• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.459-459
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• 2007

VHF ICP (Very High Frequency Inductively Coupled Plasma) 반응기에서 반응기 압력, 수증기 유량, 플라즈마 출력, 반응기온도 등의 공정변수에 따른 수증기 분해특성과 수소생성거동을 실험하였다. 플라즈마 분해 특성은 OES(Optical Emission Spectroscopy)를 사용하여 분석하였으며, QMS(Quadrapole Mass Spectroscopy)를 이용하여 배기가스 성분을 분석하여, 수증기 분해거동 및 수소생성 효율을 조사하였다. 본 연구실에서 설계한 초고주파 유도결합 플라즈마는 고밀도 플라즈마 생성과 낮은 압력에서도 안정된 플라즈마 발생 특징을 나타내었다. 플라즈마 출력의 증가에 따른 수증기의 분해와 수소생성 거동은 개시영역, 선형증가영역, 포화영역의 세 영역으로 구분되는 특징을 나타내었다. 유량 및 압력의 증가에 따라 포화에 필요한 플라즈마의 출력이 증가되는 경향을 나타내었다. 본 실험의 온도범위에서는 온도 증가에 따른 수증기 분해 및 수소생성 증가효과는 플라즈마 출력의 영향에 비하여 매우 미미한 정도로 플라즈마의 높은 에너지 전달효과를 확인할 수 있었다. 따라서, 낮은 반응기 온도에서도, 유량 및 압력에 따른 포화 플라즈마조건을 설정할 경우, 높은 에너지 효율의 수소 제조가 가능함을 알 수 있었으며, 물분해 플라즈마를 이용한 저온 산화물 박막증착에의 적용도 기대된다.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.1
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• pp.25-30
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• 2005

수소 분위기에서 10wt.%MnO와 기계적인 분쇄(반응성 기계적 분쇄)에 의해 Mg의 수소 저장 성질을 향상시켰다. 회전 속도는 250 rpm, 밀링시간은 2 h, 그리고 시료 대 볼 중량비는 1/45이었다. 준비한 Mg-10wt.%MnO 시료는 활성화를 위한 수소화물 형성 분해 싸이클링이 필요없었으며, 첫 번째 싸이클 593k 12 bar $H_2$에서, 10분 동안에 3.12wt.%, 60분 동안에 3.95wt.%의 수소를 흡수하였다. 또한 Mg-10wt.%MnO는 593k 0.8 bar $H_2$에서 60분 동안에 2.12wt.%의 수소를 방출하였다. MnO와 Mg의 방응성 분쇄는, 핵생성을 용이케하고 (Mg 입자의 표면에 결함 형성과 첨가물에 의해), Mg 입자의 표면에 crack을 만들어 Mg의 입자 크기를 줄여 그 결과 수소 원자의 확산 거리를 작게 함으로써 수소 흡수 방출 속도를 증가시킨다. 수소화물 형성 분해 싸이클링은 Mg 입자의 표면에 crack을 만들고 Mg의 입자 크기를 줄여 수소 흡수 방출 속도를 증가시킨다.

• Transactions of the Korean hydrogen and new energy society
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• v.8 no.3
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• pp.131-135
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• 1997

Aromatic primary amines were prepared by the catalytic hydrogenation of aromatic nitro compounds in a benzene solution over 50 mg of 10 % palladium on charcoal at a room temperature under 45 psi. This paper describes a study on the catalytic hydrogenation of nitrobenzene-$d_5$, $^{15}N$-labelled nitrobenzene, and 4'-nitrobenzo-15-crown-5, respectively. The infrared absorption spectra exhibited a characteristic N-H stretching vibrations at 3450 and $3350cm^{-1}$. The results suggest that the non-readily available aromatic amines would be commercially produced by catalytic hydrogenation because of its good yield and little by-product formation.

