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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 :
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
Extended Implementation of Unified Predictive Controller in Multi-Input Chemical Processes
Yoon, Jin-Kyu ; Lee, Ik-Hyung ; Yoon, En-Sup ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 659~659
A unified predictive controller(UPC), which is the unification of various well-known predictive controllers, was extended to the multi-input multi-output(MIMO) processes. The effects of tuning parameters in the closed-loop system was studied through controlling an simple process. Based upon this study, it was found that MIMO UPC rejects disturbances more efficiently and follows the several reference trajectories as well. As a result, the unstable non-minimum process and the boiler-turbine system, which has strong interaction and nonlinearity, could be controlled efficiently by the MIMO UPC.
Effect of Functional Groups of Hetero Cyclic Compound on Adsorption with Activated Carbon
Kim, Dal-Han ; Sohn, Jin-Eon ; Lee, Sung-Sik ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 669~669
The isotherm of heterocyclic compound in aqueous solution onto activated carbon was correlated with Freundlich type equation, and Freundlich product [
] appeared linear relationship with boiling point(
). Saturated adsorbed amount(
) decreased with hammett constant(
), inductive constant(
) and polar constant(
). Surface diffusion was considered to be dominant. Relationship between surface diffusivity(
) and equilibrium adsorbed amount(
. Kinetic parameter
and a was shown Table 5 for kind and position of functional groups.
Changes in Organic Structure of Coals after Treatment with Molten Caustic Leaching
Lee, Si-Hyun ; Shon, Eung-Kwon ; Park, Suk-Whan ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 675~675
Domestic anthracite and imported bituminous coals were treated according to the molten caustic leaching procedures and changes in their organic structures were investigated. The investigation was conducted through ultimate analysis, functional group analysis using IR/NMR, and vitrinite reflectance measurements and marceral analysis with microphotometer. The results of analyses showed that the H/C ratio and the highly reactive aliphatic hydrocarbon groups linked with aromatic hydrocarbons decreased and the vitrinite reflectance increased with treatment. These are changes observed when carbonization occurs. However, the results of the observation of maceral surface showed that the surface of the organic groups was severely damaged and the anisotropy, which should increase with carbonization, decreased. The decrease in the combustion temperature and the increase in combustion reactivity were attributed to the physical changes on the surface of organic groups rather than to the chemical changes such as break down in the organic groups.
Modeling of Diffusion-Controlled Kinetics in Copolymerization I. Simplification of Copolymerization Kinetics and Calculation of Conversion
Yoo, Kee-Youn ; Hwang, Woo-Hyeon ; Back, Jong-Eun ; Rhee, Hyun-Ku ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 684~684
The pseudo-kinetic rate constant method is extended and applied to the rate equations for bulk copolymerization of styrene and acrylonitrile. We use the free volume theory to quantify the diffusion-controlled propagation and termination reactions, and also consider the effect of the chain length dependent termination reaction. The simulation results from the developed model are compared to experimental data obtained under different copolymerization conditions covering wide ranges of initial mole fraction of styrene
(0.5, 0.6 and 0.8) at two levels of AIBN(2.2'-azobisisobutyronitrile) initiator concentration(0.01 and 0.05M). It is
the present model can describe very well the experimental data under various operating conditions.
Modeling of Diffusion-Controlled Kinetics in Copolymerization II. Prediction of Copolymer Composition and Average Molecular Weights
Yoo, Kee-Youn ; Hwang, Woo-Hyeon ; Back, Jong-Eun ; Rhee, Hyun-Ku ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 693~693
In Part I of this series, a mathematical model was proposed which could describe the experimental data very well under various copolymerization conditions covering wide ranges of initial mole fraction of styrene,
, at two different levels of AIBN(2.2'-azobisisobutyronitrile) initiator concentration. In this part both the copolymer composition and the number and the weight average molecular weights of the copolymer are predicted by using the model under the various operating conditions. The presented extension of the PKRCM(pseudo-kinetic rate constant method) is proven very useful in obtaining a reliable prediction of the copolymer composition and molecular weight averages.
