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Volume 27, Issue 1
Displaying 1-27 of 27 articles from this issue
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Original Papers
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Junzo Masamoto, Kazuhiko Matsuzaki1994 Volume 27 Issue 1 Pages 1-5
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSThe world’s first technology for the commercial production of methylal is the reactive distillation method. Its application to a new formaldehyde process has also been investigated. Whereas the oxidation of methanol yields one mole of water per mole of formaldehyde, methylal oxidation produces only one mole of water for every three moles of formaldehyde. Thus, the output by methylal oxidation is more than 70% formaldehyde compared with 55% by methanol oxidation.
For this purpose, basic research on methylal synthesis was conducted and the world’s first commercial production of methylal using reactive distillation was accomplished. Using this methylal, the world’s first methylal oxidation technology for manufacturing highly concentrated aqueous formaldehyde was established.
This highly concentrated aqueous formaldehyde is then fed to an acetal homopolyrner and copolymer plant having a combined capacity of 35,000 tons/year.View full abstractDownload PDF (2357K) -
Junzo Masamoto, Kazuhiko Matsuzaki1994 Volume 27 Issue 1 Pages 6-11
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSTo develop a new technology for the purification of formaldehyde from formalin by a distillation method, the theory of vapor liquid equilibrium of the formaldehyde-water binary system was investigated.
Based on the studies of Thompson and Bryant9), and Bezzi and Iliceto1), the vapor-liquid equilibria of formaldehyde and water were calculated and the results were in good agreement with the reported data.
It was found that the partial pressure of formaldehyde is determined by the free formaldehyde concentration while the partial pressure of water is determined by the mole fraction of free water.View full abstractDownload PDF (843K) -
Junzo Masamoto, Kazuhiko Matsuzaki, Hirohisa Morishita1994 Volume 27 Issue 1 Pages 12-16
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSTo develop a new technology for the purification of formaldehyde from formalin by a distillation method, the vapor-liquid equilibria of formaldehyde water binary systems and the vapor-liquid equilibria of formaldehyde water systems in the presence of diluent were investigated.
It was shown by calculation that in some cases, when the concentration of diluent is high, the volatility of formaldehyde is always higher than that of water and that these calculations are in good agreement with experimental data.
Based on this principle, the purification of formaldehyde by an extractive distillation method was established.View full abstractDownload PDF (686K) -
Meguru Kaminoyama, Kazuyoshi Arai, Mitsuo Kamiwano1994 Volume 27 Issue 1 Pages 17-24
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSA numerical analysis method of estimating power consumption for a pseudoplastic liquid in stirred vessels fitted with various plate impellers is first presented in terms of the energy dissipation distribution in the vessels. The pseudoplastic liquid used was a 1.2 wt.% aqueous solution of hydroxyethyl cellulose. Good agreement between numerically analysed results and experimental data of power consumption in a model vessel of 0.2 m diameter with various impellers and in a vessel of 0.4 m diameter with a paddle impeller proved the method to be sufficiently reliable. Subsequently, the same analysis and mixing analysis were numerically performed for geometrically similar large-scale vessels of 0.4, 0.6 and 0.8 m diameters. It was ascertained from these analyses that the relation between the scale-up ratio and the power consumption, mixing time, and mixing energy can be quantitatively estimated by a numerical analysis of stirred vessels with various types of stirring impellers for a pseudoplastic liquid.View full abstractDownload PDF (1095K) -
Takao Tsukada, Mitsunori Hozawa, Nobuyuki Imaishi1994 Volume 27 Issue 1 Pages 25-31
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSFor the crystal growth of LiNbO3, a global analysis of heat transfer in an inductively heated CZ furnace was carried out by use of the finite element method. The effects of the temperature dependency of physical properties such as viscosity and surface tension of the melt, as well as the effect of processing parameters such as crystal rotation, on the flow and temperature fields in the furnace and on the melt/crystal interface shape were investigated. With the mathematical model developed in the present work, the interface inversion caused by crystal rotation was demonstrated theoretically. It is found that the effect of the temperature dependency of viscosity on CZ crystal growth is not significant under the conditions used here, and that the thermocapillary force strongly affects crystal growth. The critical crystal rotation rate at which the interface inversion occurs becomes much larger, and the RF coil current required to keep the crystal diameter constant becomes smaller, in comparison with those without thermocapillary flow in the melt.View full abstractDownload PDF (6470K) -
Susumu Nakamura, Yoshiro Ito, Koei Iwafuchi, Masataka Shirakashi1994 Volume 27 Issue 1 Pages 32-38
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSWe have developed a new type of fluidized-bed called a circulating fluidized-bed adsorber (CFBA) that brings adsorbent particles into contact with a large quantity of water at high efficiency. In the present study, effects of outer scale and internal structure of the CFBA on the uranium uptake from natural seawater were investigated, and some improvements in the adsorption ability of the CFBA were achieved.
