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  Subjects -> CHEMISTRY (Total: 891 journals)
    - ANALYTICAL CHEMISTRY (55 journals)
    - CHEMISTRY (621 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (28 journals)
    - INORGANIC CHEMISTRY (45 journals)
    - ORGANIC CHEMISTRY (51 journals)
    - PHYSICAL CHEMISTRY (70 journals)

CHEMISTRY (621 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 14)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 26)
ACS Catalysis     Full-text available via subscription   (Followers: 43)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 21)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 23)
ACS Macro Letters     Full-text available via subscription   (Followers: 25)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 41)
ACS Nano     Full-text available via subscription   (Followers: 277)
ACS Photonics     Full-text available via subscription   (Followers: 14)
ACS Symposium Series     Full-text available via subscription  
ACS Synthetic Biology     Full-text available via subscription   (Followers: 24)
Acta Chemica Iasi     Open Access   (Followers: 5)
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chimica Slovenica     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 7)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 9)
Adsorption Science & Technology     Open Access   (Followers: 6)
Advanced Functional Materials     Hybrid Journal   (Followers: 57)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 67)
Advances in Chemical Science     Open Access   (Followers: 18)
Advances in Chemistry     Open Access   (Followers: 21)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 19)
Advances in Drug Research     Full-text available via subscription   (Followers: 24)
Advances in Environmental Chemistry     Open Access   (Followers: 5)
Advances in Enzyme Research     Open Access   (Followers: 10)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 25)
Advances in Nanoparticles     Open Access   (Followers: 15)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 16)
Advances in Polymer Science     Hybrid Journal   (Followers: 43)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Science and Technology     Full-text available via subscription   (Followers: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 3)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 65)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 20)
American Journal of Chemistry     Open Access   (Followers: 30)
American Journal of Plant Physiology     Open Access   (Followers: 11)
American Mineralogist     Hybrid Journal   (Followers: 15)
Analyst     Full-text available via subscription   (Followers: 38)
Angewandte Chemie     Hybrid Journal   (Followers: 164)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 240)
Annales UMCS, Chemia     Open Access  
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 5)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 9)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 13)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Hybrid Journal   (Followers: 2)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 9)
Applied Spectroscopy     Full-text available via subscription   (Followers: 23)
Applied Surface Science     Hybrid Journal   (Followers: 31)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 2)
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Full-text available via subscription   (Followers: 347)
Biochemistry Insights     Open Access   (Followers: 6)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 10)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 2)
Biomacromolecules     Full-text available via subscription   (Followers: 21)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 7)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 129)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 87)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 2)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 1)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 24)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 10)
Canadian Mineralogist     Full-text available via subscription   (Followers: 6)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 70)
Catalysis for Sustainable Energy     Open Access   (Followers: 8)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 7)
Catalysis Science and Technology     Free   (Followers: 8)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 10)
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 19)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 73)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 26)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 22)
Chemical Reviews     Full-text available via subscription   (Followers: 186)
Chemical Science     Open Access   (Followers: 24)
Chemical Technology     Open Access   (Followers: 25)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 55)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 24)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 32)
Chemistry & Industry     Hybrid Journal   (Followers: 7)
Chemistry - A European Journal     Hybrid Journal   (Followers: 157)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 16)
Chemistry and Materials Research     Open Access   (Followers: 21)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Hybrid Journal   (Followers: 2)
Chemistry Letters     Full-text available via subscription   (Followers: 43)
Chemistry of Materials     Full-text available via subscription   (Followers: 253)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 19)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 4)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 12)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 11)
Chromatographia     Hybrid Journal   (Followers: 24)
Chromatography     Open Access   (Followers: 2)
Chromatography Research International     Open Access   (Followers: 6)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Cogent Chemistry     Open Access   (Followers: 1)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 11)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 6)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 22)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Communications Chemistry     Open Access  
Composite Interfaces     Hybrid Journal   (Followers: 7)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 3)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 6)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 6)
Croatica Chemica Acta     Open Access  
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Chromatography     Hybrid Journal  
Current Green Chemistry     Hybrid Journal  
Current Metabolomics     Hybrid Journal   (Followers: 5)
Current Microwave Chemistry     Hybrid Journal  
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 14)
Current Research in Chemistry     Open Access   (Followers: 8)
Current Science     Open Access   (Followers: 69)
Current Trends in Biotechnology and Chemical Research     Open Access   (Followers: 3)
Dalton Transactions     Full-text available via subscription   (Followers: 23)
Detection     Open Access   (Followers: 2)
Developments in Geochemistry     Full-text available via subscription   (Followers: 2)
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Dislocations in Solids     Full-text available via subscription  

        1 2 3 4 | Last

Journal Cover
Chemical Engineering Research and Design
Journal Prestige (SJR): 0.847
Citation Impact (citeScore): 3
Number of Followers: 26  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0263-8762 - ISSN (Online) 0263-8762
Published by Elsevier Homepage  [3162 journals]
  • Impact of operating parameters on values of a volumetric mass transfer
           coefficient in a single-use bioreactor with wave-induced agitation
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Maciej Pilarek, Paweł Sobieszuk, Kamil Wierzchowski, Katarzyna Dąbkowska The knowledge of a volumetric liquid-side mass transfer coefficient (kLa) characterizing the oxygen transfer in bioreactor working at defined operating parameters, is a fundamental principle for establishing the aeration strategy for aerobic bioprocesses. The design of experiments (DoE) methodology has been applied for distinguishing relevant from irrelevant operating parameters, and for prediction of characteristics of oxygen mass transfer effects, in the whole range of values of operating parameters accessible in setup of ReadyToProcess WAVE™ 25 (WAVE 25; GE Healthcare) bioreactor equipped with 2 dm3 disposable culture bag. Due to DoE-aided analysis, rocking speed (ω), rocking angle (α) and volumetric flow of gas phase through the culture bag (QG) have been indicated as the operating parameters robustly impacting on the value of the kLa coefficient. All relevant operational parameters, i.e. ω, α and QG, exerted monotonically increasing influence on kLa. Otherwise, the influence of volume of liquid poured into culture bag (VL) and oxygen partial pressure in applied gas phase (p1) on kLa proved to be negligible. Two original correlations have been proposed to generalize the experimental results and to estimate the kLa coefficient values possible to be reached in the WAVE 25: the dimensional correlation defining the kLa coefficient, as well as the dimensionless correlation that defines Sherwood number and integrating the originally-defined Reynolds number for the liquid phase that is subjected to wave-induced mixing. The validity of results predicted by both correlations has been verified by acceptable level of the relative errors.Graphical abstractGraphical abstract for this article
       
  • STEM imaging to characterize nanoparticle emissions and help to design
           nanosafer paints
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Martin Morgeneyer, Olivier Aguerre-Chariol, Christophe Bressot The growing use of common consumer goods made of materials containing nanoparticles could increase the exposure of consumers to these substances during their lifecycle. In view of evaluating this risk a setup and experimental protocol of weathering and mechanical solicitation was realized. Tests on two paints were performed. One of them releases mainly submicronic sized nanostructured nano-objects and their agglomerates and aggregates (NOAAs) of titanium dioxide in presence of free nano-TiO2. The formulation of the emissive paint is under question.Graphical abstractGraphical abstract for this article
       
  • Comparative DEM-CFD study of binary interaction and acoustic agglomeration
           of aerosol microparticles at low frequencies
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Rimantas Kačianauskas, Vytautas Rimša, Arnas Kačeniauskas, Algirdas Maknickas, Darius Vainorius, Ruslan Pacevič The paper concerns the problem of acoustic agglomeration due to the acoustic wake in diluted aerosols and addresses the development of the time-accurate discrete element method (DEM) simulation technique. The case of weak entrainment of heavier mono-sized microparticles at low-frequency sound waves is considered. The agglomerative motion of two identical micron-sized spherical particles is simulated numerically, and contribution of the particles boundary layer in transition from the diluted to the dense phase is investigated. A comparative study of the DEM approach against more accurate computational fluid dynamics (CFD) computations is performed. The 3D incompressible viscous flow of aerosol medium described by Navier–Stokes equations is considered regarding the fine scale of particles. The numerical results regarding the agglomeration rate, drag coefficient, and perturbation velocities are discussed. Moreover, the correction to the fluid–particle interaction force is proposed to increase the accuracy of the DEM model.Graphical abstractGraphical abstract for this article
       
  • Perikinetic and orthokinetic aggregation of small solid particles in the
           presence of strong repulsive forces
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Jerzy Bałdyga, Grzegorz Tyl, Mounir Bouaifi This paper deals with aggregation of small particles in a fully developed turbulent flow field for the wide range of the Péclet number including the perikinetic and orthokinetic regimes. Colloidal particles smaller than the Kolmogorov length microscale are considered. Convective movements of these particles are characterised by the relaxation time much shorter than the Kolmogorov time microscale. A basic aggregation kernel is determined by solving the convection–diffusion equation for the pair probability function of the solid particles present in the DLVO potential field for the sub-Kolmogorov scale flow structure. The simplified aggregation kernels are proposed as well to offer a computationally less expensive method. An aggregation kernel based on the modified Fuchs stability ratio approach including effect of competition between maximum particle velocities caused by the repulsion forces and fluid flow is derived using a concept of small scale turbulent diffusion that competes with particle velocity generated by repulsion forces. The aggregation rate constants obtained using this method are close to predictions of the full model. Proposed approach is extended to take into account hydrophobic effects and particle-bubble interactions.
       
  • Characterisation of structured and functionalised particles by small-angle
           X-ray scattering (SAXS)
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Hermann Nirschl, Xiaoai Guo In this work we provided an overview about the use of small-angle X-ray scattering (SAXS) technology for non-invasive characterisation of nanostructured and functionalised particles. Firstly, we demonstrated our modular-designed laboratory SAXS camera with different options and possibilities for quick in-situ measuring various disperse particulate systems including powders and suspensions as well as aerosol nanoparticles which can be deposited on a certain substrate. The detection angle reaches 90°, allowing simultaneous wide-angle X-ray scattering (WAXS) measurement on the crystalline structures. Further extension of the sample-to-detector distance enables multi-level structural characterisation of particle systems ranging from about one nanometer to several hundred nanometers. The use of an on-line X-ray detector makes on-line in-situ analysis possible. Secondly, different data processing methods and models have been introduced for analyzing the acquired scattering data and retrieving the structural parameters of the investigated particle systems. Finally, we presented some selected experimental results obtained by SAXS–WAXS, including commercial nanoparticles, and laboratory-synthesized nanostructured and functionalised particles such as silica multiplets, silica-magnetite core–shell nanocomposites, metallic nanoparticles and catalyst nanodots on oxide support particles in different liquid- and gas-phase synthesis processes as well as nanostructured particles in particle handling processes like high pressure dispersion and high temperature calcination.Graphical abstractGraphical abstract for this article
       
  • Fractional Monte Carlo time steps for the simulation of coagulation for
           parallelized flowsheet simulations
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): G. Kotalczyk, F.E. Kruis The event-driven acceptance rejection (AR) method is a computationally very advantageous Monte Carlo (MC) simulation technique for the solution of population balance equations (PBE) of coagulating systems. In the scope of the event-driven simulation approach, the simulation time is stepwise increased by a simulation time step τ, which is given be the simulated particle properties. Within this time step τ, exactly one coagulation event takes place. The method is therefore not applicable in situations, for which specific time points have to be reached by the simulation, or the time step has to be reset to a smaller value. We propose a methodology termed ‘fractional MC step’ which allows to reset the simulation time step of the AR method to any arbitrary smaller value than the one initially proposed. The proposed method is validated by simulations of coagulation for different initial conditions and comparison with results gained from the discrete sectional method. The potential increase of the stochastic noise is investigated by comparisons with the results from conventional MC simulation techniques. The advantages of a parallel implementation are briefly discussed.
       
  • Early assessment of bulk powder processability as a part of solid form
           screening
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Pratik P. Upadhyay, Nawin Pudasaini, Manish Kumar Mishra, Upadrasta Ramamurty, Jukka Rantanen A systematic assessment of key material attributes of active pharmaceutical ingredients (APIs) using minimal material approach is illustrated at the particulate level and bulk level. At a bulk level, flowability improvement of an API through crystal habit manipulation is exemplified. The impact of crystal structures and particulate properties (crystal habit and crystal size) on their mechanical behaviour were addressed by measuring powder tabletability. Bulk powder flow and tabletability were assessed on a small scale using ring shear tester and using a single punch compaction simulator, which can be easily integrated during the process of solid form screening activity for early preformulation studies. In addition, mechanical responses on single crystals were evaluated with nanoindentation. Indentation performed on three faces of piroxicam single crystals resulted reproducible results when compared with the literature, indicating the efficiency of this technique to perform single crystal characterization. The study highlights that, the early assessment of key material properties during solid form screening can aid in selecting optimal solid forms provided physicochemical properties are acceptable.Graphical abstractGraphical abstract for this article
       
  • A quantitative analysis of drug migration during granule drying
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Anjali Kataria, Sarang Oka, David Smrčka, Zdenek Grof, František Štěpánek, Rohit Ramachandran This study investigates the extent of drug (active) migration in granules made via high shear wet granulation subject to factors such as the viscosity of the binder solution, particle size of the excipient and granule porosity. Due to the complexity of a qualitative comparison between granules having different sizes, shape and porosities, a quantification technique that is independent of these differences was developed. The radial distribution function (RDF), developed as part of this effort, quantifies the spatial distribution of the active ingredient in granules produced under different processing conditions.A two component system with potassium chloride (KCl) as the water-soluble model active and microcrystalline cellulose (MCC) was studied at 20% (w/w) active load. In order to eliminate any non-homogeneity due to segregation and difference in wettability of the two compounds, the soluble active ingredient was dissolved in the granulating vehicle and then sprayed on the powder bed to carry out granulation. The extent of drug migration and structure of the dry granules was analysed using X-ray microtomography (μ-CT).The extent of capillary migration in the resulting granules was analysed by the dividing the μ-CT images into conical sections and quantifying the distribution of the active across these conical cross-sections. Statistical analysis was performed to quantify the extent of aforementioned variables on the extent of migration.Thus, a comprehensive investigation into the causes of drug migration was carried out in this study to ascertain which factors or combination of factors have the most prominent effect on the extent of drug migration.
       
  • Model-based design of experiments in the presence of structural model
           uncertainty: an extended information matrix approach
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Marco Quaglio, Eric S. Fraga, Federico Galvanin The identification of a parametric model, once a suitable model structure is proposed, requires the estimation of its non-measurable parameters. Model-based design of experiment (MBDoE) methods have been proposed in the literature for maximising the collection of information whenever there is a limited amount of resources available for conducting the experiments. Conventional MBDoE methods do not take into account the structural uncertainty on the model equations and this may lead to a substantial miscalculation of the information in the experimental design stage. In this work, an extended formulation of the Fisher information matrix is proposed as a metric of information accounting for model misspecification. The properties of the extended Fisher information matrix are presented and discussed with the support of two simulated case studies.
       
