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  Subjects -> CHEMISTRY (Total: 921 journals)
    - ANALYTICAL CHEMISTRY (56 journals)
    - CHEMISTRY (655 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (28 journals)
    - INORGANIC CHEMISTRY (43 journals)
    - ORGANIC CHEMISTRY (47 journals)
    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (655 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: 31)
ACS Catalysis     Hybrid Journal   (Followers: 53)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 23)
ACS Combinatorial Science     Hybrid Journal   (Followers: 23)
ACS Macro Letters     Hybrid Journal   (Followers: 28)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 45)
ACS Nano     Hybrid Journal   (Followers: 333)
ACS Photonics     Hybrid Journal   (Followers: 15)
ACS Symposium Series     Full-text available via subscription   (Followers: 1)
ACS Synthetic Biology     Hybrid Journal   (Followers: 25)
Acta Chemica Iasi     Open Access   (Followers: 6)
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chimica Slovenica     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 8)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 8)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 9)
Adsorption Science & Technology     Open Access   (Followers: 7)
Advanced Functional Materials     Hybrid Journal   (Followers: 62)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 77)
Advances in Chemistry     Open Access   (Followers: 27)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 20)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Environmental Chemistry     Open Access   (Followers: 7)
Advances in Enzyme Research     Open Access   (Followers: 11)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 12)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 28)
Advances in Nanoparticles     Open Access   (Followers: 17)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 17)
Advances in Polymer Science     Hybrid Journal   (Followers: 45)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Science and Technology     Full-text available via subscription   (Followers: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 4)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 8)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alchemy : Journal of Chemistry     Open Access   (Followers: 3)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Alotrop     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 70)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 22)
American Journal of Chemistry     Open Access   (Followers: 34)
American Journal of Plant Physiology     Open Access   (Followers: 13)
American Mineralogist     Hybrid Journal   (Followers: 15)
Anadolu University Journal of Science and Technology A : Applied Sciences and Engineering     Open Access  
Analyst     Full-text available via subscription   (Followers: 37)
Angewandte Chemie     Hybrid Journal   (Followers: 191)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 278)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 4)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 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: 15)
Antiviral Chemistry and Chemotherapy     Open Access   (Followers: 2)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 9)
Applied Spectroscopy     Full-text available via subscription   (Followers: 26)
Applied Surface Science     Hybrid Journal   (Followers: 34)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 3)
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access   (Followers: 2)
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 4)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 11)
Biochemistry     Hybrid Journal   (Followers: 385)
Biochemistry Insights     Open Access   (Followers: 7)
Biochemistry Research International     Open Access   (Followers: 7)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 11)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 2)
Biomacromolecules     Hybrid Journal   (Followers: 25)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 6)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 144)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 95)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 20)
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: 25)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 12)
Canadian Mineralogist     Full-text available via subscription   (Followers: 7)
Carbohydrate Research     Hybrid Journal   (Followers: 25)
Carbon     Hybrid Journal   (Followers: 71)
Catalysis for Sustainable Energy     Open Access   (Followers: 10)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 10)
Catalysis Science and Technology     Hybrid Journal   (Followers: 10)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 14)
Cellulose     Hybrid Journal   (Followers: 14)
Cereal Chemistry     Full-text available via subscription   (Followers: 5)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 2)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 23)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 75)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 28)
Chemical Physics Letters : X     Open Access  
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 22)
Chemical Reviews     Hybrid Journal   (Followers: 223)
Chemical Science     Open Access   (Followers: 30)
Chemical Technology     Open Access   (Followers: 36)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 57)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 21)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry     Open Access  
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 34)
Chemistry & Industry     Full-text available via subscription   (Followers: 8)
Chemistry - A European Journal     Hybrid Journal   (Followers: 186)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 16)
Chemistry and Materials Research     Open Access   (Followers: 21)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 46)
Chemistry of Heterocyclic Compounds     Hybrid Journal   (Followers: 4)
Chemistry of Materials     Hybrid Journal   (Followers: 283)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 10)
Chemistry World     Full-text available via subscription   (Followers: 21)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 12)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 11)
Chromatographia     Hybrid Journal   (Followers: 22)
Chromatography     Open Access   (Followers: 3)
Chromatography Research International     Open Access   (Followers: 5)
Clay Minerals     Hybrid Journal   (Followers: 10)
Cogent Chemistry     Open Access   (Followers: 2)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 11)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 7)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 24)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Communications Chemistry     Open Access   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 8)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 13)
Computational Chemistry     Open Access   (Followers: 3)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 4)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 7)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 8)
Croatica Chemica Acta     Open Access  
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Chromatography     Hybrid Journal  
Current Green Chemistry     Hybrid Journal   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 6)
Current Microwave Chemistry     Hybrid Journal  
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 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: 77)
Current Topics in Medicinal Chemistry     Hybrid Journal   (Followers: 10)

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Similar Journals
Journal Cover
Chemical Engineering Research and Design
Journal Prestige (SJR): 0.847
Citation Impact (citeScore): 3
Number of Followers: 28  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0263-8762 - ISSN (Online) 0263-8762
Published by Elsevier Homepage  [3184 journals]
  • INVESTIGATING THE EFFECTS OF MIXING IONIC LIQUIDS ON THEIR DENSITY,
           DECOMPOSITION TEMPERATURE, AND GAS ABSORPTION
    • Abstract: Publication date: Available online 21 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Tausif Altamash, Majeda Khraisheh, M Fahed Qureshi In order to counter the detrimental effect of chemicals on the environment, the academic and industry research interest have shifted towards “green” solvents. Ionic liquids (ILs) are salt-like compounds that, with few exceptions, are known to have negligible vapor pressure and are widely proclaimed as green solvents. Their physical properties can be tailored for the desired purpose by the careful selection of cation and anion or by mixing with other solvents. In this work, we tested the gas absorption of ILs and measured the thermo-physical properties of individual ILs and their binary mixtures. Density and thermogravimetric measurements were performed on ILs choline octanoate ([Ch][Oct]), 1-methyl-3-octylimidazolium trifluoromethanesulfonate ([Omim][Otf]), and 1-methyl-3-octylimidazolium chloride ([Omim][Cl]), and their equal molar (1:1) mixtures. The effect of different anions [Otf-, Cl-] and different cation groups [Omim, Ch] on the gas absorption potential of ILs have been observed. The density and thermal stability tests have been conducted to understand the changes in the physical properties of ILs when they are mixed together in equal ratios. All samples of ILs ([Ch][Oct], [Omim][Otf], [Omim][Cl], [Ch][Oct] + [Omim][Otf], [Ch][Oct] + [Omim][Cl], and [Omim][Cl] + [Omim][Otf]) were tested as CO2 absorption media at temperatures 298.15, 305.15, and 308.15 K and pressure values ranging from 0 to 50 bar. In addition to that, the CO2 sorption results at 298.15 K were compared with experimentally measured methane (CH4) and nitrogen (N2) data. It was observed that the IL [Ch][Oct] is significantly better for CO2 absorption than [Omim][Cl] ([Ch][Oct] ≥ [Omim][Cl]> [Omim][Otf]). On comparing the CO2 absorption profiles with those of CH4 and N2, the similar trends for IL and IL mixtures were obtained: CO2> CH4> N2 and CO2> CH4> N2 respectively.Graphical Graphical abstract for this article
       
  • Dimensionless numbers for solubility and mass transfer rate of CO2
           absorption in MEA in presence of additives
    • Abstract: Publication date: Available online 21 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Abdolah Mohammadpour, Masoumeh Mirzaei, Alireza Azimi This study aimed to compare the both solubility and mass transfer rate of CO2 in monoethanolamine (MEA) in the presence of various additives, including Titanium dioxide (TiO2) and Graphene oxide (GO) nanoparticles as well as two surfactants named Tetra-n-butylammonium bromide (TBAB) and Sodium dodecyl sulfate (SDS) using dimensionless numbers. Batch gas absorption experiments were performed at ambient temperature and various concentrations of additives from 0 to 0.1 wt% at an initial pressure of 20 bar. By recording changes in the temperature and pressure of the gas in the loading tank, the number of CO2 moles consumed was obtained in terms of time. The mass transfer coefficient and solubility were then calculated by kinetic and thermodynamic analyses. The dimensionless numbers, namely ES and ER, were calculated to analyze the behavior of the system. ES represents the solubility in the presence of an additive to that in the base solvent, whereas ES shows the mass transfer coefficient in the additive-containing solvent to that in the base solvent. The new, useful dimensionless number Et was defined to investigate the mass transfer rate and solubility simultaneously. For the additives used in this study, the highest ES, ER and Et were 1.31(0.0375 g of SDS), 1.25(0.075 g of TBAB) and 1.57(0.075 g of SDS), respectively. The results shows that surfactants have better effect on solubility and mass transfer rate of CO2 in MEA.
       
  • An experimental study on single drop rising in a low interfacial tension
           liquid–liquid system
    • Abstract: Publication date: Available online 20 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Jiyizhe Zhang, Yundong Wang, Geoffrey W. Stevens, Weiyang Fei Terminal velocity of liquid drops is one of the key parameters in liquid-liquid extraction column design. It is important in determining residence time, droplet lifetime, and mass transfer rate. In present paper, the rising behavior of a single drops were investigated in a low interfacial tension system by high speed camera. An n-butanol/water system was used as test system. Correlations for terminal velocity were evaluated and compared, both explicitly and implicitly. Moreover, the influence of salt addition in aqueous phase was also studied, including salt concentrations and types. A Weber-Reynolds correlation was derived on the basis of experimental data. Drag coefficient was then calculated and showed a good agreement compared to the correlations in literatures.Graphical abstractGraphical abstract for this articleTerminal velocity of liquid drops is one of the key parameters in liquid-liquid extraction column design. It is important in determining residence time, droplet lifetime, and mass transfer rate. In present paper, the rising behavior of a single drops were investigated in a low interfacial tension system by high speed camera. An n-butanol/water system was used as test system. Correlations for terminal velocity were evaluated and compared, both explicitly and implicitly. Moreover, the influence of salt addition in aqueous phase was also studied, including salt concentrations and types. A Weber-Reynolds correlation was derived on the basis of experimental data. Drag coefficient was then calculated and showed a good agreement compared to the correlations in literatures.
       
  • Effect of residence time and energy dissipation on drop size distribution
           for the dispersion of oil in water using KMS and SMX+ static mixer
    • Abstract: Publication date: Available online 20 June 2019Source: Chemical Engineering Research and DesignAuthor(s): G. Forte, E. Brunazzi, F. Alberini The Planar Laser Induced Fluorescence technique was used to determine the drop size distribution of oil dispersed in water at the inlet and outlet of two static mixer geometries (KMS and Sulzer_SMX+) equipped with either 6 or 12 elements. A mineral oil (Lytol®), three times more viscous than the water continuous phase, was used as the dispersed phase. The oil flow rate was kept constant through all experiments forcing the drop detachment from the secondary inlet. The L-L system was very dilute (˜0.05-0.0007% v/v O/W) to avoid coalescence phenomena. The flowrate of the continuous phase (water) was altered giving values of Reynolds number from 2,000 to 12,000, covering high transitional and turbulent flow regimes. Increasing the flow rate of the continuous phase, the detached oil drops from the secondary inlet decreased in size as expected. However, same drops after flowing a length of 0.4 m of an empty pipe reached a constant size. To investigate a wider range of energy dissipation and residence time, the presence of static mixers has been investigated. Pressure drops, hence energy consumed, were measured to compare the different set ups and drop size distributions. The results show that by increasing the flow rate, the drop size decreased up to a critical point, beyond which oil droplet size reduction became inefficient. The collected data were then used to derive a methodology to identify the optimal flow conditions and choice of static mixer device to achieve best drop size reduction with less energy per unit mass.
       
  • Production of levulinic acid from glucose in sulfolane/water mixtures
    • Abstract: Publication date: Available online 20 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Marja Mikola, Juha Ahola, Juha Tanskanen Levulinic acid derived from biomass is a versatile platform molecule, which can be used in manufacturing different compounds to replace fossil-based chemicals. In this study, the effect of sulfolane as solvent in sulphuric acid catalysed levulinic acid production from glucose was investigated. The broad sulfolane concentration range was systematically studied and a kinetic model was developed to describe the levulinic acid production. A significant increase in glucose conversion rate was observed when the proportion of sulfolane in the solvent mixture was increased. The maximum selectivity of the levulinic acid production was found to be slightly over 50 % and independent of the solvent composition. Thus, with sulfolane solvent, the same yields can be obtained in a significantly shorter time or at a lower temperature as when water is used as solvent. Sulfolane was also found to keep the generated by-products in soluble form. This will decrease fouling of the process equipment, which has been a major issue in designing of levulinic acid production processes.Graphical abstractGraphical abstract for this article
       
  • Structural optimization of a demulsification and dewatering device coupled
           with swirl centrifugal and high-voltage fields by response surface
           methodology combined with numerical simulation
    • Abstract: Publication date: Available online 20 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Haifeng Gong, Bao Yu, Xianming Zhang, Ye Peng, Yunqi Liu The demulsification and dewatering treatments of emulsion are the critical link in the recycling technologies of industrial waste oil. A device coupled with centrifugal and high-voltage fields were proposed for the emulsion with a high content and a complicated composition, which cannot be achieved using a single method. Combining with the governing equations of flow field, electric field and droplet size, the numerical simulation model of the coupling device was established. The functional relationship between structural parameters and separation efficiency was further determined by response surface methodology. From this the structural optimization of the device was achieved and the influence of embedding a high-voltage field on structural optimization was examined. Results show that the response models can reasonable optimize the structure of coupling device and predict its separation efficiency. In comparison to the numerical results, the maximum deviations of the dewatering and deoiling rate models are about 0.8% and 3.7%. Embedding a high-voltage field does not influence the selection of optimal range under the single-factor conditions, but affects the multi-parameter optimization design of the coupling device. Specially, the influence of the interaction between the variables on separation efficiency changes when the electric field is applied and varied. In addition, at 11 kV, the dewatering and deoiling rates reach up to 95.8% and 96.8% when the optimal values of the nominal diameter and the large and small cone angles are 22 mm, 20.0° and 5.1°.Graphical abstractGraphical abstract for this articleThe influence of the interaction between the variables on separation efficiency changes when the electric field is applied and varied. Embedding a high-voltage field does not influence the selection of optimal range under the single-factor conditions, but affects the multi-parameter optimization design of the coupling device.
       
  • An improved design method for retrofitting industrial heat exchanger
           networks based on Pinch Analysis
    • Abstract: Publication date: Available online 19 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Bao-Hong Li, Yan Edy Chota Castillo, Chuei-Tin Chang Energy integration relies on matching process hot streams with process cold streams, and utilities are only introduced to balance the deficit in energy consumption. A systematic but simple Pinch Analysis(PA)-based retrofit approach is proposed to lessen the utility consumption of any industrial Heat Exchanger Network (HEN) under new minimum temperature approach (ΔTms) at the cost of minor capital investment. This work is an extended and improved version of our previous work (Li and Chang, 2010). Elaborate visualized tool of T-H diagram for identification of cross-pinch heat load is proposed to fully address the case that phases change in the cross-pinch heat exchanger. Main characters of industrial HENs which are large scale, varied heat capacity flow rate and multiple pinches are fully addressed. Specifically, each cross-pinch exchanger or match is identified and those matches with large cross-pinch loads are disconnected first, and then their heat loads on the hot and cold stream side are split according to pinch temperatures. Next, at either side of or between the pinches, the divided heat loads on each stream are combined and matched according to a systematic Pinch Analysis (PA) based procedure. Retrofit modifications are focused on those cross-pinch matches and utility exchangers, so the retrofit procedure of an industrial HEN is obviously simplified. An industrial case of Crude Oil Preheat Train (COPT) is retrofitted to demonstrate the effectiveness of the proposed approach.
       
