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SCI和EI收录∣中国化工学会会刊
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Table of Content
28 December 1992, Volume 7 Issue 2
    Original Article
    STUDIES ON SYNTHESIS OF SILICA SOL-ORGANIC POLYMER COMPOSITE EMULSION
    LONG Fu, WANG Wei, XU Yongshen, CAO Tongyu, HU Jinsheng
    1992, 7(2):  119-124.  doi:
    Abstract ( )   PDF (1773KB) ( )  
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    An emulsion of polystyrene/poly (butylacrylate-methyl methacrylate acrylic acid) core/shell latex particles (PS/P (BA-MMA-AA)) has been prepared by use of three synthetic methods. The effects of synthetic methods on the distribution of carboxyl groups in latex particles were studied. The results show that the seed emulsion polymerization in which the pre-emulsified monomers were added by dropping method to the second stage is the best technique for obtaining the optimum distribution of carboxyl groups on the surface of the latex particles. Furthermore, by using PS/P (BA-MMA-AA), a type of novel composite emulsion of silica sol-PS/P (BA-MMA-AA) was synthesized with the above method. By observation through transmission EM, the morphology of the latex particles obtained shows that a composite structure has been formed between silica sol particles and organic polymer particles.
    EXTENSION OF SOAVE EQUATION OF STATE TO LIQUID DENSITY
    WANG Qi, CHEN Genghua, HAN Shijun, Kwang-ChuChao
    1992, 7(2):  125-131.  doi:
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    On the basis of vapor pressures, volumes of saturated vapor and liquid, both parameters "a" and "b" in Soave equation of state are treated as temperature dependent and an extended Soave equation is proposed in this work. The VLE for 38 pure components including polar substances have been calculated. The comparison of calculated results with experimental data shows the prediction of liquid density is improved over Soave equation without losing the accuracy of prediction in vapor pressure and vapor density.
    CORRELATION OF CRITICAL LOCI FOR FLUID MIXTURES
    LI Ping, ZHENG Xiyin, LIN Jifang
    1992, 7(2):  132-143.  doi:
    Abstract ( )   PDF (2752KB) ( )  
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    The hard-sphere three-parameter equation of state proposed in our previous investigation was applied to correlate binary critical loci of alkane-alkane, aromatic-aromatic, hydrocarbon-inorganic gas and systems containing oxygenated hydrocarbons including those exhibiting type Ⅲbehaviors as classified by van Konynenberg and Scott. A new procedure was also presented which simplified mathematical manipulations and permitted the reduction of the computation time.Results were compared with those obtained by Patel-Teja equation with temperature-dependent binary interaction parameters. Significant improvements were achieved by the proposed equation with temperature-dependent parameters.In addition parameters obtained from the critical locus calculations were used to predict vapor-liquid equilibria of hydrogen-carbon monoxide and hydrogen-carbon dioxide systems. Prediction accuracies were found to be very satisfactory.
    IONIC GEL EXTRACTION IN AN ELECTRIC FIELD
    ZHANG Shicheng, FAN Zheng
    1992, 7(2):  144-150.  doi:
    Abstract ( )   PDF (1458KB) ( )  
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    This paper reports the successful synthesis of an ionic gel with good swelling property and high sensitivity to the electric field. This gel shrinks rapidly as an electric field with a low supply voltage is applied across it, and the overall shrinking process can be completed in 15 minutes. The gel would swell again when the the electric field is removed. A theoretical analysis and experimental study have been carried out on the kinetics of swelling and shrinking of the disk shape gels. The modeling of kinetics of swelling and shrinking of the disk gels is in good accordance with the experimental results.
    A STUDY ON SUPERCRITICAL FLUID EXTRACTION OF L-PROLINE
    SHEN Zhongyao, SHI Lihua, YANG Jichu, LIU Chongyi
    1992, 7(2):  151-156.  doi:
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    The extraction of L-proline from the fermentation broth filtrate with the supercritical fluid was studied. It has been proved that L-proline and most amino acids are hardly dissolved in the pure supercritical carbon dioxide fluid. When the methyl alcohol was added as an entrainer in L-proline solution or carbon dioxide fluid, the solubility of L-proline in the supercritical fluid would be greatly increased, but ethyl alcohol was unsatisfactory as an entrainer.The influences of extraction pressure, temperature, time, flow rate of fluid, concentrations of L-proline and entrainer on the yield of L-proline have been investigated for searching the optimal extraction conditions.
