KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 11 , Issue 4
Showing 1-17 articles out of 17 articles from the selected issue
  • Keiichi Tsuto, Mutsuo Nakayama, Shigeyasu Imamura, Kanji Majim
    1985 Volume 11 Issue 4 Pages 369-375
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A rising film tubular reactor was used for sulfonation or sulfation of liquid organic compounds with a gas mixture of SO3 gas and dry air. A mathematical model for design of the sulfonation or sulfation reactor is proposed on the basis of the fact that the overall reaction rate was controlled by the mass transfer rate of SO3 in the gas phase.
    Liquid conversion, liquid and gas temperature and pressure along the reactor length were calculated by mathematical modelling, and were compared with values experimentally obtained. It was found that the calculated values were in good agreement with the experimental data for the reaction of straight-chain alkylbenzene and higher alcohol in a reactor with tubediameter ranging from 12 mm to 130 mm.
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  • Masato Tanaka, Eiji O'shima
    1985 Volume 11 Issue 4 Pages 376-380
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    In suspension polymerization of styrene, the effects of location of the submerged impeller on mean droplet diameter and mean size of polymer beads were experimentally investigated. Droplet diameters were measured in the circulation and impeller regions. As a stabilizer, polyvinyl alcohol was used. The following results were obtained.
    1) Droplet diameter changes with impeller location, becoming larger as the impeller nears the liquid surface.
    2) The degree of difference in droplet and particle diameter due to impeller location decreases as impeller speed and stabilizer concentration increase.
    3) The size of polymer beads becomes larger in the order of impeller locations 0.5, 0.75, 0.25.
    4) Particle size distribution is sharpest at H=0.5.
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  • Akira Sannomiya, Mototake Yano, Yoshio Harano
    1985 Volume 11 Issue 4 Pages 381-387
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The support effect of nickel catalysts on activity and selectivity was investigated, using a model reaction of the hydrogenation of cyclopentadiene.
    Alumina (Neobead-C) interacts more strongly with nickel than silica (Aerosil-200). Therefore, on Ni/Al2O3, reducibility of NiO is reduced and adsoptivity of hydrogen is decreased.
    On Ni/Al2O3 prepared by multiple impregnation, it is clear that a metal-support interaction is strong up to 8 wt % nickel content but becomes weak above 8 wt %. The activity for hydrogenation of cyclopentadiene increases steeply above 8 wt %, accompanied by decreasing selectivity of cyclopentene. This suggests that the activity of the site on nickel particles interacting with the support strongly is lower than that on nickel particles interacting weakly with the support, but inversely the selectivity is higher.
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  • Takeo Komuro, Kenichi Gomi, Norio Arashi, Yukio Hishinuma, Osamu Kanda ...
    1985 Volume 11 Issue 4 Pages 388-393
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    In the presence of O2 and H2O, SO2 is oxidized to H2SO4 on the surface of activated carbon. Activated carbon, which adsorbs certain amounts of H2SO4, is regenerated and recycled. However, the SO2 adsorption capacity decreases gradually as the adsorption and regeneration are repeated.
    In this study, the effect of surface oxide on SO2 adsorption capacity of activated carbon was investigated. It was found that the amount of surface oxide not decomposed at the regeneration temperature (723 K) increased as the SO2 adsorption capacity decreased, and this made the surface of activated carbon hydrophilic. By decomposing the surface oxide at higher temperatures than the regeneration temperature, the SO2 adsorption capacity was found to increase. It is concluded that the increase of amount of surface oxide and hydrophilic properties cause a decrease in active sites for SO2 adsorption.
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  • Katsuhiko Fujinawa, Tamami Morishita, Mitsunori Hozawa, Hajime Ino
    1985 Volume 11 Issue 4 Pages 394-399
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The effect of coexistent substances in copper-leaching solutions on the extraction rate by liquid surfactant membranes was investigated experimentally, using a stirred cell.
    Kerosene and Span 80 were used as oil phase and surfactant, respectively. LIX64N or SME529 was used as the extraction reagent. The effect of the concentrations of Fe3+, Cl-, NO3- and SO42- on the copper extraction rate were examined. The following results were obtained. 1) The presence of Cl- increases the extraction rate, while that of SO42- decreases the rate. The concentration of NO3- does not influence the extraction rate. 2) A higher extraction rate by Cl- is noticeable when pH is less than 2, independently of the kind of cation, such as Na+, NH4+ and Fe3+. 3) The effect of the presence of Fe3+ on the copper extraction rate is insignificant.
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  • Toshio Yahata, Koji Ando, Fujio Komatsu, Kazuo Endoh
    1985 Volume 11 Issue 4 Pages 400-404
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    To evaluate the axial mixed region of a stirred vessel, the mixing time of water and corn syrup of various liquid heights-to-diameter ratio (H/Dt=1-5) was measured. Three geometrically similar stirred vessels, equipped with a turbine impeller, positioned at 1/2 the height of liquid, were used.