  • CFD-DEM modelling of particles attrition in jet-in-fluidized beds
    • Abstract: Publication date: Available online 19 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Nazanin Ghods, Shahab Golshan, Reza Zarghami, Rahmat Sotudeh-Gharebagh An improved CFD-DEM model for simulation of particles attrition is presented in this research. Hertzian contact stress was used to compute the stresses acting on particles and the Weibull distribution was used to calculate the breakage probability. Two breakage models were used to calculate size distribution of debris from particle attrition. These models were implemented to simulate a jet-in-fluidized bed. Breakage results, including spatial and size distribution of particles over time, breakage location/rate, and segregation of particles were studied. Simulation results show that, breakage rate was high in the first seconds due to stress caused by high velocity impact in the jet region, and then it increased linearly for some time and stopped due to smaller particles attrition inhibition by reducing the average stress acting on particles. About 98% of the breakages took place on the distributer zone. Particles breakage led to high degree of segregation and elutriation which was also studied here.Graphical abstractGraphical abstract for this article
       
  • Synthesis and characterization of silver loaded alumina and evaluation of
           its photo catalytic activity on photo degradation of methylene blue dye
    • Abstract: Publication date: Available online 19 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Muhammad Saeed, Majid Muneer, Nadia Akram, Atta ul Haq, Noshin Afzal, Muhammad Hamayun Visible light induced photo catalytic degradation of dyes is an inviting approach in wastewater treatment techniques. In this study, silver loaded alumina was synthesized by immobilization of Ag nanoparticles on Al2O3 by facile green method with Azadirachta indica leaves extract and characterized by different advanced techniques. The prepared Ag-Al2O3 particles were tested as photo catalyst on degradation of methylene blue under visible irradiation. Ag-Al2O3 showed improved photo catalytic performance on photo degradation of methylene blue. The deposition of Ag enhanced the photo catalytic activity of Al2O3 from 35 to 95% degradation of methylene blue. Effect of various parameters on catalytic activity were investigated. Curve Expert computer program was used for kinetics analyses of the data according to Langmuir–Hinshelwood and Eley–Rideal mechanism. A 100 mgL−1 solution (50 mL) completely degraded in 120 minutes of reaction duration at 50 °C over 0.1 g of 3% Ag-Al2O3 as catalyst. 0.01, 0.06 and 0.08 min−1 were calculated as average rate constants at 30, 40 and 50 °C respectively. 25.7 kJ mol−1 was calculated as average activation energy.Graphical Graphical abstract for this article
       
  • Liquid-liquid flow patterns and slug characteristics in cross-shaped
           square microchannel for cryogel beads preparation
    • Abstract: Publication date: Available online 19 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Tingting Guan, Qin Yan, Lizhi Wan, Songhong Zhang, Linhong Xu, Jianli Wang, Junxian Yun For preparing cryogel beads by the micro-flow-focusing and cryo-polymerization method, liquid-liquid flow patterns and slug characteristics for the system of Dex-MA and ethyl acetate and the system of Dex-MA-HEMA and ethyl acetate in a cross-shaped square microchannel were studied. The aqueous solutions of Dex-MA-HEMA and Dex-MA were used as the dispersed phase and ethyl acetate as the continuous phase. The formation mechanism of the slug flow was illustrated by analyzing the interaction of the interfacial tension between the dispersed and continuous phases, inertial forces and viscous forces of the dispersed phase and the continuous phase. The flow pattern maps for the two systems were proposed and five regimes were identified, i.e., the slug flow, bubbly flow, jetting flow, unstable flow and stratified flow. The slug lengths and the droplet diameters were also measured experimentally and correlated. The results showed that the formation of the slug flow was related to the interaction of the forces of the continuous phase and dispersed phase. The inertial and viscous force of the continuous phase promoted while the viscous force of the dispersed phase resisted the formation of the slug flow. The interfacial tension and the inertial force of the aqueous phase were shifting their effects which either promoted or resisted the formation of the slug flow. The flow pattern maps have a good agreement with those proposed in the literatures. The velocity of the continuous phase was more influential on the length of the slug segment. The obtained correlation of slug length and the droplet diameter could be helpful to the preparation of the cryogel beads.Graphical abstractGraphical abstract for this article
       
  • Kinetics of hematite to magnetite transformation by gaseous reduction at
           low concentration of carbon monoxide
    • Abstract: Publication date: Available online 19 June 2019Source: Chemical Engineering Research and DesignAuthor(s): V.P. Ponomar, O.B. Brik, Yu.I. Cherevko, V.V. Ovsienko Hematite-containing material is accumulated during exploitation and beneficiation of magnetite ore, thus forming tailings and other industrial wastes. Hence, processing the low-grade hematite ore becomes extremely important for the metallurgical industry. The transformation of weakly magnetic hematite into magnetite can enhance the efficiency of magnetic separation. In this work, chemical reduction of hematite to magnetite in an atmosphere with different gas composition was investigated. Gasification of charcoal in the flow of both air and carbon dioxide led to the formation of carbon monoxide. The output gas containing carbon monoxide was found to be an effective reductant for the transformation of hematite into magnetite. Even 5% of CO was sufficient to convert hematite into magnetite, which resulted in an increase in magnetization up to 85 Am2/kg. The kinetic analysis indicated that the reduction of hematite to magnetite is a single-step process, which can be described using the first-order reaction model.Graphical abstractGraphical abstract for this article
       
  • On the reliability of lab-scale experiments for the determination of
           membrane specific flux measurements in organic solvent nanofiltration
    • Abstract: Publication date: Available online 19 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Rebecca Goebel, Mareike Schreiber, Velichka Koleva, Melanie Horn, Andrzej Górak, Mirko Skiborowski While the scale-up from flat-sheet lab-scale experiments to larger modules for an industrial application requires consideration of the module geometry and according hydrodynamics, it is of high importance that the lab-scale experiments provide an accurate estimate of the membrane performance at ideal hydrodynamic conditions to make a proper selection and potentially allow for a model-based evaluation of the process performance. Due to inhomogeneity of the membrane material, it is however well known that the membrane flux determined by small samples in lab-scale experiments may vary in a considerable margin. The current study investigates these variations with an extensive experimental screening of lab-scale samples as well as a spiral-wound module for a commercially available polymeric membrane and pure solvent flux. This allows for an analysis of the comparability, as well as a best case estimate for the variance of the solvent flux, due to the industrially optimized membrane production process. The experimental results confirm considerable variations for single lab-scale samples, but also indicate good comparability on the basis of a statistical evaluation of the larger set of lab-scale samples. Based on the evaluation of the uncertainty of the solvent flux estimate, a minimum number of samples for an accurate estimate is determined and the recommendation is validated for additional membrane-solvent combinations. The importance of the derived uncertainty information for membrane selection and model-based conceptual process design is furthermore illustrated for a number of literature case studies.Graphical abstractGraphical abstract for this article
       
  • Computing Meaningful Models of Continuous Data
    • Abstract: Publication date: Available online 19 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Francis B. Lavoie, Koji Muteki, Ryan Gosselin Parameters controlling continuous chemical processes as well as all instruments found in such processes generate a huge amount of data. Calculating models to predict critical quality attributes (in y) from process data (in X) can be fastidious. Partial-Least-Squares (PLS) regression is now widely present in the industry for process analysis and modelling purposes. However, this methodology requires static data while the majority of chemical processes operate continuously. Some dynamic PLS variants have been developed, but they cannot associate specific critical process parameters with meaningful process dynamics. This work presents a novel Dynamic-PLS variant developed to resolve these issues. Using one real dataset and artificial cases, the performances of this novel methodology is compared to standard regression methodologies. It is demonstrated that the proposed methodology calculates the most robust models in validation. With the real dataset, it is also demonstrated that the predictive model calculated from the proposed methodology can easily be interpreted, leading to better process understanding.
       
  • Process analysis of extractive distillation for the separation of
           ethanol-water using deep eutectic solvent as entrainer
    • Abstract: Publication date: Available online 18 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Xianyong Shang, Shoutao Ma, Qi Pan, Jinfang Li, Yinhai Sun, Kai Ji, Lanyi Sun Deep eutectic solvents (DESs) as novel entrainers can be used for the separation of azeotropic mixture, and have received much attention in recent years. However, the researches about DESs mainly focus on vapor-liquid equilibrium (VLE) and extractive distillation experiment. In this work, an overall extractive distillation process for ethanol dehydration using ChCl/Urea (1:2) as entrainer is investigated. The physical properties of the DES are defined by correlating the experimental data. Three thermodynamic methods are employed to describe the phase behavior of ethanol-water-ChCl/Urea (1:2) system. COSMO-based theory is adopted to explain the differences in separation performance among ChCl/Urea (1:2), glycerol and [EMIM][BF4]. The design parameters of extractive distillation process are optimized by multi-objective generic algorithm (MOGA) with minimum total annual cost (TAC), minimum CO2 emissions (ECO2) and maximum efficiency indicator of extractive section (EExt) as objective functions. In addition, the control structure of extractive process is studied by Aspen Dynamics, and the proposed control structure could resist fresh feed flow rate and composition disturbances. The results show that ChCl/Urea (1:2) exhibits better separation performance in ethanol dehydration compared with glycerol and [EMIM][BF4]. Both COSMOSAC model relying on molecular information and NRTL model based on experimental data can well describe the vapor-liquid behavior containing ChCl/Urea (1:2). Entrainer purity plays an important role in extractive distillation process, and a proper concentration rather than nearly pure entrainer should arouse our attention in extractive distillation process. DESs as promising novel entrainers can be used in extractive distillation industrial for separating azeotrope.Graphical abstractGraphical abstract for this article
       
  • Bubble behavior in gas–solid bubbling fluidized beds based on EMMS
           model: comparison of 2D, Q2D and 3D simulation
    • Abstract: Publication date: Available online 18 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Hao Wang, Youjun Lu, Kenan Xi In this work, bubbling fluidized beds in two-, quasi-two- and three-dimensional geometries are simulated by Eulerian-Eulerian two-fluid model (TFM) coupled with energy minimization multi-scale model (EMMS). Results including bubble diameter, bubble vertical velocity, shape factor and aspect ratio as well as bed height are investigated. Simulation results show that vertical velocities of two- and quasi-two-dimensional bubbles are in good agreement with empirical correlations. Equivalent bubble diameter predicted in all dimensions of beds is also in reasonable agreement with empirical correlations. According to the comparison between simulation results (bubble diameter and vertical velocity) and empirical correlations, two- and quasi-two-dimensional simulations have better performance in predicting bubble behaviors. As for shape factor of three-dimensional bubbles, the peak value of frequency decreases with superficial gas inlet velocity and the tendency is more significant than that of two- and quasi-two-dimensional bubbles. Slightly positively skewed distributions of aspect ratio are acquired and peak value decreases with superficial gas inlet velocity especially for two- and three-dimensional bubbles. Besides, bed height of two- and three-dimensional beds has no major difference and is higher than that of quasi-two-dimensional bed.Graphical abstractGraphical abstract for this article
       
  • An Empirical Model of Absorption of Nitric Oxide with Ammoniacal Cobalt
           (II) Solutions in a Spray Tower
    • Abstract: Publication date: Available online 17 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Haiming Wang, Qinghai Li, Changfu You, Zhongchao Tan An empirical model was developed for the prediction of the absorption efficiency of nitric oxide (NO) into ammoniacal cobalt (II) solution in terms of gas flow rate, liquid flow rate, and temperature. The model parameters were determined experimentally using a spraying tower with initial absorbent solution pH of 10.0-10.2 for temperatures in the range of 281.15-323.15 K. The reactions between Co2+ complexes and NO were found to be in the fast pseudo-first-order reaction regime. The correlation between the overall mass transfer coefficient and the gas and liquid flow rates was determined for NO absorption. The liquid flow rate (0.225 to 0.730 L/min) had little influence on the NO absorption efficiency for the conditions with excessive Co2+ complexes in the solution due to the fast reaction rates. Temperature showed detrimental effects on the NO absorption for conditions in this study.Graphical abstractGraphical abstract for this article
       
  • Pilot-scale experiment and simulation optimization of dual-loop wet flue
           gas desulfurization spray scrubbers
    • Abstract: Publication date: Available online 15 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Mingchen Qin, Yong Dong, Lin Cui, Junwen Yao, Chunyuan Ma The efficiency of wet flue gas desulfurization (WFGD) used in thermal power plants that burn high-sulfur coal can be improved by adopting dual-loop spray tower (DLST). In this paper, the process of gas–liquid flow, mass transfer and chemical reaction in the DLST were fully investigated through a pilot-scale DLST and the corresponding numerical model. The numerical model was verified based on the experiment and applied to predict a DLST of 200 MW coal-fired unit. Investigation results show that higher the inlet SO2 concentration, more significant advantage on improving the desulfurization efficiency for DLST. The mass transfer resistance of liquid-film is still the main effect of SO2 absorption for the upper and lower loops in DLST. The ratios of the gas-film resistance to liquid-film resistance in the upper and lower loops are 0.65 and 0.35, respectively. The designed size of the bowl separator has a significant effect on the system resistance loss. The minimum ratio between the diameter of the bowl and the diameter of the desulfurization tower to avoid “flooding” phenomenon above the bowl separator is about 0.7. Furtherly, the lowest system operating resistance loss can be obtained when the ratio is about 0.82. The simulation results of the desulfurization efficiency and system resistance loss agree well with the test data.Graphical abstractGraphical abstract for this article
       
  • Seawater desulphurization scrubbing in spray and packed columns for a
           4.35 MW marine diesel engine
    • Abstract: Publication date: August 2019Source: Chemical Engineering Research and Design, Volume 148Author(s): D. Flagiello, A. Parisi, A. Lancia, C. Carotenuto, A. Erto, F. Di Natale Flue Gas Desulphurization (FGD) is a key topic for all combustion fossil fuel plants and industrial applications. Wet processes are usually preferred when the removal efficiency required to comply with environmental regulation exceeds 90%. Recently, seawater (SW) has been considered as a viable absorbent for FGD processes in coastal and naval applications, thanks to its natural alkalinity and, of course, its large availability. Due to the typical constraints of naval applications, process design should be optimized to improve mass transfer rates and reduce seawater requirements while keeping a suitable absorber size.In this work, we report the experimental findings on process design and optimization of two different SW-FGD units: a spray column equipped with full hydraulic spray nozzles and a packed-bed column with structured packing. The experiments are used to develop and tune suitable models for the packed and spray towers design in representative operating conditions. These models are applied to compare both the units in a reference case study: an IFO fuelled marine diesel engine (4.35 MW) that has to comply with current IMO-MARPOL VI 14 regulation for SECAs. A preliminary costs analysis is also performed for comparison.
       
  • Evaluation of different solvent performance in a 0.7 MWe pilot scale CO2
           capture unit
    • Abstract: Publication date: August 2019Source: Chemical Engineering Research and Design, Volume 148Author(s): Reynolds A. Frimpong, Heather Nikolic, Jonathan Pelgen, Mahyar Ghorbanian, Jose D. Figueroa, Kunlei Liu Novel concepts for post-combustion CO2 capture have been demonstrated in a 0.7 MWe pilot-scale facility installed at Kentucky Utilities (KU) E.W. Brown Generating Station. The process which includes two-staged solvent stripping used a secondary air stripper to provide leaner regenerated solvents, and recycled CO2 to boiler to boost inlet CO2 concentrations to the absorber for enhanced mass transfer and increased solvent capacity. The effectiveness of the secondary stripper together with other aspects of the heat-integrated process and the associated energy savings have been demonstrated from solvent campaigns with 30 wt% monoethanolamine (MEA) and other advanced solvents. Comparative analysis between advanced solvents showed that intercooling in the absorber had a more significant impact on the performance of the solvent with known high CO2 partial pressure as a result of the corresponding low heat of reaction with relative higher bicarbonate content from its reaction with CO2. The energy of regeneration of this solvent was lower than MEA at similar test conditions.Graphical abstractGraphical abstract for this article
       
  • Investigation of hydrodynamics of binary solids mixture spouted beds using
           radioactive particle tracking (RPT) technique
    • Abstract: Publication date: August 2019Source: Chemical Engineering Research and Design, Volume 148Author(s): Thaar Al-Juwaya, Neven Ali, Muthanna Al-Dahhan The hydrodynamic and mixing behavior of binary solids mixture spouted beds with particles of the same size but different densities have been investigated experimentally in gas–solid spouted beds for the first time, using an advanced non-invasive radioactive particle tracking (RPT) technique. The RPT experiments have been performed for different composition of binary mixture at different superficial gas velocity. The binary solids mixture used in the experiment consists of glass beads and steel particles of densities 2500 and 7400 kg/m3, respectively. The RPT experiments were carried out for each one of the solids phases on an individual basis, and then the statistical averages of each flow fields are combined together to formulate the entire picture of the binary solids mixture flow field. It was found that segregation always takes place in the spout due to the dissimilar behavior between the different solids phases in terms of the solids velocity field and turbulent parameters. The results also demonstrated that for the hydrodynamics of binary solids mixture spouted beds which have particles of similar size but different densities, the particle–particle interaction plays an important role, but it does not dominate the gas–particle interaction, and each contributes to the extent of the mixing and segregation phenomena inside the bed. The results and findings of our work are valuable in understanding the hydrodynamics of the binary solids mixture encountered in the gas–solid spouted beds of TRISO nuclear fuel particles and provide benchmark data to validate computational fluid dynamics (CFD).
       
