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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Korean Chemical Engineering Research
Journal Basic Information
Journal DOI :
The Korean Institute of Chemical Engineers
Editor in Chief :
Volume & Issues
Volume 50, Issue 6 - Dec 2012
Volume 50, Issue 5 - Oct 2012
Volume 50, Issue 4 - Aug 2012
Volume 50, Issue 3 - Jun 2012
Volume 50, Issue 2 - Apr 2012
Volume 50, Issue 1 - Feb 2012
Selecting the target year
Separation Processes of Biologically Produced 1,3-Propanediol
Hong, Yeon-Ki ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 759~765
DOI : 10.9713/kcer.2012.50.5.759
As the biodiesel production is increasing rapidly, the crude glycerol, which is principal by-product of biodiesel production, has also been generated in a large amount. Many research studies on value-added utilization of glycerol are under investigation. 1,3-Propandiol is a promising chemical which can be produced from fermentation of glycerol because the application of 1,3-propanediol is mainly in the production of bio-PTT (Poly(trimethylene terephthalate). However, the cost of downstream processes in the biological production of 1,3-propanediol can make a high portion in the total production cost. This review summarizes the present state of separation processes in each step studied for the removal of impurities and the recovery of 1,3-propanediol from its fermentation broth. Furthermore, ATPE (Aqueous Two Phases Extraction) process is suggested as an attractive alternative for the primary separation process of 1,3-propanediol because ATPE is convenient for the simultaneous removal of microbial cells and impurities such as salts of organic acids and the separation of 1,3-propanediol from fermentation broth.
Reaction Kinetics for the Synthesis of Diphenyl Carbonate from Dimethyl Carbonate
Choi, Yu-Mi ; Cho, Im-Pyo ; Cho, Hoon ; Lee, Jin-Hong ; Han, Myung-Wan ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 766~771
DOI : 10.9713/kcer.2012.50.5.766
PC (polycarbonate) is one of the widely used engineering plastics. Polycarbonate (PC) is traditionally produced by the reaction of phosgene and bisphenol-A. This phosgene process has the disadvantage as the high toxicity and corrosiveness of phosgene. The main point of focus to overcome the disadvantage of phosgene based process has been a route through dimethyl carbonate (DMC) to diphenyl carbonate (DPC). In this paper, for the DPC synthesis reaction using PBO as a catalyst, the effect of reaction temperature, reactant ratio, catalyst concentration on the reaction yield was investigated. A kinetic model for the DPC synthesis reaction was proposed and kinetic parameters for the proposed model was determined from batch reactor experiments. The predicted results by the proposed model were in good agreement with the experimental results.
Effects of Calcium on the Activity of V
Catalysts in SCR Processes
Kim, Jin-Kil ; Park, Kwang-Hee ; Hong, Sung-Chang ; Lee, Eui-Dong ; Kang, Yong ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 772~777
DOI : 10.9713/kcer.2012.50.5.772
Factors acting on the deactivation of
catalysts were investigated in the selective catalytic reduction(SCR) process for long term operation. The activity of
catalysts was decreased rapidly after 8 months from the starting of operation in the selective catalytic reaction processes. From ICP-AES analysis, the deactivation of the used catalysts could be caused from the calcium component included in urea solution as a reducing agent. It was found from the
-TPD experiments that the strong basic element like Ca component drastically affected the acidity of the
catalyst. The results gave an explanation on the reason why the component of Ca, even though its concentration is very low, could lead to the deactivation of
catalyst in the selective catalytic reaction processes.
Degradation Accelerated Stress Test of Electrode and Membrane in PEMFC
Song, Jin-Hoon ; Kim, Sae-Hoon ; Ahn, Byung-Ki ; Ko, Jai-Joon ; Park, Kwon-Pil ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 778~782
DOI : 10.9713/kcer.2012.50.5.778
Until a recent day, degradation of PEMFC MEA (membrane and electrode assembly) has been studied, separated with membrane degradation and electrode degradation, respectively. But membrane and electrode were degraded coincidentally at real PEMFC operation condition. Therefore in this work, AST (Accelerated Stress Test) of MEA degradation was done at the condition that membrane and electrode were degraded simultaneously. There was interaction between membrane degradation and electrode degradation. Membrane degradation reduced the decrease range of catalyst active area by electrode degradation. Electrode degradation reduces increase range of the hydrogen crossover current and FER (Fluoride Emission Rate) by membrane degradation.