    The mixing process of liquid where liquid height was high was observed by the color reaction method, and photographs of the mixing process were taken and analysed.
    The results obtained were : 1) The axial velocity of the color boundary propagation was remarkably slow in the region over a certain distance away from a mixing impeller, and from this fact the existence of the region affected by stirring with an impeller, Hic was estimated. 2) The maximum value of liquid height under which mixing time is proportional to liquid height approximately agreed with that of the above-mentioned mixing region, Hic. Accordingly, in a vessel whose liquid height is high the maximum height can be regarded as a measure of the length of the axial mixed region. 3) The relation between a mixing region, Hic, and the operational condition can be expressed as follows :
    Hic/Dt=0.45·NRe=2.9×102-1.7×102
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  • Tatsuo Nishimura, Toru Takumi, Yuji Kawamura, Hiroyuki Ozoe
    1985 Volume 11 Issue 4 Pages 405-411
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Natural convection heat transfer was experimentally investigated in rectangular enclosures heated and cooled from vertical side walls. The space in the enclosure was horizontally divided into two regions : a region filled with water and a region filled with porous medium of glass beads. The heat transfer rate through the enclosure was measured by changing the porous portion of the enclosure. Flow visualization and temperature measurement in the enclosure were also carried out to make clear the natural convection mechanism for this system.
    The heat transfer rate decreased with increasing porous portion, and its value was always smaller than the calculated one on the assumption that natural convection occurs independently in each region. There were two flow modes in the enclosure for this system : circulation over the enclosure and circulation in the fluid region only.
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  • Masaaki Suzuki, Kasra Etemadi, Emil Pfender
    1985 Volume 11 Issue 4 Pages 412-417
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    To reveal basic characteristics, temperature and velocity distributions of the gas-stabilized free-burning arc reactor which we developed, numerical calculations were made of momentum conservation, energy conservation and electrical potential equations governing the entire arc. In the present paper the electrical characteristics of this free-burning arc with a ring-shaped anode was approximated by those of a similar planar anode, assuming that the main discharge phenomena occurs near the cathode region far from the anode and that the effect on the solutions of the boundary condition of the anode to be small. Calculated temperature distributions are in good agreement with experimental ones obtained by spectrometric measurements and it may confirm calculated results of velocity and temperature distributions to be adequate.
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  • Jun Fukai, Takatoshi Miura, Shigemori Ohtani
    1985 Volume 11 Issue 4 Pages 418-423
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The effective thermal conductivity of a packed bed of coal is measured by the modified hot-wire method, which is applicable to the continuous heating process in the previous report. Measurements were carried out for binary mixtures of eleven kinds of coal as well as for each of them : Itmann, Peak Down, Coal Cliff, Goonyella, Pittstone, Moura, Bank, Blair Athol, Daiyon, Akabira and Sufco, at a heating rate of 0.05 K/s and an apparent density of 850 kg/m3 from 300 to 1200 K.
    Reproducibilities were obtained satisfactorily in these measurements. The effective thermal conductivities for packed beds of each of the eleven kinds of coal except for Coal Cliff, Blair Athol and Akabira can be correlated by vitrinite reflectance. The correlation equations are also valid for the effective thermal conductivities of binary mixtures of eight kinds of coal.
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  • Tadaatsu Ido, Hajime Tariki, Shigeo Goto
    1985 Volume 11 Issue 4 Pages 424-431
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Oxidation of benzyl alcohol in various solvents (organic phase) by sodium hypochlorite in distilled water (aqueous phase) was investigated at 303 K in a batch reactor containing an anion exchange resin (solid phase). When benzene, xylene and carbon tetrachloride were used as solvents, the kinetics was the same as for toluene in a previous paper; that is, a consecutive reaction of first order occurred in the aqueous phase and on the solid phase. On the other hand, a special solvent effect was attributed to ethyl acetate, and the reaction rate in ethyl acetate was much higher than that in other solvents.
    To elucidate this effect, decomposition of sodium hypochlorite in distilled water was investigated in a batch reactor containing an anion exchange resin and an organic solvent such as ethyl acetate or toluene. When ethyl acetate was present, the decomposition took place in the aqueous phase and on the solid phase. When toluene was present, however, no decomposition occurred in any phase. It was concluded from these results that the mechanism of oxidation in ethyl acetate was different from that in other solvents.
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  • Kiyoshi Idogawa, Koji Ikeda, Takashi Fukuda, Shigeharu Morooka
    1985 Volume 11 Issue 4 Pages 432-437
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The gas holdup and bubble size in a bubble column of 5 cm diameter equipped with a perforated plate as gas distributor were measured by the electric resistivity probe method under pressures up to 5 MPa. The gas phase was H2, He or air, and the liquid phase was H2O, CH3OH, C2H5OH, CH3COCH3 or aqueous solutions of alcohols.
    Gas holdup and bubble frequency increased with increasing gas density and gas velocity. Bubble size decreased with increasing pressure and was not much affected by gas velocity in the range of 0.5-5 cm·s-1.
