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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Korean Chemical Engineering Research
Journal Basic Information
Journal DOI :
The Korean Institute of Chemical Engineers
Editor in Chief :
KIM JAE JEONG
Volume & Issues
Volume 26, Issue 6 - Dec 1988
Volume 26, Issue 5 - Oct 1988
Volume 26, Issue 4 - Aug 1988
Volume 26, Issue 3 - Jun 1988
Volume 26, Issue 2 - Apr 1988
Volume 26, Issue 1 - Feb 1988
Selecting the target year
Spillover Phenomena in the Hydrogenation of Benzene over Supported Metal Catalysts
Lee, Tae-Jin ; Kim, Yoon-Kap ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 121~121
Hydrogen spillover phenomena on various supported metal catalysts were studied by means of hydrogen chemisorption and vapor phase hydrogenation of benzene. Enhancement of the adsorption of hydrogen by increasing the amount of diluents in contact with the catalysts was the result of migration of the spillover hydrogen from the metal to the support and diluent. However, the reaction activity increased with the degree of dilution of the catalysts with the diluents and then decreased in more diluted systems. The results obtained could be interpreted by the double spillover effect, the migrating distance and the recombination of hydrogen on the supports and diluents by collision. The reaction activity was influenced by the dilution ratio and the reaction temperatures, but the activation energy and the reaction mechanism did not change even if hydrogen spillover occurred.
Coalescence of Liquid Droplets and Separation in a Mixer-Settler (Part 2: Continuous Experiments)
Kim, Sung-Seok ; Choi, Chang-Kyun ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 128~128
The study on liquid-liquid separation characteristics in continuous mixer-settler systems was investigated experimentally. Since separation phenomena in a batch system was similar to those in the dispersion band in a continuous system, the coalescence mechanism was investigated by existing correlations. In the present experimental range it may be stated that drop coalescence was caused mainly by drop collisions. Finally, the following correlation to connect the separation performance of a batch system with that of a continuous system was generated:
The Residence of Materials in the Cavity Containing an Eddy
Park, Joong-Kon ; Hong, Heon-Cheol ; Cheon, Il-Kun ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 135~135
The mean residence time of a material in the system containing an eddy was calculated with the experimental results. The relation between the system mean time which was obtained by the first moment of the stimulus-response curve and the mean residence time which was the ratio of the system volume to the fluid flow rate was investigated. If there was no eddy in the system, the system mean time equaled to the mean residence time. For the system containing an eddy, the system mean time was greater than the mean residence time. And the numerical value of the discrepancy between them increased with the aspect ratio, AR and inversely with the Reynolds number.
Formation of Iodate on Rutile-Type Metal Oxide Electrode(I)
Nam, Chong-Woo ; Lee, Choong-Young ; Kang, Byung-Hak ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 141~141
Cyclic voltammogram and current-voltage curve of potassium iodide were measured on
electrode, prepared by thermal decomposition method, to study the reaction for iodate formation by oxidation of iodide and macro-electrolysis was carried out to investigate the optimum conditions for electrolytic preparation of iodate from potassium iodide solution. At first, iodide is oxidized to iodine by reversible electrode reaction and then iodine is oxidized to iodate, depends on the pH of electrolyte, by irreversible electrode reaction or chemical reaction. The electrolytic preparation of iodate is effective in weak alkaline solution (pH 10). As a result of electrolysis at constant voltage and constant current, maximum current efficiency was obtained at 1.05 V and
Synthesis of Maleic Anhydride over Mixed Oxide Catalyst(I) -Catalytic Oxidation of Cyclopentadiene over V-Mo-P Catalyst-
Kim, Jae-Seung ; Park, Nam-Cook ; Kim, Young-Chul ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 149~149
The vapor phase catalytic oxidation of cyclopentadiene to maleic anhydride was studied over V-Mo-P mixed oxide catalysts with different compositions of catalysts and different supports. The acidity, reducibility and average oxidation number of vanadium increases with an increase in the molybdenium and phosphorus content. The acidity and reducibility of
-Alumina supported catalyst are higher than for titania supported catalyst. The conversion of cyclopentadiene and the selectivity of maleic anhydride are related to the acidity and oxidation number of vanadium, respectively. The absorption band of
is not observed in higher reducible catalysts and the selectivity of maleic anhydride is low in these catalysts.
