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  Subjects -> CHEMISTRY (Total: 876 journals)
    - ANALYTICAL CHEMISTRY (54 journals)
    - CHEMISTRY (614 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (26 journals)
    - INORGANIC CHEMISTRY (43 journals)
    - ORGANIC CHEMISTRY (48 journals)
    - PHYSICAL CHEMISTRY (70 journals)

CHEMISTRY (614 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 13)
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: 42)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 20)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 20)
ACS Macro Letters     Full-text available via subscription   (Followers: 25)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 40)
ACS Nano     Full-text available via subscription   (Followers: 265)
ACS Photonics     Full-text available via subscription   (Followers: 13)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 23)
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 Chimica Slovenica     Open Access  
Acta Chromatographica     Full-text available via subscription   (Followers: 8)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 6)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 8)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 5)
Advanced Functional Materials     Hybrid Journal   (Followers: 54)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 65)
Advances in Chemical Science     Open Access   (Followers: 16)
Advances in Chemistry     Open Access   (Followers: 20)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 19)
Advances in Drug Research     Full-text available via subscription   (Followers: 21)
Advances in Enzyme Research     Open Access   (Followers: 9)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 7)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 9)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 25)
Advances in Nanoparticles     Open Access   (Followers: 15)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15)
Advances in Polymer Science     Hybrid Journal   (Followers: 43)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 17)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 18)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Science and Technology     Full-text available via subscription   (Followers: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 3)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 61)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 15)
American Journal of Chemistry     Open Access   (Followers: 29)
American Journal of Plant Physiology     Open Access   (Followers: 11)
American Mineralogist     Hybrid Journal   (Followers: 15)
Analyst     Full-text available via subscription   (Followers: 38)
Angewandte Chemie     Hybrid Journal   (Followers: 164)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 236)
Annales UMCS, Chemia     Open Access  
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 5)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 9)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 13)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Hybrid Journal   (Followers: 1)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 8)
Applied Spectroscopy     Full-text available via subscription   (Followers: 22)
Applied Surface Science     Hybrid Journal   (Followers: 31)
Arabian Journal of Chemistry     Open Access   (Followers: 5)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 1)
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Full-text available via subscription   (Followers: 337)
Biochemistry Insights     Open Access   (Followers: 6)
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: 20)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 7)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 119)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 84)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 2)
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: 6)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 71)
Catalysis for Sustainable Energy     Open Access   (Followers: 7)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 7)
Catalysis Science and Technology     Free   (Followers: 8)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 9)
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: 18)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 73)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 26)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 22)
Chemical Reviews     Full-text available via subscription   (Followers: 181)
Chemical Science     Open Access   (Followers: 23)
Chemical Technology     Open Access   (Followers: 22)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemical Week     Full-text available via subscription   (Followers: 7)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 24)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 32)
Chemistry & Industry     Hybrid Journal   (Followers: 6)
Chemistry - A European Journal     Hybrid Journal   (Followers: 151)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 16)
Chemistry and Materials Research     Open Access   (Followers: 20)
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: 44)
Chemistry of Materials     Full-text available via subscription   (Followers: 245)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 19)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 4)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 11)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 11)
Chromatographia     Hybrid Journal   (Followers: 24)
Chromatography     Open Access   (Followers: 2)
Chromatography Research International     Open Access   (Followers: 6)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Cogent Chemistry     Open Access  
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 11)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 6)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 5)
Combustion Science and Technology     Hybrid Journal   (Followers: 22)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 7)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 11)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 3)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 6)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 5)
Croatica Chemica Acta     Open Access  
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Chromatography     Hybrid Journal  
Current Green Chemistry     Hybrid Journal  
Current Metabolomics     Hybrid Journal   (Followers: 5)
Current Microwave Chemistry     Hybrid Journal  
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 14)
Current Research in Chemistry     Open Access   (Followers: 8)
Current Science     Open Access   (Followers: 70)
Current Trends in Biotechnology and Chemical Research     Open Access   (Followers: 3)
Dalton Transactions     Full-text available via subscription   (Followers: 23)
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  

        1 2 3 4 | Last

Journal Cover Chemical Engineering Research and Design
  [SJR: 0.873]   [H-I: 65]   [26 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0263-8762 - ISSN (Online) 0263-8762
   Published by Elsevier Homepage  [3177 journals]
  • Effect of mixing conditions on the wet preparation of ceramic foams
    • Authors: A. Celani; S. Blackburn; M.J.H. Simmons; E.H. Stitt
      Pages: 1 - 14
      Abstract: Publication date: June 2018
      Source:Chemical Engineering Research and Design, Volume 134
      Author(s): A. Celani, S. Blackburn, M.J.H. Simmons, E.H. Stitt
      Ceramic foams are a promising alternative to conventional catalyst supports due to their macro-porosity, which should enhance mass transport properties during reactions. Whilst direct foaming is a straightforward production method, the use of kitchen mixers commonly reported in the literature to initially froth the ceramic slurry limits understanding of scale-up. This study reports a systematic experimental investigation of the impact of mixing parameters on the properties of the foams produced in an agitated baffled vessel of diameter, T=175mm, equipped with an up-pumping pitch blade turbine with diameter of either D=0.23T or 0.51T and a bottom round sparger with a diameter of 45mm. The flow conditions in the present study were in the low to mid transitional regime (50<Re<1000). Design of Experiments (DoE) was employed to generate a series of screening experiments by variation of sparging time, air flow rate, impeller speed and impeller diameter. The mixing behaviour was described as a function of relevant dimensionless groups (Re, Fr, Flg, etc.) whilst the gas–liquid flow regime was estimated by examination of a ceramic particles free system. The properties of the foams obtained were correlated with key dimensionless numbers, though the exponents obtained deviated from values in the published literature. In addition, the rheology of the foam was correlated to the bubble size distribution showing that rheology measurements have potential for at-line measurement to control the structure of the produced material.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.044
      Issue No: Vol. 134 (2018)
       
  • An analysis of the mini-tablet fluidized bed coating process
    • Authors: Rok Šibanc; Magdalena Turk; Rok Dreu
      Pages: 15 - 25
      Abstract: Publication date: June 2018
      Source:Chemical Engineering Research and Design, Volume 134
      Author(s): Rok Šibanc, Magdalena Turk, Rok Dreu
      Mini-tablets with diameters of 2.0, 2.5, and 3.0mm are coated in two different lab-scale fluidized bed coaters equipped with a Wurster draft tube. The main focus of the research is to evaluate the inter-particle coating variability, and to assess the contribution of cycle time variation. Cycle times are measured using a photoluminescent tracer with a detector mounted on the top of the draft tube. The number of passes variability is represented from 5 to 28% of the total coating variability. Additionally, transmittance measurements at the top of the Wurster draft tube are performed in order to assess the inter-particle sheltering effects. Transmittance results are correlated to the amount of coating deposited per single pass of the spray zone and are converted to solids volume fractions. The dynamics of the transmittance signal further reveal the persistence of a particle arrangement within the draft tube of the two different coaters. The gathered results give insight into the different performance of two fluidized bed coaters in terms of inter-particle coating variability.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.020
      Issue No: Vol. 134 (2018)
       
  • Multi-stage granulation: An approach to enhance final granule attributes
    • Authors: Ali Z. Al hassn; Sonja Jeßberger; Michael J. Hounslow; Agba D. Salman
      Pages: 26 - 35
      Abstract: Publication date: June 2018
      Source:Chemical Engineering Research and Design, Volume 134
      Author(s): Ali Z. Al hassn, Sonja Jeßberger, Michael J. Hounslow, Agba D. Salman
      A new method in a high shear wet granulation process was implemented to enhance the final granule attributes. The granulation process in this method is divided into stages. In each stage different impeller speed was used. For this reason, this method of wet granulation is named here as multi-stage granulation (MSG) to be distinguish from the normal granulation (NG) in which the impeller speed is fixed throughout the granulation process. The experimental work revealed that by following the multi-stage granulation a noticeable change in the granules attributes has been observed. In this work, a high shear mixer (Eirich EL1) has been used. Calcium carbonate and melted polyethylene glycol (PEG1000) were used as a primary powder and binder respectively. The speed of impeller has been changed in a pulse mode throughout the granulation process from moderate speed to high speed in different intervals of time. Analysis of the produced granules showed that the granule characteristics with the multi-stage granulation were different to that with the normal granulation process. The granule median size affected clearly during the process. However, the granule porosity did not influence enormously during the process. The surface area of the granules also increased to some extent after the pulse change in the impeller speed. This increase in the surface area is reflected on the granules dissolution process. The collected granules after the pulse change were dissolving a slightly faster than the granule samples before the pulse change. This may due to the increase in the surface area of the granules.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.038
      Issue No: Vol. 134 (2018)
       
  • Optimization of steady-state and dynamic performances of water–gas shift
           reaction in membrane reactor
    • Authors: Shuey Z. Saw; Jobrun Nandong; Ujjal K. Ghosh
      Pages: 36 - 51
      Abstract: Publication date: June 2018
      Source:Chemical Engineering Research and Design, Volume 134
      Author(s): Shuey Z. Saw, Jobrun Nandong, Ujjal K. Ghosh
      Membrane rector technology has been increasingly recognized as a promising solution to produce high-purity hydrogen and to support future realization of hydrogen economy. Although some of the economic evaluations have shown that the inclusion of membrane reactor into an existing IGCC plant may be a viable option, it remains to be answered whether the added system can be easily controlled or not. This paper presents a feasibility study of four pre-defined membrane reactor flowsheets (including auxiliary units) based on nominal throughput 23,200t/day. The net present value (NPV) and v-gap metric are used as the economic and controllability performance criteria respectively. Considering uncertainties in future prices of hydrogen and electricity, the optimal NPV and v-gap metric are US$ 0.471 billion and 0.253 respectively. This suggests that the optimized membrane reactor flowsheet is feasible on the economic and controllability grounds.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.045
      Issue No: Vol. 134 (2018)
       
