joseph A. Ferrar; Leonid Pavlovsky, Yanliang Liu, Eric Viges, Michael J. Solomon
      Abstract: We report a two-step process for the continuous production of monodisperse polystyrene colloidal ellipsoids of aspect ratios up to 6.8 at rates that exceed 1.0 g per day, an improvement upon previously reported synthetic batch processing rates of nearly a factor of 20. This scale up is accomplished by continuous evaporative processing of a polymer solution into an elastomeric film embedded with colloidal spheres. Subsequently, the film is continuously elongated at a temperature that stretches the embedded spheres into ellipsoids. The method is used to deform initially 1.0 μm diameter spheres into ellipsoids of aspect ratio 1.27 ± 0.15, 3.31 ± 0.44, 3.91 ± 0.72, 4.14 ± 0.47, and 6.77 ± 1.01. The particle production rate reported here opens new possibilities for applications of monodisperse ellipsoids, such as self-assembly and optical characterization of complex crystalline unit cells, as well as rheological characterization of dilute gels and dense suspensions. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-19T11:06:30.057101-05:
      DOI: 10.1002/aic.16009
       
  • Liquid-Liquid Two-Phase Flow in Ultrasonic Microreactors: Cavitation,
           Emulsification and Mass Transfer Enhancement
    • Authors: Shuainan Zhao; Zhengya Dong, Chaoqun Yao, Zhenghui Wen, Guangwen Chen, Quan Yuan
      Abstract: The effects of ultrasound on the hydrodynamic and mass transfer behaviors of immiscible liquid-liquid two-phase flow were investigated in a domestic ultrasonic microreactor. Under ultrasonic irradiation, cavitation bubble was generated and underwent violent oscillation. Emulsification of immiscible phases was initiated by virtue of oscillating bubbles shuttling through the water/oil interface. The pressure drop was found to decrease with increasing ultrasound power, with a maximum decrement ratio of 12% obtained at power 30 W. The mass transfer behavior was characterized by extraction of Rhodamine B from water to 1-octanol. An enhancement factor of 1.3-2.2 on the overall mass transfer coefficient was achieved under sonication. The mass transfer performance was comparable to passive microreactor at similar energy dissipation rate (61-184 W/kg). The extraction equilibrium was reached under a total flow velocity 0.01 m/s and input power 20 W and 30 W, exhibiting its potential use in liquid-liquid extraction process. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-19T11:06:19.903927-05:
      DOI: 10.1002/aic.16010
       
  • Multivariable Model Predictive Control of a Novel Rapid Pressure Swing
           Adsorption System
    • Authors: Matthew D. Urich; Vemula Rama Rao, Mayuresh V. Kothare
      Abstract: A multivariable model predictive control (MPC) algorithm is developed for the control and operation of a rapid pressure swing adsorption (RPSA) based medical oxygen concentrator (MOC). The novelty of the approach is the use of all four step durations in the RPSA cycle as independent manipulated variables in a truly multivariable context. The RPSA has a complex, cyclic, nonlinear multivariable operation that requires feedback control, and MPC provides a suitable framework for controlling such a multivariable system. The multivariable MPC presented here uses a quadratic optimization program with integral action and a linear model identified using sub-space system identification techniques. The controller was designed and tested in simulation using a complex, highly coupled, nonlinear RPSA process model. The model was developed with the least restrictive assumptions compared to those reported in the literature, thereby providing a more realistic representation of the underlying physical phenomena. The resulting MPC effectively tracks set points, rejects realistic process disturbances and is shown to outperform conventional PID control. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-19T11:05:22.900109-05:
      DOI: 10.1002/aic.16011
       
  • Receding horizon optimal operation and control of a solar-thermal district
           heating system
    • Authors: Xiaodong Xu; Yuan Yuan, Stevan Dubljevic
      Abstract: This work focuses on the receding horizon optimal control for a solar-thermal district heating (STDH) system containing lumped parameter and distributed parameter subsystems. A common STDH system includes solar collector system, a short term energy storage tank and a district heating loop system with a secondary gas boiler system. The inclusion or exclusion of these components leads to different operational and working modes. Detailed system description and mathematical models are provided, and three working modes are introduced and in each mode several operations are demonstrated and addressed. Single-objective and multi-objective problems are formulated. Moreover, in the mode where gas boiler system is included to help addressing the district heating demand, the internal model based boundary servo-control approach is proposed and applied to obtain desired boiler water temperatures such that the expected district heating demand can be satisfied. Moreover, a boundary state observer is designed for the considered solar collector system. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-19T11:00:23.030221-05:
      DOI: 10.1002/aic.16007
       
