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ENGINEERING (1201 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 7)
3D Research     Hybrid Journal   (Followers: 19)
AAPG Bulletin     Full-text available via subscription   (Followers: 5)
AASRI Procedia     Open Access   (Followers: 14)
Abstract and Applied Analysis     Open Access   (Followers: 3)
Aceh International Journal of Science and Technology     Open Access   (Followers: 2)
ACS Nano     Full-text available via subscription   (Followers: 207)
Acta Geotechnica     Hybrid Journal   (Followers: 6)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 1)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Active and Passive Electronic Components     Open Access   (Followers: 7)
Adaptive Behavior     Hybrid Journal   (Followers: 10)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 4)
Advanced Science     Open Access   (Followers: 4)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 4)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 6)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 18)
Advances in Artificial Neural Systems     Open Access   (Followers: 3)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 14)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 9)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 18)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 7)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 28)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in OptoElectronics     Open Access   (Followers: 5)
Advances in Physics Theories and Applications     Open Access   (Followers: 13)
Advances in Polymer Science     Hybrid Journal   (Followers: 40)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 34)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aerobiologia     Hybrid Journal   (Followers: 1)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 4)
AIChE Journal     Hybrid Journal   (Followers: 28)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access  
Alexandria Engineering Journal     Open Access  
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 28)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 11)
American Journal of Engineering Education     Open Access   (Followers: 9)
American Journal of Environmental Engineering     Open Access   (Followers: 16)
American Journal of Industrial and Business Management     Open Access   (Followers: 23)
Analele Universitatii Ovidius Constanta - Seria Chimie     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Regional Science     Hybrid Journal   (Followers: 7)
Annals of Science     Hybrid Journal   (Followers: 7)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 5)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 6)
Applied Clay Science     Hybrid Journal   (Followers: 4)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 3)
Applied Nanoscience     Open Access   (Followers: 8)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 4)
Applied Sciences     Open Access   (Followers: 3)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 8)
Arkiv för Matematik     Hybrid Journal  
ASEE Prism     Full-text available via subscription   (Followers: 2)
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 1)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 7)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Current Engineering & Maths     Open Access  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 9)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 7)
Avances en Ciencias e Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 3)
Batteries     Open Access   (Followers: 3)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 24)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 3)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Motor Trade Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 2)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Survey of Business Conditions in Manufacturing : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Retail : An Executive Summary     Full-text available via subscription   (Followers: 3)
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Biofuels Engineering     Open Access  
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 8)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 16)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 31)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 8)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 1)
Biotechnology Progress     Hybrid Journal   (Followers: 40)
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription  
Boundary Value Problems     Open Access   (Followers: 1)
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 14)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 3)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers, Droit, Sciences et Technologies     Open Access  
Calphad     Hybrid Journal  
Canadian Geotechnical Journal     Full-text available via subscription   (Followers: 14)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 40)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 7)
Case Studies in Thermal Engineering     Open Access   (Followers: 4)
Catalysis Communications     Hybrid Journal   (Followers: 6)
Catalysis Letters     Hybrid Journal   (Followers: 3)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 7)
Catalysis Science and Technology     Free   (Followers: 6)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 5)
CEAS Space Journal     Hybrid Journal  
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 4)
Central European Journal of Engineering     Hybrid Journal   (Followers: 1)
CFD Letters     Open Access   (Followers: 6)
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 2)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Science Bulletin     Open Access   (Followers: 1)
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencias Holguin     Open Access   (Followers: 1)
CienciaUAT     Open Access  
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Full-text available via subscription   (Followers: 10)
CIRP Journal of Manufacturing Science and Technology     Full-text available via subscription   (Followers: 13)
City, Culture and Society     Hybrid Journal   (Followers: 20)
Clay Minerals     Full-text available via subscription   (Followers: 8)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Coal Science and Technology     Full-text available via subscription   (Followers: 4)
Coastal Engineering     Hybrid Journal   (Followers: 10)
Coastal Engineering Journal     Hybrid Journal   (Followers: 3)
Coatings     Open Access   (Followers: 2)
Cogent Engineering     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Color Research & Application     Hybrid Journal   (Followers: 1)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 13)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 23)
Composite Interfaces     Hybrid Journal   (Followers: 5)
Composite Structures     Hybrid Journal   (Followers: 242)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 175)
Composites Part B : Engineering     Hybrid Journal   (Followers: 215)
Composites Science and Technology     Hybrid Journal   (Followers: 159)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 12)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Science and Engineering     Open Access   (Followers: 17)
Computers & Geosciences     Hybrid Journal   (Followers: 25)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 5)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 4)
Computers and Geotechnics     Hybrid Journal   (Followers: 8)
Computing and Visualization in Science     Hybrid Journal   (Followers: 6)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 25)
Conciencia Tecnologica     Open Access  
Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 6)
Control and Dynamic Systems     Full-text available via subscription   (Followers: 7)
Control Engineering Practice     Hybrid Journal   (Followers: 40)
Control Theory and Informatics     Open Access   (Followers: 7)
Corrosion Science     Hybrid Journal   (Followers: 24)
CT&F Ciencia, Tecnologia y Futuro     Open Access  
CTheory     Open Access  
Current Applied Physics     Full-text available via subscription   (Followers: 4)

        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  [1616 journals]
  • Data-Driven Adaptive Nested Robust Optimization: General Modeling
           Framework and Efficient Computational Solution Algorithm for Decision
           Making under Uncertainty
    • Authors: Chao Ning; Fengqi You
      Abstract: We propose a novel data-driven adaptive robust optimization framework that leverages big data in process industries. A Bayesian nonparametric model – the Dirichlet process mixture model – is adopted and combined with a variational inference algorithm to extract the information embedded within uncertainty data. We further propose a data-driven approach for defining uncertainty set. This machine learning model is seamlessly integrated with adaptive robust optimization approach through a novel four-level optimization framework. This framework explicitly accounts for the correlation, asymmetry and multimode of uncertainty data, so it generates less conservative solutions. Additionally, the proposed framework is robust not only to parameter variations, but also to anomalous measurements. Because the resulting multi-level optimization problem cannot be solved directly by any off-the-shelf solvers, an efficient column-and-constraint generation algorithm is proposed to address the computational challenge. Two industrial applications on batch process scheduling and on process network planning are presented to demonstrate the advantages of the proposed modeling framework and effectiveness of the solution algorithm. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-22T19:01:44.651063-05:
      DOI: 10.1002/aic.15717
  • Predicting Phase Behavior in Aqueous Systems without Fitting Binary
           Parameters I: CP-PC-SAFT EOS, Aromatic Compounds
    • Authors: Polishuk Ilya; Yulia Sidik, Dong NguyenHuynh
      Abstract: This study examines an accuracy of CP-PC-SAFT attached by the 4C cross-association scheme and zero values of binary parameters in predicting the high temperature-high pressure phase behavior in aqueous systems of aromatic compounds containing one and two benzoic rings, CO2 and cis-decalin. In spite of the noteworthy complexity of these systems and the entirely predictive nature of the current approach, it correctly predicts the topology of phase behavior and typically yields the quantitatively accurate estimations of critical loci and the hydrocarbon-rich liquid phases in wide range of conditions. The available single phase volumetric data are also predicted accurately. Unfortunately, it is not a case of the water-rich phases exhibiting very small hydrocarbon concentrations. Nevertheless, the model is still capable of capturing the solubility minima characteristic for these phases around the room temperature. Predictions of the recent version of Simplified PC-SAFT proposed by Liang et al. (2014) are also discussed. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-22T19:01:10.574953-05:
      DOI: 10.1002/aic.15715
