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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 25, Issue 6 - Dec 1987
Volume 25, Issue 5 - Oct 1987
Volume 25, Issue 4 - Aug 1987
Volume 25, Issue 3 - Jun 1987
Volume 25, Issue 2 - Apr 1987
Volume 25, Issue 1 - Feb 1987
Selecting the target year
Modeling and Simulation of Particle Size Distribution in Steady State Continuous CVD Fluidized Bed Reactor
Han, Myung-Wan ; Jeon, Jong-Yeol ; Kang, Sin-Ee ; Park, Dae-Won ; Yoon, Poong ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 327~327
A model was proposed to predict the particle size distribution in a steady state continuous CVD fluidized bed reactor and in outflow stream by variation of feed rate of input stream. In CVD fluidized bed reactor high purity polycrystalline silicon particles were grown by a pyrolysis of silane gas (
) and chemical vapor deposition (CVD) on seed particles. It was found from the computer simulation that the average size and output rate of product particles increased with decreasing silicon feed rate, and that the particle size distribution was broadened by the decrease of the feed rate, which is unfavorably influenced in a continuous CVD fluidized bed reactor. It was also demonstrated that the simulation results were in good agreement with experimental ones on a 4 inch CVD fluidized bed reactor and the model could be used in the estimation of operation conditions of CVD fluidized bed reactor.
Controlled Feeding of Solid Particles by Pneumatic Transport
Lee, Joong-Kee ; Park, Dal-Keun ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 336~336
Characteristics of solids feeding to a fluidized bed by pneumatic transport were studied experimentally. Sand, bituminous coal and anthracite particles were used as feed material. Studied variables were orifice ID, length and ID of conveying line, flow rate and pressure of transport air, and "hopper
". It was experimentally proved that feeding rate of solid particles can be controlled by manipulating transport air rate and "hopper
", without use of any moving machinery. Design procedures for the pneumatic transport of solid particles to a fluidized bed is suggested as well. We also found that the effect of pressure of transport air can be estimated by considering kinetic energy only.
An Experimental Study on Intrinsic Combustion Kinetics of Korean Anthracite by Thermogravimetric Analysis
Park, Kyun-Young ; Park, Young-Cheol ; Son, Jae-Ek ; Park, Won-Hoon ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 345~345
A microscale combustion experiment was performed under the chemical reaction control conditions in order to measure the intrinsic combustion kinetic data of coal. Daechon coal(low calorific value) and Hamtae coal(normal calorific value) are chosen as two representative Korean anthracites for thermogravimetric analysis. Measured activation energy, frequency factor, and reaction order of oxygen concentration are 28.5 kcal/g-mol,
, 0.7 for Daechon coal ; 27.0 kcal/g-mol,
, 1.0 for Hamtae coal, respectively, under atmospheric pressure, and between
. It is found the most important to predetermine the sample mesh size of each coal, so that the chemical reaction control conditions are guranteed. The reaction rates are observed to increase with time until they reach a maximum, then decrease slowly as reaction goes to completion. This phenomenon can be explained to be caused by the change of reaction surface area, i.e., by the change of pore structure as the reaction progresses.
Modeling of a Combined Suspension Preheater and the Fluidized Calciner of a Cement Plant
Choi, Hong-Young ; Lee, Chai-Sung ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 355~355
The preheating of cement raw meals is drastically improved by suspending them with the hot kiln gas in a multistage cyclone preheater. Furthermore, the heat load of a rotary kiln is cut down to such an extent that more than a half of the calcination is achieved in the preheater by employing a newly devised equipment, known as the Mitsubishi fluidized calciner, which works as a part of the preheater proper. In this work a total of 51 input parameters including 22 program variables are scrupulously chosen to describe the system by setting up complete material and energy balance equations for each system component in operation under steady state conditions. Five important variables, such as raw meal feed rate, coal feed rate to the fluidized calciner, cyclone efficiencies, radiation losses, and dust circulation rate from the riser duct are chosen to check the impacts of their variations upon the preheater performance. It is found that the calculated results explain reasonably well of the actually observed preheater behaviors. It is also possible that the predicted results can be used as the guide for more energy efficient preheater operations.
Chemical Pretreatment of Rice Straw for Lignin Extraction and Glucose Production
Kim, Woo-Sik ; Sung, Joon-Yong ; Yoo, In-Sang ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 367~367
As a pretreatment of agricultural waste to utilize their useful components, rice straw was delignified by using butanol and water as solvent in the presence of p-Toluenesulfonic acid. Optimum condition were
and 2 hr. At that time separated lignin was 87% and reaction rate was first order reaction,
. The amount of glucose was 14 mg/ml after hydrolysis pretreated rice straw.
Solubilities of Biphenyl and Naphthalene in Benzene and Cyclohexane
Choe, Byeong-Hyeok ; Kim, Ji-Dong ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 372~372
Solubilities of the coal derived solids naphthalene and biphenyl in the solvents benzene and cyclochexane were measured from the temperature near to the melting point of the solutes to that of the solvents, and then the solid-liquid phase diagrams were constructed from the experimental data. The solubilities were accurately predicted by estimating the activity coefficients in the solid solubility equations using the Scatchard-Hildebrand regular solution theory. For the benzene solutions which were close to an ideal solution, the accuracy could be achieved by using the physical properties of the pure components only. For the cyclohexane solutions which were highly non-ideal, however, binary parameter
was needed to improve the accuracy of prediction. The eutectic points of the binary systems were also closely estimated by the method.
