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  Subjects -> CHEMISTRY (Total: 931 journals)
    - ANALYTICAL CHEMISTRY (58 journals)
    - CHEMISTRY (663 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (27 journals)
    - INORGANIC CHEMISTRY (43 journals)
    - ORGANIC CHEMISTRY (48 journals)
    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (663 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 15)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 31)
ACS Applied Polymer Materials     Hybrid Journal  
ACS Catalysis     Hybrid Journal   (Followers: 55)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 22)
ACS Combinatorial Science     Hybrid Journal   (Followers: 21)
ACS Macro Letters     Hybrid Journal   (Followers: 29)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 46)
ACS Nano     Hybrid Journal   (Followers: 381)
ACS Photonics     Hybrid Journal   (Followers: 15)
ACS Symposium Series     Full-text available via subscription   (Followers: 1)
ACS Synthetic Biology     Hybrid Journal   (Followers: 25)
Acta Chemica Iasi     Open Access   (Followers: 6)
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chimica Slovenica     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 8)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 8)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 9)
Adsorption Science & Technology     Open Access   (Followers: 7)
Advanced Functional Materials     Hybrid Journal   (Followers: 65)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 88)
Advances in Chemistry     Open Access   (Followers: 29)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 20)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Environmental Chemistry     Open Access   (Followers: 8)
Advances in Enzyme Research     Open Access   (Followers: 11)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 29)
Advances in Nanoparticles     Open Access   (Followers: 19)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Polymer Science     Hybrid Journal   (Followers: 49)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
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: 13)
Aerosol Science and Engineering     Hybrid Journal  
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 5)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 8)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alchemy : Journal of Chemistry     Open Access   (Followers: 3)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Alotrop     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 71)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 22)
American Journal of Chemistry     Open Access   (Followers: 35)
American Journal of Plant Physiology     Open Access   (Followers: 13)
American Mineralogist     Hybrid Journal   (Followers: 14)
Anadolu University Journal of Science and Technology A : Applied Sciences and Engineering     Open Access  
Analyst     Full-text available via subscription   (Followers: 37)
Angewandte Chemie     Hybrid Journal   (Followers: 193)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 291)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 4)
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: 8)
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: 15)
Antiviral Chemistry and Chemotherapy     Open Access   (Followers: 2)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 9)
Applied Spectroscopy     Full-text available via subscription   (Followers: 26)
Applied Surface Science     Hybrid Journal   (Followers: 33)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 3)
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access   (Followers: 2)
Atomization and Sprays     Full-text available via subscription   (Followers: 5)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 4)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 11)
Biochemistry     Hybrid Journal   (Followers: 403)
Biochemistry Insights     Open Access   (Followers: 7)
Biochemistry Research International     Open Access   (Followers: 7)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 11)
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     Hybrid Journal   (Followers: 25)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 6)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 185)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 91)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 17)
Biosensors     Open Access   (Followers: 3)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences     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: 25)
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: 12)
Canadian Mineralogist     Full-text available via subscription   (Followers: 7)
Carbohydrate Research     Hybrid Journal   (Followers: 24)
Carbon     Hybrid Journal   (Followers: 73)
Catalysis for Sustainable Energy     Open Access   (Followers: 10)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 10)
Catalysis Science and Technology     Hybrid Journal   (Followers: 10)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 14)
Cellulose     Hybrid Journal   (Followers: 14)
Cereal Chemistry     Full-text available via subscription   (Followers: 5)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 2)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 23)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 76)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 27)
Chemical Physics Letters : X     Open Access   (Followers: 2)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 23)
Chemical Reviews     Hybrid Journal   (Followers: 237)
Chemical Science     Open Access   (Followers: 33)
Chemical Technology     Open Access   (Followers: 49)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 21)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry     Open Access  
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 32)
Chemistry & Industry     Full-text available via subscription   (Followers: 8)
Chemistry - A European Journal     Hybrid Journal   (Followers: 192)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 17)
Chemistry Africa : A Journal of the Tunisian Chemical Society     Hybrid Journal  
Chemistry and Materials Research     Open Access   (Followers: 22)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 46)
Chemistry of Heterocyclic Compounds     Hybrid Journal   (Followers: 4)
Chemistry of Materials     Hybrid Journal   (Followers: 288)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 10)
Chemistry World     Full-text available via subscription   (Followers: 21)
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: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
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: 12)
Chromatographia     Hybrid Journal   (Followers: 22)
Chromatography     Open Access   (Followers: 3)
Chromatography Research International     Open Access   (Followers: 5)
Clay Minerals     Hybrid Journal   (Followers: 10)
Cogent Chemistry     Open Access   (Followers: 2)
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: 8)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 24)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Communications Chemistry     Open Access   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 8)
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: 2)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 13)
Computational Chemistry     Open Access   (Followers: 3)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 4)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 7)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 8)
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   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 6)
Current Microwave Chemistry     Hybrid Journal  
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 10)

        1 2 3 4 | Last

Similar Journals
Journal Cover
Chemical Engineering Research and Design
Journal Prestige (SJR): 0.847
Citation Impact (citeScore): 3
Number of Followers: 27  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0263-8762 - ISSN (Online) 0263-8762
Published by Elsevier Homepage  [3181 journals]
  • Fault diagnosis of nonlinear systems using recurrent neural networks
    • Abstract: Publication date: January 2020Source: Chemical Engineering Research and Design, Volume 153Author(s): Hadi Shahnazari In this work, we propose a fault detection and isolation (FDI) methodology that enables diagnose of single, multiple and simultaneous actuator and sensor faults regardless of the utilized model structure. The basis of the proposed methodology is modelling and inversion of nonlinear systems using recurrent neural network (RNN)s. To this end, a bank of RNNs is used to estimate system inputs and/or outputs and build predictive models using the obtained estimates and an RNN as the plant model. Then a bank of residuals is generated in a way each residual is sensitive to a subset of faults and insensitive to the rest and as a result of this, a unique fault signature is obtained for each fault scenario. RNNs can be replaced by other machine learning techniques such as partial least square (PLS)s, random forest, etc. One of the advantages of the proposed methodology is that it does not require the existence of plant fault history or first principles models unlike other existing results in the literature. Also, it enables isolation of actuator and simultaneous actuator and sensor faults in highly interconnected systems. The effectiveness of the proposed FDI scheme is shown via simulation examples.
       
  • New prognosis approach for preventive and predictive maintenance —
           Application to a distillation column
    • Abstract: Publication date: January 2020Source: Chemical Engineering Research and Design, Volume 153Author(s): Alaa Daher, Ghaleb Hoblos, Mohamad Khalil, Yahya Chetouani The maintenance, repair, and rehabilitation of industrial reactors are expensive and time-consuming. Sudden interruptions may adversely affect the production process and may lead to harmful effects and disastrous results. Therefore, lifetime prediction is extremely important to prevent catastrophic breakdowns leading to complete cessation of production. This paper aims to propose a prognosis reliable method that can be used to estimate the degradation path of a distillation column and calculate the lifetime percentage of this system. The work presents a direct monitoring approach based on the technique of adaptive neuro-fuzzy inference system (ANFIS) combined with fuzzy C-means algorithm (FCM). At the beginning, ANFIS is used to detect the small variations in the signal over time. Secondly, a new strategy is proposed to find the system degradation path. Thirdly, ANFIS is combined with FCM to predict the future path and calculate the lifetime percentage of the system. The methodology is tested on real experimental data obtained from a distillation column. Results demonstrate the validity of the proposed technique to achieve the needed objectives with a high-level accuracy, especially the ability to determine a more accurate Remaining Useful Life (RUL) when it applied on the automated distillation process in the chemical industry.Graphical abstractGraphical abstract for this article
       
  • Optimization of reactive extraction of propionic acid with ionic liquids
           using central composite design
    • Abstract: Publication date: Available online 15 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Emine Ayan, Nilay Baylan, Süheyla Çehreli Propionic acid is widely utilized in different chemical applications and industries such as plastic, coating, agricultural, chemical and perfume industries. However, propionic acid occurs in the waste streams of these industries and is produced in aqueous solutions by fermentation processes. Thus, removal of propionic acid from both waste streams and production medium is an important topic. In this experimental and optimization study, the reactive extraction of propionic acid from its aqueous solutions was investigated. Imidazolium-based ionic liquids namely, 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM][PF6]) and 1-hexyl-3-methylimidazolium bis(triflorometilsülfonil)imid ([HMIM][Tf2N]), were utilized as diluents, and tributyl phosphate (TBP) was utilized as an extractant. The effect of different factors like initial acid concentration (5-10%, w/w), initial TBP concentration in ionic liquids (0-3 mol.L−1), and aqueous/organic phase ratio (0.5-1.5) on the extraction efficiency was investigated. The optimal conditions were determined by using central composite design (CCD) based on response surface methodology (RSM). The optimization work showed that within the investigated parameters, the most effective parameter was the initial TBP concentration in ionic liquids. The optimum extraction conditions were obtained as initial propionic acid concentration of 5% (w/w), TBP concentration in ionic liquids of 3 mol.L−1 and phase ratio of 0.5. Under these conditions, the experimental extraction efficiencies were found to be 87.56% and 88.16% for [HMIM][PF6] and [HMIM][Tf2N], respectively.Graphical abstractGraphical abstract for this article
       
  • Experimental Study and Modeling on Supercritical CO2 Extraction of
           Indonesian Raw Propolis using Response Surface Method: Influence of
           Pressure, Temperature and CO2 Mass Flowrate on Extraction Yield
    • Abstract: Publication date: Available online 15 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Boy Arief Fachri, Puspita Sari, Sih Yuwanti, Erna Subroto It is well-known that propolis shows potential as an antioxidant. A common method to extract propolis is organic solvent extraction which has drawbacks such as long extraction times and solvent residues. To overcome this, the SC-CO2 extraction method was applied in this work. The milled raw propolis was fed into a vessel. The extraction consists of two stages, static (60 min) and dynamic (240 min). During the extraction, the process variables (temperature, pressure and CO2 flow rate) were set to constant. When the extraction time was completed, the liquid product was prepared for analysis using HPLC. This work provides the amount of propolis wax was 7.02 wt% and the highest yield of propolis extract was 14.4 wt%. The effect of the variables on the yield was experimentally investigated and modeled using response surface method approach. The extract containing bioactive compounds such as galangin and CAPE was proved to have 24.77 μg/mL of IC50 which is closer to IC50 of ascorbic acid.Graphical abstractGraphical abstract for this article
       
  • Synthesis and characterization of Tunisian organoclay: Application as
           viscosifier in oil drilling fluid
    • Abstract: Publication date: Available online 15 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Imed Msadok, Noureddine Hamdi, M.A. Rodríguez, Begoña Ferrari, Ezzeddine Srasra In this study, the viscosifiers for diesel oil drilling fluid were prepared using Tunisian clay modified with cationic surfactant for five concentration levels from 0.5 to 4.0 times the cationic exchange of purified clay (CEC). The organo-modified clay samples were characterized by X-ray diffraction (XRD), Infrared spectroscopy (FTIR), scanning electron micrography (SEM) and specific surface area (BET model). Oil–clays suspensions were investigated using polarized light optical microscopy (PLOM) and double cone rheometer. The influence of surfactant concentration on rheological properties of suspensions is related to the different microstructures development which depend on surfactant arrangement in the interlayer of clay. The results showed the growth of yield stress and consistency coefficient as the surfactant concentration is increased and the best behaviors were observed for the 3.0 CEC concentration. This sample was tested for two weight percents (5 and 10 wt %), the higher Herschel Bulkley parameters (τ0= 3.6 Pa, K = 0.397 and n = 0.85) were found for the organoclay at 10 wt%. The latest sample has the high thixotropy loop area so can be used as viscosity enhancer for the oil drilling fluid.
       
  • Study on Hydrodynamic Characteristics of Oil-Water Annular Flow in
           90° Elbow
    • Abstract: Publication date: Available online 15 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Junqiang Wu, Wenming Jiang, Yang Liu, Yi He, Jianan Chen, Liang qiao, Tianyu Wang The transportation of heavy oil surrounded by water annular can significantly reduce the resistance and reduce energy consumption. In the process of conveying high viscosity oil, it will inevitably pass through elbow components. In the present study, the stability in the development of core annular flow (CAF) by the influence of the elbow was investigated by computational fluid dynamics (CFD). The simulated data matched well with the previous experimental data and empirical correlation, which indicates the reliability and practicability of the model. The effects of inlet water fraction, the oil-water property (density ratio, viscosity ratio), and the geometric parameters (diameter ratio, curvature ratio) on hydrodynamic performance, eccentricity and oil transportation efficiency were analyzed, and the results could provide a reference for the design of 90° elbow structures and the optimization of flow parameters.Graphical abstractGraphical abstract for this article
       
  • Simulation of non-Newtonian fluid seepage into porous media stacked by
           carbon fibers using micro-scale reconstruction model
    • Abstract: Publication date: Available online 14 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Licheng Wang, Tongqi Li, Ting Guo, Wangfeng Cai, Dahai Zhang, Feng Xin Ceramic matrix composite of carbon fiber framework reinforced by silicon carbide (Cf/SiC) is a new material with excellent properties. In order to improve its preparation process, the flow of polycarbosilane solution in carbon fiber is studied based on the computational fluid dynamics method. CT images of carbon fiber porous media are obtained by Micro-CT imaging technology and optimized by means of ImageJ software. The 3D solid matrix and pore space models of carbon fiber porous media are established by using Mimics software, and the pore space model is meshed. Using the computational fluid dynamics software Fluent, the VOF multiphase flow model is adopted, the surface tension model and contact angle model are introduced considering the micro-pore effect of porous media, and a suitable mathematical model for the transport of gas-liquid two-phase flow in carbon fiber porous media is established. The validity of CFD mathematical model is verified by comparing experimental data with simulation results. Based on the CFD simulation results, the effects of feed pressure, surface tension coefficient and contact angle on fluid flow are studied. It is found that the larger the feed pressure and contact angle, the more uniform the distribution of liquid phase, pressure and velocity in the medium, which is conducive to the flow of liquid phase in porous media. The larger the surface tension coefficient, the longer the breakthrough time of liquid, and the more uneven the liquid distribution. This study is helpful to understand the law of fluid transport in porous media and provides theoretical basis for the preparation of Cf/SiC composites.Graphical Graphical abstract for this article
       
  • Ionic liquid-water flow in T-shaped microchannels with different aspect
           ratios
    • Abstract: Publication date: Available online 13 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Anna A. Yagodnitsyna, Alexander V. Kovalev, Artur V. Bilsky In this article we investigate the influence of a rectangular microchannel aspect ratio on the liquid-liquid flow. An ionic liquid was chosen as one of the working fluids due to a vast scope of applications. Immiscible ionic liquid-water flow in T-shaped microchannels with 160 μm hydraulic diameter and aspect ratios equal to 2 and 4 was studied experimentally. Flow pattern maps were drawn and compared for two channels in terms of We*Oh dimensionless number. Parallel flow was shown to prevail for the channel with higher aspect ratio. The influence of channel aspect ratio on plug flow peculiarities was studied in detail. Plug length and velocity were measured at different bulk flow rates. Velocity fields in aqueous plugs were measured using the micro-PTV technique. Velocity circulations were calculated for different flow rates. Total circulation value inside plugs was found to be higher in the channel with the lower aspect ratio.Graphical abstractGraphical abstract for this article
       
  • Model-based Experimental Design for Nonlinear Dynamical Systems with
           Unknown State Delay and Continuous State Inequalities
    • Abstract: Publication date: Available online 13 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Yiting Liang, Chunhua Yang, Bei Sun This paper studied the model-based design of experiment (MBDoE) for nonlinear dynamical systems with unknown state delay and continuous state inequalities (SDCSI). The design problem is formulated as a time-delay optimal control problem of a dynamic system governed by augmented sensitivity-state equations (ASSE). Consider the co-existence of control delay and multiple state delays in the ASSE, each continuous state inequality constraint is approximated by an integral constraint using a constraint-handling technique based on local smmoothing approximation and contraint transcription, which guaranteed the satisfaction of state inequality constraints during the experiment. In addition, an efficient numerical procedure is derived to determine the gradients of the objective function and constraints, which involved integrating an auxiliary impulsive time-delay system backward in time. The procedure is combined with standard gradient-based optimization methods to solve the MBDoE-SDCSI problem. The performance of the proposed scheme is illustrated through the experimental design of a fed-batch biomass fermentation process.
       
