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  Subjects -> CHEMISTRY (Total: 901 journals)
    - ANALYTICAL CHEMISTRY (55 journals)
    - CHEMISTRY (635 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (28 journals)
    - INORGANIC CHEMISTRY (43 journals)
    - ORGANIC CHEMISTRY (48 journals)
    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (635 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 14)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 29)
ACS Catalysis     Hybrid Journal   (Followers: 48)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 22)
ACS Combinatorial Science     Hybrid Journal   (Followers: 23)
ACS Macro Letters     Hybrid Journal   (Followers: 27)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 42)
ACS Nano     Hybrid Journal   (Followers: 316)
ACS Photonics     Hybrid Journal   (Followers: 14)
ACS Symposium Series     Full-text available via subscription  
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: 3)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 8)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 9)
Adsorption Science & Technology     Open Access   (Followers: 6)
Advanced Functional Materials     Hybrid Journal   (Followers: 61)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 75)
Advances in Chemical Science     Open Access   (Followers: 19)
Advances in Chemistry     Open Access   (Followers: 24)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 19)
Advances in Drug Research     Full-text available via subscription   (Followers: 25)
Advances in Environmental Chemistry     Open Access   (Followers: 7)
Advances in Enzyme Research     Open Access   (Followers: 10)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 12)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 27)
Advances in Nanoparticles     Open Access   (Followers: 16)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 17)
Advances in Polymer Science     Hybrid Journal   (Followers: 45)
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: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 3)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 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)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 68)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 22)
American Journal of Chemistry     Open Access   (Followers: 32)
American Journal of Plant Physiology     Open Access   (Followers: 13)
American Mineralogist     Hybrid Journal   (Followers: 15)
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: 182)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 263)
Annales UMCS, 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: 9)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 14)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
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: 34)
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  
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 3)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 11)
Biochemistry     Hybrid Journal   (Followers: 377)
Biochemistry Insights     Open Access   (Followers: 6)
Biochemistry Research International     Open Access   (Followers: 6)
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: 24)
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: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 137)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 92)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 19)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 1)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 24)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 11)
Canadian Mineralogist     Full-text available via subscription   (Followers: 6)
Carbohydrate Research     Hybrid Journal   (Followers: 25)
Carbon     Hybrid Journal   (Followers: 70)
Catalysis for Sustainable Energy     Open Access   (Followers: 8)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Hybrid Journal   (Followers: 9)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 12)
Cellulose     Hybrid Journal   (Followers: 10)
Cereal Chemistry     Full-text available via subscription   (Followers: 5)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 22)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 75)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 27)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 22)
Chemical Reviews     Hybrid Journal   (Followers: 210)
Chemical Science     Open Access   (Followers: 28)
Chemical Technology     Open Access   (Followers: 34)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 22)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 33)
Chemistry & Industry     Hybrid Journal   (Followers: 8)
Chemistry - A European Journal     Hybrid Journal   (Followers: 173)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 16)
Chemistry and Materials Research     Open Access   (Followers: 21)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 46)
Chemistry of Materials     Hybrid Journal   (Followers: 271)
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: 11)
Chromatographia     Hybrid Journal   (Followers: 22)
Chromatography     Open Access   (Followers: 3)
Chromatography Research International     Open Access   (Followers: 6)
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: 7)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 23)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Communications Chemistry     Open Access  
Composite Interfaces     Hybrid Journal   (Followers: 7)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 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: 1)
Current Metabolomics     Hybrid Journal   (Followers: 5)
Current Microwave Chemistry     Hybrid Journal  
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 14)
Current Research in Chemistry     Open Access   (Followers: 9)
Current Science     Open Access   (Followers: 74)
Current Trends in Biotechnology and Chemical Research     Open Access   (Followers: 2)
Dalton Transactions     Full-text available via subscription   (Followers: 24)
Detection     Open Access   (Followers: 4)
Developments in Geochemistry     Full-text available via subscription   (Followers: 2)

        1 2 3 4 | Last

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  [3161 journals]
  • Absorption and desorption mass transfer rates as a function of pressure
           and mixing in a simple hydrocarbon system
    • Abstract: Publication date: Available online 14 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Alden B Daniel, Sayeed A Mohammad, Michael A Miranda, Clint P Aichele Determining the time required for degassing within a gas-liquid separator is usually accomplished by assuming thermodynamic equilibrium between the two phases and calculating the time required for entrained gas bubbles to rise out of the liquid. However, if the gas-liquid separation is being performed at elevated pressures, the inlet multiphase fluid may not be at thermodynamic equilibrium, thus the chance for solution gas to evolve out of the liquid must also be accounted for. There is, however, a paucity of mass transfer data in hydrocarbon systems available at elevated pressures. For the current experimental study, the rates of absorption and desorption of methane in a n-dodecane solution were measured in a batch stirred tank system at pressures ranging from 3.45 to 10.34 MPa and mixing speeds ranging from 100 to 250 rpm. All absorption and desorption experiments were performed using the same physical and hydrodynamic conditions. Additionally, care was taken in ensuring that the gas-liquid interface during mass transfer remained flat, allowing for the explicit calculation of the liquid-side mass transfer coefficient. Within the experimental variability, the rates of absorption and desorption were found to be the same in most cases. The mixing speed was found to be the main variable affecting the rate of mass transfer, while the saturation pressure was found to have little effect. The process was well described by the theoretically derived solid surface eddy cell model presented by Lamont and Scott, resulting in an average absolute error of 12.3 % between the predicted and measured mass transfer coefficients.
       
  • Kinetic study of soybean oil hydrolysis catalyzed by lipase from solid
           castor bean seeds
    • Abstract: Publication date: Available online 12 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Felipe de A. S. Corradini, Ediane Sá Alves, Willian Kopp, Marcelo P.A. Ribeiro, Adriano A. Mendes, Paulo W. Tardioli, Roberto C. Giordano, Raquel L.C. Giordano Soybean oil hydrolysis catalyzed by castor bean (Ricinus communis L.) seeds lipase was investigated. The optimum operational temperature (in the range 25-50 °C) was 37 °C, and Na+ increased reaction velocities. When stirring at 300 rpm, gum arabic enhanced the rate of hydrolysis, but at F1000 rpm the emulsifier decreased long-term conversions. Experiments using different particle sizes indicated the presence of diffusion delays above 300 µm A parsimonious model for this complex system was proposed. Initial rates (V0) experiments, spanning 0.01-0.5 w/w of oil, showed a decrease in V0 for high substrate concentrations, depending on the stirring conditions, indicating coalescence of substrate droplets. This hypothesis was confirmed by experiments with more impeller paddles. A pseudo-homogeneous Michaelis-Menten model with substrate inhibition (to represent coalescence effects), fitted well to the initial rates. Product inhibition for high loads of substrate and enzyme deactivation were also considered. The kinetic model was validated by independent experiments, and thus may be useful for design and optimization of industrial enzymatic reactors.Graphical abstractGraphical abstract for this article
       
  • Techno-Economic Comparison of Reverse Water Gas Shift Reaction to Steam
           and Dry Methane Reforming Reactions for Syngas Production
    • Abstract: Publication date: Available online 12 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Ebrahim Rezaei, Stephen Dzuryk This work evaluates the economics of syngas production processes by the reverse water gas shift (rWGS) reaction against the dry methane reforming (DMR) reaction and its combination with the steam methane reforming reaction (SMR-DMR). The DMR and SMR-DMR processes show lower total annual costs comparing to the rWGS process for the production of syngas with H2/CO ratio of 1 and 2, respectively. Breakeven analysis has been performed on the price of H2, natural gas, and CO2 tax rate. At a H2 price of $1/kg, the rWGS process is comparable to the DMR process when natural gas price and CO2 tax rate are $0.53/m3 (STP) and $44/1000 kg, respectively. For the rWGS process to be as economical as the SMR-DMR process, natural gas prices in the range of $0.35 to 0.53/ m3 (STP) and CO2 tax rates up to $60/1000 kg are needed while keeping the H2 price below $2/kg.
       
