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  Subjects -> ENGINEERING (Total: 2265 journals)
    - CHEMICAL ENGINEERING (188 journals)
    - CIVIL ENGINEERING (179 journals)
    - ELECTRICAL ENGINEERING (99 journals)
    - ENGINEERING (1210 journals)
    - ENGINEERING MECHANICS AND MATERIALS (384 journals)
    - HYDRAULIC ENGINEERING (55 journals)
    - INDUSTRIAL ENGINEERING (60 journals)
    - MECHANICAL ENGINEERING (90 journals)

ENGINEERING (1210 journals)            First | 1 2 3 4 5 6 7 | Last

Showing 201 - 400 of 1205 Journals sorted alphabetically
CT&F Ciencia, Tecnologia y Futuro     Open Access  
Current Applied Physics     Full-text available via subscription   (Followers: 4)
Current Science     Open Access   (Followers: 19)
Dams and Reservoirs     Hybrid Journal   (Followers: 3)
Data Handling in Science and Technology     Full-text available via subscription   (Followers: 5)
Design Journal : An International Journal for All Aspects of Design     Hybrid Journal   (Followers: 25)
Designed Monomers and Polymers     Hybrid Journal  
Designs, Codes and Cryptography     Hybrid Journal   (Followers: 6)
Development Engineering     Open Access  
Developments in Clay Science     Full-text available via subscription  
Developments in Geotechnical Engineering     Full-text available via subscription   (Followers: 4)
Developments in Mineral Processing     Full-text available via subscription   (Followers: 2)
Diálogos Interdisciplinares     Open Access  
Diamond Light Source Proceedings     Full-text available via subscription  
Diffusion Foundations     Full-text available via subscription  
Digital Signal Processing     Hybrid Journal   (Followers: 11)
Discrete Optimization     Full-text available via subscription   (Followers: 5)
Doct-Us Journal     Open Access  
Documents pour l'histoire des techniques     Open Access   (Followers: 1)
Dyes and Pigments     Hybrid Journal   (Followers: 1)
Dyna     Open Access  
Dynamical Systems : An International Journal     Hybrid Journal  
E&S Engineering and Science     Open Access  
El Hombre y la Máquina     Open Access  
Electromagnetics     Hybrid Journal   (Followers: 2)
Electrophoresis     Hybrid Journal   (Followers: 20)
Elementos     Open Access  
Elsevier Geo-Engineering Book Series     Full-text available via subscription   (Followers: 2)
Elsevier Ocean Engineering Series     Full-text available via subscription  
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 31)
ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations     Open Access  
Energies     Open Access   (Followers: 3)
Energy and Power Engineering     Open Access   (Followers: 15)
Energy Conversion and Management     Hybrid Journal   (Followers: 7)
Energy Engineering     Full-text available via subscription   (Followers: 9)
Energy for Sustainable Development     Hybrid Journal   (Followers: 8)
Energy Procedia     Open Access   (Followers: 2)
Energy Science & Engineering     Open Access   (Followers: 3)
Energy Science and Technology     Open Access   (Followers: 13)
Energy Sources, Part A: Recovery, Utilization, and Environmental Effects     Hybrid Journal   (Followers: 1)
Energy Sources, Part B: Economics, Planning, and Policy     Hybrid Journal   (Followers: 6)
Energy Systems     Hybrid Journal   (Followers: 12)
ENGEVISTA     Open Access   (Followers: 1)
ENGI : Revista Electrónica de la Facultad de Ingenieria     Open Access  
Engineer : Journal of the Institution of Engineers, Sri Lanka     Open Access  
Engineering     Open Access   (Followers: 1)
Engineering & Technology     Hybrid Journal   (Followers: 21)
Engineering : The official journal of the Chinese Academy of Engineering and Higher Education Press     Open Access   (Followers: 1)
Engineering Analysis with Boundary Elements     Hybrid Journal   (Followers: 1)
Engineering Computations     Hybrid Journal   (Followers: 3)
Engineering Economics     Open Access   (Followers: 4)
Engineering Economist, The     Hybrid Journal   (Followers: 6)
Engineering Failure Analysis     Hybrid Journal   (Followers: 63)
Engineering Geology     Hybrid Journal   (Followers: 8)
Engineering International     Open Access  
Engineering Journal     Open Access   (Followers: 1)
Engineering Management Journal     Hybrid Journal   (Followers: 18)
Engineering Management Research     Open Access   (Followers: 5)
Engineering Management Reviews     Open Access   (Followers: 1)
Engineering Optimization     Hybrid Journal   (Followers: 7)
Engineering Science and Technology, an International Journal     Open Access  
Engineering Sciences     Open Access   (Followers: 1)
Engineering Studies     Hybrid Journal  
Engineering With Computers     Hybrid Journal   (Followers: 7)
Engineering, Technology & Applied Science Research     Open Access  
Entramado     Open Access  
Entropy     Open Access   (Followers: 4)
Environmental & Engineering Geoscience     Full-text available via subscription   (Followers: 3)
Environmental and Ecological Statistics     Hybrid Journal   (Followers: 6)
Environmetrics     Hybrid Journal  
Épités - Épitészettudomány     Full-text available via subscription   (Followers: 1)
EPJ Photovoltaics     Open Access   (Followers: 3)
Épsilon     Open Access  
Ergonomics in Design: The Quarterly of Human Factors Applications     Hybrid Journal   (Followers: 13)
ESAIM: Control Optimisation and Calculus of Variations     Full-text available via subscription  
ESAIM: Mathematical Modelling and Numerical Analysis     Full-text available via subscription   (Followers: 4)
ESAIM: Proceedings     Open Access  
Estuaries and Coasts     Hybrid Journal   (Followers: 18)
European Journal of Combinatorics     Full-text available via subscription   (Followers: 3)
European Journal of Engineering Education     Hybrid Journal   (Followers: 3)
European Journal of Lipid Science and Technology     Hybrid Journal   (Followers: 1)
European Journal of Mass Spectrometry     Full-text available via subscription   (Followers: 16)
European Medical Device Technology     Full-text available via subscription   (Followers: 3)
European Physical Journal - Applied Physics     Full-text available via subscription   (Followers: 7)
European Transport Research Review     Open Access   (Followers: 21)
Evolutionary Intelligence     Hybrid Journal  
Evolving Systems     Hybrid Journal  
Exacta     Open Access  
Experimental Techniques     Hybrid Journal   (Followers: 55)
Experiments in Fluids     Hybrid Journal   (Followers: 7)
Fibers and Polymers     Full-text available via subscription   (Followers: 4)
Filtration & Separation     Full-text available via subscription   (Followers: 4)
Finite Fields and Their Applications     Full-text available via subscription   (Followers: 4)
Fire Science Reviews     Open Access   (Followers: 5)
Flexible Services and Manufacturing Journal     Hybrid Journal   (Followers: 1)
Flow, Turbulence and Combustion     Hybrid Journal   (Followers: 21)
Fluid Dynamics     Hybrid Journal   (Followers: 7)
Fluid Dynamics Research     Full-text available via subscription   (Followers: 9)
Fluid Phase Equilibria     Hybrid Journal   (Followers: 4)
Focus on Catalysts     Full-text available via subscription  
Focus on Pigments     Full-text available via subscription   (Followers: 3)
Focus on Powder Coatings     Full-text available via subscription   (Followers: 3)
Focus on Surfactants     Full-text available via subscription   (Followers: 3)
Food Engineering Reviews     Hybrid Journal   (Followers: 3)
Food Science and Technology     Open Access   (Followers: 3)
Formación Universitaria     Open Access   (Followers: 3)
FORMakademisk     Open Access  
Formal Methods in System Design     Hybrid Journal   (Followers: 7)
Forschung     Hybrid Journal  
Forschung im Ingenieurwesen     Hybrid Journal   (Followers: 1)
Foundations and Trends in Systems and Control     Full-text available via subscription  
Foundations and Trends® in Communications and Information Theory     Full-text available via subscription   (Followers: 7)
Foundations and Trends® in Electronic Design Automation     Full-text available via subscription  
Foundations of Science     Hybrid Journal  
Frontiers in Aerospace Engineering     Open Access   (Followers: 7)
Frontiers in Energy     Hybrid Journal   (Followers: 3)
Frontiers in Geotechnical Engineering     Open Access   (Followers: 2)
Frontiers of Environmental Science & Engineering     Hybrid Journal   (Followers: 4)
Frontiers of Nanoscience     Full-text available via subscription   (Followers: 1)
Fuel and Energy Abstracts     Full-text available via subscription   (Followers: 4)
Fuel Cells     Hybrid Journal   (Followers: 3)
Fuel Cells Bulletin     Full-text available via subscription   (Followers: 4)
Fusion Engineering and Design     Hybrid Journal   (Followers: 9)
Fuzzy Information and Engineering     Open Access   (Followers: 3)
Fuzzy Sets and Systems     Hybrid Journal   (Followers: 4)
Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards     Hybrid Journal   (Followers: 8)
Geoscience and Remote Sensing, IEEE Transactions on     Hybrid Journal   (Followers: 46)
Geotechnical Testing Journal     Full-text available via subscription   (Followers: 9)
Géotechnique     Hybrid Journal   (Followers: 12)
Geothermics     Hybrid Journal   (Followers: 5)
Glass Technology - European Journal of Glass Science and Technology Part A     Full-text available via subscription   (Followers: 3)
Global Journal of Engineering Research     Full-text available via subscription  
Global Perspective on Engineering Management     Open Access   (Followers: 1)
GPS Solutions     Hybrid Journal   (Followers: 15)
Graphs and Combinatorics     Hybrid Journal   (Followers: 6)
Grass and Forage Science     Hybrid Journal   (Followers: 6)
Great Circle: Journal of the Australian Association for Maritime History, The     Full-text available via subscription   (Followers: 7)
Handai Nanophotonics     Full-text available via subscription  
Handbook of Adhesives and Sealants     Full-text available via subscription   (Followers: 1)
Handbook of Sensors and Actuators     Full-text available via subscription   (Followers: 8)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 2)
Heat Exchangers     Open Access   (Followers: 1)
Heat Transfer - Asian Research     Hybrid Journal   (Followers: 7)
Heat Transfer Engineering     Hybrid Journal   (Followers: 22)
Historical Records of Australian Science     Hybrid Journal   (Followers: 2)
Human Factors in Ergonomics & Manufacturing     Hybrid Journal   (Followers: 5)
Iberoamerican Journal of Project Management     Open Access   (Followers: 3)
IBM Journal of Research and Development     Hybrid Journal   (Followers: 17)
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 35)
IEEE Antennas and Wireless Propagation Letters     Hybrid Journal   (Followers: 31)
IEEE Communications Magazine     Full-text available via subscription   (Followers: 45)
IEEE Control Systems Magazine     Full-text available via subscription   (Followers: 53)
IEEE Engineering Management Review     Full-text available via subscription   (Followers: 28)
IEEE Geoscience and Remote Sensing Letters     Hybrid Journal   (Followers: 43)
IEEE Industry Applications Magazine     Full-text available via subscription   (Followers: 16)
IEEE Instrumentation & Measurement Magazine     Full-text available via subscription   (Followers: 45)
IEEE Journal of Biomedical and Health Informatics     Hybrid Journal   (Followers: 11)
IEEE Journal of Oceanic Engineering     Hybrid Journal   (Followers: 11)
IEEE Journal of Selected Topics in Quantum Electronics     Hybrid Journal   (Followers: 8)
IEEE Journal of Selected Topics in Signal Processing     Hybrid Journal   (Followers: 26)
IEEE Journal of Solid-State Circuits     Full-text available via subscription   (Followers: 19)
IEEE Journal on Selected Areas in Communications     Hybrid Journal   (Followers: 12)
IEEE Latin America Transactions     Full-text available via subscription   (Followers: 2)
IEEE Microwave and Wireless Components Letters     Hybrid Journal   (Followers: 15)
IEEE Microwave Magazine     Full-text available via subscription   (Followers: 27)
IEEE Potentials     Full-text available via subscription   (Followers: 18)
IEEE Signal Processing Letters     Hybrid Journal   (Followers: 30)
IEEE Spectrum     Full-text available via subscription   (Followers: 127)
IEEE Technology and Society Magazine     Full-text available via subscription   (Followers: 2)
IEEE Transactions on Advanced Packaging     Full-text available via subscription   (Followers: 6)
IEEE Transactions on Antennas and Propagation     Full-text available via subscription   (Followers: 26)
IEEE Transactions on Applied Superconductivity     Hybrid Journal   (Followers: 3)
IEEE Transactions on Automation Science and Engineering     Full-text available via subscription   (Followers: 9)
IEEE Transactions on Circuits and Systems II: Express Briefs     Hybrid Journal   (Followers: 13)
IEEE Transactions on Components and Packaging Technologies     Full-text available via subscription   (Followers: 13)
IEEE Transactions on Control Systems Technology     Hybrid Journal   (Followers: 39)
IEEE Transactions on Education     Hybrid Journal   (Followers: 6)
IEEE Transactions on Electronics Packaging Manufacturing     Full-text available via subscription   (Followers: 16)
IEEE Transactions on Energy Conversion     Hybrid Journal   (Followers: 9)
IEEE Transactions on Engineering Management     Hybrid Journal   (Followers: 21)
IEEE Transactions on Evolutionary Computation     Hybrid Journal   (Followers: 9)
IEEE Transactions on Information Theory     Hybrid Journal   (Followers: 15)
IEEE Transactions on Instrumentation and Measurement     Hybrid Journal   (Followers: 38)
IEEE Transactions on Intelligent Transportation Systems     Hybrid Journal   (Followers: 6)
IEEE Transactions on Knowledge and Data Engineering     Hybrid Journal   (Followers: 24)
IEEE Transactions on Magnetics     Hybrid Journal   (Followers: 9)
IEEE Transactions on Microwave Theory and Techniques     Hybrid Journal   (Followers: 22)
IEEE Transactions on Nuclear Science     Hybrid Journal   (Followers: 7)
IEEE Transactions on Plasma Science     Hybrid Journal   (Followers: 7)
IEEE Transactions on Power Delivery     Hybrid Journal   (Followers: 16)
IEEE Transactions on Professional Communication     Hybrid Journal   (Followers: 5)
IEEE Transactions on Reliability     Hybrid Journal   (Followers: 27)
IEEE Transactions on Semiconductor Manufacturing     Hybrid Journal   (Followers: 5)
IEEE Transactions on Signal Processing     Hybrid Journal   (Followers: 52)
IEEE Transactions on Vehicular Technology     Hybrid Journal   (Followers: 2)
IEEE Vehicular Technology Magazine     Full-text available via subscription   (Followers: 8)
IEEE/ACM Transactions on Computational Biology and Bioinformatics     Hybrid Journal   (Followers: 14)
IERI Procedia     Open Access  
IET Circuits, Devices & Systems     Hybrid Journal   (Followers: 18)
IET Generation, Transmission & Distribution     Hybrid Journal   (Followers: 2)

  First | 1 2 3 4 5 6 7 | Last

Journal Cover AIChE Journal
  [SJR: 1.098]   [H-I: 104]   [27 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  [1598 journals]
  • Particle Dynamics and Relaxation in Bimodal Suspensions during Drying
           Using Multi‐speckle Diffusing Wave Spectroscopy
    • Authors: Gwi Jeong Oh; Ji Won Hwang, Seong Jae Lee, Ki Wan Bong, Hyun Wook Jung
      Abstract: The motion of polystyrene particles in a bimodal suspension drop during drying was characterized via multi‐speckle diffusing wave spectroscopy. The fast and slow dynamics of bimodal particles, which were expressed in terms of autocorrelation function data from two kinds of cameras, were well connected in short and long lag time regimes. Characteristic time of β‐relaxation, representing the rapid movement of bimodal particles, became lower in the short lag time region as the portion of small particles increased, reflecting their fast Brownian motion. The difference in the relaxation features between bimodal suspension with large and small particles and unimodal suspension with only large particles became more evident as the size ratio between particles was high. Drying temperature could encourage the particle movement at the early stages of drying, leading to lower relaxation time, and inversely retard the relaxation behavior when drying time further elapsed, due to the structural rearrangement of particles. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-23T03:25:32.064819-05:
      DOI: 10.1002/aic.15437
       
  • A Water Droplet Size Distribution Dependent Modeling of Hydrate Formation
           in Water/Oil Emulsion
    • Abstract: Experimental data on chord length distributions and growth rate during methane hydrate formation in water‐in‐oil emulsions were obtained in a high pressure stirring reactor using FBRM and PVM. The experiments were carried out at 274.2 K for 10%‐30% water cuts and agitation rates ranging from 200 to 500 rpm initially at 7.72 MPa. Rapid growth was accompanied by gradually decrease in rate. Free water was observed to become depleted during rapid growth while some water remained encapsulated inside hydrate layers constituting a mass transfer barrier. The apparent kinetic constants of methane hydrate formation and free‐water fractions were determined using a newly developed kinetic model independent of the dissolution rate at the gas‐oil interface. It was illustrated that continued growth depends on distribution and transfer of water in oil‐dominated systems. This perception accords with observations of hydrate film growth on suspended water droplet in oil and clarifies transfer limits in kinetics. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-23T03:25:31.068071-05:
      DOI: 10.1002/aic.15436
       
  • Identification of Cell‐Nucleation Mechanism in Foam Injection
           Molding with Gas‐counter Pressure via Mold Visualization
    • Authors: Vahid Shaayegan; Guilong Wang, Lun Howe Mark, Chul B. Park
      Abstract: The mechanisms of cell nucleation and growth are investigated in foam injection molding using gas‐counter pressure (GCP). An in‐situ mold visualization technique is employed. The application of GCP suppresses cell nucleation, and prevents the blowing agent from escaping during mold‐filling. The inherent structural heterogeneity in the regular foam injection molding can be improved because of the uniform cavity pressure when employing GCP. The cavity pressure profiles show much faster pressure‐drop rates using GCP, because the single‐phase polymer/gas mixture has a lower compressibility than the two‐phase polymer/bubble mixture. Therefore, both the cell nucleation and growth rates are significantly increased through a higher pressure‐drop rate upon the removal of the GCP. The effect of GCP magnitude on the cell morphology is explored. When the GCP is lower than the solubility pressure, bimodal foaming occurs. As the GCP increases above the solubility pressure, the cell density increases because of the higher pressure‐drop rate. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-23T02:50:38.033947-05:
      DOI: 10.1002/aic.15433
       
