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  Subjects -> CHEMISTRY (Total: 846 journals)
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CHEMISTRY (597 journals)                  1 2 3 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 7)
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: 31)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 17)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 23)
ACS Macro Letters     Full-text available via subscription   (Followers: 22)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 39)
ACS Nano     Full-text available via subscription   (Followers: 218)
ACS Photonics     Full-text available via subscription   (Followers: 10)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 20)
Acta Chemica Iasi     Open Access   (Followers: 2)
Acta Chimica Sinica     Full-text available via subscription  
Acta Chimica Slovaca     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 7)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 5)
Advanced Functional Materials     Hybrid Journal   (Followers: 48)
Advanced Science Focus     Free   (Followers: 3)
Advances in Chemical Engineering and Science     Open Access   (Followers: 53)
Advances in Chemical Science     Open Access   (Followers: 12)
Advances in Chemistry     Open Access   (Followers: 12)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Enzyme Research     Open Access   (Followers: 10)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 14)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 18)
Advances in Nanoparticles     Open Access   (Followers: 12)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15)
Advances in Polymer Science     Hybrid Journal   (Followers: 40)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 18)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Science and Technology     Full-text available via subscription   (Followers: 10)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 2)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 65)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 14)
American Journal of Chemistry     Open Access   (Followers: 25)
American Journal of Plant Physiology     Open Access   (Followers: 13)
American Mineralogist     Full-text available via subscription   (Followers: 12)
Analyst     Full-text available via subscription   (Followers: 38)
Angewandte Chemie     Hybrid Journal   (Followers: 153)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 204)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 1)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 3)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 7)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 14)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Hybrid Journal  
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 6)
Applied Spectroscopy     Full-text available via subscription   (Followers: 22)
Applied Surface Science     Hybrid Journal   (Followers: 26)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 2)
Asian Journal of Biochemistry     Open Access   (Followers: 1)
Atomization and Sprays     Full-text available via subscription   (Followers: 3)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access   (Followers: 1)
Biochemical Pharmacology     Hybrid Journal   (Followers: 9)
Biochemistry     Full-text available via subscription   (Followers: 278)
Biochemistry Insights     Open Access   (Followers: 5)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 9)
Bioinspired Materials     Open Access   (Followers: 3)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access  
Biomacromolecules     Full-text available via subscription   (Followers: 18)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 4)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 109)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 99)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 2)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 24)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 2)
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Full-text available via subscription   (Followers: 10)
Canadian Mineralogist     Full-text available via subscription   (Followers: 3)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 67)
Catalysis for Sustainable Energy     Open Access   (Followers: 6)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 6)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 7)
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 12)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 69)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 23)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 19)
Chemical Reviews     Full-text available via subscription   (Followers: 165)
Chemical Science     Open Access   (Followers: 21)
Chemical Technology     Open Access   (Followers: 15)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 4)
Chemical Week     Full-text available via subscription   (Followers: 7)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 55)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 25)
ChemInform     Hybrid Journal   (Followers: 7)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 6)
Chemistry & Biology     Full-text available via subscription   (Followers: 30)
Chemistry & Industry     Hybrid Journal   (Followers: 5)
Chemistry - A European Journal     Hybrid Journal   (Followers: 137)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 15)
Chemistry and Materials Research     Open Access   (Followers: 17)
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: 43)
Chemistry of Materials     Full-text available via subscription   (Followers: 189)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry-Didactics-Ecology-Metrology     Open Access  
ChemistryOpen     Open Access   (Followers: 2)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 2)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 8)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 10)
Chromatographia     Hybrid Journal   (Followers: 23)
Chromatography Research International     Open Access   (Followers: 7)
Clay Minerals     Full-text available via subscription   (Followers: 9)
Cogent Chemistry     Open Access  
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 10)
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 8)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 3)
Combustion Science and Technology     Hybrid Journal   (Followers: 18)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 2)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 9)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 2)
Copernican Letters     Open Access  
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 5)
Crystal Structure Theory and Applications     Open Access   (Followers: 3)
CrystEngComm     Full-text available via subscription   (Followers: 10)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 4)
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Research in Chemistry     Open Access   (Followers: 8)
Current Science     Open Access   (Followers: 48)
Dalton Transactions     Full-text available via subscription   (Followers: 18)
Detection     Open Access   (Followers: 2)
Developments in Geochemistry     Full-text available via subscription   (Followers: 2)
Diamond and Related Materials     Hybrid Journal   (Followers: 11)
Dislocations in Solids     Full-text available via subscription  
Doklady Chemistry     Hybrid Journal  
Drying Technology: An International Journal     Hybrid Journal   (Followers: 3)
Eclética Química     Open Access   (Followers: 1)
Ecological Chemistry and Engineering S     Open Access   (Followers: 4)
Ecotoxicology and Environmental Contamination     Open Access  
Educación Química     Open Access   (Followers: 1)
Education for Chemical Engineers     Hybrid Journal   (Followers: 5)
EJNMMI Radiopharmacy and Chemistry     Open Access  
Elements     Full-text available via subscription   (Followers: 2)
Environmental Chemistry     Hybrid Journal   (Followers: 8)
Environmental Chemistry Letters     Hybrid Journal   (Followers: 4)
Environmental Science & Technology Letters     Full-text available via subscription   (Followers: 5)
Environmental Science : Nano     Partially Free   (Followers: 1)
Environmental Toxicology & Chemistry     Hybrid Journal   (Followers: 19)

        1 2 3 | Last

Journal Cover Chemical Engineering Research and Design
  [SJR: 0.873]   [H-I: 65]   [23 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0263-8762 - ISSN (Online) 0263-8762
   Published by Elsevier Homepage  [3031 journals]
  • Effect of multi-walled carbon nanotubes on linear viscoelastic behavior
           and microstructure of zwitterionic wormlike micelle at high temperature
    • Authors: Wenlong Qin; Lei Yue; Guoqi Liang; Guanfeng Jiang; Jiang Yang; Yang Liu
      Pages: 14 - 22
      Abstract: Publication date: July 2017
      Source:Chemical Engineering Research and Design, Volume 123
      Author(s): Wenlong Qin, Lei Yue, Guoqi Liang, Guanfeng Jiang, Jiang Yang, Yang Liu
      The effects of hydroxyl functionalized multi-walled carbon nanotubes (MWCNTs) on linear viscoelastic behavior and microstructure of zwitterionic surfactant oleylamido propyl betaine (BET) micellar solutions were investigated by Cryo-Transmission Electron Microscopy (Cryo-TEM), Fourier Transmission Infrared Spectroscopy (FT-IR) and rheological measurements. In this study, the addition of MWCNTs has obvious effects on the rheological behavior of the mixed system: an increase in the zero-shear viscosity of the system, and appearance of shear thinning non-Newtonian behavior instead of Newtonian behavior at dilute micellar solution. The addition of MWCNTs also obviously increases the semidilute micellar solution's relaxation time, reptation time and storage modulus. Moreover, the temperature resistance of the system with MWCNTs is greatly improved compared with that without MWCNTs. The results of Cryo-TEM and FT-IR measurement demonstrate that the MWCNTs can associate with wormlike micelle to form a strong and complex network structure by micellar end-cap adsorption and hydrogen bonding interaction. The synergistic interaction enhances the viscosity and elasticity of the zwitterionic surfactant fluids at high temperature.
      Graphical abstract image

      PubDate: 2017-05-17T19:12:10Z
      DOI: 10.1016/j.cherd.2017.04.027
      Issue No: Vol. 123 (2017)
  • Prediction of the instantaneous fouling resistance of sodium alginate
           during water rinsing
    • Authors: Yadong Kong; Zhan Wang; Yu Ma; Hao Wang; Bushra Khan
      Pages: 121 - 131
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Yadong Kong, Zhan Wang, Yu Ma, Hao Wang, Bushra Khan
      Based on swelling and dissolution mechanism, a model describing first-order parallel-reversible process was developed to predict the fouling resistance of 0.1μm polyacrylonitrile (PAN) membrane fouled with sodium alginate (SA) during water rinsing. The results showed that there were good agreements between model predictions and experimental values (R2 >0.9). Especially in the situation when the impact of water rinsing condition on model parameter was considered. Moreover, the applicability of the proposed model was validated by a series of rinsing experiments with 0.1μm polyvinylidene fluoride (PVDF) membrane or active sludge suspension. In addition, feed concentration had a great role in the fouling process while temperature impact on the cleaning process was also very appreciable. And the reversibility of SA fouling was well explained by the electrostatic and hydrophilic repulsions between PAN membrane and SA.

