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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
A Study on Reaction Mechanisms of Crystallization of Zeolite A and Y
Lee, Kwang-Ja ; Han, Sang-Sup ; Cho, Chan-Hwi ; Lee, Han-Ju ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 245~245
This study concernes with the reaction mechanisms of zeolite A and Y crystallization. Currently, there are two different mechanisms proposed : the solution transport mechanism and the solid phase transformation mechanism. In an attempt to clarify this matter of mutually conflicting theories, three different types of experiments were carried out as follows. 1) Circulating reactions, in which clear solution is separated from solid gel and continually circulated through solid gel bed. 2) Separate reactions, in which clear solution and solid gel phases are separated and kept at reaction temperature in separate flasks. 3) Mixed reactions, in which the gel solution mixture is dept at reaction temperature in the conventional way. Samples of clean solution as well as solid gel were analyzed by XRD and IR for zeolite formation, and concentration changes of these samples were analyzed by I.C.P.A. From these experiments, the following conclusions were obtained. In crystallization of zeolite A, the predominating mechanism is the solid phase transformation, although some ions are consummed from the solution phase on incorporation in the solid phase reaction. In crystallization of zeolite Y, the aluminate ions in solution phase are transported to the solid phase until the Si/Al ratio reaches about 2, then the solid phase is transformed to zeolite Y crystals.
Production of APT from the Scheelite Concentrate by the Decomposition with
Hyun, Seong-Ho ; Lee, Chul-Tae ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 253~253
A new process for the production of APT from the scheelite concentrate
by the decomposition of scheelite concentrate with
was attempted. The proper conditions for the decomposition of scheelite concentrate were reaction temperature
, weight ratio of
to the scheelite ore 6.0, reaction time 2hr, and particle size of scheelite concentrate -200mesh. Tungsten component of about 98% in the scheelite concentrate was leached out from the decomposed scheelite concentrate by water leaching. APT was produced from the stripped solution through solvent extraction and the APT was identified as
by X-ray diffraction analysis.
Conversion of Olefins over SAPO-34 Molecular Sieve Catalyst
Ko, Tae-Seog ; Seo, Gon ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 264~264
Olefin(1-pentene, 1-hexene, 1-heptene, 1-octene) conversions over SAPO-34 molecular sieve catalyst were studied. Deactivation was fast for the conversion of lower olefin at low temperature. Reaction path of olefin conversion was discussed from the product distribution. Olefin conversion was mainly proceeded through oligomerization and cracking for lower olefins over deactivated catalyst, while the product distribution of higher olefins could be explained by cracking without oligomerization.
An Expert System to Aid Blast Furnace Operation Using Artificial Neural Network Techniques
Choi, Tae-Hwa ; Yoon, En-Sup ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 270~270
An expert system has been developed to support blast furnace operations in the integrated iron and steelmaking works. In the present study, a technique to diagnose furnace abnormality, using the artificial neural network, is proposed to overcome problems of the conventional rule-based expert system, such as lack of in-system automatic regulation and the limits of knowledge expression, etc. In order to enhance diagnostic resolution and robustness to counteract various furnace abnormalities, the data acquired by several sensors installed in the blast furnace were pretreated before using them as imput sources for diagnosis. For the diagnosis of abnormal conditions, back-propagation type of artificial neural networks were constructed, which consist of input, hidden and output layers. Diagnostic procedures are structured hierarchically, that is, first the diagnostic network finds the abnormal conditions and then carries out a detailed diagnosis ac-cording to the type of abnormality. In this study, an action guidance is suggested through the analysis of actual operation results according to the type and progress of the abnormal conditions. The expert system was tested using the operation data obtained from the abnormalities in a real blast furnace. Without the expert system, the operator could not recognize the initial irregularity due to the gradual change of furnace conditions. On the other hand the expert system could find the initial furnace abnormality and suggested appropriate counteractions.