  • Experimental operation of a reactive dividing wall column and comparison
           with simulation results
    • Authors: Christoph Ehlers; Torben Egger, Georg Fieg
      Abstract: Reactive dividing wall columns (RDWC) are a special type of distillation column that allow for the targeted realization of chemical reactions and the separation into multiple product fractions in one shell. However, despite their huge economical and ecological potentials for certain fields of application, this innovative technology has not found its way into industrial production processes yet. The very limited availability of experimental research studies verifying the prediction capabilities of respective modeling concepts for this type of distillation column might be one decisive reason for that. Therefore, the present study puts its focus on the detailed comparison between experimental operation of RDWC and the corresponding simulation results for steady‐state. For the first time, the mentioned comparison is carried out for a chemical system with non‐negligible side reactions. It is shown that even for this highly complex system, the mathematical model is capable of predicting the column operation. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-20T18:10:23.105795-05:
      DOI: 10.1002/aic.15435
       
  • Krypton‐Xenon Separation Properties of SAPO‐34 Zeolite
           Materials and Membranes
    • Authors: Yeon Hye Kwon; Christine Kiang, Emily Benjamin, Phillip Crawford, Ramesh Bhave, Sankar Nair
      Abstract: Separation of the radioisotope 85Kr from 136Xe is an important target during used nuclear fuel recycling. We report a detailed study on the Kr and Xe adsorption, diffusion, and membrane permeation properties of the silicoaluminophosphate zeolite SAPO‐34. Adsorption and diffusion measurements on SAPO‐34 crystals indicate their potential for use in Kr‐Xe separation membranes, but also highlight competing effects of adsorption and diffusion selectivity. SAPO‐34 membranes are synthesized on α−alumina disk and tubular substrates via steam assisted conversion (SAC) seeding and hydrothermal growth, and are characterized in detail. Membrane transport measurements reveal that SAPO‐34 membranes can separate Kr from Xe by molecular sieving, with Kr permeabilities around 50 Barrer and mixture selectivity of 25‐30 for Kr at ambient or slight sub‐ambient conditions. The membrane transport characteristics are modeled by the Maxwell‐Stefan equations, whose predictions are in very good agreement with experiment and confirm the minimal competing effects of adsorption and diffusion. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-20T10:30:37.513337-05:
      DOI: 10.1002/aic.15434
       
  • Adsorption of iodine on hydrogen‐reduced silver‐exchanged
           mordenite: Experiments and modelling
    • Authors: Yue Nan; David W. DePaoli, Lawrence L. Tavlarides
      Abstract: The adsorption process of iodine, a major volatile radionuclide in the off‐gas streams of spent nuclear fuel reprocessing, on hydrogen‐reduced silver‐exchanged mordenite (Ag0Z) was studied at the micro‐scale. The gas‐solid mass transfer and reaction involved in the adsorption process were investigated and evaluated with appropriate models. Optimal conditions for reducing the silver‐exchanged mordenite (AgZ) in a hydrogen stream were determined. Kinetic and equilibrium data of iodine adsorption on Ag0Z were obtained by performing single‐layer adsorption experiments with experimental systems of high precision at 373 – 473 K over various iodine concentrations. Results indicate approximately 91% to 97% of the iodine adsorption was through the silver‐iodine reaction. The effect of temperature on the iodine loading capacity of Ag0Z was discussed. The Shrinking Core model describe the data well, and the primary rate controlling mechanisms were macro‐pore diffusion and silver‐iodine reaction. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-14T18:32:20.989268-05:
      DOI: 10.1002/aic.15432
       
  • A Tribute to Roger Sargent
    • Authors: Ignacio E. Grossmann; Michael F. Doherty, Michael P. Harold
      PubDate: 2016-07-14T09:05:39.440547-05:
      DOI: 10.1002/aic.15423
       
  • Synthesizing bromobutyl rubber by a microreactor system
    • Authors: Pei Xie; Kai Wang, Peijian Wang, Yang Xia, Guangsheng Luo
      Abstract: Bromobutyl rubber (BIIR) is an important synthetic rubber with better vulcanizing behavior than traditional butyl rubber (IIR). It is hard to synthesize for the high reactant viscosity and strong corrosion caused by Br2 and HBr. A microreactor platform was developed to solve the corrosion problem with cheap materials and obtain high quality BIIR based on microscaled mixing. The results showed that low reaction temperature and quickly eliminating HBr from the reacting solution were crucial to obtain high selectivity of demanded molecule structure and prevent polymer from decomposition. Owing to the corrosion resistance ability, a water assistant technology was successfully implemented in the microreactor system, which produced high quality BIIR with almost 100% selectivity and less reduced molecule weight. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-13T18:45:24.516304-05:
      DOI: 10.1002/aic.15431
       
  • A new optimization model and a customized solution method for natural gas
           production network design and operation
    • Authors: Dan Li; Xiang Li
      Abstract: This paper proposes to tackle integrated design and operation of natural gas production networks under uncertainty, using a new two‐stage stochastic programming model, a novel reformulation strategy, and a customized global optimization method. The new model addresses material balances for multiple key gas components, pressure flow relationships in gas wells and pipelines, and compressor performance. This model is a large‐scale nonconvex mixed‐integer nonlinear programming problem that cannot be practically solved by existing global optimization solvers or decomposition‐based optimization methods. With the new reformulation strategy, the reformulated model has a better decomposable structure, and then a new decomposition‐based global optimization method is developed for efficient global optimization. In the case study of an industrial naturals production system, it is shown that the proposed modeling and optimization methods enable efficient solution, and the proposed optimization method is faster than a state‐of‐the‐art decomposition method by at least an order of magnitude. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-13T17:55:52.225316-05:
      DOI: 10.1002/aic.15428
       
  • Error‐triggered on‐line model identification for
           model‐based feedback control
    • Authors: Anas Alanqar; Helen Durand, Panagiotis D. Christofides
      Abstract: In industry, it may be difficult in many applications to obtain a first‐principles model of the process, in which case a linear empirical model constructed using process data may be used in the design of a feedback controller. However, linear empirical models may not capture the nonlinear dynamics over a wide region of state‐space and may also perform poorly when significant plant variations and disturbances occur. In the present work, an error‐triggered on‐line model identification approach is introduced for closed‐loop systems under model‐based feedback control strategies. The linear models are re‐identified on‐line when significant prediction errors occur. A moving horizon error detector is used to quantify the model accuracy and to trigger the model re‐identification on‐line when necessary. The proposed approach is demonstrated through two chemical process examples using a model‐based feedback control strategy termed Lyapunov‐based economic model predictive control (LEMPC). The chemical process examples illustrate that the proposed error‐triggered on‐line model identification strategy can be used to obtain more accurate state predictions to improve process economics while maintaining closed‐loop stability of the process. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-13T17:55:49.258028-05:
      DOI: 10.1002/aic.15430
       
  • Improving the operational stability of the multi‐chamber
           spout‐fluid bed via the insertion of a submerged partition plate
    • Authors: Shiliang Yang; Yuhao Sun, Liangqi Zhang, Jia Wei Chew
      Abstract: The effect of a submerged partition plate on improving the gas‐solid flow robustness and stability in a three‐dimensional spout‐fluid bed with multiple inter‐connected chambers is numerically investigated by means of computational fluid dynamics coupled with discrete element method (CFD‐DEM). Notably, multiple‐chamber beds are necessary in scaling up the spout‐fluid bed. The influence of plate height on gas‐solid distribution, spout‐annulus interaction and chamber interaction are also studied to optimize the design. The results demonstrate that inserting a partition plate with height above a certain threshold can effectively improve the stability of spouting and uniformly re‐distribute the flux load in each chamber, giving rise to parallel fountains and lower circulation flux of the solid phase. Results indicate that the plate height should be at least 80% of the packed bed height investigated, with the most optimal being about 92% based on steady spouting, and the maximum solid and gas exchanging fluxes between the chambers. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-13T17:55:47.909722-05:
      DOI: 10.1002/aic.15427
       
  • Structure‐based model for prediction of electrical conductivity of
           pure ionic liquids
    • Abstract: A structure‐based method was proposed to estimate the electrical conductivity of ionic liquids covering wide ranges of temperature (238.15‐484.1 K) and electrical conductivity (0.0001524‐19.3 S/m) based on experimental data collect from literature from 1998 to 2015. The influences of temperature and ion structure on electrical conductivity were also discussed. The mean absolute percentage error between the calculated and literature data was 6.02%, with 6.12% for the training set (1978 data points, 177 ILs) and 5.10% for the test set (217 data points, 11 ILs). This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-13T17:55:45.298651-05:
      DOI: 10.1002/aic.15429
       
  • Simulation of dry powder inhalers: Combining micro‐scale,
           meso‐scale and macro‐scale modeling
    • Abstract: The flow of carrier particles, coated with active drug particles, is studied in a prototype dry powder inhaler. A novel, multi‐scale approach consisting of a discrete element model (DEM) to describe the particles coupled with a dynamic large eddy simulation (LES) model to describe the dynamic nature of the flow is applied. The model consists of three different scales: the micro‐scale, the meso‐scale and the macro‐scale. At the micro‐scale, the interactions of the small active drug particles with larger carrier particles, with the wall, with the air flow, and with each other is thoroughly studied using discrete element modelling and detailed computational fluid dynamics (CFD), i.e resolving the flow structures around the particles. This has led to the development of coarse‐grained models, describing the interaction of the small active drug particles at the larger scales. At the meso‐scale the larger carrier particles, and all of their interactions are modelled individually using DEM and CFD‐LES. Collisions are modeled using a visco‐elastic model to describe the local deformation at each point of particle‐particle contact in conjunction with a model to account for cohesion. At the macro‐scale, simulations of a complete prototype inhaler are carried out. By combining the relevant information of each of the scales, simulations of the inhalation of one dose from a prototype inhaler using a patient relevant air flow profile show that fines leave the inhaler faster than the carrier particles. The results also show that collisions are not important for particle‐particle momentum exchange initially but become more important as the particles accelerate. It is shown that for the studied prototype inhaler the total release efficiency of the fine particles is between 10% and 30%, depending on the Hamaker constant, using typical settings for the properties of both particles. The results are also used to study regions of recirculation, where carrier particles can become trapped, and regions where fines adhere to the wall of the device. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-13T17:55:41.430245-05:
      DOI: 10.1002/aic.15424
       
  • A tribute to professor roger sargent: Intellectual leader of process
           systems engineering
    • Authors: Michael F. Doherty; Ignacio E. Grossmann, Costas Pantelides
      PubDate: 2016-07-12T21:25:22.189365-05:
      DOI: 10.1002/aic.15425
       
  • Mathematical Simulation of Wet Spinning Coagulation Process: Dynamic
           Modeling and Numerical Results
    • Authors: Nan Xu; Yongsheng Ding, William E. Schiesser, Mayuresh V. Kothare
      Abstract: In this paper, a dynamic model of polymer wet spinning coagulation process is proposed. The model is built based on the double diffusion phenomenon, phase separation process, continuity balance, and momentum balance of the entire coagulation process. The uniqueness of the model lies in its dynamic feature. The model can simulate the system's dynamic response to any variation in system inputs/parameters. Steady‐state system solutions can also be produced as the long‐time solutions of the dynamic model; a settling time can be observed at the same time. This paper employs a computationally efficient method of lines (MOL) numerical algorithm for solving the dynamic model. A simulation experiment on a selected non‐solvent‐solvent‐polymer ternary system is carried out to verify the model as well as the numerical method. The dynamic simulation results are analyzed and discussed. At the end of the paper, h‐refinement and p‐refinement are used to confirm the spatial convergence of the numerical solutions. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-12T21:20:22.948584-05:
      DOI: 10.1002/aic.15426
       
  • Modeling Study for the Effect of Particle Size on Char Gasification with
           CO2
    • Authors: Zhongjie Shen; Jianliang Xu, Haifeng Liu, Qinfeng Liang
      Abstract: This study applied a high temperature stage microscope to investigate the temperature effect caused by particle size on char gasification. Experiments were carried out with different particle sizes for raw chars and chars on molten slag surface, respectively. Heat transfer models were built for the raw char of two temperature distributions and char particle on molten slag, respectively. Results showed that reaction layer temperature of raw char decreased in the reaction dominant while char on molten slag had higher temperature. Temperature difference between two distributions increased with the initial particle size, indicating the temperature effect on large particles was obvious. Shrinking core model was applied and modified herein coupled with the modification of reaction layer temperature and reaction area. Model prediction and experimental data showed good agreements of carbon conversion and reactivity index for raw char and char on molten slag, respectively. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-11T03:30:56.517164-05:
      DOI: 10.1002/aic.15417
       
  • Improved predictions of alarm and safety system performance through
           process and operator response‐time modeling
    • Authors: Ian H. Moskowitz; Warren D. Seider, Jeffrey E. Arbogast, Ulku G. Oktem, Ankur Pariyani, Masoud Soroush
      Abstract: Dynamic risk analysis (DRA) has been used widely to analyze the performance of alarm and safety interlock systems of manufacturing processes. Because the most critical alarm and safety interlock systems are rarely activated, little or no data from these systems are often available to apply purely‐statistical DRA methods. Moskowitz et al. (2015)1 introduced a repeated‐simulation, process‐model‐based technique for constructing informed prior distributions, generating low‐variance posterior distributions for Bayesian analysis1, and making alarm‐performance predictions. This paper presents a method of quantifying process model quality, which impacts prior and posterior distributions used in Bayesian Analysis. The method uses higher‐frequency alarm and process data to select the most relevant constitutive equations and assumptions. New data‐based probabilistic models that describe important special‐cause event occurrences and operators' response‐times are proposed and validated with industrial plant data. These models can be used to improve estimates of failure probabilities for alarm and safety interlock systems. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-11T03:26:08.315423-05:
      DOI: 10.1002/aic.15419
       
  • Resolved‐particle Fixed Bed CFD with Microkinetics for Ethylene
           Oxidation
    • Authors: Behnam Partopour; Anthony G. Dixon
      Abstract: The incorporation of an ethylene oxidation microkinetic model into fixed‐bed CFD is studied using two different approaches. The first is based on mapping pre‐calculated reaction rates into quadratic splines under steady‐state conditions without any further assumptions or simplification of the elementary steps. The second approach uses conventional reaction engineering assumptions such as quasi‐equilibrium (QE) and hybrid steady state (HSS) to reduce the kinetic model and generate lumped rate expressions. Both kinetic models are implemented for illustrative resolved‐particle CFD simulations in a randomly packed bed of 120 spheres. It is shown that the QE and HSS assumptions are not valid throughout the range of reacting conditions. Comparison of the temperature and species profiles for these two approaches shows that the strong gradients inside the bed cause significant deviations in the reduced model compared to using the splines method with full microkinetics, which produces accurate results without increasing the computational time. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-11T03:25:38.199862-05:
      DOI: 10.1002/aic.15422
       
  • Bicriteria Optimization Approach to Analyze Incorporation of Biofuel and
           Carbon Capture Technologies
    • Abstract: Environmental considerations has become a central issue in the process industries. The energy sector attracts the majority of attention, since it is responsible from 83% of anthropogenic greenhouse gas emissions. Although the renewable energy technologies are surging, fossil fuels are expected to continue dominating the sector for the next decades. Therefore, it is important to analyze the performance of emerging technologies that can be integrated into existing facilities, such as biofuels and carbon capture and storage technologies. In this paper, we present a multi‐period bicriteria optimization model that represents traditional cogeneration processes and integrate biodiesel and CCS technologies. Then, the efficient set for the problem is obtained by using a novel two‐phase solution method. The results show that the modeling approach is effective in identifying the set of efficient solutions for the integration strategies of biodiesel and CCS technologies. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-11T03:25:29.129296-05:
      DOI: 10.1002/aic.15421
       
  • Influence of Catalyst Pore Network Structure on the Hysteresis of
           Multiphase Reactions
    • Abstract: The effects of the catalyst pore network structure on multiphase reactions in catalyst pellets are investigated by using the experimentally validated pore network model proposed in our recent work (AIChE J. 2016, 62, 451). The simulations display hysteresis loops of the effectiveness factor. The hysteresis loop area becomes significantly larger, when having small volume‐averaged pore radius, wide pore size distribution, and low pore connectivity; however, the loop area is insensitive to pellet size, even though it affects the value of the effectiveness factor. The hysteresis loop area is also strongly affected by the spatial distribution of the pore size, in particular for a bimodal pore size distribution. The pore network structure directly influences mass transfer, capillary condensation, and pore blocking, and subsequently passes these influences on to the hysteresis loop of the effectiveness factor. Recognizing these effects is essential when designing porous catalysts for multiphase reaction processes. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-11T03:20:53.108119-05:
      DOI: 10.1002/aic.15415
       
  • A Simple Model for Predicting Solid Concentration Distribution in
           Binary‐solid Liquid Fluidised Beds
    • Authors: Zhengbiao Peng; Behdad Moghtaderi, Elham Doroodchi
      Abstract: A simple mathematical model for predicting the solid concentration profile in binary‐solid liquid fluidised beds is presented. The main assumption is that the solid concentration distribution follows the logistic function, which is supported by the literature. Various equations have been derived to solve key system quantities (e.g., bed expansion height, length and position of the transition zone). In contrast to previous models that often involve adjustable parameters and strongly rely on the availability of experimental data, the present model only requires inputs of fluid and particle properties, operating conditions and correlations for dispersion and slip velocity. The results showed that the model is applicable to different binary‐solid systems that have size and/or density differences. The model's capability of predicting the layer inversion phenomenon has also been demonstrated. The model is simple but proves capable of accurately predicting key information for the design, operation and scale up of liquid fluidised beds. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-11T03:20:37.772202-05:
      DOI: 10.1002/aic.15420
       
  • Operational Strategy and Planning for Raw Natural Gas Refining Complexes:
           Process Modeling and Global Optimization
    • Authors: B. J. Zhang; Q. L. Chen, Jie Li, C. A. Floudas
      Abstract: Optimal operational strategy and planning of a raw natural gas refining complex (RNGRC) is very challenging since it involves highly nonlinear processes, complex thermodynamics, blending, and utility systems. In this paper, we first propose a superstructure integrating a utility system for the RNGRC, involving multiple gas feedstocks and different product specifications. Then, we develop a large‐scale nonconvex mixed‐integer nonlinear programming (MINLP) optimization model. The model incorporates rigorous process models for input and output relations based on fundamentals of thermodynamics and unit operations and accurate models for utility systems. To reduce the noncovex items in the proposed MINLP model, equivalent reformulation techniques are introduced. Finally, the reformulated nonconvex MINLP model is solved to global optimality using state of the art deterministic global optimization approaches. The computational results demonstrate that a significant profit increase is achieved using the proposed approach compared to that from the real operation. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-11T03:20:36.307135-05:
      DOI: 10.1002/aic.15416
       
