KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 23 , Issue 1
Showing 1-20 articles out of 20 articles from the selected issue
  • Pingwei Zhang, Katsutoshi Inoue, Kazuharu Yoshizuka, Hiromi Tsuyama
    1997 Volume 23 Issue 1 Pages 1-10
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A new solvent extraction process using a single extractant, PC-88 A, was developed for efficient separation and recovery of rare metals such as molybdenum, vanadium, aluminum, cobalt and nickel from an aqueous solution, derived from total dissolution of spent hydrodesulfurization catalysts in sulfuric acid solution. In this process, preferential extraction and separation of molybdenum and vanadium over aluminum is achieved at low pH based on the differences in equilibria and kinetics of extraction between these metals. The co-extracted vanadium together with molybdenum is eliminated from the loaded organic phase by selective scrubbing with sulfuric acid solution. Molybdenum in the scrubbed organic phase is easily stripped and separated from small amouns of iron by employing an aqueous solution of NH4OH+NH4Cl and recovered as ammonium molybdate. Vanadium in the scrub solution is separated from small amounts of aluminum and recovered as vanadyl sulfate by extraction with PC-88 A after adjustment of pH to approx. 1.5 with ammonia solution, followed by stripping with sulfuric acid solution. The raffinate obtained after recovery of molybdenum and vanadium is contacted with an organic solution of PC-88 A neutralized by ammonia so as to quantitatively extract aluminum and separate from cobalt and nickel. Aluminum sulfate is obtained after stripping the organic phase with sulfuric acid solution. Cobalt in the raffinate is further recovered as cobalt sulfate with high purity by extraction with PC-88 A, followed by scrubbing with an aqueous solution of CoSO4+ H2SO4 and then, by stripping with dilute sulfuric acid. Nickel in the final raffinate is readily concentrated and recovered as high-purity nickel sulfate after direct extraction with PC-88 A, followed by stripping with dilute sulfuric acid. This process has the potential for incorporating a practical system on a commercial scale.
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  • Shuichi Aoki, Yasuhisa Nakamura
    1997 Volume 23 Issue 1 Pages 11-17
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    To estimate the noise emitted by an industrial tube burner, numerical and experimental analyses are carried out. Firstly, combustion noise was measured and the overall characteristic of the noise is examined. Secondly, a one-dimensional noise analysis programed with a transfer matrix method was used. A lot of effort has been made to analyze the noise from home use combustion devices considering the temperature distribution inside the tube. In this study, the distribution of heat generation rate is taken into account to obtain sufficient accuracy for the noise at the exhaust tube outlet, in addition to the conventional temperature distribution.
    The distribution of heat generation rate is numerically analyzed considering the heat transfer at the inner and outer surface and the radiation at the outer surface of the combustion tube. As a result, the theoretical results show relatively good agreement with the experimental results and the analytical method employed in this study has been confirmed to be practical for noise analysis of industrial tube burners.
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  • Fumiki Ueda, Nobuo Yoshida, Ryouichi Hashimoto, Tadayoshi Muramatu, Sh ...
    1997 Volume 23 Issue 1 Pages 18-27
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The behavior of trace elements in four coals during entrained-bed coal gasification in a 50 t/d plant (HYCOL) was characterised by their distribution in solid, water and gas. More volatile elements were present in dust from water scrubbing (cake) than in slag from the gasifier. The cake contained submicron particles. Results from leaching tests on slag and cake showed that water emissions were below the regulatory limit. More than 90% of the coal sulfur was liberated and converted to H2S and COS in the syngas and a few percent of the coal nitrogen converted to NH2 and HCN. Since almost all NH2 and HCN can be removed by water scrubbing, their contents in syngas were less than a few ppm. The scrubbing system will remove a significant proportion of submicron particles and nitrogen compounds from syngas.
    The trace elements in syngas and the elements possibly accumulated in the plant devices must be measured directly to understand the behavior more precisely.
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  • Takeichiro Takamatsu, Masaru Nakaiwa, Toshinari Nakanishi, Kazumasa As ...
    1997 Volume 23 Issue 1 Pages 28-36
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The ideal Heat Integrated Distillation Column (HIDiC) has no reboiler and no condenser, and then it does not need to heat to vaporize at the reboiler. Therefore, HIDiC is expected to save energy to operate it comparing with conventional columns, but some energy to raise the pressure of the enriching section is necessary to make possible transfer of heat from the enriching section to the stripping section.
    In this report, it is shown by thermodynamical consideration that the ideal HIDiC has some possibility to reduce the exergy loss in the operation comparing with conventional column. This consideration was done under the simplification of constant relative volatility, latent heat, specific heat, and no pressure drop through the column.
