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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 42, Issue 6 - Dec 2004
Volume 42, Issue 5 - Oct 2004
Volume 42, Issue 4 - Aug 2004
Volume 42, Issue 3 - Jun 2004
Volume 42, Issue 2 - Apr 2004
Volume 42, Issue 1 - Feb 2004
Selecting the target year
Hydrogen & Fuel Cell Technology
Son, Jae-Ek ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 1~9
Among various technologies using hydrogen-energy, fuel cells have been considered as the most energy efficient technology. A conventional combustion-based power plant typically generates electricity at efficiencies of 33 to 35 percent, while fuel cell plants can generate electricity at efficiencies of up to 60 percent. When fuel cells are used to generate electricity and heat (co-generation), they can reach efficiencies of up to 85 percent. Moreover, fuel cells generate virtually zero pollution including greenhouse gases such as
. Therefore, the fuel cells are believed as a most promising alternative power producing technology, which can solve global problems facing 21st century such as exhaustion of fossil fuels and environmental pollution at the same time. In this review, recent trends in fuel cell R&D are summarized focusing on PEMFC and DMFC which are closest to the practical use and can be used for batteries, electrical power sources for automobiles and immobile structures such as buildings.
Effects of Reaction Conditions on the Synthesis of
Park, Jung-Hoon ; Park, Sang-Do ; Nam, Sung-Chan ; Lee, Hae-Jeang ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 10~19
fine powder was prepared by hydrothermal synthesis with various precursor materials selected in view of yield and reactivity. The effect of reaction temperature, time and raw material was investigated in the above process. While
were used as starting material, it was not possilbe to prepare
without mineralizer, however the same can be synthesized at
without mineralizer using
. The synthesis of
was favored by higher pH of the reaction solution and conversion was found dependent on the reaction temperature instead of time. Experimental data suggested that
seemed to be synthesized hydrothermally through reaction pathway that included dissolution of hydrous titania by nucleophilic attack of
group in aqueous medium, nucleation by dehydration between Ba ion and titanium complex dissolved and the growth of nuclei.
A Continuous Denitration Process Combining Chemical and Electrolytic Systems for the Destruction of High Concentration of Nitric Acid (I)
Kim, Kwang-Wook ; Kim, Soo-Ho ; Lee, Eil-Hee ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 20~25
This work has improved the conventional batch denitration by formic acid which has been used for controlling the acidity of solution for the solvent extractions to partition the long lived-radionuclides from the high level radioactive liquid waste. The characteristics of destructions of nitric acid and formic acid and their destructive products in a continuous denitration process combining a continuous denitration system by formic acid and an electrolytic residual acid-trimming system suggested in this work was evaluated. The continuous denitration by formic acid reached a steady state in 30 minutes and showed the dependence of the final acidity on the residence time of feeding solution into the reactor. Also the system had the lowest final acidity at a mole ratio of formic acid to nitric acid of 1.5 like the batch denitration. In a
electrolytic cell, the destructive rates of formic acid and nitric acid were
, respectively. The nitric acid and the formic acid were destructed through the reduction at the Ti cathode and the oxidation at the
anode, respectively. The newly suggested continuous denitration process combining the denitation by formic acid and residual acid-electrolytic treatment could control continuously a feeding nitric acid of 2.0 M to below about 0.1 M.
Characteristics of a Continuous Denitration Process Combining Chemical and Electrolytic Systems with Accompanying the Precipitation of Metal ions
Kim, Kwang-Wook ; Kim, Soo-Ho ; Lee, Eil-Hee ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 26~32
This work has studied the characteristics of destruction of nitric acid and precipitation of several metal ions in a continuous denitration process combining a denitration by formic acid and a residual acid-electrolytic trimming system. The process could treat continuously and effectively a feeding nitric acid of 2.0 M to below about 0.1 M. The metal ions of Zr, Mo, Fe, and Nd did not affect the electrodes at the step of electrolytic trimming of the residual acid after denitration by formic acid. The Mo ion in electrolytic solution enhanced the generation of nitrite ion during the electrolytic reaction. The mole ratio of formic acid to nitric acid fed into the continuous denitration reactor using formic acid affected much the final acidity, the precipitation yields of metal ions, the precipitate morphology. At the ratio of 1.65, the process had the lowest final acidity of less than 0.1 M, and the precipitation yields of Zr and Mo reached 95% and 83%, respectively as the highest values. Only the precipitate generated in the mole ratio of formic acid to nitric acid between 1.5 and 1.7 had a needle-shaped morphology, otherwise it was granular-shaped.
