JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 9 , Issue 1
Showing 1-16 articles out of 16 articles from the selected issue
  • KIICHI TERUYA, SHUJI HOSAKO, TATEO NAKANO, ISSEI NAKAMORI
    1976 Volume 9 Issue 1 Pages 1-5
    Published: February 29, 1976
    Released: March 29, 2006
    JOURNALS FREE ACCESS
    A simple and convenient method has been derived for estimating the water activities, aw, of the aqueous solution containing electrolytes 1, 2, ..., k by the following relation:
    aw=1/ITkIkaow(k)
    where aow(k) is the water activity of a solution containing only the electrolyte k at the same ionic strength as the mixture; IT is the total ionic strength of the mixture and Ik is the ionic strength of the electrolyte k in the mixture. In the systems HCl-NaCI-H2O, HCl-BaCl2-H2O, HC1-NaClO4-H2O, HCl-Ba(ClO4)2-H2O, HCl-Na2SO4-H2O and HCl-NaClO4-Ba(ClO4)2-H2O, the water activities calculated by the above relationship agree within 2% deviation with the experimental results obtained from measurement of water vapor pressures by the dynamic method using a gas chromatograph.
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  • ISAMU NAGATA, MASATAKA NAGASHIMA
    1976 Volume 9 Issue 1 Pages 6-11
    Published: February 29, 1976
    Released: March 29, 2006
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    A new expression for the liquid-phase activity coefficient is presented. It is a modification of the quasi-chemical theory. The new equation contains only two adjustable parameters per binary system provided that the coordination number is fixed to be 4 to 6. The capability of the equation is tested with typical nonideal binary systems. Extension of the equation to ternary systems is demonstrated with examples of vapor-liquid and liquid-liquid equilibrium prediction from binary data alone.
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  • HIROSHI SUGI, TOMOSHIGE NITTA, TAKASHI KATAYAMA
    1976 Volume 9 Issue 1 Pages 12-16
    Published: February 29, 1976
    Released: March 29, 2006
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    Liquid-liquid equilibria for the three systems methanol-ethyl ether-cyclohexane, methanoltetrahydrofuran-cyclohexane, and methanol-methyl acetate-cyclohexane were measured at 25°C. For these systems, the applicability of the extended Kretschmer-Wiebe equation was examined by taking account of both the self-association of methanol and the association of unlike molecules between methanol and polar solvents. For methanol ethyl ether cyclohexane system, experimental data gave reasonable agreement with the binodal curve calculated by use of the parameters obtained from binary data alone. For the other two systems, the agreement between experimental and calculated binodal curves were not satisfactory.
    The NRTL equation was also utilized to calculate the ternary liquid-liquid equilibria from the constituent binary data, but it failed to represent the experimental solubility data.
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  • KORETSUNE UEYAMA, JUN-ICHI HATANAKA
    1976 Volume 9 Issue 1 Pages 17-22
    Published: February 29, 1976
    Released: March 29, 2006
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    The effects of surface active impurity on flow around and inside a spherical liquid drop in another liquid phase are studied theoretically, on the basis of the "stagnant cap model" developed by Savic and by Davis and Acrivos. It is found that only a little modification is sufficient for the previous theory, which completely neglected the viscosity effect of the drop phase. Bulk-phase transfer of the surfactant is taken into account. Available data on terminal velocities of drops are analyzed by the calculated results.
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  • SHIGERU MATSUMOTO, SHOZABURO SAITO, SIRO MAEDA
    1976 Volume 9 Issue 1 Pages 23-28
    Published: February 29, 1976
    Released: March 29, 2006
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    An ellipsoid bouncing model, previously presented to express the irregular bounce of particles on a duct wall, was extended to simulation of gas-solid suspension flow in a circular pipe. Simulated results were compared with experiments in terms of concentration distribution, particle velocity, additional pressure drop and frequency of particle collisions with the pipe wall. If the mean observed deformation, ηob, was taken as the value of the parameter, the mechanism of particle motion was explained for the most part by the simulation.
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  • SATOSHI OHSHIMA, TOSHIICHI TAKEMATSU, YASUNORI KURIKI, KAZUO SHIMADA, ...
    1976 Volume 9 Issue 1 Pages 29-34
    Published: February 29, 1976
    Released: March 29, 2006
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    Packed-bed cocurrent up-flow reactors gave better results than conventional trickling flow reactors in hydrodesulfurization of heavy oil. To find the characteristics of this up-flow type reactor, liquid-phase mass transfer coefficient, gas-liquid interfacial area and gas holdup in a column packed with 0.1, 0.28 or 0.43 cm glass beads were studied using the oxidation reaction of sodium sulfite.
    Experiments were carried out at a reaction temperature of 20°C. Superficial liquid and gas velocities based on empty column, ul and ug, were 1-6 and 0.5-6cm/sec, respectively, for any size of glass beads. With the values of ul and ug, glass beads bed remained stationary, expanded or fluidized.
    Stagnant gas holdup was observed under the condition of ul<ulmf (minimum fluidization liquid velocity).
    It was found that the stagnant gas holdup was almost ineffective on mass transfer. Volumetric mass transfer coefficient, kLa, and gas-liquid interfacial area, ", were well correlated with dynamic gas holdup, εgd, which was a difference between total and stagnant gas holdups. When ul< uimf, the correlation was represented in a simple equation of kLa=fpεgd (fp: constant depending on particle size, dp).
    kLa was found to be mainly affected by gas-liquid interfacial area. Larger packing particles gave larger values of kLa. They were larger than those in bubble columns when dp≥0.28 cm and smaller when dp=0.1cm.
