• New & Renewable Energy
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• v.2 no.2 s.6
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• pp.102-107
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• 2006

In Japan, research and development were undertaken on gas hydrate-side industrial processes associated with power generation system connections that may particularly be necessary to develop gas hydrated technology-based industrial systems. In so doing, data and engineering technologies useful n formulating guidelines on design of practical process were accumulated. In addition, basic research into theoretical evidence were carried out to promote and support the development of technological elements for those processes. In basic research designed to promote and support the research and development of elemental technologies, microanalyses were conducted to understand the decomposition mechanism of mixed gas hydrate. Moreover, measurement technologies that can be applied in industrial processes, such as numerical analyses and concentration measurement, were examined. Japan has developed a highly efficient gas hydrate formation process using micro-bubbles with a tubular reactor. Higher formation rate over conventional systems has been obtained by the process. As mentioned above, the technical problems were clarified and the economics were studied from a view point of the NGH technology in this study. The results can be applied for utilization and must contribute to popularization of gas hydrate production.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.415-418
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• 2006

In Japan, research and development were undertaken on gas hydrate-side industrial processes associated with power generation system connections that may particularly be necessary to develop gas hydrated technology-based industrial systems. In so doing, data and engineering technologies useful n formulating guidelines on design of practical process were accumulated. In addition, basic research into theoretical evidence were carried out to promote and support the development of technological elements for those processes. In basic research designed to promote and support the research and development of elemental technologies microanalyses were conducted to understand the decomposition mechanism of mixed gas hydrate. Moreover, measurement technologies that can be applied in industrial processes, such as numerical analyses and concentration ion measurement, were examined. Japan has developed a highly efficient gas hydrate formation process using micro-bubbles with a tubular reactor. Higher formation rate over conventional systems has been obtained by the process. As mentioned above, the technical problems were clarified and the economics were studied from a view point of the NGH technology in this study. The results can be applied for utilization and must contribute to popularization of gas hydrate production.

• Membrane Journal
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• v.13 no.3
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• pp.182-190
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• 2003

Carbon molecular sieve (CMS) membranes were prepared by the pyrolysis of polyvinylpyrrolidone containing polyimide precursors. We have prepared the polymer precursors, pyrolyzed polymer and investigated the effect of pyrolyzing polymer on the characteristics of carbon structures and gas separation properties of the CMS membranes. Thermogravimetric analysis (TGA) showed the two-step decomposition of polymer precursor. First decomposition of the pyrolyzing polymer began around $400^{\circ}C$ while carbonizing polymer showed the decomposition around $550^{\circ}C$. The gas permeabilities through the CMS membranes were enhanced by the introduction of the pyrolyzing polymer and decreased with increased final pyrolysis temperature. The CMS membrane pyrolyzed at $550^{\circ}C$. derived from precursor containing 5wt% PVP as a pyrolyzing polymer showed gas permeability for $O_2$ of 808 Barrers [$10^{-10}cm^3 (STP)cm/cm^2scmHg]$ and $O_2/N_2$ selectivity of 7.

• Journal of the Korean Applied Science and Technology
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• v.17 no.1
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• pp.55-61
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• 2000

$Zn_{x}Fe_{3-x}O_{4}(0.00.<X<0.08)$ was synthesized by air oxidation method for the decomposition of carbon dioxide. We investigated the characteristics of catalyst, the form of methane by gas chromatograph after decomposition of carbon dioxide and kinetic parameter. $Zn_{x}Fe_{3-x}O_{4}(0.00.<X<0.08)$ was spinel type structure. The surface areas of catalysts($Zn_{x{Fe_{3-x}O_{4}(0.00.<X<0.08)$) were $15{\sim}27$ $m^{2}/g$. The shape of $Zn_{0.003}Fe_{2.997}O_{4}$ was sphere. The optimum temperature for the decomposition of carbon dioxide into carbon was $350^{\circ}C$. $Zn_{0.003}Fe_{2.997}O_{4}$ showed the 85% decomposition rate of carbon dioxide and the degree of reduction by hydrogen(${\delta}$) of $Zn_{0.003}Fe_{2.997}O_{4}$ was 0.32. At $350^{\circ}C$, the reaction rate constant and activation energy of $Zn_{0.003}Fe_{2.997}O_{3.68}$ for the decomposition of carbon dioxide into carbon were 3.10 $psi^{1-{\alpha}}/min$ and 0.98 kcal/mole respectively. After the carbon dioxide was decomposed, the carbon which was absorbed on the catalyst surface was reacted with hydrogen and it became methane.

