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YOSHINARI BABA, TOSHIYA EGUCHI, KATSUTOSHI INOUE
1986 Volume 19 Issue 5 Pages
361-366
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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The mechanism of palladium extraction from aqueous ammonium chloride solutions with dihexyl sulfide in toluene was investigated at 303 K from the viewpoints of extraction equilibrium and kinetics. The result of a loading test suggests that palladium is extracted as a 1:2 metal-reagent complex. The concentration dependencies of the reactant species were examined using a stirred transfer cell with a constant interfacial area to investigate the extraction rate mechanism. The observed extraction rate was reasonably explained in terms of a simple reaction scheme involving complex formation between the intermediate complex adsorbed at the interface and a free extractant molecule dissolved in the aqueous phase as the rate-determining step.
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IBRAHIM ABDEL HAMID KHATTAB, MASARU ISHIDA
1986 Volume 19 Issue 5 Pages
367-374
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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A new system, consisting of a two-dimensional optical fiber array probe, video system and microcomputer, was used to visualize the behavior of jets and bubbles in a three-dimensional fluidized bed. By this system a series of successive pictures with time difference 1/30 s was obtained. The bed was 28 cm in diameter, provided with a nozzle of 0.325 cm i.d. fixed at the center of the gas distributor.
The behavior of jets and initial bubbles in the grid region was visualized. The effect of bed material, distributor configuration, superficial gas velocity and nozzle gas velocity on this behavior was examined. The results showed that the jet height was affected by the properties of the bed material, but that the initial bubble diameter was scarcely affected thereby. Gas distributor configuration had an important effect on jet height and initial bubble properties other than frequency. Initial bubble shape and frequency were strongly dependent on superficial gas velocity rather than on nozzle gas velocity. A correlation to evaluate the jet height is proposed.
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TADASHI SHIROTSUKA, KAORU ONOE, AYUMU YOKOYAMA
1986 Volume 19 Issue 5 Pages
375-379
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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A previous study showed that oxidation of LaNi
5 could produce catalysts with a relatively high Ni dispersion.
This study focuses on the effect of Ni atomic percent α upon Ni dispersion δ and turnover frequency
TF, using La-Ni compounds. It was found that the value of δ was higher in the order of LaNi
5 >La
2Ni
7 >LaNi
3 > LaNi and that this order was related to oxidation rate. The value of
TF, on the other hand, was higher in the reverse order, indicating that high oxidation rate causes severe defects on the surface of Ni crystallites.
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TING-CHIA HUANG, RUEY-SHIN JUANG
1986 Volume 19 Issue 5 Pages
379-386
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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Kinetic studies of the extraction of zinc from aqueous sulfate solution by di(2-ethylhexyl) phosphoric acid in kerosene were made, using a constant interfacial area cell. Measurements of the extraction and stripping rates led to the identification of rate expressions and a suggested mechanism of this reaction. Based on the nature of the extractant and the reaction mechanism for the formation of zinc complex in the aqueous phase, a simple extraction scheme is proposed in which the rate-controlling step is interfacial. The mass-action constant obtained in the present kinetic study is considered to agree with the extraction constant obtained in the previous equilibrium study. Effects of the total sulfate concentration in the aqueous phase on the extraction and stripping rates were also investigated.
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HIROSHI INOMATA, KAZUHIRO TUCHIYA, KUNIO ARAI, SHOZABURO SAITO
1986 Volume 19 Issue 5 Pages
386-391
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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A new flow-type apparatus was developed using an overflow-type liquid level self-control system and a back pressure regulator. The present apparatus makes possible vapor-liquid equilibrium measurements at high temperatures by minimizing the residence time of heat-sensitive substances. It was shown that the resulting vapor-and liquid-phase compositions were independent of the sample flow rate within the range of flow rates employed.