  • Brick by Brick Computation of the Gibbs Free Energy of Reaction in
           Solution Using Quantum Chemistry and COSMO-RS
    • Authors: Arnim Hellweg; Frank Eckert
      Abstract: The computational modelling of reactions is simple in theory but can be quite tricky in practice. This article aims at the purpose of providing an assistance to a proper way of describing reactions theoretically and provides rough guidelines to the computational methods involved.Reactions in liquid phase chemical equilibrium can be described theoretically in terms of the Gibbs free energy of reaction. This property can be divided into a sum of three disjunct terms, namely the gas phase reaction energy, the finite temperature contribution to the Gibbs free energy, and the Gibbs free energy of solvation. The three contributions to the Gibbs free energy of reaction can be computed separately, using different theoretico–chemical calculation methods. While some of these terms can be obtained reliably by computationally cheap methods, for others a high level of theory is required to obtain predictions of quantitative quality.In order to propose workflows which can strike the balance between accuracy and computational cost, a number of benchmarks assessing the precision of different levels of theory is given.As an illustrative example, the low-temperature hydrogenation reaction of acetaldehyde to ethanol in solvent toluene is shown. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-22T19:01:08.01424-05:0
      DOI: 10.1002/aic.15716
  • Formation process of core-shell microparticles by solute migration during
           drying of homogenous composite droplets
    • Authors: Nan Fu; Winston Duo Wu, Zhangxiong Wu, Fei Tzhung Moo, Meng Wai Woo, Cordelia Selomulya, Xiao Dong Chen
      Abstract: Particle formation process during spray drying profoundly impacts particle morphology and microstructure. This study experimentally investigated the formation of core-shell-structured microparticles by one-step drying of composite droplets made of Eudragit® RS (a polycationic acrylic polymer in nanoparticle form) and silica sol. The formation of an incipient surface shell was monitored using single droplet drying technique, and the freshly formed shell was recovered for subsequent analyses. Adding silica to RS precursor increased the shell formation time and altered the properties of the incipient shell from water-dispersible to non-dispersible. The incipient shell formed from RS/silica droplets with mass ratios of 1.5%:1.5% and 0.5%:2.5% showed ingredient segregation with a preferential accumulation of RS, similar to the shell region of dried microparticles. After shell formation, excess silica sol in the liquid phase could flow inwards, producing a dense core. This mobility-governed solute migration would be useful for constructing core-shell microparticles using other precursor systems. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-20T03:35:35.224604-05:
      DOI: 10.1002/aic.15713
  • A Superstructure-based Model for Multistream Heat Exchanger Design within
           Flowsheet Optimization
    • Authors: Harsha N. Rao; Iftekhar A. Karimi
      Abstract: Multistream heat exchangers (MHEXs) are often used in energy-intensive cryogenic processes. Modeling them within a process optimization formulation has been a challenge due to the needs to accommodate phase changes and ensure temperature approach. In this work, we present a nonlinear model for MHEXs based on a novel single-stage superstructure of two-stream exchangers. Our formulation guarantees a minimum temperature approach for all heat exchanges, estimates heat exchange areas for individual stream matches, requires no prior knowledge of phase changes, uses no Boolean variables, and enables seamless optimization of a process with multiple MHEXs. Furthermore, it facilitates dedicated constant-phase intervals that allow accurate estimation of heat transfer parameters for various stream matches. We optimize two natural gas liquefaction processes involving MHEXs, and report better solutions than the existing literature. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-20T03:35:30.355073-05:
      DOI: 10.1002/aic.15714
  • Issue information
    • Abstract: Cover illustration. Oxycombustion flowsheet from: Eason JP, Biegler LT. A trust region filter method for glass box/black box optimization. AIChE J. 2016;62(9):3124–3136. Boiler thermal image from: Dowling AW, Eason JP, Ma J, Miller DC. Coal oxycombustion power plant optimization using first principles and surrogate boiler models. Energy Procedia 2014;63:352–361. 10.1002/aic.15674
      PubDate: 2017-03-18T15:16:42.269793-05:
      DOI: 10.1002/aic.15469
  • Optimal Water Management in Macroscopic Systems under Economic Penalty
    • Authors: Jaime Garibay-Rodriguez; Vicente Rico-Ramirez, Jose M. Ponce-Ortega
      Abstract: This paper proposes an integrated optimization approach to assess the sustainability of water management strategies in a macroscopic system. Those strategies include alternative water sources, such as rainwater harvesting, and the design of distributed water treatment systems. To deal with the economic challenges inherent to wastewater treatment, an economic penalization scheme is presented as an alternative that can achieve better cost-effectiveness and pollution abatement than traditional command and control practices. The proposed approach results in an MINLP multi-period model, which has been solved through the GAMS® modeling environment. The solution of our case-study allows finding the minimum investment to meet the desired environmental goals with respect to freshwater consumption and pollution abatement. Results include the number, size and location of rainwater storage devices as well as treatment technologies, the total amount of recycled wastewater and the total amount of fines charged to the users for violation of environmental regulations. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-14T03:30:50.954051-05:
      DOI: 10.1002/aic.15712
  • Efficient removal of organic dye pollutants using covalent organic
    • Authors: Xiang Zhu; Shuhao An, Yu Liu, Jun Hu, Honglai Liu, Chengcheng Tian, Sheng Dai, Xuejing Yang, Hualin Wang, Carter W. Abney, Sheng Dai
      Abstract: A rational design and synthesis of covalent organic frameworks (COFs) displaying efficient adsorption of surrogates for common organic pollutants is demonstrated herein. Significantly, the top performing mesoporous triazine-functionalized polyimide COF exhibits superior adsorption of the small dye molecule methylene blue, achieving a maximum adsorption capacity of ∼1691 mg g−1 (∼169 wt %), surpassing the performance of all previously reported nanoporous adsorbents. The experimental results and accompanying in silico simulations suggest that both the size of the organic dye molecules and the intrinsic pore-size effect of the COF material should be taken into account simultaneously for the construction of COF-based adsorbents with efficient dyes adsorption capacities. The structural diversity of COF materials along with the understanding of the encapsulation of organic dyes on COFs holds great promise for developing novel COF adsorbents for the efficient removal of organic pollutants from wastewater. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-13T22:30:42.479794-05:
      DOI: 10.1002/aic.15699
  • Metal-free boron nitride adsorbent for ultra-deep desulfurization
    • Authors: Jun Xiong; Huaming Li, Lei Yang, Jing Luo, Yanhong Chao, Jingyu Pang, Wenshuai Zhu
      Abstract: Activated metal-free boron nitride (BN) adsorbent has been prepared by a surfactant assisted regulation strategy. By tuning the variety of surfactants (such as P123, PVP, F127), usage and reaction temperature, the adsorptive performance of activated BN was optimized. The optimized BN-P123 adsorbent displays porous structure with a high surface area about 1185 m2/g and exhibits excellent adsorptive desulfurization activity for dibenzothiophene (45.7 mg S/g adsorbent for 500 ppmw sulfur model oil), which is comparable or even superior to the state-of-the-art adsorbent. Additionally, this activated BN-P123 could realize the ultra-deep desulfurization through adsorptive process to reach the latest international standard (less than 10 ppmw). Considering the nontoxic metal-free feature and the excellent adsorption performance, the obtained activated BN-P123 may be a powerful candidate to meet the requirements of potential industrial applications. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-11T10:05:28.863551-05:
      DOI: 10.1002/aic.15695
  • On the modeling of the co2-catalyzed sintering of calcium oxide
    • Authors: Juan C. Maya; Farid Chejne, Suresh K. Bhatia
      Abstract: A comprehensive mathematical model for the CO2-catalyzed sintering of CaO is proposed. It takes into account the mechanisms of surface diffusion and grain boundary diffusion, catalyzed by CO2 chemisorption and dissolution, respectively. In addition, the model proposed here considers the change in pore size distribution during sintering, grain growth, and the densification by lattice diffusion, which is the intrinsic sintering mechanism of the CaO. Model predictions are validated using experimental data on the sintering of two CaO samples, one of them derived from pure CaCO3 and the other from limestone. It is found that impurities in limestone-derived CaO do not significantly affect the CO2 dissolution or chemisorption processes; however, they strongly increase the rate of sintering by lattice diffusion. It is also established that low temperatures and CO2 partial pressures promote the coarsening by surface diffusion, whereas high temperatures and CO2 partial pressures favor densification. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-11T09:55:32.27356-05:0
      DOI: 10.1002/aic.15696
  • 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-10T11:04:34.410192-05:
      DOI: 10.1002/aic.15660
  • Equation-Oriented Simulation and Optimization of Flowsheets with Detailed
           Spiral-Wound Multistream Heat Exchanger Models
    • Authors: Calvin Tsay; Richard C. Pattison, Michael Baldea
      Abstract: Multiple chemical processes rely on multistream heat exchangers (MHEXs) for heat integration, particularly at cryogenic temperatures. Owing to their geometric complexity, the detailed design of MHEXs is typically iterative: the exchanger geometric parameters are selected to match process specifications resulting from a flowsheet optimization step; then, the flowsheet is re-optimized with the predictions of the MHEX model, and these steps are repeated until a convergence criterion is met. This paper presents a novel framework that allows –for the first time, to our knowledge– for the simultaneous optimization of the process flowsheet and the detailed MHEX design. Focusing on spiral-wound MHEXs, we develop an equation-oriented exchanger model using industry-accepted heat transfer and pressure drop correlations for single- and multi-phase streams. We embed this model in our previously-developed pseudo-transient equation-oriented process simulation and optimization framework. We demonstrate our approach on an industrial case study, the PRICO® natural gas liquefaction process. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-10T10:34:56.806604-05:
      DOI: 10.1002/aic.15705
  • A New Qualitative Trend Analysis Algorithm based on Global Polynomial Fit
    • Authors: Bo Zhou; Hao Ye, Haifeng Zhang, Mingliang Li
      Abstract: Qualitative trend analysis (QTA) is an effective tool for process data analysis, the applications of which can be found in a variety of fields, such as process monitoring, fault diagnosis, and data mining. Reliable and accurate trend extraction of sensor data is the first and indispensable step in QTA. In this paper, a new trend extraction algorithm is developed that is based on global optimization of the polynomial fit of the process data. Different from most existing works, this newly proposed algorithm solves the trend extraction task by simultaneously and globally estimating the episode number, the boundary time points of the episode, and the fitted polynomial coefficients, which shows improved performance over other non-globally optimal trend extraction algorithms and requires less a priori knowledge than the existing globally optimal trend algorithms. The effectiveness of the algorithm is illustrated by testing on a variety of simulation and real blast furnace data. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-10T10:34:51.292253-05:
      DOI: 10.1002/aic.15706
  • 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-09T19:28:32.128503-05:
      DOI: 10.1002/aic.15671
  • Performance and kinetics of membrane and hybrid moving bed
           biofilm-membrane bioreactors treating salinity wastewater
    • Authors: Alejandro Rodríguez-Sánchez; Juan Carlos Leyva-Díaz, José Manuel Poyatos, Jesús González-López
      Abstract: A pilot-plant membrane bioreactor (MBR) and two pilot-plant hybrid moving bed biofilm reactor–membrane bioreactors (MBBR–MBRs), divided into three aerobic and one anoxic chambers, were started up for the treatment of salinity-amended urban wastewater. The MBBR–MBR systems worked with and without carriers in the anoxic zone (MBBR–MBRanox and MBBR–MBRn/anox, respectively). The systems were operated from start-up to stabilization, showing high removal of organic matter—a maximum of 90% chemical oxygen demand and 98% biochemical oxygen demand on the fifth day for MBBR–MBRn/anox in the stabilization phase—but low nitrogen elimination—30% maximum for MBBR–MBRn/anox in the stabilization phase. Biofilm attached to carriers reached less than 50 mg L−1 in the hybrid system. MBR showed faster kinetics than the two MBBR–MBR systems during start-up, but the opposite occurred during stabilization. Maximum specific growth rates for heterotrophic and autotrophic biomass were 0.0500 and 0.0059 h−1 for MBBR–MBRn/anox in the stabilization phase. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-09T11:25:27.071477-05:
      DOI: 10.1002/aic.15694
  • Data mining and control loop performance assessment: The multivariate case
    • Authors: Laya Das; Raghunathan Rengaswamy, Babji Srinivasan
      Abstract: Control loop performance assessment (CLPA) 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 CLPA 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 one of the 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 CLPA and can be applied to large scale interacting multivariate systems. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-09T11:20:45.943263-05:
      DOI: 10.1002/aic.15689
  • Multi-Rate Observer Design for Process Monitoring Using Asynchronous
           Inter-Sample Output Predictions
    • Authors: Chen Ling; Costas Kravaris
      Abstract: In this paper, the problem of observer design in linear multi-output systems with asynchronous sampling is addressed. The proposed multi-rate observer is based on a continuous-time Luenberger observer design coupled with an inter-sample predictor for each sampled measurement, which generates an estimate of the output in between consecutive measurements. The sampling times are not necessarily uniformly spaced, but there exists a maximum sampling period among all the sensors. Sufficient and explicit conditions are derived to guarantee exponential stability of the multi-rate observer. The proposed framework of multi-rate observer design is examined through a mathematical example and a gas-phase polyethylene reactor. In the latter case, the amount of active catalyst sites is estimated, with a convergence rate that is comparable to the case of continuous measurements. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-09T05:40:47.233473-05:
      DOI: 10.1002/aic.15707
  • Experimental Investigations of Non-Newtonian/Newtonian Liquid-Liquid Flows
           in Microchannels
    • Authors: Evangelia Roumpea; Maxime Chinaud, Panagiota Angeli
      Abstract: The plug flow of a non-Newtonian and a Newtonian liquid was experimentally investigated in a quartz microchannel (200 μm ID). Two aqueous glycerol solutions containing xanthan gum at 1000 ppm and 2000 ppm were the non-Newtonian fluids and 0.0046 Pa s silicone oil was the Newtonian phase forming the dispersed plugs. Two-colour Particle Image Velocimetry was used to obtain the hydrodynamic characteristics and the velocity profiles in both phases under different fluid flowrates. The experimental results revealed that the increase in xanthan gum concentration produced longer, bullet-shaped plugs and increased the thickness of the film surrounding them. From the shear rate and viscosity profiles, it was found that the polymer solution was in the shear-thinning region while the viscosity was higher in the middle of the channel compared to the region close to the wall. Circulation times in the aqueous phase increased with the concentration of xanthan gum. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-09T05:40:44.468287-05:
      DOI: 10.1002/aic.15704
  • Microscopic Insights into the Efficiency of Capacitive Mixing Process
    • Authors: Manman Ma; Shuangliang Zhao, Honglai Liu, Zhenli Xu
      PubDate: 2017-03-09T05:40:43.439484-05:
      DOI: 10.1002/aic.15708
  • Gas Solubility in Long-Chain Imidazolium-Based Ionic Liquids
    • Authors: Chengna Dai; Zhigang Lei, Biaohua Chen
      PubDate: 2017-03-09T05:40:39.835876-05:
      DOI: 10.1002/aic.15711
  • Distributed Economic Model Predictive Control for Operational Safety of
           Nonlinear Processes
    • Authors: Fahad Albalawi; Helen Durand, Panagiotis D. Christofides
      Abstract: Achieving operational safety of chemical processes while operating them in an economically-optimal manner is a matter of great importance. Our recent work integrated process safety with process control by incorporating safety-based constraints within model predictive control (MPC) design; however, the safety-based MPC was developed with a centralized architecture, with the result that computation time limitations within a sampling period may reduce the effectiveness of such a controller design for promoting process safety. To address this potential practical limitation of the safety-based control design, in this work, we propose the integration of a distributed model predictive control architecture with Lyapunov-based economic model predictive control (LEMPC) formulated with safety-based constraints. We consider both iterative and sequential distributed control architectures, and the partitioning of inputs between the various optimization problems in the distributed structure based on their impact on process operational safety. Moreover, sufficient conditions that ensure feasibility and closed-loop stability of the iterative and sequential safety distributed LEMPC designs are given. A comparison between the proposed safety distributed EMPC controllers and the safety centralized EMPC is demonstarted via a chemical process example. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-09T05:40:30.948237-05:
      DOI: 10.1002/aic.15710
  • A New Model for Correlation and Prediction of Equilibrium CO2 Solubility
           in N-methyl-4-piperidinol Solvent
    • Authors: Min Xiao; Ding Cui, Helei Liu, Paitoon Tontiwachwuthikul, Zhiwu Liang
      Abstract: In this work, the equilibrium CO2 solubility in the aqueous tertiary amine,N-methyl-4-piperidinol (MPDL) was measured over a range of temperatures, CO2 partial pressures and amine concentrations. The dissociation constant of the MPDL solution was determined as well. A new thermodynamic model was developed to predict the equilibrium CO2 solubility in the MPDL-H2O-CO2 system. This model, equipped with the correction factor (Cf), can give reasonable prediction with an average absolute deviation of 2.0%, and performs better than other models (i.e. KE model, Li-Shen model and Hu-Chakma). The second-order reaction rate constant (k2) of MPDL and the heat of CO2 absorption (-ΔHabs) into aqueous MPDL solutions were evaluated as well. Based on the comparison with some conventional amines, MPDL revealed a high equilibrium CO2 loading, reasonably fast absorption rate when compared with other tertiary amines, and a low energy requirement for regeneration. It may therefore be considered to be an alternative solvent for CO2 capture. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-09T05:35:26.9795-05:00
      DOI: 10.1002/aic.15709
  • Biodegradable and Bioreducible Poly(beta-amino ester) Nanoparticles for
           Intracellular Delivery to Treat Brain Cancer
    • Authors: Yuan Rui; Gabriella Quiñones, Jordan J. Green
      Abstract: There is an urgent need for new treatment modalities to treat aggressive brain cancers such as glioblastoma. Recent advances in genetic nanomedicine hold great promise for innovative treatment strategies. In particular, polymeric nanoparticle-mediated delivery of DNA and short interfering RNA (siRNA) has the potential of safe and specific delivery to cancer cells that can achieve therapeutic effects through novel mechanisms of action. In this Perspective, we describe challenges for nucleic acid delivery to the brain as well as polymer and nanoparticle design strategies that can be used to overcome them. We highlight our development of poly(beta-amino ester)s (PBAEs), including biodegradable polymers that self-assemble with DNA into nanoparticles and bioreducible polymers that self-assemble with siRNA, for cancer therapy. The insights discovered by investigating PBAEs can enable researchers to further enhance nucleic acid delivery for a personalized precision medicine approach to treat brain cancer. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-08T03:40:39.405433-05:
      DOI: 10.1002/aic.15698
  • 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 fluidized bed revealing excellent agreement with the reference fine grid solution. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-07T08:46:15.957647-05:
      DOI: 10.1002/aic.15684
  • 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 scanning electron microscope/energy dispersive X-ray analysis) of fresh filter and filter subjected to repeated regeneration tests. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-07T08:40:45.270806-05:
      DOI: 10.1002/aic.15688
  • Volume diffusion in purification by sublimation
