JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 30 , Issue 4
Showing 1-31 articles out of 31 articles from the selected issue
Review Paper
  • Kiyotaka Sakai
    1997 Volume 30 Issue 4 Pages 587-599
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    Since artificial organs are intended to replicate chemical processes, knowledge of chemical engineering is essential in their design so that they will function with the maximum efficiency. The most commonly used artificial organ is the artificial kidney, a machine that performs a treatment known as hemodialysis. This process cleanses the bodies of renal failure patients by dialysis and filtration which are simple physicochemical processes. Hemodialysis membranes act to remove accumulated uremic toxins, excess ions and water from the patient via the dialysate, and to supply from the dialysate those ions that are insufficient.
    This paper describes dialysis membranes and dialyzers for blood purification, the solute transport mechanism of the membrane, and a technical evaluation of the dialysis membrane. Lastly, the next generation of artificial kidney is reviewed.
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Original Papers
  • Toyozo Hamada, Masahito Taya, Setsuji Tone, Shuji Nakatsuka
    1997 Volume 30 Issue 4 Pages 600-608
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    The pervaporation (PV) behavior of water and 2-propanol mixtures is compared with vapor permeation (VP) behavior using three types of water-selective composite or asymmetric membranes with different materials in their skin layers, i.e., membranes of polyion complex with polyacrylic acid (PIC-PAAc), polyion complex with partially hydrolyzed polyacrylonitrile (PIC-PAN), and polyparabanic acid (PPAc). From solubility measurements of water-2-propanol mixtures in dense membranes at 356 K, it is found that in liquid phase experiments PIC-PAAc and PIC-PAN membranes show higher solubility of water than PPAc membrane, although no significant difference in solubilities of water vapor among the three membranes is observed in vapor phase experiments. In permeation experiments at 356 K, the PV water fluxes through the three membranes are higher than those for VP if the mole fractions of 2-propanol in the feed solution (x1p) are below 0.90. Using PIC-PAAc and PIC-PAN membranes, higher fluxes of 2-propanol are obtained for PV at less than x1p = 0.6 as compared with those for VP. However, remarkable differences in 2-propanol fluxes are not observed between PV and VP using a PPAc membrane.
    Based on the solution-diffusion theory and taking account of water solubility in the membranes, the fluxes of water and 2-propanol for both PV and VP are analyzed for PIC-PAAc, PIC-PAN and PPAc membranes. Approximate coincidence in the estimated values of diffusion coefficients without swelling and the swelling parameters for water and 2-propanol, which indicated their diffusivities in the membranes, are obtained for PV and VP using the respective membranes.
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  • Tetsuo Suzuki, Koreyoshi Imamura, Keiji Yamamoto, Takuya Satoh, Morio ...
    1997 Volume 30 Issue 4 Pages 609-613
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    The thermal stabilization effect of sugars on freeze-dried proteins is studied, particularly the relation between stabilizing effect and the degree of sugar crystallinity. Three kinds of enzymes, alcohol dehydrogenase (ADH), lactate dehydrogenase (LDH), and malate dehydrogenase (MDH), were used as model proteins. Aqueous solutions of enzymes with sugars were freeze-dried and stored in dry air at 65°C. The stabilities of freeze-dried enzymes improve remarkably by addition of trehalose or raffinose. By measurement of X-ray diffractometry, the sugars are found to form fully amorphous matrix in freeze-dried samples. Furthermore, sucrose stabilizes enzymes to a great extent when it is amorphous in samples, though it shows little stabilizing effect when it is crystalline. These results indicate that the stabilizing effect of sugars closely relates to the amorphous matrix formed by the sugars.
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  • Eiji Iritani, Yukihiko Toyoda, Toshiro Murase
    1997 Volume 30 Issue 4 Pages 614-619
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    Microfiltration experiments were conducted under a constant pressure of 196 kPa, using a dead-end filter. The filtration properties were studied using titanium dioxide suspensions of the rutile form to determine the effects of such solvent environments as pH and the added salt. Both the average porosity and the average specific filtration resistance of the filter cake were determined. It was highlighted through this study that the electrical nature of particles depending on the solution environment plays a significant role in determining the structure of the filter cake which, in turn, influenced the filtration rate in microfiltration of dispersions of metal oxides. It was demonstrated unequivocally that the average porosity in the filter cake had a maximum and the average specific filtration resistance was minimal around the isoelectric pH. These results were in contrast to those observed with ultrafiltration of protein solutions. Such charge effects of particles were weakened in the presence of salts.
