JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Online ISSN : 1881-1299
Print ISSN : 0021-9592
33 巻, 2 号
選択された号の論文の26件中1~26を表示しています
Thermodynamics, Physical Properties and Molecular Simulation
Transport Phenomena, Fluid Mechanics and Mixing
Catalysis, Kinetics and Reactor Design
Materials and Devices
  • Hiroshi Sato, Isao Komasawa
    2000 年 33 巻 2 号 p. 262-266
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    The preparation of ultrafine CdS and ZnS particles is studied by combining particle preparation in reverse micelles and liquid-liquid extraction. Sodium bis(2-ethylhexyl)sulfosuccinate (AOT) was added to the organic phase solution containing the extractant-metal ion complex, and either a reverse micellar solution containing Na2 or simply H2S gas was then added to the solution. The process of particle formation was followed by means of measurement of the absorption spectra. The key step is the release of the metal ion from the complex. The rate for the release governs the rate for particle growth, and thus controls the particle size. When the complex is stabilized too much, no particles are formed. The preparation of CdS and ZnS particles at high concentrations was also carried out.
  • Masakatsu Miura, Harumi Kaga, Shigenobu Tanaka, Kenji Takahashi, Koji ...
    2000 年 33 巻 2 号 p. 299-302
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    Rapid microwave pyrolysis has been applied to a relatively large piece of larch (60 mm diameter and 60 mm height), namely a piece of lumber, within a short irradiation time. The yields of charred residue and tar were about 39 to 35%, and 20%, respectively, after 6 to 8 min of microwave irradiation. Based on the dry weight of the wood, an overall yield of 2.4% of levoglucosan was obtained. The specific surface area of the charred residue obtained from the central region of the wood was 550 to 655 m2·g−1. This surface area is much greater than that of char produced by a conventional carbonization process.
  • Yasumasa Takao, Makio Naito
    2000 年 33 巻 2 号 p. 317-322
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    Optical microscopy in reflection and transparent modes with normal and cross-polarized lights contributes to understand the particle-aggregated structures and their peculiar characteristics in the viscosity of an epoxy resin composite system filled with silica particles. The apparent viscosity of a 17 μm-SiO2 particle filled system shows minimum values compared with those of 13 and 27 μm particle systems. Only SiO2 primary properties such as particle size distribution and specific surface area are not enough for the understanding of the characteristics. Optical microscopy reveals that the 17 μm particle system has the smallest particle-aggregated structure of SiO2 in epoxy resin. This appears to explain the rheological properties and confirmed the possibility of the optical characterization to identify the particle-aggregated structure of epoxy composite filled with silica particle.
Separations
  • Hongmei Lou, Fei Dong, Yoshiro Tominaga, Akio Kodama, Motonobu Goto, T ...
    2000 年 33 巻 2 号 p. 205-210
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    The separation performance of air dehumidification is investigated over a wide range of experimental conditions by using an isothermal PSA apparatus. Velocity ratio of purge to feed (γ), half cycle time, column length (L), and particle size are found to have a great effect on the product concentration, while the independent effect of pressure ratio (β) seems relatively small with fixed values of the other parameters. A simplified analytical model proposed previously, short cycle time approximation, is extended to the Langmuir isotherm to derive the following new algebraic equation which identifies the combination of the operating and design parameters.

    ln[(1 – β)(CA1/CA0)] – ln(1 – 1/γ) = –(No′ – A)/r

    in which No′ is a combined number of mass transfer units given by

    No′ = (KAamL)/(1 + KA/KD)(1/uA – 1/uD)

    and the parameter A in the equation is a simple function given by the velocity ratio γ and Langmuir coefficient r. Good agreement between the calculated results and the experimental data show that the short cycle time approximation is suitable for estimating the separation performance of the purification PSA process such as the present air dehumidification system with a better understanding of the role of each parameter on the separation performance.
  • Nobuaki Egoshi, Hiroshi Kawakami, Koichi Asano
    2000 年 33 巻 2 号 p. 245-252
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    Measurements of the rates of mass transfer in binary cryogenic distillation of the nitrogen-oxygen and the argon-oxygen systems by a packed column with structured packings under total reflux conditions were made for a wide range of vapor flow rates, concentrations, and total pressures.
