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  Subjects -> ENGINEERING (Total: 2278 journals)
    - CHEMICAL ENGINEERING (190 journals)
    - CIVIL ENGINEERING (182 journals)
    - ELECTRICAL ENGINEERING (102 journals)
    - ENGINEERING (1206 journals)
    - HYDRAULIC ENGINEERING (55 journals)
    - INDUSTRIAL ENGINEERING (64 journals)
    - MECHANICAL ENGINEERING (89 journals)

ENGINEERING (1206 journals)            First | 1 2 3 4 5 6 7 | Last

Showing 201 - 400 of 1205 Journals sorted alphabetically
Current Applied Physics     Full-text available via subscription   (Followers: 4)
Current Science     Open Access   (Followers: 46)
Dams and Reservoirs     Hybrid Journal   (Followers: 4)
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: 28)
Designed Monomers and Polymers     Hybrid Journal   (Followers: 1)
Designs, Codes and Cryptography     Hybrid Journal   (Followers: 6)
Development Engineering     Open Access  
Developments in Clay Science     Full-text available via subscription   (Followers: 1)
Developments in Geotechnical Engineering     Full-text available via subscription   (Followers: 4)
Developments in Mineral Processing     Full-text available via subscription   (Followers: 3)
Diálogos Interdisciplinares     Open Access  
Diffusion Foundations     Full-text available via subscription   (Followers: 2)
Digital Signal Processing     Hybrid Journal   (Followers: 13)
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: 5)
Electrophoresis     Hybrid Journal   (Followers: 19)
Elementos     Open Access  
Elsevier Geo-Engineering Book Series     Full-text available via subscription   (Followers: 2)
Elsevier Ocean Engineering Series     Full-text available via subscription   (Followers: 1)
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 40)
Emitter : International Journal of Engineering Technology     Open Access  
ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations     Open Access   (Followers: 1)
Energies     Open Access   (Followers: 3)
Energy and Power Engineering     Open Access   (Followers: 17)
Energy Conversion and Management     Hybrid Journal   (Followers: 10)
Energy Engineering     Full-text available via subscription   (Followers: 9)
Energy for Sustainable Development     Hybrid Journal   (Followers: 9)
Energy Procedia     Open Access   (Followers: 2)
Energy Science & Engineering     Open Access   (Followers: 3)
Energy Science and Technology     Open Access   (Followers: 12)
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: 13)
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: 2)
Engineering & Technology     Hybrid Journal   (Followers: 23)
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: 5)
Engineering Economist, The     Hybrid Journal   (Followers: 6)
Engineering Failure Analysis     Hybrid Journal   (Followers: 64)
Engineering Geology     Hybrid Journal   (Followers: 10)
Engineering International     Open Access  
Engineering Journal     Open Access   (Followers: 1)
Engineering Management Journal     Hybrid Journal   (Followers: 19)
Engineering Management Research     Open Access   (Followers: 6)
Engineering Management Reviews     Open Access   (Followers: 1)
Engineering Optimization     Hybrid Journal   (Followers: 7)
Engineering Science and Technology, an International Journal     Open Access   (Followers: 1)
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: 4)
Épsilon     Open Access  
Ergonomics in Design: The Quarterly of Human Factors Applications     Hybrid Journal   (Followers: 15)
ESAIM: Control Optimisation and Calculus of Variations     Full-text available via subscription   (Followers: 1)
ESAIM: Mathematical Modelling and Numerical Analysis     Full-text available via subscription   (Followers: 4)
ESAIM: Proceedings     Open Access   (Followers: 1)
Estuaries and Coasts     Hybrid Journal   (Followers: 17)
European Journal of Combinatorics     Full-text available via subscription   (Followers: 4)
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: 2)
European Physical Journal - Applied Physics     Full-text available via subscription   (Followers: 16)
European Transport Research Review     Open Access   (Followers: 21)
Evolutionary Intelligence     Hybrid Journal   (Followers: 1)
Evolving Systems     Hybrid Journal  
Exacta     Open Access  
Experimental Techniques     Hybrid Journal   (Followers: 56)
Experiments in Fluids     Hybrid Journal   (Followers: 11)
Fibers and Polymers     Full-text available via subscription   (Followers: 6)
Filtration & Separation     Full-text available via subscription   (Followers: 5)
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: 24)
Fluid Dynamics     Hybrid Journal   (Followers: 11)
Fluid Dynamics Research     Full-text available via subscription   (Followers: 10)
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: 5)
Focus on Surfactants     Full-text available via subscription   (Followers: 4)
Food Engineering Reviews     Hybrid Journal   (Followers: 3)
Food Science and Technology     Open Access   (Followers: 4)
Formación Universitaria     Open Access   (Followers: 4)
FORMakademisk     Open Access  
Formal Methods in System Design     Hybrid Journal   (Followers: 7)
Forschung     Hybrid Journal   (Followers: 1)
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   (Followers: 1)
Frontiers in Aerospace Engineering     Open Access   (Followers: 11)
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: 5)
Fuel Cells     Hybrid Journal   (Followers: 4)
Fuel Cells Bulletin     Full-text available via subscription   (Followers: 4)
Fusion Engineering and Design     Hybrid Journal   (Followers: 10)
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: 125)
Geotechnical Testing Journal     Full-text available via subscription   (Followers: 9)
Géotechnique     Hybrid Journal   (Followers: 14)
Geothermics     Hybrid Journal   (Followers: 6)
Glass Technology - European Journal of Glass Science and Technology Part A     Full-text available via subscription   (Followers: 4)
Global Journal of Engineering Research     Full-text available via subscription  
Global Perspective on Engineering Management     Open Access   (Followers: 3)
GPS Solutions     Hybrid Journal   (Followers: 17)
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: 8)
Groundwater for Sustainable Development     Full-text available via subscription  
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: 3)
Heat Exchangers     Open Access   (Followers: 3)
Heat Transfer - Asian Research     Hybrid Journal   (Followers: 10)
Heat Transfer Engineering     Hybrid Journal   (Followers: 26)
Historical Records of Australian Science     Hybrid Journal   (Followers: 2)
Human Factors in Ergonomics & Manufacturing     Hybrid Journal   (Followers: 8)
IBM Journal of Research and Development     Hybrid Journal   (Followers: 17)
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 52)
IEEE Antennas and Wireless Propagation Letters     Hybrid Journal   (Followers: 40)
IEEE Communications Magazine     Full-text available via subscription   (Followers: 68)
IEEE Control Systems Magazine     Full-text available via subscription   (Followers: 68)
IEEE Engineering Management Review     Full-text available via subscription   (Followers: 35)
IEEE Geoscience and Remote Sensing Letters     Hybrid Journal   (Followers: 118)
IEEE Industry Applications Magazine     Full-text available via subscription   (Followers: 18)
IEEE Instrumentation & Measurement Magazine     Full-text available via subscription   (Followers: 58)
IEEE Journal of Biomedical and Health Informatics     Hybrid Journal   (Followers: 16)
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: 29)
IEEE Journal of Solid-State Circuits     Full-text available via subscription   (Followers: 21)
IEEE Journal on Selected Areas in Communications     Hybrid Journal   (Followers: 18)
IEEE Latin America Transactions     Full-text available via subscription   (Followers: 3)
IEEE Microwave and Wireless Components Letters     Hybrid Journal   (Followers: 18)
IEEE Microwave Magazine     Full-text available via subscription   (Followers: 33)
IEEE Potentials     Full-text available via subscription   (Followers: 19)
IEEE Signal Processing Letters     Hybrid Journal   (Followers: 36)
IEEE Spectrum     Full-text available via subscription   (Followers: 139)
IEEE Technology and Society Magazine     Full-text available via subscription   (Followers: 7)
IEEE Transactions on Advanced Packaging     Full-text available via subscription   (Followers: 7)
IEEE Transactions on Antennas and Propagation     Full-text available via subscription   (Followers: 39)
IEEE Transactions on Applied Superconductivity     Hybrid Journal   (Followers: 4)
IEEE Transactions on Automation Science and Engineering     Full-text available via subscription   (Followers: 12)
IEEE Transactions on Circuits and Systems II: Express Briefs     Hybrid Journal   (Followers: 17)
IEEE Transactions on Components and Packaging Technologies     Full-text available via subscription   (Followers: 15)
IEEE Transactions on Control Systems Technology     Hybrid Journal   (Followers: 45)
IEEE Transactions on Education     Hybrid Journal   (Followers: 9)
IEEE Transactions on Electronics Packaging Manufacturing     Full-text available via subscription   (Followers: 19)
IEEE Transactions on Energy Conversion     Hybrid Journal   (Followers: 11)
IEEE Transactions on Engineering Management     Hybrid Journal   (Followers: 25)
IEEE Transactions on Evolutionary Computation     Hybrid Journal   (Followers: 9)
IEEE Transactions on Information Theory     Hybrid Journal   (Followers: 21)
IEEE Transactions on Instrumentation and Measurement     Hybrid Journal   (Followers: 51)
IEEE Transactions on Intelligent Transportation Systems     Hybrid Journal   (Followers: 7)
IEEE Transactions on Knowledge and Data Engineering     Hybrid Journal   (Followers: 30)
IEEE Transactions on Magnetics     Hybrid Journal   (Followers: 14)
IEEE Transactions on Microwave Theory and Techniques     Hybrid Journal   (Followers: 26)
IEEE Transactions on Nuclear Science     Hybrid Journal   (Followers: 9)
IEEE Transactions on Plasma Science     Hybrid Journal   (Followers: 8)
IEEE Transactions on Power Delivery     Hybrid Journal   (Followers: 18)
IEEE Transactions on Professional Communication     Hybrid Journal   (Followers: 7)
IEEE Transactions on Reliability     Hybrid Journal   (Followers: 33)
IEEE Transactions on Semiconductor Manufacturing     Hybrid Journal   (Followers: 6)
IEEE Transactions on Signal Processing     Hybrid Journal   (Followers: 64)
IEEE Transactions on Vehicular Technology     Hybrid Journal   (Followers: 4)
IEEE Vehicular Technology Magazine     Full-text available via subscription   (Followers: 8)
IEEE/ACM Transactions on Computational Biology and Bioinformatics     Hybrid Journal   (Followers: 16)
IERI Procedia     Open Access  
IET Circuits, Devices & Systems     Hybrid Journal   (Followers: 18)
IET Generation, Transmission & Distribution     Hybrid Journal   (Followers: 2)
IET Image Processing     Hybrid Journal   (Followers: 15)

  First | 1 2 3 4 5 6 7 | Last

Journal Cover AIChE Journal
  [SJR: 1.122]   [H-I: 120]   [28 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  [1605 journals]
  • Molecular understanding of pyridinium ionic liquids as absorbents with
           water as refrigerant for use in heat pumps
    • Authors: Pablo B. Sánchez; Mounir Traikia, Alain Dequid, Josefa García, Agílio A. H. Pádua
      Abstract: Aiming at developing new absorbent/refrigerant working pairs for heat pumps, thermodynamic and transport properties of two pyridinium ionic liquids, N-ethylpyridinium bis(trifluoromethanesulfonyl)amide and N-ethylpyridinium trifluoromethanesulfonate were studied using molecular simulation and nuclear magnetic resonance techniques. The microscopic structure of the ionic liquids and the solvation environment of water, including hydrogen bonding, were studied. Free-energies of solvation of water were obtained using perturbation methods, and the values agree with experimental observations. Self-diffusion coefficients and viscosity were computed and compared with nuclear magnetic resonance measurements and literature. Simulations predict slower dynamics when compared with experiment: diffusion coefficients are underpre- dicted, whereas viscosity is overpredicted. As such, simulation is consistent in a Stokes-Einstein sense. The trends in transport properties due to changing anion, to the presence of water and the effect of temperature are well predicted. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-18T10:36:05.312541-05:
      DOI: 10.1002/aic.15690
  • Data Mining and Control Loop Performance Assessment: The Multivariate Case
    • Authors: Laya Das; Raghunathan Rengaswamy, Babji Srinivasan
      Abstract: Control loop performance assessment techniques assume that the data being analyzed is generated during steady state operation with fixed plant dynamics and controller parameters. However, in industrial settings one often encounters environmental and feedstock variations which can induce significant changes in the plant dynamics. Availability of data sets corresponding to fixed configurations is therefore questionable in industrial scenarios, in which case it becomes imperative to extract the same from routine plant operating data. This article proposes a technique for segmenting multivariate control loop data into portions corresponding to fixed steady state operation of the system. The proposed technique exploits the fact that changes in the operating region of the system lead to changes in variance-covariance matrix of multivariate control loop data. The univariate interval halving technique is fused with Mahalanobis distance to develop a multivariate tool that accounts for interactions between variables. The resulting data segments can be used for reliable control loop performance assessment and/or for user defined benchmarking of control loops. A multivariate control loop performance index is also proposed that requires significantly less data as compared to previously proposed techniques. The proposed technique requires only routine operating data from the plant, and is tested on benchmark systems in the literature with simulations. Experimental validation on a model predictive control system aimed at maintaining the temperature profile of a metal plate demonstrates applicability of the technique to industrial systems. The proposed technique acts as a tool for preprocessing data relevant to control loop performance assessment and can be applied to large scale interacting multivariate systems. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-18T10:36:04.080274-05:
      DOI: 10.1002/aic.15689
  • Volume Diffusion in Purification by Sublimation
    • Authors: Narendra Singh; T. E. Schwartzentruber, Russell J. Holmes, E. L. Cussler
      Abstract: The amount sublimated of large organic molecules varies with the square of the diameter of the tube in which sublimation occurs. This implies that the velocity profile in the tube is nearly flat, consistent with volume diffusion, but not with laminar flow, Knudsen diffusion, or slip flow. However, molecular simulation calculations show that under the conditions used, the velocity profile is near parabolic when there is no deposition on the tube wall, inconsistent with volume diffusion, but in agreement with laminar flow. These calculations also show that deposition on the wall does result in velocity which is almost constant with radial position. The result is a laminar flow profile which is nearly flat, and hence a total flux proportional to the square of the tube diameter, which is observed both in these simulations and in physical experiments. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-18T10:36:00.164262-05:
      DOI: 10.1002/aic.15691
  • Aqueous-phase ketonization of acetic acid over Zr/Mn mixed oxides
    • Authors: Kejing Wu; Mingde Yang, Yu Chen, Weihua Pu, Husheng Hu, Yulong Wu
      Abstract: Aqueous-phase ketonization possesses significant advantages over gas- or organic-phase ketonization for improved conversion efficiency of aqueous fraction accompanied by algal bio-oil production. In this study, synthetized ZrO2 and Zr/Mn oxides are used for aqueous-phase ketonization of acetic acid. ZrMn0.5Ox shows the highest ketonization activity at 340°C for 12 h, achieving maximum acetone yield of 88.27%; and all catalysts exhibited selectivity higher than 96.75%. Apparent activation energy and acid reaction order are 161.2 kJ mol−1 and 0.70, respectively. Results suggest high ketonization activity of poorly crystallized tetragonal ZrO2. Addition of Mn results in ZrO2/MnOx solid solution and improves active sites. Acid property and Mn4+ content are important factors, and oxygen vacancy demonstrates relationship with ketonization activity for ZrO2. Examination of recovered catalysts indicates that ZrMnyOx exhibits improved stability, and Mn leaching and crystal phase transformation are main causes of deactivation in aqueous-phase ketonization. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-18T10:30:29.261917-05:
      DOI: 10.1002/aic.15687
  • Ceria-Coated Diesel Particulate Filters for Continuous Regeneration
    • Authors: Valeria Di Sarli; Gianluca Landi, Luciana Lisi, Almerinda Di Benedetto
      Abstract: The potential of diesel particulate filters wash-coated with highly dispersed nano-metric ceria particles for continuous regeneration has been investigated. To this end, catalytic filters were prepared, soot-loaded (avoiding the formation of the cake layer), and regenerated - under isothermal conditions - at temperature ranging from 200-600°C.Results have shown that catalytic oxidation of soot starts from 300°C and, at all temperatures, the selectivity to CO2 is higher than 99%. 475°C is the minimum temperature at which the filter is regenerated via catalytic path. At this temperature, the catalytic filter maintains substantially the same performance over repeated cycles of soot loading and regeneration, indicating that the thermal stability of ceria is preserved. This has been further confirmed by comparison between the outcomes obtained from characterization (X-ray powder diffraction, N2 adsorption at 77 K, Hg intrusion porosimetry and SEM/EDX analysis) of fresh filter and filter subjected to repeated regeneration tests. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-18T10:30:25.05185-05:0
      DOI: 10.1002/aic.15688
  • Euler–Euler anisotropic Gaussian mesoscale simulation of homogeneous
           cluster-induced gas-particle turbulence
    • Authors: Bo Kong; Heng Feng, Jesse Capecelatro, Ravi Patel, Olivier Desjardins, Rodney O. Fox
      Abstract: An Euler-Euler anisotropic Gaussian approach (EE-AG) for simulating gas-particle flows, in which particle velocities are assumed to follow a multivariate anisotropic Gaussian distribution, is used to perform mesoscale simulations of homogeneous cluster-induced turbulence (CIT). A three-dimensional Gauss–Hermite quadrature formulation is used to calculate the kinetic flux for ten velocity moments in a finite-volume framework. The particle-phase volume-fraction and momentum equations are coupled with the Eulerian solver for the gas phase. This approach is implemented in an open-source CFD package, OpenFOAM, and detailed simulation results are compared with previous Euler-Lagrange simulations in a domain size study of CIT. The results demonstrate that the proposed EE-AG methodology is able to produce comparable results to EL simulations, and this moment-based methodology can be used to perform accurate mesoscale simulations of dilute gas-particle flows. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-16T03:10:54.131987-05:
      DOI: 10.1002/aic.15686
  • In situ characterization of mixing and sedimentation dynamics in an
           impinging jet ballast tank via acoustic backscatter
    • Authors: Jaiyana Bux; Neepa Paul, Jeffrey Peakall, Timothy N. Hunter, Jonathan M. Dodds, Simon Biggs
      Abstract: Impinging jets are utilized in numerous applications, including nuclear waste treatment, for both the erosion of sediment beds and maintaining particulates in suspension. Pulse-echo ultrasonic methods offer great potential for the in situ monitoring of critical mixing and settling dynamics, in concentrated dispersions. A non-active scaled version of a Highly Active Storage Tank at Sellafield, UK, was profiled with an acoustic backscatter system under various jet firing conditions. An advanced analysis technique enabled the direct quantification of dispersion concentration changes from the converted backscatter attenuation. Hence, the erosion and mixing capability of the jets, and settling kinetics were characterized. It was found that jet operation alone provided inadequate localized mixing of eroded sediment. An additional air-lift process operation was required to hinder the rapid re-settling of dispersed particulates.Particle Technology and Fluidization This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-16T03:10:43.468161-05:
      DOI: 10.1002/aic.15683
  • Controlled Surface Topography of Nanostructured Particles Prepared by
           Spray Drying Process
    • Authors: Ratna Balgis; Lusi Ernawati, Takashi Ogi, Kikuo Okuyama, Leon Gradon
      Abstract: Nanostructured particles (clusters) with complex and periodic topography at the microscopic scale show unique structural patterns. Hence, good properties should be obtained when the surface topography of such clusters, especially those containing nanoparticles (NPs) of different sizes, can be carefully tuned. The coffee-ring structure is one of the most interesting structures for catalyst and photonic crystal applications or porous particle molds. Here, well-defined clusters with a coffee-ring structure were prepared by spray drying. The complexity of the NP distribution in the resulting two- and three-component systems is discussed. A better understanding of how finite groups of different NPs self-organize in a moving droplet to form a confined geometry may aid in controlling the structure of matter at multiple length scales. Interestingly, the configuration of the large microsphere clusters was found to be influenced by the presence of the small particles, which formed a ring-like structure. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-16T03:05:39.206243-05:
      DOI: 10.1002/aic.15682
  • Column Absorption for Reproducible Cyclic Separation in Small Scale
           Ammonia Synthesis
    • Authors: Kevin Wagner; Ming Zhu, Mahdi Malmali, Collin Smith, Nicholas C. A. Seaton, Alon McCormick, E. L. Cussler
      Abstract: Ammonia is rapidly and reversibly absorbed on magnesium chloride supported on alumina. The absorption at ambient temperature is twice that on alumina alone, but much of the ammonia is still captured at 400°C, closer to the temperature of ammonia synthesis. Regeneration at 450°C is complete in 30 minutes; partial regeneration is faster, and is correlated with the temperature and the regeneration time. The supported absorbent column works for many cycles, reproducibly, because submicron-sized MgCl2 crystals are trapped in similarly sized pores in the alumina itself, and the confinement prevents deterioration of the microstructure during absorption or regeneration. In contrast, while ammonia absorption into pure magnesium chloride is potentially much larger at equilibrium, the ammonia absorbs very slowly, and the chloride loses available capacity with use, probably because of fusing and deterioration of microstructure. A simplified model was constructed to simulate ammonia absorption into pure magnesium chloride and alumina-supported magnesium chloride. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-16T03:05:36.743333-05:
      DOI: 10.1002/aic.15685
  • A spatially-averaged two-fluid model for dense large-scale gas-solid flows
    • Authors: Simon Schneiderbauer
      Abstract: We present a spatially-averaged two-fluid model (SA-TFM), which is derived from ensemble averaging the kinetic-theory based TFM equations. The residual correlation for the gas-solid drag, which appears due to averaging, is derived by employing a series expansion to the microscopic drag coefficient, while the Reynolds-stress-like contributions are closed similar to the Boussinesq-approximation. The subsequent averaging of the linearized drag force reveals that averaged interphase momentum exchange is a function of the turbulent kinetic energies of both, the gas and solid phase, and the variance of the solids volume fraction. Closure models for these quantities are derived from first principles. The results show that these new constitutive relations show fairly good agreement with the fine grid data obtained for a wide range of particle properties. Finally, the SA-TFM model is applied to the coarse grid simulation of a bubbling fluidised bed revealing excellent agreement with the reference fine grid solution. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-16T03:05:31.112263-05:
      DOI: 10.1002/aic.15684
  • The kinetics of polyurethane structural foam formation: Foaming and
    • Authors: Rekha Rao; Lisa Mondy, Kevin Long, Mathew Celina, Christine Roberts, Melissa Soehnel, Nicholas Wyatt, Victor Brunini
      Abstract: We are developing kinetic models to understand the manufacturing of polymeric foams, which evolve from low viscosity Newtonian liquids, to bubbly liquids, finally producing solid foam. Closed-form kinetics are formulated and parameterized for PMDI-10, a fast curing polyurethane, including polymerization and foaming. PMDI-10 is chemically blown, where water and isocyanate react to form carbon dioxide. The isocyanate reacts with polyol in a competing reaction, producing polymer. Our approach is unique, though it builds on our previous work and the polymerization literature. This kinetic model follows a simplified mathematical formalism that decouples foaming and curing, including an evolving glass transition temperature to represent vitrification. This approach is based on IR, DSC, and volume evolution data, where we observed that the isocyanate is always in excess and does not affect the kinetics. The kinetics are suitable for implementation into a computational fluid dynamics framework, which will be explored in subsequent papers. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-15T03:25:46.997942-05:
      DOI: 10.1002/aic.15680
  • The kinetic modeling of carbonate formation during kraft pulping of
           eucalyptus wood chips
    • Authors: Jing Li; Huichao Hu, Xinsheng Chai
      PubDate: 2017-02-15T03:25:29.706935-05:
      DOI: 10.1002/aic.15681
  • Thermodynamic modeling of HNO3-H2SO4-H2O ternary system with symmetric
           electrolyte NRTL model
    • Authors: Meng Wang; Harnoor Kaur, Chau-Chyun Chen
      Abstract: The nitric acid concentration/sulfuric acid concentration (NAC/SAC) process has been widely used for concentrating dilute aqueous nitric acid and recovering spent sulfuric acid. Dilute nitric acid (65 to 80 wt.%) is concentrated by employing sulfuric acid to bind water and break the nitric acid-water azeotrope at approximately 68 wt.% nitric acid. To support heat and mass balance calculations and process simulation for NAC/SAC processes, we develop a comprehensive thermodynamic model for nitric acid-sulfuric acid-water ternary system based on previously published thermodynamic models of nitric acid-water and sulfuric acid-water binary systems with eNRTL equation. The ternary system model correlates well the isobaric vapor-liquid equilibrium data at one atmosphere and the water and nitric acid activities data at 273.15 K for the ternary. Contour plots of boiling points, vapor phase composition, and specific heat capacity of the ternary system, as well as a Merkel enthalpy-concentration chart are generated for engineering use. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-14T17:50:36.265298-05:
      DOI: 10.1002/aic.15679
  • Real Gas Transport in Tapered Non-Circular Nanopores of Shale Rocks
    • Authors: Jinze Xu; Keliu Wu, Sheng Yang, Yi Pan, Jili Cao, Bicheng Yan, Zhangxin Chen
      Abstract: We present a model for gas transport in tapered non-circular nanopores of shale rocks with integrating real gas effect, molecular kinetic and transport behavior. The proposed model is well validated with experimental and simulation data, including six kinds of gases, under different pressures and temperatures. Results show that neglect of real gas effect results in the misleading flow conductance. The adsorbed gas transport ratio and the ratio of area occupied by adsorbed gas increase along the length of nanopore. Pore proximity induces the faster gas transport and omitting pore proximity leads to the enlargement of the adsorbed gas-dominated region. Increasing taper ratio (ratio of inlet size to outlet size) and aspect ratio weakens real gas effect and lowers free gas transport. Moreover, it lowers the total transport capacity of the nanopore, and the tapered circular nanopore owns the greatest transport capacity, followed by tapered square, elliptical and rectangular nanopores. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-14T17:50:34.851535-05:
      DOI: 10.1002/aic.15678
  • Highly active and selective Co-based Fischer–Tropsch catalysts derived
           from metal–organic frameworks (MOFs)
    • Authors: Yanpeng Pei; Zhong Li, Yingwei Li
      Abstract: The design of supported Co-based Fischer–Tropsch (F–T) catalysts with suitable reducibility, dispersion, loading, and nanoparticle structure is necessary so that high catalytic activity and selectivity for C5+ hydrocarbons can be achieved. Herein, we report that pyrolyzing a Co-MOF-71 precursor can provide porous carbon-supported Co catalysts with completely reduced, well-dispersed face-centered cubic Co nanoparticles (∼10 nm in average size). The catalysts can be further tailored dimensionally by doping with Si species, and the face-centered cubic Co nanoparticles can be partially transformed into hexagonal close-packed Co via a Co2C intermediate. All the as-prepared catalysts had extremely high Co site density (>3.5 × 10−4 mol/g-cat.) because they had a high number of Co active sites and low mass. Aside from having high F–T activity and C5+ selectivity, with diesel fuels being the main constituents, they showed unprecedentedly high C5+ space time yields (up to 1.45 g/(g-cat. h)) as compared to conventional Co catalysts. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-10T18:05:37.136261-05:
      DOI: 10.1002/aic.15677
  • New Nonlinear Programming Paradigms for the Future of Process Optimization
    • Authors: Lorenz T. Biegler
      PubDate: 2017-02-08T11:10:26.299367-05:
      DOI: 10.1002/aic.15674
  • Equilibrium and Non-equilibrium Gas-Liquid Two Phase Flow in Long and
           Short Pipelines Following a Rupture
    • Authors: A. Nouri-Borujerdi; A. Shafiei Ghazani
      Abstract: The two-phase flow following the blowdown of pipeline carrying flashing liquid is numerically investigated by using thermodynamic equilibrium and non-equilibrium models. Model equations are solved numerically by the finite volume method. The values ​​of fluxes at cell boundaries are obtained by AUSM+-up. To obtain proper values for the coefficients of dissipation, both single phase liquid and two phase shock tube problems are investigated. The transient release from the pressurized pipeline is studied for two cases of long and short pipes. Comparison of the predictions against experimental data reveals non-equilibrium model performs a little better than equilibrium model in the prediction of temporal variations of pressure and void fraction of the long pipe. However, equilibrium model totally overestimates pressure and void fraction of the short pipe. The relative error of equilibrium model in the prediction of pressure variation with time exceeds 50 percent and it is 20 percent for non-equilibrium model. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-08T10:50:31.073057-05:
      DOI: 10.1002/aic.15675
  • Diffusion-limited Dissolution of Spherical Particles - a Critical
           Evaluation and Applications of Approximate Solutions
    • Authors: Xiaoling Guo; Zhi Sun, Jilt Sietsma, Muxing Guo, Yongxiang Yang
      Abstract: The analytical and numerical description of the effective dissolution kinetics of spherical particles into a solvent is often difficult in chemical and metallurgical engineering. The crucial first step is to identify the dissolution mechanisms, and subsequently, relevant kinetics parameters can be calculated. In this paper, three frequently used approximations, i.e. the invariant-field (IF) (Laplace), reverse-growth (RG), and invariant-size (IS) (stationary-interface) approximations, are systematically discussed and compared with numerical simulation results. The relative errors of the dissolution curves and total dissolution time of the three approximations to the numerical simulations are calculated. The results reveal the appropriate application ranges of the approximations for given precision levels. With further experimental validation, this research provides a methodology to properly assess dissolution kinetics and adequately estimate effective diffusion coefficients and activation energy under the experimental uncertainties. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-08T10:50:26.000016-05:
      DOI: 10.1002/aic.15676
  • Transport phenomena in eccentric cylindrical coordinates
    • Authors: P.H. Gilbert; C. Saengow, A.J. Giacomin
      Abstract: Studies in transport phenomena have been limited to a select few coordinate systems. Specifically, Cartesian, cylindrical, spherical, Dijksman toroidal, and bipolar cylindrical coordinates have been the primary focus of transport work. The lack of diverse coordinate systems, for which the equations of change have been worked out, limits the diversity of transport phenomena problem solutions. Here, we introduce eccentric cylindrical coordinates and develop the corresponding equations of change (continuity, motion, and energy). This new coordinate system is unique, distinct from bipolar cylindrical coordinates, and does not contain cylindrical coordinates as a special case. We find eccentric cylindrical coordinates to be more intuitive for solving transport problems than bipolar cylindrical coordinates. Specific applications are given, in the form of novel exact solutions, for problems important to chemical engineers, in momentum, heat and mass transfer. We complete our analysis of eccentric cylindrical coordinates by using the new equations to solve one momentum, one energy, and one mass transport problem exactly. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-07T11:20:38.217566-05:
      DOI: 10.1002/aic.15671
  • Mass Transfer Performance and Correlations for CO2 Absorption into Aqueous
           Blended of DEEA/MEA in a Random Packed Column
    • Authors: Hongxia Gao; Bin Xu, Liang Han, Xiao Luo, Zhiwu Liang
      Abstract: The mass transfer performance of CO2 absorption into blended N,N-Diethylethanolamine (DEEA)/Ethanolamine (MEA) solutions was investigated using a lab-scale absorber (H=1.28m, D=28mm) packed with Dixon ring random packing. The mass transfer coefficient KGav, the unit volume absorption rate Φ, outlet concentration of CO2 (yCO2) and the bottom temperature Tbot of CO2 in aqueous DEEA/MEA solutions were determined over the feed temperature range of 298.15K to 323.15K, lean CO2 loading of 0.15-0.31mol/mol, over a wide range of liquid flow rate of 3.90-9.75m3/m2-hr, by using inert gas flow rate of 26.11-39.17kmol/m2-hr and 6-18kPa CO2 partial pressure. The results show that liquid feed temperature, lean CO2 loading, liquid flow rate and CO2 partial pressure had significant effect on those parameters. However, the inert gas flow rate had little effect. To allow the mass transfer data to be really utilized, KGav and yout correlations for the prediction of mass transfer performance were proposed and discussed. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-07T11:20:34.85384-05:0
      DOI: 10.1002/aic.15673
  • Magnetic ionic liquid-water Janus droplets: Preparation, structure and
           morphology adjustment and magnetic manipulation
    • Authors: Peng Guo; Changfeng Zeng, Chongqing Wang, Lixiong Zhang
      Abstract: Surfactant-free magnetic ionic liquid (MIL)-water Janus microdroplets with adjustable structures and morphologies are prepared in [[strike_start]]a[[strike_end]] capillary-based microfluidic devices. Their morphologies (e.g. sizes, curvatures of the interfaces and structures from Janus to core/shell) can be adjusted in a wide range by changing the flow rate ratio of water to MIL, adding different mass fractions of PEG in water, and using soybean oil rather than liquid paraffin as the continuous phase. MIL-water-MIL ternary Janus magnetic microdroplets with adjustable symmetric and asymmetric structures are also prepared. These Janus microdroplets can be manipulated by magnetic attraction, leading to easy formation of water-MIL-water, MIL-water-oil, necklace-structured MIL-water alternative Janus droplets as well as more complex Janus droplets, such as MIL-CO2-in-water and MIL-water-water droplets. Such preparation strategy is simple and can be applied in fields like pharmaceuticals, multi-drug chemotherapies, and catalysis with expensive materials. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-06T11:15:37.352976-05:
      DOI: 10.1002/aic.15672
  • Computational fluid dynamics (CFD) based steam cracking furnace
           optimization using feedstock flow distribution
    • Authors: Yu Zhang; Pieter A. Reyniers, Carl M. Schietekat, Wenli Du, Feng Qian, Kevin M. Van Geem, Guy B. Marin
      Abstract: Nonuniform temperature fields in steam cracking furnaces caused by geometry factors such as burner positions, shadow effects and asymmetry of the reactor coil layout are detrimental for product yields and run lengths. The techniques of adjusting burner firing (zone firing) and feedstock mass flow rate (pass balancing) have been practiced industrially to mitigate these effects but could only reduce the nonuniformities between the so-called modules (a group of many coils). An extension of the pass balancing methodology is presented to further minimize the intra-module nonuniformities, i.e. variation between the coils within a module, in floor fired furnaces. Coupled furnace-reactor CFD-based simulations of an industrial ultra-selective conversion (USC) furnace were performed to evaluate four different feedstock flow distribution schemes, realizing equal values for coil outlet temperature (COT), propene/ethene mass ratio (P/E), maximum coking rate and maximum tube metal temperature (TMT) respectively over all the reactor coils. It is shown that feedstock flow distribution creates a larger operating window and extends the run length. Out of the four cases, the coking rate as criterion leads to the highest yearly production capacity for ethene and propene. Uniform maximum coking rates boost the annual production capacity of the USC furnace with a nameplate ethene capacity of 130 103 metric tons per year with 1000 metric tons for ethene and 730 metric tons for propene. For industrial application, achieving uniform maximum TMT is more practical due to its measurability by advanced laser based techniques. Most steam cracking furnaces can be retrofitted by optimizing the dimensions of venturi nozzles that regulate the feedstock flow to the coils. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-06T03:30:32.097165-05:
      DOI: 10.1002/aic.15669
  • Modeling the membrane formation of novel PVA membranes for predicting the
           composition path and their final morphology
    • Authors: Denis Bouyer; Oualid M'Barki, Céline Pochat-Bohatier, Catherine Faur, Eddy Petit, Patrick Guenoun
      Abstract: Herein, a numerical model is developed for investigating the appropriate operating conditions for obtaining porous membranes from PVA/water system. The main interest of such novel polymeric system lies in the use of water as solvent instead of classical organic solvent. In that context, the membrane formation involves three coupled and interdependent phenomena: phase inversion, crosslinking and solvent evaporation. The mass transfer model involves thermodynamic description by Flory-Huggins theory, specific diffusion formalism for dilute system and external mass transfers in free convection. Since the system evolves from monophasic to diphasic region during membrane formation, the diffusion formalisms were adjusted depending on the composition path to simulate the solvent and catalyzer evaporation. The simulations exhibit that due to mass transfers occurring concomitantly to phase inversion and crosslinking, the operating conditions (final temperature, catalyzer, initial solution thickness) must be carefully chosen to ensure the formation of a porous membrane with PVA/water system. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-06T03:25:33.721793-05:
      DOI: 10.1002/aic.15670
  • Sand Consolidation via Latex Destabilization
    • Authors: Wei Jin Gun; Alexander F. Routh, Dana Aytkhozhina, Mark Aston
      Abstract: This article investigates the use of a commercial latex dispersion for the purpose of sand consolidation in oil wells. The aim is to consolidate sand without compromising permeability and to prevent sanding during water breakthrough. This is achieved by injecting latex dispersions into a sand-pack and relying on potassium chloride flushes, or irreducible saline water in the reservoir, to destabilise the latex onto the sand surface. This forms a latex network connecting and holding the sand grains together. The strength of the consolidation in the laboratory is determined by flowing water and oil at various flowrates and investigating the amount of sand produced. The effect of different parameters, such as the amount of latex injected, the latex salinity and salinity of the irreducible water are discussed. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-04T03:15:35.720334-05:
      DOI: 10.1002/aic.15668
  • Issue information
    • Abstract: Cover illustration. Microreaction technology has matured from early devices in parallel with process intensification efforts and converged with organic chemistry into flow chemistry - the continuous small scale synthesis of fine chemical and pharmaceuticals. Advances have been made in synthesis techniques, automated reaction optimization, scaling of processes, and flexible portable manufacturing units. 10.1002/aic.15642
      PubDate: 2017-02-03T15:14:56.333204-05:
      DOI: 10.1002/aic.15467
  • Kinetic Modeling and Process Analysis for Desmodesmus sp. Lutein
    • Authors: Ehecatl Antonio del Rio-Chanona; Nur rashid Ahmed, Dongda Zhang, Yinghua Lu, Keju Jing
      Abstract: Lutein is a high-value bioproduct synthesised by microalga Desmodesmus sp. In the current study two aspects of this process are thoroughly investigated: identifying the complex effects of light intensity and nitrate concentration on biomass growth and lutein synthesis, and constructing an accurate kinetic model capable of simulating the entire bioprocess dynamic performance neither of which has been previously addressed. Three original contributions are presented here. First, it is found that completely opposite to a nitrogen-limiting culture, under nitrogen-sufficient conditions a higher lutein content is caused by a higher light intensity and lower nitrate concentration. Second, contrary to lutein content, total lutein production always increases with the increasing nitrate concentration. Third, through experimental verification, the proposed kinetic model is characterised by high accuracy and predictability, indicating its competence for future process design, control, and optimisation. Based on the model, optimal light intensities for lutein production and microalgae growth are identified. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-02T17:50:30.976958-05:
      DOI: 10.1002/aic.15667
  • Parameters Affecting the Localized Fluidization in a Particle Medium
    • Authors: Sarah E. Mena; Li-Hua Luu, Pablo Cuellar, Pierre Philippe, Jennifer Sinclair Curtis
      Abstract: The current study presents experiments for the initial stages of fluidization induced by a localized fluid injection. The process was studied by recording high-speed videos in a 2D-region far from the boundaries using Planar Laser Induced Fluorescence and Refractive Index Matching. The experimental setup allowed for several parameters to be systematically studied including particle sizes, initial bed heights, and injection port diameters. The results show that the critical flow rate required for fluidization is primarily dependent on the initial height of the granular bed. However, this dependence is not a linear relation but progressively plateaus for larger heights. Conversely, the diameter of the chimney relates only slightly to the injection port diameter and significantly more to the diameter of the particles. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-02T17:50:25.836162-05:
      DOI: 10.1002/aic.15665
  • Steam-air blown bubbling fluidized bed biomass gasification (BFBBG):
           Multi-scale models and experimental validation
    • Authors: Richard B. Bates; Whitney S. Jablonski, Daniel L. Carpenter, Christos Altantzis, Aaron Garg, John L. Barton, Ran Chen, Randall P. Field, Ahmed F. Ghoniem
      Abstract: During fluidized bed biomass gasification, complex gas-solid mixing patterns and numerous chemical and physical phenomena make identification of optimal operating conditions challenging. In this work, a parametric experimental campaign was carried out alongside the development of a coupled reactor network model (CRNM) which successfully integrates the individually validated sub-models to predict steady-state reactor performance metrics and outputs. The experiments utilized an integrated gasification system consisting of an externally-heated, bench-scale, 4-inch, 5kWth, fluidized bed steam/air blown gasifier fed with woody biomass equipped with a molecular beam mass spectrometer (MBMS) to directly measure tar species. The operating temperature (750-850 ○C) and air/fuel equivalence ratio (ER=0-0.157) were independently varied in order to isolate their effects. Elevating temperature is shown to improve the char gasification rate and reduce tar concentrations. Air strongly impacts the composition of tar, accelerating the conversion of lighter polycyclic-aromatic hydrocarbons into soot precursors, while also improving the overall carbon conversion. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-02T17:45:29.425129-05:
      DOI: 10.1002/aic.15666
  • Hierarchical monitoring of industrial processes for fault detection, fault
           grade evaluation and fault diagnosis
    • Authors: Lijia Luo; Robert J. Lovelett, Babatunde A. Ogunnaike
      Abstract: Traditional process monitoring methods cannot evaluate and grade the degree of harm that faults can cause to an industrial process. Consequently, a process could be shut down inadvertently when harmless faults occur. To overcome such problems, we propose a hierarchical process monitoring method for fault detection, fault grade evaluation and fault diagnosis. First, we propose fault grade classification principles for subdividing faults into three grades: harmless, mild and severe, according to the harm the fault can cause to the process. Second, two-level indices are constructed for fault detection and evaluation, with the first-level indices used to detect the occurrence of faults while the second-level indices are used to determine the fault grade. Finally, to identify the root cause of the fault, we propose a new online fault diagnosis method based on the square deviation magnitude. The effectiveness and advantages of the proposed methods are illustrated with an industrial case study. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-31T18:21:37.900288-05:
      DOI: 10.1002/aic.15662
  • Large eddy simulation of inertial fibre deposition mechanisms in a
           vertical downward turbulent channel flow
    • Authors: Derrick O. Njobuenwu; Michael Fairweather
      Abstract: The deposition pattern of elongated inertial fibres in a vertical downward turbulent channel flow is predicted using large eddy simulation and Lagrangian particle tracking. Three dominant fibres deposition mechanisms are observed, namely, diffusional deposition for small inertial fibres, free-flight deposition for large inertial fibres, and the interception mechanism for very elongated fibres. The fibres are found to exhibit orientation anisotropy at impact, which is strongly dependent on the fibre elongation. An increase in the fibre elongation increases the wall capture efficiency by the interception mechanism. The diffusional deposition mechanism is shown to dominate for fibres with large residence time, tres+, in the accumulation zone and small deposition velocities, vz+, while the free-flight mechanism governs deposition for fibres with small tres+ and large vz+. This study describes how particles deposit on a surface and, ultimately for many practical applications, how such deposition may promote fouling. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-31T18:21:22.185047-05:
      DOI: 10.1002/aic.15664
  • Synergetic coupling of photo and thermal energy for efficient hydrogen
           production by formic acid reforming
    • Authors: Rui Song; Bing Luo, Maochang Liu, Jiafeng Geng, Dengwei Jing, Huan Liu
      Abstract: Most photocatalytic reactions are conducted near room temperature. In this work, we explored photothermal hydrogen production in a carefully designed photo reactor with external heating. Light sources of different wavelength bands were investigated. Formic acid was used as sacrificial regent to study the photothermal hydrogen production activity. Interestingly, the photothermal reaction is not the simple sum of the photo and thermal effects but their synergetic coupling and at 90°C it is 8.1 and 4.2 times of that under photo or thermal conditions alone. With thermal excitation, the bound electrons in Pt can be excited which can easily overcome the energy barrier between Pt and LUMO of the adsorbed reactants. Activation of the substrate itself by light is also found to be crucial to trigger such photothermal reaction. It is therefore different from traditional plasma resonance induced photothermal reaction where long wavelength IR light is more preferred. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-31T18:21:05.916104-05:
      DOI: 10.1002/aic.15663
  • Conceptual Design of Ammonia-Based Energy Storage System: System Design
           and Time-Invariant Performance
    • Authors: Ganzhou Wang; Alexander Mitsos, Wolfgang Marquardt
      Abstract: Chemicals-based energy storage is promising for integrating intermittent renewables on the utility scale. High round-trip efficiency, low cost and considerable flexibility are desirable. To this end, an ammonia-based energy storage system is proposed. It utilizes a pressurized reversible solid-oxide fuel cell for power conversion, coupled with external ammonia synthesis and decomposition processes and a steam power cycle. A coupled refrigeration cycle is utilized to recycle nitrogen completely. Pure oxygen, produced as a side-product in electrochemical water splitting, is used to drive the fuel cell. A first-principle process model extended by detailed cost calculation is used for process optimization. In this work, the performance of a 100 MW system under time-invariant operation is studied. The system can achieve a round-trip efficiency as high as 72%. The lowest levelized cost of delivered energy is obtained at 0.24 $/kWh, which is comparable to that of pumped hydro and compressed air energy storage systems. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-28T03:30:36.765131-05:
      DOI: 10.1002/aic.15660
  • Modulating Morphology and Textural Properties of ZrO2 for Supported Ni
           Catalysts towards Dry Reforming of Methane
    • Authors: Weizuo Li; Zhongkui Zhao, Guiru Wang
      Abstract: This work presents a facile and efficient approach to modulate morphology and textural properties of ZrO2 through ammonium fluoride-urea assisted hydrothermal (FUAH) method with diverse parameters including molar ratio of NH4F to zirconium (nf/z), molar ratio of urea to zirconium (nu/z), hydrothermal temperature (Thydroth), and hydrothermal time (thydroth), which serve as support for supported Ni catalysts towards dry reforming of methane (DRM) to produce synthesis gas. The plausible mechanism for forming ZrO2 supports with different morphologies under diverse hydrothermal conditions was proposed. Various characterization techniques were employed to investigate the effect of preparation parameters on the morphology and textural properties of the as-synthesized ZrO2 supports, as well as to reveal the structure-performance relationship of the Ni/ZrO2 catalysts prepared by L-arginine assisted incipient wetness impregnation method towards DRM reaction. The developed supported Ni catalyst on hierarchically structured ZrO2 with pinecone shape prepared by FUAH method (Ni/ZrO2-FUAH) demonstrates higher activity and stability for DRM than that on ZrO2 prepared by traditional hydrothermal method (Ni/ZrO2-H). The higher activity of Ni/ZrO2-FUAH than Ni/ZrO2-H can be ascribed to the higher Ni dispersion, smaller Ni crystalline size, and enhanced reducibility of NiO, significantly affected by morphology of support, as well as the highercoke-resistance catalytic stability can be ascribed to smaller Ni particle size and stronger Ni-support interaction, strongly dependent on morphology and textural properties of ZrO2 supports that affected by FUAH process parameters. The outstanding catalytic performance of the developed Ni/ZrO2-FUAH catalyst allows it to be a promising candidate for synthesis gas production through DRM reaction. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-28T03:30:31.228269-05:
      DOI: 10.1002/aic.15661
  • An in Silico Evaluation of Data-Driven Optimization of Biopharmaceutical
    • Authors: Zhenyu Wang; Christos Georgakis
      Abstract: Two methodological improvements of the Design of Dynamic Experiments1 for the modeling and optimization of (semi-) batch processes are proposed. Their effectiveness is evaluated in two representative classes of biopharmaceutical processes. Firstly, we incorporate prior process knowledge in the design of the experiments. Many batch processes and, in particular, biopharmaceutical processes are usually not understood completely to enable the development of an accurate knowledge-driven model. However, partial process knowledge is often available and should not be ignored. We demonstrate here how to incorporate such knowledge. Secondly, we introduce an evolutionary modeling and optimization approach to minimize the initial number of experiments in the face of budgetary and time constraints. The proposed approach starts with the estimation of only a linear Response Surface Model, which requires the minimum number of experiments. Accounting for the model's uncertainty, the proposed approach calculates a process optimum that meets a maximum uncertainty constraint. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-27T10:40:28.143496-05:
      DOI: 10.1002/aic.15659
  • Dynamic Analysis and Open-loop Start-up of an Integrated Radiant Syngas
           Cooler and Steam Methane Reformer
    • Authors: Jaffer H. Ghouse; Dominik Seepersad, Thomas A. Adams
      Abstract: The transient performance of an integrated Radiant Syngas Cooler (RSC) of an entrained-bed gasifier and Steam Methane Reformer (SMR) is investigated. Base-case designs using either co-current or counter-current configurations are subjected to operating transients to evaluate the feasibility to transition to new steady-states. Each system, under open loop, is subjected to changes in key variables of the SMR feed on the tube side and disturbances to variables of the coal-derived syngas on the RSC side to determine the dynamics and stability of the integrated system. The results indicate that the co-current configuration is flexible to move to new operating steady-states and more safe than the counter-current configuration, although it provides less cooling and has poorer methane conversion. The variables likely to violate the design limit in the event of a disturbance are identified. A start-up procedure is also established based on industrial practices employed for entrained-bed gasifiers and methane reformers. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-25T20:11:04.052905-05:
      DOI: 10.1002/aic.15655
  • Estimation of Spatial Alumina Concentration in an Aluminum Reduction Cell
           using a Multi-Level State Observer
    • Authors: Yuchen Yao; Cheuk-Yi Cheung, Jie Bao, Maria Skyllas-Kazacos, Barry J. Welch, Sergey Akhmetov
      Abstract: In the Hall-Héroult process, spatial variations in alumina concentration are very difficult to measure and impossible to estimate from the conventionally monitored line amperage and cell voltage. This paper presents an approach to estimate in real time the alumina concentration distribution in an aluminum reduction cell based on individual anode current measurements. One of the key difficulties is that the localized mass transfer rates are unknown. To overcome this issue, a multi-level state observer is developed based on the robust extended Kalman filter. The approach utilizes a dynamic model of a reduction cell that is discretized subsequently level by level, where the estimated variables at each level are used to estimate more detailed alumina concentration spatial distribution at the next level. The proposed approach is validated in an experimental study using an industrial cell. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-25T20:05:43.188308-05:
      DOI: 10.1002/aic.15656
  • Sandwiched liquid metal membrane (SLiMM) for hydrogen purification
    • Authors: Pei-Shan Yen; Nicholas D. Deveau, Ravindra Datta
      PubDate: 2017-01-25T20:05:40.960172-05:
      DOI: 10.1002/aic.15658
  • Numerical Modelling of Adhesive Particle Mixing
    • Authors: Mohammadreza Tamadondar; Anders Rasmuson, Kyrre Thalberg, Ingela Niklasson Björn
