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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 27, Issue 6 - Dec 1989
Volume 27, Issue 5 - Oct 1989
Volume 27, Issue 4 - Aug 1989
Volume 27, Issue 3 - Jun 1989
Volume 27, Issue 2 - Apr 1989
Volume 27, Issue 1 - Feb 1989
Selecting the target year
The Study on Permeability and Selectivity of Oxygen and Nitrogen by Preparing Conditions of Polymeric Membranes
Lee, Pil-Kyung ; Chang, Ho-Nam ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 1~1
Permeabilities and selectivities of oxygen and nitrogen were studied using 3 flat polymeric membranes: silicone rubber, polyurethane, and cellulose acetate. Flow rate of permeates linearly increased with increasing pressure differences and was inversely proportional to membrane thickness. In silicone rubber membrane permeabilities of oxygen and nitrogen were 390 and 170 Barrers, respectively and selectivity of oxygen to nitrogen gas was 2.3. In polyurethane membrane permeabilities of oxygen and nitrogen were 1.5 and 0.39 Barrers, respectively and selectivity was 3.8. In addition the flow rate of permeates of the polyurethane membrane which was made using chloroform as solvent and vacuum drying was 10 times as large as those obtained from the polyurethane membranes made without using chloroform and vacuum drying. Only in freeze-dried cellulose acetate membranes the fluxes of oxygen and nitrogen were proportional to pressure differences. But the cellulose acetate membrane could not be used for oxygen/nitrogen separation process because the permeability of oxygen was almost the same as that of nitrogen.
The Effect of Sulfur on Dehydrocyclization of n-Heptane over Platinum Catalyst
Kim, Moon-Chan ; Song, Myeong-Sug ; Kim, Kyung-Lim ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 7~7
The dehydrocyclization of n-heptane was studied over 0.6wt%
and presulfied 0.6wt%
catalysts in a fixed bed continuous flow reactor. The ranges of experimental conditions were at temperatures between 658 and 773K, the pressures between
mole ratios between 3 and 7 and the contact times between 0.2 and 0.6g-cat.hr/g-feed. The dehydrocyclization increased with increasing temperatures, decreasing total pressure and decreasing
mole rations. The presulfied Pt catalyst showed increased selectivity and stability of dehydrocyclization and the surface of presulfied Pt catalyst was well dispersed rather than Pt catalyst. Both reactions of Pt and presulfied Pt catalyst were the first order with respect to n-heptane and their activation energies were 32.5 and 50.4 kcal/mole, respectively.
Methanol Synthesis from Synthesis Gas over
Hahm, Hyun-Sik ; Kim, Eui-Yong ; Sung, Byuk-Pa-Jung ; Lee, Wha-Young ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 16~16
Methanol synthesis from synthesis gas over four supported Pd catalysts has been carried out at
and 10-20 atm of total pressure. CaO, MgO, and
, were used as promoters. The activity for methanol synthesis decreased in the order of $Pd+Ca/SiO_2>Pd+Mg/SiO_2>Pd+La/SiO_2>Pd/SiO_2$. The selectivities for methanol increased with space velocity over all catalysts. At high space velocity(
and 10atm of total pressure(
) the selectivities of methanol were almost 98% for all three promoted catalysts and about 50% for unpromoted
catalyst. It is suggested that promoters do not change the mechanism of methanol formation in this study.
Gas Holdup and Volumetric Mass Transfer Coefficient in Slurry Bubble Column of Acicular
Koh, Jae-Cheon ; Kim, Beom-Sik ; Lee, Jung-Min ; Rhee, Bo-Sung ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 23~23
It was found that a slurry prepared from acicular
in long axis and standard deviation is
) in 1N-NaOH aqueous solution obeys the Power Law of Ostwald-de Waele by measuring the viscosity of the slurry for each solid concentration. Subsequently, the gas holdup and volumetric mass transfer coefficient of oxygen were determined by measuring slurry density and dissolved oxygen in a slurry bubble column (10cm in diameter and 200cm in height) equipped with a perforated plate (1cm thickness of acryl) having 89 holes (0.5cm in diameter) with 1cm rectangular interval and filled with 6 liters of the above slurry, using air flow rate of 1.4-15.0cm/sec at
. Gas holdup and volumetric mass transfer coefficient can be represented by the following equations.