  • Dynamic study of the evaporation stage of an integrated first and second
           generation ethanol sugarcane biorefinery using EMSO software
    • Abstract: Publication date: Available online 13 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Erick Y. Emori, Jimena Ferreira, Argimiro R. Secchi, Mauro A.S.S. Ravagnani, Caliane B.B. Costa Brazil is the largest producer of sugarcane ethanol in the world. Among the technologies that aim to improve the process, second-generation ethanol is one of the most promising. Although still in development, it is a consensus that this process must be integrated into the production of first generation ethanol. Most of the work on this subject is involved in evaluating the steady-state process. However, the knowledge of the process dynamics plays an important role on the operational efficiency and control. In this work multiple effect evaporation is addressed. A dynamic phenomenological model of this step was developed in EMSO process simulator. A stream of glucose syrup is mixed with sugarcane juice stream at the entrance of the system and simulations were performed to analyze the integrated system dynamics. Step disturbances were applied in the sugar concentration, volumetric flow rate and temperature of the juice individually and simultaneously. Glucose syrup concentration and flow rate was also disturbed. PI/PID controllers were tested in order to control the system and the model consistency was verified in Aspen Dynamics. The analysis suggests that an adequate control system at the liquid and vapor output of each vessel cannot be achieved using only classical controllers.Graphical abstractGraphical abstract for this article
       
  • Evaluation of the membrane efficiency of both Nafion and sulfonated poly
           (ether ether ketone) using electrochemical membrane reactor toward
           desulfurization of a model diesel fuel
    • Abstract: Publication date: Available online 13 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Foad Mehri, Mojtaba Ghamati, Soosan Rowshanzamir, Waldemar Sauter, Uwe Schröder In this paper, the desulfurization of a model diesel fuel containing thiophene and/or benzothiophene using an electrochemical membrane reactor was studied using commercial Nafion and synthesized sulfonated poly ether ether ketone (SPEEK) with the same 40 wt.% Pt/C electrocatalyst. Thiophene and benzothiophene desulfurization under different current density and constant total charge were investigated toward optimum desulfurization conditions. Dihydrobenzothiophene (DHBT) and thiophene as hydrogenation products and H2S as the product of desulfurization were detected. Desulfurization efficiency of 85% at 20 mA cm−2 and 75% at 30 mA cm−2 was obtained for thiophene using Nafion and SPEEK respectively, while benzothiophene desulfurization efficiency was about 70% and 65% related to Nafion and SPEEK. Also, the maximum yield of 85% for DHBT at 40 mA cm−2. Based on the indirect calculation, the H2S yield approaches 98% and 96% for Nafion and SPEEK system at about 100% selectivity in electroreduction of benzothiophene.Graphical abstractGraphical abstract for this article
       
  • Purification step enhancement of the 2,3-butanediol production process
           through minimization of high pressure steam consumption
    • Abstract: Publication date: Available online 12 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Junaid Haider, Muhammad Abdul Qyyum, Le Quang Minh, Moonyong Lee 2,3-butanediol which is produced via the fermentation of biomass, has been recognized as a sustainable and renewable liquid fuel, mainly due to its high anti-knock index and high heating value. However, high thermal energy is required to remove the excess water in the fermentation broth in order to achieve 99% purity. Recently, 2,3-butanediol has been separated and purified adopting hybrid-blower-and-evaporator-assisted distillation with significant consumption of high-pressure steam, which ultimately increases the total annualized costs. In this context, this study proposes dual column-based separation and purification schemes that utilize low and medium-pressure steam rather than high-pressure steam. The overall energy efficiency of the proposed dual-column structure was further enhanced through pressure optimization and an appropriate heat integration approach. With the heat-integrated evaporator-assisted dual column configuration after pressure optimization the savings in operating cost and TAC were approached to 54.2 and 49.9%, respectively. Subsequent to analysis of the potential benefits of the dual-column-based separation and purification schemes, a dividing wall column (DWC) was also proposed and analyzed in order to make intensified separation and purification step for 2,3-butanediol. Conclusively, compared to base case, the evaporator-assisted DWC and heat-integrated-blower-assisted DWC offer potential reductions of the total annualized cost of ∼25.2% and 25%, respectively.Graphical abstractGraphical abstract for this article
       
  • Enhanced decolorization of rhodamine B solution through simultaneous
           photocatalysis and persulfate activation over the Fe/C3N4 photocatalyst
    • Abstract: Publication date: Available online 12 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Hamed Heidarpour, Mohsen Padervand, Mohammad Soltanieh, Manouchehr Vossoughi In this study, organic contaminant degradation was intensified by increasing the oxidative capacity of the reaction system through simultaneous photocatalysis and heterogeneous persulfate activation. Fe nanoparticles were served as a multifunctional modifier to enhance the photoactivity of graphitic carbon nitride (CN), by tuning optical properties as well as persulfate (PS) activation rate, by introducing a new activation pathway. The synthesized photocatalysts were characterized by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-vis DRS), and photoluminescence (PL) analysis. Oxidation power of the proposed system was examined by the degradation of Rhodamine B (RhB) as a model pollutant under visible light irradiation. The effect of operating parameters contributing to the degradation process, including initial pH, and the concentration of the photocatalyst and potassium persulfate were investigated in detail. Scavenging experiments proved that the photocatalyst hole and sulfate radicals play a major role in RhB degradation and a plausible mechanism for the generation of oxidative species was proposed. Furthermore, reusability tests revealed that the photocatalysts possess excellent stability after three repetitive experiments.Graphical abstractGraphical abstract for this article
       
  • Characterization and enhancement of the gas separation properties of mixed
           matrix membranes: Polyimide with nickel oxide nanoparticles
    • Abstract: Publication date: Available online 12 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Wrya Mohammadi Aframehr, Banafsheh Molki, Rouhollah Bagheri, Pejman Heidarian, Seyyed Mohammadreza davoodi Here, we report for the first time the fabrication of a glassy polymer/nickel oxide hybrid membrane as a gas separation membrane. A PI (Matrimid) is used as a continuous phase, and nickel oxide nanoparticles (NiO) were utilized as a dispersed phase. The structure of mixed matrix (MMMs) and pure Matrimid membranes are investigated by employing various characterization techniques including scanning electron microscopy (SEM), Fourier transforms infrared (FT-IR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and tensile stress-strain to characterize the NiO nanoparticles. The effect of NiO nanoparticles content (0-5 wt%) on gas permeability of pure CO2, CH4, O2, and N2 gases at different operating temperatures (24–40 °C) and feed pressures (1-5 bar) were surveyed. The results revealed that the CO2 permeability almost did not change and CO2/CH4 selectivity of PI was enhanced with low-level loadings of NiO while the gas permeability of N2, CH4, and O2 was educed. Our results indicated that since NiO nanoparticles have high interaction with CO2 as Lewis pairs, they have high potential to improve the gas permeability properties of polymer-based membranes. This approach allows predicting the gas transport properties, structure/solubility quantitative relationships of different gases, especially CO2 through the MMMs system.Graphical abstractGraphical abstract for this article
       
  • Cross-flow deposited hydroxyethyl cellulose (HEC)/polypropylene (PP)
           thin-film composite membrane for aqueous and non-aqueous nanofiltration
    • Abstract: Publication date: Available online 11 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Meihong Liu, Yiyang Wu, Yuchen Wu, Mingfu Gao, Zhenhua Lü, Sanchuan Yu, Congjie Gao In this study, hydroxyethyl cellulose (HEC) was cross-flow deposited on flat-sheet polypropylene (PP) porous support and insolubilized by cross-linking using glutaraldehyde (GA) to fabricate cost-effective thin-film composite membrane for aqueous and non-aqueous nanofiltration. Membrane physico-chemical property, permeation performance, as well as tolerance to acid, alkaline and organic solvents were systematically characterized. The obtained HEC/PP composite membrane was found to be effectively modulated in pore size via changing HEC and GA contents and possessed good fabrication reproducibility. The desired HEC/PP composite membrane with an average pore diameter of around 2.21 nm exhibited high fluxes of 41.0 and 8.2 L/m2 h to pure water and ethanol, respectively, and removals of 99.9, 99.9 and 96.7% to 50 mg/L dye aqueous solutions of methyl blue, Congo red and sunset yellow, respectively. Soaking tests revealed that the HEC/PP composite membrane possessed good tolerance to acid, alkali and organic solvents of tetrahydrofuran, ethyl acetate and ethanol. Continuous filtration of dye/ethanol solution demonstrated that the HEC/PP membrane possessed excellent long-term durability in ethanol solution, maintaining a stable flux higher than 4.6 L/m2 h and removals of 95.4 and 84.2% to methyl blue and Congo red, respectively, during the whole filtration of 110 h.Graphical abstractGraphical abstract for this article
       
  • Batch and continuous flow studies of Cr(VI) adsorption from synthetic and
           real wastewater by magnetic pine cone composite
    • Abstract: Publication date: Available online 11 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Agnes Pholosi, Eliazer B. Naidoo, Augustine E. Ofomaja Magnetic pinecone (MNP-PCP) was synthesised via co-precipitation of Fe2+/Fe3+ onto different masses of pine to determine effect of magnetite to pine cone ratio on the Cr(VI) removal capacity. Interaction between magnetite and pine was determined using FTIR, TGA and TEM spectroscopy while iron oxide phase, possible bonding and magnetic properties were confirmed using XRD, XPS and VSM analysis. The composite with 1.5 g of pine removed more Cr(VI) at all solution pH's applied and pH 3 being optimum at which Fe(III) leached into solution was less than 0.01 mg/L. The Langmuir monolayer capacity was observed to be 15.24 mg/g at 26 °C. while Dubinin-Radushkevish free energy ranged from 15.80 to 16.80 kJ/mol suggesting ligand-ion exchange mechanism. Dynamic studies were done using breakthrough curve to evaluate concentration effect of Cr(VI) adsorption. Thomas model best described the dynamic behaviour while desorption studies showed that four adsorption-desorption and regeneration cycles were possible with an elution efficiency>87% and only 15% loss of capacity after four cycles. Performance of MNP-PCP for real wastewater were comparable with synthetic wastewater.Graphical abstractGraphical abstract for this article
       
  • Diblock Sodium Alginate Grafted Poly (N-vinylimidazole) in Blank
           Copolymeric Beads and Immobilized Algal Beads for Water Treatment
    • Abstract: Publication date: Available online 11 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Mohammad M. Fares, Fahmi A. Abu Al-Rub, Tareq Talafha Synthesis of diblock sodium alginate grafted poly (N-vinylimidazole), SA-g-PNVI, was investigated as preliminary step toward preparation of blank copolymeric beads (BCB) and immobilized algal beads (IAB) for the removal of phenol from aqueous solutions. The diblock SA-g-PNVI was self-crosslinked via calcium ions to make BCB, and crosslinked with dead green algae (Chlorella pyrenoidosa) to make the IAB. The diblock SA-g-PNVI was fully characterized using spectroscopic, thermal and optical means. Adsorption optimization parameters like effect of solution pH, dynamics, and adsorption isotherms were investigated; Optimum pH value for phenol removal was found at pH = 5.0 for blank copolymer beads (BCB) and immobilized algal beads (IAB). The adsorption kinetics demonstrated pseudo-second order phenol removal with major contribution of intraparticle diffusion mechanism. Adsorption isotherms were fitted to equilibrium data in linear and nonlinear regressions using different objective functions. The low cost, natural origin, biodegradability and environmentally friendly characteristics of the diblock SA-g-PNVI sorbents adapt them to play promising role in recovery of missing ecology and in wastewater management.Graphical abstractGraphical abstract for this article
       
  • Volume averaging theory (VAT) based modelling for longitudinal mass
           dispersion in structured porous medium with porous particles
    • Abstract: Publication date: Available online 10 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Chen Yang, Rong Huang, Yixiong Lin, Ting Qiu In this study, to investigate the mass transport characteristics in a structured porous medium with porous particles under an interfacial concentration discontinuity, a macroscopic solute transport equation is proposed based on the volume averaging theory. A typical three-dimensional geometry (a body center cubic arrangement of spheres) was chosen as the representative elementary volume. The corresponding closure problem was solved to obtain the longitudinal mass dispersion. Based on the numerical results, a new correlation of the longitudinal mass dispersion for a structured porous medium with porous particles is presented. Through a comparison with the correlation of the longitudinal mass dispersion for a random porous medium, it can be determined that, for a mechanical dispersion, the dependence of a random porous medium and that of a structured porous medium on the Péclet number Pe are linear and quadratic, respectively. Furthermore, it was also determined that for a holdup dispersion, a structured porous medium is less dependent on the ratio of diffusivity of the fluid phase to the diffusivity of the porous particle phase. In addition, it is more dependent on the inverse ratio of the solubilities of the solute in the fluid and in the catalyst particles than in a random porous medium.
       
  • Crystal engineering of hierarchical zeolite in dynamically maintained
           Pickering emulsion
    • Abstract: Publication date: January 2020Source: Chemical Engineering Research and Design, Volume 153Author(s): Xiaoling Zhao, Hongchang Duan, Shanbin Gao, Zheru Shi, Kake Zhu, Xinggui Zhou Crystal engineering of hierarchical zeolites is regarded as a promising way to enhance diffusion-dependent catalytic properties of zeolitic materials. Crystallization process control on crystal size and pore-structure is desirable over porogen based protocols and post-synthetic methods for the low cost, high yield and potential scalability. Herein, a tumbling crystallization of hierarchical ZSM-5 zeolite in immiscible water/toluene Pickering emulsion inspired by energy dissipating structure occurring in nature is presented. The structure and acid properties of the obtained hierarchical material have been revealed using a panoply of characterization techniques such as powder X-ray diffraction, N2 physisorption isotherms, SEM, TEM, mercury protrusion measurements, NH3-TPD and pyridine IR spectroscopy, showing that the material contains high crystallinity, and penetrating macropores. Crystallization is found to proceed through a Pickering emulsion structure maintained by emulsifying effect of constant tumbling. Such an emulsion structure has hindered attachment growth of primary nanocrystals formed at the nucleation stage to further grow into larger size via coalescense. The hierarchical zeolite exhibits architecture-dependent prolonged catalyst lifetime and light olefin yield in dimethylether-to-olefin conversion. This process control to generate hierarchical zeolites opens up new ways toward inexpensive, high level control and efficient engineering of zeolite morphology.Graphical abstractGraphical abstract for this article
       
  • A facile coating to intact SAPO-34 membranes for wet CO2/CH4 mixture
           separation
    • Abstract: Publication date: January 2020Source: Chemical Engineering Research and Design, Volume 153Author(s): Rashid Ur Rehman, Qingnan Song, Li Peng, Zhengqi Wu, Xuehong Gu The excellent performance of SAPO-34 membranes for CO2/CH4 separation is detracted by the water interaction, resulting in membrane instability and low durability. Herein, a new facile coating strategy using α, ω-dihydroxypolydimethylsiloxane (PDMS) has been developed for surface protection of SAPO-34 membranes by dip-coating. The fabrication of coating layer was optimized by finely tailoring the coating solution parameters, such as the viscosity and PDMS concentration. The developed membranes were evaluated under dry and wet CO2/CH4 mixture systems with effect of temperature and pressure. PDMS/SAPO-34 membrane could provide high separation performance in both systems. The separation selectivity of 68 and CO2 permeance of 1.41 × 10−7 mol m−2 s−1 Pa−1 was achieved for wet mixture of CO2/CH4 at 80 °C during 120 h continuous operation. Furthermore, the PDMS/SAPO-34 membrane showed a wonderful performance after half a year storage, with 5–8% changes of CO2 permeance and selectivity for the dry CO2/CH4 mixtures, while for un-modified SAPO-34 membrane, a decline of 71% in CO2 permeance and 85% in CO2/CH4 separation selectivity was observed. The results demonstrated that the PDMS-coated SAPO-34 membrane could be a promising candidate for natural gas purification.Graphical abstractGraphical abstract for this article
       
  • Heat transfer coefficient in internal mixers for different polymers and
           processing conditions
    • Abstract: Publication date: December 2019Source: Chemical Engineering Research and Design, Volume 152Author(s): Vithória A.D. Marinho, Luanna V. Cesario, Anna Raffaela M. Costa, Laura H. Carvalho, Tatiara G. Almeida, Eduardo L. Canedo Tests with five different neat polymers, two different blends and one composite were conducted on a Haake Rheomix 3000 and Rheomix 600 internal laboratory mixers with two different types of rotors. The heat transfer coefficient per unit area was determined from the temperature and torque values recorded by each equipment. In all cases, dispersion of the experimental data was significant. Results showed that the heat transfer coefficient in internal mixers is higher than in common single screw extruders and similar to the values found for corrotational twin screw extruders. Data indicates that heat transfer coefficient in internal mixers is independent of the internal mixer capacity, the type of rotor used, the processing temperature and the type of neat polymer processed. In contrast, it is dependent on the nominal speed of the rotors and the polymer for incompatible polymer blends and for polymer matrix composites.
       