Design of a Fault Detection and Isolation System for a Liquid Transportation System
Kim, Tae-Han ; Hahm, Yeong-Min ; Lee, Kee-Sang ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 700~700
In this study, a fault detection and isolation system(FDIS) is constructed for the supervision of the liquid transportation system that is composed of DC-motor, centrifugal pump and pipe-lines. The FDIS consists of the residual generator, detection logic and fault isolation logic and it can be classified as the dedicated observer scheme(DOS). The system can detect the occurrence of sensor faults and identify the failed sensor. And the process faults that may occur in the components such as DC-motor, centrifugal pump and pipe-lines can be promptly detected and diagnosed with the FDIS. It may provide an effective way that will enhance the safety and the functional reliability of the fluid transportation systems.
Removal of Linear Alkylbenzene Sulfonate(LAS) and Its Intermediate, Sulfophenylalkanoates(SPA) Using a Bioreactor
Lee, In-Ku ; Kim, Ji-Hyeon ; Yoo, Young-Je ; Kim, Hwa-Yong ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 712~712
A fluidized-bed bioreactor was used to treat the industrial wastewater containing linear alkylbenzene sulfonate(LAS). Microorganism obtained by acclimation showed low growth rate and substrate inhibition at relatively high substrate concentration. It was found from the experiment using fluidized-bed bioreactor that
-thick biofilm was made after 15 days. The 93.4% LAS removal efficiency in the reactor was obtained at 120mg/L of intial LAS concentration. while the removal efficiency of sulfophenylalkanoates(SPA) which is a representative intermediate of biodegradation of LAS was 60-88% depending on the initial concentration of LAS. When sodium benzoate was added to the second reactor, the remaining SPA become lowered by 40% compared to the control experiment. And when activated carbon was added to the reactor, the removal efficiency of SPA was 96.2% and that of LAS was 100% when initial inflowing concentration of LAS was 350 mg/L.
A Study on Adsorption Equilibrium of
Mixture at Elevated Pressure
Han, Sang-Sup ; Lee, Han-Ju ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 720~720
The results of adsorption equilibria of pure gases(
) as well as their binary mixture on pelletized 5A zeolite showed strong selectivity for CO and found applicability to adsorption processes. For mixed gas adsorption isotherm, extended Langmuir model, loading ratio correlation(LRC), Dubinin-Radushkevich model, and Wilson-vacancy solution model(W-VSM) were compared, and the LRC model showed the smallest average relative deviation and temperature dependencies of its parameters could be suitably expressed by an appropriate mathematical form. Also this model, although not thermodynamically rigorous, was the most useful isotherm for the simulation of breakthrough curve and PSA process because of its mathematical simplicity, noniterative procedure for the calculation and reduction of computation time.
Scheduling of Multi-product Batch Processes with Earliness and Tardiness Penalties Using Genetic Algorithm
Lee, Chang-Hyung ; Jung, Jae-Hak ; Lee, In-Beum ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 734~734
Improving customer service and reducing inventory costs become more and more important aspects in the production scheduling of many batch processes. From this point of view, one of the important problems is to determine the optimum production sequence of a list of products or single-product campaigns so as to minimize the total penalty cost with earliness and tardiness where tardiness means any later deliveries than the due date and earliness is any early production resulting in the inventory cost. In this paper, we present a Genetic Algorithm(GA) for multi-product batch process scheduling problems with minimum cost of earliness and tardiness penalties. For this algorithm, we have improved the three basic operators, reproduction, crossover and mutation. Additionally we have developed the extended operators, so called Crowding Factor Model, Elitist Model and Generation Gap. To evaluate the performance of this study, we have tested various scheduling problems with UIS and NIS policies and the results are compared with Simulate Annealing(SA) method by Ku and Karimi. Finally the GA by this work is outperformed to SA.
Effect of Fluorination over
Catalysts on CFC-113a Hydrogenation
Kim, Kwang-Su ; Yang, Jae-Choon ; Ahn, Byung-Sung ; Shul, Yong-Gun ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 747~747
The effect of fluorination over
catalyst have been investigated in the hydrogenation of CFC-113a. Fluorinated
catalysts showed higher conversion of CFC-113a than
catalysts. Fluorination treatment, from the characterization of used catalysts by XRD, TEM and EXAFS, prevented sintering of palladium particles during reaction and some parts of palladium formed a matallic state palladium as well as fluorinated Pd(Pd-F) upon fluorination. The Pd-F bonding suggested strong interaction with support which can decrease the sintering of Pd particles during reaction. Simultaneously, it was also confirmed that
phase changed to
and the surface area decreased after fluorination process.