  • An Experimental and Theoretical Study of Glycerol Oxidation to
           1,3‐Dihydroxyacetone over Bimetallic Pt‐Bi Catalysts
    • Abstract: It is important to utilize glycerol, the main by‐product of biodiesel, to manufacture value‐added chemicals such as 1,3‐dihydroxyacetone (DHA). In the present work, the performance of five different catalysts (Pt‐Bi/AC, Pt‐Bi/ZSM‐5, Pt/MCM‐41, Pt‐Bi/MCM‐41 and Pt/Bi‐doped‐MCM‐41) was investigated experimentally, where Pt‐Bi/MCM‐41 was found to exhibit the highest DHA yield. To better understand the experimental results and to obtain insight into the reaction mechanism, density functional theory (DFT) computations were conducted to provide energy barriers of elementary steps. Both experimental and calculated results show that for high DHA selectivity, Bi should be located in an adatom‐like configuration Pt, rather than inside Pt. A favorable pathway and catalytic cycle of DHA formation were proposed based on the DFT results. A cooperative effect, between Pt as the primary component and Bi as a promoter, was identified for DHA formation. Both experimental and theoretical considerations demonstrate that Pt‐Bi is efficient to convert glycerol to DHA selectively. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-11T03:20:25.989465-05:
      DOI: 10.1002/aic.15418
       
  • Computing MOSCED Parameters of Nonelectrolyte Solids with Electronic
           Structure Methods in SMD and SM8 Continuum Solvents
    • Authors: Jeremy R. Phifer; Kimberly J. Solomon, Kayla L. Young, Andrew S. Paluch
      Abstract: An efficient method to predict MOSCED parameters for nonelectrolyte solids using electronic structure calculations in SMD and SM8 continuum solvents is proposed and applied to acetanilide, acetaminophen, and phenacetin. The resulting parameters are ultimately used to predict the equilibrium solubility in a range of solvents over a range of temperatures. By combining MOSCED with SMD and SM8, we are able to leverage the strengths of both methods while eliminating shortcomings that would prevent their use alone for solvent selection in design processes involving nonelectrolyte solid solutes. Comparing to 77 non‐aqueous experimental solubilities of acetaminophen over the range 10 to 30 $^\circ$C, the proposed method has an average absolute error of 0.03 and 0.04 mol fracs for SMD and SM8 regressed parameters, respectively. Aqueous solubilities of acetaminophen over this temperature range are predicted with an average error of 0.030 and 0.0023 mol fracs, respectively. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-08T04:26:29.035354-05:
      DOI: 10.1002/aic.15413
       
  • Power consumption and form drag of regular and fractal‐shaped
           turbines in a stirred tank
    • Authors: K. Steiros; P. J. K. Bruce, O. R. H. Buxton, J. C. Vassilicos
      Abstract: Previous wind‐tunnel measurements have shown that fractal shaped plates have increased drag compared to square plates of the same area. In this study we measure the power consumption and drag of turbines with fractal and rectangular blades in a stirred tank. Power number decreases from rectangular to fractal impellers by over 10\%, increasingly so with fractal iteration number. Our results suggest that this decrease is not caused by the wake interaction of the blades, nor solely by the wake interaction with the walls either. Pressure measurements on the blades' surface show that fractal blades have lower drag than the rectangular ones, opposite to the wind tunnel experiment results. All tested blades' centre of pressure radius increases with Re, while their drag coefficient decreases, a possible effect of the solid body rotation increase with Re. Spectral analysis of the pressure signal reveals two peaks possibly connected to the blades' roll vortices. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-08T04:26:27.930102-05:
      DOI: 10.1002/aic.15414
       
  • Outer approximation algorithm with physical domain reduction for
           computer‐aided molecular and separation process design
    • Authors: Smitha Gopinath; George Jackson, Amparo Galindo, Claire S. Adjiman
      Abstract: Integrated approaches to the design of separation systems based on computer‐aided molecular and process design (CAMPD) can yield an optimal solvent structure and process conditions. The underlying design problem, however, is a challenging mixed integer nonlinear problem (MINLP), prone to convergence failure as a result of the strong and nonlinear interactions between solvent and process. To facilitate the solution of this problem, a modified outer‐approximation algorithm is proposed. Tests that remove infeasible regions from both the process and molecular domain are embedded within the outer‐approximation framework. Four tests are developed to remove sub‐domains where constraints on phase behaviour that are implicit in process models or explicit process (design) constraints are violated. The algorithm is applied to three case studies relating to the separation of methane and carbon dioxide at high pressure. The process model is highly nonlinear, and includes mass and energy balances as well as phase equilibrium relations and physical property models based on a group‐contribution version of the statistical associating fluid theory (SAFT‐γ Mie) and the GC+ group contribution method for some pure component properties. A fully automated implementation of the proposed approach is found to converge successfully to a local solution in 30 problem instances. The results highlight the extent to which optimal solvent and process conditions are interrelated and dependent on process specifications and constraints. The robustness of the CAMPD algorithm makes it possible to adopt higher‐fidelity nonlinear models in molecular and process design. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-08T04:26:26.621923-05:
      DOI: 10.1002/aic.15411
       
  • Surface DEAE Groups Facilitate Protein Transport on Polymer Chains in
           DEAE‐Modified‐and‐DEAE‐Dextran‐Grafted
           Resins
    • Authors: Linling Yu; Lingli Gong, Shu Bai, Yan Sun
      Abstract: Sepharose FF was modified with diethylaminoethyl‐dextran (DEAE‐dextran, DexD) and/or DEAE (D) to fabricate three types of ion exchangers FF‐DexD (grafting‐ligand resin), FF‐D (surface‐ligand resin), and FF‐D‐DexD (mixed‐ligand resin), for protein adsorption equilibria and kinetics study. It was found that both adsorption capacity and uptake rate (effective diffusivity, De) were significantly enhanced by grafting DEAE‐dextran. Notably, the De values on FF‐DexD and FF‐D‐DexD (De/D0>1.4) were six times greater than those on FF‐D (De/D0
      PubDate: 2016-07-08T04:26:07.594004-05:
      DOI: 10.1002/aic.15412
       
  • Issue information
    • Abstract: Cover illustration. Overview of onshore/offshore oil field infrastructure and key optimization decisions related to its integrated planning, development, design, and operation. M. S. Tavallali searched and adapted the base image from http://victortechnologies.com/stoody/oil-a-gas. Both M. S. Tavallali and I. A. Karimi edited it further and added keywords. 10.1002/aic.15209
      PubDate: 2016-07-05T11:55:38.818988-05:
      DOI: 10.1002/aic.14995
       
  • Moving horizon closed‐loop production scheduling using dynamic
           process models
    • Authors: Richard C. Pattison; Cara R. Touretzky, Iiro Harjunkoski, Michael Baldea
      Abstract: The economic circumstances that define the operation of chemical processes (e.g., product demand, feedstock and energy prices) are increasingly variable. To maximize profit, changes in production rate and product grade must be scheduled with increased frequency. To do so, process dynamics must be considered in production scheduling calculations, and schedules should be recomputed when updated economic information becomes available. In this paper, we address this need by introducing a novel moving horizon closed‐loop scheduling approach. We represent process dynamics explicitly in the scheduling calculation via low‐order models of the closed‐loop dynamics of scheduling‐relevant variables, and build a feedback connection on these variables using an observer structure to update model states. The feedback rescheduling mechanism consists of, i) periodic schedule updates that reflect updated price and demand forecasts, and, ii) event‐driven updates that account for process and market disturbances. The theoretical developments are demonstrated on the model of an industrial‐scale air separation unit. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-04T18:35:46.546883-05:
      DOI: 10.1002/aic.15408
       
  • Effect of potassium ion on the stability and release rate of hydrogen
           peroxide encapsulated in silica hydrogels
    • Authors: Ezgi Melis Dogan; Fulya Sudur Zalluhoglu, Nese Orbey
      Abstract: Hydrogen peroxide (H2O2) is encapsulated in silica hydrogels using sol‐gel method and the effects of the K+: Na+ ion ratio on gelation time, hydrogel structure, stability, and release rate of H2O2 were investigated. As the amount of K+ ions increased relative to the amount of Na+ ions at the same pH, the gel structure became less compact and the pore diameter increased. Hydrogen peroxide retention values up to 90% and 80% were observed at the end of 7 and 20 days respectively in the presence of K+ ions at low pH values when the initial H2O2 concentration was 19.9 wt% . Release rate of hydrogen peroxide decreased with decreasing pH for the two K+: Na+ ion ratios studied. This work presents an environmentally friendly, low cost, and easy to scale up method to increase the stability of high initial concentrations of H2O2 at room temperature and customize the release rate. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-04T18:35:35.025247-05:
      DOI: 10.1002/aic.15406
       
  • Loading of fibrous filter media and newly designed filter configurations
           by salt particles: An experimental study
    • Authors: Pengfei Zhao; Peng Cheng, Bruce J. Tatarchuk
      Abstract: Various fibrous filter media, including surface filter media, depth filter media, woven and nonwoven filter media, were tested and particle loading capacity was calculated using bench‐scale setup via a new estimation approach which was proposed and experimentally verified with Novick‐Kozeny model. Multi‐Element Structured Arrays (MESAs) developed by our research group were evaluated as well for particle loading capacity and filter lifetime on 24” × 24” full scale test rig (based on ASHRAE 52.2 Standard). Effects of varying filter media type, filter depth, pleat count and MESAs' element count on salt particle loading performance were experimentally investigated. The experimental studies showed that nonwoven activated carbon fiber (ACF) filter media have allowed significantly higher salt particle loading capacity and longer useful lifetime compared to woven or nanofiber entrapped media. Furthermore, MESAs were able to significantly enhance loading capacity for salt particles and useful lifetime due to higher filtration area and lower filtration velocity. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-04T18:35:32.124745-05:
      DOI: 10.1002/aic.15407
       
  • Strategy to improve catalytic trend predictions for methane oxidation and
           reforming
    • Authors: Byeongjin Baek; Abraham Aboiralor, Jacob D. Massa, Shengguang Wang, Purnima Kharidehal, Lars C. Grabow
      Abstract: Computational catalysts screening is an increasingly popular technique, in which the mechanism from a known good catalyst is commonly adopted, parameterized from linear scaling relationships, and then used a microkinetic model to identify other metal alloys with incrementally improved activity. This strategy, however, fails to identify truly novel catalysts that operate under non‐traditional reaction conditions and exhibit alternative dominant reaction pathways. Using methane oxidation and reforming we investigated a series of O* and OH*‐assisted C‐H scission and C‐O bond formation pathways. Notably, for methane oxidation we discovered a second local optimum for O*‐assisted C‐H bond activation near Ag, which is inactive if only the direct C‐H scission route is considered. In light of the significant qualitative difference in the predicted catalytic trends when parallel mechanisms are allowed, we propose a minimum barrier assumption to rapidly screen for potentially important alternative pathways without the need for costly density functional theory simulations. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-04T18:35:31.515331-05:
      DOI: 10.1002/aic.15404
       
  • Hydrophobic mesoporous acidic resin for hydroxyalkylation/alkylation of
           2‐methylfuran and ketone to high‐density biofuel
    • Abstract: Hydroxyalkylation/alkylation of biomass‐derived 2‐methylfuran (2‐MF) with cyclic ketones (cyclopentanone and cyclohexanone) has great potential in synthesizing high‐density biofuel. But the conversion and selectivity are still unsatisfactory because the in‐situ formed water decreases the acidity of catalyst and induces side reaction. Herein, hydrophobic mesoporous resins with sulfonic acid group (PS) and fluoride sulfonic acid group (PCS) were synthesized by a simple solvothermal reaction and ion exchange treatment, which have good mesoporous structure with surface area of 300‐700 m2/g. Notably, PS and PCS have better hydrophobicity and oleophilicity as compared to widely used sulfonic acid functional amberlyst‐15 and fluoride sulfonic acid functional nafion‐212. In the hydroxyalkylation/alkylation reaction, PS shows higher activity and selectivity than amberlyst‐15 while PCS surpasses nafion‐212. Furthermore, both PS and PCS have good recycling stability in consecutive 5 runs. After hydrodeoxygenation, two high‐density biofuels with density of 0.819 g/ml and 0.825 g/ml were obtained. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-04T18:35:28.514963-05:
      DOI: 10.1002/aic.15410
       
  • Fluid inhomogeneity within nanoslits and deviation from
           Hagen‐Poiseuille flow
    • Authors: Yuying Wang; Junbo Xu, Chao Yang
      Abstract: Recently, the deviation of nano‐confined flows from classical hydrodynamic theories has been frequently reported. In this work, such a flow is theoretically investigated by means of dissipative particle dynamics (DPD) simulation. The simulation results show that the density and viscosity inhomogeneities near solid/fluid interfaces depends on the slit wettability only. Flow enhancement relative to the Hagen‐Poiseuille flow occurs together with the flow inhomogeneity. Combining of flow inhomogeneity and the Stokes equation, a theoretical model for flux calculation is established. As the slit being widened, the model can be simplified by gradually eliminating the higher order traces, and be simplified into the model with Navier's slip condition and the well‐known Hagen‐Poiseuille relation at last. The theoretical results of flux are in good agreement with the simulations by DPD. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-04T18:35:23.851363-05:
      DOI: 10.1002/aic.15409
       
  • Optimization‐based support for process design under uncertainty: A
           case study
    • Authors: J. Steimel; S. Engell
      Abstract: The paper discusses the use of two‐stage stochastic optimization for the support of the solution of process design problems in the early phase of process development where the different potential elements of the production process can only be described with significant uncertainty. The first stage variables are the design decisions which are fixed after the process has been built, while the second stage variables are the operational parameters which can be adapted to the realization of the uncertainties. We demonstrate the application of the approach to the design of a hydroformylation process in a thermomorphic solvent system. The proposed designs which are computed using the software framework FSOpt are analyzed and compared using different graphic representations which provide insight into what the most important design decisions are. Finally, we review our experience with the proposed formulation and solution techniques and point out where further advances are needed. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-04T18:30:35.863174-05:
      DOI: 10.1002/aic.15400
       
  • Efficient synthesis of iron nanoparticles by self‐agglomeration in a
           fluidized bed
    • Authors: Jun Li; Jing Kong, Qingshan Zhu, Hongzhong Li
      Abstract: A two‐stage, fluidized reduction route is proposed to synthesize iron nanoparticles (NPs), with the aim of enhancing the quality of fluidization and preventing sintering activity. At both low and high temperatures, the degree of metallization η is approximately 80% due to the defluidization. Defluidization is mainly caused by the rapid sintering of the newly formed Fe NPs. The proposed two‐stage fluidization approach successfully resolves the defluidization problem through the self‐agglomeration of nanoparticles cultivated at low temperatures. These self‐agglomerated NPs showed an improved resistance to sintering at high temperatures. The high‐purity Fe NPs prepared by this approach exhibited excellent combustion activity, indicative of the potential as oxygen carriers in chemical looping combustion systems. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-04T18:30:34.552158-05:
      DOI: 10.1002/aic.15402
       
  • A smart manufacturing methodology for real time chemical process diagnosis
           using causal link assessment
    • Authors: R. Rathinasabapathy; M. J. Elsass, J.R. Josephson, J.F. Davis
      Abstract: Industrial chemical plant diagnosis is the task of analyzing process data to sufficiently pinpoint the causes of abnormal events as fast and as accurately as possible so corrective action can be taken in a timely manner. The need to identify failures explicitly and support human centered decision making becomes pronounced for enterprises. Qualitative diagnostic models are offer robustness in capturing diagnostic behaviors when there is little or no data on fault conditions. This paper develops, analyzes, and demonstrates a qualitative diagnostic methodology called Causal Link Assessment (CLA). CLA avoids the drawbacks of other methodologies while leveraging several new concepts that include dynamic pattern generation, single time step modeling with multi‐time step interpretation, and discretized, low granularity dynamic modeling. CLA is demonstrated for an existing ethylene production facility. Model building, robustness, reusability, unaccounted for faults and failures and alignment with emerging Smart Manufacturing infrastructure concepts are discussed. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-04T18:30:32.378472-05:
      DOI: 10.1002/aic.15403
       
  • A compartmental CFD‐PBM Model of High Shear Wet Granulation
    • Abstract: The conventional, geometrically lumped description of the physical processes inside a high shear granulator is not reliable for process design and scale‐up. In this study, a compartmental Population Balance Model (PBM) with spatial dependence is developed and validated in two lab‐scale high shear granulation processes using a 1.9L MiPro granulator and 4L DIOSNA granulator. The compartmental structure is built using a heuristic approach based on computational fluid dynamics (CFD) analysis, which includes the overall flow pattern, velocity and solids concentration. The constant volume Monte Carlo approach is implemented to solve the multi‐compartment population balance equations. Different spatial dependent mechanisms are included in the compartmental PBM to describe granule growth. It is concluded that for both cases (low and high liquid content), the adjustment of parameters (e.g. layering, coalescence and breakage rate) can provide a quantitative prediction of the granulation process. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-04T03:26:05.639092-05:
      DOI: 10.1002/aic.15401
       
  • Tuning Carbon Molecular Sieves for Natural Gas Separations: A Diamine
           Molecular Approach
    • Authors: Graham B. Wenz; William J. Koros
      Abstract: This paper introduces a new post‐synthetic modification method for tuning the separation properties of carbon molecular sieve (CMS) membranes. Polymeric hollow fibers of 6FDA/BPDA‐DAM were pyrolyzed to 550 °C under inert Argon, and were then exposed to a tetrahydrofuran solution containing PPM levels of paraphenylenediamine dopant. The original goal of the treatment was to modify the morphology in a manner to prevent relaxation of the CMS to suppress physical aging, envisioned to be analogous to that in glassy polymer membranes where reduction of “unrelaxed free volume” causes reduced permeance with a mild increase in selectivity. Results of long‐term CO2 and CH4 permeation experiments of doped fibers showed that aging‐resistant membranes did not result. This fact notwithstanding, results revealed this approach provides a valuable new tuning tool for CMS transport properties. Complementary gas sorption experiments performed suggest the amine dopants tune large ultramicropores, thereby increasing size and shape based diffusion selectivity. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-04T03:25:44.901652-05:
      DOI: 10.1002/aic.15405
       