Cyclotrimerization of Acetylene on Pd/titania Catalyst
Jung, Yong-Hwa ; Lee, Tae-Jin ; Kim, Ki-Seok ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 33~37
Cyclotrimerization of acetylene was studied by means of atmospheric flow reaction at 373 K on Pd/titania catalyst to investigate variations of catalytic reactivity and product distribution. While ethylene and benzene were obtained as the major products, rapid decrease in acetylene conversion resulted from catalyst poisoning with the lapse of reaction time. For a fixed flow rate (space velocity
), as acetylene concentrations decreased from 50 to 25, to 12.5 vol%, benzene yields decreased, whereas catalyst poisoning was attenuated. Comparison of benzene evolution signals from the variation of acetylene concentrations showed that the rate of benzene formation is first-order in acetylene pressure. In addition, for a fixed concentration (25 vol%) of acetylene, as space velocity increased from 4,000 to
, benzene yields also increased and catalyst poisoning was attenuated. Optimization of acetylene concentration and flow rate may be necessary to accomplish the attenuation of catalyst poisoning as well as enhancement of benzene yield from acetylene cyclotrimerization by flow reaction. It can be deduced from this study that oxygen anion vacancies at palladium-titania interface and reduced titania made contributions toward catalytic activity for benzene formation at the temperature 100 K lower than those reported by previous researchers.
Catalyst and Evaluation of its Reactivity for the Removal of
Kim, Young-Joo ; Hwang, Un-Yeon ; Koo, Kee-Kahb ; Kim, Yong-Ryul ; Park, Jong-Soo ; Yoon, Wang-Lai ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 38~43
Various ruthenium(Ru) based catalysts, which were less expensive than Pt-Pd based catalysts, were prepared and their activity with
(Halogenated Volatile Organic Compounds) was evaluated.
was found to have the most desirable effect on the destruction of HVOCs. Tin taken as a structural promoter was found to increase the amount of oxygen adsorption and to generate various oxygen ions. Oxygen atoms were found to be mainly adsorbed on the surface of ruthenium and tin and HVOCs such as
to be adsorbed on Bronsted and Lewis acid sites of
supports. It was found that the formation of HCl by the reaction of chlorine in HVOCs with hydrogen atom on Bronsted acid site was the main reaction mechanism in the destruction of HVOCs.
Dimethyl Ether Production using a Reactive Distillation Process
Koo, Young-Hwa ; Han, Myung-Wan ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 44~52
In this study, we propose a reactive distillation process for production of dimethyl ether (DME). The conventional process for the production of DME consists of one reactor and two distillation columns. The reaction-distillation hybrid process for the production of DME  is an interlinked system between one reactor and one distillation column. The newly proposed process for the production of DME is a reactive distillation column in which the reaction and separation occurs simultaneously and the reaction takes place on liquid phase only. This characteristics of the reactive distillation process bring about great benefits. Comparison between these three processes shows a great advantage of the proposed one over the other two processes in the reduction of energy and capital cost. We examine and analyze the effect of design and operation variables on the performance of the proposed process and provide design guides for the process.
A Methanolysis Process for Recycling Polyester Oligomer Waste
Kim, Seung-Kyom ; Han, Myung-Wan ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 53~58
Oligomer sludges generated from polyester production line as polyester waste can be recycled to its constituent monomers, that is, dimethyl terephthalate (DMT) and ethylene glycol by methanolysis. We examined the effects of methanol feeding rate, methanol purity, reaction pressure, reaction temperature, and amount of catalyst on DMT production yield in the proposed continuous methanolysis reactor. DMT production yield increases with methanol feeding rate and shows a maximum at reaction temperature
and reaction pressure 3-6 atm.