      PubDate: 2017-05-02T14:54:20Z
      DOI: 10.1016/j.cherd.2017.03.039
      Issue No: Vol. 122 (2017)
  • Steady state equivalence in speciation: Reaction networks in
           acid–base aqueous solutions
    • Authors: J. Martín Méndez-González; Ismael P. Páez; R. Femat
      Pages: 132 - 140
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): J. Martín Méndez-González, Ismael P. Páez, R. Femat
      Acidity levels affect water chemistry and the Chemical Reaction Networks (CRN) encountered within it. In other words, pH is an external factor that influences speciation, precluding or promoting the appearance of certain chemical species as shown by distribution diagrams. Therefore, there is not a unique CRN for the entire pH spectrum. Moreover, it might be the case that an operative CRN for a given pH interval also supports the steady states values engendered by a second CRN which is operative for a distinct pH interval. In this sense, the first CRN is steady state equivalent with respect to the second CRN. Due to their importance for pH regulation in water chemistry and similarity in their speciation diagrams, we consider the well-known phosphoric acid-calcium carbonate system as a case study to show how steady state equivalence allows us to find relationships between reactions in speciation.
      Graphical abstract image Highlights

      PubDate: 2017-05-02T14:54:20Z
      DOI: 10.1016/j.cherd.2017.04.014
      Issue No: Vol. 122 (2017)
  • A dynamic time delay analysis approach for correlated process variables
    • Authors: Bo Yang; Hongguang Li; Bo Wen
      Pages: 141 - 150
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Bo Yang, Hongguang Li, Bo Wen
      Generally, dynamic characteristics of time delays between process correlated variables are major concerns in the process control community. However, traditional delay time analysis methods have limited ability to deal with dynamics of time delays. In response to this problem, this paper proposes a dynamic time delay analysis (DTA) based on the technology of time series data mining, aiming at effectively estimating transfer time delays between process correlated variables. Employing dynamic sliding windows, dynamic time delays can be estimated offline by calculating similarities between correlated variables. Subsequently, through an additional correlation analysis between the time delay and process variables, main variables influencing the time delay can be obtained. By providing relevant trend variables, an improved fuzzy interpolation prediction method is suggested to estimate the transfer time delay between process correlated variables online. In addition, a DTA dynamic directed time graph is created by combining dynamic transfer time delays of mutually dependent variables. Finally, performances of the DTA method are tested through a numerical study and a distillation column simulation.

      PubDate: 2017-05-02T14:54:20Z
      DOI: 10.1016/j.cherd.2017.04.010
      Issue No: Vol. 122 (2017)
  • Effective removal of methylene blue from aqueous solutions using magnetic
           loaded activated carbon as novel adsorbent
    • Authors: Esra Altıntıg; Hüseyin Altundag; Mustafa Tuzen; Ahmet Sarı
      Pages: 151 - 163
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Esra Altıntıg, Hüseyin Altundag, Mustafa Tuzen, Ahmet Sarı
      In this study, magnetic characteristic was added to activated carbon (AC) obtained by ZnCl2 activation of acorn shell. The produced magnetic AC (Fe-AC) was used effectively for the removal of methylene blue (MB) from aqueous solution. The effects of different batch parameters such as adsorbent dosage (0.05–0.2g/100mL), initial pH (3–9), temperature (298–318K), initial dyestuff concentration (50–250mg/L) and contact time (5–60min) on the adsorption process were examined. The structural and chemical characterization of the synthesized AC and Fe-AC adsorbents were carried out by using various analytical techniques such as XRD, SEM/EDS, FT-IR and BET analysis techniques. The MB concentration in the solution was determined by UV–VIS spectrophotometer. From the Langmuir isotherm model, the maximum adsorption capacity was found as 330.0 and 357.1mg/g for AC and Fe-AC adsorbents at 298K, respectively. The investigations on the effect of the temperature and calculated thermodynamic parameters exposed the endothermic nature of the adsorption process under the studied temperature range. The adsorption/desorption cycling test indicated that the prepared Fe-AC adsorbent had good reusability performance especially up to fourth cycle. Additionally, by considering all results it was concluded that the produced AC and Fe-AC adsorbents as novel adsorbents offer a great promise for the cleaning of MB dyestuff from aqueous solutions because of the advantage of their producibility from a cheap source, high adsorption capacity and fast uptake feasibility.
      Graphical abstract image

      PubDate: 2017-05-02T14:54:20Z
      DOI: 10.1016/j.cherd.2017.03.035
      Issue No: Vol. 122 (2017)
  • Genetic programming (GP) approach for prediction of supercritical CO2
           thermal conductivity
    • Authors: Alireza Rostami; Milad Arabloo; Hojatollah Ebadi
      Pages: 164 - 175
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Alireza Rostami, Milad Arabloo, Hojatollah Ebadi
      Gas thermal conductivity is one of the thermophysical properties that inevitably enters into mathematical models of real systems used in the design of chemical engineering processes or in the gas industry. In this study, via implementing a powerful and newly applied equation generator algorithm known as, genetic programming (GP) mathematical strategy, a novel correlation for estimation of supercritical CO2 thermal conductivity is established. The proposed correlation is developed and validated based on a comprehensive databank of 752 thermal conductivity datasets from open literature. By using various statistical quality measures, the result of the proposed GP model was compared with commonly used literature models. As a result, the proposed GP model gives the best fit and satisfactory agreement with the target data with an average absolute relative error of 2.31% and R2 =0.997. A parametric sensitivity analysis showed that pressure and density of the CO2 gas stream have considerable impact on the thermal conductivity at supercritical condition. The results of this study can be of enormous practical worth for scientist and expertise in order to efficiently compute the thermal conductivity in any supercritical industry involving CO2.

      PubDate: 2017-05-02T14:54:20Z
      DOI: 10.1016/j.cherd.2017.02.028
      Issue No: Vol. 122 (2017)
  • Design of liquid–liquid separation hydrocyclones using parabolic and
           hyperbolic swirl chambers for efficiency enhancement
    • Authors: Abdul Motin; André Bénard
      Pages: 184 - 197
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Abdul Motin, André Bénard
      The wall profile of the swirl chamber greatly impacts the internal flow structures and separation efficiency of a liquid–liquid separation hydrocyclone. The objective of this study is to examine the effects of parabolic and hyperbolic wall profiles of hydrocyclone swirl chamber on the internal flow structures and separation efficiency based on the numerical simulations. The internal flow structures observed for the different wall profiles of swirl chamber motivates the redesign of hydrocyclone geometry to achieve enhanced separation efficiency. Results show that, for a dilute system (oil concentration less than 1%), the hyperbolic and parabolic swirl chambers without a tail pipe yield, respectively, 16.5% and 25% higher separation efficiency for a droplet size of 30μm when compared with a conical swirl chamber without tail pipe. However, the hyperbolic swirl chamber has a greater potential for the reduction of effective length of hydrocyclone with maintaining high separation efficiency. In addition, a hydrocyclone with truncated hyperbolic swirl chamber and tail pipe provides very long reverse flow core and yields 17% and 33% higher efficiency than that of full hyperbolic and conical swirl chambers without tail pipe, respectively.
      Graphical abstract image

      PubDate: 2017-05-02T14:54:20Z
      DOI: 10.1016/j.cherd.2017.04.012
      Issue No: Vol. 122 (2017)
  • A continuum model of stresses in a vertical silo with a flow channel in
           the vicinity of the wall, using the principal stress cap surface approach
           for the bulk solids
    • Authors: A.J. Matchett; P.A. Langston; D. McGlinchey
      Pages: 211 - 225
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): A.J. Matchett, P.A. Langston, D. McGlinchey
      Eurocode 1 (2006) gives design equations for eccentric stresses in silos, including flow channels adjacent to the wall. This has been modelled using the approach of Matchett et al. (2015, 2016). A three zone model was developed, consisting of: • The flow channel. • The transition zone. • The bulk of the solids. The flow channel and the transition zone were modelled by Janssen-type equations. The bulk was modelled by the principal stress cap approach. The transition zone is a complex region and has several purposes: 1. To shelter the low stress flow channel from the high stresses around. 2. To allow high principal stresses at the transition/bulk interface, within the yield locus. 3. To form a transition between the dynamic flow channel and the static bulk. 4. To allow transition from passive stress in the flow channel to active stress in the bulk. The model was calibrated against the data of Chen et al. (2007) for a full-scale silo, and described the data reasonably well, scaling axially and azimuthally. Large experimental data sets are required to calibrate a model. Unfortunate data points cannot be arbitrarily rejected. Further extensive, experimental data are needed to calibrate models.
      Graphical abstract image

      PubDate: 2017-05-02T14:54:20Z
      DOI: 10.1016/j.cherd.2017.04.013
      Issue No: Vol. 122 (2017)
  • Real-time optimization of converter inlet temperature in acid production
           with flue gas
    • Authors: Mingxing Jia; Chunhua Chen; Wenqi Kou; Dapeng Niu; Fuli Wang
      Pages: 226 - 232
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Mingxing Jia, Chunhua Chen, Wenqi Kou, Dapeng Niu, Fuli Wang
      The conversion rate of SO2 is of great significance to the efficiency of sulfuric acid production with flue gas. However, the existing optimization methods for SO2 conversion rate can hardly achieve the optimal effect, because the parameters change and the working conditions fluctuate during the production process. Therefore, we propose a modifier-adaptation strategy with regulatory factors for real-time optimization of SO2 conversion process in this paper. We first establish the optimization model of converter inlet temperature. Then, considering that the plant-model mismatch during the process of sulfuric acid production with flue gas is mainly caused by the change of initial oxygen concentration, initial SO2 concentration, gas flow rate, catalyst activity and other factors, we study a modifier-adaptation strategy for real-time optimization with regulatory factors, designing and ameliorating the modifier term. We use the measurement values and gradient information in the real industrial process to revise the original optimization problem continuously, so that the solution will converge to the optimal set point of the real industrial process. The simulation results show that both the convergence rate of the proposed optimization strategy and the total conversion rate of SO2 have been improved.