• Analytical Science and Technology
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• v.13 no.5
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• pp.659-665
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• 2000

The changes in $UV_{254}$ and concentrations of $H_2O_2$ formed by ozonation of aqueous humic acid in ozone/high pH, peroxone process and in the presence of radical scavenger, $HCO_3{^-}$ were investigated. This study confirmed that the formation of $H_2O_2$ by ozonation may undergo different reaction pathways compared to those of $UV_{254}$ reduction in the degradation of the humic acid. The concentration of $H_2O_2$ produced by ozonation was found to be increased with decreasing pH of the sample solution due to the higher stability of ozone molecules at acidic conditions. On the while, $UV_{254}$ reduction was found to be higher at alkaline conditions or larger amount of $H_2O_2$ additions as a radical promoter in which the producing of ${\cdot}OH$, ${\cdot}HO_2$ radicals can be more favorable. From the results, it has been suggested that the formation of $H_2O_2$ by ozonation depends mainly on the direct reactions of ozone with humic acid molecules, while $UV_{254}$ reduction is affected by both the indirect reactions of the radicals and direct reactions of ozone with humic acid.

• Korean Journal of Microbiology
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• v.24 no.1
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• pp.62-66
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• 1986

Many photosynthetic bacteria capable of hydrogen production were isolated from samples of mud flats of paddy field collected in Kim Hae and Dae Jeo. A strain 230 was selected for the high capability of hydrogen evolution. As the results of examination in physiological, morghological and cultural characteristics, the strain 230 was identified as Rhodopseudomonas sphaeroides.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.247-247
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• 2004

가압 중수로형 원자력발전소에서는 원자로의 감속재 및 냉각재로 사용하는 중수(heavy water)로 인한 삼중수소(tritium)의 생성이 전체 방사선 준위 상승의 가장 중요한 원인이 되고 있다. 따라서 4기의 중수로가 운전 중인 우리나라에서도 월성원자력 발전소에 삼중수소 제거 설비(Tritium Removal Facility)가 건설 중에 있다. 이 시설로부터 99% 이상의 순도인 삼중수소가 회수되며, 회수된 삼중수소는 장기적인 저장을 위하여 안전하게 포장되어야 한다.(중략)

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.633-638
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• 1998

벼의 성장시기에 다른 대기중 삼중수소의 식물채내 흡수실험을 수행하였다. 투명한 아크릴로 만들어진 피폭상자(50x60x120cm)내의 피폭조건은 비록 같은양(18.5 MBq)의 HTO를 증발시키더라도 동일한 농도를 유지하는 것이 거의 불가능하였다. 벼꽃의 매화 직후부터 수확기까지 이삭의 생성시기별로 HTO에 피폭시킨 후 잎, 줄기 및 이삭으로 구분된 시료에서 피폭 후 시간별로 조직자유수의 삼중수소 농토를 측정하였다. 조직자유수의 삼중수소 농도는 이삭에서 가장 느리게 감소하였으나 조직결합수의 삼중수소 농도는 이삭 성장이 가장 왕성한 시기에 높게 측정되었다.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.1
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• pp.131-138
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• 2006

In this study, the optimum condition of pH was investigated on the hydrogen gas production under anaerobic fermentation process. The results of the experiment showed that the optimum condition was observed at pH 6, resulting in 1175.87 mL/L of hydrogen gas production rate and 22.51% theoretical hydrogen conversion ratio. Hydrogen gas production rate and theoretical hydrogen conversion ratio were 901.77 mL/L and 17.48 % respectively at pH 5. At pH 7 and 8, the production rate of hydrogen gas was little low as 82.15 mL/L. Among the organic acids from the sucrose fermentation, propionate was observed as the dominant acid at pH 7 and 8 but butyrate was the dominant at pH 5 and 6.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.908-912
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• 2012

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 $400^{\circ}C$ to $700^{\circ}C$. 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.

• Applied Chemistry for Engineering
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• v.19 no.4
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• pp.432-438
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• 2008

Hydrogenation reactions of p-toluidine over Ru/C were performed while varying reaction temperature, the hydrogen pressure, catalyst loading, solvent, and alkali additive and the effects on the reaction rates and product distribution were examined. 4-Methylcyclohexylamine was generated as a main product and bis(4-methyl cyclohexyl)amine was obtained as a resentative side-product for the hydrogenation reaction of p-toluidine. The selectivity of MCHA decreased with reaction temperature and the hydrogen pressure while increased with catalyst loading. IPA was the best solvent for MCHA. A mechanism of hydrogenation reaction of p-toluidine was suggested from the results. It was found that the presence of alkali salt increased MCHA by reducing BMCHA and rates of hydrogen reaction increased.