  • Multilayer petal-like enzymatic-inorganic hybrid micro-spheres
           [CPO-(Cu/Co/Cd)3(PO4)2] with high bio-catalytic activity
    • Authors: Shengjie Wang; Yu Ding; Rui Chen; Mancheng Hu; Shuni Li; Quanguo Zhai; Yucheng Jiang
      Pages: 52 - 61
      Abstract: Publication date: June 2018
      Source:Chemical Engineering Research and Design, Volume 134
      Author(s): Shengjie Wang, Yu Ding, Rui Chen, Mancheng Hu, Shuni Li, Quanguo Zhai, Yucheng Jiang
      CPO, a versatile enzyme, has limitations in industrial applications due to its poor stability and the difficulty of reuse. The preparation of stable immobilized enzymes with high catalytic activity is therefore desirable, but remains a challenge. A facile preparation of a series of enzyme-inorganic hybrid micro-spheres [chloroperoxidase (CPO)-(Cu/Co/Cd)3(PO4)2] and its application in the decolorization of crystal violet is reported in this work. All the hybrid micro-spheres show a multilayer petal-like structure. The formation of hybrid micro-spheres were proposed via four stages: crystallization, in-situ coordination, self-assembly and size growth. The process was entropy-driven, and there was a competition between precipitation of phosphate and coordination of M2+ with amide groups of CPO. The introduction of excess of chloride ions retarded the phosphate from precipitating by forming [MCl4]2− complexes, while simultaneously promoting the coordination of M2+ with amide groups. These hybrid materials showed high bio-catalytic activity in the decolorization of crystal violet. The decolorization efficiency reached 99.66%, 98.44% and 98.05% just within 3min using CPO-Cu3(PO4)2, CPO-Cd3(PO4)2 and CPO-Co3(PO4)2 respectively. They also have good thermal stability, and can keep 52.89% catalytic activity after 8 cycles of use. CPO-inorganic hybrid micro-spheres [chloroperoxidase (CPO)-(Cu/Co/Cd)3(PO4)2] is promising in the treatment of waste water containing crystal violet. It also has potential application for treatment of other soluble organic dyes in industrial wastewater.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.036
      Issue No: Vol. 134 (2018)
       
  • Optimal heat exchanger network synthesis based on improved cuckoo search
           via Lévy flights
    • Authors: Hongliang Zhang; Guomin Cui
      Pages: 62 - 79
      Abstract: Publication date: June 2018
      Source:Chemical Engineering Research and Design, Volume 134
      Author(s): Hongliang Zhang, Guomin Cui
      Heat exchanger network synthesis (HENS) is still a challenging task for minimizing the Total Annual Cost (TAC). In this work, a Cuckoo Search Algorithm (CSA) is introduced to solve the NonLinear Programming (NLP) problem of the fixed heat exchanger network design to determine the optimal heat load distribution, which can help improve the heat load configurations of previously found optimum configurations. The improved CSA (ICSA) is used to solve the Mixed Integer NonLinear Programming (MINLP) problem for optimal HENS, which can simultaneously optimize continuous and integer variables, and the proposed stream arrangement strategy aims to optimize the stream match search space by lowering the stage demands, i.e. reducing the number of independent variables, which is a promising means for an easier solution of large and medium sized HENS problems. Four large and medium sized benchmark cases have been investigated, obtaining no-splits results with lower TAC in a shorter computational time. In addition, a special feature from case 3 and 4 is analyzed, which is useful in order to achieve a lower TAC by using modified Stage-Wise Superstructure (SWS) models with flexible utility placement.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.046
      Issue No: Vol. 134 (2018)
       
  • An innovative bioprocess for methane conversion to methanol using an
           efficient methane transfer chamber coupled with an airlift bioreactor
    • Authors: Mohammad Ali Ghaz-Jahanian; Ali Baradar Khoshfetrat; Maliheh Hosseinian Rostami; Mohammad Haghighi Parapari
      Pages: 80 - 89
      Abstract: Publication date: June 2018
      Source:Chemical Engineering Research and Design, Volume 134
      Author(s): Mohammad Ali Ghaz-Jahanian, Ali Baradar Khoshfetrat, Maliheh Hosseinian Rostami, Mohammad Haghighi Parapari
      Biosynthesis of methanol from methane as a direct method takes place at ambient temperature and pressure which causes a considerable reduction in process costs. In this study an efficient methane transfer chamber along with an external-loop airlift bioreactor were developed to dissolve methane and oxygen in the culture separately. Mass transfer coefficients for oxygen in the bioreactor and methane in the transfer chamber were obtained 97.2h−1 and 70.8h−1 respectively. Two strains of methanotroph bacteria (AS1 and AS2) were also isolated from activated sludge. Factorial design of experiments for operational parameters showed a maximum productivity for AS1 strain at 28°C when using nitrate as nitrogen source. Batch runs in airlift bioreactor using the AS1 strain and optimized operating parameters represented a peak of 1600mg/L in methanol synthesis during the first 3:30h without using inhibitor for methanol dehydrogenase (MDH) enzyme. Sequencing batch process, at the next step, was used to create intermediate lag phase and to increase the stability of microorganisms by forming flocs. The results of this study cleared that the designed system is safe and efficient to scale-up, and it can be considered as a potential alternative method in the production of methanol.
      Graphical abstract image

      PubDate: 2018-04-25T05:26:41Z
      DOI: 10.1016/j.cherd.2018.03.039
      Issue No: Vol. 134 (2018)
       
  • An outlook towards hydrogen supply chain networks in 2050 — Design of
           novel fuel infrastructures in Germany
    • Authors: Anton Ochoa Bique; Edwin Zondervan
      Pages: 90 - 103
      Abstract: Publication date: June 2018
      Source:Chemical Engineering Research and Design, Volume 134
      Author(s): Anton Ochoa Bique, Edwin Zondervan
      This work provides a comprehensive investigation of the feasibility of hydrogen as transportation fuel from a supply chain point of view. It introduces an approach for the identification the best hydrogen infrastructure pathways making decision of primary energy source, production, storage and distribution networks to aid the target of greenhouse gas emissions reduction in Germany. The minimization of the total hydrogen supply chain (HSC) network cost for Germany in 2030 and 2050 years is the objective of this study. The model presented in this paper is expanded to take into account water electrolysis technology driven by solar and wind energy. Two scenarios are evaluated, including a full range of technologies and “green” technologies using only renewable resources. The resulting model is a mixed integer linear program (MILP) that is solved with the Advanced Integrated Multidimensional Modeling System (AIMMS). The results show that renewable energy as a power source has the potential to replace common used fossil fuel in the near future even though currently coal gasification technology is the still the dominant technology.

      PubDate: 2018-04-25T05:26:41Z
      DOI: 10.1016/j.cherd.2018.03.037
      Issue No: Vol. 134 (2018)
       
  • Process design and techno-economical analysis of hydrogen production by
           aqueous phase reforming of sorbitol
    • Authors: Dmitry A. Sladkovskiy; Lidia I. Godina; Kirill V. Semikin; Elena V. Sladkovskaya; Daria A. Smirnova; Dmitry Yu. Murzin
      Pages: 104 - 116
      Abstract: Publication date: June 2018
      Source:Chemical Engineering Research and Design, Volume 134
      Author(s): Dmitry A. Sladkovskiy, Lidia I. Godina, Kirill V. Semikin, Elena V. Sladkovskaya, Daria A. Smirnova, Dmitry Yu. Murzin
      The present study was focused on detailed sorbitol aqueous phase reforming (APR) process design. Aspen HYSYS software was used to design a 500kg/h hydrogen production plant operation with sorbitol syrup as a feedstock. For reactor modelling a complex reaction network was taken into account along with phase equilibrium simulations which determined to have a significant impact on the total process heat due to possibility of water evaporation. The model was adjusted and verified using the experimental data with 1%Pt/Al2O3. The process optimization has included several conceptual improvements such as middle pressure steam co-generation and hot water recycle which can significantly decrease the operation costs. The total costs of hydrogen were estimated as 12.97$/kg, where feedstock costs take the major contribution of 91.8%. The most feasible way of making APR economical attractive is production of polyols from the lignocellulosic biomass.
      Graphical abstract image

      PubDate: 2018-04-25T05:26:41Z
      DOI: 10.1016/j.cherd.2018.03.041
      Issue No: Vol. 134 (2018)
       
  • Structure of shear-enhanced flow on membrane surface with horizontal
           vibration and its effect on filtration performance
    • Authors: Kazutaka Takata; Katsuyoshi Tanida
      Pages: 130 - 139
      Abstract: Publication date: June 2018
      Source:Chemical Engineering Research and Design, Volume 134
      Author(s): Kazutaka Takata, Katsuyoshi Tanida
      Back-and-forth horizontal vibration of a membrane can produce a high shear rate in fluid near a membrane surface. The present study investigated the relationship between the flow structure near the membrane surface and the characteristics of separation performance. A numerical calculation was performed to analyze the flow field near the membrane surface. Results revealed that the velocity of fluid near the membrane surface lags that of the membrane. The delay depends on the magnitudes of the inertia and viscosity of the fluid. Additionally, the thickness of the velocity boundary layer on the membrane surface obtained from numerical calculation was found to be identical to that provided by the boundary layer theory of horizontal vibration. Furthermore, the permeate flux measured using emulsion solution was well correlated with the shear rate as a function of amplitude and frequency.

