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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 33, Issue 6 - Dec 1995
Volume 33, Issue 5 - Oct 1995
Volume 33, Issue 4 - Aug 1995
Volume 33, Issue 3 - Jun 1995
Volume 33, Issue 2 - Apr 1995
Volume 33, Issue 1 - Feb 1995
Selecting the target year
Selective Oxidation of Butane and Butene over Vanadium-Bismuth Based Catalysts
Jung, Ji-Hoon ; Huh, Sung-Ki ; Hong, Suk-In ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 273~273
The effect of reducing agents and bismuth as a additives used in preparing the VPO catalysts were investigated through selective oxidation of butane and butene to maleic anhydride. Bismuth added catalyst(VPBiO) increased the formation of maleic anhydride in butene oxidation, but it decreased the selectivity of maleic anhydride in butane oxidation. UV-DRS analysis showed that the charge transfer energy of VPBiO catalysts were higher than VPO catalysts, and it resulted in increasing the selectivity of maleic anhydride in butene oxidation. XRD study showed that the portion of
structure and the ratio of  face of
structure were increased with adding bismuth, and it was related to the selectivity of maleic anhydride. Also the mean valence of vanadium was increased with increasing the portion of
Rheological Characteristics of Coal-Water Mixture Fuel and Pressure Losses in Pipe Flow
Roh, Nam-Sun ; Kim, Kwang-Ho ; Kim, Dong-Chan ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 282~282
The rheological characteristics of coal-water mixture(CWN) fuel, based on the power law model, were investigated using the Haake rotational viscometer, which produced shear rates from 0.1 to
. Test results showed that all the slurries exhibited non-Newtonian properties of shear-thinning behavior, i.e., pseudoplastic or yield-pseudoplastic. The slurries become more viscous as the temperature, the mean particle size, and the amount of anionic surfactant were lowered. Furthermore, the yield stress measured in the case of no additive varied with the solid volume fraction and the coal particle size. The CWMs displayed a higher degree of pseudoplasticity with an increase in coal content and with a decrease in the mean size of the coal particles, the amount of additive, and the temperature. The pressure loss data obtained in the CWM test loop were coincided with the calculated values from the correlation based on the power law constants. Also, the generalized Reynolds number(
)-friction factor(f) relationship could be applied to the laminar flow of CWM fuel.
Preparation of Silica Fibers by the Sol-Gel Process
Song, Ki-Chang ; Chung, In-Jae ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 292~292
Silica fibers were prepared by the sol-gel process from
solution as a starting material. Various factors, such as the molar ratios
, alcohol and HCl to
, were investigated in order to find appropriate experimental conditions for the spinnability of the solution. The most important factor determining the spinnability of the solution was the molar ratio of
in the solution. The solutions with
ratios less than about 3 showed a marked spinnability just before gelling. Most silica fibers showed the elliptical cross sections except that prepared from the solution with
molar ratio 3, which had a circular cross-section.
Adsorption-Desorption Characteristics of CFC-113 on Activated Carbon
Park, Jong-Ho ; Jun, Jae-Ho ; Hwang, Kye-Soon ; Lee, Won-Kook ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 301~301
Adsorption isotherms of CFC-113 on activated carbon were determined at various temperature (298K, 313K, 343K, 373K, 393K). The isotherms were predicted by Langmuir model fairly well and the results were used to simulate the adsorption and desorption experimental data. Fixed bed adsorption experiments were performed, varying flow rate, concentration and temperature. Mass transfer coefficients were estimated comparing constant pattern solution with experimental breakthrough curves. Fixed bed adsorption experiments were made, varying temperature and flow rate. A nonequilibrium, nonadiabatic model was used to simulate experimental data. In the model, mass transfer rate was expressed by linear driving force with mass transfer coefficients varying with temperature and thermal equilibrium between adsorbent and gas phase was used.
Comparison of 2-Dimensional Model with 3-Dimensional Model of Non-Newtonian Fluid Flow in a Coat-Hanger Die
Na, Su-Yeon ; Kim, Do-Hyun ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 310~310
Flow of non-Newtonian fluid following power-law model in coat-hanger die has been studied through 2-dimensional and 3-dimensional model. Finite element codes for numerical simulation were developed for each model. The mathematical model of coat-hanger die was constructed according to the analytic design equation based on one-dimensional flow rate distributions, pressure distributions, streamlines, and pathlines were calculated for comparison between two models. The validity of the two-dimensional analysis was investigated based on the three-dimensional analysis. The two- dimensional model was found to be inadequate in regions of the manifold and the die side wall. There was a significant difference in the flow rate distribution and the total pressure drop between two models.
