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Liu D.,East China University of Science and Technology | Yao C.,East China University of Science and Technology | Zhang J.,East China University of Science and Technology | Fang D.,East China University of Science and Technology | Chen D.,Shanghai Wujing Chemical Co.
Fuel | Year: 2011

A γ-Al 2O 3 catalyst was modified with metal oxide (Nb 2O 5) in order to improve its activity and stability for dimethyl ether (DME) synthesis from methanol. A series of modified γ-Al 2O 3 catalysts were prepared with Nb 2O 5 and characterized by X-ray diffraction and temperature programmed desorption of ammonia. Results showed that the γ-Al 2O 3 catalyst containing 10 wt.% of Nb 2O 5 exhibited the highest surface area among the modified ones. The number of acid sites of the modified catalysts was increased by the Nb 2O 5 modification. In the chemical reaction of DME synthesis, it was found that the Nb 2O 5 modified γ-Al 2O 3 catalyst exhibited a higher activity in the low temperature region (240 °C-260 °C) and a higher activity than did the untreated γ-Al 2O 3 catalyst. © 2010 Elsevier Ltd. All rights reserved.


Chen D.-S.,East China University of Science and Technology | Chen D.-S.,Shanghai Wujing Chemical Co. | Zhang H.-T.,East China University of Science and Technology | Ying W.-Y.,East China University of Science and Technology | Fang D.-Y.,East China University of Science and Technology
Huadong Ligong Daxue Xuebao/Journal of East China University of Science and Technology | Year: 2011

The ranges of effective thermal conductivity coefficients of stagnant fixed-bed, which packed with methanol synthesis catalyst, dehydration catalyst and mixed catalyst were measured as 0.2380-0.2860, 0.2060-0.2862 and 0.2092-0.2753, respectively, using the steady state method from 180 °C to 320°C. Compared the experimental results with the calculated data from some prediction formula, Kunii equation gave the best mathing results. The maximum deviation and standard deviation of the calculated value of the Kunii formula with three experimental results are 4.96%, 3.63%, 3.60% and 0.78%, 0.62%, 0.63%, respectively. It is concluded that the formula proposed by Kunii was suitable to calculate the effective thermal conductivity coefficient of fixed bed for dimethyl ether synthesis from syngas.


Yang Z.,East China University of Science and Technology | Zhu J.,East China University of Science and Technology | Wu B.,East China University of Science and Technology | Chen K.,East China University of Science and Technology | Ye X.,Shanghai Wujing Chemical Corporation Ltd.
Journal of Chemical and Engineering Data | Year: 2010

Isobaric vapor-liquid equilibrium (VLE) data for (acetic acid + cyclohexane) and (cyclohexane + acetylacetone) were determined at a pressure of 101.3 kPa and those for (acetic acid + acetylacetone) at a pressure of 60.0 kPa. A minimum boiling azeotrope was found for (acetic acid + cyclohexane). The nonideality of the vapor phase of (acetic acid + acetylacetone) and (acetic acid + cyclohexane) was investigated by using the Hayden-O'Connell equation. Thermodynamic consistency was tested for all of the VLE data. The experimental data were correlated satisfactorily by the Wilson, NRTL, and UNIQUAC models. Correlation results were in good agreement with experimental data. © 2009 American Chemical Society.


Yang Z.,East China University of Science and Technology | Zhu J.,East China University of Science and Technology | Wu B.,East China University of Science and Technology | Chen K.,East China University of Science and Technology | Ye X.,Shanghai Wujing Chemical Corporation Ltd.
Journal of Chemical and Engineering Data | Year: 2010

Liquid - liquid equilibrium (LLE) data of the solubility curves for ternary systems of water + pentane-2,4-dione + ethyl ethanoate and tie-line compositions for both of the ternary systems of water + pentane-2,4-dione + ethyl ethanoate and water + pentane-2,4-dione + cyclohexane were determined at (298.15 and 313.15) K and at a pressure of 101.3 kPa. Distribution coefficients were evaluated for the immiscible region. The reliability of the experimental tie-lines has been confirmed by using the Othmer - Tobias correlation. The experimental data were fitted using the nonrandom two-liquid (NRTL) and universal quasichemical activity coefficient (UNIQUAC) equations; parameters of these two models were regressed. © 2010 American Chemical Society.