  • Short-cut method for assessing solvents for gas cleaning by reactive
           absorption
    • Abstract: Publication date: Available online 9 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Dan Vasiliu, Elmar Kessler, Erik von Harbou, Hans Hasse A new short-cut method (NoVa) for assessing solvents for gas cleaning by reactive absorption is presented. It considers the absorption / desorption cycle using the assumption of infinite number of stages in both columns. For a given feed and removal rate, the method yields an estimate for the specific regeneration energy q as a function of the solvent circulation rate L/G. The sole solvent-dependent input consists of two correlations describing the gas solubility at absorber and desorber conditions and estimates of caloric properties. Furthermore, a simple equation (SolSOFT) for correlating the gas solubility as a function of the gas loading of the solvent is presented. A theoretical analysis of the process reveals general properties of the dependency of q on L/G. The NoVa method is described and tested using amine-based solvents for post combustion carbon capture as examples.
       
  • Non-isothermal evaporation and heat transfer of the salt solution layer on
           a structured wall in the presence of corrosion
    • Abstract: Publication date: Available online 9 November 2019Source: Chemical Engineering Research and DesignAuthor(s): S.Y. Misyura The layer evaporation with and without corrosion on an iron micro-structured wall with ceramic coating is investigated experimentally. SiO2 coating is obtained. A structured wall is used to intensify heat transfer. Hydrophobic ceramic coating is used to reduce the aggressive effect of salts on the metal wall. Rapid wall corrosion at high temperatures is a significant problem for desalination technologies, high-temperature generators of adsorption heat pumps, and chemical technologies using salts. The evaporation rate of the salt solution (CaCl2/H2O and NaCl/H2O) on the structured heated wall with SiO2 is 25-30% higher than on the smooth surface. Often, to simplify the simulation of heat transfer, free convection in the layer is neglected due to the low layer height and high viscosity of the solution. The novelty of this work lies in the fact that it is free convection that plays a key role. The combined effect of microstructured roughness and anticorrosion coating on heat transfer and convection is considered for the first time. The role of convection depends on whether the salt belongs to the first or second group, characterized by a certain character of evaporation. To date, there are no models that take into account structured surface, corrosion and natural convection on non-isothermal evaporation and heat transfer in a thin solution layer.Graphical abstractThe ratio of evaporation rates j1/j2: j1 is for the microstructured wall coated by SiO2; j2 is for the structured surface without SiO2 coating (with corrosion): 1 – NaCl; 2 – CaCl2.Graphical abstract for this article
       
  • CFD Analysis of a Luminescent Solar Concentrator-Based Photomicroreactor
           (LSC-PM) with Feedforward Control Applied to the Synthesis of Chemicals
           under Fluctuating Light Intensity
    • Abstract: Publication date: Available online 8 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Gabriela X. de Oliveira, Jéssica O.B. Lira, Dario Cambié, Timothy Noël, Humberto G. Riella, Natan Padoin, Cíntia Soares The luminescent solar concentrator-based photomicroreactor (LSC-PM) is a novel technology applied to the synthesis of chemicals coupling the advantages of sunlight modulation/concentration and micro flow chemistry. In this work, a virtual model of this device, based on computational fluid dynamics (CFD), was implemented. The CFD model was developed considering a kinetic law that takes into account the effect of light intensity on the reaction performance for the [4 + 2] cycloaddition of 9,10-diphenylanthracene (DPA), used as benchmark. Then, a feedforward control algorithm was implemented and the system's performance under different functional dependences of light intensity through time was investigated, being able to maintain the conversion at the desired level despite the power fluctuations. Thus, the CFD model was independently validated considering the control framework associated to the experimental data. Finally, the effect of varying some geometrical features of the photomicroreactor was investigated, highlighting the capability of using a computational model for engineering purposes (design and optimization). Therefore, this work represents a contribution towards a fully predictable model for the investigation of the performance and for the des`ety of chemical processes.Graphical abstractGraphical abstract for this article
       
  • Development of facilitated transport membranes composed of a dense gel
           layer containing CO2 carrier formed on porous cylindrical support
           membranes
    • Abstract: Publication date: Available online 7 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Eiji Kamio, Shohei Kasahara, Farhad Moghadam, Hideto Matsuyama It is well known that facilitated transport membranes (FTMs) containing CO2 carriers have high CO2 permeability and excellent permselectivity of CO2 over other light gases. The major challenge in developing FTMs for practical applications is the formation of a separation layer containing CO2 carriers on a support membrane. In this research, we prepared composite membranes by forming a dense gel layer containing glycine as the CO2 carrier on polysulfone (PSf) and ceramic (α-alumina) support membranes. Because of the smaller pore size of the PSf support membrane, the gel layer formed on the PSf membrane was thinner and had higher CO2 permeance than that formed on the alumina membrane. However, the CO2 permeabilities of the FTMs formed on the two support membranes showed different temperature dependences; the FTM formed on PSf membrane had higher CO2 permeability at elevated temperatures of more than ca. 350 K and lower CO2 permeability at low temperatures up to ca. 350 K than the FTM formed on alumina support. The different temperature dependences on the CO2 permeability resulted from the different properties of the gel layer formed on the support membranes. Improvement of the CO2 permeability of FTMs could be enabled by selecting an adequate support membrane.
       
  • Effect of contact force modeling parameters on the system hydrodynamics of
           
    • Abstract: Publication date: Available online 7 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Taraborbin Yurata, Pornpote Piumsomboon, Benjapon Chalermsinsuwan In this study, the effects of contact force modeling parameters, which included the particle-particle friction coefficient (A), spring constant (B), ratio of the tangential spring constant to normal spring constant (C), normal restitution coefficient (D), and tangential restitution coefficient (E) presenting in the linear spring-dashpot contact model on the hydrodynamics profile of spouted bed reactor, were investigated via computational fluid dynamics coupled with discrete element method (CFD–DEM) using Multiphase Flow with Interphase eXchange (MFIX). First, the base case simulation was validated with the experimental data. Next, the 2k factorial experimental design and an analysis of variance (ANOVA) was conducted to identify the significant main and interaction contact force modeling parameters. Four response variables were observed: the translation kinetic energy of particles, the rotational kinetic energy of particles, the bed expansion, and the standard deviation of pressure drop. Based on these results, the particle-particle friction coefficient, spring constant, and normal restitution coefficient were the major contact force modeling parameters that affected the system hydrodynamics in the spouted bed system. In addition, the effects of main and interaction contact force modeling parameters were summarized, which enhanced our knowledge of the modeling parameters on system hydrodynamics. Contact force modeling parameters must be carefully selected when simulating the spouted bed reactor or related gas-solid multiphase flow process, such as fluidized bed reactor.Graphical abstractContour plots of the averaged void fraction on the central xy-plane of the spouted bed reactor with different contact force modeling parameters.Graphical abstract for this article
       
  • A review of in-line and on-line measurement techniques to monitor
           industrial mixing processes
    • Abstract: Publication date: Available online 7 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Alexander Lewis Bowler, Serafim Bakalis, Nicholas James Watson Mixing is a ubiquitous operation in process engineering. It is not only used for combining materials, but also for promoting heat and mass transfer, increasing aeration, suspending solids, and modifying material structure. Measurement techniques have the potential to optimise industrial mixing processes and improve product quality by monitoring critical process parameters. Real-time sensing techniques that do not require manual material sampling are of particular interest owing to their automatic data acquisition capability. This makes them suitable for use in control systems for process automation and eventually as connected sensors in Industry 4.0. This review article focuses on these measurement techniques, defined as in- and on-line, along with their capability for implementation in industrial processes. The applications reviewed include liquid-liquid, gas-liquid, solid-liquid, solid-gas-liquid, in addition to solids blending. A technique selection section discussing the decision-making process when choosing a sensor and a summary table including the advantages, disadvantages, applications and limitations of each technique are provided. The article concludes by discussing the future of monitoring techniques for mixing processes.Graphical abstractGraphical abstract for this article
       
  • Corrigendum to “Detailed numerical solution of pore volume and surface
           diffusion model in adsorption systems” [Chem. Eng. Res. Des. 122 (2017)
           298–307]
    • Abstract: Publication date: Available online 6 November 2019Source: Chemical Engineering Research and DesignAuthor(s): P.R. Souza, G.L. Dotto, N.P.G. Salau
       
  • An efficient tool to determine physical properties of ternary mixtures
           containing 1-alkyl-3-methylimidazolium based ILs and molecular solvents
    • Abstract: Publication date: December 2019Source: Chemical Engineering Research and Design, Volume 152Author(s): Ebrahim Soroush, Mohammad Mesbah, Sohrab Zendehboudi Ionic liquids (ILs) are considered as a proper alternative for conventional solvents. However, they have high viscosity that may result in poor transport phenomena behaviors. This problem can be overcome by mixing ILs with less viscous solvents. Furthermore, several IL processes involve molecular solvents as solvents/reactants and products. Hence, appropriate values of physical characteristics of ILs/molecular solvent systems are required to design and optimize corresponding processes. This clearly implies the necessity to develop deterministic tools for forecasting physical properties of ILs/molecular solvents mixtures. In this study, the physical properties (density, refractive index, and viscosity) of 1-alkyl-3-methylimidazolium cation (Cnmin+) based ILs with molecular solvents, at 298.15 K and atmospheric pressure, are estimated using a connectionist tool. The proposed correlation strategy offers a strong model, which relates density, refractive index, and viscosity of the Cnmin+ based ILs-molecular solvent ternary mixtures to independent parameters including molecular weight and normal boiling temperature, simultaneously. A proper statistical analysis is performed to assess strength and generalization of the deterministic model. The developed network results in the coefficient of determination (R2) of 0.9999, 0.9993, and 0.9995 in obtaining density, refractive index, and viscosity, respectively. In addition, the error analysis shows the mean squared error (MSE) of 7.54 × 10−7, 6.91 × 10−7, and 1.59 × 10−1 while determining density, refractive index, and viscosity. A parametric sensitivity analysis is also conducted to evaluate influences of the input variables on the output parameters. This study can be instructive for design and optimization of chemical processes which employ IL/solvent mixtures.Graphical abstractGraphical abstract for this article
       
  • Effects of elongated particles rotation on discharge flow of mixed
           granular systems
    • Abstract: Publication date: December 2019Source: Chemical Engineering Research and Design, Volume 152Author(s): Lizhuo Zhu, Ningsheng Wang, Haifeng Lu, Haifeng Liu Previous study has reported that adding elongated particles to cohesive granular matters can significantly improve their flowability. In this study, the mechanism of how the elongated particles work to this system was experimentally investigated. The experimental system included a quasi-two-dimensional visualization hopper and a high speed camera to record the flow behavior of the mixed granular systems consisting of glass beads and elongated particles during hopper discharge. Experiments revealed that the discharge rate first increased and then decreased as the mass fraction of elongated particles increased. It was observed that during the discharge flow, the elongated particles rotated and caused local secondary flow of the glass beads. This resulted in a significant increase in flowing layer thickness. Consequently, the effect of elongated particles rotation on discharge flow was discussed. Finally, the estimation of rotational torque of elongated particles was proposed to quantitatively describe the increase of discharge rate.Graphical abstractGraphical abstract for this article
       
  • Investigation of the apparent kinetics of air and oxy-fuel biomass
           combustion in a spouted fluidised-bed reactor
    • Abstract: Publication date: Available online 6 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Yongliang Yan, Peter T. Clough, Edward J. Anthony A bench-scale spouted fluidised-bed reactor was used to investigate the combustion kinetics of pulverised woody biomass under air and oxy-fuel atmospheres. Bed temperatures were in the range of 923-1073 K and O2 concentrations were varied from 20-35 vol%. The activation energies and apparent orders of reaction were calculated for air and oxy-fuel combustion by means of an nth order Arrhenius equation approach. Results indicated that the apparent order of reaction for both air and oxy-fuel combustion was approximately zero. The activation energies were calculated assuming a zero-order reaction mechanism and were averaged over all oxygen concentrations for air and oxy-fuel combustion and found to be 18.95 kJ/mol and 26.93 kJ/mol, respectively. The rate of combustion under oxy-fuel conditions was, on average, 37.5% higher compared to air combustion. The shrinking core model with a reaction-controlled step was found to accurately represent the biomass combustion reactions under both air and oxy-fuel conditions.Graphical abstractGraphical abstract for this article
       
  • Zone economic model predictive control of a coal-fired boiler-turbine
           generating system
    • Abstract: Publication date: Available online 5 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Yi Zhang, Benjamin Decardi-Nelson, Jianbang Liu, Jiong Shen, Jinfeng Liu In this work, a zone economic model predictive controller is proposed for the operation of a boiler-turbine generating system. The control objective is to optimize the operating economics while satisfying the power generation demand from the grid. First, the considered boiler-turbine system is introduced and the economic performance indices are formulated. Then, a moving horizon estimator (MHE) is designed to provide state estimates for the controller in virtue of its ability in dealing with nonlinearities and constraints. Subsequently, an economic model predictive control (EMPC) design integrated with a zone tracking objective is proposed for the boiler-turbine generating system. Extensive simulations under different scenarios illustrate the effectiveness of the proposed EMPC design compared with the conventional set-point tracking model predictive control.
       