  • Multi‐Enterprise Supply Chain: Simulation and Optimization
    • Authors: Nihar Sahay; Marianthi Ierapetritou
      Abstract: The advancements in connectivity among the entities belonging to industrial supply chain have given rise to more complex, global supply chain networks. These networks are often constituted of entities that belong to multiple such networks. Interactions among the entities in such networks are also influenced by whether they belong to the same enterprise or different ones. This work takes into consideration the effect of such interactions. The entities belonging to different enterprises are assumed to interact through auctions. An agent based simulation model that incorporates such auctions is used to represent multi‐enterprise supply chain networks. The dynamics of the supply chain affected by the auction mechanism are investigated. Also a derivative free optimization methodology is proposed to find the optimal warehouse capacities for the minimization of total cost. This article is protected by copyright. All rights reserved.
      PubDate: 2016-07-04T03:20:28.842616-05:
      DOI: 10.1002/aic.15399
       
  • New Materials for Catalysis and Energy Storage Devices
    • Authors: Harold H. Kung
      PubDate: 2016-06-29T09:45:26.377711-05:
      DOI: 10.1002/aic.15386
       
  • Why Not Try Active Learning?
    • Authors: John L. Falconer
      PubDate: 2016-06-29T09:45:21.50596-05:0
      DOI: 10.1002/aic.15387
       
  • Explicit Model Predictive Control of Hybrid Systems and Multiparametric
           Mixed Integer Polynomial Programming
    • Authors: Vassilis M. Charitopoulos; Vivek Dua
      Abstract: Hybrid systems are dynamical systems characterized by the simultaneous presence of discrete and continuous variables. Model‐based control of such systems is computationally demanding. To this effect, explicit controllers which provide control inputs as a set of functions of the state variables have been derived, using multi‐parametric programming mainly for the linear systems. In the present work, hybrid polynomial systems are considered resulting in a Mixed Integer Polynomial Programming (MIPP) problem. Treating the initial state of the system as a set of bounded parameters, the problem is reformulated as a multi‐parametric Mixed Integer Polynomial optimization (mp‐MIPOPT) problem. A novel algorithm for mp‐MIPOPT problems is proposed and the exact explicit control law for polynomial hybrid systems is computed. The key idea is the computation of the analytical solution of the optimality conditions while the binary variables are treated as relaxed parameters. Finally, using symbolic calculations exact non‐convex critical regions are computed. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-27T17:50:28.668756-05:
      DOI: 10.1002/aic.15396
       
  • Quantitative Evaluation of Mass Transfer near the Edge of Porous Media by
           Absorption Photometry
    • Authors: Taiki Tanikoshi; Ryoko Otomo, Shusaku Harada
      Abstract: This paper reports the intensive investigation of mass transfer near the entrance (edge) of porous media by quantification of the surrounding concentration field. We have adopted a non‐invasive and real‐time system based on light absorption photometry for measurement of the concentration field in a quasi‐two dimensional cell. This system is, in principle, applicable to the measurement of various substances due to the generality of light absorption. This measurement system was applied to a simple model of the gravity‐driven transport of a substance in a fluid near the edge of a porous medium in the presence of a reaction at the surface. The temporal variation of the complicated concentration field is appropriately captured with a spatial resolution of several tens of micrometers to millimeters. Quantitative analyses revealed that the geometry of the porous edge considerably affects the convection flow and invasion of substances into the medium. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-27T13:30:25.255347-05:
      DOI: 10.1002/aic.15397
       
  • Visualization and simulation of the transfer process of
           index‐matched silica microparticle inks for gravure printing
    • Authors: A.M.P. Boelens; S. Lim, B.Y. Ahn, L. Francis, J.A. Lewis, J.J. de Pablo
      Abstract: A combined experimental and computational study of the transfer of transparent index‐matched silica‐particle inks between two flat plates is presented for gravure printing applications. The influence of printing speed and initial ink droplet size on the ability to accurately transfer ink during the printing process is explored systematically. Smooth interface Volume Of Fluid simulations are able to capture experimentally observed ink transfer over a wide range of printing speeds for inks having a modest to intermediate content of silica particles. However, for high‐content silica‐particle inks, transfer is structurally underpredicted. Our calculations indicate that for ink droplets with characteristic dimensions in the vicinity of 10, which are of particular interest for gravure printing applications, ink transfer improves due to the diminishing effect of gravity, and the increased importance of capillary forces at small length scales. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-27T13:25:23.67395-05:0
      DOI: 10.1002/aic.15392
       
  • Design of Multi‐Actor Distributed Processing Systems: A
           Game‐Theoretical Approach
    • Authors: Ana I. Torres; George Stephanopoulos
      Abstract: The manufacturing of a final product could be the result of a value chain involving several processing plants distributed across several distinct owners; a feature that may prevent the application of classical process design approaches that depend on a centralized treatment of the complete processing network. In this paper we propose and develop a game‐theoretical framework and specific methodologies, which allow the optimal design of distributed processing systems, through the decentralized strategies of independent actors. The resulting process design corresponds to a Nash Equilibrium point among the interacting actors. Its optimality and the justification of the independent strategies that led to it, are theoretically based on (and constrained by) the properties of the 2‐level Lagrangian approach. The paper also discusses the use of penalty‐term approaches, which can extend the applicability of the proposed framework and design methodologies to problems for which the underlying convexity assumptions of the 2‐level Lagrangian approach may not be possible to ascertain. A series of case studies illustrate the application of the proposed ideas to distributed processing networks of various structures. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-27T12:55:48.723555-05:
      DOI: 10.1002/aic.15395
       
  • Half Order Plus Time Delay (HOPTD) Models to Tune PI Controllers
    • Authors: Jietae Lee; Yongjeh Lee, Dae Ryook Yang, Thomas F. Edgar
      Abstract: Methods based on the first‐order plus time delay (FOPTD) model are very popular for tuning proportional‐integral (PI) controllers. The FOPTD model‐based methods are simple and their utility has been proved with many successful applications to a wide range of processes in practice. However, even for some overdamped processes where the FOPTD model has been applied successfully, these empirical FOPTD model‐based methods can fail to provide stable tuning results. To remove these drawbacks, a PI controller tuning method based on half‐order plus time delay (HOPTD) model is proposed. Because FOPTD model‐based methods can be applied to higher order processes, the proposed HOPTD model‐based method can be applied to higher order processes as well. It does not require any additional process information compared to the FOPTD model‐based method and hence can be used for overdamped processes in practice, complementing the traditional FOPTD model‐based methods. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-27T12:55:41.175039-05:
      DOI: 10.1002/aic.15394
       
  • General optimization model for the energy planning of industries including
           renewable energy: A case study on oil sands
    • Authors: Mohamed Elsholkami; Ali Elkamel
      Abstract: A multi‐period optimization model is developed for the energy procurement planning of industries including renewable energy. The model is developed with the objective of identifying the optimal set of energy supply technologies to satisfy a set of demands (e.g. power, heat, hydrogen, etc.) and emission targets at minimum cost. Time dependent parameters are incorporated in the model formulation, including demands, fuel prices, emission targets, carbon tax, lead time, etc. The model is applied to a case study based on the oil sands operations over the planning period 2015 – 2050. Various production alternatives were incorporated, including renewable, nuclear, conventional and gasification of alternative fuels. The results obtained indicated that the energy optimization model is a practical tool that can be utilized for identifying the key parameters that affect the operations of energy‐intensive industrial operations, and can further assist in the planning and scheduling of the energy for these industries. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-27T12:55:27.731664-05:
      DOI: 10.1002/aic.15393
       
  • CFD‐DEM Simulation of Tube Erosion in a Fluidized Bed
    • Authors: Yongzhi Zhao; Lei Xu, Jinyang Zheng
      Abstract: The erosion of the immersed tubes in a bubbling fluidized bed is studied numerically using an Eulerian‐Lagrangian approach coupling with a particle‐scale erosion model. In this approach, the motion of gas and particles is simulated by the CFD‐DEM method, and an erosion model SIEM (shear impact energy model) is proposed to predict the erosion of the tubes. The model is validated by the good agreement of the simulation results and previous experimental data. By analyzing the simulation results, some characteristics of the tube erosion in the fluidized bed are obtained, such as the distribution of the erosion rate around the tube, the variation of the erosion rate with the position of the tube, the effect of the friction coefficient of particles on the erosion, the relationship between the maximum and the average erosion rate, etc. The micro‐scale behavior of particles around the tubes is also revealed and the linear relationship between the erosion and the shear impact energy is confirmed by the simulation results and experiment. The agreement between simulation and experiment proves that the micro‐scale approach proposed in this paper has high accuracy for predicting erosion of the tubes in the fluidized bed, and has potential to be applied to modeling the process in other chemical equipment facing solid particle erosion. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-27T12:10:56.041293-05:
      DOI: 10.1002/aic.15398
       
  • Designing an Artificial Golgi Reactor to achieve targeted glycosylation of
           monoclonal antibodies
    • Authors: Oleksiy V. Klymenko; Kate E. Royle, Karen M. Polizzi, Nilay Shah, Cleo Kontoravdi
      Abstract: The therapeutic efficacy of monoclonal antibodies (mAbs) is dependent upon their glycosylation patterns. As the largest group of currently approved biopharmaceuticals, the microheterogeneity in mAb oligosaccharide profiles deriving from mammalian cell production is a challenge to the biopharmaceutical industry. Disengaging the glycosylation process from the cell may offer significant enhancement of product quality and allow better control and reproducibility in line with the Quality by Design paradigm. Three potential designs of an Artificial Golgi reactor implementing targeted sequential glycosylation of mAbs are proposed including a (i) microcapillary film reactor, (ii) packed bed reactor with non‐porous pellets, and (iii) packed bed reactor with porous pellets. Detailed mathematical models are developed to predict their performance for a range of design and operational parameters. While all three reactor designs can achieve desired conversion levels, the choice of a particular one depends on the required throughput and the associated cost of enzymes and co‐substrates. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-24T22:25:30.372333-05:
      DOI: 10.1002/aic.15388
       
  • A Comparative Computational Study of Diesel Steam Reforming in a Catalytic
           Plate Heat‐Exchange Reactor
    • Authors: Harsh Dhingra; Mayur Mundhwa, Rajesh D. Parmar
      Abstract: A two‐dimensional steady‐state model of a catalytic plate reactor for diesel steam reforming is developed. Heat is provided indirectly to endothermic reforming sites by flue gas from a SOFC tail‐gas burner. Two experimentally‐validated kinetic models on diesel reforming on platinum (Pt) catalyst were implemented for a comparative study; the model of Parmar et al.19 for a Pt/Al2O3 and the model of Shi et al.20 for a Pt/Gd‐CeO2 (GDC). The kinetic models were compared for: species concentration, approach to equilibrium, gas hourly space velocity and effectiveness factor. Co‐current flow showed better heat transfer compared to counter‐current flow arrangement. The comparison between the two kinetic models showed that different supports plays significant role in the final design of a reactor. The study also determined that initial 20% of the plate reactor has high diffusion limitation suggesting to use graded catalyst to optimize the plate reactor performance. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-24T22:25:28.431356-05:
      DOI: 10.1002/aic.15391
       
  • Reaction Mechanism and Kinetics for Hydrolytic Dehydrogenation of Ammonia
           Borane on a Pt/CNT Catalyst
    • Authors: Wenyao Chen; Dali Li, Zijun Wang, Gang Qian, Zhijun Sui, Xuezhi Duan, Xinggui Zhou, Isaac Yeboah, De Chen
      Abstract: A reaction mechanism is proposed for hydrolytic dehydrogenation of ammonia borane on a Pt/CNT catalyst. A combination of thermodynamic analysis and FTIR measurement reveals that B‐containing byproducts are mainly in the form of an NH4B(OH)4‐B(OH)3 mixture rather than NH4BO2 reported previously. The revised main reaction is NH3BH3+4H2O→NH4++B(OH)4‐+3H2↑, involving the B‐H, B‐N and O‐H bond cleavages. Isotopic experiments using D2O instead of H2O as reactant or introducing D2 into the reaction atmosphere suggest the O‐H bond cleavage being in the rate‐determining step, and an unfavorable occurrence of the chemisorbed H2O dissociation (i.e., the direct O‐H bond cleavage), respectively. Different reaction pathways with indirect O‐H bond cleavages are analyzed, and then NH3BH2*+H2O*→NH3BH2(OH)*+H* is suggested as the rate‐determining step. Subsequently, a Langmuir‐Hinshelwood kinetic model is developed, which fits well with the experimental data. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-24T22:25:27.442625-05:
      DOI: 10.1002/aic.15389
       
  • A High‐Throughput Assay for Screening Modifiers of Calcium Oxalate
           Crystallization
    • Authors: Jun Ha Kwak; Sriram Ramamoorthy, Sahar Farmanesh, Jeffrey D. Rimer, Pankaj Karande
      Abstract: Controlling crystal habit using growth modifiers provides novel avenues for tailoring properties of crystalline materials. Here, we report on the design of a high‐throughput screening assay for rapid identification of growth modifiers using calcium oxalate monohydrate crystallization as a model system. We conducted a systematic study of assay parameters (sample volume, shaking and temperature) on crystallization kinetics. Crystallization half‐time (CHT, t1/2), defined as the time at which crystallization is 50% complete, was obtained from the logistic fit of kinetic data and used as a measure of growth modifier potency. A test library of 13 peptides composed of aspartic acid and alanine residues was screened to determine their growth promotion or inhibition potentials. Leads identified from this study are in good agreement with ion‐selective electrode (ISE) measurements and a single time point measurement of free calcium ion concentration is an excellent end‐point for evaluating modifier potency. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-24T22:25:25.910689-05:
      DOI: 10.1002/aic.15390
       
  • Cohesive grains: Bridging micro‐level measurements to
           macro‐level flow behavior via surface roughness
    • Authors: Peiyuan Liu; Casey Q. LaMarche, Kevin M. Kellogg, Stuart Leadley, Christine M. Hrenya
      Abstract: Understanding fine‐particle flows relies on van der Waals cohesion modeling, requiring a method to consider measured surface roughness. We propose a robust scheme to extract roughness parameters from AFM surface maps, achieving accurate predictions of micro‐scale measured cohesion. Macro‐scale quantitative agreement is demonstrated by comparing defluidization predictions to measurements, which are sensitive to cohesion and system‐size independent. Agreement in both micro‐ and macro‐scale comparisons highlights the role of individual particle properties on bulk granular systems. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-18T10:21:02.002845-05:
      DOI: 10.1002/aic.15383
       
  • Kinetic study of hydrogen peroxide decomposition at high temperatures and
           concentrations in two capillary microreactors
    • Abstract: On the background of the direct adipic acid synthesis from cyclohexene and H2O2, a kinetic model was derived for the H2O2 decomposition catalyzed by sodium tungstate at high H2O2 concentrations and high temperatures. A perfluoroalkoxy (PFA) and a stainless steel micro‐flow capillary match commonly used microreactor materials. In the PFA capillary, the decomposition of hydrogen peroxide increased with residence time, reaction temperature and catalyst loading. The reaction order with respect to hydrogen peroxide and sodium tungstate was zero and one, respectively. Simulated data fit well with experimental data in the PFA capillary. While showing a similar trend as that in the PFA capillary, the stainless steel capillary exhibited much higher reaction rates. The steel surface participated in the decomposition process as a heterogeneous catalyst. Key influencing factors of the H2O2 decomposition provided some clues on the reaction mechanism of the adipic acid synthesis and its process optimization. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-18T10:20:41.93671-05:0
      DOI: 10.1002/aic.15385
       
  • Metal‐Organic Frameworks for Highly Efficient Adsorption of
           Dibenzothiophene from Liquid Fuels
    • Authors: Weijia Tang; Jianlei Gu, Hongliang Huang, Dahuan Liu, Chongli Zhong
      Abstract: By taking desulfurization of liquid fuels as a demonstrative example, a bottom‐up selection was performed to find the MOF‐type adsorbents with highly efficient adsorption performance of large molecules. Through carefully analyzing the adsorption mechanism for typical S‐heterocyclic compounds like dibenzothiophene (DBT), PCN‐10 was selected in consideration of the simultaneous inclusion of several kinds of interactions in the framework. Experimental results demonstrate that this MOF exhibits extraordinary high DBT adsorption capacity (75.24 mg S g−1), showing record uptake among all the reported porous materials for the removal of thiophenicsulfur from fuels (below 1000 ppmwS), to the best of our knowledge. Moreover, the removal rate for the low sulfur concentration (50 ppmwS) can reach beyond 99%. This strategy can be conveniently extended to the screening and design of MOFs for the efficient removal of other important large guest molecules. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-18T10:20:24.565114-05:
      DOI: 10.1002/aic.15384
       
  • Uncertainty quantification via Bayesian inference using Sequential Monte
           Carlo methods for CO2 adsorption process
    • Authors: Jayashree Kalyanaraman; Yoshiaki Kawajiri, Ryan P. Lively, Matthew J. Realff
      Abstract: This work presents the uncertainty quantification, which includes parametric inference along with uncertainty propagation, for CO2 adsorption in a hollow fiber sorbent, a complex dynamic chemical process. Parametric inference via Bayesian approach is performed using sequential Monte Carlo, a completely parallel algorithm, and the predictions are obtained by propagating the posterior distribution through the model. The presence of residual variability in the observed data and model inadequacy often present a significant challenge in performing the parametric inference. In this work, residual variability in the observed data is handled by three different approaches: (a) by performing inference with isolated data sets, (b) by increasing the uncertainty in model parameters, and finally, (c) by using a model discrepancy term to account for the uncertainty. The pros and cons of each of the three approaches are illustrated along with the predicted distributions of CO2 breakthrough capacity for a scaled‐up process. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-18T10:15:33.377806-05:
      DOI: 10.1002/aic.15381
       