      PubDate: 2017-05-02T14:54:20Z
      DOI: 10.1016/j.cherd.2017.04.002
      Issue No: Vol. 122 (2017)
  • Modeling the solidification of O/W-emulsion droplet in solvent evaporation
    • Authors: Ting Shao; Lin Bai; Binhang Yan; Yong Jin; Yi Cheng
      Pages: 233 - 242
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Ting Shao, Lin Bai, Binhang Yan, Yong Jin, Yi Cheng
      The removal of organic solvent plays an important role in the fabrication of polymer spheres by emulsion-based solvent evaporation technique. Mathematical model describing the mass transfer of fluorobenzene (FB) inside the O/W emulsion droplet, from the droplet to the continuous phase and from the continuous phase to the atmosphere to produce millimeter-sized polystyrene (PS) spheres was established. A novel approach based on finite volume method was developed to numerically solve the mathematical equations concerning the shrinkage of the solidifying droplet. Using this method, the variations of the droplet size and the concentration field inside the droplet were captured. The details of the solidification process which cannot be obtained using experimental methods were revealed. Several factors influencing the curing rate and mass transfer process, such as droplet number, initial droplet diameter, initial concentration and addition of FB in the continuous phase, were investigated in detail. The simulation results indicated that changing the initial concentration or changing the initial diameter of the droplet to tune the solidified particle size were essentially the same considering their effects on the details of the solidification process. When adding FB in the continuous phase to reduce the curing rate and concentration gradient, dispersing the added FB into droplets with the same diameter to that of the PS/FB droplet to be solidified has the most significant effect.

      PubDate: 2017-05-12T19:03:30Z
      DOI: 10.1016/j.cherd.2017.04.022
      Issue No: Vol. 122 (2017)
  • Experimental evaluation and semi-empirical modeling of a small-capacity
           reverse osmosis desalination unit
    • Authors: Vanessa Haluch; Everton F. Zanoelo; Christian J.L. Hermes
      Pages: 243 - 253
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Vanessa Haluch, Everton F. Zanoelo, Christian J.L. Hermes
      The present paper carries out a performance assessment of a small-capacity reverse osmosis system. Semi-empirical models to predict the exergy efficiency, the volumetric flow rate of permeate, and the salt rejection as functions of the feed water concentration, and the pump and the membrane characteristics were proposed. An experimental setup was designed and constructed to obtain the key process parameters required for the analysis and validation of the models. Experiments were conducted following a full factorial design in order to point out the most influencing factors affecting the performance indicators. Comparisons between experimental data and model predictions were also reported. It was found that the feed concentration of salt is the most important factor affecting the exergy efficiency, the volumetric flow rate of permeate, and the salt rejection. It was also observed that there exists an optimal feed concentration which maximizes the salt rejection. When compared to the experimental data, the semi-empirical models predictions agreed to their experimental counterparts within the measurement uncertainties thresholds.

      PubDate: 2017-05-12T19:03:30Z
      DOI: 10.1016/j.cherd.2017.04.006
      Issue No: Vol. 122 (2017)
  • Bubble size and flow characteristics of bubbly flow downstream of a
           ventilated cylinder
    • Authors: Can Kang; Wei Zhang; Yiping Gu; Ning Mao
      Pages: 263 - 272
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Can Kang, Wei Zhang, Yiping Gu, Ning Mao
      Bubbly flows downstream of a ventilated cylinder in a water tunnel are experimentally studied. Emphasis is placed upon the relationship between bubble property and carrier flow parameters. Under no-ventilation condition, the pure-water wake flow is measured with particle image velocimetry technique. Bubbles are generated with ventilation and the bubbly flow is visualized using shadow image velocimetry. The separation and statistical treatment of bubbles in the captured images are accomplished with an in-house code. The influence of upstream flow velocity and air flow rate is examined. Sauter mean diameter of the bubbles and bubble velocity distribution are obtained. Instantaneous bubbly flow pattern is in accordance with the carrier flow characteristics. Across the high-vorticity region, bubbles experience a remarkable bubble size variation, large bubbles are annihilated. As for cross-sectional bubble size distribution, the tendency obtained with image processing agrees with the result obtained with the formula associating turbulent kinetic energy dissipation with bubble size. As upstream velocity increases, the percentage of small bubbles increases. Both bubble volume fraction and the most predominant bubble size increase with air flow rate. The percentage of large bubbles varies slightly with air flow rate.

      PubDate: 2017-05-12T19:03:30Z
      DOI: 10.1016/j.cherd.2017.04.019
      Issue No: Vol. 122 (2017)
  • Estimation of kinetic parameters from adiabatic calorimetric data by a
           hybrid Particle Swarm Optimization method
    • Authors: Zi-Chao Guo; Li-Ping Chen; Wang-Hua Chen
      Pages: 273 - 279
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Zi-Chao Guo, Li-Ping Chen, Wang-Hua Chen
      Due to the intense non-linear behavior in the task of estimation of the kinetic parameters from the experimental adiabatic data, a hybrid Particle Swarm Optimization (PSO) is proposed to estimate the kinetic parameters. This method is applied to two real cases: decomposition of DTBP and a nitro-compound under adiabatic conditions. By comparing the experimental and calculated temperature rise rate curve, the accuracy of the fitted parameters is verified. These two cases reasonably prove the validation of this hybrid PSO algorithm in the estimation of kinetic model parameters of adiabatic data.
      Graphical abstract image

      PubDate: 2017-05-12T19:03:30Z
      DOI: 10.1016/j.cherd.2017.04.020
      Issue No: Vol. 122 (2017)
  • Detailed numerical solution of pore volume and surface diffusion model in
           adsorption systems
    • Authors: P.R. Souza; G.L. Dotto; N.P.G. Salau
      Pages: 298 - 307
      Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): P.R. Souza, G.L. Dotto, N.P.G. Salau
      In this work, the numerical solution of pore volume and surface diffusion model (PVSDM) was developed and presented in detail. The finite difference approximations method was employed to solve the partial differential equations of the diffusional model. The experimental adsorption of Malachite Green dye (MG) on bentonite clay was selected as case study. The equilibrium data were obtained from batch systems and, the Redlich–Peterson isotherm was suitable to represent the results. Due to non-linearity of the isotherm, the non-linear least squares technique was used to estimate the diffusional parameters. The Biot number has shown that the adsorption was simultaneously controlled by external mass transfer and intraparticle diffusion. Thus, both internal resistances (pore volume and surface) must be considered. The MG concentrations as a function of time decreases and the amount of MG mass adsorbed on bentonite clay as a function of the radial position increases until reaching equilibrium. The experimental concentration decay curve of MG was properly represented by PVDSM model. Further, the amount of MG mass adsorbed at higher radial positions was larger than at lower radial positions, within the PVSDM boundaries (particle boundaries), indicating that the method of finite difference approximations was appropriate for the numerical solution of PVSDM model.
      Graphical abstract image

      PubDate: 2017-05-17T19:12:10Z
      DOI: 10.1016/j.cherd.2017.04.021
      Issue No: Vol. 122 (2017)
  • Asymmetrical temperature control of a BTX dividing-wall distillation
    • Abstract: Publication date: July 2017
      Source:Chemical Engineering Research and Design, Volume 123
      Author(s): Yang Yuan, Kejin Huang, Haisheng Chen, Liang Zhang, Shaofeng Wang
      On account of the intensive interaction between the prefractionator and main distillation column involved, achieving tight product purity control with a small set of temperature measurements represents a considerably challenging issue in the derivation of temperature inferential control systems for dividing-wall distillation columns (DWDCs). Although double temperature difference control (DTDC) scheme appears more effective than temperature control and temperature difference control schemes, the former should not always be considered as the best control decision under the premise of maximally three temperature measurements in each control loop. Instead of a symmetrical temperature control (STC) structure as the DTDC scheme, an asymmetrical temperature control (ATC) structure with each control loop involving a different number of temperature measurements can be derived and lead to not only a simplified control structure but also improved control system performance. In the current work, such possibility is highlighted with reference to a frequently studied benzene–toluene–o-xylene DWDC system. With the perfect maintenance of the four controlled product compositions on their specifications, the three kinds of controlled variables, i.e., temperature, temperature difference, and double temperature difference, are assessed with reference to all kinds of feed composition disturbances and the one with the minimum averaged variability is screened out for each control loop. In combination with the interaction analysis, three ATC schemes are finally derived. Closed-loop evaluations of these ATC schemes are carried out through in-depth comparison with the DTDC scheme and the former ones all show comparable transient responses and improved steady-state behaviors in comparison with the latter. Although the three ATC schemes result in relatively great steady-state discrepancies in the intermediate product purity, the drawback can be suppressed completely with the addition of two temperature measurements in the intermediate control loop. These findings demonstrate the feasibility and potential of adopting the ATC schemes for the tight inferential control of the DWDC.
      Graphical abstract image

      PubDate: 2017-05-28T13:47:29Z
  • Process integration by application of an extractive dividing-wall column:
           An industrial case study
    • Abstract: Publication date: July 2017
      Source:Chemical Engineering Research and Design, Volume 123
      Author(s): Daniel Staak, Thomas Grützner
      Extractive distillation for the separation of azeotropic or narrow-boiling mixtures has been known for a long time and is well established in the chemical industry. For the separation of zeotropic ternary mixtures, however, dividing wall columns have gained importance for two decades. Both processes incorporate a high degree of intensification, which yields in a considerable reduction of both, capital and operational costs. The trend towards intensified processes is unbroken in the chemical industry, particularly in the industrial nations, since it facilitates the struggle with high energy prices and helps to withstand the increasing competition from low-cost countries. The combination of extractive distillation and dividing wall column allows the separation of narrow-boiling or azeotropic components in one single column tube, using a suitable entrainer. Recently, the Lonza AG has successfully developed and implemented an extractive dividing wall column. The entire equipment design was exclusively carried out based on simulations without carrying out time-consuming pilot or mini plant experiments. This approach considerably shortens the time-to-market cycle and reduces the development costs to a large extent. Despite their great potential to notably reduce costs, only a very limited number of extractive dividing wall columns are being operated in the chemical industry and published data is scarce. This paper aims to close this gap.