Chen D.-S.,East China University of Science and Technology | Chen D.-S.,Shanghai Wujing Chemical Co. | Cheng C.-Y.,East China University of Science and Technology | Zhang H.-T.,East China University of Science and Technology | And 2 more authors.
Meitan Xuebao/Journal of the China Coal Society | Year: 2011

The global kinetics of direct synthesis of DME from syngas was investigated in the internal circle gradientless reactor, under the condition of the temperature 220~260°C, the space velocity 1000~3000 mL/(g·h), the pressure 5 MPa. The catalyst was the bi-functional catalyst which is mixed with methanol synthesis and dehydration catalyst as 1:1 mass ratio. The effects of temperature and space velocity on the reaction were studied. The hyperbolic kinetics equations based on Langmuir-Hinshelwood adsorption was selected. The Levenberg-Marquardt method was utilized to estimate the parameters of the kinetics equations. A proper global kinetics model was gained. It is proved that the model is reliable examined by the mathematical statistics and residual error analysis.


Liu D.,East China University of Science and Technology | Huang X.,East China University of Science and Technology | Hu L.,East China University of Science and Technology | Fang D.,East China University of Science and Technology | And 2 more authors.
Journal of Natural Gas Chemistry | Year: 2010

Ethylidene diacetate was prepared by reacting dimethyl ether, acetic acid and syngas in the presence of a catalytic system comprising RhI3, PPh3 and CH3I. The effects of reaction temperature, pressure, time and the CO/H2 molar ratio on the conversion of dimethyl ether and the product selectivity were investigated under the same catalyst formulation. Results showed that a maximum conversion of dimethyl ether was obtained when a mixture consisting of 0.3 mol dimethyl ether and 120 ml acetic acid was reacted at 180 °C and 3.0 MPa for 10 h at a stirring speed of 600 rpm under a syngas flow with a CO/H2 molar ratio of 2.5, which was catalyzed by a catalyst mixture comprising 0.3 g RhI3, 6g PPh3 and 1.3 g CH3I. The selectivity of ethylidene diacetate increased with temperature, decreased with the CO/H2 molar ratio and exhibited a maximum with pressure. © 2010 CAS/DICP.


Chen D.-S.,East China University of Science and Technology | Chen D.-S.,Shanghai Wujing Chemical Co. | Zhang H.-T.,East China University of Science and Technology | Ying W.-Y.,East China University of Science and Technology | Fang D.-Y.,East China University of Science and Technology
Journal of Coal Science and Engineering | Year: 2011

Mathematical simulation was performed on tube-shell reactor for dimethyl ether (DME) synthesis from coal-based syngas. The model was established based on kinetics of dimethyl-ether synthesis from syngas over a bifunctional catalyst, which is mixed by methanol synthesis catalyst and dehydration catalyst as 1:1 mass ratio. Methanol synthesis from CO and CO2 and methanol dehydration were selected as three-independent reactions, CO, CO2, and DME as key components to establish the one-dimensional mathematical model of the reactor. The gas concentration and temperature profiles inside the reactor tubes were obtained. The operating conditions affecting DME synthesis were also discussed based on the model. The simulations indicate that higher pressure and lower temperature at the inlet and rich hydrogen in the reactant are favorable in direct DME synthesis in fixed-bed process, and the temperature of boiling water affect the reactor performance seriously. © 2011 The Editorial Office of Journal of Coal Science and Engineering (China) and Springer-Verlag Berlin Heidelberg.


Yang Z.,East China University of Science and Technology | Zhu J.,East China University of Science and Technology | Wu B.,East China University of Science and Technology | Chen K.,East China University of Science and Technology | Ye X.,Shanghai Wujing Chemical Corporation Ltd.
Fluid Phase Equilibria | Year: 2011

Liquid-liquid equilibrium data of the solubility curves and tie-line compositions were determined for ternary systems of water. +. acetyl acetone. +. propyl acetate at 288.15. K, 298.15. K and 313.15. K and atmospheric pressure. Distribution coefficients were evaluated for the immiscibility region. The reliability of the experimental tie-lines has been confirmed by using Othmer-Tobias and Bachman correlation. The experimental data were fitted using the NRTL and UNIQUAC equations, parameters of these two models were regressed. © 2011 Elsevier B.V.

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