KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 11 , Issue 3
Showing 1-16 articles out of 16 articles from the selected issue
  • Tatsuro Sawada, Yoshitoshi Nakamura
    1985 Volume 11 Issue 3 Pages 247-252
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The degradation of lignin in sulfite pulp wastewater by ozonation was carried out under a range of operational conditions of pH, temperature and concentration of feed ozone. An effective condition of operation for lignin degradation was studied from the dynamic behavior of experimental data at UV absorption at 280 nm with oxalic acid. The degradation rate of lignin increased with increasing pH and temperature. The remarkable difference of concentration of oxalic acid between acidic condition and alkaline condition was considered from the probable degradation pathways of lignin. From the experimental results in the range of temperature T=288-323 K and pH=4-12, the following equation at UV absorption X at 280 nm was obtained.
    -dXdt=2.32×1013exp(-79000/RT)[OH-]0.12CzX0.5
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  • Kiyoshi Idogawa, Koji Ikeda, Takashi Fukuda, Shigeharu Morooka
    1985 Volume 11 Issue 3 Pages 253-258
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The behavior of bubbles in a bubble column of 5 cm diameter was measured by the electric resistivity probe method in the gas velocity range of 0.5-5 cm·s-1 under pressurized conditions up to 15 MPa.
    With an increase in pressure, gas holdup and bubble frequency increased, and bubble size decreased. When the pressure of gas bubbles was more than 5 MPa, the bubble size distribution became narrow and the size of gas bubbles became almost uniform.
    These bubble characteristics were affected greatly by the type of gas distributor under atmospheric pressure. However, the effect of gas distributor upon bubble characteristics decreased with increasing pressure, and above a pressure of 10 MPa no effect was observed. The pressure had no effect on bubble shape.
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  • Keiichi Tsuto, Shigeyasu Imamura, Kensuke Takei, Kanji Majima
    1985 Volume 11 Issue 3 Pages 259-266
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The overall reaction rate for sulfonation or sulfation of organic compounds with a gas mixture of dry air and SO3 gas was investigated in a rising-film tubular reactor. The reaction rate for sulfonation of straight-chain alkylbenzene were explained by gas absorption with an instantaneous chemical reaction in preliminary experiments in a wetted-wall column. Further, the reaction rates for sulfonation of straight-chain alkylbenzene and sulfation of lauryl alcohol were examined in a rising-film tubular reactor, and the controlling step of reaction rate and the reaction region were studied. As a result, under industrial conditions such as equi-molar reaction and SO3 concentration of 1-6 volume % in the gas, it was found that the reaction occurred instantaneously within the gas-liquid interface and that the overall reaction rate was controlled by the mass transfer rate of SO3 in the gas phase.
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  • Takeshi Sako, Ichiro Hayano, Toshikatsu Hakuta, Hiroshi Yoshitome
    1985 Volume 11 Issue 3 Pages 267-271
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Vapor-liquid equilibria (VLE) for the systems HNO3-H2O, HNO3-H2O-Mg(NO3)2 and HNO3-H2O-Ca(NO3)2 were measured at 101.3 kPa. The vapor pressures of aqueous solutions of Mg (NO3) 2 and Ca (NO3) 2, which were necessary for correlation of ternary VLE data, were also measured. From the two ternary VLE data, it was found that the salting-out effect of magnesium salt was larger than that of calcium salt and that the mole fraction of HNO3 in the azeotropic mixture decreased linearly with increasing salt concentration.
    The VLE data for the ternary systems were well correlated by use of the method proposed by the authors. The calculated results of the vapor phase composition and boiling point were in good agreement with the experimental data.
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  • Akira Sannomiya, Yasutaka Oyanoki, Mototake Yano, Yoshio Harano
    1985 Volume 11 Issue 3 Pages 272-279
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Hydrogen adsorption on two sorts of γ-alumina supported nickel (AI13.5 and AM3.5) were characterized by volumetric and TPD measurement at 573 K and room temperature, respectively. After adsorption at 573 K, TPD spectra were detected in the low-temperature region (LTR) at 353-393 K and in the higher-temperature region (HTR) at 573-773 K and their desorbed amounts were designated Vd, L, and Vd, H, respectively. Saturated amounts of adsorbed hydrogen Vas and desorbed hydrogen (Vd, L+Vd, H) on AI13.5 and AM3.5 at the adsorption temperature of 573 K are both about 43 mmol/kg-cat, and the ratios of Vd, H/Vd, L are 9.8 (AI13.5) and 2.9 (AM3.5), respectively. So it is suggested that the hydrogen of Vd, H is spillover hydrogen.
    Next, saturated amounts of adsorbed hydrogen at room temperature Vas were formally represented in the same form as Vas=VL+Vd, L, on both AI13.5 and AM3.5, where VL is the amount of hydrogen desorbed from 198 K to room temperature by TPD. Assuming that the values of Vd, L are proportional to nickel content, the value of VL of AI13.5 is abnormally larger than the value VL of AM3.5.