  • Simulation on Hydrogen Storage Properties of Metal-Organic Frameworks
           Cu-BTC at 77K∼298K
    • Authors: Shumin Chen; Yumei Shi, Bo Gu
      Abstract: In recent years, many researchers have studied on the hydrogen storage properties of metal-organic frameworks (MOFs) by grand canonical Monte Carlo (GCMC) simulation. At present, the GCMC studies of Cu-BTC (BTC: benzene-1,3,5-tricarboxylate) which is a prototypical metal-organic framework mainly adopt the classical force fields, the simulation temperatures are mainly focus on 298K and 77K, and most researchers didn't consider the effects of quantum effects at low temperature. Therefore, we used the quantum effects to correct the classical force fields and the force fields with more accurate simulation results were used to simulate the hydrogen adsorption performances of Cu-BTC in the temperature range of 77K∼298K and the pressure range of 1∼8MPa at each temperature. The results show that the effects of quantum effects on the hydrogen storage of Cu-BTC cannot be neglected and the corrected Dreiding force field can simulate hydrogen adsorption performances of Cu-BTC more accurately at low temperature. This article is protected by copyright. All rights reserved.
      PubDate: 2017-10-19T11:00:19.409574-05:
      DOI: 10.1002/aic.16008
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • Issue information - table of contents
    • Pages: 5237 - 5237
      PubDate: 2017-11-02T11:29:43.766841-05:
      DOI: 10.1002/aic.15484
       
  • How nano-scale roughness impacts the flow of grains influenced by
           capillary cohesion
    • Authors: Casey Q. LaMarche; Andrew W. Miller, Peiyuan Liu, Stuart Leadley, Christine M. Hrenya
      Pages: 5250 - 5257
      Abstract: We show that nano-scale changes in surface roughness affect the macro-scale (many-particle) behavior of granular materials influenced by cohesion. Macro-scale effects of roughness are investigated for conditions where cohesion is dominated by either humidity-induced or van der Waals-induced forces. Surface-topography measurements are used to calculate the relevant interparticle cohesive forces. The (force-dominated) macro-scale cohesion measurements are explained via the ratio of the predicted interparticle cohesive force to gravity, thus reinforcing the importance of roughness to cohesion. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5250–5257, 2017
      PubDate: 2017-07-04T15:15:24.438465-05:
      DOI: 10.1002/aic.15830
       
  • CO2 capture in a multistage CFB: Part I: Number of stages
    • Authors: Sutthichai Boonprasop; Dimitri Gidaspow, Benjapon Chalermsinsuwan, Pornpote Piumsomboon
      Pages: 5267 - 5279
      Abstract: The most common technology for postcombustion of CO2 capture is the amine solvent scrubber. The energy consumption for capturing CO2 from flue gases using amine solvent technology is 15–30% of the power plant electricity production. Hence, there is a need to develop more efficient methods of removing CO2. A circulating fluidized bed using sodium or potassium carbonates is potentially such a process, as their high decomposition pressures allow regeneration at low temperatures using waste heat rather than steam from the power plant. But equilibrium data for the sorbents require the use of several cooled stages to achieve high CO2 conversions. Here, a method of computing such a number of stages for a given CO2 conversion was developed using multiphase computational fluid dynamics. It was found that it required six equilibrium stages to remove 96% of CO2 with the initial mole fraction of 0.15 in a sorption riser. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5267–5279, 2017
      PubDate: 2017-05-14T18:16:05.821873-05:
      DOI: 10.1002/aic.15776
       