      PubDate: 2017-05-28T13:47:29Z
  • Inside Front Cover
    • Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122

      PubDate: 2017-05-28T13:47:29Z
  • Development of a novel Volumetric Matrix Dump Combustor for VOC reduction
    • Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Soo Hyuk Yoon, Young Nam Chun
      VOCs (Volatile Organic Compounds) are produced mainly at work places or laundries using painting processes or organic solvents. These are composed of hydrocarbon of diversified forms and low calories due to the low concentration as they are released to atmosphere as to be diluted, making difficult direct burning by a conventional burner. In the present study, a new form of VMDC (Volumetric Matrix Dump Combustor) has been proposed to process such a low-calorie gas of VOC. This combustor is configured in the form of combining characteristics of a plasma burner, a dump combustor and a volumetric matrix burner. Hence, the VMDC is configured as a structure capable of securing sufficient decomposition temperature and residence time required for stable flame formation and VOC decomposition. To investigate performance and operation characteristics of the VMDC, experiments were conducted as parameters of gas feed rate, toluene concentration, VOC injection position, plasma input power, and heat recuperator by using toluene as a representative VOC. With the plasma burner, shortening of ignition time upon initial starting, enhancement in flame stability and combustibility, and expansion of flammable range were enabled, while not only high-efficiency decomposition but also processing of large amounts of VOC was possible by formation of a recirculation region in the dump combustor. And low-temperature, super-adiabatic, complete combustion and decomposition of VOC was made possible by the volumetric matrix burner. The optimum operation condition for VMDC involves the case where VOC with a toluene concentration of 3000ppm was supplied at 450L/min, where the VOC decomposition efficiency was 89.6%, and the specific input energy 333.3J/L, showing excellent performance as compared with the existing waste gas incinerators.

      PubDate: 2017-05-28T13:47:29Z
  • Selective separation and recovery of vanadium from a multiple impurity
           acid leaching solution of stone coal by emulsion liquid membrane using
           di-(2-ethylhexyl)phosphoric acid
    • Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Hong Liu, Yimin Zhang, Jing Huang, Tao Liu, Nannan Xue, Kui Wang
      In order to overcome the problem of long extraction stages and huge consumption of organic phase in the solvent extraction process, selective separation and recovery of vanadium from a multiple impurity acid leaching solution of stone coal by emulsion liquid membrane (ELM) using di-(2-ethylhexyl)phosphoric acid (D2EHPA), as well as the effects of various parameters (surfactant, carrier, paraffin concentration and treat ratio (TR)) were studied. The extraction behaviors of V (V), V (IV), Fe (III), Fe (II), Mg (II), K (I), Na (I) in ELM process were reported and the effects of various impurities on vanadium extraction were also investigated. Finally, a separation flow sheet for a real solution was designed and an enriched vanadium solution was obtained with V 6.10g/L, Fe 0.30g/L, Al 3.20g/L, Mg 0.62g/L, K 0.24g/L, Na 0.20g/L, which revealed that vanadium was successfully separated and recovered from the stone coal acid solution bearing multiple impurity ions.
      Graphical abstract image

      PubDate: 2017-05-28T13:47:29Z
  • Corrigendum to “Development of a combined solver to model transport and
           chemical reactions in catalytic wall-flow filters” [Chem. Eng. Res. Des.
           117 (2016) 681–687]
    • Abstract: Publication date: June 2017
      Source:Chemical Engineering Research and Design, Volume 122
      Author(s): Mohamed Hatem Allouche, Romain Enjalbert, Federico Alberini, Mostapha Ariane, Li Liu, Sam K. Wilkinson, Alessio Alexiadis

      PubDate: 2017-05-28T13:47:29Z
  • Proper Orthogonal Decomposition (POD) Analysis of CFD Data for Flow in an
           Axisymmetric Sudden Expansion
    • Abstract: Publication date: Available online 27 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Clint Howard, Sushen Gupta, Ali Abbas, Timothy A.G. Langrish, David F. Fletcher
      CFD simulations of swirling flow in a 2:1 axisymmetric sudden pipe expansion are performed and used to understand the structure of the flow. The k-ε and SAS-zonal LES models available in ANSYS CFX are used to model turbulence. Comparison of these results shows that the scale-resolving simulation captures much more detail of the flow and provides much more physical results in terms of the flow structures that are resolved. As well as conventional analysis using typical CFD post-processing techniques and Fast Fourier Transforms (FFTs), Proper Orthogonal Decomposition (POD) is used to extract reduced order models of the wall pressure data. This technique is used to extract dominant structures in the spatial domain and to investigate transient behaviour. Data from a finite set of monitor points located at the pipe wall are also examined as a potential means of detecting flow behaviour for use in flow control models that utilise differential wall pressure input data. Such models are required to control, for example, inlet swirl to minimise wall impaction in spray dryers.

      PubDate: 2017-05-28T13:47:29Z
  • Electrolysis-electrodialysis process for removing chloride ion in wet flue
           gas desulfurization wastewater (DW): influencing factors and energy
           consumption analysis
    • Abstract: Publication date: Available online 26 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Lin Cui, Guangpei Li, Yuzhong Li, Bo Yang, Liqiang Zhang, Yong Dong, Chunyuan Ma
      Wastewater must be discharged for limestone-gypsum wet flue-gas desulfurization process in order to regulate the concentration of chloride in the desulfurization slurry. The desulfurization wastewater (DW) is difficult to be treated and recycled because of high amount of chloride. In this research, an electrolytic–electrodialysis process was proposed to resolve the difficulty of removing Cl− in DW and obtain Cl2, H2 and Ca(OH)2. The effects of the current densities, and the Cl− concentrations in the electrolysis and electrodialysis chambers on the current efficiency, electrolytic cell voltage, and energy consumption were studied using a triple-chambered electrolysis–electrodialysis apparatus, and the optimal operating condition of the lab-scale electrolytic–electrodialysis process was obtained. Pursuing extremely low average energy consumption can increase the actual volume of DW for treatment greatly in the electrolysis–electrodialysis process. Under the optimal condition, the Cl− treatment cost from the energy consumption is 0.15 $/(kg Cl−), with considering the by-products profit of the Cl2, H2, and Ca(OH)2. The results prove that the electrolytic-electrodialysis process for DW treatment can achieve the DW zero discharge and resource utilization, and be economically feasible.

      PubDate: 2017-05-28T13:47:29Z
  • Reducing the carbon footprint of cement industry by post-combustion CO2
           capture: Techno-economic and environmental assessment of a CCS project in
    • Abstract: Publication date: Available online 26 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Ana-Maria Cormos, Calin-Cristian Cormos
      Reducing the carbon dioxide emissions from the energy-intensive industrial sectors is of great importance in the fight against climate change. The cement industry is responsible for about 5% of global CO2 emissions. In this article, two reactive absorption and adsorption post-combustion CO2 capture methods are assessed in conjunction with cement production. The gas-liquid absorption method uses alkanolamine (MDEA) as chemical solvent and the gas-solid adsorption method uses calcium looping (CaL) technology. The carbon capture rate is set to 90%. The analysis considers a conventional size of cement plant (1 Mt/y) focusing on mass and energy integration aspects of the carbon capture unit as well as quantification of main techno-economic and environmental indicators of the cement plant with carbon capture. The evaluated designs were modeled and simulated, the mass and energy balances being used to assess the overall performances. For comparison reason, a cement plant without carbon capture was also considered to assess the energy and cost penalties for the carbon capture designs. The analysis shows that the CaL system has significant technical and economic advantages compared to the gas-liquid absorption case (e.g. higher energy efficiency, lower capital, operational and maintenance (O&M), cement production and CO2 avoidance costs).