      Abstract: The Discrete Element Method (DEM) is used to investigate adhesive particle mixing in a system includes large carrier particles and fine particle agglomerates in a Couette mixer. The simulation starts with 200 carriers and 10 agglomerates with 1000 fine particles each. During mixing, the agglomerates are broken, fractions adhere to the carriers, and there is continuous redistribution of fines between carriers. The focus is to obtain information on the quantity and quality of fine particles adhered to carriers by post-processing the simulation data. Variation in the structure of agglomerates due to shearing is studied over mixing time. Findings indicate that major fraction of fine particles are dispersed evenly onto the surface of carriers and the rest are in form of free debris. A time-dependent index is introduced to predict the degree of mixing. Finally, the adhesion force between carriers and coated layers is observed to have a peak at 1nN. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-25T20:05:26.7151-05:00
      DOI: 10.1002/aic.15654
  • Characterizations of Surfactant Synthesized from Jatropha Oil and its
           Application in Enhanced Oil Recovery
    • Authors: Sudhir Kumar; Amit Kumar, Ajay Mandal
      Abstract: Surfactants are frequently used in chemical enhanced oil recovery (EOR) as it reduces the interfacial tension (IFT) to an ultra-low value and also alter the wettability of oil-wet rock, which are important mechanisms for enhanced oil recovery. However, most of the commercial surfactants used in chemical enhanced oil recovery (EOR) are very expensive. In view of that an attempt has been made to synthesis an anionic surfactant from non-edible Jatropha oil for its application in enhanced oil recovery. Synthesized surfactant was characterized by FTIR, NMR, DLS, TGA, FESEM and EDX analysis. Thermal degradability study of the surfactant shows no significant loss till the conventional reservoir temperature. The ability of the surfactant for its use in chemical EOR has been tested by measuring its physicochemical properties, viz. reduction of surface tension, interfacial tension (IFT) and wettability alteration. The surfactant solution shows a surface tension value of 31.6 mN/m at its critical micelle concentration (CMC). An ultra-low IFT of 0.0917 mN/m is obtained at CMC of surfactant solution, which is further reduced to 0.00108 mN/m at optimum salinity. The synthesized surfactant alters the oil-wet quartz surface to water-wet which favours enhanced recovery of oil. Flooding experiments were conducted with surfactant slugs with different concentrations. Encouraging results with additional recovery more than 25% of original oil in place above the conventional water flooding have been observed. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-25T16:24:20.890554-05:
      DOI: 10.1002/aic.15651
  • Hydrogen Separation at Elevated Temperatures using Metallic Nickel Hollow
           Fiber Membranes
    • Authors: Mingming Wang; Jian Song, Yuan Li, Yuanyuan Chu, Xiaoyao Tan, Shaomin Liu
      Abstract: Nickel is a cheaper metallic material compared to palladium membranes for H2 separation. In this work, metallic Ni hollow fiber membranes were fabricated by a combined phase inversion and atmospheric sintering method. The morphology and membrane thickness of the hollow fibers was tuned by varying the spinning parameters like bore liquid flow rate and air gap distance. H2 permeation through the Ni hollow fibers with N2 as the sweep gas was measured under various operating conditions. A rigorous model considering temperature profiles was developed to fit the experimental data. The results show that the hydrogen permeation flux can be well described by using the Sieverts' equation, implying that the membrane bulk diffusion is still the rate-limiting step. The hydrogen separation rate in the Ni hollow fiber module can be improved by 4 ∼ 8% when switching the co-current flow to the countercurrent flow operation. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-20T20:40:30.705179-05:
      DOI: 10.1002/aic.15652
  • Particle migration and alignment in slot coating flows of elongated
           particle suspensions
    • Authors: I. R. Siqueira; R. B. Rebouças, M. S. Carvalho
      Abstract: We analyze slot coating flows of elongated particle suspensions and investigate particle concentration and average orientation at the coated film. Shear-induced particle migration is described by the Diffusive Flux Model, and particle orientation is given by the principal direction of the particle conformation tensor. The conformation evolution and the constitutive equation for the resulting complex liquid are adapted from classical models that describe the behavior of suspensions of cylinders and fibers and polymeric solutions of almost rigid rod-like molecules. The proposed fully coupled model is applied to slot coating flows, and is solved using the DEVSS-TG/SUPG Finite Element Method. The results show that the wet coated film is highly non-uniform. Particle concentration and orientation vary along the film thickness and are a strong function of the operating parameters of the process, such as the film thickness-to-coating gap ratio and the capillary number of the flow. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-20T20:40:28.279937-05:
      DOI: 10.1002/aic.15653
  • One-Pot Synthesis of Silver-Modified Sulfur-Tolerant Anode for SOFCs with
           an Expanded Operation Temperature Window
    • Authors: Jifa Qu; Wei Wang, Tao Yang, Yubo Chen, Zongping Shao
      Abstract: To develop solid oxide fuel cells (SOFCs) capable of operating on sulfur-containing practical fuels at intermediate temperatures, further improvement of the sulfur tolerance of a Ni+BaZr0.4Ce0.4Y0.2O3-δ (BZCY) anode is attempted through the addition of some metal modifiers (Fe, Co and Ag) by a one-pot synthesis approach. The effects of these modifiers on the electrical conductivity, morphology, sulfur tolerance and electrochemical activity of the anode are systematically studied. As a result, the cell with Ag-modified Ni+BZCY anode demonstrates highest power output when operated on 1000 ppm H2S-H2 fuel. Furthermore, the Ag-modified anode displays much better stability than Ni+BZCY with 1000 ppm H2S-H2 fuel at 600°C. These results suggest that the addition of Ag modifier into Ni+BZCY is a promising and efficient method for improving the sulfur tolerance of SOFCs. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-17T04:36:22.37746-05:0
      DOI: 10.1002/aic.15649
  • Analysis of Roll Wave Characteristics under Low Liquid Loading Two-phase
           Flow Conditions
    • Authors: Hamidreza Karami; Eduardo Pereyra, Carlos F. Torres, Cem Sarica
      Abstract: An experimental study is conducted using a 0.152-m ID facility to investigate the wave characteristics of two-phase stratified wavy flow in horizontal pipelines. The experiments are conducted under low liquid loading condition, which is very commonly observed in wet gas pipelines. The experiments are conducted with water as the liquid phase, and repeated with 51 wt% of monoethylene glycol (MEG) in the aqueous phase to analyze the effects of MEG presence on wave characteristics.The experimental range of this study covers superficial gas velocity, vSg, values of 9-23 m/s and superficial liquid velocity, vSL, values of 0.01-0.02 m/s. Similar test matrices are completed for the cases with and without MEG in the aqueous phase. A conductivity probe system is used to measure the wave characteristics at the liquid-gas interface. These characteristics include the wave celerity, frequency, amplitude, length, and liquid film thickness. The experimental oil-air wave characteristics data of Gawas et al. (2014)1 is also used for comparison purposes. The trends in the resulting wave characteristics with respect to input parameters are investigated, for oil, water, or MEG-water mixture as the liquid phase.Common predictive methods for interfacial wave celerity, including shallow water theory, Watson (1989)2, Paras et al. (1994)3, Al-Sarkhi et al. (2012)4, and Gawas et al. (2014)1 are evaluated in comparison with the experimental data. The results of the wave frequency correlation of Al-Sarkhi et al. (2011)4 are also compared with the experimental wave frequency data. Lastly, a correlation is developed to predict the relative wave amplitude, as a function of superficial gas Weber number and liquid velocity number.Most of the commonly used two-phase stratified flow models are developed with the assumption of steady-state conditions, and neglect the transient wave effects. This study provides valuable experimental results on wave characteristics of stratified wavy flow for different types of liquid phase. Moreover, a comprehensive analysis of the parameters affecting the wave characteristics of stratified wavy flow is presented. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-17T04:20:25.918723-05:
      DOI: 10.1002/aic.15650
  • Effects of Tunable Acidity and Basicity of Nb-KIT-6 Catalysts on Ethanol
           Conversion: Experiments and Kinetic Modeling
    • Authors: Hongda Zhu; Anand Ramanathan, Jian-Feng Wu, Raghunath V. Chaudhari, Bala Subramaniam
      Abstract: The relative amounts of acidic and basic sites in niobium-containing ordered mesoporous silicates (Nb-KIT-6) are tunable with metal loading. The acidity and basicity change from 0.11 to 0.34 mmol NH3-equiv./g cat. and 0.17 to 0.31 mmol CO2-equiv./g cat., respectively, as the Nb loading is increased from 1.5% to 10.9%. This work harnesses this unique feature to better understand acidity and basicity effects on ethanol conversion activity and product selectivity. It is shown that the yields of ethylene and acetaldehyde, the dominant products, are tuned with Nb loading. Catalyst characterization results and designed kinetic experiments provide evidence of acid-base pairs involved in the formation of various products. A macrosite kinetic model based on these observations and published mechanistic pathways fits the data for formation of the major products (ethylene, acetaldehyde, diethyl ether, and ethane) remarkably well. These results provide guidance for the rational design of bifunctional mesoporous materials exhibiting tunable acidity and basicity. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-17T04:15:36.486327-05:
      DOI: 10.1002/aic.15648
  • Highly efficient and reversible CO2 capture by tunable
           anion-functionalized macro-porous resins
    • Authors: Xi He; Ke Mei, Rina Dao, Jingsong Cai, Wenjun Lin, Xueqian Kong, Congmin Wang
      Abstract: Anion functionalized strategy has been proposed for the synthesis of macro-porous resins [IRA-900][An] through the neutral reaction of the basic resin [IRA-900][OH] with the corresponding donors. Combining CO2 adsorption results and FT-IR, solid-state 13C NMR characterization as well as quantum chemical calculations, chemical adsorption mechanism was verified and tunable capture of CO2 was realized. Among them, the anion functionalized resin [IRA-900][Triz] exhibits an extremely high adsorption capacity (4.02 mmol g−1 at 25°C, 0.15 bar), outperforming many other good adsorbents. Finally, we discuss the thermostability and recycling stability of [IRA-900][Triz], which shows a great potential in the industrial capture of CO2. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-17T04:15:29.723655-05:
      DOI: 10.1002/aic.15647
  • Arbitrary shaped ice particle melting under the influence of natural
    • Authors: Hemant Bansal; Petr Nikrityuk
      Abstract: This work is devoted to numerical simulations of an arbitrary shaped ice particle melting inside water under the influence of natural convection. Specifically, four different shapes of the ice particle have been studied: sphere, cylinder, cross shaped cylinder and irregular sphere with radial bumps on its surface. A 2D axisymmetric particle-resolved numerical model has been employed on a fixed grid to study the detailed melting dynamics of an ice particle. The solid-liquid interface is treated as a porous medium characterized by the permeability coefficient which is used to damp the velocity values inside the interface. The model results have been compared with an existing experimental results produced by A. Shukla et al. (Metal. Mater. Trans. B, 42(1):224–235, 2011). Very good agreement between our predictions and experimental data have been achieved. Based on the analysis of numerical simulation results, melting process is found to advance through two distinct regimes, namely, establishment of the natural convection and active melting of ice particle exhibiting substantial amount of fluidparticle interactions. A set of dimensionless parameters have been identified to distinguish between regimes. Finally, we developed a semi-empirical to predict the melting of any arbitrary shaped ice particle and validated it against the particle-resolved numerical simulation and experimental results. The comparison showed good agreement. Finally, the presented semiempirical model can be used as sub-grid model in Euler-Lagrange based numerical models to study the phase change phenomena in particulate flow systems. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-11T18:10:32.881842-05:
      DOI: 10.1002/aic.15643
  • Robust Batch-to-Batch Optimization in the Presence of Model-Plant Mismatch
           and Input Uncertainty
    • Authors: Rubin Hille; Jasdeep Mandur, Hector M. Budman
      Abstract: In model-based optimization in the presence of model-plant mismatch, the set of model parameter estimates which satisfy an identification objective may not result in an accurate prediction of the gradients of the cost-function and constraints. To ensure convergence to the optimum, the predicted gradients can be forced to match the measured gradients by adapting the model parameters. Since updating all available parameters is impractical due to estimability problems and overfitting, there is a motivation for adapting a subset of parameters for updating the predicted outputs and gradients. This paper presents an approach to select a subset of parameters based on the sensitivities of the model outputs and of the cost function and constraint gradients. Furthermore, robustness to uncertainties in initial batch conditions is introduced using a robust formulation based on polynomial chaos expansions. The improvements in convergence to the process optimum and robustness are illustrated using a fed-batch bioprocess. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-11T18:10:29.727885-05:
      DOI: 10.1002/aic.15645
  • Investigation of CO2 Removal by Immobilized Carbonic Anhydrase Enzyme in a
           Hollow-Fiber Membrane Bioreactor
    • Authors: Ion Iliuta; Maria C. Iliuta
      Abstract: Gas-liquid membrane contactors are compelling candidate bioreactors for implementing CO2 capture because of large mass transfer rates and liquid-solid interfaces, low pressure drop, low axial dispersion and mixing, modularity, simple scale-up or scale-down and operational suppleness. Binding the carbonic anhydrase (CA) enzyme on the membrane surface adds extra advantages due to the impressive large hydration turnover number and offers an attractive way for CO2 capture. This novel approach to CO2 removal by immobilized CA in a hollow-fiber membrane bioreactor (HFMB) was investigated via a multiscale steady-state model, under gas-filled and partially liquid-filled membrane pores conditions. The impact of CA loading, buffer acid-base constant and concentration, membrane wetting, uncatalyzed/catalyzed CO2 hydration in the wetted membrane zone, operating conditions and cocurrent/countercurrent flow orientation on the HFMB performance was analyzed. The results showed that this low-cost, green, and environmentally friendly technology could be an appealing alternative to CO2 capture from stationary emissions sources. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-11T18:05:32.260496-05:
      DOI: 10.1002/aic.15646
  • A Game Theoretic Framework for Petroleum Refinery Strategic Production
    • Authors: Philip Tominac; Vladimir Mahalec
      Abstract: A game theoretic framework for strategic refinery production planning is presented in which strategic planning problems are formulated as non-cooperative potential games whose solutions represent Nash equilibria. The potential game model takes the form of a nonconvex nonlinear program (NLP) and we examine an additional scenario extending this to a nonconvex mixed integer nonlinear program (MINLP). Tactical planning decisions are linked to strategic decision processes through a potential game structure derived from a Cournot oligopoly-type game in which multiple crude oil refineries supply several markets. Two scenarios are presented which illustrate the utility of the game theoretic framework in the analysis of production planning problems in competitive scenarios. Solutions to these problems are interpreted as mutual best responses yielding maximum profit in the competitive planning game. The resulting production planning decisions are rational in a game theoretic sense and are robust to deviations in competitor strategies. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-11T18:05:27.285315-05:
      DOI: 10.1002/aic.15644
  • Flow chemistry – Microreaction technology comes of age
    • Authors: Klavs F. Jensen
      PubDate: 2017-01-11T18:05:24.737609-05:
      DOI: 10.1002/aic.15642
  • A Geometric Framework for Monitoring and Fault Detection for Periodic
    • Authors: Ray Wang; Thomas F. Edgar, Michael Baldea
      Abstract: This paper focuses on data-driven monitoring and fault detection for processes subject to periodic operation. Although cyclical operation systems are relatively widespread in practice (notably in the realm of physical separations, e.g., pressure-swing adsorption and chromatography), the development of specific fault detection mechanisms has received little attention compared to the extensive efforts dedicated to continuous or batch processes. Here, we propose a novel geometric approach for process fault detection. Specifically, we develop a time-explicit multivariable representation of data collected from the process, which provides a natural framework for defining “normal” operation and the corresponding confidence regions. On this basis, we proceed with a two-step fault detection approach, based on detecting inter-cycle variations to locate a faulty cycle, and intra-cycle changes to determine the exact timing of a fault. We illustrate the theoretical developments with two simulation case studies. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-10T17:50:34.813509-05:
      DOI: 10.1002/aic.15638
  • Erratum: Why Not Try Active Learning
    • Authors: Cecilia Banzon
      Abstract: John L. Falconer. Why Not Try Active Learning? AIChE J. 2016;62:4174–4181.In this recently published article, John L. Falconer, the winner of the “2015 Warren K. Lewis Award for Chemical Engineering Education,” was inadvertently omitted. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-10T17:50:22.631981-05:
      DOI: 10.1002/aic.15639
  • Regulating the Micromixing Efficiency of a Novel Helical Tube Reactor by
           Premixing Behavior Optimization
    • Authors: Jiang-Zhou Luo; Guang-Wen Chu, Yong Luo, Moses Arowo, Bao-Chang Sun, Jian-Feng Chen