  • Optimization of simultaneously propagating multiple fractures in hydraulic
           fracturing to achieve uniform growth using data-based model reduction
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Prashanth Siddhamshetty, Kan Wu, Joseph Sang-Il Kwon In multi-stage hydraulic fracturing treatments, simultaneously propagating multiple fractures with close spacing often induce non-uniform fracture development due to stress-shadow effects, resulting in one or two dominant fractures due to the uneven distribution of fracturing fluids. Motivated by this, first, we present a dynamic model of hydraulic fractures to describe stress-shadow effects in simultaneously propagating multiple fractures. Second, we develop a new model order-reduction technique for simultaneously propagating multiple fractures by integrating the analytical models to calculate the pressure drop due to perforation friction and wellbore friction, and a data-based reduced-order model (ROM) developed using the data generated from the high-fidelity process model to describe the pressure drop along the fractures due to stress-shadow effects. Lastly, we propose a model-based design technique by utilizing the integrated ROM and the limited entry design technique to compute the flow rate of fracturing fluids and the perforation conditions which will promote equal distribution of fracturing fluids to achieve uniform growth of multiple fractures while mitigating the undesired stress-shadow effects. We present a base case with the uneven development of multiple fractures and demonstrate that the proposed design technique is able to outperform the base case with respect to achieving uniform fracture growth, by explicitly handling stress-shadow effects.
       
  • Thermodynamic modeling of the system of CO2 and potassium taurate solution
           for simulation of the carbon dioxide capture process
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Stefania Moioli, Minh T. Ho, Dianne E. Wiley, Laura A. Pellegrini Absorption of carbon dioxide from gaseous sources such as flue gases from power plants is accomplished for environmental reasons with the aim to reduce emissions of greenhouse gases. Generally, aqueous solutions of alkanolamines are employed with Monoethanolamine (MEA) considered the benchmark solvent. However, it has drawbacks, primarily its volatility and toxicity, and the need for a lot of energy for regeneration. Recently, new solvents such as amino acid aqueous solutions have started to be considered as alternatives to traditional amines.This paper is focused on the development of a model for the simulation of the absorption and regeneration system using potassium taurate for the capture of carbon dioxide. Detailed modelling of this system is currently limited by the lack of thermodynamic parameters for use in simulations. ASPEN Plus® has been chosen as the framework for developing the model. Species not present by default in the database have been added and appropriate parameters have been determined for obtaining a reliable description of the Vapor–Liquid–Solid Equilibrium by means of the Electrolyte-NRTL method.
       
  • An efficient and sustainable [P6,6,6,14]2[BDOAC] ionic liquid based
           extraction–precipitation strategy for rare earth recovery
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Xiang Su, Xiangguang Guo, Zeyuan Zhao, Yamin Dong, Yanliang Wang, Fujian Li, Xiaoqi Sun Ionic liquids are the key materials for the recovery of rare earths, which have attracted considerable attentions in the recent years. In this article, a novel ionic liquid [trihexyl(tetradecyl)phosphonium]2[benzene-1,4-dioxydiacetate] ([P6,6,6,14]2[BDOAC]) has been developed for rare earth (RE) recovery. Experiments show that [P6,6,6,14]2[BDOAC] can form solid extracting complexes with rare earth ions from aqueous phase. The precipitation process of [P6,6,6,14]2[BDOAC] was investigated by IR and single-crystal X-ray diffraction analysis (SC-XRD), respectively. Nd[BDOAC]1.5(H2O)z is given as a proposed structure of the precipitate. The sizes of obtained precipitated particles are larger than those from conventional precipitation methods. Stripping of RE from the precipitate by 0.015 mol/L HCl is effectively achieved. [P6,6,6,14]2[BDOAC] can be regenerated in the RE recovery strategy. Because of bifunctional [BDOAC]2−, the [P6,6,6,14]2[BDOAC] reveals better recovery capacity for RE. The recovery of RE from simulated waste NdFeB feed solution using [P6,6,6,14]2[BDOAC] was studied. The recovery rate of RE achieves 90.6%, and the purity of RE increases from 44.9% to 98.1%.Graphical abstractGraphical abstract for this article
       
  • CO2 gas-adsorption calorimetry applied to the study of
           chemically activated carbons
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Débora Aline Soares Maia, José Carlos Alexandre de Oliveira, Marcelo Sandro Nazzarro, Karim Manuel Sapag, Raul Horácio López, Sebastião Mardônio Pereira de Lucena, Diana Cristina Silva de Azevedo In this work, the microporous structure of a series of H3PO4 chemically activated carbons from peach stones with increased activation degree were investigated. CO2 Adsorption equilibrium isotherms and differential enthalpy curves were simultaneously measured at 300 K using a Tian-Calvet microcalorimeter coupled to an adsorption manometric setup. Temperature programmed decomposition experiments were used to assess density of oxygen functional groups and determine the impact of surface chemistry on CO2 adsorption capacity. Computer based theoretical calculations were also performed to attempt to predict the adsorption enthalpy profiles. The most activated sample (Xp = 0.90) has an average adsorption enthalpy which is approximately 8 kJ/mol lower than that of the non-activated samples carbonized under the same conditions. The combination of techniques enabled a better understanding of the pore filling regimes with increasing coverage, since the use of CO2 as a probe gas allows accessing small pores, which otherwise would not be identified from N2 isotherms at 77 K. The oxygen content on the carbon surface decreased almost 80% with the increasing degree of activation and did not influence in the CO2 adsorption. Besides providing information about carbon chemistry, CO2 adsorption calorimetry can also be successfully applied to the screening of carbons intended for CO2 capture.Graphical abstractGraphical abstract for this article
       
  • Reusable carbon nanofibers for efficient removal of methylene blue from
           aqueous solution
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Abdul Sameeu Ibupoto, Umair Ahmed Qureshi, Farooq Ahmed, Zeeshan Khatri, Muzamil Khatri, Maryam Maqsood, Rafi Zaman Brohi, Ick Soo Kim This work demonstrates the preparation of polyacrylonitrile (PAN) based activated carbon nanofibers (ACNFs) through electrospinning followed by thermal treatment. Resulted activated carbon nanofibers having diameters in the range of 240–280 nm were then examined for the adsorption capability for methylene blue dye from aqueous solution. Batch mode experiments were carried out at room temperature to study the effect of amount of nanofiber, contact time and pH on dye adsorption. It was found that activated carbon nanofibers showed remarkable adsorption efficiency while completely decolorizing the dye solution within 60 min of contact. Results revealed that the adsorption data followed Langmuir isotherm giving maximum adsorption capacity of 72.46 mg/g and pseudo second order kinetic model. Furthermore, the reusability of activated carbon nanofibers had shown removal efficiency more than 80% up to 3 cycles. Morphology and structure of PAN nanofibers and ACNFs were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FTIR).Graphical abstractGraphical abstract for this article
       
  • Purification of crude wax using a filter medium modified with a nanofiber
           coating
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Juliano Missau, Juliana de Gregori da Rocha, Guilherme Luiz Dotto, Daniel Assumpção Bertuol, Luciano Peske Ceron, Eduardo Hiromitsu Tanabe The presence of inorganic substances in the composition of crude wax decreases its commercial value, necessitating purification of the product. A new physical surface treatment for filter media involving the application of nanofibers of Nylon-6 polymer was developed using the Forcespinning® equipment. The performance of the nanofiber-coated filter was compared with the results obtained for other filter media of the same composition (nonwoven aramid fiber fabric), one without physical treatment, and another treated using singeing. An experimental design was carried out to find the optimum operating temperature and pressure (170 °C and 2.5 bar, respectively). The filtrate volume, specific resistance of the filter cake, and filter medium resistance were determined, keeping the filtration time, temperature, and pressure constant at 1 h, 170 °C, and 2.5 bar, respectively. The nanofiber-coated filter showed the best performance, providing a higher wax filtrate volume and greater retention of inorganics, with values of 5.39 × 10−5 m3 and 99.6%, respectively.
       
  • Removal of copper(II) ions from aqueous solutions by
           complexation–ultrafiltration using rotating disk membrane and the shear
           stability of PAA–Cu complex
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Shu-Yun Tang, Yun-Ren Qiu The stability of polymer–metal complex in the shear field is of great significance for the industrial applicaion of complex-ultrafiltration. The shear stability of PAA–Cu complex was investigated for the first time. Polyacrylic acid sodium (PAAS) was applied to remove Cu(II) from aqueous solutions by complexation–ultrafiltration using a rotating disk membrane. As important factors, solution pH and P/M (the mass ratio of polymer to metal ions) on the rejection of Cu(II) were investigated, and the rejection of Cu(II) could reach 99.6% at pH = 6.0, P/M = 25. The rotating disk was applied to generate shear rate on the membrane surface, and the radial distribution of shear rate on the membrane surface was calculated. The critical rotating speeds at which the rejection of Cu(II) begins to decrease were 1000, 900, 700 rpm at pH values 6.0, 5.0, 4.0, respectively, and the corresponding critical shear rates (γc) at which the PAA–Cu complex begins to dissociate were 8.0 × 104, 6.6 × 104 and 4.2 × 104 s−1, respectively. Furthermore, the critical shear radius and the radial distribution of substances on the membrane surface were obtained using a segmentation model. The shear stability, especially the critical shear rate of the polymer–metal complex, can give guidance to the selection of the delivery pumps so that high removal efficiency can be obtained in the industrial application of complexation–ultrafiltration. In addition, shear induced dissociation and ultrafiltration was first applied to regenerate PAAS.Graphical abstractGraphical abstract for this article
       
  • Magnetic thiolated/quaternized-chitosan composites design and application
           for various heavy metal ions removal, including cation and anion
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Xiaoli Song, Ling Li, Lei Zhou, Pei Chen In this work, we designed and prepared a novel magnetic thiolated/quaternized-chitosan composite as an adsorbent for removal of various heavy metal ions from solution, including cation and anion. Characterizations by Fourier transform infrared spectroscopy (FTIR), scanning electronic microscopy (SEM), vibrating sample magnetometer (VSM) and thermogravimetric analysis (TGA) confirmed the structure and composition of this adsorbent. Adsorption experiments indicated that the initial pH of the solution influenced the adsorption ability of the composite for heavy metal. The composite showed high removal efficiency for all the tested metal ions (As(V), As(III), Cu2+, Hg2+, Zn2+, Cd2+, Pb2+) under neutral condition within a short time, especially for Pb2+, with a high adsorption capacity of 235.63 mg/g. Adsorption kinetic and XPS analysis indicated that the major adsorption mechanism for heavy metal removal by the composite was chemisorption. Moreover, the composite showed good regeneration performance, and its removal efficiency for Pb2+ was still over 93% even after 5 recycles.Graphical abstractGraphical abstract for this article
       
  • Removal of scale forming species from cooling tower blowdown water by
           electrocoagulation using different electrodes
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Omar M. Hafez, Madiha A. Shoeib, Mohamed A. El-Khateeb, Hussein I. Abdel-Shafy, Ahmed O. Youssef This work investigates the effect of electrocoagulation (EC) using Al, Fe, and Zn electrodes for removing hardness ions and dissolved silica from cooling tower blowdown (CTB) water. The real samples were collected from urea fertilizer factory (Helwan Fertilizer Company), Cairo, Egypt. The effect of operational parameters, such as current density, electrolysis time, inter-electrode distance and stirring rate were studied and evaluated for the maximum efficiency. At the optimum operational conditions, Al-electrode removed the scale forming species from CTB water more efficiently than Zn and Fe electrodes. Al, Fe, and Zn electrodes removed 55.36% and 99.54%, 36.99% and 98.93% as well as 38.63% and 95.62% for the total hardness and silica ions, respectively. In order to rationalize the removal mechanism, the EC generated sludge was characterized by SEM-EDX, XRD, and FTIR. The present investigation inferred that Al-EC generates amorphous nature crystalline and other anode materials (Fe and Zn) forms definite crystalline particles. EDX showed the presence of Ca2+, Mg2+, and silica ions in the sludge which proved the removal of these scale species from CTB water. As a conclusion, this study revealed that EC process using Al-electrode is a promising technology for the removal of scale forming species from CTB water.Graphical abstractGraphical abstract for this article
       
  • Recovery of ethanol via vapor phase by polydimethylsiloxane membrane with
           excellent performance
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Zhihao Si, Houchao Shan, Song Hu, Di Cai, Peiyong Qin To improve the selectivity of recovering bioethanol from fermentation broth, prevent membrane fouling by the components in fermentation, and enhance market competitiveness of bioethanol, the application of gas stripping assisted vapor permeation (GSVP) in bioethanol recovery and its potential in the integrated fermentation–separation processes were investigated in this work. As a result, a separation factor of 48, with the total flux of 866 g/m2 h, was obtained in separating model solution that contained 6 wt.% of ethanol at 65 °C. In the case of recovering bioethanol from the realistic fermentation broth, GSVP process showed long-time stability, no membrane fouling and no reduction of performance. Moreover, the evaporation energy requirement for GSVP process was at least 54% and 57% less than that of the conventional distillation and pervaporation processes.
       
  • Feasibility, mechanisms, and optimisation of organic pollutant degradation
           by thermally activated persulphate
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Ikechukwu A. Ike, John D. Orbell, Mikel Duke The thermally activated persulphate (TAPS) degradation process, although recognised as an effective means for pollutant degradation, is challenged by the high cost of energy and a sub-optimal operation due to the limited elucidation of its mechanisms. In this laboratory study, it is shown that waste heat from industries such as textile dyeing is adequate for the rapid degradation and mineralisation of orange G, a typical azo dye used as the main organic probe compound, in the absence or presence of a high concentration of inorganic salts relevant to the textile industry. Other probe compounds investigated are humic acid, salicylic acid, and caffeine. The study, for the first time, highlights the important role of radical kinetic energy in determining the rate and effectiveness of TAPS mineralisation of pollutants. One effect of the kinetic energy of radicals is the existence of an optimal mineralisation temperature. For an uncatalysed persulphate activation, the optimal temperature, independent of the target pollutant, was identified as 90 °C. Overall, the study provides important new insights for the design and operation of TAPS degradation processes.Graphical abstractGraphical abstract for this article
       
  • New modules for membrane bioreactors: Improving fouling control
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Robson Rodrigues Mororó, Cristiano Piacsek Borges, Frederico de Araujo Kronemberger New hollow fiber membrane modules with air injectors coupled to their base are presented in this paper. The transport resistances were analyzed through permeation tests with yeast cells suspensions varying parameters such as surface air velocity and filtration pressure. Five different modules were investigated, and the lowest resistances were observed in the module with 64 holes in the air injector and packing density equal to 650 m2 m−3. The modules with 32 holes in the air injector and packing density of 650 m2 m−3 showed the best relation between the efficiency in reducing transport resistance and the aeration energy expenditure.
       