      PubDate: 2017-05-28T13:47:29Z
  • Removal of ciprofloxacin from aqueous solution using humic acid- and
           levulinic acid- coated Fe3O4 nanoparticles
    • Abstract: Publication date: Available online 26 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Selen Tuğba Danalıoğlu, Şahika Sena Bayazit, Özge Kerkez, Basma G. Alhougbi, Mohamed Abdel Salam
      Humic acid (HA)- and levulinic acid (LA)-coated magnetic Fe3O4 nanoparticles were prepared and subsequently characterized using scanning electron microscopy, X-ray diffraction spectroscopy, Fourier transformer infrared spectroscopy, thermogravimetric analysis, particle size distribution analysis, and zeta-potential analysis. These magnetic nanoparticles were used for ciprofloxacin adsorption from aqueous solutions. Non-linear Langmuir and Freundlich adsorption isotherm models were used to explain the adsorption equilibria. The Langmuir adsorption capacities (qm ) were 101.93mg/g for HA-coated Fe3O4 and 53.76mg/g for LA-coated Fe3O4. The appropriate contact times were 40min for HA-coated Fe3O4 and 60min for LA-coated Fe3O4. The adsorption rates and mechanisms were determined using pseudo-first-order and pseudo-second-order kinetic models. After the adsorption studies, the loaded nanoparticles were used for desorption studies, and their desorption kinetics were investigated.
      Graphical abstract image

      PubDate: 2017-05-28T13:47:29Z
  • A grey wolf optimizer-based support vector machine for the solubility of
           aromatic compounds in supercritical carbon dioxide
    • Abstract: Publication date: Available online 26 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Xiao-Qiang Bian, Qian Zhang, Lu Zhang, Jing Chen
      The prediction of solute solubility in supercritical carbon dioxide (SCCO2) is crucial for the development of supercritical applications. Many models have been developed to calculate the solubility of aromatic compounds. In this work, a grey wolf optimizer-based support vector machine (GWO-SVM) was proposed for correlating solute solubility in SCCO2. The proposed GWO-SVM model utilized the temperature, pressure and the density of SCCO2 as input parameters and the solubility of different solutes in SCCO2 as target parameter on the basis of gray correlation analysis. The new model successfully correlated solute solubility of 18 compounds (1148 data points including 814 training data points and 334 testing data points) in SCCO2, which were collected from the published literature. A comparison of the 27 commonly used empirical models and the proposed GWO-SVM model showed that the overall average absolute relative deviation of the proposed model is the lowest (3.20%). It was also found that the overall average absolute relative deviation is less dependent on material type for the proposed GWO-SVM model.

      PubDate: 2017-05-28T13:47:29Z
  • Optimization of circuitry arrangements for heat exchangers using
           derivative-free optimization
    • Abstract: Publication date: Available online 25 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Nikolaos Ploskas, Christopher Laughman, Arvind U. Raghunathan, Nikolaos V. Sahinidis
      Optimization of the refrigerant circuitry can improve a heat exchanger's performance. Design engineers currently choose the refrigerant circuitry according to their experience and heat exchanger simulations. However, the design of an optimized refrigerant circuitry is difficult. The number of refrigerant circuitry candidates is enormous. Therefore, exhaustive search algorithms cannot be used and intelligent techniques must be developed to explore the solution space efficiently. In this paper, we formulate refrigerant circuitry design as a binary constrained optimization problem. We use CoilDesigner, a simulation and design tool of air to refrigerant heat exchangers, in order to simulate the performance of different refrigerant circuitry designs. We treat CoilDesigner as a black-box system since the exact relationship of the objective function with the decision variables is not explicit. Derivative-free optimization (DFO) algorithms are suitable for solving this black-box model since they do not require explicit functional representations of the objective function and the constraints. The aim of this paper is twofold. First, we compare four mixed-integer constrained DFO solvers and one box-bounded DFO solver and evaluate their ability to solve a difficult industrially relevant problem. Second, we demonstrate that the proposed formulation is suitable for optimizing the circuitry configuration of heat exchangers. We apply the DFO solvers to 17 heat exchanger design problems. Results show that TOMLAB/glcDirect and TOMLAB/glcSolve can find optimal or near-optimal refrigerant circuitry designs after a relatively small number of circuit simulations.

      PubDate: 2017-05-28T13:47:29Z
  • Numerical simulations of bubble formation and acoustic characteristics
           from a submerged orifice: the effects of nozzle wall configurations
    • Authors: Jingting Liu; Ning Chu; Shijie Qin; Dazhuan Wu
      Abstract: Publication date: Available online 17 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Jingting Liu, Ning Chu, Shijie Qin, Dazhuan Wu
      The detachment of bubbles from an underwater nozzle inevitably generates distinct acoustic signals. This work proposes numerical simulation models to investigate the effect of different nozzle wall configurations on bubble formation and acoustic characteristics. A combination of large eddy simulation (LES) model and Ffowcs Williams–Hawkings (FW-H) equation is successfully applied to predict bubble acoustic pressures. The adaptive filtering techniques of signal processing are utilized in bubble acoustic analyses. In particular, transient spectrum based on time–frequency analyses can not only precisely count the bubbling period but also effectively measure the bubble sizes. The numerical results for bubble size are in good agreement with the theoretical data (less than 10% deviation). The main results of this research show that the structure of the nozzle wall plays a guiding role in vortex motion around bubbles. The bubble size also increases with the increase in exit-lip thickness, whereas the bubbling rate decreases.
      Graphical abstract image

      PubDate: 2017-05-17T19:12:10Z
      DOI: 10.1016/j.cherd.2017.05.002
  • Optimization of vanadium (IV) extraction from stone coal leaching solution
           by emulsion liquid membrane using response surface methodology
    • Authors: Hong Liu; Yi-min Zhang; Jing Huang; Tao Liu; Nan-nan Xue; Qi-hua Shi
      Abstract: Publication date: Available online 13 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Hong Liu, Yi-min Zhang, Jing Huang, Tao Liu, Nan-nan Xue, Qi-hua Shi
      In order to further improve the vanadium (IV) extraction from stone coal leaching solution in one step and reduce the reagent consumption by emulsion liquid membrane (ELM), the experiments using response surface methodology (RSM) was investigated. The liquid membrane was composed of paraffin as membrane stabilizer, D2EHPA as mobile carrier, span80 as surfactant and H2SO4 as stripping solution. Emulsification speed and emulsification time in emulsion formation was optimized to obtain a stable emulsion. An orthogonal 24 Box–Behnken design (BBD) having five replicates at the center point was used to estimate the coefficients of the response function. The linear effects, square effects and interactive effects of the parameters were analyzed by ANOVA. In addition, the signification of the parameters was also ranked. In the further study, the effect of electric demulsification and membrane recycle ability were studied under the optimized parameters. All of the results revealed that RSM was successfully used to optimize the extraction of V (IV) via ELM and indicated the potential industrially application for vanadium concentration and purification in one step from stone coal acid leaching solution.
      Graphical abstract image

      PubDate: 2017-05-17T19:12:10Z
      DOI: 10.1016/j.cherd.2017.05.001
  • On the assessment of power consumption and critical impeller speed in
           vortexing unbaffled stirred tanks
    • Authors: F. Scargiali; A. Tamburini; G. Caputo; G. Micale
      Abstract: Publication date: Available online 10 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): F. Scargiali, A. Tamburini, G. Caputo, G. Micale
      Unbaffled stirred tanks are increasingly recognized as a viable alternative to common baffled tanks for a number of processes and bio-processes where the presence of baffles is undesirable. Notwithstanding the increasing industrial interest towards unbaffled tanks, available experimental information on their behaviour is still very poor, even for important parameters such as mechanical power drawn and critical impeller speed (Ncr ) at which the transition between non-aerated (sub-critical regime) and aerated (super-critical regime) conditions occurs. In this work the influence of Reynolds and Froude numbers on power consumption characteristics of unbaffled stirred tanks is presented for tanks operating both in non-aerated (sub-critical regime) and aerated (super-critical) conditions. Influence of scale-up, impeller to tank size, liquid height aspect-ratio and presence or not of a top-cover is investigated in order to provide a general correlation able to assess (i) the critical rotational speed Ncr and (ii) the power number Np under any fluid dynamic regime. Experimental results obtained show that the proposed general correlation is fully validated when scaling-up the system. Moreover, the variation of geometrical features such as impeller to tank size, liquid aspect ratio and the presence or not of a top-cover do not modify the functional dependencies of power number on Re and Fr and only different (dimensionless) multiplying shape factors must be adopted. Finally, an overall general correlation for critical rotational speed (Ncr ) assessment is also proposed.
      Graphical abstract image

      PubDate: 2017-05-12T19:03:30Z
      DOI: 10.1016/j.cherd.2017.04.035
  • Removal of p-chlorophenol from aqueous solutions by carbon nanotube hybrid
           polymer adsorbents
    • Authors: Liheng Xu; Zhongmiao Wang; Shian Ye; Xiaoyu Sui
      Abstract: Publication date: Available online 8 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Liheng Xu, Zhongmiao Wang, Shian Ye, Xiaoyu Sui
      Aiming to remove chlorophenols from aqueous solution, carbon nanotube (CNT) hybrid polymer beads were fabricated via the phase inversion method, and were adopted as adsorbents to remove p-chlorophenol in this study. The CNT hybrid bead was composed of a smooth outer surface and hierarchical porous inner structure, with worm-like CNTs lying on/embedded in the polymer slices. The incorporation of CNTs in the polymer beads resulted in a dramatically improvement of the surface area. The adsorption kinetics and isotherms of p-chlorophenol from aqueous solutions on CNT hybrid adsorbents were studied, and the impacts of temperature and pH value on the adsorption were also explored. The adsorption capacity of CNT hybrid adsorbents towards p-chlorophenol was significantly superior to that of the neat polymer adsorbent and pristine CNT. And the CNT hybrid adsorbents also showed an outstanding separation performance from water treatment system after adsorption. The adsorption process of p-chlorophenol on CNT hybrid adsorbents was found to be an exothermic process, and physical adsorption was the predominant mechanism. The neutral p-chlorophenol molecule was a more effective form for adsorption than was the ionic form. The interaction between p-chlorophenol and the CNT hybrid adsorbents responsible for the adsorption was assumed mainly non-polar forces such as hydrophobic interactions and π–π electron coupling.
      Graphical abstract image

