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CHEMISTRY (598 journals)                  1 2 3 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 8)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 26)
ACS Catalysis     Full-text available via subscription   (Followers: 32)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 17)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 23)
ACS Macro Letters     Full-text available via subscription   (Followers: 23)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 39)
ACS Nano     Full-text available via subscription   (Followers: 227)
ACS Photonics     Full-text available via subscription   (Followers: 11)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 21)
Acta Chemica Iasi     Open Access   (Followers: 2)
Acta Chimica Sinica     Full-text available via subscription   (Followers: 1)
Acta Chimica Slovaca     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 7)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 5)
Advanced Functional Materials     Hybrid Journal   (Followers: 50)
Advanced Science Focus     Free   (Followers: 3)
Advances in Chemical Engineering and Science     Open Access   (Followers: 53)
Advances in Chemical Science     Open Access   (Followers: 13)
Advances in Chemistry     Open Access   (Followers: 14)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Enzyme Research     Open Access   (Followers: 9)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 19)
Advances in Nanoparticles     Open Access   (Followers: 14)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 19)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5)
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: 2)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 67)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 14)
American Journal of Chemistry     Open Access   (Followers: 26)
American Journal of Plant Physiology     Open Access   (Followers: 13)
American Mineralogist     Hybrid Journal   (Followers: 13)
Analyst     Full-text available via subscription   (Followers: 38)
Angewandte Chemie     Hybrid Journal   (Followers: 158)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 208)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 1)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 3)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 8)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 14)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Hybrid Journal  
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7)
Applied Spectroscopy     Full-text available via subscription   (Followers: 23)
Applied Surface Science     Hybrid Journal   (Followers: 28)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 2)
Asian Journal of Biochemistry     Open Access   (Followers: 1)
Atomization and Sprays     Full-text available via subscription   (Followers: 3)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access   (Followers: 1)
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Full-text available via subscription   (Followers: 283)
Biochemistry Insights     Open Access   (Followers: 5)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 9)
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: 1)
Biomacromolecules     Full-text available via subscription   (Followers: 19)
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: 4)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 108)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 93)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 2)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 24)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 10)
Canadian Mineralogist     Full-text available via subscription   (Followers: 3)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 67)
Catalysis for Sustainable Energy     Open Access   (Followers: 6)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 6)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 7)
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 12)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 70)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 23)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 19)
Chemical Reviews     Full-text available via subscription   (Followers: 170)
Chemical Science     Open Access   (Followers: 21)
Chemical Technology     Open Access   (Followers: 16)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemical Week     Full-text available via subscription   (Followers: 8)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 55)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 25)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 6)
Chemistry & Biology     Full-text available via subscription   (Followers: 30)
Chemistry & Industry     Hybrid Journal   (Followers: 5)
Chemistry - A European Journal     Hybrid Journal   (Followers: 144)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 15)
Chemistry and Materials Research     Open Access   (Followers: 18)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Hybrid Journal   (Followers: 2)
Chemistry Letters     Full-text available via subscription   (Followers: 45)
Chemistry of Materials     Full-text available via subscription   (Followers: 226)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 22)
Chemistry-Didactics-Ecology-Metrology     Open Access  
ChemistryOpen     Open Access   (Followers: 2)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 2)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 9)
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: 10)
Chromatographia     Hybrid Journal   (Followers: 24)
Chromatography Research International     Open Access   (Followers: 7)
Clay Minerals     Full-text available via subscription   (Followers: 9)
Cogent Chemistry     Open Access  
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 10)
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 8)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 3)
Combustion Science and Technology     Hybrid Journal   (Followers: 18)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 2)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 9)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 2)
Copernican Letters     Open Access  
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 5)
Crystal Structure Theory and Applications     Open Access   (Followers: 3)
CrystEngComm     Full-text available via subscription   (Followers: 11)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 5)
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Research in Chemistry     Open Access   (Followers: 8)
Current Science     Open Access   (Followers: 56)
Dalton Transactions     Full-text available via subscription   (Followers: 20)
Detection     Open Access   (Followers: 2)
Developments in Geochemistry     Full-text available via subscription   (Followers: 2)
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Dislocations in Solids     Full-text available via subscription  
Doklady Chemistry     Hybrid Journal  
Drying Technology: An International Journal     Hybrid Journal   (Followers: 4)
Eclética Química     Open Access   (Followers: 1)
Ecological Chemistry and Engineering S     Open Access   (Followers: 4)
Ecotoxicology and Environmental Contamination     Open Access  
Educación Química     Open Access   (Followers: 1)
Education for Chemical Engineers     Hybrid Journal   (Followers: 5)
EJNMMI Radiopharmacy and Chemistry     Open Access  
Elements     Full-text available via subscription   (Followers: 2)
Environmental Chemistry     Hybrid Journal   (Followers: 9)
Environmental Chemistry Letters     Hybrid Journal   (Followers: 4)
Environmental Science & Technology Letters     Full-text available via subscription   (Followers: 5)

        1 2 3 | Last

Journal Cover Chemical Engineering Research and Design
  [SJR: 0.873]   [H-I: 65]   [23 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0263-8762 - ISSN (Online) 0263-8762
   Published by Elsevier Homepage  [3042 journals]
  • Estimation of gas induction in jet loop reactors: Influence of nozzle
    • Authors: Deepankar V. Sharma; Ashwin W. Patwardhan; Vivek V. Ranade
      Pages: 24 - 34
      Abstract: Publication date: September 2017
      Source:Chemical Engineering Research and Design, Volume 125
      Author(s): Deepankar V. Sharma, Ashwin W. Patwardhan, Vivek V. Ranade
      Jet loop reactors are used widely for conducting gas liquid reactions because of the high mass transfer achieved in the gas–liquid ejector. Studies have shown that the mass transfer has a very strong correlation to the amount of gas induced in the ejector, and hence it is important to understand gas induction to enhance the performance of any gas–liquid nozzle. In this work, we used a single phase CFD model of the ejector with one adjustable parameter for estimating gas induction rates. After establishing that the model adequately describes the experimental data, the model was used for a quick evaluation of ejector geometries. Influence of key geometric parameters of gas–liquid ejectors like nozzle diameter, mixing tube length, distance between the nozzle outlet and mixing tube, suction chamber geometry and diffuser angle was investigated. It was found that dependence of gas induction on geometric parameters like distance between nozzle—mixing tube, suction chamber geometry, diffuser angle was either weak or had a clear maxima at or beyond a certain value of the geometric parameter. Other parameters like mixing tube length and nozzle diameter have a more complex impact on gas induction. The presented approach and results will be useful for quantifying influence of nozzle designs on gas induction rate in jet loop reactors.

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.06.027
      Issue No: Vol. 125 (2017)
  • CFD modeling of styrene polymerization in a CSTR
    • Authors: Chao-Zhong Xu; Jia-Jun Wang; Xue-Ping Gu; Lian-Fang Feng
      Pages: 46 - 56
      Abstract: Publication date: September 2017
      Source:Chemical Engineering Research and Design, Volume 125
      Author(s): Chao-Zhong Xu, Jia-Jun Wang, Xue-Ping Gu, Lian-Fang Feng
      A computational fluid dynamics (CFD) approach coupled with polymerization kinetics is implemented to investigate styrene polymerization using azobisisobutyronitrile (AIBN) as initiator and toluene as solvent in a lab-scale continuous stirred tank reactor (CSTR). The integration of kinetic model and CFD model taking molecular weight distribution into consideration is accomplished by a user-defined function (UDF) code using the method of moments. The results predicted by CFD compare with literature data satisfactorily. The effects of operating variables such as species diffusion coefficient, impeller speed, residence time and reaction temperature are analyzed. As the impeller speed increases, the degree of mixing homogeneity is improved, which results in decreasing conversion and molecular weight distribution. The proposed method can be used to predict polymerization behaviors in non-ideal mixing industrial reactors.
      Graphical abstract image

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.06.028
      Issue No: Vol. 125 (2017)
  • Process development for chemical stabilization of fly ash from municipal
           solid waste incineration
    • Authors: Chrisanthi Vavva; Epaminondas Voutsas; Kostis Magoulas
      Pages: 57 - 71
      Abstract: Publication date: September 2017
      Source:Chemical Engineering Research and Design, Volume 125
      Author(s): Chrisanthi Vavva, Epaminondas Voutsas, Kostis Magoulas
      Α detailed characterization of fly ash collected from a municipal solid waste incinerator, which involves both its physicochemical properties and its leaching behavior, is presented. For the classification of the fly ash, the European standard leaching test EN 12457/2 was carried out and the leaching test results indicate that leachate concentration of Pb, TDS, chloride and sulfate ions, exceed the legal limit values for non-hazardous waste landfilling, according to Council Decision 2003/33/EC. Two techniques, phosphoric acid stabilization and water washing were used for the treatment of fly ash. Several parameters that affect the two processes were tested. Phosphoric acid proved to be very effective for the stabilization of Pb. Water washing reduced effectively the soluble fraction but attention was given to the mobilization of toxic heavy metals and to the wastewater which is produced. The combination of phosphoric acid stabilization and water washing was investigated, aiming to the successful stabilization of fly ash and the production of the best wastewater quality. The effect of various parameters, such as phosphoric acid to ash ratio, pH, the sequence of the two processes and different phosphate sources, was examined. The results indicate that using phosphoric acid with an acid to ash ratio of 7% w/w followed by water washing, successfully stabilizes the fly ash and produces a non-hazardous waste. In addition, the wastewater produced from this treatment method is less polluted with heavy metals than the other tested methods.