Effect of Catalyst on Lignite Char-Steam Gasification Reaction
Kim, Jung-Rae ; Kwon, Tae-Wahn ; Kim, Sang-Done ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 379~379
The catalytic effects of potassium carbonate on the rate of steam gasification of an Australian lignite char having mean particle diameter 0.3mm have been investigated under the atmospheric pressure in a 5.5cm
height thermobalance. The effect of
concentration (1-5 wt%) and the reaction temperature (
) on the rate of gasification have been examined. The reaction orders with respect to carbon were found to be 2/3 for noncatalytic reaction and zero for
catalytic reaction. The reaction rate increased linearly with the reaction temperature and the amount of
loading. Activation energy decreased exponentially with the amount of
loading which has been correlated with the following relation:
Activation energies and frequency factors of the catalytic reactions were smaller than those of the comparable noncatalytic steam gasification reactions which may exhibit the compensation effect in the reactions.
Extraction of Arsenic and Sulfur Component from Arsenic Bearing Sulfide Ore
Lee, Cheol-Tae ; Hwang, Mu-Yeong ; Yu, Yeong-Hong ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 386~386
This study was carried out to find a new nonpollutant process for the extraction of arsenic and sulfur component from arsenic bearing sulfide ore by means of the inert roasting and water leaching. The proper conditions for the inert roasting of arsenic bearing ore were that roasting temperature :
, roasting time : 3 min per lg ore and particle size of ore :-140 mesh under
atmosphere. The optimum conditions for the water leaching of the inert roasting product were that leaching temperature :
, amount of water : 50 ml per lg inert roasting product and leaching time : 60 min. The analyses of the final product through the both treatments under the above mentioned conditions showed that the content of
was 98.21% and the x-ray diffraction pattern was identified as arsenolite.
Flow Transition of Solids in a Three Phase Fluidized Bed
Kang, Yong ; Kim, Sang-Done ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 394~394
Flow transition of solids in a three phase fluidized bed has been studied in a 15.2cm-ID pyrex glass column. The relation between the fluid flow rate and the bed porosity in a three phase fluidized bed has been obtained by means of effective volumetric flux of fluid from the modification of the Richardson and Zaki's equation. Effects of gas (4-12 cm/s) and liquid (4.0-16.0 cm/s) velocities, particle sizes (1.7-8.0mm), and bed porosity on the flow transition of solid have been determined. Water as the liquid phase, glass beads as the solid phase and filtered compressed air as the gas phase have been used in this study. The modified particle Reynolds Number which describes the effective bulk motions of solid particles and gas and liquid elements exhibited its maximum value with the variation of bed porosity in a three phase fluidized bed. The drag coefficient which is the ratio of drag per unit projected area of particle to the velocity head changed its slope apparently at the bed porosity where the maximum modified particle Reynolds Number could be obtained. From literatures, immersed heater-to-bed heat transfer coefficient, wall-to-bed heat transfer coefficient, radial mixing coefficient of liquid phase were found having maximum values at these flow transition conditions in three phase fluidized beds.
The Treatment of Phenol by Immobilized Candida tropicalis in Fluidized Bed Reactor
Kim, Woo-Sik ; Youm, Kyung-Ho ; Cho, Jae-Hyun ; Cha, Soo-Young ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 401~401
The removal efficiency of phenol was experimented by the C.tropicalis immobilized on calcium alginate gel in the 2-phase and 3-phase fluidized bed reactor respectively. The removal efficiency of phenol above 70% was obtained at the feed concentration of 100 mg/l, feed velocity of 0.25 cm/s and recycle ratio of 3. The phenol degradation was satisfied as the follows equation;
Cation Exchange Characteristics of Korean Natural Zeolite
Ha, Ki-Sung ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 409~409
The characteristics of natural zeolite originated from Kyungbuk, Korea such as X-ray diffraction, cation exchange capacity, ion exchange equilibrium and ion exchange reaction heats were investigated for application to wastewater treatment and other use. Japanese and American natural zeolite samples were also tested to compare with Korean sample. The selectivity coefficient of cation in these materials defined from mass action law does not a constant value as in the case of organic exchange resin.
Variation of Porosity and Specific Resistance in Cake Filtration
Yun, Seok-Ho ; Gang, Yong ; Go, Hyang-Hui ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 419~419
Variations of porosity and specific local resistance in cake filtration were studied in a filter cell by increasing filtration pressure. The cross sectional area of filter cell was
, and the slurries used were made of water and
, Talc(I) and Talc(II), respectively. The amount of solids added to water was 30 wt% to make highly concentrated slurries. The net loading pressure to the filter cake as well as the pressure to the filter cell were considered to verify the dependence of porosity and specific resistance on the loading pressure. From the experimental results, the cake porosity decreased and the specific local resistance increased linearly with the increasing pressure in log-log plots, respectively. The addition of the porous dialite as a body-feeding filter aid into slurries increases the cake porosity and decreases the specific local resistance of the filter cake.
Synthesis and Characterization of ZSM-5 Zeolite Catalyst
Woo, Myung-Wu ; Kim, Man-Hoe ; Rhee, Hyun-Ku ; Lee, Wha-Young ;
Korean Chemical Engineering Research, volume 25, issue 4, 1987, Pages 427~427
Various ZSM-5 zeolite catalysts were prepared by using the reaction mixture
. The composition and pH of the reaction mixture, the reaction temperature, and the reaction time were found to be important factors for the formation and growth of ZSM-5 crystal. The physical and chemical characteristics of the ZSM-5 catalysts were examined by employing the XRD, SEM, XPS, TPD, IR, and TG-DTA-DTG methods, and their activities were tested by conducting the methanol conversion experiment. The ZSM-5 catalyst was obtained favorably when the
ratio was greater than 20, the pH in the range from 9 to 10.5 and the reaction temperature about
. The catalyst so prepared proved to be very active for the conversion of methanol.