  • Validation of the pressure drop-flow rate relationship predicted by
           lattice Boltzmann simulations for immiscible liquid-liquid flows through
           SMX static mixers
    • Abstract: Publication date: Available online 4 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Sébastien Leclaire, David Vidal, Louis Fradette, François Bertrand Single-phase and two-phase flows through SMX static mixers were modeled using the color-gradient multiphase lattice Boltzmann method and the results were compared with experimental data from the scientific literature. In particular, the relationship between pressure drop and flow rate was investigated for single-phase and immiscible liquid-liquid interfacial systems in laminar and transitional flow regimes. The hydrodynamic simulations of immiscible liquid-liquid flows at various volume fractions accounted for interfacial effects such as coalescence and breakage. Every simulation was performed at a prescribed pressure drop corresponding to the one observed experimentally, and the resulting dimensionless Reynolds number was predicted and compared to the experimental one. Good agreement between simulations and experiments were obtained. From a practical standpoint, it is also shown that the addition of a more viscous dispersed phase in a continuous phase increases the pressure drop at a given Reynolds number in the laminar flow regime. In the transitional flow regime, the results suggest that the addition of a small fraction of the dispersed phase could actually reduce the pressure drop.Graphical abstractGraphical abstract for this article
       
  • Sustainable production of glucaric acid from corn stover via glucose
           oxidation: an assessment of homogeneous and heterogeneous catalytic
           oxidation production routes
    • Abstract: Publication date: Available online 2 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Vaishali B. Thaore, Robert D. Armstrong, Graham J. Hutchings, David W. Knight, David Chadwick, Nilay Shah Glucaric acid is being used increasingly as a food additive, corrosion inhibitor, in deicing, and in detergents, and is also a potential starting material for the production of adipic acid, the key monomer for nylon-66. This work describes a techno-economic analysis of a potential bio-based process for the production of pure glucaric acid from corn stover (biomass). Two alternative routes for oxidation of glucose to glucaric acid are considered: via heterogeneous catalytic oxidation with air, and by homogeneous glucose oxidation using nitric acid. Techno-economic and lifecycle assessments (TEA, LCA) are made for both oxidation routes and cover the entire process from biomass to pure crystalline glucaric acid that can be used as a starting material for the production of valuable chemicals. This is the first TEA of pure glucaric acid production incorporating ion exchange and azeotropic evaporation below 50 °C to avoid lactone formation. The developed process models were simulated in Aspen Plus V9. The techno-economic assessment shows that both production routes are economically viable leading to minimum selling prices of glucaric acid of ∼ $2.53/kg and ∼ $2.91/kg for the heterogeneous catalytic route and the homogeneous glucose oxidation route respectively. It is shown that the heterogeneous catalytic oxidation route is capable of achieving a 22% lower environmental impact than the homogeneous glucose oxidation route. Opportunities for further improvement in sustainable glucaric acid production at industrial scale are identified and discussed.Graphical abstractGraphical abstract for this article
       
  • Deformation and breakage of biofuel wood pellets
    • Abstract: Publication date: Available online 1 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Alexander Russell, Sylvia Larsson, Shishir Shekhar, Isaac Solomon, Hamid Salehi, Jordi Subirana, Robert Samuelsson A convenient approach to employ an elliptic load-deformation elastoplastic approximation has been proposed and used to evaluate the mechanical behavior of pinewood biofuel pellets from lab-scale compressive load-deformation measurements. Verification of model predictions has been attempted against apparent finite element method based simulations. A database of essential mechanical properties has been established. This submission is intended as a model for being able to study the deformation and breakage behavior using lab-scale compression tests.Graphical abstractGraphical abstract for this article
       
  • Fabricating a hydrophobic modified flocculant through UVC irradiation
           initiation for metalworking wastewater treatment
    • Abstract: Publication date: Available online 1 November 2019Source: Chemical Engineering Research and DesignAuthor(s): Wei Chen, Jiujing Peng, Bin Du, Liangqian Fan, Hongbing Luo, Yanbo Lu, Keqin Feng, Huaili Zheng In this work, a hydrophobically modified cationic polyacrylamide (CPAC) flocculant was polymerized by short-wave ultraviolet (UVC) initiation with acrylamide, acryloyloxyethyl trimethylammonium chloride, and coconut diethanolamide (CDEA) as monomers to enhance the destabilization and separation efficiency of emulsified oil and particles/colloids from metalworking fluids wastewater (MWFs). The parameters for flocculant polymerization were optimized, and the features of UVC-initiated polymerization were studied. Moreover, the structural and morphological characteristics of the polymers were explored, and the flocculation performance of CPAC in MWFs treatment was evaluated. The characterization results suggested that flocculants with a multilayer, loose-sheet morphology and intrinsic viscosity of 11.32 dL·g-1 could be successfully polymerized by UVC-initiated polymerization. Compared with traditional UV, UVC irradiation initiation promoted the copolymerization of flocculants with a high monomer conversion rate and intrinsic viscosity. We observed the low dosage requirement and acid resistance of the flocculant synthesized by UVC-initiated polymerization, which produced the lowest residual turbidity, highest chemical oxygen demand, and most efficient oil removal during MWFs treatment among the samples studied. Besides charge neutralization and bridging effects, the adsorption effect between hydrophobic CDEA blocks and nonpolar oil/colloids facilitated the formation of microflocs and improved the flocculation efficiency of the flocculant.Graphical abstractGraphical abstract for this article
       
  • A nonequilibrium thermodynamics perspective on nature-inspired chemical
           engineering processes
    • Abstract: Publication date: Available online 31 October 2019Source: Chemical Engineering Research and DesignAuthor(s): V. Gerbaud, N. Shcherbakova, S. Da Cunha Nature-inspired chemical engineering (NICE) is promising many benefits in terms of energy consumption, resilience and efficiency etc. But it struggles to emerge as a leading discipline, chiefly because of the misconception that mimicking Nature is sufficient. It is not, since goals and constrained context are different. Hence, revealing context and understanding the mechanisms of nature-inspiration should be encouraged. In this contribution we revisit the classification of three published mechanisms underlying nature-inspired engineering, namely hierarchical transport network, force balancing and dynamic self-organization, by setting them in a broader framework supported by nonequilibrium thermodynamics, the constructal law and nonlinear control concepts. While the T1-T3 mapping is not complete, the NET and CL joint framework opens also new perspectives. This novel perspective goes over classical chemical engineering where equilibrium based assumptions or linear transport phenomena and control are the ruling mechanisms in process unit design and operation. At small-scale level, NICE processes should sometimes consider advanced thermodynamic concepts to account for fluctuations and boundary effects on local properties. At the process unit level, one should exploit out-of-equilibrium situations with thermodynamic coupling under various dynamical states, be it a stationary state or a self-organized state. Then, nonlinear phenomena, possibly provoked by operating larger driving force to achieve greater dissipative flows, might occur, controllable by using nonlinear control theory. At the plant level, the virtual factory approach relying on servitization and modular equipment proposes a framework for knowledge and information management that could lead to resilient and agile chemical plants, especially biorefineries.
       
  • Improved transport of gold(I) from aurocyanide solution using a green
           ionic liquid-based polymer inclusion membrane with in-situ
           electrodeposition
    • Abstract: Publication date: Available online 31 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Yan Sun, Ziyue Wang, Yating Wang, Men Liu, Shengjian Li, Lihong Tang, Shixiong Wang, Xiangjun Yang, Siping Ji Ionic liquid-based polymer inclusion membranes (PIMs) are an environmentally benign separation technology. PIMs are especially suitable for separation of dilute substances, but their application is hindered by their relatively low permeability rate. In this paper, a novel ionic liquid-based PIM system integrated with an electroplating unit was developed to improve the permeability of gold from aurocyanide solutions. Under the optimal conditions, 98.6% of gold(I) was transported, and more than 96.4% of gold was simultaneously deposited on the copper cathode. The gold(I) transport rate was considerably enhanced with in-situ electrodeposition of gold in the stripping phase. With a constant voltage of 1.50 V applied to the stripping solution, the permeability coefficient increased from 9.25 × 10-6 m/s (with no voltage) to 21.5 × 10-6 m/s (with voltage). SEM and EDX analysis show metallic state gold was coated evenly on the surface of the electrode. Results of a stability evaluation experiment show that the PIM can be operated stably for 10 cycles on a continuous run mode. The method of simultaneous transport and in-situ electrodeposition expands the application of the PIM technology for separation, which shows good prospects for the removal and recovery metal ions.Graphical abstractGraphical abstract for this article
       
  • Modeling and Simulation of an industrial falling film evaporator for
           Alumina Production
    • Abstract: Publication date: Available online 30 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Xiaoli Wang, Pan Xiong, Sen Xie, Yongfang Xie, Chunhua Yang A mathematical model was developed by combining a lumped parameter model (LPM) and a distributed parameter model (DPM) for an industrial falling film evaporator used for evaporation of sodium aluminate solution (SAS) in alumina production process. In the LPM, the dynamic equations were deduced to calculate the concentration of the evaporator outlet. The DPM was developed to study the evaporation happened in each heating tube, in which, residence time, film thickness, liquid load of feed and heat transfer quantity were established as functions of the longitudinal location from the entrance down the tube. Material properties related to the compositions, such as density and viscosity were fitted from industrial measured data in a heat balance test. Overall heat transfer coefficient was modeled and discussed based on fluid mechanics knowledge. Affection of scaling, which was an obstacle in accurate modeling, was considered using the industrial history data combined with mass and heat balance equations to calculated. The simulated concentrations of the products showed quite good accuracy of the model.
       
  • A linear, analytical solution to the principal stress cap, force balance
           equations for asymmetrical stresses in cylindrical silos
    • Abstract: Publication date: Available online 29 October 2019Source: Chemical Engineering Research and DesignAuthor(s): A.J. Matchett A linear, analytical solution to the principal stress cap force balance equations for asymmetrical stress in a circular silo has been derived. Principal stress relationships are linearly through gradients J1 and J2 and intercepts T1 and T2.The solution gives first-order ordinary differential equations in Z over the principal stress cap surface. The solution to the equation can either be Janssenian(stresses approach limiting values), or exponential(stresses increase exponentially with depth).Exponential stress can be caused by •reversal of the direction of vertical shear stress from upwards(positive) for Janssenian: to downwards(negative) for exponential(vertical stress reversal exponential stress)and/or•the inclination of the principal stress cap (λ-line) directing gravitational forces to the lower region of the stress cap(σ2 exponential stress)Symmetrical systems; systems with low Eccentricity; and concave systems give Janssenian stress throughout with the appropriate state of stress (passive/convex; active/concave).Exponential stress systems could cause high stresses and large variations around the perimeter of the silo, with potentially catastrophic effects.The model is relatively simple and can form a basis for the planning and design of experiments, and a base case for more sophisticated models.
       
  • Application of a New Pilot-Scale Distillation System for Monoethylene
           Glycol Recovery Using an Energy Saving Falling Film Distillation Column
    • Abstract: Publication date: Available online 28 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Ana Paula Braga Pires, Valdemar Francisco da Silva Filho, José Luiz Francisco Alves, Cintia Marangoni, Ariovaldo Bolzan, Ricardo Antônio Francisco Machado Monoethylene glycol (MEG) is a desiccant widely used in the Oil and Gas and Sugar Cane Alcohol industries and generates a large volume of MEG-water mixture effluent. This original study explores the use of a new pilot-scale distillation system for separating MEG from a MEG-water mixture. The distillation tests were performed with a single-tube falling film distillation column assisted by a thermosyphon system operating at atmospheric pressure (Destubcal Technology). The results attained high MEG contents, with a MEG loading of 66.00% (m/m), yielding a MEG separation of 88.61%. Additionally, a distillation arrangement with two single-tube falling film distillation columns in series was able to reach values of separation similar to those used by companies in the Oil and Gas sector, while operating at atmospheric pressure. It was also found that Destubcal Technology leads to a 46.93% reduction of the energy required and is more compact than a conventional-industrial distillation column.Graphical abstractGraphical abstract for this article
       
  • Amoxicillin removal by Fe-based nanoparticles immobilized on
           polyacrylonitrile membrane: Individual nanofiltration or Fenton reaction,
           vs. Engineered combined process
    • Abstract: Publication date: Available online 28 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Hanieh Karimnezhad, Amir H. Navarchian, Touraj Tavakoli Gheinani, Sirus Zinadini In this study, nanofiltration (NF) membrane process was combined with Fenton reaction (FT) by incorporating Fe-based nanoparticles (NPs), i.e., goethite (Goe) and maleate ferroxane (Mf) in the structure of polyacrylonitrile (PAN) film to improve the antifouling property and filtration performance of the membrane for amoxicillin (AMX) removal. The relation between the microstructure of the resulted composite with the antifouling properties and membrane performance is extensively investigated. It was found that by NF/FT combined process, foulants could be degraded and the AMX separation efficiency enhanced by 92.3 and 86.3% for PAN/Mf and PAN/Goe membranes, respectively. The permeate fluxes were also increased to 1.4 and 1.2 times of NF membrane filtration alone, respectively. Due to degradation of foulants, the combined NF/FT process exhibited better antifouling properties including flux recovery ratio (FRR) of 97.3 and 96.2% for PAN/Mf and PAN/Goe, respectively. The ratio of irreversible fouling to reversible fouling for NF/FT was lower than individual membrane process. Furthermore, the four cycles of AMX rejection, indicated the good stability and reusability of Fe-based NPs in composite membranes with FT reaction. Consequently, this research proves the successful combination of FT and NF membrane processes.Graphical abstractGraphical abstract for this article
       
  • Membrane dehydration-enhanced esterification for biodiesel production from
           a potential feedstock of Firmiana platanifolia L.f. seed oil
    • Abstract: Publication date: Available online 25 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Enmin Lv, Tong Dou, Shaoxuan Ding, Jie Lu, Zhuang Li, Weiming Yi, Jianxin Li, Jincheng Ding A two-step acid/alkali-catalysis method was developed to produce biodiesel from Firmiana platanifolia L.f. seed oil obtained from continuous-screw squeezing and solvent extraction by absolute ethanol. The esterification of Firmiana platanifolia L.f. seed oil with ethanol was carried out with the strong-acid cation exchange resin to decrease the content of free fatty acids (FFAs) below 1 wt. %. A NaA zeolite membrane was used for dehydration in the coupled reactor. Alkali-catalysis transesterification was performed with 0.08% (m/m oil) of KOH and 6:1 of molar ratio of methanol to oil, reaction time of 30 min, and reaction temperature of 60 °C. Results showed that the combination of esterification with vapor permeation (VP) or pervaporation (PV) could greatly shift the reaction equilibrium forward. The FFAs conversion rates higher than 99.0% were obtained under the conditions of ethanol to oil molar ratio of 15:1, catalyst dosage of 40.0 wt. % and temperature of 78 °C, and operation time of 7 h. Moreover, the properties of the biodiesel meet the standards of American Society for Testing Material (ASTM), European Norm (EN) and Chinese Standard (GB).Graphical abstractGraphical abstract for this article
       
  • Linking process variables to residence time distribution in a hybrid
           flowsheet model for continuous direct compression
    • Abstract: Publication date: Available online 25 October 2019Source: Chemical Engineering Research and DesignAuthor(s): S.C. Galbraith, S. Park, Z. Huang, H. Liu, R.F. Meyer, M. Metzger, M.H. Flamm, S. Hurley, S. Yoon Continuous manufacturing of oral-dosage pharmaceuticals is widely understood to ensure consistent product quality and higher productivity at lower costs. Here, a hybrid flowsheet model is developed in order to link the process variables to the residence time distribution (RTD) of mixed pharmaceutical powders in a continuous direct compression (CDC) process containing two separate powder blending units. An empirical equation is regressed from collected RTD data for one formulation that calculates parameters for a tanks-in-series model as a function of system throughput and blender impeller speed. The prediction power of the hybrid flowsheet was tested against the regression dataset and validated against five conditions that were not used in the regression. The hybrid flowsheet was found to perform accurately against the regression dataset and could predict the behavior of the validation dataset. The potential applications of the hybrid flowsheet were demonstrated by developing a soft sensor for predicting off-target material based on a large in-silico dataset generated by the hybrid flowsheet. The soft sensor was demonstrated to accurately predict diversion events triggered by off-target material as well as adjust the throughput and blender speed to prevent the diversion event from occurring.Graphical abstractGraphical abstract for this article
       
  • Fabrication of a new emulsion polyvinyl chloride (EPVC) nanocomposite
           ultrafiltration membrane modified by para-hydroxybenzoate alumoxane (PHBA)
           additive to improve permeability and antifouling performance
    • Abstract: Publication date: Available online 25 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Marzie Farjami, Vahid Vatanpour, Abdolreza Moghadassi New emulsion polyvinyl chloride (EPVC) microporous nanocomposite ultrafiltration membranes were fabricated by doping them using various amounts of para-hydroxybenzoate alumoxane (PHBA) via the phase inversion technique. High hydrophilicity of PHBA particles made it an outstanding selection for improving the membranes performance. The prepared membranes were characterized with scanning electron microscopy (SEM), energy dispersive X-ray (EDX), atomic force microscopy (AFM) techniques along with water contact angle, permeation, rejection and fouling tests. The modified EPVC membranes indicated an improvement in hydrophilicity and pure water flux because of the attendance of hydrophilic PHBA additive. All of the fabricated membranes demonstrated higher flux recovery ratio (FRR (%)) in comparison with the pristine EPVC membrane. The modified membrane with 0.5 wt.% of PHBA showed the highest water flux growth (47.1%) and the best antifouling performance (FRR = 65.3%). In addition, the rejection of the bovine serum albumin (BSA) was more than 98% for all of the prepared membranes. The performance of the neat and optimum membranes was evaluated for reusability and concentrating the whey protein and the obtained results showed that the modified nanocomposite membrane had higher fouling resistance and permeability.Graphical abstractGraphical abstract for this article
       
  • Hydro-processing of Biomass-derived Oil into Straight-chain Alkanes
    • Abstract: Publication date: Available online 25 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Wei-Cheng Wang, Chung-Hung Hsieh Initially converting the glyceride-based oils derived from biomass into straight-chain alkanes are necessary for producing hydro-processed renewable jet (HRJ). In this study, palm oil was turned into C15-C18 alkanes over two different catalysts, Pd/C and NiMo/γ-Al2O3, with various reaction conditions such as temperature, pressure, weight hourly space velocity (WHSV) and H2-to-oil ratio. The fresh and used catalysts after hydro-processing reaction were then characterized through the techniques including TGA, FTIR, XRD and SEM. The liquid products were analysed through GC-MS/FID and the concentrations of C15-C18 were determined. The gas products, such as CO2, CO, C3H8, CH4 and H2, were analysed through GC-TCD for indirectly “visualizing” the reaction, including the performances of hydro-deoxygenation (HDO) as well as decarbonylation / decarboxylation, hydrogenolysis, the occurrence of methanation and the consumption of hydrogen. The suggested experimental conditions over these two catalysts were elaborated based on the concentration of n-alkanes and gas products.
       
