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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Korean Chemical Engineering Research
Journal Basic Information
Journal DOI :
The Korean Institute of Chemical Engineers
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Volume & Issues
Volume 29, Issue 6 - Dec 1991
Volume 29, Issue 5 - Oct 1991
Volume 29, Issue 4 - Aug 1991
Volume 29, Issue 3 - Jun 1991
Volume 29, Issue 2 - Apr 1991
Volume 29, Issue 1 - Feb 1991
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Separation Characteristics of Dissolved Salt(NaCl) with Asymmetric and Composite Membranes for Reverse Osmosis
Pak, Jong-Weon ; Min, Byoung-Ryul ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 1~1
The similarity between three models by applying experimental data of NaCl solution permeation of composite and asymmetric membrane to the membrane transport models and the separation characteristics of each membrane was studied. The plot of rejection coefficient (R) vs. total volume
showed that the experimental data were in accordance with the linear and nonlinear model below the NaCl solution concentration of 15000mg/l. The reflection coefficients of the composite and asymmetric membrane showed Spigler-Kedem nonlinear model to have more validity compared with the linear model. In case, the exponential term in nonlinear model is very small as to be neglected, the nonlinear model is converted into the solution-diffusion model using the Taylor-series. The composite membrane showed better rejection rates as high as 6%(2.45MPa) to 34%(0.98MPa) than those of asymmetric membrane(SEPA-97) below the NaCl solution concentration of 10000mg/l. Among the composite membranes used in the experiment, FT-30 and SU-700 composite membranes gave the best performance in respect to the permeation flux and selectivity.
A Study of Hydrodemetallation of Ni-TPP Catalyzed by
Kang, Sang-Yoon ; Koo, Heon-Seo ; Choi, Ki-Sup ; Kim, Kyung-Lim ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 11~11
Hdyrodemetallation(HDM) of Ni-tetraphenylporphyrin(Ni-TPP) was studied over
catalyst at temperatures between
, the total pressure between
, the contact times between 0.009 gcat.hr/ml feed and 0.034 gcat.hr/ml feed, and pyridine concentrations between 3.6mole% and 16.7mole%. HDM of Ni-TPP was inhibited by pyridine because the increase of pyridine concentration caused the decrease of HDM conversion. The reaction rate of Ni-TPP was found to be apparently 1st order over
and its activation energy was determined to be about 10kcal/mole by Arrhenius plot. Pore mouth-plugging phenomena were shown by ad/de-sorption isotherm and pore size distribution of fresh and aged catalysts.
Knowledge Base Representation for the Fault Diagnostic Expert System Using the Fault-Consequence Digraph
Yoon, Byung-Suk ; Oh, Jeon-Kun ; Yoon, En-Sup ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 19~19
The objective of this study is to implement the real time fault diagnostic expert system for the naphtha furnace process and to prove the effectiveness of Fault-Consequence Digraph(FCD) as a knowledge model. The FCD represents a quite simple graphical knowledge model of a hypothetical fault candidate. Since each fault occurring in the chemical process plant possesses the distinctive symptom pattern, the generated symptom pattern of a fault from a FCD can be checked whether it really occurs or not. The SUN3/260 workstation and the AI tool, KEE of IntelliCorp have been used in this study, which implements the FCD model. From qualitative reasoning in a naphtha furnace, 226 symptoms were generated and 314 fault-candidates were prepared. To implement this suggested FCD model, each FCD model has been tested by logical fault simulation. As a result of more than 20 case studies, the FCD model has been proven to be an appropriate and quite effective tool for the fault diagnostic expert system.
The Behavior and Reaction Characteristics of Yeast Cell Immobilized in the Ca-alginate Gel Bead
Kim, Woo-Sik ; Yoo, In-Sang ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 33~33
The efficiency of ethanol fermentation is increased and the high cell concentration is maintained through the immobilization of yeast cell in the Ca-alginate gel bead. Yeast cell concentration in the gel bead is increased with the increase of the initial entrapped yeast cell concentration, and the highest concentration distribution of yeast cells is found at the outlayer of the gel bead. The gradient of yeast cell concentration in the gel bead is changed with the particle radius. In the case of decrease of the substrate diffusivity with linearity, the fermentation model is well fitted with the experimental data.
Methane Oxidation on Oxides of Transition Metals on Mordenite
Ghil, Jun-Ho ; Lee, Chang-Yong ; Ha, Baik-Hyon ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 42~42
Combustion oxidation catalysts were prepared by impregnation of oxides of copper, chrome, nickel and cobalt on aluminum-deficient mordenites
, which were redox-treated in reduction/oxidation atmosphere at
, respectively. For these catalysts methane combustion was carried out. X-ray diffraction analysis indicates that the metal oxides were dispersed with the average particle size of about 20-30nm in the form of CuO,
and NiO. Redox-treated in reduction/oxidation atmosphere at
reduced the crystallinity of the mordenite, but chrome addition improved the stability. This improvement in stability may be explained with the effect of remaining chrome ions in the mordenite pores which is formed when impregnating its salt as well as reoxidation pretreatment. On the catalysts containing two kinds of metal oxides, XRD study informs that the oxides were dipersed individually without formation of new oxide compounds. The catalytic activities for
were appeared as the following order; $CuO/DM>Cr_2O_3/DM>Co_3O_4/DM$, NiO/DM. However catalytic activities for the catalysts redox-treated at
was much reduced compared with the activities at
, which is also explained with the reduction of mordenite crystallinity which makes the reducton of metal ion concentration and also of copper oxide particle size.
