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  Subjects -> CHEMISTRY (Total: 881 journals)
    - ANALYTICAL CHEMISTRY (54 journals)
    - CHEMISTRY (616 journals)
    - CRYSTALLOGRAPHY (21 journals)
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    - INORGANIC CHEMISTRY (43 journals)
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    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (616 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: 27)
ACS Catalysis     Hybrid Journal   (Followers: 44)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 22)
ACS Combinatorial Science     Hybrid Journal   (Followers: 23)
ACS Macro Letters     Hybrid Journal   (Followers: 26)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 41)
ACS Nano     Hybrid Journal   (Followers: 290)
ACS Photonics     Hybrid Journal   (Followers: 14)
ACS Symposium Series     Full-text available via subscription  
ACS Synthetic Biology     Hybrid Journal   (Followers: 24)
Acta Chemica Iasi     Open Access   (Followers: 5)
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chimica Slovenica     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 8)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 9)
Adsorption Science & Technology     Open Access   (Followers: 6)
Advanced Functional Materials     Hybrid Journal   (Followers: 59)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 68)
Advances in Chemical Science     Open Access   (Followers: 18)
Advances in Chemistry     Open Access   (Followers: 22)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 19)
Advances in Drug Research     Full-text available via subscription   (Followers: 24)
Advances in Environmental Chemistry     Open Access   (Followers: 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: 25)
Advances in Nanoparticles     Open Access   (Followers: 15)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 17)
Advances in Polymer Science     Hybrid Journal   (Followers: 44)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Science and Technology     Full-text available via subscription   (Followers: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 3)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 8)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 66)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 21)
American Journal of Chemistry     Open Access   (Followers: 31)
American Journal of Plant Physiology     Open Access   (Followers: 11)
American Mineralogist     Hybrid Journal   (Followers: 15)
Analyst     Full-text available via subscription   (Followers: 38)
Angewandte Chemie     Hybrid Journal   (Followers: 169)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 253)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 5)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 9)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 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: 24)
Applied Surface Science     Hybrid Journal   (Followers: 32)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 2)
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Hybrid Journal   (Followers: 364)
Biochemistry Insights     Open Access   (Followers: 6)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 10)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 2)
Biomacromolecules     Hybrid Journal   (Followers: 22)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 7)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 133)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 87)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 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: 10)
Canadian Mineralogist     Full-text available via subscription   (Followers: 6)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 70)
Catalysis for Sustainable Energy     Open Access   (Followers: 8)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 7)
Catalysis Science and Technology     Free   (Followers: 8)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 10)
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 22)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 74)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 26)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 22)
Chemical Reviews     Hybrid Journal   (Followers: 194)
Chemical Science     Open Access   (Followers: 26)
Chemical Technology     Open Access   (Followers: 28)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 57)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 24)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 32)
Chemistry & Industry     Hybrid Journal   (Followers: 7)
Chemistry - A European Journal     Hybrid Journal   (Followers: 157)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 16)
Chemistry and Materials Research     Open Access   (Followers: 21)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 44)
Chemistry of Materials     Hybrid Journal   (Followers: 262)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 20)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 4)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 12)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 11)
Chromatographia     Hybrid Journal   (Followers: 24)
Chromatography     Open Access   (Followers: 2)
Chromatography Research International     Open Access   (Followers: 6)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Cogent Chemistry     Open Access   (Followers: 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: 6)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 22)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Communications Chemistry     Open Access  
Composite Interfaces     Hybrid Journal   (Followers: 7)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 4)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 6)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 6)
Croatica Chemica Acta     Open Access  
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Chromatography     Hybrid Journal  
Current Green Chemistry     Hybrid Journal   (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: 71)
Current Trends in Biotechnology and Chemical Research     Open Access   (Followers: 3)
Dalton Transactions     Full-text available via subscription   (Followers: 23)
Detection     Open Access   (Followers: 3)
Developments in Geochemistry     Full-text available via subscription   (Followers: 2)
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Dislocations in Solids     Full-text available via subscription  

        1 2 3 4 | Last

Journal Cover
Chemical Engineering Research and Design
Journal Prestige (SJR): 0.847
Citation Impact (citeScore): 3
Number of Followers: 26  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0263-8762 - ISSN (Online) 0263-8762
Published by Elsevier Homepage  [3161 journals]
  • Incorporation of Sustainability in Process Control of Hydraulic Fracturing
           in Unconventional Reservoirs
    • Abstract: Publication date: Available online 17 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Priscille Etoughe, Prashanth Siddhamshetty, Kaiyu Cao, Rajib Mukherjee, Joseph Sang-II KwonAbstractTypically, the term shale oil refers to natural oil trapped in rock of low porosity and ultra-low permeability. What has made the recovery of shale oil and gas economically viable is the extensive use of hydraulic fracturing. Research on the relationship between the distribution of propping agent, called proppant, and shale well performance indicates that uniformity of proppant bank height and suspended proppant concentration across the fracture at the end of pumping determines the productivity of produced wells. However, it is important to note that traditional pumping schedules have not considered the environmental and economic impacts of the post-fracturing process such as treatment and reuse of flowback water from fractured wells. Motivated by this consideration, a control framework is proposed to integrate sustainability considerations of the post-fracturing process into the hydraulic fracturing process. In this regard, a dynamic model is developed to describe the flow rate and the concentration of total dissolved solids (TDS) in flowback water from fractured wells. Thermal membrane distillation is considered for the removal of TDS. An optimization problem is formulated to find the optimal process that consists of hydraulic fracturing, storage, transportation, and water treatment, through minimizing annualized cost and water footprint of the process. The capabilities of the proposed approach are illustrated through the simulation results of different scenarios that are performed to examine effects of water availability on the productivity of stimulated wells. Finally, the environmental impact of flowback water treatment is evaluated using TRACI, a tool for the reduction and assessment of chemical and other environmental impacts.
       
  • Partitioning for Distributed Model Predictive Control of Nonlinear
           Processes
    • Abstract: Publication date: Available online 15 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Rosiane R. Rocha, Luís Cláudio Oliveira-Lopes, Panagiotis D. ChristofidesAbstractA distributed model predictive control (DMPC) strategy brings interesting features of topology, flexibility and maintenance to large-scale nonlinear systems. This work presents contributions in the study of distributed controllers for nonlinear and large-scale systems. Two types of distributed predictive control based on model (DMPC) are proposed: non-cooperative locally linearized DMPC and cooperative locally linearized DMPC. The decomposition is performed based on a local linearized version of the process model by using local matrices representing interactions between controlled outputs, states and inputs. The proposed strategy was successfully evaluated and compared to the centralized control strategy.
       
  • Modelling and simulation of cooling water systems subjected to fouling
    • Abstract: Publication date: Available online 14 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Aline R.C. Souza, André L.H. CostaAbstractThis paper presents the modelling and simulation of cooling water systems, encompassing the cooling tower, the pump, the set of interconnected pipe sections, and the coolers. The model is composed of mass, energy, and mechanical energy balances, also contemplating the influence of the fouling rate in the heat exchangers. The simulation can determine the flow rates and temperatures along the network for each time instant during the investigated time period. The fouling rate evaluation considers its dependence with local temperature and velocity. Consequently, the heat exchanger equations are not represented by analytical solutions, but by differential energy and mechanical energy balances which allow the determination of the fouling rate at each point along the heat exchanger surface (i.e. the fouling thermal resistance and the corresponding deposit thickness are calculated at each point along the thermal surface of each cooler). The utilization of the proposed approach is demonstrated through three examples of cooling water systems. The first example contains one cooler and illustrates that the system behavior is the result of the hydraulic and thermal interactions among its elements (cooling tower, pump, pipe sections, and coolers), which indicates that analysis focusing on isolated elements may compromise the accuracy of the simulation results. The second example explores the inclusion of control loops in the proposed model. The third example is composed of three coolers and analyzes the interactions of multiple exchangers aligned in parallel, which shows that the behavior of each cooler in the network depends on the operation of the other exchangers in the system.
       
  • Facile and Efficient Microwave Combustion Fabrication of Mg-Spinel as
           Support for MgO Nanocatalyst Used in Biodiesel Production from Sunflower
           Oil: Fuel Type Approach
    • Abstract: Publication date: Available online 13 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Sina Yousefi, Mohammad Haghighi, Behgam Rahmani VahidMgAl2O4 spinel was synthesized through microwave-assisted combustion method using three different fuels, including urea, glycine and glycerin. This spinel was then used as a support for MgO/MgAl2O4 nanocatalyst in order to produce biodiesel. Results of XRD, EDX, FTIR, BET, TGA, FESEM and SPSD analyses indicated that heating via microwave irradiation results in the synthesis of a catalyst of far superior characteristics for the biodiesel production reaction. Results of the conducted analyses as well as reactor test results demonstrated that the nanocatalyst synthesized using glycine and microwave irradiation outperformed the other catalysts in terms of physiochemical characteristics and catalytic performance in biodiesel production. Therefore, under moderate conditions (reaction temperature: 90 °C, catalyst concentration: 3 wt.%, reaction time: 3 hours, and alcohol to oil molar ratio: 12), the conversion reached 92.7%. In addition, investigating reusability of the catalysts, the nanocatalyst synthesized using microwave irradiation and glycine outperformed the other catalysts when it came to triglyceride transesterification reaction. The conversion exhibited insignificant changes following six rounds of use. The presented results were indicative of the synthesis of a well favorable catalyst for the process of producing a green and valuable fuel − biodiesel.Graphical abstractIn this paper, MgAl2O4 spinel support was synthesized using combustion method with different fuels (urea, glycine and glycerin) and two heating methods (conventional and microwave). In all samples, as active phase, MgO was deposited on the synthesized samples via impregnation method. In order to evaluate the performance of the synthesized MgO/MgAl2O4 nanocatalysts, transesterification reaction under moderate conditions was used. Results of XRD, EDX, FTIR, BET, TGA, and FESEM analyses indicated that, heating via microwave irradiation results in the synthesis of a catalyst of superior characteristics for the biodiesel production reaction. It should be noted that, the results of reactor test indicated that, conversion of the nanocatalyst, wherein glycine was used as fuel and microwave irradiation was used as the heating method, was measured at 92.7%, and. The mentioned MgO/MgAl2O4 spinel nanocatalyst synthesized through the above-mentioned method exhibited good stability in reusability tests.Graphical abstract for this article
       
  • Flow Pulsation Plays an Important Role for High-Pressure Homogenization in
           Laboratory-Scale
    • Abstract: Publication date: Available online 13 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Andreas HåkanssonAbstractMost experimental and numerical investigations of high-pressure homogenizers assume that the valve is fed with a constant flowrate. However, technical homogenizers use piston pumps with either 3 or 5 pistons (production- and pilot-scale machines) or a single piston (laboratory-scale machines). This results in flow pulsation. It is still unknown to what extent this influences valve hydrodynamics. Moreover, it is unknown if the difference in the number of pistons has implications for scale-up. This study uses a piston pump model and CFD simulations to elaborate on these questions. It is concluded that the constant flow assumption is justifiable for homogenizers using piston pumps with 3 or 5 pistons (pilot- and production-scale), but that homogenizers run with a single piston (i.e. laboratory-scale machines) will obtain a substantially different flow field. Most notably, the jet extending from the single-piston homogenizer gap will become highly unsteady and smaller drop sizes are expected (when keeping all other settings constant). This adds to previous findings suggesting substantial fundamental differences between laboratory- and production-scale homogenizers.
       
  • 3Hydrodynamic Study of an Emulsion Liquid Membrane Containing Carbon
           Nanotube in a Mixer-Settler: Mean Size and Size Distribution of Emulsion
           Globules
    • Abstract: Publication date: Available online 13 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Maliheh Raji, Hossein Abolghasemi, Jaber Safdari, Ali KargariMean size and size distribution of emulsion globules are indicative of interfacial area available for mass transfer in an emulsion liquid membrane (ELM) system. In this study, emulsion globules size of an ELM containing different amounts of multi-walled carbon nanotube (MWCNT) in a horizontal mixer–settler has been measured and analyzed. For this purpose, MWCNTs were dispersed in the membrane phase composed of kerosene as diluent and Span80 as surfactant. The influences of the presence and concentration of MWCNT and also key hydrodynamic parameters such as turbulent energy dissipation per unit mass and emulsion phase volume fraction on globule size have been investigated. According to the results, adding MWCNT in ELM caused 11.42-14.85% decrease in the Sauter mean diameter (D32) of emulsion globules. It was also observed that presence of MWCNT led to increase in the density of small globules and narrower globule size distribution. Also in agreement with these observations, stability results showed that introducing MWCNT to the system led to 62.26% reduction in breakage ratio. Furthermore, a new empirical correlation for prediction of D32 was proposed with an average absolute relative error (AARE) of 3.36%. Finally, the normal and log-normal probability distribution functions were used to predict the globule size distribution and their parameters (α and β) were well predicted by the dimensionless correlations wherein the MWCNT concentration introduced as a new independent parameter.Graphical abstractGraphical abstract for this article
       
  • CFD analysis of flow distributor designs for numbering-up of biodiesel
           synthesis
    • Abstract: Publication date: Available online 12 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Mariana Garcia Mendonça Lopes, Harrson Silva Santana, Vinícius Felix Andolphato, João Lameu Silva, Osvaldir Pereira TarantoMicro-chemical plants increased production by the parallelization of microdevices. The uniform distribution of flow through the microdevices are made by the flow distributor. Inadequate distributor design reduces the micro-chemical plant performance. The present research aims to perform a numerical analysis of distributor designs. Three designs were evaluated varying the distributor height and the presence or absence of internal obstacle. Analyses of flow rate and phase distribution uniformity and the prediction of biodiesel synthesis occurrence inside the distributors were performed. Different numerical approaches were used for the specific systems, including single-phase flow, multi-component flow and Volume of Fluid (VOF) simulations. The VOF-based model provided good agreement with experimental data of water flow. The viscous dominated oil flow, presented good distribution in all proposed designs. Water and ethanol presented bulk recirculation inside the distributor, depreciating the flow uniformity. The ethanol-oil mixture flow resulted in high flow nonuniformity and in the occurrence of biodiesel synthesis for all operating conditions. Based on the numerical predictions, the micro-chemical plants require two distributors in order to perform the transesterification reaction only inside the microdevices. The simulations were employed as a design tool providing flow details and substantiating the project optimization for further development of micro-chemical plants.Graphical abstractGraphical abstract for this article
       
  • Modeling of plate heat exchanger based on sensitivity analysis and model
           updating
    • Abstract: Publication date: Available online 12 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Yuming Guo, Fuli Wang, Mingxing Jia, Shuning ZhangIn this paper, an efficient modeling method for plate heat exchanger (PHE) is developed. Firstly, the mechanistic model is established according to heat transfer equation and heat balance equation. Due to the existence of multiple unknown parameters in the mechanistic model, sensitivity analysis is employed to study the influence of these parameters on the model output. Then, the parameters which have a significant influence on the model output are estimated using real data, and the values of parameters with low influence on the output are acquired from previous works. With PHE running, the performance of PHE deteriorates due to the fouling deposits on plate surface, the corrosion and erosion damages to plates and other unknown factors. To track the changes of outlet cooling water temperature caused by above factors, Gaussian mixture model (GMM) is used to assess the performance of mechanistic model. According to the assessment results, model output offset updating or model parameter updating is activated. Finally, the feasibility and efficiency of the proposed modeling method are demonstrated by applications to three PHEs in a steel plant. The presented modeling method lays an important foundation for energy-saving optimization of circulating cooling water system.Graphical abstractAn efficient modeling method for plate heat exchanger (PHE) is developed. Firstly, the mechanistic model is established and the sensitivity analysis is employed to study the influence of unknown parameters on the model output. Based on the analysis results, the parameters with a significant influence on the model output are estimated using real data, and the values of parameters with low influence on the output are acquired from previous works. To track the changes of outlet cooling water temperature with high precision, Gaussian mixture model (GMM) is used to assess the model performance. According to the assessment results, model output offset updating or model parameter updating is activated.Graphical abstract for this article
       
  • A possibilistic Location-Inventory model for multi-period perishable
           pharmaceutical supply chain network design
    • Abstract: Publication date: Available online 12 September 2018Source: Chemical Engineering Research and DesignAuthor(s): E. Savadkoohi, M. Mousazadeh, S. Ali TorabiAbstractIn this paper, a location-inventory model is developed for a three-echelon pharmaceutical network design problem. The problem includes several strategic and tactical decisions (i.e. opening of manufacturing and distribution centers, material flows in the network, and the optimal inventory policy taking into account products’ perishability) while aiming at minimizing the total cost of the network. A possibilistic programming approach is devised to cope with the imprecise parameters. In order to verify and analyze the proposed model, it is tested on a real case study and useful managerial insights are provided by conducting several sensitivity analyses.
       
