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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 :
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
Direct Reduction of Iron Oxides with Fixed Carbon from Heavy Oils
Kim, Hark-Ryeong ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 1~1
Mixture of metallic iron and carbon was made by heating the mixture of iron oxides and fixed carbon separated from heavy oils. Overall reaction rate was faster than that of iron oxides with pure carbon monoxide under similar conditions. It seemed that the direct reduction of iron oxides with carbon layer surrounding throughly all over the surfaces of iron oxide particles took place dominantly evolving carbon dioxide and carbon monoxide simultaneously instead of the reaction between solids through gaseous intermediates for conventional system of iron oxides and solid carbon. This result could be applied to making iron more effectively than ever and reducing the cost of ironmaking considerably by utilization of light fraction of heavy oil as by-product.
Deactivation for Toluene Disproportionation on Aluminum-Extracted Mordenites
Park, Hyeon-Cheol ; Lee, Young-Sub ; Ha, Baik-Hyon ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 7~7
A series of aluminum-extracted mordenites having different silica-alumina ratio were prepared by both acid-leaching and steam treatment. For these catalysts, catalytic activities of toluene disproportionation reaction were measured at a point of view of deactivation properties and discussed with the results of nitrogen adsorption isotherm measurement as well as the ammonia adsorption study by infrared techniques. It leads to the conclusion that a maximum point in catalytic activity appeared at about silica-alumina ratio of 22, which has been explained by the increased acid strength due to aluminum extraction, but fast coke formation at the beginning of catalyst use could rather give the better explanation. For the low catalytic activity of starting acidic mordenite having platinum metal, it could be explained with the coke formation on the crystal surface as well as the partial blocking of platinum grain in the pore channel, which makes reactant molecules diffuse difficultly.
Effect of Potassium Addition to Silica-Supported Nickel Catalysts on the Methanation Kinetics
Rhee, Chong-Hyup ; Suh, Dong-Jin ; Ihm, Son-Ki ; Moon, Sang-Heup ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 15~15
The kinetic behavior of
in CO methanation has been studied in a differential reactor as potassium is added to the catalyst up to 5 wt%. The potassium addition gives stronger carbon monoxide adsorption and weaker hydrogen adsorption on the catalyst, and also reduces its methanation activity. There is a maximum methanation rate for a wide range of carbon monoxide pressure and the reaction rate increases with hydrogen pressure. Potassium addition decreases CO pressure that gives the maximum methanation rate, increases slightly the order to hydrogen pressure, and increases the activation energy of methanation.
A Study on the Catalytic Synthesis of Hydrocarbons from Methanol
Jeong, Gil-Mo ; Lee, Ho-In ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 22~22
The catalytic performance and availability of Y-type zeolite and ion-exchanged Y-type zeolite were studied in vapor phase methanol conversion to hydrocarbons in order to get low olefins among various hydrocarbons. In general, the experiments were carried out at
, equimole of methanol and nitrogen, 0.79 gr-feed/hr gr-cat of LWHSV(Liquid Weight Hourly Space Velocity) and under atmospheric pressure. The study was performed for the effects of temperature, partial pressure of methanol and contact time on product distribution, and it was extended to the deactivation process of catalyst and its effect on product distribution. Temperature was less effective than the other reaction parameters, and the selectivity for low olefins was improved by lowering partial pressure of methanol and by reducing contact time. As deactivation proceeded, the selectivity for low olefins was increased. The effect of ion-exchange was also studied. It was revealed that the ion-exchange of catalyst could improve both of the selectivity for low olefins and catalyst's life time.
Sulfonation of Dialkylbenzene
Lee, Hak-Sung ; Kim, Jong-Ho ; Lee, Jung-Min ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 33~33
This paper deals with the sulfonation of dialkylbenzene by oleum, and by gaseous sulfur trioxide. At
, and with the weight ratio of oleum to dialkylbenzene equals to 1.6 : 1, the sulfonation led to a high value of total acid number (TAN) without side reaction for two hours. However, 87% of feed oleum formed acid sludge as a byproduct. The sulfonation with gaseous
led to a low TAN value, and also led to about 10% of side reaction. The products thus obtained were usable as a intermediate of lubricating oil additives. The optimum conditions for the reaction were found to be about
, 6-8% of
concentration in air and with the mole ratio of total
to dialkylbenzene equals to 1.2 : 1. To suppress the side reaction, the heat of reaction should be removed properly in addition to using a perfectly dried air.