  • Improvement of recovery of gaseous fluids using the replacement of
           supersonic separator instead of Joule–Thomson valve in dehydration/NGL
           recovery unit with computational fluid dynamic modeling
    • Abstract: Publication date: August 2019Source: Chemical Engineering Research and Design, Volume 148Author(s): Sina Nabati Shoghl, Reza Nazerifard, Abbas Naderifar In this study, we employed the computational fluid dynamic (CFD) technique in conjunction with a thermodynamic EOS package to investigate the liquid hydrocarbon recovery of dehydration/NGL recovery unit. The effect of modification in dehydration/NGL recovery unit using the supersonic separator was studied. The Peng–Robinson equation of state in conjunction with the thermodynamic process modeling package were used to simulate the heavy hydrocarbon separation in the supersonic separator. The κ–ε turbulence model was used to simulate the natural gas flow in supersonic separator and the behavior of gas pressure reduction on refrigeration performance was studied under the conditions of specified boundary layers. The CFD modeling results revealed a satisfactory agreement with the measured data reported in literature. The results showed that cooling performance was improved for this system compared to J–T valve and turbo-expander. The performance of this system can be further intensified by comparing the refrigeration effect in the same pressure difference. Furthermore, the condensation process of natural gas stream was investigated with the modification of design of dehydration/NGL recovery unit. Compared to the Joule–Thomson valve, this new method derives about 2.85 time higher of C3+. The results showed that, when the pressure reduction of this device is equal to that of Joule–Thomson valve, the supersonic separator has a better cooling and separation performance.Graphical abstractGraphical abstract for this article
       
  • Mathematical modeling and process parametric study of CO2 removal from
           natural gas by hollow fiber membranes
    • Abstract: Publication date: August 2019Source: Chemical Engineering Research and Design, Volume 148Author(s): Yunhan Chu, Arne Lindbråthen, Linfeng Lei, Xuezhong He, Magne Hillestad Hollow fiber membranes show a great potential in natural gas sweetening by removing CO2 to meet gas grid specifications. A membrane model with high prediction accuracy is developed to model multicomponent gas transport through hollow fiber modules. The influences of hollow fiber diameter and length, and packing density on module efficiency related to pressure drops in both sides were systematically investigated based on the developed model. The total pressure drop along the length is less than 1% if the inner diameter of hollow fibers (0.6 m length) is larger than 200 μm. Moreover, the highest module packing density was found to be dependent on hollow fiber dimension, and too high packing density will cause extreme high pressure drops. Both feed CO2 concentration and pressure were found to significantly influence membrane module performance related to the required specific membrane area and hydrocarbon loss based on process parametric study of CO2 removal from natural gas. Larger pressure drops along fiber length was found for the more-permeable polyimide membranes compared to the less-permeable cellulose acetate and carbon membranes. The developed model can be used for guiding the design of efficient hollow fiber membrane modules and potentially process simulation of membrane gas separation.
       
  • Comparative assessment of different image processing methods to determine
           the gas–liquid interfacial area in froth regimes of sandwich packings
           from ultrafast X-ray tomography image data
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): J. Sohr, M. Bieberle, G.R. George, S. Flechsig, E.Y. Kenig, M. Schubert, U. Hampel Sandwich packings consist of alternatingly stacked structured packing layers of different specific surface area. In such packings froth two-phase flow appears when the packing is operated between the loading limits of the layers. For this highly agitated flow regime, there is a lack of hydrodynamic data, in particular on gas-liquid interfacial area. Ultrafast X-ray tomography, a cross-sectional imaging technique with a frame rate of more than 1000 cross-sectional images per second, is applied to visualize the gas-liquid flow and to extract the gas–liquid interfacial area data via image post-processing methods. For that, we assessed different segmentation methods, that are, level set and gray level contour techniques.
       
  • Realistic interplays between data science and chemical engineering in the
           first quarter of the 21st century: Facts and a vision
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Patrick M. Piccione Data science, digit(al)ization, Industry 4.0, smart manufacturing: all these terms are receiving heavy interest from industry and funding institutions. While some definitions remain hazy, the financial success of the digital giants has led to a bandwagon all too many companies are happy to jump on. Successes are also reported in the chemical and engineering sciences, driven by specific enablers as well as technical specificities of the application areas. High expectations for data science applications in chemical engineering have resulted, together with a loss of visibility of the limits of a purely data-centric approach. At the same time, chemical engineers may not be fully prepared to embrace the digital revolution in general, and data science in particular. This Short communication, aimed at all stakeholders of the digital transformation of the chemical industry, sets out an aspirational vision for the data science–chemical engineering interplay, together with needs, opportunities, and suggested approaches to address them. Several frameworks are also given to inform technical strategies: activity classes; workflows; and a decision tree to consciously assess what approaches to privilege.Graphical abstractGraphical abstract for this article
       
  • Experimental and bifurcation analysis of a hybrid CSTR plant
    • Abstract: Publication date: Available online 14 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Piotr Skupin, Mieczyslaw Metzger, Piotr Laszczyk, Malgorzata Niedzwiedz The classical continuous stirred tank reactor (CSTR) with an exothermic chemical reaction is known for its complex nonlinear behaviour. Therefore, it is often used as a benchmark plant for testing control algorithms. Since experimenting with a real chemical process can be dangerous (thermal runaway), computer simulations can be used in the controller design. On the other hand, simulation results are obtained for mathematical models that often include many simplifying assumptions. Hence, the goal of this study was to design a hybrid CSTR (hCSTR) plant with real reactor vessel and jacket, but simulated chemical reaction. Based on bifurcation analysis and laboratory experiments, it is shown that the hCSTR plant exhibits the same qualitative behaviour (multiplicity of steady states and limit cycles) as the classical CSTR system. The analysis is performed assuming hard-saturation constraints on the reaction heat, since the heating power in the real hybrid plant is also constrained. Finally, a proportional-integral (PI) controller for stabilization of temperature in the vessel is designed and tested by using the hCSTR plant.
       
  • Capillary condensation mechanism for gas transport in fiber reinforced
           poly (ether-b-amide) membranes
    • Abstract: Publication date: Available online 13 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Mohammad Bagher Karimi, Shadi Hassanajili, Ghader Khanbabei One of the most important shortcomings of the polymeric membranes in comparison with inorganic membranes is the trade-off between permeability and selectivity. Gas permeability in inorganic membranes follows different mechanisms including capillary condensation mechanism. The aim of present study was improving the polymeric membranes performance by introducing capillary condensation mechanism for the gas transport similar to that observed in the inorganic membranes. Capillary condensation of gases needs a continuous diffusion pathway, therefore in the present study short glass wool fibers (with a micro size in diameter and millimeter size in length) were chosen as a proper alternative instead of nanoparticles. Short glass wool fibers present proper dispersion in the Pebax matrix as a result of its good compatibility with polymer segments. Gas permeability behavior in such composite membranes was assisted using pure CO2, CH4 and N2 gases. Obtained results demonstrated that gas permeability behavior in the short fiber reinforced composite membranes is depends on the fiber content. At lower content of the fiber, such reinforcement causes simultaneous increment in gas permeabilities in a way that 62.37%, 32.12% and 50.71% increase in permeability was observed for CO2, CH4, and N2 respectively. But at higher content due to formation of more continuous interface, capillary condensation was appeared for more condensable gas (CO2) which results in 17.65 % reduction in its permeability. Based on the results the using of short fiber instead of nanoparticles in polymeric membranes can be more beneficial in performance and economic point of view.Graphical abstractGraphical abstract for this article
       
  • Iron oxide nanoparticles incorporated polyethersulfone electrospun
           nanofibrous membranes for effective oil removal
    • Abstract: Publication date: Available online 13 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Issa Sulaiman Al-Husaini, Abdull Rahim Mohd Yusoff, Woei-Jye Lau, Ahmad Fauzi Ismail, Mohammed Zaher Al-Abri, Mohd Dzul Hakim Wirzal This paper reports the synthesis and characterization of novel ultrafiltration (UF) electrospun nanofibrous membranes (ENMs) incorporated with iron oxide (Fe3O4) nanoparticles (NPs) for effective oily solution treatment. Three strategies were employed to improve the physiochemical properties of the resultant ENMs. Firstly, n-methyl-pyrrolidinone (NMP) was added to dimethylformamide (DMF) wherein the solvent stimulated fusion of the inter-fiber junctions was enhanced. Secondly, Fe3O4 NPs were introduced into the ENMs to improve their hydrophilicity and anti-fouling resistance against oil molecules. Thirdly, hot pressed technique was adopted to strengthen the electrospun mat, avoiding delamination of the ENMs layer during liquid filtration processes. The findings indicated that the developed Fe3O4 NPs incorporated ENMs exhibited outstanding oil elimination (94.01%) and excellent water flux recovery (79.50%) when tested with synthetic oil solution (12,000 ppm). Water productivity of over 3200 L/m2h was achieved without forfeiting the rate of oil removal under gravity. Extraordinarily low flux declination disclosed by the proposed ENMs was attributed to their tailored surface resistance mediated oil anti-fouling character. The enhanced mechanical and oil anti-fouling traits of the prepared ENMs were established to be potential for the treatment of diverse oily effluents (especially emulsions of oil-water) in the industries.Graphical abstractGraphical abstract for this articleFE-SEM micrographs showing the ENMs before and after hot press process.
       
  • CuBTC metal organic framework incorporation for enhancing separation and
           antifouling properties of nanofiltration membrane
    • Abstract: Publication date: Available online 13 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Nurasyikin Misdan, Normarina Ramlee, Nur Hanis Hayati Hairom, Syarifah Nazirah Wan Ikhsan, Norhaniza Yusof, Woei Jye Lau, Ahmad Fauzi Ismail, Nik Abdul Hadi Md Nordin Novel thin film nanocomposite (TFN) nanofiltration membrane with tunable physico-chemical properties and separation performances was fabricated by incorporating the copper benzene-1,3,5-tricarboxylate (CuBTC) nanoparticles with different concentrations (ranging from 0–0.75 wt.%) in the polysulfone (PSf) substrates, followed by the interfacial polymerization process of trimesoyl chloride (TMC) and piperazine (PIP) to establish top selective layer. Charaterization results show that both chemical and physical properties of poly(piperazineamide) selective layer was altered when PSf substrate was modified by CuBTC. The introduction of CuBTC nanoparticles improved the hydrophilicity of the TFN membranes (from 70.25º to 59.02º) and promoted formation of more linear structure of poly(piperazineamide) entangled with –COOH pendant groups. By incorporating 0.25 wt.% of CuBTC into the PSf substrate, the resultant membrane flux was enhanced by 22% with MgSO4 rejection remained at 97.31%. Furthermore, a notable increment of rejection against NaCl could be attained by increasing the CuBTC content in the substrate. This could be explained by the Donnan potential effect occurred on the more linear structures of poly(piperazineamide) surfaces, which results in an increase in the selectivity of monovalent salts. Moreover, the incorporation of CuBTC rendered the TFN membranes to exhibit good anti-fouling property against bovine serum albumin.Graphical abstractGraphical abstract for this article
       
  • Experimental and numerical investigations of convection heat transfer in
           
    • Abstract: Publication date: Available online 13 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Raheem K. Ajeel, W.S-I.W. Salim, Khalid Hasnan Combining corrugated surfaces and nanofluids technologies have a significant advantage to develop compact heat exchangers in order to produce more efficient and reliable thermal systems. In this paper, the employment of alumina oxide (Al2O3) in water nanofluid for heat transfer enhancement with corrugation is performed numerically and experimentally over Reynolds number ranges of 10,000–30,000. Three corrugated channels, semicircle (SCC), trapezoidal (TCC), and straight (SC) are fabricated and tested with nanofluid Al2O3 volume fractions of 0%, 1%, and 2%. Thermophysical properties of the prepared nanofluid are measured experimentally. Numerically, the governing equations are solved in the computational domain using the finite volume method, and the results are presented in terms of velocity and isotherms contours. The findings clarified that the corrugation profile has a significant impact on heat transfer enhancement compared to the straight profile. Furthermore, heat transfer enhancement increases with increasing the volume fraction of nanoparticles. The new style of trapezoidal corrugated channel has the best heat transfer enhancement. This result may clarify the best use of corrugated channels in heat exchange devices to obtain the required thermal improvement. The numerical results are compared with the corresponding experimental data, and the results are in a good agreement.
       
  • Life Cycle Assessment and Optimization of Claus Reaction Furnace through
           Kinetic Modeling
    • Abstract: Publication date: Available online 12 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Samane Zarei A reaction scheme was developed to comply with the experimental data provided by the laboratory setup and industrial plants for the Claus reaction furnace. The proposed reaction scheme was applied in analyzing an industrial Claus reaction from environmental and economic points of view. By applying the modified Claus process, the total emissions from the processed acid gas was reduced about 52.34% compared to acid gas without treatment. The case studies showed that hydrogen sulfide and oxygen mole percentages in the furnace inlet have considerable impacts on the relative, normalized and total environmental impacts of the system. In addition, sulfur efficiency was also influenced by their variations. The 80.41% and 58.98% declines in total environmental impacts and the 71% and 48.41% enhancements for sulfur efficiency were acquired by hydrogen sulfide and oxygen variations, respectively. Therefore, any variation which led to raising hydrogen sulfide conversion to sulfur results in sulfur efficiency improvement and, consequently, has several economic benefits. The optimal operating conditions of an industrial Claus reaction furnace were also investigated.Graphical abstractGraphical abstract for this article
       
  • Dynamic Analysis and Multiple Model Control of Continuous Microbial Fuel
           Cell (CMFC)
    • Abstract: Publication date: Available online 12 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Ashish Yewale, Ravi Methekar, Shailesh Agrawal Water and energy scarcity are among the most serious challenges currently faced by the society. Microbial fuel cell is one such a technology, which simultaneously produces water and energy from waste water or organic matters. A robust control strategy is needed for smooth and continuous operation of cell. In this paper, first principle based model of microbial fuel cell is simulated and validated with experimental data from the literature. Selection of the manipulated variable is carried out by analyzing the dynamic and steady state response of the cell. It is found that the inlet substrate flow rate is the most suitable manipulated variable among all the considered variables. A multiple model based control strategy is developed using various switching criteria such as recursive Bayesian, k-nearest neighbour, and Hotelling’s T2 methods. An efficacy of the proposed control scheme is tested on servo and regulatory problems and comparison of switching methods are presented. Settling time for positive and negative set points is found to be 133 and 93 hours, respectively and shows 47.3% improvement over the single model linear controller. This work helps in understanding the dynamics of the cell and development of robust nonlinear control for the microbial fuel cell.Graphical abstractGraphical abstract for this article
       
  • Techno-economic modeling and optimization of catalytic reactive
           distillation for the esterification reactions in bio-oil upgradation
    • Abstract: Publication date: Available online 31 May 2019Source: Chemical Engineering Research and DesignAuthor(s): M. Arif Khan, Yusuf G. Adewuyi Equilibrium reactive distillation (RD) process simulation and economic evaluation were carried out for the esterification of complex mixtures of several fatty acids and water (representative of crude bio-oils) with n-butanol using Aspen PLUS process simulator and economic analyzer. Complete design and optimization were carried out using evolutionary techniques from simplest system to the most rigorous one with introduction of intermittent progressive complexity. Prior to distillation design, esterification reaction kinetics and binary/ternary interactions were analyzed using Aspen RGibbs reactor module and Property PLUS, respectively. Simple distillation column was designed and optimized to obtain the initial trial parameters to be used in RD simulation. UNIQUAC is used as base property method and reaction equilibria estimated by minimization of Gibbs free energy. Near atmospheric column pressure, reflux ratio of 0.95, distillate to feed ratio of 0.505 and total 18 stages were found to be optimum based on attainable reaction conversion, ester separation, heat duties, and capital and operating costs. The effects of butanol:acid feeding ratio and water percent in bio-oil and their relationship were also analyzed to predict butanol requirement. The results of this study, including the optimized parameters, could serve as design platforms for pyrolysis bio-oil upgradation to transportation fuels.Graphical Graphical abstract for this article
       