  • Predicting effects of operating condition variations on breakage rates in
           stirred media mills
    • Abstract: Publication date: Available online 11 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Greta Fragnière, Stefan Beinert, Achim Overbeck, Ingo Kampen, Carsten Schilde, Arno KwadeAbstractIn order to model predictively the breakage kinetics in stirred media mills, it is required to determine the effect of operating conditions on the breakage rate. In this study specific breakage rates are measured for grinding experiments in wet-operated stirred media mills for various operating parameters. The experimental specific breakage rates are compared against two different models using yeast cells and limestone as test materials. A simple stressing energy model is able to predict the effect of changes in grinding bead size, grinding bead material, stirrer speed and mass concentration on the specific breakage rate. A more detailed model, which takes stressing energy distributions achieved by mill simulations and material breakage energy distributions from material tests as input, shows promising results. However, the latter is less robust and needs precise input data. Yeast cells prove to be a good test material for the purpose of model validation because of its well described breakage behaviour.
       
  • Analysis of MHD micro-mixers with differential pumping capabilities for
           two different miscible fluids
    • Abstract: Publication date: Available online 11 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Xuejiao Xiao, Tiantian Li, Chang Nyung KimIn this study, newly devised is a magneto-hydrodynamic (MHD) micro-mixer capable of differential pumping of two different miscible fluids, and numerically investigated are the mixing performance and the mass flow rates of the two fluids. By artfully applying different potentials to different electrode pairs, Lorentz-force with different sizes can be created, driving the liquids in a desired direction for pumping, and inducing fluid circulation at a cross-section for mixing. The results show that the micro-mixer proposed in this study can achieve high mixing performance for electrolytes, together with differential pumping capabilities for the two different miscible fluids. The effect of the total difference in potential applied to the electrodes in pumping section on the mixing performance is numerically analyzed. Also, rectangular and H-shaped cross-sections for pumping section have been examined to explore the geometrical effect on the differential pumping capability.Graphical abstractTo create your abstract, type over the instructions in the template box below. &z.rtrif; Fonts or abstract dimensions should not be changed or altered.Graphical abstract for this article
       
  • Numerical simulation and experimental study of liquid–liquid flow
           dispersion in conical spiral pipes
    • Abstract: Publication date: Available online 10 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Ting Zhang, Kai Guo, Chunjiang Liu, Aiguo Feng, Hongwei Cai, Siyuan RenAbstractThis paper presents the numerical simulation and experimental study of an immiscible liquid–liquid flow dispersion in conical spiral pipes for oil–water separation. Flow patterns of oil–water flow in the pipe are identified. The flow characteristics such as pressure drop, cross sectional phase distribution, and outlet flow rate are obtained. In addition to flow behavior, separation performance of the conical spiral pipes is examined under different operating conditions. The effects of geometric parameters such as conical angle, pipe diameter, pitch height, and outlet split ratio, on oil–water separation are revealed. Moreover, the effects of inlet velocity, inlet oil concentration, and operating temperature on the separation are obtained. In addition, it has shown that surface treatment for the conical spiral pipes has an impact on the oil-water separation. In particular, the V-shaped sawtooth surface microstructure can enhance the oil–water separation, and Graphene-coated surface exhibits good separation capacity under high flow velocity.
       
  • An Area-wide Layout Design Method Considering Piecewise Steam Piping and
           Energy Loss
    • Abstract: Publication date: Available online 8 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Yan Wu, Ruiqi Wang, Yufei Wang, Xiao FengPipeline layout is a significant factor influencing an area-wide layout. But in the most of published works, piping system only consists of the one-to-one connection pipelines with constant diameters. In addition, energy loss is sometime ignored in previous works. In this work, energy loss due to pressure loss and heat loss is taken into consideration originally. An improved method is proposed to design an industrial area-wide layout considering the optimization of pipe network. The pipe length of steam piping is optimized based on Kruskal algorithm. The diameters of steam piping are piecewise considered. The flow rates are obtained by solving an linear programming (LP) model. The problem of area-wide layout optimization is solved by genetic algorithm (GA). Finally, the results of a case study show that the optimization of piecewise steam piping can reduce the total flow rate and energy loss of all branches in the pipe network.Graphical abstractGraphical abstract for this article
       
  • Adsorption of xylene isomers using Ba-faujasite type zeolite: Equilibrium
           and kinetics study
    • Abstract: Publication date: Available online 8 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Maryam Ahmadi-Pour, Mohammad Reza Khosravi-Nikou, Ahmad ShariatiAbstractIn the present study, liquid phase isotherm adsorption of single component of para xylene, meta xylene, ortho xylene, and ethylbenzene onto a commercial molecular sieve adsorbent (SPX3000-fine) at three different temperatures of 25, 50 and 75 °C had been investigated. It was found that para xylene was the most adsorbed component followed by ethylbenzene, meta xylene and ortho xylene, showing the strong adsorption of para xylene by the understudy adsorbent. All kinds of used xylene isomers brought out decreased adsorption loading on SPX3000-fine zeolite with increasing the temperature in the range of 25–75 °C. Aims to study the description of equilibrium adsorption data, Langmuir, Freundlich, and Tempkin isotherms were applied, which superiority of Langmuir model to describing equilibrium isotherm data with the highest R2 values was obtained. The kinetic study was performed by applying three kinetic models of pseudo-first-order, pseudo-second-order and intraparticle diffusion. According to the obtained results, the pseudo-second-order model is the best representative model to describe the kinetic adsorption data. Also, thermodynamic study revealed that due to the negative values of adsorption heat and Gibbs free energy changes, the adsorption of para xylene in the binary system proceeded an exothermic spontaneous process.
       
  • Large Characterization of shapes and volumes of droplets generated in PDMS
           T-junctions to study nucleation
    • Abstract: Publication date: Available online 8 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Elena Cândida dos Santos, Agnieszka Ladosz, Giovanni Maria Maggioni, Philipp Rudolf von Rohr, Marco MazzottiWe characterize shapes and volumes of droplets generated in PDMS T-junctions and assess the use of this type of microfluidic device to generate droplets suitable for the study of nucleation. Water droplets were formed in oil in a PDMS T-junction and subsequently stored. Droplet volume reproducibility and stability were investigated from acquired micrographs. By theoretically analyzing the influence of the mean volume of a population of droplets on the estimation of nucleation rates, we have shown that deviations in mean volumes can seriously affect the estimates, unless such deviation is smaller than 10%. This condition is fulfilled if experiments are repeated using the same microdevice. Measured droplet polydispersity remained low enough to treat the droplets as monodisperse. Immersing the microdevice in a water bath mitigates solvent evaporation, and allows for very accurate temperature control. Finally, a screening procedure was used to select the ideal operating conditions to obtain droplets with the desired sizes. Applying this method in devices with increasing T-junction cross sectional area, we have demonstrated a scaling-up of droplet volumes close to an order of magnitude while tuning the droplet shape, i.e., the average length to width ratio, at values between 1 and 1.2.Graphical abstractGraphical abstract for this article
       
  • Influence of rheological properties of stirred liquids on the axial and
           tangential forces in a vessel with a PMT impeller
    • Abstract: Publication date: Available online 8 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Anna Story, Zdzisław Jaworski, Marta Major-Godlewska, Grzegorz StoryAbstractBased on literature information, the role of both tangential and axial forces in stirred liquids on the formation of circulation regions is discussed. Rheological measurements of seven applied liquids show that five liquids are pure Newtonian and two other liquids exhibit shear-thinning rheology. Those liquids are used in experiments in a baffled vessel stirred by a Prochem Maxflo T (PMT) type impeller in a broad range of its rotational speed. Both the tangential and axial forces, exerted by the impeller on the stirred liquids, are calculated on the basis of measured values of torque and apparent mass change of the stirred tank for the studied range of agitator speed. The total, resultant force is also calculated. A significant impact of the stirred liquid viscosity on the relationship of the three forces vs. the impeller power consumption is determined. Relationships of the three forces on the impeller power are also analysed and relevant correlation equations are proposed.
       
  • Data quality and assessment, validation methods and error propagation
           through the simulation software: Report from the Round-Table Discussion at
           the 10th World Congress of Chemical Engineering in Barcelona (October
           1–5, 2017)
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s):
       
  • Inside Front Cover
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s):
       
  • Computational fluid dynamics study of full-scale aerobic bioreactors:
           Evaluation of gas-liquid mass transfer, oxygen uptake, and dynamic oxygen
           distribution
    • Abstract: Publication date: Available online 5 September 2018Source: Chemical Engineering Research and DesignAuthor(s): Mohammad J. Rahimi, Hariswaran Sitaraman, David Humbird, Jonathan J. StickelAbstractHydrodynamics, oxygen transfer, and oxygen uptake in bubble-column and airlift bioreactors were studied using multiphase Euler-Euler computational fluid dynamics (CFD) simulations. Interphase mass transfer of oxygen was modeled with a liquid mass-transfer coefficient and sustained driving force provided by a phenomenological model for microbial oxygen uptake rate (OUR). Laboratory-scale reactor simulations of a bubble-column (0.15 m diameter and 0.75 m initial liquid height) showed reasonable agreement with gas holdup and mass transfer experiments reported in the literature. Commercial-scale bubble-column and airlift reactor simulations (5 m diameter and 25 m initial liquid height) were simulated using this validated model. Similar trends for the variation of overall gas holdup and oxygen concentrations with superficial velocity were observed for both of the commercial-scale reactors. However, the simulation results indicate differences in hydrodynamics, such as better recirculation in the airlift reactors that enables favorable distribution of oxygen in the reactor.
       
  • Smart Models to Predict the Minimum Spouting Velocity of Conical Spouted
           Beds with Non-porous Draft Tube
    • Abstract: Publication date: Available online 5 September 2018Source: Chemical Engineering Research and DesignAuthor(s): S.H. Hosseini, M.J. Rezaei, M. Bag-Mohammadi, H. Altzibar, M. OlazarThe minimum spouting velocity, Ums, is a critical topic, and an exact prediction of this parameter certainly can be useful in design and scale-up of the conical spouted beds. In the present study, a number of intelligence methods was applied to predict Ums in conical spouted beds equipped with non-porous draft tube. Six dimensionless moduli comprising the essential operating and geometric parameters, namely, the gas density, the gas viscosity, the particle diameter, the particle density, the cone angle, the nozzle diameter, the static bed height, the length of the tube, the entrainment height, and the tube diameter were taken as models inputs. The total number of data samples is 1004 that includes 572 data points to train the smart models and 432 data points to test those models. The self-organizing map (SOM) was used to examine the effect of inputs correlation on the performance of the chosen smart models. Among the different models, a multi-layer perceptron (MLP) trained by Bayesian Regulation (BR) incorporating SOM i.e. (MLP-BR-SOM) predicted the best results with mean relative error of 9.71 and 12.45% for train and test data, respectively. In addition, sensitivity analysis (SA) of the proposed model was performed and it was shown the Ar, DT/D0, and H0/D0 have most influential parameters in prediction of Ums.Graphical abstractGraphical abstract for this article
       
  • Step by step methodology of designing a liquid-solid circulating fluidized
           bed using computational fluid dynamic approach
    • Abstract: Publication date: Available online 30 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Ritesh Ramesh Palkar, Suresh P.V., Vidyasagar ShilapuramAbstractIn this work, a systematic step-by-step methodology has been developed to identify the type of instabilities arise in achieving the continuous solids circulation achieved between riser and downcomer, and in establishing the proper pressure balance among the various units of a liquid-solid circulating fluidized bed (LSCFB) using transient three dimensional computational fluid dynamic (CFD) simulations. Different type of instabilities has been identified and systematically eliminated by choosing the appropriate measure in-terms of the geometry of a LSCFB. This resulted in studying five variant designs of LSCFB studies using CFD. The Eulerian-Eulerian approach is used to simulate the two-phase flow in LSCFB system. The hydrodynamic behavior of the system is studied in terms of the pressure drop, solids holdup at various locations as well as the axial solids hold up distribution. The steady state in the system has been characterized by the solids volume fraction and the pressure balance loop across the closed loop LSCFB. The effect of solids inventory, primary and auxiliary liquid flow, and viscosity of liquid on average solids holdup has been studied with the final LSCFB design.
       
  • PVDF-co-HFP/superhydrophobic acetylene-based nanocarbon hybrid membrane
           for seawater desalination via DCMD
    • Abstract: Publication date: Available online 29 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Mustafa Mohammed Aljumaily, Mohammed Abdulhakim Alsaadi, N. Awanis Hashim, Qusay F. Alsalhy, Farouq S. Mjalli, Muataz Ali Atieh, Ahmed Al-HarrasiSurface hydrophobicity is the most desirable characteristic for high DCMD performance. Superhydrophobic carbon nanomaterials/powder activated carbon (CNMs/PAC) has unique properties and believed to be the proper candidate to increase the membrane hydrophobicity with maintaining good mechanical properties and high porosity at the same time. In this work, we introduce a phase inversion process based on central composite design, aimed at minimizing the number of experiments required for membrane fabrication. The hydrophobic membrane fabrication conditions are modeled as independent parameters, with the flux provided as the model response. The analyses performed on the membrane structure and surface, as well as its mechanical properties revealed that the superhydrophobic CNMs/PAC significantly enhances the hydrophobicity of the composite membrane surface. The accuracy measurements obtained by analysis of variance showed that the model developed and all the proposed parameters have significant effects on the flux. However, the CNMs/PAC emerged as the most significant influential factor and interacted with polymer concentration and casting knife thickness to exert effects on the permeate flux. The optimum preparation parameters were 775.21 mg carbon loading, PVDF-HFP concentration of 21.86 g and casting knife thickness of 118.93 μm, as these values yield the highest flux of about 102 kg/m2h.Graphical abstractGraphical abstract for this article
       
  • A Prediction and Outlier Detection Scheme of Molten Steel Temperature in
           Ladle Furnace
    • Abstract: Publication date: Available online 29 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Biao Wang, Zhizhong Mao, Keke HuangMolten steel temperature prediction is a crucial step in ladle furnaces (LFs). Due to the complicated working conditions, process data usually suffers from various types of outliers. However, most of existing temperature models have not taken robustness to outliers into account. Hence, their accuracies usually cannot satisfy the industrial production. In this paper, we propose a comprehensive scheme that integrates temperature prediction with outlier detection. Of this scheme, we develop a three-level ensemble model where Gaussian Process (GP) is used as the base learner, to accomplish the prediction task. Motivation for GP base leaner is two-fold. One is that GP models perform well on the nonlinear regression problem. The other is that GP is a Bayesian method and its output can be used in the outlier detection step. Motivation for our ensemble model is also two-fold. First two problems regarding GP, i.e. high computational complexity and model selection, can be alleviated. Second, the predictive accuracy can be further improved. As for the outlier detection task, we develop two types of detectors implemented for both training and testing data points. We proposed a novel detector based on one-class classification (OCC) and use it for training samples and inputs of testing data. And the detector for the output values of testing data is constructed from outputs of the prediction model. Finally, we verify the prediction performance on several real-world data sets and compare their performance with several competitors. The significance of the proposed outlier detection step is also validated. Experimental results approve the potential of our scheme.Graphical abstractGraphical abstract for this article
       