  • Novel conical section design for ultra-fine particles classification by a
           hydrocyclone
    • Abstract: Publication date: Available online 12 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Junxiang Ye, Yanxia Xu, Xingfu Song, Jianguo Yu To overcome the limitation of the conventional hydrocyclone for the ultra-fine particles classification, the novel conical section design of the hydrocyclone is computationally investigated in this work. The electrolytic manganese dioxide (EMD, MnO2) powder, whose size is in the range from 0.2 μm to 70 μm, is took as a study case, and the feed solid concentration (SC) is up to 20%wt. The conical section with the modified cone design is proposed to enhance the performance of hydrocyclones. In addition, all the hydrocyclones are equipped with an arc inlet to obtain the pre-classification effect. The micron particles classification with the demarcation at 5 μm is accomplished in the novel hydrocyclone as the classification sharpness (Ss) is improved from 0.833 to 0.938 at the feed solid concentration of 5%wt. The combination of moderate conical length and modified cone with wide radial space near spigot is the outline of the high classification sharpness hydrocyclone. The dynamics analysis illustrates that the classification performance is attributed to the comprehensive effects of force, residence time, and separation space.Graphical abstractGraphical abstract for this articleRadial drag acceleration (force) profile in hydrocyclones with different modified cone designs (SC = 10%wt, 5 μm particle phase).
       
  • Bubble characterization and gas-liquid interfacial area in two phase
           gas-liquid system in bubble column at low Reynolds number and high
           temperature and pressure
    • Abstract: Publication date: Available online 11 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Dan Feng, Jean-Henry Ferrasse, Audrey Soric, Olivier Boutin Bubbles hydrodynamic in gas liquid contactor, including bubble size distribution, bubble size and gas-liquid interfacial area, was evaluated as a function of superficial gas velocity, superficial liquid velocity, temperature, pressure and different gases (N2 and He) and liquids (water and ethanol/water mixture) phases. The results showed that with the increase of superficial gas velocity, the bubble size distribution shifted from smaller- to larger-size bubble and the Sauter mean diameter, the gas holdup and the interfacial area generally increased due to the increase of coalescence. The effect of superficial liquid velocity on bubble characteristics was not significant. Pressure and temperature showed slight influence on gas holdup and interfacial area. The bubble characteristics were not significantly influenced by the type of gas phase, but mainly affected by the liquid composition. Correlations to predict Sauter mean bubble diameter and the gas holdup are developed using Kanaris correlation and in good agreement with experimental results.
       
  • Preparation of thiourea-modified magnetic chitosan composite with
           efficient removal efficiency for Cr(VI)
    • Abstract: Publication date: Available online 11 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Weiquan Cai, Feng Zhu, Hong Liang, Yihong Jiang, Wenjun Tu, Zhijun Cai, Junrong Wu, Jiabin Zhou The thiourea-modified magnetic chitosan (CS) Fe3O4@Al2O3-CS with high adsorption capacity and separation efficiency for Cr(VI) was prepared successfully, and its physicochemical properties were characterized via XRD, SEM, TEM, N2 adsorption-desorption, FT-IR, TGA-DSC, Zeta-potential and VSM, respectively. The batch adsorption results show that its kinetic data match the pseudo-second order well, and the equilibrium data are well depicted by the Langmuir adsorption isotherm with the maximum adsorption capacity of 327.8 mg/g. The thermodynamic parameters of the adsorption process reveal its spontaneous and endothermic characteristic. Most importantly, the Fe3O4@Al2O3-CS shows good selective and recyclable performance for Cr(VI), indicating that it has a good application prospect to remove heavy metals ions from wastewater.Graphical abstractGraphical abstract for this article
       
  • Just-in-time learning based soft sensor with variable selection and
           weighting optimized by evolutionary optimization for quality prediction of
           nonlinear processes
    • Abstract: Publication date: Available online 11 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Bei Pan, Huaiping Jin, Li Wang, Bin Qian, Xiangguang Chen, Si Huang, Jiangang Li Just-in-time (JIT) learning based soft sensors have been widely used for predicting product quality variables of nonlinear processes. They dynamically build online local models by selecting the samples most relevant to the query data from a historical database whenever an estimate is requested. However, building high-performance JIT soft sensors remains challenging due to difficulties defining similarity measures and the selection of input variables for facilitating efficient relevant sample selection and model building. In this study, we propose a novel soft sensing framework, referred to as JIT learning with variable selection and weighting (JIT-VSW). In this framework, a mixture weighted similarity (MWS) measure is defined by combining multiple weighted Euclidean distance (WED) based similarity measures. The MWS measure enables variable weighting embedded in WED measures to account for the relevance between input and output variables and facilitates the handling of highly complex process characteristics through the mixture-type similarity measure. Meanwhile, a wrapper optimization approach using evolutional algorithms is proposed for input variable selection. Further, the selection of input variables and the determination of MWS parameters, i.e., weights assigned to input variables and mixture coefficients of WED similarity measures, are formulated as a mixed integer optimization problem and solved simultaneously by using the mixed integer genetic algorithms (MIGA). The effectiveness and superiority of JIT-VSW are verified through three real-world applications.
       
  • New deterministic tools to systematically investigate fouling occurrence
           in membrane bioreactors
    • Abstract: Publication date: Available online 11 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Hamideh Hamedi, Majid Ehteshami, Seyed Ahmad Mirbagheri, Sohrab Zendehboudi Membrane fouling as a major concern in development and optimization of membrane bioreactor (MBR) technologies has been the focus of numerous engineering and research investigations. Considering the complexity of membrane fouling occurrence, mathematical modelling techniques have been progressively proposed to forecast this phenomenon for optimizing MBR performance. A majority of the models are not reliable and accurate enough in terms of theoretical and practical prospects. In this research work, smart methods including artificial neural network (ANN), gene expression programming (GEP), and least square support vector machine (LSSVM) are suggested to avoid utilization of complex modelling methodologies and costly and time-consuming measurements. The developed models relate fouling resistance to key parameters such as permeate flux, temperature, and transmembrane pressure. To enhance the performance of conventional connectionist tools, particle swarm optimization (PSO) algorithm with global optima is utilized. This study aims to simulate the MBR efficiency by calculating membrane fouling resistance. The performance of the smart models is evaluated based on mean square error (MSE), maximum absolute percentage error (MAAPE), minimum absolute percentage error (MIAPE), and coefficient of determination (R2). The results reveal that the developed LSSVM tool has the lowest MSE (0.0002) and MAAPE (3.18), and MIAPE (0.01), and the highest R2 (0.99) in the testing phase. The transmembrane pressure and permeate flux are the most important parameters affecting membrane fouling resistance. This study can help to obtain a better understanding of membrane fouling process to achieve optimal conditions for MBR systems in terms of design, operation, and optimization prospects.Graphical Graphical abstract for this article
       
  • Facile synthesis of chitosan/gelatin filled with graphene bead adsorbent
           for orange II removal
    • Abstract: Publication date: Available online 10 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Min Wu, Wenjuan Chen, Qinghua Mao, Yunshan Bai, Hongzhu Ma In this work, the bead adsorbent derived from chitosan and gelatin, filled with graphene for orange II (ORII) removal was prepared facilely. The synthesized samples were analyzed by means of Fourier transform infrared spectroscopy, X-ray powder diffraction, Zetasizer Nano, field emission scanning electron microscopy and thermogravimetric analysis. The analysis of adsorption behavior of the as-prepared composite toward ORII was conducted, where the effects of the contact time, pH, the initial ORII concentration, swelling behavior and recyclability were studied. The highest removal efficiency of 84.3 % at the optimum conditions (0.03 g beads, 10 mL 50 mg L-1 ORII, original pH (7.14), 120 min) was obtained. In addition, the effects of salts and surfactants on the adsorption performance were also investigated. Subsequently, the adsorption kinetics and isotherms were performed and analyzed in order to achieve a thorough comprehension of dyes adsorption mechanism. The results revealed that electrostatic interactions and hydrogen bonding played an important role in the dye adsorption process. Based on these analyses, it can be concluded that the as-prepared chitosan-gelatin-graphene trinary composite should be acted as a promising adsorbent for high-efficiency dye removal to deal with water pollution.Graphical abstractGraphical abstract for this article
       