  • Detailed geometrical analysis of statistical activity variations in
           diluted catalyst beds
    • Abstract: Publication date: Available online 31 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Gunnar Ganzer, Andreas Daniel, Hannsjörg Freund In multitubular fixed bed reactors for heterogeneously catalyzed, highly exothermic gas phase reactions the catalyst bed is usually diluted with inert particles for improving the heat management. To help balancing the heat generation and heat removal out of the reactor by catalyst bed dilution, the active and inert particles have to be mixed as well as possible. Otherwise, the thermal stability of the reactor cannot be guaranteed and, e. g., catalyst deactivation or thermal runaway may take place because of the formation of local hotspots. Since loading a mixture of active and inert particles into a reactor tube inherently is a statistical process, fluctuations in local activity cannot be avoided. We have analyzed this phenomenon in detail based on numerically generated 3-dimensional randomly packed beds of spheres. The statistical process of loading a mixture of particles into a reactor tube was mimicked by a random number based approach. The simulations show that activity variations are evenly distributed along the axial direction, whereas in radial direction the fluctuations become larger towards the tube center. The synthetic packed beds provide detailed information about the packed bed structure, which has been used to identify accumulations of active particles in local clusters. This evaluation reveals significant non-idealities compared to the assumption of a uniform activity profile, e. g., clusters of up to 20 active particles could be observed. Especially for highly diluted beds and/or low D/d ratios typical for highly exothermic reactions this aspect should be kept in mind during process development and design.Graphical abstractGraphical abstract for this article
       
  • Molecular Dynamic Simulations to Evaluate Dissociation of Hydrate
           Structure II in the Presence of Inhibitors: A Mechanistic Study
    • Abstract: Publication date: Available online 27 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Javad Kondori, Sohrab Zendehboudi, Lesley JamesABSTRACTThe present work aims to investigate stability and decomposition of hydrate structure II of methane, propane, and isobutane systems at various temperatures, pressures, and compositions in the absence and/or presence of inhibitor molecules. To assess the stability of gas hydrates, a comprehensive knowledge of the structural, thermodynamic, and dynamic properties of the hydrates is needed. The structure II of gas hydrates is embedded in a molecular dynamic (MD) approach and the simulations are carried out under constant temperature-constant volume (NVT) and constant temperature-constant pressure (NPT) conditions by employing the consistent valence force field (CVFF). In this work, first, the mean square displacement (MSD) and diffusion coefficient are evaluated to demonstrate the movement of host molecules. The radial displacement function is then utilized to display characteristic configurations of structure II under different process and thermodynamic conditions. In addition, other vital properties including lattice parameter and potential energy are determined. The effect of inhibitors on stability and/or decomposition of hydrate structure II is investigated. The achieved results are in good agreement with previous theoretical and experimental outputs, confirming reliability and appropriateness of the simulation method. The inhibition capability of different inhibitors based on the simulation results has the following order: methanol > ethanol > glycerol. The findings of this study can help for better understanding of hydrate dissociation in molecular scale as well as for proper selection and design of effective inhibitors for hydrates with different structures and characteristics.Graphical abstractGraphical abstract for this article
       
  • Liquid distributor design for random packed columns
    • Abstract: Publication date: Available online 23 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Florian Hanusch, Michael Künzler, Michael Renner, Sebastian Rehfeldt, Harald Klein Liquid distributors are the second most important internal in packed columns, as they ensure sufficient initial distribution, which is crucial to achieve optimum separation performance. In this work, a liquid distributor design method is presented, which applies the TUM–WelChem Cell Model to consider the interaction between the liquid distributor and the packing. Liquid distribution in the packing is estimated in dependence of the liquid distributor design. An overall maldistribution quality is determined as a characteristic value for evaluation. Two common methods, the coefficient of variation and the liquid distribution quality by Moore and Rukovena, are implemented for reference. A parameter study with an exemplary column design provides optimum drip point densities for different types of packing. Moreover, the spacing between the outermost drip points and the column wall is considered in detail, suggesting an optimum distribution quality for high wall spacing. Further application of the method suggests an increase of the optimum drip point density for smaller column diameters. Application of the TUM–WelChem Cell Model to liquid distributor design provides a potent tool for an optimized distributor layout with sufficient initial distribution at minimized material usage and high free space for the gas flow.Graphical abstractGraphical abstract for this article
       
  • Liquid phase axial mixing in distillation column packed with structured
           packing: effect on column performance
    • Abstract: Publication date: Available online 20 May 2019Source: Chemical Engineering Research and DesignAuthor(s): F.J. Rejl, T. Čmelíková, L. Valenz, J. Haidl, T. Moucha, T. Kracík We present values of the Bodenstein number, BoL, characterizing liquid phase axial mixing, for the atmospheric distillation of three binary mixtures of primary alcohols and a mixture of cyclohexane/n-heptane, all of which were distilled in a column packed with Mellapak 250.Y or Mellapak 452.Y. In addition, volumetric mass transfer coefficients (kLa, kGa) were evaluated from the experimental composition profiles along the distillation column. To describe the distillation process, axial mixing in the phases was considered and modelled as axial dispersion. The results of our modelling call for a reassessment of the relative importance of the process-affecting phenomena. In particular, while vapour phase mass transfer resistance was confirmed as most important, liquid phase axial mixing is shown to have a significant impact under all conditions. For the C6/C7 mixture on Mellapak 452.Y, liquid phase mass transfer resistance was negligible when axial mixing was taken into account. Conversely, non-zero liquid phase mass transfer resistance was found for the alcohol mixtures in all cases. However, our investigation revealed that this is most likely a relic of the usage of the simplistic plug flow model.
       
  • Extended performance comparison of different pressure drop, hold-up and
           flooding point correlations for packed columns
    • Abstract: Publication date: Available online 20 May 2019Source: Chemical Engineering Research and DesignAuthor(s): V. Wolf-Zöllner, F. Seibert, M. Lehner Eight correlations for the prediction of pressure drop, liquid hold-up and flooding for packed columns were evaluated in an initial analysis in Wolf-Zoellner et al. 2019. The best predictions were achieved with the Wolf 2014 model and a modified model of Maćkowiak 2003 by Wolf-Zoellner.The objective of this work is to extend the performance investigation to other well-known correlations available in literature: Spiegel and Maier 1992, Brunazzi 2002, Bozzano 2007, NNA-Model of Piché 2001, GPDC of Kister 2007, Robbins 1991, Jammula 2014.Therefore, the significant combined databases of the Separation Research Program (SRP) at The University of Texas and the Montanuniversitaet Leoben (MUL) provide the perfect basis to evaluate the correlations. The databases include pressure drop, hold-up and flooding point data for 50 different random (2nd, 3rd and 4th generation) and structured packings (sheet and grid structured packings) for different test systems under absorption and distillation conditions. At present 32 packings are included in the study.Based on this evaluation, the Kister GPDC-charts show the best agreement for pressure drop and flooding point estimation. Generally, all examined models perform well for pressure drop calculation but none of the considered models are able to predict reliable liquid-hold ups. In addition, the overall poor modelling performance involving viscous liquids is obvious and needs further investigations.
       
  • Economic analysis of a horizontal diabatic separation system
    • Abstract: Publication date: Available online 18 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Emmanouil Papadakis, Jakob K. Huusom, Jens Abildskov Model-based methods and tools are applied to preliminary analysis of a mobile heat integrated horizontal separation system. An economic model, based on Guthrie’s modular approach, is developed for analysis of capital and operational expenditures. The separation system consists of two, co-axially arranged tubes. The inner one is serving as a stripping section and the outer one as rectifying section. First, a steady state model is developed using n non-equilibrium stages based on mass transfer modeling. Sensitivity analysis has been performed to assess the impact on system performance, of variations of transport coefficients and design variables. The model together with an economic model has been applied to identify design and operational limitations on such a unit. The analysis investigates the total annual cost dependence of heat transfer area, alcohol concentration in the feed and rejected amount of water in the stripping section for different locations of interest. It has been found that the overall operating costs are significantly reduced for higher alcohol concentration in the feed and high discharge of water at the end of the stripping section. On the other hand, increased heat transfer area between the stripping and rectifying section leads to higher capital costs and is not necessarily balanced by lower operating costs.Graphical abstractGraphical abstract for this article
       
  • Experimental investigations of the fluid dynamics in liquid falling films
           over structured packing geometry
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Sören J. Gerke, Jens-Uwe Repke The objective of this study was to adapt an optical non-invasive measurement methodology for the investigation of the fluid dynamics in thin liquid falling films. The technique should allow to directly observe effects of the surface topology of structured packings on the flow field and film thickness distribution during flow over real packing surfaces. Three-component planar velocity vector fields were determined by means of stereoscopic particle image velocimetry. Optical distortion could be avoided by measuring from the back through specially-prepared transparent moldings of packing surfaces which match the refractive index of the liquid. The adapted stereoscopic particle image velocimetry was validated for laminar liquid film flow over a smooth inclined plate. The results for laminar flow over an inclined plate with a tetrahedral micro-structured packing surface indicate an increased exchange of fluid elements over the liquid film height and in the liquid film between micro-structures. Furthermore, the technique allowed spatially resolved complex observations of liquid flow behavior in real packing channel geometries. The methodology may be used to attain basic data for validation of numerical studies to improve understanding the geometry effects of complex surface topologies on liquid film flow dynamics and for numerical studies on packing structure optimization.Graphical abstractGraphical abstract for this article
       
  • Power consumption prediction in a coalescent liquid in mechanically
           agitated gas–liquid reactors
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Radim Petříček, Tomáš Moucha, Tomáš Kracík, Jan Haidl In mechanically agitated gas–liquid contactors design, transport characteristics such as volumetric mass transfer coefficients, power input, and gas hold-up often become the key parameters. Therefore, their values should be estimated as precisely as possible. The power input is usually used as the scale of energy dissipation for other characteristics. The goal of this work is to establish reliable power input correlations for industrial processes design, where the coalescent batch is used. The experiments were carried out in a pilot-plant and laboratory vessel. Different types of impellers, as well as their different diameters, were used, and also the combinations of radially and axially pumping impellers on a common shaft. Energy consumption was measured in a multi-impeller vessel with different impeller frequencies and several gas flows. Correlation equations describing the behavior of individual impellers were evaluated. The correlations we suggested can be used for impeller power prediction in industrial scale vessels under a wide range of operational conditions.
       
  • Multiscale computational fluid dynamics modeling of thermal atomic layer
           deposition with application to chamber design
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Yichi Zhang, Yangyao Ding, Panagiotis D. Christofides This work develops a first-principles-based three-dimensional, multiscale computational fluid dynamics (CFD) model, together with reactor geometry optimizations, of SiO2 thin-film thermal atomic layer deposition (ALD) using bis(tertiary-butylamino)silane (BTBAS) and ozone as precursors. Specifically, an accurate macroscopic CFD model of the ALD reactor chamber gas-phase development is integrated with a detailed microscopic kinetic Monte Carlo (kMC) model that was developed in Ding et al. (2019), accounting for the microscopic lattice structure, atomic interactions and detailed surface chemical reactions. The multiscale information exchange and the transient simulation of the microscopic distributed kMC algorithms and the macroscopic CFD model are achieved through a parallel processing message passing interface (MPI) structure. Additionally, density functional theory (DFT)-based calculations are adopted to compute the key thermodynamic and kinetic parameters for the microscopic thin-film growth process. Recognizing the transient non-uniformity and the possibility to reduce the current ALD cycle time, the optimal configuration of reactor geometry is designed and evaluated including a showerhead panel adjustment and geometry modifications on reactor inlet and upstream. It is demonstrated that with suitable reactor chamber design the required BTBAS ALD half-cycle time can be reduced by 39.6%.Graphical abstractGraphical abstract for this article
       
  • Optimal design of shale gas supply chain network considering MPC-based
           pumping schedule of hydraulic fracturing in unconventional reservoirs
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Yuchan Ahn, Prashanth Siddhamshetty, Kaiyu Cao, Jeehoon Han, Joseph Sang-Il Kwon Several approaches have been developed to design shale gas supply chain network (SGSCN) in an economically viable manner, but the connection between hydraulic fracture geometry, shale gas production, and wastewater recovery has not received much attention. Specifically, the final fracture geometry in unconventional reservoirs significantly affects shale gas production rate and it indirectly determines the amount of recovered wastewater. To take into account the relations among hydraulic fracturing jobs, wastewater generation and management, and shale gas production and management, we focus on the development of a novel framework that integrates a model predictive control (MPC)-based pumping schedule of hydraulic fracturing and a SGSCN model. Based on this developed framework, the optimal SGSCN configuration, which maximizes the overall profit, is determined by solving a mixed-integer linear programming problem. The proposed SGSCN design framework is compared to the case when the same SGSCN model is integrated with a suboptimal pumping schedule like Nolte’s pumping schedule. The overall profit of the former is 4.49% higher than that of the latter.
       
  • A hydrodynamic analogy based modelling approach for zero-gravity
           distillation with metal foams
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Sebastian Rieks, Marc Wende, Niklas Preußer, Tatiana Gambaryan-Roisman, Eugeny Y. Kenig Zero-gravity distillation (ZGD) is one of the few ways to establish a small-scale distillation process. In contrast to conventional distillation columns, capillary forces, e.g. induced by metal foams, are exploited to ensure liquid flow in ZGD units. In order to strengthen the knowledge basis necessary for the ZGD equipment design, understanding of the relevant transport phenomena is necessary. In this work, a model for the description of ZGD processes was developed. It includes momentum, heat and species transport in both liquid and vapour phases. Evaporation and condensation influence on momentum transfer is captured in a simplified manner, allowing an approximate local flow velocity determination. The developed model was implemented in the OpenFOAM® software and used to numerically simulate methanol/ethanol distillation processes in 2D approximation. In particular, the model was applied to investigate the influence of the metal foam porosity and thickness as well as the length of the foam-free compartment on the velocity, temperature and mass fraction distributions.
       
  • On the evaluation of density of ionic liquids: towards a comparative study
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Alireza Rostami, Alireza Baghban, Saeed Shirazian Superior physicochemical properties of ionic liquids (ILs) including dissolution potential for a large number of compounds, recyclability, suitable thermal stability, tuneability characteristics and trivial volatility make them attention-grabbing in electrochemistry and chemical industries. Owing to this fact, the accurate knowledge of ILs properties is demanded for the thermodynamic calculations involved in such processes. Amongst such properties, density is crucially significant in separation processes including CO2 absorption, extractive distillation and liquid–liquid extraction; thereby, creating and/or seeking a robust technique for density prediction is of great importance. In the present study, a new and combined version of least-square support vector machine as a powerful machine learning theory, and group contribution technique (GC-LSSVM) was extended for estimating the ILs density. It is worthwhile mentioning that genetic algorithm (GA) is applied to find the best values of kernel and regularization coefficients involved in GC-LSSVM. A widespread database was collected from the reliable open sources including 918 data points relevant to the 747 classes of ILs in relation with 47 substructures, pressure and temperature. The data was randomly separated into two subsets of test and train using a computer program. After the model was developed, graphical techniques and parametric statistics were executed to show the supremacy of the suggested GC-LSSVM in this study. The model findings were also compared to the available empirical and theoretical models in literature. Hence, the developed tool in this study gives the best match with target data and the least deviations from the actual ones with mean square error (MSE) of 0.0004 and coefficients of determination (R2) of 0.9925. The residual error analysis and outliers detection demonstrated the highest accuracy of GC-LSSVM model, and the validity of the employed database for density modeling, respectively. It can be concluded that the recommended tool in this study is a new combinatorial model which is employed for the first time in computation of ILs density.
       
  • Prediction of volumetric mass transfer coefficient in mechanically and
           pneumatically agitated contactors
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Tomáš Kracík, Tomáš Moucha, Radim Petříček The volumetric mass transfer coefficient (kLa) plays a crucial role in industrial design in the case of the process controlled by gas–liquid mass transfer. Prediction of kLa is nowadays mostly based on literature correlations. Our research goal is to establish suitable kLa correlations for different types of devices that would be based on the experimental dataset. This article aims at the description of one universal correlation that would be viable for mechanically agitated gas–liquid contactors and also for pneumatically agitated gas–liquid contactors such as airlift reactor.
       