    • Authors: Narendra Singh; Thomas 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-07T08:30:44.402104-05:
      DOI: 10.1002/aic.15691
  • Liquid-like wave structure on granular film from granular jet impact
    • Authors: Zhe-Hang Shi; Wei-Feng Li, Hai-Feng Liu, Fu-Chen Wang
      Abstract: Results in the literature show that a granular film appears from a dense granular jet impacting on a circular target under certain conditions (Cheng X, Varas G, Citron D, Jaeger HM, Nagel SR, Phys Rev Lett. 2007; 99(18):188001). In current study, granular jet impacts are experimentally studied using a high-speed camera, and interesting liquid-like wave structures on the granular film are observed with increasing granular jet velocities or decreasing solid fractions of granular jets. Effects of the particle diameter, the granular jet velocity, and the solid fraction of granular jet on the wave structures are investigated. The dynamic characteristics of granular wave such as the wave frequency and velocity are demonstrated and compared with the liquid jet impact. Results reveal that increasing pushing pressure enhances the gas-particle interaction inside the nozzle, which causes the granular jet instability and further gives rise to the granular wave at lower solid fractions and higher granular jet velocities. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-07T08:20:39.040666-05:
      DOI: 10.1002/aic.15693
  • 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, Agílio A. H. Pádua, Josefa García
      Abstract: Aiming at developing new absorbent/refrigerant working pairs for heat pumps, thermodynamic and transport properties of two pyridinium ionic liquids (ILs), N-ethylpyridinium bis(trifluoromethanesulfonyl)amide and N-ethylpyridinium trifluoromethanesulfonate were studied using molecular simulation and nuclear magnetic resonance techniques. The microscopic structure of the ILs 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 underpredicted, 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-07T08:12:20.641107-05:
      DOI: 10.1002/aic.15690
  • Modeling Study of Oxygen Permeation through an Electronically
           Short-Circuited YSZ-based Asymmetric Hollow Fiber Membrane
    • Authors: Yun Jin; Xiuxia Meng, Naitao Yang, Bo Meng, Jaka Sunarso, Shaomin Liu
      Abstract: Here, oxygen fluxes through an electronically short-circuited asymmetric Ag-YSZ YSZ LSM-YSZ hollow fiber prepared via a combined spinning and sintering route were tested and correlated to an explicit oxygen permeation model. The average oxygen permeation through such asymmetric hollow fiber with a 27 μm-thick YSZ dense layer reached 0.52 mL (STP) cm−2 min−1 at 1173 K. From the model results, we can obtain the characteristic thickness, the effects of the temperature, and the effect of He sweep gas flow rate to the individual step contribution. The oxygen partial pressure variation in the permeate side, the local oxygen flux, and the three different resistance distribution along the axial direction of the asymmetric hollow fiber are theoretically studied; providing guidelines to further improve the membrane performance for oxygen separation. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-07T03:50:38.886475-05:
      DOI: 10.1002/aic.15703
  • A Comparison of Efficient Uncertainty Quantification Techniques for
           Stochastic Multiscale Systems
    • Authors: Grigoriy Kimaev; Luis A. Ricardez-Sandoval
      Abstract: The aim of this paper is to compare the performance of efficient uncertainty propagation techniques (Polynomial Chaos (PCE) and Power Series (PSE) expansions) for uncertainty quantification in multiscale systems where discrete (molecular) scale is modelled without closed-form expressions. A multiscale model of thin film formation by chemical vapour deposition was used to study the effects of single parameter and multivariate uncertainty. For the single parameter uncertainty, 2nd order PSE approximations were the most accurate and computationally attractive. For the multivariate uncertainty, PSE performance deteriorated, while 2nd order PCE provided the highest accuracy when its expansion coefficients were calculated using the Least Squares method. However, comparable accuracy was achieved at half the computational cost when the coefficients were calculated using Non-Intrusive Spectral Projection (NISP). The response variables were subsequently controlled using robust optimization, and the results obtained using PCE NISP satisfied the optimization constraints more closely than other methods. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-07T03:26:18.364732-05:
      DOI: 10.1002/aic.15702
  • Mass Transfer Enhancement in Non-dispersive Solvent Extraction with
           Helical Hollow Fiber Enabling Dean Vortices
    • Authors: Qingran Kong; Youwei Cheng, Lijun Wang, Xi Li
      Abstract: In this work mass transfer enhancement of non-dispersive solvent extraction by use of helical hollow fiber membranes (HHFM) was investigated by means of experiment and model simulation. Purified terephthalic acid (PTA) wastewater treatment by extraction with p-xylene as solvent was chosen as the application case. Experiments showed that extraction efficiency of the HHFM was doubly enhanced compared with that of the straight hollow fiber. A comprehensive mathematical model of the HHFM extraction was developed in an orthogonal helical coordinate system with an analytical solution of the 3-D velocities. Model simulation revealed that Dean vortices circulate the peripheral fluid to the center, which enhances the mass transfer in the lumen side where radial diffusion is the rate determining step of the extraction. Relations of effluent impurity concentration and enhancement factor with the Graetz number and dimensionless curvature, were obtained by model simulation. Optimal parameters were selected for HHFM extraction design. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-07T03:26:17.064662-05:
      DOI: 10.1002/aic.15700
  • A novel CeO2 – xSnO2/Ce2Sn2O7 pyrochlore cycle for enhanced solar
           thermochemical water splitting
    • Authors: Chongyan Ruan; Yuan Tan, Lin Li, Junhu Wang, Xiaoyan Liu, Xiaodong Wang
      Abstract: A novel CeO2 – xSnO2/Ce2Sn2O7 pyrochlore stoichiometric redox cycle with superior H2 production capacities is identified and corroborated for two-step solar thermochemical water splitting (STWS). During the first thermal reduction step (1400°C), a reaction between CeO2 and SnO2 occurred for all the CeO2 – xSnO2 (x=0.05-0.20) solid compounds, forming thermodynamically stable Ce2Sn2O7 pyrochlore rather than metastable CeO2-δ. Consequently, substantially higher reduction extents were achieved owing to the reduction of CeIV to CeIII. Moreover, in the subsequent reoxidation with H2O (800°C), H2 production capacities increased by a factor of 3.8 as compared to the current benchmark material ceria when x=0.15, with the regeneration of CeO2 and SnO2 and the concomitant reoxidation of CeIII to CeIV. The H2O-splitting performance for CeO2 – 0.15SnO2 was reproducible over seven consecutive redox cycles, indicating the material was also robust. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-07T03:26:11.842241-05:
      DOI: 10.1002/aic.15701
  • Euler–euler anisotropic gaussian mesoscale simulation of homogeneous
           cluster-induced gas–particle turbulence
    • Authors: Bo Kong; Rodney O. Fox, 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 10 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-03T09:10:45.919574-05:
      DOI: 10.1002/aic.15686
  • Role of Free Surface on Gas-Induced Liquid Mixing in a Shallow Vessel
    • Authors: Abdul Quiyoom; S.K. Ajmani, Vivek V. Buwa
      Abstract: The present work is carried out to understand the effect of the free surface on liquid velocity distribution, dynamics and liquid phase mixing in a shallow Basic Oxygen Furnace (BOF). 3D/transient Euler-Lagrange (EL) without/with Volume-of-Fluid (VOF) simulations of dispersed gas-liquid flow in a scaled-down model of the BOF were performed. For lower H/D ratios, EL simulations performed with no-slip and free-slip boundary conditions led to oscillatory plume behaviour and higher liquid velocity regions which in turn led to smaller mixing time. In contrast, EL+VOF simulations led to reduced meandering motion of bubble plumes and lower liquid velocities resulting in higher mixing times. Interestingly, the mixing time predicted using EL+VOF approach was found to be in good agreement with the measurements. The results presented in this work show that the free surface has a significant effect on dynamics of gas-liquid flow and liquid phase mixing for shallow vessels with H/D ≤ 0.5. This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-02T18:20:32.76466-05:0
      DOI: 10.1002/aic.15697
  • 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-02T01:06:10.333024-05:
      DOI: 10.1002/aic.15682
  • 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-02T00:55:43.689402-05:
      DOI: 10.1002/aic.15687
  • In situ characterization of mixing and sedimentation dynamics in an
           impinging jet ballast tank via acoustic backscatter
    • Authors: Jaiyana Bux; Neepa Paul, Timothy N. Hunter, Jeffrey Peakall, 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-02T00:50:59.491611-05:
      DOI: 10.1002/aic.15683
  • Real gas transport in tapered noncircular nanopores of shale rocks
    • Authors: Jinze Xu; Keliu Wu, Sheng Yang, Jili Cao, Zhangxin Chen, Yi Pan, Bicheng Yan
      Abstract: A model for gas transport in tapered noncircular nanopores of shale rocks with integrating real gas effect, molecular kinetic, and transport behavior was presented. 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 transport 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-02T00:46:57.150396-05:
      DOI: 10.1002/aic.15678
  • The kinetic modeling of carbonate formation during kraft pulping of
           eucalyptus wood
    • Authors: Jing Li; Huichao Hu, Xinsheng Chai
      Abstract: This article conducted an investigation on the carbonate formation during kraft pulping (KP) process of eucalyptus under different conditions, from which a kinetic model for predicting the carbonate formation was proposed. It was also found that the time-dependent effective alkali concentration and H factor are the major parameters affecting the carbonate formation. Results showed that the proposed model could describe the carbonate formation during KP at various process conditions, and there is a good correlation (R2 = 0.923) between the measured and predicted data. According to the model, about 54% of total carbonate formation was contributed from lignin in wood. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-01T05:48:23.38815-05:0
      DOI: 10.1002/aic.15681
  • Steam-air blown bubbling fluidized bed biomass gasification (BFBBG):
           Multi-scale models and experimental validation
    • Authors: Richard B. Bates; Ahmed F. Ghoniem, Whitney S. Jablonski, Daniel L. Carpenter, Christos Altantzis, Aaron Garg, John L. Barton, Ran Chen, Randall P. Field
