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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 28, Issue 6 - Dec 1990
Volume 28, Issue 5 - Oct 1990
Volume 28, Issue 4 - Aug 1990
Volume 28, Issue 3 - Jun 1990
Volume 28, Issue 2 - Apr 1990
Volume 28, Issue 1 - Feb 1990
Selecting the target year
A Study of Hydrocracking and Hydroisomerization of n-Heptane over Supported Ru Catalysts
Lee, Won-Mook ; Kim, Kyung-Lim ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 255~255
The hydrocracking and hydroisomerization of n-heptane were studied over Ru/La-Y based catalyst, and as an experimental apparatus a CATATEST minipilot licensed by IFP was used in this study. Co and Ni were used as promoters, so the effects of promoters impregnated into the prepared catalyst were observed. The results showed that the order of the magnitude of activity of each catalyst was Ni-Ru>Co-Ru>Ru-catalysts, and that the promoters Ni and Co increased the activity of hydrocracking and isomerization, and they had an inhibiting effect on the secondary splitting. Through an experiment on the deactivation of catalysts, it was confirmed that coke formation on the catalysts surface and sintering of active sites deactivated the catalysts. In a study of the turnover number of each catalyst used in hydrocracking, it was revealed that all of the reactions were structure-sensitive.
Equilibrium in the Extraction of Pb(II) by
Lee, Jae-Hong ; Nam, Se-Jong ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 264~264
Measurements of the extraction equilibrium of lead acetate aqueous solution with di(2-ethylhexyl) phosphoric acid(
) in carbon tetrachloride, and diphenylthiocarbazone (dithizone) in choloroform were carried out at
. Over the range of loading ratios less then 0.05 for
and 0.03 for dithizone, the extracted organic metal species and equilibrium constants were found to
for dithizone. Upon increasing the loading ratio above the threshold value, the extracted chemical species and equilibrium constants were estimated to
, and to
for dithizone. The equilibrium constants were found to decrease upon adding of acetic buffers, and to a little increase by addition of Span#80.
Activity, Selectivity and Stability of pt and Pt-Re Bimetallic Catalysts Supported on HY Zeolite in n-Hexane Reforming Reaction
Woo, Seong-Ihl ; Noh, Ou-Sun ; Yang, O-Bong ; Kim, Young-Gul ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 271~271
Pt and Pt-Re bimetallic clusters supported on HY zeolite were prepared and their catalytic activities, selectivities and stabilities were evaluated in the n-hexane reforming reaction. The mole ratio of
/n-hexane was 5 and the reaction temperature and calcination temperature were varied in the range of temperature between 300 and
, respectively. The selectivity of the HY zeolite supported catalyst towards
isomers was 2 times higher than that of the alumina supported catalyst. The catalytic activity and selectivity of Pt-Re/HY are dependent on the temperature of calcination and the higher selectivity to
products was obtained with Pt-Re/HY catalyst. The value of hydrogen chemisorption (H/M)of Re/HY is negligible and H/M value of Pt(0.5)Re(0.5)/HY is about one over third of that of Pt(0.5)/HY. These results indicate that Pt-Re bimetallic clusters were formed on HY zeolite. The addition of Re on Pt caused the deactivation rate to be decreased to one half of deactivation rate of Pt/HY catalyst. The selectivity of Pt-Re/HY towards
isomers is lower than that of Pt/HY, while the selectivity to cracking products is higher than that of Pt/HY.
The Anodic Evolution of Oxygen on DSA Electrodes in Acid Solutions
Kim, Hyung-Sun ; Cho, Byung-Won ; Yun, Kyung-Suk ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 279~279
DSA(Dimensionally Stable Anode) electrodes for reducing oxygen overvoltage were prepared by forming
on perforated titanium plate and their anodic polarization characteristics, life time of electrodes and surface morphology of zinc electrodeposits were investigated in acid solutions. The crystal structure, surface composition and thermal property of oxides were investigated by XRD, ESCA and DTA. The
electrode formed by mixing
as stabilizer showed good in electrolysis property and stability and the depolarization effect of this electrode was about 450 mV compared with lead electrode.