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.06.021
      Issue No: Vol. 125 (2017)
  • Techno-economic impacts of varied compositional profiles of sugarcane
           experimental hybrids on a biorefinery producing sugar, ethanol and
    • Authors: F.M. Mendes; M.O.S. Dias; A. Ferraz; A.M.F. Milagres; J.C. Santos; A. Bonomi
      Pages: 72 - 78
      Abstract: Publication date: September 2017
      Source:Chemical Engineering Research and Design, Volume 125
      Author(s): F.M. Mendes, M.O.S. Dias, A. Ferraz, A.M.F. Milagres, J.C. Santos, A. Bonomi
      Evaluation of processes parameters along with the economic return are crucial aspects for selection of sugarcane characteristics for different biorefinery configurations. In this context, six sugarcane hybrids with varied compositional characteristics and field productivity were assessed through process simulation for potential use in first generation ethanol production. A computational platform, the Virtual Sugarcane Biorefinery, which includes Aspen Plus simulations and spreadsheets, was used as tool to estimate production of electricity, sugar and ethanol in first generation biorefineries. The same platform also provided sugarcane costs and economic performance, mostly based on −internal rate of return (IRR) calculations. Results show that sugarcane characteristics including components composition, mainly lignin, sucrose and fiber contents, as well as field productivity, must be evaluated simultaneously in the biorefinery context. The three hybrids with the highest field productivity and fiber content (H89, H58 and H140) achieved the best economic indicators. Parametric sensitivity analysis evaluated the influence of investments, and prices of sugarcane, sugar, ethanol and electricity on the IRR values. Variation in sugarcane and ethanol prices and in the investments were more significant for the final IRR values. Ethanol price was especially critical for IRR of autonomous distilleries, strengthening the importance of multiproduct biorefineries.

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.06.023
      Issue No: Vol. 125 (2017)
  • A new empirical model to correlate solute solubility in supercritical
           carbon dioxide in presence of co-solvent
    • Authors: Saeede Soltani; Seyed Hossein Mazloumi
      Pages: 79 - 87
      Abstract: Publication date: September 2017
      Source:Chemical Engineering Research and Design, Volume 125
      Author(s): Saeede Soltani, Seyed Hossein Mazloumi
      In this work, correlation of solute solubility in supercritical fluid in presence of co-solvent has been carried out using a new density-dependent empirical equation. The new model has five parameters for each system. The parameters of the new correlation have been obtained for various ternary systems including 1668 experimental solubility data. The overall percent of absolute average deviations (%AARD) are 1.57 and 2.35 using different density calculation methods The comparisons of the new equation and the published models show its good capability in calculating solute solubility in supercritical fluid in presence of co-solvent.

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.006
      Issue No: Vol. 125 (2017)
  • Feasibility study of LSCF5582 membrane integration into a nitrogen based
           chemical looping air separation process
    • Authors: Khadijeh Paymooni; Elham Doroodchi; Julius Motuzas; João C. Diniz da Costa; Behdad Moghtaderi
      Pages: 96 - 107
      Abstract: Publication date: September 2017
      Source:Chemical Engineering Research and Design, Volume 125
      Author(s): Khadijeh Paymooni, Elham Doroodchi, Julius Motuzas, João C. Diniz da Costa, Behdad Moghtaderi
      This study investigates the suitability and effectiveness of La0.5Sr0.5Co0.8Fe0.2O3-δ (LSCF5582) membrane for integration into the reduction reactor of a Nitrogen based chemical looping air separation (CLAS) process for exclusive separation of oxygen. First, the structural and chemical characteristics as well as the oxygen separation properties of LSCF5582 membranes, prepared at sintering temperatures of 1050–1350°C, were examined to obtain the optimum range of sintering temperatures resulting in membranes with enhanced oxygen separation from air. This was achieved by determining the oxygen permeation properties of LSCF5582 membranes under the reducing environment of the Nitrogen based CLAS process, whereby oxygen is liberated from CuO oxygen carriers on the feed side of the membrane using nitrogen as a reducing gas. Membrane characterisation results showed that a single phase dense LSCF5582 membrane was formed at the sintering temperature range of 1200–1225°C obtaining a maximum oxygen permeation flux of 0.67mlmin−1 cm−2 and oxygen recovery of 27% at the sintering and operating temperatures of 1200°C and 900°C, respectively. At the same operating temperature, under the reducing environment of nitrogen, the LSCF5582 membrane sintered at 1225°C was found to perform best achieving an oxygen permeation flux and oxygen recovery of 0.77mlmin−1 cm−2 and 76%, respectively.
      Graphical abstract image

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.008
      Issue No: Vol. 125 (2017)
  • Temperature controlled interval contact design for ultrasound assisted
           liquid–liquid extraction
    • Authors: Jinu Joseph John; Simon Kuhn; Leen Braeken; Tom Van Gerven
      Pages: 146 - 155
      Abstract: Publication date: September 2017
      Source:Chemical Engineering Research and Design, Volume 125
      Author(s): Jinu Joseph John, Simon Kuhn, Leen Braeken, Tom Van Gerven
      This work aims at constructing a design which integrates a direct (solid) contact method with temperature control for chemical process applications. To realise this integration a two-step approach is proposed. Firstly, temperature control is achieved by suspending the tubing in a temperature controlled and sonicated liquid medium (indirect contact). Secondly, direct contact elements are introduced at regular intervals along the tubing. Therefore, this design is termed the hybrid contact reactor, as it incorporates both direct and indirect approaches of ultrasound transfer. Furthermore, two possible configurations, open and closed interval connection to the tubing, were assessed. Both hybrid reactors performed better than the indirect contact reactor (20–27% increase in yield) for residence times of less than 45s and similar for residence times above. Even though the performance of the two hybrid designs was similar the closed interval resulted in more reproducible and distinct yields. This configuration was then scaled up 10 times in internal volume using a 2mm ID tube. This design showed a relative performance similar to the interval contact design which gave the highest yields thus far for the same operating conditions.

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.06.025
      Issue No: Vol. 125 (2017)
  • Evaporation of excess alcohol in biodiesel in a microchannel heat
           exchanger with Peltier module
    • Authors: Harrson S. Santana; Geovanni B. Sanchez; Osvaldir P. Taranto
      Pages: 20 - 28
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Harrson S. Santana, Geovanni B. Sanchez, Osvaldir P. Taranto
      Transesterification is the most common method for biodiesel production, typically occurring with excess alcohol to shift the reaction balance towards the products. After the reaction, this alcohol can be removed and recovered. On both macro and micro scale, such process occurs in evaporators or even in distillation columns. In view of the above, this article intends to apply a microchannel heat exchanger based on a Peltier module on the separation of excess alcohol from the biodiesel in microscale. Three variables were assessed in the process: temperature, fluid flow rate in the micro-exchanger and alcohol/biodiesel molar ratio. The results revealed that temperature has a positive effect on the evaporation efficiency, whereas the variables of flow rate and molar ratio showed a negative effect on the process. Accordingly, we have thus shown the possibility of using heat micro-exchangers on the separation of excess alcohol from biodiesel.
      Graphical abstract image

      PubDate: 2017-06-22T14:48:18Z
      DOI: 10.1016/j.cherd.2017.05.022
      Issue No: Vol. 124 (2017)
  • A thermally coupled reactive distillation and pervaporation hybrid process
           for n-butyl acetate production with enhanced energy efficiency
    • Authors: Gregorius Rionugroho Harvianto; Faizan Ahmad; Moonyong Lee
      Pages: 98 - 113
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Gregorius Rionugroho Harvianto, Faizan Ahmad, Moonyong Lee
      This paper presents a novel hybrid process combining thermally coupled reactive distillation with membrane-based pervaporation for enhanced production of n-butyl acetate. A conventional reactive distillation process was used as the base case and first optimized for the transesterification of methyl acetate with n-butanol to produce n-butyl acetate. It was observed that methyl acetate recovered in the recycle stream significantly affects the conversion in the reactive distillation column and overall energy efficiency of the whole process. The existing and proposed configurations were evaluated and optimized by simulation in Aspen Plus. The integration of thermally coupled reactive distillation and pervaporation improved the energy efficiency of the reactive distillation process by preventing remixing effect in the reactive distillation column and eliminating the azeotropic nature of the methanol and methyl acetate in the recycle stream, respectively. Finally, integration of the thermally coupled reactive distillation with a commercial pervaporation membrane was explored to take synergistic advantage of the thermally coupled reactive distillation and pervaporation hybrid configuration. As a result, the proposed hybrid design showed remarkably improved energy efficiency and economics. The total reboiler duty and total annual cost reduced to 63 and 43%, respectively, compared to those of the base case.
      Graphical abstract image