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  • KYOJI SATO, MASARU ISHIDA, TAKASHI SHIRAP
    1976 Volume 9 Issue 1 Pages 35-39
    Published: February 29, 1976
    Released: March 29, 2006
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    A porous solid sphere 3.92 cm in diameter was soaked with water and dried in a fluidized bed maintained at a constant temperature between 80°C and 140°C. The pressure increase and the temperature profiles within the solid sphere were continuously measured. The pressure increase ΔP, which has been utterly ignored heretofore, was found to be enormous (30 to 246 mmHg).
    The dynamic effective diffusivity and the flow equation interrelating the gradient of concentration and that of the total pressure provided data to predict accurately this pressure increase during the course of drying.
    The evaporation temperature Tc was also predictable by solving the flow equations and a simplified equation of heat transfer simultaneously.
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  • TAKESHI TSUBOKA, TAKASHI KATAYAMA
    1976 Volume 9 Issue 1 Pages 40-45
    Published: February 29, 1976
    Released: March 29, 2006
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    A new general method for mathematical simulation of multicomponent equilibrium stage processes is presented. The procedure consists of solving component material balance equations with a tridiagonal matrix algorithm and performing equilibrium calculation based on the "pseudoequilibrium" concept, instead of solving simultaneous equilibrium equations by some optimization method. The present method is simple, fast and numerically stable.
    The application of the method to multistage, multicomponent extraction problems is described. Moreover, the feasibility of the modified Wilson equation to extraction problems is shown.
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  • YASUSHI TAKEUCHI, KUNITARO KAWAZOE
    1976 Volume 9 Issue 1 Pages 46-52
    Published: February 29, 1976
    Released: March 29, 2006
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    The adsorption of CO2 on the fixed beds of Molecular Sieves 4A, 5A and 13X, respectively, was studied by use of isotopic exchange between CO2 and 14CO2.
    Fixed-bed breakthrough curves obtained were analyzed, comparing them with theoretical curves, and the values of intraparticle diffusion resistance were calculated.
    The values were further analyzed based on the authors'' diffusion model with the aid of physical properties of adsorbent particles.
    The intraparticle diffusivity is greatly affected by the ratio of micropore radius (in this case the openings of crystalline cavity) to diffusing molecules.
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  • SHIMIO SATO, SHIGERU IGARASHI, MINORU MORITA
    1976 Volume 9 Issue 1 Pages 53-57
    Published: February 29, 1976
    Released: March 29, 2006
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    Effective rate equations corresponding to an intermolecular and an intramolecular mechanism were derived, taking into account the reaction properties. Reaction mechanism was experimentally studied. As a consequence, the intramolecular mechanism was considered to be much more rational than the intermolecular one, and its effective rate equation could well represent the reaction characteristics. Also, rate parameters for the mechanism proposed were determined from experimental data.
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  • HIROSHI UTSUGI, YASUHIKO ARAI, KUNIO ARAI, SHOZABURO SAITO
    1976 Volume 9 Issue 1 Pages 58-63
    Published: February 29, 1976
    Released: March 29, 2006
    JOURNALS FREE ACCESS
    A more rigorous method is proposed for determining experimentally the kinetic parameters, i.e. rate constant and order of reaction for pyrolysis of hydrocarbons from low conversion data obtained in a wide range of initial concentrations using a flow reactor. It was experimentally confirmed that the reactor used satisfied the boundary condition of constant wall temperature. The mass and heat transfer equations describing radial and axial profiles for the flow reactor in laminar are solved numerically using an apparent first-order rate equation, and this technique can be easily applied to the determination of kinetic equations for pyrolysis of hydrocarbons. For example, the pyrolysis of ethane was carried out at different initial concentrations, and using the data obtained here the rate equation for pyrolysis of ethane was determined by the method proposed in this paper.
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  • TERUO KIKUTA, SHINZO OMI, HIROSHI KUBOTA
    1976 Volume 9 Issue 1 Pages 64-70
    Published: February 29, 1976
    Released: March 29, 2006
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    The emulsion copolymerization of acrylonitrile and styrene was carried out. The rate of reaction, the number of polymer particles and the compositions of copolymer were determined experimentally under various initial monomer concentrations, volume fractions of monomers and emulsifier concentrations.
    A mathematical model of this copolymerization system, in which one monomer is hydrophilic and the other is hydrophobic, has been derived based on the assumptions that the reaction takes place inside polymer particles and that there exists a partition equilibrium of acrylonitrile between the aqueous and the oil phases. The Lewis-Mayo equation was modified by the introduction of the parameter B, the ratio of concentrations of two monomers in polymer particles. It was shown that B is a function of a, the partition coefficient of acrylonitrile, and the monomerwater phase ratio. The Lewis-Mayo equation was solved numerically, and the calculated results coincided well with the observed ones.
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  • TADASHI SHIROTSUKA, YOSHINORI KAWASE
    1976 Volume 9 Issue 1 Pages 71-73
    Published: February 29, 1976
    Released: March 29, 2006
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  • TAKESHI KATAOKA, HIROYUKI YOSHIDA
    1976 Volume 9 Issue 1 Pages 74-75
    Published: February 29, 1976
    Released: March 29, 2006
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  • HIROMU OHNO, Em NAKANISHI
    1976 Volume 9 Issue 1 Pages 76-78
    Published: February 29, 1976
    Released: March 29, 2006
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  • MANABU YAMAGUCHI, TAKASHI KATAYAMA, KORETSUNE UEYAMA
    1976 Volume 9 Issue 1 Pages 79
    Published: February 29, 1976
    Released: March 29, 2006
    JOURNALS FREE ACCESS
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