  • Enhancing the separation performance of vanadium from a black shale
           leaching solution by supported liquid membrane using trialkylamine
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Hong Liu, Yi-min Zhang, Jing Huang, Tao Liu, Nan-nan Xue, Da-shuang Luo To enhance the separation efficiency of vanadium from impurities, the highly selective separation of vanadium from multiple impurities and the transport mechanism of vanadium from a black shale leaching-solution, by a supported liquid membrane (SLM) using trialkylamine (N235) as the carrier, were investigated. The effects of parameters such as feed-solution pH, carrier concentration, stripping-solution species, and diluent nature were studied. The separation performance of the SLM system for vanadium from the main impurities in the black shale acid leaching-solution—Fe, Al, P, Si, K, and Mg—was also discussed. The diffusion parameters and facilitated transport mechanism were evaluated using a first-order kinetic model. By enhancing the mass transfer of vanadium and the competitive extraction between vanadium and the impurity ions, the performance of the SLM system for the separation of vanadium from the highly impure black shale leaching-solution was significantly improved. These results show that highly selective separation of vanadium from impurities can be achieved using the N235-SLM system, indicating promising prospects for application in the vanadium industry.Graphical abstractGraphical abstract for this article
       
  • Predictive dimensionless solubility (pDS) model for solid solutes in
           supercritical CO2 that requires only pure-component physical properties
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Masaki Ota, Yoshiyuki Sato, Richard L. Smith, Hiroshi Inomata Dimensionless analysis was used to develop a correlative dimensionless solubility (DS) model and a predictive dimensionless solubility (pDS) model for estimating solid solubilities in supercritical carbon dioxide. Solubilities of 20 organic compounds made up of 685 data were used in developing the DS model and an additional 10 organic compounds were used for assessing the pDS model. Average relative deviation (ARD) in logarithmic solubility for literature model correlations were: Jouyban (2.06%), Hozhabr (2.09%), Jafarinejad (2.27%), Chrastil (2.49%), and Mendez-Santiago–Teja (3.46%). The proposed DS model had an ARD of 2.35% and the pDS model had an ARD of 10.5%. When the pDS model was optimized to the entire database, an ARD of 10.3% was obtained. The pDS model requires only pure solute properties (melting point, molar volume, entropy-based solubility parameter) and pure CO2 density for predicting solubility of solids in supercritical CO2.Graphical abstractGraphical abstract for this article
       
  • Pervaporative desalination of high-salinity water
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Dihua Wu, Aoran Gao, Hongting Zhao, Xianshe Feng Desalination of high salinity water by pervaporation using hydrophilic poly(ether-block-amide) membranes was investigated. A flux of 1680 g/(m2 h) and almost complete salt rejection (>99.9%) were achieved at 65 °C. Increasing salt concentration from 1 to 20 wt% resulted in a 50% reduction in water flux, whereas the salt rejection was not influenced. The salt rejection was not influenced by the salt type (i.e., NaCl, MgCl2 or Na2SO4) either. With an increase in temperature, the water flux through the membrane increased in spite of a decrease in the water permeability coefficient. The temperature dependence of water flux obeyed an Arrhenius type of relationship. Batch operation over a period of 10 h showed that the water flux decline could be recovered by washing the membrane with deionized water and there was no irreversible fouling during the pervaporative desalination process.
       
  • Desulfurization of FCC gasoline by using spiral wound pervaporation
           module: Removal of different types of sulfur containing species
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Manish Jain, Sharad Kumar Gupta In last decade, pervaporation has been recognized as a promising novel process for desulfurization of FCC (Fluidized Catalytic Cracking) gasoline. This study deals with the comparison of the removal of different types of sulfur containing species by a spiral wound pervaporation module. For this, different binary systems containing 2-methyl thiophene, 1-butanethiol and diethyl sulfide as solute and n-heptane as solvent are selected as model gasoline. Results reported in our previous study on n-heptane/thiophene systems are also included in the analysis. Experiments were performed on a spiral wound module with PDMS/PI (Polydimethylsiloxane/Polyimide) composite membrane at a variety of operating conditions. A suitable mathematical model was then used to predict the module performance theoretically. Some of the experimental results were used to predict the membrane transport parameters for different sulfur containing compounds, and the remaining experimental results were then used to validate the mathematical model. Comparison of the model predictions and experimental results validated the mathematical model, which suggests that the reported mathematical model can be applied to design the spiral wound pervaporative modules to remove higher molecular weight thiophenes as well as other sulfur containing compounds.The presented results show that the PDMS/PI membrane is selective for all three sulfur containing compounds. However, the pervaporation process is found more suitable for removal of lower molecular weight thiophenes. Results further show that the optimum operating conditions for sulfur removal may depend on the functional groups present and molecular weight of sulfur containing compounds present in the gasoline.Graphical abstractGraphical abstract for this article
       
  • Relating speed of sound and echo amplitude with biodiesel manufacture
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Monique K.K. Figueiredo, Cristiane E.R. Silva, André V. Alvarenga, Rodrigo P.B. Costa-Félix Biodiesel has a potential not completely exploited as substitute of diesel oil, despite it is known as biodegradable, nontoxic, and has a low-emission profile. The aim of this paper is to propose an ultrasonic method as a tool for real-time monitoring transesterification reactions by using low-power ultrasound based on a pulse/echo scheme. Two catalytic routes were tested, both using degummed soybean oil as source and KOH as catalyser. The difference between catalytic routes was the type of alcohol used (methanol and ethanol). Three different reaction times were studied: 10, 20, and 30 min. Low power (less than 100 mW) ultrasonic time-gated bursts were applied to the reactional media at 1 MHz. The eco was measured during the reaction, and small amounts of the reaction media were collected every 2 min for chemical analysis. Time of flight and echo waveform amplitude were the ultrasonic parameter of interest. The amplitude of the ultrasonic waveform was related with the variation of the ethanol-transesterification reaction rate and could help in qualitatively monitoring that reaction. Furthermore, density measurements where consistent with the variations observed on time of flight, confirming the possibility of monitoring the reaction using ultrasonic parameters. The behaviour of the ultrasonic parameters varied depending on the alcohol and the presence or not of heating during the reaction. As a common rule, the stabilization of the ultrasonic parameters indicates that the maximum yield for each catalytic route is achieved, indicating that the reaction should be stopped for maximum energy efficiency. Results disclose that the proposed method is a feasible way to monitor the reactions of biodiesel during its production, in real time, and with relatively low-cost equipment. Further development shall be done to use it in industrial scale, mainly regarding the ultrasound power and frequency to be employed.
       
  • Kinetic modeling of cellobiose by a β-glucosidase from
           Aspergillus fumigatus
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Mateusz Wojtusik, Clara M. Yepes, Juan C. Villar, Arno Cordes, Miguel Arroyo, Felix Garcia-Ochoa, Miguel Ladero The final step in lignocellulose enzymatic saccharification is the cellobiose conversion to glucose by β-glucosidases (BG). In this work, a valid kinetic model to describe cellobiose degradation for an industrial mixture of BG enzymes present in Aspergillus fumigatus is selected. Firstly, the enzyme mixture was characterised in terms of protein content and enzymatic activity on p-NPG (1326 U mLpreparation−1), determining the molecular weight of the only BG activity band observed in zymograms by SDS-PAGE and MALDI-TOF: 94 kDa. Subsequently, to select the correct kinetic model for the enzymatic hydrolysis of cellobiose, a combined strategy was performed: Firstly, non-linear regressions were applied to initial hydrolysis rate data for different enzyme concentrations and initial substrate and product concentrations, observing inhibition by cellobiose and glucose. Secondly, the optimal kinetic model was discriminated by a coupled non-linear regression-DOE numerical integration approach, by fitting several possible kinetic models involving different product inhibition mechanisms to progress curve data from runs at various initial substrate concentrations and temperatures. The best kinetic model involves non-competitive substrate inhibition and product competitive inhibition with two binding sites for glucose.Graphical abstractGraphical abstract for this article
       
  • A molecular collision based Lattice Boltzmann method for simulation of
           homogeneous and heterogeneous reactions
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Yousef Abdollahzadeh, Zahra Mansourpour, Hamed Moqtaderi, Seyed Nader Ajayebi, Mahyar Mohaghegh Montazeri A novel molecular collision based Lattice Boltzmann model at mesoscale was extended for representing hydrodynamics and concentration field of three typical reactive systems: (a) a reactive flow in a catalytic pore, (b) a fluid flow in a rectangular channel with a homogeneous reaction in the bulk and (c) a fluid flow that passes a reactive cylindrical obstacle in a channel. For detailed comparison of the performance of the model, all problems were solved by conventional reactive Lattice Boltzmann models. Also, three Damkohler numbers including advection-based and diffusion-based were derived using dimensional analysis. For the numerical validations, the results of collision model showed a good agreement with finite element method and demonstrated the ability of the proposed model for capturing different reaction problems especially heterogeneous reactions.
       
  • A review of catalytic partial oxidation of fossil fuels and biofuels:
           Recent advances in catalyst development and kinetic modelling
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): P. Arku, B. Regmi, A. Dutta Synthesis gas production is a technology that dates to the 1950s. Recently, the conversion of hydrocarbons to syngas has played an important role in various applications from gas-to-liquid (GTL) processes to fuel cell applications. However, the current industrial production method is only profitable when large quantities of syngas are produced and generates high amounts of CO2 as a by-product. With the growing demands for smaller-scale and mobile syngas production technology, the catalytic partial oxidation of hydrocarbons has become a promising alternative to the conventional methane steam reforming technology. With the infrastructure for production and distribution of many commercial fuels already in place, numerous studies have been done on conversion of these fuels into syngas. This paper reviews the research that has been done in the past decade on the catalytic partial oxidation of conventional fuels and biofuels. The challenges faced in catalyst development are described as well as solutions that have been proposed to address those challenges. Advances in kinetic modelling of catalytic partial oxidation are presented, and techniques used to develop such models have also been highlighted. Finally, research gaps have been identified and recommendations have been given for further investigations to address current challenges.
       
  • Modeling and simulation of a direct ethanol fuel cell considering
           overpotential losses and variation of principal species concentration
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): R.S. Gomes, M.M. De Souza, A.L. De Bortoli In this paper, we use a three-dimensional mathematical model to analyze the flow in a direct ethanol fuel cell (DEFC). The overpotential losses are estimated based on the operating parameters of the cell, and based on the reactive flow within the channels, in the diffusion layer, and on the electrocatalyst surface. The model includes fuel consumption and the formation of acetic acid and acetaldehyde, and the rate of ethanol crossover through the membrane. The numerical simulation of the reactive flow was made based on the central finite difference method. The equations were discretized in time using the Crank–Nicolson method. The model calculates the flow velocity and species concentration along the inlet channel, the diffusion layer and the catalyst surface. The molar fraction of the species is calculated according to the current density in the DEFC. The results for the cell voltage versus current density were obtained for different catalysts on the anode side, for three temperatures and two initial concentrations of ethanol. The results obtained are consistent with the experimental data found in the literature.Graphical abstractGraphical abstract for this article
       
  • Gas distribution characteristics for heterogeneous flows in the slender
           particle-containing scrubbing–cooling chamber of an entrained-flow
           gasifier
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Xin Peng, Yifei Wang, Zongyao Wei, Guangsuo Yu Dual-tip conductivity probes and a high-speed camera were used to study the gas distribution characteristics in a cold model apparatus of the slender particle-containing scrubbing–cooling chamber. The three-dimension column was 200 mm in internal diameter and 1353 mm in height. The effects of superficial gas velocities, fiber volume fractions and fiber aspect ratios on global gas holdups were determined. The results showed that under the influence of reverse buoyancy and negative pressure gradients, plume gas flow went up along the outside of the downcomer in downcomer spout region. Local radial gas holdup which was closely related with the internals and flow patterns presented obviously proximate core peak distribution in bubble-breaking plate region. The foam region consisted of bubble coalescence and breakup as well as droplets formation and splashing. At higher gas velocities, the increasing rate of global gas holdup gradually reduced. With the increase of fiber volume fraction, global gas holdup slightly increased at low gas velocities due to suppressed bed turbulence and bubble loading, but decreased at high velocities for increased liquid viscosity and vortex-shedding. Due to suppressed small-scale velocity fluctuation, global gas holdup increased with increased fiber aspect ratio. A modified drift-flux model containing crowding factor and fiber number density for global gas holdup correlations was proposed and all of the data could be calculated with a relative deviation less than 10%.Graphical abstractGas–water–fiber mixing regime of the scrubbing–cooling chamber containing dilute nylon fiber suspensions can be divided into three regions: downcomer spout region, bubble-breaking plate region and foam region. A modified drift-flux model containing crowding factor and fiber number density for global gas holdup correlations was proposed and all of the data could be calculated with a relative deviation less than 10%.Graphical abstract for this article
       
  • Inhibition effect of CeO2 promoted SiO2 coating on coke growth during
           steam cracking of ethane
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): E. Mahmoudi, A. Hafizi, M.R. Rahimpour, A. Bolhasani, A. Shariati The main goal of this research is to develop an effective coating to inhibit the direct contact of hydrocarbon with reactor metal wall along with the catalytic conversion of coke to carbon oxides. For this purpose, CeO2 promoted SiO2 coatings were deposited on the surface of an industrial HP 40 alloy. With the purpose of obtaining an effective passive coating with an appropriate morphology and low defects, different synthesis parameters such as the pretreatment of sublayer with sodium carbonate and sulfuric acid solutions and the roughness of HP 40 coupon is investigated. Afterwards, the SiO2 coating was improved with cerium oxide using different Ce/Si molar ratios (0, 0.25, 0.5, 0.75 and ∞) according to characterization and ethane cracking results. The amount of deposited coke is reduced with increasing the Ce/Si molar ratio up to 0.75. The coke is reduced from 1.6 mg for blank HP 40 to about 0.5 and 0.6 mg for 0.75CeO2/SiO2/HP40 and CeO2/SiO2/HP40 specimens, respectively. In addition, the characterization results of coked samples after ethane cracking revealed that the coating of different optimal layers successively inhibited the formation of filamentous carbon and metal migration. Thus, the deposited coke on the optimal coating coupons is mostly composed of amorphous soft carbon.Graphical abstractGraphical abstract for this article
       
  • Effect of ammonia on gasification performances of phenol in supercritical
           water
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Yuzhen Wang, Yitong Zhu, Zhuan Liu, Changqing Fang, Jianqiao Yang, Yanfeng Guo, Shuzhong Wang The solutions of phenol and the mixture of phenol and ammonia were gasified in a continuous supercritical water reactor to evaluate the influences of ammonia on the hydrogen production and the degradation pathways of phenol. The effects of temperature (560–640 °C), reaction time (2–20 s) and concentration of ammonia (500–2000 mg/L) on gaseous distributions, gasification efficiencies and reactants removal efficiencies were investigated. In addition, the effects of ammonia on the kinds of intermediate products were analyzed. Results showed that the increasing temperature greatly promoted the hydrogen production and degradation of phenol. Longer reaction time gave a positive effect on gasification efficiencies in 10 s, while the effect was little when the reaction time longer than 10 s. Ammonia prevented the production of hydrogen and the degradation of phenol, which was mainly due to the generation of more stable nitrogen polycyclic compounds. The possible degradation pathways for the mixture of phenol and ammonia were proposed.
       