The Effect of Additives on the Mechanical Properties of Rigid Polyurethane
Na, Seok-En ; Choi, Hwan-Oh ; Lee, Jeon-Kyu ; Kim, Si-Young ; Ju, Chang-Sik ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 783~788
DOI : 10.9713/kcer.2012.50.5.783
Stern tube bearing is a shaft device playing important roles to reduce the friction of axial rotation and to support the weight of shaft. However, because there is no domestic producer of stern tube bering, imported stern tube bearings have many practical problems including prices, delivery and after services. This is why stern tube bearing should be localization. For the purpose of development of polyurethane resin for stern tube bearings, the effect of additives on the hardness, tensile strength and elongation of the polyurethane resin were systematically investigated. For the preliminary researches, depending on the type of curing agent, MOCA type and non-MOCA type polyurethanes were synthesized. Preliminary researches concluded that MOCA type polyurethane resin has more excellent mechanical properties than non-MPCA type for stern tube bearings that Tensile strength and Hardness of non-MOCA type investigated 23 D, 4.3 Mpa. Therefore, MOCA type polyurethane was adapted as base resin of this research. Silica, calcium carbonate and graphite were selected as additives for the enhancement of mechanical properties of polyurethane resin. Effect of the type and the dosage of these additives on the hardness, tensile strength, elongation of the polyurethane resin were experimentally examined. However, addition of calcium carbonate and graphite showed only minor effect on the hardness of the resin. Polyurethane resin with silica showed relatively excellent hardness, tensile strength and improved elongation.
Preparation and Application Characteristics of Carboxylated Styrene Butadiene Latex for Polymer Cement Mortar
Lee, Bong-Kyu ; Ju, Chang-Sik ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 789~794
DOI : 10.9713/kcer.2012.50.5.789
For the purpose of development of the latex suitable for polymer cement mortar, experiments on the preparation of carboxylated styrene butadiene latex by the method of the two-step emulsion polymerization were performed. Methyl methacrylate, methacrylic acid and acrylic acid were selected as carboxylic co-monomer, styrene and butadiene as monomer, sodium dodecylbenzene sulfonate and sodium salt of lauryl sulfonate as anionic emulsifiers, and nonylphenoxy poly (ethyleneoxy) ethanol (n=10, 20, 40) as latex stabilizer. Potassium persulfate and sodium bisulfite were also used as redox initiator, and sodium monohydrogen phosphate and potassium carbonate as electrolytes. The effects of categories and concentration of carboxylic co-monomer, molecular weight control agent, crosslinking agent, and styrene/butadiene monomer ratio on the characteristics of latex were investigated. Polymerization recipes for preparation of polymer cement mortar could be proposed. The prepared latexes were tested for the physical properties such as compressive and flexural strength when latexes were mixed with cement mortar. The results showed that the latex could be adapted to polymer cement mortar. Also, it was recognized that the compressive and flexural strength were exhibited 25.4% and 45.3% respectively higher improvement than the quality standards at 28 days curing time.