  • Removal of Ni(II) from fuel ethanol by PAMAM dendrimers/silica hybrid
           materials: Combined experimental and theoretical study
    • Abstract: Publication date: Available online 10 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Zhoumin Qiu, Yuzhong Niu, Tiantian Fu, Ke Wang, Qiuhong Mu, Feng Wang The adsorption of Ni(II) from fuel ethanol by polyamidoamine (PAMAM) dendrimers/ silica hybrid materials (SG-G0.5˜SG-G3.0) was performed combining experimental and theoretical method. The influences of terminal functional group, dendrimer generation, adsorption time, temperature, and initial concentration of Ni (II) on the adsorption were demonstrated. Equilibrium adsorption shows that the adsorption capacity of amino-terminated product is higher than their counterpart ester-terminated product. Adsorption kinetic indicates the adsorption equilibration can be reached at 350 and 270 min for amino- and ester- terminated products, respectively. Adsorption kinetic can be described by pseudo-second- order model. Boyd film diffusion model demonstrates film diffusion process is the rate limiting step during the adsorption process. Adsorption isotherm implies the adsorption can be promoted by increasing initial Ni(II) concentration and temperature. Langmuir model is more suitable than Freundlich model to describe the isotherm adsorption, indicating the adsorption proceeds by monolayer behavior. The results of D-R model indicate the adsorption is chemical adsorption process. The uptake of Ni (II) is proved to be spontaneous, endothermic, and entropy increasing by thermodynamic parameters. FTIR demonstrates the chemical nature of the adsorption process with the participation of nitrogen and carbonyl oxygen atoms. Density functional theory (DFT) calculation indicates the formation of tetra-coordination chelates by carbonyl O atoms and secondary amine N atoms dominates the adsorption for both ester- and amino-terminated PAMAM dendrimer. This work may provide promising adsorbents for the effective removal of Ni(II) from fuel ethanol with practical values.Graphical abstractGraphical abstract for this article
       
  • Hierarchical batch-to-batch optimization of cobalt oxalate synthesis
           process based on data-driven model
    • Abstract: Publication date: Available online 8 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Runda Jia, Zhizhong Mao, Dakuo He, Fei Chu The synthesis process has been widely used in cobalt hydrometallurgical industry. To better operate the cobalt oxalate synthesis process, a data-driven model based hierarchical batch-to-batch optimization method is presented in this work. In the upper level of hierarchy, the proposed response surface model based modifier-adaptation (MA) strategy is used to calculate the nominal control profile for the next level, and the design of dynamic experiment (DODE) method is also employed to symmetrically generate the dataset for response surface model building. In the lower level of hierarchy, the batch-wise unfolded PLS (BW-PLS) model based self-tuning batch-to-batch optimization method is utilized to further refine the control profile on the basis of the result of the upper level. The main advantages of the proposed method are: (i) the size of the dataset for data-driven model building are rather modest, (ii) the control profile can be discretized into a large number of intervals to further improve the optimization performances, and (iii) the unqualified batches is efficiently avoided during the evolution of batch-to-batch optimization. The superior performances for the cobalt oxalate synthesis process are verified through simulation study.Graphical Graphical abstract for this article
       
  • Microbubble-Enhanced DBD Plasma Reactor: Design, Characterisation and
           Modelling
    • Abstract: Publication date: Available online 8 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Alexander Wright, Matteo Taglioli, Faraz Montazersadgh, Alex Shaw, Felipe Iza, H C Hemaka Bandulasena The emerging field of atmospheric pressure plasmas (APPs) for treatment of various solutions and suspensions has led to a variety of plasma reactors and power sources. This article reports on the design, characterisation and modelling of a novel plasma-microbubble reactor that forms a dielectric barrier discharge (DBD) at the gas-liquid interface to facilitate the transfer of short-lived highly reactive species from the gas plasma into the liquid phase. The use of microbubbles enabled efficient dispersion of long-lived reactive species in the liquid and UVC-induced oxidation reactions are triggered by the plasma radiation at the gas-liquid interface. A numerical model was developed to understand the dynamics of the reactor, and the model was validated using experimental measurements. Fluid velocities in the riser region of the reactor were found to be an order of magnitude higher for smaller bubbles (˜500 µm diameter) than for larger bubbles (˜2500 µm diameter); hence provided well-mixed conditions for treatment. In addition to other reactive oxygen species (ROS) and reactive nitrogen species (RNS), a dissolved ozone concentration of 3 μM was recoded after a 15-minute operation of the reactor, demonstrating the suitability of this design for various applications.
       
  • Modification of a Tri-Reforming reactor based on the feeding policy to
           couple with methanol and GTL units
    • Abstract: Publication date: Available online 6 February 2019Source: Chemical Engineering Research and DesignAuthor(s): M. Fekri, M. Farsi, M.R. Rahimpour The main idea of this research is the modification of methane tri-reforming reactor to increase syngas production capacity. Since methane tri-reforming is an integration of steam reforming, dry reforming, and partial oxidation, the feeding policy is a key solution to shift reaction network toward the desired condition. In this regard, the conventional fixed bed reactor is divided into three equal beds in series, and the optimal distribution of steam, carbon dioxide and oxygen between beds is calculated to maximize hydrogen production. The conventional and proposed configurations are heterogeneously modeled based on the mass and energy conservation laws at steady state condition. Then, the accuracy of the developed model and considered assumptions is proved. To calculate the optimal condition of the proposed multi-bed tri-reformer, a single objective optimization problem is formulated considering process limitations. Based on the optimization results steam and carbon dioxide injection between beds increases hydrogen production about 2.93% at the same catalyst loading. The main advantages of the proposed configuration are higher hydrogen production, adequate hydrogen to carbon monoxide ratio, and higher carbon dioxide conversion. The results shows that carbon dioxide conversion in the proposed multi-bed configuration is about 16%.Graphical abstractGraphical abstract for this article
       
  • Solvent Selection for Extractive Distillation Processes to Separate
           Close-Boiling Polar Systems
    • Abstract: Publication date: Available online 5 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Lisette M.J. Sprakel, Peter Kamphuis, Anna L. Nikolova, Dylan J. Keijsper, Boelo Schuur Solvent selection is key in extractive distillation process development and solvent effects are often predicted based on the activity coefficients at infinite dilution. For close-boiling polar systems with strong or specific interacting species, standard simulation tools, e.g. using UNIFAC or COSMO-RS, often predict poor as the activity coefficients at infinite dilution not always reflect the selectivity in the process. For these systems, a heuristic solvent selection method in which molecular properties such as acidity, hydrogen bonding and polarity are applied is desired as first estimate in the solvent selection. To explore the key parameters for such a first selection, solvent effects on the relative volatility (α) were measured for three different industrially relevant polar mixtures, valeric acid - 2-methylbutyric acid, diethylmethylamine – diisopropylether, and 2-butanol - 2-butanone. For each of the cases the effect of potential solvents on α was measured in an ebulliometer. For the acids, the difference in pKa of 0.1 was too small to separate based on acidity with a moderately basic solvent. Stronger basic solvents resulted in thermal and chemical instability. Although the solvent of methyl-2-methyl butyrate is not suitable as a solvent because of reactivity, this structurally similar solvent showed selectivity, indicating also in extractive distillation the like dissolves like phenomenon can be applied to induce selectivity. A larger difference in basicity of the mixture components (amine – ether mixture) and a difference in hydrogen bonding affinity between the mixture components (ketone – alcohol mixture) allowed for increasing α based on differences in acidity and hydrogen bonding, respectively .Graphical abstractGraphical abstract for this article
       
  • Onaccounting for equipment-control interactions in economic model
           predictive control via process state constraints
    • Abstract: Publication date: Available online 5 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Helen Durand Traditionally, chemical processes have been operated at steady-state; however, recent work on economic model predictive control (EMPC) has indicated that some processes may be operated in a more economically-optimal fashion under a time-varying operating policy. It is unclear how time-varying operating policies may impact process equipment, which must be investigated for safety and profit reasons. It has traditionally been considered that constraints on process states can be added to EMPC design to prevent the controller from computing control actions which create problematic operating conditions for process equipment. However, no rigorous investigation has yet been performed to analyze whether, when a process is operated in a time-varying fashion, constraints on the process states (rather than states of the equipment behavior itself) are the most appropriate way of preventing unsafe conditions. In this work, we investigate the use of process state constraints for preventing equipment damage due to the operating conditions set up by an EMPC over time when the equipment behavior is modeled within a context based on forces, deformation, and fracture. Through a chemical process example, we elucidate that there are situations in which process state constraints are likely to be adequate for use in preventing an EMPC from setting up operating conditions that may not be desirable, but that there also may be situations when process state constraints are not adequate and constraints on equipment states may be an alternative. We elucidate a number of challenges that remain to be addressed for this proposed method to be practical.
       