The Representation of Ternary Systems by the Estimation of Group-Group and Interaction Parameters for MRSM-1 Model
Ha, Dong-Myeong ; Park, Jong-Chul ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 284~284
As one of the new estimation method, the MRSM-1 model which represents the relationship between equilibrium temperatures and compositions of vaper and liquid phase of the binary and ternary systems is proposed. By means of the MRSM-1 model, the temperatures of various compositions of five ternary systems are predicted. Representations of the isothermal lines and estimation of azeotropes are at-tempted using computer graphics. The MRSM-1 model provides a new method of predicting and depicting the isothermal lines, and existence and characteristics of the azeotropes of ternary systems.
Generalized Predictive Control for Bilinear Processes
Lo, Kun ; Yeo, Yeong-Koo ; Song, Hyung-Keun ; Yoon, En-Sup ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 300~300
A generalized predictive controller for discrete-time MIMO bilinear processes is derived based on a new bilinear CARIMA model with integral action. Using this model a multistep ahead optimal predictor is derived. Two alternative solution methods-rigorous and short-cut-of the minimization problem of a longrange cost-function are introduced and used to calculate control input. Several simulation results show that the proposed control methods have robustness to the limited prior knowledge of the process.
Extraction of Cu from Chalcopyrite by Thermal Decomposition with Ammonium Salt
Kim, Jae-Yong ; Yoo, Young-Hong ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 316~316
A new process for the extraction of Cu component from the chalcopyrite was attempted by thermal decomposition method of ammonium salts such as ammonium chloride or ammonium sulfate. This process consists of chlorination of chalcopyrite with
and sulfation of Synthetic CuS which was obtained from the chlorination of chalcopyrite with
. Through this process, overall 99.55% Cu component was extracted from the chalcopyrite.
Isothermal Coal Char Combustion and Char-Steam Gasification Reactivity
Bak, Young-Cheal ; Yang, Hyun-Soo ; Son, Jae-Ek ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 323~323
Thermal analyses were conducted by isothermal technique in order to characterize the combustion and steam gasification reaction of coal chars that were carbonized from Dong-won anthracite, Australian Coalex(HD) bituminous coal, Australian Victoria subbituminous coal, and Pakistian Lakla lignite. Char combustion reactions were carried out with respect to various factors : char particle size(0.08-0.5mm), isothermal reaction temperature
, oxygen concentration(5%-20%), and pyrolysis conditions. Char-steam gasification reactions were carried out at isothermal temperatures of
. In combustion reaction, measured reaction orders of oxygen concentration and activation energy were 0.56-0.98 and 53-123kJ/g-mol, respectively. In char-steam gasification reaction, measured activation energy were in the range between 113kJ/g-mol and 165kJ/g-mol. The kinetic equation of char combustion and char-steam reaction was correlated with various factor.
The Effect of Process Parameters on the Properties of PECVD Silicon Nitride Film
Nam, Chul-Woo ; Woo, Seong-Ihl ; Kim, Yong-Tae ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 336~336
PECVD silicon nitride film was deposited on P-type (100) silicon wafer in a parallel plate type reactor. The effect of different process parameters such as substrate temperature, RF power, and feed gas composition on the properties of silicon nitride layer was studied. Hydrogen content of nitride film was strongly influenced by substrate temperature and decreased with increasing substrate temperature. RF power influenced the type of bond configuration in the film. Si-H bond was dominant at the RF power lower than 40W, while N-H bond became dominant at the RF power higher than 40W. Etch rate in buffered HF solution was increased with the increment of hydrogen content in the film. The films deposited in
diluent showed hydrogen content and etch rate higher than those deposited in
diluent. Interface charge density decreased as the flow rate of ammonia increased.