Effect of Hydrogen Ion Concentration on the Cu(II) Removal by the Foam Separation Techniques
Choi, Sang-June ; Ihm, Son-Ki ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 158~158
Experimental investigations on the removal of Cu(II) from aqueous solution were carried out through various foam separation techniques; foam fractionation, precipitate flotation, and adsorbing colloid flotation using sodium lauryl sulfate as collector. The optimum pH for Cu(II) removal was found to be in the range of pH less than 6 for the foam fractionation, to be about 9 for the precipitate flotation, about 7 for the adsorbing colloid flotation with
and about 8 for the adsorbing colloid flotation with
. The working ranges of pH(6.5-9.0) for an effective removal of Cu(II) could be extended by the addition of Al(III) on adsorbing colloid flotation with
. The effective removal of copper(II) could be achieved by adsorbing colloid flotation due to coprecipitation and carrier flotation at lower pH than by precipitate flotation.
Gas Evolution Behavior in Slow Pyrolysis of Coal
Kim, Kyong-Tae ; Kim, Ki-Hong ; Lee, Geun-Seong ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 164~164
Gas evolution behavior in slow pyrolysis of 14 different coals at 3 K/min under nitrogen atmosphere has been investigated. The overall yield of volatile matter is consistently lower than that measured using the standard proximate analysis test, and evolution rates of pyrolyzed gases were dependent on temperature level. The formations of CO and
are considered as a result of carbon-steam gasification together with thermal decomposition of coal. The composition of hydrogen and hydrocarbon gases other than methane increased with the value of VM(daf) of coal, while the amount of CO evolved increased with the value of O(daf) of coal.
Turbidity and Stability of Sonicated Lecithin Liposomes
Kim, Jin-Gu ; Kim, Jong-Duk ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 171~171
The stability of a small unilamellar liposome, prepared by sonication from the turbid aqueous solutions of egg yolk phosphatidylcholine with the cuphorn ultrasonic system, were investigated by measuring the absorbance of visible light in the range of wavelengths from 425 nm to 750 nm. The absorbance of the freshly sonicated and centrifuged liposome solution followed the linear relationship with 1/wavelength4 of the Rayleigh scattering theory. For the incubated liposomal dispersions, a transient turbidity model was proposed in order to explain the change of turbidity by combining with Smoluchowski fast flocculation, and the model has been shown to be appropriate for the prediction of the changes of liposomal particles, i.e., number, size and shape.
Determination of Mesophase Content by Degree of Crystallinity and Kinetics of Mesophase Formation
Kim, Hong ; Rhee, Bo-Sung ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 178~178
A method of crystallinity degree was first developed as a new method for measuring the mesophase content in pitches. This method reflects mesophase content more accurately than conventional methods. With this study it could be cleared that the mesophase formation was a growth limiting process because the growth time was greater than the nucleation time obtained from Cardew equation. The kinetic parameters of mesophase formation which are determined by the crystallinity method are more accurate than other methods such as Q.I. measurement, DSC and TGA. The reaction order of K-220, a pitch obtained from Yukong Co, was 1.40 and activation energy 208.6 KJ/mole. The kinetics parameters of A-240, a pitch obtained from Ashland Co, were respectively 1.46 and 219.5 KJ/mole.
Concentration Profile of Nickel Supported on
Jang, Keung-Sool ; Moon, Hee ; Park, Heung-Chul ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 186~186
After impregnating nickel from
-alumina, the concentration profile of nickel, an active material was measured by an electron probe micro-analysis(EPMA). Experimental results showed that the distribution and amounts of nickel could be controlled by changing initial pH, concentration and temperature of the solution, and pretreatment conditions of the support. The impregnation mechanism of Ni/
-alumina system could be explained satisfactorily by the deposition due to difference in solubilities of the active material in the solution which exists in the pore.