      PubDate: 2018-04-25T05:26:41Z
      DOI: 10.1016/j.cherd.2018.03.042
      Issue No: Vol. 134 (2018)
       
  • Robust state estimation of feeding–blending systems in continuous
           pharmaceutical manufacturing
    • Authors: Jianfeng Liu; Qinglin Su; Mariana Moreno; Carl Laird; Zoltan Nagy; Gintaras Reklaitis
      Pages: 140 - 153
      Abstract: Publication date: June 2018
      Source:Chemical Engineering Research and Design, Volume 134
      Author(s): Jianfeng Liu, Qinglin Su, Mariana Moreno, Carl Laird, Zoltan Nagy, Gintaras Reklaitis
      State estimation is a fundamental part of monitoring, control, and real-time optimization in continuous pharmaceutical manufacturing. For nonlinear dynamic systems with hard constraints, moving horizon estimation (MHE) can estimate the current state by solving a well-defined optimization problem where process complexities are explicitly considered as constraints. Traditional MHE techniques assume random measurement noise governed by some normal distributions. However, state estimates can be unreliable if noise is not normally distributed or measurements are contaminated with gross or systematic errors. To improve the accuracy and robustness of state estimation, we incorporate robust estimators within the standard MHE skeleton, leading to an extended MHE framework. The proposed MHE approach is implemented on two pharmaceutical continuous feeding–blending system (FBS) configurations which include loss-in-weight (LIW) feeders and continuous blenders. Numerical results show that our MHE approach is robust to gross errors and can provide reliable state estimates when measurements are contaminated with outliers and drifts. Moreover, the efficient solution of the MHE realized in this work, suggests feasible application of on-line state estimation on more complex continuous pharmaceutical processes.

      PubDate: 2018-04-25T05:26:41Z
      DOI: 10.1016/j.cherd.2018.03.017
      Issue No: Vol. 134 (2018)
       
  • Optimization-based design of crude oil distillation units using surrogate
           column models and a support vector machine
    • Authors: Dauda Ibrahim; Megan Jobson; Jie Li; Gonzalo Guillén-Gosálbez
      Pages: 212 - 225
      Abstract: Publication date: June 2018
      Source:Chemical Engineering Research and Design, Volume 134
      Author(s): Dauda Ibrahim, Megan Jobson, Jie Li, Gonzalo Guillén-Gosálbez
      This paper presents a novel optimization-based approach for the design of heat-integrated crude oil distillation units, which are widely used in refineries. The methodology presented combines, within a unified framework, surrogate distillation column models based on artificial neural networks, feasibility constraints constructed using a support vector machine, and pinch analysis to maximize heat recovery, in order to optimize the distillation column configuration and its operating conditions. The inputs to the surrogate column model are given by the column structure and operating conditions, while the outputs are related to the column performance. The support vector machine classifier filters infeasible design alternatives from the search space, thus reducing computational time, and ultimately improves the quality of the final solution. The overall optimization problem takes the form of a mixed-integer nonlinear program, which is solved by a genetic algorithm that seeks the design and operating variables values that minimize the total annualized cost. The capabilities of the proposed approach are illustrated using an industrially–relevant case study. Numerical results show that promising design alternatives can be obtained using the proposed method. The approach can help engineers to design and operate petroleum refineries optimally, where these are expected to continue to play a major role in the energy mix for some years.

      PubDate: 2018-04-25T05:26:41Z
      DOI: 10.1016/j.cherd.2018.03.006
      Issue No: Vol. 134 (2018)
       
  • Role of cerium in improving NO reduction with NH3 over Mn–Ce/ASC
           catalyst in low-temperature flue gas
    • Authors: Shan Ren; Jie Yang; Tianshi Zhang; Lijun Jiang; Hongming Long; Fuqiang Guo; Ming Kong
      Pages: 1 - 10
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Shan Ren, Jie Yang, Tianshi Zhang, Lijun Jiang, Hongming Long, Fuqiang Guo, Ming Kong
      Mn–Ce mixed oxide was loaded onto activated semi-coke (ASC) via impregnation method and the low temperature selective catalytic reduction (SCR) of NO with NH3 was investigated. The NO conversion and NO oxidation rates were both influenced by the ratios of Ce/(Mn+Ce), and Mn–Ce(0.3)/ASC with loading 5% (mass ratio) Mn–Ce oxides performed the highest catalytic conversion rate of 96.6% and NO oxidation rate of 18.4% at 250°C and GHSV=6000h−1. The changes of physical properties, microstructure, functional groups, crystal structure, surface atomic state, redox property and acid strength for the catalysts were characterized by BET, SEM, FT-IR, XRD, XPS, H2-TPR and NH3-TPD. The results showed that surface functional groups were increased after nitric acid treatment and abundant oxygen groups were observed on semi-coke surface, which were considered to be beneficial for the gas adsorption. Ce doping could raise the Mn4+/Mn x+ rate which played a vital role in catalytic reaction, enhancing the amount of weak and strong acid sites, increasing oxygen vacancies and accelerating the molecular oxygen turning into reactive oxygen species, which could enhance the NO oxidation activity thus contributed to the denitration efficiency.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.02.041
      Issue No: Vol. 133 (2018)
       
  • A support assisted by photocatalytic Fe3O4/ZnO nanocomposite for thin-film
           forward osmosis membrane
    • Authors: Rezvaneh Ramezani Darabi; Mohsen Jahanshahi; Majid Peyravi
      Pages: 11 - 25
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Rezvaneh Ramezani Darabi, Mohsen Jahanshahi, Majid Peyravi
      Novel thin-film nanocomposite (TFN) membranes were fabricated by incorporation of Magnetite/Zinc oxide (Fe3O4/ZnO) nanocomposite for the forward osmosis (FO) processes. Different concentrations of Fe3O4/ZnO nanocomposite (0.1, 0.2 and 0.3wt%) were added to the sublayer and also 0.02wt% of Fe3O4/ZnO nanocomposite was added to the active layer. The prepared TFN membranes were characterized with aspects to membranes surface and structure properties, separation properties and also FO membrane performance and subsequently compared with thin-film composite (TFC) membrane. The hydrophilicity of TFN membranes surface was improved with increasing Fe3O4/ZnO in the casting and aqueous solution due to the activation of Fe3O4/ZnO nanocomposite under UV light irradiation. Compared to the TFC membrane, the TFN FO membrane water flux was reported to increase remarkably from 16.5 to 29.3L/m2 h (10mM NaCl as feed water (FW)) and 14.5 to 27.2L/m2 h (Acarbose solution as FW) when 2M NaCl salt was utilized as draw solution (DS). The improvement in FO water flux was ascribed to the lower S parameter of modified PES sublayer and the decline of internal concentration polarization (ICP). Long-term experiments demonstrated that the modified FO membranes had lower flux reduction compared to control TFC FO membrane.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.02.029
      Issue No: Vol. 133 (2018)
       
  • Performance of agitated-vessel U tube heat exchanger using spiky twisted
           tapes and water based metallic nanofluids
    • Authors: M. Khoshvaght-Aliabadi; S. Davoudi; M.H. Dibaei
      Pages: 26 - 39
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): M. Khoshvaght-Aliabadi, S. Davoudi, M.H. Dibaei
      An experimental study is performed to investigate hydrothermal characteristics of agitated-vessel U tube heat exchanger. In order to augment the rate of heat transfer in the tube side, two passive enhancement techniques, namely spiky twisted tapes and water based metallic nanofluids, are used. Three twist ratios (α =0.33, 0.67, and 1) with different values of width/depth for peripheral cuts (β =0.33, 0.5, 0.67, 1, 1.5, 2, and 3) and three metallic nanofluids (Cu/water, Fe/water, and Ag/water) are tested. The experiments are done in turbulent flow regime for Reynolds numbers ranging from 7000 to 18,000. The Reynolds number is determined based on hydraulic dimeter of considered geometries as well as inlet flow rate and physical properties of applied working fluid. The results show that spiky twisted tapes and metallic nanofluids both realize great heat transfer enhancement in the agitated-vessel U tube heat exchanger. Utilization of spiky twisted tapes leads to an increase in the range of 11%–67% for the heat transfer coefficient compared with the smooth case. The considered performance factor displays that the most efficient configuration is the spiky twisted tape with α = β =0.33. Also, it is found that the heat transfer enhancement of Ag/water nanofluid is more intensive than Cu/water and Fe/water nanofluids; a maximum enhancement by 18.2% is identified compared with base fluid, while the maximum rise in the pressure drop is only 8.5%.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.02.030
      Issue No: Vol. 133 (2018)
       
  • Simulated exergy and energy performance comparison of physical–chemical
           and chemical solvents in a sour gas treatment plant
    • Authors: Tahereh Nejat; Azam Movasati; David A. Wood; Hassan Ghanbarabadi
      Pages: 40 - 54
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Tahereh Nejat, Azam Movasati, David A. Wood, Hassan Ghanbarabadi
      A feasibility simulation study evaluates the utilization of the physical–chemical solvent Sulfolane plus Methyl di-ethanol amine (MDEA) plus H2O (Sulfinol-M), to replace the aqueous amine solvent (MDEA) currently used in the sour-gas treatment unit of the large-scale Khangiran gas processing plant (Iran). Physical–chemical solvents, such as Sulfinol-M, have the advantages over chemical solvents in that: (1) their absorption of pollutants is not limited by their stoichiometry; (2) they can be easily regenerated by reduction of pressure alone; and, (3) they demonstrate a strong capability to remove sulphur compounds. The simulation and exergy analysis of this gas treatment plant compare the performance of the currently used MDEA solvent with the Sulfinol-M solvent in various concentrations. The influences of different parameters, including inlet solvent temperature, composition and flow rate of solvents on the removal of H2S and CO2, together with associated exergy and energy losses are evaluated for the MDEA solvent and a range of concentrations of the Sulfinol-M solvent. The simulated exergy analysis demonstrates suitable absorption of acid gases by the Sulfinol-M solvent for less energy and cost than the MDEA solvent.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.02.040
      Issue No: Vol. 133 (2018)
       