  • Construction of a Microbubble Generation and Measurement Unit for Use in
           Flotation Systems
    • Abstract: Publication date: Available online 25 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Pedro Pinto Ferreira Brasileiro, Leonardo Bandeira dos Santos, Marcos José Chaprão, Darne Germano de Almeida, Rita de Cássia Freire Soares da Silva, Bruno Augusto Cabral Roque, Valdemir Alexandre dos Santos, Leonie Asfora Sarubbo, Mohand Benachour Flotation with microbubbles is one of the most viable methods for separating oil from water. Microbubbles are formed by the injection of a small air flow through a pressurized liquid flow. In the present study, a microbubble generation and measurement unit (MBGMU) was constructed to measure mean microbubble size through the liquid flow and airflow of the system. The liquid flow rate was measured by a Hall effect-type sensor, whereas it was necessary to construct a sensor for bubbles immersed in glycerin for the determination of the airflow rate. This sensor was used to determine the minimum and maximum airflow limits, and the airflow measurements were compared with pressure gauge readings to establish a calibration curve. The Arduino UNO R3® board was the microcontroller of the MBGMU for the determination of the liquid flow rate. A coupled system involving a GoPro® Hero 6 camera and microscope lenses was assembled to capture images of the microbubbles. The airflow rate ranged from 0.001 to 10,000 l/h, and a high linear regression coefficient was found (98%) for the calibration between airflow and the variation in pressure. Images of microbubbles in motion were captured for future analyses. This innovative device is a promising system to be applied in industrial processes for the control of microbubbles produced in flotation systems.Graphical abstractGraphical abstract for this article
       
  • Photocatalytic degradation using ZnO for the treatment of RB 19 and RB 21
           dyes in industrial effluents and mathematical modeling of the process
    • Abstract: Publication date: Available online 24 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Jorge Rodrigues, Tahmasb Hatami, Jorge Marcos Rosa, Elias Basile Tambourgi, Lucia Helena Innocentini Mei ZnO-based catalysts impregnated with the metals Ag and Pd were synthesized for the photocatalytic degradation of two reactive dyes RB 19 and RB 21 in the textile effluents using an annular UV photoreactor. Among three synthesized catalysts, only the ZnO catalyst preserved the photodegradation of the dyes in the effluents. The density, mean particle diameter, surface area and porosity of the ZnO catalyst were 5550 kg/m3, 1.19 × 10-7 m, 16.830 m2/g, and 0.1, respectively. It was found that the ZnO nanoparticles photodegradated the RB 19 and RB 21 by 100 and 91 % respectively over six hours. The photocatalytic degradation process was then modeled successfully based on the mass conservation law. The maximum photocatalytic degradation by the model can be obtained at the smaller catalyst size, lower initial dye concentration, and higher length per diameter ratio of the photocatalytic reactor.Graphical abstractGraphical abstract for this article
       
  • Pyrometer-based control of a steam cracking furnace
    • Abstract: Publication date: Available online 24 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Stijn Vangaever, Pieter A. Reyniers, Steffen H. Symoens, Nenad D. Ristic, Marko R. Djokic, Kevin M. Van Geem, Guy B. Marin Optical thermometry offers great precision, repeatability, flexibility, and stability, hence providing performance advantages in non-contact temperature measurement. To assess its potential for controlling the temperature of steam cracking furnaces, ethane steam cracking experiments were carried out on pilot plant scale. The control performance of the pyrometer was found to be comparable to that of a weld-on type K thermocouple, the latter being representative of the industrial standard. The tested optical thermometer is suited as a sensor to measure tube metal temperatures of a steam cracking reactor coil, either inside or outside of the firebox. Due to its fast response time, optical thermometer temperature measurements help to prevent temperature overshoots, which have an adverse effect on the tube longevity and coke formation. Flexibility in positioning makes optical thermometry a viable alternative compared to conventional type K thermocouples.Graphical abstract (for TOC only)Graphical abstract for this article
       
  • A Thermo-economic Multi-objective Optimization Model for Simultaneous
           Synthesis of Heat Exchanger Networks Including Compressors
    • Abstract: Publication date: Available online 19 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Rui Yang, Yu Zhuang, Lei Zhang, Jian Du, Shengqiang Shen Two significant forms of energy widely used in chemical industries are heat and work related to temperature and pressure manipulation. Since complex relationship exists in these strongly interacting properties (heat, work, temperature, pressure), it is essential to investigate work and heat integration as a whole. In this paper, an enhanced stage-wise superstructure is proposed that involves simultaneous optimization of compressor placement and heat integration for each pressure-changing sub-stream in stages. It explicitly considers non-isothermal mixing in each stage and enables the optimized selection of pre-coolers, end-heaters as well as end-coolers to adjust temperature requirements. A novel thermo-economic multi-objective mixed-integer nonlinear programming (MINLP) model is formulated to synthesize sub and above-ambient heat exchanger networks between constant-pressure streams and pressure-changing streams with multi-stream compression. The new model aims to achieve the optimal balance between thermodynamic and economic performances, with the objective of minimizing exergy consumption and total annual cost (TAC), respectively. Three case studies are conducted, where the results illustrate the well-known trade-off between thermodynamic and economic objective that is a decrease of 12.6%, 7.6%, 23.8% in TAC, while exergy consumption is increased by 14.8%, 12.8%, 4%. The Pareto curve is plotted for decision-makers to determine the optimal alternatives in terms of process requirement.>
       
  • Experiments and CFD modelling for two phase flow in a vertical annulus
    • Abstract: Publication date: Available online 18 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Raj Kiran, Ramadan Ahmed, Saeed Salehi Simulations of two-phase (air and water) flow in a pipe are among the widely discussed topics; however, with the increased understanding of multiphase flow in pipes, the application of computational fluid dynamics (CFD) in other complex flow geometries involved in oilfield operations is becoming more common. This study is aimed to investigate and better understand two-phase flow characteristics in the annulus using computational fluid dynamics and experimental approaches. The experimental study included two sets of five tests with increasing superficial gas velocity (9.2 to 47.2 m/s) at a constant liquid flow rate. Experiments were conducted in concentric annulus test Section (35 mm × 82.5 mm) that had an overall length of 5.5 m. Two flow patterns (churn and annular) were observed during the experiment.Using CFD simulation, pressure drop, void fraction, and flow regime are determined. The VOF multiphase model and two turbulence models (realizable k-ε and SST k-ω models) were implemented, and comparative study was conducted to understand the relevance of each method in high gas velocity scenarios for flow in the annulus. The simulated macroscopic behavior of the flow shows consistent pressure gradient patterns and mimics the void fraction behavior. Probability density functions were implemented on time series evolution of void fraction to identify the flow regime for the CFD results. The simulation results show a reasonable agreement with the experimental data within a mean error of 20%.
       
  • Adsorption of propane and propylene on M-MOF-74 (M=Cu, Co): Equilibrium
           and Kinetic study
    • Abstract: Publication date: Available online 18 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Hassan Abedini, Ahmad Shariati, Mohammad Reza Khosravi-Nikou In this study, adsorption equilibria and kinetics of propane and propylene on Cu-MOF-74 and Co-MOF-74 were investigated at temperatures of 303, 323, 343 and 363 K and pressures up to 100 kPa. Pure component adsorption isotherms and uptake curves were determined via volumetric method. Dual Site Sips model could better fit the experimental data than the Langmuir and Sips models. Isosteric heat of adsorption and IAST selectivity were calculated using Dual Site Sips model. Both adsorbents showed high affinity toward propylene over propane due to the presence of the open metal sites in their structure. Obtained results showed that Cu-MOF-74 exhibits higher selectivity (12.7) to propylene as well as higher adsorption capacity (7.6 mmol/g) compared to Co-MOF-74, making this material as one of the most favorable adsorbents for propane/propylene separation which has been studied so far. The diffusion time constants of the adsorbates were also calculated by measuring transient uptake curves. Results indicated that the micropore diffusion model could predict the data points accurately. The rapid uptake of the adsorbates along with cyclable property suggest the Cu-MOF-74 as a highly reliable adsorbent for propane/propylene separation via vacuum pressure swing adsorption.Graphical abstractGraphical abstract for this article
       
  • Computational Fluid Dynamic Design of Spent Coffee Ground Cabinet Dryer
           Using Recycled Heat from Air Compressor
    • Abstract: Publication date: Available online 18 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Chattip Prommuak, Norapat Tharangkool, Prasert Pavasant, Pimporn Ponpesh, Teeraya Jarunglumlert This study designed a cabinet dryer assembled to an air compressor to utilize a free-of-charge waste heat for drying. Spent coffee ground (SCG), a residue from coffee brewing, was the tested material. Applying computational fluid dynamics (CFD), an appropriate cabinet dryer configuration could be achieved. As varying the hot air inlet/outlet position, the best drying characteristics providing uniform air flow occurred when hot air entered the chamber at the top and left the chamber at the bottom, opposite side to the inlet. A model dryer was then developed and used to validate the CFD prediction of dryer capacity which was dependent on the maximum numbers of mounted trays and the thickness of SCG layer. The computational prediction agreed well with the experimental results, showing that the dryer loading SCG at 3 cm thickness performed best with two trays in the chamber. Adding another tray would result in an obstruction of the air flow, leaving more than 20% of the moisture content in the final product. Experimental determination of drying duration for drying SCG with varying thickness indicated that each centimeter of the increase in SCG bed thickness extended the drying duration by 3 fold. Particularly at the SCG layer thickness of 4 cm, this fitted well with the simulation results at 97.2% accuracy. Mounted with 3 trays, each loaded 300 g SCG (1 cm bed thickness), the dryer could complete 6 cycles within regular operation hours of a coffee shop (12 hours) and thus accounted for 5,400 g of SCG as daily capacity of a dryer.Graphical abstractGraphical abstract for this article
       
  • Graphene-based adsorbents for water remediation by removal of organic
           pollutants: Theoretical and experimental insights
    • Abstract: Publication date: Available online 18 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Mandeep, Gulati Archa, Kakkar Rita Graphene-based materials have emerged as promising candidates as adsorbents for water treatment. The high surface area, low production costs, large porosities and robustness makes them excellent materials for adsorption studies and removal of toxic compounds such as pesticides, dyes, aromatic polar and non-polar compounds, nitro compounds, halogenated compounds, antibiotics, etc. from aqueous solutions. In recent years, there have been many structural modifications in the 2-D graphene sheet for synthesizing superior materials such as graphene-metal composites, metal oxide composites, bio-composites, hydrogels, etc. for improving the structural properties and widen its applications. In this review, we have incorporated the examples from both experimental and density functional theory studies (DFT) for water remediation by removal of toxic organic pollutants using graphene-based materials from the recent literature, and have further outlined the challenges and future perspectives in this direction.Graphical abstractGraphical abstract for this article
       
  • Design of a 1,000L pilot-scale airlift bioreactor for nitrification with
           application of a three-phase hydrodynamic mathematical model and
           prediction of a low liquid circulation velocity
    • Abstract: Publication date: Available online 18 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Bojan Pelivanoski, Bettina Detmann, Kristoffer Ooms, Mari Winkler, Ekaterina Vasyukova, Martin Denecke In this study, a 1,000 L pilot scale internal loop airlift bioreactor was operated and compared to a mathematical model to determine the best design for optimal supply of oxygen for nitrification and sufficient air for biomass fluidization. The design model is based on parameters such as geometry, carrier density, and airflow of the 1,000 L pilot scale bioreactor. The model predicts a range of superficial air velocities (0.009 – 0.013 m/s) under which the airlift bioreactor was fluidized. Three superficial air velocities (0.009 m/s, 0.011 m/s and 0.013 m/s) were experimentally tested in the pilot plant and the obtained circulation velocities were compared with the predicted design scenarios. The predicted velocity was in agreement with the measured velocity. The aim of the mathematical model and the calculations of different geometry scenarios was to define the optimal geometry design for the physical model. The results show that the ratio of the cross-sectional area between the riser and the downcomer of 1.33 resulted in the lowest superficial liquid velocity of 0.076 m/s in the riser at a relative low superficial air velocity of 0.011 m/s and a carrier density of 1,030 kg/m3. This bioreactor design enabled longest retention time of particles in the oxygenated riser.Graphical Graphical abstract for this article
       
  • Ultrasonically Assisted Adsorption of Methyl Orange Dye using Aliquat-336
           Impregnated Amberlite XAD-4 in Batch and Recirculating Flow Vessel
    • Abstract: Publication date: Available online 17 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Muzaffar Iqbal, Dipaloy Datta Ultrasonically assisted adsorption of methyl orange (MO) dye from aqueous solution was performed using Amberlite XAD-4 resin wet-impregnated with Aliquat-336 (SIR) loaded in three different ratio (0.25/0.50/1 g per g of resin). To study the effect of different parameters like ultrasonication time (tus: 0.5to 10.5 min), adsorbent dosage (W: 0.05 to 0.25 g), (pH: 2 to 10) and concentration of MO dye in solution ( Cdyein : 5 to 65 mg/L), and their interaction on the dye removal efficiency, Central Composite Design of Response Surface Methodology was applied to obtain the optimized values of these parameters. At optimized condition (tus = 10.2 min, W =0.23 g, pH = 9.5, and Cdyein =35 mg/L), the percent removal of MO was found to be 97.14 ± 0.5% which is very close to the predicted value (96.58%). Equilibrium and kinetic studies were also performed at optimized conditions. Freundlich and pseudo-second-order models best suited the experimental batch values. Time taken for the removal of dye by ultrasonication, water bath shaker, magnetic stirring and simple diffusion at optimized conditions were compared. The used resin was regenerated using 2 M HCl solution up to five cycles without any significant loss in the adsorption capacity of SIR. Finally, continuous study was performed in a recirculating flow vessel (RFV). Dye removal in RFV with ultrasonication saved 37.24% of energy and could process larger volume of dye containing water per unit of time effectively.Graphical abstractGraphical abstract for this article
       