  • Crystallization kinetics in an airlift and a stirred draft tube
           crystallizer; Secondary nucleation models revisited
    • Abstract: Publication date: Available online 29 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Fatemeh Anisi, Herman J.M. KramerIn this research, a process model has been developed for an airlift and compared with that of a draft tube stirred crystallizer to clarify the crystallization kinetics in this novel type of crystallizer. Recently it has been shown that although secondary nucleation is strongly suppressed in this crystallizer, it is not completely absent and further development and scale up requires a more quantitative prediction of the kinetics in this type of crystallizer.A number of growth and nucleation models were examined in a parameter estimation study in which a dataset of a number of seeded batch experiments has been used to estimate the kinetics in both an airlift and a draft tube stirred crystallizer.It is shown that a kinetic model, consisting of a two-step growth model and two additive nucleation mechanisms, i.e. an attrition based and a surface nucleation mechanism, gives an excellent and statistically acceptable description of all studied experiments with one parameter set each for both type of crystallizers. The main difference in the two types of crystallizers being that the attrition terms by crystal-impeller and crystal-crystal collisions in the airlift crystallizer can be completely neglected.Graphical abstractGraphical abstract for this article
       
  • CFD modeling a fluidized bed large scale reactor with various internal
           elements near the heated particles feeder
    • Abstract: Publication date: Available online 28 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Olga V. Soloveva, Sergei A. Solovev, Svetlana R. Egorova, Alexander A. Lamberov, Alexey V. Antipin, Emil V. ShamsutdinovA numerical study of the fluidized bed industrial reactor in the presence of various internal elements is carried out by CFD methods A simple reactor heating efficiency function of chemical reaction with heat absorption is considered. The main emphasis is placed on the circulation flows of the catalyst particles and heating of the reactor. The analysis of the impact of various design elements on the heating efficiency of the reactor is carried out. Particular attention is paid to the possibility of baffles applying, which allows redirecting the flow. This effect may have an especially important value when the rapid heating of the reactor is required for temperature dependent reactions. The influence of heated catalyst feeder design on the efficiency of whole reactor heating is educed. The influence of the fractional composition of the catalyst, namely the presence of fine particles, on the reactor heating efficiency for different reactor design features is also studied. The results are carried out for a specific reactor example, but contribute to the overall branch of fluidized bed engineering.Graphical abstractGraphical abstract for this article
       
  • Solution enhanced dispersion by supercritical fluids (SEDS): An approach
           in particle engineering to modify aqueous solubility of andrographolide
           from Andrographis paniculata extract
    • Abstract: Publication date: Available online 25 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Sin Yee Lee, Luqman Chuah Abdullah, Russly Abdul Rahman, Faridah Abas, Wei Kiat Tan, Gun Hean ChongThe objective of study is to improve aqueous solubility of andrographolide through particle engineering using Solution Enhanced Dispersion by Supercritical Fluids (SEDS) approach. The precipitation pattern of sticky crude Andrographis paniculata extract from CO2-Acetone system and CO2-Acetone:Ethanol (v/v) 1:1 system as well as the aqueous solubility of andrographolide precipitated were first studied at different pressure (100, 150 bar) and temperature (40, 50 °C) combination (full factorial design). The modification of aqueous solubility of andrographolide was then attempted by manipulating its precipitation process from CO2-solvent systems consisting of single solvent and solvent mixture at different proportions (v/v) at the appropriate pressure-temperature combination. A. paniculata powder precipitated from CO2-Acetone system at 150 bar, 40 °C was found to be large, irregularly shaped, less crystalline with the highest andrographolide aqueous solubility (twofold increment compared to crude extract) and recovery compared to those precipitated from CO2-Ethanol system and other CO2-solvent mixture systems. Complete dissolution of andrographolide from A. paniculata powder precipitated from CO2-Acetone system had been achieved within 90 min. For SEDS precipitation under solvent mixture system, with increment of proportion of ethanol from 25% to 75%, larger particles and change of powder morphology from stripes into plates were resulted. Based on the higher aqueous solubility and dissolution of andrographolide, recovery as well as a different morphology observed from the less crystalline A. paniculata powder precipitated from CO2-Acetone system, less impurities could have co-precipitated with andrographolide.Graphical abstractGraphical abstract for this article
       
  • Characterization and selection of waste oils for the absorption and
           biodegradation of VOC of different hydrophobicities
    • Abstract: Publication date: Available online 25 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Margaux Lhuissier, Annabelle Couvert, Abdeltif Amrane, Abdoulaye Kane, Jean-Luc AudicThe purpose of this study was to test different kinds of industrial waste oils to be implemented as Non-Aqueous-Phase for Volatile Organic Compounds absorption and degradation in a process coupling a packed column and a Two-Phase Partitioning Bioreactor. Engine, hydraulic, transformer and vegetable oils were tested. The VOC targeted were: n-heptane, ethyl acetate, isopropanol, methylisobutylketone, toluene, m-xylene and 1,3,5-trimethylbenzene. Several parameters were determined: volatility, viscosity, VOC partition coefficients and toxicity. Results allowed to conclude that hydraulic, transformer and vegetable oils are technically appropriate for the process. According to availability and cost data of waste oils, hydraulic oil was selected.Graphical abstractGraphical abstract for this article
       
  • Effect of nozzle diameter on bubble generation with gas self-suction
           through swirling flow
    • Abstract: Publication date: October 2018Source: Chemical Engineering Research and Design, Volume 138Author(s): Xiao Xu, Xiaoling Ge, Yundong Qian, Bohan Zhang, Hualin Wang, Qiang YangUnderstanding the effects of nozzle geometry on bubble generation is very important in nozzle design. Gas self-suction is discussed with different nozzle diameter by detecting the pressure at gas inlet. The effects of nozzle diameter on the bubble size distribution and spray morphology of bubble generators were investigated to assess the aeration capabilities. The increase in the geometric criterion K from 3.2 to 4.8 leads to an amazing transformation from non-self-suction to the maximum vacuum degree. The maximum vacuum degree with a geometric criterion K of 4.8, the maximum aeration capability with a K of 8.0, and the minimum bubble diameter with a K of 12 were achieved. The liquid handling capacity and spray angle increase together with increasing K. This work contributes to the foundation for the design of an industrial bubble generator through a pressure-swirl nozzle.Graphical abstractGraphical abstract for this article
       
  • Multilayered Pd nanocatalysts with nano-bulge structure in a microreactor
           for multiphase catalytic reaction
    • Abstract: Publication date: Available online 24 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Hao Feng, Biao Zhang, Xun Zhu, Rong Chen, Qiang Liao, Ding-ding Ye, Jian Liu, Ming Liu, Gang ChenMicroreactors are promising for fine chemistry and value-added chemical synthesis, but the small dimension places significant challenges in catalyst layer fabrication. Meanwhile, enhancing catalyst dispersion to obtain smaller particle size are of great interests. We proposed a multilayered Pd nanocatalysts with nano-bulge structure inside a microreactor for multiphase catalytic reaction. The unique bulged nanostructure can provide more accessible sites for precursor (PdCl42−) adsorption, and extend the available area to reduce the Pd nanoparticle size. Experimental results show rugged Pd catalyst layer with the nano-bulge structure was prepared, and both the precursor utilization rate and Pd nanocatalysts dispersion were enhanced, resulting in 35.4% higher catalyst loading and 4-fold smaller particle size. Benefitting from these advantages, compared with conventional Pd coated polydopamine catalyst layer, the proposed multilayered Pd nanocatalyst can significantly intensify the reaction rate and obtain an order of magnitude longer durability in nitrobenzene hydrogenation. This versatile and convenient fabrication method can be used in fabricating high performance and durable catalyst layers in microreactors.Graphical abstractGraphical abstract for this article
       
  • Adsorption equilibrium models: computation of confidence regions of
           parameter estimates
    • Abstract: Publication date: Available online 24 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Natália Tolazzi, Evandro Steffani, Elisa Barbosa-Coutinho, João B. Severo Júnior, José Carlos Pinto, Marcio SchwaabAbstractEstimation of parameter values of adsorption equilibrium models from available experimental data is a common practice, but the evaluation of parameter uncertainties is not usually performed. Furthermore, adsorption equilibrium models generally present two or more parameters and the uncertainty analysis must be performed with help of confidence regions, allowing for evaluation of parameter correlations. In the present work confidence regions of estimated parameters were determined for Langmuir, Freundlich, Sips and Redlich-Peterson isotherms through the elliptical approximation and the likelihood ratio method, using experimental data related to dyes adsorption from liquid solutions. The effects caused by the number of measurements, the experimental data region and the definition of experimental measurement variance were also evaluated. The results showed that changes of the experimental region can exert large influence on the precision of the estimated parameters when experimental variances are estimated with the minimum value of the least squares objective function, since in this case model performance affects directly the estimated parameter uncertainties. On the other hand, when experimental variances are obtained independently, parameter uncertainties become less dependent on model performance, as expected. It was also observed that the elliptical and likelihood ratio approaches for determination of confidence regions lead to similar results when uncertainties of the parameter estimates are low, even when nonlinear models are considered. Finally, it was shown that the proper evaluation of the experimental uncertainty exerts a major effect on the obtained confidence regions, so that the use of replicates in the experimental grid must certainly be encouraged.
       
  • Performance Evaluation of Venturi Scrubber for the Removal of Iodine in
           Filtered Containment Venting System
    • Abstract: Publication date: Available online 22 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Manisha Bal, Thamatam Tejaswini Reddy, B.C. MeikapFiltered containment venting system (FCVS) is an essential technology in nuclear power plants for the removal of iodine. A laboratory scale venturi scrubber has been designed, developed and fabricated.The maximum removal efficiency of iodine is obtained as 82.32% at 3 × 10−3 kmol/m3 of KI solution, used as the scrubbing liquid for the throat gas velocity of 18 m/s and liquid flow rate of 0.033 kg/s with iodine inlet concentration of 0.39 kg/m3. A semi-empirical model has been developed to predict the removal efficiency of iodine scrubbing using the experimental results and the variables which show the impact on the scrubber performance.Graphical abstractGraphical abstract for this article
       
  • Stability criterion for the intensification of batch processes with model
           predictive control
    • Abstract: Publication date: Available online 22 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Walter Kähm, Vassilios S. VassiliadisThermal runaways in batch processes can lead to significant issues for safety and performance during normal operation in industry. This is usually circumvented by running such processes at lower temperatures than necessary, hence losing the opportunity to intensify production and therefore reduce reaction time. The detection of the thermal stability of batch systems can potentially be embedded in an advanced control scheme, therefore improving the performance by being able to intensify the process, achieving higher yields while keeping a stable operation.The derivation of stability criterion K for high-order reactions is presented in this work, resulting in better control when embedded in Model Predictive Control (MPC) schemes than standard nonlinear MPC schemes, based on the work in Kähm and Vassiliadis (2018). The non-trivial extension of stability criterion K for multi-component reactions with application to MPC systems is discussed in detail. The logic and verification of the form of the resultant Damköhler number in particular is discussed and demonstrated with case studies. A comparison of various MPC schemes is presented, showcasing that the implementation using criterion K results in intensified processes kept stable at all times, whilst reducing computational cost with regards to standard nonlinear MPC schemes. Furthermore, reaction times are reduced by at least two-fold with respect to processes run at constant temperatures.Graphical abstractGraphical abstract for this article
       
  • Describing Physical Properties of CO2 Unloaded and Loaded
           MDEA+PZ solutions
    • Abstract: Publication date: Available online 22 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Stefania Moioli, Laura A. PellegriniAcid gas (CO2 and H2S) removal from industrial gas streams by amine scrubbing is usually employed in industry. Among different amines, n-MethylDiEthanolAmine (MDEA) is preferred because of its high equilibrium loading capacity and low heat of reaction with carbon dioxide, associated to low energy requirement in the regeneration section. Piperazine (PZ) can be used as promoter because of its rapid transformation to carbamates with carbon dioxide when mixed to MDEA (PZ rate constant value has been found to be one order of magnitude higher than the one of MEA). A correct representation of properties of the absorbent solution, such as density and viscosity, is essential for rate-based calculations.This paper gives an in-depth analysis and calculation of the properties involved in the modeling of mass transfer of absorbed species and on the development of general correlations for the description of density and viscosity of the MDEA + PZ solution to be applied for a wide range of concentrations and temperatures. In this work, in addition, the influence of carbon dioxide loading on the solvent properties has been taken into account too.Graphical abstractGraphical abstract for this article
       
  • Kinetic modelling and kinetic parameters calculation in the
           lipase-catalysed synthesis of geranyl acetate
    • Abstract: Publication date: Available online 22 August 2018Source: Chemical Engineering Research and DesignAuthor(s): M.D. Murcia, M. Gómez, E. Gómez, J.L. Gómez, A.M. Hidalgo, A. Sánchez, P. VergaraThe interest in new natural products used in cosmetic industry has increased the research in order to synthesize those compounds. The aim of this work is to assess the reaction of the transesterification between geraniol and vinyl acetate for the enzymatic synthesis of geranyl acetate, using Novozym® 435 as catalyst, as well as to obtain a kinetic model for the bioprocess and the values of the kinetic parameters. Five experimental series have been performed with variation of: enzyme amount, concentrations of geraniol and vinyl acetate in molar ratio 1:1, stirring rate, temperature and, finally, substrates molar ratio. A conversion of geranyl acetate of 98.4% has been obtained in the best experimental conditions and, also, high conversions were obtained for most of the other conditions assayed. It has been concluded that the catalyst amount is the most significant variable on the reaction kinetics and the reaction yield and that both the stirring rate and the initial substrates concentrations have no significant influence. Finally, a Ping Pong Bisubstrate kinetic model has been applied and its kinetic parameters have been determined by using an improved version of a procedure developed by authors in a previous work. The values obtained for the Michaelis constants show that, for the equal substrates concentrations series, the Ping-Pong model can be simplified to a pseudo-first order kinetic model, which has been confirmed, with high correlation coefficients, by using the “Curve Expert” software.Graphical abstractGraphical abstract for this article
       
  • Numerical research on vapor splitter in divided wall column
    • Abstract: Publication date: Available online 31 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Yuqi Hu, Shuang Chen, Chunli LiAbstractIn order to lower the difficulty to control the vapor split ratio of divided wall column (DWC) and to optimize auto-allocated vapor flow rate on the both side of the divided wall in real industry, this paper presents a new vapor ratio regulator. The splitter, which is based on the Coanda effect, is installed in the bottom section of the DWC to control vapor flow rate on both sides of the DWC and solve the problem of vapor allocation in the DWC. In this research, Auto-cad, computational, Tecplot, and Origin are used to do data analysis. By tracking the vapor flow trajectory and analyzing the splitter’s allocation rule, it is shown that the RV can be effectively regulated by adjusting the velocity of the gas inlet. In order to achieve a high uniformity of the vapor flow field of regulator, the installation location of the device is optimized.
       