  • Sn-Based Deep Eutectic Solvents Assisted Synthesis of Sn and SnO2
           Supported Hexagonal Boron Nitrides for Adsorptive Desulfurization
    • Abstract: Publication date: Available online 4 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Hongping Li, Jinrui Zhang, JianJian Yi, Jing Luo, Siwen Zhu, Linghao Sun, Jun Xiong, Wenshuai Zhu, Huaming Li Adsorptive desulfurization (ADS) from fuels is considered as the most promising strategy due to the advantage of low energy consumption, to treat on sulfur which would induce serious air pollution. In this work, Sn-based DESs with urea were firstly synthesized and introduced into hexagonal boron nitride (h-BN) as both reaction solvents and metal sources. Adsorption experiments show that the as-prepared adsorbents present higher adsorption capacity for dibenzothiophene (DBT) from model oils as compared with the commercial BN. Especially, the Sn-BN-800 (SnO2 supported BN with -OH groups substitution at B sites) shows the highest performance. By combining experimental and theoretical analysis, we propose that the performance enhancement arises from the π-complexation and hydrogen bonding interaction between SnO2 and DBT. In addition, the -OH groups, which were substituted at the edge site of B, may also enhance the electron transfer from DBT to Sn-BN-800, leading to the improved adsorption capacity.Graphical abstractGraphical abstract for this articleSn based DESs with urea were firstly synthesized and introduced into hexagonal boron nitride. These materials present higher adsorption capacity for dibenzothiophene (DBT) from model oils. The nature of the ADS source from the π-complexation and hydrogen bonding interaction between SnO2 and DBT.
       
  • Poly(vinyl alcohol)/ZSM - 5 zeolite mixed matrix membranes for
           pervaporation dehydration of isopropanol/water solution through response
           surface methodology
    • Abstract: Publication date: Available online 4 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Zhen Huang, Xiao-fei Ru, Ya-Tong Zhu, Yu-hua Guo, Li-jun Teng Mixed matrix membranes (MMMs) of poly(vinyl alcohol) (PVA) containing certain amounts of ZSM-5 zeolite were evaluated for pervaporation dehydration of highly concentrated isopropanol aqueous solution. The effects of zeolite content, feed composition and feed temperature on the membrane separation performance are in detail examined by using a preliminarily one-factor-each time method and a systematically response surface methodology (RSM). Preliminarily results show the dehydration separation factor/selectivity have been greatly boosted but without the cost of pervaporation flux/permeance after adding zeolite ZSM-5, and it is consistent very well with the Arrhenius activation energy estimations where water molecules require much less energy whereas ethanol molecules need much more energy to transport through the membrane, probably because of the favorable hydrophilic and porous features of zeolite ZSM-5 as revealed by swelling and water contact angle results. High feed isopropanol concentration and low feed temperature are both observed to lead to very low pervaporation flux/permeance but very relatively high separation factor/selectivity. The RSM results suggest that zeolite content, feed composition and feed temperature all have highly significant impacts on total pervaporation flux and separation factor. The interaction effect of zeolite content and feed temperature on separation factor is for the first time found to be also significant. The polynomial models established according to the RSM analysis can fit very well against the experimental data with a very high coefficient of determination and the predictions given for optimized conditions have been experimentally confirmed by the validation results with a deviation of less than 2.0%.Graphical abstractGraphical abstract for this article3D response surface plots for total pervaporation flux and water/IPA separation factor as a function of (a) zeolite content and feed temperature, (b) zeolite content and feed IPA concentration, (c) feed temperature and feed IPA concentration.
       
  • A NEW HYBRID PHOTOBIOREACTOR DESIGN FOR MICROALGAE CULTURE
    • Abstract: Publication date: Available online 1 February 2019Source: Chemical Engineering Research and DesignAuthor(s): Mariany C. Deprá, Luis G.R. Mérida, Cristiano R. de Menezes, Leila Q. Zepka, Eduardo Jacob-Lopes The objective of this study was to develop a new design of photobioreactor for microalgae culture. Hydrodynamic characterization, growth kinetics, removal of carbon dioxide and oxygen release rates, carbon and energy balances, and requirements of the surface area were determined. The results showed that the hybrid photobioreactor presented high hydrodynamic performance (mixing time of 98s, circulation time of 39s, Reynolds number of 2500 and empty bed residence time of 60s). The carbon dioxide bioconversion kinetics for Scenedesmus obliquus CPCC05 showed maximum specific growth rates of 0.96 d-1, and a maximum cell biomass of 2.8 kg/m³. In parallel, an average carbon dioxide conversion and oxygen release rates of 45.32kgCO2/m³/d and 33.98kgO2/m³/d were obtained, respectively. The carbon balance indicated that a small fraction (1.28%) of the carbon dioxide is fixed into a biomass form. Volatile organic compounds (82.75%) were the main products formed in the photobioreactor. The energy balance provided a net energy ratio of 2.49. Finally, this photobioreactor configuration requires a volumetric surface area in order to 0.22 m²/m³.Graphical abstractGraphical abstract for this article
       
  • Mass transfer from a soluble Taylor bubble to the surrounding flowing
           liquid in a vertical macro tube — A numerical approach
    • Abstract: Publication date: Available online 1 February 2019Source: Chemical Engineering Research and DesignAuthor(s): M.C.F. Silva, J.B.L.M. Campos, J.D.P. Araújo Gas-liquid mass transfer is a phenomenon with a wide practical relevance and, besides many other possible advantages, its fundamentals can be used to enhance or regulate chemical and biological processes. In this work, the specific case of the mass transfer of oxygen from a Taylor bubble to the surrounding flowing liquid was studied using CFD techniques. This study was performed for a range of flow conditions (different Reynolds numbers) and a liquid with a viscosity (and constant Morton number) typical of bio-fluids. The flow field, gas-liquid interface and concentration field were determined simultaneously by coupling the VOF methodology with the species mass balance equation and setting a constant solute concentration at the bubble surface. The mass transfer behavior on the different hydrodynamic regions (nose, film and tail) was inspected and quantified based on local coefficients. It was possible to verify that these values increase along the nose and reach a maximum at the fully developed film region, where it tends to stabilize regardless of the bubble length (for bubble lengths between 2D and 9D). An opposite tendency was found along the bubble tail, where a decrease was verified on the local mass transfer coefficient values. Average mass transfer coefficients based on the simulation data were also determined. The comparison of these results with theoretical predictions allowed to infer that the film theory is the most adequate to describe the gas-liquid mass transfer between a Taylor bubble and the surrounding liquid.
       
  • Comparison of heterogeneous azeotropic and pressure-swing distillations
           for separating the diisopropylether/isopropanol/water mixtures
    • Abstract: Publication date: Available online 31 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Chao Guang, Xiaojing Shi, Zhishan Zhang, Chao Wang, Chen Wang, Jun Gao Isopropanol and diisopropylether are the two important organic solvents in the chemical industry. The diisopropylether/isopropanol/water mixtures contain multiple homogenous and heterogeneous minimum-boiling azeotropes being sensitive to the pressure. In the present study, three separation alternatives, including a new heterogeneous azeotropic distillation (HAD) and two conventional pressure-swing distillations (PSD), are designed conceptually on the ternary diagram of this mixture. And then their optimal design parameters are obtained via the sequential iterative search procedure based on the minimum total annual cost. Furthermore, several partial or full heat integration schemes of the optimal configuration are constructed and explored by using the temperature-enthalpy diagram. The result shows that the most competitive heat-integrated PSD configuration compared to the HAD can save 19.47% and 16.14% in the energy consumption and TAC, respectively.
       
  • CO2 capture and adsorption kinetic study of amine-modified
           MIL-101 (Cr)
    • Abstract: Publication date: Available online 30 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Suresh Mutyala, Madhavi Jonnalagadda, Harisekhar Mitta, Raveendra Gundeboyina MIL-101 (Cr) was synthesized by a hydrothermal method and used as support to prepare a series of polyethylenimine (PEI) incorporated MIL-101 (Cr) by wet impregnation method. All characterization results revealed that the structure of MIL-101 (Cr) was well-maintained by the incorporation of polyethylenimine and confirmed the presence of PEI within MIL-101 (Cr). The CO2 adsorption studies were carried out in a fixed bed reactor from 30 to 90 °C, 1 bar. The adsorption of CO2 has been increased by the incorporation of PEI. It was due to the chemical interaction between the –NH2 and CO2 groups to form a carbamate. The high CO2 adsorption capacity 3.81 mmol g−1 was shown by 70 wt% PEI loaded MIL-101 (Cr) at 75 °C, 1 bar, because of more number of –NH2 groups and a high number of CO2 molecules diffusion. Its adsorption capacity was 4.7 times higher than the adsorption capacity of MIL-101 (Cr) (0.80 mmol g−1). Moreover, in moisture condition, CO2 adsorption capacity was increased to 4.4 mmol g−1 by the formation of ammonium bicarbonate and showed good adsorption stability throughout each adsorption-desorption cycle. The Avrami adsorption kinetic model was well fitted with experimental breakthrough CO2 adsorption data of MIL-101 (Cr)-PEI-70. It suggested that the adsorption of CO2 on PEI incorporated material was chemical adsorption.
       