Vapor-liquid equilibrium data were measured with this apparatus for the systems CO
2-
n-heptane, CO
2-
n-decane, CO
2-
teans-decalin, CO
2-tetralin, CO
2-quinoline, benzene-tetralin and benzene-quinoline in the temperature range from 340 to 710 K at several pressures up to 23 MPa.
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A. L. MYERS, D. VALENZUELA
1986 Volume 19 Issue 5 Pages
392-396
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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Adsorption equilibria of gas mixtures are predicted from single-gas isotherms that obey the Toth equation by a graphical procedure. Since the design of gas adsorbers requires repetitive calculations, a fast-converging algorithm has been designed for execution on a computer. Predicted adsorption isotherms agree very well with experimental data at low and moderate surface coverage.
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KAZUHARU YOSHIZUKA, KAZUO KONDO, FUMIYUKI NAKASHIO
1986 Volume 19 Issue 5 Pages
396-400
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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Using four kinds of alkylbenzene-substituted
N-8-quinolylsulfonamides of different alkyl-chain length and their copper chelate complexes, kinetic studies concerning the extraction of copper with extractant and the stripping of copper with sulfuric acid were carried out in a membrane extractor using a hollow fiber.
It was found that the interfacial reaction between the adsorbed copper complex (CuR
+ad) and the adsorbed extractant (HR
ad) is a rate-controlling step among the interfacial reaction steps of the extraction and stripping processes, regardless of the alkyl-chain length of the extractants, and that the reaction rate constant of the ratecontrolling step is proportional to the equilibrium constant of this reaction for each of the four kinds of extractants.
The validity of a diffusion model with the interfacial reaction was confirmed by agreement of the observed extents of copper extracted and stripped with those calculated over a wide range of experimental conditions.
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YASUO KOUSAKA, KIKUO OKUYAMA, MOTOAKI ADACHI, TADAAKI MIMURA
1986 Volume 19 Issue 5 Pages
401-407
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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Effect of Brownian diffusion on the electrical classification of ultrafine particles in the differential mobility analyzer (DMA) has been studied theoretically and experimentally. Two kinds of particle losses which are undesirable in size analysis, (1) loss caused by the Brownian diffusion of particles traversing the sheath air stream toward the collector rod of the DMA, and (2) loss caused by Brownian diffusive deposition of particles on every wall of the DMA excluding the collector surface, were theoretically evaluated by solving the diffusion equation. Some of the calculation results were confirmed by experiments for particles of various sizes, two different lengths of DMA and various ratios of flow rate of aerosol to sheath air.
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TAKESHI KATAOKA, TADAAKI NISHIKI
1986 Volume 19 Issue 5 Pages
408-412
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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The change of (W/O) emulsion drop size in (W/O)/W emulsion with respect to time was measured in a stirred tank. The effects of various factors on the Sauter mean diameter d
32 of the (W/O) emulsion drops and its variation with time were investigated. They are affected by the kind of surfactant, the presence of carrier and the solute permeation in addition to the stirring speed, the oil-phase viscosity and the composition of inner water phase. The value of d
32 can be correlated with a dimensionless group containing the Weber number for each surfactant, i.e., Span 80 and ECA 4360J.
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KUNIO ARAI, HIROMI YAMAGUCHI, SHOZABURO SAITO, EUI SARASHINA, TAKASHI ...
1986 Volume 19 Issue 5 Pages
413-419
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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A kinetic study was performed on the bulk thermal polymerization of styrene. The conversion and average molecular weights were measured. Rate equations were derived on the basis of a model proposed in a previous paper which introduced the gel effect into each elementary reaction by considering the decrease of segmental jump frequency during polymerization. The model could successfully simulate the conversion and the average molecular weight.