      PubDate: 2017-05-12T19:03:30Z
      DOI: 10.1016/j.cherd.2017.04.034
  • Methoxylation of dihydromyrcene in an intensified fixed bed reactor
    • Authors: Xiangpo He; Ruyin Xu; Yunpeng Wang; Feng Zhang; Yu Lei; Zheng Zhou; Zhibing Zhang
      Abstract: Publication date: Available online 6 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Xiangpo He, Ruyin Xu, Yunpeng Wang, Feng Zhang, Yu Lei, Zheng Zhou, Zhibing Zhang
      In this work we systematically investigated scale-up of methoxylation of dihydromyrcene (DHM) to produce dihydromyrcenyl methyl ether (DME) using cation exchange resin catalysts. Optimization of the reaction conditions for the methoxylation of DHM was initially carried out in a 500mL stirred tank reactor (STR). A subsequent scale-up to carry out the reaction in a 5L STR under the same reaction conditions failed to reproduce the high yield of DME due to possible limitation in mass and heat transfer. Successful scale-up was achieved by using an intensified fixed bed reactor (IFBR) where mass transfer limitation was essentially eliminated. The thermodynamic and kinetic parameters of the methoxylation of DHM were determined in the IFBR. The equilibrium constants of the methoxylation of DHM decreased with increasing reaction temperature, indicating an exothermic reaction. The kinetic data suggested that the methoxylation of DHM follows the Eley–Rideal mechanism.
      Graphical abstract image

      PubDate: 2017-05-07T16:23:13Z
      DOI: 10.1016/j.cherd.2017.04.033
  • Improved Cost-optimal Bayesian Control Chart based Auto-correlated
           Chemical Process Monitoring
    • Authors: Ying Tian; Wenli Du; Viliam Makis
      Abstract: Publication date: Available online 4 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Ying Tian, Wenli Du, Viliam Makis
      Traditional chemical process monitoring methods focus on higher detection rate and ignore monitoring system cost. To minimize the cost, we propose improved cost-optimal Bayesian control chart for auto-correlated chemical process monitoring. First, the least square support vector machine (LSSVM) is used to model the auto-correlated process and obtain the independent residuals. Then, a two-condition hidden Markov model (HMM) is used to describe the residuals. Finally, the cost-optimal Bayesian control chart is developed through semi-Markov decision process (SMDP) framework to achieve cost-optimal control limit minimizing the long run expected average cost as well as the monitoring statistic. The monitoring results verify that the improved cost-optimal Bayesian control chart achieves better economic performance.
      Graphical abstract image

      PubDate: 2017-05-07T16:23:13Z
      DOI: 10.1016/j.cherd.2017.04.024
  • High Throughput Screening of Homogenously Catalyzed Hydrogenations in a
           Continuously Perfused Membrane Reactor
    • Authors: Arno Behr; Martin Halama; Lutz Domke
      Abstract: Publication date: Available online 4 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Arno Behr, Martin Halama, Lutz Domke
      A new concept of a continuously working membrane reactor was developed and successfully used for hydrogenation screening reactions. Thus, an innovative concept intends the separation of the hydrogen source from the reaction medium. This method guarantees a constant pressure over the reaction time, but allows at the same time a rapid variation of the reaction conditions (reaction time, temperature, pressure of hydrogen), what can be carried out easily. Investigations concerning the choice of membrane material, retention times of each run and phase separation of the sequences were conducted. Using toluene as reaction solvent and propylene carbonate and water as a wash solution, 1-octene, carvone and (–)-β-pinene were hydrogenated and the results compared to those yielded with a batch reactor.
      Graphical abstract image

      PubDate: 2017-05-07T16:23:13Z
      DOI: 10.1016/j.cherd.2017.04.030
  • Simultaneous Optimization of Performance Parameters and Energy Consumption
           in Induced Draft Cooling Towers
    • Authors: Kuljeet Singh; Ranjan Das
      Abstract: Publication date: Available online 4 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Kuljeet Singh, Ranjan Das
      In the present work, a model based on experiments is presented to simultaneously optimize all possible performance parameters as well as ensure minimum energy consumption from an induced draft cooling tower operating under a given set of conditions. Empirical correlations are obtained for performance parameters such as range, approach, tower characteristic ratio, effectiveness and evaporation rate against air and water flow rates, which in turn are selected as discrete objective functions to formulate a multi-objective optimization problem. Unlike previous studies which neglected the simultaneous consideration of five performance parameters aimed at minimum possible power consumption, here an unconstrained optimization of all objective functions is carried out using elitist Non-dominated Sorting Genetic Algorithm (NSGA-II). Considering five performance parameters, the air flow rate has been estimated under a given water flow rate using a decision making matrix-based criterion. Among various performance parameters, the maximization of the range for diverse water flow rates implicitly satisfies different loads imposed on the cooling tower, thereby avoiding the necessity of formulating an additional constraint. Furthermore, due to maximization of the approach and minimization of the evaporation rate, minimum operating cost is ensured from the induced draft cooling tower.

      PubDate: 2017-05-07T16:23:13Z
      DOI: 10.1016/j.cherd.2017.04.031
  • Adsorption Equilibrium and thermodynamics of anionic reactive dyes from
           aqueous solutions by using a new modified silica gel with
           2,2'-(pentane-1,5-diylbis (oxy))dibenzaldehyde
    • Authors: Alireza Banaei; Shabnam Ebrahimi; Hossein Vojoudi; Soheyla Karimi; Eslam Pourbasheer
      Abstract: Publication date: Available online 4 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Alireza Banaei, Shabnam Ebrahimi, Hossein Vojoudi, Soheyla Karimi, Eslam Pourbasheer
      The 2,2'-(pentane-1,5-diylbis(oxy))dibenzaldehyde (BP) functionalized silica gel (Si-APTES-BP) was synthesized successfully by a normal method and a vice versa method. These new materials were characterized by Fourier Transform Infrared (FT-IR), Scanning Electron Microscopy (SEM), Thermogravimetric Analyzes (TGA) and Ultraviolet Visible (UV-Vis). The modified silica gel with normal method was used as a sorbent for removal of anionic reactive dyes Reactive Blue 19 (RB19) and Reactive Yellow 84 (RY84) from their aqueous solutions by batch adsorption procedure. Batch adsorption experiments were performed to study the effect of various experimental parameters such as the solution pH, contact time, initial dye concentration, adsorbent dose and temperature. Moreover, the isotherm data of both investigated dyes were analyzed by the Langmuir and Freundlich adsorption models. Based on the correlation coefficient values, it has been deduced that the Langmuir model is better fitted to the experimental data. On the basis of the Langmuir analysis, the maximum adsorption capacities were found to be 37.45 and 32.36mg/g for Reactive Blue 19 (RB19) and Reactive Yellow 84 (RY84), respectively at room temperature. The results showed that the adsorption capacity of Reactive Blue 19 (RB19) and Reactive Yellow 84 (RY84) dyes were enhanced with increase temperature of solution. The maximum uptake value for Reactive Blue 19 (RB19) and Reactive Yellow 84 (RY84) dyes were obtained at pH 5 and pH 9, respectively. In addition, thermodynamic studies were conducted to calculate the changes in Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°). The negative values of ΔG° and the positive value of ΔH° indicated that the adsorption process of both investigated dyes was a spontaneous and endothermic process in nature. The obtained results indicate that the silica gel modified with 2,2'-(pentane-1,5-diylbis(oxy))dibenzaldehyde is an effective adsorbent for the removal of anionic reactive dyes from aqueous solutions.
      Graphical abstract image

      PubDate: 2017-05-07T16:23:13Z
      DOI: 10.1016/j.cherd.2017.04.032
  • Equilibrium, kinetic and thermodynamic studies on adsorption of cationic
           dyes from aqueous solutions using graphene oxide
    • Authors: Wojciech Konicki; Małgorzata Aleksandrzak; Ewa Mijowska
      Abstract: Publication date: Available online 4 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Wojciech Konicki, Małgorzata Aleksandrzak, Ewa Mijowska
      The adsorption of cationic dyes Basic Yellow 28 (BY28) and Basic Red 46 (BR46) from an aqueous solution by graphene oxide (GO) as adsorbent is presented. Graphene oxide is prepared using a modified Hummers’ method and characterized by Fourier Transform-Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Atomic Force Microscopy (AFM), Raman spectroscopy, Transmission Electron Microscopy (TEM) and zeta potential measurements. Adsorption properties of cationic dyes using GO were studied in different dye concentrations (10–50mgL−1), pH of the solutions (3.0-11.0), and temperature range of 20–60°C. The Langmuir and Freundlich isotherm models were applied to fit the adsorption data. Equilibrium data fitted very well with the Langmuir isotherm model. The maximum monolayer adsorption capacity of BY28 and BR46 onto GO was 68.5 and 76.9mgg−1, respectively. The experimental kinetics data were analyzed using pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models. The kinetic studies showed that the adsorption data followed the pseudo-second-order kinetics model. In addition, various thermodynamic parameters, such as the Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) were calculated and it was revealed that the adsorption of BY28 and BR46 was spontaneous and endothermic.
      Graphical abstract image

