KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 10 , Issue 4
Showing 1-16 articles out of 16 articles from the selected issue
  • Katsuroku Takahashi, Hiroshi Takeuchi
    1984 Volume 10 Issue 4 Pages 409-414
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Extraction rate of copper from aqueous solution by LIX65N-kerosene solution was studied by use of an agitated vessel with a plane interface. The extraction rate was found to increase with repeated regeneration of the LIX solution with sulfuric acid solution. Such behavior is due to impurities contained in commercial LIX65N. They are surface-active substances that participate in a reaction between the extractant reagent and copper ion at the liquid-liquid interface; they are liable to be dissolved out by contacting with diluted sulfuric acid. As a result, the rates of copper extraction by LIX65N are proportional to ([RH]i/[H+]i)p. When the reaction is affected by impurities in the extractant, the exponent p was found to be 0.5. When refined LIX solution was used, the value of p was more than unity. Even for the original LIX65N solution, however, the values of p for extraction in a contactor with large interfacial area or from aqueous solution of low pH become more than unity.
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  • Toshikuni Yonemoto, Takayoshi Sindo, Hiroyuki Inomata, Teiriki Tadaki
    1984 Volume 10 Issue 4 Pages 415-420
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    For the purpose of examining the influence of ionic migration on the absorption rate of carbon dioxide by aqueous solutions of sodium hydroxide, the proper diffusion equations were written for all species present in the liquid phase with the inclusion of an ionic migration term. The system was solved through finite difference numerical computations, under both isothermal and adiabatic conditions. The validity of our analysis was confirmed by absorption experiments conducted in a wetted-wall column. We have also made a detailed comparison of our theoretical and experimental results with theoretical results previously reported in the literature. It was found that, through the present method of analysis, the absorption rate can be predicted on an almost quantitative basis even in the case of concentrated solutions, something not previously achieved by other methods of theoretical analysis. It was clarified that sodium ion, in spite of its chemical inertness, considerably lowers the absorption rate due to its finite migration rate.
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  • Hideki Yamamoto, Akira Kurata, Seiji Sanga
    1984 Volume 10 Issue 4 Pages 421-426
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The specific heats and the differential heats of solution for NH4Br-NH3 and NH4I-NH3 systems were measured in order to construct enthalpy-concentration charts for these systems.
    A twin calorimeter was used. Specific heat measurements were carried out at concentrations of ammonium bromide or ammonium iodide from 0 to 70 wt% and temperatures from 10 to 50°C. Differential heats of solution were measured over a concentration range from 0 to 70 wt% at 25°C. Integral heats of mixing were calculated from the differential heats of solution observed in this work and the differential heats of dilution estimated from the activities of these solution systems.
    The accuracy of the twin calorimeter was examined by measuring the heat of solution of tris (hydroxymethyl) aminomethane (THAM) in 0.1 N HCl (aq.) and 0.1 N NaOH (aq.) at 25°C The maximum deviation from literature data was within 3%.
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  • Yasuo Kato, Yoshifumi Taura, Tokihiro Kago, Shigeharu Morooka
    1984 Volume 10 Issue 4 Pages 427-431
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The heat transfer coefficient between bed and vertical tube wall was measured in three-phase fluidized beds of 12 and 19 cm i. d. Glass spheres of various diameters (particle diameter = 0.52-2.2 mm, particle density =2500 kg · m-3) and alumina spheres (particle diameter = 3.2 mm, apparent particle density 1620 kg · m-3) were fluidized by fluid media of air-water or air-aqueous solution of carboxymethyl cellulose. The superficial velocities of gas and liquid were varied in the range of 2.0-16 cm · s-1 and 0.05-8.0 cm · s-1, respectively.
    The critical liquid velocity, ul3, of the stable fluidization state was correlated as follows.
    ul3/ut=0.336 (ηl0l) 0.5/ (1.9+Fr0.9)
    where ut =terminal velocity of particle, ηl3=water viscosity, ηl=liquid viscosity, Fr=ug2/gdp, ug = superficial gas velocity, g = acceleration of gravity, and dp=particle diameter.