Process Development for the Distillation of Ethanol from Fermentation Broth Containing Glucose
Kim, Jin-Hyun ; Sohn, In-Churl ; Peck, Seung-Yoon ; Yoo, Young-Je ; Hong, Ju-An ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 345~345
Vapor-liquid equilibrium data were obtained for the ethanol-water system with glucose at atmospheric pressure. Ethanol enriched vapor phase was obtained by adding glucose to ethanol-water system. The degree of enrichment increases with the increase in the glucose concentration. The equation correlating the activity coefficient and ethanol concentration in the liquid phase adequately represents the equilibrium behavior. In the conventional distillation column, the theoretical number of plate and cost of distillation decrease with the increase in the glucose concentration. This result can be used to develop an ethanol fermentation-distillation process aiming for high productivity and low energy consumption.
Low Temperature Planarization Technology Using Spin-On Glass for Multilevel Interconnections in Submicron Devices
Choi, Dong-Kyu ; Ko, Chul-Gi ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 352~352
Low temperature planarization technology using spin-on glass(SOG) was studied in the multilevel interconnection structures to increase the integration density of semiconductor device. The problems of forbid-den gabs, V-grooves and voids between metal line steps were solved as a result of SOG application in double level metallization structure. SOG film showed 10-20% volume shrinkage after SOG film was cured in
for 30 minutes, and it has less water and organic matter than before curing. 2MV/cm breakdown voltage and
leakage current were also obtained from the semiconductor parameter analyzer. In addition, this process showed low via resistance
tensile stress and 80% degree of planarization.
Thermal Energy Storage Capacity of Reversible Liquid Phase Reaction
Park, Chan-Young ; Ryu, Dong-Wan ; Cho, Chong-Hyun ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 358~358
By means of a set point change in an isothermal calorimeter the thermal energy storage capacity of the reversible liquid phase reaction mixture could be measured. From the storage capacities obtained in the wide range of temperatures between 298 and 368K the heat of reaction and the heat capacities of the product species, which would be difficult to measure directly because of the reversibility, were determined by analyzing the results statistically. The heat of reaction between 2-methyl furan and maleic anhydride and the heat capacity of the adduct were 61,200J/molK and
, respectively. The former was found to be slightly higher than that of previous workers. The storage capacities for the aqueous reaction of methyl ethyl ketone, acetone, and iso-butyraldehyde with sodium bisulfite were reported too.
Characteristics of Spherical Screen Packings
Kwon, Seung-Beom ; Wee, Jung-Ho ; Lee, Jung-Hun ; Chun, Hai-Soo ; Lee, Hee-Cheol ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 365~365
To investigate the characteristics of screen-packing for industrial application, measurements of absorption rates of carbon dioxide into potassium carbonate-bicarbonate buffer solution containing sodium hypochlorite as a catalyst in the screen packing column were carried out. The mass transfer coefficient and gas-liquid interfacial area of the screen packings were obtained, and also the pressure drop and liquid hold-up in the screen packing column were measured. In consideration of physical properties of the solution, 50 and 60 mesh spherical packings were used. It was found that the spherical screen packing showed the higher mass transfer rate than the ordinary commercial packings, and that the 60mesh spherical packings was better than 50mesh packings for the absorption.
Design of a Decentralized Control System with Loop Failure Tolerance by New Interaction Measure
Lee, Jie-Tae ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 373~373
Recently new interaction measure has been proposed by Lee et al. . The interaction measure improves the generalized Gershgorin band and the
measure. Here, using the interaction measure, a method to design a decentralized controller having loop failure tolerance is proposed.
Thermal Instability of Natural Convection over Inclined Isothermally Heated Plates
Chun, Young-Ho ; Choi, Chang-Kyun ;
Korean Chemical Engineering Research, volume 29, issue 3, 1991, Pages 381~381
A theoretical study for analyzing onset conditions of secondary flow in the form of vortex rolls in the primary natural convection over an inclined isothermally heated plate is carried out by employing the order-of-magnitude analysis under linear stability theory. For this purpose the propagation theory considering the variation of disturbances in the main flow direction is tested here. The present critical conditions for the infinite Prandtl number are found to approach the experimental data of water more closely than other theoretical results.