JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 21 , Issue 3
Showing 1-22 articles out of 22 articles from the selected issue
  • SHINTARO FURUSAKI
    1988 Volume 21 Issue 3 Pages 219-230
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Engineering problems in applying immobilized biocatalysts to the production of useful materials are discussed. The scope of the review covers immobilized enzymes, immobilized microorganisms, immobilized mammalian cells, immobilized plant cells and the use of membranes for immobilization. Recent developments in these subjects are reviewed especially as to reaction analyses, mass-transfer effects, bioreactions using an organic phase and problems concerning reactor design. The future scope of research in this field is briefly described in the final section.
    Download PDF (1112K)
  • MIKI FUKUMA, MAKOTO SATO, KATSUHIKO MUROYAMA, AKIRA YASUNISHI
    1988 Volume 21 Issue 3 Pages 231-237
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Mass transfer from solid particles to liquid in gas-liquid-solid fluidization was experimentally investigated by means of an electrochemical method with 7-9 particle electrodes fixed at various radial positions in a column of 82.9 mm i.d. Supplementary measurements were also conducted for the solid-to-liquid mass transfer in single liquid flow, gas-liquid two-phase upflow and liquid-solid fluidization.
    The effects of particle size and liquid and gas flow rates on the solid-to-liquid mass transfer coefficient, Ks, in all the systems were investigated and the mass transfer coefficient was well correlated by the following equation proposed by Ohashi et al. for Ks in a packed bed with single liquid flow.
    Shs = 2 + O.51(E1/3dp4/3/V1)0.06Sc1/3
    where E is the energy dissipation rate per unit mass of liquid, dp the particle diameter, vl the kinematic viscosity of liquid, Shs the Sherwood number and Sc the Schmidt number. The value of E was expressed by the sum of the kinetic energy supply terms due to viscous drag force across a particle and to gas agitation.
    Download PDF (572K)
  • MASAKUNI MATSUOKA, KENTA TSUBOHARA, TAKAMASA YASUKAWA
    1988 Volume 21 Issue 3 Pages 238-243
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A composite heat-storage material composed of organics and metal fiber was proposed and examined experimentally. By the addition of copper fiber up to 1 volume percent in naphthalene, supercooling on solidification was greatly reduced and apparent thermal diffusivities were found to increase threefold. The rate of heat release from the composite material was analyzed by a model based on the experiments, in which the heat transfer in the solid phase is governed by conduction and the liquid-phase transfer is expressed in terms of the heat transfer coefficient. Also, the presence of a mushy zone at the phase boundary is assumed where the temperature is uniform. The thickness of the mushy zone was determined and the temperature change during the heat discharge was well analyzed. Consequently, the composite heat-storage material was found to be promising.
    Download PDF (541K)
  • NICKOS PAPAYANNAKOS, GEORGE GEORGIOU
    1988 Volume 21 Issue 3 Pages 244-249
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A kinetic model for hydrogen consumption during catalytic residue hydrodesulphurization, is presented. The intrinsic reaction rates are described by use of a second-order kinetic equation. The intraparticle diffusional effects are discussed by means of the effective diffusivity. Kinetic experiments were carried out in an isothermal trickle-bed reactor, in which two commercial Co-Mo/Al2O3 catalysts were used in a temperature range of 350-430°C, a liquid hourly space velocity ranging from 0.25 to 3h-1, and a constant pressure of 50 × 105 Pa. The remaining catalyst activity varied between 1.0 and 0.2. Crushed particles and cylindrical extrudates-for each type of catalyst-were used in experimentation. The atmospheric residue of Greek petroleum deposits in the Aegean Sea served as feedstock. Specific rate constants, activation energies and effective diffusivities were determined. Hydrogen consumption increased as either the remaining activity of the catalyst, the reactor temperature or the catalyst size decreased.
    Download PDF (437K)
  • KENJI HASHIMOTO, TAKAO MASUDA, KAZUCHIKA ISOBE
    1988 Volume 21 Issue 3 Pages 249-255
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The deactivation function of silica-alumina catalysts during steam sintering is presented. Silica-alumina catalysts sinter rapidly at high temperature in steam atmosphere, undergoing irreversible changes in both pore structure and acidic properties that result in deactivation. Change in acid strength distribution during sintering was well represented by a population balance equation. By combining this equation with the previous two models developed by the authors, one for the rate of decrease in surface area during sintering, the other for the relationship between catalytic activity and acidic properties, the deactivation function of the catalyst during sintering was found to be expressible in terms of its surface area. Changes in acidic properties and catalytic activity were well predicted by the model equations.
    Download PDF (556K)
  • TOSHITATSU MATSUMOTO, NOBUYUKI HIDAKA, HIROSHI KAMIMURA, MIHOKO TSUCHI ...
    1988 Volume 21 Issue 3 Pages 256-261
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The axial turbulent diffusion coefficient of liquid, El, was investigated experimentally and theoretically in a three-phase fluidized bed where the solid concentration at the bottom of the column was less than 1200kg/slurrym3. The measurement was conducted in a column of 0.07 m diameter and 4.25 m maximum height. The solid phase was glass beads of 230 μm and 450 μm diameter. No appreciable effect of the solid concentration on gas holdup was observed under the present conditions. It was also shown that a model based on the turbulent mixing-length theory was in good agreement with experimental values of El. Data in the literature for column diameters of 0.07-1.07 m were also well explained by the present model.