    HETPs in cryogenic distillation show irregular scattering with vapor Reynolds numbers, and are observed to vary with oxygen concentration, whereas vapor phase diffusion fluxes were well correlated. A new correlation was proposed for the vapor phase diffusion fluxes for binary cryogenic distillation of the nitrogen-oxygen and the argon-oxygen systems by a packed column with structured packings. Prediction of separation performance of a binary cryogenic packed column distillation by simulation techniques based on the proposed local flux correlation was made to show good agreement with observed data. Application of the binary correlation to ternary cryogenic distillation of air by a pilot scale air separation plant is also discussed.
  • Kunio Funakoshi, Hiroshi Takiyama, Masakuni Matsuoka
    2000 年 33 巻 2 号 p. 267-272
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    Agglomeration kinetics of sodium chloride crystals in batch crystallization are examined from the changes of the number of suspended particles experimentally. Product purity was measured and the mechanism of purity decrease by agglomeration is discussed. From the changes in particle size distributions and the number of suspended particles, rapid agglomeration of NaCl crystals is found to occur immediately after seeding. The agglomeration kinetics were correlated with the number of the suspended particles and the solution supersaturation. The product purity is found to be lower when the average number of elementary crystals constituting agglomerates is larger. It also becomes lower when the number of seed crystals is larger and the initial supersaturation is higher.
  • Monali Dutta, Narendra N. Dutta, Krishna G. Bhattacharyya
    2000 年 33 巻 2 号 p. 303-307
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    The adsorption of certain beta-lactam antibiotics such as 7-aminocephalosporanic acid, 7-aminodeacetoxy cephalosporanic acid, cephalexin, cefadroxyl, cephalosporin-C, and 6-aminopenicillanic acid in aqueous solution is studied using two different types of polymeric resins and activated carbon as the adsorbents. Adsorption affinity expresses as the slope of the linear region of the isotherm for a solute is found to be different for different adsorbents, and this difference can be interpreted from sorbent surface chemistry and morphological structure. The adsorptive interaction on the polymeric resins and activated carbon was computed based on the Frontier Orbital Theory. Electronic states of the adsorbent and adsorbate were calculated using the semiempirical molecular orbital (MO) method from which the characteristic energy of adsorption in aqueous solution was estimated. Adsorption affinity was correlated by the ratio of characteristic energy to that of the reference adsorbate. It was found that charge transfer interaction plays an important role in the adsorption of beta-lactams in aqueous solution. The experimentally measured enthalpy of adsorption was also correlated by the ratio of the characteristic energy to that of the reference adsorbate. The enthalpy of adsorption seems to correlate well with the adsorptive interaction energy computed from molecular orbital theory.
  • Masashi Iwata
    2000 年 33 巻 2 号 p. 308-312
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    The final states of materials after electro-osmotic dewatering are investigated. Based on our theory, the liquid pressure near the anode becomes negative if the materials are negatively charged. This negative pressure is offset by the positive solid compressive pressure arising from the force balance, resulting in a decrease in the local moisture content of the material. This propagates from the anode to the cathode until the pressure flow cancels out the electro-osmotic flow in any layer of the material. This paper explains the moisture distribution of the material at the end of the dewatering process. It is also shown that reversing the polarity of the electrodes results in a further decrease in the moisture content of the material.
  • Shigeo Goto, Suttichai Assabumrungrat, Tomohiko Tagawa, Piyasan Praser ...
    2000 年 33 巻 2 号 p. 330-333
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    A composite palladium membrane consists of a thin film of palladium layer coated on a ceramic support. Two kinds of models are formulated for the direction of permeation through the composite membrane (CP mode and PC mode). The apparent order of hydrogen pressure is varied from 0.5 to 1.0 by the relative values between two resistances of palladium film and ceramic support for the hydrogen permeation rate through the composite membrane. The relation between the apparent order and the relative resistance is dependent on the operating conditions. Once the apparent order can be determined from the linearity of experimental data, we can estimate the relative resistance.
  • Izumi Kumakiri, Takeo Yamaguchi, Shin-ichi Nakao
    2000 年 33 巻 2 号 p. 333-336
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    The reverse osmosis process needs no phase transformation during separation, and thus it has a potential in saving energy for liquid mixture separations. Application of reverse osmosis to organic liquid is limited, owing to the lower stability of polymer membranes against organic liquid. Zeolites are inorganic materials having durability against organic liquid and heat, and they show good separation ability in pervaporation. In this study, zeolite membrane was firstly applied to the reverse osmosis process. Zeolite A membrane, having thickness around 5 μm, showed 0.44 rejection from 10wt% ethanol water mixture. The membrane was stable to applied pressures up to 50 kgf cm–2.