Synthesis of Dodecanethiol-Capped Nanoparticles Using Ionic Liquids
Lee, Young-Eun ; Lee, Seong-Yun ; You, Seong-Sik ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 795~801
DOI : 10.9713/kcer.2012.50.5.795
Nanoparticles have received significant attention because of their unusual characteristics including high surface area to volume ratios. Thiol ligand have been used as stabilizers of metal nanoparticles since Brust et al. They reported the preparation method of ligand capped metal nanoparticles by protecting the nanoparticles with a self-assembled monolayer of dodecanethiolate. In this method, volatile organic compounds (VOCs) were used as sovents. This study was carried out to replace these VOCs with room temperature ionic liquids (RTILs). We used two type of ILs to prepare metal nanoparticles. One is a hydrophobic IL, [BMIM][[
] (1-Butyl-3-methylimidazolium hexafluorophosphate) purchased from IL maker, C-Tri from Korea and the other one is a hydrophilic one, [BMIM][Cl] (1-Buthy-3-methylimdazolium chloride) sinthesized by us. In the case of preparing Ag and Au nanoparticles using [BMIM][Cl], we didn't use phase transition reagents and ethanol because it has hydrophilic property and preparing Au, Ag nanoparticles using [BMIM][[
] the method is as same as Brust et al.'s except using [BMIM][[
] instead of organic solvent because it has hydrophobic property. FT-IR and UV-vis, TEM, TGA analysis have been used in an attempt to determine the particle size and verify functional groups. The particle size obtained from TEM was very similar to those obtained by Brust et al. This is a clear example of ligand capped metal nanoparticles prepared using ionic liquids. And the experimental result demonstrated ionic liquids can act as a highly effective medium for the preparation and stabilization of gold and silver metal nanoparticles.
Autothermal Reforming Reaction at Fuel Process Systems of 1Nm
Koo, Jeong-Boon ; Sin, Jang-Sik ; Yang, Jeong-Min ; Lee, Jong-Dae ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 802~807
DOI : 10.9713/kcer.2012.50.5.802
The autothermal reforming of methane to syngas has been carried out in a reactor charged with both a Ni (15 wt%)-Ru (1 wt%)/
-MgO metallic monolith catalyst and an electrically-heated convertor (EHC). The standalone type reactor has a start-up time of less than 2 min with the reactant gas of
fed to the autothermal reactor. The
ratio governed the methane conversion and temperature profile of reactor. The reactor temperature increased as the reaction shifted from endothermic to exothermic reaction with decreasing
ratio. Also the amount of
in the products increases with increasing
ratio due to water gas shift reaction. The 97% of
conversion was obtained and the reactor temperature was maintained
at the condition of
and feed ratio (
). In this condition, the maximum flow rate of the syngas generated from the reactor charged with 170 cc of the metallic monolith catalyst is
Preparation of Zinc Oxide by Hydrothermal Precipitation Method and their Photocatalytic Characterization
Jeong, Sang-Gu ; Na, Seok-Eun ; Kim, Si-Young ; Ju, Chang-Sik ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 808~814
DOI : 10.9713/kcer.2012.50.5.808
Photocatalytic zinc oxide powders were prepared from precursor zinc acetate and ammonia solution at elevated temperature,
, by hydrothermal precipitation method. The effect of operating parameters, pH of ammonia solution and concentration of zinc acetate solution, on the characteristics of zinc oxide powders were experimentally examined. Zinc oxide powders prepared at the conditions of pH 11, zinc acetate concentration of 1.0 M, precipitation temperature of
, showed smallest average particle diameter of
. SEM and XRD analysis confirmed that prepared zinc oxide has hexagonal rods structure, and Anatase type crystallinity. In addition, DRS and PL analysis showed that the zinc oxide has activity at the range of 200~400 nm of UV light. And the zinc oxide decomposed 57% of a food-color stamp Brilliant blue FCF for 3 hours under the UV radiation.
Profile Position Control of Extractive Thermally Coupled Distillation System
Cho, Hoon ; Choi, Yu-Mi ; Lee, Jin-Hong ; Cho, Im-Pyo ; Han, Myung-Wan ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 815~824
DOI : 10.9713/kcer.2012.50.5.815
Extractive distillation system can be used when the components to be separated have close boiling points or form azeotropes. Extractive distillation is one of the most important and widely used separation methods in chemical process industry. The main disadvantage of the distillation is its high-energy requirements. Thermally coupled distillation system (TCDS) can provide significant savings in energy consumption and capital cost over the operation of sequences based on conventional distillation column. Despite such advantages of the thermally coupled distillation system, the process is not widely used in industry because control and operation of the column are difficult. In this study, we propose several control schemes for thermally coupled distillation system to overcome the difficulties and make the column stable when the process is confronted with feed disturbances. Profile position control scheme shows best control performance among the proposed control schemes.