    Download PDF (384K)
  • HIROSHI YUKAWA, TERUHIKO HOSHINO, TOSHIYUKI KASAKOSHI, MASARU HAKODA
    1988 Volume 21 Issue 3 Pages 262-266
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The continuous separation of each protein from a colloidal solution containing several kinds of proteins was investigated by isoelectric focusing. A separation device comprising three separation cells divided by semipermeable Teflon membranes and two electrode compartments was used in this experiment. A colloidal solution containing bovine serum albumin and bovine hemoglobin was used as a sample and ampholytes were used as a buffer reagent. The costly ampholytes were recovered from effluent by ultrafiltration for reuse as buffer solution. The equation for separation efficiency was analysed semi-theoretically and the adaptability of the equation was examined experimentally. A separation efficiency of over 95 % was obtained.
    Download PDF (406K)
  • HARUO ISHIKAWA, KATSUHIKO OKADA, HARUO HIKITA
    1988 Volume 21 Issue 3 Pages 267-272
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The applicability of the pseudo-steady state assumption to an enzyme-substrate complex was examined for an irreversible single-substrate reaction which obeys the Michaelis-Menten mechanism by using computer simulation. The pseudo-steady state solutions of the time courses of the substrate and product were compared with the exact solutions calculated by using a complete set of rate equations under various conditions. The maximum relative errors of the pseudo-steady state solutions to the exact solutions could be correlated well only in terms of a dimensionless parameter, which the authors designate ψM and define by the ratio of the pseudo-steady state solution of the intermediate complex at t = 0 to the initial substrate concentration. The simulations showed that if ψM ?? 0.05, the pseudo-steady state solutions are accurate within a tolerable error of 5 % and therefore the pseudo-state assumption holds.
    Download PDF (479K)
  • TAKAAKI OHTAKE, TADASHI HANO, KAZUMI TAKAGI, FUMIYUKI NAKASHIO
    1988 Volume 21 Issue 3 Pages 272-276
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The effects of operating conditions on mechanical water entrainment into W/O emulsion drops in a (W/O)/W emulsion system were studied in a stirred tank in the absence of permeation due to osmotic pressure.
    The water entrainment was influenced by surfactant concentration, water volume fraction in W/O emulsion, inner water drop size, salt concentration in the external water phase, and agitation speed in the stirred tank. There was a satisfactory correlation between the extent of water entrainment and the weight of surfactant per unit interfacial area. These observations suggested that water entrainment proceeded as a result of additional emulsification at the drop surface. This idea was confirmed by examining the water entrainment in an oil-water dispersion system where water entrainment occurred by ernulsification. The effects of the operating conditions on water entrainment in the oil-water dispersion system were quite similar to those in the (W/O)/W emulsion system. In addition, the volume of water entrained per unit surface area of dispersed oil drops was in fair agreement with that in the (W/O)/W emulsion system. These results supported the proposed mechanism of water entrainment.
    Download PDF (354K)
  • YOSHIYUKI YAMASHITA, SHIGERU MATSUMOTO, MUTSUMI SUZUKI
    1988 Volume 21 Issue 3 Pages 277-282
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    It is difficult to control the start-up of a packed-bed catalytic reactor with exothermic reaction by conventional controller. In this paper, a controller based on the fuzzy set theory is applied to such a system. The controller treats heuristic rules by fuzzy interpretation, and it is also equipped with adaptive scaling factors. The performance of the controller is experimentally examined with a reactor for the catalytic oxidation of hydrogen.
    Download PDF (456K)
  • IBRAHIM A. KHATTAB, CHIAKI KURODA, MASARU ISHIDA
    1988 Volume 21 Issue 3 Pages 282-287
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The radial and vertical distributions of the interstitial gas velocity in a fluidized bed of group B particles were measured over a wide range of superficial gas velocity by applying the optical fiber technique with ozone used as tracer gas. The bed materials were sand particles, dp = 184 μm, and alumina beads, dp = 250 μm.
    The interstitial gas velocities in the jet region were found to be higher than those predicted by the ideal two-phase postulate. This increase reached 30% and 20% of (Uo- Umf) for sand particles and alumina beads respectively. These velocities decreased with height above the distributor, approaching those at incipient fluidization near the bed wall but taking still higher values at mid-points.
    The leakage factor K calculated from the observed interstitial gas velocity was compared to that predicted by a recently developed bubble simulator which was inherently based on the observation of radial and vertical distributions of size and frequency of bubbles, and good agreement was obtained.
    Download PDF (425K)
  • AKIRA SUZUKI, TADASHI NAKAMURA, SHIN-YA YOKOYAMA, TOMOKO OGI, KATSUYA ...