  • Qualitative and Quantitative DEM analysis of cohesive granular material
           behaviour in FT4 shear tester
    • Abstract: Publication date: Available online 11 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Haithem Louati, Xavier Bednarek, Sylvain Martin, Abibatou Ndiaye, Olivier Bonnefoy The macroscopic behaviour of cohesive granular material in the FT4 shear tester is studied using the discrete element method (DEM). The shear test is simulated faithfully to the experimental procedure (filling, compaction, pre-shearing and shearing). The angle of internal friction and the apparent bulk cohesion are the macroscopic properties analysed as a result of the variation of the microscopic parameters: the sliding friction coefficient and the adhesive surface energy. The simplified JKR model was used to account for the cohesive contact between spheres. The results of the shear test show that the adhesive forces influence the dilatancy of the granular bed and the incipient failure point. In general, the shear stress increases with the adhesive energy. The sliding friction coefficient and the adhesive energy affect the Yield locus and therefore the angle of internal friction and the apparent cohesion. Two correlations were established between the angle of internal friction and sliding friction coefficient and between cohesion and adhesive energy. The effect of the initial consolidation on the shear test results is also discussed.
       
  • Analysis of entrained liquid by use of optical measurement technology
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Jonas Schulz, Hans-Jörg Bart A novel approach to investigate entrainment with aid of a photographic probe enables inline analysis of entrained liquid above column internals at different radial and axial positions. Latest CMOS camera technology allows precise assessment of form and size of droplets at high image qualities and small outer dimensions. A DN 450 cold flow test rig equipped with sieve and fixed valve trays generates droplets over a broad range of gas (1.0–2.75 Pa) and liquid (1.0–20 m3/mh) flows. Results show a strong dependence of droplet sizes on many operation parameters of the column. An increased gas factor of 1.0 Pa above the sieve tray reduces the share of droplets below 500 μm from 87% to 18%. Sieve tray experiments show a reduction of droplet size with higher liquid loads. Measurements at greater heights above the fixed valve tray reveal a decrease of the most frequent droplet size (25–50 μm) by factor 2.9. Closer to the column wall, the fixed valve entrains smaller droplets. An extrapolation from local to integral entrainment rates for comparison with the conservative capture tray method achieves satisfactory agreement. Capability of models from literature to cope with the available data are discussed.Graphical abstractGraphical abstract for this article
       
  • Hydraulic and mass transfer performances of a commercial hybrid packing:
           The RSP200X — Key modelling parameters for gas treatment applications
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Pascal Alix, John Roesler, Xavier Courtial, Michael Schultes The RSP200X, as one of the latest generation of Raschig’s structured packings (Raschig Super-Pak, RSP), has been investigated for use in scrubbing columns operating at high liquid loads where it could be particularly well adapted. These RSP packings offer a good potential for increasing capacity while maintaining mass transfer efficiencies at high levels. IFPEN has measured hydraulic and mass transfer performances in two columns of different diameters (146 mm and 1000 mm). Flooding limits were in agreement with literature, however at high liquid loads and for the tested X-Style RSP they were 30–40% lower than those calculated with the Winsorp Software delivered by Raschig. With the support of the present results a modified version of Winsorp has been elaborated for high liquid loads and X-Style RSP. In terms of mass transfer, the CO2/MDEA system was used to measure kLae while the classic CO2/NaOH and SO2/NaOH systems were used for ae and kGae measurements. The RSP200X was found to develop a high interfacial area compared to its geometric area. While for standard packings the gas flow rate is often considered to have only a small effect on effective area when operating below the loading point, its effect measured on RSP200X is significant and of the same order as for liquid load. Measurements of kLa and kGa further confirm these trends.
       
  • Comparison of porous and nonporous filler effect on performance of poly
           (ether-block-amide) mixed matrix membranes for gas separation applications
           
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Mohammad Salehi Maleh, Ahmadreza Raisi Choosing appropriate filler is a crucial challenge in the preparation of the mixed matrix membranes (MMMs) for the gas separation applications. Hence, the filler type has a significant effect on the filler/polymer interface and gas separation performance relation. In this study, the MMMs were prepared by loading three different nano-fillers including NaX zeolite, ZIF-8 and silica (SiO2) nanoparticles into the poly (ether-block-amide) (PEBA) polymer as a selective layer on the polyethersulfone membrane as a support layer. It was found that porous nanoparticles of NaX and ZIF-8 with the suitable interface and uniform distribution have a much better effect on the microstructure of the MMMs compared to the non-porous SiO2 nanoparticles. Based on the gas permeation results, the incorporation of NaX zeolite and ZIF-8 porous nano-filler up to 2 %wt extraordinarily increased the selectivity of CO2/N2 from 61.53 to 108.2 and 107.13, respectively, while the loading ZIF-8 (up to 2 %wt) and SiO2 (up to 1 %wt) improved the permeability of CO2 gas to 120% and 44%. In addition, the MMM comprising 2 %wt NaX zeolite had the highest O2/N2 selectivity (6.06).Graphical abstractGraphical abstract for this article
       
  • Distillation & Absorption 2018
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Elisabetta Brunazzi, Tony Cai, Tony Kiss, Jens-Uwe Repke, Mirko Skiborowski, Eva Sorensen
       
  • Phase equilibrium measurement, thermodynamics modeling and process
           simulation for extraction of phenols from coal chemical wastewater with
           methyl propyl ketone
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Yun Chen, Kangning Xiong, Meiling Jiang, Ran Lv The extraction of phenols from coal chemical industry wastewater with methyl propyl ketone was studied in this work by experimental determination and process simulation. Phenol and hydroquinone were separately selected as the representatives of phenolic pollutants in the phenols-containing coal chemical industry wastewater. The liquid–liquid phase equilibrium data for methyl propyl ketone + phenol + hydroquinone + water quaternary system were measured at 40 °C and 101.3 kPa. The NRTL and UNIQUAC models were used to correlate the experimental data to achieve binary interaction parameters. The process simulation for the extraction of phenols from coal chemical industry wastewater with methyl propyl ketone was developed to obtain optimized operation parameters with the binary interaction parameters fitted from the experiment. The simulation results show that, the concentration of total phenols in the coal chemical industry wastewater could be reduced from 12,700 mg L−1 to 313 mg L−1 in the stream of the bottom in the stripping column, which is suitable for further biochemical treatment of the wastewater. The extraction solvent could be recycled through the distillation column and the stripping column. The crude phenols would be as by product in the phenols extraction and solvent recovery.Graphical abstractGraphical abstract for this article
       
  • Mechanistic assessment of Seidlitzia Rosmarinus-derived surfactant for
           restraining shale hydration: A comprehensive experimental investigation
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Saeed Khezerlooe-ye Aghdam, Aghil Moslemizadeh, Mohammad Madani, Mehdi Ghasemi, Khalil Shahbazi, Mostafa Keshavarz Moraveji The physicochemical aspect of wellbore stability is linked to the interaction between the drilling fluid and rock (e.g., shale). By far, most of the surfactants utilized in the oil industry are identified with environmental drawbacks. This paper appraises for the first time the functionality of a novel environmentally-friendly bio-based surfactant, Seidlitzia Rosmarinus leaf and stem extract (SRLSE), in water-based drilling fluids (WBDF) for inhibiting shale hydration. The swelling inhibitive property of SRLSE was thoroughly evaluated using several experiments including clay inhibition, cuttings dispersion, filtration, particle size measurement, scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). The findings implied that as opposed to deionized water, the aqueous solution of SRLSE indicated fairly low rheological profiles which resulted in a greater degree of montmorillonite (MMT, an active mineral in shale) loading (22.5 mass%). Addition of 3 mass% SRLSE and 8 mass% SRLSE to deionized water resulted in a shale cuttings recovery improvement of 20.8% and 40.5%, respectively. MMT in deionized water gave a fluid loss of 26 ml. However, it exhibited a poor fluid loss control in the aqueous solution of SRLSE so that the fluid loss volume increased up to 73 ml. As opposed to deionized water, the particle size of MMT in SRLSE aqueous solution rose extremely. According to TGA, the modified MMT in the aqueous solution of SRLSE imposed 2.88% less water content with respect to the modified MMT in deionized water. From SEM observations, MMT in SRLSE aqueous solution exhibited larger aggregates than deionized water. In addition to the aforementioned results, compatibility tests proved that SRLSE is well-compatible with typical WBDF additives. All the experimental results implied that SRLSE can be considered a capable shale inhibitor in WBDF. The interaction between the hydrophilic tail of saponin (a dominant constituent of SRLSE) and MMT's surfaces which forms a hydrophobic shell is perhaps the leading inhibition mechanism for SRLSE.Graphical abstractGraphical abstract for this article
       
  • Turbulent statistics of flow fields using large eddy simulations in batch
           high shear mixers
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Vikash, Vimal Kumar Large eddy simulations (LES) have been carried out for the first time to characterize the flow and turbulent characteristics in three different batch high shear mixers (HSMs) at a constant rotor speed of 4000 rpm. Three HSMs having different stator heads such as circular, square and inclined stator head with 6, 92 and 210 numbers of stator holes, respectively have been investigated. Dynamic Smagorinsky model with sliding mesh method is used for the sub-grid scale stresses at a Reynolds number of 52,000, to overcome the prediction of RANS models. Numerical methodology is validated, in terms of Power number with the available numerical and experimental studies and found in fairly good agreement. The velocity flow patterns and fluctuations at different planes are predicted and vortexes have been observed within the stator holes and bulk fluid. It is observed that velocity magnitude fluctuation is a function of rotor rotations and stator holes size, and fluctuations in one jets emerging from stator holes affect the fluctuations in other plane jets. Further, it is found that smaller the stator holes size, greater is the energy distribution and hence greater will be the drop size distribution in the mixer. Therefore, the inclined stator head HSM can be used for the uniform size distribution in application to de-agglomeration and dispersion. It is found that the energy spectrum of Kolmogorov is followed over the entire length scale for all HSMs and LES provided the richer flow and turbulent information as compared to RANS model.Graphical abstractGraphical abstract for this article
       
  • Operating the CO2 absorption plant in a post-combustion unit in flexible
           mode for cost reduction
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Stefania Moioli, Laura A. Pellegrini Carbon dioxide greatly contributes to climate change and its emissions must be limited. Combustion of fossil fuels in power plants to produce electricity generates the largest amount of CO2 released into the atmosphere, therefore application of Carbon Capture and Storage (CCS) to this sector would help in reducing the emissions of this acid gas.CO2 absorption with aqueous amines is the most common capture technology for post-combustion CO2 removal and is characterized by high energy requirements, mainly for CO2 release from the solvent and compression of the obtained rich-CO2 stream. For this reason operating the CCS system in a power plant significantly reduces the power output and, consequently, the revenues from selling electricity.In order to deal with this issue while maintaining low carbon dioxide emissions, flexible operation may be applied.In this work, a detailed analysis of the application of the solvent storage mode for flexible operation of the CO2 removal section of a natural gas combined cycle power plant has been performed.Simulations in ASPEN Plus®, properly customized for the description of the system, and a techno-economic model created by the GASP group of Politecnico di Milano have been run to find the best solution. The variation of price of electricity from hour to hour for key days and for the overall year have been considered. Different values of carbon tax to be applied have been also taken into account.
       
  • Magnetite synthesis using iron oxide waste and its application for
           phosphate adsorption with column and batch reactors
    • Abstract: Publication date: Available online 8 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Muhammad Kashif Shahid, Yunjung Kim, Young-Gyun Choi The magnetite particles were synthesized by reverse coprecipitation of mill scale (iron oxide waste). The particle characterization was done and confirmed by SEM, EDS, BET, XRF, FTIR and XRD. Scherrer equation determined 11.64 nm single crystalline size of the magnetite and the BET surface area was found nearly 75.77 m2 g-1. The expected stoichiometry (3:4) of Fe:O was confirmed by elemental analysis. The magnetite particles were proven as effective adsorbent for phosphate ions from the contaminated water. The phosphate removal efficiency was inspected with several experimental setups including column reactor fed from top to bottom, from bottom to top and sequencing batch reactor. The maximum P-adsorption capacity of magnetite was determined 11.78 mg g-1. The P-carrying adsorbent is regenerated with different concentrations of NaOH and NH4OH solutions for 1, 2 and 5 days. Though both solutions were appeared effective for regeneration of used particles, NaOH was appeared more efficacious than that of NH4OH. The regeneration competence of magnetite particles is also evaluated with repetitive regeneration of used particles with 0.1 N NaOH. As compared with initial value, almost 20% of the adsorption capacity was reduced after 12 successive rounds of phosphate adsorption and desorption onto the surface of magnetite. The obtained results have established fine potentiality for the magnetite particles synthesized by reverse coprecipitation to be applied as phosphate adsorbent in wastewater treatment.Graphical abstractGraphical abstract for this article
       
  • Modeling the multistage process of the linear alkylbenzene sulfonic acid
           manufacturing
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Irena Dolganova, Emilia Ivanchina, Igor Dolganov, Elena Ivashkina, Anastasia Solopova Linear alkylbenzene sulfonic acid (ASA) is used to produce industrial and domestic synthetic detergents and is obtained via a multistage technology. Unsteady mathematical models were developed for all technological stages. With use of the developed models we studied how the modes in the dehydrogenation reactor influence the product quality and yield. It was found that increase in the hydrogen/feedstock ratio in the dehydrogenation reactor from 6 to 8 mol/mol decreases the outlet dienes concentration from 0.57 to 0.46%wt. This reduces the amount of heavy aromatic compounds (HAR) formed in the alkylation reactor, as well as the optimal flow rate of alkylation HF catalyst to regeneration from 4.5 to 4.1 m3/h. The decrease of the hydrogen/feedstock ratio in the dehydrogenation reactor from 6.5 to 6 mol/mol intensifies the highly viscous component accumulation in the sulfonation reactor, reducing the period between the reactor washings from 13 to 10 days.Graphical abstractGraphical abstract for this article
       
  • Improving cyclone efficiency for small particles
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Sepideh Akhbarifar, Mansour Shirvani Test results of a new highly efficient add-on for cyclones are reported. The add-on has the same beneficial characteristics as cyclones (versatility, long-lasting, low construction and maintenance cost, simple design, little investment, little extra space, flexible operating conditions). The new device was tested in combination with Stairmand cyclones. Efficiencies without any additional filters reached 98% for a particle size distribution with an average of 1.6 μm and>99% for particles ≥10 μm. In the most effective mode of operation the dust enters the cyclone(s) and the depleted stream leaves for the add-on, a ‘jet impingement chamber’, which contains an air-blowing nozzle pipe pushing dust particles toward the wall creating clean gas in the center, which is released. The dust-enriched stream is recycled, i.e., added to the fresh feed for the cyclones. Experiments were performed under large-scale operating conditions and design methods applied to fully characterize the system’s efficiency with all variables of operation including three dust particle size distributions covering the range from 0.3 to 200 μm.Graphical abstractGraphical abstract for this article
       
  • Experimental and numerical investigation on mixing of dilute oil in water
           dispersions in a stirred tank
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Sepehr Khajeh Naeeni, Leila Pakzad Stirred tanks are commonly employed for liquid–liquid dispersion processes in many industries. This study investigated the effects of agitation speed, and oil type and volume fraction on the hydrodynamic characteristics and chord length distribution (CLD) of dilute oil in water dispersions in a stirred tank. Electrical resistance tomography (ERT) and a focused beam reflectance measurement (FBRM) instrument were used to assess the liquid–liquid flow and to measure droplet size inside the tank, respectively. We also simulated flow field via computational fluid dynamic and modeled droplet size distribution in a stirred tank by population balance modeling. An increase in agitation speed was found to decrease the mean and Sauter mean diameter while improving the homogeneity of the system. Wider distributions were observed at higher oil volume fractions, without a significant change in droplet size. Increasing the viscosity of the oil phase resulted in poor mixing, with a gradual shift towards smaller droplets. The effect of the dispersion process on droplet shape and deformation rate were also investigated using CLD results. Further shape analysis was performed using Python coding. Our results show that the shape of the droplets changed from sphere to spheroid with an increase in agitation speed. An increase in droplet deformation rate was also observed with an increase in the oil phase viscosity and a decrease in the interfacial tension between the two immiscible liquids.
       