Oxidation of Diphenylmethane by
Gas with Tetrabutylammonium Hydrogen Sulfate
Park, Sang-Wook ; Park, Dae-Won ; Suh, Dong-Soo ; Heo, Nam-Hwan ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 318~318
The oxidation of diphenylmethane by oxygen was carried out in a liquid-liquid heterogeneous system with benzene solution of tetrabutylammonium hydrogen sulfate as a phase transfer catalyst and aqueous solution of sodium hydroxide as a base using a stirred absorber at
and an atmospheric pressure. The equilibrium constants,
between the intermediates of catalyst, base, and reactant were obtained from equilibrium experiment, and their values,
, respectively. The reaction rate constants of oxidation of diphenylmethane with oxygen was obtained from the experimental enhancement factor of initial rate of oxygen absorption, and its value 1.01 l/mol s. The reaction mechanism by the phase transfer catalyst at the interface of the gas-liquid-liquid heterogeneous system was analyzed by mass transfer mechanism with chemical reaction using the film theory.
A New Estimation Method for the Macropore and Micropore Effective Diffusivities
Song, Dong-Ik ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 328~328
A new method to estimate the macro-and micropore(or macropore and solid phase) effective diffusivities of the bidisperse particles was introduced. This method used the relationship between the single and two effective diffusivities which was obtained by matching the second moments or variances from the single and two effective diffusivity diffusion models. It was shown that the new method was suitable for estimation of the two effective diffusivities, based on the results of experiments to adsorb n-butane gas in the beds packed with alumina or zeolite 5A particles.
Microstructure and Oxygen Reduction Reaction in Phosphoric Acid Fuel Cell Electrodes
Choi, Byung-Woo ; Kim, Chang-Soo ; Song, Rak-Hyun ; Shin, Dong-Ryul ; Choi, Soo-Hyun ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 336~336
Electrodes were made with different preparative conditions (
sintering temperature and 25-65wt% PTFE content) and the pore size distribution and electrolyte uptake for each electrode were measured. From these data we calculated porosities, electrolyte and gas volume fractions of the electrocatalyst layer and agglomerate regions. Percentage acid occupation decreased by the increase of PTFE content and sintering temperature due to an increase of hydrophobicity. Porosities of electrocatalyst and agglomerate remained constant regardless of preparative conditions. The electrolyte occupied part of micropore, perferentially smaller radius of pore with increased hydrophobicity. Oxygen reduction reaction in 105% phosphoric acid resulted in
(transfer coefficient)=2/3 and a proportionality between Tafel slope and temperature in the range of
. The activation energy at equilibrium potential was calculated as 68 KJ/mol in the temperature range of
A Study on the Analysis of Axial Dispersion Model by the Weighted-Moment Method
You, Won-Suk ; Lim, Il-Woong ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 345~345
The weighted-moment method for the parameter evaluation of the axial dispersion model was investigated with tracer response curves obtained at two points of a liquid phase flowing through a cylindrical vertical column packed with ceramic spheres. The long tail of response curves was approximated by the exponential decay function in order to obtain model parameters of better fitness. The weighted-moment method was performed through the linear regression method applied with different ranges of Laplace Parameter. The fitness of model parameters evaluated by each method was determined by comparing the hypothetical response curve obtained from the evaluated model parameters with the actual response curve obtained experimentally. The weighted-moment method performed with appropriate range of Laplace parameter had provided more reliable model parameters than those obtained from the moment method.
Measurement of the Minimum Fluidization Velocity of a Binary Mixture of Different Density Particle System Using Pressure Fluctuations
Jang, Hyun-Tae ; Hong, Sung-Chang ; Doh, Dong-Sup ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 353~353
The determination method of minimum fluidization velocity from the linear regression of standard deviation of pressure fluctuation according to air velocity was investigated with binary mixture of sand and PMMA in a 0.109 m I.D. fluidized bed. The experiments were performed with change of operating variables such as the fraction of flotsam and particle size, and the measured values of the minimum fluidization velocity were compared with those obtained by the other researchers. The air velocity for this method has limited from well mixed region to freely bubbling region in a fluidized bed. The optimal measuring height of pressure fluctuations seems to be at middle levels on the axis of a bed, where the solid is well mixed.