      PubDate: 2017-05-07T16:23:13Z
      DOI: 10.1016/j.cherd.2017.03.036
  • Effects of amino functionalized polyhedral oligomeric silsesquioxanes on
           cross-linked poly (ethylene oxide) membranes for highly-efficient CO2
    • Authors: Songwei Li; Xu Jiang; Qian Yang; Lu Shao
      Abstract: Publication date: Available online 2 May 2017
      Source:Chemical Engineering Research and Design
      Author(s): Songwei Li, Xu Jiang, Qian Yang, Lu Shao
      In this study, the hybrid cross-linked membranes consisting of amino functionalized polyhedral oligomeric silsesquioxanes (POSS-NH2) nanoparticles and CO2-philic poly (ethylene oxide) (PEO) are prepared via a facile one-step method. Porous POSS-NH2 with abundant amino groups in the polymer matrix generates a compatible interface between the polymer matrix and nanoparticles, enhancing the CO2 permeability. Due to the synergetic effects of nanoporous POSS-NH2 and CO2-philic PEO, the hybrid cross-linked membranes exhibit excellent CO2 permeability and selectivity. A high CO2 permeability of 385.8 Barrer in the hybrid cross-linked membrane is achieved, which is 242% of that of pristine cross-linked membrane. The gas transport performance is explained based on the solution-diffusion mechanism and diffusion coefficient and solubility coefficient are evaluated. Furthermore, thermodynamics is explored to clarify the enhancement of gas transport performance in hybrid cross-linked membranes. The gas permeability of CH4, H2, N2, and CO2 continuously improved with temperatures. The activation energies of CH4, N2, H2 and CO2 in hybrid cross-linked membranes are typically lower than those in the pristine cross-linked membrane, which results in the fast transportation of gases. Our developed membranes have demonstrated a promising prospect for sustainable CO2 separations.
      Graphical abstract image

      PubDate: 2017-05-07T16:23:13Z
      DOI: 10.1016/j.cherd.2017.04.025
  • Modeling and optimal operation of batch closed-loop diafiltration
    • Authors: Ayush Sharma; Martin Jelemenský; Radoslav Paulen; Miroslav Fikar
      Abstract: Publication date: Available online 21 April 2017
      Source:Chemical Engineering Research and Design
      Author(s): Ayush Sharma, Martin Jelemenský, Radoslav Paulen, Miroslav Fikar
      The paper derives mathematical model and optimal operation of batch diafiltration processes with partial recirculation of retentate, i.e. batch closed-loop membrane processes. A generalized mathematical model of the process is developed in the form of a set of non-linear ordinary differential and algebraic equations. Two process variables are used as manipulated and optimized degrees of freedom: recirculation rate and diluant addition rate. Optimal operation aims to minimize a weighted combination of processing time, power consumption, and diluant consumption. A theoretical analysis of the process is combined with numerical optimization techniques. Based on selected case studies, conclusions are drawn on economics of the process operation to identify when the process design with recirculation adds substantial benefits compared to the classical (open-loop) design without recirculation. Simulation studies suggest that minimum time operation does not require recirculation loop. On the other hand, minimum power operation consumes about 70-95% less power in closed-loop design when compared to open-loop setup.
      Graphical abstract image Highlights

      PubDate: 2017-04-25T02:51:26Z
      DOI: 10.1016/j.cherd.2017.04.016
  • Screening of ionic liquids for efficient extraction of methylxanthines
           using COSMO-RS methodology
    • Authors: Tomasz Jeliński; Piotr Cysewski
      Abstract: Publication date: Available online 19 April 2017
      Source:Chemical Engineering Research and Design
      Author(s): Tomasz Jeliński, Piotr Cysewski
      The COSMO-RS methodology was used to perform a screening of ionic liquids as the most effective media for extraction of methylxanthines from natural sources. The computational methodology was validated based on the values of experimentally obtained extraction yields of caffeine from guarana seeds. A linear dependence between the extraction yields and computed thermodynamic activity coefficients of caffeine was found. A total of 23 cations and 38 anions commonly used in ionic liquids were used in the studies comprising a total of 874 ionic liquids. It was found that the ionic liquid based on the 1-dodecyl-3-methylimidazolium cation an d tetraphenyl borate anion was responsible for the best extraction efficiency equal to 10.1wt%, which is more than 50% higher than the best experimentally studied ionic liquid. Furthermore, the effectiveness of recyclability of methylxanthines from the aqueous solutions of ionic liquids was modeled. It was found that the partition coefficient values of caffeine are a good qualitative measure of re-extraction efficiency of the solvents. Since ionic liquids with high extraction efficiency have a strong affinity towards aqueous solutions, while those with high recyclability towards the organic phase it is indispensable to take both these steps into account when modelling the extraction process.

      PubDate: 2017-04-25T02:51:26Z
      DOI: 10.1016/j.cherd.2017.04.015
  • Design of multivariate alarm systems based on online calculation of
           variational directions
    • Authors: Kuang Chen; Jiandong Wang
      Abstract: Publication date: Available online 13 April 2017
      Source:Chemical Engineering Research and Design
      Author(s): Kuang Chen, Jiandong Wang
      Alarm systems are critically important for safety and efficiency of industrial plants, but are severely suffering from alarm overloading. This paper proposes a method to design a multivariate alarm system based on variational directions of involved process variables, in order to alleviate the severity of alarm overloading. By using adaptive time scales, time gradients of signals are extracted to calculate variational directions in an online manner. Adaptive time scales are determined from a function between time scales and volatilities of process variables. Alarms arise at the moment that a nominal relationship of variational directions among process variables is invalidated. Numerical and industrial examples illustrate the effectiveness of the proposed method.

      PubDate: 2017-04-18T08:31:00Z
      DOI: 10.1016/j.cherd.2017.04.011
  • Comparative Analyses on Isothermal Kinetics of Water Evaporation and PAAG
           Hydrogel Dehydration under the Microwave Heating Conditions
    • Authors: Gigov
      Abstract: Publication date: Available online 12 April 2017
      Source:Chemical Engineering Research and Design
      Author(s): B. Adnadjević, M. Gigov, J. Jovanović
      The isothermal kinetic of water evaporation and poly(acrylic-g-gelatin) hydrogel (PAAG) dehydration in temperature range from 333K to 363K was investigated under microwave heating conditions (MWH). The isothermal kinetic curves of water evaporation and hydrogel dehydration could be entirely mathematically described by the Polanyi-Winger equation. The values of the rate constant for water evaporation and hydrogel dehydration and their kinetics parameters were calculated. Both the value of activation energy (E a) and pre-exponential factor (lnA) for hydrogel dehydration under MWH is higher than those for water evaporation. The existence of a linear correlation relationship − compensation effect was established between the values of kinetics parameters for water evaporation and hydrogel dehydration. The values of thermodynamic parameters of activated complex formation for water evaporation and hydrogel dehydration (standard enthalpy of activation (ΔH *), standard entropy activation (ΔS *), and standard free Gibbs energy of activation (ΔG *)) were calculated. The mechanism of water molecules activation, both for evaporation and dehydration, by the resonant transfer of certain energy amount from the reaction system to the libration vibration of molecules of water is suggested.
      Graphical abstract image

      PubDate: 2017-04-18T08:31:00Z
  • Buoyancy – driven convection of nanofluids in inclined enclosures
    • Authors: Alessandro Quintino; Elisa Ricci; Emanuele Habib; Massimo Corcione
      Abstract: Publication date: Available online 12 April 2017
      Source:Chemical Engineering Research and Design
      Author(s): Alessandro Quintino, Elisa Ricci, Emanuele Habib, Massimo Corcione
      A two-phase model based on the double-diffusive approach is used to perform a numerical study on natural convection of water-based nanofluids in square cavities differentially heated at two opposite walls, and inclined with respect to gravity so that the heated wall faces upwards. It is assumed that Brownian diffusion and thermophoresis are the only slip mechanisms by which the solid phase can develop a significant relative velocity with respect to the liquid phase. The system of the governing equations of continuity, momentum and energy for the nanofluid, and continuity for the nanoparticles, is solved through an in-house developed computational code which incorporates three empirical correlations for the evaluation of the effective thermal conductivity, the effective dynamic viscosity, and the thermophoretic diffusion coefficient, all based on literature experimental data. The pressure-velocity coupling is handled by way of the SIMPLE-C algorithm. Numerical simulations are executed for three different nanofluids, using the diameter and the average volume fraction of the suspended nanoparticles, as well as the tilting angle of the enclosure, the enclosure width, the average temperature of the nanofluid, and the temperature difference imposed across the cavity, as independent variables, whose effects are thoroughly analyzed and discussed. The existence of an optimal tilting angle of the enclosure and an optimal particle loading for maximum heat transfer is detected. In addition, a thermophoresis-induced periodic flow at tilting angles larger than 50 deg is found to occur for low to moderate values of both the nanofluid average temperature and the volume fraction of the suspended solid phase.
      Graphical abstract image

      PubDate: 2017-04-18T08:31:00Z
      DOI: 10.1016/j.cherd.2017.04.007
  • Kinetic and regenerator modeling of the coke combustion in the moving bed
           MTP process
    • Authors: Binbo Jiang; Bingjie Zhou; Yuntao Jiang; Xiang Feng; Zuwei Liao; Zhengliang Huang; Jingdai Wang; Yongrong Yang
      Abstract: Publication date: Available online 12 April 2017
      Source:Chemical Engineering Research and Design
      Author(s): Binbo Jiang, Bingjie Zhou, Yuntao Jiang, Xiang Feng, Zuwei Liao, Zhengliang Huang, Jingdai Wang, Yongrong Yang
      A moving bed regenerator concept is introduced to the regeneration of HZSM-5 catalyst in the methanol to propylene process. A coke combustion kinetic model has been obtained by considering the effect of coke content and oxygen pressure. Then a moving bed regenerator model is proposed, implying a radial cross flow between catalyst and regeneration gas. An industrial scale regeneration process has also been investigated. A “reversal phenomena” has been observed both in the temperature and coke distribution in the regenerator. A multi-zone and a flow direction changing operation mode have been advanced thus making the whole regeneration process more effective.

