• 조명전기설비학회논문지
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• 제25권10호
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• pp.116-124
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• 2011

In this work, the effect of the initial concentration of methanol and ethanol, and the addition of oxygen molecules were discussed to improve the hydrogen generation using non-thermal plasma reactor effectively. In addition, the effect of ozone decomposition catalyst of manganese dioxide and its quantity was investigated. First, hydrogen concentration increased until an initial concentration of about 40,000[ppm] of methanol and thereafter it was saturated. Henceforth, hydrogen concentration decreased with increasing the oxygen percent on the carrier gas of nitrogen about both substances. Related with the effect of catalyst, it increased upto 60[g], but it was not changed largely after that. Consequently, it is confirmed that the hybrid process using plasma process and catalytic surface chemical reaction is a very promising way to increase the efficiency of hydrogen generation as investigated in this work.

• Nuclear Engineering and Technology
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• 제16권4호
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• pp.217-223
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• 1984

본 연구에서는 냉각수 상실사고(LOCA)시 격납용기내의 수소농도를 제어하기 위해 수소재결합기 없이 수소 퍼지계통만을 사용할 때의 타당성을 분석하였다. 이 타당성 연구를 위해 격납응기내의 수소농도, 수소퍼지 계통의 수소제거, 그리고 퍼지로 인한 추가소외 선량이 계산되었다 또한 비용-편익 개념을 사용하여 수소 재결합기 계통(2대의 재결합기 설치)의 경제성을 분석하였다. 분석결과, 수소퍼지 계통은 수소 재결합기 없이도 수소농도를 제어하기에 충분하며, 10 CFR 100에 있는 선량 제한치를 만족시키고 있었다. 비용-편익 개념에 의하면 수소 재결합기 계통은 동일부지내에 있는 4∼6기의 발전소에 공용될 때 경제성이 있는 것으로 입증되었다.

• 한국수소및신에너지학회논문집
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• 제34권1호
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• pp.38-46
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• 2023

Carbon neutrality policies have been strengthened to reduce emissions, and the importance of technology road maps has been emphasized. In the global industrial boiler market, carbon neutrality is implemented through fuel diversification of methane-hydrogen mixture gas. However, various problems such as flashback and flame unstability arise. There is a limit to implementing the actual system as it remains in the early stage. Therefore, it is necessary to secure the source technology of methane-hydrogen hybrid combustion system applicable to industrial fields. In this study, control program for methane-hydrogen fuel conversion was developed to expect various parameters. After determining the hydrogen mixing ratio and the input air flow, the fuel conversion control algorithm was constructed to get the parameters that achieve the target oxygen concentration in the exhaust gas. LabVIEW program was used to derive correlations among hydrogen mixing rate, oxygen concentration in exhaust gas, input amount of air and heating value.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.476-479
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• 2000

In this study, mesh-type PECVD system was suggested to minimize the hydrogen concentration. The main structural difference between the triode system and a conventional system is that a mesh was attached to the substrate holding electrode. We investigated several conditions to compare with conventional PECVD. The main effect of mesh was to minimize the substrate damage by ion bombardment and to enhance the surface reaction to induce hydrogen desorption. It was also found that hydrogen concentration decreased but deposition rate increased as increasing applied dias. Applied DC bias enhanced sputtering process. Intense ion bombardment causes the weakly bonded hydrogen or hydrogen-containing species to leave the growing film and increased adatom mobility. Furthermore, addition of hydrogen gas enhance the surface diffusion of adatom. The structural properties of poly-Si films were analyzed by scanning electron microscopy(SEM).

• 신재생에너지
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• 제20권1호
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• pp.175-181
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• 2024

This study analyzed the hydrogen conversion rate and microbial community in conjunction with changes in carbohydrate concentration during hydrogen fermentation using food waste, and presented comprehensive research results for the condition 80 g Carbo COD/L, which showed the highest efficiency with a carbohydrate removal rate of 98.1% and a hydrogen conversion rate of 1.76 mol H₂/mol. The microbial community analysis found that Clostridium sp., widely known as a hydrogen-producing microorganism, was released in 80 g Carbo COD/L and confirmed that it was a dominant species at 98.1%. Conversely, in 100 g Carbo. Under COD/L conditions, Leuconostoc sp. showed the maximun prevalence, which is believed to hinder hydrogen production.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2004년도 International Meeting of the Microbiological Society of Korea
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• pp.101-104
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• 2004