  • Gas–liquid mixing in dual agitated vessels in the heterogeneous
           regime
    • Authors: Amna Jamshed; Michael Cooke; Zhen Ren; Thomas L. Rodgers
      Pages: 55 - 69
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Amna Jamshed, Michael Cooke, Zhen Ren, Thomas L. Rodgers
      Gas–liquid multi-phase processes are widely used for reactions such as oxidation and hydrogenation. There is a trend for such processes to increase the productivity of the reactions, one method of which is to increase the gas flow rate into the vessel. This means that it is important to understand how these reactors perform as high gas flow rates occurs well into the heterogeneous regime. This paper investigates the mixing performance for the dual axial radial agitated vessel of 0.61m in diameter. 6 blade disk turbine (Rushton turbine) below a 6 Mixed flow Up-pumping and down-pumping have been studied at very high superficial gas velocities to understand the flow regimes operating at industrial conditions. Electrical resistance tomography have been used to produce the 3D images using Matlab, along with analysing the mixing parameters such as Power characteristics, gas hold-up and dynamic gas disengagement. Minimal difference between the two configurations have been reported in terms of gas hold-up, however with the choice of upward and downward pumping impeller power characteristics show significant difference at very high gas flow rates. Also at these high superficial gas velocities, this report introduces a 3rd bubble class, as seen in dynamic gas disengagement experiments, which corresponds to very large slugs of gas.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.02.034
      Issue No: Vol. 133 (2018)
       
  • Optimisation of stirred vessel geometry for the drawdown and incorporation
           of floating solids to prepare concentrated slurries
    • Authors: Thomas Wood; Mark J.H. Simmons; E. Hugh Stitt
      Pages: 70 - 78
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Thomas Wood, Mark J.H. Simmons, E. Hugh Stitt
      This paper reports on a Design of Experiments (DoE) approach to optimise the geometric configuration for effective drawdown and incorporation of floating solids to prepare high solid content slurries. The impeller speed and power draw required to ensure all dry powder is incorporated within four seconds of addition to the vessel free surface, NJI and PJI, were used as metrics to determine incorporation performance. Mixed flow pitched blade turbines at D/T=0.5 were used. The main parameters considered were the impeller pumping direction (up versus down), impeller submergence, eccentricity, and angle of tilt. DoE was used to examine both the independent effects of the main parameters and their interactions. Pumping mode was found to be the most significant parameter, with down-pumping impellers generally providing the best drawdown and incorporation performance. This is related to the strong interaction between pumping mode and all other parameters, where adding tilt or eccentricity reduced drawdown performance for up-pumping impellers, yet caused improvement in the case of down-pumping impellers. The optimal geometry from the DoE was found using a down-pumping PBT, 10° tilt, 10% of the vessel diameter eccentricity and placed at an initial submergence of half the liquid height. This geometry is shown to reduce the time required to prepare a 50wt% slurry by two thirds compared to a generic Rushton turbine design, emphasising the benefits of rational impeller and vessel design.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.002
      Issue No: Vol. 133 (2018)
       
  • Simultaneous synthesis of a multiple-effect evaporation system with
           background process
    • Authors: Yinghua Jiang; Lixia Kang; Yongzhong Liu
      Pages: 79 - 89
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Yinghua Jiang, Lixia Kang, Yongzhong Liu
      Multiple-effect evaporation (MEE) is one of the energy-intensive processes. To reduce the energy consumption of this process, it is effective to integrate the MEE with its background process as a whole system. In this paper, a stage-wise superstructure model is proposed, which takes all possibilities in integration of the MEE coupled with its background process into consideration. The corresponding mathematical programming model, featuring a mixed-integer nonlinear programming formulation is then presented to minimize the total energy consumption (TEC) and the total annual cost (TAC) of the system. The optimal topology and operating parameters of the whole system are determined simultaneously by solving the proposed model. The application and effectiveness of the proposed model are illustrated through a case study of a concentrating sugar juice production process. The results obtained by the proposed method agree well with those obtained by the analytical methodology in literature when the energy demand is targeted. To further clarify the advantages of the proposed method, the coupled system with the lowest TAC is also analyzed and discussed, in which the stream matches and operating parameters are determined accordingly.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.02.037
      Issue No: Vol. 133 (2018)
       
  • CO2 gas–liquid mass transfer and kLa estimation: Numerical investigation
           in the context of airlift photobioreactor scale-up
    • Authors: Mbalo Ndiaye; Emilie Gadoin; Caroline Gentric
      Pages: 90 - 102
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Mbalo Ndiaye, Emilie Gadoin, Caroline Gentric
      This paper deals with gas–liquid mass transfer in an airlift via CFD simulations in the context of photobioreactor (PBR) scale-up. Two aspects are emphasized. Firstly, since carbon uptake by microalgae is of crucial importance as part of PBRs, CO2 transfer is in focus, and numerical simulations are developed to take into account CO2 gas–liquid transfer and dissociation in the aqueous phase. Secondly, since estimating k L a is of crucial importance when scaling-up PBRs, different ways to evaluate k L a are discussed using numerical experiments. Firstly, k L a may be estimated as the volume average value of the local mass transfer coefficients calculated from steady-state hydrodynamics and Higbie penetration model. Secondly, k L a can be deduced from classical dynamic gassing-out/gassing-in experiments. This second method is simulated for O2, as commonly performed experimentally, and also with CO2 since it is the transferred species in PBRs. Results show that k L a field is strongly heterogeneous, as expected in airlifts where gas is mainly present in the riser. Performed with O2, the gassing-in method leads to quite accurate estimation of the spatial average value of local k L a. But, gassing-in methods performed with O2 and CO2 lead to discordant results. In fact, CFD shows that the CO2 depletion in the gas phase has to be accounted for to predict k L a from CO2 gassing-in method, especially at large scale. This study also puts into evidence the potentialities of CFD which allows to get detailed image of local gas–liquid mass transfer, depending on two-phase hydrodynamics, gas phase distribution and transferred species solubility.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.001
      Issue No: Vol. 133 (2018)
       
  • Footprint of droplets after impact onto paper surfaces with a hydrophobic
           barrier
    • Authors: J.O. Marston; M. Moradiafrapoli; C. Li; T. Lam; M.E. Razu; J. Kim
      Pages: 103 - 110
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): J.O. Marston, M. Moradiafrapoli, C. Li, T. Lam, M.E. Razu, J. Kim
      This paper presents findings from a study of the impact of liquid droplets onto papers which have been treated to incorporate a hydrophobic barrier. Such papers are currently being explored as new paper-based microfluidic technology for chemical, biological and medical applications, where discrete volumes of liquid (i.e. droplets) are deposited on the paper. We experimentally capture the impingement stage with the aid of high-speed videography and analyze the spreading, retraction and final footprint of the droplets. Understanding the maximum spread and final footprint is important for paper-based devices because it can determine whether or not a droplet that impinges upon them will reach the hydrophilic wicking matrix. We conclude that the final contact area (footprint) could be tuned simply by varying the impact energy of the droplet and vapor deposition time. In contrast to untreated papers, droplets impinging on treated papers impregnate the porous structure but there is no subsequent wicking, i.e. the contact line always pins, which is explained by the interaction of the droplet with fibers of the paper.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.007
      Issue No: Vol. 133 (2018)
       
  • Modelling of transport mechanisms and drying shrinkage for multilayer
           ceramic membrane structure
    • Authors: Zawati Harun; Tze Ching Ong; Takeshi Matsuura; Siti Khadijah Hubadillah; Mohd Hafiz Dzarfan Othman; Ahmad Fauzi Ismail
      Pages: 111 - 125
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Zawati Harun, Tze Ching Ong, Takeshi Matsuura, Siti Khadijah Hubadillah, Mohd Hafiz Dzarfan Othman, Ahmad Fauzi Ismail
      In ceramic membrane preparation, the understanding of drying phenomena is very important to ensure no defects and failures that may present in the membrane layers. The combination of hygroscopic and non-hygroscopic multilayer systems that possess different properties is always associated with the failure of the consolidated structure of ceramics during the drying and sintering process. Hence, a two-dimensional mathematical model that coupled mass, heat, and gas transfer was employed to describe the drying process as a whole multilayer ceramic membranes structure. The finite element method was used to solve the model and computation was carried out using a Skyline solver to capture the highly nonlinear and transient process. This study emphasises on the evolution of transport variables during the drying that can be correlated to shrinkage mechanism. The side surface heating boundary was performed with a conclusion that hygroscopic materials have low drying rate due to the material characteristic which inherent higher water retention in a solid matrix. This characteristic also causes higher pore water pressure and gas pressure. The drying of hygroscopic layer has resulted in higher moisture gap which in turn increased the possibilities of cracking. The results obtained from this study enable the optimisation with respect to drying time and material selection thus significantly contributes to the energy saving as well as reducing the environmental effect via less waste energy loss.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.02.039
      Issue No: Vol. 133 (2018)
       
  • Optimization of extraction conditions using central composite design for
           
    • Authors: Faegheh Vafaei; Rezvan Torkaman; Mohammad Ali Moosavian; Parisa Zaheri
      Pages: 126 - 136
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Faegheh Vafaei, Rezvan Torkaman, Mohammad Ali Moosavian, Parisa Zaheri
      The extraction conditions for the removal of cobalt(II) from chloride aqueous solution were studied by using supported liquid membrane. The effects of four factors such as the acidity of feed solution (pH), Cyanex301 concentration, cobalt ion concentration in the feed phase as well as sulfuric acid concentration in the stripping phase were investigated by using central composite design which is a subcategory of response surface methodology. The optimum conditions obtained for pH, Cyanex301 concentration, initial cobalt concentration in feed solution, and sulfuric acid concentration were 6, 1mol/L, 98.86mg/L and 1.26mol/L, respectively. The percentage of cobalt extraction equal to 48.21% obtained from the predicted model was in agreement with the experimental data (45.84%), after 3.5h in the experimental conditions. In addition, the other factors such as the types of solvent as a diluent, stripping solution, and the types of extractants and mixtures were studied at the optimum point. The results showed that the percentage of cobalt extraction achieved was 46.85% within 3.5h, in the extraction conditions (Cyanex301 as an extractant, kerosene or chloroform as a diluent and the mixture of sulfuric acid and nitric acid as the stripping phase).
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.010
      Issue No: Vol. 133 (2018)
       