    1988 Volume 21 Issue 3 Pages 288-293
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    To investigate optimum starting materials and catalyst loading for conversion of sewage sludge to heavy oil, various kinds of sewage sludges were liquefied at a temperature of 300°C, a pressure of 12 MPa, and a catalyst (sodium carbonate) loading of 0-20 wt %. The optimum kind of sewage sludge was found to be either raw primary sludge or raw mixed sludge because average oil yields of these sludges reached 43 %-higher than those of other kinds of sludges. For most sewage sludges, oil production proceeded satisfactorily without the addition of any catalyst.
    Download PDF (461K)
  • YUKIHIRO SHIMOGAKI, HIROSHI KOMIYAMA, HAKUAI INOUE, TSUYOSHI MASUMOTO, ...
    1988 Volume 21 Issue 3 Pages 293-299
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The hydrogenation of carbon monoxide over amorphous NixZr100-x (x = 91, 67, 50, 40, 33) alloys was investigated. During the reaction, amorphous Ni50Zr50 and Ni67Zr33 alloys spontaneously increased their catalytic activity by more than two orders of magnitude. The formation of porous structure within the amorphous bulk alloy is mainly responsible for the activity increase. The development process of the porous structure, which finally leads the alloys to segregate into nickel species and ZrO2, can be stopped by decreasing the reaction temperature. This process can, therefore, expose fresh alloy surfaces for use in catalytic reactions and enlarges the specific surface area of amorphous alloy. It is shown that NiZr alloys are catalytically more active than pure Ni for the hydrogenation of carbon monoxide.
    Download PDF (545K)
  • HAJIME NISHIMURA, MASAHIKO HIRAO
    1988 Volume 21 Issue 3 Pages 300-305
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A long-cycle oscillation sometimes appears in the iterative solution of nonlinear simultaneous equations. It occurred in simulation of extractive distillation by the successive approximation method and the cause of instability was investigated. A small deviation of the pressure and the total flow rate calculated from the material balance was found to travel down the column as a growing wave because of a poor temperature updating algorithm. An algorithm was proposed to stabilize it by revising the composition before updating temperature using information on the difference between the total flow rates calculated from the material and heat balances. The stability of the algorithm was quantitatively analyzed by evaluating the transformation matrix which corresponds to the successive deviation of the temperature profile. The absolute value of the dominant eigenvalue became less than unity, while that for the conventional method exceeded unity. The conventional method when stabilized by this algorithm was found to be competitive with the full Newton method.
    Download PDF (446K)
  • MORIHIRO YASUDA, AKIRA OHKAWA, SABURO YASUKAWA, TARO SEKINE
    1988 Volume 21 Issue 3 Pages 306-310
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Using a rectangular cell with three fluidized-bed electrodes (RTFBEs) separated by two electro-conductive partition plates (ECPs), the electrodeposition of copper from CuSO4 solution was carried out to examine the electrochemical activity of the respective fluidized beds (FBs).
    The particles in each FB were activated as an electrode by the bipolar action of the ECP. Their activity depended on the material of the ECP, the electro-conductivity of the solution and the bed expansion. The current efficiency of copper electrodeposited on fluidized particles using copper or copper-plated Pt plates as ECPs was higher than that using Pt plates. Since the bed thickness in the direction of the electric current could be effectively increased by inserting the ECPs, the electrolytic capacity in this type of cell with FBEs was found to be considerably large compared to that in a cell with a single FBE.
    Download PDF (382K)
  • ILPO K. SILVENTOINEN, JOUNI T. KORHONEN, SEPPO M. PALOSAARI
    1988 Volume 21 Issue 3 Pages 311-315
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The purification of crystalline solids by the temperature gradient method was studied by a novel experimental method, and a mathematical model was developed to simulate the process. The experimental method was based on measurement of the impurity concentration profile in the whole crystal layer. Our results show that the amount of impurities in a crystal layer maintained under a temperature gradient decreased with time. This can be explained by a mechanism in which liquid inclusions move under the influence of a temperature gradient. The validity of the mathematical model for the concentration profile was shown through reference to experimental results.
    Download PDF (410K)
  • NOBUYUKI TOKUNAGA, MASAHIDE ABE, TOMOSHIGE NITTA, TAKASHI KATAYAMA
    1988 Volume 21 Issue 3 Pages 315-318
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Download PDF (284K)
  • MICHIAKI MATSUMOTO, MASAHIRO GOTO, KAZUO KONDO, FUMIYUKI NAKASHIO
    1988 Volume 21 Issue 3 Pages 318-320
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Download PDF (199K)
  • SATORU KATO, JUNJIRO KAWASAKI
    1988 Volume 21 Issue 3 Pages 321-323
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Download PDF (199K)
  • XI-YIN ZHENG, GUANG-WEN WU, NAI-WEN ZHANG
    1988 Volume 21 Issue 3 Pages 323-325
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Download PDF (221K)
  • A. K. BIN
    1988 Volume 21 Issue 3 Pages 326-328
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Download PDF (224K)
  • AKIRA OHKAWA, DAISUKE KUSABIRAKI, NOBUYUKI SAKAI
    1988 Volume 21 Issue 3 Pages 327-328
    Published: June 20, 1988
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Download PDF (224K)
feedback
Top