  • Ehanced catalytic ozonation of NO over black-TiO2 catalyst under
           inadequate ozone (O3/NO molar ratio = 0.6)
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Chenyang Han, Shule Zhang, Lina Guo, Yiqing Zeng, Xiaohai Li, Zhencang Shi, Yi Zhang, Baoqiang Zhang, Qin Zhong Catalytic ozonation is an attractive method for low-temperature denitrification in recent years. However, the research concerning catalytic ozonation of NO by inadequate ozone (the molar ratio of O3/NO 
       
  • Hydrolysis kinetics of epoxypropyltrimethylammonium chloride in
           ethanol/water solution system
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Xiao-Fang Wan, Meng-Zhen Liu, Teng Yu, Xin-Sheng Chai, You-Ming Li, Ke Lin, Guang-Xue Chen NaOH-based hydrolysis of epoxypropyltrimethylammonium chloride (ETA) was carried out in a batch reactor using ethanol/water system. The analytic technique, headspace-gas chromatography, was employed in order to follow the time evolution of ETA aqueous solution. Various effects on hydrolysis degree, such as, molar ratio of ethanol/water, NaOH concentration, reaction temperature, and dosage of hydrolysis product (2,3-dihydroxypropyl trimethylammonium chloride) were investigated. And then the kinetic model of the hydrolysis of ETA was developed and the possible mechanism of nucleophilic ring opening reaction was proposed. Furthermore, the model parameters of the process were also determined by data fitting. The results show that ETA hydrolysis follows the pseudo-first order law and kinetic model agrees well with the experimental results. Therefore, based on this kinetic model we could control the hydrolysis degree of ETA during ETA-involved cationic etherification of natural polymer in order to improve the etherification efficiency.Graphical abstractGraphical abstract for this article
       
  • Influence of reagents choice (buffer, acid and inert salt) on triiodide
           
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Carlos Baqueiro, Nelson Ibaseta, Pierrette Guichardon, Laurent Falk This work studies how deeply the reagents choice influences micromixing characterisation by the Villermaux–Dushman method, when applying it to a 1 L stainless steel standard vessel with two baffles, stirred by an inclined blade turbine. For the first time, borate and phosphate buffer are compared on their use in the method. It is observed that triiodide production is higher when borate buffer is used. Moreover, perchloric acid leads to higher triiodide production than sulphuric acid, when injecting the same concentration of both acids. Finally, the influence of the ionic strength is also studied, since there has been a great deal of controversy about it over the last years. The results show that the ionic strength affects triiodide production, although relatively slightly. Advice concerning the choice of the reagents is given in conclusion.Graphical abstractGraphical abstract for this article
       
  • A new feedback predictive control approach for processes with time delay
           in the manipulated variable
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Derrick K. Rollins, Yong Mei The scope of this work is time delay (θ) in the manipulated variable (MV) and not in the controlled variable (CV), addressed by approaches such as the Smith Predictor. The classical algorithm for dead time in MV is model predictive control (MPC). The MPC control law is for the future predicted value of CV to be at the set point an integer value of sampling time steps (J) beyond θ time in the future. Hence, the effectiveness of MPC depends strongly on the accuracy of the future prediction of CV, which decreases as J increases. In addition, the larger the time lag for MV, the longer it takes to reach the set point and the greater J will be also. Therefore, to overcome these limitations, this work presents a new FBC predictive control approach that has a control law that uses a future prediction of CV a distance θ into the future. Thus, it prediction horizon is minimal and it is not affected by the MV time lag. This approach is compared with MPC in two studies. The first one uses a mathematical transfer function model and the second study uses a mathematically simulated CSTR.
       
  • Multi-mode plant-wide process operating performance assessment based on a
           novel two-level multi-block hybrid model
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Yuqing Chang, Xiaoyu Zou, Fuli Wang, Luping Zhao, Wei Zheng Process operating performance assessment judges the optimal degree of the process performance and identifies the cause for non-optimality in real-time. Therefore, process operating performance assessment is of great significance in both the theoretical research and practical application. In this article, the multiple working modes, the plant-wide process characteristics, and the coexistence of both the quantitative and qualitative information are considered. To solve the above problems, a novel two-level multi-block hybrid model based operating performance assessment approach is proposed. Under each working mode, the two-level hybrid model is established. Due to the novel offline modeling method, the global performance grade is directly determined by the sub-block performance grades and the sub-blocks can be modeled separately with different modelling techniques. In this article, a quantitative information dominated sub-block is modeled by the quantitative method, while a qualitative information dominated sub-block is modeled by the qualitative approach. When any non-optimal operating performance occurs, a contribution rate based non-optimal cause identification technique is developed within the non-optimal sub-blocks. At the end, the developed assessment approach is applied to a gold hydrometallurgy process to illustrate its feasibility and validity.
       
  • Compared novel thermally coupled extractive distillation sequences for
           separating multi-azeotropic mixture of acetonitrile/benzene/methanol
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Chao Wang, Chao Guang, Yue Cui, Chen Wang, Zhishan Zhang In this paper, extractive distillation applies to separate acetonitrile/benzene/methanol, the medicine is a compounding of multi-azeotropes via introducing chlorobenzene as a solvent. In order to achieve the purpose of energy saving and CO2 emission reduction, ten novel thermally coupled separation sequences including direct sequences, indirect sequences, hybrid sequences and solvent splitting sequences are established and explored based on extractive dividing wall column (EDWC) and side-stream extractive distillation column (SSED). The corresponding optimal parameters are determined by effective and convenient sequential iterative optimization procedures on the basis of minimized total annual cost (TAC) and meanwhile CO2 emissions are calculated to evaluate environmental impact. The comparison results illustrate that the solvent splitting SSED sequence has more advantages in energy consumption, environment impact and economic cost than others, reducing at most 38.44%, 32.84% and 38.41% in terms of total reboiler duty, TAC and CO2 emissions.
       
  • Determination of steady-states in a tubular biofilm bioreactor with axial
           dispersion
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Szymon Skoneczny, Monika Cioch The paper presents the method of modelling and numerical simulation of bioreactors with biofilm and axial dispersion of the liquid. Such bioreactors belong to systems with distributed state variables. The mathematical model was compared with a model assuming perfect mixing and a model assuming piston-flow of the liquid. According to calculations performed, the piston flow of the liquid can be assumed for Peclet numbers above 40. In turn, Peclet numbers below 0.5 justify perfect-mixing approximation. It was shown that there may exist an optimal value of Peclet number for which a maximum degree of conversion of the limiting substrate at the bioreactor outlet is obtained. The existence of the optimal Peclet number depends on the operating conditions of the bioreactor.Graphical abstractGraphical abstract for this article
       
  • Performance analyses of LP and MILP solvers based on newly introduced
           scale: Case studies of water network problems in chemical processes
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Gaurav Kumar Silori, Shabina Khanam To meet fresh water requirement as well as to tackle wastewater generation are serious issues in process industries in the present scenario. To deal with water network problems, various models and computer aided tools have been used. GAMS software is used for this purpose since many years. All kind of water network models including LP, NLP, MILP and MINLP are extensively solved by this tool. However, it appears that no specific work is available in literature to observe the behaviour of different solvers on industrial case studies. The present study addresses this gap through behaviour analysis of LP and MILP solvers. Four case studies are considered from open literature, which include water networks for single contaminant, multi-contaminant and process as well as treatment units. LP models of all cases are solved through three different solvers i.e. CPLEX, CONOPT and MINOS. Further, piping cost is incorporated into LP models and thus, converted these to MILP, which are solved using three solvers such as BDMLP, CBC and SCIP. Results obtained through six solvers are compared at BECOTA scale. MINOS performs better for LP models as compared to CPLEX- a traditionally used LP solver. However, CBC is better amongst other MILP solvers considered. It is observed that selection of a particular solver may significantly influence the water network design as well as plant economy. Hence, selection of solvers should be carried out carefully.
       
  • Optimal design of dynamic experiments in the development of cybernetic
           models for bioreactors
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Martin F. Luna, Ernesto C. Martínez Cybernetic models of bioreactors are appealing due to their capacity to account for regulatory mechanisms in cell metabolism by modeling the synthesis of enzymes and their activities. For a given objective of interest, experimental data used to fit the cybernetic model parameters should be maximally informative. To excite purposefully the most relevant metabolic pathways, a dynamic experiment is designed by accounting for the sensitivity of the chosen objective to time-varying operating conditions. In this work, the bioreactor feeding profile and sampling times are designed to maximize the information content. A Bayesian optimization approach is proposed to solve the resulting mathematical program. As a case study, biomass production is used as the objective to be maximized in fed-batch cultivation of Saccharomyces cerevisiae growing on glucose as a carbon source. Experimental results demonstrate that the proposed approach helps to iteratively improve a cybernetic model by designing experiments that maximize the information content.Graphical abstractGraphical abstract for this article
       
  • Multi-criterion control of a bioprocess in fed-batch reactor using EKF
           based economic model predictive control
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Anilkumar Markana, Nitin Padhiyar, Kannan Moudgalya This research paper presents an offline and online user defined priority driven multi-objective optimal control study of a bioprocess in a fed-batch reactor. Productivity and the amount of substrates used in the process are considered as the two control objectives in that order of priority for this purpose. The priorities in the objective functions are realized using the lexicographic approach by sequentially solving multiple objectives to arrive at a Pareto solution point. This approach is not sensitive to the tuning of weighting parameters as compared to the scalarized objective, practiced conventionally. The weighting factors tuning issue is demonstrated with an offline optimal control. The lexicographic optimization approach is then implemented to overcome this thing issue. Subsequently, the online optimal control problem is solved using economic model predictive control (EMPC) owing to the economic nature of the control objectives. Often, the Pareto curve is such that marginally relaxing one objective results into a significant improvement in the other objective. This can easily be implemented with the lexicographic approach and is demonstrated using EMPC. Moreover, unlike the continuous processes, the batch processes operate for a specific batch time. Hence, the shrinking horizon approach along with the EMPC framework is employed in the fed-batch bioreactor for online control with extended Kalman filter (EKF).
       
  • Novel technological solutions for eco-protective water supply by
           economical and sustainable seawater desalination
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Duygu Topaloglu, Yasemin Melek Tilki, Seyda Aksu, Tugba Nur Yilmaz, Emin Ender Celebi, Salim Oncel, Coskun Aydiner Development of novel and economical technological solutions for enviro-sensitive seawater desalination enabling the abolishment of marine ecosystem deteriorations due to brine discharges has a vital and indispensable importance for sustainable water supply worldwide. The encouragement of environmental decision policies that focus on reducing energy footprints by novel water and wastewater treatment plants is also prioritized as a very prominent reality for their widespread acceptability and realization in new age. In this respect, eleven innovative systems differentiated into two main groups, namely with and without brine discharge, were developed for exposing their techno-economical sustainability capabilities in enviro-protective seawater desalination. Depending on experimental performances, the systems arranged with different configurations of membrane distillation and forward osmosis at three heat recovery choices for natural gas or waste heat usage were individually simulated in real scale. The field simulations revealed that a more economical seawater desalination was provided by waste heat than that by RO, MD, and MED regardless of carbon tax liability. Zero brine discharge was assured using external fresh water with no additional cost at 31% loss per drinking water. This study finally claims that the developed systems can be successfully and cost-effectively implemented for eco-protective water supply from seawater in semi-arid, sub-tropical, temperate, and weak-temperate countries.Graphical abstractGraphical abstract for this article
       
  • Design and control of extractive distillation process for separation of
           the minimum-boiling azeotrope ethyl-acetate and ethanol
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Qingjun Zhang, Meiling Liu, Chenxiaodong Li, Aiwu Zeng Design and control of extractive distillation process is explored by taking the separation of minimum-boiling azeotrope ethyl-acetate and ethanol as an example. The two evaluation indicators of second-law efficiency and CO2 emissions are employed to evaluate different alternatives, which consist of conventional case, F-E process (hot solvent stream to preheat fresh feed of extractive column), B1-E process (hot solvent stream to preheat feed of recovery column), and F-B1-E process (hot solvent stream to preheat feed of extractive and recovery column). The conventional case can reduce 32.23% in total annual cost (TAC), 28.81% in energy-saving comparing to economically optimum fully heat-integrated pressure-swing distillation process. Besides, it can further cut 4.38% in TAC and 9.79% in steam cost by heat integration B1-E configuration while others are 1.11% (1.30%) in TAC and 10.45% (12.11%) in steam cost, where, data in the brackets are for F-B1-E process. Furthermore, the control of extractive distillation process is explored since the interaction of parameters is complicated. For conventional process, the effectiveness of single-end control strategy is determined by the method of feed composition sensitive analysis. The appropriate control scheme (CS3) is screened by the indicator of integral absolute error (IAE) since its deviations of product purities to specifications are the least. A new control scheme of bypassing portion of hot stream around economizer with dual-point temperature control strategy is proposed for the efficient economics thermal integration alternative, and it can still achieve robust control performance at facing feed flowrate and composition disturbances.Graphical abstractGraphical abstract for this article
       
  • Characteristics of bubble, cloud and wake in jetting fluidised bed
           determined using a capacitance probe
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Jikai Huang, Youjun Lu Detailed properties of bubble, cloud and wake in a jetting fluidised bed are studied by a capacitance probe method in this paper. In a jetting fluidized bed, when smaller particles are fluidised, bubble size and rising velocity initially increase near the distributer and maintains almost constant values with the increase in bed height. When bigger particles are fluidized, the bubble size and rising velocity decreased with the increase in bed height. The bubbles in bed when bigger particles are fluidised are smaller than those when smaller particles are fluidised under the same operating conditions. Background gas velocity has a more significant influence on bubble size, whereas the jetting gas velocity has a more significant influence on bubble rising velocity. The effect of operating conditions and bubble size on the averaged voidage of cloud or wake is negligible. Besides, the thickness of cloud and wake increases with bubble size, and the thickness of cloud is greater than that of wake.Graphical abstractGraphical abstract for this article
       
  • Micromechanical analysis on the compaction of tetrahedral particles
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Yi He, Feihong Guo Understanding the roles of particle properties in powder compaction is important to many industrial products, such as tablets in pharmaceutics, briquettes in iron ore handling and green compacts in powder metallurgy. However, the role of particle shape in bulk compression and how it is related to the properties of the final compact are not well understood. In this study, we investigated the structural evolution, force distribution and compact strength of tetrahedral particles using discrete element method, with a focus on the effect of particle interlocking due to non-spherical particle shape. Tetrahedral particles were constructed using clumped sphere approach, which allows multiple contacts being set up between two contacted particles. Die compaction followed by unconfined compression were conducted on the assemblies of both spherical and tetrahedral particles. The results showed that the tetrahedral particle shape reduces the degree of particle rearrangement at the early stage of bulk compression but enhances the resistance to bulk deformation at the later stage due to enhanced shear resistance at interparticle contacts. The compact of tetrahedral particles presents a higher compressive strength due to increased number of interparticle bonding. Compared to the spherical particles, the macroscopic failure mode tends to be more ductile for the tetrahedral particles. The tetrahedral particle shape has no effect on the dominant bond failure mode but leads to a wider shear banding, more dispersed bond breakage and a slower bond breakage process. This work highlights the role of particle shape in densification mechanism and mechanical response of the formed powder compact.Graphical abstractGraphical abstract for this article
       
  • Continuous protein crystallisation platform and process: Case of lysozyme
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Huaiyu Yang, Peter Peczulis, Pavan Inguva, Xiaoyu Li, Jerry Y.Y. Heng In this work, we designed and built a continuous crystallisation oscillatory flow platform. The lysozyme crystallisation behaviours were investigated at concentrations from 30 to 100 mg/mL, under oscillatory conditions with amplitude (x0) from 10 to 25 mm and frequency (f) from 0.05 to 0.25 Hz in a batch oscillatory flow crystallisation platform. The nucleation rate increased with increase in concentration of initial lysozyme solution, and was also found to increase with increase in shear rate. By learning the thermodynamics and kinetics of lysozyme crystallisation in batch oscillatory flow, the batch crystallisation process was successfully transferred to a continuous oscillatory flow crystallisation process. The equilibrium state of continuous crystallisation reached at residence time 200 min, and the final product crystals shape and size were consistent during the continuous process. This work demonstrates the feasibility of oscillatory flow based platforms for the development of continuous protein crystallisation as for downstream bioseparation.Graphical abstractGraphical abstract for this article–Development of the new generation of continuous crystallisation platform.–Successfully demonstrated the crystallisation of proteins with the oscillatory flow crystalliser.–The equilibrium state (with consistent crystal size and solution concentration) of continuous crystallisation achieved.–With same oscillatory condition, the crystallisation processes in continuous/batch oscillatory flow crystallizer were in consistence.
       