Permeation Flux of Surface-modified Hydrophilic Polysulfone Membrane
Song, Kun-Ho ; Kim, Kang-Hee ; Cho, Seong-Heon ; Lee, Kwang-Rae ; Lim, Jong-Ho ; Bae, Sung-Su ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 59~64
A hollow-fiber type polysulfone UF membrane was surface-coated with 2-hydroxyethylmethacrylate(HEMA). The effect of various coating parameters on permeation flux was investigated, such as concentration ratio of Azobisisobutyronitrile(AIBN)/HEMA, solvent (water or methanol), and UV irradiation time. The membrane coated with a solution of AIBN/HEMA/methanol showed about 2.65 times higher water flux than that coated with a solution of AIBN/HEMA/water. The membrane coated with a solution of higher AIBN/HEMA ratio and a longer UV irradiation time exhibited a higher permeation flux. The membrane coated with a solution of lower AIBN/HEMA ratio needed a longer UV irradiation time for coating to get a same level of permeation flux. In order to have a greater permeation flux than uncoated membrane, the membrane should be coated with a solution of a certain AIBN/HEMA ratio and UV irradiation time. The fouling by oil emulsion occurred to both of the coated and the uncoated membrane. However, the fouling of coated membrane was much less than uncoated one; the water flux ($0.2683\;g/cm^2\;min$) through the uncoated membrane.
Measurement of Dimensionless Henry's Law Constants of some Aromatic Compounds using a Headspace Sampler with a Gas Chromatography
Park, Soo-Jin ; Lim, Hwa-Yun ; Park, So-Jin ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 65~69
Dimensionless Henry's law constants of aromatic compounds in water were measured at various temperatures between 318.15-355.15 K using a headspace autosampler with a gas chromatography. This measuring system prevent, sample losses due to volatilization from equilibration, sampling, and chemical concentration analysis by a high precision headspace sampler and gives relatively accurate results. Dimensionless Henry's law constant is calculated by thermodynamic relation and the mass balance with gas chromatographic peak area. Different equilibrium concentration in gas phase was made by using different gas-liquid volume ratio in sample vial. The temperature dependence of dimensionless Henry's law constant was correlated with the classical van't Hoff equation as a function of temperature. The extrapolated data at 298.15 K from correlated equation were compared with available literature data in order to test this method.
Synthesis of Aluminium/Titanium Oxide by a Sol-Gel Method and Adsorption Characteristics of Pb(II) in Aqueous Solutions
Hong, Sung-Chul ; Chung, Jay-Gwan ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 70~77
Aluminium/titanium oxide was synthesized by a sol-gel method at pH 6 using TTIP (titanium tetra-isopropoxide) and AIP (aluminium isopropoxide). Adsorption characteristics and overall adsorption rate of Pb(II) on synthesized oxide particles were determined in aqueous solutions. The dispersion property of aluminium/titanium oxide, whose mole ratio of TTIP:AIP was 1:1, was better than those whose mole ratios of TTIP:AIP was 2:1, 3:1, and 4:1, respectively. The adsorption amount of Pb(II) on oxide particles, of which mole ratio of TTIP:AIP was 1:1, was better by about 10-20% than those, too. The adsorptivity at calcination temperature of
was higher than those at 300 and
, respectively, in oxide particles of which mole ratio of TTIP:AIP was 1:1. The adsorption amount increased rapidly from pH 2 to 6 and decreased over pH 6, where the adsorption amount was maximum at pH 6. Correlation coefficients(
) of Langmuir and Freundlich adsorption isotherms were 90.6% and 91.4%, respectively. The overall adsorption rate was determined by a differential bed reactor at 200 ml/min.