  • APPLICABILITY OF THE POWER MODEL TO MIXED SLURRIES WITH NON-SPHERICAL
           PARTICLES AND NETWORKING EFFECT
    • Abstract: Publication date: Available online 29 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Basak Kutukcu, Inci AyranciIndustrial applications of solids suspension generally consist of mixed slurries that contain many solid phases with irregularly shaped particles at high concentrations. Since solid–liquid mixing is a power intensive operation it is critical to predict the just suspended speed, Njs, accurately. There is only one model available for mixed slurry Njs predictions: the power model. This model was developed for spherical particles. In this study, suspension behaviour of mixed slurries with non-spherical particles was investigated. It was seen that the presence of non-spherical particles decreases Njs, but the power model is still applicable. The original limits of applicability of the power model is for spherical particles and up to 27 wt% solids concentration, without networking mechanism. The networking mechanism is seen when the small and less dense particles significantly ease the suspension of larger and denser particles in the slurry. In this study, a correction factor to the power model was recommended to account for the networking mechanism. The power model can now be applied to mixed slurries of any shape of particles up to 55 wt% solids, with or without networking mechanism. The effect of shape was also investigated for unimodal slurries, but no significant deviation was found in the predictions.Graphical abstractGraphical abstract for this article
       
  • Investigation of the Flow Patterns Produced from Sudden Expansion
           Geometries using Pressure Difference Measurements and Flow Visualisation
           Techniques
    • Abstract: Publication date: Available online 27 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Xing Huang, Timothy A.G. Langrish, Ali Abbas, David F. FletcherThe aim of this study was to investigate the flow behaviour produced from inward sudden and outward expansion geometries. A flow apparatus made of Perspex has been used to measure the variations of pressure differences, and to observe the visualised flow streams, downstream of the expansions. For the outward expansion, the pressure measurements showed two types of oscillations: low frequencies at around 1 Hz and high frequencies at around 10 Hz. The oscillations at low frequencies have been found to be more dominant and related to the precession of the air flow. Further pressure measurements, together with the visualisation results, showed that this precessing behaviour was stronger near the wall of the expansion chamber. In comparison, the pressure measurements in the inward expansion showed higher overall flow stability. Measurements at different radial distances showed that the low-frequency precessing behaviour appeared to be confined to the central area of the chamber (33 to 50% diameter from the radial centre). This precession has been found to have a small influence on the flow field near the chamber wall, which may contribute to the flow stability. This finding was also supported by the visualisation results. A swirl module has also been used to investigate the effects of inlet swirl angle on the air flow pattern, where the pressure measurements showed no apparent changes in the overall flow behaviour, but a reduction has been observed in the dominance of the low-frequency oscillations and an increase in the frequencies of the high-frequency oscillations. Flow visualisation of the swirler case showed that the precessing eddies started dissipation at a shorter distance from the expansion point. This study showed the close relationship between the flow behaviours and the geometries of the inlet expansions, and possibility of controlling the flow behaviours by design features such as swirler modules. Such findings are valuable to processes such as spray-drying, which require both sufficient mixing and flow stability. The study also illustrated the use of flow visualisation techniques as complimentary tools to assess complex flow behaviour.Graphical abstractGraphical abstract for this article
       
  • Modeling of a double effect evaporator: Bond graph approach
    • Abstract: Publication date: Available online 27 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Samia Ben-AliThis paper deals with the modeling of a chemical engineering system, which is the double effect evaporator (DEE). The main physical phenomenon encountered in this system is the heat transfer during distillation and concentration process. The modeling of DEE is carried out using bond graph approach. It allows description of interdisciplinary systems involving energetic, thermodynamic, hydraulic and thermal phenomena. In this study a dynamical models for the different parts of the DEE system are established. Simulation data are presented and confronted to the experimental results. To supervise the DEE system, the bond graph model is used to obtain analytical redundancy relations (ARR). They allow detection and isolation of faults.Graphical abstractGraphical abstract for this article
       
  • A Superstructure Optimization Approach for Process Synthesis under Complex
           Reaction Networks
    • Abstract: Publication date: Available online 21 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Gautham Madenoor Ramapriya, Wangyun Won, Christos T. MaraveliasAbstractIn this work, we present mixed integer linear programming methods for the synthesis of processes that involve complex reaction networks. Specifically, we consider the modeling of reactors and interconnecting streams in systems where the composition of the reactor inlet streams can vary substantially, thereby making the determination of the limiting component as well as the calculation of the stream heating/cooling and power requirements challenging. First, towards the modeling of reactors we develop an extent-based method which detects the limiting reactant of each reaction occurring in parallel with others, based on the inlet flows of the reactants. Second, we develop a computationally tractable method for the calculation of the work and heating/cooling duty needed to condition any stream of a process based on simple calculations that can be performed offline. Finally, we present how the two aforementioned components can be integrated in an optimization model generated based on a process superstructure. We demonstrate the application of the developed methods for the synthesis of a biorefinery.
       
  • Drop behavior in a pilot plant asymmetric rotating disc extraction column
           for three various liquid–liquid systems
    • Abstract: Publication date: Available online 8 April 2018Source: Chemical Engineering Research and DesignAuthor(s): Mehdi Asadollahzadeha, Meisam Torab-Mostaedi, Rezvan TorkamanAmong the liquid dispersion properties affecting the ARDC column behavior, the drop size distribution is one of the important parameters. Its control could positively contribute to optimize the column performance. The experimental works were carried out in a pilot plant ARDC column with three different systems. The effect of operating parameters on the Sauter mean drop diameters and drop size distributions were investigated. The drop size distribution is largely dependent on the agitation conditions in the column, but, the effect of phase flow rates is not significant. The empirical drop size distributions in the ARDC column are compared with the five common theoretical distribution functions (normal, log-normal, Gamma, Inverse Gaussian, Weibull).The constant parameters in these functions were correlated with operating conditions and physical properties of three systems. The Weibull is found to perform adequately and accurately in fitting the drop size distributions. Except for these findings, an empirical correlation is proposed for estimation of the Sauter mean drop diameter in terms of operating variables, column geometry and physical properties.Graphical abstractGraphical abstract for this article
       
  • Optimisation Approaches for Supply Chain Planning and Scheduling under
           Demand Uncertainty
    • Abstract: Publication date: Available online 20 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Adrián M. Aguirre, Songsong Liu, Lazaros G. PapageorgiouAbstractThis work presents efficient MILP-based approaches for the planning and scheduling of multiproduct multistage continuous plants with sequence-dependent changeovers in a supply chain network under demand uncertainty and price elasticity of demand. This problem considers multiproduct plants, where several products must be produced and delivered to supply the distribution centres (DCs), while DCs are in charge of storing and delivering these products to the final markets to be sold. A hybrid discrete/continuous model is proposed for this problem by using the ideas of the Travelling Salesman Problem (TSP) and global precedence representation. In order to deal with the uncertainty, we proposed a Hierarchical Model Predictive Control (HMPC) approach for this particular problem. Despite of its efficiency, the final solution reported still could be far from the global optimum. Due to this, Local-Search (LS) algorithms are developed to improve the solution of HMPC by rescheduling successive products in the current schedule. The effectiveness of the proposed solution techniques is demonstrated by solving a large-scale instance and comparing the solution with the original MPC and a classic Cutting Plane approach adapted for this work.
       
  • Exploration of Oligomeric Sodium Carboxylates as Novel Draw Solutes for
           Forward Osmosis
    • Abstract: Publication date: Available online 20 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Qingwu Long, Jiaqi Huang, Shu Xiong, Liang Shen, Yan WangFO technology has attracted growing attention in water treatment and desalination applications recently. The development of a suitable draw solute with high performance and low cost is therefore in high demand to facilitate practical FO applications. In this study, two oligomeric carboxylates — poly maleic acid sodium (PMAS) and poly(itaconate-co-acrylate) sodium [P(IA-co-AA)] with controllable molecular weights of 400–1000 Da, are synthesized via one-step polymerization and employed as novel draw solutes for FO applications. The successful synthesis is confirmed via by various characterization techniques. The osmotic pressure, relative viscosity and FO performance of PMAS and P(IA-co-AA) draw solutions with different concentrations are studied systematically. Two types of FO membranes are employed, and their performance is compared using PMAS draw solution. With 0.5 mol/kg PMAS draw solution and DI water feed solution, high water fluxes of 30.6 and 62.4 LMH can be achieved using HTI-TFC and homemade PSf-TFC membrane in the FO tests, respectively. 0.5 mol/kg PMAS draw solution is further studied for the desalination of 0.6 mol/kg NaCl solution via FO, with a water flux of 6.63 LMH obtained. The diluted PMAS solution after FO test can be recovered by nanofiltration with a high rejection rate. The excellent performance and available recovery route of the developed oligomeric carboxylates imply their great potential as promising draw solutes for FO applications.Graphical abstractGraphical abstract for this article
       
  • Synthesis and functionalization of graphene oxide (GO) for salty water
           desalination as adsorbent
    • Abstract: Publication date: Available online 20 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Marzieh Zahed, Parisa sadat Parsamehr, Maryam Ahmadzadeh Tofighy, Toraj MohammadiAbstractIn this article, graphene oxide (GO) was synthesized by the Hummers and the modified Hummers methods and functionalized with chitosan and used as adsorbents for salty water desalination application. The results demonstrated that GO prepared via the modified Hummers method has higher adsorption capacity of sodium ions than GO prepared via the Hummers method. Also, functionalization with chitosan improved sodium ions adsorption capacity of the GO prepared via the modified Hummers method from 770.2 to 830.3 mg/g at an initial sodium ion concentration of 40,000 mg/l. Langmuir and Freundlich isotherms and two kinetic models were applied to fit the experimental data. Regeneration performance of the prepared adsorbents was also studied. The results demonstrated that both isotherms and the pseudo-second-order kinetic model match the obtained experimental data very well. It was found out that the chitosan functionalized GO with higher adsorption capacity and better regeneration performance can be considered as an effective adsorbent for salty water desalination.
       
  • Production of Gas Hydrate in a Semi-Batch Spray Reactor Process as a Means
           for Separation of Carbon Dioxide from Methane
    • Abstract: Publication date: Available online 20 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Behzad Partoon, Khalik M. Sabil, Lau Kok Keong, Bhajan Lal, Khashayar NasrifarThe formation of gas hydrate shows good potential to work as separation medium for gas mixtures. However, to put it in practice, the impact of process parameters, such as flow rates, operational temperature and pressure are required to be adequately investigated. In this work, a new gas hydrate reactor is introduced for fast production of gas hydrate. The reactor is used for separation of carbon dioxide from methane in a series of semi-batch experiments. Results indicated that fast hydrate production is achievable. In addition, carbon dioxide is effectively separated from methane by producing gas hydrate from a gas mixture containing more than 60% carbon dioxide.Graphical abstractGraphical abstract for this article
       
  • Ignition of Homo/Hetero Combustion of Propane in a Microreactor with
           Catalyst Segmentation
    • Abstract: Publication date: Available online 20 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Moulish Kommu, Niket S. KaisareAbstractThe ignition behavior of propane/air mixtures in a microreactor with catalyst segmentation is investigated using 2D computational fluid dynamics simulations. The steady state ignition bifurcation and the transients during cold-start ignition in a segmented microreactor is compared with the typical case of continuous catalyst. Catalyst segmentation in microreactor allows significant reduction in the amount of catalyst without significantly affecting the ignition temperature or the time required for ignition of homo/catalytic combustion. The effect of segmentation on the rates of catalytic and homogeneous reactions, as well as the local Sherwood number is analyzed. Creating alternating segments of catalytic and non-catalytic regions is suggested in the literature in order to promote homogeneous chemistry in non-catalytic regions at steady state. However, enhancement of homogeneous combustion in non-catalytic regions does not affect ignition because sequential light-off of catalytic followed by homogeneous chemistry is observed. Finally, the effect of inlet velocity and microreactor dimensions on ignition in segmented microreactor is also presented.
       
  • Optimal multi-floor process plant layout with production sections
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Jude O. Ejeh, Songsong Liu, Lazaros G. PapageorgiouAbstractThis paper addresses the multi-floor process plant layout problem by developing four mixed integer linear programming (MILP) models. The problem involves decisions concerning the optimal spatial arrangement of process plant equipment and/or auxiliary units considering equipment connectivity, pumping and construction costs, and other factors. These considerations are extended to account for tall equipment items that span across floors and the availability of predefined production sections. The proposed models determine simultaneously the number of floors per section, floor areas per section, plot layout and site layout, and are applied to two case studies with up to 22 units and 6 production sections to demonstrate their applicability.
       
  • Biodiesel separation using ultrafiltration poly(ether sulfone) hollow
           fiber membranes: Improving biodiesel and glycerol rich phases settling
    • Abstract: Publication date: Available online 17 August 2018Source: Chemical Engineering Research and DesignAuthor(s): M.A. Noriega, P.C. Narváez, A.C. HabertAfter alkali-catalyzed transesterification reaction for biodiesel production, the glycerol-rich phases have to be separated. These phases are traditionally separated by settling, requiring long residence time, especially when soaps and gels are formed. In this work, biodiesel, and glycerol rich phases separation was experimentally assessed using poly(ether sulfone) hollow fiber membranes (PES-HFM). Experimental data were obtained in a continuous bench scale system. The effect of pressure difference through the membrane (0–0.6 bar), feed composition and biodiesel-rich phase mass fraction (0–0.8) on permeability and permeate composition were studied. In addition, a mathematical model adopting the Hagen-Poiseuille transport equation for membrane ultrafiltration, where permeate fluxes and compositions depend on the Liquid–Liquid Equilibrium (LLE), was proposed, correlated and experimentally validated. Experimental results demonstrated only glycerol-rich phase permeated through the membrane following the LLE. Glycerol-rich phase flux increased when pressure difference through the membrane augmented, and decreased when permeate viscosity increased. The highest experimental permeability (33.2 kg bar−1h−1m−2) was obtained at the highest methanol content in the feed stream, 66%wt., equivalent to a molar ratio methanol to oil 18:1 fed to the reactor. The mathematical model predicts an increase in the glycerol-rich phase flux when temperature and methanol content augment. The transport mechanism coupled to the mathematical model explained accurately the membrane role in the separation of the compounds involved in transesterification of vegetable oils, as well as the membrane selectivity.Graphical abstractGraphical abstract for this article
       
  • Bipolar Membrane Electrodialysis for the Recycling of Ammonium Chloride
           Wastewater: Membrane Selection and Process Optimization
    • Abstract: Publication date: Available online 17 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Yan Lv, Haiyang Yan, Baojun Yang, Cuiming Wu, Xu Zhang, Xiaolin WangAbstractHere, bipolar membrane electrodialysis (BMED) with BP-A configuration is employed to convert ammonium chloride wastewater into hydrochloric acid and ammonium hydroxide to overcome the shortcomings of conventional treatment methods First, different commercial anion exchange membranes (TWEDA2, AMV, JAM-II and CJMA-2) and bipolar membranes (BP-1, BPM-I and FBM) were used to conduct the BMED process.Resultsshow that AMV and BPM-I are regarded as the optimum membranes in consideration of process performance, energy consumption and process cost comprehensively. Second, BMED process is optimized by changing current density, initial NH4Cl concentration and initial volume ratio of acid solution and NH4Cl solution.Resultsindicate that as current density increases from 70 to 90 mA/cm2, energy consumption and generated HCl concentration can increase from 1.51 to 2.83 kW h/kg HCl and 2.45 to 2.84 mol/L respectively, and the total process cost of 70 mA/cm2 is the highest (0.80 $/kg HCl); meanwhile, increasing initial NH4Cl concentration can increase energy consumption, generated acid concentration and total process cost; in addition, with the increment of initial volume ratio from 0.5 to 1.0, energy consumption varies between 1.46 and 1.62 kW h/kg HCl and generated acid concentration improves from 1.95 to 2.71 mol/L, while total process cost decreases from 0.63 to 0.42 $/kg HCl. In short, based on these results, the optimum operation condition is that current density is 80 mA/cm2, initial NH4Cl concentration is 1 mol/L and initial volume ratio of acid solution and NH4Cl solution is 0.67–0.83.
       