  • CO2 capture in a multistage CFB: Part II: Riser with multiple cooling
           stages
    • Authors: Sutthichai Boonprasop; Dimitri Gidaspow, Benjapon Chalermsinsuwan, Pornpote Piumsomboon
      Pages: 5280 - 5289
      Abstract: A 1 m in diameter and 3.55 m tall fluidized bed riser internally with water tubes, which required six equilibrium stage of riser-sorber for capturing about 95% of CO2 emitted from a coal power plant, were designed to replace the multisingle risers. At the optimum operating condition, the temperature of the cooling tubes in the bottom, the middle and the top of the riser were kept constant values at 50, 40, and 30°C, respectively. The hot water (57°C) from lowest exchanger section can be used to preheat the spent sorbent for the regeneration in a downer. The rest of the heat for the regenertion is obtained from the stack gas (100–130°C). This new concept promises to reduce the energy consumption for CO2 removal from flue gas. The only energy requirement is for pumping fluid and fluidizing particles in the bed. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5280–5289, 2017
      PubDate: 2017-05-14T18:23:26.344589-05:
      DOI: 10.1002/aic.15777
       
  • Analysis of the effect of small amounts of liquid on gas–solid
           fluidization using CFD-DEM simulations
    • Authors: C. M. Boyce; A. Ozel, J. Kolehmainen, S. Sundaresan
      Pages: 5290 - 5302
      Abstract: Gas–solid fluidization involving small amounts of liquid is simulated using a CFD-DEM model. The model tracks the amount of liquid on each particle and wall element and incorporates finite rates of liquid transfer between particles and pendular liquid bridges which form between two particles as well as between a particle and a wall element. Viscous and capillary forces due to these bridges are modeled. Fluidization–defluidization curves show that minimum fluidization velocity and defluidized bed height increase with Bond number (Bo), the ratio of surface tension to gravitational forces, due to cohesion and inhomogeneous flow structures. Under fluidized conditions, hydrodynamics and liquid bridging behavior change dramatically with increasing Bo, and to a lesser extent with capillary number, the ratio of viscous to surface tension forces. Bed fluidity is kept relatively constant across wetting conditions when one maintains a constant ratio of superficial velocity to minimum fluidization velocity under wet conditions. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5290–5302, 2017
      PubDate: 2017-06-21T18:36:04.878746-05:
      DOI: 10.1002/aic.15819
       
  • Coaxial electrohydrodynamic atomization toward large scale production of
           core-shell structured microparticles
    • Authors: Wei-Cheng Yan; Yen Wah Tong, Chi-Hwa Wang
      Pages: 5303 - 5319
      Abstract: In this work, a double-nozzle coaxial electrohydrodynamic atomization (CEHDA) system was designed as an instructive case toward large-scale production of core-shell microspheres. The effect of nozzle-to-nozzle distance was investigated to reveal that the interference between neighboring nozzles significantly affect the product quality in terms of morphology and core-shell structure. Optimal spacing indicated that ∼3000 nozzle/m2 packing density may be achieved with minimum interference of electric field from neighboring nozzle by adjusting the nozzle-to-nozzle distance greater than 0.018 m. The proposed multi-scale model also showed that the X-component of electric field strength (Ex) at the region near side nozzles increases with increasing nozzle number, and the bending of jets/sprays at the side may be reduced by using dummy nozzle at the edge side. The model could guide the design of multi-nozzle CEHDA system for production of core-shell microparticles in large-scale. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5303–5319, 2017
      PubDate: 2017-06-29T08:11:12.972435-05:
      DOI: 10.1002/aic.15821
       
  • An efficient and reliable predictive method for fluidized bed simulation
    • Authors: Liqiang Lu; Sofiane Benyahia, Tingwen Li
      Pages: 5320 - 5334
      Abstract: In past decades, the continuum approach was the only practical technique to simulate large-scale fluidized bed reactors because discrete approaches suffer from the cost of tracking huge numbers of particles and their collisions. This study significantly improved the computation speed of discrete particle methods in two steps: First, the time-driven hard-sphere (TDHS) algorithm with a larger time-step is proposed allowing a speedup of 20–60 times; second, the number of tracked particles is reduced by adopting the coarse-graining technique gaining an additional 2–3 orders of magnitude speedup of the simulations. A new velocity correction term was introduced and validated in TDHS to solve the over-packing issue in dense granular flow. The TDHS was then coupled with the coarse-graining technique to simulate a pilot-scale riser. The simulation results compared well with experiment data and proved that this new approach can be used for efficient and reliable simulations of large-scale fluidized bed systems. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5320–5334, 2017
      PubDate: 2017-06-29T08:31:35.569024-05:
      DOI: 10.1002/aic.15832
       