  • RANS-based predictions of dense solid–liquid suspensions in
           turbulent stirred tanks
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): F. Maluta, A. Paglianti, G. Montante This work is aimed at investigating the impact of different meso-scale models and constitutive equations for the RANS-based two-fluid model simulations of a turbulent solid–liquid stirred vessel with high solids loading. The model assessment is preceded with a grid convergence study, which confirms the variability of the discretization requirements depending on the observed variable. The simulation results demonstrate that for the investigated system the high solids loading contribution modelled by the kinetic theory of granular flows is negligible, both in incomplete and complete suspension conditions. Instead, the particle concentration fluctuations contribution included in the momentum equations dramatically affect the predictions, particularly in incomplete suspension conditions. The evaluation of the models is completed by the comparison of the predicted solids concentration profiles with experimental data measured by Electrical Resistance Tomography. The computational strategy for achieving realistic predictions of the solid distribution both in complete and incomplete suspension conditions is outlined.Graphical abstractGraphical abstract for this article
       
  • Optimization of a hybrid sludge drying system with flush drying and
           microwave drying technology
    • Abstract: Publication date: Available online 5 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Hanki Eom, Young Hee Jang, Dongyoon Lee, Sung Su Kim, Sang Moon Lee, Eun Man Cho The purpose of this study is to optimize a hybrid sludge drying system using a primary cold flush drying system and a secondary microwave drying system filled with a heating material. The system also includes an odor reduction facility to remove the complex odors generated from sludge drying. Through operating the system, the final dry sludge moisture content was reduced to an average of 15.8%. The energy consumption was 711.6 kcal kg-1. The advantage of this system is that it can achieve high efficiency sludge drying with low energy consumption, and it can apply a complex heating technology to each drying section, depending on the physical properties and operating conditions of the target material to be dried. Therefore, this system is expected to achieve a high drying efficiency while simultaneously reducing the energy and processing costs in future sludge drying processes.Graphical abstractGraphical abstract for this article
       
  • Bubble rise velocity and bubble size in thickened waste activated sludge:
           Utilising Electrical resistance tomography (ERT)
    • Abstract: Publication date: Available online 3 June 2019Source: Chemical Engineering Research and DesignAuthor(s): Veena Bobade, Geoffery Evans, Nicky Eshtiaghi Bubble columns are intensively used in many different industries as multiphase contactors. The gas phase properties in the bubble column significantly impact on the hydrodynamics of the column which effects on heat and mass transfer rates within the column. In this paper, electrical resistance tomography together with dynamic gas disengagement technique is used to determine the gas holdup and bubble rise velocity within the column at four different gas flow rates (1 to 7 L/min) and two different total solids concentrations of waste activated sludge (3% & 5.5%). For the first time, effective shear rate and bubble size are calculated based on the Herschel-Bulkley model. A linear relation was observed for the bubble rise velocity with stress imposed and between gas holdup and natural logarithm of stress imposed by gas injection.Graphical abstractGraphical abstract for this article
       
  • Development of a mesoscale model for the gas phase fluid dynamics in
           structured packings based on fundamental experiments and CFD
           investigations
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Johannes Sacher, Jens-Uwe Repke This paper presents a new mesoscale model simulating the gas phase fluid dynamics and concentration distribution in structured packings, used in absorption and distillation columns. The model describes the structured packing as an arrangement of triangular channel sections and is implemented with an own developed mesoscale simulation code (StructuPack). The velocity field is stored at the cell faces and is driven by pressure, inertial and viscous forces. The coupled continuity and momentum equations are solved with the SIMPLE-algorithm, that is usually applied in CFD solvers. The development of the model is based on fundamental investigations with CFD simulations and experiments, described in the first part of the paper. Particularly, the concentration distribution in a representative geometry of structured packings, a single crisscrossing junction of triangular channels, is analysed. As one result of the fundamental investigations the CFD solver could be validated as a predictive tool with respect to concentration distribution for the laminar regime in structured packings. In the second part, the mesoscale model is described in detail and validated with a scenario of tracer distribution in a packing layer. By means of comparison with CFD simulations of the same scenario it was shown that the mesoscale model has the ability to yield good representations of concentration, pressure and velocity profiles in a structured packing. Thereby the mesoscale computational performance was three orders of magnitudes more efficient with respect to CFD. At the advent of high-performance computing this means that models at intermediate scale are a viable tool to simulate scenarios like maldistribution effects in industrial sized structured packings of distillation and absorption columns.
       
  • On controllability of a fully thermally coupled four-product dividing wall
           column
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): G. Lukač, I.J. Halvorsen, Ž. Olujić, I. Dejanović Although potential for reduction of energy requirement and related carbon dioxide emissions is highly attractive – around 50% compared to conventional three column sequences – process industries are still reluctant to consider implementation of fully thermally coupled four products dividing wall columns, mainly due to concerns related to controllability of two or three vapour splits as encountered in complex DWC arrangements. This paper presents results of a simulation study that could bring some relief in this respect, indicating that a temperature-based control structure, in conjunction with tight control of temperature profiles in prefractionation section, as well as in the product draw regions of the column, is capable of restoring the operation to health from typical disturbances in feed quality and quantity. Combining temperature-based control with two composition controllers enables the column to be operated within finer margins, resulting in minimal over-purification and overall energy requirement.
       
  • Ultrasound-assisted extraction of biologically active compounds and their
           successive concentration by using membrane processes
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Anna Trojanowska, Iren Tsibranska, Daniela Dzhonova, Michalina Wroblewska, Monika Haponska, Petar Jovancic, Valentina Marturano, Bartosz Tylkowski Sideritis scardica and Sideritis syriaca are considered highly valuable plant materials and their total polyphenols (TP) and total flavonoids (TF) extracts can be employed in nutraceutics and cosmetics. A two-step process was proposed consisting in the ultrasound-assisted extraction (UAE) and concentration of the biologically active compounds via nanofiltration (NF). An extensive comparison between UAE and conventional high-temperature stirring was performed, taking into account the effect of process parameters such as solvent, temperature and ultrasonication. In terms of radical scavenging activity and time optimization, UAE was found more effective, providing – after only 1 h – extraction yields comparable to 20 h of the conventional thermo-mechanical method. The extract was then concentrated by nanofiltration in tangential mode at 20 bar using 300 and 500 Da cut-off Duramem membranes. Permeate and rejection flux was monitored during the filtration process. The lower molecular weight membrane showed higher permeability towards TP and TF and contributed to a more stable flux and lower fouling processes. To predict operational drawbacks, computational fluid dynamic simulations were performed to model the complex rotational flow occurring during membrane filtration.
       
  • Diffusion–reaction phenomenon for negative-order reactions in flow
           reactors
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Shephali Singh, Divesh Bhatia The phenomenon of simultaneous diffusion, reaction, and external mass transfer in a spherical catalyst particle is studied for a reaction exhibiting negative order with respect to the reactant species. With external mass transfer considered, it is shown that for a reaction exhibiting a negative order for all the concentrations, a solution to the diffusion–reaction equations does not exist for high values of Thiele modulus. An algorithm is developed to calculate the concentration profile in a spherical catalyst particle for a negative-order reaction. With the proposed algorithm, the solution is obtained even for conditions for which a solution was not found in previous studies. The algorithm successfully captures the multiplicity of the solutions as well as the transition from kinetic/internal-diffusion controlled regime to the external mass-transfer controlled regime. The developed algorithm is further utilized to calculate the axial concentration profile in a packed-bed reactor for a negative-order reaction. Additionally, the radial concentration profile in a spherical particle is evaluated for a multi-component reaction system wherein the reaction exhibits both positive and negative order with respect to various species. The algorithm is particularly useful for power-law type negative order kinetics which are widely reported in the literature.Graphical abstractGraphical abstract for this article
       
  • Thermal coupling opportunities for floating natural gas liquefaction
           plants
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): I.J. Halvorsen, I. Dejanović, Ž. Olujić, S. Skogestad In order to meet current carbon dioxide emissions reduction challenges, natural gas processing and refining industries have to find new ways to minimize energy requirements. Building on foundations laid down in a preceding effort, this paper shows that this could be achieved in a cost-effective way for the distillation section in natural gas liquids fractionation plants. A conventional demethanizer column, combined with either a thermally coupled direct sequence of deethanizer and propane–butane recovery columns or a dividing wall column, produces significant savings in capital and hot utilities costs as compared to conventional distillation with a direct sequence, without any temperature penalty on cold utilities side. The choice between available options will largely depend on important process considerations that may differ for offshore and onshore plants and specific site requirements.
       
  • Preparation of CoFe2O4 nanoparticles based on high-gravity technology and
           application for the removal of lead
    • Abstract: Publication date: Available online 27 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Guisheng Qi, Huiyun Ren, Honglei Fan, Youzhi LiuABSTRACTThe aim of this paper is to explore a simple method for the preparation of magnetic bimetallic oxides with high production efficiency and high adsorption capacity of Pb(II). In this work, the CoFe2O4 nanoparticles were continuously synthesized through a high-gravity reactive precipitation method using an impinging stream-rotating packed bed reactor with a theoretical production rate of 0.704 kg h-1. The samples were characterized by XRD, TEM, N2 adsorption-desorption technique and VSM. The obtained results show that the as-prepared CoFe2O4 nanoparticles have higher surface area (89.15 m2 g-1) and saturation magnetization (75.43 A m2 kg-1) than that of single metal oxides (Fe2O3 and Co3O4). The adsorption data of Pb(II) onto CoFe2O4 nanoparticles fit well to pseudo-second order kinetic model and Langmuir isotherm model. The maximum adsorption capacity of Pb(II) onto CoFe2O4 was 326.79 mg g-1, while for Fe2O3 and Co3O4 nanoparticles were 140.84 and 284.90 mg g-1, respectively. Moreover, the proposed adsorbent exhibited good reusability for up five adsorption-desorption cycles. Hence, the high-gravity technology could prepare high adsorption adsorbent with high production efficiency, which brings good prospects in wastewater treatment.Graphical abstractGraphical abstract for this article
       
  • RSM Optimization of Oil-In-Water Microemulsion Stabilized by Synthesized
           Zwitterionic Surfactant and its Properties Evaluation for Application in
           Enhanced Oil Recovery
    • Abstract: Publication date: Available online 22 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Amit Kumar, Rohit Kumar Saw, Ajay Mandal Recent advances in formulation and designing of microemulsion with improved viscosity and an ability to reduce interfacial tension, miscibility with oil, have led to their application in enhanced oil recovery (EOR). The physicochemical properties of microemulsion varies widely depending on its composition, stability and temperature. In present study, an investigation has been made to formulate microemulsion using zwitterionic surfactant as amphiphile and mineral oil as oleic phase. The optimization of formulation of microemulsion with desired properties was obtained by response surface methodology (RSM). The accuracy and significance of model developed by RSM was tested by analysis of variance (ANOVA) and the model generated was used to analyse the effect of individual components on microemulsion formulation. The optimized microemulsion obtained using RSM was characterized by particle size and zeta potential analysis. The stability and miscibility tests of microemulsion showed excellent results for applicability in chemical EOR. The viscosity of the microemulsion was found to be around 300 mPa.S at 10 s-1 shear rate, which is highly encouraging for its application in EOR to improve the mobility ratio. The interfacial reduction and wettability alteration properties of microemulsion was also found to be superior to that of surfactant solution. The core flooding experiment showed that the optimized microemulsion was able to recover 26.83% of additional oil as compared to 20.01% of oil recovery by surfactant flooding, over the conventional water flooding.
       
  • The objective of these preliminary testsA study on the caking behaviour of
           binary mixtures of lactose due to solid-state crystallisation of the
           amorphous phase
    • Abstract: Publication date: Available online 21 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Zahra Afrassiabian, Mohammed Guessasma, Khashayar Saleh This work deals with caking behaviour of lactose monohydrate powders containing small amounts of amorphous lactose. The objective was to elucidate the relation between the caking ability of powder mixtures and the crystallisation behaviour of amorphous lactose. Binary mixtures consisting of amorphous lactose and α-lactose monohydrate were prepared and tested using an accelerated caking test. Amorphous lactose samples were prepared using the freeze-drying process. Two caking devices were developed to characterize the caking ability of powders. The effect of amorphous content, relative humidity, temperature and pressure on the caking behaviour of samples was investigated. The results showed that the presence of even small amounts of amorphous lactose (as low as 0.125%) could cause caking. The more influencing parameters were found to be the relative humidity and the temperature whereas the pressure had no significant effect. The caking behaviour was shown to be closely linked with crystallisation extent and kinetics. A dimensionless time based on Avrami model for crystallisation rate was defined allowing unifying the experimental data.Graphical abstractGraphical abstract for this article
       
  • Comparison of NLDH and g-C3N4 nanoplates and formative Ag3PO4
           nanoparticles in PES microfiltration membrane fouling: Applications in MBR
           
    • Abstract: Publication date: Available online 20 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Leila Ghalamchi, Soheil Aber, Vahid Vatanpour, Mohsen Kian Development of antifouling membranes for wastewater treatment technology can serve as an economic and efficient approach urgently demanded. Attempts have been made to develop cost-effective blended microfiltration membranes containing ZnAlCu nanolayered double hydroxide (NLDH) or g-C3N4 nanosheets, and Ag3PO4 and NH2-Ag3PO4 nanoparticles with the view of finding the effect of their chemical and structural properties on the membranes performance. The obtained ZnAlCu-NLDH/polyethersulfone (PES) and g-C3N4/PES nanocomposite membranes exhibited the significant flux recovery ratio (FRR), as an antifouling index, of 75.8 and 70.7%, respectively, as compared with the pristine PES membrane having 50.9% of FRR. Inclusion of Ag3PO4 and NH2-Ag3PO4 nanoparticles remarkably increased the permeate flux of the membranes, so that the pure water flux of nanoparticles blended membranes at the pressure of 0.5 bar was found to be 292.6 and 319.5 L m-2 h-1, respectively, as compared with 229.2 L m-2 h-1 for the pristine PES microfiltration membrane. Moreover, the fabricated membrane containing Ag3PO4/NLDH and NH2-Ag3PO4/g-C3N4 nanofillers showed a high flux, wettability and antifouling properties, with regard to the prevention of the interaction of the organic foulant and the hydrophilic membranes. Consequently, the self-cleaning property of nanocomposite blended membranes and the low leaching of nanocomposites could lead to the fabrication of a promising mixed matrix membrane for practical wastewater treatment in membrane bioreactors (MBRs). The increase in the critical flux (CF) also showed the desirable application of the nanocomposite microfiltration (MF) in MBR.Graphical abstractGraphical abstract for this article
       
  • Mixed matrix PES-based nanofiltration membrane decorated by
           (Fe3O4-polyvinylpyrrolidone) composite nanoparticles with intensified
           antifouling and separation characteristics
    • Abstract: Publication date: Available online 19 May 2019Source: Chemical Engineering Research and DesignAuthor(s): S.M. Hosseini, M. Afshari, A.R. Fazlali, S. Koudzari Farahani, S. Bandehali, B. Van der Bruggen, E. Bagheripour In this study, the physico-chemical properties, separation performance and antifouling ability of mixed matrix PES-based nanofiltration membranes decorated by (Fe3O4-polyvinylpyrrolidone) composite nanoparticles were investigated. The morphology of resulted membranes was characterized by scanning electron microscopy )SEM), scanning optical microscopy (SOM) and 3D surface images. The effect of incorporated nanoparticles on membrane properties and performance was determined using water contact angle, water content, membrane pore size and porosity, tensile strength, water flux, salt rejection and BSA solution filtration. The membrane water content was enhanced slightly by embedding Fe3O4/PVP up to 0.1 wt.% in membrane body and then reduced again by more NPs ratio. The water contact angle also decreased from 65.18 ° for neat membrane to 50.5 ° for the modified ones. All mixed matrix membranes showed higher water flux compared to pristine membrane that measured 3.14 (L/m2.h) for bare membrane and 9.96 (L/m2.h) for the superior ones. Salt rejection measured 82% for the pristine membrane whereas that was between 77%-90% for the nanocomposite membranes. Membrane tensile strength also improved by increase of composite NPs ratio into the polymer matrix. The nanocomposite membranes showed more BSA solution flux and outstanding antifouling properties compared to bare ones. The FRR measured ˜46.2% for bare membrane whereas that was (˜69.9 % to ˜89.5 %) for the nanocomposite membranes.Graphical abstractGraphical abstract for this article
       