      PubDate: 2017-07-02T15:15:43Z
      DOI: 10.1016/j.cherd.2017.05.007
      Issue No: Vol. 124 (2017)
  • A sol–gel route to synthesize vanadium doped silica through ionic liquid
           control and methylene blue degradation
    • Authors: Harshad R. Patil; Z.V.P. Murthy
      Pages: 134 - 144
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Harshad R. Patil, Z.V.P. Murthy
      Silica and vanadium doped silica nanoparticles were obtained by sol–gel technique using ionic liquid (IL) 1-ethyl-3-methylimidazolium trifluoromethane sulfonate, [EMIM][TfO]. In order to understand characteristics of the nanoparticles without IL, we synthesized silica and vanadium doped silica nanoparticles without IL. Synthesis was also conduced without IL to interpret the nanoparticles characteristics in absence of IL. As-synthesized, as well as calcined (400°C/4h) nanoparticles were evaluated by HR-SEM, XRD, FTIR and TGA characterization. Morphology and size of the nanoparticles were found to be influenced due to the presence of IL during the synthesis. The EDX showed 8–10wt% presence of vanadium on silica surface validating the formation of vanadium doped silica nanoparticles. Photodegradation efficiency of doped nanoparticles were assessed for methylene blue. Among different nanoparticles synthesized, vanadium doped and IL assisted silica nanoparticles showed higher photodegradation due to the reduced band gap energy substantiated by measurement of bandgap by UV-DRS.
      Graphical abstract image

      PubDate: 2017-07-02T15:15:43Z
      DOI: 10.1016/j.cherd.2017.06.006
      Issue No: Vol. 124 (2017)
  • A shortcut procedure for calculation of process side heat duty of refinery
           fired heaters
    • Authors: Constantinos Plellis-Tsaltakis
      Pages: 152 - 158
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Constantinos Plellis-Tsaltakis
      Absorbed heat duty of process side of a fired heater often requires rigorous vapor–liquid equilibrium calculations and is usually performed with costly process simulator software. An alternative, shortcut method is proposed, which may be easily and efficiently implemented in a spreadsheet. The results of the proposed procedure were checked against those of a process simulator and against the results of the indirect efficiency calculation method, for three different existing refinery furnaces. The accuracy of the proposed method was found comparable to both the others.
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      PubDate: 2017-07-02T15:15:43Z
      DOI: 10.1016/j.cherd.2017.06.002
      Issue No: Vol. 124 (2017)
  • System optimization of turbo-expander process for natural gas liquid
    • Authors: Yajun Li; Feiyu Xu; Canteng Gong
      Pages: 159 - 169
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Yajun Li, Feiyu Xu, Canteng Gong
      Turbo-expander process is a complex technology to recover the light hydrocarbon in natural gas where energy is highly integrated and some important parameters such as demethanizer pressure and precooling temperature interact with each other, which also codetermine both the recovery and energy consumption of the system. Based on an NGL recovery engineering of 60×104 Nm3/h pipeline gas, this paper focuses on the optimization for NGL recovery system. The overall profits of whole process are chosen as objective function and optimization model is developed. Considering all the influential factors and restrictions such as CO2 freezing, a proper optimization strategy is put forward which is based on SQP (Sequential Quadratic Programming) along with constraint boundary research. The optimization model is solved by Aspen Plus combined with Excel VBA to determine the optimal value of parameters which satisfy both the constraints of the process and the maximum economic benefits of the system. After optimization, it turns out that the overall profits have been improved by 13.5%. The optimization model and the corresponding solution algorithm can provide theoretical guidance for process design and production practice of the turbo-expander process.

      PubDate: 2017-07-02T15:15:43Z
      DOI: 10.1016/j.cherd.2017.06.001
      Issue No: Vol. 124 (2017)
  • IMC-PID controller design based on loop shaping via LMI approach
    • Authors: Hamideh Najafizadegan; Farshad Merrikh-Bayat; Abolfazl Jalilvand
      Pages: 170 - 180
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Hamideh Najafizadegan, Farshad Merrikh-Bayat, Abolfazl Jalilvand
      This paper presents a new approach to designing a PID controller based on internal model control (IMC). For this purpose, the parameters of PID controller in the standard structure of IMC are calculated such that the gain crossover frequency, phase margin, and phase and amplitude of the open-loop system at various frequencies are separately adjusted to the desired values. This loop shaping procedure is wholly formulated as a linear matrix inequality (LMI) generalized eigenvalue problem (GEVP). Hence, using this approach, one can combine the advantages of PID, IMC, and LMI. Unlike the traditional methods, here the LMIs are derived directly in the frequency domain without using state-space models. The proposed method was applied to various widely used process models to verify its efficiency, and the results were compared with competing methods.
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      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.007
      Issue No: Vol. 124 (2017)
  • Pervaporative performance of
           polydimethylsiloxane–graphene/polyethersolfune hybrid membrane: Effects
           of graphene structure and surface properties
    • Authors: Azam Khodadadi Dizaji; Hamid Reza Mortaheb; Babak Mokhtarani; Saghar Rahmani
      Pages: 181 - 192
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Azam Khodadadi Dizaji, Hamid Reza Mortaheb, Babak Mokhtarani, Saghar Rahmani
      Graphene was produced either by chemical reduction of graphene oxide (GO) using hydrazine hydrate (HG)/sodium borohydride (BG) or by straight electrochemically exfoliation of graphite (EG). The X-ray diffraction and Raman spectroscopy confirmed smaller in-plane crystalline sizes for the chemically produced graphenes, and more number of layers and therefore lower structural defects for the EG sample. The graphene samples were used to prepare polydimethylsiloxane (PDMS)–graphene (G)/polyethersulfone (PES) hybrid membranes to investigate their pervaporative performances. All three produced hybrid membranes had better separation performances for removal of phenol from water in terms of phenol flux and selectivity compared to the unfilled membrane (1.3g/m2 h and 11.09, respectively). An appropriate interfacial structure for the BG- and HG-filled membranes (having lower number of layers) was achieved at 0.2wt% graphene content while for the EG-filled membrane, it was attained at 0.4wt% graphene content. PDMS–BG/PES had the highest phenol flux of 3.6g/m2 h due to the lowest carboxylic functional groups and highest C/O ratio of the filler, and PDMS–HG/PES had the best selectivity of 40.02 due to the lowest C/O ratio of the filler and hence the lowest water flux.
      Graphical abstract image

      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.026
      Issue No: Vol. 124 (2017)
  • On the mechanism controlling the redox kinetics of Cu-based oxygen
    • Authors: M.A. San Pio; F. Gallucci; I. Roghair; M. van Sint Annaland
      Pages: 193 - 201
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): M.A. San Pio, F. Gallucci, I. Roghair, M. van Sint Annaland
      Copper oxide on alumina is often used as oxygen carrier for chemical looping combustion owing to its very high reduction rates at lower temperatures and its very good mechanical and chemical stability at temperatures below 1000°C. In this work, the redox behaviour of CuO/Al2O3 has been studied in great detail together with the redox behaviour of CuO/SiO2 to identify the main phenomena affecting the observed redox kinetics. Combination of TGA results with detailed characterisation with XRD of the oxygen carriers at different stages during the redox cycling allowed elucidating the causes for the sudden decrease in the reaction rate observed at higher conversions for the CuO/Al2O3 oxygen carriers. The main results of the study can be summarized as: i) oxidation reaction reaches always full conversion independent of the reaction temperature; ii) reduction reaction reaches only full conversion at very high temperatures, showing a significant decrease in the reaction rate at lower temperatures at higher particle conversions; iii) the observed sudden decrease in the reduction rate is related to the spinel reduction of CuAl2O4 and CuAlO2.
      Graphical abstract image