  • Effect of moisture content and length of flexible filamentous particles on
           cluster characteristics in a fluidized bed dryer
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Kai Wu, Linyu Gao, Zhulin Yuan, Bin Li, Wenkui Zhu, Ying Wu, Ke Zhang, Duanfeng Lu, Dengshan Luo Flexible filamentous particles have been widely applied in the industrial fluidized drying process. The hydrodynamic characteristics and equipment drying performance will be greatly influenced by the inhomogeneity of the special particle flow. So it is of great importance to gain more insight into this cluster phenomenon. In this paper, a new measurement algorithm is used to study the cluster distribution characteristics of the flexible filamentous particles in a cold fluidized riser. Specifically, influence of the particle length, moisture content and operating parameters on cluster distribution is emphasized. Moreover, the distribution of solid volume fraction inside the clusters is studied. The experimental results are compared with the clustering characteristics of spherical particles. Last, the correlation of the average cluster diameter and the frequency are formed. The results showed that the particle length, moisture content and operating condition has a significance influence on the fluidization behavior and the distribution characteristics of clusters. This work would provide an important reference for the drying process of this particular particle. All these will benefit the design and scale-up of related equipment.Graphical abstractRelationship between solid volume fraction in clusters and cluster equivalent diameter at height-4. The ordinate shows the average solid volume fraction of the cluster with their respective cluster equivalent diameters on the abscissa. (tobacco 1, moisture content = 19%, Ms = 500 g, Ug = 7.82m/s)Graphical abstract for this article
       
  • Critical electric field strength for partial coalescence of droplets on
           oil–water interface under DC electric field
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Donghai Yang, Mojtaba Ghadiri, Yongxiang Sun, Limin He, Xiaoming Luo, Yuling Lü Water droplets dispersed in crude oil have to be separated and this is most commonly done by electrical dehydration. Under high strength electric fields, partial coalescence may occur and leave fine secondary droplets, which reduce the separation efficiency. The critical electric field strength (Ecrit) for partial coalescence occurrence depends on several factors. In this paper, the effects of droplet radius, conductivity, interfacial tension, viscosity (changed by adding alkali, surfactant, and polymer respectively) and oil density on Ecrit have been studied experimentally. Ecrit increases linearly with the inverse of the square root of droplet radius, R−0.5, but the slope Ecrit/R−0.5 (k) can be changed. Increasing surfactant concentration reduces Ecrit and the slope k decreases, which indicates reducing interfacial tension promotes partial coalescence. Whereas, adding alkali or polymer improve Ecrit and the slope k increases with the increase of its concentration, because of the changes in water conductivity or viscosity. In addition, Ecrit is proportional to the product of density difference and oil viscosity. A proposed formula expressing the Ecrit, albeit in an empirical way, was given which takes account of the relevant parameters. These results will be of guiding significance to the choice of electrical field strength for electro-dehydration.Graphical abstractGraphical abstract for this article
       
  • Effect of shear rate on primary nucleation of para-amino benzoic acid in
           solution under different fluid dynamic conditions
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Valentina Nappo, Rachel Sullivan, Roger Davey, Simon Kuhn, Asterios Gavriilidis, Luca Mazzei The influence of shear rate on the primary nucleation of para-amino benzoic acid in water has been investigated via a series of cooling crystallization experiments. For each experiment, we recorded the induction time at various temperatures and supersaturation ratios, employing two flow devices: a capillary tube in which the solution was divided into hundreds of monodisperse droplets and a set of stirred vials. The capillary tube was used to perform experiments in stagnant conditions (motionless droplets) and low shear rate conditions (flowing droplets), while the stirred vials were used to perform experiments at relatively high shear rates. In this way, a wide range of shear rates was investigated. Comparing the results obtained for the motionless and flowing droplets, we saw that the nucleation rate is significantly increased (by several orders of magnitude) by the shear field; however, when the shear rate increases beyond a certain level (stirred vials experiments), we observed a drop in the nucleation rate. Thus, the results demonstrate a non-monotonic dependence of primary nucleation rate on shear rate. Various mechanisms to explain the effect of shear on nucleation are quantitatively and qualitatively discussed; however, at present no definitive conclusion can be drawn to identify the controlling mechanism.
       
  • Heat transfer analysis of hydromagnetic water–graphene oxide nanofluid
           flow in the channel with asymmetric forced convection on walls
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): M. Javanmard, M.H. Taheri, M. Abbasi, S.M. Ebrahimi In this paper, heat transfer of hydromagnetic water–graphene oxide nanofluid flow in the channel with asymmetric forced convection on walls is analyzed. The basic partial differential equations include momentum and energy for this problem are reduced to the ordinary differential equations which are solved numerically by using finite element method (FEM) using FlexPDE software package. For validity, the results are compared with 4th order Runge–Kutta numerical solution. The effects of different physical parameters such as the nanoparticle volume fraction, the Magnet parameter, the Biot number and the Eckert number on the dimensionless velocity profile, the dimensionless temperature profile and the dimensionless gradient temperature profile are discussed. It was concluded that with increase in the nanoparticle volume fraction and Magnet parameter, the dimensionless velocity profiles of flow reduce. With rising of the Biot number, the dimensionless temperature decreases and dimensionless gradient temperature profile increases. Moreover, by increasing of the nanoparticle fraction volume, the dimensionless temperature profiles of flow is increased and the heat transfer coefficient enhanced. In addition, by increasing of the nanoparticle fraction volume, the convection on walls increases within the channel. Also, with increases of the Eckert number, the dimensionless temperature profile increases and the heat transfer rate on the channel walls is increased.Graphical abstractGraphical abstract for this article
       
  • Enhanced mass transfer from the installation of a sieve tray subject to
           the variation of liquid heights and flow regimes in a bubble column
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Hanjin Im, Shinbeom Lee, Jae W. Lee This work addressed the gas–liquid (G/L) mass transfer limitation coming from the increasing liquid height and the circumvention of the limitation by introducing a sieve tray in a bubble column. Either monoethylene glycol (MEG) solution or n-hexane was adopted as a liquid phase and argon was used as a gas phase in the bubble column. The gas holdup and the mass transfer coefficient became lowered by the static liquid height increase due to the increase of bubble size. The loss of mass transfer was overcome by installing a sieve tray inside the column. The two sieve trays with different hole sizes were employed and both bubble diameter and standard deviation of pressure were investigated to understand the effect of the sieve tray on the mass transfer. With a smaller size hole sieve (1 mm), the mass transfer deteriorated in both liquid systems (MEG and n-hexane) due to the formation of gas cap below the sieve while with a larger hole sieve (3 mm), it was enhanced because of the reduction of bubble diameters without any gas cap formation. However, it was found that the sieve tray effect was weakened when the flow regime changes from homogeneous to heterogeneous.Graphical abstractGraphical abstract for this article
       
  • Shear rate and mass transfer coefficient in internal loop airlift reactors
           involving non-Newtonian fluids
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Nikesh Kumar, Ajay Bansal, Renu Gupta The shear rate and mass transfer coefficient play a key role in the chemical/biochemical processes and are considered as the most important parameters for the design of airlift reactors. Experimental investigations on the average shear rate and mass transfer coefficient have been made in internal loop airlift reactor. Tap water and glycerol–water solutions were taken as Newtonian fluids whereas non-Newtonian fluids include carboxymethyl cellulose and Xanthan in water. The average shear rate for the non-Newtonian fluids was estimated in terms of power due to aeration and rheological parameters. It is observed that average shear rate increased with increase in superficial gas velocity and decreased with increase in concentration. The apparent viscosity of the non-Newtonian fluids decreased with increase in superficial gas velocity due to increase in average shear rate. Overall volumetric mass transfer coefficient was evaluated by using dissolved oxygen concentration vs. time data. Volumetric mass transfer coefficient for Newtonian and non-Newtonian fluids is affected by superficial gas velocity and viscosity/apparent viscosity of the liquid phase. The overall volumetric mass transfer coefficients have been increased, with the increase in superficial gas velocity and decrease in viscosity/apparent viscosity of the Newtonian and non-Newtonian fluids and have been empirically correlated.Graphical abstractGraphical abstract for this article
       
  • Second law analysis for flow of a nanofluid containing graphene–platinum
           nanoparticles in a minichannel enhanced with chaotic twisted perturbations
           
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Mehdi Bahiraei, Nima Mazaheri The second law and entropy generation characteristics of a new hybrid nanofluid containing graphene nanoplatelets decorated with platinum nanoparticles are evaluated in a chaotic twisted channel. Although several investigations have been carried out on flows inside chaotic channels in the relevant literature, very few studies have employed nanofluids as working fluids in such configurations. The geometrical perturbations cause formation of counter rotating Dean roll-cells which intensify mixing in the flow and disturb the boundary layer. The intensity of perturbations considerably enhances at higher Dean numbers. The maximum velocity is shifted toward the outer wall due to the centrifugal force, and the maximum frictional entropy generation occurs there. Because the roll-cells lead to more uniform temperature distribution, thermal entropy generation reduces with increase of distance from the inlet of each bend. Moreover, by increasing concentration and Dean number, thermal entropy generation and Bejan number decrease while frictional entropy generation intensifies, however, due to dominance of thermal entropy generation, overall irreversibility of the nanofluid flow reduces. Besides, the temperature gradients become greater at higher wall heat fluxes which lead to the more intense thermal entropy generation. In addition, the difference between the Bejan numbers related to different wall heat fluxes is more noticeable at higher concentrations.
       
  • DEM simulations of screening processes under the influence of moisture
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Frederik Elskamp, Harald Kruggel-Emden In a wide field of applications, screening is required to separate bulk materials according to their particle sizes. Due to environmental, material or process related effects, particles frequently prevail in moist conditions, which is not preferred due to attractive forces altering the screening efficiency, but often not preventable. As for the design of dry screening processes detailed particle-based simulation approaches like the discrete element method (DEM) and phenomenological models are available, a step towards meeting the requirements for real particle systems under moist conditions is made. Therefore, batch screening under the influence of moisture is investigated experimentally and by using DEM simulations involving different sized polyoxymethylene and glass spheres. For this purpose, a DEM code is extended to calculate forces caused by liquid bridges, forming out between particles or walls close to each other under moist conditions. Thereby, the bridge formation and rupture and the liquid distribution are considered. First, the DEM framework is validated against experiments by monitoring the capillary and viscous force acting on two liquid bridge contact partners. Further extensive validations are performed by comparing the fraction retained over time and the final liquid distribution for discontinuous screening under the influence of various amounts of liquid for different mechanical agitations in experiments and simulations. Finally, the detailed liquid distribution over time in the DEM simulations is examined and general conclusions are drawn. The overall aim is to use the framework and the respective data, to extend phenomenological process models for screening under moist conditions in subsequent studies.Graphical abstractGraphical abstract for this article
       
  • Preparation and characterization of Chilean propolis coprecipitates using
           Supercritical Assisted Atomization
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Alessia Di Capua, Arturo Bejarano, Renata Adami, Ernesto Reverchon Propolis is a natural resinous material with antimicrobial, anti-inflammatory, antioxidant, antibiotic and anti-carcinogenic properties. Propolis coprecipitation was attempted by Supercritical Assisted Atomization (SAA) using two carriers: hydroxypropyl-β-cyclodextrin (HPβCD) and polyvinylpyrrolidone (PVP), with the aim to protect propolis bioactivity against oxidation and to improve its bioavailability. Propolis/carrier ratio and overall solute concentration were investigated to understand their effect on the success of coprecipitation as solid dispersion of propolis in the carrier matrix and on particle morphology and particle size distribution. The results confirmed the efficiency of SAA process: spherical amorphous particles were obtained in which propolis and carrier were coprecipitated, with a mean diameter ranging between about 0.20 and 0.37 μm for HPβCD coprecipitates and between about 0.23 and 0.50 μm for PVP coprecipitates. SAA particles showed a polyphenol loading efficiency up to 100% for HPβCD coprecipitates and up to 96% for PVP coprecipitates, with a half inhibition concentration of DPPH radical up to (17.2 ± 2.8) μg/mL and (17.3 ± 1.0) μg/mL, respectively. These particles rich in bioactive compounds can be used as functional component in formulations of new food or pharmaceutical products.Graphical abstractGraphical abstract for this article
       
  • Fabrication and investigation of PEBAX/Fe-BTC, a high permeable and CO2
           selective mixed matrix membrane
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Fatereh Dorosti, Asghar Alizadehdakhel Mixed matrix membranes comprising commercial poly (ether-block-amid) or PEBAX® (1657) as continues phase and Fe-BTC metal organic framework as disperse phase are fabricated via phase inversion method. To investigate membrane structure various analysis including SEM, TGA, DLS and FTIR are performed. CO2 and CH4 permeability and Selectivity are measured for all membranes at 25 °C and different pressures from 3 to 25 bar. Moreover, mixed gas tests are implemented for 10/90 CO2/CH4 mixture. Cross section SEM images showed proper particles distribution and good interaction between polymer and particles. The replacement of various bounds in FTIR test confirmed the good compatibility of Fe-BTC with polymer matrix too. TGA results showed acceptable thermal resistance of all membranes. Membranes permeability increased with increase in particles loading percent due to high porosity of particles and also high adsorption capacity especially for CO2 molecules. The highest CO2 permeability was belong to PEBAX/Fe-BTC 40 wt.% membrane which was 425.4 Barrer. Mixed matrix membranes showed selectivity enhancement too. However, PEBAX/Fe-BTC 20 wt.% membrane had the best selectivity of 22.19, in membrane with higher loading percent particles agglomeration made interfacial voids which caused selectivity decrement specially in 40 wt.% loading percent. All membranes showed permeability and selectivity growth till 7 bar pressures however, selectivity decreased due to plasticization effect at higher pressures of 15 and 25 bar. Membrane with 25 wt.% loading percent showed 50% and 9% increase in CO2 permeability and selectivity at 7 bar compare to base pressure of 3 bar.
       