A Study on the NOx Reduction of Flue Gas Using Un-divided Electrolysis of Seawater
Kim, Tae-Woo ; Choi, Su-Jin ; Kim, Jong-Hwa ; Song, Ju-Yeong ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 825~829
DOI : 10.9713/kcer.2012.50.5.825
In this study, we investigated NO oxidation characteristic that depends on available chlorine concentration and temperature of seawater which is treated by un-divided electrolysis. Reactant gas passed through bubbling reactors which is filled with electrolyzed water and then NO concentration change was analyzed. In the closed-loop electrolysis system, concentration of available chlorine increased with electrolysis time. The higher oxidation rate of NO to
was obtained with the higher concentration of available chlorine. Oxidation of NO was fast when temperature of electrolyzed water was high, in the case of same concentration of available chlorine.
New Approach Using the Continued Fraction Expansion for the Dead Time Approximation
Cho, Won-Hui ; Lee, Jie-Tae ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 830~836
DOI : 10.9713/kcer.2012.50.5.830
Dead times appear often in describing process dynamics and raise some difficulties in simulating process dynamics or analyzing process control systems. To relieve these difficulties, it is needed to approximate the infinite dimensional dead time by the finite dimensional transfer function and, for this, the Pade approximation method is often used. For the accurate approximation of the dead time, high order Pade approximation is needed and the high order Pade approximation is not easy to memorize and is not stable numerically. We propose a method based on the continued fraction expansion that provides the same transfer functions. The method is excellent numerically as well as systematic to be memorized easily. It can be used conveniently for the process control lecture and computations.
Combustion Study of 1MWe Circulating Fluidized Boiler for RDF
Shun, Do-Won ; Bae, Dal-Hea ; Jo, Sung-Ho ; Lee, Seung-Yong ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 837~842
DOI : 10.9713/kcer.2012.50.5.837
A pilot scale circulating fluidized boiler (CFB) for refuse derived fuel (RDF) is designed and constructed to demonstrate a performance of CFB technology for waste fuel utilization. The boiler has a design capacity of 6 MWth with
38 ata steam generation performance. The maximum steam rate of the boiler was about 8 ton/h. The main component of the fuel was RDF (Refuse Derived Fuel) with high volatile contents and showed fast ignition and easy combustion. The pilot plant showed over 99.5% of combustion efficiency. Stable operation of RDF CFBC depended on the content of non combustion materials other than ash and fast removal of them. Emission level was under legal limit except that of HCl without external flue gas treatment facilities. Also about 60% of fuel chlorine was absorbed to fly ash particles. For HCl emission control flue gas treatment technology is required such as wet and dry scrubber in order to comply with Korean regulation.
Method for Improvement of Reduction Reactivity at High Temperature in a Chemical-Looping Combustor
Ryu, Ho-Jung ; Park, Sang-Soo ; Lee, Dong-Ho ; Choi, Won-Kil ; Rhee, Young-Woo ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 843~849
DOI : 10.9713/kcer.2012.50.5.843
When we use NiO based particle as an oxygen carrier in a chemical looping combustion system, the fuel conversion and the
selectivity decreased with increasing reaction temperature within high temperature range (>
) due to the increment of exhaust CO concentration from reduction reactor. To improve reduction reactivity at high temperature, the applicable metal oxide component was selected by calculation of the equilibrium CO concentration of metal oxide components. After that, feasibility of reduction reactivity improvement at high temperature was checked by using solid mixture of the selected metal oxide particle and NiO based oxygen carrier. The reactivity was measured and investigated using batch type fluidized bed. The solid mixture of
(10%) and OCN706-1100(90%) showed higher fuel conversion, higher
selectivity and lower CO concentration than OCN706-1100(100%) cases. Consequently, we could conclude that improvement of reduction reactivity at high temperature range by adding some
based oxygen carrier was feasible.