Changes in Characteristics of MTBE Synthesis and Cracking with Sulfonic Acid Group Distributions in Porous Poly(styrene-co-divinylbenzene) Resin Catalysts
Lee, Dong-Keun ; Kim, Sung-Bae ; Ahn, Jou-Hyeon ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 49~49
Sulfonated Poly(styrene-co-divinylbenzene) resin catalysts were prepared to have two different types of sulfonic acid group distribution : the one having sulfonic acid group distributed uniformly throughout gelular microparticles, the other having sulfonic acid group located mainly at the exterior surface of gelular microparticles. MTBE synthesis and cracking reaction were carried out on the catalysts, and the changes in characteristics of the reactions with sulfonic acid group distributions were investigated. The activity and selectivity of the reactions were always much higher on the catalyst having sulfonic acid group outside the gelular microparticles(type E catalyst) than on the one with uniform distribution(type A catalyst), and this was thought to be due to gelular microparticle diffusion limitation and secondary reaction on the sulfonic acid group within gelular particles.
A Study on the Dynamic Behavior of Screen Packed Fluidized Bed Combustor
O, Gwang-Jung ; Hong, Seong-Chang ; Choe, Cheong-Song ; Do, Dong-Seop ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 55~55
The dynamic behavior of a screen packed fluidized bed combustor of 6.7cm inside diameter was investigated by the residence time distribution and the temperature profile of combustion. The low grade anthracite coal(H.V.<3000kcal/kg) of uniform size was used in this experiment and the thermal analysis was performed in order to know the combustion characteristics of coal particles. Considering the dynamic behavior of the packed fluidized be combustor, a combustion model which was consisted of a mixed zone and a dispersed zone of particles was proposed. It was found from the model that the particle mixing, which was caused by the counter-current flow of particles was influenced by the heating value of coal and that a packed fluidized be was more effective for the combustion of low grade anthracite coal having high segregation effect of burning particles.
Adsorption of Uranium on Amidoxime Type Resin
Huh, Kwang-Sun ; Suh, Gil-Duk ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 63~63
In order to develop an effective adsorbent for the recovery of dissolved uranium in seawater, the macroreticular acrylonitrile(AN)-divinylbenzene(DVB) copolymer beads were synthesized by suspension polymerization in the presence of toluene as diluent. The macroreticular chelating resins(RNH) containing amidoxime groups with various degree of crosslinking were prepared by the reaction of AN-DVB copolymer beads with hydroxylamine in methanol. The effect of degree of crosslinking on the physical properties, adsorption equilibrium, adsorptive ability and adsorption mechanism for uranium of amidoxime type resin(RNH) were investigated. The chemical and the physical properties and adsorptive ability of uranium on amidoxime type resin were effected by various degree of crosslinking. The adsorption of uranium on amidoxime type resin was not only effected by the chemical structure but also by physical structure. Equilibrium and mechanism of adsorption of uranium for amidoxime type resin were correlated with Freundlich equation and intraparticle diffusion controlling respectively and Freundlich constant(1/n) and effective pore volume diffusivities were ranged of 0.058-0.236 and
Analysis of Mesophase Formation from Pitch by Multiple Reaction Kinetics
In, Se-Jin ; Lee, Jin-Gi ; Kim, Jong-Pil ; Yu, Seung-Gon ; Lee, Bo-Seong ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 73~73
Kinetic studies on the mesophase formation in the pitch were carried out. Naphtha tar pitch(NTP) and straight asphalt(SA) were heat-treated in the temperature range of
. The weight loss(V) of the pitches during the reaction was measured and the heat-treated pitches were also fractionated into benzene solubles(R), benzene insolubles/quinoline solubles(S) and quinoline in-solubles(C). The kinetics of the mesophase formation can be analysed by the following multiple reaction model in which the rate equation of each step is assumed to be first order: (equation omitted) The activation energies(E) of each step for NTP and SA were 15-65 and 29-61kcal/mole, respectively. The kinetic studies indicate that the following heat treatment conditions would be appropriate for preparing a spinnable mesophase: - NTP : a low temperature since $E_1
A Study of Metal-Semiconductor Schottky Diode Gas Sensor Using Stannic Oxide
Cho, Won-Il ; Cho, Byung-Won ; Lee, Seong-Rae ; Yun, Kyung-Suk ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 81~81
Metal-semiconductor schottky diode type gas sensors for enhancing gas selectivity were prepared by ion coating of gold on sintered
pellets which were impregnated by Pd, Pt and Co. Their gas sensitivities and selectivites, gas detection methods and their I-V characteristics were investigated with the variation of sensing temperatures, gas concentrations and the kinds of gas. The gas sensitivity was improved by Pd and Pt, especially for Pd impregnated sensor element its sensitivity to
was confirmed at room temperature. Also the gas selectivity could be improved by setting the sensing temperature at optimum value. The potentiostatic method was better than the galvanostatic method in the regeneration aspect of a sensor element. From the I-V characteristics of diode type gas sensor,
concentration was measured at room temperature by detecting the current under low bias potential and the gas sensitivity to hydrogen was higher in the presence of Pd than Pt.