  • Efficient Hybrid Modeling of CO2 Absorption in Aqueous Solution of
           Piperazine: Applications to Energy and Environment
    • Abstract: Publication date: Available online 29 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Amir Dashti, Mojtaba Raji, Amir Razmi, Nima Rezaei, Sohrab Zendehboudi, Morteza AsghariABSTRACTCarbon dioxide (CO2) considerably contributes to the greenhouse effects and consequently, global warming. Thus, reduction of its emissions/concentration in the atmosphere is an important goal for various industrial and environmental sectors. In this research work, we study CO2 capture by its absorption in mixtures of water and Piperazine (PZ). Experimental techniques to obtain the equilibrium data are usually costly and time consuming. Thermodynamic modeling by Equations of State (EOSs) and connectionist tools leads to more reliable and accurate results, compared to the empirical models and analytical modeling strategies. This research work utilizes Genetic Programming (GP) and Genetic Algorithm-Adaptive Neuro Fuzzy Inference System (GA-ANFIS) to estimate the solubility of CO2 in mixtures of water and Piperazine (PZ). In both methods, the input parameters are temperature, partial pressure of CO2, and concentration of PZ in the solution. A total number of 390 data points is collected from the literature and used to develop GP and GA-ANFIS models. Assessing the models by the statistical methods, both models are found to acceptably predict the CO2 solubility in water/PZ mixtures. However, the GP exhibits a superior performance, compared to GA-ANFIS; the Average Absolute Relative Error (AARD) are 5.3213% and 9.7143% for the GP and GA-ANFIS models, respectively. Such reliable predictive tools can assist engineers and researchers to effectively determine the key thermodynamic properties (e.g., solubility, vapor pressure, and compressibility factor) which are central in design and operation of the carbon capture processes in a variety of chemical plants such as power plants and refineries.
       
  • Mixing of highly concentrated slurries of large particles: Applications of
           electrical resistance tomography (ERT) and response surface methodology
           (RSM)
    • Abstract: Publication date: Available online 29 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Argang Kazemzadeh, Farhad Ein-Mozaffari, Ali Lohi Industrial applications of solid-liquid mixing generally comprise of high solids loadings with a wide range of large particles. Since the required power for the mixing of highly concentrated slurries is extremely high, it is critical to accurately assess the just-suspended impeller speed, power number as well as the degree of homogeneity. The major objective of this study was to analyze the suspension of large solid particles in highly concentrated slurries. Design of experiment (Box–Behnken Model) was used for the response surface methodology (RSM) analysis. Electrical resistance tomography (ERT) was employed to measure the extent of homogeneity in a slurry reactor. The effects of different variables such as impeller type (PBT, PF3, and A310 impellers), impeller clearance (from 0.050 to 0.133 m), solids loading (30 ≤ x  wt%≤55), and particle size (753, 2900, and 5000 μm) were investigated on the performance of the solid-liquid mixing operation. The collected data revealed that the average Zwietering solids loading exponent increased from n = 0.13 at low solids concentrations (5 
       
  • A Data-driven Method for Pipeline Scheduling Optimization
    • Abstract: Publication date: Available online 24 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Qi Liao, Haoran Zhang, Tianqi Xia, Quanjun Chen, Zhengbing Li, Yongtu Liang The detailed scheduling of distributing products through pipelines is one of the most essential tasks in the management of multiproduct pipelines. The current methods of scheduling optimization are still limited by the dilemma between optimality and efficiency, especially when dealing with real-world scheduling issues. This paper introduces a two-stage mathematical model based on the event sequence, whose model scale greatly decreases after stripping the terms of event sequence. Then, a data-driven method is presented to learn a large number of existing scheduling data and accelerate the calculation of first-stage model. The method is decomposed into three parts: (1) take cold start to generate a good deal of basic training data; (2) train the neural network for the fast solution of first-stage model; (3) take real-world cases to improve the self-learning of neural network. A multiproduct pipeline in China is taken as the example to prove the practicability and superiority of the proposed method. The experimental results show that the proposed method could decrease the computation time from about several hours to several minutes.
       
  • CFD Model of Fluid Flow and Particle Deposition during Cryogenic
           Condensation
    • Abstract: Publication date: Available online 22 January 2019Source: Chemical Engineering Research and DesignAuthor(s): James R. Hendry, Jonathan G.M. Lee, Michael J. Battrum Cryogenic condensation is an attractive option for controlling VOC emissions. Cryogenic condensation can offer lower operational costs than conventional abatement technologies like thermal oxidation and adsorption. At the low temperatures (ca. −100 °C) used in cryogenic condensation, many high melting point VOCs will freeze or desublimate. A fine particulate solid could form under the temperature gradients inside the condenser, becoming entrained in the gas phase on exit. This paper reports results in modelling the process using CFD. In this paper we present an inert DPM model in 3D and a dynamic DPM model in 2D to investigate this problem through CFD.The 3D results demonstrate particles must grow beyond a certain size to prevent entrainment in the outlet gas flow. These sizes are: 12 μm at 150 Nm³/hr (Stk99% = 0.18 at Redh = 4600); 16 μm at 100 Nm³/hr (Stk99% = 0.22 at Redh = 3000); 23 μm at 50 Nm³/hr (Stk99% = 0.23 at Redh = 1500). The 2D results demonstrate a DPM model (Eulerian-Lagrangian model) of nucleation and growth of particles during cryogenic condensation.
       
  • Generalizing the effects of the baffling structures on the
           buoyancy-induced turbulence in secondary settling tanks with eleven
           different geometries using CFD models
    • Abstract: Publication date: Available online 22 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Haiwen Gao, M.K. Stenstrom Computational fluid dynamics (CFD) models are applied to understand the effects of baffling structures on the buoyancy-induced turbulence flow in secondary settling tanks (SSTs). Eleven SST geometries, including four circular SSTs and seven rectangular SSTs, are evaluated in this study. The main research tool is a Fluent-based two-dimensional SST model. The model is verified with observations from literature. The validated model is then applied to compare the predictions of the effluent suspended solids (ESS) by the buoyancy-decoupled and buoyancy-coupled turbulence models on each SST geometry. Next, the effects of the SST baffling structures on the turbulence properties are compared and quantified. Additionally, stress tests are simulated on the SSTs, to predict their performances using both the buoyancy-decoupled and buoyancy-coupled turbulence models.The results for the original flow conditions show that the effects of the SST baffling structures on the buoyancy-induced turbulence can be divided into three zones: Zones A, where the baffling structures have negligible damping effects, and only the buoyancy-coupled turbulence model provides accurate predictions; Zone B, where the baffling structures partially dissipate the effect of buoyancy on turbulence, and the buoyancy-coupled model continues to provide accurate predictions but the buoyancy-decoupled turbulence model only provides qualitative but similar predictions; and Zone C, where the baffling structures fully dissipate the effect of buoyancy on turbulence, and both models provide similar, accurate predictions. Two indicators, the densimetric Froude number and the differences in turbulent kinetic energy can be used to predict the need for buoyancy coupling.Graphical abstractGraphical abstract for this article
       
  • Techno-economic analysis of water precipitation for lignin value prior to
           pulping
    • Abstract: Publication date: March 2019Source: Chemical Engineering Research and Design, Volume 143Author(s): Natasha J. Chrisandina, Thomas T. Kwok, Andreas S. Bommarius, Matthew J. Realff Lignocellulosic biorefinery strategies are evolving to include recovering value from lignin as well as the sugar components. Dissolving the lignin in a solvent to separate it from the cellulose fraction is a popular strategy. Lignin solvation techniques must be paired with complementary lignin and solvent recovery strategies. Water precipitation to decrease the solvent concentration is a popular method of laboratory-scale lignin precipitation, but it requires solvent concentrations of 3–10% v/v. High lignin precipitation yields must be tempered by the economic challenges of recovering the dilute solvent in an industrial process. Herein we describe several solvent recovery strategies and their implementation for lignin value prior to pulping (LVPP) with water precipitation. We model the use of distillation, multi-effect evaporation, and reverse osmosis (RO) to concentrate and recover solvent. Two different solvents, low and high boiling, above and below water, (b.p. 120 °C), are concentrated from dilute to pretreatment solutions of 70% v/v and 90% v/v. We show that the annual costs of solvent recovery after water precipitation, given current industrial separation techniques, would be prohibitive for lignin commercialization due to a required lignin selling price of a few times its fuel value.Graphical abstractGraphical abstract for this article
       