A Devolatilization Model of Woody Biomass Particle in a Fluidized Bed Reactor
Kim, Kwang-Su ; Leckner, Bo ; Lee, Jeong-Woo ; Lee, Uen-Do ; Choi, Young-Tai ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 850~859
DOI : 10.9713/kcer.2012.50.5.850
Devolatilization is an important mechanism in the gasification and pyrolysis of woody biomass, and has to be accordingly considered in designing a gasifier. In order to describe the devolatilization process of wood particle, there have been proposed a number of empirical correlations based on experimental data. However, the correlations are limited to apply for various reaction conditions due to the complex nature of wood devolatilization. In this study, a simple model was developed for predicting the devolatilization of a wood particle in a fluidized bed reactor. The model considered the drying, shrinkage and heat generation of intra-particle for a spherical biomass. The influence of various parameters such as size, initial moisture content, heat transfer coefficient, kinetic model and temperature, was investigated. The devolatilization time linearly increased with increasing initial moisture content and size of a wood particle, whereas decreases with reaction temperature. There is no significant change of results when the external heat transfer coefficient is over 300
, and smaller particles are more sensitive to the outer heat transfer coefficient. Predicted results from the model show a similar tendency with the experimental data from literatures within a deviation of 10%.
The Duel Fuel Combustion of Low Calorific Biomass Syngas with Fuel Oil
Yoon, Sang-Jun ; Kim, Young-Ku ; Jeon, Chang-Joon ; Lee, Jae-Goo ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 860~865
DOI : 10.9713/kcer.2012.50.5.860
Although biomass syngas is very low calorific gas, it is utilized by means of dual fuel combustion technology in the fields of industrial furnace and boiler as a substitute oil technology. The basic structure of duel fuel combustion burner is designed so that low caloric gas fuel is supplied around an oil burner in the middle. In the present study, three types of mixing burners were manufactured to conduct performance experiment. Low caloric gas was evenly distributed around the oil burner and the method of changing the angle of gas nozzle was applied. CO generation decreased according to the increase of the amount of air for combustion. In addition, the shapes and colors of flame changed according to the proportions of gas and oil used. Remained flame after combustion was from the lack of atomization at the exit of oil burner. Although it was difficult to maintain the optimum air ratio due to different required air ratio for oil and syngas, stable combustion was able to maintained within excess oxygen concentration of 4.7~8.2%. From this study, it was shown that the oil atomization at the exit of fuel oil nozzle was promoted by the increased rate of syngas combustion and the CO concentration in flue gas lower than only fuel oil combustion.
Comparative Simulation of 3-zone SMB (Simulated Moving Bed) and 4-zone SMB for IgY (Immunoglobulin Yolk) Purification
Yun, Sang-Hee ; Kim, In-Ho ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 866~873
DOI : 10.9713/kcer.2012.50.5.866
IgY (Immunoglobulin Yolk) is a specific antibody in egg yolk, and it protects human body from virus and antigen. There are a lot of egg yolk components such as lipoprotein and protein. To separate IgY, HPLC (High Performance Liquid Chromatography) and precipitation were used in a batch mode and SMB (Simulated Moving Bed) was adopted for continuous purification of yolk proteins. IgY and other proteins in yolk were separated by using three-zone and four-zone SMB chromatography. Before performing SMB experiments, batch chromatography simulation parameters and adsorption isotherms were obtained. The parameters of batch chromatography were used to simulate SMB using Aspen chromatography. To compare three-zone and four-zone SMB chromatography, simulations in
plane on the triangle theory were carried out. In terms of concentration and purity of both IgY and other lipoproteins, 3-zone SMB process is considered as ideal at the vertex of triangle (
=0.1, 1.1). 4-zone SMB yields the highest IgY purity at the coordinate (
=0.06, 0.5), which is the pure raffinate region. In 3-zone SMB without recycle, other lipoproteins in extract are largely affected in purity by small shift from the vertex of triangle (
Effect of Buffers on Citric Acid Production by Aspergillus niger NRRL 567 in Solid Substrate Fermentation
Kim, Jin-Woo ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 874~878
DOI : 10.9713/kcer.2012.50.5.874
In the submerged fermentation of fungi, it was known pH had significant effect on the citric acid production. Various growth conditions were applied with different buffer on citric acid production by Aspergillus niger NRRL 567 grown on peat moss to find the optimum pH and most effective buffer solution. The initial pHs of different buffer solutions significantly influenced on the citric acid production and A. niger NRRL 567 produced citric acid more efficiently at high pHs. A phosphate buffer and a carbonate buffer with pH 8.6 and pH 10.0 were identified as suitable buffer solutions for citric acid production. The maximal citric acid production of 564.3 g/kg solid substrate was achieved employing carbonate buffer at pH 10.0.