  • Modelling of auto-agglomeration of cohesive powders
    • Authors: Vincenzino Vivacqua; Mojtaba Ghadiri
      Pages: 137 - 141
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Vincenzino Vivacqua, Mojtaba Ghadiri
      Fine particles in the micron size range or smaller are usually so cohesive that they cannot exist as individual entities and are in cluster form, the size of which depends on the stress history. During handling, transportation or storage, the powder is subjected to mechanical vibration and/or agitation and, as a result of which clumping of particles or “snowballing” can occur even without the presence of any binder. This is an undesirable feature, as it is responsible for poor flow behaviour, cohesive arching, segregation of lumps and inducing flaws in products. Nevertheless, the mechanism of auto-agglomeration of cohesive powder has not received due attention and the conditions under which such clusters/lumps form, their size, structure and strength has not been analysed extensively. In this work we present a preliminary model to predict the equilibrium cluster size based on two separate energy balances to predict the granule solid fraction and equilibrium size, respectively. Despite some broad approximations, this approach can capture the trend of variation of the agglomerate size with the vibration intensity for some data reported in the literature. The proposed model also identifies the mechanism controlling the growth of the agglomerates as the balance between the cohesive energy of the particles and the disruptive energy of vibration.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.018
      Issue No: Vol. 133 (2018)
       
  • Modified approach of total site integration for energy conservation: A
           case study of sponge iron cluster
    • Authors: Venkata Ramanaiah; Shabina Khanam
      Pages: 142 - 154
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Venkata Ramanaiah, Shabina Khanam
      In the present work, a modified approach to conserve energy in total site of plants of similar type is developed where conventional methods are not applicable. The approach includes iterative method, if utility and process streams are same, as well as non-iterative method, if these are different. Further, if coal is treated as utility and process streams, a revised model to compute its consumption is also proposed. To illustrate the new approach a cluster of three sponge iron plants are considered where two different strategies are proposed. Results show that reduction in coal consumption, predicted for Strategy-1, is higher than that of Strategy-2. Strategy-1 recovers 99.8% of waste heat available in the modified total site. Thus, through Strategy-1 total amount of energy wasted in the cluster is reduced from 43% to 7.6%. Along with this, Strategy-1 reduces waste gas emissions significantly while making sponge iron cluster more environment friendly. Moreover, 97.9% reduction of water in total site is also observed using Strategy-1, which is an added advantage. Results are compared well with that of the published literature. Further, this approach can be applicable effectively in the site of similar plants irrespective of the operating condition.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.014
      Issue No: Vol. 133 (2018)
       
  • Experimental and numerical investigation on the blade angle of axial-flow
           swirling generator and drainage structure for supersonic separators with
           diversion cone
    • Authors: Yingguang Wang; Dapeng Hu
      Pages: 155 - 167
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Yingguang Wang, Dapeng Hu
      The effect of axial-flow swirling generator and drainage structure with diversion cone on separation performance is very important to supersonic separators. But there is in the absence of experimental studies on separation characteristics of above-mentioned structure. In this paper, both experimental and numerical methods are utilized to investigate the influences of swirling generator and drainage structure. Good agreements are achieved between experimental data and high-order numerical simulation. The results demonstrate that the rotation strength decreases as the outlet angle of the swirler increases. The rotational flow causes the inconsistency of the radial distribution of the fluid in the nozzle and the inconsistency is more noticeable with the increase of rotation intensity. So the blade angle of swirling generator should be determined to find the balance between the expansion characteristic and swirling flow. Comparing two types of drainage structures, the internal extension structure has seriously damaged the supersonic flow in the nozzle, while the flush type drainage port has less influence on fluid. And the smaller outlet angle of drainage port can reduce the effect of drainage port on supersonic flow. When the pressure ratio is 1.4 for the flush type drainage structure, the optimal structural parameter is that the outlet angle of swirler is 55° and the inclination of the drainage structure is 22°. Under the optimum conditions, the ethanol removal rate is 57.06%.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.008
      Issue No: Vol. 133 (2018)
       
  • Simulation and optimisation of spiral-wound reverse osmosis process for
           the removal of N-nitrosamine from wastewater
    • Authors: M.A. Al-Obaidi; C. Kara-Zaïtri; I.M. Mujtaba
      Pages: 168 - 182
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): M.A. Al-Obaidi, C. Kara-Zaïtri, I.M. Mujtaba
      N-nitrosamine in wastewater treatment processes can contribute to several public health impacts including human carcinogens even at very low concentration. In this work, spiral-wound reverse osmosis (SWRO) process is used to remove N-nitrosamine compounds from wastewater. Effects of operating parameters of the SWRO process on the removal of N-nitrosamine, total water recovery, and specific energy consumption for a SWRO configurations are evaluated via simulation and optimisation. For this purpose, the one-dimensional distributed model developed earlier by the authors is modified by including different mass transfer coefficient correlation, temperature dependent water and solute permeability correlations and energy equations. The model is first validated by estimating a new set of model parameters using eight set of experimental data from the literature and is then used to simulate the process with and without energy recovery device to facilitate deeper insight of the effect of operating conditions on the process performance. The model is then embedded within an optimisation framework and optimisation problems to maximise N-nitrosamine rejections and to minimise specific energy consumption are formulated and solved while the operating conditions are optimized simultaneously.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.012
      Issue No: Vol. 133 (2018)
       
  • Ghost Particle Velocimetry as an alternative to μPIV for
           micro/milli-fluidic devices
    • Authors: Marco Riccomi; Federico Alberini; Elisabetta Brunazzi; Daniele Vigolo
      Pages: 183 - 194
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Marco Riccomi, Federico Alberini, Elisabetta Brunazzi, Daniele Vigolo
      Ghost Particle Velocimetry (GPV) has only been recently introduced and has already been proven useful in small scale phenomena investigations, such as the study of the flow field during single droplets generation in microfluidic devices. In this work, GPV was used to experimentally investigate fluid flow close to a T-shaped branched junction in a millimetre sized device. The experimental setup allowed for the first time, the study of complex fluid dynamic structures such as vortices and recirculation zones. Several experiments were performed to exploit the capability of GPV in carrying out flow field measurements, at different Reynolds numbers within the laminar flow regime and for two channel sizes. The results were validated by verifying the steady state and stability conditions and by comparing them with results obtained using the well-established micron-scale Particle Image Velocimetry (μPIV). Differences between these two velocimetry techniques were analysed in terms of qualitative and quantitative parameters, to attain a performance comparison and understand the strengths and weaknesses of each respective method.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.005
      Issue No: Vol. 133 (2018)
       
  • Rigorous thermodynamic evaluation of the extractive distillation process
    • Authors: Rivana Mabel Lucena Oliveira Souto; Gilvan Wanderley Farias Neto; Fabricia Sales de Araújo; Marcella Feitosa de Figueiredo; Wagner Brandão Ramos; Karoline Dantas Brito; Romildo Pereira Brito
      Pages: 195 - 203
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Rivana Mabel Lucena Oliveira Souto, Gilvan Wanderley Farias Neto, Fabricia Sales de Araújo, Marcella Feitosa de Figueiredo, Wagner Brandão Ramos, Karoline Dantas Brito, Romildo Pereira Brito
      The extractive distillation process has received special attention from researchers due to its high energy consumption and low thermodynamic efficiency. However, the thermodynamic performance has been approached in the literature in a superficial way and it is common to affirm that intensifying processes increases the thermodynamic efficiency without presenting quantitative results. The main objective of this work is to determine the operational conditions that result in maximum thermodynamic efficiency of the extractive distillation process (global optimum). Thus, the process was divided into three blocks in order to identify the irreversibility sources. The results show that the use of a solvent to enable the separation is the main cause of the low thermodynamic efficiency of the extractive distillation process, and depending on the chemical system and the operating condition, negative values ​​for the extractive column are observed. In order to make the thermodynamic analysis more didactic, a methodology to calculate the individual and overall lost work is proposed, which allows for identifying and quantifying, as well as where to act in order to increase the thermodynamic efficiency of the separation. The azeotropic binaries used as case studies consisted of ethanol (ETOH), water (H2O), acetone (ACET) and methanol (METOH), while the solvents used to promote separation were ethylene glycol (EG) and dimethyl sulfoxide (DMSO), respectively.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.003
      Issue No: Vol. 133 (2018)
       
  • Fate and distribution of phosphorus in laboratory-scale membrane
           bioreactors
    • Authors: Yanpeng Mao; Chao Xue; Qinyan Yue; Wenlong Wang; Zhanlong Song; Xiqiang Zhao; Chunyuan Ma
      Pages: 204 - 209
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Yanpeng Mao, Chao Xue, Qinyan Yue, Wenlong Wang, Zhanlong Song, Xiqiang Zhao, Chunyuan Ma
      In this study, the removal efficiencies of phosphorus from synthetic wastewater using laboratory-scale membrane bioreactors (MBRs) with the addition of different iron salts were investigated. The distributions of phosphorus in the effluent, suspension, and sludge of the MBR systems after the addition of iron salts were analyzed. The removal efficiency of phosphorus in actual domestic sewage via the combination of MBR and Fe(II) was also investigated. The results indicated that after the MBR system effluent stabilized, the added Fe(II) was more efficient than Fe(III) was in removing phosphorus. Among the suspensions present in different zones of the MBR systems, the phosphorus concentrations varied significantly. Namely, the concentration of phosphorus in the first anoxic zone was the highest, for which the concentration of phosphorus in the MBR with added Fe(II) was higher than that in the MBR with added Fe(III). In addition, the percentage of the dissociable phosphorus in the sludge was relatively low. For the treatment of actual domestic sewage using the combination of MBR and Fe(II), a specific concentration of Fe(II) resulted in greater than 99% phosphorus removal efficiency as well as a stable effluent concentration. Furthermore, microbes present in the sludge exhibited better tolerance to Fe(II).
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.011
      Issue No: Vol. 133 (2018)
       