  • Diatomite precoat filtration for wastewater treatment: Filtration
           performance and pollution mechanisms
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Dan Guo, Hualin Wang, Pengbo Fu, Yuan Huang, Yi Liu, Wenjie Lv, Fei WangAs wastewater processing facilities deal with increasing amount in combination with enhanced environmental pressures, diatomite precoat filtration is becoming one of the promising methods for wastewater treatment. Filtration performance of diatomite precoat filtration with five different coating layer thicknesses for wastewater treatment was investigated in terms of permeate flux, fouling grade, filtration resistance, permeate quality and fouling reversibility. Pollution mechanism was revealed by fitting Hermia’s fouling models, detecting the pollutant transport and analyzing the changes in microstructure of diatomite. The optimal thickness of diatomite precoat filtration was 4 mm, which exhibited that the highest average permeate flux was 16.53 L/m2h, total fouling resistance reduced by 59.5%, and lowest cake water content was 55.1%. Contact angle measurement indicated that the fouling formed on the diatomite coating layer was highly reversible. Compared with individual fouling model, the combination of three Hermia’s fouling models at different stages fitted the flux data well. FESEM images of diatomite particles confirmed high filtration flux and supported the pollutant transport results. The superiority of diatomite precoat filtration in improving filtration performance and mitigation fouling was demonstrated. The present study could also provide an experimental basis for optimizing precoat filtration process.Graphical abstractGraphical abstract for this article
       
  • Mixed-time mixed-integer linear programming for optimal detailed
           scheduling of a crude oil port depot
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Haoran Zhang, Yongtu Liang, Qi Liao, Jie Gao, Xiaohan Yan, Wan ZhangAbstractCrude oil port depots are key hubs in oil trade and thus play a vital role in the crude oil supply chain. Based on the characteristics of the scheduling system in an oil port depot, the development of a precise schedule is essential for handling asynchronous upstream supply and downstream market demand, thereby reducing operation cost as well as the impact of market fluctuations. Most previous studies focused only on the depot system, and few have taken the export transport scheduling into consideration. In this study, the diversity of crude oil storage modes, complexity of operations, and variety of transportation modes are considered. To minimize the total operation cost, a mixed-time representation based on a mixed-integer linear programming model is established. Finally, three real cases in a crude oil port depot in China are studied, and the monthly schedules of the depot are developed. Compared with previous algorithms, this method yields more accurate results in a considerably shorter time with improved computational stability.
       
  • Effects of elevated pressure on bubble properties in a two-dimensional
           gas-solid fluidized bed
    • Abstract: Publication date: Available online 16 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Jialong Song, Daoyin Liu, Jiliang Ma, Xiaoping ChenPressurized fluidization has been developed in quite a few industrial applications, such as newly proposed pressurized oxy-fuel combustion for CO2 capture. Quite a few studies reported that there are some differences of hydrodynamics between the pressurized and the atmospheric conditions. However, it is not very clear whether the correlations of the bubble size and rise velocity originally developed for the atmospheric condition can be used in pressurized condition. In this work, the effects of elevated pressure on the minimum fluidization velocity (umf), bubble properties (bubble size (Db) and bubble rise velocity (ub)) and bed expansion ratio are investigated in a lab-scale, pressurized fluidized bed, covering a range of 0.1 to 0.6 MPa. Results show that the umf, bed expansion ratio (H/H0), Db and ub decrease with increasing pressure, and this change trend is more obvious for the larger particles. The predictions of the average bubble diameter in pressurized conditions are close to the prediction of the Cai correlation. The bubble rise velocity is well predicted by the Shen correlation and Davidson correlation without the (ug − umf) term. The relationships between the average bubble rise velocity and bubble diameter at different pressures satisfy the form of correlation ub=kgDb. With the pressure increasing from 0.1 MPa to 0.6 MPa, the coefficient k decreases slightly for different particles.Graphical abstractGraphical abstract for this article
       
  • Effect of Additives on Liquid-Liquid Equilibrium Properties of
           Butane/Bitumen Systems with Applications to Solvent Aided Bitumen Recovery
           Processes
    • Abstract: Publication date: Available online 14 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Hassan Sadeghi Yamchi, Mohsen Zirrahi, Hassan Hassanzadeh, Jalal Abedi, Hossein FadaeiSolvent-aided bitumen recovery processes are relatively new approaches to reduce the negative environmental impacts and production costs of steam assisted gravity drainage (SAGD). Thermo-physical properties of these systems such as density, viscosity, phase partitioning and saturation pressure are of great importance in design of solvent-aided processes. Butane is a promising solvent for solvent-aided bitumen recovery processes. Addition of light or heavier solvents to butane can provide an engineering solution to improve the efficiency of solvent-aided processes. In this study, equilibrium measurements of butane and bitumen mixture were conducted at temperatures of 40 and 60 °C and pressures well above vapor pressure of the solvent. Then, the effect of introducing a second solvent as an additive to the butane-bitumen mixture was investigated. Propane, toluene and dimethyl ether were added to the original mixtures of butane and bitumen in separate sets of experiments and changes in thermo-physical properties were determined. It was determined that adding butane can lower the viscosity of the bitumen by several orders of magnitude. It was also concluded that although propane can significantly increase the saturation pressure of the mixture, it results in higher amount of asphaltene precipitation. The effect of dimethyl ether however is favourable because not only increases the vapour pressure but also reduces the asphaltene precipitation similar to toluene.Graphical abstractGraphical abstract for this article
       
  • Semi-analytical models of non-spherical particle shapes using optimised
           spherical harmonics
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Urtė Radvilaitė, Álvaro Ramírez-Gómez, Dainius Rusakevičius, Rimantas KačianauskasDetermining particle shape is vital for many industrial processes such as those found in the pharmaceutical, agricultural, and bioenergy industries. With modelling being an essential tool to acquire an understanding of the behaviour of particulates in industrial processes, numerical methods such as DEM are needing numerical solutions to formulate and implement particle shape models that overcome current limitations. Whereas pharmaceutical particles have a regular shape, agricultural and biomass particles often are specific, irregular and non-analytic. Because the diversity of real shapes is enormous, a variety of methods for describing particle shapes currently exist. Recently, the series of spherical harmonics (SHs) has gained much interest through their application in many other fields. This paper focuses on the application of the semi-analytical SH technique and addresses the development of a universal modelling tool for describing different particle shapes using a finite number of SHs. The results obtained from modelling pharmaceutical, agricultural, and biomass particles prove the applicability of SHs to regular as well as irregular shapes. In this regard, their optimised description by minimising the number of non-zero expansion coefficients is demonstrated. To proceed with a smaller number of low-order SHs, surface segmentation is introduced. Sufficient accuracy in the shape description of the particles selected was achieved with less than 16 SHs.Graphical abstractGraphical abstract for this article
       
  • Blending in above ground storage tanks with side-entering agitators
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): R.K. Grenville, J.J. Giacomelli, G.J. VanOmmeren, C.F. Hastings, M.J. WaltersAbstractThe blending of fluids in large, above ground storage tanks is widely practiced in the petroleum industry yet there have been very few studies of this mixing operation. The most demanding application is found when the tank contents have been allowed to stratify creating a light and heavy layer. The blend time in this case is defined as the time taken for the density of the fluid to become axially homogeneous.Wesselingh (1975) measured blend times using brine and water to produce the heavy and light layers and measured conductivity changes to assess the blending process. He only looked at one propeller geometry but did study the effects of several important geometrical system properties, such as the ratio of propeller to vessel diameter and liquid depth to vessel diameter.The study reported here uses Wesselingh’s technique but examines the blending performance of four commercially available propellers. The results show that the Advanced Pitch propeller sold by Philadelphia Mixing Solutions Ltd. and Mixing Solutions Ltd. is significantly more efficient than the competitors’ propellers when compared based on energy usage.These results, and Wesselingh’s, show that there are two operating regimes which are separated by a critical Froude number, FrC. At high Froude numbers (Fr > FrC) the dimensionless blend time is constant, and at lower Froude numbers (Fr 
       
  • Performance of continuous countercurrent extractor on the fractionation of
           Citrus bergamia essential oil using ethanol/water mixtures as solvents
    • Abstract: Publication date: Available online 13 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Daniel Gonçalves, Cristina Chiyoda Koshima, Fábio Rodolfo Miguel Batista, Christianne Elisabete da Costa RodriguesBergamot model mixture and crude bergamot essential oil (CBEO) were fractionated in a perforated rotating disc contactor (PRDC) using as solvents ethanol with 30% (Et30) and 40% (Et40) water, in mass. The apparatus performance was evaluated by experimental extraction indices, essential oil (EO) folding and estimative of mass transfer coefficients. The effects of the solvent to feed mass flow ratio (S/F), disc rotation speed (DRS), feed composition, and water content in the solvent over the process performance were thus appraised. Furthermore, the fractionation of model mixtures was simulated by Aspen Plus software. It was experimentally verified that higher S/F improved the extraction indices and mass transfer, whereas solvent Et40 and higher DRS also contributed for that results. Solvent Et40 extracted lower amount of components from the EO, but the Folds were similar to the ones achieved using solvent Et30. The simulation followed the same tendency. For the model mixture, a 1.54-fold EO was obtained, while for the CBEO a 1.4-fold EO was reached. Overall, solvent Et40, S/F close to 2, and low DRS exhibited the best results for the fractionation of CBEO in PRDC.Graphical abstractGraphical abstract for this article
       
  • Effect of decaying swirl flow on tubular turbulent heat transfer
           enhancement by using short length helical tapes
    • Abstract: Publication date: Available online 11 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Yuxiang Hong, Juan Du, Shuangfeng Wang, Si-Min Huang, Wei-Biao YeAbstractThis study deals with an experimental investigation on turbulent thermal-hydraulic performances in a plain tube (PT) mounted with swirl flow devices of short length helical tapes (SL-HTs). The heat transfer experiments were conducted at constant heat flux wall conditions while the pressure drop tests were performed at iso-thermal wall conditions. Effects of Reynolds number (Re) at 5000-19000, tape length ratios (L/D) at 31.034-46.552, hole diameter ratios (W/D) at 0.276-0.414 and pitch length ratios (P/D) at 1.034-1.724 were explored by employing air as working fluid. The main findings are that the Nusselt number (Nu) and friction factor (f) in the PT inserted with SL-HTs could be enhanced by around 1.58-2.64 times and 4.72-16.26 times respectively in comparison with the alone use of PT. The obtained information also provides that both the Nu and f increase with increasing L/D, decreasing W/D and decreasing P/D while the PEC increases as L/D and P/D increases. In addition, the maximum PEC of about 1.17 is gained by the SL-HT at Re = 5971, L/D = 46.552, W/D = 0.276 and P/D = 1.724. The comparisons with some previous studies indicate that the SL-HTs hold certain competitive advantage. At last, the thermal-hydraulic characteristics correlations are developed with Re, L/D, W/D and P/D and the deviations from the experimental values are within ±5% for Nu and ±9.0% for f.
       
  • A study of bubble size evolution in Jameson flotation cell
    • Abstract: Publication date: Available online 11 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Hongzheng Zhu, Alejandro López Valdivieso, Jinbo Zhu, Shaoxian Song, Fanfei Min, Mario Alberto Corona ArroyoAbstractThe Sauter mean diameter (d32) of bubbles was characterized for a gas-liquid system in a laboratory Jameson-type flotation cell with focus on the size variation in the uprising path of the bubbles in the riser of the flotation cell. Methyl isobutyl carbinol (MIBC) was used as frother for bubble stability. The effect of MIBC concentration, sampling height in the riser, gas flow rate (Jg) and liquid flow rate (Jl) in the downcomer on d32 was investigated. The d32 significantly decreased with increasing MIBC concentration until the Critical Coalescence Concentration (CCC), above which the d32 was almost constant at 0.645 mm. CCC95, CCC90 and CCC85 were calculated to be 0.059, 0.046 and 0.038 mmol/L, respectively for a Jg of 1.32 cm/s and Jl of 11 cm/s. Four frother concentrations covering these three values were selected for detailed studies. The size variation of bubbles was related to the Reynolds number (Re) in the downcomer, where the Re was influenced by Jl and Jg. Bubble size increased with the sampling height in the riser at MIBC concentrations below CCC95. This bubble size decreased with the Re and, for all the MIBC concentrations used in this investigation, it reached a critical value, even at MIBC concentrations below the CCC85.
       
  • Removal of nickel from industrial effluent using a synergistic mixtures of
           acidic and solvating carriers in palm oil-based diluent via supported
           liquid membrane process
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Raja Norimie Raja Sulaiman, Norasikin Othman, Norul Fatiha Mohamed Noah, Norela JusohThe utilization of environmentally benign diluent of palm oil in the supported liquid membrane (SLM) process is able to reduce both environmental and economic problems due to the consumption of the petroleum-based diluent. A preliminary study has been conducted on the removal of nickel ion via SLM using bis(2-ethylhexyl) phosphate (D2EHPA), octanol, kerosene and sulfuric acid solution as a carrier, synergist, diluent and stripping agent, respectively. Several process variables involve namely D2EHPA, octanol and sulfuric acid concentration as well as feed flowrate were optimized using the Box–Behnken design (BBD). Results showed that about 90 and 95% of the nickel ions were successfully removed and recovered, respectively after 6 h at a permeation coefficient of 6.94 × 10−6 cms−1 under optimum conditions of 1.25M D2EHPA, 15% (v/v) octanol, 1.75M sulfuric acid and 100 mL/min of feed flowrate. Using the aforementioned optimum condition, a further investigation on the removal and recovery performance of nickel has been carried out by means of the palm oil as a diluent. Interestingly, the result showed that about 91 and 65% of the nickel ions were successfully removed and recovered, respectively. Hence, it revealed that palm oil has high prospective as a substitute for sustainable diluent in the SLM process as well as offering a better insight in the separation process that deals with an environmentally friendly materials in the future. Besides, the stability of the membrane was found to be satisfactory over ten consecutive cycles of operation.Graphical abstractGraphical abstract for this article
       
  • Modeling and optimal control of conversion section of styrene plant to
           overcome effect of catalyst deactivation on production capacity
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Z. Edraki, M. Farsi, M.R. RahimpourAbstractIn this research, a pseudo steady state model is developed based on the mass and energy balance equations to simulate conversion section of a styrene monomer production plant. The conversion section includes three radial flow reactors in series, equipped with inter stage coolers. Typically, dehydrogenation catalyst experiences deactivation due to loss and migration of promoters, and increasing temperature and steam flow rate are practical solutions to prevent production decay in the plant. In the first step, accuracy of the simulation results is proved against plant data. Since there are different paths to overcome catalyst decay and maintain production capacity at desired level, the main challenge is selection and sequence of manipulated variables to control production capacity considering minimum effort. In this research, a real time optimization strategy is proposed to calculate the optimal trajectory of manipulated variables to control production and selectivity at desired level based on the optimal control theory. The optimization results indicated applying obtained optimal trajectories on the system increases production capacity about 16.13%.
       