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  • Hiroyo Matsumoto, Akihiro Hamasaki, Norio Sioji, Yosiaki Ikuta
    1997 Volume 30 Issue 4 Pages 620-624
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    The influence of CO2, SOx, NOx and soot dust on the productivity of microalgae was considered using Nannochloropsis salina and Phaeodactylun tricornutum. Microalgae are viewed as a possible means of combeting global warming.
    These microalgae can be easily cultivated in a high CO2 gas concentration of 15 vol%.
    SO2 gas itself does not influence the growth of microalgae. However, when the SO2 concentration is high, the pH of the medium decreases and the productivity of the microalgae is lowered.
    The presence of NO does not influence the growth of microalgae. NO absorbed in the medium is changed to NO2 and utilized as a nitrogen source.
    As for Ni and V contained in soot dust, when the dissolved concentrations of these metals in the medium exceed more than 1 and 0.1 ppm, respectively, the microalgae productivity decreases, however, under actual conditions, their concentrations are normally lower than these values.
    The above results obtained in a small scale test using a simulated gas were confirmed in a field test using a raceway-type reactor with actual flue gas.
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  • Yoshitugi Kikkawa, Moritaka Nakamura, Shigeru Sugiyama
    1997 Volume 30 Issue 4 Pages 625-630
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    A new liquefaction process for natural gas is developed to improve process thermal efficiency while using industrial standard equipment. The new process consists of a pre-cooling section which uses mixed refrigerant with brazed aluminum plate-fin exchangers or a spool wound heat exchanger, and a liquefaction section which uses an iso-entropic expander. Thermal efficiency of the new liquefaction process is confirmed to be of the highest level compared with other liquefaction processes. Also, since the new liquefaction process is constructed with commonly available industrial equipment, it can be readily adapted to liquefaction plants of any capacity without requiring expensive and specially designed equipment.
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  • Koji Kuramoto, Tadatoshi Chiba, Toshimasa Hirama
    1997 Volume 30 Issue 4 Pages 631-636
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    The effect of static pressure variation at a downcomer bottom, Pdo, on axial bed density (ABD) distribution in a riser was examined in a circulating gas fluidized bed system consisting of a 0.1 m i.d. and 10.0 m high riser, a 0.2 m i.d. and 8.2 m high downcomer and a screw feeder between them. The ABD distribution and Pdo were determined from simultaneous measurements of static pressure distributions in the riser and the downcomer at a fixed superficial gas velocity of 1.3 m·s–1 as a function of the circulating solid flux, Gs, and the initial height of solid particles in the downcomer, Hsd, employing 0.054 mm FCC particles as a bed material. For most combinations of Gs and Hsd, no essential effect of the variation of Pdo was found on steady-state ABD distributions. The distributions depended appreciably on Pdo only when Gs takes a certain value where a dense region appears in the lower part of the riser. Under such conditions, a fluctuation of the height of the lower dense region was observed in correspondence to a transitional change in the pressure distribution in the downcomer. In addition, the steady-state dense region height was found to increase with the static pressure at the downcomer bottom which was varied through the change of Hsd and by aeration to the downcomer bottom.
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  • Chyi-Tsong Chen, Shih-Tien Peng, Wei-Der Chang
    1997 Volume 30 Issue 4 Pages 637-646
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    In this paper, a nonlinear control strategy based on using a shape-tunable neural network is developed for adaptive control of nonlinear processes. Based on the steepest descent method, a learning algorithm that enables the neural controller to possess the ability of automatic controller output range adjustment is derived. The novel feature of automatic output range adjustment provides the neural controller more flexibility and capability, and therefore the scaling procedure, which is usually unavoidable for the conventional fixed-shape neural controllers, becomes unnecessary. The advantages and effectiveness of the proposed nonlinear control strategy are demonstrated through the challenge problem of controlling an open-loop unstable nonlinear continuous stirred tank reactor (CSTR).