  • Life cycle assessment of a biomass CHP plant in UK: The Heathrow energy
           centre case
    • Authors: C. Tagliaferri; S. Evangelisti; R. Clift; P. Lettieri
      Pages: 210 - 221
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): C. Tagliaferri, S. Evangelisti, R. Clift, P. Lettieri
      Bioenergy has an important role to play in helping the UK meet its carbon target in 2050 and the European Renewable Energy Directive objectives for 2030. There are however uncertainties associated with the use of bioenergy, and whether or how much it contributes to green-house gas emission reductions. In order to help identifying environmental benefits and burdens associated with biomass use for energy production, an attributional life cycle assessment has been carried out of a biomass-fired CHP plant: the Heathrow Airport energy centre. This facility burns woodchips sourced from nearby forests providing 2 MWe of electricity and 8 MWth of thermal energy which delivers heat and cooling to Heathrow Terminal 2 and low temperature hot water to Terminal 5. A hot spot analysis is conducted to identify the process steps with the largest environmental impact, starting from the harvesting of the forest residue to the disposal of the boiler ash. A scenario analysis is performed to compare the impacts of the biomass plant against fossil alternatives and to identify which renewable energy sources, between biomass and MSW, should be prioritised for development and investment. The results show a reduction in GHG emissions from using biomass, with further benefits if the bottom ash is collected and re-used as a soil conditioner for land-farming or forestry. The paper also discusses the treatment of biogenic carbon in the assessment.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.022
      Issue No: Vol. 133 (2018)
       
  • Preparation and characterization of MWCNT-TEPA/polyurethane nanocomposite
           membranes for CO2/CH4 separation: Experimental and modeling
    • Authors: Keivan Mohammad Gheimasi; Omid Bakhtiari; Mojtaba Ahmadi
      Pages: 222 - 234
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Keivan Mohammad Gheimasi, Omid Bakhtiari, Mojtaba Ahmadi
      In the current study, multiwall carbon nanotubes (MWCNTs) were functionalized with Tetraethylene Pentamine (TEPA) and added into polyurethane (PU) polymer matrix to prepare PU-MWCNT-TEPA nanocomposite membranes. The prepared membranes were characterized using FT-IR, XRD and SEM analysis. The analysis results showed that MWCNTs were properly functionalized with TEPA and also uniformly dispersed in polymer matrix. The CO2 permeability increased by 99.8% at 10wt.% loading of MWCNTs-TEPA. The nanocomposite membrane’s CO2/CH4 selectivity was also increased by 9.6%. Impacts of operating pressure and temperature on the membranes’ CO2 permeability and CO2/CH4 ideal selectivity were also investigated. Finally, the gaseous penetrants permeabilities through the nanocomposite membranes were predicted using the Maxwell, the KJN, and the modified KJN models by AAREs of 31.4–35.2, 27.8–31.6, and 4.4–5.7%, respectively.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.028
      Issue No: Vol. 133 (2018)
       
  • Impregnation of multiwall carbon nanotubes in alginate beads dramatically
           enhances their adsorptive ability to aqueous methylene blue
    • Authors: Bing Wang; Bin Gao; Andrew R. Zimmerman; Xinqing Lee
      Pages: 235 - 242
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Bing Wang, Bin Gao, Andrew R. Zimmerman, Xinqing Lee
      In this work, novel environmentally benign nanocomposites, carboxyl functionalized multiwall carbon nanotubes (MWCNT-COOH) impregnated into calcium-alginate (CA) beads (CA-MWCNT-COOH), were tested for their abilities to remove a common dye contaminant, methylene blue (MB), from aqueous solution. Kinetic studies showed that the adsorption process of CA-MWCNT-COOH had similar speed to that of CA beads but was slower than that of undispersed MWCNT-COOH. With a Langmuir maximum MB adsorption capacity of 1189mgg−1, the CA-MWCNT-COOH performed best, outperforming both CA beads alone (1144.7mgg−1) and the undispersed MWCNT-COOH (33.4mgg−1). Furthermore, the impregnation also dramatically enhanced the adsorption of MB onto other types of MWCNTs, indicating CA beads are an excellent supporting material to disperse and stabilize carbon nanotubes for their optimal application as a high-capacity adsorbent.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.026
      Issue No: Vol. 133 (2018)
       
  • A comprehensive study on equilibrium and kinetics of morpholine extraction
           from aqueous stream with CA in toluene: Experimental evaluation,
           extraction model and parametric optimization employing desirability
           function
    • Authors: Alka Kumari; B. Karuna; B. Satyavathi
      Pages: 243 - 254
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Alka Kumari, B. Karuna, B. Satyavathi
      The present study explores the equilibrium and kinetics for the reactive extraction of morpholine, an important industrial reagent from its aqueous stream using capric acid, CA (extractant) in toluene (diluent). An equilibrium model that employs the mass action law was also developed to evaluate the optimum apparent equilibrium constants (K E ), stoichiometric ratio (m) and physical constant (S). Equilibrium model was valid in representing the mechanism of morpholine extraction. Moreover, for the first time the study availed the simultaneous optimization of two significant response characteristics; extraction efficiency ( % E ) and loading ratio ( Z ) using Box–Behnken design (33) employing multivariate desirability function. The statistical models predicted %E of 80.2 and Z of 0.64 for the optimum combination of process parameters as follows: CMO =5%, CCAO =5% and T=303.15K with the desirability of 0.947. Further, the intrinsic kinetics of the extraction model demonstrated that the reactions between morpholine and CA fall in regime 3 (fast chemical reaction in diffusion film), follows first order kinetics with respect to morpholine and displays exothermicity of the process as revealed from thermodynamic studies. The equilibrium and kinetic data is useful for the development, design and reliable scale-up of the extraction process.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.027
      Issue No: Vol. 133 (2018)
       
  • Laminar convection heat transfer and flow performance of Al2O3–water
           nanofluids in a multichannel-flat aluminum tube
    • Authors: Wenwen Guo; Guoneng Li; Youqu Zheng; Cong Dong
      Pages: 255 - 263
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Wenwen Guo, Guoneng Li, Youqu Zheng, Cong Dong
      The heat transfer experiments of Al2O3–water nanofluids were carried out at fixed Reynold number and velocity in a multichannel-flat aluminum tube. The studies we have performed revealed that the convection heat transfer coefficient increased about 5.9% at 0.5vol.% Al2O3 concentration at Re=1732. While at a constant velocity, higher addition of nanoparticles had no evident influence on the heat transfer performance. Compared with theoretical correlations, the data obtained were accorded with Shah equation (deviation <10%) except for those in the entrance. Then a comparative study of Al2O3–water nanofluids and the base fluid was made on the local heat transfer coefficient. The results indicated a higher heat transfer augmentation (11.1%) in the entrance region for 0.5vol.% Al2O3-DW nanofluid, which seems to have a bearing on the thermal conductivity enhancement and the thermal boundary layer thickness reduction. The friction factor and the pressure drop were also studied and the results revealed that the pressure drop slightly increased with the volume concentration of nanoparticles. For 0.5vol.% Al2O3-DW, the average pressure drop increased about 4.4%.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.009
      Issue No: Vol. 133 (2018)
       
  • Integrating crystallization with experimental model parameter
           determination and modeling into conceptual process design for the
           purification of complex feed mixtures
    • Authors: Martin Lucke; Iraj Koudous; Maximilian Sixt; Maximilian J. Huter; Jochen Strube
      Pages: 264 - 280
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Martin Lucke, Iraj Koudous, Maximilian Sixt, Maximilian J. Huter, Jochen Strube
      In this study, crystallization process simulation combined with experimental model parameter determination at lab-scale is investigated in order to allow the integration of crystallization unit operation into conceptual process design for the purification of complex mixtures and possibly assist in formulation. A one-dimensional population balance model is combined with experiments, which are selected and carried out as a typical example for an industrial fermentation broth (e.g. vanillin), focusing on determination of solubility and growth kinetics as well as kinetics of agglomeration and breakage. Model parameter determination and model validation show that the named effects are adequately described by the model. Hence, model-based process design of purification by crystallization and particle formation enabling integration into formulation considering relevant effects regarding a complex feed mixture becomes possible within a conceptual process design. Further applications are under consideration.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.029
      Issue No: Vol. 133 (2018)
       
  • Twin screw granulation: An evaluation of using micronized lactose as a
           solid binder
    • Authors: Qing Ai; Michael J. Hounslow; Agba D. Salman
      Pages: 281 - 293
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Qing Ai, Michael J. Hounslow, Agba D. Salman
      In twin screw wet granulation process, the binding excipients could be added in two ways: premixed with powder materials before granulation or dissolved in water as a solution. In this paper, the feasibility of using micronized lactose as a solid binder excipient in twin screw granulation process was examined. Different proportions of micronized lactose were mixed with lactose and microcrystalline cellulose (MCC) powder before granulation, respectively. As a comparison, hydroxypropyl cellulose (HPC) was prepared in solid and liquid phase (i.e. premixed with powder and dissolved as solution respectively). Granulation was carried out to investigate the binding potential by studying the effect of micronized lactose and HPC on the granules properties such as size, shape and surface structure. Due to its small size, micronized lactose was proven to be an ideal alternative as a solid binding excipient to provide strong bonds and produce granules with improved granule size distributions. Furthermore, the binding capacity of micronized lactose was also examined on the compact powder bed where the contact angle, nucleus hardness and surface structure were studied.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.021
      Issue No: Vol. 133 (2018)
       
  • Series versus parallel reboilers in distillation columns
    • Authors: William L. Luyben
      Pages: 294 - 302
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): William L. Luyben
      Multiple reboilers are used in distillation columns for several reasons such as implementing heat integration, intermediate reboilers, auxiliary reboilers and vapor recompression. If there is a single source of hot vapor to be used in multiple heat exchangers, the flowsheet can use either a series or a parallel arrangement, depending on the temperature levels of the heat sinks. The purpose of this paper is to point out that the series arrangement can present difficult control problems because of interaction between the units. In the parallel configuration, the heat transferred to each sink can be easily divorced from the others. In the series configuration, more complex methods must be used such as bypassing and flooding to adjust heat transfer in individual units. The controllability of the parallel configuration is demonstrated for a lower-partitioned divided-wall reactive distillation column with vapor recompression.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.025
      Issue No: Vol. 133 (2018)
       
