• Journal of the Korean Society of Combustion
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• v.13 no.1
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• pp.10-16
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• 2008

Numerical simulations of freely propagating premixed flames burning mixtures of methane and chlorinated hydrocarbons in fuel are performed at atmospheric pressure in order to understand the effect of chlorinated hydrocarbons on the formation of nitrogen oxide. A detailed chemical reaction mechanism is used, the adopted scheme involving 89 gas-phase species and 1017 elementary forward reaction steps. Chlorine atoms available from chlorinated hydrocarbons inhibit the formation of nitrogen oxides by lowering the concentration of radical species. The reduction of NO emission index calculated with thermal or prompt NO mechanism is not linear and is probably related to the saturation effect as $CH_3Cl$ addition is increased, In the formation or consumption of nitrogen oxide, the $NO_2$ and NOCl reactions play an important role in lean flames while the HNO reactions do in rich flames. The molar ratio of Cl to H in fuel has an effect on the magnitude of NO emission index.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.16-23
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• 1994

In an argon thermal plasma CVD system diamond of metastable state was synthesized on molydenum substrate and concentration ratio of methane to hydrogen. Diamond was relatively well obtained when surface temperature of substrate was $890^{\circ}C$ and concentration of methane ratio was 0.5 percents.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.289-290
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• 2001

비메탄계 휘발성 유기화합물(Non-Methane Volatile Organic Compounds; NMVOCs)은 많은 부분이 용제를 사용하는 공정에서 발생되어 광화학적 산화물 형성 등의 대기질 악화를 초래시키는 것으로 알려져 있다. 반면에 메탄가스는 지구온난화의 원인물질로 환경에 많은 영향을 미치는 것으로 알려져 있고, 국내의 쓰레기 매립지에서 발생되는 양은 년간 112만톤으로 추정되어 메탄의 자원화나 처리에 대한 연구가 매우 필요한 실정이다. (중략)

• Journal of Energy Engineering
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• v.15 no.1 s.45
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• pp.52-59
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• 2006

This paper examined the conversion of methane to hydrogen and other higher hydrocarbons using dielectric barrier discharge with AC pulse power. Two metal electrodes of a coaxial-type plasma reactor were separated by gas gap and an alumina tube. The inner electrode was located inside the alumina tube. The alumina tube was located inside the stainless steel tube, which was used as the outer electrode. Effect of feed gas composition (methane, oxygen, argon, water and helium), flow rate, applied frequency, input volt-age on methane conversion and product distribution were studied. The major products of plasma chemical reactions were ethylene, ethane, propane, buthane, hydrogen, carbon monoxide and carbon dioxide. The increment of applied voltage and the usage of inert gas as the background (helium and argon) enhanced the selectivity of hydrocarbons and methane conversion. The addition of water in the feed stream enhanced the conversion of methane and yield of hydrogen. Higher voltage leads to higher yield of $C_2H_6,\;C_3H_8,\;C_4H_{10}$ and yield or $C_2H_2\;and\;C_2H_4$ appeared highly in lower voltage.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.242-251
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• 2010

In comparison with other terrestrial ecosystems, rice paddies are unique because they provide the primary food source for over 50% of the world's population, and act as major sources of global methane. The present paper summerizes a long-term field study that combine carbon isotopes, and canopy-scale flux measurements in an irrigated rice paddy, in conjugation with continuous monitoring of environmental, and vegetational factors. Both $CO_2$, and methane fluxes were largely influenced by soil temperature, and moisture conditions, especially across drainage events. Soil-entrapped $CO_2$, and methane showed a gradually increasing trend throughout growing season, but rapidly decreased upon flood water drainage. These variations in flux were well correlated with changes in concentration, and isotope ratio of soil $CO_2$, and methane, and of atmospheric $CO_2$, and methane within, and above the canopy. The isotopic signature of the gas exchange process varied markedly in response to change in contribution of soil respiration, belowground storage, fraction of $CO_2$ recycled, magnitude, and direction of $CO_2$ exchange, transport mechanism, and fraction of methane oxidized. Our results clearly demonstrate that stable isotope analysis can be a useful tool to study underlying mechanisms of gas exchange processes under natural conditions.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.153-156
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• 2014

This study was aimed to assess combustion stability for coaxial swirl injector and FOOF impinging injector which would be candidates in liquid rocket engine combustors. Simulating combustion tests under atmospheric condition have been conducted by gaseous oxygen and the mixture of methane and propane, using two actual injectors. By analyzing the measured dynamic pressure signals, we have evaluated the combustion stability margin of both injectors by drawing a stability map.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.268-270
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• 2008

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.389-390
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• 2000

최근 지구 온난화의 55% 이상을 차지하고 있는 이산화탄소를 유용한 화합물로 전환하고자 메탄을 환원제로 사용한 이산화탄소 개질반응으로부터 합성가스 생성에 관한 연구가 활발히 진행되고 있다. 메탄의 이산화탄소 개질반응은 수증기 개질반응보다 낮은 합성 가스비의 생성, 온실효과를 유발하는 이산화탄소의 저감, 반응의 높은 흡열도를 이용한 화학에너지 전송 시스템의 응용 면에서 그 의의가 있다. (중략)

• Journal of the Korean Vacuum Society
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• v.10 no.4
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• pp.411-415
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• 2001

Using the plasma that we developed to generate a low-temperature plasma at atmospheric pressure, we have investigated the etching possibility of tin oxide $(SnO_2)$ thin films. Hydrogen and methane radicals generated from the plasma were observed and their intensity was found to be dependent on the cathode material by an analysis with optical emission spectroscopy as well as by the plasma impedance. The etching ability of this plasma was evaluated by an emission intensity as well as by the evaluation of impedance using a plasma I-V curve.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.4
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• pp.299-312
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• 2001

The analysis of vent -emitted Hg concentrations and relevant environmental parameters was made from the inlet of 42 ventpipes in Nan-Ji-Do area of Seoul during September/october of 2000. Using these data, the fluxes of Hg from the ventpipes were also derived. The mean concentration of Hg, computed using the data sets collected from 42 ventpipes, was 420$\pm$619ng m$^{-3}$ with the range of 3.45~2,952ng m$^{-3}$ . Because of large differences in concentration levels between two sectors 1 and 2 and between plain and slope areas. evaluation of the data was made by dividing them into four different categories such as plain areas of sectors 1 and 2 (and/or slope areas of sectors 1 and 2). When this classification was applied, the computed fluxes were highly different among each group with the generally enhanced fluxes in plain area relative to slope area. The computed fluxes were then used to make comparative analysis of different source processes in the study area.