Synthesis of Silver Nanoparticles by Chemical Reduction Method
Seo, Won-Sik ; Kim, Tae-Hwan ; Sung, Jae-Suk ; Song, Ki-Chang ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 78~83
Silver powders were prepared by chemical reduction method using reductants in
aqueous solutions. The effect of the type of reductants (
) was investigated on the properties of the obtained powders. In addition, the effect of the addition of a surfactant (Tween20) during particle synthesis was studied. The Ag powders prepared using the sodium borohydride as a reductant were found to be
in particle diameter, while those using the hydrazine showed
in particle diameter. The mean particle size of Ag nanopowders, prepared by the addition of Tween20 as a surfactant, was 50 nm, which is smaller than
powders formed without the surfactant.
Analysis of Pressure Fluctuation Signals in Bubble Column by Wavelet Transform
Park, Soung-Hee ; Kim, Sang-Done ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 84~88
Pressure fluctuations experiments were carried out in a bubble column with a moderately large column of 0.376 m ID at different flow regimes such as bubbly and churn-turbulent flow regime. The recently developed technique of wavelet transform based on localized wavelet functions is applicable to analysis of the fluctuating signals. The time series of pressure fluctuation signals have been analyzed by means of coefficients of discrete wavelet transform, wavelet decomposition and time scale representation. By resorting to this technique, the objects in bubbly flow regime have fine scales than ones in churn-turbulent flow regime. Thus, this wavelet transform method enables us to obtain the scale content of local complex flow behaviors in a bubble column.
Preparation of PU-g-PAAc Foams through One Atmospheric Pressure Plasma Treatment
Yeom, Young-Ho ; Myung, Sung-Woon ; Choi, Ho-Suk ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 89~95
We successfully modified the surface of PU (Polyurethane) foam (10 PPI) through atmospheric pressure plasma treatment and subsequent grafting of AAc (acrylic acid). The plasma treatment can generate large amount of peroxides on the surface of PU foam and the peroxide groups act as initiators for further grafting of AAc in the monomer solution. To introduce large amount of peroxides on the surface of PU foam, we studied the effect of plasma rf-power and treatment time on the maximum grafting of AAc. Through this study, we found that the optimum rf-power was 100 W and the optimum treatment time was 100 sec. On the other hand, we also studied the effect of graft reaction conditions such as temperature, monomer concentration and reaction time on the change of grafting degree (GD). The GD increased with temperature and increased with reaction time before it leveled off at 3 hr after reaction. At low concentration of AAc, the GD was very low but it showed the maximum at the monomer concentration between 60% and 70%. The surface of the modified PU foam was qualitatively and quantitatively analyzed with FT-IR and by weight measurement, respectively. We also observed the surface change before and after plasma induced graft co-polymerization through photo and SEM analysis. Finally, we confirmed the immobilization of Lysozyme through the electrophoresis analysis of proteins, which were recovered by the PU-g-PAAc foam from egg white.
Preparation of Alumina Sol for Nanoporous Alumina Membrane by Sol-Gel Method
Park, Ja-Lyong ; Kim, Tae-Hwan ; Sung, Jae-Suk ; Song, Ki-Chang ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 96~101
Alumina (boehmite) sol was prepared by the sol-gel method from aluminum isopropoxide (AIP) through hydrolysis and peptization processes. Powders were obtained by drying the sol in drying oven, and the powder properties, such as crystalline phase composition and pore structure, were studied as a function of heat-treatment temperatures. The powders showed boehmite phase at
, and transformed to
. The powders, heat-treated at
after being peptized at HCl/AIP=0.10, had 4 nm in average pore diameter. The average pore diameter of the powders decreased with increasing HCl concentrations added during peptization process, but increased with increasing heat-treatment temperatures.
Crack Resistance Properties of Anodized Carbon Fibers/Epoxy Matrix Composites
Park, Soo-Jin ; Oh, Jin-Seok ; Suh, Dong-Hack ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 102~106
Anodic oxidation on the surfaces of carbon fibers was carried out to enhance the mechanical interfacial properties of carbon fibers-reinforced epoxy matrix composites. And the surface characteristics of untreated and treated carbon fibers were studied by FT-IR, XPS, and contact angle measurements after modifications. Crack resistance of the composites was investigated using by two types of testing method, namely critical energy release rate mode I(
) and mode II(
ratio of the carbon fibers was increased after anodic treatment, due to the introductions of the oxygen-containing functional groups, or the specific components of surface free energy of the carbon fibers. It was found that the mechanical properties at interfaces, including
of the composites had been improved by the oxidation, which could probably be attributed to the increase of the degree of adhesion at interfaces between fibers and resin matrix in the composite system.