    Liquid viscosity had no effect on the bubble characteristics in the viscosity range of 0.35-3 mPa·s. Surface tension of liquid had little effect on them as the pressure reached 5 MPa.
    Empirical correlations for gas holdup and bubble size were obtained as a function of physical properties of gas and liquid and operational conditions.
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  • Michitaka Suzuki, Hisaki Ichiba, Isamu Hasegawa, Toshio Oshima
    1985 Volume 11 Issue 4 Pages 438-443
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Experimental measurements and computer simulation are reported on the void fraction of multi-component randomly packed beds with log-normal, log-uniform, Rosin-Rammler or Andreasen (Gaudin-Schuhmann) size distributions. Packing experiments were done by two methods, i.e. rodding and tapping. Glass beads (spherical particles) and crushed glass (irregularly shaped particles) were used for these experiments.
    The following results were obtained from the experiments and the simulations. A minimum void fraction of a packed bed with Andreasen distribution exists in the range of Fuller constant q = 0.5-0.8, and the void fractions of packed beds with the other three distributions decrease as the size distribution spreads.
    The experimental and the simulated results for void traction were compared with values calculated by our model and agreement between them was fairly good. This model is useful for estimating the void fraction in a multi-component randomly packed bed of spherical and irregularly shaped particles with size distribution.
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  • Mitsutaka Kitamura, Tasuku Nakai
    1985 Volume 11 Issue 4 Pages 444-449
    Published: July 10, 1985
    Released: November 12, 2009
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    Separation of p- and m-xylene isomers by adductive crystallization using tetra (4-methyl-pyridine) nickel (II) thiocyanate was investigated by the differential crystallization method.
    The m-xylene concentration in clathrate crystals precipitated from solutions containing p- and m-xylenes was observed to increase linearly with increasing m-xylene concentration in solutions. On the other hand, m-xylene concentration in crystals increased at first but decreased after passing through a maximum with increasing p-xylene concentration in solutions. The increase at an early stage is considered due to the “anchor effect”; i.e., m-xylene molecules are dragged into the crystal with p-xylene molecules in the crystallization process.
    Berthelot-Nernst's law was applied to the relationship between solid and solution compositions, but the separation factor γ was found to vary from 30 to 150, depending on solution compositions and crystallization temperature.
    A crystallization model was proposed, assuming that the relative concentrations of p-and m-xylenes in crystals are proportional to the ratio of precipitation rates of each liquid clathrate. With this crystallization model, separation factor β including equilibrium constants for formations of liquid clathrates and precipitation rates of the clathrates was defined. It was observed that the value of β is independent of solution composition and of crystallization temperatures in the ranges of this work.
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  • Toshio Kajiuchi, Naohiro Shiragami, Minoru Hatayama
    1985 Volume 11 Issue 4 Pages 450-455
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Pressure differences for laminar divergent and convergent flows of Bingham fluid in a tapered tube were studied experimentally.
    On the basis of the integral energy balance, an equation of pressure difference of Bingham fluid flow was obtained. By introducing a correction factor for characteristic kinetic energy and a generalized Reynolds number, the non-dimensional equation for pressure difference can be written in a form similar to that of Newtonian fluid. The calculation procedure for predicting pressure difference is also shown.
    The pressure difference calculated from this equation was in good agreement with experimental results.
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  • Masanori Inuzuka, Isao Saito, Takeshi Moriya, Ikuho Yamada, Setsuro Hi ...
    1985 Volume 11 Issue 4 Pages 456-461
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The rates of evaporation of binary solutions, DBP(dibutyl phthalate)-EHP(di-2-ethyl-hexyl phthalate) and EHP-EHS(di-2-ethylhexyl sebacate), and the compositions of distillate were measured, using a pot still with stirrer under the vacuum. Then the following results were obtained.
    1) The observed relative rates of evaporation were found to be smaller than the theoretical ones obtained from the rate of evaporation of pure liquids.
    2) The relative rate of evaporation increases with increase of rotating speed, but decreases with increase of rates of evaporation.
    3) The results mentioned above can be well explained by a simultaneous heat and mass transfer model, in which both convection and diffusion are considered in the liquid film.
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  • Yoshifumi Tsuge, Hisayoshi Matsuyama
    1985 Volume 11 Issue 4 Pages 462-470
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A method of evaluating the accuracy of fault diagnosis based on the signed directed graph is described. Its accuracy is represented by the collection of the envelope sets of candidates, which are assured not to be proper subsets of any set of candidates obtained by the fault diagnosis. An acetic acid manufacturing process is taken as an illustrative example to show the usefulness of this method.
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  • Kazuho Tamano, Mitsuharu Ide, Jiro Mada, Shigeo Goto, Koji Nishimura, ...
    1985 Volume 11 Issue 4 Pages 471-496
    Published: July 10, 1985
    Released: November 12, 2009
    JOURNALS FREE ACCESS
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