      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 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-in., 5 kWth, fluidized bed steam/air blown gasifier fed with woody biomass equipped with a molecular beam mass spectrometer to directly measure tar species. The operating temperature (750–850°C) and air/fuel equivalence ratio (ER = 0–0.157) were independently varied 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-01T05:35:54.148406-05:
      DOI: 10.1002/aic.15666
  • The kinetics of polyurethane structural foam formation: Foaming and
    • Authors: Rekha R. Rao; Lisa A. Mondy, Kevin N. Long, Mathew C. Celina, Nicholas Wyatt, Christine C. Roberts, Melissa M. Soehnel, Victor E. Brunini
      Abstract: Kinetic models have been developed 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, although 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 articles. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-03-01T05:30:29.476213-05:
      DOI: 10.1002/aic.15680
  • Column absorption for reproducible cyclic separation in small scale
           ammonia synthesis
    • Authors: Kevin Wagner; Mahdi Malmali, Collin Smith, Alon McCormick, E. L. Cussler, Ming Zhu, Nicholas C. A. Seaton
      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 min; 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-28T12:15:33.342838-05:
      DOI: 10.1002/aic.15685
  • 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 using 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-28T12:15:28.850174-05:
      DOI: 10.1002/aic.15679
  • 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% and it is 20% for non-equilibrium model. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-25T07:35:29.004995-05:
      DOI: 10.1002/aic.15675
  • Highly active and selective Co-based Fischer–Tropsch catalysts derived
           from metal–organic frameworks
    • 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-metal–organic framework-71 precursor can provide porous carbon-supported Co catalysts with completely reduced, well-dispersed face-centered cubic (FCC) Co nanoparticles (∼10 nm in average size). The catalysts can be further tailored dimensionally by doping with Si species, and the FCC 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-25T07:25:28.726803-05:
      DOI: 10.1002/aic.15677
  • Sandwiched liquid metal membrane (SLiMM) for hydrogen purification
    • Authors: Pei-Shan Yen; Nicholas D. Deveau, Ravindra Datta
      Abstract: Palladium-based membranes are currently the most advanced membranes for hydrogen separation and are on the verge of practical application. However, the search for alternative membranes continues in an effort to lower their cost and susceptibility to poisons. Here for the first time we report a novel sandwiched liquid metal membrane (SLiMM) for hydrogen separation. Permeation experiments indicate that the Ga/SiC SLiMM has a permeability of 2.75 ×10−7 mol/ms⋅Pa0.5 at 500°C, which is 35 time higher than that for Pd under similar conditions. This promises a potential for application of SliMM in hydrogen purification. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-25T07:20:30.947539-05:
      DOI: 10.1002/aic.15658
  • Modularization Strategy for Syngas Generation in Chemical Looping Methane
           Reforming Systems with CO2 as Feedstock
    • Authors: Mandar Kathe; Charles Fryer, Peter Sandvik, Fanhe Kong, Yitao Zhang, Abbey Empfield, L.-S. Fan
      Abstract: This study considers a CO2 feedstock in conventional methane reforming processes and metal oxide lattice oxygen based chemical looping reforming. Lattice oxygen from iron-titanium composite metal oxide provides the most efficient co-utilization of CO2 with CH4. A modularization chemical looping strategy is developed to further improve process efficiencies using a thermodynamic rationale. Modularization leverages the ability of two or more reactors operating in parallel to produce a higher quality syngas than a single reactor operating alone while offering a direct solution to scale up of multiple parallel reactor processes. Experiments conducted validate the thermodynamic simulation results. Simulation and experimental results ascertain that a cocurrent moving bed in a modularization system can operate under CO2 neutral or negative conditions. The results for a modularization process system for 7,950 m3 per day (50,000 barrels per day) of liquid fuel indicate a ∼23% reduction of natural gas usage over baseline-case. This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-24T03:30:32.123598-05:
      DOI: 10.1002/aic.15692
  • New nonlinear programming paradigms for the future of process optimization
    • Authors: Lorenz T. Biegler
      PubDate: 2017-02-22T14:05:39.228194-05:
      DOI: 10.1002/aic.15674
  • 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 = 1.28 m, D = 28 mm) 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 298.15–323.15 K, lean CO2 loading of 0.15–0.31 mol/mol, over a wide range of liquid flow rate of 3.90–9.75 m3/m2-h, by using inert gas flow rate of 26.11–39.17 kmol/m2-h and 6–18 kPa 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-22T09:40:27.040091-05:
      DOI: 10.1002/aic.15673
  • Diffusion-limited dissolution of spherical particles: A critical
           evaluation and applications of approximate solutions
    • Authors: Xiaoling Guo; Jilt Sietsma, Yongxiang Yang, Zhi Sun, Muxing Guo
      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 article, 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-22T09:35:49.549336-05:
      DOI: 10.1002/aic.15676
  • Estimation of spatial alumina concentration in an aluminum reduction cell
           using a multilevel 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 article 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 multilevel 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-21T14:41:41.791104-05:
      DOI: 10.1002/aic.15656
  • Computational fluid dynamics-based steam cracking furnace optimization
           using feedstock flow distribution
    • Authors: Yu Zhang; Pieter A. Reyniers, Carl M. Schietekat, Kevin M. Van Geem, Guy B. Marin, Wenli Du, Feng Qian
      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, that is, variation between the coils within a module, in floor fired furnaces. Coupled furnace-reactor computational fluid dynamics-based simulations of an industrial ultraselective conversion (USC) furnace were performed to evaluate four different feedstock flow distribution schemes, realizing equal values for coil outlet temperature, propene/ethene mass ratio, 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-18T15:45:35.518555-05:
      DOI: 10.1002/aic.15669
  • 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 synthesized 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 characterized by high accuracy and predictability, indicating its competence for future process design, control, and optimization. Based on the model, optimal light intensities for lutein production and microalgae growth are identified. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-15T09:20:29.28594-05:0
      DOI: 10.1002/aic.15667
  • 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 destabilize 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 flow rates 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-15T09:15:31.948448-05:
      DOI: 10.1002/aic.15668
  • 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-13T12:20:33.534537-05:
      DOI: 10.1002/aic.15670
  • Parameters affecting the localized fluidization in a particle medium
    • Authors: Sarah E. Mena; Li-Hua Luu, Pablo Cuéllar, 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 2-D-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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-10T08:36:02.620545-05:
      DOI: 10.1002/aic.15665
  • An in silico evaluation of data-driven optimization of biopharmaceutical
    • Authors: Zhenyu Wang; Christos Georgakis
      Abstract: Two methodological improvements of the design of dynamic experiments (C. Georgakis, Ind Eng Chem Res. 2013) for the modeling and optimization of (semi-) batch processes are proposed. Their effectiveness is evaluated in two representative classes of biopharmaceutical processes. First, 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. Second, 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-10T08:35:51.475635-05:
      DOI: 10.1002/aic.15659
  • Modulating morphology and textural properties of ZrO2 for supported Ni
           catalysts toward 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 toward 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 toward 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 higher coke-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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-09T11:05:43.443821-05:
      DOI: 10.1002/aic.15661
  • 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-09T11:01:03.158302-05:
      DOI: 10.1002/aic.15662
  • 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 lowest unoccupied molecular orbital 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-09T11:00:38.519548-05:
      DOI: 10.1002/aic.15663
  • 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, conversely, can suffer from slow convergence and requires experience in choosing appropriate tear variables. In this article, 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. © 2016 American Institute of Chemical Engineers AIChE J, 2016
      PubDate: 2017-02-09T01:24:17.985383-05:
      DOI: 10.1002/aic.15622
  • Large eddy simulation of inertial fiber deposition mechanisms in a
           vertical downward turbulent channel flow
    • Authors: Derrick O. Njobuenwu; Michael Fairweather
      Abstract: The deposition pattern of elongated inertial fibers in a vertical downward turbulent channel flow is predicted using large eddy simulation and Lagrangian particle tracking. Three dominant fibers deposition mechanisms are observed, namely, diffusional deposition for small inertial fibers, free-flight deposition for large inertial fibers, and the interception mechanism for very elongated fibers. The fibers are found to exhibit orientation anisotropy at impact, which is strongly dependent on the fiber elongation. An increase in the fiber elongation increases the wall capture efficiency by the interception mechanism. The diffusional deposition mechanism is shown to dominate for fibers with large residence time, tres+, in the accumulation zone and small deposition velocities, vz+, while the free-flight mechanism governs deposition for fibers 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-08T22:05:45.719681-05:
      DOI: 10.1002/aic.15664
  • 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. © 2016 American Institute of Chemical Engineers AIChE J, 2016
      PubDate: 2017-02-08T10:35:33.190333-05:
      DOI: 10.1002/aic.15618
  • 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, for example, 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 performed 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. © 2016 American Institute of Chemical Engineers AIChE J, 2016
      PubDate: 2017-02-06T13:05:33.785704-05:
      DOI: 10.1002/aic.15615
  • 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. © 2016 American Institute of Chemical Engineers AIChE J, 2016