  • Modelling of hydrodynamic cavitation with orifice: Influence of different
           orifice designs
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Alister Simpson, Vivek V. Ranade Hydrodynamic cavitation (HC) may be harnessed to intensify a range of industrial processes, and orifice devices are one of the most widely used for HC. Despite the wide spread use, the influence of various design and operating parameters on generated cavitation is not yet adequately understood. This paper presents results of computational investigation into cavitation in different orifice designs over a range of operating conditions. Key geometric parameters like orifice thickness, hole inlet sharpness and wall angle on the cavitation behaviour is discussed quantitatively. Formulation and numerical solution of multiphase computational fluid dynamics (CFD) models are presented. The simulated results in terms of velocity and pressure gradients, vapour volume fractions and turbulence quantities etc. are critically analysed and discussed. Orifice thickness was found to significantly influence cavitation behaviour, with the pressure ratio required to initiate cavitation found to vary by a factor of 10 for orifice thickness to diameter (l/d) ratios in the range of 0–5. Inlet radius similarly has a pronounced effect on cavitational activity. The results offer useful guidance to the designer of HC devices, identifying key parameters that can be manipulated to achieve the desired level of cavitational activity at optimised hydrodynamic efficiencies. The models can be used to simulate detailed time-pressure histories for individual vapour cavities, including turbulent fluctuations. This in turn can be used to simulate cavity collapse and overall performance of HC device. The presented approach and results offer a useful means to compare and evaluate different cavitation device designs and operating parameters.
       
  • CFD modeling of air and highly viscous liquid two-phase slug flow in
           horizontal pipes
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): H. Pineda-Pérez, T. Kim, E. Pereyra, N. Ratkovich Computational Fluid Dynamics (CFD) approach, encoded on STAR-CCM+ was used to simulate air and highly viscous liquid two-phase slug flow in a 50.8-mm (2-in.) ID and 18.9-m (62 ft.) long horizontal pipe. The Volume of Fluid (VOF) method, the Continuum Surface Force (CSF) model and the High Resolution Interface Capturing (HRIC) scheme were utilized. The liquid viscosity varied from 161 to 567 mPa s based on the experimental data. A sensitivity analysis of the sharpening factor, the angle factor, and the Interface Momentum Dissipation (IMD) model was carried out to obtain the best combination of parameters. Besides, comparison with experimental measurements concerning slug frequency, average liquid holdup and velocity profiles in the liquid region was carried out. The comparison shows a fair correspondence in terms of behavior and magnitude with the experimental results obtained by Particle Image Velocimetry (PIV). It was observed that the velocity profile is not fully developed near the bottom of slug body. Finally, extrapolation to the extended velocity conditions was performed. The reduction of translational velocity at higher mixture velocity conditions was investigated. A certain amount of gas passing from the tail to the front of the liquid slug body was visualized by three-dimensional velocity profiles. This phenomenon supports the reduction of translational velocity above the certain level of mixture velocity.Graphical abstractGraphical abstract for this article
       
  • Natural frequency analysis of a cantilevered piping system conveying
           gas–liquid two-phase slug flow
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Gang Liu, Yueshe Wang Intermittent feature of slug flow could lead to variations of flow parameters varying with time and position along the pipe, which may influence dynamic behaviors of the piping system a lot. By considering significance of intermittent characteristic for two-phase slug flow, a dynamic model of a cantilevered horizontal piping system conveying gas–liquid two-phase slug flow is established to analyze natural frequency of the piping system. The functions indicated the variations of flow parameter associated with position along the pipe and time are calculated to analyze various forms of integral equations which are caused by the intermittent characteristic of slug flow to obtain the final matrix equation. The results show that intermittent feature of slug flow could have a crucial impact on natural frequency of the piping system especially when both of superficial gas velocity and pipe length are large enough. Flow parameters in gas bubble zone could play a more significant role for these cases. In addition, it is stated that in the process of predicting natural frequency by the correlation utilized in piping system conveying single-phase flow, it is pivotal to select appropriate forms of liquid holdup and liquid velocity.Graphical abstractGraphical abstract for this article
       
  • Flow and power characteristics of an axial discharge rotor-stator mixer
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Benjamin A. Minnick, Jung W. Kim, Derrick I. Ko, Richard V. Calabrese Flow and power characteristics of a two-stage inline axial flow rotor-stator mixer have been investigated via CFD simulation of the RANS equations. The realizable k–ε turbulence model with enhanced wall treatment was used to predict the mean velocity field, turbulent kinetic energy, and energy dissipation rate, as well as flow and power number. The results from different computational meshes are compared. The periodic behavior of throughput and torque is attributed to rotor position and shown to be related to number of blades and stator slots. The flow, power number, and energy dissipated in different fluid regions are reported for various backpressure operating conditions.
       
  • The interaction of confined swirling flow with a conical bluff body:
           Numerical simulation
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Nabil Kharoua, Lyes Khezzar, Mohamed Alshehhi Large Eddy Simulations LES were conducted to study single-phase flow in a geometry with a bluff body inserted into a long pipe as a simplified case of a more complex separator. Two configurations, without bluff body and without swirl generator, were considered for comparison. While studies on swirling flows inside pipes do exist in the literature and plenty of information is available, the present simulations address the case where the swirling flow interacts with a bluff body which was scarcely considered hitherto.The results showed a persisting core flow reversal till the bluff body location under the flow conditions considered. The swirling flow has a Rankine-vortex structure with more turbulence at its core. The bluff body undergoes the effects of recirculation zones at its front and wake regions which affect the corresponding drag and lift forces considerably. The swirl number decays from 1.5 to unity close to the bluff body. No dominant frequency was noticed in the core region. All these findings represent a starting point for an optimization work on the appropriate location and shape of the bluff body for the real separator.
       
  • Equal split of gas–liquid two-phase flow at variable extraction
           ratio
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Fachun Liang, Shitao Sun, Jifeng Gao, Luyuan Han, Guobin Shang In this work, a special distributor is proposed to distribute gas–liquid two-phase flow equally at different extraction ratio. A swirl vane is inserted at the entrance to achieve uniform swirling annular flow and ensure all the splitting holes have identical inlet conditions. A balance pipe is also applied to balance the pressure difference between the sample fluid loop and main fluid loop. Experiments were conducted in an air–water two-phase flow loop. The effect of gas and liquid superficial velocity, inlet flow pattern and splitting hole’s diameter were investigated. The results demonstrate that the extraction ratio is only dependent on the ratio of sample fluid hole number to that of main fluid. The fraction of gas and liquid taken off is not influenced by flow gas and liquid velocity, inlet flow pattern and size of the splitting hole. The desired extraction ratio can be obtained by regulating the number of sample fluid holes.Graphical abstractGraphical abstract for this article
       
  • Gas holdup and liquid velocity distributions in the up flow jet-loop
           reactor
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Yongxiang Gao, Du Hong, Haoran Lu, Youwei Cheng, Lijun Wang, Xi Li Hydrodynamics in an up flow jet-loop reactor (JLR) is experimentally investigated. The overall gas holdup, radial and axial distributions of local gas holdup and liquid velocity are presented. A modified drift-flux model was developed for correlating the “S-shape” relationship of overall gas holdup and gas velocity. Experiments show that the gas–liquid co-injection mode results in larger gas holdup and liquid circulation velocity than those of the gas jet alone mode. Liquid velocity distribution is more prone to reach the fully developed regime than the gas holdup, and the gas–liquid co-injection promotes the flow development. Comparison of JLR with the conventional bubble column (BC) and airlift reactor (ALR) shows that the JLR has a largest liquid circulation velocity, which is mostly beneficial to liquid mixing and solid suspension.Graphical abstractGraphical abstract for this article
       
  • Complementary methods for the determination of the just-suspended speed
           and suspension state in a viscous solid–liquid mixing system
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Olivier Bertrand, Bruno Blais, François Bertrand, Louis Fradette A poor understanding of mixing dynamics may lead to major economic losses in numerous industries due to poor yields and waste of raw materials. Then processes can be optimized through a better understanding of solid–liquid mixing dynamics.Previous studies have characterized the suspension of solid particles in a viscous medium using a standard high shear impeller (a pitched-blade turbine or PBT) and have measured the fraction of suspended particles using the pressure gauge technique (PGT). Since the PGT cannot be applied in a straightforward way to close-clearance impellers, we developed a novel technique based on the PGT to determine the fraction of suspended particles in a system using a close-clearance impeller such as a double helical ribbon (DHR).We studied a solid–liquid suspension in the laminar and transitional regimes with high particle loadings and a DHR. Since the dynamic pressure cannot be subtracted from the total pressure determined by the PGT, we developed two alternative methods. The first was the pressure difference method, which we used to determine a range of speeds where Njs is located. The second was the sedimentation-based method which we used to accurately quantify Njs and effectively eliminate the dynamic pressure. Their pertinence and applicability were demonstrated.Graphical abstractGraphical abstract for this article
       
  • Optimal design of an intensified column with side-reactor configuration
           for the methoxy-methylheptane process
    • Abstract: Publication date: August 2018Source: Chemical Engineering Research and Design, Volume 136Author(s): Arif Hussain, Moonyong Lee In an effort to diminish energy consumption and improve economic performance, a distillation column coupled with an adiabatic side-reactor column configuration is proposed. The production of 2-methoxy-2-methylheptane is examined to show the promising potential of process intensification using the proposed side-reactor column configuration. In order to design a side-reactor that restricts the temperature of catalyst activity to 423 K, the pressure of the column and the flow rate of the feed stream withdrawn for the side-reactor are examined. An economic steady-state flowsheet is developed that minimizes the total annual cost by optimizing the column pressure, side-stream flowrate, side-stream withdrawn location, and reactor effluent reentry location. For the 2-methoxy-2-methylheptane process, the proposed side-reactor column configuration appears overwhelmingly superior in terms of capital, energy, and total annual cost compared to that of a conventional energy-intensive scheme. In addition, compared to a reactive distillation process, the proposed configuration reduces total capital investment by decreasing column diameter with a smaller catalyst load. Furthermore, additional benefits such as less expensive hardware requirement, easy catalyst removal/regeneration could be achieved. Finally, a multi-effect heat integration sequence is suggested to improve the energy and economic performance of the proposed configuration.Graphical abstractGraphical abstract for this article
       
  • Process Simulation of Dehydration Unit for the Comparative Analysis of
           Natural gas Processing and Carbon Capture application
    • Abstract: Publication date: Available online 11 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Aban Sakheta, Umer Zahid Dehydration is a common step employed before the transmission of natural gas and/or carbon dioxide in order to avoid hydrate formation. This study is focused on the simulation of dehydration process for the natural gas and CO2 stream using triethylene glycol (TEG) solvent as the dehydrating agent. This study relates the experiences from the natural gas processing to the application of carbon capture and storage technology for CO2 dehydration. Two design configurations namely, conventional and stripping gas design are investigated using Aspen HYSYS to compare the performance improvement. The developed simulation model is first validated against the plant data and then the comparative analysis has been performed to understand the analogy between the natural gas and CO2 dehydration. Finally, a sensitivity has been performed using the stripping gas configuration to test the possible variables that can affect the process performance in terms of dehydrated stream purity, reboiler energy requirement and solvent losses. The results showed that Aspen HYSYS can reasonably predict the dehydration plant performance. The findings of this study also revealed that the CO2 dehydration process requires more energy compared to the same level of natural gas dehydration.
       
  • Modeling and simulation of downward vertical two-phase flow with pipe
           rotation
    • Abstract: Publication date: Available online 10 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Farhad Raeiszadeh, Ebrahim Hajidavalloo, Morteza Behbahaninejad, Pedram Hanafizadeh One of the major problems in two-phase flow research is prediction of flow pattern at different configurations without requiring expensive experimental tests. Numerical modeling and simulation is a suitable and emerging approach for this purpose which has many benefits including saving in time and cost. In this study, for the first time, the effect of pipe rotation on the flow patterns of air-water two-phase flow in downward direction was numerically studied. For this reason, Eulerian-Eulerian multi-fluid approach was utilized in Ansys-Fluent software. At first, apparent conditions of each regime in various revolution were recorded from experimental tests and then the simulation was carried out to find if the results are compatible. It was shown that pipe rotation has important effects on the flow patterns map and shift transitions boundaries of slug and annular flow toward lower gas superficial velocity. Comparison of numerical results with experimental data show acceptable match for all regimes. Good agreement was observed for falling film, bubbly and slug regimes but the least agreement was observed for froth regime due to high turbulence and perturbation of flow.
       
  • Design Considerations for Small Scale Rotating Fluidized Beds in Static
           Geometry with Screens for Fine Particles
    • Abstract: Publication date: Available online 9 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Zoe Lavrich, David R. Wagner, Zachary Taie, Devin Halliday, Christopher L. Hagen Design of a small scale rotating fluidized bed (RFB) with diameter of 4–6 cm to fluidize 40–80 micron diameter particles was investigated using computational fluid dynamics (CFD). Simulations explored the impact of the following components on pressure drop and fluidized behavior of the device: particle size, particle density, outer diameter, solids loading, height, number of inlet slots, inlet slot width, angle of inlet slots, chimney diameter, chimney number of slots, chimney slot width, chimney slot angle, and position of the chimney relative to the inlets. Fluidized behavior was evaluated based on a “fluidization quality” metric yielding information about the distribution of particles in the device. Although additional work is required to elucidate design guidelines for small scale RFBs for fine particles, the initial designs evaluated in this work indicate potential for developing a fluidized bed of relatively small diameter, presenting opportunities for process intensification for numerous potential applications.
       