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  • Yuji Sano, Shuichi Yamamoto
    1997 Volume 23 Issue 1 Pages 37-46
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The integral form of the diffusion equation for a slab with a constant surface concentration based on the dissolved solid coordinate is derived, which presents the relation between desorption rate and integral average diffusion coefficient by the ratio of the 0 and 1 st moments of concentration distribution. The relation between the 0 and 1 st moments is quite insensitive to the concentraion distribution governed by the diffusion equation with the concentration dependent diffusion coefficients and is satisfactorily estimated by the ratio of average to center concentration at the starting point of the regular regime. From these equations, one desorption curve is quantitatively transformed to the integral average diffusion coefficients as a function of center concentrations. The diffusion coefficient is calculated as a function of concentration by differentiating the integral average diffusion coefficients. As an example, the isothermal drying data of skim-milk aqueous solution are analyzed.
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  • Jong-Hwa Kim, Jong-Gyu Yang, Eiichi Kunugita
    1997 Volume 23 Issue 1 Pages 47-52
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The purpose of this study is development of separation processes by which metal elements worth using for raw materials of chemicals (for examples Cd, Cu, Mn, Pb, Zn and so on) are recovered from incineration fly ash of municipal solid wastes.
    Candidate Process (D) evolved out of Candidate Process (C), which was synthesized with a computer-aided procedure. The process consists of addition of Na2S to nitric solution as leachate of the fly ash for forming precipitate of sulfides, and consecutive dissolution of sulfides with dil-H2SO4, conc-H2SO4 and HNO3 to separate Mn2+, Zn2+ and Cd2+ from each other and to leave CuS insoluble in the acids. For further purification of metals, Candidate Process (D) was modified into Candidate Process (E), in which solvent extraction of Zn2+ from Mn2+ and Cd2+ fractions with bis (2-ethylhexyl) phosphoric acid (D 2 EHPA), and addition of NH2aq or (NH4) 2CO3 to form [Cu (NH3) 4] 2+ and to leave PbS insoluble were adopted.
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  • Kazuharu Yoshizuka, Hiroaki Ohta, Keisuke Ohto, Katsutoshi Inoue
    1997 Volume 23 Issue 1 Pages 53-58
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Controlled-release behavior of nicotine from chitosan microparticles coated with two artificial lipids was investigated. These lipid coating chitosan microparticles can control the release rate of nicotine under zero-order kinetics for a long period as well as a wide range of release extents. Additionally, the release rates of nicotine significantly increased beyond 3437°C, possibly due to the phase transition phenomena of artificial lipid coatings. These lipid coating chitosan microparticles may be applied to transdermal nicotine patches for controlled-release as well as long preservation period.
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  • Toshifumi Ishikura, Hiroshi Nagashima, Mitsuharu Ide
    1997 Volume 23 Issue 1 Pages 59-66
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The objectives of this study are to investigate the basic fluid characteristics for spout-fluid beds of binary mixtures of particles, and to compare the hydrodynamics with that of coarse particles only.
    As results, two patterns of flow in spout-fluid beds, that is, spouting with aeration (SA) and spouting with fluidization (SF), were mapped as the regions depending on the relative values of the central and auxiliary gas flow rates. The operation regions for SA were reduced by the increase of the ratio of fine particles. Also, a correlation for predicting the minimum SF velocity was presented.
    It was found that the overall bed pressure drop under minimum SA condition increased linearly and also the gas velocity through the annulus increased, as the proportion of the auxiliary flow rate to a fixed total gas flow rate was increased for operation in the SA region of binary mixtures. The values as described above were smaller than those in the case of using coarse particles only. Moreover, the particle circulation rate increased and also both the average spout diameter and the fountain height decreased, as the proportion of the auxiliary flow rate to a fixed total gas flow rate was increased.
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  • Toshitaka Funazukuri, Masahiro Nishio
    1997 Volume 23 Issue 1 Pages 67-73
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Measurements of infinite dilution binary diffusion coefficients D12 of ethanol in water at 2.3 to 60°C and of carbon dioxide in water at 3.8 to 50°C, both at an atmospheric pressure, were made by the Taylor dispersion method. The D12 values for both solutes were determined by the method of curve fitting in the time domain. Erroneous values for D12 of CO2 were obtained by the moment method due to the response curves having tailing. The measured D12 values for both solutes were well correlated with the water viscosity with the average absolute deviation AAD = 1.2% for ethanol and AAD = 6.3% for CO2. The Wilke-Chang equation was less accurate in predicting the D12 for both solutes.