      PubDate: 2017-02-06T13:00:34.744687-05:
      DOI: 10.1002/aic.15617
  • 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
  • A continuum-approach modeling of surface composition and ternary component
           distribution inside low fat milk emulsions during single droplet drying
    • Authors: Aditya Putranto; Martin Foerster, Meng Wai Woo, Cordelia Selomulya, Xiao Dong Chen
      Abstract: Surface composition of dairy powders plays an important role in determining the functionality. However, the surface composition may be different from the bulk composition because of component migration during drying. In this study, a comprehensive mathematical model has been developed to describe the phenomena. To the best of our knowledge, it is the first mathematical model which predicts the dynamics of surface composition during drying. The model consists of a set of equations of conservation of mass of water, lactose, protein, and fat as well as conservation of heat and momentum in which the effects of diffusion induced material migration and surface activity are incorporated. This model is applicable to describe the kinetics of surface composition of dairy droplets during drying. It suggests that both diffusion and protein surface activity govern the component segregation during drying. The study indicates that the model implementing the measured initial surface composition as the initial conditions generates more realistic profiles than the one using the bulk composition. The modeling confirms that the difference between the surface and bulk composition that occurs prior to drying is not primarily governed by diffusion, but the emulsion's atomization behavior seems to play an essential role in the overrepresentation of fat. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-06T10:20:31.172833-05:
      DOI: 10.1002/aic.15657
  • 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-04T21:30:29.845115-05:
      DOI: 10.1002/aic.15655
  • 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-04T21:25:37.018348-05:
      DOI: 10.1002/aic.15644
  • Robustness of bioprocess feedback control to biodiversity
    • Authors: Francis Mairet; Olivier Bernard
      Abstract: The design of control laws for bioprocesses is 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. This paper proposes 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' is the approach is illustrated 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, 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. © 2016 American Institute of Chemical Engineers AIChE J, 2016
      PubDate: 2017-02-03T15:05:35.422234-05:
      DOI: 10.1002/aic.15604
  • Particle migration and alignment in slot coating flows of elongated
           particle suspensions
    • Authors: Ivan R. Siqueira; Rodrigo B. Rebouças, Marcio 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 nonuniform. 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-03T11:15:35.692711-05:
      DOI: 10.1002/aic.15653
  • Analysis of roll wave characteristics under low liquid loading two-phase
           flow conditions
    • Authors: Hamidreza Karami; Eduardo Pereyra, Cem Sarica, Carlos F. Torres
      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. (Int J Multiphase Flow. 2014;63:93–104) 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 (Proceedings of the 4th International Conference in Multi-Phase Flows, Nice, France. 1989:495–512), Paras et al. (Int J Multiphase Flow. 1994;20(5):939–956), Al-Sarkhi et al. (AIChE J. 2012;58(4):1018–1029), and Gawas et al. (Int J Multiphase Flow. 2014;63:93–104) are evaluated in comparison with the experimental data. The results of the wave frequency correlation of Al-Sarkhi et al. (AIChE J. 2012;58(4):1018–1029) 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-02T13:35:48.542377-05:
      DOI: 10.1002/aic.15650
  • 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 EOR. However, most of the commercial surfactants used in chemical 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 EOR. Synthesized surfactant was characterized by FTIR, NMR, dynamic light scattering, thermogravimeter analyser, 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, 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 favors 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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-02T13:35:45.969035-05:
      DOI: 10.1002/aic.15651
  • 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 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. © 2016 American Institute of Chemical Engineers AIChE J, 2016
      PubDate: 2017-02-02T13:35:29.013383-05:
      DOI: 10.1002/aic.15619
  • A geometric framework for monitoring and fault detection for periodic
    • Authors: Ray Wang; Thomas F. Edgar, Michael Baldea
      Abstract: Although cyclical operation systems are relatively widespread in practice (notably in the realm of physical separations, for example, 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, a novel geometric approach for process fault detection is proposed. Specifically, 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 is developed. On this basis, a two-step fault detection approach is proposed, based on detecting intercycle variations to locate a faulty cycle, and intracycle changes to determine the exact timing of a fault. The theoretical developments are illustrated with two simulation case studies. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-02T13:30:55.92151-05:0
      DOI: 10.1002/aic.15638
  • Numerical modeling of adhesive particle mixing
    • Authors: Mohammad R. Tamadondar; Anders Rasmuson, Kyrre Thalberg, Ingela Niklasson Björn
      Abstract: The discrete element method is used to investigate adhesive particle mixing in a system that 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 postprocessing 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 1 nN. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-02T13:25:28.079371-05:
      DOI: 10.1002/aic.15654
  • Effects of tunable acidity and basicity of Nb-KIT-6 catalysts on ethanol
           conversion: Experiments and kinetic modeling
    • Authors: Hongda Zhu; Raghunath V. Chaudhari, Bala Subramaniam, Anand Ramanathan, Jian-Feng Wu
      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. © 2017 American Institute of Chemical Engineers AIChE J, 2017
      PubDate: 2017-02-02T13:20:30.733713-05:
      DOI: 10.1002/aic.15648
  • 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 article 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. © 2016 American Institute of Chemical Engineers AIChE J, 2016
      PubDate: 2017-02-01T16:20:47.628147-05:
      DOI: 10.1002/aic.15605
  • 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 (SVF), especially, in the inter-phase boundary (i.e., cluster boundary). The resulting drag model is a function of particle Reynolds number, SVF and the gradient of SVF. 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. © 2016 American Institute of Chemical Engineers AIChE J, 2016
      PubDate: 2017-02-01T16:15:56.639296-05:
      DOI: 10.1002/aic.15573
  • 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 artificial neural network models (radial basis function neural network [RBFNN] and back-propagation neural network [BPNN] models) with an acceptable absolute average deviation 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 ions (1DEA2P, 1DEA2PH+,HCO3−, CO32−) speciation plots of the 1DEA2P-CO2-H2O system were developed 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 4-(diethylamino)−2-butanol [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. © 2016 American Institute of Chemical Engineers AIChE J, 2016
      PubDate: 2017-02-01T16:10:35.575259-05:
      DOI: 10.1002/aic.15621
  • 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
  • Issue information - table of contents
    • Pages: 1177 - 1177
      PubDate: 2017-03-18T15:16:39.0812-05:00
      DOI: 10.1002/aic.15468
  • Particle entrainment from gas-solid fluidized beds: Conductive vs.
           dielectric fines
    • Authors: Farzam Fotovat; John R. Grace, Xiaotao T. Bi
      Pages: 1194 - 1202
      Abstract: Conductive and non-conductive fine powders were entrained by air at atmospheric temperature and pressure in a fluidization column of diameter 0.15 m made of stainless steel. Under equivalent operating conditions, entrainment of the conductive particles was markedly higher than for non-conductive species. This finding cannot be explained by hydrodynamic factors. Examining the electrostatic interaction between touching particles reveals that dominance of the inter-particle attractive forces hinders independent motion of non-conductive particles in the freeboard. In addition, because of non-uniform distribution of the electrical charges over the surface of dielectric particles, they are subject to stronger electrostatic forces than for particles made of conductive materials. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1194–1202, 2017
      PubDate: 2016-10-05T07:36:44.832851-05:
      DOI: 10.1002/aic.15514
  • An approach for drag correction based on the local heterogeneity for
           gas–solid flows
    • Authors: Tingwen Li; Limin Wang, William Rogers, Guofeng Zhou, Wei Ge
      Pages: 1203 - 1212
      Abstract: The drag models typically used for gas–solids interaction are mainly developed based on homogeneous systems of flow passing fixed particle assembly. It has been shown that the heterogeneous structures, i.e., clusters and bubbles in fluidized beds, need to be resolved to account for their effect in the numerical simulations. Since the heterogeneity is essentially captured through the local concentration gradient in the computational cells, this study proposes a simple approach to account for the non-uniformity of solids spatial distribution inside a computational cell and its effect on the interaction between gas and solid phases. To validate this approach, the predicted drag coefficient has been compared to the results from direct numerical simulations. In addition, the need to account for this type of heterogeneity is discussed for a periodic riser flow simulation with highly resolved numerical grids and the impact of the proposed correction for drag is demonstrated. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1203–1212, 2017
      PubDate: 2016-10-10T09:21:17.538402-05:
      DOI: 10.1002/aic.15507
  • Pinch-based shortcut method for the conceptual design of adiabatic
           absorption columns
    • Authors: Christian Redepenning; Wolfgang Marquardt
      Pages: 1213 - 1225
      Abstract: Shortcut methods are valuable tools for the fast evaluation of key performance indicators in the early phase of conceptual process design. For the design of absorption columns, operation at minimum solvent demand represents a thermodynamically sound indicator, which is, however, difficult to determine because an infinite number of separation stages need to be considered. Instead, the suggested shortcut model exploits the existence of the pinch point to identify operation at minimum solvent demand. Existing shortcut concepts, such as the well-known equation of Kremser (Natl Pet News, 22, 43–49, 1930), are significantly outperformed by the novel shortcut model, which can be gradually refined to any desired accuracy. Integration into a stepwise procedure results in reliable solutions. The model covers rigorous thermodynamics; no simplifications regarding phase equilibrium, heat effects, or number of components are required. The performance of the method is illustrated by several case studies with up to seven components. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1213–1225, 2017