Comparative Analysis of the TPTT, MPMT and RSM Models
Park, Jong-Chul ; Kim, Moon-Gab ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 194~194
The analysis of the various estimation methods of thermodynamic properties phase equilibrium behavior among TPTT, MPMT and RSM models is attempted based on the solution theory and thermodynamical view point. As the effect of molecular interaction among molecules in the solutions is largely significant, it is found the TPTT(two parameters two terms) equations in general have difficulties to express various multicomponent systems due to their excessive simplification. The MPMT(multiple parameters multiple terms) equations also possess various difficulties in application of multicomponent systems due to many unknown parameters to be estimated, furthermore, estimations of the numerous parameters are excessively difficult and complex. To correct this situation, RSM(response surface methodology) models which represent the relationship between equilibrium temperatures and compositions of vapor and liquid phase of ternary and the other multicomponent systems are optimized. The optimized model is satisfactory in representing independent variables contributions and molecular interactions among various variables.
Anisotropic Properties of Natural Graphite-Mesophase Pitch Based Composites Containing Chopped Carbon Fiber in Low Concentration
Rhee, Bo-Sung ; Ryu, Seung-Kon ; Choi, Ik-Soo ; Kim, Young-Il ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 205~205
Thermal anisotropic composites were fabricated by extrusion of natural graphite powder-pitch precursor mixture, to which 1-2 wt% of chopped carbon fiber was added. The extruded green body was stabilized in an autoclave up to
and carbonized up to
. Chopped carbon fibers were aligned along the longitudinal direction by extrusion, and contributed to the enhancement of interfacial adhesion between filler and binder. Therefore, the mechanical properties such as tensile strength, E-modulus, and flexural strength of composites were increased. Especially the properties of longitudinal direction were increased two or three times than those of transverse direction due to the alignment of chopped carbon fiber. The thermal conductivity of longitudinal direction was about 12-20 times larger than that of transverse direction in the temperature range of
by adding 2 wt% chopped carbon fiber, and the thermal anisotropic factor of composites were varied on the amount of chopped carbon fiber added.
Biological Treatment of Toluidine Sulfonic Acid Wastewater and Combined Wastewater in a Dye Plant
Ju, Seung-Pal ; Lee, Min-Gyu ; Park, Tae-Ju ; Song, Seung-Gu ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 212~212
An laboratory-scale experiment was carried out to determine the characteristics and treatability of toluidine sulfonic acid (TSA) process wastewater and combined wastewater in a dye plant. Chemical treatment with aluminium sulfate, 300 mg/l at pH 6.5 showed about 40% COD removal efficiency. With a completely-mixed-activated-sludge (CMAS) unit, the removal efficiencies of
and COD were achieved more than 88% and 66%, respectively, at aeration time longer than 86 hours, that corresponded to the F/M ratio below 0.074 kgBOD/ kgMLSS/ day. Design parameters, such as
applied to CMAS mathematical equations were found as the range of
, 68.8-152.6 mg/l, 0.445-0.653 and
CNDO/2 MO Calculations for Dealumination Mechanism of Faujasite Type Zeolite
Kim, Jong-Taik ; Kim, Myung-Chul ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 221~221
The CNDO/2 calculations have been applied on cluster models for the representative T sites in faujasite to get atomic charge densities, wiberg bond orders and total energies. The chemical stabilities of suggested models for the dealumination mechanism were also explained in terms of total energies. The calculated charge densities and bond orders of cluster models have been changed remarkally according to the
attack. The calculated results showed the dealumination of faujasite in acidic solution was caused of Al-O bond weakening by acid attack.
A Theoretical Study on the Migration of Radionuclides in a Radwaste Disposal System
Choi, Heui-Joo ; Lee, Han-Soo ; Hahn, Pil-Soo ; Han, Kyong-Won ; Park, Hun-Hwee ;
Korean Chemical Engineering Research, volume 26, issue 2, 1988, Pages 229~229
Migration Performance of radioactive nuclides in the disposal system of low and intermediate level radwaste was investigated. The migration of Sr-90 through fractures and rock matrix were modeled herein and a sensitivity analysis for the approach was performed. The results show that the fracture width and groundwater velocity are the dominant parameters to the release of radionuclides from a radwaste repository.