      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.019
      Issue No: Vol. 124 (2017)
  • Modeling the liquid phase autoxidation of cyclohexylbenzene to
    • Authors: Weizhen Sun; Shenglu Zhang; Junfeng Qiu; Zhimei Xu; Ling Zhao
      Pages: 202 - 210
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Weizhen Sun, Shenglu Zhang, Junfeng Qiu, Zhimei Xu, Ling Zhao
      The liquid phase autoxidation of cyclohexylbenzene (CHB) to CHB hydroperoxide (CHBHP) is the key step of green production of phenol. The CHB oxidation kinetics was originally investigated by semibatch experiments under various oxygen partial pressures. Kinetic models to deal with oxygen-rich and oxygen-poor conditions were developed on the basis of free radical chain mechanism. It was found that the activation energy of the rupture of the bond OO of molecule CHBHP was close to that of cumene hydroperoxide, while the activation energy of hydrogen abstraction from the tert-butyl carbon of CHB was reasonably larger than that of cumene due to the steric effect. The kinetic model involving the oxygen addition to R (Model II) can be used to deal with various oxygen partial pressure conditions. Based on the developed kinetic model, the simulation of well-mixed reactor operated under continuous conditions was performed, and the results were in good agreement with continuous experiments.
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      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.024
      Issue No: Vol. 124 (2017)
  • Mass and heat transfer behavior of a new heterogeneous stirred tank
           reactor with serpentine tube baffles
    • Authors: M.S. Soliman; S.A. Nosier; M. Hussein; G.H. Sedahmed; A.A. Mubarak
      Pages: 211 - 221
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): M.S. Soliman, S.A. Nosier, M. Hussein, G.H. Sedahmed, A.A. Mubarak
      Rates of mass transfer at a serpentine tube baffle in a cylindrical stirred tank reactor were measured by the diffusion controlled dissolution of copper in acidified dichromate. The serpentine tube baffle has the potential to act as a catalyst support and a cooler. As such stirred tank reactors with serpentine tube baffles are suitable for conducting exothermic diffusion controlled liquid–solid catalytic reactions which need rapid temperature control e.g. immobilized enzyme catalyzed biochemical reactions. Variables studied were impeller rotation speed, impeller geometry, physical properties of the solution, pitch (copper tube separation within the serpentine tube) and diameter of the serpentine tube baffle. Mass transfer data for axial and radial flow impeller were correlated by dimensionless mass transfer equations which can be used in scaling up the present reactor as well as calculating the rate of heat transfer (by analogy) across the serpentine tube baffle cooler. The advantages of the present reactor compared to other heterogeneous stirred tank reactor such as the slurry reactor were pointed out.
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      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.012
      Issue No: Vol. 124 (2017)
  • Simultaneous removal of dyes onto nanowires adsorbent use of ultrasound
           assisted adsorption to clean waste water: Chemometrics for modeling and
           optimization, multicomponent adsorption and kinetic study
    • Authors: Mehdi Dastkhoon; Mehrorang Ghaedi; Arash Asfaram; Mohammad Hossein Ahmadi Azqhandi; Mihir Kumar Purkait
      Pages: 222 - 237
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Mehdi Dastkhoon, Mehrorang Ghaedi, Arash Asfaram, Mohammad Hossein Ahmadi Azqhandi, Mihir Kumar Purkait
      In this study, Ni doped Ferric Oxy-hydroxide FeO(OH) nanowires (Ni:FeO(OH)-NWs) were synthesized and loaded on activated carbon (AC). Synthesized adsorbent was characterized by field emission scanning electron microscopy (FESEM) and X-ray diffraction analysis (XRD). Isotherms and kinetic behaviors of Safranin-O (SO) and Indigo Carmine (IC) adsorption onto Ni:FeO(OH)-NWs-AC were explained by extended Freundlich‎ and pseudo second order kinetic models. The adsorption performance was critically analyzed using response surface methodology (RSM), artificial neural network (ANN) and linear algebra based models and compared. The influence of process variables (initial dyes concentration, adsorbent mass and sonication time) on the removal of both dyes was investigated by central composite rotatable design (CCRD) of RSM, Multi-Layer Perceptron (MLP) neural network and Doolittle Factorization Algorithm (DFA). All the models (RSM, ANN and DDA) were statistically compared by the coefficient of determination (R2), root mean square error (RMSE), mean absolute error (MAE) and absolute average deviation (AAD) based on the validation data set. The coefficient of determination (R2) calculated from the validation data for RSM, ANN and DDA models were 0.98, 0.99 and 0.99 For IC and 0.99, 0.99 and 0.99 for SO dye, respectively. The ANN model was found to be more precise compared to the other models. However, it was demonstrated that DDA can reduce the orders of data and needs a little time for analysis. So it has bright prospects in chemometrics and it is feasible that the Doolittle Algorithm could be applied to model the real systems. The sensitivity analysis confirmed that sonication time was the essential factor affecting the removal of SO and IC with the relative importance of 36.63% and 12.60%, respectively. The monolayer adsorption capacity of the IC and SO was 29.09 and 37.85mgg−1, respectively.
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      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.011
      Issue No: Vol. 124 (2017)
  • Determination of liquid mass-transfer coefficients for the absorption of
           CO2 in alkaline aqueous solutions in structured packing using numerical
    • Authors: Bing Dong; X.G. Yuan; K.T. Yu
      Pages: 238 - 251
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Bing Dong, X.G. Yuan, K.T. Yu
      A 3D volume of fluid (VOF) model was used and a convection–diffusion equation was implemented to simulate the reactive absorption process of CO2 into NaOH aqueous solution. The simulations were performed based on a representative element unit (REU) of Mellapak 500Y structured packing using direct numerical simulation (DNS) and turbulent simulation. We proposed a method to locate the gas–liquid interface, based on which the effective area of mass-transfer was determined, using the information provided by the VOF model. Using the simulation results and material balance around the liquid phase in the REU, the liquid mass transfer coefficient was calculated. The obtained mass transfer coefficient was shown to agree well with existing models. We also showed a two-equation turbulent model which consumes much less computation efforts than the DNS, but it can also be applied for the same purpose. The procedure proposed in this paper is expected to be a general approach to determining systematically the mass-transfer coefficient in structured packing without relying on empirical correlations or experiments.
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      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.017
      Issue No: Vol. 124 (2017)
  • Tunable adsorption properties of bentonite/carboxymethyl
           cellulose-g-poly(2-(dimethylamino) ethyl methacrylate) composites toward
           anionic dyes
    • Authors: Wenyun Li; Ping Zuo; Dandan Xu; Yunlong Xu; Kewang Wang; Yunshan Bai; Hongzhu Ma
      Pages: 260 - 270
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Wenyun Li, Ping Zuo, Dandan Xu, Yunlong Xu, Kewang Wang, Yunshan Bai, Hongzhu Ma
      Organo-modification of bentonite is necessary for enhancement of its adsorption capacity toward the organic dyes pollutants due to its negative-charged surface. In this study, novel adsorbent, carboxymethyl cellulose (CMC) grafted by poly(2-(dimethylamino) ethyl methacrylate) modified bentonite (Bent/CMC-g-P(DMAEMA)) composite, was synthesized. Its structure was characterized by SEM, TEM, XRD, TG, FT-IR, Zeta potential and nitrogen sorption measurements. The tunable adsorption property of Bent/CMC-g-P(DMAEMA) toward the anionic dyes(congo red (CR) and methyl orange (MO)) was investigated by changing the mass ratio of CMC to Bent+CMC in Bent/CMC-g-P(DMAEMA) composite. The adsorption property of 20CMC-Bent (20% of CMC in total amount of CMC+Bent) in the cationic and anionic binary dyes system, methylene blue (MB)/MO was also investigated. The results showed that both MO and MB could be removed effectively and sodium dodecyl sulfate exhibited selective suppressing effect toward MO in the binary system. Three isotherm models in linear and non-linear regressions were employed and assessed by various error functions. Considering all these unique characteristics, Bent/CMC-g-P(DMAEMA) can be considered as potential material for anionic dye removal from textile wastewater in industry.
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      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.034
      Issue No: Vol. 124 (2017)
  • Finding multiple stationary points of the Gibbs tangent plane distance
           function via the topographical global initialization
    • Authors: Nélio Henderson; Janaína Imbiriba; Marroni de Sá Rêgo
      Pages: 271 - 282
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Nélio Henderson, Janaína Imbiriba, Marroni de Sá Rêgo
      In order to find multiple stationary points of the Gibbs tangent plane distance function, often required in the stability analysis used in phase equilibrium calculations, in this article we apply a recently revisited version of the topographical global initialization. This initialization technique is a simple and ingenious approach based on elementary concepts of graph theory. Here, the topographical initialization is employed to generate good starting points to solve a constrained global minimization problem, whose solutions are the roots of a nonlinear system, which describes the first-order stationary conditions associated with the Gibbs plane tangent criterion for phase stability analysis. To accomplish the task of local search, in the minimization step we use a well-established interior-point method. Our methodology was compared against another robust method using benchmarks from the literature. Results indicated that the present approach is a powerful strategy for finding multiple stationary points of the Gibbs tangent plane distance function, having demonstrated high efficiency and robustness.
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      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.018
      Issue No: Vol. 124 (2017)
  • Prediction of the gas hold-up in a large-diameter bubble column with
           liquid mixtures and electrolytes
    • Authors: Giorgia De Guido; Laura Annamaria Pellegrini
      Pages: 283 - 298
      Abstract: Publication date: August 2017
      Source:Chemical Engineering Research and Design, Volume 124
      Author(s): Giorgia De Guido, Laura Annamaria Pellegrini
      Many correlations are available in the literature for computing the gas hold-up in bubble columns, mainly in pure liquids. Contrarily, very few works deal with the gas hold-up in liquid mixtures, giving different opinions about the successful application of Andrew’s dynamic surface tension model. This work further investigates this topic using more recent gas hold-up data presented in a previous work for the binary mixture comprising monoethylene glycol and water and measured for a large-diameter bubble column, which differs from the equipment used in the other few works that have pointed out the unusual behavior of the gas hold-up in binary liquid mixtures. The correlation proposed for representing the experimental data on the basis of the dynamic surface tension theory has been applied in the entire range of gas superficial velocities (0.004–0.20m/s) and it has been also generalized to predict the gas hold-up enhancement due to the presence of electrolytes. The results suggest that the dynamic surface tension model allows to reproduce the experimental gas hold-up data in a qualitative way, but a quantitative agreement is still lacking since the maximum frothing ability has been experimentally observed for a monoethylene glycol concentration lower than that predicted by Andrew’s theory.
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      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.022
      Issue No: Vol. 124 (2017)
  • Equilibrium and Kinetic of Uranium(VI) Extraction from a Sulfate Leach
           Liquor Solution by Alamine 336 Using Single Drop Technique
    • Authors: Fereshte Khanramaki; Amir Saeed Shirani; Jaber Safdari; Rezvan Torkaman
      Abstract: Publication date: Available online 23 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Fereshte Khanramaki, Amir Saeed Shirani, Jaber Safdari, Rezvan Torkaman
      The equilibrium extraction of U(VI) from a sulfate leach liquor was studied using Alamine 336 in kerosene. The effects of operating parameters and temperature were investigated on the extraction process. On the basis of the slope analysis data, the composition of the extracted species was [UO 2 2+] with the extraction equilibrium constant (logKeq)=(2.79±0.05). The influence of the temperature on the value of the equilibrium extraction constant indicated an exothermic and spontaneous extraction. In this work for the first time, the kinetic parameters of U(VI) extraction from sulfate solution was measured by the single drop technique. The effects of the main parameters such as column height, nozzle diameter, temperature, aqueous phase pH, extractant, uranium and sulfate concentrations were separately studied on the extraction rate. The results showed that the uranium extraction rate was mainly controlled by diffusion mechanism and the chemical reaction occurred at the interface of the two phases. The forward extraction rate was obtained as follows: RU (kmol/m2s)=2.65×10−5 [UO2 2+] 1.5 [R3N] 0.5 [SO4 2−]−0.5 [H+]−0.2
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      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.026
  • Formulation optimization of reverse microemulsions using design of
           experiments for nanoparticle synthesis
    • Authors: Ehsan Nourafkan; Hui Gao; Zhongliang Hu; Dongsheng Wen
      Abstract: Publication date: Available online 23 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Ehsan Nourafkan, Hui Gao, Zhongliang Hu, Dongsheng Wen
      The present work investigates the development of water/mixed nonionic surfactant/co-surfactant/cyclohexane reverse microemulsions (RM)suitable for nanoparticles synthesis. The mixture of Span 80 (oil soluble) and Tween 80 (water soluble) was selected as the surfactants. Optimum formulation of RM was obtained by using the Box-Behnken (33) experimental design method to evaluate the effect of three independent process variables, i.e., pH, Span 80wt% in surfactant mixture, and propyl alcohol wt% in mixture of cyclohexane and propyl alcohol, on the preferred responses: average droplet size (ADS) and polydispersity index (PDI) of droplets. The model was validated experimentally based on an ANOVA table, and was optimized to reach the optimum formulation to yield the ADS and PDI for RMs.The determination coefficient (R2) values of 0.991for ADS and 0.975 for PDI show that Box-Behnken design is a useful platform for the optimization of RMs formulation. Finally, iron oxide nanoparticles were synthesized under the optimum RM conditions and the uniform nanoparticle distribution with an average particle size of 2.1±0.49 nanometer and a polydispersity of 0.06±0.011 were obtained.