  • Revealing the role of bromide in the H2O2 direct synthesis with the
           Catalyst Wet Pretreatment Method (CWPM)
    • Abstract: A tailor‐made Pd0/K2621 catalyst was subjected to post synthesis modification via a wet treatment procedure. The aim was the understanding of the role of promoters and how ‐ if any ‐ improvements could be qualitatively related to the catalyst performance for the H2O2 direct synthesis. The Catalyst Wet Pretreatment Method (CWPM) was applied in different methanolic solutions containing H2O2, NaBr and H3PO4, either as single modifiers or as a mixture. The catalyst was characterized by Transmission Electron Microscopy (TEM) and X‐ray Photoelectron Spectroscopy (XPS). It was concluded that the modified catalysts give rise to higher selectivities compared to the pristine reference catalyst thus opening a possibility to exclude the addition of the undesirable selectivity enhancers in the reaction medium. This work provides original evidence on the role of promoters, especially bromide, allowing the formulation of a new reaction mechanism for one of the most challenging reactions recognized by the world. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-18T10:15:27.038814-05:
      DOI: 10.1002/aic.15382
       
  • Physical Mixtures as Simple and Efficient Alternative to Alloy Carriers in
           Chemical Looping Processes
    • Abstract: Chemical Looping Combustion is a clean combustion technology for fossil or renewable fuels. We have previously demonstrated application of chemical looping to CO2 activation via reduction to CO with concurrent production of synthesis gas (CO+ H2) from CH4 via rationally designed Fe‐Ni alloys. Here, we demonstrate that that a simple physical mixture can even outperform the equivalent alloy based on an intricate gas phase mediated coupling between the two metals: Ni cracks methane to carbon and H2. The latter then reduces iron oxide carrier, forming steam, which gasifies the carbon deposits on Ni to produce a mixture of CO + H2, thus regenerating the active Ni surface. We suggest that the principle demonstrated here—the gas phase‐mediated coupling of two solid reactants with distinct functionalities—should be applicable broadly towards oxidation reactions and hence opens a new avenue for rational design of chemical looping processes. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-18T10:10:25.445974-05:
      DOI: 10.1002/aic.15380
       
  • Catalytic membrane reactor for Suzuki‐Miyaura C‐C
           cross‐coupling: Explanation for its high efficiency via modeling
    • Abstract: A polymeric catalytic membrane was previously prepared that showed remarkable efficiency for Suzuki‐Miyaura C‐C cross‐coupling in a flow‐through configuration. A mathematic model was developed and fitted to the experimental data to understand the significant apparent reaction rate increase exhibited by the catalytic membrane reactor compared to the catalytic system under batch reaction conditions. It appears that the high palladium nanoparticles concentration inside the membrane is mainly responsible for the high apparent reaction rate achieved. In addition the best performance of the catalytic membrane could be achieved only in the forced flow‐through configuration, that, conditions permitting to the reactants be brought to the catalytic membrane by convection. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-17T06:55:29.011669-05:
      DOI: 10.1002/aic.15379
       
  • Experimentally‐Based Constitutive Relations for Co‐Current
           Gas‐Liquid Flow in Randomly Packed Beds
    • Authors: Paul Salgi; Vemuri Balakotaiah
      Abstract: We use experimental observations on average pulse velocity and frequency in concurrent gas‐liquid (down) flow through randomly packed beds to extract constitutive relations for the gas‐liquid interaction and mean curvature terms that appear in a recently proposed volume‐averaged two‐fluid model for bubbly flow. The proposed closures lead to a reasonably quantitative prediction of the average pressure drop and liquid saturation under bubbly flow conditions and in the near pulse regime. In addition, the proposed closures provide realistic estimates for the location of the bubble‐to‐pulse transition in microgravity and in 1g down‐flow and predict the disappearance of the bubbly flow pattern at low liquid fluxes in 1g down‐flow. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-16T19:50:55.855697-05:
      DOI: 10.1002/aic.15377
       
  • Nonsmooth Model for Dynamic Simulation of Phase Changes
    • Authors: Ali M. Sahlodin; Harry A. J. Watson, Paul I. Barton
      Abstract: Dynamic modeling of processes involving phase changes can be challenging due to changes in the model equations caused by appearance and disappearance of equilibrium phases. Dynamic simulation of these processes requires the ability to detect the change in the number of phases and adapt the model to the new phase regime on the fly. In this work, an easy‐to‐use nonsmooth model for dynamic simulation of processes with vapor‐liquid equilibrium is presented. The presented model does not introduce any auxiliary variables or equations, nor does it require solution of an optimization problem to determine the new phase regime during the dynamic simulation. It can therefore be used for comprehensive simulation of, e.g., distillation columns, where the number of phases present can change during startup and shutdown. The nonsmooth model is illustrated through examples of an evaporator and a distillation column. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-16T19:50:52.107117-05:
      DOI: 10.1002/aic.15378
       
  • Computational Study of Core‐shell Droplet Formation in Coaxial
           Electrohydrodynamic Atomization Process
    • Abstract: In this study, a computational fluid dynamic (CFD) model was developed to simulate the liquid cone‐jet and core‐shell droplet formation in the Coaxial Electrohydrodynamic Atomization (CEHDA) process. Validation experiments were conducted using poly(lactic acid) (PLA) and poly(lactic‐co‐glycolic acid) (PLGA) solutions as core and shell materials, respectively. Good agreement was obtained between experimental results and simulation predictions in terms of both particle size and core‐shell structure. Investigation of interfacial tension between core and shell fluids showed that a stable compound cone‐jet and droplet can be easily formed using miscible or partially miscible liquids compared with immiscible liquids with higher interfacial tension. It was also found that the nozzle tip configuration has significant effects on droplet production due to differences in fluid motion. The results also showed that the productivity of the CEHDA process, i.e. slow production of core‐shell microparticles due to low flow rates, could be enhanced by using optimal cone‐shaped nozzle configuration. Overall, this computational model provided a means of designing and optimizing CEHDA processes for large‐scale core‐shell microparticle fabrication in pharmaceutical application, such as selections of materials and nozzle configuration. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-15T08:50:59.946622-05:
      DOI: 10.1002/aic.15361
       
  • A generalized stochastic modelling approach for crystal size distribution
           in antisolvent crystallization operations
    • Authors: Roberto Baratti; Stefania Tronci, Jose A. Romagnoli
      Abstract: A generalized formulation for the development of stochastic models to predict the Crystal Size Distribution (CSD) in antisolvent crystallization processes is proposed. Exploiting the result of the noise induced dynamic in stochastic processes, new results are provided to represent the CSD as function of the operational parameters. The generalized formulation enables the full description of the CSD using nonlinear drift term in conjunction with multiplicative noise i.e., state dependent diffusion. For the first time a deterministic nonlinear differential equation to represent the mean and most probable size (mode) time evolution as function of the model parameters is provided. Furthermore, the analytical solution of the asymptotic probability distribution of the CSD can also be obtained. Finally, a global model formulation is finally presented by defining relationships between the model parameters and the operating conditions. Experimental results and validations are provided using the ternary system of NaCl, water and ethanol. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-15T03:40:49.461204-05:
      DOI: 10.1002/aic.15372
       
  • Erratum to “An Integrated Framework for Scheduling and Control Using
           Fast Model Predictive Control”
    • Authors: Lisia S. Dias; Jinjun Zhuge, Marianthi G. Ierapetritou
      PubDate: 2016-06-15T03:40:48.164693-05:
      DOI: 10.1002/aic.15375
       
  • Integrated design of agricultural and industrial processes: A case study
           of combined sugar and ethanol production
    • Authors: Kotaro Ouchida; Yasuhiro Fukushima, Satoshi Ohara, Akira Sugimoto, Masahiko Hirao, Yasunori Kikuchi
      Abstract: Bioethanol production from molasses has advantages in greenhouse gas emissions because of its energy acquisition from bagasse. However, the improvement of bioethanol productivity is challenging; while each elemental technology option can be greatly improved, the trade‐offs between the production of raw sugar and bioethanol are complex. This issue should be addressed through the optimization of the whole system, including both agricultural and industrial processes. In this study, we constructed a model of combined raw sugar and bioethanol production from sugarcane considering agricultural and industrial technology options. Data were acquired through a detailed investigation of actual sugar mills. Case studies on the redesign of combined raw sugar and bioethanol production demonstrated that the simultaneous implementation of both technology options increases production of food, materials, and energy from plant‐derived renewable resources, thus demonstrating the effectiveness of the interdisciplinary approach. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-15T03:40:45.875901-05:
      DOI: 10.1002/aic.15374
       
  • Macro‐Economic Multi‐Objective Input‐Output Model for
           Minimizing CO2 Emissions: Application to the U.S. Economy
    • Abstract: Designing effective environmental policies for mitigating global warming is a very challenging task that requires detailed knowledge of the international channels through which goods are traded. This work presents a decision‐support tool that minimizes the impact at a global macroeconomic scale by performing changes in the economic sectors of an economy. Our tool combines multi‐objective optimization, environmentally extended input‐output tables and life cycle assessment within a unified framework. Our results on the US economy to minimize CO2 emissions identify sectors that should be regulated first to reach a given environmental target while maximizing the demand satisfaction. The impact of shale gas is also studied. Our findings show that the application of process systems engineering tools at a macroeconomic level can provide valuable insight for public policy makers into problems of general interest. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-15T03:40:40.611982-05:
      DOI: 10.1002/aic.15376
       
  • Polynomial chaos‐based robust design of systems with probabilistic
           uncertainties
    • Authors: Dongying E. Shen; Richard D. Braatz
      Abstract: A new algorithm is proposed for the design of nonlinear dynamical systems with probabilistic uncertainties. The dependence of the design objective and constraints on uncertainties is quantified by the polynomial chaos expansions (PCEs), while the relationships between the design parameters and the design objective/constraints are parameterized by Legendre polynomials. In two case studies, the polynomial chaos‐based algorithm reduces the number of system evaluations required by optimization by an order of magnitude. Quantifying the dependence on uncertain parameters via the PCEs and including the quantification in design optimization simultaneously improved the distribution of the performance index and the probability of constraint fulfillment. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-15T03:35:39.014455-05:
      DOI: 10.1002/aic.15373
       
  • A controllability analysis of a pilot‐scale CO2 capture plant using
           ionic liquids
    • Abstract: Nowadays there is a world concern on the impact and effect of large CO2 atmospheric concentrations on human health. Fossil‐fuel combustion processes in power plants are among the major contributors to this issue. Hence, it becomes important to develop new clean and sustainable processes aimed to reduce the amount of CO2 released to atmosphere by combustion processes in power plants. One of the best feasible manners to achieve this purposes lies in the use of a closed‐loop control system able to keep the amount of green‐house gases under specification even in the presence of unexpected scenarios. Of course, CO2 capture has been extensively researched in the past. However, in this regard the industrial practice has consisted in using Amines leading to sustainability and safety issues. Hence, it makes sense to seek for new and potentially environmental friendly process design to address CO2 reduction from power plants but applying a new type of sustainable stripping solvents. In this work we address the sustainable CO2 reduction issue from a process control point of view applying a previous design proposed by our research team based on the deployment of Ionic Liquids as potential green solvents and developing an efficient and decentralized multi‐loop control system. We demonstrate that the closed‐loop system is able to maintain the CO2 concentration levels under specification by testing in presence of several demanding scenarios. Overall, from an economic, sustainable and control point of view it looks feasible to replace the traditional amines‐based CO2 capture process by other alternatives based on the application of ionic liquids as potential green solvents. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-15T03:35:37.930387-05:
      DOI: 10.1002/aic.15371
       
  • Optimal processing network design under uncertainty for producing fuels
           and value‐added bioproducts from microalgae: Two‐stage
           adaptive robust mixed integer fractional programming model and
           computationally efficient solution algorithm
    • Authors: Jian Gong; Fengqi You
      Abstract: Fractional metrics, such as return on investment (ROI), are widely used for performance evaluation, but uncertainty in the real market may unfortunately diminish the results that are based on nominal parameters. This paper addresses the optimal design of a large‐scale processing network for producing a variety of algae‐based fuels and value‐added bioproducts under uncertainty. We develop by far the most comprehensive processing network with 46,704 alternative processing pathways. Based on the superstructure, a two‐stage adaptive robust mixed integer fractional programming model is proposed to tackle the uncertainty and select the robust optimal processing pathway with the highest ROI. Since the proposed problem cannot be solved directly by any off‐the‐shelf solver, we develop an efficient tailored solution method that integrates a parametric algorithm with a column‐and‐constraint generation algorithm. The resulting robust optimal processing pathway selects biodiesel and poly‐3‐hydroxybutyrate as the final fuel and bioproduct, respectively. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-15T03:35:29.375466-05:
      DOI: 10.1002/aic.15370
       
  • Heterogeneous Fenton and Photo‐Fenton Oxidation for Paracetamol
           Removal using Iron Containing ZSM‐5 Zeolite as Catalyst
    • Authors: Filipa Velichkova; Henri Delmas, Bogdana Koumanova, Carine Julcour
      Abstract: Paracetamol is commonly found in wastewaters, as a consequence of its high consumption and incomplete elimination by conventional treatments. Homogenous (photo‐)Fenton oxidation has proved efficient for its remediation, but it suffers from uneasy dissolved iron recovery. Therefore this work examines the performance and stability of an iron containing zeolite (Fe/MFI) as catalyst for this reaction. Effects of reaction parameters (pH, temperature, catalyst and H2O2 concentrations, UV/vis irradiation) are investigated in batch conditions, by comparing the pollutant and Total Organic Carbon disappearance rates in solution, as well as the overall mineralization yield (including solid phase) and oxidant consumption. At near neutral pH paracetamol can be fully converted after five hours, while TOC removal reaches up to 60%. Finally, thanks to good catalyst stability (low leaching), a continuous process coupling oxidation and membrane filtration is proposed, showing constant TOC conversion over 40 h and iron loss in the permeate 
      PubDate: 2016-06-13T11:21:43.297592-05:
      DOI: 10.1002/aic.15369
       
  • Oxidative dehydrogenation of butenes over Bi‐Mo and Mo‐V based
           catalysts in a two‐zone fluidized bed reactor
    • Authors: Julius Rischard; Robert Franz, Claudia Antinori, Olaf Deutschmann
      Abstract: The oxidative dehydrogenation of a 1‐butene/trans‐butene (1:1) mixture to 1,3‐butadiene was carried out in a two‐zone fluidized bed reactor using a Mo‐V‐MgO and a γ‐Bi2MoO6 catalyst. The significant operating conditions temperature, oxygen/butene molar ratio, butene inlet height and flow velocity were varied to gain high 1,3‐butadiene selectivity and yield. Furthermore, axial concentration profiles were measured inside the fluidized bed to gain insight into the reaction network in the two zones. For optimized conditions and with a suitable catalyst, the two‐zone fluidized bed reactor makes catalyst regeneration and catalytic reaction possible in a single vessel. In the lower part of the fluidized bed, the oxidation of coke deposits on the catalyst as well as the filling of oxygen vacancies in the lattice can occur. The oxidative dehydrogenation reaction takes place in the upper zone. Thorough particle mixing inside fluidized beds causes permanent particle exchange between both zones. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-13T11:21:37.507966-05:
      DOI: 10.1002/aic.15368
       
  • Design of Parallel Cyclones based on Stability Analysis
    • Authors: Chenxi Zhang; Qi Wang, Zhao Jia, Usman Muhammad, Weizhong Qian, Fei Wei
      Abstract: The uniform distribution of gas solids flow across parallel cyclones is required for high efficiency. In this study we introduced mass flow rate ratio between solids and gas (CT) to present multi‐phase interaction. And the direct Liapunov method is used to detect the instability of uniformity. Due to the special symmetry in this system, the criterion can be simplified into identifying the concavity (concave or convex) of pressure drop across a single cyclone with respect to CT. Then, based on the stability analysis of uniformity, a novel design principle is provided to prevent non‐uniform distribution at dense phase. The effect of geometrical factor, i.e. dimensionless vortex finder diameter dr, on the stability of uniformity has been further investigated. The phase diagram, illustrating the effects of both operational parameter (CT) and geometrical parameter (dr) on stability of uniformity is calculated to give a clue of designing a robust parallel cyclones system. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-10T03:41:32.281836-05:
      DOI: 10.1002/aic.15366
       
  • Amphiphilic Poly(ether sulfone) Membranes for Oil/Water Separation: Effect
           of Sequence Structure of the Modifier
    • Authors: Guangfa Zhang; Jingxian Jiang, Qinghua Zhang, Xiaoli Zhan, Fengqiu Chen
      Abstract: Oil‐contaminated wastewater threatens our environment and health, thus novel membrane materials with low‐ or non‐fouling properties are an immediate need for oily wastewater treatment in a cost‐effective and environmentally friendly manner. In this study, three types of amphiphilic random, gradient, and block copolymers with similar molecular weights and chemical compositions, based on poly(ethylene glycol) methyl ether methacrylate (PEGMA) and 3,3,4,4,5,5,6,6,7,7,8,8,8‐tridecafluorooctyl acrylate (TFOA), were synthesized by the RAFT method. The amphiphilic Poly(ether sulfone) (PES) membranes were then fabricated by blending with these copolymers via a facile coupled process of non‐solvent induced phase separation (NIPS) and surface segregation. Accompanying the phase inversion process of polymer matrix, the hydrophilic and hydrophobic segments in the amphiphilic modifiers would migrate and immobilize onto the membrane surfaces. This surface segregation process leaded to a chemical heterogeneous membrane surface comprising both hydrophilic PEGMA and low surface energy PTFOA brushes, which was confirmed by X‐ray photoelectron spectroscopy (XPS) and surface wettability analyses. Oil‐in‐water emulsion filtration test of the membranes displayed a lower permeate flux decline and a higher flux recovery (as high as 99.8%), establishing their considerably elevated antifouling properties. Additionally, cyclic oil/water separation and long‐term underwater immersion tests demonstrated that the as‐prepared membranes modified by these amphiphilic additives possessed excellent antifouling stabilities. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-10T03:35:33.782941-05:
      DOI: 10.1002/aic.15365
       