Response Surface Optimization of Fermentation Parameters for Citric Acid Production in Solid Substrate Fermentation
Kim, Jin-Woo ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 879~884
DOI : 10.9713/kcer.2012.50.5.879
In this present study, Aspergillus niger NRRL 567 was cultivated on an inert support material and the effects of various fermentation parameters including temperature, nutrient solution pH, inoculation level, and moisture content were observed and optimized by one-factor-at-a-time (OFAT) and response surface methodology (RSM), sequentially. It was found that the incubation temperature of
with 75% moisture content, nutrient solution pH of 7.1 and inoculation level of
spores/ml were the most favorable. Again, fermentation parameters were optimized using RSM. The determined optimum condition is
, pH 9.9, 75.1%, and
spores/ml. Under this optimized condition, A. niger NRRL 567 produced 118.8 g citric acid/kg dry peat moss at 72 hr. Maximum citric acid production of optimized condition by RSM represented a 1.6-fold increase compared to that obtained from control experiment.
Effects of Inorganic-organic Additives on CO
Adsorption of Activated Carbon
Jo, Dong-Hyun ; Cho, Ki-Sook ; Park, Cheong-Gi ; Kim, Sung-Hyun ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 885~889
DOI : 10.9713/kcer.2012.50.5.885
In this study, amine and metal oxide additives were investigated to improve
adsorption capacity of activated carbons (ACs). The characteristics of surface modified ACs were studied by X-ray photoelectron spectroscopy (XPS),
adsorption, X-ray diffraction (XRD), and BET. Amine surface treatment decreased specific surface area and pore volume of ACs, but increased alkalinity by the incorporated nitrogen functional groups. Adsorption capacities of amine functionalized ACs was larger than original ACs, because basic group which can react with
was grafted on the ACs surface. Presence of copper oxides on ACs also enhances the carbon dioxide adsorption. The copper oxides could increase the adsorption rate of carbon dioxides due to the acid-base interaction (or electron acceptor-donor interaction). It was found that copper oxide loading was a promising method to improve the
adsorption capacity of ACs.
Investigation on Formation Behaviors of Synthesized Natural Gas Hydrates
Lee, Jong-Won ; Lee, Ju-Dong ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 890~893
DOI : 10.9713/kcer.2012.50.5.890
Gas hydrates are solid crystal structures formed by enclathration of gaseous guest species into 3-dimensional lattice structure of hydrogen-bonded water molecules. These compounds can be potentially used as an energy storage/transportation medium because they can hold a large amount of gas in a small volume of the solid phase. In addition, huge amount of natural gas, buried in seabeds or permafrost region in the form of the solid hydrate, is regarded as a future energy source. In this study, synthesized natural gas, whose composition is 90.0 mol% of methane, 7.0 mol% of ethane, and 3.0 mol% of propane, was used to identify formation behaviors of natural gas hydrates for the purpose of applying the gas hydrate to a storage/transportation medium of natural gas. According to the experimental results obtained by means of the solid-state NMR and high-resolution powder XRD methods, it is found that formed natural gas hydrates have crystal structure of the structure-II hydrate, and that methane occupies both small and large cages, while the others only occupy large ones. In addition, both the NMR spectroscopy and the gas chromatograph showed that there exists preferential occupation among the natural gas components during the hydrate formation. Compositional changes after the hydrate formation revealed that the preferential occupation is in order of propane, ethane, and methane (propane is the most preferential guest species when forming natural gas hydrates).