Reaction Characteristics of Ni and NiO Based Oxygen Carrier Particles for Chemical-Looping Combustor
Ryu, Ho-Jung ; Bae, Dal-Hee ; Jo, Sung-Ho ; Jin, Gyoung-Tae ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 107~114
To find a suitable oxygen carrier particle for chemical-looping combustor, four kinds of particles (NiO 26, 44, 58, 78 wt%) were prepared and the reactivity of the reduction was measured and investigated by a thermo-gravimetrical analyzer. From the viewpoint of oxygen transfer capacity and reaction rate, the particle containing 60 wt% of NiO showed better performance than the other particles. Also, we have prepared two kinds of oxygen carrier particles to investigate the effect of the starting material for a metal oxide component (i.e., Ni based and NiO based particles, where the weight percents of both samples were set at 60 wt% as NiO). The reaction rate, regenerative ability, duration of the reduction, and
selectivity were measured and investigated by a thermo-gravimetrical analyzer and a fixed bed reactor. The results obtained here indicated that the NiO based oxygen carrier particle containing 60 wt% of NiO showed better regenerative ability, reaction rate,
selectivity, and duration of the reduction, compared with the other particles, therefore we selected this particle as an optimum oxygen carrier particle.
An Experimental Study for Hydrate Dissociation Phenomena and Gas Flowing Analysis by Electric Heating Method in Porous Rocks
Sung, Won-Mo ; Lee, Ho-Seob ; Yang, Ho-Joon ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 115~120
In this study, an experimental apparatus has been designed and set-up to analyze the dissociating phenomena of hydrate in porous rock using electric heating method supplied at down hole. The electric heat injecting experiments have been performed to investigate the heat transfer within the core, the dissociating phenomena of hydrate, and the productivities of dissociated gas and water. These experiments were under constant heat injecting method as well as preheating methods. From the experimental results, it is seen that dissociation of hydrate is accelerated with heat. The injected heat is consumed for the dissociation and also it is lost together with outflow of the dissociated gas and water. From the investigation of gas producing behavior for various heat injecting methods, as the injected heat is greater, dissociation is accelerated faster at outlet and hence the initial gas production becomes higher. Also, it is shown that the initial gas productivity under the constant heating method is better, however, the heat is low because of smaller amount of the produced gas comparing to the amount of heat injected. In the experiments of preheating method, it was seen that gas production only initial stage is different with the preheating time, but the producing behaviors of gas production are similar.
A Lexicographic Search Algorithm for Synthesis of Four Reaction Clusters for Water Decomposition
Choi, Soo-Hyoung ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 121~123
Most of the studies on water decomposition currently deal with clusters composed of three or less reactions, but four or five reaction clusters are also being experimented. A method is proposed in this paper, which expands the previously proposed lexicographic search algorithm so that clusters composed of four reactions can be sought in spite of combinatorial explosion. As a case study, this method is applied to a set of thermodynamically feasible reactions, and shows that it can generate a lot of candidate clusters that are feasible at relatively low temperatures. If the proposed search algorithm is applied to a set of reactions whose operability is confirmed, it is expected to be able to synthesize efficient reaction clusters for water decomposition.
Comparative Study on the Performance of Saturated Vapor Density Correlations for Pure Substances
Park, Kyoung-Kuhn ;
Korean Chemical Engineering Research, volume 42, issue 1, 2004, Pages 124~127
A saturated vapor density correlation, which relates logarithmic density to the inverse of temperature, is used to fit the saturated vapor density data for 41 pure substances. The equation with 4 terms in it yields an average AAD of 0.12%, which compares with 0.27% of 5-term conventional equation, so that the performance is improved while the number of terms is reduced. The equation used in this study is valid over the entire temperature range from critical point to triple point or the lowest temperature where data points exist.