JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 16 , Issue 3
Showing 1-15 articles out of 15 articles from the selected issue
  • MASATAKA TANIGAKI, NOBUKATSU KOMATSU, MAKOTO HARADA, WATARU EGUCHI
    1983 Volume 16 Issue 3 Pages 167-172
    Published: June 20, 1983
    Released: April 04, 2006
    JOURNALS FREE ACCESS
    Diffusion coefficients of tin, antimony and silver in lead-bismuth liquid mixtures were measured using the capillary-reservoir technique at 773 K. The observed values were comparable with the existing data in the literature. The dependency of the measured diffusion coefficients upon the composition of the solvent mixture was found to be qualitatively estimated by the extended relaxation model proposed by Harada et al., though the quantitative evaluation of the model was not possible due to the uncertainty in the self-diffusion coefficients in pure bismuth reported in the literature.
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  • S. D. KIM, C. H. KIM
    1983 Volume 16 Issue 3 Pages 172-178
    Published: June 20, 1983
    Released: April 04, 2006
    JOURNALS FREE ACCESS
    The axial dispersion characteristics of liquid phase in two (gas-liquid, liquid-solid) and three (gas-liquid-solid) phase fluidized beds were studied in a 14.5 cm-I.D. column.
    The effects of liquid velocity (2-13 cm/s), gas velocity (0-12 cm/s), liquid viscosity (1-27 cP), surface tension (38.5-76 dyn/cm) and particle size (1.7-6.0 mm) on axial dispersion of liquid phase were examined.
    Liquid-phase axial dispersion in terms of Peclet numbers were correlated empirically by equations involving the ratio of fluid velocities and the ratio of particle-to-column diameters. The dispersion coefficients increased with gas flow rate, liquid surface tension and viscosity. However, liquid viscosity generally reduced the coefficient in beds of smaller particles at higher gas rates.
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  • KUNIO KATO, ICHIRO ONOZAWA, YOSHIKAZU NOGUCHI
    1983 Volume 16 Issue 3 Pages 178-182
    Published: June 20, 1983
    Released: April 04, 2006
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    Wet activated alumina particles were dried in the constant drying rate period in a dispersed bed. The heat transfer coefficients between the particles and gas were measured.
    The Nusselt number for gas-particle heat transfer in the dispersed bed was affected by the particle Reynolds number and the void fraction. The empirical equation for gas-particle heat transfer in the dispersed bed was obtained.
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  • NORIAKI WAKAO, SHIGEHARU TANISHO
    1983 Volume 16 Issue 3 Pages 182-186
    Published: June 20, 1983
    Released: April 04, 2006
    JOURNALS FREE ACCESS
    Theoretical calculations were carried out for the separation of light and heavy species in a gaseous mixture. It is shown that a heavy species present in low concentration in a gas is effectively enriched by a batchwise diffusion unit in which the gas is imposed a number of times as a pulse on a porous separating membrane.
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  • MAKOTO HARADA, MASATERU MORI, MOTONARI ADACHI, WATARU EGUCHI
    1983 Volume 16 Issue 3 Pages 187-192
    Published: June 20, 1983
    Released: April 04, 2006
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    The mechanism and rates of aqueous-phase reactions in cupric ion and benzoylacetone system were elucidated. The exchange reaction between enol and keto forms was expressed by ?? The rate constants for enol and keto forms were determined as kE = 81s-l and kK = 0.018s-1, respectively. The reaction rate between enolate ion and cupric ion was well interpreted by Eigen''s mechanism and the rate constant of second-order reaction was kCB = 1.1 × 109 dm3/mol•s. Direct reactions between cupric ion and the enol and keto forms of benzoylacetone were observed. The rate constants for the enol and the keto forms were 2000 and 12 dm3/mol•s, respectively.
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  • MAKOTO HARADA, MASATERU MORI, MOTONARI ADACHI, WATARU EGUCHI
    1983 Volume 16 Issue 3 Pages 193-203
    Published: June 20, 1983
    Released: April 04, 2006
    JOURNALS FREE ACCESS
    The aim of the present work is to elucidate the extraction mechanism of metals by chelating agents. We selected the benzoylacetone-copper system as a typical one, in which the reaction of the complex formation is very rapid due to the Jahn-Teller effect and the chelating agent has relatively large solubility in water. Therefore, the contribution of the aqueousphase reaction to metal extraction seems to be stronger in this system than in other systems involving slower complexation reaction with less watersoluble chelating agents. It will be shown that the interfacial reaction process plays an important role in metal extraction even in this case.
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  • YOSHIKAZU MIYAKE, YOICHIRO TAKENOSHITA, MASAAKI TERAMOTO
    1983 Volume 16 Issue 3 Pages 203-209
    Published: June 20, 1983
    Released: April 04, 2006
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    The physicochemical properties of anti 2-hydroxy-5-nonylacetophenone oxime, the active species of SME 529, were measured in the system consisting of Dispersol, a commercial organic diluent, and aqueous sulphate solution. The initial extraction rate of copper with this chelating agent was studied by use of a transfer cell with a free flat interface. The effects of the concentrations of copper, proton and extractant on the initial extraction rate were reasonably interpreted by a mechanism where by the extraction rate is determined by the secondary complex formation and the diffusion of extractant in the organic phase.