  • 2D magnetic scallion sheathing-based biochar composites design and
           application for effective removal of arsenite in aqueous solutions
    • Abstract: Publication date: Available online 16 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Xiaoli Song, Yun Zhang, Xiadan Luo, Pei Chen, Junliang Liu In this study, 2D magnetic composites based on Fe3O4 and scallion sheathings biochar were designed and prepared via simple hydrothermal method for removal of As (III) in aqueous solutions. The effects of acid/base pretreatment of biochar on the physicochemical properties and As(III) adsorption performance of the composites were investigated. The mechanism was discussed by XPS study and sorption isotherm models. The results revealed that oxygen content on the surface of the acid/base pretreated biochar decreased, which directly reduced the Fe3O4 content loaded on the biochar. The removal efficiency of As(III) by the composites based on original biochar, HCl-pretreated biochar and NaOH-pretreated biochar could reach 93.19%, 92.84% and 79.61%, respectively. XPS, adsorption kinetics, and isothermal adsorption model studies have shown that As(III) adsorption by these three composites is a chemical process with the maximum adsorption capacity of 39.47, 31.37 and 28.54 mg/g, respectively. In addition, the magnetic biochar composites still showed good reusability after 5 times of reuse. This study shows that the magnetic biochar composites possessed excellent performance to remove As(III) from solutions, especially the composites based on original biochar, indicating it is a promising adsorbent for arsenic removal from contaminated water.Graphical abstractGraphical abstract for this article
       
  • Aggregation in mixing tanks – The role of inter-particle forces
    • Abstract: Publication date: Available online 16 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Jee Wen Lim, J.J. Derksen We study aggregation of equally-sized spherical particles under mildly turbulent flow conditions (Reynolds numbers in the range 4000 to 8000) in a mixing tank through numerical simulation. The dynamics of the liquid flow is solved in terms of the volume-averaged Navier-Stokes equations by an extended lattice-Boltzmann method on a fixed uniform cubic grid. The particle dynamics is updated through applying Newton’s second law to each particle. The simulations include a two-parameter model for the attractive force between the particles that causes aggregation. The dynamics of solids and liquid are two-way coupled through a mapping procedure. An overall solids volume fraction of 10% has been investigated. The level of aggregation of particles in the mixing tank mainly depends on the strength of the attractive force and on the impeller-based Reynolds number, not so much on the distance over which the aggregative force is active. A higher Reynolds number leads to less aggregation.Graphical abstractGraphical abstract for this article
       
  • Computational fluid dynamic (CFD) simulation of a cuboid packed-bed
           chromatography device
    • Abstract: Publication date: Available online 16 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Umatheny Umatheva, Guoqiang Chen, Raja Ghosh Flow non-uniformity is a major problem with process columns which typically have small bed height to diameter ratios. In recent publications, we have proposed box-shaped or cuboid packed-bed devices as efficient alternative to process columns for carrying out high-resolution chromatographic separations. Cuboid packed-bed devices show superior performance in terms of number of theoretical plates, peak width, and peak resolution in multicomponent separations. This paper attempts to explain this based on computational fluid dynamic (CFD) simulations of a cuboid packed-bed device and its equivalent column, i.e. having the same bed height and area of cross-section, and packed with the same chromatographic media. The radial velocity in the column headers decreased very rapidly from the axis to the periphery resulting in significant variation in average velocity along the different flow paths within the column. By contrast, the velocity decreased linearly in the top channel and increased linearly in the bottom channel of a cuboid packed-bed device, resulting in significantly lower variation in the average velocity. Simulated flow-through peaks obtained with the cuboid packed-bed device using dextran as a macromolecular and sodium chloride as a low molecular weight tracer were significantly sharper and more symmetric. Experimental results were in good agreement with those obtained by simulation. Overall, the superior performance of the cuboid packed-bed device could be primarily attributed to the narrower solute residence time distribution resulting from greater flow uniformity.
       
  • Dewatering Parameters in a Screw Press and their Influence on the Screw
           Press Outputs
    • Abstract: Publication date: Available online 11 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Bouchaib El idrissi, Éric Loranger, Robert Lanouette, Jean Pierre Bousquet, Mark Martinez A Thune SP23 screw press dewatering parameters were studied. The dewatering efficiency was affected more by the rotational speed and the pulp properties. The counter-pressure affects dewatering near the discharge end, and it was observed to influence the outlet consistency and filtrate flow rate of Kraft, which has much longer fibres and fewer fines compared to TMP and BCTMP.The feed stock freeness and consistency are very important variables to consider in the screw press performance. The freeness reflects the degree of drainage, which is an important parameter to consider when optimising the screw press, while the feed consistency is a parameter of the fibre-fibre contact degree. The pulp properties, especially the fines content and fibre flexibility are also two very important parameters that affect the screw press performance.This study was to provide an insight of the screw press performance and to show the complex effect of the operational parameters on the dewatering characteristics. Using three different pulps, Kraft and TMP softwood fibres and a BCTMP hardwood fibres, we have shown that the fines content and fibre properties are two dominant properties that should be highly considered when operating a screw press.Graphical abstractGraphical abstract for this article
       
  • An integrated MILP method for gathering pipeline networks considering
           hydraulic characteristics
    • Abstract: Publication date: Available online 11 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Bingyuan Hong, Xiaoping Li, Guojia Di, Yu Li, Xingshuai Liu, Shilin Chen, Jing Gong High investment highlights the importance of optimizing gathering pipeline networks. In view of the problem of ignoring hydraulic characteristics in previous studies, an integrated mixed-integer linear programming (MILP) model for gathering pipeline networks is developed in this study. Taking the minimum total construction cost as the objective function, the proposed model considers the economic and technical constraints such as obstacles, three-dimensional terrain, pipeline topological structures, pipe diameters, wellhead back pressure, and pressure equipment. The ant colony optimization algorithm is used for route optimization to provide parameters for the proposed model. Moreover, a piecewise method is employed to linearize the nonlinear hydraulic equations. Then, the model is solved by the CPLEX solver to obtain the optimal solution integrally, including the optimal connection topology, the location of the central processing facility, the position of pressure equipment, the diameter and detailed route of each pipeline, the pipeline flowrate and the node pressure. Finally, two real-world gas fields and a virtual oil field are taken as examples to demonstrate the feasibility and practicality of the model. The optimal results illustrate that this model can be implemented as a decision-support tool to optimize gathering pipeline networks in the actual design process.
       
  • Effect of interparticle force on gas dynamics in a bubbling gas-solid
           fluidized bed: A CFD-DEM study
    • Abstract: Publication date: Available online 11 October 2019Source: Chemical Engineering Research and DesignAuthor(s): S.M. Okhovat-Alavian, J. Shabanian, H.R. Norouzi, R. Zarghami, J. Chaouki, N. Mostoufi The influence of cohesive interparticle force (IPF) on gas dynamics in a bubbling gas-solid fluidized bed was numerically investigated while the bed hydrodynamics was described with the help of computational fluid dynamics and discrete element method (CFD-DEM). The model was validated by experimental results in terms of total bed pressure drop profile, probability density distribution of instantaneous local bed voidage signals, and Eulerian solid velocity field. The results showed that the model can satisfactorily predict the hydrodynamics of a bubbling gas-solid fluidized bed that is impacted by the presence of cohesive IPF. The validated CFD-DEM model was adopted to delineate the effects of IPF on the distribution of fluidizing gas between the bubble and emulsion phases and bubble characteristics, such as bubble stability and rise path, which could hardly be explored experimentally. Simulation results revealed that the presence of IPF in the bubbling bed alters the distribution of the fluidizing gas between the bubble and emulsion phases in favor of an increase in the propensity of gas to pass through the bed in the emulsion phase. The results also indicated that the bubble stability increases and the straight rise path of bubbles changes to a tortuous path when enhancing IPF.
       
  • Suggestion of new correlations for the exergy efficiency and coefficient
           of exergy performance of annulus section of conically coiled tube-in-tube
           heat exchangers
    • Abstract: Publication date: Available online 11 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Khaled AlSalem, Ebrahim Hosseini, Alireza Nohesara, Mohsen Mehri, Mohamed Ali, Redhwan Almuzaiqer, Ashkan Alimoradi, Tlili Iskander In this study, the steady state heat transfer and fluid flow in the annulus section of tube-in-tube conically coiled heat exchanger (TTCCHE) is numerically investigated. The flow in the annulus is simulated using the Realizable K-ɛ turbulence model and validated by comparison with published Nusselt numbers. The effect of geometrical and operational parameters of the heat exchanger on the exergy characteristics of the annulus section is obtained. The results allowed for obtaining two correlations for estimation of the annulus section exergy efficiency and coefficient of exergy performance. Furthermore, it was found that the highest values of the turn number and the minimum values of the Reynolds number, (dt,o/dc,max), (p/dc,max), Prandtl number, tube diameter ratio and the cone angle in the studied range maximize the exergy efficiency and coefficient of exergy performance.
       
  • An experimental study on the effect of conductivity, frequency and
           droplets separation on the coalescence of two aqueous drops under an
           electric field
    • Abstract: Publication date: Available online 9 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Vikky Anand, Vinay A Juvekar, Rochish M Thaokar The coalescence of water drops, dispersed in oil, is critical to the destabilization of a water-in-oil emulsion under an electric field. In this work, we determine the conditions for coalescence or non-coalescence of two aqueous water drops that are suspended in an insulating oil and subjected to a uniform electric field. Specifically, we investigate the effect of the conductivity of the droplet phase (σ), the type of oils (silicone oil and castor oil), the effect of waveform AC and DC and frequency, and the separation between the droplets on the electrocoalescence/non-coalescence of two suspended aqueous drops. The main highlights are, (i) We provide expressions for critical electrocapillary number (Cac) vs. σ for silicone oil (Cac = 0.010 × σ−0.20) that shows cone-cone and castor oil (Cac = 0.022 × σ−0.15) that shows cone-dimple mode of contact. (ii) Two closely spaced drops can coalesce at electrocapillary numbers much higher than the critical electrocapillary number for widely spaced drops due to a smaller cone angle at the point of contact. These results should be important in the design of industrial electrocoalescers.Graphical abstractGraphical abstract for this article
       
  • Method to assess the drying performance of water vapour-permeable membrane
           pouches for fruit juice preservation: Authors (Family name, Given name)
    • Abstract: Publication date: Available online 9 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Randi Phinney, Ingegerd Sjöholm, Karolina Östbring, Marilyn Rayner The aim of this work was to develop a method for assessing the drying performance of a hygienic, small-scale fruit juice preservation process called Solar Assisted Pervaporation (SAP). SAP is a batch process that allows for fruit juices or purées to be solar dried in water vapour-permeable membrane pouches in rural and remote areas. Traditional methods for measuring water vapour flux through membrane materials are not directly applicable for assessing the performance of SAP pouches, and so a new method was developed, considering a constant boundary condition on the inside of the pouch (i.e. water activity of 1.0). This paper presents a statistical validation of the method and then illustrates how it can be used to characterise membrane performance, identify a two-level factorial regression model for drying flux as a function of temperature, relative humidity and air velocity and their interaction effects, and estimate an operational window for drying juices in SAP pouches in an indirect solar dryer. The repeatability of the method is high with a precision of 95% or more. The regression model and operational window can be used to optimise the design of an indirect solar dryer specifically suited for SAP pouches filled with fruit juices.Graphical abstractGraphical abstract for this article
       
  • Measurements by using an automatic pressure control and predictions of
           isobaric VLE at 1.5 MPa for binary mixtures of methyl acetate, ethyl
           acetate, 1–propanol and 1–butanol
    • Abstract: Publication date: Available online 9 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Pedro Susial, Diego García Vera, Isabel Montesdeoca, Rodrigo Susial, Silvia Díaz Stevenson, Nayra Pulido Melián The experimental data of vapor–liquid equilibrium for the binary systems methyl acetate+1–propanol, methyl acetate+1–butanol and ethyl acetate+1–propanol at 1.5 MPa has been obtained, using an ebulliometer made of stainless steel. This equipment works through the Cottrell pump effect, so that the liquid and vapor phases are recirculated. The isobaric data T–x–y are informed and analyzed with respect to the literature data. The evolution of the azeotropic point with the pressure in the binary system of ethyl acetate+1–propanol is included. The thermodynamic consistency of the systems was verified by employing the Peng–Robinson equation of state in different forms and using the φ–φ approach.Graphical abstractGraphical abstract for this article
       
  • Electrocoalescence of Water Droplets in Sunflower Oil Using a Novel
           Electrode Geometry
    • Abstract: Publication date: Available online 8 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Bin Li, Vincenzino Vivacqua, Junfeng Wang, Zhentao Wang, Zhiqian Sun, Zhenbo Wang, Mojtaba Ghadiri Electrocoalescence is an energy-efficient and environmentally-friendly process for breaking water-in-oil emulsions. It has been used extensively in the oil and petroleum industries. However, the current technology requires long residence times, giving rise to bulky vessels for industrial scale operations and making it less attractive for offshore application. It is also highly desirable to develop compact devices for down-the-well use. In this study, the performance of a novel electrode geometry, a ladder-shaped set of electrodes through which the emulsion flows, is assessed for enhancing the electrocoalescence, hence providing the potential for a compact design. The electrodes are formed into a V shape, with the apex pointing towards the direction of flow. This configuration enables nesting a series of electrodes in a compact form. Furthermore, the water-in-oil emulsion flows through the electrodes rather than passing by them, thus maximizing the effect of the electric field for coalescence. The system under study uses dispersed water droplets in sunflower oil, flowing in a narrow rectangular duct through the electrodes, providing essentially a two-dimensional flowing stream. The performance of this design is investigated for different electrical parameters (i.e. electric field intensity, frequency and waveform), fluid physical properties (i.e. conductivity and water content) and residence time. Of the three types of electric field waveform (i.e. half-sinusoidal, square and sawtooth), sawtooth performs best at high conductivities. Experiments reveal the existence of optimal values of electric field intensity, electric field frequency, salt concentration and water concentration, where the coalescence efficiency is maximum for the current design. Numerical simulation of the electrocoalescence process is conducted to assess the influence of various geometric and process parameters on the coalescence mechanisms of the V-shape electrodes. The outcome of this work is potentially useful for optimizing the design of compact and efficient oil-water separators.Graphical abstractGraphical abstract for this article
       
  • Macroscopic and microscopic characteristics of particles in a novel
           gas–solid cyclone reactor
    • Abstract: Publication date: Available online 8 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Anjun Li, Guotao Wang, Kun Wang, Liyun Zhu, Zhenbo Wang A downward gas–solid cyclone reactor (GSCR) was developed for conquering side reactions in fluid catalytic cracking technology. The ideal situation in the application of GSCR is that heavy gases are thrown to the vicinity of the outer wall and light phase products are pushed into the inner wall. Hence, the gradient distribution of particle concentration and gas products is beneficial to the cracking of heavy gases and the recovery of light gas products. In order to get insight into the flow pattern and microscopic characteristics of this gas–solid system, transient solid holdup at various axial and radial positions was measured by the PV–6. By adopting probability density function, power spectral density and cluster analysis, macroscopic and microscopic characteristics were analyzed and discussed. Experimental results show that an annular–core–annular structure exists in the diffusion chamber and agglomeration chamber. Solid holdup fluctuations near the outer wall of the diffusion chamber are severe. The probability is mainly distributed in low concentration band (εs = 0.0–0.01), and the number of dense phases near the outer wall increases with the rising of particulate loading. The number of dominant frequencies decreases with the decline of particulate loading. Cluster analysis was carried out in the vicinity of the outer wall. The number of cluster group is higher while the duration time is lower in the agglomeration chamber.Graphical abstractGraphical abstract for this articleAn annular-core-annular structure was observed on the radial profiles of solid holdup. The outer annular is beneficial to the cracking of heavy gases while the inner annular is detrimental to the recovery of light gases.A cluster would be thus recognized if the instantaneous solid concentration exceeds this threshold, and a cluster group is considered as clusters appearing in a continuous period of time (T1-T2).
       