By improving the internal structure of the CFBA, the total amount of uranium recovered from natural seawater became 1.6 times larger than that in an adsorber developed at the beginning of the study. The uranium recovery efficiency of the CFBA was compared with that of a conventional fluidized-bed adsorber. The amount of uranium adsorbed per unit volume of the CFBA was evaluated to be 20% larger than that of the fluidized-bed adsorber.
Operational stability of the CFBA was examined for eighteen days. In spite of using unfiltered seawater, clogging did not occur during the adsorption period. The CFBA ran very stably.View full abstractDownload PDF (1015K) -
Yunghyo Lee, Sunwon Park1994 Volume 27 Issue 1 Pages 39-44
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSIn batch reactor operation, a reliable method of knowing the reaction state on-line is an important requirement for quality regulation between batches and minimum batch cycle time. An on-line quality control scheme using conductance measurement of the reaction mixture is presented for a pre-defined optimized operation of a batch esterification reactor. Through a series of experimental studies, a semi-empirical equation for the conductance-conversion correlation is derived. Using this conductance measurement together with a reaction model, a cascade nonlinear control scheme for the batch esterification reactor is designed. Additionally, to solve the problem of model inaccuracies and uncertainties, the extended Kalman filter is applied for the reaction state estimation. Experimental studies have been conducted to illustrate the performance of the control scheme. The proposed approach shows better control performance than the commonly used temperature control approach in controlling the batch esterification reactor.View full abstractDownload PDF (965K) -
Jong-Nam Kim, Kuck-Tack Chue, Kwon-Il Kim, Soon-Haeng Cho, Jong-Duk Ki ...1994 Volume 27 Issue 1 Pages 45-51
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSThe binary adsorption of nitrogen and carbon dioxide on zeolite-X was investigated. The adsorption equilibria of pure and binary systems were measured by static methods. In the binary system the equilibrium Selectivity of CO2 over N2 was very high: about 525 at a CO2 mole fraction of 0.14 and a temperature of 15°C. Consequently, N2 can be considered as inert when its mole fraction is less than 0.8. The ideal adsorbed-solution theory (IAST) predicted quite well the binary equilibrium data, while the extended Langmuir isotherm showed a great deviation. The dynamics of fixed-bed adsorption of CO2-N2 gas mixture (CO2 14.86 mole percent) was analyzed by the cell model under non-isothermal conditions, incorporated with binary adsorption equilibria, mass and heat transfer resistances and variation of gas velocity in the bed. The concentration and temperature history curves were determined and compared with the theoretical results. This cell-model with IAST predicted well the dynamic behavior of the adsorption bed.View full abstractDownload PDF (2791K) -
Kenji Takeshita, Mikio Kumagai, Yoichi Takashima, Shiro Matsumoto1994 Volume 27 Issue 1 Pages 52-56
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSA solid extractant, a porous styrene-divinylbenzene copolymer (SDB) impregnated with dihexyl-N,N-diethylearbamoylmethylphosphonate (CMP), was developed for the extraction of rare-earth elements. Solid extractants supported by SDB particles with different crosslinking and pore volume were prepared and the extraction of Ce(III) from aqueous phase containing nitrate ion was examined.
SEM observation suggested that the impregnated CMP was dissolved in the SDB polymer network. The CMP content increased by use of SDB particles with lower crosslinking and higher pore volume. The stoichiometric relation for the extraction reaction was represented by
Ce3+ + 3NO3– + 3CMP ↔ Ce (NO3) 3·3CMP
which was the same as that for the liquid-liquid extraction.