    The heat transfer coefficient, h, in the stable fluidization state was correlated as follows.
    Nu'= {0.058 (RePr) 0.78+2.3} (dh/dh0) -0.5
    where, Nu'=hdpεl/ {kl (1-εl)}, Re'=dpulρl/ {ηl (1-εl)}, Pr=cplηl/kl, dh=heater diameter (2.2-6.3 cm), dh0 =2.2 cm, εl =liquid holdup, kl =thermal conductivity of liquid, ul=superficial liquid velocity, ρl =liquid density, and cplspecific heat of liquid.
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  • Hikoji Inazumi, Junjiro Kawasaki, Takanori Suzuki, Masato Watanabe, Hi ...
    1984 Volume 10 Issue 4 Pages 432-438
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Gas absorption experiments were carried out for the CO2-water system using an inclined plate. Liquid-phase concentration, surface velocity and thickness of liquid film in liquid flow direction were measured to clarify the relationship between mass transfer rates and flow conditions of liquid film.
    Critical points were observed in the concentration curves of CO2, and the flow conditions probably can be classified into two regions (laminar and turbulent).
    For the laminar region, the experimental values coincided very well with the theoretical ones of the penetration model.
    For the turbulent region, the surface renewal model could be applied to reproduce the experimental results. Better correlations between the fractional rate of surface renewal, liquid Reynolds number and a factor involving the effect of plate inclination were obtained.
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  • Masaki Funakoshi, Chang Zang Xing, Hakuai Inoue
    1984 Volume 10 Issue 4 Pages 439-445
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Partial oxidation of propylene by an aluminum tube wall catalytic reactor was carried out. The catalyst used was copper metal deposited on the inner wall of the reactor, and under various conditions the catalyst activities at the initial stage and after long continuous reaction time were measured and analyzed. Though the catalyst activity at the initial stage could be nearly constant, it changed slowly and approached definite constant values.
    At this final stage the effects of reaction conditions on catalytic activity were studied experimentally, and it was found that the catalyst showed two different acrolein production rates depending on the partial pressures of propylene and oxygen; that is, it had high- and low-activity regions. The former was found to be about 100 times higher than the latter, and by analysis of the reaction conditions the difference was assumed to be due to the difference in oxidative state of the copper catalyst.
    To prove these characteristics of the catalyst, its weight change under these reaction conditions was measured by a temperature gravimetry method.
    The results showed that in the state of high acrolein activity the total weight of the catalyst was nearly equal to that of the original copper, and in the low-activity state the weight increase from the original copper corresponded to its oxide state.
    These distinct characteristics of acrolein production activity were observed only for the catalyst after long continuous reaction time.
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  • Hitoshi Funayama, Kojiro Ogiwara, Takuo Sugawara, Hiroyasu Ohashi
    1984 Volume 10 Issue 4 Pages 446-453
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A new chemical actinometer has been developed which detects absolute light intensity in heterogeneous photoreactors where light reflection and dispersion are superimposed by dispersed phases.
    Dilute potassium trisoxalatoferrate aqueous solution (concentration of 0.03 mol. m-3) containing 1, 10-phenanthroline, 0.135 moil·m-3, and potassium oxalate, 1.5 mol·m-3, was irradiated by 366 nm monochromatic parallel light in a temperature range from 20 to 40°C;and the photolysis of potassium trisoxalatoferrate was kinetically studied. Two parameters were determined in the derived reaction-rate equation in consideration of the effects of diffusions of reactants and products, and that of internal light filtering.
    The absolute light intensity including the effect of reflection was measured in a cell-type batch reactor with a reflector, with using this aqueous solution (dilute potassium trisoxalatoferrate chemical actinometer, or DPOF chemical actinometer). A method is shown for determining the absolute light intensity in heterogeneous photoreactors with DPOF chemical actinometer having optical lengths for which internal light filtering is negligible.