Recycling of Separate Glass Fiber from Waste Printed Circuit Boards Using Attrition Mill and DMF
Kim, Jong-Seok ; Lee, Jae-Cheon ; Jeong, Jin-Ki ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 894~899
DOI : 10.9713/kcer.2012.50.5.894
In recent years, recycling process has come to be necessary for separating metals, glass fibers and polymer from WPCBs (waste printed circuit boards) due to an increasing amount of electronic device waste. In this study, dimethylformamide (DMF) and attrition mill reactor were used to separate the component such as metals, glass fiber and epoxy resin from WPCBs. Separation of glass fiber from WPCBs was carried out under stirring rates 300~600 revolution per minute (rpm) for 1~2 h as the various agitator. The recycled glass fibers (RGF) were analyzed by thermogravimetric analyzer (TGA) for degree of separation of epoxy resin in the WPCBs. The degree of separation of epoxy resin of WPCBs increased in attrition mill agitator as a mechanochemical process for recycling WPCBs. The RGF separated in the WPCBs was applied as a reinforcement in the RGF/unsaturated polyester composites to reuse as a reinforcement.
Analysis of Forward Osmosis Membrane Technology Using International Patent Classification
Im, Eun-Jung ; Kim, Sung-Hyun ; Kim, Sang-Gon ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 900~907
DOI : 10.9713/kcer.2012.50.5.900
Research and development is entering on more complicated aspect gradually and tends to increase sharply in a quantitative manner. Technology competition is getting higher. This study intends to raise recognition of a necessity of productivity in a rapidly-changing research and development field and to suggest alternatives for improving its research productivity. For it, the research productivity was analyzed by utilizing two processes of patent and paper analysis. In this paper, we propose a patent analysis method for technology forecasting of the Forward Osmosis Membrane using objective patent data. The application status of patents showed a tendency to increase slightly. The current of FOM technology development in such countries as Korea, USA, Japan, China and EU was analyzed by classifying the patents for 1990 through 2011 according to registration country, assignee, calendar year and technology area.
Production of Hydrogen by Thermochemical Transition of Lauan Sawdust in Steam Reforming Gasification
Park, Sung-Jin ; Kim, Lae-Hyun ; Shin, Hun-Yong ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 908~912
DOI : 10.9713/kcer.2012.50.5.908
Lauan sawdust was gasified by steam reforming for hydrogen production from biomass waste. The fixed bed gasification reactor with 1m height and 10.2 cm diameter was utilized for the analysis of temperature and catalysts effect. Steam was injected to the gasification reactor for the steam reforming effect. Lauan sawdust was mixed with potassium carbonate, sodium carbonate, calcium carbonate, sodium carbonate + potassium carbonate and magnesium carbonate + calcium carbonate catalysts of constant mass fraction of 8:2 which was injected to the fixed gasification equipment. The compositions of production gas of gasification reaction were analyzed at the temperature range from
. Fractions of hydrogen, methane and carbon monoxide gas in the production gas increased when catalysts were used. Fractions of hydrogen, methane and carbon monoxide gas were increased with increasing temperature. The highest hydrogen yield was obtained with sodium carbonate catalyst.
Characteristic of Mass Transfer Volumetric Coefficient and Sauter Mean Diameter in a Liquid-Liquid Agitated Vessel
Lee, Young-Sei ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 913~922
DOI : 10.9713/kcer.2012.50.5.913
Grasp of characteristics within liquid-liquid agitated vessel are very important to environment and chemical industry. Mass transfer volumetric coefficient and the Sauter mean diameter of near the droplet were measured by varying the impeller position and liquid height using the alkaline hydrolysis reaction of esters. As a result, following their good correlation was obtained.