Removal of Heavy-Metal Ions from Aqueous Solution by Hydroxyapatite
Seo, Yang-Gon ; Lee, Dong-Keun ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 360~360
Removal of divalent heavy metal ions,
, respectively, from their chloride or nitrate aqueous solutions was studied by the addition of hydroxyapatite in a batch system. The isotherms for heavy metal ions were of the rectangular type so that the amounts removed from aqueous phase were constant irrespective of the concentration of solutions. The selectivity for the cations on hydroxyapatite can be explained in terms of the ionic radii and the its electronegativities. Kinetic experiments were carried out in an agitated tank adsorber. Effective diffusivities of cupric chloride, zinc chloride and cadmium chloride inside hydroxyapatite were
was also exchanged very quickly with
and easily removed by hydoxyapatite.
Investigation of the Purification Process of Alumina by the Volatilization Method
Suh, Dong-Soo ; Kim, Hyo-Joong ; Cho, Jun-Hyung ; Suh, Tae-Soo ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 367~367
This study was undertaken to establish an industrial process for the preparation of low-soda alumina useful in the manufacture of electronic ceramics. First, starting material,
, was admixed with the chlorine-containing compounds.
or HCl, employed as the treating agent for reducing the soda in starting material, and then admixture was calcined at a temperature sufficient to eliminate the soda as a volatilizable compound which was produced by reaction of the soda and the above mentioned treating agents. This treatment is so-called the volatilization method. The results obtained in the study show that addition amount of treating agents has an enormous effect on the elimination of soda, and that optimum addition amount of
and HCl is 2.43 and 8.38(mole of treating agent/mole of
Thermal Convective Instability in Translucent Inclined Porous Media with Radiative Heat Transfer
Park, Hung-Mok ; Byun, Jae-Sik ; Yoo, Ki-Pung ; Lee, Kun-Hong ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 376~376
The onset of thermal convection in a translucent inclined porous layer in considered. Attention is focused on the effects of radiative heat transfer and inclined angle on the critical Rayleigh-Darcy number and the convection cell size. If we consider the contribution of radiative heat transfer, the basic temperature profile is non-linear and the thermal convective instability is influenced by the ratio of conduction to radiation heat flux, the temperatures at the boundary surfaces and radiative parameters such as wall emissivity(
), scattering albedo(
) and extinction coefficient(
) as well as the usual Rayleigh-Darcy number. In the present work, effects of inclination angle and radiative heat transfer on the basic state temperature profile and onset of convective instability are investigated with the help of linear stability theory employing Darcy's law and the radiative transport equation simplified by the
approximation. The increased effective thermal conductivity due to radiation inhibits the onset of convection and causes higher critical Rayleigh-Darcy number and smaller convection cell size. As the inclination angle increases, the effective buoyancy force decreases and the heating rate needed to induce convection increases due to the increased flow rate, resulting in larger critical Rayleigh-Darcy number and smaller critical wave number.
Mathematical Model for the Cell Lysis of E. coli Double-lysogen by UV-irradiation
Park, Soon-Suk ; Koo, Yoon-Mo ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 386~386
A mathematical model was proposed in order to explain the lytic behaviors of the UV-irradiated E. coli double-lysogen[P90c/(
)]. The UV dosage that lysogen had received was represented by the normal distribution, so that the survival, lysis and death fractions of the irradiated lysogen were described by the function of UV dosage. Using this model, the characteristics of the protein production and the cell lysis of the irradiated double-lysogen were studied. Finally, the optimum conditions for the cell lysis were predicted by changing the related parameters.
Micropore Size Distribution of Activated Carbon Fibers by Image Analysis
Lee, Ki-Bong ; Park, Bang-Sam ; Chae, Ju-Seung ; Ryu, Seung-Kon ;
Korean Chemical Engineering Research, volume 33, issue 3, 1995, Pages 393~393
Micropore structure and size distribution of activated carbon fibers(ACFs) were studied by image analyzer. Especially, TEM photos of cross sectional view of ACFs with the same amount of burn-off(40%) but different burn-off conditions were prepared for the comparison of microporosity and adsorption characteristics. It is confirmed that the ACF with larger specific surface area in consequence of larger amount of smaller size micropores, show higher adsorption capacity. Image analysis can be applied for the indirect, yet quantitative analysis of microporosity of ACFs including pore size distribution, pore volume distribution and area fraction of cross-section.