  • Sparse Bayesian learning for data driven polynomial chaos expansion with
           application to chemical processes
    • Abstract: Publication date: Available online 10 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Pham Luu Trung Duong, Le Quang Minh, Muhammad Abdul Qyyum, Moonyong LeeUncertainties are ubiquitous in process system engineering. Hence, to develop a safe and profitable process, uncertainty quantification (UQ) is necessary in a reliability, availability, and maintainability (RAM) analysis. Generalized polynomial chaos expansions can be used as an efficient approach to UQ and work efficiently under the assumption of perfect knowledge with regard to the probability density distribution function of uncertainties. However, this assumption can hardly be satisfied in a real process scenario, mainly because of the limited knowledge regarding the probability density distribution function of uncertainties. To solve these issues, this study investigates the performance of orthogonal polynomial chaos in the UQ of chemical processes, including synthesis gas production and natural gas dehydration. Simultaneously, the limitations of orthogonal polynomial chaos were also investigated by an overwhelming sparse Bayesian learning approach considering a complicated nonlinear crude oil distillation unit with moderate uncertainty numbers. We found that the application of orthogonal polynomial chaos was limited to a small number of uncertainties, mainly because of using the polynomial’s tensor product. Finally, the orthogonal polynomial chaos and sparse Bayesian learning approach were rendered computationally effective in comparison with the conventional Monte Carlo method (approximately 96.5% improvement).Graphical abstractGraphical abstract for this article
       
  • DESIGN METHOD FOR CONTINUOUS BIOREACTORS IN SERIES WITH RECIRCULATION AND
           PRODUCTIVITY OPTIMIZATION
    • Abstract: Publication date: Available online 10 August 2018Source: Chemical Engineering Research and DesignAuthor(s): C.A. Gómez-Pérez, Jairo EspinosaA design method for continuous bioreactors in series with recirculation is found using Singular Value Decomposition (SVD). The optimal dilution rate and recirculation proportion which are found to maximize the productivity. Using the biomass balance equations, a set of linear equations of the form Ax = 0 is obtained. The nontrivial solution, which is obtained by a matrix null space, is dependent on the dilution rate and the recirculation proportion. Since the solution has infinite options determined by the dimension of the null space, the real biomass concentration solution is fixed by the substrate consumption and its conversion. Using an iterative method to manage the non-linear equations it is possible to obtain the non-trivial solution and to calculate the productivity, which has a maximum at an optimum dilution rate. The method obtained will help to the implementation of complex continuous bioreactors.Graphical abstractGraphical abstract for this article
       
  • Role of Oxygen Storage/Supply Capacity of Mixed Oxides of Ce and Zr in
           Ethanol Oxidation
    • Abstract: Publication date: Available online 10 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Paresh H. Rana, Parimal A. ParikhAbstractA series of CexZr1-xO2 (x = 0.25, 0.5, 0.75) was prepared by precipitation method and wet impregnation method was employed for the synthesis of Au/CexZr1-xO2 catalysts. All prepared catalysts were characterized by XRD, TEM, EDX, TGA, and FTIR spectroscopy. Catalytic activity was studied in the temperature range of 200 to 350 °C and total pressure of 5 atm maintaining GHSV of 18000 mLgcat−1h−1 for oxidation of ethanol (aqueous solution with a typical concentration in bioethanol, i.e., 10 wt%). Results showed that insertion of Zr to Ce framework improved the oxygen storage capacity (OSC) which subsequently enhances supply of oxygen for the reaction and ultimately leading to increased ethanol conversion. Increased Zr content in Ce framework led to enhance ethanol conversion, while reverse trend was observed for acetaldehyde selectivity. Au/CexZr1-xO2 catalysts exhibited good catalytic behavior in terms of conversion and selectivity towards acetaldehyde and displayed time-on-stream.
       
  • Characterization of a vibromixer: Experimental and modelling study of
           mixing in a batch reactor
    • Abstract: Publication date: Available online 10 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Pawel M. Orlewski, Yan Wang, Mercedeh Sadat Hosseinalipour, David Kryscio, Martin Iggland, Marco MazzottiAbstractExperimental as well as modeling approach has been combined to characterize mixing in a batch reactor using a Fundamix vibromixer. Competitive-parallel chemical reactions were used to study the effect of the geometrical properties of the agitator (i.e. disc diameter, number of frusta) and the operational parameter (amplitude of vibrations) on the mixing intensity. By deriving an expression for Reynolds number, the joint effect of the geometrical properties and the operational parameters on the mixing performance of the system could be studied. Furthermore, a CFD model of the system using a commercially available software has been developed and the modeling results have been combined with the experimental information by showing how the product of the slow reaction is controlled by the Damköhler number. Having the capability to simulate the process, a comparison of the vibromixer with a traditional impeller by comparing the generated shear rate at the same level of mixing intensity for both devices has been made.
       
  • Experimental investigation of oil-in-water microfiltration assisted by
           Dielectrophoresis: Operational condition optimization
    • Abstract: Publication date: Available online 8 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Maryam Abbasi Monfared, Mohammad Sheikhi, Norollah Kasiri, Toraj MohammadiAbstractMembrane filtration is an efficient method in treating oily waste water containing fine oil droplets. However rapid fouling of membrane and decay in process performance has resulted in limited industrial application of membrane processes for oily waste water treatment. In this paper, electric field is used as an assisting force to improve oil in water microfiltration performance. An electrically safe membrane module is fabricated and used for microfiltration studies in the presence of electric field. A statistical study is developed for conducting necessary experiments to identify optimum processing conditions in the presence of an AC electric field. Two response functions of stable flux and oil rejection are defined and optimized with response surface methodology and central composite design. The effects of trans membrane pressure, cross flow velocity, feed concentration and applied voltage on stable permeate flux and oil rejection are studied for an emulsion of 1.93 μm oil droplets in water in a microfiltration system with cellulose acetate membrane of 0.45 μm pore size. Results reveal that induction of electric field can considerably improve process performance. Variation in studied factors results in the flux ranging from 64 to 140 L/m2hr while rejection varies between 85% and 97%. Quadratic models are suggested for flux and rejection with 0.93 and 0.83 R2 values respectively. Optimum conditions are predicted at 136.2 L/m2hr for flux and 94.1% for rejection, observed at 360 V, 1.1 m/s, 900 ppm and 2.5 bar. The real values for flux and rejection are 131.8 L/m2hr and 88.7% respectively representing −3.4% and −6.0% relative errors for the correlations.
       
  • Reduction of energy demand by use of air sparging during ultrafiltration
           of alkali-extracted wheat bran hemicelluloses
    • Abstract: Publication date: Available online 8 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Johan Thuvander, Anders Arkell, Ann-Sofi JönssonThe flux during membrane filtration can be enhanced by the use of a two-phase gas-liquid flow. This has been shown to be an energy-efficient alternative to increasing the cross-flow velocity. In this work, air sparging was used to increase the flux during ultrafiltration of alkali-extracted wheat bran hemicelluloses. Batch filtration was performed in a pilot unit with a ceramic ultrafiltration membrane with a nominal cut-off of 10 kDa. Parametric studies with and without air sparging were performed at temperatures of 30 °C, 50 °C and 80 °C and cross-flow velocities of 1, 3, 5 and 7 m/s. The limiting flux was not affected by air sparging at 30 °C, while a slight increase was observed at 50 °C and a considerable increase was obtained at 80 °C. Air sparging reduced the energy demand per m3 permeate produced during dead-end batch ultrafiltration at 80 °C and 1 m/s from 0.96 kW/m3 to 0.51 kW/m3.Graphical abstractGraphical abstract for this article
       
  • Computational fluid dynamic (CFD) simulation of laterally-fed membrane
           chromatography
    • Abstract: Publication date: Available online 8 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Umatheny Umatheva, Pedram Madadkar, P. Ravi Selvaganapathy, Raja GhoshCurrently, most bioseparation processes used for purification of bio-pharmaceutical products such as vaccines, monoclonal antibodies, and enzymes use resin-based column chromatography. Resolution and productivity are two of the major factors that should be optimized in any purification process. While column chromatography techniques give high-resolution and consequently very high product quality, they are slow, leading to low-productivity and high production cost. One of the alternatives to resin-based columns is membrane chromatography, where a stack of membrane sheets is used as chromatographic media. Membrane chromatography is a fast and scalable technique; however, it is not commonly used for some of the critical purification steps due to its low-resolution capability. A technique newly developed in our group called laterally-fed membrane chromatography (or LFMC) combines high-resolution separation with high-productivity. It is, therefore, suitable for rapid, multicomponent protein purification. LFMC not only gives higher resolution than other membrane chromatography devices, it gives comparable resolution to that obtained with equivalent resin-based packed bed columns, even at significantly higher flow rates, as demonstrated in our previous work. This paper examines the system fluid dynamics in an LFMC device using computational fluid dynamics (CFD) simulations and explains the reasons behind its superior separation attributes.Graphical abstractGraphical abstract for this article
       
  • Intensity and efficiency of droplet dispersion: Pulsating flow type
           apparatus vs. static mixers
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): M.P. Vasilev, R.Sh. AbievThis paper presents an experimental study of the basic and most important characteristics of novel type of static disperser — a pulsating flow type apparatus (PFA). The pressure drop for single-phase flow and droplets size distribution for emulsification process at turbulent flow regime (20 000 
       
  • Post-combustion CO2 capture using supported K2CO3: Comparing physical
           mixing and incipient wetness impregnation preparation methods
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): S.Toufigh Bararpour, Davood Karami, Nader MahinpeyCO2 capture performance of 50 wt.% K2CO3/alumina was investigated using various types of alumina supports such as γ-Alumina, Boehmite and Aerogel. Physical mixing and incipient wetness impregnation were used for preparing sorbents. Physically mixed K2CO3/γ-Alumina was the most efficient sorbent, with a maximum CO2 capture capacity of 5.5 mmol CO2/g K2CO3. γ-Alumina displayed the lowest, and Aerogel the highest, hydrophilicity and surface area. Increasing hydrophilicity and surface area also increased water adsorption capacity, which adversely affected the CO2 capture capacity of the physically mixed sorbents. The excess water adsorption capacity converted K2CO3 to an almost inactive precursor of K2CO3·1·5H2O. BET and SEM results showed that recrystallization of K2CO3 from water had an adverse impact on the physical structure of the impregnated sorbents which affected their CO2 capture performance. The kinetic behavior of the samples was analyzed using the Avrami kinetic model. K2CO3/γ-Alumina prepared by physical mixing and impregnation methods showed the highest carbonation rates with K-values of 0.1168 and 0.2260, and n-values of 1.1257 and 1.2004, respectively. K2CO3/Aerogel and K2CO3/Boehmite prepared by the physical mixing method exhibited higher performance than the respective impregnated sorbents in terms of carbonation rate and CO2 capture capacity.Graphical abstractGraphical abstract for this article
       
  • Characterization and aerosolization performance of mannitol particles
           produced using supercritical assisted atomization
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Hsien-Tsung Wu, Yung-Chuan Su, Yi-Min Wang, Hong-Ming TsaiDifferent shapes and sizes of water-soluble mannitol (MAN) particles were prepared using a supercritical assisted atomization (SAA) process. The needle-shaped and spheroidal mannitol particles were prepared using water and aqueous ethanol, respectively, as solvent of the MAN solution. The size of mannitol particles increased with increasing the concentrations of MAN solution and deceased with increasing saturator temperatures and CO2-solution flow ratios. The in vitro aerodynamic behavior of the mannitol particles as dry powder inhaler (DPI) formulations was investigated using an Andersen cascade impactor. The effects of the morphology and the size of mannitol particle on powder deagglomeration and flowability were evaluated. In vitro aerosolization tests showed that the spheroidal particles favor deagglomeration of mannitol powder and the fine particle fraction (FPF) was enhanced by the excellent powder flowability of the larger mannitol microparticles.Graphical abstractGraphical abstract for this article
       
  • Gas-liquid mass transfer rates in unbaffled tanks stirred by PBT: scale-up
           effects and pumping direction.
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Radim Petříček, Libor Labík, Tomáš Moucha, Alberto Brucato, Francesca ScargialiAbstractUnbaffled stirred tanks are increasingly recognized as a viable alternative to common baffled tanks for a range of applications such as biochemical, food or pharmaceutical processes where the presence of baffles is undesirable for some reason.In this work, the mass transfer performance of unbaffled stirred tanks with pitched blade turbine, operating either in up-pumping or down-pumping mode, was investigated. The influence of impeller size and liquid viscosity were also investigated.The mass transfer intensity was measured by means of the Simplified Dynamic Pressure.MethodThe measurements concerned both coalescent and non-coalescent (viscous) batches.Resultsconfirm that increasing apparatus size has a slightly positive effect on gas-liquid mass transfer coefficient. It was also found that when the PBT is operating in the up-pumping mode the formation of surface oscillations, which lead to undesired instabilities of the whole apparatus, is conveniently minimized. In the super-critical regime, the unbaffled tanks provide a performance comparable with that of the standard (baffled) bioreactors at the same power dissipation, which makes them a viable alternative for general fermentation operations and other gas–liquid reactions.
       
  • Optimal selection of operating pressure for distillation columns
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Chengtian Cui, Siyao Liu, Jinsheng SunOptimal design of distillation columns is complex because of many entangled design variables, such as operating pressure, reflux ratio, number of stages, product specifications, etc. Amongst these parameters, operating pressure is the premise towards more economic performance related to not only capital investment but also energy cost. A common heuristic is to arbitrarily fix the pressure if inexpensive cooling water can be used at condenser. However, it cannot always guarantee an optimum column. The traditional way to obtain the optimum pressure is to perform time-consuming iterative rigorous simulations. That is, basically no handy systematical method is available to quick determine optimum column pressure. To eliminate this research gap, this study is devoted to provide an equation-oriented shortcut optimization model to determine optimum pressure avoiding manual iterative calculation. The proposal pathway can estimate column total annualized cost considering capital and energy costs simultaneously before being used to initialize rigorous design. Feasibility and accuracy of this approach are perfectly verified on Aspen Plus through five case studies — propylene–propane, benzene–toluene, cyclohexane–cyclohexanol, methanol–water, and n-pentane–n-hexane–n-heptane systems.Graphical abstractGraphical abstract for this article
       
  • Rheometric assessment and numerical simulation of steady-state and
           periodic flows of fabric-water mixtures in household top-load washing
           machines
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Felipe R. Loyola, Waldyr de Lima e Silva, Luiz G.C. Campos, Christian J.L. HermesAbstractThe washing process in household top load washing machines relies on the mass and momentum transport from an agitator to the fluid stream. In such cases, such a periodic flow follows a pattern that recalls the so-called Taylor–Couette flow, whose main characteristic is the confinement between two rotating cylinders. The present paper is aimed at steady-state and periodic-unsteady-state flows of non-Newtonian fluids formed by fabric and water mixtures. A simplified coaxial double cylinder geometry is used as the physical domain for the numerical analyses, whereas an agitation profile (angular swept and speed) was imposed to the inner cylinder. The rheological properties of the working fluid made of aqueous fabric suspensions were obtained in-house by solving the Couette inverse problem using a wide-gap rheometry approach. Four different NNF models have been evaluated – namely, Bingham, Casson, Robertson–Stiff, and Herschel–Bulkley – for data reduction and correlation, when it was observed that the last one provided the best results for different fabric-water suspensions. Numerical simulations were performed using a 3D homemade finite-volume model, and experimental tests (234 runs at steady-state and 80 runs at periodic flow conditions) were carried out by means of a purpose-built testing facility. The simulation model was validated against experimental data indicating an agreement between numerical and experimental torques and velocities within the 20% thresholds.
       