• Journal of the Korean Ceramic Society
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• v.38 no.10
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• pp.901-907
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• 2001

Magnetite was synthesized using $0.2M-FeSO_4{\cdot}7H_{2}O$ and 0.5 M-NaOH by air oxidation method for carbon dioxide decomposition to carbon. The carbon dioxide decomposition was successfully carried out after reduction of ${Fe_3}{O_4}$ for 2 hrs using hydrogen gas. The carbon dioxide decomposition at 325, 350, 375, 400, $425^{\circ}C$, 88% was the highest at $350^{\circ}C$ and the activation energy of ${Fe_3}{O_4}$ in carbon dioxide decomposition was 30.96 kJ/mol. After $CO_2$ decomposition, the carbon of surface of catalyst reacted with hydrogen produced methane.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.367-375
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• 2017

In this study, NO oxidation process was studied to increase the NO treatment efficiency of pollutant present in exhaust gas. $H_2O_2$ catalytic cracking was introduced as a method of producing dry oxidizing agents with strong oxidizing power. The $K-Mn/Fe_2O_3$ heterogeneous catalysts applicable to the $H_2O_2$ decomposition process were prepared and their physico-chemical properties were investigated. The prepared dry oxidant was applied to the NO oxidation process to treat the simulated exhaust gas containing NO, NO conversion rates close to 100% were confirmed at various flow rates (5, 10, 20 L/min) of the simulated flue gas.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.914-917
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• 2002

Fabrication of micro carbon structures and patterns using laser-assisted chemical vapor deposition is studied. Argon ion laser and ethylene were used to grow micro carbon rod through pyrolytic decomposition of the reaction gas. The influence of reaction gas pressure and incident laser power on the diameter and growth rate of the micro carbon rod was experimentally investigated. The diameter of micro carbon rods increases linearly with respect to the laser power but is almost independent of the reaction gas pressure. Growth rate of the rod changes little with gas pressure when the laser power remains below 1W. When the carbon rod was grown at near threshold laser power, a very smooth surface is obtained on the rod. By continuously moving the focusing lens in the direction of growth, a micro carbon rod with a diameter of 28 ${\mu}{\textrm}{m}$ and aspect ratio of 100 was fabricated.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.2
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• pp.72-75
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• 2005

In oil-filled equipment such as transformers, partial discharge or local overheating will precede a final shutdown. Accompanied with such problems is a decomposition of insulating material into gases, which are dissolved into the transformer oil. The gases dissolved in oil can be separated with some membranes based on the differences in permeability of membranes to different gases. This paper discuss the permeability characteristics of several membranes for separation hydrogen gas in oil. With result of this paper, it may become possible to detect fault-related gases from transformer oil and predict incipient failures in the

• Journal of Environmental Science International
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• v.13 no.1
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• pp.41-45
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• 2004

In this study, The decomposition of gas-phase Benzene and Toluene, Xylene in air streams by direct UV Photolysis, UV/TiO$_2$ and UV/TiO$_2$/A.C process was studied. The experiments were carried out under various UV light intensities and initial concentrations of B.T.X to investigate and compare the removal efficiency of the pollutant. B.T.X was determined by GC-FID of gas samples taken from the a glass sampling bulb which was located at reactor inlet and outlet by gas-tight syringe. From this study, the results indicate that UV/TiO$_2$/A.C system (photooxidation-photocatalytic oxidation-adsorption process) is ideal for treatment of B.T.X from the small workplace. Although the results needs more verifications, the methodology seems to be reasonable and can be applied for various workplace (laundry, gas station et al.).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.224-225
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• 2018

Modern people are more interested in the indoor environment as they spend more time indoors than in the past. Among the air pollutants in the indoor air, ladon gas is a colorless, tasteless, odorless, inert gas produced by nuclear decomposition of naturally occurring uranium in rocks and soils. It has been proven that ladon gas is introduced into the room through cracks on the floor of the building or basement wall, and it causes various diseases such as lung cancer when exposed to radon during human breathing. The US Environmental Protection Agency (EPA) specifies 4pCi / L as a necessary measure for radon, and the Korea Environmental Protection Agency has implemented comprehensive indoor radon management measures since 2007. Therefore, in this study, we intend to adsorb and reduce radon in indoor air pollutants.