  • Comparison of capacity expansion strategies for chemical production plants
    • Abstract: Publication date: Available online 28 December 2018Source: Chemical Engineering Research and DesignAuthor(s): Heiko Radatz, Kevin Kühne, Christian Bramsiepe, Gerhard Schembecker Changing market conditions and production requirements in chemical and biochemical industry force engineers to depart from conventional plant design. Adaptability to the market demand, a reduced investment risk and a shorter time-to-market are gaining importance besides technical excellence.A reduced investment risk and an increased adaptability can be achieved by designing smaller plants and use step-wise capacity expansions. The use of modules offers the possibility to reduce the time-to-market.This work introduces an approach to determine the best expansion strategies for modular equipment-wise capacity expansions and compares its results to line-wise capacity expansion strategies and to a conventionally designed plant for a given market demand development using a detailed process simulation. In a case study, the modular equipment-wise expansion strategy offers a 30 % lower initial investment risk while increasing the absolute profit up to 40 %, although the overall investment increased up to 40 % compared to the conventional design. Additionally, an approach to design reactor modules with a larger operating window is proposed and compared in light of an equipment-wise capacity expansion strategy. Two final key statements to exploit the full potential of an equipment-wise capacity expansion are: (a) The determination of operating windows based on process-technological and mechanical operating constraints is a necessity and (b) Equipment modules need to be designed for a large operating window to offer a capacity expansion by numbering-up without a gap in the operating window.Graphical abstractGraphical abstract for this article
       
  • Particle technology as a uniform discipline' Towards a holistic
           approach to particles, their creation, characterisation, handling and
           processing!
    • Abstract: Publication date: Available online 29 November 2018Source: Chemical Engineering Research and DesignAuthor(s): Martin Morgeneyer, Alvaro Ramirez, Massimo Poletto, Steve W. Smith, Richard Tweedie, Jerry Heng, Sebastian Maass, Christophe Bressot "Can particle technology, in spite of its multiplicity, be regarded, and scientifically taught, as a uniform discipline'" wondered H. Rumpf, one of the founding fathers of particle science, in a programmatic speech which he gave 40 years ago. Given his passion for particle science, he of course answered his question with "yes". Now, 40 years later, working parties of the European Federation of Chemical Engineering, all working on particle technology, managed to organize their second joint event called 'International Conference on Processing, Handling and Characterization of Particulate Materials - PARMAT', in the framework of which this issue of CHERD was edited.
       
  • Robust Stability Analysis for Barrier-Based Equation-free Multi-linear
           Model Predictive Control
    • Abstract: Publication date: Available online 16 November 2018Source: Chemical Engineering Research and DesignAuthor(s): Panagiotis Petsagkourakis, William P. Heath, Constantinos Theodoropoulos On-line optimization strategies such as model predictive control (MPC) have been widely used to compute control actions for a range of complex industrial systems. Barrier based MPC has recently been introduced, bringing together theory and algorithms for analysing the stability of linear models, however such models may not describe complex systems dynamics adequately. Multi-model linear MPC configurations can be used as a more reliable solution as piecewise affine (PWA) models can describe the underlying nonlinear dynamics more accurately. Additionally, model order reduction can be applied to large-scale distributed systems, to reduce their dimensionality, jeopardising however their closed-loop stability. As a result, there is a clear need for an input to output stability analysis for closed loop systems under unstructured uncertainty when multi-model barrier MPC is utilized. In this work, we combine equation-free model reduction with integral quadratic constraints (IQCs) for the stability analysis of large-scale closed-loop systems under unstructured uncertainties, including model approximation errors and nonlinearities, including MPC. An illustrative example is used to elucidate the proposed methodology.
       
  • Improvement of product distribution through enhanced mass transfer in
           isobutane/butene alkylation
    • Abstract: Publication date: Available online 17 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Yu Zhao, Tao Li, Xiangzhan Meng, Hongyan Wang, Yongqiang Zhang, Hui Wang, Suojiang Zhang The isobutane/butene alkylation catalyzed by H2SO4 is a liquid/liquid reaction, and the limited solubility of the hydrocarbon in the catalyst inhibits mass transfer, leading to occurrence of side reactions. Amphiphilic surfactant could enhance mass transfer in multiphasic systems. In this study, a series of quaternary ammonium and phosphonium surfactants were used as the additive to enhance the catalytic performance of H2SO4 for isobutane/butene alkylation. Ammonium surfactants showed much better activity to improve product distribution than the phosphonium one. The enhanced product distribution and alkylate quality were attributed to the well dispersion of the hydrocarbon in the acid and increased hydrocarbon solubility in the catalytic system, i.e., enhanced mass transfer in the reaction system. The reaction parameters were optimized, and under these conditions, weight percentage of C8 in the product was 87.5%, and research octane number (RON) of the alkylate could reach 97.8. Lifetime of the surfactant/H2SO4 system was 130 times compared with 51 times for the system with no additive due to inhibition of the formation of acid soluble oil (i.e., products of side reactions). This proposed catalytic system with the ammonium surfactant as the additive is promising to be employed in industrial C4 alkylation process.Graphical abstractGraphical abstract for this article
       
  • Characterization of a centrifugal partition chromatographic column with
           spherical cell design
    • Abstract: Publication date: Available online 16 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Simon Roehrer, Mirjana Minceva A new centrifugal partition chromatography (CPC) column with spherical cells, insignificant duct (channel) volume, and without PTFE plates between the disks was evaluated. Due to the reduced duct volume, almost the entire column volume is available for the separation. This allows operation at higher pressure drop and thus increased rotational speed and flow rates. The new column was characterized in terms of stationary phase retention, column efficiency and resolution as a function of flow rate and rotational speed. The separation performance was compared to that of two conventional twin-cell CPC columns of the same total volume. The new column leads to an increased productivity especially at higher flow rates and outperforms columns with smaller cells in terms of higher separation factors and reduced purity or recovery requirements.Graphical abstractGraphical abstract for this article
       
  • Volumetric Mass Transfer Coefficient for Carbon Monoxide in a Dual
           Impeller Stirred Tank Reactor Considering a Perfluorocarbon-water Mixture
           as Liquid Phase
    • Abstract: Publication date: Available online 15 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Fabiana M.B. Coelho, Alanna M. Botelho, Otávio F. Ivo, Priscilla F.F. Amaral, Tatiana F. Ferreira Overall volumetric mass transfer coefficient (kLa) of carbon monoxide in a perfluorocarbon-distilled water mixture was evaluated in a dual impeller stirred tank bioreactor (Rushton-type and Smith-type). Two agitation speeds (300 and 500 rpm), three specific gas flow rates (2.0, 2.5 and 2.7 vvm), two working volumes (0.75 and 1 L) were tested, as well as four different liquid phase compositions: pure distilled water; distilled water and perfluorodecalin (PFC); distilled water and Tween® 80; and distilled water, PFC and Tween® 80. CO concentration in liquid phase was determined using a myoglobin bioassay technique and kLa and saturated CO concentration were determined using Maximum Likelihood Estimation (MLE) with a hybrid optimization strategy. A maximum kLa of 603.48 h-1 was obtained at 500 rpm, 2.7 vvm and distilled water, PFC and Tween® 80 as liquid phase. Tween® 80 was responsible for increasing mass transfer when mixing these three components comparing to a liquid phase composed of PFC and distilled water (7 time increase at 2.7 vvm and 500 rpm), and pure distilled water (2.9 time increase at 2.0 vvm and 1.6 times at 2.5 vvm). Moreover, MLE proved to be a valuable tool to critically analyse experimental uncertainty in parameter estimation.
       