Among biological hydrogen production processes, fermentative processes have some advantages. In this research, the hydrogen producing bacterium was isolated from domestic landfill area and identified as Enterobacter sp. The strain was named Enterobacter sp. SNU-1453. Important parameters for the hydrogen process include pH, temperature, concentration of initial glucose, and kind of sugars. The pH of the culture medium significantly decreased as fermentation proceeded due to the accumulation of various organic acids, and this inhibited the $H_2$ production seriously. When pH was controlled at pH 7.0, hydrogen production was 2614.5 m1/1 in 17 hours. The increase of glucose concentration resulted in higher $H_2$ production. The productivity of this strain was 6.87 mmol $H_2/l$ per hi on concentration of 25g glucose/l. Enterobacter sp. SNU-1453 could utilize various sugars. These results indicate that Enterobacter sp. SNU-1453 has a high potential as a fermentative $H_2$ producer.

• 한국광학회지
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• 제30권3호
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• pp.114-119
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• 2019

본 논문은 원격으로 수소 가스의 계측이 가능한 광 계수 방식의 소형 라만 라이다 시스템 개발에 관한 것이다. 수소 가스에 의한 라만 신호는 매우 미약한 신호로서, 신호 대 잡음비가 매우 낮다. 광 계수기는 광 판별기를 갖고 있어, 레이저에 의하여 발생한 배경 신호의 전기적 잡음을 제거할 수 있는 장점을 갖고 있다. 본 연구에서는 출력이 낮은 레이저와 광 계수기를 이용하여 소형의 라만 라이다 시스템을 개발하였다. 개발된 광 계수 방식의 라만 라이다 시스템의 원격 수소 가스 검출 능력을 증명하기 위하여 수소 가스 농도를 조절할 수 있는 가스 챔버를 이용하여 수소 가스 농도 측정 실험을 수행하였다. 그 결과 10 m 거리에서 최소 0.65 vol.%의 수소 가스 농도 검출이 가능하였다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 춘계학술대회논문집
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• pp.176-182
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• 2009

In the present study, a numerical simulation for the diffusion of hydrogen jet in a enclosure was performed to aid the leakage test of the hydrogen for the safety of the hydrogen vehicle. The temporal and spatial distributions of the hydrogen concentration in the test chamber are predicted from the present numerical analyses. Flammable region of 4-74% and explosive region of 18-59% hydrogen by volume was identified from the present results. Factors influencing the diffusion of the hydrogen jet were examined to evaluate the effectiveness of forced ventilation for relieving the accumulation of the leaked hydrogen gas in the chamber, which include location of open windows, size of leakage nozzle, and leakage rate among others. The distribution of the concentration of the leaked hydrogen for various cases can be used as a database in various applications for the hydrogen safety.

• 한국전산유체공학회지
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• 제14권2호
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• pp.32-38
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• 2009

In the present study, a numerical simulation for the diffusion of hydrogen jet in a enclosure was performed to aid the leakage test of the hydrogen for the safety of the hydrogen vehicle. The temporal and spatial distributions of the hydrogen concentration in the test chamber are predicted from the present numerical analyses. Flammable region of 4-74% and explosive region of 18-59% hydrogen by volume was identified from the present results. Factors influencing the diffusion of the hydrogen jet were examined to evaluate the effectiveness of forced ventilation for relieving the accumulation of the leaked hydrogen gas in the chamber, which include location of open windows, size of leakage nozzle, and leakage rate among others. The distribution of the concentration of the leaked hydrogen for various cases can be used as a database in various applications for the hydrogen safety.

• 대한환경공학회지
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• 제36권10호
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• pp.672-678
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• 2014

본 연구는 음식물 쓰레기 내 질소농도에 따른 발효과정에서 수소생성 특성과 미생물의 군집변화를 살펴보았다. 음식물 쓰레기 내 질소의 함량이 200 mg/L일 때 가장 높은 수소생산 효율을 보여주었으며, 이 때 수소생산율은 83.43 mL/g dry wt biomass/hr이였다. 질소의 함량이 600 mg/L 이상이 되면 수소생산이 저해되는 것으로 나타났으며 수소생산량과 B/A ratio (Butric acid/Acetic acid)의 비례적 상관관계는 관찰되지 않았다. 16S rDNA의 PCR-DGGE결과 대부분 군집은 Clostridium sp. 미생물로 규명되었으며 수소생성에 기여도가 큰 미생물은 Enterococcus faecium partial, Klebsiella pneumoniae strain ND6, Enterobacter sp. NCCP-231, 그리고 Clostridium algidicarnis strain E107 등으로 판명되었다.