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  • Takashi Sasaki, Shigehiko Yamamoto, Iori Hashimoto
    1997 Volume 23 Issue 1 Pages 74-81
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    We have developed an algorithm that defines position correspondence, which is the most important tuning factor in basis weight profile control for paper machines, automatically through results of step response tests. The algorithm is composed of two parts. One is the part that analyzes the result of step response test of each slice by using wavelet transform. And the other is the part that compensates position correspondence of the rest slices to which step response tests have not been applied, and defines total position correspondence by using back propagation in neural networks.
    We introduce an example where position correspondence was corrected by actually using this algorithm and show the effect of this algorithm.
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  • Jun Fukai, Hiromi Omori, Akira Oishi, Osamu Miyatake
    1997 Volume 23 Issue 1 Pages 82-87
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    In an attempt to reduce thermal resistance of heat storage material, carbon fibers were mixed with it. Paraffin whose thermal conductivity km=0.2-0.3 W/ (m·K) and carbon fibers (kf = 25 and 220 W/ (m · K)) were used. Transient temperature responses within the composite material contained in cylindrical capsules were measured in the melting and freezing stages. The volume fraction of the carbon fibers (Xf) was varied up to 1.1%. The fibers increased the melting period because they inhibit natural convection within the liquified paraffin phase. However, the fibers had sufficient effort on the reduction of the freezing period even at Xf <1%. For instance, the freezing period of the composite where Xf = 0.5% and kf=220 W/ (m · K) was approximately half of that with free of fibers.
    The effective thermal conductivity of the composite was moreover discussed based on the effective thermal diffusivity measured from the temperature responses.
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  • Kiyotaka Tahara, Toshinori Kojima, Atsushi Inaba
    1997 Volume 23 Issue 1 Pages 88-94
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    CO2 payback times were calculated for renewable energy electric power plants (hydroelectric, OTEC (Ocean Thermal Electric Conversion) and PV (photovoltaic)) by LCA (Life Cycle Assessment), using fossil fuel-fired electric power plants (coal, oil and LNG) as a reference.
    The CO2 emissions resulting from plant construction and production of plant construction materials were calculated for each case. The amounts of materials for construction of each power plant were taken from previous papers. The resulting LCI (Life Cycle Inventory) was calculated by “NIRE-LCA”, LCA software using a bottom-up approach developed at the National Institute for Resources and Environment.
    The calculated total CO2 emission from the construction of each power plant was divided by annual net generated electricity. Subsequently, CO2 payback times were calculated from estimates of CO2 emissions from construction and operation of renewable energy power plants with fossil fuel-fired power plants used as the reference. CO2payback times for hydroelectric and OTEC (100 MW) power plants were very short in comparison to PV power plants, which was mainly due to CO2 emissions construction. It was also suggested that CO2 payback times for all renewable energy electric power plants evaluated by the present paper were much shorter than typical operational lifetimes of renewable energy electric power plants.
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  • Hiroyoshi Kim, Tatsuo Kanki, Tsuyoshi Asano
    1997 Volume 23 Issue 1 Pages 95-102
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    In extraction of ferric ion with D 2 EHPA, concentrations of ferric ion near the interface were measured by a position-scanning spectrophotometer, and the dependencies of reaction rate on ferric ion, extractant dimer, and hydrogen ion concentrations were elucidated. Based on the experimental results, with the aid of concentration dependencies of interfacial tension, it was clarified that 1) in the extraction region, emulsions are formed in the organic phase, 2) the extractant reacts with ferric ion to form a 1 : 2 intermediate complex, 3) the rate of reaction is proportional to ferric ion concentration and is inversely proportional to hydrogen ion concentration, showing a first-order dependency on dimer extractant concentration in lower extractant concentrations, but zero-order in higher extractant concentrations, and 4) the rate of reaction can be explained by assuming that the kinetic model in which the primary 1 : 2 intermediate complex formation reaction between ferric ion and adsorbed dimer extractant is rate-determining.
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  • Youichi Kawaguchi, Meguru Kaminoyama, Kazuhiko Nishi, Mitsuo Kamiwano
    1997 Volume 23 Issue 1 Pages 103-109
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A mixing process for a wet particle system is advanced by using fundamental operations such as compression, shearing, rolling, and folding. Here, we present a simulation method based on these fundamental operations in order to quantitatively understand the mixing process even in the microspaces between particles.
    We developed model experimental apparatus, and a simulation method based on a dispersion model, and compared the results by both methods. Using the model analysis, the mixing process can be quantitatively understood until the micromixing of the wet particles is mutually completed. It was also found that a mixing process proceeds rapidly and that the mixing state proceeds regularly and uniformly using proposed model operation that is dominated mainly by the folding operation.