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.023
  • Development of a zone flow model for the confined impeller stirred tank
           (CIST) based on mean velocity and turbulence measurements
    • Authors: A.E. Komrakova; Z. Liu; M.B. Machado; S.M. Kresta
      Abstract: Publication date: Available online 23 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): A.E. Komrakova, Z. Liu, M.B. Machado, S.M. Kresta
      The confined impeller stirred tank (CIST) is a test cell designed to scale down elevated local mixing conditions to the bench scale in a more uniform mixing field than the conventional stirred tank. In this study a zone flow model was developed to describe the flow in the vessel, based on mean and fluctuating velocities measured using a laser Doppler velocimeter (LDV). A set of 5 Rushton turbines were used for this first model with water as the test fluid. The impeller rotational speed was kept high enough to ensure fully turbulent flow in the entire vessel (Re≥20 000). It is shown that all five impeller discharge streams have similar behaviours and that the jet leaving the impeller blades does not expand axially as much as the discharge flow in a single impeller stirred tank because the confined return flow reduces the jet width. The radial decay of mean velocity close to the centerline of the blades is proportional to 1/r, and the radial decay of energy dissipation is proportional to 1/r2. A single impeller stirred tank presents a much faster decay of dissipation proportional to 1/r4. Based on these results, and a number of other experimental measurements, the tank was divided into 5 volumes or zones. A zone flow model was developed to describe the flowrate and dissipation rate in each zone, giving the mean residence time and mixing energy for each zone as outputs. It is shown that the CIST has a more uniformly distributed energy dissipation (εmax/εave =8.3) than a single impeller stirred tank (εmax/εave >20).
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      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.025
  • Experimental Characterization of Stable Liquid Rivulets on Inclined
           Surfaces: Influence of Surface Tension, Viscosity and Inclination Angle on
           the Interfacial Area
    • Authors: Henning Bonart; André Marek; Jens-Uwe Repke
      Abstract: Publication date: Available online 22 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Henning Bonart, André Marek, Jens-Uwe Repke
      In this work, liquid rivulets on inclined, smooth surfaces were examined experimentally using light-induced fluorescence. The influence of viscosity, surface tension and inclination angle was studied in terms of the Reynolds and Kapitza numbers. Detailed results on the interfacial area of the rivulets were obtained. Based on the experimental results, a correlation of the interfacial area in dependence on the Reynolds and Kapitza numbers is proposed. It is found, that the correlation can reproduce the experiments very well.
      Graphical abstract image Highlights

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.022
  • Energy Efficient Configuration of Membrane Distillation Units for Brackish
           Water Desalination Using Exergy Analysis
    • Authors: Emad Ali
      Abstract: Publication date: Available online 20 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Emad Ali
      Membrane Distillation (MD) became a promising technology for water desalination. MD is energy-driven process and with the limitation and cost of energy resources it is imperative to examine improving the energy effectiveness of such units. For this purpose, Exergy analysis is applied to a validated model of typical MD module to identify the sources of inefficiencies. Reject brine is found to be an origin for exergy losses when the energy of the geothermal feed is not fully utilized. In this case, feeding the reject brine to sequential MD units connected in series can capitalize the production rate and energy utilization. In fact, the exergy losses are reduced from 70% to 30%. The enhanced energy efficiency made the exiting warm permeate responsible for another exergy losses if disposed to the environment. Repeated recycling of the outlet permeates to successive MD vessels connected in parallel improves the process performance. This cascaded structure of the desalination process converts most of the available exergy in the geothermal source into work to produce additional fresh water and dispose the salty brine and warm permeate at very low exergy levels.
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      PubDate: 2017-07-24T11:30:43Z
  • Fabrication of a magnetic porous hydrogel sphere for efficient enrichment
           of Rb+ and Cs+ from aqueous solution
    • Authors: Yongfeng Zhu; Huifang Zhang; Wenbo Wang; Xiushen Ye; Zhijian Wu; Aiqin Wang
      Abstract: Publication date: Available online 20 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Yongfeng Zhu, Huifang Zhang, Wenbo Wang, Xiushen Ye, Zhijian Wu, Aiqin Wang
      A series of magnetic porous hydrogel spheres were prepared from the oil in water (O/W) Pickering emulsion stabilized with silicone-modified magnetic attapulgite (APT), using hydroxypropyl cellulose (HPC) as the grafting backbone and acrylic acid (AA) as the monomer. The structure, morphologies and physico-chemical features of the Pickering emulsions and the hydrogel spheres were characterized by TEM, SEM, XRD and TGA techniques. The results revealed that the Fe3O4 was attached on the surface of APT with good dispersion, and the magnetic APT (MAPT) was modified successfully with silane. The emulsion with HPC, AA, initiator and crosslinker inside can be directly dropped into hot liquid paraffin to form hydrogel sphere. The rod-like APT as the stabilizer facilitated to form open pore and interconnected pores. The magnetic porous hydrogel sphere can rapidly adsorb the rare elements Rb+ and Cs+, with the maximum adsorption capacities of 232.46 and 239.88mg/g, respectively. The adsorbed Rb+ and Cs+ ions can be recovered by a simple desorption process, and the hydrogel sphere also showed excellent reusability after five consecutive adsorption–desorption cycles. This porous sphere with excellent adsorption capability and rate is potential adsorbent for the adsorption and enrichment of rare metals Rb+ and Cs+.
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      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.021
  • Residence time distribution in a biomass pretreatment reactor:
           experimentation and modeling
    • Authors: Ziad Youssef; Fabrice Ducept; Hamdi Bennaceur; Barbara Malinowska; Giana Almeida; Patrick Perre; Denis Flick
      Abstract: Publication date: Available online 20 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Ziad Youssef, Fabrice Ducept, Hamdi Bennaceur, Barbara Malinowska, Giana Almeida, Patrick Perre, Denis Flick
      The production of cellulosic bioethanol, one of the two main possibilities of second generation biofuels, involves four dependent steps: pretreatment, enzymatic hydrolysis, fermentation and distillation. This work concerns the first step which purpose is to modify the structure of the lignocellulosic biomass hence allowing cellulose to become more accessible to enzymatic hydrolysis. In this paper, the biomass flow is characterized in a pretreatment reactor. This is done by performing residence time distribution (RTD) experiments along with the use of new methodology well adapted to our system, industrial pilot plant presenting tough thermodynamic conditions. In this novel methodology, the tracer, sodium carbonate, reacts with the acidified biomass. Our protocol consists in measuring the variation of electrical conductivity and pH at the reactor entrance and exit. Two experiments were performed in the reactor for two different theoretical residence times. A chemical model was developed allowing the determination of tracer concentrations from the measured data. The experimental residence time distributions in the reactor, obtained by deconvolution, are well represented by using CSTR and axial dispersion models. The obtained results point out the nearly plug-flow behaviour of the pretreatment reactor.
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      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.015
  • Hybrid process for the purification of water contaminated with nitrites:
           Ion exchange plus catalytic reduction
    • Authors: Gustavo Mendow; César I. Grosso; Agustina Sánchez; Carlos A. Querini
      Abstract: Publication date: Available online 20 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Gustavo Mendow, César I. Grosso, Agustina Sánchez, Carlos A. Querini
      Water polluted with nitrites represents a big risk to human health. In this work, palladium supported on macroporous anionic exchange resin was used in the catalytic nitrite reduction. This process is compared with the traditional ion exchange procedure using the same catalytic resin. Both, the resin and the catalyst behaviour were evaluated in a fix-bed reactor, feeding water containing nitrites and other competitor ions, such as sulphate, bicarbonate, and chlorides, and adjusting the pH with carbon dioxide. When feeding water containing only nitrites, it was observed that the catalytic reduction makes it possible to treat 55% more water than when using the ion exchange process, at the same level of nitrites elimination. Moreover, in steady state it was possible to obtain a nitrite conversion to nitrogen of 54% with high selectivity, obtaining an ammonium concentration lower than 0.2mg/L. In the case of having other ions present in the system, both the conversion and the selectivity decreased. A regeneration strategy is also developed, using a very low hydrogen flow rate at atmospheric pressure and room temperature. This treatment leads to the reduction of more than 99% of the nitrites present in the contaminated water. The catalyst was used in several consecutive cycles maintaining a very good performance, even in the presence of competitor ions. The process was scaled up to a pilot level obtaining identical results.
      Graphical abstract image