  • Fractionation of polyethylene wax by pilot-scale molecular distillation:
           new insights on process development
    • Abstract: Publication date: Available online 7 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Eluize Vayne Maziero, Rafael Budel Salles, Laura Plazas Tovar, Eduardo Hiromitsu Tanabe, Daniel Assumpção Bertuol A falling film molecular distillation (FFMD) process was used in a pilot plant to fractionate a polyethylene wax (PE-Wax) into light paraffin wax (LP-Wax) and super-microcrystalline wax (SM-Wax). The pseudoization technique was applied to represent the molecular distribution of the PE-Wax by pseudo-components (PS1 and PS2). Investigation was made of the influences of the evaporator temperature (EVT), feed flow rate (FF), and condenser temperature (CT) on the percent recovery of distillate (DP), the yield of PS1 in the distillate (YD_PS1), and the distillate flow rate/feed flow rate ratio (DF). The predictive models and the multi-response optimization provided decision criteria about the most suitable operating conditions for fractionating PE-Wax. The best experimental data for DP,YD_PS1, and DF (63.4%, 81.5%, and 0.60, respectively) were obtained with EVT of 184 °C, FF of 1.81 kg/h, and CT of 28 °C, at 0.1 Pa. The LP-Wax, recovered mainly in the distillate, exhibited a normal distribution throughout the carbon number range from n-C13 to n-C30. The SM-Wax, recovered in the residue, showed a higher latent heat of storage (>169 kJ/kg), according to the phase-change performance of the material. These results offer new insights into processing PE-Wax to obtain value-added products with narrower carbon number distributions.Graphical abstractGraphical abstract for this article
       
  • Mixed-Integer Nonlinear Programming (MINLP) for Production Optimisation of
           Naturally Flowing and Artificial Lift Wells with Routing Constraints
    • Abstract: Publication date: Available online 7 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Emmanuel I. Epelle, Dimitrios I. Gerogiorgis Real-time decision making by production engineers in a petroleum field can be very challenging, especially when multiple wells with diverse operating conditions and production behaviours are present. Hence, semi-analytic or heuristic procedures are unlikely to yield an optimal operating strategy. This paper implements a Real-Time Production Optimisation (RTPO) approach to maximising production from naturally flowing, gas-lifted and Electrical Submersible Pump (ESP)-assisted wells while satisfying multiple operational constraints. This is achieved via the application of reduced order models which are developed by querying a black box production network simulator multiple times using different inputs. Also exploited in this work is the inherent decomposable property of the production network, into smaller components (wells, valves pipelines and separators), such that mass balance equations comprise the algebraic constraints of the optimisation framework which is solved as an MINLP. The adopted formulation also offers the advantage of flexibility for problem adjustment under different practical operating conditions which are presented as case studies. The changes incorporated into the production system include: increased liquid handling capacity of downstream separators, decreased well productivity/increased water cut and well intervention problems. The ability of the adopted framework to provide accurate and speedy computations of the optimal production scenario makes it reliable for real-time decision support.Graphical abstractGraphical abstract for this article
       
  • Oil shale reactor: process analysis and design by CFD
    • Abstract: Publication date: Available online 7 October 2019Source: Chemical Engineering Research and DesignAuthor(s): C. Stahnke, M.K. Silva, L.M. Rosa, D. Noriler, W.P. Martignoni, J.C.S.C Bastos, H.F. Meier The oil shale pyrolysis process using a moving bed reactor was investigated with a three-dimensional mathematical model considering turbulent and multiphase flow in a porous moving bed, under non-isothermal and reactive conditions. Mass, heat and momentum balances involving chemical reactions of interest were formulated following a Eulerian approach to represent the process behavior. In the present approach, the shale bed was modeled as a porous medium and the advection due to its movement was implemented. Process analysis via CFD enabled the location of the drying, heating, reacting and cooling zones to be identified in the pilot-scale reactor. Moreover, it was possible to analyze in detail the conversion of organic matter to products, according to the reaction mechanism. The effects of heat and mass transfer inside the reactor were assessed through parametric sensitivity analysis, considering five parameters and five response values. The results were analyzed using the response surface method, which established the influence of each variable. The best values obtained for the thermal-energy consumption and the mechanical-energy consumption were 126.16 and 12.39 kJ/kg, respectively. Considering the best operational conditions, scaling-up effects were also evaluated to shed light on the technical viability as well to carry out the design and analysis of the process.Graphical abstractGraphical abstract for this article
       
  • Continuous viral filtration for the production of monoclonal antibodies
    • Abstract: Publication date: Available online 7 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Laura David, Jens Niklas, Bastian Budde, Martin Lobedann, Gerhard Schembecker Continuous processing is the future manufacturing method for monoclonal antibodies (mAb). Consequently, also continuous viral clearance has to be investigated. Viral filtration is one of the two standard methods for viral clearance within mAb production processes. This work investigates key differences in operation of batch and continuous viral filtration and provides first data on the performance of four different filters under continuous mAb production conditions. The scenario applied shows that continuous viral filtration for mAb production has to be operated under fundamentally different conditions than batch filtration, operating at low pressure conditions of 0.3 L/m²/h instead 30-60 L/m²/h. Consequently, no data from filter validation or application notes exist which answer the question whether or not the existing filters can be used for continuous viral filtration. Two first-generation filters and two second-generation filters were tested. Continuous filtration for 72 h at 0.3 L/m²/h as well as start-stop scenarios were investigated, identifying the filter types that are possible candidates for the continuous production of mAb. The two first generation filters (Pall SV4 and Sartorius Virosart CPV), did not achieve a LRV > 4 under the conditions tested. The two tested second-generation filters, Pall Pegasus Prime and Sartorius Virosart HF were able to maintain a LRV > 4 for at least 20 L/m² or the entire filtration time, respectively. All filters tested showed a state of constant LRV after an initial decrease. Additional experiments with short and long-term stops with the Pall Pegasus Prime filter revealed that the steady state observed before is reached earlier with stops, independently of the stop duration.
       
  • Effect of column inclination and oscillation on liquid spreading in a
           trickle bed
    • Abstract: Publication date: Available online 7 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Milinkumar T. Shah, Ranjeet P. Utikar, Vishnu K. Pareek Gas-liquid-solid flow in a trickle bed installed on a floating production unit is affected by oscillations imparted by sea waves. The oscillations may affect the spreading of liquid, and in turn, the performance of a reactor. The present work investigates the effect of bed inclination and two types of oscillations (roll and roll + pitch) on the spreading of liquid in a cylindrical trickle bed with a single point liquid injection by using computational fluid dynamics. In the simulations, column tilt varied in a range of 0-15˚ and three oscillation frequencies (0.1, 0.2 and 0.5 Hz) were considered. Initially, a three-phase Eulerian model was validated using the published experimental data for a stationary column. The effect of closure models such as capillary pressure model and Ergun drag model constants on predictions was analyzed for the selection of these closures. In a tilted column, liquid was pushed to flow in the direction of tilt. Increase in tilt angle from 0 to 15˚ resulted in increase in the flow segregation and ∼20% reduction in pressure drop. Oscillations (both roll and roll + pitch) resulted in more uniform liquid spreading and higher liquid holdup compared to a vertical column. With decrease in oscillation frequency, the index of uniformity in the radial liquid distribution further increased. The higher uniformity and liquid holdup caused by oscillations can be attributed to higher radial velocity of liquid due to the effect of gravity in the radial direction. Compared to the roll type oscillations, the roll + pitch type resulted in higher radial velocity and radial distribution of liquid.Graphical abstractGraphical abstract for this article
       
  • Study on Flow Characteristics of Dilute Phase Flexible Ribbon Particles in
           a Fluidised Bed Riser Using Particle Tracking Velocimetry
    • Abstract: Publication date: Available online 7 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Kai Wu, Li Dai, Bin Li, Conghui Gu, Zhulin Yuan, Dengshan Luo Flexible ribbon particles tend to rotate, deform (bend) and intertwine with each other in a fluidised bed due to their high flexibility and filamentous shapes. The movements of these particles have a significant influence on the formation of the so-called clusters, which lead to the complex hydrodynamic characteristic and subsequently poor equipment performance. However, there is currently no method for accurately defining and effectively measuring these complex particle movements, especially for their non-translational movements. In this paper, the flow characteristics of these particular flexible ribbon particles in a cold fluidised riser are studied using an improved particle tracking velocimetry (PTV) method. A certain number of characteristic points are selected in the longitudinal direction of a single flexible ribbon particle. The translation and non-translation movements of the characteristic points are defined and measured, and then the motion characteristics of the flexible ribbon particles are obtained. This work aims to provide an insight into this particular type of particle flow and to benefit the design and scale-up of related equipment. It is found that particles are most likely to collide, rotate and deform in the neighbouring wall regions with small superficial gas velocity. However, excessive particle contacts inhibit their free movements. By using regression analysis, an empirical correlation is established among the fractions of particles undergoing movement (both translational and non-translational), mass flow ratio (solid to gas) and particle Reynolds number.Graphical abstractGraphical abstract for this articleA flexible ribbon particle with characteristic points and the empirical correlation among the fraction of particles undergoing translational movement, mass flow ratio (solid to gas) and particle Reynolds number.
       
  • Kinetic study of the effect of the heating rate on the waste tyre
           pyrolysis to maximise limonene production
    • Abstract: Publication date: Available online 5 October 2019Source: Chemical Engineering Research and DesignAuthor(s): N.M. Mkhize, B. Danon, P. van der Gryp, J.F. Görgens The formation of isoprene and dl-limonene during waste tyre pyrolysis was investigated in terms of the effect of the heating rate (up to 100 °C/min). Ion current signals were used to track during pyrolysis the evolution of the predominant ions of isoprene (isoprene 67) and dl-limonene (limonene 93), by using a thermogravimetric analyser coupled with mass spectrometry (TGA/MS). The combined model-free and model-based kinetics were used to estimate the activation energy (Ea) for isoprene and dl-limonene formation at 131 and 115 kJ/mole, respectively, based on the Kissinger method. Reaction order (n) values were estimated at 1.2 and 1.1 for isoprene and dl-limonene, respectively. Better model fit (R2 = 0.998) of the experimental data to the Arrhenius equation for isoprene and dl-limonene, respectively, was observed when the Kissinger method was used compare to Friedman method. Although the Ea values for isoprene and dl-limonene were not significantly different, the combined three kinetic parameters (Ea, pre-exponential constant (A), and n) may be significantly different. Therefore, for dl-limonene formation selectivity over isoprene, the differences in the three kinetic parameters values for each compound model and heating rate on the reaction progress was significant. The reaction progress at peak isoprene and dl-limonene formation rate increased from 0.42 to 0.45 and more significantly from 0.35 to 0.44, respectively as the heating rate was increased from 15 to 100 °C, confirming that the preferred strategy to maximise dl-limonene production is rapid heating to the moderate final pyrolysis temperature.
       
  • The Role of Rheological Parameters on Drying Behaviour of a Water-Based
           Cast Tape
    • Abstract: Publication date: Available online 4 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Masoud Jabbari, Mohammad Nasr Esfahani In this paper we studied the migration of secondary particles in tape casting of a non-Newtonian ceramic slurry through a generalised local viscosity function in order to obtain the particle distribution along tape thickness. The particle distribution were then used to calculate porosity and permeability of the tapes. We, moreover, linked the aforementioned results to a coupled free-flow-porous-media model on the Representative Elementary Volume (REV) scale for simulating room-temperature drying of the tapes with flow of a relatively dry air (relative humidity of 25%). Finally, we investigated the influence of rheological parameters, i.e. the power-law index, η, and the consistency factor, m, of a typical Ostwald-de Waele power-law fluid on the resultant drying behaviour of the tapes. The results showed that the low consistency and low power-law index values reduce the drying rate (slightly) as well as the final drying time, that favours the manufacturing of tapes by reducing the risk of crack initiation/growth in ceramics.
       
  • Machine learning-based adaptive model identification of systems:
           Application to a chemical process
    • Abstract: Publication date: Available online 4 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Bhavana Bhadriraju, Abhinav Narasingam, Joseph Sang-Il Kwon Many of the existing offline system identification methods cannot completely comprehend the dynamics of an evolving complex process without relying on impractically large data sets. As a solution to this, a systematic procedure capable of identifying and predicting the nonlinear dynamics on the fly promises to provide a useful representation of the process model. Motivated by this, an adaptive model identification framework that relies on the methods of sparse regression and feature selection is presented in this work. The proposed method is a three-step procedure: (1) identifying potential functions from a candidate library using recently developed Sparse Identification of Nonlinear Dynamics (SINDy), (2) updating coefficients of the identified model using ordinary least-squares regression, (3) selecting the most important features using stepwise regression. The proposed algorithm is implemented as follows. Initially, a baseline model is identified offline using SINDy, and as a new data becomes available, the subsequent online steps are triggered based on a pre-specified tolerance to further update the model. Such an adaptive identification scheme facilitates in perceiving the model structure using a less amount of data than its offline counterpart, SINDy. To highlight its significance, the dynamics of a continuous stirred tank reactor is identified using the proposed adaptive method and is compared with a model identified using SINDy alone.
       
  • Multi-Fluid VoF Model Assessment to Simulate the Horizontal Air-Water
           Intermittent Flow
    • Abstract: Publication date: Available online 3 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Mohammad Akhlaghi, Vahid Mohammadi, Nowrouz Mohammad Nouri, Morteza Taherkhani, Mehdi Karimi Numerical simulation of the plug and the slug flow regimes have been performed using the Multi-Fluid VoF and Shear Stress Transport (SST) k-ω models in a horizontal pipe with 44 mm diameter. The superficial velocities during the current study were set at 0.16, 1.64 & 3 m/s for the gas phase and 1 m/s for the liquid one. The pressure and the velocity equations were solved together, utilizing the PIMPLE algorithm in all cases of the present study. The VoF model, as well as the experimental outcomes, were applied to assess the results of Multi-Fluid VoF model. The qualitative comparison of numerical results with the experimental visualization revealed that the Multi-Fluid VoF model simulates precisely the interfacial structure of slug and plug flows, as well as the chronological formation of the slug. The length ratio of the gas slug to the liquid slug goes up with the gas superficial velocity increment; this issue increases the probability at low liquid hold-ups and decreases the higher ones. The Multi-Fluid VoF provided much more matching with the mentioned probability changes in comparison to the VoF model. The pressure drop calculated using Multi-Fluid VoF in the Lockhart–Martinelli framework illustrated a 21.8 % improvement averagely in comparison to the VoF model. The obtained transitional slug velocities showed that the Multi-Fluid VoF model presented a maximum error of 8.17% versus the experimental values, while the mentioned error for the VoF model was estimated at 22.01%. Notwithstanding the mentioned advantages, the Multi-Fluid VoF model significantly increased, both the execution time of simulation as well as the associated costs.Graphical abstractGraphical abstract for this article
       
  • Preparation of Amino Functionalized Titanium Oxide Nanotubes and Their
           Incorporation within Pebax/PEG Blended Matrix for CO2/CH4 Separation
    • Abstract: Publication date: Available online 2 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Zahra Noroozi, Omid Bakhtiari Raw and tetraethylene pentamine (TEPA) functionalized titanium oxide nanotubes (TiNTs) were used as filler particles to prepare nanocomposite membranes. Polyethylene glycol (PEG) was blended with the Pebax-1657 as matrix and incorporated by TiNT-TEPA to prepare Pebax-1657/PEG/TiNT-TEPA nanocomposite membranes based on Response Surface and Central Composite Design methods of experimental design. The TiNT-TEPA and the Pebax/PEG/TiNT-TEPA were characterized using TEM, FESEM, SEM, FTIR or ATR-FTIR, XRD (EDS) and mechanical strength analysis. CO2 adsorption capacity of TiNTs and TiNT-TEPA-70 % were found as 0.71 and 4.2 mmol/g, respectively. CO2 permeability and ideal selectivity of optimum (in term of separation performance) membrane, as Pebax (7 Wt. %) /PEG (7.5 Wt. %)/TiNT-TEPA (3 Wt. %), were increased by 67.7 and 11.7 %, respectively, compared with the neat Pebax membrane.The optimum membrane’s CO2 permeability and CO2/CH4 ideal selectivity were investigated at operating temperatures of 20 - 45 °C and reveled 18.5 and - 9 % changes, respectively. Its transmembrane pressures increment form 4 to 10 bar for single and CO2 (50)/CH4 (50) mixed gas resulted in CO2 permeability and CO2/CH4 ideal selectivity enhancements by 19 and 20 %, respectively. The optimum membranes’ mixed gas separation performance were found lower than that of single pure gases at the same operating condition.Graphical abstractGraphical abstract for this article
       