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  • Kenji Nakano, Masahiko Shimoda, Yoshimitsu Uemura, Yasuo Hatate
    1997 Volume 23 Issue 1 Pages 110-113
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The vapor-liquid equilibrium ratios of the water-ethanol system containing a minute amount of triacetin and tributyrin were measured at 101.3 kPa by use of an Othmer-type still. Triacetin and tributyrin vapor-liquid equilibrium ratios were calculated by ASOG.
    The experimental values of triacetin and tributyrin vapor-liquid equilibrium ratios in ethanol were constant at lower triacetin and tributyrin concentrations than 0.1 mol %, whereas the ratios at higher triacetin and tributyrin concentrations decreased with their increasing concentrations. In ethanol aqueous solution, triacetin and tributyrin vapor-liquid equilibrium ratios became lower with increasing ethanol concentration. The results of calculated ASOG were not in fair agreement with the experimental results.
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  • Atsushi Ikari, Yasuo Hatate, Yoshimitsu Uemura
    1997 Volume 23 Issue 1 Pages 114-120
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Vapor-liquid equilibria of a water-methanol-ethanol system containing a minute amount of furfural were measured at atmospheric pressure by use of an Othmer-type still.
    The experimental results are represented by four triangular diagrams against the liquid compositions of the major components (water, methanol and ethanol), in which three diagrams show the vapor composition of the major components, respectively, and one diagram shows the equilibrium ratio of the trace component (furfural).
    The curved surface of the equilibrium ratio of the trace component exhibits a gentle downward slope in most areas, but shows a half-saddle face in the neighborhood of the water-ethanol side.
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  • Yasuhiro Imamura, Satoji Kobayashi, Hikoji Inazumi
    1997 Volume 23 Issue 1 Pages 121-124
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    The characteristics of mass transfer accompanied by heat trasfer for humidification of air were experimentally investigated by using a vertical ejector with a water jet. The values of volumetric coefficient of mass transfer in the gas phase, kG a increased with increases in the mass velocity of air, Gi and liquid, Li, and were proportional to Gi1.29 and Li0.49 in a case of single nozzle. Moreover, the relationship between the values of volumetric coefficient of heat transfer in the gas phase, hGa and the operating conditions was investigated in the case of a single nozzle. As a result, an empirical correlation by which the observed values of hGa can be predicted within an error of ±15% was obtained.
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  • Kazuya Ijichi, Hidekazu Yoshizawa, Tutomu Ashikari, Yoshimitsu Uemura, ...
    1997 Volume 23 Issue 1 Pages 125-128
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    Polymeric hollow microspheres of a few ten μm in diameter were prepared by removal of the encapsulated solution from polymeric microcapsules by in situ polymerization. As a result, no rupture of microcapsules occured and a high yield of polymeric hollow microspheres was obtained under the condition of lower ratio of the encapsulated solution to monomer and slower rate of solution removal. The compressive stress to rupture of hollow microspheres increased with decreasing encapsulated-solution/ monomer ratio and removal rate of encapsulated solution.
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  • Tatsuo Go, Kunio Kato
    1997 Volume 23 Issue 1 Pages 129-131
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    High purity titanium tetrachloride hydrate is one of the fundamental materials to synthesize high purity titanium dioxide and its double oxide for the perovskite structure of electronic materials in the liquid phase and it is used not only in industrial production but also in much research and development. It is synthesized by the partial hydrolysis of titanium tetrachloride and the reactivity of the reaction is violent.
    In this study a new method to produce titanium tetrachloride hydrate is shown. The titanium tetrachloride hydrate is safely produced by this reactor in large scales. The hydrate produced by this process is transparent without any crystallized deposits and it is of very high purity.
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  • Tomoaki Satoh, Shozaburo Saito, Yuuji Ajihara, Hiroshi Inomata
    1997 Volume 23 Issue 1 Pages 132-135
    Published: January 10, 1997
    Released: November 12, 2009
    JOURNALS FREE ACCESS
    A numerical study was made on convective heat transfer in supercritical carbon dioxide contained in a two-dimensional duct that consisted of two parallel walls and two adiabatic walls. The temperatures of the parallel walls were set at 305 and 306 K, and the pressure was varied between 7.5 MPa and 9.5 MPa. At 7.5 MPa, which is near the critical pressure of carbon dioxide, the velocity and temperature profiles were highly unsymmetric and skewed. The variation of Nusselt number with Rayleigh number for supercritical carbon dioxide was found to have a similar slope to those for atmospheric air and water systems.
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