    Determination of nickel particle size on the catalysts under the condition of the difference of the values Vas and Vd, L at room temperature, one method is proposed and is proved by the kinetic consideration of the surface diffusion rate of dissociated hydrogen atom from nickel particle to support. In this case, it is found that the value of Vas at room temperature must be used to estimated nickel particle size.
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  • Tetsuya Kohya, Masafumi Kuriyama, Masayuki Toda, Eiji Harada, Hirotaka ...
    1985 Volume 11 Issue 3 Pages 280-285
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The heat transfer coefficients of parallel-horizontal rows which are exposed to corona discharge are measured to obtain the fundamental data for practical compact heat exchangers. Three or nine cylinders of 10 mm diameter are placed horizontally and in parallel at the same pitch and several discharge needle electrodes are installed along the axial direction above the central cylinder of the row. Negative high voltages are applied at the needle electrodes to generate a corona wind.
    It is found that an increase of corona current increases the heat transfer coefficients of the cylinders placed in the space, the same as the vertical minimum distance between the needle electrodes and the central cylinder of a cylinder row. The corona wind is analyzed on the basis of the momentum equation to obtain the functional formula for the heat transfer coefficient of each cylinder. It is shown that the theoretical equation correlates well all experimental data obtained for three or nine horizontal in-line cylinders.
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  • Tsutomu Aragaki, Shinji Nakayama, Masanori Suzuki, Shigeki Toyama
    1985 Volume 11 Issue 3 Pages 286-292
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Water film was formed along smooth vertical tubes of various diameters and 800 mm in effective length, and the holdup was measured by a balanced lever. The model of Hanratty et al., based on a concept of boundary layer and mixing length, was modified to correlate the measured data by taking into account the effect of waves in the laminar region. A suggested equation showed good agreement with experimental data over a wide range of Reynoldsnumber, namely 24-6300.
    The shearing force at the wall was measured by an electrochemical method. The friction coefficient obtained from the experimental data indicated clear critical points at both ends of the transition zone (from Re≅170 to Re≅900).
    Wave characteristics were measured by a conductance method with a 10-mm electrode. Wave velocity was determined from cross correlation function. Wave thickness was statistically analyzed and it was found that with increasing Reynolds number the frequency curves tend to be flat and unsymmetrical.
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  • Katsuhiko Fujinawa, Tamami Morishita, Mitsunori Hozawa, Hajime Ino
    1985 Volume 11 Issue 3 Pages 293-299
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The optimum operating conditions in the extraction of copper by (W/O) /W type liquid membranes were studied using a stirred cell, with regard to stability of W/O emulsion, leakage of acid through the membranes and mechanical entrainment of outer water phase into the emulsion. In the experiments, kerosene and Span 80 were used as the oil phase and the surfactant, respectively. LIX64N and SME529 were used as the extraction reagent. The following results were obtained. 1) The acid in the inner water phase leaks into the outer one besides breakage of the membrane under our experimental conditions, and the amount of leakage of HNO3, HCl and H2SO4 decreases in that order. 2) Mechanical entrainment occurs at the initial stage of agitation. It can be depressed by improving the method of feeding the emulsion into the stirred cell. 3) From the leakage of acid and the stability of the emulsion, the optimum concentration of the extraction reagents is about 10 wt% when the surfactant concentration in liquid membrane is 4 wt%.
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  • Yoshinari Baba, Yuji Okamoto, Katsutoshi Inoue
    1985 Volume 11 Issue 3 Pages 300-303
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The adsorption equilibria of phenol on anion exchange resins (KEX 212, KEX 202) with pyridyl group as a functional group were studied at 30°C at relatively high concentrations of phenol
    Anion exchange resins of nitrate, perchlorate, sulfate (only in this case, KEX 202 was used) and chloride forms were prepared by treating the free base resin (KEX 212) using the corresponding acids to investigate the adsorption equilibria of phenol on these five kinds of resins for comparison.
    For the free base form, perchlorate form and sulfate form resins, the adsorption equilibria. could be interpreted by the model on the basis of the following consecutive reactions by addition of phenol (A) molecules to a pyridyl group (B) of the resin.
    B+iA_??_BAi (i=1, 2, 3)
    For chloride form and nitrate form resins, equilibria could be reasonably explained by considering the following consecutive reactions by the simultaneous addition of three phenol molecules.
    B+A_??_BA (CAW<2×102mol/m3)
    BA+3A_??_BA4 (CAW>2×102mol/m3)
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  • Hiroshi Takahashi, Takao Takeuchi
    1985 Volume 11 Issue 3 Pages 304-310
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The heat transfer characteristics in solids-fluid countercurrent moving beds heated externally were analyzed, based on a homogeneous model for temperature field. The solid particles used were glass spheres and alumina spheres of uniform size, and air was used as fluid.