The extraction rate increased with decrease of particle size. The rate-controlling step was the intraparticle diffusion of Ce(III) for solid extractant of diameter greater than 0.2 mm. For smaller particles, it changed to the reaction between CMP and Ce(III).View full abstractDownload PDF (2569K) -
Tetsuo Fuchino, Kazuo Yamaguchi, Masaaki Muraki, Toyohiko Hayakawa1994 Volume 27 Issue 1 Pages 57-64
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSDesigning of multipurpose batch plants is a problem of optimizing the plant configuration and the equipment sizes under the constraint of the production plan. However, these decision variables are strongly interactive with each other through scheduling, so that simultaneous optimization is impossible.
In this study, the design problem of multipurpose batch plants is considered on the basis of cyclic production, and the evolutionary method is adopted from the analysis of this design problem. The plant configuration is decided as the evolutionary variable, and two IP (Integer Programming) models are developed to generate the initial and/or neighboring plant configurations. The initial plant configuration with minimum number of equipment units is obtained through these IP models, and the equipment sizes under this initial plant configuration are optimized through cyclic scheduling. The neighboring plant design can be generated repeatedly through the developed IP model and the cyclic scheduling from this initial one, and an evolutionary design method for the multipurpose batch plants is developed. The effectiveness of the developed method is demonstrated through an example design problem.View full abstractDownload PDF (1228K) -
Akira Hirata, Shin-ichi Nishizawa, Motoharu Noguchi, Masato Sakurai, S ...1994 Volume 27 Issue 1 Pages 65-71
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSMarangoni convection in a silicone oil liquid bridge under microgravity conditions during parabolic flight was observed. The developing process of axis-symmetric laminar Marangoni convection was studied experimentally and numerically. To reach a steady state of the temperature field, much more time was needed than to reach a steady state of the velocity field.
The effects of initial temperature conditions inside a liquid bridge, heat transfer across the free surface, and temperature dependence of viscosity on both velocity and temperature field were studied numerically.View full abstractDownload PDF (7016K) -
Makoto Hirata, Katsumi Nemoto, Akira Hirata1994 Volume 27 Issue 1 Pages 72-76
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSThe solubility of N-(benzyloxycarbonyl)-L-aspartyl-L-phenylalanine methyl ester (Z-APM) was studied in an aqueous system with coexisting L-phenylalanine methyl ester (L-Phe-OMe). It was found that the Z-APM solubility shows very complicated behavior. Under acidic pH condition (pH < 3.5), pure Z-APM was precipitated and the solubility increased uniformly with increasing pH and L-Phe-OMe concentration. Under moderate pH condition (4.5 < pH < 8), Z-APM was precipitated with L-Phe-OMe, forming a complex of Z-APM·L-Phe-OMe. The solubility varied with the pH following a U-shaped curve and decreased with increasing L-Phe-OMe concentration at the same pH. The pH value at the transient point from pure Z-APM precipitation to Z-APM·L-Phe-OMe precipitation shifted toward acidic pH with increasing L-Phe-OMe concentration. From the experimental results it was assumed that the Z-APM·L-Phe-OMe complex was not only formed by ionic bond. An equilibrium model of the precipitation considering the formation of complex was proposed that well explains the complicated behavior of the solubility.View full abstractDownload PDF (694K)
Short Communication
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Makoto Hirata, Nozomu Shibuya, Akira Hirata, Masahiko Inamo, Noriyuki ...1994 Volume 27 Issue 1 Pages 77-78
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSDownload PDF (300K)
Original Papers
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Nobuyoshi Nakagawa, Shunji Arita, Hitoshi Uchida, Nobuhiro Takamura, T ...1994 Volume 27 Issue 1 Pages 79-84