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  • Teruhiko Hoshino, Michio Kasahara, Hiroshi Yukawa
    1984 Volume 10 Issue 4 Pages 454-460
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The phase-separation needs of a liquid-liquid extraction operation with emulsification were studied experimentally in the absence of mass transfer.
    Objects of this study were to investigate the characteristics of filtration, to search for an excellent filter medium, to clarify the filtration mechanism and to obtain the equation of filtration in the case where emulsion is filtered with glass-fiber filter paper under constant pressure.
    It was experimentally confirmed that filter paper made of glass fiber is superior to that of cellulose for filtration of O/W emulsion. There is a critical filtration pressure which is the maximum pressure at which the emulsion can be filtered clearly. The analytically obtained equation of filtration is valid for O/W emulsion with glass fiber filter paper.
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  • Fujio Watanabe, Masanobu Hasatani
    1984 Volume 10 Issue 4 Pages 461-468
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    From the measurement of equilibrium relations of three water-soluble organic compounds containing nitrogen, dicyandiamide (S1), melamine (S2) and p-phenylene diamine (S3), on active carbon, it was found that these adsorbates have the same order of magnitude of adsorbability as those of other organic adsorbates which have high adsorbabilities on active carbon.
    The intraparticle distributions of accumulated average concentration, Qx, exp. were measured by the nitrogen-tracer method. The Qx, exp.-values were then compared with the Qx, calc.values calculated from diffusion equations, and on the basis of the above comparisons the adsorption and desorption rates as well as the intraparticle diffusion mechanisms were studied. 1) The shapes of the intraparticle distributions of accumulated average concentration showed close linkage to the diffusion mechanism assumed. For sample S2, simultaneous pore- and surface-diffusion dominate the rates. On the other hand, the adsorption rates of samples Si and S3 are controlled by surface diffusion alone. 2) The same diffusion mechanism is valid for both adsorption and desorption, and the surface diffusivity, Ds, of sample S1 for desorption has almost the same value as that for adsorption. For sample S2, the Ds-value for desorption is 0.1 to 0.3 times smaller than that in adsorption.
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  • Ken Toyokura, Yasuo Yamazaki
    1984 Volume 10 Issue 4 Pages 469-474
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Two correlative equations were derived from population balance using Crystal Size Distribution (C. S. D) of a continuous crystallizer under steady-state operation. One related production rate, nucleation rate and crystal size; the other related production rate, growth rate, void fraction and crystal size. Product C. S. D. was expressed as cumulative amount derived from the Rosin-Rammler Method. Linear growth rate affected by crystal size was expressed as the Bransom equation. Nucleation rate and volumetric shape factor were expressed as power functions and these indexes.
    A new design chart directly indicated these characteristic indexes. Industrial data reported by Aoyama were plotted on this chart and indexes were obtained from each system. These results suggest a new method of design and determination of operation conditions of industrial crystallizers.
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  • Hiroyuki Kawashima, Motoyuki Suzuki
    1984 Volume 10 Issue 4 Pages 475-482
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Because of attached algae respiration at the river bed, deterioration of water qualities at nighttime occurs in shallow and eutrophic rivers.
    A mathematical model is presented to describe the water qualities, such as SS, DOC, DO, total inorganic nitrogen (TIN) and phosphate in such rivers. The model incorporates growth respiration of the attached microbes and accumulation of sediment with the water qualities. After a rainfall, the sediment and the attached microbes are washed out, and they start accumulation or growing in the following days.
    The model is compared with observation at the Nogawa River, a tributary of the Tama River, and is found reasonable in simulation of TIN, phosphate and DO concentrations in the river.
    Alternative plans to recover water qualities are assessed through simulation by means of the proposed model and it is found that decreasing nutrient inflow is effective in restoring the DO level at night, even 10 days after a rain.
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  • Satoshi Ohshima, Morio Suzuki, Kazuo Shimada, Motoo Yumura, Toshiichi ...
