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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 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
Selecting the target year
Effects of Particle Size on Pressure Fluctuations along the Axial Direction in a Gas Fluidized Bed
Hong, Sung-Chang ; Oh, Kwang-Joong ; Choi, Cheong-Song ; Doh, Dong-Sup ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 127~127
The pressure fluctuations along the axial distance above the distributor were measured by a differential pressure transducer in a 0.109m ID fluidized bed of sand particles(0.715, 0.359 and 0.194mm). The pressure fluctuations were analyzed by the standard deviation and the distribution of power spectrum. The effect of particle size on the pressure fluctuations was investigated with different gas velocities and static bed heights to interpret the fluidized bed behavior such as bubble motion and particle mixing. The amplitude of pressure fluctuation was greatly affected by the particle size and exhibited a maximum value at which the distribution of power spectrum has the most wide and complicate peaks, thus, the most vigorous bubble motion and particle mixing took place at that position in a fluidized bed.
Oxidation of Propylene to Acrylic Acid on a
Na, Suk-Eun ; Chun, Sung-Woo ; Choi, Myung-Jae ; Chung, Jong-Shik ; Park, Dae-Won ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 134~134
The vapor-phase oxidation of propylene to acrylic acid using
catalyst was studied at steady state and transient state operations. The yield of acrylic acid was increased with the increase of reaction temperature and with the decrease of the ratio of propylene to air partial pressure. The unsteady state experiments such as Redox operation and periodic reactivation of catalyst showed that the activity was decreased with the formation of deposits on the catalyst surface, and that it could be regenerated with the treatment of oxygen.
Isobaric Vapor-Liquid Equilibria of the Ternary System Oxazole-Acetonitrile-Water
Park, So-Jin ; Schmidt, Adolf P. ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 143~143
New vapor-liquid equilibrium data for the ternary mixture oxazole-acetonitrile-water, which are by-products of acrylonitrile manufacturing process in Hoechst Co., were determined by using recirculating still at 1013 mbar. These experimental data were satisfactorily correlated by Wilson and NRTL equation for the activity coefficient and were found to be thermodynamically consistent by two point consistency test for a multicomponent.
Prediction of Distillation Efficiencies in Multicomponent System
Kang, Yun-Whan ; Choi, Dae-Ki ; Lee, Youn-Yong ; Lee, Won-Kook ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 149~149
The concentration profiles of the ternary system(acetone/methanol/water)in a distillation column were predicted by the following four different solutions : the general or approximately linearized solutions of Maxwell-Stefan equation, two solutions with the assumptions of the constant number of overall gas phase mass transfer
along the dispersion height or the constant binary Murphree efficiency. The experiments were performed in a 5cm I.D. distillation column with 5 plates under the conditions of the liquid flow rate of 2.0g-mole/min and total reflux. The calculated concentration profiles were compared with the experimental data. It showed that the concentration profiles with the constant binary Murphree efficiency were severely deviated from the experimental data, but the profiles of the other three methods were in good agreements.
A Study on the Growth of Balls in a Disk Granulator
Kim, Dong-Kwon ; Lee, Jung-Min ; Rhee, Bo-Sung ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 159~159
Granulation is an operating process for solid treating in which powdered material grows into spherical granules of some sizes on a rotating disc by adding a certain amount of an appropriate binder and spraying water continuously. In this research a mathematical model for prediciting the sizes growing granules with time was proposed and its applicability was examined through a series of experiments. Adhesion coefficient D increased as the feed rate(F) of powdered graphite decreased and when feed rate(F) was fixed, the D values increased as the spraying rate of water(W) and rpm(N) of the disc increased. An empirical correlation between adhesion coefficient D and operating variables was obtained as follows,
Finally, the theoretical results of D from the proposed mathematical model were in good agreement with those from experiments and so the assumed model may well be applicable to other systems of spherical growing ball.
Mass Transfer in the Solid Particle-Liquid System with a Mechanically Agitated Vessel
Park, Sang-Wook ; Lee, Jong-Wook ; Park, Moon-Ki ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 168~168
The mass transfer coefficients between fine particles and liquids were measured in an agitated vessel. As the particle's diameter decreased, the values of mass transfer coefficient deviated below the previous correlation for large particles and approached the value of the theoretical molecular diffusion theory. The mass transfer with fine particles in the turbulent agitation was analysed with the conventional concept of a specific power group from the Kolmogorov theory. An approximate solution for the mass transfer in the wide range of experimental variables was also obtained by using the Beek-Bakker model with which the experimental data were in good agreement.