    VAPOR-LIQUID EQUILIBRIUM IN THE SYSTEM CARBON DIOXIDE/ISO-PENTANE FROM 253 TO 443 K AT PRESSURES UP TO 10 MPa
    CHENG Huazhe, JohnA.Zollweg, William B.Streett
    1992, 7(2):  157-163.  doi:
    Abstract ( )   PDF (1877KB) ( )  
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    Equilibrium pressures and compositions for the binary mixture carbon dioxide-iso-pentane were measured on nine isotherms from 253K to the iso-pentane critical temperature. On each isotherm, the entire pressure range of phase coexistence was covered. The mixture critical line has been located and is shown to be contiuous in Pressure-Temperature-Composition (P-T-X) space between the critical points of the pure components. Comparisons are made between the experimental results obtained by Besserer-Robinson and this work with predictions of the Soave-Redlich Kwong, Peng-Robinson, Kubic-Martin, and Adachi-Lu-Sugle cubic equations of state. None was able to correlate the data within our estimated experimental error.
    PARTICLE FLOW PATTERNS IN THE RISER AND DOWNER OF CIRCULATING FLUIDIZED BED
    YANG Yonglin, JIN Yong, YU Zhiqing, WANG Zhanwen
    1992, 7(2):  164-172.  doi:
    Abstract ( )   PDF (2222KB) ( )  
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    This paper presents an experimental study on the flow patterns of FCC particles in a 140 mm ID Circulating Fluidized Bed with concurrent upflow and downflow gas-solid suspension. Based on the distribution of local particle velocity and particle concentration measured by a Fiber-Optical Probe Laser Doppler Velocimeter and a Fiber Optical Probe System respectively, the different flow patterns of local particls concentration, local particle velocity, local particle fluctuating velocity and sectionally average particle velocity in concurrent upflow and downflow gas-solid system have been investigated. It is found that the particle flow in the concurrent downflow is much more uniform radially than that in the concurrent upflow riser. The investigation of flow patterns in different flow systems is of significance to the development of a new gas-solid reactor.
    ON THE RESPONSE FUNCTION AND RESIDENCE TIME DISTRIBUTION OF THE AXIAL DISPERSION MODEL FOR TUBULAR REACTORS
    MAO Zaisha, CHEN Jiayong
    1992, 7(2):  173-187.  doi:
    Abstract ( )   PDF (3092KB) ( )  
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    In view of confusion on the residence time distribution and transfer fucntions for dispersion models, the solution of the model subject to possible combinations of closed and open type boundaries at the ends of a chemical reactor is investigated systematically. In particular, some new results are obtained for the closed-open and open-closed types of reactors. It is found that the interchange of boundary conditions for these reactors is not immaterial. In several cases, caution is necessary to distinguish whether the transfer function is applied to the concentration or the flux. When the dispersive flux is notable, measurement techniques must be carefully selected to match the kind of transfer functions derived.
    STUDY ON THE PERFORMANCE OF VERTICAL TUBULAR LEACHING REACTOR
    LI Kuanhong, CHEN Xiaoxiang
    1992, 7(2):  188-196.  doi:
    Abstract ( )   PDF (1911KB) ( )  
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    Hydrodynamics in vertical tubular leaching reactor was studied in this work. Based on the observation of particle saltation in curved and square return bends, the inclined return bend was developed and examined. For the narrow and wide size distribution particle system, the method for calculating the particle holdup in upflow and downflow tubes was derived on the basis of generalized fluidization equation. The model of unit pressure drop was given and examined by experiments.