  • Incorporation of graphene oxide/nanodiamond nanocomposite into PVC
           ultrafiltration membranes
    • Abstract: Publication date: Available online 1 October 2019Source: Chemical Engineering Research and DesignAuthor(s): S. Khakpour, Y. Jafarzadeh, R. Yegani Polyvinylchloride (PVC) ultrafiltration membranes with different amounts of graphene oxide-nanodiamond (GO-ND) nanocomposite were prepared via phase inversion method. The results of XRD and FTIR analyses showed that GO-ND nanocomposite was successfully synthesized and FESEM images showed that ND nanoparticles were uniformly attached on GO nanosheets with no agglomeration. Then, fabricated PVC/GO-ND membranes were characterized using a set of analyses including FESEM, AFM, Raman spectroscopy, contact angle, pure water flux, abrasion resistance, tensile strength, elongation and pore size distribution. The results showed that the hydrophilicity and surface roughness of membranes were improved with addition of GO-ND nanocomposite. Moreover, pure water flux was increased from 200 Lm−2 h−1 for neat PVC membrane to 440 Lm−2 h−1 for 0.15 wt. % GO-ND embedded membrane due to the enhancement of hydrophilicity and number of pores on surface surface of nanocomposite membranes. Besides, tensile strength and abrasion resistance of membranes were improved because of the reinforcement effect of GO-ND nanocomposite which can be attributed to the uniform dispersion of nanocomposite throughout PVC matrix. Finally, performance of membranes was evaluated in filtration of 1.0 g L-1 BSA solution and it was revealed that antifouling properties and BSA rejection of membranes were enhanced with increasing GO-ND content up to 0.10 wt. % and then were decreased.Graphical abstractGraphical abstract for this article
       
  • Nature-inspired geometrical design of a chemical reactor
    • Abstract: Publication date: Available online 1 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Elisa Magnanelli, Simon Birger Byremo Solberg, Signe Kjelstrup We explore the possibility to actively use the system geometry to search for states of minimum entropy production in a chemical reactor. This idea is inspired by the energy-efficient mass and energy transfer that takes place in the reindeer nose thanks to its complex geometry. A cylindrical plug-flow reactor for oxidation of sulfur dioxide is used as example, while optimal control theory is used to formulate the problem. We hypothesize that the nasal anatomy of the reindeer has evolved to its present shape to help reducing energy dissipation during respiration in extreme ambient temperatures.A comparable optimal diameter-profile in the plug-flow reactor resulted in 11% reduction of the total entropy production, compared to a cylindrical reference reactor. With, in addition, an optimal reactor length, the reduction is 16%. These reductions are largely due to reductions in viscous dissipation. In practice, this translates into smaller pressure drops across the system, which reduce the loads of upstream/downstream compressors. Moreover, the peak in the temperature profile was reduced with respect to that obtained by controlling the temperature of the cooling medium.With today's technological solutions, the optimal diameter profile might be easier to realize than other optimal control strategies. The possible gains from this first example are encouraging, and may serve as inspiration for further applications.
       
  • Increasing operational efficiency through the integration of an oil
           refinery and an ethylene production plant
    • Abstract: Publication date: Available online 1 October 2019Source: Chemical Engineering Research and DesignAuthor(s): Elham Ketabchi, Evgenia Mechleri, Harvey Arellano-Garcia In this work, the optimal integration between an oil refinery and an ethylene production plant has been investigated. Both plants are connected using intermediate materials aiming to remove, at least partially, the reliance on external sourcing. This integration has been proven to be beneficial in terms of quality and profit increase for both production systems. Thus, three mathematical models have been formulated and implemented for each plant individually as well as for the integrated system as MINLP models aiming to optimise all three systems. Moreover, a case study using practical data is presented to verify the feasibility of the integration within an industrial environment. Promising results have been obtained demonstrating significant profit increase in both plants.Graphical abstractGraphical abstract for this article
       
  • Artificial neural network modeling on the prediction of mass transfer
           coefficient for ozone absorption in RPB
    • Abstract: Publication date: Available online 28 September 2019Source: Chemical Engineering Research and DesignAuthor(s): Taoran Liu, Yiran Liu, Dan Wang, Yingwen Li, Lei Shao It has been proved that Higee technology can intensify the processes involving the multiphase mass transfer, and be applied to the ozone-based advanced oxidation processes. Modeling and prediction of mass transfer coefficient are rare in this field. A modeling approach based on artificial neural network (ANN) was developed in this work to predict mass transfer coefficient of ozone absorption process in rotating packed bed (RPB). Serial experiments were conducted to obtain data for the establishment of ANN model, which was then employed to predict the overall mass transfer coefficient (KLa) using dimensionless quantities such as Reynolds number of gas and liquid, Froude number and Weber number, calculated in terms of the geometry of RPB and operating conditions. To optimize the model structure and performance, random grid search for hyperparameters was adopted in this work. The final model exhibits a prediction ability with R2 of 0.9896 and 0.9877, RMSE of 0.01801 and 0.03085, and MAE of 0.01265 and 0.02219 on the training set and the test set, respectively.Graphical abstractGraphical abstract for this article
       
  • Digital and Lean Development Method for 3D-printed Reactors Based on CAD
           Modeling and CFD Simulation
    • Abstract: Publication date: Available online 27 September 2019Source: Chemical Engineering Research and DesignAuthor(s): Sven Bettermann, Felix Kandelhard, Hans-Ulrich Moritz, Werner Pauer The compatibility of computer-aided design (CAD) with computational fluid dynamics (CFD) softwares was used to establish a digital and lean development method for 3D-printed reactors which allows for shorter development cycles and targeted process setup. CAD modeling, as the starting point of an additive manufacturing process, creates 3D-designs, which can be directly evaluated by CFD simulation. Thus, challenging assumptions or issues regarding the performance of a tubular reactor can be visualized and redefined to create iteratively new strategies and solutions in a cost- and time-effective way. Our approach enables to build and deliver reactor designs incrementally and faster as it can be performed digitally and tailored to specific requirements. The developed reactor design subsequently can be fabricated directly by 3D printing techniques. The method is based on an established 3D-printed tubular bended reactor for emulsion polymerizations, without being limited to a specific case and enabled the lean fabrication of a tubular reactor being developed to proactively use Dean vortices by reducing dead zones in a more compact design. Optimized flow patterns were further obtained by the tailor-made implementation of static mixing elements at targeted positions of the reactor design.Graphical Graphical abstract for this article
       
  • Surface Modification of Carbon Nanotube: Effects on Pulsating Heat Pipe
           Heat Transfer
    • Abstract: Publication date: Available online 26 September 2019Source: Chemical Engineering Research and DesignAuthor(s): Amin Kazemi-Beydokhti, Naeem Meyghani, Masoud Samadi, Seyed Hasan Hajiabadi The role of new nanofluid based on multi-walled carbon nanotube (MWCNT) on the heat transfer efficiency of a closed loop pulsating heat pipe (CLPHP) has been investigated in this research. For this purpose, surface modification of MWCNT was utilized to prepare uniform and stable nanofluids. Therefore, chemical surface modification and polymer wrapping treatment were conducted on the nanotubes, and then, the thermal conductivity of synthesized nanofluids was measured to investigate the effect of these Nano complexes on the thermal resistance of CLPHP system. In addition, the effect of other CLPHP parameters such as filling ratio, operating pressure and different working fluids were investigated. The results revealed that these nanofluids could enhance the heat transfer coefficient (HTC) of the system by up to 27% when they used as the working fluid in a CLPHP. Furthermore, these experiments indicated that the CLPHP increased the HTC by up to 30% compared to a copper fin that is known for its higher HTC among the metals.Graphical abstractGraphical abstract for this article
       
  • The Limerick Bubbly Flow Rig: Design, Performance, Hold-up and Mixing
           Pattern
    • Abstract: Publication date: Available online 26 September 2019Source: Chemical Engineering Research and DesignAuthor(s): Corné Muilwijk, Harry E.A. Van den Akker As Euler-Euler CFD simulations of bubbly flows suffer from uncertainties due to the many underpinning models, there is an obvious need of accurate experimental data for validation. With this in mind, a new bubbly flow test rig was built to be operated with and without liquid co-flow, with bubble size as uniform as possible in the range 4-7 mm, and with a very even horizontal bubble distribution. We designed the gas sparging system such that we can also produce an essentially bi-modal bubble size distribution. The column consists of two square sections to allow for studying the mixing of two originally separated bubbly flows with either the same or a different bubble size. The bubbles are produced from 2 × 196 needles, bubble sizes are determined with high-speed imaging and with a simple acoustical method, overall volume fractions in the column by means of air chamber pressure measurements. Overall volume fractions are presented as a function of gas and liquid flow rates, with slip velocity mostly increasing with increasing void fraction. First results are obtained on (a) producing bi-model bubble size distributions and the pertinent volume fractions in the column, and (b) flow patterns in the case of unequal aeration.Graphical abstractGraphical abstract for this article
       
  • Computer-Aided Reaction Solvent Design Considering Inertness using Group
           Contribution-based Reaction Thermodynamic Model
    • Abstract: Publication date: Available online 23 September 2019Source: Chemical Engineering Research and DesignAuthor(s): Qilei Liu, Lei Zhang, Kun Tang, Yixuan Feng, Jinyuan Zhang, Yu Zhuang, Linlin Liu, Jian Du Solvents have been widely used in process manufacturing industries. When involved in liquid-phase organic synthesis reactions, solvents can reduce the activation energy of reactions between the reactants and the transition state through solvation effects. However, undesirable side reactions can also be performed between solvents and the reaction system (the reactants and products), which should be avoided for producing unnecessary byproducts in the reaction system. In this paper, an optimization-based methodology is proposed for inert reaction solvent design. In this method, first, a Group Contribution (GC)-based reaction thermodynamic model is developed to quantitatively identify the thermodynamic feasibility of side reactions between solvents and the reaction system. Then, the SMARTS (SMiles Arbitrary Target Specification)-based reaction generation algorithm is employed to generate possible side reactions between solvents and the reaction system, helping to integrate the developed GC-based reaction thermodynamic model with the Computer-Aided Molecular Design (CAMD) problem for designing inert reaction solvents through the formulation and solution of the Mixed-Integer Non-Linear Programming (MINLP) model. Due to the nonlinear equations in the MINLP model, a decomposition-based solution strategy is employed to solve the optimization problem. Finally, two case studies are presented to demonstrate the feasibility and effectiveness of the proposed optimization-based methodology for promising inert reaction solvent design.
       
  • Facile synthesis of protonated g-C3N4 and acid-activated montmorillonite
           composite with efficient adsorption capacity for PO4 3- and Pb (II)
    • Abstract: Publication date: Available online 21 September 2019Source: Chemical Engineering Research and DesignAuthor(s): Xia Wan, Muhammad Asim Khan, Fengyun Wang, Mingzhu Xia, Wu Lei, Sidi Zhu, Chenlu Fu, Yong Ding A novel protonated graphite carbon nitride and acid-activated montmorillonite (g-C3N4/Mt) composite was prepared and evaluated its removal efficiency for PO43- and Pb (II) from aqueous media. The as-prepared composite was characterized by XRD, FT-IR, TG, XPS, SEM, BET and Zeta potential. Batch experiments were carried out under various conditions such as the amount of adsorbent, initial adsorbate concentration (Co), solution pH, temperature, and contact time. 2.0%-g-C3N4/Mt presented maximum adsorption capacity for PO43- and Pb (II) as compared to single g-C3N4, Mt or other synthesized composites. The removal efficiency of the as-prepared composite (2.0%-g-C3N4/Mt) was significantly elevated owing to the synergistic effects and the saturated adsorption capacities of PO43- and Pb (II) on 2%-g-C3N4/Mt was 5.06 mg/g and 182.7 mg/g respectively. While the saturated adsorption capacity of bare g-C3N4 was only 1.56 mg/g and 22.3 mg/g for PO43- and Pb (II) respectively, and bare Mt showed adsorption capacity of 0.65 mg/g and 124.2 mg/g for PO43- and Pb (II) respectively. The adsorption process for both contaminants showed well-fitting with the pseudo-second-order kinetic model, and the adsorption isotherm for both contaminants followed the Langmuir model. The thermodynamic study suggested that the adsorption of Pb (II) was a spontaneous and endothermic process.Graphical abstractGraphical abstract for this article
       
  • Conversion of levoglucosan to glucose using an acidic heterogeneous
           Amberlyst 16 catalyst: kinetics and packed bed measurements
    • Abstract: Publication date: Available online 20 September 2019Source: Chemical Engineering Research and DesignAuthor(s): R.M. Abdilla-Santes, C.B. Rasrendra, J.G.M. Winkelman, H.J. Heeres Levoglucosan (1,6-anhydro-β-D-glucopyranose) is an anhydrosugar found in significant amounts in pyrolysis liquids obtained from lignocellulosic biomass. Levoglucosan is an attractive source for glucose, which can be used as a feedstock for biofuels (e.g. bioethanol) and biobased chemicals. Here, we report a kinetic study on the conversion of LG to GLC in water using Amberlyst 16 as the solid acid catalyst at a wide range of conditions in a batch set-up. The effects of the reaction temperature (352–388 K), initial levoglucosan intake (100–1000 mol m-3), catalyst loading (1–5 wt%), and stirring rate (250-1000 rpm) were determined. The highest glucose yield was 98.5 mol% (388 K, 5 wt% Amberlyst 16, CLG,0 = 500 mol m-3 at 500 rpm stirring rate and t =60 min). The experimental data were modelled and relevant kinetic parameters were determined using a first order approach including diffusion limitations of LG inside the Amberlyst particles. Good agreement between experiments and kinetic model was obtained. The activation energy was found to be 132.3 ± 10.1 kJ mol-1. Experiments in a continuous packed bed set-up for up to 30 h show that catalyst stability is good. In addition, the steady state levoglucosan conversion (73 mol%) and the GLC selectivity were in line with the kinetic model obtained in the batch reactor.
       
  • A two-stage strategy for the pump optimal scheduling of refined products
           pipelines
    • Abstract: Publication date: Available online 16 September 2019Source: Chemical Engineering Research and DesignAuthor(s): Shengchao Xin, Yongtu Liang, Xingyuan Zhou, Wenjing LI, Jie Zhang, Xuan Song, Chunquan Yu, Haoran Zhang As one of the major means to link refineries to local markets, pipelines are crucial for refined oil supply chains. Pump scheduling is vital to optimally operate the refined products pipelines. Existing studies mostly quantified the number of pump stop/restart in the form of cost, whereas the cost coefficient was often subjectively selected. The present study built a multi-objective mixed-integer linear programming (MOMILP) model for refined products pipelines to minimize the number of pump stop/restart and reduce the pump running cost simultaneously. In this study, the minimum continuous running time of pumps, changing electricity price (i.e., time-changing electricity price and local electricity) and the pressure limits of special points were considered meticulously, e.g. high-elevation points, low-elevation points and pump stations. In the first stage, the improved augmented ε-constraint method (AUGMECON) was adopted to deal with this model, and obtained a seris of pump operating schemes, acting as a Pareto set. Then the results of the AUGMECON were evaluated by an established evaluation model based on neural network. Finally, two cases from a refined products pipeline system in China were employed to verify the practicability and accuracy of the proposed model. The results of this study can effectively guide the pump scheduling of refined products pipelines.Keywords: refined products pipelines pump scheduling; pump stop/restart; changing electricity price; AUGMECON; neural network
       
 
 
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