      PubDate: 2016-09-23T09:20:30.580724-05:
      DOI: 10.1002/aic.15499
  • Input–output pairing accounting for both structure and strength in
    • Authors: Xunyuan Yin; Jinfeng Liu
      Pages: 1226 - 1235
      Abstract: Input–output pairing is an important problem in control system design and is often performed using the relative gain array (RGA) based approaches. While RGA-based approaches have been very successful in many applications, they have some well-known limitations. For example, they may give results which are not consistent with the physical topology since only the strength of interaction between inputs and outputs is taken into account in the RGA. In this work, we propose a new measure for input–output pairing that explores both strength and structural information in input–output coupling. Specifically, we take advantage of the tool of relative degree to measure the physical closeness of input–output pairs and to explore the strength of interaction progressively with respect to the relative degree. We call the proposed measure relative sensitivity array (RSA) between inputs and outputs. Detailed analysis is performed to reveal the relationship between the gain matrix used in the RGA and the sensitivity matrix in the RSA from a mathematical point of view. Since the RSA is an analog of the RGA, many existing pairing guidelines developed for the RGA can be used in the proposed RSA-based pairing. The proposed RSA-based approach is applied to two examples. The results show that pairs formed by the proposed approach are consistent with the physical topologies of the processes. Also, the results show that the proposed approach can handle larger systems that cannot be effectively handled by RGA-based approaches. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1226–1235, 2017
      PubDate: 2016-10-05T08:15:53.810099-05:
      DOI: 10.1002/aic.15511
  • Pinch-based shortcut method for the conceptual design of isothermal
           extraction columns
    • Authors: Christian Redepenning; Sebastian Recker, Wolfgang Marquardt
      Pages: 1236 - 1245
      Abstract: Shortcut methods are valuable tools for a comprehensive evaluation of key performance indicators in the early phase of conceptual process design. For the design of extraction columns, operation at minimum solvent demand represents a thermodynamically sound indicator, which is, however, difficult to determine. The suggested shortcut model therefore exploits the existence of the pinch point to directly identify operation at minimum solvent demand. It is solved quickly and reliably by a step-by-step procedure. The final step allows a reduction of the approximation error to any desired degree of accuracy. No simplifications regarding the number of components in the mixture or its thermodynamic behavior are introduced. Hence, arbitrary mixtures can be tackled. The performance of the method is highlighted by a fully automated screening of thousands of solvents for the recovery of fermentation products acetone, 1-butanol, and ethanol from aqueous solution. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1236–1245, 2017
      PubDate: 2016-10-05T07:40:51.828877-05:
      DOI: 10.1002/aic.15523
  • Thermodynamic equilibrium solutions through a modified Newton Raphson
    • Authors: Marianna Marinoni; Jérôme Carrayrou, Yann Lucas, Philippe Ackerer
      Pages: 1246 - 1262
      Abstract: In numerical codes for reactive transport modeling, systems of nonlinear chemical equations are often solved through the Newton Raphson method (NR). NR is an iterative procedure that results in a sequential solution of linear systems. The algorithm is known for its effectiveness in the vicinity of the solution but also for its lack of robustness otherwise. Therefore, inaccurate initial conditions can lead to non-convergence or excessive numbers of iterations, which significantly increase the computational cost. In this work, we show that inaccurate initial conditions can lead to very ill-conditioned system matrices, which makes NR inefficient. This efficiency is improved by preconditioning techniques and/or by coupling the NR method with a zero-order method called the positive continuous fraction method. Numerical experiments that are based on seven different test cases show that the ill-conditioned linear systems within NR represent a problem and that coupling NR with a method that bypasses the computation of the Jacobian matrix significantly improves the robustness and efficiency of the algorithm. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1246–1262, 2017
      PubDate: 2016-10-02T17:00:42.392936-05:
      DOI: 10.1002/aic.15506
  • Splitting CO2 with a ceria-based redox cycle in a solar-driven
           thermogravimetric analyzer
    • Authors: M. Takacs; S. Ackermann, A. Bonk, M. Neises-von Puttkamer, Ph. Haueter, J. R. Scheffe, U. F. Vogt, A. Steinfeld
      Pages: 1263 - 1271
      Abstract: Thermochemical splitting of CO2 via a ceria-based redox cycle was performed in a solar-driven thermogravimetric analyzer. Overall reaction rates, including heat and mass transport, were determined under concentrated irradiation mimicking realistic operation of solar reactors. Reticulated porous ceramic (RPC) structures and fibers made of undoped and Zr4+-doped CeO2, were endothermally reduced under radiative fluxes of 1280 suns in the temperature range 1200–1950 K and subsequently re-oxidized with CO2 at 950–1400 K. Rapid and uniform heating was observed for 8 ppi ceria RPC with mm-sized porosity due to its low optical thickness and volumetric radiative absorption, while ceria fibers with μm-sized porosity performed poorly due to its opacity to incident irradiation. The 10 ppi RPC exhibited higher fuel yield because of its higher sample density. Zr4+-doped ceria showed increasing reduction extents with dopant concentration but decreasing specific CO yield due to unfavorable oxidation thermodynamics and slower kinetics. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1263–1271, 2017
      PubDate: 2016-10-05T08:05:50.789297-05:
      DOI: 10.1002/aic.15501
  • Highly stable hydrophobic SiNCO nanoparticle-modified silicon nitride
           membrane for zero-discharge water desalination
    • Authors: Jun-Wei Wang; Lin Li, Jian-Qiang Gu, Ming-Ye Yang, Xin Xu, Chu-Sheng Chen, Huan-Ting Wang, Simeon Agathopoulos
      Pages: 1272 - 1277
      Abstract: Membrane distillation water desalination can attain a significantly higher water recovery than reverse osmosis, while the lack of stable hydrophobic membranes limits its commercial applications. This article presents the preparation of a new hydrophobic membrane by modifying a porous Si3N4 substrate with vesicular SiNCO nano-particles. The membrane had a water contact angle of 142°, due to the presence of –Si–CH3 terminal groups and the high surface roughness. The contact angle remained nearly the same after exposures of the membrane to boiling water, aqueous solutions with pH ranging from 2 to 12, and benzene. The membrane exhibited satisfactory water desalination performance on highly concentrated NaCl solutions and simulated seawater. With the highly stable membrane, it is promising to develop a zero-discharge water desalination process for simultaneous production of fresh water for daily uses and brine for industrial uses. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1272–1277, 2017
      PubDate: 2016-09-20T08:55:22.814509-05:
      DOI: 10.1002/aic.15500
  • High-rate hydrogen separation using an MIEC oxygen permeable membrane
    • Authors: Wenping Li; Zhongwei Cao, Xuefeng Zhu, Weishen Yang
      Pages: 1278 - 1286
      Abstract: In this study, we propose using mixed ionic-electronic conducting (MIEC) oxygen permeable membrane to separate hydrogen via the water splitting reaction. To do that, steam was fed to one side of the membrane (side I) and a low-purity hydrogen was fed to the other side (side II). Oxygen from water splitting on side I permeates through the membrane driven by an oxygen chemical potential gradient across the membrane to react with the low-purity hydrogen on side II. After condensation and drying, high-purity hydrogen is acquired from side I. Thus, the hydrogen separation process is realized based on the fact that the low-purity hydrogen is consumed and high-purity hydrogen is acquired. We achieved a high hydrogen separation rate (13.5 mL cm−2 min−1) at 950°C in a reactor equipped with a 0.5-mm-thick Ba0.98Ce0.05Fe0.95O3-δ membrane. This research proofed that it is feasible to upgrade hydrogen purity using an MIEC oxygen permeable membrane. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1278–1286, 2017
      PubDate: 2016-09-27T09:35:38.86579-05:0
      DOI: 10.1002/aic.15502
  • Simultaneous removal of NO and SO2 using aqueous peroxymonosulfate with
           coactivation of Cu2+/Fe3+ and high temperature
    • Authors: Yangxian Liu; Yan Wang
      Pages: 1287 - 1302
      Abstract: A novel process on simultaneous removal of NO and SO2 using aqueous peroxymonosulfate (PMS) with synergic activation of Cu2+/Fe3+ and high temperature in an impinging stream reactor is developed for the first time. Effects of PMS concentration, Cu2+/Fe3+ concentration, reaction temperature, solution pH, flue gas flow, liquid–gas ratio, gas components, and inorganic ions on NO/SO2 removals were investigated. Active species and products were determined by electron spin resonance spectroscopy and ion chromatography. Removal pathways of NO/SO2 were revealed, and mass transfer-reaction kinetics of NO removal was studied. The optimal experimental conditions are obtained. H2SO4 and HNO3 are the main products. It is found that there is a clear synergy between Cu2+/Fe3+ and high temperature for activating PMS. SO4− and ·OH are found to be the main oxidants for NO removal. NO removals belong to pseudo-first fast reactions in the two investigated oxidation systems. Besides, the kinetic parameters are also measured. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1287–1302, 2017
      PubDate: 2016-10-02T16:45:40.421593-05:
      DOI: 10.1002/aic.15503
  • Preparation of thin film nanocomposite membranes with surface modified MOF
           for high flux organic solvent nanofiltration
    • Authors: Xiangyu Guo; Dahuan Liu, Tongtong Han, Hongliang Huang, Qingyuan Yang, Chongli Zhong
      Pages: 1303 - 1312