  • Production of N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid by
           BMED process using porous P84 co-polyimide membranes
    • Abstract: Publication date: Available online 4 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Mengjie Sun, Meng Li, Pin Wang, Xu Zhang, Cuiming Wu, Yonghui WuAbstractAnion exchange membranes are prepared by phase inversion of P84 co-polyimide to obtain porous structure, and then chemically modified by branched polyethylenimine. The porous membranes are compared with a dense P84 membrane. The dense membrane is hydrophobic with large area resistance (> 85 Ω cm2), while the porous membranes are hydrophilic with low area resistance (2.4–3.5 Ω cm2), lower than that of commercial membrane CJMA-3 (6.0 Ω cm2). The ion exchange capacities are in the range of 0.83–0.86 mmol/g and the water uptake values are 90–130%, both of which are higher than those of dense P84 membrane and CJMA-3 membrane (0.5–0.6 mmol/g; 15–20%).The P84 co-polyimide membranes are utilized in bipolar membrane electrodialysis (BMED) process to produce N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES). The porous membranes can decrease the transport resistance of HEPES− ions and yield high recovery ratio and current efficiency, while the dense membrane is unsuitable for BMED. The output of HEPES is increased significantly if the membranes have finger- or tear-like pores, as well as higher ion exchange capacity. The HEPES− recovery ratios are 52.3 − 61.6% after running 6 h under 40 V, which are higher than that of membrane CJMA-3 (46.5%). The current efficiency can reach up to 86.1% and the energy consumption is only 3.92 kW h/kg by using the optimal porous membrane M-1, which are better than membrane CJMA-3 (65.5%, 5.15 kWh/kg). Hence, the porous membranes have high potential for producing organic acid with high molecular weight.
       
  • Flow Regimes in Gas-Solid Fluidized Bed with Vertical Internals
    • Abstract: Publication date: Available online 4 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Haidar Taofeeq, Muthanna Al-DahhanAbstractIn this work, the impact of the vertical internals on the flow regimes and their transition velocities has been studied in a 0.14 m inside diameter gas-solid fluidized bed. The identification of the flow regimes was accomplished statistically (standard deviation) and chaotically (Kolmogorov entropy) by analyzing the pressure drop fluctuations. Circular configurations of vertical tubes with two different sizes (0.0254 and 0.0127 m diameter), two kinds of solid particles of Geldart B type (glass beads and aluminum oxide), and a wide range of superficial gas velocities (0.15-1.2 m/s) have been implemented in this study. Generally, it was demonstrated that the vertical internals have a significant effect on the flow regimes, transition velocities, and transition velocity ranges of each individual flow regime.However, such effect is a function of the physical properties of the used solid particles in which the turbulent transition velocity (Uc) decreased in the case of glass beads and increased in the case of aluminum oxide for both of the configuration designs of vertical internals used in the present work. In addition, the 0.0254 m vertical internals type has been shown to be more efficient either in minimizing the turbulent transition velocity (Uc) and superficial gas velocity within the range of slugging flow regime and increasing the range of the superficial gas velocity within the range of bubbling flow regime or in reducing the pressure drop and pressure fluctuations inside the bed.
       
  • Liquid-liquid extraction-based process concepts for recovery of carboxylic
           acids from aqueous streams evaluated for dilute streams
    • Abstract: Publication date: Available online 3 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Ehsan Reyhanitash, Thomas Brouwer, Sascha R.A. Kersten, A.G.J. van der Ham, Boelo SchuurAbstractIn this manuscript carboxylic acid extraction processes are reviewed and compared on energy efficiency, especially in situations with very low carboxylic acid concentrations. Production of carboxylic acids by fermentation rather than petrochemical routes aims at reducing dependency on petroleum resources. Wastewater streams are potential carbon sources for fermentation. However, their limited carbon content results in low carboxylic acid concentrations (∼1 wt%) that render separation of waste-derived carboxylic acids challenging. This necessitates implementation of cost-effective separation concepts. The incentive to review liquid-liquid extraction (LLX)-based processes for carboxylic acids was to evaluate their applicability to low carboxylic acid concentrations. Although a thorough study of recent solvent developments was beyond the scope of this work, a brief discussion on their families supported the LLX-based process developments that were assessed in terms of energy demand by simulating their thermal unit operations with Aspen Plus. They were simulated both under their reported conditions and with their initial concentration set to 1 wt%. A process proposed by Urbas (Urbas, 1983) that makes use of CO2, CO2-switchable solvents and low-boiling organic solvents outperformed the others for low carboxylic acid feed concentrations. With a heating duty of about 36 MJ/kgproduct, it could recover both volatile and non-volatile carboxylic acids from fermentation broths with 1 wt% initial carboxylic acid loading. Future developments in the field may be based on this process design, but with more environmentally friendly solvents such as the bio-based furan derivatives.
       
  • Response surface optimization, kinetic study and process design of n-butyl
           levulinate synthesis
    • Abstract: Publication date: Available online 2 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Manali B. Kokare, Ranjani V, C.S. MathpatiLevulinic acid is an important intermediate chemical, derived from biomass. It is considered platform chemical as its derivatives have numerous applications in various fields. n-butyl levulinate is a levulinic acid derived ester which has wide applications, such as plasticizing, flavouring agent, solvent, and fuel additive. The present work deals with reaction parameters optimization using response surface method for n-butyl levulinate synthesis with Amberlyst 15 catalyst. The process parameters such as acid to alcohol molar ratio, catalyst loading and temperature have been considered. Under optimized conditions, the levulinic acid conversion of 97.03% was obtained. Intrinsic kinetics was studied based on the Langmuir Hinshelwood Hougen Watson model (LHHW) model and the activation energy was found to be 39.89 kJ/mol. The commercial viability of the process was evaluated for the capacity of 500 kg/hr using aspen simulations. Conventional reactive distillation and divided wall reactive distillation schemes were evaluated and cost of production per kg of product was estimated.Graphical abstractGraphical abstract for this article
       
  • Cold-model investigation of effects of operating parameters and overflow
           outlet diameter on separation with a liquid-liquid cyclone reactor for
           isobutane alkylation catalyzed by ionic liquid
    • Abstract: Publication date: Available online 2 August 2018Source: Chemical Engineering Research and DesignAuthor(s): Zhenbo Wang, Mingyang Zhang, Zhichang Liu, Liyun Zhu, Youhai Jin, Chunming XuAbstractA liquid-liquid cyclone reactor (LLCR) was designed to enhance mixing and accelerate separation between reaction products and catalysts during isobutane alkylation catalyzed by ionic liquid. The LLCR was designed on the basis of the axial-flow hydrocyclone. The effect of total inlet flow (Qt), feed ratio (rf), overflow ratio (ro) and overflow outlet diameter (Do) on the performance of LLCR (pressure drop, ΔP, and recovery, R) was investigated. The LLCR’s performance indices underflow pressure drop (ΔPu), overflow pressure drop, (ΔPo), glycerin water solution recovery (Rg), kerosene recovery (Rk), reduced efficiency were determined. The results were used to establish an empirical models predicting LLCR efficiencies from total inlet flow, feed ratio, overflow ratio and overflow outlet diameter. Besides, an optimal overflow ratio, ror, was proposed to realize the optimization of two-phase recovery, which is linear with the expression of feed ratio. The results show that the range of the empirical coefficients (k) in the expression of ror is 1.02 ∼ 1.14.
       
  • Kinetic study and process simulation of esterification of acetic acid and
           ethanol catalyzed by [HSO3-bmim][HSO4]
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Ruining He, Yun Zou, Yanbo Dong, Yaseen Muhammad, Sidra Subhan, Zhangfa TongEthyl acetate is an important chemical and versatile organic solvent. However, use of hazardous catalyst for preparing ethyl acetate, can lead to serious environmental problems. Herein we report two acid sites containing ionic liquid i.e. 1-sulfobutyl-3-methylimidazolium hydrogen sulfate ([HSO3-bmim][HSO4]) as a green catalyst in the esterification of acetic acid with ethanol. The reaction kinetics was investigated using IH and NIH models and the effect of reaction temperature, catalyst concentration, and initial reactant molar ratio were analyzed. To study the industrialization prospect of [HSO3-bmim][HSO4], reactive distillation process was established in Aspen Plus and the influence of catalyst amount, theoretical stages, reflux ratio, liquid holdup, and ethanol feeding location were investigated. Simulation results indicated the purity of ethyl acetate was 98.94 wt.% while ethanol conversion was 91.51% under optimized operating conditions. [HSO3-bmim][HSO4] was found as superior catalyst, both in conversion and reaction rate, than an equivalent amount of Amberlyst 15 (in terms of H+ ion concentration). The present study based on the application of [HSO3-bmim][HSO4] as a green catalyst instead of sulfuric acid, can be envisaged as a promising alternative approach for the esterification of acetic acid on industrial level.Graphical abstractGraphical abstract for this article
       
  • A systematic decision analysis approach to design biomass combined heat
           and power systems
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Wen Choong Ling, Viknesh Andiappan, Yoke Kin Wan, Denny K.S. NgAbstractDesigning a biomass combined heat and power (CHP) system that fulfils uncertain energy demands is a challenging task. This task becomes increasingly complex when historical data and probability distributions are not well defined. This work presents a newly developed decision analysis design framework for biomass CHP system which considers three types of decision-makers, namely optimistic, pessimistic and cautious decision-makers. To illustrate the proposed framework, a palm-based biomass CHP case study is solved. In addition, sensitivity analysis is performed to evaluate the effect of Feed-in Tariff (FiT) rates towards the design of CHP system. The optimum biomass CHP design is then further analysed to determine the “must-have”, “optional” and “must-avoid” equipment within a given range of power demand. The proposed decision analysis design framework enables decision makers to make informed decisions.
       
  • Synthesis of a biobased monomer derived from castor oil and
           copolymerization in aqueous medium
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Larissa S. Laurentino, Anderson M.M.S. Medeiros, Fabricio Machado, Cristiane Costa, Pedro H.H. Araújo, Claudia SayerVegetable oils-based polymers are promising materials with application in the industry of coatings and adhesives. Chemically-modified ricinoleic acid obtained from castor oil was used in this study to produce polymeric materials. The adopted strategy consisted in the epoxidation of the double bonds of ricinoleic acid, followed by the ring opening reaction in the presence of acrylic acid to form the acrylated ricinoleic acid (ARA). Free radical copolymerizations of ARA and methyl methacrylate (MMA) were carried out in miniemulsion, resulting in latexes stable over a long storage time. DLS measurements revealed the formation of submicron polymeric particles of different sizes strongly dependent on the fraction of the biobased monomer ARA, exhibiting diameters ranging from approximately 80 nm to 150 nm, as the ARA fraction was increased up to 80 wt%. It was possible to prepare polymers with broad ranges of mass-average molar masses in the range from 1137 kDa to 65 kDa and glass transition temperatures lying in the interval from approximately 124 °C–50 °C by varying the concentration of the comonomer ARA. Crosslinked copolymers were obtained by increasing the proportion of ARA.Graphical abstractA biobased monomer acrylated ricinoleic acid was synthesized from castor oil and copolymerized with methyl methacrylate in miniemulsion forming polymeric nanoparticles. The addition of the biobased monomer led to a decrease in the glass transition temperature of the copolymer and to the formation of a small fraction of gel, resulting in materials with interesting properties for future applications.Graphical abstract for this article
       
  • Experimental and modeling investigations towards tailoring cellulose
           triacetate membranes for high performance helium separation
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Ali Soleimany, Javad Karimi-Sabet, Seyed Saeid HosseiniIn this study, novel membranes are designed and fabricated using CTA as the main matrix with contributions of PEG and as-synthesized ZIF-8 nanoparticles. Gas permeation properties of blend membranes containing 25–45 wt.% PEG and MMMs containing 2–20 wt.% ZIF-8 crystals are evaluated for the separation of He from N2 and CH4 at various temperatures and pressures. The properties of synthesized ZIF-8 nanoparticles as well as membranes are well characterized. Among all the prepared membranes, the MMMs membrane with composition of CTA/PEG/ZIF-8 (60/20/20 wt.%) exhibits the best performance (PH2 = 73.25 Barrer) for He/N2 (α = 43) and He/CH4 (α = 40) separations. In addition, various predictive permeation models are investigated in order to gain more insights about the systems and for validation of the experimental results. The %AAREs of the models are high, while the best value is obtained by applying the Maxwell model (5.98). Also, by choosing Lewis–Nielsen model and taking into account some of the non-ideal effects such as particle pore blockage, polymer chains rigidification as well as the effect of particles size on the rigidified layer thickness, a new while accurate model is proposed. Finally, the accuracy of the newly developed model is examined utilizing several experimental data.Graphical abstractSchematic representation of the possible molecular interactions between CTA, PEG and ZIF-8 nanoparticles.Graphical abstract for this article
       
  • Propane/propylene separation and CO2 capture in magnetic ionic liquid
           [bmim][FeCl4]
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Maogang He, Siqi Liu, Lihang Bai, Xiangyang LiuAbstractMagnetic ionic liquids (MILs), combines the general properties of ionic liquid with magnetic properties, are starting to attract interest in the field of propane/propylene separation and CO2 capture. Solubility data of propane, propylene, cyclopropane and CO2 in magnetic ionic liquid 1-butyl-3-methylimidazolium tetrachloroferrate [bmim][FeCl4] at temperatures of (303, 313, 323, 333, 343) K and pressures up to 3300 kPa were determined in the present work. The relative expanded uncertainty of solubility measurement is estimated to be less than 4% with a level of confidence of 95%. The Henry’s constants for the four gases in [bmim][FeCl4] and selectivity of C3H6/C3H8 in [bmim][FeCl4] were calculated. And the thermodynamic properties of solvation concerned about the Gibbs energy (ΔsolG∞), the enthalpy (ΔsolH∞) and the entropy (ΔsolS∞) of solvation were also obtained to offer knowledge for understanding the progress of gases dissolved in [bmim][FeCl4]. The experimental results were correlated with a modified KK equation and NRTL equation.
       
  • Controlled synthesis of Nix-Co(1-x) bimetallic nanoparticles using the
           thermogravimetric method
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Hassan Ghanbarabadi, Behnam KhoshandamIn the present study, Nix-Co(1-x) (x = 0, 0.2, 0.4, 0.6, 0.8, 1) nanoparticles(NPs) were synthesized using the thermogravimetric method. The production of these NPs was carried out through the reduction reaction of nickel and cobalt oxides, as metal precursors, and methane gas, as a reducing agent, under atmospheric pressure. The raw materials and the products were characterized using XRD, FESEM, XRF, EDS and Map analysis. Initially, the duration of the reduction reaction and conversion of NiO and CoO to Ni and Co NPs was predicted using a grain model simulation. The effect of different parameters such as methane volume percentage and reduction temperature on the duration of conversion were investigated by this model in order to properly choose the optimum temperature and volume percentage of methane gas for the experiments. The experimental results demonstrated that the reaction time of nickel and cobalt oxides with 23 vol.% methane at 830 °C for the production of Ni and Co NPs was 39 and 14 min, respectively, which was in good agreement with the predicted results. Investigation of the reaction time for (NiO)x-(Co3O4)(1-x) binary mixture with methane was evaluated by considering the relative compositions of NiO(x = 0, 0.2, 0.4, 0.6, 0.8, 1). The results showed that as the content of NiO in the binary mixture increased, the duration of Nix-Co(1-x)‌ NPs production decreased. XRD and EDS analysis confirmed the formation of about 96% of Ni0.6-Co0.4 BNPs and over 97% of Ni and Co NPs. In addition, the effect of methane diffusion into the pellets was investigated on (NiO)0.4-(CoO)0.6 with sintered and non-sintered modes.Graphical abstractGraphical abstract for this article
       
  • SUSCAPE: A framework for the optimal design of SUStainable ChemicAl
           ProcEsses incorporating data envelopment analysis
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Andres Gonzalez-Garay, Gonzalo Guillen-GosalbezDeveloping computer aided tools for process design is of paramount importance in the transition toward a more sustainable chemical industry. In this work, we present a framework to incorporate sustainability principles in the design of chemical processes that combines a palette of tools, including life cycle assessment, surrogate modeling, objective reduction, multi-objective optimization and data envelopment analysis (DEA). The latter methodology facilitates the post-optimal analysis of the Pareto front by narrowing down the number of designs and ranking them without the need to define weights in an explicit manner. DEA provides in turn improvement targets for the suboptimal alternatives that if attained would make them optimal, thereby guiding retrofit efforts toward the most effective actions based on benchmarking them against the best technologies available. The capabilities of the framework are demonstrated in a case study based on the production of methanol from CO2 and hydrogen.Graphical abstractGraphical abstract for this article
       