    AN OBJECT-ORIENTED EXPERT SYSTEM FOR TROUBLESHOOTING REFINERY DISTILLATION COLUMNS
    WANG Xuezhong, XU Yifang, SHI Zhongzhi, SHEN Fu +
    1992, 7(2):  197-207.  doi:
    Abstract ( )   PDF (2303KB) ( )  
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    An object-oriented prototype expert system ORDEES for off-line trouble-shooting of refinery distillation columns is developed. It is found that highly modular knowledge base can be designed, and different types of data (e.g., graphs, numberical data, and algorithms) may be manipulated, by using object-oriented knowledge representation. In addition, a method termed Object-Oriented Multifunction Switcher is proposed for building multifunction expert systems. The results of the study are expected to be useful for designing multifunction expert systems for complex petroleum refining and petro-chemical processes with many kinds of equipment.
    ADSORPTION EQUILIBRIUM OF ETHYLENE-CARBON DIOXIDE MIXTURE ON ZEOLITE ZSM5 AND ITS CORRELATION
    WANG Jinqu, ZHANG Yongchun, MaYiHua, LiHaiqing, TangTude
    1992, 7(2):  208-215.  doi:
    Abstract ( )   PDF (1760KB) ( )  
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    Binary gas mixture adsorption equilibrium data for the ethylene-carbon dioxide system were obtained for cation exchanged forms of ZSM5 (Li~+, Na~+, K~+, Rb~+, Mg~(+2), Ca~(+2), Sr~(+2), and Ba~(+2)) for the gas phase CO_2 mole fracion of 0.766 at 308K and 101. 3kPa. The experimental adsorption phase diagrams were obtained for CO_2-C_2H_4 on NaZSM5 and MgZSM5. Single component adsorption isotherms for CO_2 and C_2H_4 were also obtained for these two zeolites. The single component data were used to obtain parameters derived in the vacancy solution model (VSM) and the statistical thermodynamic model(STM). These parameters were, in turn, used to predict binary mixture isotherms for these two zeolites. The agreement between experimental data and predicted value is generally good.
    NONUNIFORMITY OF TWO PHASE FLOW IN CAPILLARY SYSTEMS
    MAO Zaisha , CHEN Jiayong
    1992, 7(2):  216-224.  doi:
    Abstract ( )   PDF (2119KB) ( )  
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    Gas-liquid flow in simple systems consisting of capillaries is analyzed by theory of irreversible thermodynamics so as to shed light on induction of nonuniformity of multiphase flow. By the Prigogine’s theorem of minimum entropy production, stability of uniform two-phase flow and possible transition to nonuniform distribution are discussed. The analysis of model systems suggests potential application of irreversible thermodynamics to research of multiphase hydrodynamics in chemical reactors.
    GIBBS ENSEMBLE MONTE CARLO SIMULATION OF VAPORLIQUID EQUILIBRIA FOR SIMPLE FLUIDS
    GUO Mingxue , WANG Wenchuan, LU Huanzhang
    1992, 7(2):  225-234.  doi:
    Abstract ( )   PDF (1972KB) ( )  
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    The Gibbs ensemble Monte Carlo simulation method has been investigated and used to calculate the vaporliquid equilibria of a real binary mixture, argon-methane. In this simulation, the micro-structural and macroscopic properties, including the distribution function, internal energy, densities and compositions of coexisting vapor and liquid phases as well as the enthalpy of vaporization are obtained. Compared with experimental data and calculated results from equations of state, our simulated phase equilibrium properties are of good accuracy, which demonstrates that this simulation methods is a powerful tool in research on phase equilibria of fluids.
    CONTRIBUTION TO PACKED COLUMNS SCALE-UP IN SEPARATION PROCESSES
    Reinhard Billet
    1992, 7(2):  235-252.  doi:
    Abstract ( )   PDF (5305KB) ( )  
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    Correlations will be presented to describe liquid hold up, loading and flooding capacity, volumetric mass transfer coefficients on liquid and gas or vapour phase and the pressure drop as a basis for computing packed columns, dumped and regular as well, including the influence of end effects on scaling. The relationships are found on a sound physical and mathematical basis and their validity were confirmed by experimental investigations of many packings; some of them were selected to be considered in this work.