The Stabilization of Mesophase Pitch Based Carbon Fiber
Jung, Doo-Hwan ; Lee, Young-Seak ; Rhee, Bo-Sung ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 89~89
This study was performed to investigate the properties of mesophase pitch based carbon fibers during stabilization. The stabilization of those was carried out in the range of 230, 280,
under atmospheric condition for 0-3 hours. The characteristics of the reactions were observed by chemical and optical analysis. The condition of stabilization was determined by testing the mechanical properties of carbonized fibers. The stabilization of mesophase pitch based carbon fibers was progressed with permeating oxygens to fibers, escaping hydrogens and carbons from those. The skin-core structure, a random and mosaic structure is progressed by oxidant from the surface of stabilized fibers to the center of those, was confirmed by using the polarized micrograph. The cross-sectional structure of carbonized fibers was controlled by the structure of stabilized fibers. The mechanical properties of carbonized fibers were determined using the stabilization time, temperature and the introduced oxygen contents. The tensile strength and Young's modulus of carbonized fibers stabilized at
for 1 hour with 8.9wt% of oxygen contents were founded to be superier to others.
Study on Adhesion and Degradation of Adhesion between Metal Plate and Rubber Compound by Using XPS
Seo, Gon ; Kang, Sang-Yong ; Kim, Min-Ho ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 97~97
The adhesion between metal plate(Cu, Zn, and Cu/Zn) and rubber compound, and the degradation processes were studied by using X-ray photoelectron spectroscopy. Copper sulfide layer was formed at the interface through the reaction of copper plate and sulfur in rubber compound, but copper plate didn't adhere to rubber compound because copper sulfide layer was separated from copper plate. Zinc plate did not show good adhesion to rubber compound, because the formation rate of zinc sulfide layer at the interface was too slow. Brass plate strongly adhered to rubber compound. Excellent adhesion can be interpreted in terms of fast formation of copper sulfide layer at the interface, but excessive growth of the layer is controlled by the presence of metallic zinc. The adhesion between brass plate and rubber compound was severely deteriorated after hot water aging, and similar results were found for the adhesion of zinc plate after salt solution aging. The degradation of adhesion was also discussed in related to chemical composition and phenomenological deformation at the interface.
Heat Treatment of Coal Tar Pitch under Air Blowing
Kim, Je-Young ; Lee, Seong-Young ; Choi, Jae-Hoon ; Park, Yang-Duk ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 106~106
Coal tar pitch was heat treated in the temperature range of
under air blowing conditions and their properties such as solubility, C/H ratio, and optical texture were characterized. Solubility and C/H ratio were not varied by the heat treatment time over 90min at each heat treatment temperature and higher toluene insoluble fraction and C/H ratio were obtained as heat treatment temperature increased at the given treatment time. The heat treated pitch had the dormant mesophase property when the toluene insoluble fraction was higher than 20wt% and C/H ratio higher than 1.7. Preparation of carbon solids without a binder could be achieved using these pitches.
A Study on Concentration of Ethanol by Supercritical Fluids & Salts(I) -High Pressure Vapor-Liquid Equilibria for
Cho, Jeong-Shik ; Park, Sun-Keun ; Lim, Jong-Sung ; Kim, Jae-Duck ; Lee, Youn-Yong ; Chun, Hai-Soo ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 111~111
High pressure vapor-liquid equilibria for
system were measured at three temperatures of 313.2K, 323.2K and 333.2K using a circulation type of apparatus in which both vapor and liquid phase were continuously recirculated over a pressure range from ca. 5MPa up to near mixture critical point. The critical pressures of the mixtures were about 8.1MPa, 9.3MPa and 10.6MPa at the three temperatures, respectively. This result shows that the temperature increases with the critical pressure of the mixture. The high pressure vapor-liquid equilibrium data for
systems were satisfactorily correlated by applying the Patel-Teja equation of state with the Adachi-Sugie mixing rule.
Selective Chlorination of Chalcopyrite with
Kim, Jae-Yong ; Yu, Yeong-Hong ;
Korean Chemical Engineering Research, volume 29, issue 1, 1991, Pages 118~118
The selective chlorination of FeS in the chalcopyrite with
was investigated to find a new process for the separation FeS and CuS in the chalcopyrite. The proper conditions for this selective chlorination were that reaction temperature
, reaction time 30min,
weight ratio to the chalcopyrite 11.0 and particle size of chalcopyrite -325mesh in the
atmosphere. Under the above mentioned conditions FeS in the chalcopyrite was converted to
, selectively. Synthetic CuS was produced by the leaching the chlorinated product with
was identified as covellite structure and was found to contain 55.89% Cu.