Effect of Sol-gel Transition Parameters of TEOS on the Properties of
Gung, Kyeong-Taek ; Lee, Dong-Jo ; Shul, Yong-Gun ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 176~176
In order to evaluate the effects of sol-gel transition parameters of TEOS(tetra-ethyl-ortho-silicate) on properties of
, we studied whole process from sol-gel transition of TEOS by hydrolysis reaction to a sintering step to form
. Initial hydrolysis parameters of TEOS had an influence on gel shape and transition properties as well as on the bulk density and surface area of the final sintered products of
. In acid catalyst system, with increasing hydrolysis reaction temperature, fiber drawing zone of sol-gel had become smaller. In closed system no fiber was obtained. Incease in
concentration enhanced the initial hydrolysis reaction of TEOS. The hydrolysis reaction was faster in base catalyst system than in acid catalyst system. In acid catalyst, increasing the water concentration resulted in formation of a big primary particles in bulk
gel. On the other hand, in base catalyst system increasing the water concentration didn't form a bulk gel, which is due to the formation of segregated fine powders before the bulk gel transition.
Effects of Preparation Conditions of Pt/C Electrode on the Cathode Performance in a Fuel Cell
Rho, Yong-Woo ; Augh, Ki-Han ; Kim, Jin-Soo ; Shul, Yong-Gun ; Lee, Tae-Hee ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 183~183
Effects of sintering atmosphere, average particle size and loading density of Pt and preparation method of Pt/C catalyst on the performance of porous carbon electrode were examined in a half cell of 20wt% sulfuric acid electrolyte. From the XRD data, the average Pt particle size prepared by the colloidal method was confirmed to be less than
. From the TEM data, it was confirmed that the average Pt particle sizes sintered under
atmosphere were maintained at
respectively but it grew to
atmosphere sintering. For the average Pt particle size of
, the corresponding performance of the electrode was shown to be 260, 230 and
respectively at 700mV. As the Pt loading was increased to 5, 10 and 20wt%, the corresponding performance of the electrode was improved to 150, 230 and
Hydrolytic Enzyme Immobilization by Cross-linked Silica Gel and Their Kinetic Behaviors in Packed Bed Reactor
Han, Sang-Sub ; Cho, Chan-Hwi ; Lee, Han-Ju ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 190~190
This study is for the immobilization of a hydrolytic enzyme, trypsin, within cross-linked silica gels and their kinetic behaviors in a packed bed reactor using a sensible amide substrate, DL-BAPNA. In the range of linear velocity of 25 to 200cm/hr, Michaelis constants(Km') and maximum reaction rates(Vm') for immobilized trypsin were less and greater than those for a soluble trypsin, respectively. In comparison with free enzyme, Michaelis constants decreased but maximum reaction rates increased as linear velocity increased. In the case of supported silica-gel with the spherical diameter of 0.6mm, the internal diffusion resistance was negligible because the effectiveness factor was found to be in the range of
and the mass transfer
was in the range of
. In addition, Michaelis constant was the function of the amount of immobilized trypsin(immobilization density) and the conversion was found to be maximized at the immobilization density of 10mg trypsin/g silica gel.
A Study on the Synthesis of Tetrachloroisophthalonitrile from Isophthalonitrile in a Fluidized Bed Reactor
Lim, Byung-Kyu ; Ju, Dong-Pyo ; Kim, Chul ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 199~199
Macroscopic reaction kinetics of the chlorination reaction of isophthalonitrile(IPN) to produce tetrachloroisophthalonitrile(TPN) was studied and the optimal design and operating conditions of a fluidized bed reactor for the chlorination of IPN were investigated experimentally. Comparing the experimental data obtained from a fixed bed reactor with the theoretical ones, the
type consecutive reaction mechanisms and pseudo-first order reaction rate for each step were found satisfactory and the kinetic rate constants for each step at
were obtained. Experiments were conducted in a lab-scale fluidized bed column in order to obtain the information on the minimum fluidizing velocity of catalyst which in turn served as the basis for the design and operation of a bench-scale fluidized bed reactor. The chlorination reactions were undertaken in this reactor using the 30wt%
carbon particles of -70+100 mesh sizes as the catalyst to determine the optimal operating conditions for the production of TPN of purity greater than 95%, which include temperature, molar ratio of
in the feed and mean residence time. Optimal H/D ratio was proposed also for the design.
