• Journal of Environmental Health Sciences
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• v.31 no.4 s.85
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• pp.322-326
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• 2005

연속반응조에서의 수소생산에 대한 수리학적체류시간(희석율, D)의 영향을 $1\%$ sucrose를 함유한 $37{\pm}1^{\circ}C$ 조건에서 조사하였다. 실험결과 수리학적체류시간(희석율)의 각각의 조건에 따라 생성된 가스중 수소성분은 $50~71\%$의 범위로 발생되었다. $H_2/CO_2$ 비율은 희석율이 증가할 때 $H_2/CO_2$ 비율도 증가하였다. 최대수소생성 수율은 희석율 0.14 l/h까지는 증가하다가 이후에는 감소하였고, 수소생성 수율은 0.81 l/g sucrose이었다. Acetate 생성 수율은 butyrate생성 수율 보다 희석율 조건변화에 민감하게 변화하였다. propionate 및 solvents는 희석율 변화에 영향을 받지 않았다 biomass 수율은 희석율이 0.2 l/h 까지는 증가하였으나, 그 이상의 조건에서는 감소하였다.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.176-182
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• 2009

Hydrogen producing bacterium, strain MeL 6-2 was isolated from the sludge of the factory areas in Anyang through the acclimation in basal salt medium (BSM) supplemented with 10 g/L of sucrose. Isolated strain MeL 6-2 was a facultative anaerobe which could grow in both aerobic and anaerobic environments. An aerobically grown pure culture isolated from enriched culture was analyzed by 16S rDNA sequencing and identified as Rhodopseudomonas sp. MeL 6-2. Effects of the concentrations of glucose and sucrose on the hydrogen production rate and the hydrogen production yield were investigated. When glucose in the range of 1~12 g/L was supplemented to the BSM, strain MeL 6-2 could grow without lag phase. An increased glucose concentration increased the specific hydrogen production rate linearly to $4.2\;mmol-H_2{\cdot}L^{-1}{\cdot}h^{-1}$ at 10 g/L, and $60\;mmol-H_2{\cdot}mg-DCW^{-1}{\cdot}h^{-1}$, but decreased slightly as the concentration increased to 12 g/L. The hydrogen production yield was maintained over a range from 2.6 to $3.1\;mol-H_2{\cdot}mol-glucose^{-1}$. When sucrose in the range of 1~12 g/L was supplemented to the BSM, strain MeL 6-2 could grow after ten hours. An increased sucrose concentration increased the specific hydrogen production rate and the hydrogen production yield to $163\;mmol-H_2{\cdot}mg-DCW^{-1}{\cdot}h^{-1}$ and to $4.5\;mol-H_2{\cdot}mol-sucrose^{-1}$, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.1
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• pp.57-63
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• 2011

Development of alternative energy is needed as the fossil is started to be exhausted. This alternative energy should be environmental friendly and renewable. Currently, the alternative energy which gets the most attraction is hydrogen. Hydrogen can be produced by a number of different processes. Among those methods, hydrogen production in biological way is considered as the most environmental friendly method. However, productivity of biological hydrogen production is not good enough to be commercialized yet. Thus, many researchers are trying to improve productivity and yield of biohydrogen production. Here, progress in the diverse developmental approaches on biological hydrogen production, is reviewed.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.1
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• pp.1-9
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• 2013

Long term hydrogen production was investigated in an anaerobic sequencing batch reactor (ASBR) using mixed microflora. Glucose (about 8,250 mg/L) was used as a substrate for the ASBR operation under the condition of pH 5.5 and $37^{\circ}C$ with mixing at 150 rpm. The experiment was carried out over a period of 160 days. Hydrogen yield was 0.8mol $H_2/mol$ glucose with F/M ratio 2 at initial operation period. The hydrogen yield reached to maximum 2.6 mol $H_2/mol$ glucose at 80th day operation. However decreased hydrogen yield was observed after 80 days operation and eventually no hydrogen yield. Although well-known hydrogen producer Clostridium sp. was detected in the reactor by PCR-DGGE analysis, changed reactor operation was the major reason of the decreased hydrogen production, such as low F/M ratio of 0.5 and high propionic acid concentration 2,130 mg/L. Consequently the long period operation resulted in MLSS accumulation and then low F/M ration stimulating propionic acid formation which consumes hydrogen produced in the reactor.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.83-88
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• 2012

The algal bloom, resulting from eutrophication, has caused serious water quality problems in river and lake. Therefore, it has to be removed by any means including physicochemical or biological treatment for preserving water quality. This study was conducted to investigate the microalgae removal and energy production using combined electro-flotation and anaerobic hydrogen fermentation processes. The result showed that algae removal efficiency based on chlorophyll a removal increased with the current. At a current of 0.6A, the maximum microalgae removal efficiency of 95.9% was achieved. The treatability of anaerobic hydrogen fermentation was investigated to recover energy from microalgae removed by electro-flotation. The ultimate hydrogen yields of algae before and after ultrasonic pretreatment were 17.3 and 61.1 ml $H_2/g$ dcw(dry cell weight), respectively. The ultrasonic pretreatment of algae led to 3.4-fold higher $H_2$ production due to the increase of hydrolysis rate.