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.019
  • Hydrodynamic Performance of the ASI Impeller in an Aerated Bioreactor
           Containing the Biopolymer Solution through Tomography and CFD
    • Authors: Fariba Khalili; M.R. Jafari Nasr; Argang Kazemzadeh; Farhad Ein-Mozaffari
      Abstract: Publication date: Available online 19 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Fariba Khalili, M.R. Jafari Nasr, Argang Kazemzadeh, Farhad Ein-Mozaffari
      In this study, the performance of the ASI impeller, a new impeller designed in our research group, was assessed for the gas dispersion in the non-Newtonian fluids. The effects of volumetric gas flow rate, impeller speed, and fluid rheology on power drawn and mixing time were explored. The non-Newtonian fluids were xanthan gum solutions at different concentrations. These biopolymer solutions are pseudoplastic fluids with yield stress and their rheological behaviors were assessed using the Herschel-Bulkley model. The hydrodynamic performance of this new impeller was compared to performance of the pitched blade turbine and the Rushton impeller. The electrical resistance tomography (ERT) was employed to measure the mixing time and gas holdup. The Eulerian-Eulerian approach was employed to simulate the gas-liquid flow inside this bioreactor through computational fluid dynamics (CFD). The CFD model was successfully validated by comparing the measured gas holdup and impeller torque values to the simulation results. The data analysis indicated that the ASI exhibited minimal effect of the gassing on power consumption (36%) compared to the Rushton turbine (50%). Furthermore, the experimental and CFD results in regard to the mixing time, power consumption upon aeration, and flow field generated in the aerated reactor proved that the ASI impeller was more energy efficient compared to the pitched blade turbine and the Rushton impeller.
      Graphical abstract image

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.016
  • Integrating a vapor recompression heat pump into a lower partitioned
           reactive dividing-wall column for better energy-saving performance
    • Authors: Shenyao Feng; Qing Ye; Hui Xia; Rui Li; Xiaomeng Suo
      Abstract: Publication date: Available online 19 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Shenyao Feng, Qing Ye, Hui Xia, Rui Li, Xiaomeng Suo
      In this study, four integrated lower partitioned reactive dividing-wall columns (LRDWCs) with vapor recompression heat pump (VRHP) models are developed to reduce the energy consumption of a reactive dividing-wall column. Energy-saving, economic, and environmental performances of the integrated LRDWC with VRHP models are compared with the corresponding LRDWC. The results indicate that the integration of VRHP into the LRDWC significantly reduces the energy consumption and CO2 emissions associated with the process. The application of a preheater further improves the energy-saving and economic performance of the process. With the aid of a preheater, the integrated LRDWC with the VRHP model saves 49.86% energy consumption and 13.76% total annual cost with a payback period corresponding to five years, and reduces all CO2 emissions when compared with the corresponding LRDWC.
      Graphical abstract image

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.017
  • Numerical study on flow behavior of ultrafine powders in conical spouted
           bed with coarse particles
    • Authors: Liyan Sun; Kun Luo; Jianren Fan
      Abstract: Publication date: Available online 17 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Liyan Sun, Kun Luo, Jianren Fan
      Fluidization of ultrafine particles differ significantly and stable spouting is difficult to achieve. However, the stability of a spouted bed with ultrafine powders can be improved by adding coarse particles. In this work, the aggregation process and flow behavior of ultrafine powders in a spouted bed are simulated and analyzed under varying operating conditions using two-fluid model coupling with the population balance equation. The effect of additional coarse particles is determined and analyzed by the proposed model. The simulation results indicate that the agglomerate diameter decreases with the addition of non-cohesive coarse particles. Furthermore, the influence of operating parameters on the diameter distribution, solid volume fraction and mixing behavior is analyzed.
      Graphical abstract image

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.010
  • Modeling of Purge-Gas Recovery Using Membrane Separation
    • Authors: Demei Zhang; Haizhi Wang; Chunxi Li; Hong Meng
      Abstract: Publication date: Available online 17 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Demei Zhang, Haizhi Wang, Chunxi Li, Hong Meng
      In methanol synthesis, hydrogen from purge gas is commonly recycled. In order to recycle hydrogen in a methanol synthesis loop effectively, multicomponent mathematical model for a hydrogen recycling process using membrane separation is established. With the help of L’Hopital’s rule, get the boundary conditions easily, which greatly simplified the calculation. The mathematical software MATLAB was used to solve the model. Various operating conditions and membrane separator parameters were considered to investigate the effects of various parameters on the hydrogen recovery.Results from the model are in good agreement with literature values. This model can therefore be used in the analysis of operating conditions for hydrogen recovery from purge gas and in the analysis of other gas separation processes. It can be a significant guide to industrial applications of gas separation process.

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.002
  • ZnO nanoparticles loaded different mesh size of porous activated carbon
           prepared from Pinus eldarica and its effects on simultaneous removal of
           dyes: multivariate optimization
    • Authors: Maryam Jafari; Mahmood Reza Rahimi; Mehrorang Ghaedi; Kheibar Dashtian
      Abstract: Publication date: Available online 17 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Maryam Jafari, Mahmood Reza Rahimi, Mehrorang Ghaedi, Kheibar Dashtian
      In this work, mesoporous activated carbon in different mesh size (35-200) was prepared from Pinus eldarica stalks (PES) as good, cheap and useful support for deposition of ZnO nanoparticles. This new material was characterized by FTIR, XRD, BET, BJH, SEM and EDS-mapping techniques and subsequently was used for the simultaneous ultrasound assisted removal of azure II (AZ-II) and auramine O (AO) dyes from aqueous solutions in batch method. The influence of operational parameters such as the sonication time, adsorbent mass, pH and initial AZ-II and AO concentration on adsorption efficiency were investigated and optimized via central composite design (CCD). Optimal conditions of adsorption experiments at desirability value of 0.98 were set as at 4.0min of sonication time, 25mgL−1 of AZ-II and AO concentration, 0.05g of adsorbent and pH 7.0 which provides removal percentage of 90.42 and 98.14% for AO and AZ-II, respectively. The experimental equilibrium data for all mesh size showed that the Langmuir model is a good and suitable model for evaluation and the actual behavior of adsorption of understudy dyes. Kinetic studied of experimental data for all mesh size revealed that adsorption processes were good followed by pseudo-second-order. These results clearly demonstrated that this material is an efficient and low cost adsorbent for treatment of wastewater containing AZ-II and AO dyes.

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.011
  • Simultaneous design of separation sequences and whole process energy
    • Authors: Duncan Leeson; Paul Fennell; Niall Mac Dowell; Nilay Shah
      Abstract: Publication date: Available online 15 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Duncan Leeson, Paul Fennell, Niall Mac Dowell, Nilay Shah
      This paper presents a novel methodology for the optimisation of the preliminary design of heat-integrated multicomponent distillation sequences. This is achieved through use of a reduced process superstructure where the role of splitting each adjacent key component pair is assigned to an individual separation column, greatly reducing the size and complexity of the problem. This methodology uses information about other process streams on site with which heat can be exchanged within the initial design in order to find a plant-wide optimal separation configuration with the aim of reducing the cost of heating provided by utilities including those used for heating and cooling process streams. In order that this model can be formulated as a mixed-integer linear program, this model utilises a discretised temperature grid where stream temperatures are allowed to vary. This methodology was tested on an example of a mixed alkane feed stream, with the sequence changing dependent on the degree of process integration. The method was found to have the potential for significant cost reductions compared to a heuristic design, with the example exhibiting a cost saving of over 50% and a reduction in CO2 associated with process heating of almost 60%, though the magnitude of these savings is highly dependent on the specific example to which it is applied.