      Abstract: In this work, a novel helical tube reactor (HTR) was constructed, including a pre-mixer for adjusting the premixing behavior of reactants and a helical tube as a further mixing unit. The pre-mixer was modified to optimize the premixing behavior by using two methods, named as tangential-feeding and insertion of a helical baffle. The premixing behaviors were investigated via computational fluid dynamics (CFD) simulation. Simulation results indicated that both methods can change the fluid flow, enhance the turbulence kinetic energy, and improve the premixing performance in the pre-mixers. Based on the results of CFD simulation, it could be predicted that the micromixing efficiency of the HTR can be regulated by these methods accordingly. Then the predicated results were confirmed experimentally by a parallel competing reaction. Furthermore, the relationship between the premixing performance increasing and the corresponding micromixing efficiency increasing of the HTR was quantitatively analyzed. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-10T17:11:46.535397-05:
      DOI: 10.1002/aic.15641
  • The influence of injection velocity and relaxation time on the spreading
           of tracers in viscoelastic liquids agitated by submerged, recirculating
           jets with low reynolds numbers
    • Authors: P.K. Bhattacharjee; S.P. Kennedy, Q. Xu, Nicky Eshtiaghi, R. Parthasarathy
      Abstract: We provide experimental demonstration that the spread of tracer elements in a tank containing a viscoelastic liquid and agitated by a submerged jet pointing to the base of the tank can be influenced by the relaxation time of the liquid. We analyzed the temporal spreading of the boundary of a tracer-front in two dimensions using flow visualisation at early stages and found that for a given fluid, the evolution of the tracer-front at various injection velocities follows a universal trajectory when considered on a normalised time scale of t/νN2/κ, where t is observation time, νN is injection velocity and κ is the effective diffusivity of the tracer elements in the medium. For a different fluid, at a given vN, the trajectory scales with the relaxation time of the fluid. The importance of relaxation time to the evolution of a tracer-front is something previously unreported. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-10T17:05:39.981894-05:
      DOI: 10.1002/aic.15640
  • Molecular Mechanism for Liquid–liquid Extraction: Two-film Theory
    • Authors: Yangxu Hu; Zhiping Liu, Xigang Yuan, Xianren Zhang
      Abstract: We investigate here the molecular mechanism for liquid–liquid extraction and revisit the classical two-film theory. With equilibrium and non-equilibrium molecular dynamics simulations, we illustrate the kinetics of solute crossing the interface and in particular the structure of the interface at which two stagnant liquid films adhere. Our simulation results show that beyond the two-film theory, the interface is well structured and plays an essential role in solute transfer. We found that at the well-developed interface region the overall density profile exhibits a dip, while the solute concentration shows a significant maximum. Free energy analysis demonstrates the interfacial enrichment of solute molecules serving as a potential well for solute adsorption. Thus, different from the assumption of the two-film theory, our simulations show that there exists a resistance for solute molecules crossing the interface, which could be overcome only at high interface concentration of solute caused by interfacial enrichment. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-05T04:05:32.940094-05:
      DOI: 10.1002/aic.15636
  • Design and Construction of an Equipment for the Determination of
           Solubility of Gases in Liquids
    • Authors: Luis C.A. Garzon; Carmen M. Romero, Andres F. Suarez
      Abstract: This paper presents the design and construction of a new isochoric saturation apparatus for the determination of gas solubility in liquids based on the gas drop pressure method. The major improvement of this design is the separation between the solubility and the gas cells. With this separation, the change of pressure and temperature inside the system is minimum when the gas gets in contact with the liquid and it allows degassing the liquid in an easy way. The performance of the equipment was evaluated measuring the solubility of argon and nitrogen in pure water at (283.15, 288.15, 293.15 y 298.15) K. The gas solubility was calculated according to the Henry's law. The results obtained and the comparison with literature values show that the equipment provides an accurate and precise method for determination of gas solubility in water. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-05T04:00:35.331266-05:
      DOI: 10.1002/aic.15637
  • High performance of La-promoted Fe2O3/α-Al2O3 oxygen carrier for
           chemical looping combustion
    • Authors: Ming Tian; Chaojie Wang, Lin Li, Xiaodong Wang
      Abstract: Iron oxide supported oxygen carrier (OC) is regarded to a promising candidate for chemical looping combustion (CLC). However, phase separation between Fe2O3 and supports often occurs resulted from the severe sintering of supports during calcination, which leads to the sintering and breakage of Fe2O3 thus the decrease of redox reactivity. In this paper, La-promoted Fe2O3/α-Al2O3 were used as OCs for CLC of CH4 and for the first time found that the OC with the addition of 18 wt% La exhibited outstanding reactivity and redox stability during 50 cycles of CLC of CH4. Such a superior performance originated from the formation of LaAl12O19 hexaaluminate (La-HA) phase with not only small particle size but also excellent thermal stability at CLC conditions, which worked as a binder to prevent the phase separation thereby the sintering and breakage of active species α-Fe2O3 were avoided during reaction. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-05T03:55:27.78545-05:0
      DOI: 10.1002/aic.15634
  • Effect of the Presence of Organic Matter on Bubble Points of Oils in
    • Authors: Manas Pathak; Palash Panja, Raymond Levey, Milind Deo
      Abstract: The relative amounts of oil and gas produced in prolific plays like Eagle Ford are affected by the oil bubble point. The oil and kerogen (organic matter) are found in the same rock and the oil may remain in contact with the kerogen. Bulk experiments and molecular simulations clearly show that kerogen preferentially absorbs hydrocarbons. The absorbed oil phase remains in multi-component equilibrium with the expelled oil produced at the surface. Results from a model proposed to calculate the bubble points (at 400 K) of in-situ oils (absorbed + free) in the presence of kerogen indicate suppression of about 4150 kPa – 16350 kPa from the original value of 28025 kPa of produced Eagle Ford oil. These calculations depend on the type and level of maturity of kerogen. The prediction of accurate saturation pressures has key implications on volumes of recovery and rates of production from liquid rich shales. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-05T03:50:23.549307-05:
      DOI: 10.1002/aic.15635
  • Removal of NO from Flue Gas Using UV/S2O82- Process in A Novel
           Photochemical Impinging Stream Reactor
    • Authors: Yangxian Liu; Jun Zhang
      Abstract: A novel photochemical impinging stream reactor was developed for the first time. Removal process of NO from flue gas using sulfate radical (SO4-·) and hydroxyl radical (·OH) from UV-light activation of persulfate (UV/S2O82 advanced oxidation process) was investigated in the novel reactor. Experiments were conducted to evaluate the effects of S2O82- concentration, solution pH, UV power, solution temperature, liquid-gas ratio, flue gas flow, NO, SO2 and O2 concentrations on removal of NO. Mechanism and kinetics of NO removal were also studied. The results show that increasing UV power, solution temperature, S2O82- concentration or solution circulation rate promotes NO removal. Increasing solution pH (1.2 to 11.9), NO concentration or flue gas flow weakens NO removal. O2 concentration has no significant effect on NO removal. SO4-· and ·OH were the major active species for NO removal. Absorption rate equation and kinetic parameters of NO removal were obtained. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-03T18:05:27.998493-05:
      DOI: 10.1002/aic.15633
  • Synthesis and optimization of membrane cascade for gas separation via
           mixed-integer nonlinear programming (MINLP)
    • Authors: Alicia Aliaga-Vicente; José A. Caballero, María J. Fernández-Torres
      Abstract: Currently, membrane gas separation systems enjoy widespread acceptance in industry As multistage systems are needed to achieve high recovery and high product purity simultaneously, many such configurations are possible. These designs rely on the process engineer's experience and therefore sub-optimal configurations are often the result. This paper proposes a systematic methodology for obtaining the optimal multistage membrane flowsheet and corresponding operating conditions. The new approach is applied to cross-flow membrane modules that separate CO2 from CH4, for which the optimization of the proposed superstructure has been achieved via a MINLP model, with the gas processing cost as objective function. The novelty of this work resides in the large number of possible interconnections between each membrane module, the energy recovery from the high pressure outlet stream and allowing for non-isothermal conditions. The results presented in this work comprise the optimal flowsheet and operating conditions of two case studies. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-03T18:05:25.108554-05:
      DOI: 10.1002/aic.15631
  • Non-ionic soft materials influence on filtration resistance and cake dry
           matter content
    • Authors: Mogens Hinge; Morten Lykkegaard Christensen
      Abstract: Filtration of organic slurries is important in many industries but challenging because the hydraulic resistance is high due to gel materials in the slurries. Particles with solid polystyrene (PS) core and varying amount of poly(N-isopropylacrylamide) (PNIPAM) gel surface were synthesized. At low amount of gel, the gel deformed and partly filled the cake void increasing the resistance. This was successfully fitted using a semi-theoretical model for deformable particles. At high amount of gel, the gel deformed filling the entire cake void and the resistance was dominated by the gel. During consolidation, the primary retardation time increased three orders of magnitude with gel thickness as expected as primary consolidation were dominated by the dissipation of pore water. The secondary retardation time also increased but not as pronounced as primary retardation time. Secondary consolidation was due to local compression of the gel and therefore less dependent on gel thickness. This article is protected by copyright. All rights reserved.
      PubDate: 2017-01-03T18:05:23.361243-05:
      DOI: 10.1002/aic.15632
  • Issue information - table of contents
    • Pages: 857 - 857
      PubDate: 2017-02-03T15:15:01.480988-05:
      DOI: 10.1002/aic.15466
  • Intensified and safe ozonolysis of fatty acid methyl esters in liquid CO2
           in a continuous reactor
    • Authors: Michael D. Lundin; Andrew M. Danby, Geoffrey R. Akien, Padmesh Venkitasubramanian, Kevin J. Martin, Daryle H. Busch, Bala Subramaniam
      Abstract: We demonstrate a continuous reactor for performing the ozonolysis of fatty acid methyl esters (FAMEs) using liquid CO2 as solvent. The fast reaction kinetics allows the use of small-volume reactors to completely convert the FAMEs, forming secondary ozonides as the primary products. The short residence times also help maximize the yields of the secondary ozonides by minimizing over-oxidation and the formation of oligomeric products. The liquid CO2 medium promotes safe reactor operation by providing an essential fraction of overall reactor cooling and by diluting the vapor phase organics. We also demonstrate a continuous stirred reactor for the safe thermal decomposition of the secondary ozonides to their corresponding acids and aldehydes. Using a lumped kinetic model for the thermal decomposition of the ozonolysis products, we estimate activation energy values of 108.6±0.6 kJ mol−1 for the decomposition of secondary ozonides and 122±3 kJ mol−1 for the decomposition of the undesired oligomeric species. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-30T03:15:30.931109-05:
      DOI: 10.1002/aic.15630
  • Hydrogenation of methyl acetate to ethanol by Cu/ZnO catalyst encapsulated
           in SBA-15
    • Authors: Yue Wang; Junyu Liao, Jian Zhang, Shengping Wang, Yujun Zhao, Xinbin Ma
      Abstract: The hydrogenation of methyl acetate (MA) is one of the important key processes for synthesis of ethanol from syngas. This work reports a highly efficient Cu-ZnO/SBA-15 catalyst prepared by facile solid-state grinding method. Both copper and zinc species were encapsulated in SBA-15 in high dispersion with the presence of organic template. The mixed homogeneity and interaction between copper and zinc species was enhanced as well with the help of organic template, resulting in the formation of Cu+ species in the reduced catalysts. Moreover, TOFCu(0) linearly increased with the Cu+/Cu0 ratio, indicating that a high proportion of Cu+/Cu0 induced by ZnO should be a key prerequisite to achieve favorable hydrogenation performance. It seems that the Cu+ species originated from Cu-ZnOx species are more active than that from Cu-O-Si species in the activation of MA. These results may provide an inspiration in rational design of Cu-ZnO based catalysts for esters hydrogenation. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-30T03:15:27.651931-05:
      DOI: 10.1002/aic.15620
  • Bouncing of a bubble at a liquid-liquid interface
    • Authors: K.K. Singh; F. Gebauer, H.-J. Bart
      Abstract: Significant industrial relevance of gas-liquid-liquid flows calls for understanding of their various aspects. This study focusing on one such aspect i.e. interaction of a single bubble with a liquid-liquid interface is aimed at providing the experimental evidence of a hitherto unreported phenomenon of conditional bouncing of a bubble at the interface between two immiscible, initially quiescent liquids. Bouncing of the bubble is observed for two of the six pairs of the immiscible liquids used in the experiments. The data, obtained by conducting experiments with different pairs of the lighter and heavier liquids, bubble diameters and rise heights, suggest that a bubble crossing a liquid-liquid interface is expected to bounce when its approach velocity is less than a threshold value that depends on the interfacial tension and the viscosity of the heavier liquid. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-29T18:00:43.276962-05:
      DOI: 10.1002/aic.15625
  • Depositing Lignin on Membrane Surfaces for Simultaneously Upgraded Reverse
           Osmosis Performances: An Upscalable Route
    • Authors: Feng Zhang; Yaping Wu, Weixing Li, Weihong Xing, Yong Wang
      Abstract: Reverse osmosis (RO) have been widely used to produce clean water and there is a strong need to enhance their permeability at no sacrifice of their other performances, e.g. selectivity. We deposit low-cost biopolymer, lignin, onto the surface of RO membranes by a simple filtration method. Lignin is deposited to the membrane surface via both hydrogen bonding and π-π interaction. Lignin deposition reduces the surface roughness of the membrane and enhances its negatively charging, while the surface hydrophilicity is maintained. Surprisingly, water permeation, salt rejection, and fouling resistance of the lignin-deposited membranes are simultaneously improved. More importantly, we demonstrate that this deposition method can be easily extended to modify commercial RO membrane modules, indicating the excellent upscalability of this method. We use the lignin-deposited membranes to treat real effluents of dyeing and papermaking and they perform much better than the virgin, unmodified membranes. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-29T18:00:42.248781-05:
      DOI: 10.1002/aic.15628
  • Absorption Behaviors and Kinetic Models Analysis of Li4SiO4 under Various
           CO2 Partial Pressures
    • Authors: Zhang Qi; Peng Dong, Zhang Sai, Ye Qian, Wu Yongqiang, Ni Yanhui
      Abstract: The absorption behaviors of Li4SiO4 sorbent under various CO2 partial pressures and temperatures were investigated through numerical and experimental methods. It was found that Li4SiO4 showed poor absorption capacity at high temperatures (> 525°C) under CO2 partial pressure of 5066 Pa. This phenomenon was explained by the thermodynamic results from FactSage5.5 software. Meanwhile, a modified Jander model based on the double-shell structure of the Li4SiO4 sorbent was developed to describe the absorption kinetic behaviors of CO2 on Li4SiO4. The results showed that the modified Jander model could fit the kinetic experimental data well. Furthermore, the influence of steam on CO2 absorption was also analyzed by the modified Jander model. The results showed that the activation energy in the absorption process with steam was smaller than that without steam, which indicated that the presence of steam could promote the CO2 diffusion in product layer, therefore, improving the sorption capacity. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-29T18:00:40.081231-05:
      DOI: 10.1002/aic.15627
  • Stability of Gravitationally Unstable Double Diffusive Transient Boundary
           Layers with Variable Viscosity in Porous Media
    • Authors: Nasser Sabet; Hassan Hassanzadeh, Jalal Abedi
      Abstract: We study the double diffusive convection (DDC) in porous media through linear stability analysis (LSA) and direct numerical simulations (DNS). Unlike the previous studies that assume static solutal or thermal fields, the developed model is able to capture the transient behavior of both fields. We show that under the assumption of static field, the role of Lewis number cannot be distinguished. Under transient fields, we conclude that higher Lewis numbers result in earlier instability of the boundary layers. Moreover, the effect of viscosity contrast is explained in terms of the mobility of the boundary layer. The DNS results confirm the validity of LSA predictions. We also obtain the critical Rayleigh number and show that in the presence of viscosity contrast, it can be much smaller than the conventional limit of 4π 2. This study provides a better understanding of the transient nature of DDC in the presence of viscosity variations. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-29T18:00:35.641534-05:
      DOI: 10.1002/aic.15626
  • Direct Silanization of Polyurethane Foams for Efficient Selective
           Absorption of Oil from Water
    • Authors: Sen Xiong; Zhaoxiang Zhong, Yong Wang
      Abstract: Absorption is an effective method to collect oil spills and solvent leakages from water. However, the currently used oil absorbents are still suffering from high cost, tedious preparation, and low recyclability. In this work, we report an extremely simple and low-cost strategy to produce oil absorbents by directly coupling alkoxysilane onto the surface of polyurethane foams. Such direct silanization renders the initially amphiphilic foams a strong hydrophobicity and consequently a water-repelling and oil-absorptive functionality. The silanized foams exhibit highest absorption capacities as well as best recyclability among all polyurethane-based oil absorbents. More practically, the silanized PU foams can be used to recover crude oil spills with an absorption capacity of higher than 75 times of their own weight, and maintain 90% of the initial absorption capacity after 8 times reusage. Interestingly, we invent portable oil suckers for continuous oil absorption from water by filling vacuum cleaners with the silanized foams. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-29T18:00:26.34447-05:0