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MASAAKI TERAMOTO, HIDETO MATSUYAMA, TAKUMI YAMASHIRO, YUJI KATAYAMA
1986 Volume 19 Issue 5 Pages
419-424
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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Experimental results for the facilitated transport of ethylene through supported liquid membranes containing silver nitrate as a carrier are presented. The selectivity factor in the separation of ethylene and ethane increases with increasing carrier concentration, reaching about 1000 when silver nitrate concentration is 4mol/dm
3. An approximation method for calculating the rate of facilitated transport accompanied by an instantaneous reversible reaction is proposed. This method is applicable even to the case where the diffusivities of the carrier and the complex differ from each other. It is found that the effect of experimental condition on the permeation rate of ethylene is satisfactorily explained by assuming that the reaction between ethylene and Ag
+ is instantaneous and reversible
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HIROYUKI HATANO, IBRAHIM ABDEL HAMID KHATTAB, KYOKO NAKAMURA, MASARU I ...
1986 Volume 19 Issue 5 Pages
425-430
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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Spatiotemporal measurements of bubble properties in a three-dimensional free-bubbling fluidized bed were done by using double-line arrays of reflective optical fiber probes and a microcomputer-aided data processing system. The measuring system could get real bubble shapes and the bimodal lateral distribution of the bubble frequency and holdup.
The aspect ratio
D''
B/
DB to express the extent of bubble deformation was correlated with the coalescence index defined by (
Uo-
Umf)/
UB. In the case of two vertically aligned bubbles which were going to coalesce, the average aspect ratio of the leading bubble was almost constant, while that of the following bubble increased sharply with coalescence index.
By plotting the bubble rising velocity
UB against the real bubble diameter
DB, three kinds of bubbles, viz., spherical cap, elongated and slug, could be distinguished. On the other hand, by plotting it against the bubble height
D''
B, the data for these three kinds of bubbles crowded around a line of
KB = 0.9, showing that the three kinds of bubbles in real situations cannot be distinguished by such plot.
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KENJI HARAYA, KENZABURO OBATA, TOSHIKATSU HAKUTA, HIROSHI YOSHITOME
1986 Volume 19 Issue 5 Pages
431-436
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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Permeation rates of hydrogen, helium, methane, nitrogen, carbon monoxide, oxygen, argon, carbon dioxide and propane through asymmetric cellulose acetate membranes were measured in the temperature range from 273 to 373 K. Membranes constants of the transport model equation consisting of solution-diffusion flow through the polymer matrix and Knudsen flow through the micropores were determined by permeabilities of zero pressure limit of helium and nitrogen. The permeabilities of other gases can be predicted well by the model equation with these constants. The variety of data which depends on the membrane structures and the measuring temperatures has been explained reasonably by the transport model.
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SHUN WACHI, HISASHI MORIKAWA
1986 Volume 19 Issue 5 Pages
437-443
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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Liquid-phase chlorination of ethylene and 1, 2-dichloroethane in a dark system was investigated, by using an agitated vessel with a flat free gas-liquid interface. The results were analysed to obtain the chemical reaction kinetics through a theoretical treatment of simultaneous absorption and reaction for gas-liquid heterogeneous systems.
The chemical reaction kinetics for chlorine addition to ethylene and. for chlorine substitution to 1, 2-dichloroethane showed respectively (1, 1)- and (1, 2)-order dependencies on the concentrations of ethylene and chlorine. In the absence of ethylene, however, chlorine substitution to 1, 2-dichloroethane, where the reaction occurred homogeneously, obeyed (1, 1)-order dependency on the concentrations of chlorine and 1, 2-dichloroethane.
It is explained by the radical chain mechanisms of chlorine substitution reaction that the presence of ethylene enhances the initiation to produce chlorine radical and that the termination step is controlled by the deactivation of 1, 2-dichloroethyl radical. Without ethylene, the production of chlorine radical is so slow that the deactivation of chlorine radical controls the termination step.
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AKIRA YASUNISHI, MIKI FUKUMA, KATSUHIKO MUROYAMA
1986 Volume 19 Issue 5 Pages
444-449
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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Bubble properties such as gas holdup, bubble frequency, bubble length and bubble rising velocity in a slurry bubble column were measured by using a dual electroresistivity probe method.