Enzymatic Hydrolysis of Rice Straw Cellulose to Glucose -In the Range of High Substrate Concentration-
Kim, Woo-Sik ; Yoo, In-Sang ; Lee, Byoung-Chul ; Song, Dong-Yoon ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 39~39
This study was investigated on the kinetics and characteristics of enzymatic hydrolysis of rice straw cellulose, especially at high substrate concentration for the purpose of effective use of the rice straw. In the range of high substrate concentration(5-20 w/v%) the rate limiting step of the hydrolysis reaction is physical adsorption step and reaction mechanism was shown as modified Michaelis-Menten equation(product inhibition reaction). The value of kinetic parameters were
, respectively. Meanwhile, when 200 mg/ml of milled rice straw (which is pretreated with 0.8% p-TSA for two hours) under 30 unit/ml of cellulase was hydrolyzed for 30 hours, about 98% conversion of glucose was obtained.
Coalescence of Liquid Droplets and Separation in a Mixer-Settler (Part 1: Batch Experiments)
Kim, Sung-Seok ; Choi, Chang-Kyun ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 45~45
The study on liquid-liquid separation characteristics in a mixer-settler system which is strongly influenced by mixing intensity was conducted experimentally. The experimental systems considered here are binary distilled water-organic solvent (n-heptane, iso-octane, ethyl acetate or n-hexane) systems. By performing batch tests, the relationship between the mean drop size and the Weber number was generated by
. Also, the separation characteristics for multiparticle systems were presented, based on the relative velocity of the continuous phase:
Steady State Simulation of Catalytic Converter for Automotive Emissions Control
Bang, Hyeong-Su ; Jo, Byeong-Rin ; An, Hwa-Seung ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 54~54
The steady state response of a monolith catalytic converter to changes in operating conditions and monolith design parameters has been examined on the basis of a mathematical model. The model considers both catalytic and gas phase homogeneous reactions of a hydrocarbon and allow for axial conduction of hear in the solid substrate. Higher inlet temperatures and concentrations, and lower gas velocities are shown to result in higher conversion efficiencies. Metallic monoliths, having higher channel density offer superior performance to ceramics, and channel size and shape had significant influence on conversion and temperature profiles along the monolith channel. A proper choice of catalyst distribution along the monolith axial dimension resulted in a solid temperature profile subjected to less thermal stress. The possible effect of changes in catalytic material on the overall converter performance has been also examined.
Preparation of Porous Poly (vinylidene fluoride) Membranes; The Effect of Casting Solvents on the Ultrafiltration Performances
Kim, Kea-Yong ; Chang, Jae-Young ; Kim, Jeong-Hak ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 66~66
Poly(vinylidene fluoride)(PVDF) was prepared for the ultrafiltration membranes because of its good film forming ability, high mechanical strength, and chemical resistance to solvents. Membranes were prepared by solvent casting method on a glass plate. To investigate the effect of casting solvents on the membrane performances dimethyl formamide(DMF), dimethyl sulfoxide(DMSO), and dimethyl acetamide(DMAc) were used as casting solvents. The solvent composition of casting solution was selected from one of followings; (A) homosolvent system of DMF, DMSO or DMAc, (B) binary solvent system of DMSO/DMF, DMF/DMAc or DMAc/DMSO, and (C) binary solvent system of solvent and volatile nonsolvent such as acetone. Ultrafiltration experiments were carried out with 0.2% aqueous solution of polyethylene glycol(PEG, average molecular weight of 1,500-20,000). Water flux and rejection were measured, and the cross-sectional structures of membranes were observed by a scanning electron microscope. From the result of water permeation, it was revealed that most of all the PVDF membranes had the water flux
at 2 atm. Membranes prepared by DMF solvent DMF solvent system had the high rejection values inspite of poor water fluxes in comparison with other membranes. DMAc and DMF solvent systems showed the sharp slope of rejection curves with the increase of molecular weight of solute, and especially, membranes prepared by DMSO had good performances for ultrafiltration.
Fluidized Bed Chlorination of Rutile
Youn, In-Ju ; Park, Kyun-Young ; Jung, Jin-Ki ; Jang, Hee-Dong ; Lee, Ik-Hyung ; Im, Suk-Jung ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 74~74
Experiments on the reaction between rutile and chlorine in the presence of petroleum coke were carried out in a fluidized bed reactor. Inside diameter of the reactor is 15cm in the bed zone and is expanded to 90 cm in the freeboard zone, while the height is 183 cm in the bed zone and 82 cm in the freeboard zone. The ranges of experimental conditions used are as follows : reaction temperature is
, reaction pressure is held constant at 1 atm, the chlorine mole fraction is 0-0.8, the rutile composition in the bed is 10-90 wt%, and the static bed height is 25-45cm Average particle diameters of rutile and coke are 0.1 and 0.5 mm, respectively. The effects of the reaction temperature, the chlorine mode fraction, the static bed height and the rutile composition in the bed on the chlorine conversion and on the
ratio in the product gas are investigated quantitatively. The experimental results were also compared with those of other investigators.