Study of Uranium Ion Transport through Solid-supported Liquid Membrane
Kang, Yeong-Ho ; Lee, Kang-Il ; Park, Hyeon-Su ; Chang, In-Sun ; Kim, Chun-Yeong ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 285~285
The effects of acidity, solute and carrier concentration on the mass transfer rate were investigated in a supported liquid membrane system where uranium and amine were used as the solute and carrier, respectively. The theoretical uranium permeation rate was developed assuming that the rate determining step was to depend dominently upon the diffusivity of uranium complexes within the membrane. The maximum value of the uranium flux was obtained at pH 1.3 and 30 volume percent of amine.
Adaptive Control of Dissolved Oxygen Tension in Bio-reactor
Lee, Seung-Chul ; Hwang, Young-Bo ; Chang, Ho-Nam ; Chang, Yong-Keun ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 292~292
A new adaptive dissolved oxygen tension (DOT) control algorithm considering DO probe dynamics has been developed. The adaptive algorithm was used to compensate for time-varying properties of bioreactor dynamics. The probe dynamics are considered because the widely used membrane-type of oxygen probe has a time delay that makes it difficult to properly control the DOT. A bilinear model including two parameters was used for DOT dynamics in a bioreactor. Air flow rate and agitation speed were used as manipulating variables. The parameters were estimated using the regularized constant trace method. A one-step ahead control algorithm with resetting scheme was used to establish the control law. The new control algorithm performed better than the other control algorithms tested, PID control and adaptive control without a scheme for DO probe dynamics compensation.
Adsorption of Uranium by Hydrous Titanium(IV) Oxides
Suh, Gil-Duk ; Kim, Jang-Hyon ; Hea, Kwang-Sun ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 303~303
In order to develop an effective adsorbent for the recovery of dissolved uranium in sea water, hydrous titanium(IV) oxides were prepared by the hydrolysis of titanium(IV) alkoxides under aqueous alkaline solution. Effects of hydrolysis temperature on the adsorptive characteristics of adsorbents were investigated in terms of the physical properties of adsorbents and the mechanism of adsorption. The physical properties of hydrous titanium(IV) oxides are dependent on starting material and hydrolysis temperatures. Hydrous titanium(IV) oxide prepared by TTPO at high hydrolysis temperature was more effective for the adsorption of uranium than that prepared by either TTIPO or TTBO. The amount of uranium adsorbed on hydrous titanium(IV) oxides increased with rising hydrolysis and adsorption temperature. Adsorption equilibrium relation and heat of adsorption for uranium were correlated with Freundlich equation and endothermic process respectively. Freundlich constant(1/n), heats of adsorption and activation energy values were ranged 0.11-0.28, 1.11-7.54kcl/mol and 0.97-1.97kcal/mol respectively. The mechanism of adsorption of uranium on hydrous titanium(IV) oxides were elucidated as intraparticle diffusion controlling, an effective pore volume diffusivities were ranged of
-Amylase using Cross-Flow Ultrafiltration
Kim, Hyun-Soo ; Yoo, Young-Je ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 313~313
The effects of operating conditions on the separation efficiency of
-amylase employing cross-flow ultrafiltration unit were investigated. High transmembrane pressure and low rate gave a higher separation efficiency. Severe deactivation of the enzyme during cross-flow ultrafiltration was observed when the transmembrane pressure was high and both flow rate and the enzyme concentration were low. The permeate flow rate could be well predicted by using related model equations, especially for the feed stream of low enzyme activities.
Attrition Characteristics of Domestic Low Grade Antracite Coal in a Fluidized Bed Combustor
Park, Yeong-Seong ; Son, Jae-Ek ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 320~320
Attrition characteristics of domestic low grade anthracite coal have been studied in a bench-scale fluidized bed combustor. As operating variables, excess gas velocity(
), bed temperature, and excess air ratio were applied. Attrition characteristics such as carbon attrition rate, ratio of elutriated attrited carbon to feed carbon, as well as analysis of compositions and size distributions of coals and ashes were investigated. The experimental results show that the carbon elutriation due to attrition is in the range of 5-15% of the feed carbon, increases with the excess gas velocity, and decreases with increasing bed temperature and excess air ratio. Also, the carbon attrition rate of domestic low grade anthracite coal is shown to be greater than that of other type of coals because of the higher in-bed carbon load resulting from their lower reactivity. The following correlation has been suggested for the ratio of elutriated attrited carbon to feed carbon.