  • Flow Pattern Transition in Gas‐ Liquid Downflow through Narrow
           Vertical Tubes
    • Authors: Amit Kumar; Satyabrata Bhowmik, Subhabrata Ray, Gargi Das
      Abstract: The present report studies on the flow pattern transitions during vertical air water downflow through millichannels (0.83 ≤ Eӧtvӧs no.≤ 20.63). Four basic flow patterns namely falling film flow, slug flow, bubbly flow and annular flow are observed in the range of experimental conditions studied and their range of existence has been noted to vary with tube diameter and phase velocities. Based on experimental observations, phenomenological models are proposed to predict the transition boundaries between adjacent patterns. These have been validated with experimental flow pattern maps from the present experiments. Thus the study formalizes procedure for developing a generalized flow pattern map for gas‐liquid downflow in narrow tubes. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-09T18:51:25.025167-05:
      DOI: 10.1002/aic.15364
       
  • A Novel Feasibility Analysis Method for Black‐Box Processes using a
           Radial Basis Function Adaptive Sampling Approach
    • Authors: Zilong Wang; Marianthi Ierapetritou
      Abstract: Feasibility analysis is used to determine the feasible region of a multivariate process. This can be difficult when the process models include black‐box constraints or the simulation is computationally expensive. To address such difficulties, surrogate models can be built as an inexpensive approximation to the original model and help identify the feasible region. An adaptive sampling method is used to efficiently sample new points towards feasible region boundaries and regions where prediction uncertainty is high. In this paper, cubic Radial Basis Function (RBF) is used as the surrogate model. An error indicator for cubic RBF is proposed to indicate the prediction uncertainty and is used in adaptive sampling. In all case studies, the proposed RBF‐based method shows better performance than a previously published Kriging‐based method. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-08T10:41:09.774435-05:
      DOI: 10.1002/aic.15362
       
  • Communication delays and data losses in distributed adaptive
           high‐gain EKF
    • Authors: Mohammad Rashedi; Jinfeng Liu, Biao Huang
      Abstract: In this work, we consider distributed adaptive high‐gain extended Kalman filtering for nonlinear systems subject to data losses and delays in communications. Specifically, we consider a class of nonlinear systems that consist of several subsystems interacting with each other via their states. A local adaptive high‐gain extended Kalman filter is designed for each subsystem and the distributed estimators communicate to exchange the information. Each subsystem estimator takes the advantage of a predictor accounting for the delays and data losses simultaneously. The predictor of each subsystem is used to generate state predictions of interacting subsystems for interaction compensation. To get a reliable prediction, the predictors are designed based on a prediction‐update algorithm. The convergence of the proposed distributed state estimation is ensured under sufficient conditions handling communication delays and data losses. Finally, a chemical process example is used to evaluate the applicability and effectiveness of the proposed design. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-07T19:00:30.411119-05:
      DOI: 10.1002/aic.15351
       
  • A Mathematical Optimization Framework for the Design of Nanopatterned
           Surfaces
    • Authors: Christopher L. Hanselman; Chrysanthos E. Gounaris
      Abstract: The recent explosion of capabilities to fabricate nanostructured materials to atomic precision has opened many avenues for technological advances but has also posed unique questions regarding the identification of structures that should serve as targets for fabrication. One material class for which identifying such targets is challenging are transition‐metal crystalline surfaces, which enjoy wide application in heterogeneous catalysis. The high combinatorial complexity with which patterns can form on such surfaces calls for a rigorous design approach. In this paper, we formalize the identification of the optimal periodic pattern of a metallic surface as an optimization problem, which can be addressed via established algorithms. We conduct extensive computational studies involving an array of crystallographic lattices and structure‐function relationships, validating patterns that were previously known to be promising but also revealing a number of new, nonintuitive designs. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-06T03:20:59.009724-05:
      DOI: 10.1002/aic.15359
       
  • Mass‐Transfer Enhancement in Single Drop Extraction in the Presence
           of Magnetic Nanoparticles and Magnetic Field
    • Authors: Amid Vahedi; Asghar Molaei Dehkordi, Farzad Fadaei
      Abstract: Magnetite nanoparticles with an average particle size of 28.8 nm were synthesized, coated with oleic acid, and characterized using various techniques such as DLS, FT‐IR, SEM, XRD, VSM, and UV‐Vis analysis. A nanofluid consisting of synthesized nanoparticles and 5 wt.% acetic acid in toluene as the dispersed phase was prepared and used in the chemical test system, Toluene‐Acetic Acid‐Water, for the single drop extraction in the presence and absence of an external oscillating magnetic field. Influences of various operating and design parameters such as nanoparticle concentration, drop diameter, and the applied current and frequency on the overall mass‐transfer coefficients for the mass‐transfer direction from d→c were investigated carefully. The obtained results were used to propose a general correlation for the mass‐transfer enhancement. It was found that the maximum mass‐transfer enhancement compared to that obtained in the absence of nanoparticles and the oscillating magnetic field is about 259%. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-06T03:20:43.589863-05:
      DOI: 10.1002/aic.15357
       
  • Tensorial Navier‐Slip Boundary Conditions for Patterned Surfaces for
           Fluid Mixing: Numerical Simulations and Experiments
    • Authors: Hye Kyeong Jang; Young Ju Kim, Nam Sub Woo, Wook Ryol Hwang
      Abstract: Navier‐slip boundary condition has been investigated for patterned surfaces with various grooves for the application to fluid mixing by controlling flow patterns. Simple tensorial expression is applied for anisotropically patterned surfaces and effective slip lengths for various grooves have been evaluated for a wide range of Reynolds numbers and aspect ratios using a flow rate matching technique. By doing so, the applicability of the effective tensorial slip model has been presented that replaces physical surface patterns to reduce computational cost significantly. Using a simple model agitator with a rotating disk, modification of flow characteristics with various alignment angles of the patterned surface has been investigated. We report a critical Reynolds number of O(1) for flows in agitators, below which effective slip dominates over fluid inertia. Patterned poly(dimethylsiloxane) (PDMS) sheets are fabricated using a compression‐molding/soft‐lithography technique and flow visualization with laser‐induced fluorescence reveals controllability of flow patterns with the patterned surface. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-06T03:15:37.477301-05:
      DOI: 10.1002/aic.15355
       
  • Discrete Particle Modeling of Lateral Jets into a Packed Bed and
           Micromechanical Analysis of the Stability of Raceways
    • Authors: Q.F. Hou; D.Y. E, A.B. Yu
      Abstract: Gas jets are often used to promote heat and mass transfer by forming raceways or circulating regions in a packed bed. Such an operation is common and critical in many processes. Multiple raceways can interact and be affected by the formation of different flow zones. This work develops a multiscale model to examine the formation and the stability of raceways and the underlying micromechanics. Four states are observed in the fluidized flow regime. More fundamentally, a critical bed width for the observation of different flow zones and states is found through numerical simulations and a theoretical analysis. Finally, the complicated transitions between different flow states are examined at a bed scale, and two general trends of the averaged solid velocity are found. The findings from the multiscale model are useful both scientifically for the understanding of state transitions and practically for the design and the operation of relevant chemical reactors. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-06T03:15:30.198216-05:
      DOI: 10.1002/aic.15358
       
  • Catalytic Dehydration of Glucose to 5‐Hydroxymethylfurfural with a
           Bifunctional Metal‐Organic Framework
    • Authors: Ye Su; Ganggang Chang, Zhiguo Zhang, Huabin Xing, Baogen Su, Qiwei Yang, Qilong Ren, Yiwen Yang, Zongbi Bao
      Abstract: Glucose conversion to 5‐hydroxymethylfurfural (HMF) generally undergoes catalytic isomerization reaction by Lewis acids followed by the catalytically dehydrated to HMF with Brӧnsted acid/base. In this work, a sulfonic acid functionalized metal‐organic frameworks MIL‐101(Cr)‐SO3H containing both Lewis acid and Brӧnsted acid sites, was examined as the catalyst for γ‐valerolactone‐mediated cascade reaction of glucose dehydration into HMF. Under the optimal reaction conditions, the batch heterogeneous reaction gave a HMF yield of 44.9% and selectivity of 45.8%. Reaction kinetics suggested that the glucose isomerization in GVL with 10 wt% water follows the second‐order kinetics with an apparent activation energy of 100.9 kJ mol−1. Continuous reaction in the fixed‐bed reactor showed that the catalyst is highly stable and able to provide a steady HMF yield. This work presents a sustainable and green process for catalytic dehydration of biomass‐derived carbohydrate to HMF with a bi‐functional metal‐organic framework. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-06T03:15:26.762499-05:
      DOI: 10.1002/aic.15356
       
  • Droplet Formation of H2SO4/Alkane System in a T‐junction
           Microchannel: Gravity Effect
    • Authors: Liantang Li; Jisong Zhang, Kai Wang, Jianhong Xu, Guangsheng Luo
      Abstract: A special system of concentrated sulfuric acid (H2SO4) and n‐hexane was used to study the droplet formation in a glass T‐junction microchannel with H2SO4 as the continuous phase. The effects of capillary number, flow ratio, and viscosity ratio on the droplet formation were investigated. The effect of gravity was explored by changing the flow direction in the microchannel. Results showed that the formation of transition flow pattern from squeezing to dripping is much easier for this special system compared with common aqueous/organic systems. This phenomenon is due to the considerably higher viscosity of H2SO4 than that of common aqueous phase and the higher density difference of the system compared with those of common systems. In addition to capillary number and flow ratio, gravity evidently affects the formation of droplets and flow patterns. The droplet size is smaller than that during the horizontal flow when the flow direction is consistent with gravity. By contrast, flow direction contrary to that of gravity results in larger droplet size than that at horizontal flow. This phenomenon provides guidance on the operation of these special systems in microchannels. Finally, mathematical models of droplet size at different flow patterns have been established, and these models can predict droplet size very well. This study could be helpful to extend the application of microreactors to new working systems. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-03T03:30:38.426784-05:
      DOI: 10.1002/aic.15354
       
  • The application of dynamic modeling for thermal risks analysis of the
           acid‐catalyzed hydrolysis of glycidol
    • Abstract: The aim of this work was to determine the limits of safe operation of CSTR (Continuous Flow Stirred‐Tank Reactor) for the acid‐catalyzed hydrolysis of glycidol. The stability analysis was performed by dynamic modelling. The obtained results were compared with the experimental data reported in the open literature. For this purpose, dimensionless variables and parameters were introduced and unstable material and energy balances were defined. The system equations were solved using Matcont (Matlab® software). Thus, bifurcation diagrams (in one and two dimensions) were mapped. All different dynamic states were identified and studied (thermal stability and instability, with unique and multiple solutions; Hopf bifurcations; turning points and envelope of periodic solutions). Finally, the intrinsic thermal unstable and cycle behavior of the acid‐catalyzed hydration of glycidol to produce glycerol was identified. The appropriate conditions to guarantee safe operation of CSTR were found. This article is protected by copyright. All rights reserved.
      PubDate: 2016-06-03T03:25:26.075512-05:
      DOI: 10.1002/aic.15353
       
  • Tailored Synthesis of Macroporous Pt/WO3 Photocatalyst with Nanoaggregates
           via Flame Assisted Spray Pyrolysis
    • Authors: Osi Arutanti; Aditya Farhan Arif, Ratna Balgis, Takashi Ogi, Ferry Iskandar, Kikuo Okuyama
      Abstract: High‐surface‐area macroporous WO3 particles with deposited Pt (Pt/WO3) were successfully synthesized for the first time, using flame‐assisted spray pyrolysis. Nanoparticle aggregates‐like structures (nanoaggregates) were formed, although a salt precursor was used for the synthesis. The macroporous structure was tailored by changing the mass ratio of the polystyrene template to ammonium tungstate pentahydrate. The cavities between the nanoaggregates formed mesopores, which increased the surface area. The presence of meso‐ and macro‐pores in the synthesized Pt/WO3 particles improved their photocatalytic activities in visible‐light‐induced photodegradation of rhodamine B. The combination of a high surface area and the presence of an in situ‐deposited Pt cocatalyst gave a high photodecomposition rate, approximately 9.6 times higher than that achieved with dense WO3 particles. This research provides a promising strategy for synthesizing submicron particles with high surface areas at a high production rate, and is suitable for industrial applications. This article is protected by copyright. All rights reserved.
      PubDate: 2016-05-31T04:15:26.121318-05:
      DOI: 10.1002/aic.15349
       
  • Multi‐scenario Robust Online Optimization and Control of
           Fed‐batch Systems via Dynamic Model‐based Scenario Selection
    • Abstract: The manuscript proposes a novel robust methodology for the model‐based online optimization/optimal control of fed‐batch systems, which consists of two different interacting layers executed asynchronously. The first iteratively computes robust control actions online via multi‐scenario stochastic optimization while the second iteratively re‐estimates the optimal scenario map after every single/every certain number of control action/actions. The novelty of the approach is twofold: (I) the scenario map is optimally computed/updated based on probabilistic information on the process model uncertainty as well as the sensitivity of the controlled system to the uncertain parameters; and (II) the scenario set is dynamically re‐estimated, thus accounting for the effect of disturbances and changes in the operating conditions of the target process. The proposed approach is applied to a fed‐batch Williams‐Otto process and compared to an existing multi‐scenario optimization/control algorithm as well as a non‐robust optimization/control strategy to draw conclusions about which method is more effective. This article is protected by copyright. All rights reserved.
      PubDate: 2016-05-31T04:11:15.177278-05:
      DOI: 10.1002/aic.15346
       
  • Block Adaptive Kernel Principal Component Analysis for Nonlinear Process
           Monitoring
    • Authors: Lei Xie; Zhe Li, Jiusun Zeng, Uwe Kruger
      Abstract: On‐line modeling of multivariate nonlinear system based on multivariate statistical methods has been studied extensively due to its industrial requirements. In order to further increase the modeling efficiency a fast Block Adaptive Kernel Principal Component Analysis (BAKPCA) algorithm is proposed. Comparing with the existing work the proposed algorithm (i) does not rely on iterative computation in the calculating process (ii) combines the up‐ and downdating operations to become a single one (iii) and describes it as a series of rank‐1 modification. In addition (iv) the updation of the eigenvalues and eigenvectors is of O(N2)$with high accuracy. The computational complexity analysis and the numerical study shows the derived strategy possesses better online adaptive modeling abilities to the time‐varying nonlinear variable interrelationships in process monitoring. This article is protected by copyright. All rights reserved.
      PubDate: 2016-05-31T04:10:59.178387-05:
      DOI: 10.1002/aic.15347
       
  • Polymorph Selection by Continuous Crystallization
    • Authors: Thomas C. Farmer; Corinne L. Carpenter, Michael F. Doherty
      Abstract: This paper is motivated by a remarkable observation reported recently by Myerson, Trout, and co‐workers that continuous crystallization is capable of producing metastable polymorphs in stable steady‐state operation. We explain why this phenomenon occurs and give simple design rules for reproducing it in other polymorphic systems. A linear stability analysis gives simple functions of parameters for which one can continuously produce thermodynamically metastable products based only on the relative polymorph dynamics. We demonstrate agreement with with two sets of experimental data; L‐glutamic acid grown from aqueous solution and p‐aminobenzoic acid also grown from aqueous solution. For many polymorphic compounds, engineering a process to produce a desired polymorph is as simple as finding a reasonable operating point for the continuous mixed‐suspension mixed‐product removal (MSMPR) crystallization process (temperature, residence time, initial supersaturation, etc.) according to the rules reported in this article. This article is protected by copyright. All rights reserved.
      PubDate: 2016-05-30T03:30:49.966741-05:
      DOI: 10.1002/aic.15343
       
  • Assessing the capacity of local ecosystems to meet industrial demand for
           ecosystem services
    • Authors: Varsha Gopalakrishnan; Bhavik R. Bakshi, Guy Ziv
      Abstract: Despite the importance of ecosystems, engineering activities continue to ignore or greatly undervalue their role. Consequently, engineered systems often overshoot nature's capacity to support them, causing ecological degradation. Such systems tend to be inherently unsustainable, and they often fail to benefit from nature's ability to provide essential goods and services. This work explores the idea of including ecosystems in chemical processes, and assesses whether such a techno‐ecological synergistic system can operate within ecological constraints. The demand for ecosystem services is quantified by emissions and resources used, while the supply is provided by ecosystems on the manufacturing site. Application to a biodiesel manufacturing site demonstrates that ecosystems can be economically and environmentally superior to conventional technologies for making progress toward zero emissions and net positive impact manufacturing. These results highlight the need for shifting the paradigm of engineering from that of dominating nature to embracing nature and respecting its limits. This article is protected by copyright. All rights reserved.
      PubDate: 2016-05-27T18:50:31.475421-05:
      DOI: 10.1002/aic.15340
       
  • A Study on hydrodynamic characteristics in a Φ38 pulsed extraction
           column by four‐sensor optical fiber probe
    • Authors: Yukun Yuan; Yang Gao
      Abstract: Accurate prediction of dispersed phase droplet behavior is crucial to the design and scaling‐up of an extraction column. In this paper, the dispersed droplet velocity algorithm and the diameter algorithm in a liquid‐liquid two‐phase flow have been developed based on the bubble velocity model in gas‐liquid two‐phase flow of Lucas [Measurement Science & Technology. 749, 758(2005)] and Shen [International Journal of Multiphase Flow. 593, 617(2005)]. Hydrodynamic characteristics, including droplet diameter, holdup and droplet velocity, were measured using a self‐made four‐sensor optical fiber probe in a 38mm‐diameter pulsed sieve‐plate extraction column. Water and kerosene were used as continuous and dispersed phases, respectively. The influences of the pulsed intensity, continuous and dispersed phase superficial velocity on the hydrodynamic characteristics were investigated. The experimental results show that it is reliable to use a four‐sensor optical probe to measure the hydrodynamic characteristics of a pulsed extraction column. This article is protected by copyright. All rights reserved.
      PubDate: 2016-05-19T03:51:09.451315-05:
      DOI: 10.1002/aic.15328
       
  • Applicability of the Linearized Theory of the Maxwell‐Stefan
           Equations
    • Authors: Paul S. Weber; Dieter Bothe
      Abstract: The present article aims for a better understanding of the applicability of the linearized theory of the Maxwell‐Stefan equations for multi‐component diffusion. An analysis of the theory's accuracy is performed with respect to the classical two‐bulb diffusion experiments by Duncan and Toor, from which the results are transferred to more general scenarios. It is shown that for an accurate linearized theory it is essential to have a quasi‐stationary and quasi‐one‐dimensional flux, and also a so‐called reference point. Two examples illustrating the theory's failure in case of unmet prerequisites are presented: a three‐bulb configuration and a two‐dimensional diffusion case. For the first setup the linearized theory results in negative concentrations, for the second it requires influxes at openings that are actually outlets. This article is protected by copyright. All rights reserved.
      PubDate: 2016-05-12T04:16:54.190024-05:
      DOI: 10.1002/aic.15317
       