Deposition Rate and Power Consumption Prediction of Silicon Deposition Reaction in the Bell-Jar Type Reactor
Kim, Mann-Young ; So, Won-Wook ; Yoon, Poong ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 81~81
Experiments of silicon CVD(Chemical Vapor Deposition) using trichlorosilane and hydrogen gas mixture were conducted to determine the deposition rate and power consumption for the bell-jar type reactor used for semiconductor grade polycrystalline silicon manufacture. We studied the effects of reaction temperature, flow rate of reactant gas, and trichlorosilane concentration on the silicon deposition rate experimentally. An empirical equation to predict the silicon deposition rate was proposed and was compared with experimental data. On the other hand, a model equation to predict power consumption of the bell-jar type reactor was derived from the deposition rate equation and the heat saving equation in the reactor. Predictions by this model were agreed well with experimental data.
The Mixing Rule with Excess Gibbs Energy Applicable to Cubic Equations of State
Lee, Ha-Jeong ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 89~89
The mixing rule with excess Gibbs energy was introduced into PR equation of state and UNIQUAC eq. was chosen as an expression of excess Gibbs energy. The interaction parameters of UNIQUAC were determined so as to reproduce vapor-liquid equilibrium data. As the result, the parameters of paraffin system are small enough to be neglected, but the parameters of other systems including polar components are large enough to act an important role in the fugacity coefficients of their mixtures. In fact, vapor-liquid equilibria for binary paraffin, nitrogen-ethane, alcohol-water, acetone-water, and acetone-methanol systems could be successfully reproduced in the range of low to high pressure by the mixing rule with UNIQUAC.
Cross Flow Cell Filtration by a Hollow Fiber Membrane
Lee, Youl-Lark ; Chang, Ho-Nam ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 97~97
Cross flow filtration(CFF) has been successfully employed as a means of concentrating microbial cells and proteins. While the CFF of proteins has been investigated thoroughly and could be explained in terms of the gel layer theory, the investigations on the microbial cells have been limited to the applications like concentration. In this study we aimed at studying the characteristics of CFF of microbial cells more systematically. Unlike in proteins, CFF of microbial cells could not be explained in terms of the gel layer theory. Fluxes were independent of the pressure difference which exceeded a certain level, but they increased with the flowrate in the hollow fiber and were proportional to
in the cases of E. coli and yeast respectively. Gel layer theory employing the diffusivity based on the Stokes-Einstein equation was applied to the system. But the predictions were far apart from the experimental data. Thus we suggested that the causes of the discrepancies between the theory and the experiment might be due to the tubular pinch effect or other phenomena such as gel layer slippage.
Dissolution of Nickel Matte in Acidic Ferric Chloride Solution
Lee, Hak-Sung ; Kim, Byung-Kyu ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 104~104
In order to investigate the mechanism which govern the dissolution of nickel from a matte composed essentially of heazlewoodite and ferronickel, the leaching was carried out in a mixture of HCl,
. In about 30 minutes of reaction, ferronickel was almost completely dissolved, and showed a high reactivity to
, with a tendency proportional to the
ion concentration. The activation energy was about 4.2 kcal/g mole and indicated a low temperature dependence.
ions were not directly involved in the reaction of nickel matte, and the concentrations of these ions did not exert any significant influence on the dissolution rate. The sulfur layer deposited on the leached particle did not give any internal diffusional resistance for both reactant and product. The rate of dissolution for heazlewoodite was independent of
ion concentration. The sulfur and the
having identical crystalline structure with heazlewoodite were formed on the particle, and the value of x was increased as the reaction proceeded. However, the formation of millerite, an intermediate, was not observed.
Anodic Oxidation of Iodide-Mediated Sulfur Dioxide Solution
Cho, Byung-Won ; Yun, Kyung-Suk ; Chung, In-Jae ;
Korean Chemical Engineering Research, volume 26, issue 1, 1988, Pages 113~113
The method of RDE and RRDE measurements was used to investigate the characteristics and the mechanism of the anodic oxidation of iodide-mediated sulfur dioxide solution. The intermediate products such as iodine and iodate were detected and the catalytic reaction mechanism which was composed of the electrochemical oxidation of iodide and the chemical reaction between sulfur dioxide and oxidized products was disclosed. The limiting current was increased with the increase of rotation speed of disk electrode which brought about the rapid reaction of iodine removal. The electrochemical oxidation of sulfur dioxide did not nearly occur. The collection efficiency in the electrochemical reaction of iodide-mediated sulfur dioxide solution was greatly lower than that in the electrochemical reaction of iodide and increased with the increase of rotation speed of electrode, which confirmed the catalytic reaction mechanism.