  • Magnetic particle tracking for nonspherical particles in a cylindrical
           fluidized bed
    • Authors: Kay A. Buist; Pavithra Jayaprakash, J.A.M. Kuipers, Niels G. Deen, Johan T. Padding
      Pages: 5335 - 5342
      Abstract: In granular flow operations, often particles are nonspherical. This has inspired a vast amount of research in understanding the behavior of these particles. Various models are being developed to study the hydrodynamics involving nonspherical particles. Experiments however are often limited to obtain data on the translational motion only. This paper focusses on the unique capability of Magnetic Particle Tracking to track the orientation of a marker in a full 3-D cylindrical fluidized bed. Stainless steel particles with the same volume and different aspect ratios are fluidized at a range of superficial gas velocities. Spherical and rod-like particles show distinctly different fluidization behavior. Also, the distribution of angles for rod-like particles changes with position in the fluidized bed as well as with the superficial velocity. Magnetic Particle Tracking shows its unique capability to study both spatial distribution and orientation of the particles allowing more in-depth validation of Discrete Particle Models. © 2017 The
      Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 63: 5335–5342, 2017
      PubDate: 2017-07-18T11:30:56.3055-05:00
      DOI: 10.1002/aic.15854
       
  • Quantifying the uncertainty introduced by discretization and
           time-averaging in two-fluid model predictions
    • Authors: Madhava Syamlal; Ismail B. Celik, Sofiane Benyahia
      Pages: 5343 - 5360
      Abstract: The two-fluid model (TFM) has become a tool for the design and troubleshooting of industrial fluidized bed reactors. To use TFM for scale up with confidence, the uncertainty in its predictions must be quantified. Here, we study two sources of uncertainty: discretization and time-averaging. First, we show that successive grid refinement may not yield grid-independent transient quantities, including cross-section–averaged quantities. Successive grid refinement would yield grid-independent time-averaged quantities on sufficiently fine grids. Then a Richardson extrapolation can be used to estimate the discretization error, and the grid convergence index gives an estimate of the uncertainty. Richardson extrapolation may not work for industrial-scale simulations that use coarse grids. We present an alternative method for coarse grids and assess its ability to estimate the discretization error. Second, we assess two methods (autocorrelation and binning) and find that the autocorrelation method is more reliable for estimating the uncertainty introduced by time-averaging TFM data. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5343–5360, 2017
      PubDate: 2017-07-24T15:41:54.104276-05:
      DOI: 10.1002/aic.15868
       
  • Intrusive probes in riser applications
    • Authors: Ray A. Cocco; S.B. Reddy Karri, Ted M. Knowlton, John Findlay, Thierry Gauthier, Jia Wei Chew, Christine M. Hrenya
      Pages: 5361 - 5374
      Abstract: Many of the probes used to understand hydrodynamics in circulating fluidized bed risers intrude into the environment they are measuring, although assumptions are typically asserted that the intrusive probes do not affect the data collected. This could be a poor assumption in some cases and conditions. We found that intrusive fiber-optic probe measurements consistently mis-predicted the solids concentration compared to the nonintrusive pressure drop measurements outside the fully developed flow region of a riser containing fluid catalytic cracking catalyst or glass bead particles. The discrepancy was sensitive to superficial gas velocity, solid circulation rate, probe position, and flow direction. Barracuda VR™ computational fluid dynamics simulations confirmed this, and indicated that particle momentum was lost at the leading edge of the probe and particles were spilling over to the probe tip. Accordingly, new probe designs were proposed to mitigate the intrusiveness of a fiber-optic probe for more accurate characterization. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5361–5374, 2017
      PubDate: 2017-08-12T18:41:00.283165-05:
      DOI: 10.1002/aic.15892
       
  • CFD simulation of the effect of rain on the performance of horizontal wind
           turbines
    • Authors: Hamid Arastoopour; Aiden Cohan
      Pages: 5375 - 5383
      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, simplifying assumptions were made and the validity of these assumptions was verified 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. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5375–5383, 2017
      PubDate: 2017-08-29T11:55:35.711142-05:
      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
      Pages: 5384 - 5395
      Abstract: Discrete Element Method 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: 2017-08-29T11:55:44.24063-05:0
      DOI: 10.1002/aic.15933
       