    1984 Volume 10 Issue 4 Pages 483-488
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The three-phase fluidized bed reactor is generally recognized to be most realistically applicable to a commercial-scale coal liquefaction system. However, problems of solid sedimentation caused by low linear velocities of fluids are involved in the laboratory-scale reactor. To prevent solid sedimentation, a laboratory-scale C. S. T. reactor having hydrodynamic behavior similar to that of a large-scale three-phase fluidized bed reactor was designed and tested.
    Characteristics of the reactor and their effects on coal liquefaction were examined and the following results were obtained.
    1) The reactor was a complete mixing type reactor. The dispersed gas volume and overall absorption coefficient KGa were found to increase with increasing rotational speed of the stirrer.
    2) However, it was found that the volume of dispersed hydrogen and the value of KGa did not affect the coal liquefaction reaction under the given conditions. This implies that the amount of hydrogen supplied to coal through a gas-liquid interface with an area corresponding to the cross-sectional area of the reactor was enough for coal liquefaction under the given conditions or that a sufficient amount of hydrogen is provided by the hydrogen donor components of the solvent.
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  • Teruyuki Nagamune, Isao Endo, Ichiro Inoue
    1984 Volume 10 Issue 4 Pages 489-498
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    This work aimed to obtain a practical algorithm for the maximum production of alcohol by a successive fed-batch fermentation. The authors developed the algorithm of dynamic programming for a practical use : the most appropriate grid points of both state vector and decision vector were selected. The most suitable interpolation method for calculation was investigated. In this algorithm, normalized glucose concentration was adopted instead of fermentation time as an independent variable in order to reduce the dimension of the state vector of the system and to shorten the computation time.
    This algorithm improved the accuracy of the optimal value of the objective function and enabled us to reduce the computation time to as little as 1/60 of the time usually required. It was found that this algorithm is applicable not only for optimization of the fed-batch operation but also for the real-time and on-line control of the system.
    Calculated results showed that the total amount of substrate should be fed into the system four times at most, so as to produce alcohol maximally.
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  • Shinichiro Yokoyama, Toyohiko Hayakawa
    1984 Volume 10 Issue 4 Pages 499-505
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The purpose of this study is to propose a maintenance schedule method based on condition to decide optimum starting point of diagnosis of parts in periodical scheduled maintenance.
    In this study, the mechanical fault diagnosis model is used to obtain the optimum maintenance schedule of parts in operation stage. The model assumes that each part has two failure stages. The first stage of failure is an occurrence of symptoms such as malfunction, small crack and many other defects. The second stage of failure causes the occurrence of catastrophic disaster in plant units. In addition, detection time of symptoms and repair time of parts are considered in this model. The optimum schedule is obtained by minimizing the sum of the costs of maintenance and expected disaster damage under tolerable risk using the proposed model.
    In a numerical example, two-parameter gamma distribution failure models having different shape parameters from each other at two stages are treated for one part, and a two-parameter gamma distribution is used for the probability density function of both detection time and repair time. The results show that this maintenance model has a trade-off relation between maintenance cost and expected disaster damage cost. Useful methods of optimizing the maintenance schedule and minimizing the total cost are shown in the periodical scheduled maintenance period.
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  • Teruyuki Nagamune, Isao Endo, Ichiro Inoue
    1984 Volume 10 Issue 4 Pages 506-512
    Published: July 10, 1984
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The maximum production of alcohol was calculated as functions of available amount of glucose and inoculum size of cell mass for a successive fed-batch cultivation using a brewer's yeast (Saccharomyces cerevisiae). Practical operation charts were obtained for alcohol production, yield of product for consumed glucose and productivity of alcohol. To increase the amount of alcohol, it was found that more frequent feed of substrate, three times at most, with smaller volume of initial batch culture was required for smaller inoculum size of cell mass and larger amount of available glucose.
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  • Toshinaga Kawai, Kenichi Matsumura, Osamu Miyatake, Toshiyuki Hashimot ...
    1984 Volume 10 Issue 4 Pages 513-544
    Published: July 10, 1984
    Released: November 22, 2010
    JOURNALS FREE ACCESS
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