      Abstract: Preparation of defect-free and optimized thin film nanocomposite (TFN) membranes is an effective way to enhance the process of organic solvent nanofiltration. However, it still remains a great challenge due to poor filler particle dispersibility in organic phase and compatible issue between fillers and polymers. Aiming at these difficulties, UiO-66-NH2 nanoparticles were surface modified with long alkyl chains and used in the preparation of TFN membranes. As a result, defect-free TFN membranes with ultrathin MOF@polyamide layer were successfully prepared benefited from the improved particle dispersibility in n-hexane. Significant enhancement was found in methanol permeance after nanoparticle incorporation, without comprising the tetracycline rejection evidently. Especially, the novel TFN membrane prepared with organic phase solution containing 0.15% (w/v) modified UiO-66-NH2 nanoparticles showed a superior methanol permeance of 20 L·m−2·h−1·bar−1 and a tetracycline rejection of about 99%, which is appealing to the application in pharmaceutical industry for example. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1303–1312, 2017
      PubDate: 2016-10-04T09:25:37.896206-05:
      DOI: 10.1002/aic.15508
  • Mathematical modelling and experimental validation of a novel periodic
           flow crystallization using MSMPR crystallizers
    • Authors: Qinglin Su; Chris D. Rielly, Keddon A. Powell, Zoltan K. Nagy
      Pages: 1313 - 1327
      Abstract: The challenges of insufficient residence time for crystal growing and transfer line blockage in conventional continuous mixed-suspension mixed-product removal (MSMPR) operations are still not well addressed. Periodic flow crystallization is a novel method whereby controlled periodic disruptions are applied to the inlet and outlet flows of an MSMPR crystallizer to increase its residence time. A dynamic model of residence time distribution in an MSMPR crystallizer was first developed to demonstrate the periodic flow operation. Besides, process models of periodic flow crystallizations were developed with an aim to provide a better understanding and improve the performance of the periodic flow operation, wherein the crystallization mechanisms and kinetics of the glycine-water system were estimated from batch cooling crystallization experiments. Experiments of periodic flow crystallizations were also conducted in single-/three-stage MSMPR crystallizers to validate the process models and demonstrate the advantages of using periodic flow operation in MSMPR stages. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1313–1327, 2017
      PubDate: 2016-10-06T16:06:30.72456-05:0
      DOI: 10.1002/aic.15510
  • Mechanism of the effects of microwave irradiation on the relative
           volatility of binary mixtures
    • Authors: Hong Li; Junjie Cui, Jiahui Liu, Xingang Li, Xin Gao
      Pages: 1328 - 1337
      Abstract: The use of microwave irradiation to enhance distillation processes has been reported recently. However, there is an ongoing debate in the scientific community on whether the observed enhancement is mainly a consequence of the shift of the “equilibrium” of vapor–liquid mass transfer. In this article, a developed instrument was used to determine the relative volatility of various binary mixtures under microwave irradiation. By comparing the relative volatility in the presence/absence of microwave irradiation, the shift of the “equilibrium” of vapor–liquid mass transfer was observed for certain binary mixtures under microwave irradiation. The effects of microwave irradiation on the relative volatility of binary mixtures (in addition to the mechanisms involved therein) were analyzed using the non-equilibrium thermodynamic principle. The results demonstrate that differences in the dielectric properties, microwave field intensity, intermolecular forces, and boiling point play dominant roles in determining the effects of microwaves on the relative volatility. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1328–1337, 2017
      PubDate: 2016-10-06T15:55:40.208278-05:
      DOI: 10.1002/aic.15513
  • Water content of light n-alkanes: New measurements and
           cubic-plus-association equation of state modeling
    • Authors: Mohsen Zirrahi; Hassan Hassanzadeh, Jalal Abedi
      Pages: 1384 - 1389
      Abstract: Light hydrocarbon gases such as methane, ethane, propane, and butane or other so called gaseous solvents have been suggested as steam additives to improve bitumen recovery and energy efficiency. The water content of these gases is one of the key requirements in the simulation and design of solvent-aided thermal heavy oil recovery processes. In this work, we present new experimental data for the water content of these gases at high temperatures (up to 493.15 K) and moderate pressures (P 
      PubDate: 2016-10-02T16:40:34.673464-05:
      DOI: 10.1002/aic.15512
  • Liquid-phase axial dispersion of turbulent gas–liquid co-current flow
           through screen-type static mixers
    • Authors: Fouad Azizi; Khaled Abou Hweij
      Pages: 1390 - 1403
      Abstract: This article discusses the characteristics of turbulent gas–liquid flow through tubular reactors/contactors equipped with screen-type static mixers from a macromixing perspective. The effect of changing the reactor configuration, and the operating conditions, were investigated by using four different screen geometries of varying mesh numbers. Residence time distribution experiments were conducted in the turbulent regime (4500 
      PubDate: 2016-09-22T11:00:27.702306-05:
      DOI: 10.1002/aic.15494
  • Mixing and residence time distribution in ultrasonic microreactors
    • Authors: Zhengya Dong; Shuainan Zhao, Yuchao Zhang, Chaoqun Yao, Quan Yuan, Guangwen Chen
      Pages: 1404 - 1418
      Abstract: Intensification of liquid mixing was investigated in domestic fabricated ultrasonic microreactors. Under the ultrasonic field, cavitation bubbles were generated, which undergo vigorous translational motion and surface oscillation with different modes (volume, shape oscillation, and transient collapse). These cavitation phenomena induce intensive convective mixing and reduce the mixing time from 24–32 s to 0.2–1.0 s. The mixing performance decreases with the channel size, due to the weaker cavitation activity in smaller channel. The energy efficiency is comparable to that of the conventional T-type and higher than the Y-type and Caterpillar microreactors. Residence time distribution was also measured by a stimulus-response experiment and analyzed with axial dispersion model. Axial dispersion was significantly reduced by the ultrasound-induced radial mixing, leading to the increasing of Bo number with ultrasound power. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1404–1418, 2017
      PubDate: 2016-09-23T09:30:55.38495-05:0
      DOI: 10.1002/aic.15493
  • Visualization and simulation of the transfer process of index-matched
           silica microparticle inks for gravure printing
    • Authors: Arnout M. P. Boelens; Juan J. de Pablo, Sooman Lim, Lorraine Francis, Bok Y. Ahn, Jennifer A. Lewis
      Pages: 1419 - 1429
      Abstract: A combined experimental and computational study of the transfer of transparent index-matched silica-particle inks between two flat plates is presented for gravure printing applications. The influence of printing speed and initial ink droplet size on the ability to accurately transfer ink during the printing process is explored systematically. Smooth interface volume of fluid simulations show the same trends as the ink transfer observed in experiments over a wide range of printing speeds and for inks having different silica particle loadings. Our calculations indicate that for ink droplets with characteristic dimensions in the vicinity of 10 μm, which are of particular interest for gravure printing applications, ink transfer improves significantly due to the diminishing effect of gravity, and the increased importance of capillary forces at small length scales. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1419–1429, 2017
      PubDate: 2016-09-28T09:21:14.9472-05:00
      DOI: 10.1002/aic.15392
  • A fractal model for real gas transport in porous shale
    • Authors: Lidong Geng; Gensheng Li, Shouceng Tian, Mao Sheng, Wenxi Ren, Pacelli Zitha
      Pages: 1430 - 1440
      Abstract: A model for real gas flow in shale gas matrices is proposed and consists of two main steps: (a) developing a microscopic (single pore) model for a real gas flow by generalizing our previously reported Extended Navier-Stokes Equations (ENSE) method and (b) by using fractal theory concepts, up-scaling the single pore model to the macroscopic scale. A prominent feature of the up-scaled model is a predictor for the apparent permeability (AP). Both models are successfully validated with experimental data. The impact of the deviation of the gas behavior from ideality (real gas effect) on the gas transport mechanisms is investigated. The effect of the structural parameters (porosity Ф, the maximum pore diameter Dmax, and the minimum pore diameter Dmin) of the shale matrix on the apparent permeability is studied and a sensitivity analysis is performed to evaluate the significance of the parameters for gas transport. We find that (1) the real gas transport models for a single pore and porous shale matrix are both reliable and reasonable; (2) the real gas effect affects the thermodynamic parameters of the free gas and the adsorption and transport capacity of the adsorbed gas; (3) the real gas effect decreases the effective permeability for convective flow and surface diffusion; i.e., the derivation degree of the effective permeability for bulk diffusion and Knudsen diffusion increases with increasing pressure but presents a bathtub shape when the pore diameter is smaller than 10 nm; and (4) the apparent permeability increases with Ф, Dmax, and Dmin. It is more sensitive to Dmax, followed by the porosity. Dmin has a minor impact. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1430–1440, 2017
      PubDate: 2016-10-02T16:55:34.030844-05:
      DOI: 10.1002/aic.15516
  • Spatial and temporal scaling of unequal microbubble coalescence
    • Authors: Rou Chen; Huidan (Whitney) Yu, Likun Zhu, Raveena M. Patil, Taehun Lee
      Pages: 1441 - 1450
      Abstract: We numerically study coalescence of air microbubbles in water, with density ratio 833 and viscosity ratio 50.5, using lattice Boltzmann method. The focus is on the effects of size inequality of parent bubbles on the interfacial dynamics and coalescence time. Twelve cases, varying the size ratio of large to small parent bubble from 5.33 to 1, are systematically investigated. The “coalescence preference,” coalesced bubble closer to the larger parent bubble, is well observed and the captured power-law relation between the preferential relative distance χ and size inequality γ, χ∼γ−2.079, is consistent to the recent experimental observations. Meanwhile, the coalescence time also exhibits power-law scaling as T∼γ−0.7, indicating that unequal bubbles coalesce faster than equal bubbles. Such a temporal scaling of coalescence on size inequality is believed to be the first-time observation as the fast coalescence of microbubbles is generally hard to be recorded through laboratory experimentation. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1441–1450, 2017
      PubDate: 2016-10-04T09:21:19.899168-05:
      DOI: 10.1002/aic.15504
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