Studies on the Concentration Polarization Phenomena for the Plate-and-Frame Type Pervaporation Module
Won, Jang-Mook ; Ha, Baik-Hyon ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 756~756
The concentration polarization effects for the ethanol : water=95 : 5 solution were calculated theoretically in terms of the solute concentrations on the membrane wall, intrinsic separation factors and the real permeation rates by the modified Film model for the plate-and-frame type pervaporation module. In order to calculate the concentration polarization effects, the variations of channel hight, permeability, separation factor, and feed flow rate were considered. In the case of the laminar flow to the module, it would be better that the channel height is lower and the feed flow rate faster, and the operation temperature higher to decrease the concentration polarization degree. And also, in case where the separation factor is high enough, it would affect the concentration polarization phenomena. The permeability
which could be the flux of the present commercialized module, results in no effect on the concentration polarization phenomena. For the turbulent flow, the concentration polarization effects were slightly better.
Adsorption of Trihalomethane on Activated Carbon
Kim, Hyun ; Park, Heung-Chul ; Moon, Hee ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 764~764
Adsorption of Trihalomethanes(THM) on activated carbon was studied as a removal technique for THM formed during the chlorination process of drinking water. Adsorption equilibrium data of single species were represented by Freundlich equation and binary adsorption equilibria were calculated by the ideal adsorbed solution theory(IAST). Intraparticle diffusion coefficients were obtained from batch experiments. The adsorption behavior of THM in a fixed bed adsorber was satisfactorily simulated by the linear driving force approximation(LDFA) based on surface diffusion mechanism.
Selectivity of the Drying Process of Porous Materials Containing Binary Mixture
Kim, Wee-Kyong ; Kang, An-Soo ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 771~771
The concentration of the mixture changes during the drying process of porous materials containing binary mixture, when a component is removed preferentially, so called the selectivity of the drying process. The selectivity depends on the phase equilibria, gas- and liquid-side mass transfer for given drying conditions. For this reason the less volatile component can be removed preferentially during the drying of porous materials containing binary mixture with azeotrope point. The liquid-side mass transfer rate of the constant rate period differs from that of the falling rate period. The liquid-side mass transfer rate depends on the characteristic of the porous materials(size and length of the capillary). The influence of the liquid-side mass transfer on the selectivity is, therefore, very important. In this study, the distribution of the concentration and the content of the binary mixtures in the porous materials were determined to investigate the influence of the liquid-side mass transfer on the selectivity.
Mass Transfer Effects on the Anode Reaction in MCFC
Park, Gwun-Pil ; Chun, Hai-Soo ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 780~780
The effect of mass transfer on the hydrogen oxidation reaction at molten carbonate fuel cell(MCFC) anode were studied. The effects of reactant diffusion and of products diffusion on the rate of the anode reaction were studied with steady-state polarization experiment. The exchange current densities of Ni-anode, Ni-Al anode were obtained by a transient method and diffusivities of hydrogen through these anodes were measured by galvanostatic method in MCFC anode half cell. The effect of products diffusion on the rate of anode reaction was same that of reactant diffusion. It was found that the diffusivities of hydrogen and the exchange current densities of the anodes were decreased by adding aluminum into the nickel anode. It was seemed that decrease of exchange current density resulted from decrease of hydrogen diffusivity through the anode.
Equilibrium and Kinetics of Copper Extraction by 5-methyl-3-one-hexanal
Shin, Jeong-Ho ; Jeong, Kap-Seop ; Lee, Sang-Hoon ; Lee, Ju-Young ;
Korean Chemical Engineering Research, volume 33, issue 6, 1995, Pages 787~787
To investigate the extraction characteristics of equilibrium and kinetics in the extraction of copper by ketoaldehyde-chloroform, 5-methyl-3-one-hexanal was synthesized as a chelating extractant of ketoaldehyde from ethyl formate and methylisobutylketone with sodium amide. The equilibrium constants such as the dissociation constant and the partition coefficients of ketoaldehyde, the stability constant and the partition coefficient of copper complex, and the overall equilibrium constant in the extraction of copper were determined. The effects of the concentration of hydrogen and copper ion, and of ketoaldehyde on the initial rate of extraction were examined. Percent extraction of copper by ketoaldehyde was higher than 90%, and selective extraction of copper from Zn-Cu-Cd mixture was possible. The equilibrium reaction was found to be
with the extracted species of
. The experimental equation of extraction rate was ex-pressed as