  • Process flow sheet synthesis: Systems-level design applied to synthetic
           crude production
    • Authors: James Alistair Fox; Diane Hildebrandt, David Glasser, Bilal Patel
      Pages: 5413 - 5424
      Abstract: A novel approach for conceptual design for process flow sheets at the “systems-level” is showcased in this article. A graphical technique, called the “GH-space,” is used to analyze the flows of material, heat and work within a process to provide insight into the interactions of various units within the process. Any unit process, which interacts with the surroundings by transferring heat and work, can be represented as a vector on the GH-space. While material and energy balances are normally performed on a flowsheet, this vectored approach allows the material and energy balances to be used to construct a flowsheet. This article focuses on using the GH-space to synthesis a synthetic fuels flowsheet. It was shown that a process could be designed that not only produced the desired product but could also consume carbon dioxide as a feed, along with the feeds of methane and oxygen, and could even potentially generate electricity. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5413–5424, 2017
      PubDate: 2017-06-19T18:06:30.139055-05:
      DOI: 10.1002/aic.15818
       
  • Biochar soil amendments for increased crop yields: How to design a
           “designer” biochar
    • Authors: Kyriacos Zygourakis
      Pages: 5425 - 5437
      Abstract: The development and testing of a transient adsorption/desorption model that describes the response of biochar particles to nutrient pulses simulating the application of fertilizer is presented in this study. Intraparticle nutrient transfer occurs both by diffusion through liquid-filled pores and by surface diffusion, and nutrient adsorption is described by Langmuir–Freundlich (Sips) isotherms. Simulation results show that the ability of a biochar to adsorb and then slowly release the nutrient is modulated by a complex interplay of external mass transfer, intraparticle diffusion (both pore and surface diffusion), and adsorption dynamics. The nutrient retention potential of biochar-amended soils is quantified and is shown to depend on multiple factors that include chemical and physical biochar properties, soil permeability, water flow, and the method of fertilizer application. These findings may explain why biochars with similar properties can potentially have widely different impacts on crop yields, as has been repeatedly reported in the literature. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5425–5437, 2017
      PubDate: 2017-07-28T08:01:43.260137-05:
      DOI: 10.1002/aic.15870
       
  • Complete carbon analysis of sulfur-containing mixtures using postcolumn
           reaction and flame ionization detection
    • Authors: Connor A. Beach; Kristeen E. Joseph, Paul J. Dauenhauer, Charles S. Spanjers, Andrew J. Jones, Triantafillos J. Mountziaris
      Pages: 5438 - 5444
      Abstract: Quantitative analysis of complex mixtures containing hundreds-to-thousands of organic compounds rich in heteroatoms, including oxygen, sulfur, and nitrogen, is a major challenge in the fuel, food, and chemical industries. In this work, a two-stage (oxidation and methanation) catalytic process in a 3-D–printed metal microreactor was evaluated for its capability to convert sulfur-containing organic compounds to methane. The microreactor was inserted into a gas chromatograph between the capillary column and flame ionization detector. Catalytic conversion of all sulfur-containing analytes to methane enabled carbon quantification without calibration, by the method identified as “quantitative carbon detection” or QCD. Quantification of tetrahydrothiophene, dimethyl sulfoxide, diethyl sulfide, and thiophene indicated complete conversion to methane at 450°C. Long-term performance of a commercial microreactor was evaluated for 2000 consecutive injections of sulfur-containing organic analytes. The sulfur processing capacity of the microreactor was identified experimentally, after which reduced conversion to methane was observed. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5438–5444, 2017
      PubDate: 2017-08-03T11:05:47.014848-05:
      DOI: 10.1002/aic.15888
       
  • Kinetics of glycerol conversion to hydrocarbon fuels over Pd/H-ZSM-5
           catalyst
    • Authors: Yang Xiao; Arvind Varma
      Pages: 5445 - 5451
      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%. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5445–5451, 2017
      PubDate: 2017-08-25T08:55:55.840184-05:
      DOI: 10.1002/aic.15931
       
 
 
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