  • Application of a novel tube reactor for investigation of calcium carbonate
           mineral scale deposition kinetics
    • Abstract: Publication date: Available online 7 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Ping Zhang, Nan Zhang, Yuan Liu, Yi-Tsung Lu, Amy T. Kan, Mason B. Tomson A novel plug-flow type tube reactor apparatus is reported to investigate the deposition kinetics of a common mineral scale calcium carbonate (CaCO3). Mineral scale deposition is a common phenomenon in industry and can pose a serious threat to the safe and economical operations. Compared with the conventional apparatus, the tube reactor has the advantage to maintain a constant solution pH, surface area and a controlled saturation index and hydraulic condition during the deposition study. Two scenarios of CaCO3 solid deposition were considered in this study, including deposition of CaCO3 on clean surfaces and also deposition of CaCO3 on a surface pre-coated with CaCO3 solid. The results show that the overall CaCO3 deposition process can be divided into multiple stages with different deposition kinetics and different solid morphologies. It is obvious that experimental conditions, such as solution chemistry, flow rate, temperature and saturation index, can have a considerable impact on CaCO3 deposition kinetics. These results provide an in-depth understanding of the process involving CaCO3 deposition onto the surface of a pipe material or a conduit. This novel tube reactor apparatus expands our capability of investigating mineral scale deposition kinetics and the influences of various experimental factors on scale deposition kinetics.Graphical abstractGraphical abstract for this article
       
  • Tailored catalyst pellet specification for improved fixed-bed transport
           characteristics: A shortcut method for the model-based reactor design
    • Abstract: Publication date: Available online 7 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Alexander Pietschak, Markus Kaiser, Hannsjörg Freund To improve the transport characteristics of a catalytic fixed-bed via optimal design of catalyst pellet specifications such as the pellet diameter it is necessary to account for all physicochemical phenomena influenced by the pellet. For the approximative description of the transport phenomena on the catalyst pellet scale a new shortcut method is developed in this work. It enables a generalized and system independent treatment of the aforementioned processes and can be applied to arbitrary reaction networks and reaction kinetic models. Based on linearization and decoupling of the pellet balance equations the method yields an analytical solution. This allows for model-based design of the reactor-catalyst system via dynamic optimization at reduced computational costs as the use of complex heterogeneous models is avoided. In order to ensure accurate predictions of the method, regions with high catalyst utilization are targeted.To indicate the potential of improved bed transport characteristics, the shortcut method is applied to the reactor-catalyst system for ethylene oxide synthesis. The system is optimized in terms of reducing the pressure drop while meeting other reactor performance constraints. The pressure drop could be reduced by more than 60%. The shortcut method is validated using a rigorous stand-alone model of the catalyst pellet.Graphical abstractGraphical abstract for this article
       
  • Optimization of Multi-Stage Hybrid RO-PRO Membrane Processes at the
           Water-Energy Nexus
    • Abstract: Publication date: Available online 6 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Mingheng Li Water and energy are two of the most pressing problems faced by the world today. Membrane processes such as Reverse Osmosis (RO) and Pressure Retarded Osmosis (PRO) can help alleviate both challenges. This work focuses on systematic optimization of a RO-RO-PRO-PRO process for energy-efficient seawater desalination which integrates RO for desalination and PRO for power generation into a single process. Such a hybrid process is of great significance at the water-energy nexus given that water production, pump energy consumption, and hydraulic/osmotic energy recovery are inherently intertwined. The optimization problem is formulated to minimize the Specific Energy Consumption (SEC) subject to specified total membrane area and total water recovery. By solving the optimization model the best design (e.g., allocation of membrane area among different units) and operating (e.g. applied pressure in each membrane unit) conditions are simultaneously determined. It is shown that the proposed RO-RO-PRO-PRO allows a profile of the applied pressure that more closely tracks that of the concentrate osmotic pressure than RO-PRO, thus improving energy efficiency. Challenges and opportunities in further development of hybrid RO-PRO processes are discussed.Graphical abstractGraphical abstract for this article
       
  • A general approach to module-based plant design
    • Abstract: Publication date: Available online 6 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Martin Eilermann, Christian Post, Heiko Radatz, Christian Bramsiepe, Gerhard Schembecker Increasing economic challenges lead to the need for faster plant design in process industry. In this context, a promising approach is module-based plant design. Thereby, for the accomplishment of the required design tasks modules are selected from databases and configured instead of time-consuming and tailor-made plant design.Within this work, a general approach to module-based plant design is introduced and illustrated based on an example. To structure the design procedure different types of modules are defined for different design tasks: PFD, P&ID, Equipment and 3D Layout. Additionally, module selection can be performed at different Levels of Aggregation to cope with the high variance of applications. This enables module selection and configuration avoiding time-consuming, tailored modifications. Since modules are unmodifiable and project-independent, the module-based plant design approach presented is based on a consistent module definition. This work provides a framework to integrate some of the existing modularization approaches into a general module-based plant design approach. However, most often new approaches are necessary to accomplish the design tasks within the presented module-based plant design approach. Thus, this work also identifies open research gaps that need to be filled by future research.Graphical abstractGraphical abstract for this article
       
  • Assessing the influence of viscosity and milling bead size on the
           stressing conditions in a stirred media mill by single particle probes
    • Abstract: Publication date: Available online 5 July 2018Source: Chemical Engineering Research and DesignAuthor(s): A. Strobel, J. Schwenger, S. Wittpahl, J. Schmidt, S. Romeis, W. Peukert Milling processes in stirred media mills can be essentially described by the collision bead frequency distribution (stress number) and the transferred stress energy distribution. Although general dependencies on the mills’ operating parameters have been extensively studied, the underlying distributions are widely unknown. Recently, we established an experimental protocol to determine the aforesaid distributions by using well-characterized spherical metal particle probes. To this end, the plastic deformation of the particle probes which is caused by stressing in the apparatus is accessed by electron microscopy and is related to single particle compression testing described via a finite element model. Within this account we focus on the influences of grinding media size and fluid viscosities on the stressing conditions in a small-scale horizontal stirred media mill which is operated in open circuit mode. We show that larger milling beads lead to higher stress energies, whereas an increase of viscosity leads to lower transferred stressing energies. Surprisingly, however, the overall amount of stressed particle probes decreases with the milling bead size. At the same time the fraction of the probes which has been stressed shows many contacts. We relate this effect to the slurry flow through the agitated packed milling bead bed. The effect of viscosity is attributed to squeezing flows which form as a result of approaching milling beads.Graphical abstractGraphical abstract for this articleSingle particle probes are used to characterize stress intensity and stress number distributions for different grinding bead sizes and fluid viscosities in a stirred media mill which is operated in open circuit mode.
       
  • Diatomite precoat filtration for wastewater treatment: Filtration
           performance and pollution mechanisms
    • Abstract: Publication date: Available online 4 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Dan Guo, Hualin Wang, Pengbo Fu, Yuan Huang, Yi Liu, Wenjie Lv, Fei Wang As wastewater processing facilities deal with increasing amount in combination with enhanced environmental pressures, diatomite precoat filtration is becoming one of the promising methods for wastewater treatment. Filtration performance of diatomite precoat filtration with five different coating layer thicknesses for wastewater treatment was investigated in terms of permeate flux, fouling grade, filtration resistance, permeate quality and fouling reversibility. Pollution mechanism was revealed by fitting Hermia’s fouling models, detecting the pollutant transport and analyzing the changes in microstructure of diatomite. The optimal thickness of diatomite precoat filtration was 4 mm, which exhibited that the highest average permeate flux was 16.53 L/m2h, total fouling resistance reduced by 59.5%, and lowest cake water content was 55.1%. Contact angle measurement indicated that the fouling formed on the diatomite coating layer was highly reversible. Compared with individual fouling model, the combination of three Hermia’s fouling models at different stages fitted the flux data well. FESEM images of diatomite particles confirmed high filtration flux and supported the pollutant transport results. The superiority of diatomite precoat filtration in improving filtration performance and mitigation fouling was demonstrated. The present study could also provide an experimental basis for optimizing precoat filtration process.Graphical abstractGraphical abstract for this article
       
  • In silico optimization of a bioreactor with an E. coli culture for
           tryptophan production by using a structured model coupling the oscillating
           glycolysis and tryptophan synthesis
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Gheorghe Maria, Marina Mihalachi, Cristiana Luminita Gijiu Tryptophan (TRP) is an aromatic non-polar α-amino-acid essential, whose biosynthesis maximization is of high practical importance in industry, and medicine. On one hand, it is to underline that TRP synthesis is an oscillatory process strongly connected to the glycolysis through the PEP (phosphoenolpyruvate) node. On the other hand, it is well-known that glycolysis, under certain environmental conditions, displays autonomous oscillations of the glycolytic intermediates’ concentrations thus reflecting the dynamics of the control and regulation of this major catabolic pathway with a major role in the cell central carbon metabolism (CCM) in living cells. Consequently, glycolysis model is the ‘core’ module of any systematic and structured model-based analysis of most of metabolic sub-process. By coupling two adequate reduced kinetic models for the glycolysis and TRP synthesis in the E. coli cells, adopted from literature, with the model of a semi-continuous bioreactor, this paper derives, for the first time, an in silico analysis of the optimal operating conditions of the bioreactor used for tryptophan synthesis, with accounting for the two interfering oscillatory processes.Graphical abstractGraphical abstract for this article
       
  • Kinetics and optimization studies using Response Surface Methodology in
           biodiesel production using heterogeneous catalyst
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Chandra Sekhar Latchubugata, Raghu Vamsi Kondapaneni, Kiran Kumar Patluri, Usha Virendra, Sreepriya Vedantam Biodiesel is an eco-friendly fuel is known to be an alternative source for fossil fuels. Many studies reported transesterification based reaction methods for biodiesel production from edible/non-edible oils. In this study, Calcium Oxide (CaO) has been used as a heterogeneous catalyst for transesterification of palm oil to biodiesel. Effect of process parameters such as temperature, reaction time and Methanol to oil molar ratio on biodiesel production is analyzed using Response Surface Methodology (RSM) based on Box–Behnken Design: (BBD) in statistica, with fixed catalyst concentration as an input parameter. In the present study, 3-level, 3-factor Box–Behnken statistical design was used to analyze and optimize the biodiesel production with respect to the percentage yield of Fatty Acid Methyl Esters (FAME). This has been done with 15 standard experimental runs. Kinetics of the reaction have been assumed to be of pseudo first order. Obtained biodiesel is found to be of high quality with a high FAME yield; and CaO is found to have high catalytic activity towards biodiesel production.Graphical abstractGraphical abstract for this article
       
  • A note on short-term scheduling of multi-grade polymer plant using DNA
           computing
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Deepak Sharma, Manojkumar Ramteke Short-term scheduling of batch polymer plant involves the scheduling of different orders in parallel available production lines. The scheduling becomes more challenging due to the presence of sequence-dependent changeover constraints between different orders which lead to combinatorial optimization formulation. Such combinatorial optimization problems have exponential time complexity on the silicon-based computer. DNA computing experiments are found to be promising for such combinatorial optimization problems particularly involving unique feasible optimal solution. However, use of DNA to find a solution to real-life problems involving multiple feasible solutions is an emerging area of research. The present paper illustrates the DNA solutions to the short-term scheduling of a polymer plant involving multiple feasible solutions and parallel production lines. The DNA computer aided with nearest neighbour heuristics and iterative implementation found to be successfully searching the optimal solution in a combinatorial search space for three short-term scheduling problems of multi-grade polymer plant.Graphical abstractGraphical abstract for this article
       
  • Separation of azeotrope (2,2,3,3-tetrafluoro-1-propanol + water) via
           heterogeneous azeotropic distillation by energy-saving dividing-wall
           column: Process design and control strategies
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Puyun Shi, Dongmei Xu, Jinfu Ding, Jingyu Wu, Yixin Ma, Jun Gao, Yinglong Wang To separate the azeotrope of 2,2,3,3-tetrafluoro-1-propanol (TFP) and water, the energy-saving heterogeneous azeotropic dividing-wall column (DWC) is proposed using chloroform as an azeotropic agent. Compared with the conventional design, the total condenser duty reduction of 44.57%, total reboiler duty reduction of 42.66% and TAC reduction of 37.79% by the DWC design are obtained. Based on the simulation results, the energy-saving in the DWC design is due to the thermal coupling of the conventional design and the separation of water by the decanter with the purity of 99.5 mol%, rather not to the removal of remixing effect for the column sequence. The control strategy performance for the conventional and DWC designs are satisfactory, since TFP and water are separated with high purity, despite the disturbances of the flow rate of fresh feed, fresh feed composition and liquid split ratio.
       
  • A continuous multi-stage mixed-suspension mixed-product-removal
           crystallization system with fines dissolution
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): David Acevedo, Daniel J. Jarmer, Christopher L. Burcham, Christopher S. Polster, Zoltan K. Nagy This work demonstrates how crystal particle size is affected by the addition of fines dissolution in a mixed suspension mixed product removal (MSMPR) cascade system. The cooling crystallization of paracetamol in water was used as a case study. Two MSMPR cascade configurations were evaluated: (i) nucleation-growth (NG), and (ii) nucleation-dissolution-growth (NDG). Simulation results demonstrate that adding a dissolution step in the MSMPR cascade configuration increases the average product crystal size. Larger crystals and a narrower distribution were obtained due to the removal of fine crystals through the continuous process. However, a small decrease in the achievable yield was observed. Experimental results also showed a similar effect on the final mean size and CSD. The results demonstrate that a dissolution stage can be optimized to increase the final crystal size and CSD by varying the dissolution temperature to optimize the CSD with minimum effect on the achievable yield.
       
  • An examination of Wen and Yu’s formula for predicting the onset of
           fluidisation
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): I.A. Gibson, C.J. Slim, Yaoyao Zheng, S.A. Scott, J.F. Davidson, A.N. Hayhurst Classical methods (measuring the pressure drop across a bed for different flowrates of air through the bed) were used to determine the superficial velocity for minimum fluidisation, Umf, of sieved particles of alumina. The particles were characterised optically using an instrument (Morphologi G3, Malvern Instruments), which, from pixelated, enlarged photographs, measured the particles’ mean diameter, dp, to be 0.48 ± 0.04 mm and their sphericity, ϕ, to be 0.77 ± 0.09. Values of Umf were measured for the temperature in the electrically heated bed varying from 14 to 920 °C. The results were analysed using Ergun’s equation; one outcome was that the voidage, εmf, in an incipiently fluidised bed was found to be related to the particles’ sphericity by:(1−εmf)/ϕ2εmf3=12.2±0.4.The measured Umf were significantly larger than the values predicted by Wen and Yu’s equation, if the mean diameter of the particles was taken, as recommended, to be the geometric mean of the upper and lower sieve sizes, used when preparing the particles. Alternatively, the measured values of Umf were over-predicted by Wen and Yu’s equation, when using the optically measured mean size of the particles. The best predictions of Umf were made by using the optically measured mean values of both dp and ϕ, together with Ergun’s equation and the above equation coupling εmf and ϕ. Such a procedure is proposed for estimating Umf in general. No evidence was found for εmf varying with temperature.Graphical abstractGraphical abstract for this article
       
  • Experimental and numerical studies of residence time in SK direct contact
           heat exchanger for heat pump
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Hailing Fu, Lianjie Ma, Haiyan Wang Direct contact heat exchanger (DCHE) was used in energy recovery from low-grade energy resources due to their high thermal efficiency and low cost. In this work, SK elements were used in direct contact heat exchanger to enhance heat transfer due to the improving of mixing performance. It presented the residence time to characterize flow and mixing in SK direct contact heat exchanger both experimentally and numerically. The experimental results showed that the mean residence time (MRT) increased with an increase of elements numbers and it was necessary to use more elements at high flow velocity in order to guarantee the mixing completely. The residence time distribution (RTD) was used to quantify the mixing behavior and describe the mixing features such as the dead zones, channeling and by-passing. The performance of the computational fluid dynamics (CFD) was tested against the experimental data provided, verifying that the CFD model could predict the fluid flow characteristics precisely. A new shifted lognormal distribution (SLD) mathematical model was also used to model the mixing behavior of the SK direct contact heat exchanger, and there was a good fitting between model and experimental data.
       