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  • Shi Ying Lin, Hitoki Matsuda, Masanobu Hasatani
    1997 Volume 30 Issue 4 Pages 647-653
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    Properties of the CaS produced from sulfidation of limestone and its effect on sulfidation rate were investigated by using TG, BET and SEM techniques. CaS produced from limestone had an initial specific surface area of about 6.1 × 103 m2·kg–1 with grain size about 0.25 μm, but fell to 0.6 × 103 m2·kg–1 after sulfidation of 40 minutes due to CaS sintering. The CaS sintering led the product layer to shrink and lose porosity, and in turn to affect H2S gas diffusion in to the reaction surface. Conversion of 5 μm sizes particle only reached about 45% at sulfidation of 25 minutes. An unsteady state product layer diffusion model was developed for describing a gas-solid reaction with a shrinking product layer. In the product layer, the effective diffusion coefficient, Des(r) was varied with radius r and also with time t. The Des(r) was determined by porosity changes of the product layer. Good agreement was noticed between calculation and experiment results. According to this model, conversion of 100% is possible obtained by sulfidating limestone particle smaller than 5 μm.
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  • Shimio Sato, Tadahiro Murakata, Touru Suzuki, Mayumi Chiba, Yoshinori ...
    1997 Volume 30 Issue 4 Pages 654-661
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    Lipase was covalently immobilized on silicas with differently controlled pore size distribution and utilized in benzene to catalyze esterification. When silicas were converted to alkylamino derivatives in preparation for immobilization, their physical properties, such as average pore size, changed remarkably, but were relatively unchanged during the succeeding immobilization. Thus the derivatives determined immobilized quantity of the enzyme with their physical properties such that they generally immobilized more enzyme as their pores became larger in size and in volume. The activity of the immobilized enzyme depended on the immobilized quantity of the enzyme, water content, resistance of intra-mass transfer affected by pore size distribution, chemical properties of the silica surface and an over-crowding effect possibly emerging among immobilized lipase molecules. Among these factors, the first two were principal ones and activity was highest at the water content where their pores were filled, being generally higher with an increase in the immobilized quantity of the enzyme.
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  • Yu Bing Xu, Tatsuya Okubo, Masayoshi Sadakata
    1997 Volume 30 Issue 4 Pages 662-668
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    Ultrafine (u.f.) silicon carbide (SiC) particles were synthesized from SiOx (x = 0, 1, 2) silicon (Si), silicon monoxide (SiO), or silica (SiO2)) powders (1.0–3.0 μm) and acetylene (C2H2) in an electric furnace operated under an argon (Ar) atmosphere. The particle products were analyzed by scanning electron microscopy, X-ray diffraction analysis and thermogravimetry-differential thermal analysis. The u.f. particles (25–35 nm) of cubic SiC (β-SiC) could be produced through Si + C2H2, SiO + C2H2 or SiO2 + C2H2 reaction. SiC selectivity was 43% for the Si/C2H2 System (C2H2/Si = 1.5), 79% for the SiO/C2H2 system (C2H2/SiO = 1.2), and 51% for the SiO2/C2H2 system (C2H2/SiO2 = 2.0). The tendency of the experimental results on SiC selectivity for the SiO/C2H2 system coincided with the theoretical curve based on thermodynamic equilibrium calculations.
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  • Jun Sawai, Koji Sagara, Makoto Miyagawa, Takao Kokugan, Masaru Shimizu ...
    1997 Volume 30 Issue 4 Pages 669-676
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    The pasteurization effect of far-infrared (FIR) radiation on Escherichia coli suspended in physiological phosphate buffered saline in the exponential growth phase (exponential phase) was studied. FIR irradiation decreased the number of viable cells in their exponential phase more rapidly than that in their stationary growth phase (stationary phase). By using four kinds of antibiotics as selective reagents to examine the injuries of bacteria, the damaged parts induced by FIR irradiation were specified on the basis of the changes in sensitivities to selective reagents. FIR irradiation damaged mainly RNA ploymerase of E. coli the exponential phase. Under the condition that the transient behavior of the bulk temperature of bacterial suspension irradiated by FIR was the same as that heated by thermal conduction, the pasteurization effect by FIR irradiation on the exponential phase cells was much greater than that by thermal conduction. However, both FIR irradiation and thermal conductive heating induced similar changes in the sensitivities to selective reagents for the exponential phase cells of E. coli. Under the same irradiation conditions, the changes in sensitivities to the selective reagents for the exponential phase cells were different from those for the stationary phase cells. The injuries of ribosome in the exponential phase cells were not as serious as those in the stationary phase cells. It was suggested that the mechanisms of death of the exponential phase cells and the stationary phase cells were different from each other.