      DOI: 10.1002/aic.15629
  • Effective Particle Diameters for Simulating Fluidization of Non-spherical
           Particles: CFD-DEM Models vs. MRI Measurements
    • Authors: C. M. Boyce; A. Ozel, N. P. Rice, G. J. Rubinstein, D. J. Holland, S. Sundaresan
      Abstract: CFD-DEM simulations were conducted and compared with magnetic resonance imaging (MRI) measurements1 of gas and particle motion in a 3D cylindrical bubbling fluidized bed. Experimental particles had a kidney-bean-like shape, while particles were simulated as being spherical; to account for non-sphericity, “effective” diameters were introduced to calculate drag and void fraction, such that the void fraction at minimum fluidization (εmf) and the minimum fluidization velocity (Umf) in the simulations matched experimental values. With the use of effective diameters, similar bubbling patterns were seen in experiments and simulations, and the simulation predictions matched measurements of average gas and particle velocity in bubbling and emulsion regions low in the bed. Simulations which did not employ effective diameters were found to produce vastly different bubbling patterns when different drag laws were used. Both MRI results and CFD-DEM simulations agreed with classic analytical theory for gas flow and bubble motion in bubbling fluidized beds. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-27T18:35:21.54145-05:0
      DOI: 10.1002/aic.15623
  • Handling Multi-rate and Missing Data in Variable Duration Economic Model
           Predictive Control of Batch Processes
    • Authors: Mudassir M. Rashid; Prashant Mhaskar, Christopher L. E. Swartz
      Abstract: In the present work we consider the problem of variable duration economic model predictive control (EMPC) of batch processes subject to multi-rate and missing data. To this end, we first generalize a recently developed subspace-based model identification approach for batch processes to handle multi-rate and missing data by utilizing the incremental singular value decomposition technique. Exploiting the fact that the proposed identification approach is capable of handling inconsistent batch lengths, the resulting dynamic model is integrated into a tiered EMPC formulation that optimizes process economics (including batch duration). Simulation case studies involving application to the energy intensive electric arc furnace process demonstrate the efficacy of the proposed approach compared to a traditional trajectory tracking approach subject to limited availability of process measurements, missing data, measurement noise and constraints. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-26T19:35:29.783234-05:
      DOI: 10.1002/aic.15619
  • A Hybrid Numerical-symbolic Solving Strategy for Equation-oriented Process
           Simulation and Optimization
    • Authors: Fei Zhao; Xi Chen, Lingyu Zhu
      Abstract: The equation-oriented (EO) and sequential modular (SM) methods are two typical approaches for numerical process simulation and optimization. For a large-scale system, the EO method usually suffers from difficulties in variable initialization. The SM method, on the other hand, can suffer from slow convergence and requires experience in choosing appropriate tear variables. In this paper, a novel strategy combining numerical and symbolic approaches is proposed for solving process systems represented by polynomials. First, a digraph method is developed to identify the subset of equations that should be solved simultaneously. Then, a symbolic computation method based on Gröbner basis is proposed to reformulate the simultaneous equations as a completely sequential model with a triangular structure. Last, the reformulated model is solved sequentially without any iterative tearing process. The case studies show that the proposed strategy can significantly improve the solving efficiency and robustness for process simulation and optimization. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-26T19:35:26.419613-05:
      DOI: 10.1002/aic.15622
  • Ionic Liquids for Absorption and Separation of Gases: an Extensive
           Database and a Systematic Screening Method
    • Authors: Yongsheng Zhao; Rafiqul Gani, Raja Muhammad Afzal, Xiangping Zhang, Suojiang Zhang
      Abstract: Ionic liquids (ILs) have attracted considerable attention in both the academic and industrial communities for absorbing and separating gases. However, a data-rich and well-structured systematic database has not yet been established, and screening for highly efficient ILs meeting various requirements remains a challenging task. In this study, an extensive database of estimated Henry's law constants of twelve gases in more than ten thousand ILs at 313.15 K is established using the COSMO-RS method. Based on the database, a new systematic and efficient screening method for IL selection for the absorption and separation of gases subject to important target properties is proposed. Application of the database and the screening method is highlighted through case studies involving two important gases separation problems (CO2 from CH4 and C2H2 from C2H4). The results demonstrate the effectiveness of using the screening method together with the database to explore and screen novel ILs meeting specific requirements for the absorption and separation of gases. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-23T18:53:23.323482-05:
      DOI: 10.1002/aic.15618
  • Modeling Layered Crystal Growth at Increasing Supersaturation by
           Connecting Growth Regimes
    • Authors: Carl J. Tilbury; Michael F. Doherty
      Abstract: Mechanistic modeling facilitates rational crystallization engineering and design space screening. For an accurate model, the dominant growth mechanism operating on each face must be determined, which is highly dependent on supersaturation. Considering the case of centrosymmetric growth units, we developed and connected existing mechanistic expressions for spiral and two-dimensional-nucleation growth regimes, through application of stationary nucleation rate theory. Our approach enables calculation of crossover supersaturations and forms a framework to model the specific mechanism operating on each face under given crystallization conditions. Increasing supersaturation can change the crystal morphology; as face families switch growth mechanisms, they may grow out of the steady-state shape, or influence its aspect ratio. Application of the model to naphthalene, biphenyl, pentaerythritol and β-HMX shows the ability to capture experimentally observed examples of such supersaturation-dependent crystal habits. This methodology broadens the applicability of mechanistic crystal growth modeling to include higher-supersaturation industrial processes. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-23T18:44:49.588202-05:
      DOI: 10.1002/aic.15617
  • The Analysis of Solubility, Absorption Kinetics of CO2 Absorption into
           Aqueous 1-diethylamino-2-propanol Solution
    • Authors: Helei Liu; Min Xiao, Zhiwu Liang, Paitoon Tontiwachwuthikul
      Abstract: In this present work, the CO2 absorption performance of aqueous 1-diethylamino-2-propanol (1DEA2P) solution was studied with respect to CO2 equilibrium solubility, absorption kinetics, and absorption heat. The equilibrium solubility of CO2 in 2M 1DEA2P solution was measured over the temperature range from 298 to 333 K and CO2 partial pressure range from 8 to101 kPa. The absorption kinetics data were developed and analyzed using the base-catalyzed hydration mechanism and ANN models (RBFNN and BPNN models) with an acceptable AAD of 10% for base-catalyzed hydration mechanism, 2.6% for RBFNN model and 1.77% for BPNN model, respectively. The CO2 absorption heat of 1DEA2P was estimated to be -43.6 kJ/mol. In addition, the ion (1DEA2P, 1DEA2PH+, HCO3-, CO32-) speciation plots of the 1DEA2P-CO2-H2O system were developed in order to further understand the reaction process of 1DEA2P with CO2. Based on a comparison with conventional amines (e.g. MEA, DEA, MDEA) and alternative amines (i.e.1DMA2P and DEAB), 1DEA2P exhibited good performance with respect to CO2 equilibrium solubility, reaction kinetics, and CO2 absorption heat. Meanwhile, the overall evaluation of 1DEA2P for application in CCS in terms of absorption and desorption is presented, giving helpful information for the screening of these novel amines. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-23T18:42:05.795761-05:
      DOI: 10.1002/aic.15621
  • Full-Physics Simulations of Spray-Particle Interaction in a Bubbling
           Fluidized Bed
    • Authors: Maryam Askarishahi; Mohammad-Sadegh Salehi, Stefan Radl
      Abstract: Numerical simulations of a gas-particle-droplet system were performed using an Euler-Lagrange approach. Models accounting for (i) the interaction between droplets and particles, (ii) evaporation from the droplet spray, as well as (iii) evaporation of liquid from the surface of non-porous particles were considered. The implemented models were verified for a packed bed, as well as other standard flow configurations. The developed models were then applied for the simulation of flow, as well as heat and mass transfer in a fluidized bed with droplet injection. The relative importance of droplet evaporation vs. evaporation from the particle surface was quantified. It was proved that spray evaporation competes with droplet deposition and evaporation from the particle surface. Moreover, we show that adopting a suitable surface coverage model is vital when attempting to make accurate predictions of the particle's liquid content. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-23T18:37:02.374548-05:
      DOI: 10.1002/aic.15616
  • Dissolution of Semicrystalline Polymer Fibers: Numerical Modeling and
           Parametric Analysis
    • Authors: Mohammad Ghasemi; Abhiram Y. Singapati, Marina Tsianou, Paschalis Alexandridis
      Abstract: The solvent processing of polymers is significantly constrained by polymer chain crystallinity. A phenomenological model is developed here that captures the phenomena governing the dissolution of semicrystalline polymers, e.g., solvent penetration, transformation from crystalline to amorphous domains, specimen swelling, and polymer chain untangling. The model is validated for the case of cellulose fiber swelling and dissolution in an ionic liquid. A parametric sensitivity analysis is carried out to assess the impact of decrystallization rate constant, disentanglement rate, concentration dependence of solvent diffusivity, disentanglement threshold, and thickness of external boundary layer on the swelling and dissolution of semicrystalline polymer fibers. The rate of dissolution after attaining maximum swelling is found to be mainly controlled by the polymer chain disentanglement rate. The insights obtained from this study would facilitate the design of efficient solvent systems and processing conditions for the dissolution of semicrystalline polymers such as cellulose, polyglycolic acid, and polyesters. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-20T10:59:51.384474-05:
      DOI: 10.1002/aic.15615
  • Quantification of metal-acid balance in hydroisomerization catalysts: A
           step further towards catalyst design
    • Authors: Pedro S. F. Mendes; João M. Silva, M. Filipa Ribeiro, Pascal Duchêne, Antoine Daudin, Christophe Bouchy
      Abstract: A methodology was developed to interpret the results of n-paraffins hydroisomerization over bifunctional catalysts based on two simple kinetic models used consecutively. Firstly, a macrokinetic model was used to obtain the corresponding turnover frequency over the acid sites and the maximum of C16 isomer yield. Secondly, a dual-function model was used to correlate these catalytic descriptors to the ratio of metal to acid sites of the catalyst. To illustrate the methodology, Pt/HBEA and Pt/HUSY catalysts with different Pt loadings were evaluated. The impact of metal-acid balance on the catalytic turnover frequency and the maximal C16 isomer yield were adequately captured for the bifunctional HUSY and HBEA catalysts. Moreover, the parameters of the dual-function model revealed to be intrinsic to the catalytic properties of the zeolite under the scope. This methodology is believed to be of interest for information-driven catalyst design for the hydroisomerization of n-paraffins. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-16T02:25:36.021549-05:
      DOI: 10.1002/aic.15613
  • Mass and heat transfer behavior of oscillating helical coils in relation
           to heterogeneous reactor design
    • Authors: M. H. Abdel-Aziz; I. Nirdosh, G. H. Sedahmed
      Abstract: Rates of mass and heat transfer at vibrating helical coils were studied by the electrochemical technique with the object of using helical coils as heat exchanger/reactor for conducting liquid – solid diffusion controlled reactions. Variables studied were frequency and amplitude of vibration, tube diameter and superimposed axial flow velocity. The data for vibrating coil (batch reactor) were correlated for 59 
      PubDate: 2016-12-16T02:25:27.333646-05:
      DOI: 10.1002/aic.15614
  • Novel Method for determination of Gas Solubilities in Low Vapor Pressure
    • Authors: L.F. Zubeir; P.J.L. Lipman, N. Awwad, C. J. Peters, M.C. Kroon, J. van der Schaaf
      Abstract: A modified version of a standard device for measuring gas adsorption and desorption isotherms and surface area of adsorbents and catalysts (ASAP (Accelerated Surface Area and Porosimetry System) 2020, Micromeritics USA) is used for the first time to measure gas solubilities (i.e. CO2) in low vapor pressure liquids (i.e. the IUPAC standard ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C6mim][Tf2N])) in the Henry's law region. The solubility data are in very good agreement with the reported data in literature. Furthermore, the Henry's law constants are calculated from the solubility data and compared to the experimental data found in literature. The results from this study demonstrate that Micromeritics ASAP 2020 is a suitable apparatus for gas absorption by solvents with reduced vapor pressures. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-07T08:06:30.202143-05:
      DOI: 10.1002/aic.15603
  • Robustness of Bioprocess Feedback Control to Biodiversity
    • Authors: Francis Mairet; Olivier Bernard
      Abstract: The design of control laws for bioprocesses are generally based on simplified single-species models. Biodiversity is nonetheless inherent in any bioreactor where contamination leads to a mixture of different species or strains. Here we propose to define and study the robustness to biodiversity of bioprocess control laws: given a control law designed for one species, what happens when additional species are present? We illustrate our approach with a well used control law which regulates substrate concentration using measurement of growth activity. Depending on the properties of the additional species, the control law can lead to the required objective, but also to an undesired monospecies equilibrium point, coexistence, or even a failure point. Finally, we show that, for this case, the robustness can be improved by a saturation of the control. Robustness to biodiversity is a difficult issue which should be better understood and accounted for in the control design. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-07T08:00:50.843117-05:
      DOI: 10.1002/aic.15604
  • Game Theory Approach to Optimal Design of Shale Gas Supply Chains with
           Consideration of Economics and Life Cycle Greenhouse Gas Emissions
    • Authors: Jiyao Gao; Fengqi You
      Abstract: This paper addresses the optimal design of a non-cooperative shale gas supply chain based on a game theory approach. Instead of assuming a single stakeholder as in centralized models, we consider different stakeholders, including the upstream shale gas producer and the midstream shale gas processor. Following the Stackelberg game, the shale gas producer is identified as the leader, whose objectives include maximizing its net present value (NPV) and minimizing the life cycle greenhouse gas (GHG) emissions. The shale gas processor is identified as the follower that takes actions after the leader to maximize its own NPV. The resulting problem is a multiobjective mixed-integer bilevel linear programming problem, which cannot be solved directly using any off-the-shelf optimization solvers. Therefore, an efficient projection-based reformulation and decomposition algorithm is further presented. Based on a case study of the Marcellus shale play, the non-cooperative model not only captures the interactions between stakeholders but also provides more realistic solutions. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-07T07:55:30.971393-05:
      DOI: 10.1002/aic.15605
  • Highly Efficient Removal of Bulky Tannic Acid by Millimeter-sized
           Nitrogen-doped Mesoporous Carbon Beads
    • Authors: Yanping Chong; Ke Liu, Yu Liu, Jitong Wang, Wenming Qiao, Licheng Ling, Donghui Long, Zhishan Bai
      Abstract: Millimeter-sized nitrogen-doped mesoporous carbon beads (NMCBs) with a controllable nitrogen content are synthesized for the first time via a suspension-polymerization assisted hard templating method. In contrast to conventional activated carbons, NMCBs exhibit outstanding structural advantages, including macroscopic morphology, a developed mesoporous structure and enriched surface chemistry. When used as adsorbents for the removal of the bulky organic pollutant tannic acid, these NMCBs demonstrated fast adsorption kinetics and very high adsorption capacity. The adsorption capacity strongly depends on the nitrogen content doped into the carbon framework. At a nitrogen content of 4.1 wt%, the adsorption capacity reaches 318 mg/g. The molecular mechanics simulation and zeta potential measurements suggest that the enhanced adsorption by nitrogen doping may be due to the electrostatic attraction between the nitrogen functional groups and the phenol groups of tannic acid. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-07T07:51:20.990262-05:
      DOI: 10.1002/aic.15601
  • Integrated Adsorbent-Process Optimization for Carbon Capture and
           Concentration Using Vacuum Swing Adsorption Cycles
    • Authors: Maninder Khurana; Shamsuzzaman Farooq
      Abstract: A novel approach for integrated adsorbent and process design is proposed. The traditional PSA/VSA process optimization for chosen objectives, where operating conditions are the decision variables, and CO2 purity and recovery are constraints, is expanded to include adsorbent isotherm characteristics as additional decision variables. Two VSA cycles, namely a 4-step process1, currently known to have the lowest energy consumption for CO2 capture and concentration (CCC), and a 6-step process2, recently proven to have a wider operating window for the evacuation pressure, have been investigated in the current study. The integrated optimization results simultaneously provide the lower bound of minimum energy and upper bound of maximum productivity for CCC achievable from the two VSA processes along with the operating conditions and the corresponding isotherm shapes necessary to achieve them. It may be viewed as an enabler for adsorbent design or expedient adsorbent search by process inversion. This article is protected by copyright. All rights reserved.