  • Imidazolium based ionic liquids containing methanesulfonate anion:
           comprehensive thermodynamic study
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Dzmitry H. Zaitsau, Andrei V. Yermalayeu, Andrey A. Pimerzin, Sergey P. VerevkinNew experimental vapor pressures and vaporization enthalpies of the ionic liquids [Cnmim][CH3SO3] (with the alkyl chain length n = 2, 3 and 4) have been measured by the QCM and TGA methods. Energies of combustion of [C2mim][CH3SO3] and [C4mim][CH3SO3] were measured in a high-precision rotating-bomb combustion calorimeter and used for calculation the aqueous enthalpy of formation of the ΔfHmo(CH3SO3aq−)anion. The solubility parameters of ILs under study have been derived from experimental ΔlgHmo(298.15 K) and used for estimation of miscibility of some common solutes in [Cnmim][CH3SO3]. This comprehensive thermodynamic study will facilitate chemical engineering calculations of processes involving ionic liquids.Graphical abstractGraphical abstract for this article
       
  • Influence of distributed pore size and porosity on MTO catalyst particle
           performance: Modeling and simulation
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Li-Tao Zhu, Wang-Yu Ma, Zheng-Hong LuoThis modeling study investigates the influence of spatially distributed pore size and porosity on diffusional and reactive features inside the methanol-to-olefin (MTO) porous catalyst particle. The model developed in this study integrates mass, momentum and heat balance equations, spatial pore size and porosity distribution models, multicomponent diffusion and lumped kinetic models. The proposed model was first validated by using the experimental and empirical data. The simulation results demonstrated that the pore diameter and porosity that decrease toward the particle core is the optimal distribution for the MTO catalyst particle. Subsequent parametric sensitivity analysis indicated that the temperature plays the most significant role in the effectiveness factor. The smaller pore diameter favors the larger ratio of the ethylene to the propylene. Comparing with the traditional trial-and-error methods, the proposed model is simple but effective, which is valuable for the design and optimization of porous catalyst particles.Graphical abstractGraphical abstract for this article
       
  • Prediction of surface tension of liquid normal alkanes, 1-alkenes and
           cycloalkane using neural network
    • Abstract: Publication date: Available online 20 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Mostafa Lashkarbolooki, Mahdi BayatAbstractIn the light of artificial neural network (ANN) model advantages, a predictive ANN model is proposed to correlate the surface tension of common hydrocarbons including normal alkanes (i.e. n-C4 to n-C40), linear alkenes (i.e. 1-C4 to 1-C40), and cycloalkanes (C4 to C20) in a wide range of temperatures. The most important advantage of the current proposed network is its low number of input variables which are only temperature of the system as well as carbon number and critical temperature of components utilized to differentiate among the different components. The obtained results revealed that a model trained by the Levenberg–Marquardt algorithm with hyperbolic tangent and linear transfer functions for the hidden and output layers, respectively, comprised of 27 hidden neurons is the optimum structure. In sum up, the obtained results demonstrated that the proposed ANN model is capable to satisfactorily predict and correlate the 5461 surface tension data points of normal alkanes, linear alkenes, and cycloalkanes as a function of temperature with maximum deviation of 0.47, 0.40 and 0.43 mN/m, respectively, just using three inputs parameters considering testing data subset.
       
  • Modeling of an industrial naphtha isomerization reactor and development
           and assessment of a new isomerization process
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Ahmed M. Ahmed, Aysar T. Jarullah, Fayadh M. Abed, Iqbal M. MujtabaNaphtha isomerization is an important issue in petroleum industries and it has to be a simple and cost effective technology for producing clean fuel with high gasoline octane number. In this work, based on real industrial data, a detailed process model is developed for an existing naphtha isomerization reactor of Baiji North Refinery (BNR) of Iraq which involves estimation of the kinetic parameters of the reactor. The optimal values of the kinetic parameters are estimated via minimizing the sum of squared errors between the predicted and the experimental data of BNR. Finally, a new isomerization process (named as AJAM process) is proposed and using the reactor model developed earlier, the reactor condition is optimized which maximizes the yield and research octane number (RON) of the reactor.Graphical abstractGraphical abstract for this article
       
  • A pressurized Gas Switching Combustion reactor: Autothermal operation with
           a CaMnO3−δ -based oxygen carrier
    • Abstract: Publication date: September 2018Source: Chemical Engineering Research and Design, Volume 137Author(s): Abdelghafour Zaabout, Schalk Cloete, Julian R. Tolchard, Shahriar AminiGas Switching Combustion (GSC) promises greatly simplified scale-up of highly efficient gas-fuelled chemical looping combustion (CLC) technology. The GSC uses a single reactor alternating fuel and air feeds into a bed of oxygen carrier. Such a simple standalone reactor will be much easier to scale up and pressurize than the conventional interconnected CLC configuration. This paper presents results from autothermal GSC operation completed in a pressurized lab-scale reactor using a CaMnO3−δ-based oxygen carrier which are especially suited to GSC because they greatly reduce the temperature variation across the transient GSC cycle. The reactor showed perfect performance when H2 was used as fuel, but significant fuel slip occurs with CO after the oxygen carrier was only half way reduced. Higher temperatures improved fuel conversion, while higher pressures had a negative effect. It can be expected, however, that more oxygen carrier utilization would be possible in a full-scale reactor where the gas residence time would be much higher. In addition, 2–7% CO2 release was observed in the oxidation stage (from the total molar carbon fed in the fuel stage), increasing with the degree of oxygen carrier reduction. CH4 as fuel performs well only if the reduction stage is started on a fully oxidized CaMnO3−δ-based oxygen carrier. In summary, if the CO2 release in the oxidation stage can be efficiently dealt with, CaMnO3−δ-based materials appear to be very promising for use in future GSC-IGCC power plants.Graphical abstractGraphical abstract for this article
       
  • Removal of oil from oil–water emulsions using thermally reduced graphene
           and graphene nanoplatelets
    • Abstract: Publication date: Available online 27 March 2018Source: Chemical Engineering Research and DesignAuthor(s): Ahmad Diraki, Hamish Mackey, Gordon McKay, Ahmed AbdalaThe application of thermally reduced graphene (TRG) and graphene nanoplatelets (GNP) for the removal of emulsified and dissolved oil from oil-water emulsions has been investigated under different process parameters; namely, initial oil concentration, adsorbent dosage and salinity. Batch equilibrium studies have been performed at low oil concentrations (25–200 ppm), achieving an adsorption capacity = 1550 mg oil/g for TRG and 805 mg oil/g for GNP. Batch kinetic studies were performed to assess the rate of removal and over 90% removal was achieved in less than 10 minutes. Fixed bed column adsorption studies obtained bed capacities of 1,100 mg oil/g for TRG and 850 mg oil/g for GNP. Regeneration studies revealed that both adsorbents could still adsorb over 94% of the full bed capacity after three adsorption-regeneration cycles. Increasing the emulsion salinity up to 20,000 ppm NaCl enhanced the adsorption capacities and removal efficiency, but further increases in salinity had no additional effect on capacity.Graphical abstractGraphical abstract for this articleEffect of the concentration of the diesel-water emulsion on zeta potential. Optical images of emulsion with different diesel concentration are shown in Inset.
       
  • Process Simulation of Dehydration Unit for the Comparative Analysis of
           Natural gas Processing and Carbon Capture application
    • Abstract: Publication date: Available online 11 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Aban Sakheta, Umer ZahidAbstractDehydration is a common step employed before the transmission of natural gas and/or carbon dioxide in order to avoid hydrate formation. This study is focused on the simulation of dehydration process for the natural gas and CO2 stream using triethylene glycol (TEG) solvent as the dehydrating agent. This study relates the experiences from the natural gas processing to the application of carbon capture and storage technology for CO2 dehydration. Two design configurations namely, conventional and stripping gas design are investigated using Aspen HYSYS to compare the performance improvement. The developed simulation model is first validated against the plant data and then the comparative analysis has been performed to understand the analogy between the natural gas and CO2 dehydration. Finally, a sensitivity has been performed using the stripping gas configuration to test the possible variables that can affect the process performance in terms of dehydrated stream purity, reboiler energy requirement and solvent losses. The results showed that Aspen HYSYS can reasonably predict the dehydration plant performance. The findings of this study also revealed that the CO2 dehydration process requires more energy compared to the same level of natural gas dehydration.
       
  • Modeling and simulation of downward vertical two-phase flow with pipe
           rotation
    • Abstract: Publication date: Available online 10 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Farhad Raeiszadeh, Ebrahim Hajidavalloo, Morteza Behbahaninejad, Pedram HanafizadehAbstractOne of the major problems in two-phase flow research is prediction of flow pattern at different configurations without requiring expensive experimental tests. Numerical modeling and simulation is a suitable and emerging approach for this purpose which has many benefits including saving in time and cost. In this study, for the first time, the effect of pipe rotation on the flow patterns of air-water two-phase flow in downward direction was numerically studied. For this reason, Eulerian-Eulerian multi-fluid approach was utilized in Ansys-Fluent software. At first, apparent conditions of each regime in various revolution were recorded from experimental tests and then the simulation was carried out to find if the results are compatible. It was shown that pipe rotation has important effects on the flow patterns map and shift transitions boundaries of slug and annular flow toward lower gas superficial velocity. Comparison of numerical results with experimental data show acceptable match for all regimes. Good agreement was observed for falling film, bubbly and slug regimes but the least agreement was observed for froth regime due to high turbulence and perturbation of flow.
       
  • Design Considerations for Small Scale Rotating Fluidized Beds in Static
           Geometry with Screens for Fine Particles
    • Abstract: Publication date: Available online 9 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Zoe Lavrich, David R. Wagner, Zachary Taie, Devin Halliday, Christopher L. HagenAbstractDesign of a small scale rotating fluidized bed (RFB) with diameter of 4–6 cm to fluidize 40–80 micron diameter particles was investigated using computational fluid dynamics (CFD). Simulations explored the impact of the following components on pressure drop and fluidized behavior of the device: particle size, particle density, outer diameter, solids loading, height, number of inlet slots, inlet slot width, angle of inlet slots, chimney diameter, chimney number of slots, chimney slot width, chimney slot angle, and position of the chimney relative to the inlets. Fluidized behavior was evaluated based on a “fluidization quality” metric yielding information about the distribution of particles in the device. Although additional work is required to elucidate design guidelines for small scale RFBs for fine particles, the initial designs evaluated in this work indicate potential for developing a fluidized bed of relatively small diameter, presenting opportunities for process intensification for numerous potential applications.
       
  • Application of a novel tube reactor for investigation of calcium carbonate
           mineral scale deposition kinetics
    • Abstract: Publication date: Available online 7 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Ping Zhang, Nan Zhang, Yuan Liu, Yi-Tsung Lu, Amy T. Kan, Mason B. TomsonA novel plug-flow type tube reactor apparatus is reported to investigate the deposition kinetics of a common mineral scale calcium carbonate (CaCO3). Mineral scale deposition is a common phenomenon in industry and can pose a serious threat to the safe and economical operations. Compared with the conventional apparatus, the tube reactor has the advantage to maintain a constant solution pH, surface area and a controlled saturation index and hydraulic condition during the deposition study. Two scenarios of CaCO3 solid deposition were considered in this study, including deposition of CaCO3 on clean surfaces and also deposition of CaCO3 on a surface pre-coated with CaCO3 solid. The results show that the overall CaCO3 deposition process can be divided into multiple stages with different deposition kinetics and different solid morphologies. It is obvious that experimental conditions, such as solution chemistry, flow rate, temperature and saturation index, can have a considerable impact on CaCO3 deposition kinetics. These results provide an in-depth understanding of the process involving CaCO3 deposition onto the surface of a pipe material or a conduit. This novel tube reactor apparatus expands our capability of investigating mineral scale deposition kinetics and the influences of various experimental factors on scale deposition kinetics.Graphical abstractGraphical abstract for this article
       
  • Tailored catalyst pellet specification for improved fixed-bed transport
           characteristics: A shortcut method for the model-based reactor design
    • Abstract: Publication date: Available online 7 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Alexander Pietschak, Markus Kaiser, Hannsjörg FreundTo improve the transport characteristics of a catalytic fixed-bed via optimal design of catalyst pellet specifications such as the pellet diameter it is necessary to account for all physicochemical phenomena influenced by the pellet. For the approximative description of the transport phenomena on the catalyst pellet scale a new shortcut method is developed in this work. It enables a generalized and system independent treatment of the aforementioned processes and can be applied to arbitrary reaction networks and reaction kinetic models. Based on linearization and decoupling of the pellet balance equations the method yields an analytical solution. This allows for model-based design of the reactor-catalyst system via dynamic optimization at reduced computational costs as the use of complex heterogeneous models is avoided. In order to ensure accurate predictions of the method, regions with high catalyst utilization are targeted.To indicate the potential of improved bed transport characteristics, the shortcut method is applied to the reactor-catalyst system for ethylene oxide synthesis. The system is optimized in terms of reducing the pressure drop while meeting other reactor performance constraints. The pressure drop could be reduced by more than 60%. The shortcut method is validated using a rigorous stand-alone model of the catalyst pellet.Graphical abstractGraphical abstract for this article
       
  • Optimization of Multi-Stage Hybrid RO-PRO Membrane Processes at the
           Water-Energy Nexus
    • Abstract: Publication date: Available online 6 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Mingheng LiWater and energy are two of the most pressing problems faced by the world today. Membrane processes such as Reverse Osmosis (RO) and Pressure Retarded Osmosis (PRO) can help alleviate both challenges. This work focuses on systematic optimization of a RO-RO-PRO-PRO process for energy-efficient seawater desalination which integrates RO for desalination and PRO for power generation into a single process. Such a hybrid process is of great significance at the water-energy nexus given that water production, pump energy consumption, and hydraulic/osmotic energy recovery are inherently intertwined. The optimization problem is formulated to minimize the Specific Energy Consumption (SEC) subject to specified total membrane area and total water recovery. By solving the optimization model the best design (e.g., allocation of membrane area among different units) and operating (e.g. applied pressure in each membrane unit) conditions are simultaneously determined. It is shown that the proposed RO-RO-PRO-PRO allows a profile of the applied pressure that more closely tracks that of the concentrate osmotic pressure than RO-PRO, thus improving energy efficiency. Challenges and opportunities in further development of hybrid RO-PRO processes are discussed.Graphical abstractGraphical abstract for this article
       
  • A general approach to module-based plant design
    • Abstract: Publication date: Available online 6 July 2018Source: Chemical Engineering Research and DesignAuthor(s): Martin Eilermann, Christian Post, Heiko Radatz, Christian Bramsiepe, Gerhard SchembeckerIncreasing economic challenges lead to the need for faster plant design in process industry. In this context, a promising approach is module-based plant design. Thereby, for the accomplishment of the required design tasks modules are selected from databases and configured instead of time-consuming and tailor-made plant design.Within this work, a general approach to module-based plant design is introduced and illustrated based on an example. To structure the design procedure different types of modules are defined for different design tasks: PFD, P&ID, Equipment and 3D Layout. Additionally, module selection can be performed at different Levels of Aggregation to cope with the high variance of applications. This enables module selection and configuration avoiding time-consuming, tailored modifications. Since modules are unmodifiable and project-independent, the module-based plant design approach presented is based on a consistent module definition. This work provides a framework to integrate some of the existing modularization approaches into a general module-based plant design approach. However, most often new approaches are necessary to accomplish the design tasks within the presented module-based plant design approach. Thus, this work also identifies open research gaps that need to be filled by future research.Graphical abstractGraphical abstract for this article
       
 
 
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