  • Beta-spodumene: Na2CO3:NaCl system calcination: a kinetic study of the
           conversion to lithium salt
    • Abstract: Publication date: Available online 17 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Leonardo Leandro dos Santos, Rubens Maribondo do Nascimento, Sibele Berenice Castellã PergherABSTRACTThe basic objective of the work was to evaluate the calcination step in the lithium extraction process and to obtain a kinetic model that would adjust the experimental data for the reaction of the carbonate recovery during the processing of beta-spodumene, activated by melting with sodium carbonate/sodium chloride. In this work there were obtained activation energy values using experimental data obtained from the treatment of complex systems such as minerals. This is of interest because of the contribution it makes to the field of physical chemistry. Some of the main results indicated that the best molar ratio was 3Li2O:1Na2CO3 + 5% w/w NaCl in the conversion to Li2CO3 with approximate 70% Li yield, using a 823–923 K range with a calcination cycle of 120 min. The kinetic results indicated that the pseudo-second-order kinetic modeling fits the equilibrium data well under employed temperature conditions on literature, based on second stage of reaction mechanism (chemoselective exchange reaction).Graphical abstractGraphical abstract for this article
       
  • Equilibrium and heat of water vapor adsorption on the surface of natural
           lignocellulose materials
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Saeed Ghanbari, Angie M. Diaz, Jinho Park, Hyeran Kang, Catherine H. Niu Water vapor is to be separated from industrial gaseous streams at reduced costs. Natural lignocellulose materials have demonstrated a high water adsorption capacity and great potential in industrial gas dehydration, specifically natural gas dehydration. In this work, flax shives, a representative of abundant lignocellulose materials generated as by-products of agriculture industry, was chosen as a model to investigate their water adsorption. The focus of this work is on analyzing the surface morphology and the chemistry of the material, and investigating the effects of key parameters on the equilibrium, isotherms, surface affinity, and heat of water adsorption. The results showed that total operating pressure had the most significant effect on the equilibrium, followed by the temperature. The shape of water adsorption isotherm was changed from type III to type I as the total operating pressure was decreased and temperature was increased. The Anderson, Toth, and multi-site Langmuir models successfully described the isotherms obtained at various operating conditions. The modeling results were further used to determine the standard heat of adsorption, isosteric heat, heat of individual sites, and excess heat of liquefaction that the second and subsequent adsorbed layers released. In addition, the material surface was characterized by FE-SEM and FTIR, and the water transport through the material’s structure was visualized using optical microscopy images and video. These findings contributed to the fundamental science of water adsorption and natural lignocellulose materials and provided information for the design of drying processes based on adsorption and related interface sciences.Graphical abstractGraphical abstract for this article
       
  • Modelling and experimental validation of dimethyl carbonate solvent
           recovery from an aroma mixture by batch distillation
    • Abstract: Publication date: July 2019Source: Chemical Engineering Research and Design, Volume 147Author(s): Ivonne Rodriguez-Donis, Vincent Gerbaud, Sophie Lavoine, Michel Meyer, Sophie Thiebaud-Roux, Alice Dupouyet Modelling and experimental validation of solvent recovery from an aroma mixture by batch distillation process is presented, with particular emphasis of the effect of the prediction of the physicochemical properties and the phase equilibrium data on the content of the aroma compounds in the distillate cuts. The illustrative case study refers to an industrial batch distillation to recover dimethyl carbonate (DMC) from an extract generated by a solvent extraction process involving variable natural raw materials for tailored perfume and fragrance applications. Due to the high number of aroma compounds in natural extracts, a synthetic mixture containing six target aroma compounds (α-pinene, eucalyptol, linalool, cis-3-hexenol, fenchone and benzyl acetate) was mixed with DMC for the modelling and experimental studies of the batch distillation process. The methodology is tested through the simulation of the process with BatchColumn® software. As physicochemical properties of the aroma compounds and the vapour–liquid equilibrium (VLE) of all involved mixtures are required for simulation study, group contribution methods are used to predict missing properties such as vapour pressure, vaporisation enthalpy and liquid and vapour heat capacities. For VLE calculation, the modified UNIFAC group contribution method is considered and new binary interaction parameters for the main groups COO and CH2O are regressed from experimental data. Simulation results are in good agreement with experiments carried out in a fully automated batch distillation column at 15 kPa and help optimise the industrial process operation. The proposed methodology can be applied for the design of other solvent recovery process in fragrance industry.
       
  • Modeling of 2-phenylethanol adsorption onto polymeric resin from aqueous
           solution: Intraparticle diffusion evaluation and dynamic fixed bed
           adsorption
    • Abstract: Publication date: Available online 16 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Ivan Červeňanský, Mário Mihaľ, Jozef Markoš Adsorption of 2-phenylethanol from an aqueous solution onto hyper-crossed-linked adsorption resin Macronet MN270 was investigated in a fixed bed column. Adsorption equilibrium was obtained in batch experiments and the results were fitted with the Langmuir isotherm model. A batch adsorption experiment was performed to determine the intraparticle diffusion mechanism. It was found that pore volume diffusion cannot solely govern the intraparticle mass transfer. According to the results of the batch experiment, surface diffusion plays an important role in the adsorption of 2-phenylethanol. Diffusion coefficients obtained in the batch experiment were further verified by comparison of the experimental data with the results of the mathematical model of fixed bed adsorption which was able to predict experimental breakthrough curves obtained under various conditions. A better description of the experimental data was obtained using the mathematical model which considered pore volume diffusion together with surface diffusion. The varying parameters in the measurements of breakthrough curves were: particle diameter, column diameter, volumetric flow rate and the inlet column concentration. Fixed bed adsorption experiments showed that smaller particles together with lower volumetric flow rate produce sharper breakthrough curves. The effect of external mass transfer and axial dispersion was not very significant. Lastly, fixed bed desorption of 2-phenylethanol with water was tested and was shown to be ineffective. Therefore, different solvents for 2-phenylethanol desorption were recommended.Graphical abstractGraphical abstract for this article
       
  • Pressure correction for automotive catalytic converters: A multi-zone
           permeability approach
    • Abstract: Publication date: Available online 15 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Ivan Cornejo, Petr Nikrityuk, Robert E. Hayes This paper presents an improved model for pressure drop in a honeycomb monolith reactor, which configuration is widely used in automotive exhaust gas after treatment systems. The model is based on pressure drop simulations for single channel models complemented with large eddy simulation. The model has multiple zones, and accounts for the pressure losses for flow entering, passing through, and leaving the substrate. The new multi-zone model is theoretically more consistent than those that use a single permeability for the whole the monolith, and it gives a superior result for pressure drop and hence flow distribution.
       
  • Development of highly permeable Polyelectrolytes (PEs)/UiO-66
           nanofiltration membranes for dye removal
    • Abstract: Publication date: Available online 14 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Kai Wang, Yun Qin, Shuai Quan, Yingjie Zhang, Peng Wang, Heng Liang, Jun Ma, XiQuan Cheng With suitable pore size, narrow pore size distribution and charged surface, nanofiltration (NF) membranes show great potential in removing or recovering dyes from effluents of printing and dyeing industries. However, low permeance of commercial nanofiltration membranes hampers their widespread application. Herein, we design a kind of high permeance mixed matrix membranes through layer-by-layer (LbL) self-assembly of polyelectrolytes (PEs). The additional solvent pathways constructed by incorporation of UiO-66, a type of Zr-based metal organic frameworks (MOFs), accelerate the water passing through the membranes; the pure water permeance of UiO-66 incorporated PEs membrane (PEM/UiO-66) achieves at as high as 14.8 L m-2 h-1 bar-1 which is 160% higher than the pristine PEs membrane. Meanwhile, the membrane exhibits 96.3% rejection towards MgSO4 with molecular weight cut off (MWCO) of 464.2 g mol-1. The comprehensive separation performance of the mixed matrix membrane outperforms most of state-of-the-art NF membranes fabricated by LbL self-assembly to the best of our knowledge. Most interestingly, the mixed matrix membrane demonstrates solution flux as high as 102 L m-2 h-1 with 99.9% rejection of Congo Red under optimized operation conditions in 240 hours continuous operation. Taken together, the UiO-66 incorporated NF membranes show strong promise in removing and recovery of dyes in industrial scale.
       
  • Comparative analysis on floc morphological evolution in cylindrical and
           square stirred-tank flocculating reactors with or without baffles:
           Flocculation-test and CFD-aided investigations
    • Abstract: Publication date: Available online 13 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Weipeng He, Wenjing Lu, Shirong Xu, Maolin Huang, Hongqiang Li Within the stirred-tank flocculating system under equivalent shear-rate (Gave) cases, the effects of both reactor shape (cylindrical or square) and baffles on floc morphological evolution during flocculation were investigated by applying flocculation tests with the aid of computational fluid dynamics (CFD) simulations. At a constant Gave, the recirculating times for those floc aggregates existing in water flow to the impeller region and the intensity of turbulence occurring within this region, together with the non-uniform nature of turbulence for water flow above the rotating impeller, were found to be distinct in the various stirred-tank reactors investigated, thereby affecting the development of floc size and structure. Besides, the importance of reactor shape and baffles to floc morphological evolution seemed to be largely determined by predominant growth behavior(s). For aggregation-dominated circumstances, the baffled square stirred tank formed the largest and most compact floc aggregates among all reactors, due to the most visiting times for pre-formed micro-floc aggregates to the highest turbulent-intensity impeller region; while for breakage-dominated circumstances, the most non-uniform distributions of turbulent water flow were generated via impeller-baffle interactions in this reactor, thereby giving the highest breakage rate and producing the smallest floc aggregates with the smoothest and most compact structures.Graphical abstractGraphical abstract for this article
       
  • Supercritical water oxidation of ammonia with methanol as the auxiliary
           fuel: Comparing with isopropanol
    • Abstract: Publication date: Available online 13 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Jie Zhang, Peng Li, Jinling Lu, Fengdan Xin, Xing Zheng, Senlin Chen The co-oxidation behavior of methanol on ammonia in supercritical water was investigated in a continuous tubular reactor under a range of methanol concentration (10–800 mmol/L), ammonia concentration (50–400 mmol/L), oxidation coefficient (1.05–1.7) and preheating temperature of 400 and 415 °C. Calculation based on a mechanism-based model for supercritical water oxidation of methanol/ammonia showed that the synergy between the kinetics action to supply radicals and the thermal action to elevate the reaction temperature of methanol would improve the efficient decomposition of ammonia at relatively moderate reaction conditions. Specifically, near complete conversion of ammonia (97.5%) can be achieved at [CH3OH]0 = 800 mmol/L, preheating temperature of 415 °C and oxidation coefficient of 1.5. The influence of reaction conditions on the co-oxidation behavior and the formation of nitrate were examined experimentally. Methanol and isopropanol served as the auxiliary fuel for ammonia were compared by the positive effect and exothermic performance, which reached that methanol was superior to isopropanol.Graphical abstractGraphical abstract for this article
       
  • Process Intensification in Multicomponent Distillation: A Review of Recent
           Advancements
    • Abstract: Publication date: Available online 22 April 2019Source: Chemical Engineering Research and DesignAuthor(s): Zheyu Jiang, Rakesh Agrawal Process Intensification (PI) is an emerging concept in chemical engineering that describes the design innovations that lead to significant shrinkage in size and boost in efficiency of a process plant. Distillation, the most commonly used separation technique in the chemical industry, is a crucial component of PI. Here, we systematically discuss the following aspects of PI in non-azeotropic multicomponent distillation: 1) Introducing thermal couplings to eliminate intermediate reboilers and condensers to save energy and capital cost; 2) Improving operability of thermally coupled columns by means of eliminating vapor streams in thermal couplings with only liquid transfers or column section rearrangement; 3) Enabling double and multi-effect distillation of thermally coupled configurations to further reduce heat duty; 4) Performing simultaneous heat and mass integration among thermally coupled columns to reduce the number of columns and heat duty; and 5) Conducting any thermally coupled distillation in n-product streams using 1 to n − 2 column shells with operable novel dividing wall columns. We demonstrate these aspects of PI through examples to illustrate how they lead to compact, easy-to-operate, energy efficient and cost effective multicomponent distillation system designs.
       
  • An overview on Control Strategies for CO2 Capture using Absorption/
           Stripping System
    • Abstract: Publication date: Available online 11 May 2019Source: Chemical Engineering Research and DesignAuthor(s): K.M.S. Salvinder, H. Zabiri, S.A. Taqvi, M. Ramasamy, F. Isa, N.E.M. Rozali, H. Suleman, A. Maulud, A.M. Shariff CO2 removal via absorption/stripping system using chemical solvents is a widely acknowledged technology for CO2 capture, either from natural gas or post-combustion processes. It offers higher capture efficiency. However, one of its main drawbacks is the high energy consumption in the regeneration step. Besides, for solvent-based absorption/stripping plant, the units feature nonlinearities as well as high process interactions. Hence, control strategies are crucial in the operational optimization of process set-point changes and disturbance rejections as well as reduction in the operational costs of such systems. Process control systems are key in processing plants as they direct production processes, minimise variations and regulate product consistency. In this paper, an overview on the related efforts that have been carried out in terms of basic and advanced process control strategies are reviewed to provide further understanding on the key features that are required to optimize the operation of the absorption/stripping system.
       
  • Estimation of Data Uncertainty in the Absence of Replicate Experiments
    • Abstract: Publication date: Available online 11 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Wei Dai, Selen Cremaschi, Hariprasad J. Subramanib, Haijing Gao There are many data sets in the literature without uncertainty information. This paper introduces a novel approach to estimate data uncertainty where replicate experiments are not available. For a physical phenomenon, the dependent variable generally changes smoothly with small changes in each independent variable while other independent variables are kept constant. We hypothesize that if experimental data in this form is available, the relationship between the dependent variable and each independent variable may be approximated with the best fit regression model and that the residuals of these models can be aggregated to estimate the uncertainty of the dependent variable measurements. The statistical tests calculated using the computational experiments support the hypothesis. As a case study, erosion-rate measurement uncertainty is estimated using the approach. The results reveal that the uncertainty estimates of the erosion-rate measurements are in good agreement with expert opinions and with values reported in the literature.Graphical abstractGraphical abstract for this article
       
  • Design of Heat-Integrated Columns: Industrial Practice
    • Abstract: Publication date: Available online 10 May 2019Source: Chemical Engineering Research and DesignAuthor(s): A. Rix, C. Hecht, N. Paul, J. Schallenberg Heat integration of distillation columns offers a significant potential to reduce energy costs and carbon footprint in process plants. The conceptual design for heat integration is straightforward: candidate columns may be identified simply by evaluation of the vapor pressure curves of their top and bottoms products. Once the energy and cost savings potential is estimated, the easy part is over and the real challenge for the designers begins. Successful implementation of heat integration will have a strong impact on the overall plant setup intensifying interactions between equipment design, plant layout, instrumentation, process control, and safety concept. In order to master this increased project complexity, the design team needs to begin to tackle these questions in early project stages and find sustainable solutions in the pre-basic engineering phase already.The paper outlines a useful methodology for the successful design of heat-integrated column systems. The guidelines provided help the practitioner to anticipate and solve typical problems, avoid pitfalls and find practical solutions resulting in cost-effective, reliable designs near the energy optimum. The methodology has been successfully applied in industrial practice and is demonstrated using a recent project as an example.
       
  • Investigation of the Impact of Synthesized Hydrophobic Magnetite
           Nanoparticles on Mass Transfer and Hydrodynamics of Stagnant and Stirred
           Liquid-Liquid Extraction Systems
    • Abstract: Publication date: Available online 10 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Ashkan Hatami, Zoha Azizi, Dariush Bastani The impact of modified magnetite nanoparticles (MMNPs) on hydrodynamics and mass transfer in liquid-liquid extraction process was assessed using a ternary chemical system of toluene-acetic acid-water. Organic phase containing toluene and acetic acid was dispersed through a continuous phase of water and acetic acid mass transfer between two phases was investigated. The hydrophobic modified magnetite nanoparticles (MMNPs) prepared through an optimized in-situ method were added to the dispersed phase at different concentrations of 0.001-0.005 wt%. Two separate conditions were provided in the experiments, i.e. stagnant and stirred continuous phase. The latter case was provided by a rotor at two different speeds of 330 and 450 rpm. The effect of nozzle size and acetic acid concentration were also considered. The results showed that the as-prepared MMNPs decreased the terminal velocity and increased the liquid hold-up of the drops. Under the stagnant condition, an enhancement of 103.1% in overall dispersed-phase mass transfer coefficient was achieved at the optimum concentration of 0.001 wt% of MMNPs, whereas under stirred condition, the extraction fraction enhancement was not appreciable.
       