  • Modeling bread baking with focus on overall deformation and local porosity
           evolution
    • Authors: Vincent Nicolas; Fernanda Vanin, Christophe Doursat, David Grenier, Tiphaine Lucas, Denis Flick
      Abstract: A two dimensional model of bread baking was developed including, for the first time, the dependence of dough viscosity on both temperature and moisture content, the carbon dioxide dissolved from liquid water together with gas generation from yeast at the beginning of baking and the shrinkage due to dough drying. Particular attention was paid to experimental validation of both overall and local variables such as local temperature, overall mass loss and local moisture content, overall CO2 released into the oven, and overall deformation and local expansion or shrinkage. Sensitivity studies on generation of carbon dioxide, gravity and shrinkage are presented to discuss their influences on bread geometry, porosity (reflecting the alveolar structure) and gas pressure. This article is protected by copyright. All rights reserved.
      PubDate: 2016-05-09T10:35:27.788138-05:
      DOI: 10.1002/aic.15301
       
  • Kinetics of the absorption of carbon dioxide into aqueous ammonia
           solutions
    • Abstract: Experiments were performed in a customized double stirred tank reactor (DSTR) to study the kinetics of CO2 absorption into NH3 solutions at concentrations ranging from 0.42 to 7.67 kmol·m−3 and temperatures between 273.15 and 293.15 K. The results show that the reactive absorption was 1st order with respect to CO2 but fractional order (1.6 – 1.8) with respect to ammonia. Experimental data can be satisfactorily interpreted by a termolecular mechanism using kNH3T=7.6089×108exp⁡(−4018.4T) and kH2OT=7.9161×107exp⁡(−4356.4T). This article is protected by copyright. All rights reserved.
      PubDate: 2016-05-05T11:05:23.38303-05:0
      DOI: 10.1002/aic.15296
       
  • Liver function as an engineering system
    • Abstract: Process Systems Engineering has tackled a wide range of problems including manufacturing, the environment, and advanced materials design. Here we discuss how tools can be deployed to tackle medical problems which involve complex chemical transformations and spatial phenomena looking in particular at the liver system, the body's chemical factory. We show how an existing model has been developed to model distributed behaviour necessary to predict the behaviour of drugs for treating liver disease. The model has been used to predict the effects of suppression of de novo lipogenesis, stimulation of β‐oxidation and a combination of the two. A reduced model has also been used to explore the prediction of behaviour of hormones in the blood stream controlling glucose levels to ensure that levels are kept within safe bounds using interval methods. The predictions are made resulting from uncertainty in two key parameters with oscillating input resulting from regular feeding. This article is protected by copyright. All rights reserved.
      PubDate: 2016-04-30T00:11:22.56025-05:0
      DOI: 10.1002/aic.15292
       
  • Issue information ‐ table of contents
    • Pages: 2585 - 2585
      PubDate: 2016-07-05T11:55:41.37639-05:0
      DOI: 10.1002/aic.14994
       
  • Process systems engineering perspective on the planning and development of
           oil fields
    • Authors: M. Sadegh Tavallali; I. A. Karimi, D. Baxendale
      Pages: 2586 - 2604
      PubDate: 2016-03-29T14:45:47.022379-05:
      DOI: 10.1002/aic.15209
       
  • Property prediction of crystalline solids from composition and crystal
           structure
    • Authors: Bruno A. Calfa; John R. Kitchin
      Pages: 2605 - 2613
      Abstract: Kernel regression as a data‐driven and rigorous nonparametric statistical technique to predict properties of atomic crystals is proposed. A key feature of the proposed approach is the possibility of treating predictors not only as continuous, but also as categorical data. The latter specifically allows the predictive model to capture the discrete nature of crystals with regards to composition (number of atoms in the chemical formula) and spatial configuration (finite number of crystallographic space groups). Another important aspect of using kernel regression is the direct access to its explicit mathematical form, which can be directly embedded in optimal inverse problems to design new crystalline materials with given target properties. The property prediction approach is illustrated by training models to predict electronic properties of 746 binary metal oxides and elastic properties of 1173 crystals. As a first approach to solving the inverse problem, an exhaustive enumeration algorithm is described. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2605–2613, 2016
      PubDate: 2016-04-07T20:02:00.276941-05:
      DOI: 10.1002/aic.15251
       
  • Fast access to core/shell/shell CdTe/CdSe/ZnO quantum dots via magnetic
           hyperthermia method
    • Pages: 2614 - 2621
      Abstract: The intrinsic low quantum yield (QY) of type II core shell quantum dots (QDs) composes the limitation for these heterostructured nanomaterials to be used in practical application. Herein, magnetic hyperthermia method is employed to intensify reaction process and facilely synthesize CdTe/CdSe heterostructured QDs with improved optical performance for the first time. The QY of the type II QDs is increased to 49% by further growing an inert ZnO layer. The type I interface between CdSe and ZnO helps confine electrons to the inner structure of the QDs, thus improving the QY. The successful preparation and performance enhancement of the CdTe/CdSe type II QDs via magnetic hyperthermia method demonstrate the great potential of this method for the preparation of other materials. Besides, the red‐emission QDs are used as conversion materials in white light emitting diodes to reveal their promising application in practical illumination. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2614–2621, 2016
      PubDate: 2016-05-06T14:15:25.950387-05:
      DOI: 10.1002/aic.15264
       
  • Investigating the dynamics of cylindrical particles in a rotating drum
           using multiple radioactive particle tracking
    • Pages: 2622 - 2634
      Abstract: The behavior of granular flows inside rotating drums is an ongoing area of research. Only a few studies have investigated non‐spherical particles despite the fact that particle shape is known to have a significant impact on flow behavior. In addition, the experimental techniques limit the interpretation of the results of these studies. In this work, we compared the flow behavior of cylindrical and spherical particles using the multiple radioactive particle tracking technique to capture the positions and orientations of cylindrical particles simultaneously. We analyzed two important components of the transverse flow dynamics, that is, the boundary between the active and passive layers, and the velocity profile on the free surface. For the cylindrical particles, two general models are proposed to calculate the velocity profiles on the free surface and the effective particle sizes in the active and passive layers. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2622–2634, 2016
      PubDate: 2016-04-01T10:51:02.363692-05:
      DOI: 10.1002/aic.15235
       
  • Multi‐scale analysis of acoustic emission signals in
           
    • Authors: Lelu He; Yao Yang, Zhengliang Huang, Zuwei Liao, Jingdai Wang, Yongrong Yang
      Pages: 2635 - 2648
      Abstract: Acoustic emission technique in conjunction with multiscale processing method has been utilized to investigate the flow behavior of the dense‐phase pneumatic conveying system at high pressure. A clearly defined classification of microscale, mesoscale, and macroscale signals has been put forward with the aid of wavelet transform and V statistics analysis. The detailed signals d1–d4, d5–d7, d8–d10 were recomposed into the microscale, mesoscale, and macroscale signals, respectively, which represent microscale particle‐wall interactions, mesoscale interaction between gas phase and solid phase (such as bubbles, plugs, dunes), and macroscale flow‐induced pipe vibration. Further analysis shows that as the mass flow rate of pulverized coal increases, the energy fraction (energy of detailed signal divided by the energy of original signal) of microscale signals decreases while that of mesoscale signals increases, which indicates that particles are more likely to move as particle aggregates than individual particles when mass flow rate increases. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2635–2648, 2016
      PubDate: 2016-04-01T14:11:56.956458-05:
      DOI: 10.1002/aic.15240
       
  • Toward a mesoscale‐structure‐based kinetic theory for
           heterogeneous gas‐solid flow: Particle velocity distribution
           function
    • Authors: Junwu Wang; Bidan Zhao, Jinghai Li
      Pages: 2649 - 2657
      Abstract: Mesoscience has recently been proposed as a possible general concept for describing complex systems far from equilibrium, however, concrete formulations are needed, and particularly, a statistical mechanics foundation of mesoscience remains to be explored. To this end, the mathematical theory of stochastic geometry is combined with the energy minimization multi‐scale (EMMS) principle under the concept of mesoscience to propose a statistical mechanics framework. An EMMS‐based particle velocity distribution function is then derived as an example to show how the proposed framework works, and more importantly, as a first key step toward a generalized kinetic theory for heterogeneous gas‐solid flow. It was shown that the resultant EMMS‐based distribution is bimodal, instead of the widely‐used Maxwellian distribution, but it reduces to the Maxwellian distribution when the gas‐solid system is homogeneous. The EMMS‐based distribution is finally validated by comparing its prediction of the variance of solid concentration fluctuation and granular temperature with experimental data available in literature. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2649–2657, 2016
      PubDate: 2016-04-01T11:05:51.626436-05:
      DOI: 10.1002/aic.15244
       
  • Length to diameter ratio of extrudates in catalyst technology II. Bending
           strength versus impulsive forces
    • Authors: Jean W. L. Beeckman; Natalie A. Fassbender, Theodore E. Datz
      Pages: 2658 - 2669
      Abstract: This article describes the reduction of the length to diameter ratio of extrudates, by breakage on collision with a surface. The approach links the rupture force of the extrudate by bending to the impulsive force the extrudate experiences due to collision. The bending or flexural strength of the extrudate is described by the Euler‐Bernoulli modulus of rupture. The impulsive force the extrudate experiences is described by Newton's second law. We apply the force balance at the asymptotic length to diameter ratio which is reached after many repeated impacts. This balance yields a dimensionless group as the ratio of the rupture force by bending to the impulsive force by collision. The analysis shows that the asymptotic length to diameter ratio is directly proportional to the square root of this group. This dimensionless group also allows one to define a severity of the collision via the impact velocity and the time of contact of the collision. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2658–2669, 2016
      PubDate: 2016-04-02T20:47:21.688703-05:
      DOI: 10.1002/aic.15231
       
  • Monte Carlo modeling of fluidized bed coating and layering processes
    • Pages: 2670 - 2680
      Abstract: A stochastic modeling approach based on a Monte Carlo method for fluidized bed layering and coating is presented. In this method, the process is described by droplet deposition on the particle surface, droplet drying and the formation of a solid layer due to drying. The model is able to provide information about the coating coverage (fraction of the particle surface covered with coating), the particle‐size distribution, and the layer thickness distribution of single particles. Analytical solutions for simplified test cases are used to validate the model theoretically. The simulation results are compared with experimental data on particle‐size distributions and layer thickness distributions of single particles coated in a lab‐scale fluidized bed. Good agreement between the simulation results and the measured data is observed. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2670–2680, 2016
      PubDate: 2016-04-02T20:25:13.880423-05:
      DOI: 10.1002/aic.15237
       
  • Solids volume fraction measurements on riser flow using a
           temporal‐histogram based DIA method
    • Authors: A. E. Carlos Varas; E. A. J. F. Peters, N. G. Deen, J. A. M. Kuipers
      Pages: 2681 - 2698
      Abstract: In this article we introduce a temporal histogram‐based method for digital image analysis (DIA) of pseudo‐2D fluidized bed risers. This method enables an accurate whole field measurement of the solids volume fraction in lab‐scale pseudo‐2D riser flows by successfully removing image imperfections and merely accounting for the particles’ intensity. Moreover, the new correlation between normalized intensity and solids volume fraction that is proposed in this work enables a quantitative approach for solids concentration measurements by DIA techniques. This technique can be easily adjusted with experimental settings and shows a great stability against adverse imaging conditions. The combination of this parameter‐free method with particle image velocimetry under riser flow conditions has been successfully applied, enabling the experimental acquisition of full field hydrodynamic data. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2681–2698, 2016
      PubDate: 2016-04-14T09:35:56.906011-05:
      DOI: 10.1002/aic.15243
       
  • Analysis of asymmetric morphology evolutions in iPP molded samples induced
           by uneven temperature field
    • Authors: Sara Liparoti; Giuseppe Titomanlio, Andrea Sorrentino
      Pages: 2699 - 2712
      Abstract: Mold surface temperature has a strong effect on the amount of molecular orientation and morphology developed in a non‐isothermal flowing polymer melt. In this work, a well‐characterized isotactic polypropylene was injected in a rectangular mold cavity asymmetrically conditioned by a thin electric heater specifically designed. The cavity surface was heated at temperatures ranging from 80 to 160°C for different times (0.5, 8, and 18 s) after the first contact with the polymer. Asymmetrical thermal conditions have a strong influence on the melt flow, by changing its distribution along the cavity thickness, and final part deformation. The morphology distribution of the molded samples was found strongly asymmetric with complex and peculiar features. Optical and Electron microscopy confirmed the complete reorganization of the crystalline structures along the sample thickness. X‐rays analysis reveals that molecular orientation of the sample surface decreases with the mold temperature and the heating time. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2699–2712, 2016
      PubDate: 2016-04-01T14:03:27.161089-05:
      DOI: 10.1002/aic.15241
       
  • Assessment of inherently safer alternatives in biogas production and
           upgrading
    • Authors: Giordano Emrys Scarponi; Daniele Guglielmi, Valeria Casson Moreno, Valerio Cozzani
      Pages: 2713 - 2727
      Abstract: Biogas is becoming an increasingly important resource of energy production from biomass, and a number of alternative technologies are proposed for its production and upgrading. However, in spite of the increasing number of accidents recorded, scarce attention was dedicated to date to the control and mitigation of biogas hazards. In this study, inherent safety of biogas technologies was addressed. A method for the selection of inherently safer alternatives during early design stages was further developed and combined to a Monte Carlo sensitivity analysis, accounting for uncertainty of input parameters and addressing the robustness of the ranking provided. The method was applied to the assessment of several alternative reference process schemes for biogas production and upgrading. The results allowed the identification of critical safety issues and the ranking of inherently safer solutions. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2713–2727, 2016
      PubDate: 2016-04-09T21:15:54.964984-05:
      DOI: 10.1002/aic.15224
       
  • Optimal placement of gas detectors: A P‐median formulation
           considering dynamic nonuniform unavailabilities
    • Pages: 2728 - 2739
      Abstract: A stochastic programming formulation (SPqt), based on the P‐median problem, is proposed for determining the optimal placement of detectors in mitigation systems while considering nonuniform dynamic detector unavailabilities. Unlike previously proposed formulations, SPqt explicitly considers backup detection levels. This allows the modeller to determine the maximum degree of the nonlinear products to be used based on the trade‐off between computational complexity and solution accuracy. We analyze this trade‐off on formulation SPqt results by using 4 real data sets for the gas detector placement problem while using unavailability values obtained from real industry gas detector data. For this data, our results show that two detection levels are sufficient to find objective values within 1% of the optimal solution. Using two detection levels reduces the nonlinear formulation to a quadratic formulation. Three solution strategies are proposed for this quadratic formulation and then compared from the computational efficiency perspective. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2728–2739, 2016
      PubDate: 2016-04-13T08:50:50.589369-05:
      DOI: 10.1002/aic.15259
       
  • Product design: Metal nanoparticle‐based conductive inkjet inks
    • Authors: Sze Kee Tam; Ka Yip Fung, Grace Sum Hang Poon, Ka Ming Ng
      Pages: 2740 - 2753
      Abstract: A systematic procedure that provides an efficient workflow for formulating conductive inks is developed. Qualitative product attributes of the inkjet ink are first identified and transformed into quantitative product specifications. Ingredients are then selected based on heuristics, mechanistic, and empirical models to meet the product specifications. Printability checks based on theoretical criteria are used to ensure that stable droplets can in principle be formed and coalesced properly to form a printed line of ink. Then, the conductive ink is prepared and printed to evaluate the performance of the inkjet ink experimentally. An example of preparing a copper ink for inkjet printing is used to illustrate the systematic procedure. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2740–2753, 2016
      PubDate: 2016-05-16T09:02:04.363644-05:
      DOI: 10.1002/aic.15271
       
  • Dual‐bed catalyst system for the direct synthesis of high density
           aviation fuel with cyclopentanone from lignocellulose
    • Authors: Xueru Sheng; Guangyi Li, Wentao Wang, Yu Cong, Xiaodong Wang, George W. Huber, Ning Li, Aiqin Wang, Tao Zhang
      Pages: 2754 - 2761
      Abstract: In this article, we demonstrated an integrated process for the direct production of tri(cyclopentane) with cyclopentanone which can be obtained from lignocellulose. The reaction was carried out in a dual‐bed continuous flow reactor. In the first bed, cyclopentanone was selectively converted to 2,5‐dicyclopentylcyclopentanol over the Pd‐MgAl‐HT (hydrotalcite) catalyst. Under solvent‐free and mild conditions (443 K, 0.1 MPa H2), high carbon yield (81.2%) of 2,5‐dicyclopentylcyclopentanol was achieved. Subsequently, the 2,5‐dicyclopentylcyclopentanol was further hydrodeoxygenated to tri(cyclopentane) in the second bed. Among the investigated catalysts, the Ni‐Hβ‐DP prepared by deposition‐precipitation (DP) method exhibited the highest activity for the hydrodeoxygenation step. By using Pd‐MgAl‐HT as the first bed catalyst and Ni‐Hβ‐DP as the second bed catalyst, tri(cyclopentane) was directly produced at high carbon yield (80.0%) with cyclopentanone as feedstock. This polycycloalkane has high density (0.91 kg/L) and can be used as additive to improve the density and volumetric heating value of bio‐jet fuel. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2754–2761, 2016
      PubDate: 2016-04-02T20:46:26.367385-05:
      DOI: 10.1002/aic.15248
       
  • Mathematical modeling of the full molecular weight distribution in ATRP
           techniques
    • Pages: 2762 - 2777
      Abstract: In this work the molecular weight distribution (MWD) of several atom transfer radical polymerization (ATRP) techniques has been derived and solved using the Reduced Stiffness by Quasi Steady State Approximation (RSQSSA) methodology. The Quasi Steady State Approximation has been validated on the living radicals for normal, Simultaneous Reversible and Normal Initiation and Activators Regenerated by Electron Transfer (ARGET), and it is shown that the information lost due to its application is negligible. According to these results, RSQSSA shows the best performance in terms of wall‐clock time and required memory in comparison to implicit techniques and Predici. In the case of the ARGET technique, the model predictions show good agreement with experimental data. Finally, an analysis on the impact of the slow and fast activation of the initiator on the MWD using ARGET has been carried out, indicating that the optimal initiator to control the MWD should exhibit activation‐deactivation rates very similar to those of the polymeric equilibrium. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2762–2777, 2016
      PubDate: 2016-04-06T13:06:59.288232-05:
      DOI: 10.1002/aic.15232
       