  • Improved design and optimization for separating tetrahydrofuran–water
           azeotrope through extractive distillation with and without heat
           integration by varying pressure
    • Authors: Jinglian Gu; Xinqiang You; Changyuan Tao; Jun Li; Weifeng Shen; Jie Li
      Pages: 303 - 313
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Jinglian Gu, Xinqiang You, Changyuan Tao, Jun Li, Weifeng Shen, Jie Li
      From the view of thermodynamic insight, a new concept (ROE: FE,Pope/FE,Pref), the ratio of the entrainer flow rate (FE) needed for reaching given relative volatility at operating pressure (Pope) to reference pressure (Pref), is firstly proposed to quantitatively determine the search space of operating pressure of the extractive column in a homogeneous extractive distillation (ED) process for the separation of binary minimum azeotrope with heavy entrainer. This novel concept is illustrated by the extractive distillation of tetrahydrofuran–water minimum boiling point mixture with an entrainer dimethyl sulfoxide. Six process designs under different pressures are obtained by a two-step optimization procedure and compared from the economic view based on total annual cost (TAC). Furthermore, three double-effect heat integration (DEHI) processes, are employed under atmospheric and a reduced pressure for the first time to further improve the energy efficiency and investigate the effect of pressures on the studied ED process. The final results of case study demonstrate the optimal heat integration approach with a suitable low pressure is the most economic one among the three DEHI processes. The TAC of the best proposed design exhibits a 20.3% reduction than that at atmosphere pressure. The proposed pressure selection rule and optimization process are helpful for reducing the TAC of the ED process.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.015
      Issue No: Vol. 133 (2018)
       
  • The Maxwell–Stefan description of mixture permeation across
           nanoporous graphene membranes
    • Authors: Rajamani Krishna
      Pages: 316 - 325
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Rajamani Krishna
      There is increasing research interest on the use of two-dimensional (2D) nanoporous materials, such as graphenes and graphene oxides, in a variety of membrane separation applications. The membrane permeation selectivitites are governed by a variety of factors that include surface diffusion as an important constituent. The primary objective of this article is to present a Maxwell–Stefan (M–S) formulation for surface diffusion of binary (1, 2) mixtures on 2D nanoporous graphene surfaces. In the developed formulation, adsorbate–adsorbate interactions, either attractive or repulsive, are described by the quasi-chemical (QC) mean field approximation of Guggenheim. Such interactions have a direct influence on the occupancy dependencies of the M–S diffusivities, Ð 1 and Ð 2, that quantify molecule-surface “friction”. An essential feature of the M–S formulation is the inclusion of exchange coefficients, Ð 12, that quantify correlation, or slowing-down effects for surface diffusion; the tardier-more-strongly-adsorbed species usually “slows down” the more-mobile-less-strongly-adsorbed species. Kinetic Monte Carlo (KMC) simulations on 2D square lattice of adsorption sites are used to quantify the the loading dependence of the M–S diffusivities, and also correlation effects. The usefulness of the developed model, combining QC and M–S approaches, is illustrated for CO2/CH4, CO2/H2, CO2/N2, and CH4/H2, mixture separations. For all four mixtures, the neglect of correlation effects leads to a severe underestimation of the membrane permeation selectivities that favor the more strongly adsorbed species.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.033
      Issue No: Vol. 133 (2018)
       
  • Experimental study on the solid suspension characteristics of coaxial
           mixers
    • Authors: Baoqing Liu; Zilong Xu; Fangyi Fan; Bolin Huang
      Pages: 335 - 346
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Baoqing Liu, Zilong Xu, Fangyi Fan, Bolin Huang
      Coaxial mixers as novel mixers have the characteristics of high flexibility and wide adjustability. Three kinds of coaxial mixers consisting of an outer anchor and different inner impellers (six 45° pitched-blade turbine, propeller and Rushton turbine) and single-impeller mixers were investigated and compared in viscous systems. Effects of rotation and pumping modes, outer impeller speed, inner impeller diameter, liquid viscosity, solid volume fraction and particle diameter on the just-suspension impeller speed and power consumption were also studied. Results showed that the coaxial mixers were more energy efficient than the single-impeller mixers, and had greater advantage in systems of higher viscosity and solid volume fraction. Different from single-impeller mixers, adopting up-pumping mode was more energy efficient for coaxial mixers when the anchor speed was relatively high. In addition, the coaxial mixers with the inner up-pumping propeller and six 45° pitched-blade turbine had obvious superiority compared with the combination of anchor and Rushton turbine in terms of power consumption. Based on the experimental data, a new correlation for predicting just-suspension impeller speed of coaxial mixers was proposed.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.035
      Issue No: Vol. 133 (2018)
       
  • Gas–solid fluidization of cohesive powders
    • Authors: Federica Raganati; Riccardo Chirone; Paola Ammendola
      Pages: 347 - 387
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Federica Raganati, Riccardo Chirone, Paola Ammendola
      Fine and ultrafine powders (down to nanoparticles) have recently received growing interest in both industrial and academic sectors due to their very distinctive features, mainly coming from their very small primary particle size and very large surface-to-volume ratio. Indeed, due to these characteristics, they can provide better contact efficiency and higher reaction rates per unit volume of reactor than traditional materials in the case of gas/solid and solid/solid reactions. They have been used to produce a large variety of materials, such as catalysts, sorbents, cosmetics, etc. Therefore, the interest in using this type of granular materials in a variety of industrial processes raises many questions about how they can be handled. Therefore, the interest in using this type of granular materials in a variety of industrial processes raises many questions on how they can be handled and processed (e.g. mixing, transporting and modifying the surface properties) in large-scale applications. With reference to this point, among all the available techniques for continuously handling and dispersing granular solids, gas fluidization is one of the most efficient, mainly due to the large gas–solid contact area. The aim of this work is to provide a critical review of experimental/theoretical research and latest progress in the science and technology of gas fluidization of fine/ultrafine particles, thus deeply covering the current international state-of-the-art. In particular, the challenges linked to the extensive use of these powders have been discussed, highlighting and explaining the fundamental aspects needed to comprehend the complexity of the process and provide possible answers/solutions.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.034
      Issue No: Vol. 133 (2018)
       
  • Synthesis, characterization, and application of
           trihexyl(tetradecyl)phosphonium chloride as promising solvent for
           extractive desulfurization of liquid fuel
    • Authors: Swapnil Dharaskar; Mika Sillanpaa
      Pages: 388 - 397
      Abstract: Publication date: May 2018
      Source:Chemical Engineering Research and Design, Volume 133
      Author(s): Swapnil Dharaskar, Mika Sillanpaa
      Nowadays there are serious regulations to eliminate sulfur from fuels because the SOx created through the combustion of fuel containing sulfur compounds which causes air pollution and have hazardous environmental influence. In present paper experimental data on extractive desulfurization (EDS) of dibenzothiophene (DBT), thiophene, benzothiophene, and other sulfur derivatives from liquid fuel using trihexyl(tetradecyl)phosphonium chloride [THTDP]Cl has been presented. The FTIR, NMR and TG/DSC spectra have been discussed for the molecular confirmation and thermal stability of [THTDP]Cl. Further, conductivity, solubility, and viscosity analysis were carried out. The effects of reaction time, temperature, sulfur compounds, ultra-sonication, recycling and regeneration on DBT removal from fuel were also investigated. In EDS, the DBT removal in n-dodecane was 81.5% for mass ratio of 1:1 in 30min at 30°C under the mild reaction conditions. Also, real fuels desulfurization and multistage extraction was examined. The results of the present work positively offer valuable information on synthesis, and application of phosphonium ionic liquids as promising solvents for EDS.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.016
      Issue No: Vol. 133 (2018)
       
  • Fast and green separation of malachite green in water samples by
           micro-dispersion scanometry method without heating, cooling and organic
           solvents at room temperature
    • Authors: Shahram Nekouei; Farzin Nekouei; Mohammad Ali Ferdosi Zadeh
      Abstract: Publication date: Available online 11 April 2018
      Source:Chemical Engineering Research and Design
      Author(s): Shahram Nekouei, Farzin Nekouei, Mohammad Ali Ferdosi Zadeh
      In the present work, a novel, easy, rapid, green, and, economical technique, micro-dispersion scanometry (MDS) is presented for the first time and employed using suspended Ni(OH)2 nanopowder in the micellar medium for the determination of slight amounts of malachite green chloride. In the meanwhile, we introduced a new simple method for the synthesis of Ni(OH)2 nanopowder followed by characterization via various methods such as scanning electron microscopy (SEM), X-Ray diffraction (XRD) and, Brunauer, Emmett and Teller (BET). The process of scanning (detecting) was done on the cells including the sample solution via a usual flatbed-scanner. Then, for analyzing the color of the cells, a software system designed in Visual Basic (VB 6), to R (red), G (green), and B (blue) values was applied. To build the cells, some holes were created in the plexiglas sheet. The impact of experimental variables namely pH, weight of sorbent, volume of 4% Triton X-114, eluting solution, and sample volume have been investigated and optimized in multivariate method using design Expert 7.0 software for statistical data analysis. A contrast done between the proposed and traditional UV–vis spectrophotometry methods revealed the comparable tendency in both methods Calibration curves were linear in the range of 0.37–110 and 0.45–110μgL−1 for scanometry and UV–vis methods, respectively. The detection limits were 0.060 and 0.068μgL−1 for scanometry and UV–vis methods, respectively. The capacity of Ni(OH)2 nanopowder for malachite green was 80mgg−1.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.04.008
       