  • Sand minimum transport conditions in gas-solid-liquid three-phase
           stratified flow in a horizontal pipe at low particle concentrations
    • Abstract: Publication date: Available online 15 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Olawale T. Fajemidupe, Aliyu M. Aliyu, Yahaya D. Baba, Archibong Archibong-Eso, Hoi Yeung Sand production in the life of oil and gas reservoirs is inevitable, as it is co-produced with oil and gas from reservoirs. Its deposition in petroleum pipelines poses considerable risk to production and can lead to pipe corrosion and flow assurance challenges. Therefore, it is important that pipe flow conditions are maintained to ensure sand particles are not deposited but in continuous motion with the flow. The combination of minimum gas and liquid velocities that ensure continuous sand motion is known as the minimum transport condition (MTC). This study investigates the effect both of sand particle diameter and concentration on MTC in gas/liquid stratified flow in a horizontal pipeline. We used non-intrusive conductivity sensors for sand detection. These sensors, used for film thickness measurement in gas/liquid flows, was used here for sand detection. We found that MTC increases with increase in particle diameter for the same concentration and also increases as the concentration increases for the same particle diameter. A correlation is proposed for the prediction of sand transport at MTC in air–water flows in horizontal pipes, by including the effect of sand concentration in Thomas’s lower model. The correlation accounts for low sand concentrations and gave excellent predictions when compared with the experimental results at MTC.
       
  • Pros and cons of implementing new hybrid amine solution for simultaneous
           removal of mercaptan and acid gas
    • Abstract: Publication date: Available online 15 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Ali Rostami, Yadollah Tavan The hybrid solution is industrially and theoretically investigated to achieve simultaneous removal of acid gas and mercaptan. Firstly, the proposed model is validated against industrial data with low relative error of 6 % then, the effect of addition of sulfolane and piperazine on the performance of gas sweetening unit and sulfur recovery unit as downstream unit is explored. Finally, foam formation of sulfolane is tested in the foam generator device and some hints are provided to implement this formulated solvent into more industrial plants.Graphical abstractGraphical abstract for this article
       
  • -Performance Modelling of Seawater Electrolysis in an Undivided Cell:
           Effects of Current Density and Seawater Salinity
    • Abstract: Publication date: Available online 14 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Shaolong Yang, Zhuo Wang, Zhitao Han, Xinxiang Pan Seawater electrolysis has attracted much attention in marine and offshore industries over the past few years. However, there is still not much information available to guide the design of undivided cells, especially around the energy consumption performance. In this study, four theoretical models of the seawater electrolysis in an undivided cell were developed based on physical and chemical principles. Experiments using both artificial seawater and natural seawater were conducted to obtain model parameters and verify the accuracies of these models, respectively. The total residual oxidant (TRO) concentration and cell voltage increased as the current density increased, while the current efficiency was independent of current densities at seawater salinity of 30.0 psu. The seawater salinity had significant impacts on cell performance, especially in the range of 4.0–15.8 psu. When the seawater salinity increased, the TRO concentration and current efficiency increased accordingly, while the cell voltage decreased. These phenomena were closely related to the kinetics of electrode reactions, and conductivity of the electrolyte. Additionally, prediction values of theoretical models suggested that on-site generation of relatively low concentrations of TRO from concentrated seawater discharging from desalination facilities would reduce the overall energy consumption, as well as eliminate the environmental footprints, particularly for marine and offshore applications.Graphical abstractGraphical abstract for this article
       
  • Heat transfer phenomena of glassy carbon foams
    • Abstract: Publication date: Available online 14 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Anna Gancarczyk, Wojciech Macek, Andrzej Kołodziej The aim of the study was to determine and describe the relationship between the morphological parameters of glassy carbon foams and their transport characteristics. The study was carried out on reticulated vitreous carbon (RVC) foams of different pore density. Based solely on foam morphology, using the theoretical models for laminar flow, the heat transfer properties were determined with satisfactory accuracy.Graphical abstractGraphical abstract for this article
       
  • Boosting visible light photocatalytic activity via impregnation-induced
           RhB-sensitized MIL-125(Ti)
    • Abstract: Publication date: Available online 14 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Xue Han, Xiaobin Yang, Guangbo Liu, Zhonghua Li, Lu Shao The visible light driven pollutant degradation by photocatalysis is one of the most effective and environmentally friendly strategies, which urgently requires the highly efficient catalysis. In this study, the RhB-sensitized MIL-125(Ti) photocatalyst (RhB/MIL-125) was obtained by post-impregnation strategy in dark, owing to its remarkable adsorption and structure properties of MIL-125(Ti). The nanostructure, morphology and optical properties of as-prepared RhB/MIL-125 catalyst were characterized by various physicochemical methods in detail. It was found that the RhB was successfully incorporated into the MIL-125(Ti) matrix. Excitingly, the obtained RhB-sensitized MIL-125(Ti) showed a boosted photocatalytic performance with the removal rate of MO beyond 90% in 60 minutes under visible light (λ > 420 nm) and exhibited the well stability during recycle tests. The hole (h+) and superoxide free radical (O2−) were the key reactive species during the photodegradation process and the possible photocatalytic mechanism of RhB/MIL-125 for MO degradation was proposed. Our new photocatalyst can inspire the in-depth understanding in the visible light driven process and accelerate the nanoporous materials for real-life energy and environmental applications.Graphical abstractGraphical abstract for this article
       
  • Chemical and Structural Characterization of Problematic Suspended
           Particles Enriched from Fluidized Catalytic Cracking Slurry Oil
    • Abstract: Publication date: Available online 11 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Kun Chen, Di Zhang, Yang Dai, He Liu, Zongxian Wang, Ummul-Khairi Ibrahim, Aijun Guo Suspended particles (SPs) were separated from an FCC Slurry Oil (SLO) via centrifugation with the aid of toluene-dilution. Further solvent extraction of SPs with CS2/toluene (50 V/V%) mixed solvent would generate solvent extraction insolubles (SEINS) and solubles (SES). They were sent for a series of chemical and structural characterizations, respectively, in the hope of providing clues to address issues from sedimentation and clarification processes. It was found that SPs were composed of catalyst fragments and organic substances wrapped around them, serving as a shield. The characterizations from TEM and XPS strongly suggested that the outer surface of SEINS was sufficient in oxygen-containing sites (organic functional groups and aluminosilicate), while the outer surface of SPs was not. High oxygen content and almost same nitrogen content of SES, comparable with that of asphaltenes, were detected through XPS characterization. This rationalized the strong adsorption of SES on SEINS in the form of a tedious solvent extraction process. A new structure of SPs has thus been described on the basis of these characterizations. Design sedimentation experiments verified the SPs’ structure. Furthermore, the experiments offered a promising way for acquiring high clarification efficiency with rather low usage of sinking agent through solvent pretreatment.Graphical Graphical abstract for this article
       
  • Nitric oxide removal from flue gas using dielectric barrier discharge
           coupled with negative pulse corona
    • Abstract: Publication date: Available online 11 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Lan Yang, Ke Lian, Xiang Zhang, Yanrong Li, Charles Q. Jia, Binran Zhao, Xiaoxun Ma To optimize the efficiency of nitric oxide (NO) removal, a new catalyst-free method at room temperature was developed by combining dielectric barrier discharge (DBD) and negative pulse corona (NPC). With this method, the effects of applied current, initial NO concentration, gas flow rate, O2 concentration, methanol addition, and the selection of applied current and gas flow rate on NO removal were investigated respectively. Results showed that increasing current not only promoted the NO removal but also reduced NO2 and N2O formation. The NO removal efficiency had a negative dependence on initial NO concentration and gas flow rate. A negative effect of O2 on NO removal was observed, and it also promoted the formation of NO2. However, adding methanol was able to mitigate the negative effects and eliminate NO2 exhaust. The addition of 0.5 vol% methanol raised NO removal efficiency from 30.9% to 98.6% under the condition of 1.67 A, 500 ppm NO, 0.625 L/min with 8 vol% O2 in the flue gas. The reaction path of NO removal process was strongly altered as methanol added into DBD-NPC processing. NOX (NO, NO2) can be reduced to N2 with CH3OH as a reductant. A simple combined denitration method (DBD-NPC) without the assistance of selective catalytic reduction (SCR), additional heating and pressure was developed and evaluated, which may provide potential applications for denitration industry.
       