Separation of Heavy Metal Sulfide by Precipitate Foam Adsorption
Shin, Jeong-Ho ; Min, Seong-Kee ; Jeong, Kab-Seob ; Heo, Kwang-Sun ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 33~33
In order to investigate the characteristics and the optimum condition of the gas-liquid interface adsorptive separation of metal sulfides, the coagulation-dispersion and the adsorptive separation of the single and mixed systems were experimentally carried out, and the adsorptive separation model was considered. Theoretically, the separation rate of fine particles by gas-liquid interface adsorption was derived under the assumption of adsorption by collision between rising bubbles and particles. The relation between the residual concentration of fine particles and the bubbling time was obtained as follows and this equation proved successful with the experimental results.
The effects of air flow rate, column height and ethylhexadecyldimethylammonium bromide(EHDA-Br) concentration on the collection effciency have experimentally been investigated. The collection efficiency was maximum at the optimum concentration of EHDA-Br for the coagulation, i.e., 0.06-0.13moles of EHDA-Br per unit mole of metal sulfides.
Synthesis of Maleic Anhydride over Mixed Oxide Catalyst(II) -Catalytic Oxidation of 1-Butene over Supported V-P Oxide Catalyst(II)-
Kim, Jae-Seung ; Park, Nam-Cook ; Kim, Young-Chul ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 42~42
The vapor phase catalytic oxidation of 1-butene to maleic anhydride was studied over
catalysts which different calcination temperatures. The evaluation of phase strongly depended on calcination temperature. The temperature of a structural transformation of metal oxide from amorphous to crystalline was observed at
and that of titania from anatase to rutile was at
. The structural changes had pronounced effect on the catalytic activity for the oxidation of 1-butene, and the maximum yield of maleic anhydride was observed for the catalyst calcined at
. The kinetics data were studied with a redox mechanism. The data obtained under the conditions of low partial pressure of butene could be explained in terms of the pseudo-first order kinetics.
Analysis of Flow Pattern in the Ladle of RH Degassing Process
Koo, Youn-Seo ; Lee, Sang-Min ; Lee, Sung-Woo ; Shin, Young-Kil ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 50~50
In order to recognize the effects of the process parameters on the flow pattern in the ladle during RH degassing process, a numerical approach of
turbulent model and a water model experiment were carried out. It was found that molten steel flows in the ladle have high turbulent characteristics and RH degasser is an excellent mixer. The maximum values of turbulent energy as well as dissipation rate of turbulent energy occur in the vicinity of the snorkel. The computation formula of circulation rate was derived from the results of the water model experiment. Furthermore, it was proved that the energy balance in RH degassing process is the effective means for predicting circulation rate.
Use of Arclength Continuation Method for a Sequence of Solutions on Specification Changes in Stagewise Separation Processes
Ko, Hong-Cheol ; Yoon, En-Sup ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 61~61
A computational procedure based on the arclength continuation method is designed for finding a sequence of solutions on variations of specifications in stagewise separation processes. The arclength continuation method can be implemented simply with an existing code that solves the modelling equations by Newton-Raphson method. The procedure is capable of direct handling of functional form specifications as varying variables. In order to promote the computational efficiency, emphasises are given to generation and handling of Jacobian matrices and calculation of integration step-sizes. The applicability of the designed procedure to the problems with multiple solutions is shown on numerical examples.
Anodic Oxidation of Iodide on Manganese Dioxide Electrode
Nam, Chong-Woo ; Lee, Choong-Young ; Lee, Jung-Hee ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 70~70
A study on the formation of iodate produced by oxidation of iodide was performed with cyclic voltammetry and polarization curve measurement in acidic media on the
electrode prepared by thermal decomposition method. Iodide is oxidized to iodine by the first reversible electrode reaction and then iodine is oxidized to iodate by the second irreversible electrode reaction. Each step of electrode reaction is controlled by diffusion and the reaction rate of the first step is relatively faster than the second step. The effect of pH on formation of iodine is negligible and the reaction rate of the second step is become slow according to pH increase in acidic media.
Effects of Thermal Treatment of
on the Acid Properties and Shape Selectivity
Bae, Jun-Gang ; Oh, Seung-Hoon ; Lee, Wha-Young ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 78~78
prepared in the laboratory was deammoniated under different conditions to change its acidic properties. The effect of acidic properties change on the catalytic activity and selectivity in some model reactions such as methanol conversion, cumene cracking and xylene isomerization was investigated. It was found that the catalytic activity and selectivity affected by the deammoniation conditions. This effect is attributable to the decrease in the number of strong protonic acid sites due to the dehydroxylation of the zeolite, as the deammoniation temperature is increased. It might be partly due to the dealumination and the decrease in the crystallinity of the zeolite. It is suggested that the alumina dealuminated from the framework is piled at the pore mouth to reduce the pore size and increase the shape selectivity in the xylene isomerization.