      PubDate: 2017-04-18T08:31:00Z
      DOI: 10.1016/j.cherd.2017.04.005
  • Evaluation of cooling requirements of post-combustion CO2 capture applied
           to coal-fired power plants
    • Authors: Patrick Brandl; Salman Masoudi Soltani; Paul S Fennell; Niall Mac Dowell
      Abstract: Publication date: Available online 10 April 2017
      Source:Chemical Engineering Research and Design
      Author(s): Patrick Brandl, Salman Masoudi Soltani, Paul S Fennell, Niall Mac Dowell
      Whilst CO2 capture and storage (CCS) technology is widely regarded as being an important tool in mitigating anthropogenic climate change, care must be taken that its extensive deployment does not substantially increase the water requirements of electricity generation. In this work, we present an evaluation of the cooling demand of an amine-based post-combustion CO2 capture process integrated with a coal-fired power plant. It is found that the addition of a capture unit translates into an increase in the total cooling duty of ≈47% (subcritical), ≈33% (supercritical) and ≈31% (ultra-supercritical) compared to a power plant without capture. However, as the temperature at which this cooling is required varies appreciably throughout the integrated power capture process, it is found that his increase in cooling duty (MW) does not necessarily lead to an increase in cooling water usage (kg H 2 O /MW). Via a heat integration approach, we demonstrate how astute cascading of cooling water can enable a reduction of cooling water requirements of a decarbonised power plant relative to an unmitigated facility. This is in contrast to previous suggestions that the addition of CCS would double the water footprint.

      PubDate: 2017-04-11T08:25:01Z
      DOI: 10.1016/j.cherd.2017.04.001
  • Adsorption Behaviour of Tetraethylenepentamine-Functionalized Si-MCM-41
           for CO2 Adsorption
    • Authors: Sohail Ahmed; Anita Ramli; Suzana Yusup; Muhammad Farooq
      Abstract: Publication date: Available online 9 April 2017
      Source:Chemical Engineering Research and Design
      Author(s): Sohail Ahmed, Anita Ramli, Suzana Yusup, Muhammad Farooq
      Carbon dioxide (CO2) mitigation is of prime importance due to its prodigious release into the atmosphere from power plants and other industrial sources which directly influence the climate change. Adsorption process is considered as an attractive process for CO2 separation and purification due to low energy requirement, cost-effective and ease in applicability over wide range of operating conditions. In this work, mesoporous Si-MCM-41 was functionalized with different loadings of tetraethylenepentamine (TEPA) to study its performance for CO2 adsorption using gravimetric technique. The adsorption data shows that incorporation of TEPA into Si-MCM-41 promotes CO2 adsorption and the adsorption capacity increases with increasing loading of TEPA from 10 to 50wt.%. The 50wt.% TEPA-functionalized Si-MCM-41 shows the CO2 adsorption capacity of 54.65mg/g at 25°C and 1bar. Further studies shows that the adsorption capacity of 50wt.% TEPA-Si-MCM-41 increases with increasing temperature from 25 to 75°C with the highest CO2 adsorption capacity of 70.41mg/g at 75°C and 1bar. Infrared spectroscopy was used to study the interaction mechanism of CO2 with amino groups using the 50wt.% TEPA-Si-MCM-41. FTIR spectra of CO2-saturated 50wt.% TEPA-Si-MCM-41 samples showed peaks related to carbamates formation which is the evidence of chemisorption process.
      Graphical abstract image

      PubDate: 2017-04-11T08:25:01Z
      DOI: 10.1016/j.cherd.2017.04.004
  • Certainties and Challenges in Modeling Unwashed and Washed Gums Formation
           in Brazilian Gasoline-Ethanol Blends
    • Authors: Florian Pradelle; Sergio Leal Braga; Ana Rosa Fonseca de Aguiar Martins; Franck Turkovics; Renata Nohra Chaar Pradelle
      Abstract: Publication date: Available online 9 April 2017
      Source:Chemical Engineering Research and Design
      Author(s): Florian Pradelle, Sergio Leal Braga, Ana Rosa Fonseca de Aguiar Martins, Franck Turkovics, Renata Nohra Chaar Pradelle
      During the gasoline storage, gums are formed by a slow oxidation of some unstable compounds, such as olefins. The high molecular mass oxidation products can become insoluble and form deposits. Its excess affects the injection pattern, the fuel combustion, the durability of the fuel line parts and increases the pollutant emissions. Consequently, a robust knowledge is required to assess better the behavior of the fuel, in particular the impact of biofuels. This article discussed the certainties and challenges in modelling gum formation in blends of Brazilian gasoline with anhydrous ethanol. The impact of experimental and mathematical procedures on the robustness of the model was investigated. They makes possible to assess quantitatively the impact of aging period, temperature, ethanol and additive contents in the formation of unwashed and washed gums. The results confirmed the promotion of the process with the increase of the temperature and aging period and showed the complex role of ethanol, strongly dependent on the values of the other factors. Moreover, the comparison with former literature showed that the models from this study were more robust and the dependence with chemical matrix of gasoline and ethanol quality was reduced. Recommendations were given to overcome the remaining challenges.
      Graphical abstract image

      PubDate: 2017-04-11T08:25:01Z
      DOI: 10.1016/j.cherd.2017.03.037
    • Authors: V.N. Dolgunin; A.N. Kudi; A.A. Ukolov; M.A. Tuev
      Abstract: Publication date: Available online 8 April 2017
      Source:Chemical Engineering Research and Design
      Author(s): V.N. Dolgunin, A.N. Kudi, A.A. Ukolov, M.A. Tuev
      The objective of this study is to examine the segregation and migration effects in the course of interaction of particles differing in size, density and roughness while undergoing rapid gravity-driven granular flows on a vibrated rough chute. An experimental and analytical method is proposed in order to obtain the profiles of velocity, fraction of the void volume and test particle distribution along the bed depth. It was found out that migration is the main physical mechanism of nonuniform particle interaction determining separation effect in rapid gravity-driven granular flows of granular materials on a rough chute vibrating at low frequencies. Segregation dominates when high frequencies of vibrating chute take place.
      Graphical abstract image

      PubDate: 2017-04-11T08:25:01Z
      DOI: 10.1016/j.cherd.2017.03.038
  • Analysis of maximum pressure drop for a flat-base spouted fluid bed
    • Authors: Esmail R. Monazam; Ronald W. Breault; Justin Weber
      Abstract: Publication date: Available online 6 April 2017
      Source:Chemical Engineering Research and Design
      Author(s): Esmail R. Monazam, Ronald W. Breault, Justin Weber
      For design purposes of the blower power requirements during startup of a spouting bed process, knowledge of the maximum pressure drop across a spouting bed at the onset of spouting is required. A survey of the literature for this information lead to only a few correlations which required information from a spouting bed test to be applicable. Therefore, an experimental investigation of this pressure drop and its associated superficial gas velocity in a flat based spouted bed operating with and without fluidization has been conducted. Measurements were performed using a 10cm cylindrical bed with different static bed heights and two Geldard group B particles (Al2O3 and HDPE). The results show that the taller static bed height creates a larger maximum pressure drop across the bed, as expected. The maximum pressure drop also increases with increasing fluidized gas velocity. The evolution of maximum pressure drop and its velocity were evaluated and a correlation for the maximum pressure drop and its corresponding velocity for spouted and spouted fluid beds were obtained.

      PubDate: 2017-04-11T08:25:01Z
      DOI: 10.1016/j.cherd.2017.03.032
  • Bioreactor Temperature Control using Modified Fractional Order IMC-PID for
           ethanol production
    • Authors: Nikhil Pachauri; Asha Rani; Vijander Singh
      Abstract: Publication date: Available online 4 April 2017
      Source:Chemical Engineering Research and Design
      Author(s): Nikhil Pachauri, Asha Rani, Vijander Singh
      The product quality of a fermentation process depends on a number of factors such as temperature, pH, nutrient balance, dilution rate, dissolved oxygen and CO2 concentration etc. The present work focuses on the precise temperature control of the process and to achieve desired product quality. Therefore a novel control algorithm, which is an amalgamation of fractional mathematics and IMC-PID, having less design parameters is proposed. A fractional order IMC-PID is designed and then modified (MFOIMC-PID) by incorporating an extra control loop with proportional gain to reduce the offset error. A nature inspired optimization technique i.e. water cycle algorithm is utilized for estimation of optimum design parameters of proposed controller which leads to WMFOIMC-PID controller. Fractional order PID (FOPID) and conventional PID are also designed for comparative study. Simulation results show that the proposed controller reduces Integral Absolute Error (IAE) by 57% and 72% in comparison to FOPID and PID respectively for set-point tracking. Similar reduction of IAE is observed for disturbance rejection and noise suppression. Thus WMFOIMC-PID proves to be more robust and efficient in comparison to the other designed controllers.
      Graphical abstract image

      PubDate: 2017-04-11T08:25:01Z
      DOI: 10.1016/j.cherd.2017.03.031
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