    The effective thermal conductivity in radial direction (ker) and wall heat transfer coefficient (hw) which were estimated under the various operating conditions depended not only on the flow rate of fluid, but also on heat-flow ratio m, which is a unique parameter of the moving bed. m is defined by m=qsolids/qfluid, where q= (mass flux) × (specific heat). The theory of heat transfer for fixed bed was extended with the aid of m, so as to evaluate kerand hω in the moving bed. This method made possible an approximate prediction of their values. Generally, moving solid particles form a slip region of loose packing near the wall. It was pointed out that this slip region becomes a high resistance against heat transfer from wall, which results in a considerable lowering of hw, compared with the fixed bed.
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  • Torajiro Honma, Masafumi Kuriyama, Masahiro Hasegawa, Yoshiteru Kanda
    1985 Volume 11 Issue 3 Pages 311-316
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Measurements of specific surface area of product were made on a new type of ball mill operated under centrifugal force. The results indicated that this type of mill was superior in grinding performance to the conventional ball mill operated under gravitational force and that the use of centrifugal force was effective in reducing the grinding time.
    An empirical equation was proposed for expressing the increase of specific surface area of product by the introduction of a non-dimensional parameter to evaluate the effect of centrifugal force. This equation was found to express well the grinding process under gravitational force as well as that under centrifugal force.
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  • Takashi Kanai, Hiroshi Komiyama, Hakuai Inoue
    1985 Volume 11 Issue 3 Pages 317-323
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Fine particles of TiO2 were prepared by chemical vapor deposition from titanium tetraisoproxide (TTIP) as a starting material. Due to the catalytic effects of TiO2 deposited on the reactor wall; the chemical vapor deposition occurred at temperatures as low as around 510 K. The properties of TiO2-particles changed from amorphous to crystalline (anatase) and from porous to nonporous, depending on the reaction temperature and the initial concentration of TTIP. The particles were spherical, ranging in average diameter from 0.1 to 0.5 μm. The reaction rates of TiO2 deposited on the reactor wall were well expressed by the Langmuir-Hinshelwood type of rate forms. The mechanism of particle formation, being different from the mechanism of homogeneous nucleation generally believed to be followed by the growth of the nuclei, is considered to consist of the initiation reaction of TiO2 deposited on the reactor wall, uniform nucleation and growth, and coagulation. The coagulation step plays an important role in the formation of the spherical particles of specific surface area as high as 300 m/g.
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  • Ikuho Yamada, Hideki Mori, Akira Moriya, Setsuro Hiraoka
    1985 Volume 11 Issue 3 Pages 324-330
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A rigorous plate-to-plate calculation method for reacting distillation problems by considering plate efficiency is proposed.
    Although several calculation methods for reacting distillation have been presented, all assumed the ideal stage, and did not consider the significance of its effect on separation. In the proposed method, a reaction term and a plate efficiency are introduced into a plate-to-plate calculation, and this is combined with Lyster's θ method of convergence to satisfy the condition of plate-matching. This algorithm satisfactorily gave us a rigorous, rapid solution of operational problems of reacting distillation.
    In this paper, numerical examples are presented to show the convergence characteristics of the proposed method and demonstrate the stability of solutions to initial values.
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  • Mompei Shirato, Toshiro Murase, Masashi Iwata, Niichi Hayashi, Eiji Fu ...
    1985 Volume 11 Issue 3 Pages 331-336
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    In a screw press, solid-liquid mixture trapped in a worm channel passes through a gradually reduced flow-area, being dehydrated under variable pressure. The expression pressure in crease by use of a screw-type die is studied, and the effect on dehydration of the two separate driving systems of worm and die is shown.
    The screw-type die consists of a constant pitch-constant depth screw and a fixed cylinder. The resistance against the flow of mixture is dependent on the thread depth, the axial length, and the difference in helical angles between worm and die. A high-pressure profile is produced inside the barrel when the screw-type die is used. Highly compressed cake is continuously discharged from the unit, though the die resistance is great. A further sharp increase in pressure profile can be caused by providing a driving system with different rotation for worm and die. It is shown that the improvement of performance is due to the great difference in the axial velocity components of the two separate rotations.
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  • Hiroaki Yasuoka, Eiji Nakanishi, Eiichi Kunugita
    1985 Volume 11 Issue 3 Pages 337-342
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Numerical simulations of startup operation of a distillation column for binary and ternary mixtures have shown that an experimental correlation which is described by a characteristic function defined in this study is useful in determining the optimum switching time from total reflux operation to steady-state operation. This characteristic function is easily calculated at any instant by using the observed values of temperature in the column, and the optimum switching time is approximately but rather accurately determined by finding the minimum value of the characteristic function. The use of such characteristic function as mentioned above can make it possible to design a low-cost, small-scale computer control system composed mainly of microcomputers that will achieve automatic optimum startup operation of distillation columns.
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  • Jun'ichi Shiozaki, Takashi Matsuzaki, Hisayoshi Matsuyama, Eiji O'Shim ...
    1985 Volume 11 Issue 3 Pages 343-367
    Published: May 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
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