Rate of Formation of Carbonaceous Mesophase by Heat Treatment
Kim, Je-Young ; Choi, Jae-Hoon ; Ryu, Seung-Kon ; Rhee, Bo-Sung ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 85~85
Formation of quinoline insoluble and mesophase obtained from coal tar pitch by heat treatment in the temperature range from
for various times have been studied, using solvent extraction, polarized microscope and SEM. Content of quinoline insoluble and mesophase were not equal to each other, contrary to the facts known by this time. At an early stage of heat treatment, the rate of formation of quinoline insoluble was greater than that of mesophase, and there were some isotropic secondary quinoline insoluble. At a later stage, the rate of formation of mesophase was greater than that of quinoline insoluble. The rates of formation of quinoline insoluble and mesophase were well fitted with 1st order reaction and activation energies of those were 36.6Kcal/mole and 58.5Kcal/mole, respectively. Content of volatile matter and C/H ratio were changed remarkably during nucleation of mesophase, but changed little during coalescence of mesophase.
Carbo-Chlorination of Korean Kaolinic Clay of Pink-C Grade(I) -Catalytic Effect of Metallic Chloride on Reaction Rate-
Yang, Hyeon-Su ; Kim, Yeong-Ho ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 94~94
Carbo-chlorination of Korean kaolinic clay of pink-c grade deposited in Sanchung and Hadong areas was studied to examine the effect of alkali metallic-, alkaline earth metallic- and other metallic-chlorides on the reaction rate. Alkali metallic-chloride like KCl, NaCl and LiCl enhanced the chlorination of silicon, aluminum and iron portions in clay significantly greater than alkaline earth metallic- and other metallic-chlorides. At a constant temperature of 925K, the chlorination of the aluminum with KCl was completed when only 40% conversion was made in the chlorination of clay in the absence of catalyst. The temperature providing maximum conversion of aluminum was slightly different from catalyst.
Pressure and Porosity Fluctuations in Two-Dimensional Fluidized Beds
Seo, Yong-Chil ; Park, Hun-Hwee ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 104~104
Pressure and void fluctuations were measured with a pressure transducer and with a
-ray attenuation device in a two-dimensional fluidized bed with a jet. The results were analyzed using a power spectrum analyzer with Fast Fourier Transform. Pressure and void fluctuations along the height of the bed were characterized as functions of static bed heights in the range of 11-40cm and of jet velocities in the range of 1-10m/s. The major frequency of void fluctuations in the bed could be defined as the same frequency of pressure fluctuations having unique value at every location of the bed. The major frequency could be correlated as functions of static bed heights and properties of solid, after modifying the correlations of bubble rise volocity and travclling distance. The major frequency decreases with static bed height and increases with jet velocity. The amplitude of pressure fluctuations at a certain location was found to have a relationship with the bubble size measured using a high speed movie camera.
A Study on Viscous Flow through a Porous Membrane
Yang, Seung-Man ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 113~113
Analytical results are presented for flow through a porous membrane in the range of pore size which is of comparable magnitude as the mean free path of the fluid molecules. In the present work, we consider a transfer mechanism of combined Knudsen diffusion, slip flow, and viscous capillary flow through a porous flat membrane governed by Brinkman's equation. The theory shows that as the total pressure of the system increases the Knudsen diffusion and slip flow become negligibly small, and that the dominant viscous flow reduces to a Poiseuillian in the limit of large permeability. In addition, as a model of counter-current(or cocurrent) separator module, flow behaviors through a porous hollow-fiber membrane are also analyzed to determine the relationship between the pressure variation and the permeation velocity through the porous membrane.
A Method for Calculation of Membrane Surface Area in Scale-up of Pervaporation Process
Choi, Young-Kook ; Lee, Soo-Bok ; Lee, Choul-Ho ;
Korean Chemical Engineering Research, volume 27, issue 1, 1989, Pages 120~120
In pervaporation of binary mixtures, a method has been proposed for the calculations of membrane surface area and average permeate composition when scaling up. For the method required and data on permeate composition and permeate flux measured as a function of feed composition in laboratory-scale experiments.