  • Incorporation of silica grafted silver nanoparticles into polyvinyl
           chloride/polycarbonate hollow fiber membranes for pharmaceutical
           wastewater treatment
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): A. Behboudi, Y. Jafarzadeh, R. Yegani Polyvinyl chloride/polycarbonate hollow fiber membranes incorporated with modified silver nanoparticles were prepared by wet spinning method. Fabricated membranes were then characterized by FESEM, EDX, TGA, contact angle, pure water flux and mechanical tests. It was found that the addition of modified silver nanoparticles changed the structure of hollow fiber membranes and the size of macrovoids in the middle layer decreased whereas the thickness of sponge-like outer layer increased. The results of EDX analysis showed that the modified silver nanoparticles were dispersed uniformly throughout the membranes. In addition, degradation temperature of the membranes increased as the content of nanoparticles increased which shows that thermal resistance of membranes was improved. The number of pores on the membrane surface increased due to the presence of nanoparticles but mean pore radius decreased. Addition of modified nanoparticles also improved hydrophilicity, tensile strength and elongation of hollow fiber membranes. The membranes were finally used in a membrane bioreactor system with pharmaceutical wastewater feed during 28 days and the results revealed that incorporation of modified silver nanoparticles enhanced antifouling properties of hollow fiber membranes. Moreover, pure water flux and COD removal as the criteria of membrane performance increased simultaneously.Graphical abstractGraphical abstract for this article
       
  • Sustainable production of chemical intermediates for nylon manufacture: A
           techno-economic analysis for renewable production of caprolactone
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Vaishali Thaore, David Chadwick, Nilay Shah Caprolactone is a precursor for the synthesis of caprolactam, the key monomer for nylon-6 which is produced globally at a scale of 4 million tonnes per annum. This work describes and assesses a bio-based production route to caprolactone from an agricultural residue, specifically corn stover, via glucose, fructose, 5-hydroxymethyl furfural (HMF) and 1,6-hexanediol. The material and energy balances, the cost efficiency, as well as on the potential reduction of greenhouse gas (GHG) emissions are reported and discussed. The developed process model was simulated in Aspen Plus™ with the optimization and energy integration performed for the entire process from corn stover to caprolactone. A sensitivity analysis was performed with consideration of various economic factors to explore the process economics. The results of the techno-economic and environmental assessment show that a bio-based caprolactone production process via glucose and HMF could be competitive with conventional hydrocarbon-based processes when major by-products are valorised and has a lower environmental impact. Areas where further investigation is needed to improve sustainable caprolactone production are identified and discussed.
       
  • Gas hold-up and mass transfer in a pilot scale bubble column with and
           without internals
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Onkar N. Manjrekar, Mohamed Hamed, Milorad P. Dudukovic Bubble columns are the reactors of choice for conversion of synthesis gas to liquid fuels (F–T synthesis). The F–T synthesis is an exothermic reaction and cooling internals are installed in the bubble columns to remove the heat generated in the reaction. The presence of the internals affects both the gas and liquid flow patterns in bubble column. This change is expected to reflect on the volumetric mass transfer coefficient. In this work, the impact of vertical cooling internals on overall gas hold-up and volumetric mass transfer coefficients is evaluated on 45 cm diameter pilot scale bubble column and 19 cm diameter lab scale bubble column. It was found that in presence of internals the gas hold-up in both the columns was increased, however no significant impact of presence of internals on volumetric mass transfer coefficient was observed. The gas hold-up and volumetric mass transfer coefficients evaluated in this work are compared with prediction from existing correlations.
       
  • Inside Front Cover
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s):
       
  • Assessment of biomass bulk elastic response to consolidation
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): D. Ilic, K.C. Williams, D. Ellis The value and variation in bulk density is highly influential in the economics associated with biomass valorisation. Due to its importance, increased feedstock demand is directly related to understanding the characteristics affecting bulk density and the design of biomass processing and handling systems, along the renewable resource supply chains.This paper presents assessment of the elastic response of sugarcane bagasse, wheat straw and wattle, sourced from a second generation lignocellulosic ethanol plant. The study includes testing bulk solids “springiness” and the strain response to stress. While the results of this paper are a preliminary study, the ultimate aim of this work is to establish a relationship between compaction, dilation rates and magnitude with variations in the stress applied. Benchmark tests to characterise the elastic response were performed in a small cell compressibility tester. Testing was also undertaken in a larger cylinder and included preliminary evaluation using a uniaxial test apparatus. Furthermore, preliminary assessment of the stress/stain behaviour during compaction and dilation using Discrete Element Modelling (DEM) was undertaken and a comparison to experimental results is provided. Limitations of the available testing method prevented testing at higher consolidation loads and as such this work will be used to further develop the methodology and design of a new apparatus.Graphical abstractGraphical abstract for this article
       
  • Experimental determination of particle–particle restitution coefficient
           via double pendulum method
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Jakub Hlosta, David Žurovec, Jiří Rozbroj, Álvaro Ramírez-Gómez, Jan Nečas, Jiří Zegzulka The coefficient of restitution e is determined as the ratio of the final to the initial relative velocity between two moving objects after their collision. It is also one of the basic features and parameters for contact models of the discrete element method (DEM). The virtual simulation of industrial processes using DEM modelling is currently undergoing a great development both in the ways of application and in the complexity of the individual models. Therefore, input values need to be constantly refined to ensure the quality outputs of these numerical models. This article describes an experimental method of measuring the coefficient of restitution of two particles by means of a double pendulum, which presents a number of problems especially for non-spherical particles. At the same time, this article presents three options for evaluating the proposed experiment, including their comparison and description of their pros and cons. A series of experiments with particles of different sizes, shapes and materials was performed and their coefficients of restitution were determined. The presented method allows to be used on a broad scale especially for spherical particles of>5 mm, the coefficient of restitution can be determined very accurately. To some degree, this applies to non-spherical particles of mass in tens of grams and of different materials as well. Their initial coefficient of restitution can be determined with a high degree of precision, which is important for using in contact models definition. The accuracy of the contact model is dependent on accurate specification of restitution coefficient. In this study, values of the coefficients of restitution of various shapes such as wood particles, particles of maize, spruce cylindrical pellets and coal were experimentally determined.Graphical abstractGraphical abstract for this article
       
  • Impact behaviour of microparticles with microstructured surfaces:
           Experimental study and DEM simulation
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Fabian Krull, Robert Hesse, Paul Breuninger, Sergiy Antonyuk The surface topography of a component influences lots of important macroscopic phenomena, for example friction, fatigue and wear behaviour. This study is focused on the effect of surface topography on the collision behaviour of fine particles. To obtain this behaviour an experimental study of the single particle impact with a microstructured substrate was performed. A novel experimental setup was developed to capture collisions of small particles with the surface three-dimensionally. The particle-wall collisions were performed with spherical polystyrene microparticles. As contact partners a polished and a microstructured stainless steel substrate were used. The surface microstructure was produced by a cold spray process with spherical stainless steel particles. The measured restitution coefficient significantly decreased after the microstructuring showing an additional energy dissipation due to topography. The particle impact was simulated using the Discrete Element Method. The surface topography was implemented in the model by reverse engineering and meshed with two different resolutions. The simulations were compared with the experiments regarding the energy dissipation and rebound behaviour. The calculated restitution coefficient was in good agreement with the experiments for a fine meshed surface, but deviated significantly with the coarsened mesh.Graphical abstractGraphical abstract for this article
       
  • Application of micro computed tomography for adjustment of model
           parameters for discrete element method
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Maksym Dosta, Ulrich Bröckel, Laurent Gilson, Sergiy Kozhar, Günter K. Auernhammer, Stefan Heinrich Nowadays the Discrete Element Method (DEM) is widely applied for the numerical simulation of granular materials. However, for the effective application of DEM detailed information about material properties is needed. Some material parameters of individual particles can be directly measured using various experimental set-ups like shear cell, compression tester, electron microscopy, etc. Nevertheless, in the majority of cases such measurements do not suffice to get overall information about the material. Therefore, various macroscopic experiments like determination of static or dynamic angle of repose are often used to validate DEM simulations and to adjust model parameters. In this contribution, an alternative non-intrusive technique for the estimation of unknown parameters, which is based on particle tracking in sets of the micro computed tomography images, is proposed. In comparison to other methods this technique allows to obtain detailed information about particle motion inside the granular material and does not only rely on the surface properties.In the presented contribution experiments and simulation studies were performed using a cylindrical mixer apparatus filled with polyethylene microspheres. Based on the analysis of obtained images, the exact 3D-positions of all particles in the mixing volume were determined and extracted. For numerical calculations the DEM implemented into component-based simulation framework MUSEN was used.
       
  • Agglomeration process of rice protein concentrate using glucomannan as
           binder: In-line monitoring of particle size
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Kaciane Andreola, Carlos A.M. Silva, Osvaldir P. Taranto Rice protein has raised interest from food industry due to its singular nutritional value and nutraceutical properties. However, rice protein concentrate powder presents fine particles with moderate flowability and low wettability, limiting its use. The production of large and porous granules with both high wettability and flowability can be performed by agglomeration process. In this work, the fluid bed agglomeration using konjac glucomannan as binder agent was investigated as a potential method to improve the quality attributes of the RPC powder. The influence of binder concentration and binder feed rate on particle size and quality of the product was evaluated. In-line particle size was monitored by a spatial filter velocimetry probe. Agglomeration was successfully performed in a fluid bed, resulting in large granules with low moisture content, short wetting time and improvement of the flowability. In-line particle size data allowed a better understanding of the particles growth, which was influenced by the binder concentration and binder feed rate. The best operating condition was obtained using low binder concentration and low binder feed rate, since this condition provided an instant powder with very good flowability at the highest yield.Graphical abstractGraphical abstract for this article
       
  • Dynamics of wet particle–wall collisions: Influence of wetting
           condition
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Britta Buck, Yali Tang, Niels G. Deen, J.A.M. Kuipers, Stefan Heinrich Particulate processes are characterised by intense contacts between particles and particles with the apparatus walls, where often liquid is present on the surfaces in form of droplets or liquid layers, e.g. in granulation and agglomeration processes. However, the influence of the liquid on collision dynamics is still not fully understood. Therefore, the influence of the liquid on wet particle–wall collisions is investigated via the coefficient of restitution (CoR). The CoR characterises the total energy dissipation during a collision and is defined as ratio of rebound velocity to impact velocity. In most literature regarding collision dynamics of wet particles, a target plate is covered by a liquid layer before the collision. However, this approach is often questioned of its similarity to real wet particle collisions. Therefore, during this work the particle was wetted before colliding with a dry or wet plate.Normal CoR was higher for a wet plate than for a wet particle. The case of a wet–wet collision is comparable to a superposition of collisions where a wet particle or a wet plate was used. Furthermore, during oblique collisions the tangential CoR was found to be smaller for a wet wall compared to a wet particle impacting on a dry wall.Graphical abstractGraphical abstract for this article
       
  • Advanced membranes containing star macromolecules with C60 core for
           intensification of propyl acetate production
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Aleхandra Pulyalina, Dmitry Porotnikov, Daria Rudakova, Ilia Faykov, Irina Chislova, Valeriia Rostovtseva, Ludmila Vinogradova, Alexander Toikka, Galina Polotskaya In the present work transport properties of novel polymer materials were studied in separation of quaternary mixture (n-propanol–acetic acid–propyl acetate–water) and binary mixture (water–acetic acid) by pervaporation that can be used in hybrid process “reaction + pervaporation” to optimize of the propyl acetate production. Physical methods are successfully used to modernize properties of polymer materials without changing the chemical structure of macromolecules. Poly(phenylene oxide) membrane was modified by novel star shaped macromolecules with fullerene С60 core and arms of different nature. They are twelve-arm star consisted of six nonpolar arms of polystyrene and six polar arms of poly-2-vinylpyridine that are covalently bonded to C60 core. The membrane structure and thermal stability were studied by SEM, DSC, and TGA. To characterize physical properties, density and contact angles were determined. Membranes modified with the star macromolecules exhibit selectivity to water. The growth of modifier content up to 5 wt% leads to increase of the membrane performance and selectivity, which provides shifting the esterification reaction equilibrium and increasing the ester yield.Graphical abstractGraphical abstract for this article
       
  • Foam propagation and oil recovery potential at large distances from an
           injection well
    • Abstract: Publication date: July 2018Source: Chemical Engineering Research and Design, Volume 135Author(s): Hamidreza Norouzi, Mehdi Madhi, Mojtaba Seyyedi, Mohmmad Rezaee While foam propagation, foam–oil interaction and foam oil recovery performance have been investigated by numerous research studies, most of previous works were performed on short porous media with the maximum length of 30 cm. Therefore, their results mostly represent foam behavior in the vicinity of the injection well and may not represent the foam propagation, quality and oil recovery potential at large distances from the injection well. In this study, by using a high-pressure and high-temperature rig equipped with a 12-m long porous medium and microscopic visualization facilities, foam stability in the presence and absence of a reservoir crude oil, foam propagation, foam–oil interaction, and finally foam oil recovery potential at large distances from the injection well were investigated. The oil recovery behavior of four tertiary scenarios, including Sodium Dodecyl Sulfate (SDS) foam, Alpha-Olefin Sulfonate (AOS) foam, gas, and simultaneous water alternating gas (SWAG) injection, were investigated.According to results, pressure presented a positive impact on the foam stability. The extent of this impact was a function of the surfactant type. Compared to gas and SWAG injection, in the 12-m long porous medium, foam flooding scenarios presented much stronger oil recovery potentials. This reveals the strong potential of foam flooding in producing the oil trapped in areas deep into the reservoir and far from the injection well. Based on this study, by using a suitable surfactant solution and optimum gas fractional flow, even in the presence of oil, foam can propagate to large distances from the injection well and leads to extra oil recovery.Graphical abstractGraphical abstract for this article
       
 
 
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