  • Molecular origin of decreased diffusivity with loading for benzene/HY
    • Authors: Huimin Zheng; Liang Zhao, Jingjing Ji, Qing Yang, Haokai Huang, Jinsen Gao
      Pages: 2778 - 2785
      Abstract: On the basis of our recently proposed “ideal” and “insertion” adsorption mechanisms of aromatics in HY zeolites, changes in energetic and dynamic properties with loading were investigated through Monte Carlo and molecular dynamic (MD) calculations. Loading‐dependent isosteric heat could be divided into three linear ranges. The two inflection points were attributed to adsorbate interactions and inherent adsorption mechanism changes. With regard to the loading dependence of diffusivity, diffusivity decreased faster at high loadings than at low and medium loadings, separated by an inflection point. This result confirmed a two‐stage diffusion mechanism based on the distribution of adsorbate from MD simulations which was able to qualitatively predict the further restriction of the mobility. This study provided insights into the modeling of mobility at high loadings on the basis of site‐hopping mechanism. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2778–2785, 2016
      PubDate: 2016-04-06T13:34:34.156522-05:
      DOI: 10.1002/aic.15249
       
  • Supercritical water gasification of aqueous fraction of pyrolysis oil in
           the presence of a Ni‐Ru catalyst
    • Authors: Izad Behnia; Zhongshun Yuan, Paul Charpentier, Chunbao (Charles) Xu
      Pages: 2786 - 2793
      Abstract: This study demonstrated that aqueous fraction of pyrolysis oil can be efficiently gasified into fuel gases methane and hydrogen via supercritical water gasification (SCWG) at moderate temperatures (500–700°C) over Ni20%Ru2%/γ‐Al2O3 catalyst. All experiments were performed in a bench‐scale continuous down‐flow tubular reactor packed with the catalyst. Carbon gasification efficiency of 0.91 mol/mol‐C (converted into CH4 and CO2) was achieved in SCWG of the aqueous fraction of pyrolysis oil (containing 2.98 wt % C) at 700°C in the presence of the catalyst. A similar carbon gasification efficiency (approx. 0.89 mol/mol‐C) was obtained at a lower temperature (600°C) with a diluted feedstock (0.7 wt %C). Scanning Electron Microscopy coupled with Energy Dispersive x‐ray and inductively coupled plasma analysis results confirmed that this catalyst was stable during SCWG of aqueous fraction of pyrolysis oil after 6 h on‐stream. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2786–2793, 2016
      PubDate: 2016-04-06T13:16:07.663168-05:
      DOI: 10.1002/aic.15252
       
  • Intensification of photocatalytic pollutant abatement in microchannel
           reactor using TiO2 and TiO2‐graphene
    • Pages: 2794 - 2802
      Abstract: A microfluidic device was applied to the photocatalytic degradation of methylene blue as a model pollutant. Titanium dioxide nanoparticles (TiO2–P25) and a synthesized composite TiO2‐graphene catalyst were immobilized on the inner walls of a borosilicate glass microfluidic chip. The deposition evolution of the nanoparticles was evaluated by monitoring the optical profile of the system. It was found that a higher initial reaction rate was obtained in the microreactor containing composite catalyst (TiO2‐GR) on the inner walls, but both systems (TiO2 and TiO2‐GR) achieved similar reaction rates when the steady‐state was reached. Decolorization rate of methylene blue in our microfluidic chips was found to be approximately one order of magnitude higher than equivalent macroscopic systems reported in the literature at similar experimental conditions. Additionally, computational simulations were performed to investigate the physics involved in these processes. The model was experimentally validated for further scale‐out studies. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2794–2802, 2016
      PubDate: 2016-04-13T09:05:50.233942-05:
      DOI: 10.1002/aic.15262
       
  • Oxygen transport kinetics of MIEC membranes coated with different
           catalysts
    • Authors: Yan Liu; Yue Zhu, Mingrun Li, Xuefeng Zhu, Weishen Yang
      Pages: 2803 - 2812
      Abstract: Oxygen permeation through mixed ionic‐electronic conducting membrane may be controlled by oxygen bulk diffusion and/or oxygen interfacial exchange kinetics. In this article, we chose BaCe0.05Fe0.95O3‐δ (BCF) as a representative to study the oxygen transport resistances of the membrane coated with different porous catalysts, including BCF itself, Ba0.5Sr0.5Co0.8Fe0.2O3‐δ (BSCF) and Sm0.5Sr0.5CoO3‐δ (SSC). The oxygen transport resistances of bulk, gas‐solid interfaces of feed‐side and sweep‐side of the catalyst‐coated membranes can be separately obtained through a linear regression of experimental data according to an oxygen permeation model. The three resistances of the membrane coated with BCF catalyst are smaller than those of the membrane coated with BSCF and SSC catalysts, although BSCF catalyst itself has the fastest bulk diffusion and interfacial exchange kinetics. The catalytic activities of BSCF and SSC catalysts on BCF membranes are impacted by the transport kinetics of catalysts, microstructure of catalyst layers, and cationic inter‐diffusion between the membrane and catalysts. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2803–2812, 2016
      PubDate: 2016-04-01T13:56:01.020946-05:
      DOI: 10.1002/aic.15239
       
  • High performance ZSM‐5 membranes on coarse macroporous
           α‐Al2O3 supports for dehydration of alcohols
    • Authors: Liangqing Li; Jianhua Yang, Jiajia Li, Jinqu Wang, Jinming Lu, Dehong Yin, Yan Zhang
      Pages: 2813 - 2824
      Abstract: High‐performance ZSM‐5 membranes with a low Si/Al ratio of 10.3 were prepared on cheap coarse macroporous α‐Al2O3 tubes by fluoride route without organic template. The effects of crystallization time and aluminum source on the growth, morphology and pervaporation (PV) performances of the as‐synthesized membranes were investigated. The feasibility of preparing ZSM‐5 membranes with different Si/Al ratio which was implemented by using different Al2(SO4)3·18H2O content in synthesis gel were discussed. It was found that the aluminum source had significant effect on the synthesis of membranes. The ZSM‐5 membranes prepared by using Al2(SO4)3·18H2O as an aluminum source from synthetic gel with composition of 1SiO2/0.05Al2O3/0.17Na2O/0.9NaF/45H2O showed high reproducibility and high PV performance with flux of 3.85 kg/(m2·h) and separation factor of higher than 10,000 in dehydration of 90 wt % i‐PrOH/H2O at 348 K. Moreover, the ZSM‐5 membranes exhibited high water perm‐selectivity performance for dehydration of 90 wt % n‐PrOH/H2O, n‐BtOH/H2O, and i‐BtOH/H2O mixtures, respectively. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2813–2824, 2016
      PubDate: 2016-04-02T20:40:58.086954-05:
      DOI: 10.1002/aic.15234
       
  • CO2 sorption performance by aminosilane functionalized spheres prepared
           via co‐condensation and post‐synthesis methods
    • Authors: David Madden; Teresa Curtin, John P. Hanrahan, Joseph Tobin
      Pages: 2825 - 2832
      Abstract: Amine functionalized silica microspheres were synthesised via a modified Stöber reaction for carbon dioxide (CO2) adsorption. A number of adsorbents were synthesized by co‐condensation and post synthesis immobilization of amines on porous silica spheres. CO2 adsorption studies were carried out on a fixed bed gas adsorption rig with online mass spectrometry. Amine co‐condensed silica spheres were found to adsorb up to 66 mg CO2 g−1 solid in a 0.15 atm CO2 stream at 35°C. Simple post‐synthesis addition of aminopropyltriethoxysilane to amine co‐condensed silica was found to significantly increase the uptake of CO2 to 211 mg CO2 g−1 under similar conditions, with CO2 desorption commencing at temperatures as low as 60°C. The optimum temperature for adsorption was found to be 35°C. This work presents a CO2 adsorbent prepared via a simple synthesis method, with a high CO2 adsorption capacity and favorable CO2 adsorption/desorption performance under simulated flue gas conditions. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2825–2832, 2016
      PubDate: 2016-04-06T13:11:48.419171-05:
      DOI: 10.1002/aic.15253
       
  • Efficient separation of N2 and he at low temperature using MFI membranes
    • Authors: Pengcheng Ye; Mattias Grahn, Danil Korelskiy, Jonas Hedlund
      Pages: 2833 - 2842
      Abstract: Ultra‐thin MFI membranes were evaluated for N2/He separation over the temperature range of 85–260 K for the first time. The membranes were rather nitrogen selective at all the conditions investigated. A highest N2/He selectivity of 75.7 with a high N2 flux of 83 kg/m2/h was observed at 124 K. The separation was attributed to adsorption selectivity to N2, effectively hindering the transport of He in the zeolite pores. The exceedingly high permeance even at low temperatures was ascribed to the ultrathin (
      PubDate: 2016-04-13T10:35:45.386634-05:
      DOI: 10.1002/aic.15258
       
  • Size effects of graphene oxide on mixed matrix membranes for CO2
           separation
    • Authors: Jie Shen; Mengchen Zhang, Gongping Liu, Kecheng Guan, Wanqin Jin
      Pages: 2843 - 2852
      Abstract: Graphene oxide (GO)‐polyether block amide (PEBA) mixed matrix membranes were fabricated and the effects of GO lateral size on membranes morphologies, microstructures, physicochemical properties, and gas separation performances were systematically investigated. By varying the GO lateral sizes (100–200 nm, 1–2 μm, and 5–10 μm), the polymer chains mobility, as well as the length of the gas channels could be effectively manipulated. Among the as‐prepared membranes, a GO‐PEBA mixed matrix membrane (GO‐M‐PEBA) containing 0.1 wt % medium‐lateral sized (1–2 μm) GO sheets showed the highest CO2 permeation performance (CO2 permeability of 110 Barrer and CO2/N2 mixed gas selectivity of 80), which transcends the Robeson upper bound. Also, this GO‐PEBA mixed matrix membrane exhibited high stability during long‐term operation testing. Optimized by GO lateral size, the developed GO‐PEBA mixed matrix membrane shows promising potential for industrial implementation of efficient CO2 capture. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2843–2852, 2016
      PubDate: 2016-04-13T09:55:46.675064-05:
      DOI: 10.1002/aic.15260
       
  • A molecular design method based on the COSMO‐SAC model for solvent
           selection in ionic liquid extractive distillation
    • Authors: Jing Fang; Rui Zhao, Weiyi Su, Chunli Li, Jing Liu, Bo Li
      Pages: 2853 - 2869
      Abstract: In this study, a molecular design method was used to select solvents for extractive distillation. A COSMO‐SAC model was used to screen for prospective solvents from a wide variety of ionic liquids for extractive distillation. Based on the COSMO‐SAC model, the σ‐profile database of ILs was established. Selectivity and solubility were used as the indexes for solvent screening. According to the molecular design method, three suitable extractive distillation solvents were determined for acetonitrile‐water and ethanol‐cyclohexane systems. Vapor ‐ liquid equilibrium experiment were used to test chosen ILs. This study showed that the experimental and design results were consistent with each other. Therefore, this method is effective and applicable to pick ILs solvents for extractive distillation, and the results could provide a theoretical foundation for industrial production. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2853–2869, 2016
      PubDate: 2016-04-07T19:56:08.958084-05:
      DOI: 10.1002/aic.15247
       
  • Compressed isobutane as a solvent of heavy hydrocarbons
    • Pages: 2870 - 2878
      Abstract: This research provides solubility data required for environmental applications involving the extraction of heavy hydrocarbons with compressed gases. Dibenzothiophene (DBT), 2‐nitrophenyl disulfide (NPDS), and tetramethylthiuram disulfide (TTDS) have been selected as model compounds for this type of pollutants and isobutane as compressed gas. The solubilities obtained at 367–413 K and 3.9–7.5 MPa, expressed as solute mole fractions, were in the ranges 0.025–0.106 for DBT, 1.2 × 10−4−6.3 × 10−4 for NPDS, and between 2.7 × 10−4 and 1.8 × 10−3 for TTDS. They were compared to other pollutants solubilities (anthracene and carbazole). From the comparison, the following solubility order was established: DBT > anthracene > carbazole > TTDS > NPDS. Furthermore, when comparing these isobutane solubilities to those in propane and CO2, they were found to be about one and two magnitude orders larger, respectively. Results obtained were explained considering solvent density, solute vapor pressure, and interactions between solutes and solvent. Peng–Robinson equation was used to correlate the data and a good fitting attained. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2870–2878, 2016
      PubDate: 2016-04-09T21:25:58.416656-05:
      DOI: 10.1002/aic.15216
       
  • Optimization and simulation of the Sabatier reaction process in a packed
           bed
    • Authors: Baolin Hou; Yanqiang Huang, Xiaodong Wang, Xiaofeng Yang, Hongming Duan, Tao Zhang
      Pages: 2879 - 2892
      Abstract: The Sabatier reaction in a testing packed bed was investigated experimentally and theoretically, and was used to convert waste carbon dioxide and hydrogen to provide needed water for closing the life‐support loop on orbit in space. A three‐dimensional model including fluid flow, gas dispersion, heat and mass transfer, and chemical reaction was developed by coupling some semi‐empirical correlated equations in chemical engineering science into computational fluid dynamics theory. Good agreements between the simulating results and experimental data for the effect of some parameters on reaction verified this model, for example, heat exchange between reactor and atmosphere, the material property of reactor, the catalyst deactivated and gas mass flux and so on. By using this model as the designing tools, an optimized packed bed is proposed. Compared with the testing packed bed, the relevant reactor length can be reduced from 220 to 150 mm with the same hydrogen conversion and lower pressure drop. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2879–2892, 2016
      PubDate: 2016-04-02T20:31:05.550955-05:
      DOI: 10.1002/aic.15245
       
  • An analytical model for real gas flow in shale nanopores with
           non‐circular cross‐section
    • Authors: Wenxi Ren; Gensheng Li, Shouceng Tian, Mao Sheng, Xin Fan
      Pages: 2893 - 2901
      Abstract: An analytical model for gas transport in shale media is proposed on the basis of the linear superposition of convective flow and Knudsen diffusion, which is free of tangential momentum accommodation coefficient. The present model takes into the effect of pore shape and real gas, and is successfully validated against experimental data and Lattice–Boltzmann simulation results. Gas flow in noncircular nanopores can be accounted by a dimensionless geometry correction factor. In continuum‐flow regime, pore shape has a relatively minor impact on gas transport capacity; the effect of pore shape on gas transport capacity enhances significantly with increasing rarefaction. Additionally, gas transport capacity is strongly dependent of average pore size and streamline tortuosity. We also show that the present model without using weighted factor can describe the variable contribution of convective flow and Knudsen diffusion to the total flow. As pressure and pore radius decrease, the number of molecule‐wall collisions gradually predominates over the number of intermolecule collisions, and thus Knudsen diffusion contributes more to the total flow. The parameters in the present model can be determined from independent laboratory experiments. We have the confidence that the present model can provide some theoretical support in numerical simulation of shale gas production. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2893–2901, 2016
      PubDate: 2016-04-06T13:11:14.049191-05:
      DOI: 10.1002/aic.15254
       
  • Interfacial phenomena and droplet size of particle stabilized emulsions in
           oscillatory shear
    • Authors: H. G. Gomaa; R. Sabouni
      Pages: 2902 - 2911
      Abstract: Production of particle stabilized oil in water emulsions has been investigated both theoretically and experimentally under oscillatory shear conditions using different stabilizing particles (SPs). The investigation included analysis of the interaction between particles interfacial stability and droplets breakage and coalescence. For hydrophobic SPs, droplets maintained their sizes as determined by torque balance (TB) without significant breakage or coalescence. For the more hydrophilic SPs, larger droplets formed that broke by eddies in the inertial subrange. At higher fluid shear stresses, loss of the SPs occurred during droplet formation leading to near bare droplet surface and coalescence to much larger sizes with subsequent fragmentation by capillary instabilities. The final droplet size in both cases was very different from TB model predictions. A modeling approach is proposed that combined both TB and droplet breakage and coalescence mechanisms. Comparison between the experimental results and the models predictions showed satisfactory agreement. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2902–2911, 2016
      PubDate: 2016-04-06T13:21:43.994554-05:
      DOI: 10.1002/aic.15256
       
  • LES–Lagrangian‐particles‐simulation of turbulent
           reactive flows at high Sc number using approximate deconvolution model
    • Authors: T. Watanabe; K. Nagata
      Pages: 2912 - 2922
      Abstract: Large eddy simulation (LES) with the approximate deconvolution model is combined with Lagrangian particles simulation (LPS) for simulating turbulent reactive flows at high Schmidt numbers Sc. The LES is used to simulate velocity and nonreactive scalar while reactive scalars are simulated by the LPS using the mixing volume model for molecular diffusion. The LES–LPS is applied to turbulent scalar mixing layers with a second‐order isothermal irreversible reaction at Sc = 600. The mixing volume model is implemented with the IEM, Curl's, and modified Curl's mixing schemes. The mixing volume model provides a correct decay rate of nonreactive scalar variance at high Sc independently of the number of particles. The statistics in the LES–LPS with the IEM or modified Curl's mixing scheme agree well with the experiments for both moderately‐fast and rapid reactions. However, the LPS with the Curl's mixing scheme overpredicts the effects of the rapid reaction. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2912–2922, 2016
      PubDate: 2016-04-13T09:50:56.207708-05:
      DOI: 10.1002/aic.15261
       
  • Statistics of droplet sizes generated by a microfluidic device
    • Pages: 2923 - 2928
      Abstract: The distribution of droplet sizes produced in a microfluidic T‐junction is modeled using the gamma probability distribution. The proposed model is validated using physical insight from the hypothesized mechanism of droplet breakup and statistically using the Anderson–Darling test. Where signal‐to‐noise ratio is low and the gamma distribution does not hold, an alternative probabilistic description is used to estimate the true mean of droplet sizes. In addition, a new correlation is developed to relate mean droplet sizes to T‐junction inlet flow rates and dispersed‐phase viscosity. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2923–2928, 2016
      PubDate: 2016-04-18T10:50:45.593974-05:
      DOI: 10.1002/aic.15246
       
 
 
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