  • Economic and environmental benefit analysis of a renewable energy supply
           system integrated with carbon capture and utilization framework
    • Abstract: Publication date: Available online 10 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Minsoo Kim, Kyobum Kim, Tae-hyun Kim, Jiyong Kim The recent focus on energy-related environmental issues, such as the depletion of fossil fuels and the climate change, has led to a pressing need for sustainable energy supply systems. Existing systems may, in theory, be revamped into sustainable systems by including new components such as renewable energy sources (RES) and carbon capture and utilization (CCU) frameworks. However, economically and environmentally optimal mechanisms for the integration of RES and CCU frameworks into existing energy systems have yet to be determined. Therefore, this study presents a new approach to sustainable energy supply systems by integrating a RES-based system with existing technologies, coupled with a CCU framework. To address both economic and environmental benefits of the proposed system, a multi-objective optimization technique comprising two objective functions (total daily cost and the total CO2 emission) was developed using a mixed integer linear programming (MILP). The capability of the proposed model is illustrated by a case study of the future transportation sector in Korea. The Pareto solutions for the optimal energy supply system were identified according to CO2 reduction targets under different energy price scenarios.Graphical abstractGraphical abstract for this article
       
  • Analysis of a rich vapor compression method for an ammonia-based CO2
           capture process and freshwater production using membrane distillation
           technology
    • Abstract: Publication date: Available online 9 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Asad Ullah, Mujeeb Iqbal Soomro, Woo-Seung Kim Post-combustion capturing of CO2 through chemical solvent absorption is a promising technique for reducing the CO2 emissions from the fossil fuel power plants. However, the energy penalty associated with the absorbent regeneration continues to be a critical challenge in the chemical solvent absorption process. In this study, the operating parameters of ammonia-based CO2 capture were optimized to reduce the energy penalty. This optimized process was considered a base process to which process modifications were added, with the goal of further reducing the energy consumption. These process modifications included absorber intercooling and rich vapor compression (RVC) combined with cold solvent split (CSS) processes. The combined RVC and CSS process was compared with the base process and advanced NH3-based CO2 capture processes, such as the rich split process and the inter-heating process. Compared to the base process, the combined process reduced the energy requirements by 20.2%, which was higher than the 11.6% and 8.26% energy reductions obtained via the rich split and inter-heating processes, respectively. The combined process was also compared with MEA-based process modifications. The energy savings from the combined process were higher than those of the MEA-based process modifications. To estimate the trade-offs between the energy savings resulting from the combined process vs. the capital cost of the additional equipment required, the Aspen Capital Cost Estimator (ACCE) was used. The results showed that the combined process saved $0.707 million per year. Furthermore, a membrane distillation (MD) technology was integrated with the CO2 capture unit to produce freshwater. This additional process produced freshwater at a rate of 719.240 m3/day at a feed stream temperature to the MD unit of 35.66 ℃.
       
  • Enhanced separation of maximum boiling azeotropic mixtures with extractive
           heterogeneous-azeotropic distillation
    • Abstract: Publication date: Available online 9 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Andras Jozsef Toth, Botond Szilagyi, Eniko Haaz, Szabolcs Solti, Tibor Nagy, Agnes Szanyi, Judit Nagy, Peter Mizsey In the separation industry the extractive heterogeneous-azeotropic distillation (EHAD) is a new and powerful innovation, that is capable of making the separation of highly non-ideal mixtures feasible and economical. In the last years there has been much attention paid to the separation of the minimum boiling homogeneous azeotropes. Although maximum boiling azeotropes are fewer in numbers than the minimum boiling ones but their separation is more complicated but it could be solved with the EHAD, too. Since EHAD is not limited to the separation of minimum boiling azeotropes, the separation of the maximum boiling azeotropes is studied in this work. Our work is motivated by industrial problems because there are such maximum boiling azeotropes in the liquid wastes of the fine chemical industry. The separation of highly non-ideal Water-Acetone-Chloroform-Methanol and Water-Ethyl Acetate-Chloroform-Ethanol quaternary mixtures are investigated and optimized in professional flowsheet simulator environment. Total Annual Costs are also determined. The purity requirement is 99.5 m/m% for Chloroform and the bottom product should be as clear as possible in water so that less liquid organic waste has to be incinerated. It is also an important merit of the EHAD that the chemicals in the distillate can be usually reused supporting sustainability. Different solutions for the separations supplemented with heat integration are examined. On the basis of the computer simulations and the experimental verification it can be concluded, the first time on the literature, that the separation efficiency of EHAD is superior also for the separation of the maximum boiling azeotrope mixtures.
       
  • Star type polymer grafted and polyamidoxime modified silica
           coated-magnetic particles for adsorption of U(VI) ions from solution
    • Abstract: Publication date: Available online 9 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Gulay Bayramoglu, M. Yakup Arica Polyamidoxime groups functionalized magnetic adsorbent was prepared by sequential grafting of SiO2, poly(glycidylmethacrylate) p(GMA), and diaminomelanonitrile (DAMN) on the Fe3O4 nanoparticles (MP). Firstly, the MP was synthesized by thermal co-precipitation reaction and then grafted with 3-aminopropyltriethoxysilane (APTES) to obtain amine group ended silica layer (i.e., MP/SiO2-NH2). For grafting of star type fibril polymer, atom transfer radical polymerization (ATRP) initiator was attached on the MP/SiO2-NH2 to obtain Br-ended MP/SiO2-NH-Br. Then, DAMN ligand was immobilized on the MP/SiO2/p(GMA) via epoxy ring opening reaction. The nitrile group of the DAMN ligand was converted in to amidoxime group (AO) by the reaction with hydroxylamine. The MP/SiO2/p(GMA)-AO nanoparticles were characterized by analytical methods, ATR-FTIR, SEM, X-ray diffraction (XRD), differential thermal analysis (DTA), and BET surface area analyzer. The maximum adsorption capacities as prepared adsorbents (i.e., MP, MP/SiO2-NH2, MP/SiO2/p(GMA)-OH, MP/SiO2/p(GMA)-DAMN and MP/SiO2/p(GMA)-AO for U(VI) ions were determined. The maximum adsorption pH was 6.0 for MP/SiO2/p(GMA)-AO, and the maximum amount adsorbed U(VI) ions was 760.3 mg g-1. The equilibrium time was 30 min, and the experimental data was described with the Langmuir and Temkin models. The second-order kinetic best fitted the experimental data. The MP/SiO2/p(GMA)-AO showed good reusability for ten cycles of adsorption-desorption with negligible changes in the adsorption performance and stability. The selectivity of the MP/SiO2/p(GMA)-AO was also tested using artificial water after spiking with various amount of U(VI) ions. The experimental result indicated that MP/SiO2/p(GMA)-AO has high selectivity for U(VI) ions in the presence of other metals.Graphical abstractGraphical abstract for this article
       
  • Separation of fluoride and chloride ions from ammonia-based flue gas
           desulfurization slurry using a two-stage electrodialysis
    • Abstract: Publication date: Available online 9 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Zhengwei Luo, Dan Wang, Dongmei Zhu, Jiahuan Xu, Hui Jiang, Wenhua Geng, Wuji Wei, Zhouyang Lian This study reports the use of electrodialysis (ED) to separate fluoride (F―) and chloride (Cl―) ions from an ammonia-based flue gas desulfurization (FGD) slurry. The optimal operation voltage, circular flow rate, and pH were determined based on the ion migration efficiency and energy consumption. An applied voltage of 15 V and a circular flow rate of 200 L/h were determined to be the optimum conditions, while solutions with pH values in the range of 4-6 were beneficial for the migration of F―. The field slurry was also subjected to ED after being pretreated with microfiltration and ion exchange. The selected monovalent-anion-selective ACS membrane showed superior performance towards F― and Cl― separation and SO42― retention compared with a homogeneous AMX membrane. To further separate F― and Cl― from the multicomponent ammonia-based FGD slurry, experiments were carried out in two stages. The variation of separation efficiency and specific ion selectivity during the experiment were analyzed and the appropriate operation duration was obtained. As a result, the Cl―-containing solution reached a maximum purity of 98.6%, whereas the F―-containing solution reached a purity of 51.4%. The two-stage ED treatment process investigated herein can potentially be used to separate F― and Cl― and simultaneously purify ammonia-based FGD slurry.Graphic Graphical abstract for this article
       
  • Valorization of anaerobic digestion liquid residue through the production
           of organic fertilizer by fluidized bed granulation
    • Abstract: Publication date: Available online 8 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Ivana M. Cotabarren, Jonathan Moreno, Ana L. Martínez, Fernanda A. Cabrera, Juliana Piña In this work the feasibility of developing a solid fertilizer by fluidized bed granulation, using digestate (liquid residue from anaerobic digestion) as binder and different minerals as seeds is analysed. Full characterization of the selected mineral particles and the liquid digestate was performed. Particularly, phosphorous and potassium content was assayed before and after granulation. Friability and breakage strength of product granules were tested as well. Also, the process operating conditions (bed temperature, fluidization air temperature and flowrate, digestate temperature and flowrate, etc.) that enable stable operation and the production of completely coated granules were successfully established for lab- and pilot-scale granulation units.
       
  • Optimal grade transition of a non-isothermal continuous reactor with
           multi-objective dynamic optimization approach
    • Abstract: Publication date: Available online 8 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Sandesh Shirude, Nitin Padhiyar Dynamic Optimization (DO) is a useful tool for carrying out grade transitions in polymer industry. Most open literature studies on DO emphasize such grade transitions using single objective optimization. However, there are multiple criteria which must be met simultaneously for economic benefits. In this work, we solve a multi-objective DO problem for free-radical polymerization of methyl methacrylate in a non-isothermal continuous stirred tank reactor. The process objectives considered in the DO activity include minimization of off-spec, minimization of grade transition time, and minimization of the averaged feed flowrate. The manipulated variables considered for this problem are the initiator and coolant flowrates. The DO problem is solved using control vector parameterization (CVP) approach with first order interpolation. The solution of the aforementioned multi-objective DO problem is obtained in terms of a trade-off curve, pareto curve, using non-dominated sorting genetic algorithm (NSGA II). The three-dimensional pareto front is then projected to each of the three pairs of the objectives for better visualization and analysis. Furthermore, three representative pareto solution points, namely the two end points and a utopia point are further analysed for of each of the bi-objective pareto solution curves.
       
  • Design and optimization of reactive distillation processes for synthesis
           of isopropanol based on self-heat recuperation technology
    • Abstract: Publication date: Available online 8 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Yufeng Fan, Qing Ye, Hao Cen, Jingxing Chen, Tong Liu In this work, a conventional reactive distillation process (CRD) is designed for isopropanol synthesis. Furthermore, five processes based on self-heat recuperation technology (SHRT) are designed to improve energy-saving performance of CRD. And then heat exchanger network is introduced into two processes based on SHRT to reduce more energy consumption. Finally, a reactive dividing-wall column process (RDWC) is developed to compare with other processes in energy-saving performance. The result of comparison indicates that total annual cost (TAC), total energy consumption (TEC) and CO2 emissions of processes based on SHRT and RDWC are decreased effectively compared with CRD. The performance of process based on SHRT is better than that of RDWC. The RD-VR-HEN is the optimal process. Compared with CRD, RD-VR-HEN saves 34.72% of TAC, 63.16% of TEC and 55.04% of CO2 emissions. Compared with RDWC, TAC, TEC and CO2 emissions of RD-VR-HEN decreases by 13.80%, 54.05% and 44.62%, respectively.Graphical abstractGraphical abstract for this articleFlow sheet of the RD-VR-HEN.The latent heat as well as the sensible heat is utilized effectively in the RD process based on SHRT. After combined with the HEN, more sensible heat can be recovered in the RD-VR-HEN. Compared with the CRD, the RD-VR-HEN saves 34.72% of the TAC, 63.16% of the TEC and 55.04% of the CO2 emissions, respectively.
       
  • Effects of turbulence modeling on the prediction of flow characteristics
           of mixing non-Newtonian fluids in a stirred vessel
    • Abstract: Publication date: Available online 8 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Peng Wang, Thomas Reviol, Haikun Ren, Martin Böhle Mixing characteristics of the non-Newtonian fluid in a stirred vessel with a side-entry novel propeller was investigated by using computational fluid dynamics (CFD). The SST model (SST), standard k-ω (SKO), Reynold stress model (RSM), standard k-ɛ (SKE), Realizable k-ɛ (KER), RNG k-ɛ (RNG) were evaluated for nine generalized Reynolds numbers operating at different flow conditions. In order to determine the estimated trait generalized Reynolds number at the end of the laminar regime, both the laminar and turbulent model simulations were conducted. Those results were validated with the published literature experimental results and different simulated results. By comparing the simulated and experimental literature results, the SST and RSM models are found to be more accurate than the other four turbulence models in predicting the torque. The power consumption and power numbers curves calculated from the SST and RSM models are highly consistent with the experimental results. To verify the effect of the applied turbulence models on predictive accuracy, both the velocity field, streamlines distributions, and the velocity profiles are evaluated. The RSM model was found to be more realizable for capturing mixing behavior in lower concentration solutions and with lower rotation speeds. However, this model has some drawbacks for modeling stirred vessels, such as a large number of modeled revolutions and mesh statistical required to obtain good quantities. In contrasts with the RSM model, the SST model is more reliable to predict velocity profiles and flow patterns in higher concentration solutions, especially in the near wall region.
       
  • Investigation of hydrodynamic behavior in random packing using CFD
           simulation
    • Abstract: Publication date: Available online 7 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Jia-Lin Kang, Ya-Cih Ciou, Dong-Yang Lin, David Shan-Hill Wong, Shi-Shang Jang Computational fluid dynamics (CFD) simulations of countercurrent gas-liquid flow in random packings of Raschig rings were carried out in this study. This model used gravity simulation to construct the random packing structure, and a volume expansion-recovery method to improve the meshing quality. A simple feedback control scheme was applied to control the gas inlet flow rate so that pressure drop can be estimated. The generated characteristics of the packing structure such as the number of packing elements, dry surface area and porosity were found to be close to experiments. CFD predictions of hydrodynamics properties are also validated by the experimental data using a small column section. The results indicate that our CFD model was able to capture the essential hydrodynamics behavior of the gas-liquid countercurrent flow. Hence, the approach presented in this study can be used as a basis for studying the effect of detailed packing-geometry design on hydrodynamic and mass transfer characteristics.
       
  • Boron adsorption removal by commercial and modified activated carbons
    • Abstract: Publication date: Available online 3 May 2019Source: Chemical Engineering Research and DesignAuthor(s): Joanna Kluczka, Wojciech Pudło, Katarzyna Krukiewicz Although being an essential element for plants, animals, and people, due to its many industrial applications boron content in the environment exceeds its safe levels. In this paper, the results of the studies on the effectiveness of various commercial activated carbons (CACs) in the purification of water from dissolved boron compounds are presented. To further improve boron adsorptive capacity, the CAC was modified with polyhydric chelates and the as-formed adsorbents were characterized by SEM and BET analysis. The influence of various operating factors on the adsorption of boron was investigated, including a contact time, pH of solution, initial boron concentration and temperature. Batch studies revealed that the pH of solution is a key factor affecting boron removal, and the most efficient adsorption is observed at the pH of 8.5. The adsorption was found out to follow the pseudo-second-order kinetic model, with the equilibrium state achieved within 4 h. The results indicated the exothermic and non-spontaneous nature of adsorption, the reduction of the entropy of the system, as well as the presence of a mixed, physical and chemical adsorption mechanism. Consequently, CAC modified by mannitol or xylitol is shown to serve as an efficient adsorbent for boron removal from polluted water.Graphical abstractGraphical abstract for this article
       
 
 
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