The radial distribution of local gas holdup, ε
g, was parabolic in the range, where mean solid holdup, ε
s, was less than 0.2. In the range of ε
s≥ 0.2, however, ε
g in the region of dimensionless radius, r/R
w, from 0.4 to 0.8 decreased considerably owing to the concentration of bubbles in the central region of the column. The value of cross-sectionally averaged gas holdup, ε
g, agreed fairly well with that predicted by Koide''s equation for heterogeneous flow in a slurry bubble column.
The cumulative bubble length distribution, F
l followed a log-normal distribution. On the other hand, the cumulative bubble rising velocity distribution, F
v, followed a normal distribution. The superficial gas velocity, U
g, had little effect on F
l and F
v in the slurry bubble column with high solid content.
When U
g was larger than about 4 cm/s, the median of F
l and that of F
v in the slurry bubble column were larger than the corresponding values in the bubble column. On the other hand, the variance of F
l in the slurry bubble column was almost the same as that in the bubble column and the variance of F
v in the slurry bubble column was smaller than that in the bubble column.
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TATSUO NISHIMURA, YOSHIHIKO KAJIMOTO, ATSUSHI TARUMOTO, YUJI KAWAMURA
1986 Volume 19 Issue 5 Pages
449-455
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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The relationship between flow structure and mass transfer in a wavy channel was investigated in the range from laminar to turbulent flow. Laminar flow has a steady two-dimensional structure, but turbulent flow has an unsteady three-dimensional vortical structure. In particular, the flow field in a large recirculation vortex within the furrow of a wavy wall shows an intermittent reversed flow and a nonuniformity of flow in the spanwise direction for turbulent flow. The flow intermittency is closely related to the mass transfer, and a remarkable increment of mass transfer rate is induced near the flow reattachment point in the large recirculation vortex, which suggests a renewal of the concentration boundary layer because of the flow intermittency.
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TERUO TAKAHASHI, TOSHIRO MIYAHARA, TOSHIO SATO, YASUYOSHI SANADA
1986 Volume 19 Issue 5 Pages
456-461
Published: October 20, 1986
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Pressure drop and liquid holdup for a device with a relatively short vertical pipe operating at high gas velocity were experimentally studied.
An analysis of pressure drop and liquid holdup is carried out, using the principle of minimum entropy production proposed by S. M. Zivi, which includes the friction factor for annular two-phase flow and the correction factor for predicting total pressure drop. Correlations for these parameters are obtained empirically.
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KENJI HARAYA, YUJI SHINDO, TOSHIKATSU HAKUTA, HIROSHI YOSHITOME
1986 Volume 19 Issue 5 Pages
461-464
Published: October 20, 1986
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KENJI HARAYA, KENZABURO OBATA, TOSHIKATSU HAKUTA, HIROSHI YOSHITOME
1986 Volume 19 Issue 5 Pages
464-466
Published: October 20, 1986
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MOTONOBU GOTO, SATORU MATSUMOTO, BO-LUN YANG, SHIGEO GOTO
1986 Volume 19 Issue 5 Pages
466-469
Published: October 20, 1986
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MASAAKI TERAMOTO, HIDETO MATSUYAMA
1986 Volume 19 Issue 5 Pages
469-472
Published: October 20, 1986
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TSUTOMU HIROSE, TAKATOSHI MINODA
1986 Volume 19 Issue 5 Pages
472-475
Published: October 20, 1986
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TOSHIRO MIYAHARA, HIROYUKI ISHIKAWA, TERUO TAKAHASHI
1986 Volume 19 Issue 5 Pages
475-477
Published: October 20, 1986
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Smzuo SUGAWARA, IKUO SAKURAI, MIKIO KONNO, SHOZABURO SAITO
1986 Volume 19 Issue 5 Pages
477-480
Published: October 20, 1986
Released on J-STAGE: April 19, 2006
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