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.009
  • Effects of sand and flocculation on dewaterability of kaolin slurries
           aimed at treating mature oil sands tailings
    • Authors: Chandra W. Angle; Sameh Gharib
      Abstract: Publication date: Available online 15 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Chandra W. Angle, Sameh Gharib
      In guiding dewatering of oil sands tailings we measured dewaterability of as-mined kaolin when sand was added as a process aid to both the dispersed and flocculated kaolin slurries. In batch tests, gravitational settling, inverse permeability R, and compressive yield stress Py were measured as functions of solids volume fractions Φ, as sand increased in the mixtures. We measured Py(Φ) for flocculated kaolin with an equal sand fraction, a flocculated diluted kaolin, flocculated diluted mature fine tailings(MFT), gel-point kaolin and MFT. Results indicated that an optimal quantity of sand in mixtures with kaolin increased the consolidated volume fraction of solids at equivalent compressive yield stress, reduced hindered settling function values, and enhanced gravitational settling rate. Py(Φ) vs Φ plots for gel-point volume fractions of kaolin and MFT showed MFT to be more compressible, but needed a much longer time to dewater. Two flocculants had similar Py(Φ) vs Φ responses when tested with either kaolin or MFT. Flocculated kaolin and MFT exhibited rapid settling, but flocculated was less compressible than unflocculated. Py(Φ) vs Φ plots for both kaolin and MFT that were flocculated after dilution produced a crossover at Py = 121kPa and Φ=0.41. The Py(Φ) vs Φ data from all tests followed power law.
      Graphical abstract image

      PubDate: 2017-07-24T11:30:43Z
      DOI: 10.1016/j.cherd.2017.07.014
  • Mass and heat transfer from the surface of a gas sparged pool of liquid to
           an immiscible liquid under swirl flow and potential applications
    • Authors: G.H. Sedahmeda; M.H. Abdel-Aziz; M.S.E. Abdo; M.S. Hassan; A.H. Konsowa
      Abstract: Publication date: Available online 6 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): G.H. Sedahmeda, M.H. Abdel-Aziz, M.S.E. Abdo, M.S. Hassan, A.H. Konsowa
      Rates of mass and heat transfer (by analogy) between a gas sparged mercury pool and a swirling aqueous solution were studied by the electrochemical technique. Variables studied were superficial gas velocity, physical properties of the solution, and swirl flow velocity. The data were correlated by the equation:
      Graphical abstract image

      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.037
  • Preparation, characterization and anti-fouling properties of nanoclays
           embedded polypropylene mixed matrix membranes
    • Authors: Sepideh Taghaddosi; Ali Akbari; Reza Yegani
      Abstract: Publication date: Available online 5 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Sepideh Taghaddosi, Ali Akbari, Reza Yegani
      Low water flux and high fouling characteristic of most polymeric membranes, such as polypropylene (PP), restrict their widespread application. In order to improve the anti-fouling properties of PP membrane, in this study, nanoclays embedded PP membranes containing 0, 0.5, 1, 1.5 and 2wt. % nanoparticles were fabricated by using thermally induced phase separation (TIPS) method. Also, to achieve an effective dispersion of particles in the membrane matrix, PP-g-MA (PP-grafted maleic anhydride) as a compatibilizer was used. Significant improvement in trends of membranes hydrophilicity, porosity, pure water flux, flux recovery and rejection were observed during filtration of BSA protein solution by embedding nanoclays up to 1.5wt. %. Furthermore, the thermal stability and tensile strength of membranes were improved by increasing the nanoclays loading. Anti-fouling properties of the fabricated membranes were investigated by using Hermia and combined fouling mechanisms during filtration of BSA protein solution, under trans-membrane pressure of 1.5bar. The obtained results showed that the neat PP membrane was prone to fouling strongly which is may be due to the inherent hydrophobic characteristic of PP polymer. However, it was found that incorporation of nanoclays into PP membranes could significantly mitigate fouling and improve the membranes performance.
      Graphical abstract image

      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.036
  • Synchronized Bayesian State Estimation in Batch Processes Using a
           Two-Dimensional Particle Filter
    • Authors: Sun Zhou; Yaozong Wang; Yunlong Liu; Guoli Ji
      Abstract: Publication date: Available online 4 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Sun Zhou, Yaozong Wang, Yunlong Liu, Guoli Ji
      In chemical process control, estimation of the process states, e.g. concentration or properties of the reactant or resultant, in real time is a key issue. Batch processes are typically characterized by unequal batch lengths and unsynchronized batch trajectories, posing challenges for the state estimation. Due to ignorance of such challenges, many existing methods would produce poor estimates in real applications. We design a new state estimation approach employing Bayesian filtering with consideration of batch-to-batch dynamics. To characterize the dynamics across batches with different time profiles, a synchronized two-dimensional (2-D) state-space model is constructed that contains synchronously equal- and unequal-length situations. Based on this model, a novel formulation of the particle filter is derived where the particles evolve along both the time and the batch dimensions so as to approximate the synchronized 2-D optimal estimates. Also, the convergence concern is addressed from a practitioner’s viewpoint. To incorporate appropriate data from previous batches into the current estimation, an on-line synchronization method based on the dynamic time warping technique is developed using a new alignment performance measure together with a transfer alignment strategy. The performance of the proposal is evaluated by case study on a numerical example and a three-state batch reaction process.

      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.033
    • Authors: C.A. Gómez-Pérez; Jairo Espinosa
      Abstract: Publication date: Available online 4 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): C.A. Gómez-Pérez, Jairo Espinosa
      Continuous bioreactors in series with recirculation can approximately be modeled by using a system of linear equations of the form Ax =0. Using such representation, Singular Value Decomposition (SVD) is used as analysis tool and some interesting features appear. This method is introduced as an attractive option to apply the theory of continuous bioreactors to industrial scale. Linear algebra tools are used to analyze the design, simplifying the process and shedding new insights. Nontrivial solutions of such system represent operating conditions that assure a productive biomass concentration. The design analysis helps to characterize the dilution rate and recirculation proportion avoiding wash-out problems. Therefore, the analysis given here paves the way towards the real implementation of continuous bioreactors in the industrial scale production.
      Graphical abstract image Highlights

      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.030
  • Prediction of Permeability of Realistic and Virtual Layered Nonwovens
           using Combined Application of X-ray μCT and Computer Simulation
    • Authors: Parham Soltani; Mohammad Zarrebini; Reyhaneh Laghaei; Ali Hassanpour
      Abstract: Publication date: Available online 3 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): Parham Soltani, Mohammad Zarrebini, Reyhaneh Laghaei, Ali Hassanpour
      Fundamental understanding of transport properties of fibrous porous media is contingent upon in depth knowledge of their internal structure at the micro-scale. In this work computer simulations are explicitly coupled with X-ray micro-computed tomography (μCT) to investigate the effect of micro-structure on permeability of fibrous media. In order to reach this aim, samples of layered nonwoven fabrics were produced and realistic 3D images of their structure were prepared using X-ray μCT. A series of algorithms was developed to extract micro-structural parameters of fibrous media, including fibers population, orientation and diameter of each fiber as well as the local porosity of structure from high-resolution realistic 3D images. A Matlab-based program capable of producing fibrous structures with various fiber diameters, porosities, thicknesses and 3D fiber orientations was developed. The obtained parameters from μCT images were then implemented into the simulation code to generate virtual fibrous structures. Prediction of permeability in realistic and virtual structures was done by fluid flow simulation through the micro-structure of porous media. The results indicated that both through- and in-plane permeabilities are strongly dependent on the porosity of structure. It was established that the anisotropic nature of the geometry creates anisotropic permeability, with a ratio of 1.8. The anisotropy effect was found to be more profound at higher porosity values. Comparison of numerical results with experimentally obtained data and those of empirical, analytical, numerical, and experimental models were made. Considering the porosity of structures, acceptable agreement between the results and previously published findings was observed.
      Graphical abstract image

      PubDate: 2017-07-12T09:30:42Z
      DOI: 10.1016/j.cherd.2017.06.035
  • New experimental setup for continuous mass flux measurement in
    • Authors: S.A. Toudji; J.-P. Bonnet; J.-L. Gardarein; E. Carretier
      Abstract: Publication date: Available online 1 July 2017
      Source:Chemical Engineering Research and Design
      Author(s): S.A. Toudji, J.-P. Bonnet, J.-L. Gardarein, E. Carretier
      Pervaporation is a separation process of liquid mixtures through a thin non-porous membrane. In vacuum pervaporation, the global mass flux is classically estimated by weighing the mass of permeate collected in cold traps. In this work, we propose a new experimental setup that allows a continuous measurement of the mass flux. The new mass flux method measurement was validated for single component permeation (ethanol and water) by comparing mass of permeate collected in cold traps with the level decrease of feed liquid measured with a pressure sensor. This new setup can be useful for laboratory studies dealing with the evolution of mass flux according to different parameters of the process as, for example, the permeate side pressure level or temperature of liquid feed.