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  • Toshihiko Yoshida, Atsushi Tsunoda, Hideto Koide, Takayuki Hoshina
    1997 Volume 30 Issue 4 Pages 677-682
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    The flow pattern and electrical resistance of a planar solid oxide fuel cell (SOFC) are dependent on the configuration of the cell. Chemical engineering approaches for a continuous tubular reactor with a rectangular cross section were applied to planar SOFCs using a 50 × 50 × 0.2 mm zirconia electrolyte. First, three (front, center and rear) separated anodes were printed on a zirconia electrolyte to investigate the flow pattern. Hydrogen fuel was supplied at rates of between 125 and 1250 mm3/s and the open circuit voltage of the front anode was measured when the back was discharged at 0.5 A. The theoretical voltage of the front was estimated by the Nernst equation using the fuel utilization which was equal to the fraction of hydrogen converted to steam at the back anode. The measured front voltage was in fair agreement with the theoretical value for the fuel utilization between 0.1 and 0.5. This result indicated that the hydrogen flow is approximated by the perfectly mixed model in this range. Furthermore, the dispersed plug flow model was applied. However, the measured voltage that deviated from the perfect mixed model below fuel utilization of 0.1 was ambiguous.
    The influence of cell configuration on electrical conductance was also investigated. Five planar SOFCs were fabricated using three configurations of separator and two kinds of cathodes. Simulated conductances were derived from a simple model which involves the current paths from the cathode to separator that consisted of rutted paths and ribs. In this model, the generated current in the rutted path flow in the cathode was collected by the edge of the rib and the current was then directly collected at the ribs where the separator touched the cathode. Simulated conductances were adequately correlated with the measured values. The error might be caused by the contact conductance.
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  • Minoru Miyahara, Kiyoshi Suzuki, Morio Okazaki
    1997 Volume 30 Issue 4 Pages 683-690
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    Adsorption equilibria for solvent dehydration, namely, removal of trace water from solvents by inorganic adsorbents such as silica gels and activated alumina, were measured for various combinations of solvents and adsorbents to test the applicability of the capillary phase separation concept to these systems. The concept is that a component in solution with limited mutual solubility can be separated out into narrow pores even at a concentration less than the saturated concentration, by a capillary effect similar to capillary condensation. The results show definite existence of capillary phase separation in these systems, and verify the applicability of the isotherm estimation method proposed earlier by the authors for adsorption of organic solutes from aqueous solution.
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  • Masayuki Horio, Munechika Ito
    1997 Volume 30 Issue 4 Pages 691-697
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    A simple model is presented to predict cluster size and cluster, voidage for a given set of suspension voidage and operating conditions of a circulating fluidized bed. In this model a cluster is supposed to be suspended by both gas flows inside and outside the cluster; and the gas around the cluster is supposed to form bubble like gas pockets that move upward by buoyancy force. Model predictions are successfully compared with experimental data in the literature.
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  • Kuo-Jen Hwang, Wei-Ming Lu
    1997 Volume 30 Issue 4 Pages 698-705
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    The mechanism of cross-flow filtration of power law slurry is studied through a hydrodynamic approach. The trajectories of particles in the filtration are analyzed in order to estimate the mass flux of particle deposition on the filter septum. An agreed tendency is found between the calculated results of particle flux and the experimental data. A dynamic simulation method based upon the continuity equation of cake compression and the differential-form filtration equation of power law slurry is proposed. By substituting a set of experimental data of filtration rate vs. time into the iteration procedures, the local cake properties and their variations during a course of cross-flow filtration can be simulated. The calculated results of average cake porosity and average specific filtration resistance agree very well with the experimental data.
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  • Miki Mashimo, Hiroshi Sato, Makoto Ueda, Isao Komasawa
    1997 Volume 30 Issue 4 Pages 706-711
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    The equilibria of aluminum and beryllium extraction from sulfate media are using single systems of bis(2ethylhexyl) phosphoric acid (D2EHPA) and dinonylnaphthalene sulfonic acid (DNNSA), and also the mixed system of these extractants have been studied. In the single D2EHPA system, the extraction species are found to be AIR3·HR and BeR2·2HR and separation of the two metals is satisfactory, although the extraction rate is rather slow. In the single DNNSA system, the DNNSA is found to form reverse micelles at concentrations greater than 10–5 M. Separation is poor and the extraction mechanism of the metal ions is influenced by sodium ion.
    The presence of D2EHPA increases the critical micelle concentration (CMC) of DNNSA. For DNNSA concentrations below the CMC, the extraction mechanism in the mixed system is identical to that for the single D2EHPA system. For DNNSA concentrations greater than the CMC in the mixed system, the distribution ratio increases and separation of the metals becomes more difficult. This type of synergistic effect appears to be caused by inclusion of D2EHPA molecules in the DNNSA micelles.