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSBased on experimental results from three fluid beds of different cross sections (15 × 15 cm, 8 × 8 cm and 7.1 cm i.d.), the effects of superficial gas velocity, freeboard height, cross sectional area and particle properties on the axial particle hold-up distribution in the freeboard and the elutriation rate from the top of the column were investigated. An entrainment intensity R was proposed for the particles to explain the effect of size distribution and density on the particle hold-up. The particle hold-up was found proportional to R1.87, and increased with increasing freeboard height and cross-sectional area. Empirical equations for both the particle hold-up distribution and for the particle elutriation rate were obtained.View full abstractDownload PDF (690K) -
Doudou Diagne, Motonobu Goto, Tsutomu Hirose1994 Volume 27 Issue 1 Pages 85-89
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSA new PSA process was developed and applied to the removal and enrichment of carbon dioxide from air-CO2 mixtures. This PSA process is constituted by a dual reflux policy and admission of the feed gas mixture at an intermediate axial position of the column. The influences of the feed inlet position and reflux ratio on process performance were experimentally investigated. For both parameters there is respectively an optimum value at which the process performance was relatively higher. At the optimal values it was possible to concentrate and remove the CO2 simultaneously beyond a factor of the pressure ratio Pa/Pd, a situation unattainable in the conventional PSA in which the feed gas is supplied at the end of the column.View full abstractDownload PDF (701K) -
Hsi-Kuei Chen, Chun-I. Lin1994 Volume 27 Issue 1 Pages 90-94
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSA physico-chemical model has been formulated to describe the kinetics of the carbothermic nitridation of powder alumina. Based on this model, simultaneous differential equations were derived. When the model was employed to interpret the experimental data, the rate expression of chemical reaction determined in the chemical reaction control region was used and simultaneous differential equations were solved numerically. The expression of effective gas diffusivity, which was left as a fitting parameter to calculate the theoretical predictions, was given by
DeAB/m2·s–l = 7.36 × 10–4 exp(–27.84 kJ mol–1/RT)
The correlation between the nonisothermal factor and the half-thickness of the sample as well as correlation between the Sherwood number and the Reynolds number was determined.View full abstractDownload PDF (691K) -
Kiyoshi Idogawa, Hiroshi Nagaishi, Hideo Narita, Takashi Fukuda, Takes ...1994 Volume 27 Issue 1 Pages 95-101
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSGas holdup was measured for gas-liquid (hydrogen gas/decrystallized anthracene oil/creosote oil) system and gas-slurry (hydrogen gas/Taiheiyo coal particles/decrystallized anthracene oil) systems in a 0.1 ton/day continuous direct coal liquefaction reactor. The measurements were carried out at temperatures ranging from 289 K to 723 K and a pressure of 30 MPa by two methods, a differential pressure method for the gas-liquid systems and a gas-quenching method for the gas-slurry system.
The gas holdups for both systems were correlated with the gas flow pattern just above the reactor entrance. Though the present gas holdup data were in reasonable agreement with those published by other investigators, a difference was found between the dependencies of gas holdup on superficial gas velocity in the preheater and in the reactor.View full abstractDownload PDF (931K) -
Akira Matsuda, Kenji Kawasaki, Masaaki Ishihara1994 Volume 27 Issue 1 Pages 102-106
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSThe characteristics of compression and solid-liquid separation of excess activated sludge were investigated. Compression-permeability experiments were made under low solid compressive pressure (103–105 Pa), and centrifugal settling experiments under 30–2000 Pa. In these experiments, we used excess activated sludge from a municipal wastewater treatment plant and sludge treated by a freezing and thawing process. An equation for inorganic sludge (1 – ε = E·psβ) is proposed, where ε and ps are the porosity and the solid compressive pressure, and E and β are empirical constants for each sludge. The equation can be applied to both experiments, if the average values of ε and ps which were defined previously by the authors are used in the centrifugal settling experiment. Consequently, the compression characteristics over a wide range of ps can be estimated by a centrifugal settling experiment which is relatively simple.