A Fundamental Study of Supercritical Fluid Extraction Process for Concentrating Tocopherols from Soybean Sludge
Lee, Huen ; Chung, Bong-Hyun ; Park, Young-Hoon ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 206~206
A fundamental study has been carried out to develop the extraction process for concentration 17-18wt% tocopherols from soybean sludge using supercritical carbon dioxide. In this regard, the equilibrium solubility and continuous extraction experiments for the system sterol-removed soybean sludge and supercritical carbon dioxide were performed over the temperature and pressure ranges of
and 200-400bar, respectively. Tocopherol concentration in the extract was the lowest at 250bar for all temperatures studied and the cross-over point was appeared in the vicinity of 300bar. On the basis of these results, it was confirmed that a general countercurrent extraction method can be properly used for the concentration of tocopherols from sterol-removed soybean sludge.
Development of General Purpose Dynamic Chemical Process Simulator I. General Overview of the System and Simulation Strategy
Lee, Kang-Ju ; Yoon, En-Sup ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 211~211
A simulator structure, integration strategy, input language and simulation technique are presented in order to develop a general purpose chemical process dynamic simulator, and a SCI(Sequential Clustered Integration)-based prototype simulator is implemented. The SCI is a general form of SMI(Sequential Modular Integration) but has better performance then SMI and SEI(Simultaneous Equation Integration) with respect to computational efficiency and flexibility of applications. The SCI approach is capable of introducing various mode of coupling of the process units, actually, from SMI to SEI within a single simulator structure. Examples are presented to study the clustering criteria which have significant influence on the performance of SCI and to illustrate the system performance.
Combustion Characteristics of the Gas Burner for Reheating Furnace
Cho, Kil-Won ; Park, Heung-Su ; Lee, Yong-Kuk ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 222~222
Pilot scale combustion experiments for two types of gas burner, namely 1-and 2-staged firing burners, were carried out to examine the combustion characteristics of the burners for reheating furnace. The mixture of commercial propane and nitrogen was used as the experimental fuel. For the 1-staged burner prevailing in reheating furnaces, flame stability, flame shape, temperature and flue gas composition were measured and analyzed over various experimental conditions. Performance comparison of the two types of burner was done, also. Compared with the 1-staged burner, the 2-staged burner was found to be effective in reducing
emission and in enhancing thermal efficiency.
Thermal Decomposition of Copper Sulfide with
Kim, Jae-Yong ; Yoo, Young-Hong ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 229~229
The thermal decomposition of CuS with
was investigated to find a new method for the extraction of Cu component from chalcopyrite. In this reactions, CuS was sulfated to
atmosphere and the proper conditions for this sulfation were reaction temperature
, reaction time 40min and mole ratio of
to CuS 6.0. Under these conditions, 99.62% Cu was extracted from CuS.
A Study on the Characterization of VMoPO Mixed Oxide Catalysts by Temperature Programmed Desorption and Temperature Programmed Reaction
Jung, Ji-Hoon ; Chun, Jin-Woo ; Hong, Suk-In ;
Korean Chemical Engineering Research, volume 29, issue 2, 1991, Pages 237~237
Oxidation reactions of methylcyclopentane(MCP) and cyclopentadiene(CPD) on the V-Mo-P mixed oxide catalyst were investigated with the composition of Mo and P. The conversion of MCP and CPD and the selectivity of MA were also examined at various reaction temperatures. Studies of activation points on the catalyst surfaces were performed through the temperature programmed desorption. In the oxidation of CPD, the highest value of MA selectivity was observed by using the V-Mo-P mixed catalyst(V:Mo:P=1:1.34:0.11). The conversion of MCP and CPD resulted in decreasing with increasing composition ratio of molybdenum and phosphorous in the V-Mo-P mixed oxide catalyst. The selectivity of MA in the oxidation of CPD resulted in increasing with increasing composition ratio of molybdenum and phosphorous in the catalyst. However, the selectivity of MA in the oxidation of MCP was decreased with increasing molybdenum and phosphorous composition ratio. In the temperature programmed reaction(TPR) spectrum, four desorption peaks were observed and the number of the observed peaks were same as the number of reaction products. It was founded the main product of those oxidation reactions, MA and PA, were produced at different activation point of the catalyst.