• Applied Chemistry for Engineering
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• v.18 no.2
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• pp.162-167
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• 2007

Hydrogen production and its dynamics were investigated in the continuous anaerobic digestion process using Clostridium beijerinckii Donker 1926. In this work, glucose was used as a substrate and hydraulic retention times (HRT) were 0.5, 0.25 or 0.125 day. The removal efficiency of carbohydrate was over 99% under all of HRT conditions. As HRT was shorter, COD removal efficiency became lower while hydrogen content in the total gas and hydrogen production rate became higher. The cell growth yield and hydrogen production yield were 0.27 g-VSS/g-glucose and 0.26 L/g-glucose, respectively, at the steady state. It is expected that the microorganism is able to produce hydrogen when used in the wastewater treatment containing carbohydrate such as glucose. Also, the results in this study could be applied to the actual hydrogen gas production, a promising alternative energy.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2010.04a
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• pp.192-192
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• 2010

현재 산업과 과학의 발달로 인한 무분별한 화석연료의 사용은 에너지자원의 고갈과 환경오염의 문제를 야기시켜, 이의 해결을 위한 청정 신에너지에 대한 연구가 전 세계적으로 집중되고 있다. 이 중 바이오매스는 화석연료보다 비교적 높은 H/C 비를 갖기 때문에 신에너지인 수소 또는 Syngas를 생산하기 위한 가스화 특성이 우수한 특징을 가지고 있으며, 구성성분 내 중금속, 황, 질소를 거의 함유하지 않는 점에서 환경오염 저감과 동시에 대체 신에너지로써 각광을 받고 있다. 이에 본 연구에서는 목질계 바이오매스인 Wood pellet (미송)에 대하여 고정층 반응기를 이용하여 질소분위기하에서 온도 및 Steam/Biomass Ratio(이하 SBR) 조건에 따른 가스화 특성으로 고찰하는데 그 목적을 둔다. 온도의 영향에 대하여, 높은 온도 범위에서 수소 수율이 증가함을 알 수 있었다. SBR에 대한 영향으로서, 저온 (700, $800^{\circ}C$)에서는 SBR=1에서는 수소의 수율이 증가하였으나 SBR=2, 3에서 감소하는 것을 보였다. 하지만 $900^{\circ}C$에서는 SBR이 증가 할수록 수소의 수율이 증가하는 것으로 나타났다. 또한 볼륨비로 나타내었을 경우 $H_2/CO(vol/vol)$의 경우 $900^{\circ}C$, SBR=3에서 0.73%로 water gas shift reaction이 가장 잘 일어난 것을 확인했고, $H_2/CH_4(vol/vol)$의 경우 마찬가지로 위의 조건과 동일조건에서 2.59%로 steam reforming이 가장 잘 일어난 것을 확인할 수 있었다. 최종적으로 본 실험에서는 $900^{\circ}C$, SBR=3인 경우에 가장 높은 수소수율을 얻을 수 있으며, 이때 수소의 수율은 32.7 Vol%였다.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.12
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• pp.865-872
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• 2014

The study was conducted to evaluate the effect of addition of food waste in brown water for anaerobic hydrogen production. Batch experiment was carried out to determine appropriate food waste to brown water mixing ratio. Maximum hydrogen yield of $6.92mmol\;H_2/g\;COD_{removed}$ was obtained at 70% food waste and 30% brown water. Semi-pilot scale reactor was operated based on result of batch experiment. Semi-pilot reactor operated, mixing 70% food waste and 30% brown water showed significant increment in butyric acid concentration. B/P (Butyric to propionic acid ratio) which is considered as governing factor for hydrogen production was found high (52.64). Maximum hydrogen yield of $25.03mmol\;H_2/g\;COD_{removed}$ was obtained. Result of this study concluded that mixing of food waste to brown water at appropriate ratio assists in enhanced hydrogen fermentation.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.2
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• pp.238-243
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• 2012

The purpose of this study is to search the temperature-rise time conditions for adequate reforming temperature region of hydrogen generation system. And we measured theexhaust gas at the exit of that system in order to know the combustion state of hydrogen generation system's combustor. We found the optimum condition of heat supply and temperature-rise time at well burned state. And the results were nearly same when the reactants were entered to each reactors. We will further consider the effects of temperature change near the exothermic reactors and find out hydrogen yield through reforming experiment.

• Journal of Energy Engineering
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• v.19 no.4
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• pp.221-227
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• 2010

In this study, we consider gas generation characteristics on pyrolysis of eco-fuel which were made by mixing of Pitch Pine and Lauan sawdust as biomass and polyethylene, polypropylene, polystyrene as municipal plastic wastes with catalyst in fixed bed reactor. From the result of higher heating value(HHV) measurement and of ultimate analysis, the heating value of plastic wastes and a hydrogen content in plastic sample are higher than biomass. An activation energy was reduced by a catalyst addition. However the catalyst content influence over 5 wt% was insignificant. The yield of hydrogen from gasification of biomass containing plastic wastes such as polyethylene, polypropylene and polystyrene were obtained higher than that of sole biomass. The high temperature and mixture ratio of catalyst conditions induced to high hydrogen yield in most of the samples. As the influence of catalyst, the hydrogen yield by catalytic reaction was higher than non-catalytic reaction. We confirmed that Ni-$ZrO_2$ catalyst is more active in increasing the hydrogen yield in comparison with that of carbonate catalyst. The maximum hydrogen yield was 65.9 vol.%(Pitch Pine / polypropylene / 20 wt.% Ni-$ZrO_2$(1:9) at $900^{\circ}C$).