The relationship between local specific filtration resistance α and ps can be represented by a straight line which has a bending point at the pressure where εw is nearly equal to zero. The freezing and thawing treatment of excess activated sludge diminishes the specific filtration resistance of the sludge by more than one order over the whole experimental range of ps. This implies that our treatment improves the solid-liquid separation characteristics of excess activated sludge.View full abstractDownload PDF (2588K) -
Seiya Hirohama, Toru Takatsuka, Sinji Miyamoto, Tsunehisa Muto1994 Volume 27 Issue 1 Pages 107-113
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSTrace amounts of acetaldehyde, ethyl acetate, isoamyl alcohol, n-propanol and methyl ethyl ketone were effectively extracted and removed from the ethanol aqueous solution by carbon dioxide as solvent with countercurrent contractors. The experiments were carried out at 298.2 K and 7.0 MPa or 303.2 K and 7.5 MPa with solvent-to-feed ratios from 1.3 to 5.0 mol/mol. The concentration of feed ethanol aqueous solution was 20 mol%. Packed columns with 6 mm Raschig rings were employed as contractors.
Although a certain amount of ethanol was dissolved into the solvent simultaneously with the trace components, the dissolved ethanol was easily recovered by scrubbing the solvent with a small amount of water.
Assuming the state of infinite dilution for each component, a simple calculational procedure was devised to determine the height per mass-transfer unit for some components in packed columns from the experimental data.View full abstractDownload PDF (905K) -
Hirotsugu Hattori, Takehiro Matsuse, Hiroyuki Hada1994 Volume 27 Issue 1 Pages 114-117
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSIn the previous paper, we reported that Ergun’s equation, –dp/dz = K1Ua + K2Ua2, was adopted to extend the force balance model of Mamuro et al., following Epstein and Levine. We predicted the longitudinal distribution of fluid velocity and pressure in the annulus, and the maximum ratio of spouting to fluidizing pressure drop.
In this paper we report the experimental results obtained for the longitudinal pressure distribution in the annulus. Longitudinal pressure distributions were measured for the spouted beds of different column diameters and of spherical glass particles and Soma sand of various sizes, wheat and polystyrene pellets. Experimental results were in good agreement with predicted values.View full abstractDownload PDF (455K) -
Chibun Ching, Xiaoping Liu, Kus Hidajat1994 Volume 27 Issue 1 Pages 118-123
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSA chromatographic technique was used to experimentally study the effects of solvent concentration on sorption and diffusion of cresols in a bonded β-cyclodextrin-silica with a mixed solvent of methanol and water as mobile phase. A distribution model that accounts for the non-ideality caused by the different degrees of interaction with the stationary phase for the solute and solvent components was proposed, based on the mechanism of multi-component competitive adsorption, to describe the solvent concentration dependence of the distribution coefficient. The results showed that the distribution model is in good agreement with the experimental data. The axial dispersion, external film mass transfer and intraparticle diffusion were found to be dependent on the solvent concentration. An analysis of the solvent concentration effect on the intraparticle diffusion in the range of 33.3 mol/l ≤ c1 ≤ 49.95 mol/l indicated that the effect of solvent concentration on restricted diffusion is large in comparison with the solvent concentration effect on non-restricted diffusion for each cresol.View full abstractDownload PDF (883K)
Short Communications
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Effect of L- And D-Phenylalanine on Crystallization and Transformation of L-Glutamic Acid PolymorphsMitsutaka Kitamura, Hiroshi Funahara1994 Volume 27 Issue 1 Pages 124-126
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSDownload PDF (1981K) -
Shigendo Akita, Tsuyoshi Maeda, Hiroshi Takeuchi1994 Volume 27 Issue 1 Pages 126-129
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSDownload PDF (416K) -
Makoto Kunii, Kenji Kuroda, Kazuaki Yamagiwa, Akira Ohkawa1994 Volume 27 Issue 1 Pages 129-132
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSDownload PDF (408K) -
Arne Staby, Christina Borch-Jensen, Jørgen Moller ...1994 Volume 27 Issue 1 Pages 132-134
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSDownload PDF (330K)
Prompt Papers
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Mikio Konno, Hiroshi Inomata, Takeshi Matsunaga, Shozaburo Saito1994 Volume 27 Issue 1 Pages 134-136
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSDownload PDF (2116K) -
Masaru Ishida, Takehiro Ohba1994 Volume 27 Issue 1 Pages 137-138
Published: 1994
Released on J-STAGE: March 30, 2005
JOURNAL FREE ACCESSDownload PDF (272K)
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