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  • Miki Mashimo, Hiroshi Sato, Isao Komasawa
    1997 Volume 30 Issue 4 Pages 712-717
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    The formation of reverse micelles consisting of a mixture of bis(2-ethylhexyl) phosphoric acid (D2EHPA) and dinonylnaphthalene sulfonic acid (DNNSA) and its effect on the extraction of aluminum and beryllium have been studied. The total concentration of aggregates in the organic phase was measured by the vapor pressure osmometry (VPO) method. The average aggregation number for DNNSA micelle in n-hexane was found to be 16. In the D2EHPA-DNNSA mixed system, the VPO result indicates the existence of dimeric D2EHPA and mixed reverse micelles consisting of both extractants. The mean number of D2EHPA molecules included in a mixed reverse micelle was determined by the relative concentrations of D2EHPA and DNNSA. The contributions of the reverse micelles and dimeric D2EHPA molecules to the extraction of metals were also evaluated. The distribution ratio obtained by the micelles increases substantially through inclusion of D2EHPA molecules into the micelles, with this inclusion causing a synergistic extraction of the metals in the mixed system.
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  • Michael Keßler , Shintaro Furusaki
    1997 Volume 30 Issue 4 Pages 718-723
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    The well-known viability assay with 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) is applied to plant cell suspensions. In this paper it is shown that parameters (pH, TTC concentration, incubation time) which are thought to be only dependent on different cell lines are underlying at least two additional functions (age of the culture and shear stress). Each cell in a different state of activity requires a new set of the parameters mentioned above. Furthermore the time-dependent formazan production courses vary to such an extent that they cannot be used for viability determination. Therefore the usage of TTC as a viability test implies non negligible errors compared to the Evans’ Blue staining method which does not involve cell metabolism. The values of the two different methods to determine the viability can differ by more than 50%. The data suggests abandoning the usage of TTC as a quantitative viability assay for plant cell suspensions.
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  • Qiwu Zhang, Fumio Saito
    1997 Volume 30 Issue 4 Pages 724-727
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    A non-thermal process for producing barium carbonate from barite by means of mechano-chemical treatment has been developed. This process is composed of three steps: The first step is to produce barium hydroxide and potassium sulfate powders by milling of the barite and dry potassium hydroxide powder mixture in a mill. Milling for a short time enables the reaction to be initiated. The second step is to transform the barium hydroxide obtained into barium carbonate by exposing the milled mixture to an air or CO2 gas environment. The final step is to purify the barium carbonate by removing potassium sulfate from the exposed mixture by rinsing with carbonate solution. In the present experiment, about 83% barium of barite could be recovered from a 15-minute milled mixture as barium carbonate by the proposed method when 0.2 mol/dm3 K2CO3 solution was used in the third step.
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  • Hideki Tokanai, Masafumi Kuriyama, Eiji Harada, Hirotaka Konno
    1997 Volume 30 Issue 4 Pages 728-734
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    An experimental investigation is carried out for natural-convection heat transfer to air from an array of five cylinders which are arranged in an inclined plane. The heat transfer coefficient of each cylinder in the array and the average heat transfer coefficient of the array are obtained for a variety of combinations of cylinder spacing, cylinder surface temperature and array inclination angle.
    A correlation equation for the average heat transfer coefficient of the vertical array is proposed. A method for estimating the heat transfer coefficient of each cylinder in the array is also given. Application of these results and the previously proposed heat transfer correlations for the horizontal array shows good agreement with the heat transfer coefficient of each cylinder in the inclined array.
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  • Hajime Tamon, Naoko Murakami, Morio Okazaki
    1997 Volume 30 Issue 4 Pages 735-741
    Published: 1997
    Released: February 27, 2005
    JOURNALS FREE ACCESS
    Adsorption isotherms of 21 kinds of gases and vapors were measured on an activated carbon or a silica gel, and affinity coefficients were determined by applying the DR equation to the isotherms measured. Structure-activity parameters consisting of atomic and bonding parameters are proposed to correlate the affinity coefficients on activated carbon and silica gel. The adsorptive index was assumed to be given by the arithmetical summation of atomic and bonding parameters by taking into account the structure of the adsorbate. The values of atomic refractions reported in the literature are used as the atomic parameters, and the bonding parameters were determined by the Marquardt method so that the adsorptive index correlated experimental affinity coefficients in the present and literature results. It is found that the affinity coefficient is equal to the ratio of adsorptive index of adsorbate to that of a reference adsorbate.
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