  • Gas-solid hydrodynamics of an iG-CLC system with a two-stage counter-flow
           moving bed air reactor
    • Abstract: Publication date: Available online 11 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Yali Shao, Xiaojia Wang, Baosheng Jin, Zhiwei Kong, Xudong Wang, Yong ZhangABSTRACTA cold state iG-CLC system was built consisting mainly of a two-stage counter-flow moving bed air reactor (AR), a circulating fluidized bed riser fuel reactor (FR), a separator, a loop seal and a downcomer. Experiments were carried out to study the operation performance in terms of solid circulation, pressure fluctuations and gas-solid flow characteristics under different operating parameters in the whole system. Results show that two-stage AR operation did not affect quasi-stable solid circulation, and there was almost no gas leakage between the FR and AR under the solid circulation rate of 50 kg/m2s condition, indicating independent operation of the two reactors. The FR pressure drop per unit length Δp/Δz in the upper part of the FR was smaller than that in the lower part. Due to higher solid concentration, Δp/Δz increased with a decreasing FR fluidizing number, or an increasing solid circulation rate and initial solid bed height. The particle cluster movements in the FR were the main cause of pressure fluctuations, and periodical pressure peaks occurred when the FR superficial gas velocity was too low. The pressure drop ratios between the downcomer and FR decreased with a decreasing FR superficial gas velocity, or an increasing solid circulation rate and initial solid inventory. The moving bed state and fast fluidization state were achieved in the downcomer and CFB riser, respectively.Graphical abstractGraphical abstract for this article
       
  • Effectiveness of novel xerogels adsorbents for cadmium uptake from aqueous
           solution in batch and column modes: Synthesis, characterization,
           equilibrium, and mechanism analysis
    • Abstract: Publication date: Available online 11 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Yasser Hannachi, Afifa Hafidh, Salwa Ayed In the present study, new organic-inorganic mesoporous materials are prepared. The FTIR, SEM, 29Si CP MAS NMR and nitrogen adsorption-desorption experiments are utilized to portray the novel xerogels. Application for the cadmium (II) uptake from aqueous solution using the as- synthesized hybrid materials as adsorbent is explored. Operating parameters influencing the adsorption procedure, for instance, solution pH, contact time and temperature are contemplated. The adsorption kinetic analysis abides by pseudo-second-order model and the intra-particle diffusion model display that the rate- controlled step is directed by film-diffusion before all else and afterward is taken by intra-particle diffusion. Langmuir, Freundlich and Dubinin–Radushkevich (D–R) models are assigned to portray the adsorption isotherms. Experimental data seem to be adequate with Langmuir model showing high monolayer adsorption capacities of Cd (II) onto both novel adsorbents (507- 493 mg. g-1). Mean free energy values assessed from D–R isotherm prescribe that cadmium sequestration by the two hybrid materials eventuated by chemisorption. Besides, the dynamic process exposed relatively high breakthrough capacity for both xerogels and the column data are well validated by Thomas model. Computed thermodynamic parameters depict that the adsorption of Cd(II) ions onto the two adsorbents is favorable and exothermic in nature. FTIR and XPS analysis, uncover that the fundamental mechanism of the cadmium removal is the chelation of metal ions with the ligating nitrogen atoms (N) of amino functionalized xerogel (M1). Though, onto sulfhydryl-functionalized xerogel (M2) it is presumably through the ion-exchange reaction between Cd2+ ions and (-SH) groups. The desorption investigation show that the synthesized hybrid materials possess a remarkable reusability. Prior tests produced on electroplating effluents reveal that the as-prepared xerogel could be strongly used for the cadmium uptake from real wastewater.Graphical abstractGraphical abstract for this article
       
  • Adsorption and desorption behaviour of toluene on activated carbon in a
           high gravity rotating bed
    • Abstract: Publication date: Available online 11 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Qiang Guo, Youzhi Liu, Guisheng Qi, Weizhou Jiao Rotating bed enables a fast transfer rate, which can promote the adsorption and desorption rates of processes. In this work, a rotating bed was used to adsorb toluene gas with activated carbon (AC) as the adsorbent. The influence of the operating parameters of a high gravity factor, gas flow, inlet concentration and bed thickness on adsorption rate were investigated, as were the influence of carrier gas temperature and rotational high gravity factor on desorption rate. The surface coverage and desorption rate of toluene from AC were determined to demonstrate the excellent performance of the rotating bed. In addition, the adsorption-desorption effect of the rotating bed was compared with the results of a fixed bed. The results showed that a rotating bed effectively increased the adsorption rate of toluene on AC and the desorption efficiency of AC compared with a fixed bed. AC in a rotating bed provided more effective adsorption sites, thereby improving the utilisation of AC; also, a desorption model showed that the rotating bed had a higher desorption rate and greatly reduced desorption time. In addition, AC in a rotating bed still exhibited excellent adsorption capacity after many adsorption-desorption cycles. Therefore, rotating bed can enable higher adsorption and desorption rates and effectively improve the utilisation of AC, providing an economical and environmentally friendly method.
       
  • Handling Bounded and Unbounded Unsafe Sets in Control
           Lyapunov-BarrierFunction-Based Model Predictive Control of Nonlinear
           Processes
    • Abstract: Publication date: Available online 10 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Zhe Wu, Panagiotis D. Christofides Control Lyapunov-Barrier function (CLBF) has been used to design controllers for nonlinear systems subject to input constraints to ensure closed-loop stability and process operational safety simultaneously. In this work, we developed Control Lyapunov-Barrier functions for two types of unsafe regions (i.e., bounded and unbounded sets) to solve the problem of stabilization of nonlinear systems with guaranteed process operational safety. Specifically, in the presence of a bounded unsafe region embedded within the closed-loop system stability region, the CLBF-MPC is developed by incorporating CLBF-based constraints and discontinuous control actions at potential stationary points (except the origin) to guarantee the convergence to the origin (i.e., closed-loop stability) and the avoidance of unsafe region (i.e., process operational safety). In the case of unbounded unsafe sets, closed-loop stability with safety is readily guaranteed under the CLBF-MPC since the origin is the unique stationary point in state-space. The application of the proposed CLBF-MPC method is demonstrated through a chemical process example with a bounded and an unbounded unsafe region, respectively.
       
  • A Mixed Integer Nonlinear Programming Approach for Petroleum Refinery
           Topology Optimisation
    • Abstract: Publication date: Available online 8 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Tareq A. Albahri, Cheng Seong Khor, Mohamed Elsholkami, Ali Elkamel This work presents a mixed integer nonlinear programming (MINLP)-based superstructure optimisation approach to synthesize an optimal petroleum refinery topology or configuration for large-scale grassroots refinery systems. We develop a superstructure to include many possible prospective configurations and formulate rigorous models for the 32 commercial refinery processes that constitute the configurations, which gives rise to a convex MINLP model. The objective function is to maximize the total refinery profit for a given crude oil feed subject to material and energy balance constraints. We apply a two-level optimisation procedure: a master module to construct configurations from the superstructure and a submodule to optimize the process unit conversions and product temperatures of the configurations. A numerical example based on an actual operating refinery in Kuwait is illustrated to implement the approach with a resulting configuration that agrees with real-world practices.
       
  • A Novel Strategy to Determine Titration-Based Asphaltene Precipitation in
           Various Viscosity Oil Systems: Laboratory and Modelling Investigations
    • Abstract: Publication date: Available online 2 January 2019Source: Chemical Engineering Research and DesignAuthor(s): Javad Sayyad Amin, Somayye Nikkhah, Sohrab Zendehboudi, Omid Mohammadzadeh, Ioannis Chatzis Asphaltenes are heavy fractions of petroleum mixtures, which precipitate out of homogenous bulk fluid phase due to changes in pressure, temperature, and composition. Asphaltene precipitation and subsequent deposition in porous media can adversely affect Enhanced Oil Recovery (EOR) processes as well as impede surface transportation of crude oil. It is therefore beneficial to develop accurate techniques for determination of asphaltene precipitation as well as reliable predictive modeling approaches to remedy potential production impairments. In this study, a laboratory work is performed using three different oil samples (light, medium-viscosity, and heavy crude oil) to measure the mass of precipitated asphaltenes in a series of titration experiments. The effects of various parameters such as precipitant type, pressure, dilution ratio, API gravity of oil, and resin-to-asphaltene ratio of crude oil on the amount of precipitated asphaltenes are studied. A deterministic tool, so-called Response Surface Methodology (RSM), is then proposed to estimate the mass of asphaltenes precipitated from these three oil types in a titration process as a function of selected input parameters through a systematic parametric sensitivity analysis. Analysis of Variance of (ANOVA) technique is also employed to assess the validity of the proposed predictive methodology. Among all the contributing parameters, pressure and dilution ratio are found to be the most influencing factors when predicting the mass of precipitated asphaltenes. The developed simple predictive tool appears to be an effective methodology to estimate mass of precipitated asphaltenes over a wide range of input parameters for various oil types.Graphical abstractGraphical abstract for this article
       
 
 
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