Effects of Calcium Hydroxide/Phosphoric Acid Suspending Agents on the Characteristics of Styrene-Based Suspension Polymerized Toners
Yu, Jae-Goang ; Kim, Dae-Su ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 923~928
DOI : 10.9713/kcer.2012.50.5.923
Optimizing a water-phase suspending system is very important to manufacture high-quality suspension polymerized toners. Therefore, in this study, the effects of the molar ratio of calcium hydroxide (
)/phosphoric acid (
)(Ca/P), which were used as inorganic suspending agents, and pH of the water-phase on the characteristics of styrene-based suspension polymerized toners were mainly investigated. At first, the water-phase was fixed to neutral condition (pH=7.5) and Ca/P molar ratio was changed from 1.5:1 to 1.76:1. As a result, an ideal calcium phosphate (hydroxyapatite) was prepared at the Ca/P molar ratio of 1.73:1 and polymerized toners prepared at this condition showed good particle size distribution, circularity and charging characteristic. Based on this result, Ca/P molar ratio was fixed to 1.73:1 and pH of the water-phase was changed to weak acidic (pH=5.5) and weak basic (pH=9.5) conditions. As a result, polymerized toners prepared under the weak acidic condition showed very good particle size distribution, circularity and charging characteristic along with excellent printing quality. High-quality suspension polymerized toners could be prepared via optimizing Ca/P molar ratio and pH of the water-phase.
Soft-lithography for Manufacturing Microfabricated-Circuit Structure on Plastic Substrate
Park, Min-Jung ; Ju, Heong-Kyu ; Park, Jin-Won ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 929~932
DOI : 10.9713/kcer.2012.50.5.929
Novel platform technology has been developed to replace the photolithography used currently for manufacturing semiconductors and display devices. As a substrate, plastics, especially polycarbonates, have been considered for future application such as flexible display. Other plastics, i.e. polyimide, polyetheretherketon, and polyethersulfone developed for the substrate at this moment, are available for photolithography due to their high glass transition temperature, instead of high price. After thin polystyrene film was coated on the polycarbonate substrate, microstructure of the film was formed with polydimethylsiloxane template over the glass transition temperature of the polystyrene. The surface of the structure was treated with potassium permanganate and octadecyltrimethoxysilane so that the surface became hydrophobic. After this surface treatment, the nanoparticles dispersed in aqueous solution were aligned in the structure followed by evaporation of the DI water. Without the treatment, the nanoparticles were placed on the undesired region of the structure. Therefore, the interfacial interaction was also utilized for the nanoparticle alignment. The surface was analyzed using X-ray photoelectron spectrometer. The evaporation of the solvent occurred after several drops of the solution where the hydrophilic nanoparticles were dispersed. During the evaporation, the alignment was precisely guided by the physical structure and the interfacial interaction. The alignment was applied to the electric device.
Analysis of Trace Copper Metal at The Electrode Consisting of Carbon Nanotube using Stripping Voltammetry
Choi, Chang-Kun ; Jung, Young-Sam ; Kim, Nack-Joo ; Pak, Dae-Won ; Chung, Kun-Yong ; Kim, Lae-Hyun ; Kwon, Yong-Chai ;
Korean Chemical Engineering Research, volume 50, issue 5, 2012, Pages 933~937
DOI : 10.9713/kcer.2012.50.5.933
In the present study, we evaluate the sensitivity and optimal stripping voltammetry (SV) conditions of copper (Cu), which is one of the main trace heavy metals inducing the environmental contamination, using carbon nanotube (CNT) electrode. In addition, the reaction mechanism of stripping reaction of Cu is investigated. The electrochemical analyses such as squarewave stripping voltammetry (SWSV) and linear scan voltammetry (LSV) are used for the evaluations. As a result of that, the best SWSV conditions like squarewave amplitude of 15 mV, frequency of 60 Hz, deposition potential of -1.0V vs. Ag/AgCl and deposition time of 200s are determined with the measured Cu sensitivity of
. As a driving force affecting the stripping reaction of Cu, surface reaction is more dominant one than diffusion. These results are compared with other reference results and it is confirmed that our suggested CNT electrode gives rise to better Cu sensitivity result than other references.