into Slurries(II) -Mass Transfer of
Gas into Laminar Falling Films of Slurries of Kaolin and White Carbon-
Park, Sang-Wook ; Kim, Sung-Soo ; Han, Sung-Bum ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 327~327
gas into laminar falling films of kaolin and white carbon slurries by using a wetted-wall column was studied theoretically and experimentally at
and 1 atm. The convective-diffusion equation was solved by separation of variables and the analytical solution for the average Sherwood number was obtained as a function of the Graetz number and the power-law index of the slurries. An approximate solution for the rate of mass transfer could be also obtained by using the Beek-Bakker model. The experimental results were in good agreement with the theoretical predictions.
A Study on the Distance between Two Adjacent Mixing Points of Packing Materials
Kang, Tae-Hyup ; Ju, Dong-Pyo ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 334~334
Distillation experiments for binary system ethylformate-acetone were carried out using a 15 cm I.D. and 135 cm height packed column under total reflux condition. Comparing experimental and calculated concentrations profiles of liquid phase, distances between two adjacent mixing points of 10.1, 15.18 and 19.40 mm ceramic Raschig rings were determined. The distance was increased according to the increasing dimension of packings and an empirical correlation between them was proposed. The experimental results also convinced of the utility of the model column which simulates the flow phenomena in an industrial packed column, proposed in previous article, for phenomenological study of mass transfer.
Preparation of Super-pure p-Xylene by using Distillative Freezing Method
Cho, Deug-Hee ; Park, Sang-Eon ; Lee, Young-Kil ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 342~342
Super-pure p-xylene was obtained from the various combinations of
aromatics by the distillative freezing method. The super-cooling effect was observed during distillative freezing operation. As the concentration of impurities in feed increased, the yield of product decreased. However, it was found that the concentration of p-xylene at feed composition was limited to get super-pure p-xylene. And adiabatic conditions during experiment should be considered as a great importance through distillative freezing operation.
A Study on Improvement of Sieve Tray Performance with Meshed Chamber
Cho, Sung-Yong ; Choi, Dae-Ki ; Lee, Youn-Yong ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 350~350
In an effort to improve the contacting performance of a sieve tray, a meshed chamber was placed on the sieve tray. Its hydraulic and mass transfer characteristics were measured and compared with those of the sieve tray without the meshed chamber. The hydraulic characteristics of a sieve tray with a meshed chamber such as dry pressure drops, total pressure drops, and clear liquid heads on the tray were compared with the sieve tray alone using the air-water system. Effective interfacial areas on the tray were determined from
absorption experiments in
buffer solution and compared with the tray with a meshed chamber.
Analysis of Thermochemical Heat Storage Phenomena in Diels-Alder Reaction using Active Isothermal Calorimeter
Park, Chan-Young ; Ryu, Min-Soo ; Lee, Kwang-Jin ; Kim, Tae-Sung ; Sohn, Eun-San ; Cho, Chong-Hyun ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 358~358
An active type isothermal calorimeter which can trace the progress of a liquid phase reversible reaction was constructed using electronic circuits and a digital computer. Heat storage capacity, heat of reaction, reaction equilibrium constant and reaction rate constants of a Diels-Alder reaction between maleic anhydride and 2-methyl furan in dioxane were estimated from the response curves of the calorimeter. The heat storage capacity of this mixture showed the maximum value of
initial concentration of maleic anhydride.
Reduced Order Models for Separation Process Simulation
Choi, Ho-Suk ; Cho, Young-Sang ;
Korean Chemical Engineering Research, volume 28, issue 3, 1990, Pages 366~366
Reduced order steady state models for separation columns are developed. The accuracy and efficiency of the reduced order models are also demonstrated by comparing the simulation results obtained by using the reduced order models with rigorous tray by tray calculations.