  • Demulsifier Assisted Film Thinning and Coalescence in Crude Oil Emulsions
           Under DC Electric Fields
    • Authors: Sameer Mhatre; Sébastien Simon; Johan Sjöblom; Zhenghe Xu
      Abstract: Publication date: Available online 10 April 2018
      Source:Chemical Engineering Research and Design
      Author(s): Sameer Mhatre, Sébastien Simon, Johan Sjöblom, Zhenghe Xu
      Electrocoalescence has been considered a most efficient method of crude oil dewatering; however, just electric fields are not enough when dealing with heavy crude oils. In this work we studied effect of asphaltene flocculation and effectiveness of variety of chemical demulsifiers in electrocoalescence of water-in-crude oil emulsions. A parallel plate electrode cell was used to apply linearly rising uniform DC electric field to a thin layer of emulsion and the current running through the emulsion was monitored as an indicator of progress in the coalescence. In the first part of the study, model crude oils were used to investigate the roles of flocculated asphaltenes and flocculation inhibitor in electrocoalescence process. It was observed that the asphaltene flocculation adversely affects the rate of electrocoalescence. Second part compares effectiveness of different chemical demulsifiers in breaking water-in-crude oil emulsions under electric field. The experimental observations suggest that there exist a threshold demulsifier concentration limit and further increasing the concentration does not improve electrocoalescence rate. Also the addition of a demulsifier before dispersion of water results into faster separation as compared to the electrocoalescence in emulsion where the demulsifier was added later. Further, we devised a model for qualitative prediction of film drainage between two demulsifier-laden water-crude oil interfaces under a constant DC electric field. The film thinning rates predicted by the model are consistent with the experimentally measured critical electric field values.

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.04.001
       
  • Dynamic parameter estimation and identifiability analysis for
           heterogeneously-catalyzed reactions: Catalytic synthesis of nopol
    • Authors: Daniel Casas-Orozco; Aída Luz Villa; Omar J. Guerra; Gintaras V. Reklaitis
      Abstract: Publication date: Available online 10 April 2018
      Source:Chemical Engineering Research and Design
      Author(s): Daniel Casas-Orozco, Aída Luz Villa, Omar J. Guerra, Gintaras V. Reklaitis
      In this work, a methodology for the parameter estimation of heterogeneously-catalyzed reactions is presented. A simulation-optimization framework based on a dynamic model was coupled with an identifiability analysis, in order to detect for which parameters the dynamic model is most sensitive. The implemented identifiability analysis was based on rank-revealing matrix factorizations, with singular values as criteria for parameter selection. As the dynamic equation systems describing catalytic reactions are expected to be ill-posed, a subset selection step based on identifiability analysis was included. In order to illustrate the methodology, the ODE system describing the heterogeneously-catalyzed reaction system for the production of nopol from β-pinene and formaldehyde was used as a case study. After applying the methodology, two out of five kinetic parameters were found to be identifiable, consistent with a Langmuir Hinshelwood Hougen Watson (LHHW) mechanism that considers adsorption on catalytic sites of different nature. Confidence intervals of the estimated parameters belonging to the identifiable subset were not higher than 3 % of the parameter value. The results of this work show that the proposed mechanism is capable of reproducing the dynamics of the reaction system, and are an important input for the design of a three-phase reactor for nopol production.
      Graphical abstract image Highlights

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.04.002
       
  • Synergism between Ionic Liquid and Ultrasound for Greener Extraction of
           Geraniol: Optimization using Different Statistical Tools, Comparison and
           Prediction
    • Authors: Miral R. Thakker; Jigisha K. Parikh; Meghal A. Desai
      Abstract: Publication date: Available online 10 April 2018
      Source:Chemical Engineering Research and Design
      Author(s): Miral R. Thakker, Jigisha K. Parikh, Meghal A. Desai
      A new-fangled concept of combining synthesized ionic liquid with ultrasound was executed for the isolation of geraniol, a generally recognized as safe (GRAS) terpene. Shortening the extraction time and lowering the solvent requirement along with maintaining the quality of the product were the frugal aspects of this technique. Solubilization study was performed using four different water soluble synthesized ionic liquids. N, N, N, N', N', N' − hexaethyl − propane − 1, 3 − diammonium dibromide was found to be the most suitable solvent amongst the selected ionic liquids. Optimization of process parameters viz., ultrasound power, volume of ionic liquid solution, concentration of ionic liquid and extraction time was carried out with the help of the Taguchi method as well as Box-Behnken response surface design. Box-Behnken response surface design was found to be the superlative optimization technique with 1.73% (w/w) yield of geraniol under optimized conditions (250W ultrasound power, 40mL aqueous solution having 10% ionic liquid and 18min of extraction time). Conventional extraction involving organic solvents was also investigated and compared with the proposed extraction technique. Predictive modelling of the experimental data was also performed using the artificial neural network. The extraction mechanism was explicated by microscopic study to recognize the effect of ionic liquid and ultrasound. The current technique was turned out to be the sustainable extraction technique when compared in terms of yield, solvent consumption and extraction time. Energy efficiency and reduced environmental burden were the rewarding outcome of the study. The proposed technology incorporating ionic liquid and sonication in a single system can be studied in detail for industrial perspective.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.04.003
       
  • CFD analyses of liquid flow characteristics in a rotor-stator reactor
    • Authors: Yi Ouyang; Siwen Wang; Yang Xiang; Zemeng Zhao; Jiexin Wang; Lei Shao
      Abstract: Publication date: Available online 10 April 2018
      Source:Chemical Engineering Research and Design
      Author(s): Yi Ouyang, Siwen Wang, Yang Xiang, Zemeng Zhao, Jiexin Wang, Lei Shao
      Rotor-stator reactor (RSR) is a novel device for the intensification of multiphase processes and can greatly boost mass transfer and mixing efficiency. However, due to the unique structure, the flow characteristics in the RSR is unknown and difficult to acquire by experiments. Therefore, this work employed computational fluid dynamics (CFD) technique to reveal liquid flow behaviors in an RSR for the first time. The volume of fluid (VOF) multiphase model, sliding model (SM) and standard k-ε model were used to simulate liquid flow field in a typical two-dimensional computational framework of the RSR. It was found that the droplet size and velocity in the cavity zone of the RSR were in agreement with the published data of the visual experiments. The results show that the liquid was quickly split and synchronized with the motion of the rotor layers when injected into the RSR. Two droplet formation schemes were observed in the RSR: “ligament to droplets disintegration” and “droplets disintegration”. The droplets size distribution could be well described by Rosin-Rammler model. The droplets diameter decreased but the droplet velocity increased with increasing rotational speed, while the droplets diameter increased and the droplet velocity changed little with increasing liquid inlet velocity. With the increase of the number of rotor/stator layers, droplet size decreased and velocity increased. The agreement of the experiment and simulation results indicate that the CFD technique is an effective tool to analyze the hydrodynamic characteristics of RSR.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.04.006
       
  • Modelling the Selective Removal of Sodium Ions from Greenhouse Irrigation
           Water Using Membrane Technology
    • Authors: Z. Qian; H. Miedema; L.C.P.M. de Smet; E.J.R. Sudhȍlter
      Abstract: Publication date: Available online 9 April 2018
      Source:Chemical Engineering Research and Design
      Author(s): Z. Qian, H. Miedema, L.C.P.M. de Smet, E.J.R. Sudhȍlter
      A model is presented for the Na+ and K+ levels in the irrigation water of greenhouses, specifically those for the cultivation of tomato. The model, essentially based on mass balances, not only describes the accumulation of Na+ but includes a membrane unit for the selective removal of Na+ as well. As determined by the membrane properties, some of the K+ is removed as well. Based on real-life process parameters, the model calculates the Na+ and K+ concentration at three reference points. These process parameters include the evapotranspiration rate, the K+ uptake by the plants, the Na+ and K+ content of the fertilizer, the Na+ leaching out from the hydroponic substrate material, and the Na+ and K+ removal efficiency of the membrane unit. Using these parameters and given a constant K+ concentration of the irrigation water entering the greenhouse of 6.6mM (resulting in the optimal K+ concentration for tomato cultivation), the composition of the solution is completely defined at all three reference points per irrigation cycle. Prime aim of this investigation is to explore the requirements for the selective membrane that currently is developed in our lab. It is found that even for a limited Na+ over K+ selectivity of 6, after a number of cycles the Na+ level reaches steady state at a level below the upper (toxic) threshold for tomato cultivation (20mM). Economic aspects and ways of implementation of such a system are briefly discussed.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.03.040
       
  • Coupled model based on radiation transfer and reaction kinetics of
           gas-liquid-solid photocatalytic mini-fluidized bed
    • Authors: Xiaoyun Wang; Mingyan Liu; Zhongguo Yang
      Abstract: Publication date: Available online 8 April 2018
      Source:Chemical Engineering Research and Design
      Author(s): Xiaoyun Wang, Mingyan Liu, Zhongguo Yang
      Gas-liquid-solid mini-fluidized bed could be a potential high-efficient photocatalytic reactor in wastewater treatment. Such a photocatalytic reactor with bed diameter of 6mm was developed and photocatalytic degradation of methylene blue (MB) was investigated. Mass transfer coefficient of the three-phase mini-fluidized bed was 1.9 and 4.8 times greater than that of liquid-solid mini-fluidized bed and mini-bubble column, respectively. A coupled model based on radiation transfer and reaction kinetics was built. Polychromatic Xe lamp was discretized to obtain the absorbed photons during photocatalytic reaction. The non-uniform radiation field responsible for MB local volumetric degradation rate affected by the scattering and absorption of catalyst particles and micro-bubbles in mini-reactor was solved. Based on mechanism of photocatalytic degradation MB, the reaction kinetics obtained by steady-state hypothesis was coupled into the radiation transfer model. Dispersed mini-bubble flow was obtained by proper operation conditions corresponding to higher apparent quantum efficiency of 0.19% − 0.44% also discussed.
      Graphical abstract image

      PubDate: 2018-04-16T05:12:41Z
      DOI: 10.1016/j.cherd.2018.04.004
       
 
 
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