      PubDate: 2016-12-07T07:51:18.441074-05:
      DOI: 10.1002/aic.15602
  • Pore-Network Modeling of Particle Retention in Porous Media
    • Authors: Hongtao Yang; Matthew T. Balhoff
      Abstract: Transport and filtration of micron and submicron particles in porous media is important in applications such as water purification, contaminants dispersion, and drilling mud invasion. Existing macroscopic models often fail to be predictive without empirical adjustments and a more fundamental approach may be required. We develop a physically-representative, 3D pore network model based on a particle tracking method to simulate particle retention and permeability impairment in polydisperse particle systems. The model includes the effect of hydraulic drag, gravity, electrostatic and van der Waals forces, as well as Brownian motion. A converging-diverging pore throat geometry is used to capture the mechanism of interception. With the analytical solution of fluid velocity within a pore throat, the trajectory of each particle is calculated explicitly. We also incorporate surface roughness and particle-surface interaction to determine particle attachment and detachment. Pore throat structure and conductivity are updated dynamically to account for the effect of deposited particles.Predictions of effluent concentration and macroscopic filtration coefficient are in good agreement with published experimental data. We find that the filtration coefficient is dependent on the relative angle between fluid flow and gravity. Particle deposition by interception is significant for large particle/grain size ratios. Brownian diffusion is the primary cause of retention at low Peclet numbers, especially for small gravity numbers. Particle size distribution is found to be a cause of hyperexponential deposition often observed in experiments. Permeability reduction was small for strong repulsive forces because particles only deposited in paths of slow velocity. This article is protected by copyright. All rights reserved.
      PubDate: 2016-11-25T17:15:46.225528-05:
      DOI: 10.1002/aic.15593
  • Monte Carlo Real Coded Genetic Algorithm (MC-RGA) for Radioactive Particle
           Tracking (RPT) experimentation
    • Authors: Ashutosh Yadav; Manojkumar Ramteke, Harish J. Pant, Shantanu Roy
      Abstract: Radioactive particle tracking (RPT) technique is a non-invasive velocimetry technique, extensively applied to study hydrodynamics of dense multiphase systems. In this technique, the position of a radioactive tracer particle, designed to mimic the phase of interest, is followed as a Lagrangian marker of point velocity. Computational limitations encountered during tracer particle position reconstruction (which is an inherently slow process) have thus far restricted the use of this versatile technique only to small-scale process vessels. Here, we present a noteworthy improvement over the classical Monte Carlo (MC) algorithm for tracer particle position reconstruction, whereby we enhance the convergence and computational speed of the algorithm using Real Coded Genetic Algorithm (RGA) optimization. This modification results in drastic reduction in computational time required for detector parameter estimation, and altogether eliminates the need for the “distance-count map,” which was earlier inherent to RPT experimentation. This article is protected by copyright. All rights reserved.
      PubDate: 2016-11-25T17:15:42.57679-05:0
      DOI: 10.1002/aic.15596
  • Prediction and Screening of Solubility of Pharmaceuticals in Single- and
           Mixed-Ionic Liquids using COSMO-SAC model
    • Authors: Bong-Seop Lee; Shiang-Tai Lin
      Abstract: In this work, we investigated the prediction of solubility (xd) of drug molecules in single- and mixed-ionic liquid (IL) solutions using the COSMO-SAC activity coefficient model. In particular, the effect of dissociation of IL on solubility is examined. The prediction accuracy is found to be 91% in xd (root-mean-square deviation in ln xd is 0.65) for a total of 442 data points with solubility ranging from 0.93 to 2.84 × 10−4 (mole fraction) and temperature ranging from 248.92 K to 488.3 K. The solubility of drug is found not sensitive to the treatment of dissociation of IL in the calculations. The method is used to determine the solubility of paracetamol in 2,624 single IL made from combination of 82 cations and 32 anions. The solubility of paracetamol can vary by 4 orders of magnitude in different ILs, indicating that this is a powerful method for screening for solvents with desired solubility power. The solubility of a drug in binary IL solution can be significantly higher or lower than those in pure IL components. For the 3,441,376 binary IL mixtures, about 8% of the mixtures exhibit higher solubility for paracetamol and 6% exhibit lower solubility. Our results indicate that mixing ILs can be a viable approach for tuning drug solubility. This article is protected by copyright. All rights reserved.
      PubDate: 2016-11-25T17:15:35.362597-05:
      DOI: 10.1002/aic.15595
  • Linear Model Predictive Control for Transport-Reaction Processes
    • Authors: Qingqing Xu; Stevan Dubljevic
      Abstract: The article deals with systematic development of linear model predictive control algorithms for linear transport-reaction models emerging from chemical engineering practice. The finite-horizon constrained optimal control problems are addressed for the systems varying from the convection dominated models described by hyperbolic PDEs to the diffusion models described by parabolic PDEs. The novelty of the design procedure lies in the fact that spatial discretization and/or any other type of spatial approximation of the process model plant is not considered and the system is completely captured with the proposed Cayley-Tustin transformation, which maps a plant model from a continuous to a discrete state space setting. The issues of optimality and constrained stabilization are addressed within the controller design setting leading to the finite constrained quadratic regulator problem, which is easily realized and is no more computationally intensive than the existing algorithms. The methodology is demonstrated for examples of hyperbolic/parabolic PDEs. This article is protected by copyright. All rights reserved.
      PubDate: 2016-11-22T07:10:40.852426-05:
      DOI: 10.1002/aic.15592
  • Modifying the inter-phase drag via solid volume fraction gradient for CFD
           simulation of fast fluidized beds
    • Authors: Mingze Su; Haibo Zhao
      Abstract: The conventional drag model in two-fluid simulation, which assumes uniform particle distribution in a computational grid, overestimates the drag force, thus failed in capturing the subgrid-scale strands and resolvable-scale clusters. This work proposed a new modification to the conventional drag model through considering the heterogeneous distribution of solid volume fraction, especially, in the inter-phase boundary (i.e., cluster boundary). The resulting drag model is a function of particle Reynolds number, solid volume fraction and the gradient of solid volume fraction. This straightforward modification is consistent with the elaborately filtered-approach-based modification method in nature. A CFD simulation for a two-dimensional riser was conducted to validate the new drag model. The outlet solid mass flux, axial and radial time-averaged voidages from the new drag model agreed well with the experimental measurements, and these results were far better than those from the conventional homogeneous drag models. This article is protected by copyright. All rights reserved.
      PubDate: 2016-11-08T04:12:46.301185-05:
      DOI: 10.1002/aic.15573
  • Engineering the outermost layers of TiO2 nanoparticles using in situ Mg
           doping in a flame aerosol reactor
    • Authors: Yanjie Hu; Hao Jiang, Yunfeng Li, Binqi Wang, Ling Zhang, Chunzhong Li, Yang Wang, Theodore Cohen, Yi Jiang, Pratim Biswas
      Pages: 870 - 880
      Abstract: Titanium dioxide nanoparticles with disordered outermost layer sturctures have significantly enhanced light absorption and photocatalytic properties and thus receiving enhanced attention in recent years. Engineering the outermost layers using in situ magnesium doping to tailor the band-edge of TiO2 nanoparticles was achieved via a flame aerosol reactor. The distribution of doped elements in nanoparticles could be controlled in a high temperature flame process, and which could be predicted by the comparison of different characteristic time scales, such as reaction time, coagulation time, and sintering time is proposed. In situ magnesium doping on the outermost layers effectively tailored the conduction band and electron structure of the TiO2 nanoparticles, and simultaneously improved the maximum photocurrent as well as the maximum photovoltage in dye-sensitized solar cells. These improvements were largely attributed to red-shifted light absorption, and rapid photoelectron injection into the conduction band. © 2016 American Institute of Chemical Engineers AIChE J, 63: 870–880, 2017
      PubDate: 2016-08-19T10:35:45.013218-05:
      DOI: 10.1002/aic.15451
  • Aerosol analysis of residual and nanoparticle fractions from spray
           pyrolysis of poorly volatile precursors
    • Authors: Juha Harra; Sonja Kujanpää, Janne Haapanen, Paxton Juuti, Jyrki M. Mäkelä, Leo Hyvärinen, Mari Honkanen
      Pages: 881 - 892
      Abstract: The quality of aerosol-produced nanopowders can be impaired by micron-sized particles formed due to non-uniform process conditions. Methods to evaluate the quality reliably and fast, preferably on-line, are important at industrial scales. Here, aerosol analysis methods are used to determine the fractions of nanoparticles and micron-sized residuals from poorly volatile precursors. This is accomplished using aerosol instruments to measure the number and mass size distributions of Liquid Flame Spray-generated alumina and silver particles produced from metal nitrates dissolved in ethanol and 2-ethylhexanoic acid (EHA). The addition of EHA had no effect on silver, whereas, 5% EHA concentration was enough to shift the alumina mass from the residuals to nanoparticles. The size-resolved aerosol analysis proved to be an effective method for determining the product quality. Moreover, the used on-line techniques alone can be used to evaluate the process output when producing nanopowders, reducing the need for tedious off-line analyses. © 2016 American Institute of Chemical Engineers AIChE J, 63: 881–892, 2017
      PubDate: 2016-08-29T10:10:26.137072-05:
      DOI: 10.1002/aic.15449
  • Novel model for the sintering of ceramics with bimodal pore size
           distributions: Application to the sintering of lime
    • Authors: Juan C. Maya; Farid Chejne, Suresh K. Bhatia
      Pages: 893 - 902
      Abstract: A mathematical model for the sintering of ceramics with bimodal pore size distributions at intermediate and final stages is developed. It considers the simultaneous effects of coarsening by surface diffusion, and densification by grain boundary diffusion and lattice diffusion. This model involves population balances for the pores in different zones determined by each porosimetry peak, and is able to predict the evolution of pore size distribution function, surface area, and porosity over time. The model is experimentally validated for the sintering of lime and it is reliable in predicting the so called “initial induction period” in sintering, which is due to a decrease in intra-aggregate porosity offset by an increase inter-aggregate porosity. In addition, a novel methodology for determination of mechanisms based on the analysis of the pore size distribution function is proposed, and with this, it was demonstrated that lattice diffusion is the controlling mechanism in the CaO sintering. © 2016 American Institute of Chemical Engineers AIChE J, 63: 893–902, 2017
      PubDate: 2016-08-25T09:16:03.635521-05:
      DOI: 10.1002/aic.15446
  • A positron emission particle tracking investigation of the scaling law
           governing free surface flows in tumbling mills
    • Authors: Indresan Govender; Max C. Richter, Aubrey N. Mainza, David N. De Klerk
      Pages: 903 - 913
      Abstract: Positron Emission Particle Tracking (PEPT) measurements are used to track the flow of d=5 mm glass beads within a rotating drum fitted with (and without) lifter bars and operated in the cascading and cataracting Froude regimes. After converting the Lagrangian trajectories of a representative radio-labeled glass bead (the tracer) into Eulerian fields under the ergodic assumption, the bed shape and kinematics are extracted for steady, fully developed flow conditions. Notwithstanding the azimuthal wall effects introduced by the lifter bars, we show a linear scaling 〈v〉∝h of the local flowing layer thickness (h) with local depth-averaged velocity 〈v〉 and a constant average shear 〈γ̇〉∼0.6gd for direct measurements spanning the entire flowing layer (not just the central region), and high Froude regimes (cascading and cataracting) not previously investigated by scaling analysis in the literature. © 2016 American Institute of Chemical Engineers AIChE J, 63: 903–913, 2017
      PubDate: 2016-08-29T10:10:34.878562-05:
      DOI: 10.1002/aic.15453
  • Particle size effect on the catalyst attrition in a lab-scale fluidized
    • Authors: Dongfang Wu; Fanghua Wu, Yongdan Li
      Pages: 914 - 920
      Abstract: Catalysts readily suffer from particle attrition in fluidized beds. In this article, a commercial fluid catalytic cracking catalyst was sieved into several particle-size intervals to investigate the size effect on particle attrition. It is shown that an exponential decay equation presents a suitable description of attrition and that catalyst attrition is dependent on particle size. Steady-state specific attrition rate decreases with increasing particle size; however, initial specific attrition rate and decay time parameter change irregularly. For comparison of attrition resistances, a long attrition test is required to reach steady-state attrition, and the steady-state specific attrition rate is recommended. It is seen that the smallest particle-size interval is the most seriously attrited, while the two largest particle-size intervals are the most attrition-resistant. Furthermore, weak interactions appear among attrition behaviors of different intervals, and a linear combination method is effective to combine all interval samples to predict the attrition of the original full-sized sample. © 2016 American Institute of Chemical Engineers AIChE J, 63: 914–920, 2017
      PubDate: 2016-08-29T09:40:29.898945-05:
      DOI: 10.1002/aic.15458
  • Scaling of continuous twin screw wet granulation
    • Authors: Juan G. Osorio; Ridade Sayin, Arjun V. Kalbag, James D. Litster, Laura Martinez-Marcos, Dimitrios A. Lamprou, Gavin W. Halbert
      Pages: 921 - 932
      Abstract: Scaling rules were developed and tested for a continuous twin screw wet granulation process using three scales (11, 16, and 24 mm barrel diameter) of twin screw granulators (TSG). The distributive feed screw configuration used produced high porosity granules (50–60%) with broad bimodal size distributions, especially in the 16 and 24 mm TSGs. Three dimensionless numbers, Froude number (Fr), liquid-to-solid ratio (LSR), and powder feed number (PFN), were identified and their effect on granule size distribution (GSD), porosity and liquid distribution tested. Granule size increased with increasing LSR as expected. However, Fr and PFN had no significant effect on d10 or d50 and only a small effect on d90. In contrast, granulator scale had a strong effect on GSD, with d90 increasing almost linearly with barrel diameter. This is consistent with breakage of large granules being a dominant mechanism and directly controlled by the geometry of the screw. © 2016 American Institute of Chemical Engineers AIChE J, 63: 921–932, 2017
      PubDate: 2016-09-14T10:05:25.079821-05:
      DOI: 10.1002/aic.15459
  • A new optimization model and a customized solution method for natural gas
           production network design and operation
    • Authors: Dan Li; Xiang Li
      Pages: 933 - 948
      Abstract: This article 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. © 2016 American Institute of Chemical Engineers AIChE J, 63: 933–948, 2017
      PubDate: 2016-08-02T10:06:01.754018-05:
      DOI: 10.1002/aic.15428
  • Error-triggered on-line model identification for model-based feedback
    • Authors: Anas Alanqar; Helen Durand, Panagiotis D. Christofides
      Pages: 949 - 966
      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 under LEMPC. © 2016 American Institute of Chemical Engineers AIChE J, 63: 949–966, 2017
      PubDate: 2016-08-03T22:25:50.568299-05:
      DOI: 10.1002/aic.15430
  • Continuous reactive crystallization of pharmaceuticals using impinging jet
    • Authors: Wen J. Liu; Cai Y. Ma, Jing J. Liu, Yang Zhang, Xue Z. Wang
      Pages: 967 - 974
      Abstract: For reactive crystallization of pharmaceuticals that show a rapid reaction rate, low solubility of active pharmaceutical ingredient and hence a large supersaturation, it was found in a recent study that a process design which integrates an impinging jet mixer and batch stirred tank produces high quality crystals. The current investigation examines if the short processing time of reactive crystallization permits the impinging jet mixer—stirred tank design to be modified to operate in a continuous mode. The new design combines an impinging jet mixer for feed introduction and reaction with a continuous stirred tank reactor (CSTR) and tubular reactor for crystal growth. A study of reactive crystallization of sodium cefuroxime (an antibiotic), using first a 1L CSTR then scaling to a 50L CSTR, found that the new design produces crystals of higher crystallinity, narrower particle size, and improved product stability, than batch crystallizers. © 2016 American Institute of Chemical Engineers AIChE J, 63: 967–974, 2017