Particle Technology and Fluidization
Process Systems Engineering
Biochemical, Food and Medical
  • Jun-ichi Hata, Masahito Taya
    2000 年 33 巻 2 号 p. 277-284
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    Heterotrophic and photomixotrophic cultures of liverwort cells, Marchantia polymorpha, were carried out to investigate growth properties, carbon source utilization and photosynthetic activity of the cells under varied light conditions. The cultures were conducted at incident light intensities of I0 = 0, 30 and 100 W/m2 using an externally illuminated bioreactor containing a medium with 10 kg/m3 glucose as an organic carbon source. At the end of the culture, when glucose in the medium was almost consumed, the amounts of cells harvested were 4.5, 5.5, and 7.0 kg-dry cells/m3 in the cultures at I0 = 0, 30, and 100 W/m2, respectively. The average cell yield based on glucose in the culture at I0 = 100 W/m2 was 0.70, the value of which was 1.6 and 1.3 times as large as those of the cultures at I0 = 0 and 30 W/m2, respectively. In addition, it was estimated that carbon recovery in the cells from glucose ultimately reached 77% in the culture at I0 = 100 W/m2 and this value was the highest in the cultures examined. CO2 fixation and O2 evolution by photosynthesis in M. polymorpha cells were calculated from a stoichiometric equation of cell formation, and correlated with light energy absorbed by the cells in the mixotrophic cultures. It was estimated that the cells possessed photosynthetic ability to fix most of CO2 evolved by respiration over absorbed light energy of about 200 W/kg-dry cells.
Safety, Environment and Energy
  • Yunyi Liu, Kunio Kato
    2000 年 33 巻 2 号 p. 223-231
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    A powder-particle spouted bed (PPSB) is proposed for removal of SO2 from flue gas. Experimental results of a bench scale process show that, in addition to the known advantages in a semidry desulfurization process, a PPSB enables more efficient SO2 removal. However, quantitative investigation of the relationship between SO2 removal efficiency and the influential factors is still needed before a PPSB can be used in the flue gas desulfurization industry. In this paper, based on the analysis of chemical reaction and mass transfer between sorbent particles and flue gas, a method for analyzing the SO2 removal efficiencies in the semidry desulfurization process with a PPSB is proposed. The relations of SO2 removal efficiency to such parameters as stoichiometric ratio, approach to saturation temperature, and sorbent particle diameter are established. The desulfurization efficiency is numerically simulated by this method. Comparison of the calculated results with the experimental data shows that this method is of satisfactory reliability for prediction of SO2 removal efficiency in this new flue gas desulfurization process.
  • Shu-Chen Hou, Chun-I Lin, Jung-Sung Hsu
    2000 年 33 巻 2 号 p. 239-244
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    Regeneration of spent bleaching clay by heat treatment in a gas stream was performed in a thermogravimetric analysis system. Red color indices of peanut oils unbleached and bleached with fresh or regenerated clay were determined to calculate regeneration efficiency. The effects of processing parameters such as atmosphere, temperature, time, air flow rate, and amount of clay on the regeneration efficiency have been investigated. Weight losses, specific surface areas and pore volumes of clays were measured to clarify the mechanism of regeneration. Results indicate that regeneration in an air stream is slightly more efficient than that in stagnant air, and air is more efficient than nitrogen. The regeneration efficiency of clay is found to increase with temperature and time. However, it is reduced due to sintering of the clay. Air flow rate and amount of clay do not have any effect on regeneration efficiency.
  • Koreyoshi Imamura, Atsuhiro Hiramatsu, Masanori Imada, Takaharu Sakiya ...
    2000 年 33 巻 2 号 p. 253-261
    発行日: 2000年
    公開日: 2004/04/26
    ジャーナル 認証あり
    A novel advanced oxidation system using a combined UV/H2O2 technique was constructed for application to wastewater treatment. In this system, wastewater containing H2O2 flows along a channel with a flat surface in a thin film, onto which surface UV rays with a wavelength of 253.7 nm are irradiated. As a model wastewater, we used various dye solutions and investigated decoloration rates under various conditions differing in H2O2 concentration, temperature, UV illuminance, and so on. Based on the model, which takes into consideration the formation as well as the disappearance rate of hydroxyl radical (•OH), distribution of UV illuminance along the depth of the flow, and the rate of reaction between dye and •OH, we could simulate the course of dye decomposition. Furthermore, we showed the existence of an optimum H2O2 concentration for decomposition on the basis of this model.
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