      PubDate: 2017-07-02T15:15:43Z
      DOI: 10.1016/j.cherd.2017.06.029
  • Partial oxidative gasification of sewage sludge in supercritical water
           with multi-component catalyst
    • Authors: Donghai Xu; Guike Lin; Zhijiang Ma; Yang Guo; Muhammad Umer Farooq; Shuzhong Wang
      Abstract: Publication date: Available online 20 June 2017
      Source:Chemical Engineering Research and Design
      Author(s): Donghai Xu, Guike Lin, Zhijiang Ma, Yang Guo, Muhammad Umer Farooq, Shuzhong Wang
      A new −Mn-Cu- mixture catalyst with components of 50.9wt% CuMn2O4, 46.1wt% CuO and 3.0wt% Mn2O3 was made by a co-precipitation method firstly. We adopted the multi-component catalyst together with activated carbon (AC) and Na2CO3 (N) for the first time to conduct supercritical water partial oxidative gasification (SWPO) of sewage sludge at 450°C, 25MPa, 0.3 of oxidation coefficient and 5h of residence time, so as to improve H2 production and organics removal. The results show that MnO2-AC-N, CuO-AC-N and −Mn-Cu-AC-N could obviously improve H2 yield and removal efficiency of organics in sewage sludge SWPO. At −Mn-Cu-AC-N conditions, H2 yield and XCOD (removal efficiency of chemical oxygen demand) were 202.4ml/L and 95.6wt%, much higher than 48.7ml/L and 86.2wt% obtained without catalyst, respectively. The −Mn-Cu-AC-N catalyst seemingly had the best catalytic effect on gas formation as well as on organics removal in sewage sludge SWPO among MnO2-AC-N, CuO-AC-N and −Mn-Cu-AC-N. Potential catalytic reaction pathways were proposed as well.
      Graphical abstract image

      PubDate: 2017-06-22T14:48:18Z
      DOI: 10.1016/j.cherd.2017.06.014
  • Influence of operation conditions on cake structure in dead-end membrane
           filtration: Monte Carlo simulations and a force model
    • Authors: Kang Guan; Yang Liu; Xiaoqin Yin; Weiya Zhu; Yanhui Chu; Cheng Peng; Ming Lv; Qian Sun; Pinggen Rao; Jianqing Wu
      Abstract: Publication date: Available online 19 June 2017
      Source:Chemical Engineering Research and Design
      Author(s): Kang Guan, Yang Liu, Xiaoqin Yin, Weiya Zhu, Yanhui Chu, Cheng Peng, Ming Lv, Qian Sun, Pinggen Rao, Jianqing Wu
      Understanding the cake structure during filtration is important to minimizing fouling and reducing cleaning operation. Here, a Monte Carlo model is proposed to investigate the effect of Hamaker constant, zeta potential, particle size, ionic strength and applied pressure on the profile of the particle volume fraction of the cake structure. A scaling relationship between the local deposit solid volume fraction and various operation conditions in the micro-scale is presented. This result can be well explained by a force balance model based on the two simple particle distributions. Combining this scaling relationship and a developed force accumulation and transfer model allows a better determination of the reversibility of the deposit layer, and also provides insight into selecting appropriate cleaning strategies.

      PubDate: 2017-06-22T14:48:18Z
      DOI: 10.1016/j.cherd.2017.06.008
  • Integrated Process Development for an Optimum Gas Processing Plant
    • Authors: Abd El-Rahman Sayed; Ibrahim Ashour; Mamdouh Gadalla
      Abstract: Publication date: Available online 17 June 2017
      Source:Chemical Engineering Research and Design
      Author(s): Abd El-Rahman Sayed, Ibrahim Ashour, Mamdouh Gadalla
      The aim of this work is to develop and optimize an integrated process for natural gas plant in Egypt instead of flaring these gases and losing their revenues. The natural gas is sour wet feed gas containing mercury and some of volatile organic compounds with a capacity of around 21 million cubic feet per day. These impurities require sophisticated gas treatment processes that can handle and control the pollutants to acceptable limits. The design of new gas plant will be performed through firstly, the design methodology and cascade configuration of gas plant units based on feed gas composition. Secondly, integrated development and optimization of gas treatment process model is achieved using Aspen HYSYS simulation program. Thirdly, modeling of natural gas liquids extraction unit and fractionation train is conducted based on the required marketable products specifications. Finally, Aspen process economic analyzer program is used to calculate the expected capital expenditures of the plant. Optimizing the plant configuration accounts for best selection of treatment units and processing equipment, including mercury removal unit, sulfur recovery unit, BTEX recovery unit, etc. The preliminary capital expenditures of the gas conditioning and processing plant will be around 48 MUSD.

      PubDate: 2017-06-22T14:48:18Z
      DOI: 10.1016/j.cherd.2017.05.031
  • Evaluation of Two Termination Criteria in Evolutionary Algorithms for
           Multi-Objective Optimization of Complex Chemical Processes
    • Authors: G.P. Rangaiah; Shivom Sharma; H.W. Lin
      Abstract: Publication date: Available online 8 June 2017
      Source:Chemical Engineering Research and Design
      Author(s): G.P. Rangaiah, Shivom Sharma, H.W. Lin
      Multi-Objective (or multi-criteria) Optimization (MOO) is useful for gaining deeper insights into trade-offs among objectives of interest and then selecting one of the many optimal solutions found. It has attracted numerous applications in chemical engineering. Common techniques for MOO are adaptations of stochastic global optimization methods, which include metaheuristics and evolutionary methods, for single-objective optimization. These techniques have been used mostly with maximum number of generations (MNG) as the termination criterion for stopping the iterative search. This criterion is arbitrary and computationally inefficient. Hence, this study investigates two termination criteria based on search progress (i.e., performance or improvement in solutions), for MOO of three complex chemical processes modeled by process simulators, namely, Aspen Plus and Aspen HYSYS. They are Chi-Squared test based Termination Criterion (CSTC) and Steady-State Detection Termination Criterion (SSDTC). Both these criteria are evaluated in two evolutionary algorithms for MOO. Results show that CSTC and SSDTC are successful in giving optimal solutions close to those after MNG but well before MNG. Of the two criteria, CSTC is more reliable and terminates the search earlier, thus reducing computational time substantially.

      PubDate: 2017-06-12T15:06:22Z
      DOI: 10.1016/j.cherd.2017.05.030
  • Optimal design and operating condition of boil-off CO2 re-liquefaction
           process, considering seawater temperature variation and compressor
           discharge temperature limit
    • Authors: Seok Goo Lee; Go Bong Choi; Chang Jun Lee; Jong Min Lee
      Abstract: Publication date: Available online 8 June 2017
      Source:Chemical Engineering Research and Design
      Author(s): Seok Goo Lee, Go Bong Choi, Chang Jun Lee, Jong Min Lee
      Low-temperature liquid CO2 could boil off during ship transportation because of the heat ingress from the surroundings to inside the tank, which causes the tank pressure to increase. To maintain the operating pressure range of the tank, the re-liquefaction process is indispensable. Three design alternatives to the re-liquefaction process using boil-off CO2 as a refrigerant are proposed and compared. A systematic procedure to find the optimal design of CO2 re-liquefaction is provided considering operational constraints such as the cooling water temperature and compressor discharge temperature. The optimal operating conditions of the proposed processes are determined by solving nonlinear programming. The compressor power consumption as the operation energy for the CO2 re-liquefaction ranges from 60 to 120kW/ton CO2 given the operational constraints. As the seawater temperature is lower and the discharge temperature limit is higher, the proposed Alternative 2 design consumes less power than the other designs.
      Graphical abstract image

      PubDate: 2017-06-12T15:06:22Z
      DOI: 10.1016/j.cherd.2017.05.029
  • Study on missing data imputation and modeling for the leaching process
    • Authors: Dakuo He; Zhengsong Wang; Le Yang; Wanwan Dai
      Abstract: Publication date: Available online 4 June 2017
      Source:Chemical Engineering Research and Design
      Author(s): Dakuo He, Zhengsong Wang, Le Yang, Wanwan Dai
      The leaching process is an important component in hydrometallurgy. A predictive model of the leaching rate lays the foundation for soft measurement and process optimization, and data collection is the key in such a modeling effort. However, because of the complexity and harshness of leaching process, data can only be collected sparsely, which results in data deficiency in the modeling process. Therefore, data imputation before modeling seems to be extremely significant. In this paper, expectation maximization imputation based on the Gaussian mixture model (GMM-EM) and multiple imputation (MI) are respectively applied to perform missing data imputation for leaching process under different data loss rates and data loss patterns, and then the imputation performances are evaluated. Simulation experiment results have shown that GMM-EM and MI both have advantages with regard to data imputation. Therefore, MI based on GMM (GMM-MI), which combines the advantages of GMM and MI, is proposed in this paper. The effectiveness of GMM-MI is verified by a series of simulations.

      PubDate: 2017-06-07T14:46:32Z
      DOI: 10.1016/j.cherd.2017.05.023
  • Design and optimization of heat-integrated configurations with variable
           feed composition by using a Boltzmann-based estimation of distribution
           algorithm as optimizer
    • Authors: Roberto Gutiérrez-Guerra; Rodolfo Murrieta-Dueñas; Jazmin Cortez-González; Juan Gabriel Segovia-Hernández; Salvador Hernández; Arturo Hernández-Aguirre
      Abstract: Publication date: Available online 3 June 2017
      Source:Chemical Engineering Research and Design
      Author(s): Roberto Gutiérrez-Guerra, Rodolfo Murrieta-Dueñas, Jazmin Cortez-González, Juan Gabriel Segovia-Hernández, Salvador Hernández, Arturo Hernández-Aguirre
      The economic, energetic, and environmental performance of heat-integrated columns used to separate close-boiling mixtures with variable feed composition is presented. A Boltzmann-based estimation of distribution algorithm was used as optimizer. The total annual cost was defined as the fitness function of the problem. We study three mixtures of hydrocarbons and one mixture of polar compounds. The results show that the BUMDA algorithm leads continuously to obtain good values of the fitness function. The analysis carried out showed that the influence of the feed composition was larger in the energy consumption than in the TAC at each case study. In addition, the best compromise between energy consumption and the total annual cost was obtained in mixtures with a feed composition of 0.75/0.25 for most case studies. These HIDiC configurations showed energy savings between 85 and 87%. Thus, similar reductions in the energy consumption, carbon dioxide emissions and cooling water were obtained. On the other hand, the TAC of the best HIDiC designs varies from HIDiC designs with a reduction of 27% to HIDiC schemes with a TAC 2% larger than the corresponding TAC of the traditional configurations.
      Graphical abstract image

      PubDate: 2017-06-07T14:46:32Z
      DOI: 10.1016/j.cherd.2017.05.025
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