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  • ISAO KOMASAWA, TSUTAO OTAKE, ICHIZO HATTORI
    1983 Volume 16 Issue 3 Pages 210-217
    Published: June 20, 1983
    Released: April 04, 2006
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    Extraction equilibrium formulations were established for the distribution of nickel, cobalt and sodium between n-heptane and xylene containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester ((LH)2) and 5 × 102 mol/m3 (Na, H)NO3. The composition of the organic phase species is NiL22(LH)2, CoL2(LH)2 and NaL(3/2)(LH)2, over a range of loading ratio, [M]1/[(LH)2]feed, less than 0.08 for cobalt and 0.008 for nickel. The ratio of the extraction constant for the commonly used di-(2-ethylhexyl)phosphoric acid to that using the present reagent is of the order of 10 for cobalt, copper and sodium, but increases to the order of 100 for nickel.
    With increase in loading ratio, successively larger aggregated species such as (NiL2(LH)2)n(LH)2 and (CoL2)n(LH)2 (n=l, 2, 3, ...) appear. Identification of these species has been established on the assumption that the extraction constants are independent of the number of metal atoms, n, in the species.
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  • SHOICHI KIMURA, YOSHIKAZU TAKAGI, SETSUJI TONE, TSUTAO OTAKE
    1983 Volume 16 Issue 3 Pages 217-223
    Published: June 20, 1983
    Released: April 04, 2006
    JOURNALS FREE ACCESS
    Oxidation of porous zinc sulfide pellets, composed of fine grains having log-normal size distributions, was carried out using a differential flow reactor under oxygen partial pressure of 1-16 kPa and temperature of 953-1113 K.
    The overall conversion rate data were represented by a simple power law rate expression. The reaction order with respect to the solid reactant varied with the standard deviation of the grain size distribution. This variation agreed well with the theoretical prediction by the grain model accounting for grain size distribution. The reaction order with respect to the gaseous reactant was 1/2.
    The surface rate constant was then found to be correlated in an Arrhenius equation. K''= 5.56×108e-244/RT (mol1/2/m1/2 • s) The rate constant agreed well with that for oxidation of sphalerite single crystals by other workers as well as with the rate constant reproduced from the data in the literature on oxidation of porous pelleted zinc sulfide.
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  • MOTONOBU GOTO, SHIGEO GOTO, HIDEO TESHIMA
    1983 Volume 16 Issue 3 Pages 223-228
    Published: June 20, 1983
    Released: April 04, 2006
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    Hydrolysis of diethyl succinate as a consecutive reaction was investigated in a batch slurry reactor catalysed by cation exchange resin.
    Two models, one realistic and one simplified, were derived. The differences between the models were not significant under the conditions of this study, and both showed good agreement with experimental data.
    The catalytic activities for gel-type resins were higher than for a macroreticular (MR)-type resin and a free acid. For gel-type resins, the reaction rate per equivalent increased as crosslinking decreased.
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  • MOTOAKI ADACHI, KIKUO OKUYAMA, YASUO KOUSAKA
    1983 Volume 16 Issue 3 Pages 229-235
    Published: June 20, 1983
    Released: April 04, 2006
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    The electrical neutralization of charged aerosol particles by bipolar ions in a flow-type chamber was studied theoretically and experimentally. The time-dependent changes in electrical charge of aerosol particles were evaluated by numerically solving the "birth-death" equation under various conditions. The calculated results were arranged using dimensionless parameters, and the necessary conditions for charged particles to attain equilibrium charge distributions were clarified. The graphs presented in this paper enable one to estimate the minimum concentration of bipolar ions required to neutralize the charged particles under various conditions. Some of these results are found to agree with experimental results obtained by means of the visual technique in the measurement of particle size and electrical mobility.
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  • HIROKAZU NISHITANI, EIICHI KUNUGITA
    1983 Volume 16 Issue 3 Pages 235-241
    Published: June 20, 1983
    Released: April 04, 2006
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    Efficient use of both energy and resources in process design was studied by the multi-objective analysis. Exergy consumption and total investment cost are used to measure energy and resource conservation, respectively. A family of ε-constraint problems, in which the constraint is the exergy consumption, was formulated to obtain the trade-off between the two objectives and was solved successively by the max-sensitive method. The preferred solution is easily obtained for a specified condition by using the sensitivity profile along the non-inferior solution curve. An evaporator system for milk concentration is solved as an illustration.
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  • MASAO IMAEDA, HIROMI OTSU
    1983 Volume 16 Issue 3 Pages 241-245
    Published: June 20, 1983
    Released: April 04, 2006
    JOURNALS FREE ACCESS
    This study is directed toward establishing a DDC algorithm which gives better control performance than the usual analog PID controller. The fundamental concept of this DDC algorithm is based on the minimal prototype algorithm. Its control seems to be ideal, but the response has a hidden oscillation. The reason is that the control works too rapidly on the manipulated variable to settle to the reference value. In this paper, the desired response is made to settle slowly to the reference value, that is, it needs one or more samplings compared with the minimal prototype algorithm. This nonminimal algorithm has one or two adjustable parameters, like the analog PID controller. With suitable values of these parameters the nonminimal prototype DDC algorithm shows excellent performance compared with the analog or the discrete digital PID. These adjustable parameters are optimized for the 2nd-order system with time delay and are related to the process parameters. Once approximate values of the process parameters are known, the optimum DDC can then be obtained.
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  • HIROSHI YUKAWA, KAZUHIRO SHIMURA, AKIHIRO SUDA, AKIO MANIWA
    1983 Volume 16 Issue 3 Pages 246-248
    Published: June 20, 1983
    Released: April 04, 2006
    JOURNALS FREE ACCESS
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  • SHINZO OMI, MAKOTO NEGISHI, JIRO TANAKA, MAMORU ISO
    1983 Volume 16 Issue 3 Pages 248-251
    Published: June 20, 1983
    Released: April 04, 2006
    JOURNALS FREE ACCESS
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