      PubDate: 2016-08-15T09:30:28.170025-05:
      DOI: 10.1002/aic.15438
  • Novel operability-based approach for process design and intensification:
           Application to a membrane reactor for direct methane aromatization
    • Authors: Juan C. Carrasco; Fernando V. Lima
      Pages: 975 - 983
      Abstract: This article introduces a novel operability-based approach for process design and intensification of energy systems described by nonlinear models. This approach is applied to a membrane reactor (MR) for the direct methane aromatization (DMA) conversion to benzene and hydrogen. The proposed method broadens the scope of the traditional path of the operability approaches for design and control, mainly oriented to obtain the achievable output set (AOS) from the available input set, and compare the computed AOS to a desired output set. In particular, an optimization algorithm based on nonlinear programming tools is formulated for the calculation of the desired input set that is feasible considering process constraints and intensification targets. Results on the application of the operability method as a tool for process intensification show reduction of the DMA-MR footprint (≈77% reactor volume and 80% membrane area reduction) for an equivalent level of performance, when compared to the base case. This case study indicates that the novel approach can be a powerful tool for process intensification of membrane reactors and other complex chemical processes. © 2016 American Institute of Chemical Engineers AIChE J, 63: 975–983, 2017
      PubDate: 2016-08-19T10:26:07.749828-05:
      DOI: 10.1002/aic.15439
  • Thermo-hydraulic analysis of refinery heat exchangers undergoing fouling
    • Authors: E. Diaz-Bejarano; F. Coletti, S. Macchietto
      Pages: 984 - 1001
      Abstract: A complete, systematic approach is presented for the analysis and characterization of fouling and cleaning in refinery heat exchangers. Bringing together advanced thermo-hydraulic dynamic models, some new formulations, and a method for dynamic analysis of plant data, it allows: extracting significant information from the data; evaluating the fouling state of the units based on thermal measurements and pressure drops, if available; identifying the range of deposit conductivity leading to realistic pressure drops, if pressure measurements are unavailable; estimating key fouling and ageing parameters; estimating the effectiveness of cleaning and surface conditions after a clean; and predicting thermal and hydraulic performance with good accuracy for other periods/exchangers operating in similar conditions. An industrial case study demonstrates the performance prediction in seamless simulations that include partial and total cleanings for over 1000 days operation. The risks of using thermal effects alone and the significant advantages of including pressure drop measurements are highlighted. © 2016 American Institute of Chemical Engineers AIChE J, 63: 984–1001, 2017
      PubDate: 2016-08-30T10:05:29.461103-05:
      DOI: 10.1002/aic.15457
  • Synthesizing bromobutyl rubber by a microreactor system
    • Authors: Pei Xie; Kai Wang, Peijian Wang, Yang Xia, Guangsheng Luo
      Pages: 1002 - 1009
      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. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1002–1009, 2017
      PubDate: 2016-08-03T08:55:42.209376-05:
      DOI: 10.1002/aic.15431
  • A water droplet size distribution dependent modeling of hydrate formation
           in water/oil emulsion
    • Authors: Yi-Ning Lv; Chang-Yu Sun, Bei Liu, Guang-Jin Chen, Jing Gong
      Pages: 1010 - 1023
      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 focused beam reflectance measurement and particle video microscope. 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. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1010–1023, 2017
      PubDate: 2016-08-12T17:40:39.790426-05:
      DOI: 10.1002/aic.15436
  • Adsorption of iodine on hydrogen-reduced silver-exchanged mordenite:
           Experiments and modeling
    • Authors: Yue Nan; Lawrence L. Tavlarides, David W. DePaoli
      Pages: 1024 - 1035
      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 describes the data well, and the primary rate controlling mechanisms were macro-pore diffusion and silver-iodine reaction. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1024–1035, 2017
      PubDate: 2016-08-03T08:55:40.02036-05:0
      DOI: 10.1002/aic.15432
  • Experimental operation of a reactive dividing wall column and comparison
           with simulation results
    • Authors: Christoph Ehlers; Torben Egger, Georg Fieg
      Pages: 1036 - 1050
      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. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1036–1050, 2017
      PubDate: 2016-08-12T17:36:30.962135-05:
      DOI: 10.1002/aic.15435
  • Adsorptive cyclic purification process for CO2 mixtures captured from coal
           power plants
    • Authors: Yo-Han Kim; Jae-Jeong Kim, Chang-Ha Lee
      Pages: 1051 - 1063
      Abstract: CO2 capture technology combined with bulk separation and purification processes has become an attractive alternative to reduce capture costs. Furthermore, the required purity in the application for CO2 conversion and utilization is more stringent than that required from a captured CO2 mixture for geological storage. In this study, an adsorptive cyclic purification process was developed to upgrade a CO2/N2 mixture captured from greenhouse gas emission plants as a feasibility study for a second capture unit or captured CO2 purifier. To purify 90% CO2 with balance N2 as a captured gas mixture, two-bed pressure swing adsorption and pressure vacuum swing adsorption (PVSA) processes using activated carbon were experimentally and theoretically studied at adsorption pressures of 250–650 kPa and a fixed vacuum pressure of 50 kPa. CO2 with higher than 95% purity was produced with more than 89% recovery. However, a four-bed PVSA process could successfully produce CO2 with greater than 98% purity and 90% recovery. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1051–1063, 2017
      PubDate: 2016-08-15T09:25:27.651951-05:
      DOI: 10.1002/aic.15440
  • CO2 abatement in oscillating packed-bed scrubbers: Hydrodynamics and
           reaction performances for marine applications
    • Authors: Ion Iliuta; Faïçal Larachi
      Pages: 1064 - 1076
      Abstract: Gas-liquid flow dynamics and CO2-monoethanolamine absorption performances of an oscillating countercurrent packed bed were analyzed by means of a transient 3D nonisothermal two-fluid flow model with a goal to understand the behavior of scrubbing units on-board floating production, storage and offloading platforms. Gas-liquid flow deviation from axial symmetry was significant at larger vessel inclinations prompting noticeable liquid accumulation in the column lowermost area. Conversely, in static vertical and slightly inclined columns only a reduced fraction of the liquid was subject to transverse segregation. Externally-generated column oscillations brought about complex secondary flows in radial and tangential directions resulting in oscillatory patterns with amplitude and propagation frequency affected by the packed bed oscillations. CO2 abatement in inclined and asymmetrically oscillating columns suffered perceptible deviations with respect to vertical configuration while symmetrically oscillating columns gave rise to CO2 performances oscillating around the steady-state solutions of the vertical column. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1064–1076, 2017
      PubDate: 2016-08-26T13:40:29.574968-05:
      DOI: 10.1002/aic.15450
  • New development in flow-through pressure-swing frequency response method
           for mass-transfer study: Ethane in ZIF-8
    • Authors: Yu Wang; Charanjit S. Paur, Peter I. Ravikovitch
      Pages: 1077 - 1090
      Abstract: A new pressure-swing frequency response (PSFR) method has been developed to study mass transfer in adsorption systems as a function of temperature and pressure, from −70 to 180°C, and up to 7 bar. New in-phase and out-of-phase functions have been derived for the PSFR in a general way to allow information extracted from it independent of whether the system is operated in a batch volume swing or a flow-through pressure swing mode. A new mathematical model that considers distribution of diffusion rates has been introduced to account for diffusive transport in heterogeneous samples. Numerical simulation results have shown that a single rate diffusion model works well when heterogeneity can be described by a normal distribution, but not for asymmetrically bimodal distributions. As a test reference system, the transport of ethane in ZIF-8 was investigated at different pressures and temperatures using the new PSFR method. The mass transfer was found to be dominated by micropore diffusion. Diffusivity was found to be weakly dependent on pressure or loading, but quite strongly dependent on temperature. The results agree very well with our independent batch volume frequency response technique experiments. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1077–1090, 2017
      PubDate: 2016-11-24T10:50:35.838788-05:
      DOI: 10.1002/aic.15560
  • Rheology of cubic particles in a concentrated colloidal dispersion
           suspending medium
    • Authors: Colin D. Cwalina; Kelsey J. Harrison, Norman J. Wagner
      Pages: 1091 - 1101
      Abstract: The flow behavior of mixtures of micron-sized cubic particles suspended in a concentrated colloidal dispersion is investigated across a broad range of cubic particle concentrations. In the semi-dilute regime, the qualitative shape of the dynamic moduli and flow curves reflect those of the underlying colloidal dispersion medium. These curves are superimposed with the underlying colloidal dispersion using shift factors that are found to be larger than those obtained in a recent study of suspensions of non-colloidal spherical particles in the same colloidal dispersion medium. At higher concentrations of cubic particles, deviations from this shifting procedure are apparent. Scaling calculations suggest depletion interactions are responsible for the increase in the low shear viscosity and confinement of the underlying colloidal dispersion can be expected to enhance the shear thickening behavior at high shear stresses. The results of this study provide guidance for formulating suspensions through control of particle shape and mixture concentration. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1091–1101, 2017
      PubDate: 2016-08-15T13:25:26.145967-05:
      DOI: 10.1002/aic.15443
  • A comparative computational study of diesel steam reforming in a catalytic
           plate heat-exchange reactor
    • Authors: Mayur Mundhwa; Christopher P. Thurgood, Harsh Dhingra, Rajesh D. Parmar, Brant A. Peppley
      Pages: 1102 - 1113
      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., Fuel. 2010;89(6):1212–1220 for a Pt/Al2O3 and the model of Shi et al., International Journal of Hydrogen Energy. 2009;34(18):7666–7675 for a Pt/Gd-CeO2 (GDC). The kinetic models were compared for: species concentration, approach to equilibrium, gas hourly space velocity and effectiveness factor. Cocurrent flow arrangement between the reforming and the flue gas channels showed better heat transfer compared to counter-current flow arrangement. The comparison between the two kinetic models showed that different supports play 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. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1102–1113, 2017
      PubDate: 2016-08-02T09:55:32.473033-05:
      DOI: 10.1002/aic.15391
  • Particle dynamics and relaxation in bimodal suspensions during drying
           using multispeckle diffusing wave spectroscopy
    • Authors: Gwi Jeong Oh; Ji Won Hwang, Ki Wan Bong, Hyun Wook Jung, Seong Jae Lee
      Pages: 1114 - 1121
      Abstract: The motion of polystyrene particles in a bimodal suspension drop during drying was characterized via multispeckle 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. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1114–1121, 2017
      PubDate: 2016-08-12T17:36:37.644002-05:
      DOI: 10.1002/aic.15437
  • Slot coating flows of non-colloidal particle suspensions
    • Authors: Diego M. Campana; Luis D. Valdez Silva, Marcio S. Carvalho
      Pages: 1122 - 1131
      Abstract: Slot coating is used in the manufacturing of functional films, which rely on specific particle microstructure to achieve the desired performance. Final structure on the coated film is strongly dependent on the suspension flow during the deposition of the coating liquid and on the subsequent drying process. Fundamental understanding on how particles are distributed in the coated layer enables optimization of the process and quality of the produced films. The complex coating flow leads to shear-induced particle migration and non-uniform particle distribution. We study slot coating flow of non-colloidal suspensions by solving the mass and momentum conservation equations coupled with a particle transport equation using the Galerkin/Finite element method. The results show that particle distribution in the coating bead and in the coated layer is non-uniform and is strongly dependent on the imposed flow rate (wet thickness). © 2016 American Institute of Chemical Engineers AIChE J, 63: 1122–1131, 2017
      PubDate: 2016-08-15T13:20:51.180434-05:
      DOI: 10.1002/aic.15444
  • Characterization of liquid-liquid flows in horizontal pipes
    • Authors: Jing Shi; Hoi Yeung
      Pages: 1132 - 1143
      Abstract: Diverse flow regimes have been encountered in liquid-liquid flows. Some degree of consistency in the observed flow patterns is shown in reported studies, while inconsistency exits when physical properties of the two phases concerned are wide enough. An attempt was made in this study to investigate the mechanisms behind flow patterns of liquid-liquid flows in horizontal pipes. A literature review on flow patterns of liquid-liquid flows in horizontal pipes was conducted. The ratio of the gravitational force to viscous force was proposed to characterize liquid-liquid flows in horizontal pipes into gravitational force dominant, viscous force dominant, and gravitational force and viscous force comparable flow featured with different basic flow regimes. Comparisons of the proposed characterization criterion with the literature data show good agreement. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1132–1143, 2017
      PubDate: 2016-08-26T13:45:29.23281-05:0
      DOI: 10.1002/aic.15452
  • Current distribution in a rectangular flow channel manufactured by 3-D
    • Authors: Horacio A. Figueredo-Rodríguez; Rachel D. McKerracher, Carlos Ponce de León, Frank C. Walsh
      Pages: 1144 - 1151
      Abstract: The characterization and improvement of a rectangular channel electrolyte flow compartment used in an iron-air flow battery was carried out by using an arrangement of copper electrodes to measure the current density distribution employing the limiting current technique. The present work addresses the hydrodynamics and mass transport distribution in the compartment and their improvement by an improved electrolyte compartment that results in a more uniform current distribution. The current distribution was evaluated as the ratio between the local and the averaged limiting current densities during the reduction of copper ions over a range of mean linear flow velocity across the electrode surface (2–30 cm s−1). The initial compartment, showed larger differences between the minimum and maximum currents than the electrolyte compartment that resulted as part of the design process and showed a higher pressure drop at a given mean linear flow velocity. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1144–1151, 2017
      PubDate: 2016-08-30T09:55:27.011949-05:
      DOI: 10.1002/aic.15454
  • Immersed boundary method (IBM) based direct numerical simulation of
           open-cell solid foams: Hydrodynamics
    • Authors: Saurish Das; Niels G. Deen, J. A. M. Kuipers
      Pages: 1152 - 1173
      Abstract: A sharp interface implicit immersed boundary method is developed and used for direct numerical simulations of the flow through open-cell solid foams with a cellular structure. The complex solid structure of the foam is resolved on a non-boundary fitted Cartesian computational-grid. A single representative unit cell of the foam is considered in a periodic domain, and its geometry is approximated based on the structural packing of a tetrakaidecahedron. Simulations are performed for a wide range of porosities (0.638–0.962) and Reynolds numbers (0–500). Flow is enforced by applying a constant body force (momentum source) for three different flow directions along the {100}, {110}, and {111} lattice-vectors. The drag force on the foam is calculated and a non-dimensional drag/pressure drop correlation is proposed that fits the entire data set with an average deviation of 5.6%. Moreover, the accurate numerical simulations have helped to elucidate the detailed fluid-solid interaction in complex porous media. © 2016 The
      Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 63: 1152–1173, 2017
      PubDate: 2016-09-16T11:10:50.49666-05:0
      DOI: 10.1002/aic.15487
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