• Title/Summary/Keyword: Bio-hydrogen production

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Fermentative Water Purification based on Bio-hydrogen (생물학적 수소 발효를 통한 수처리 시스템)

  • Lee, Jung-Yeol;Chen, Xue-Jiao;Min, Kyung-Sok
    • Journal of Korean Society on Water Environment
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    • v.27 no.6
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    • pp.926-931
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    • 2011
  • Among various techniques for hydrogen production from organic wastewater, a dark fermentation is considered to be the most feasible process due to the rapid hydrogen production rate. However, the main drawback of it is the low hydrogen production yield due to intermediate products such as organic acids. To improve the hydrogen production yield, a co-culture system of dark and photo fermentation bacteria was applied to this research. The maximum specific growth rate of R. sphaeroides was determined to be $2.93h^{-1}$ when acetic acid was used as a carbon source. It was quite high compared to that of using a mixture of volatile fatty acids (VFAs). Acetic acid was the most attractive to the cell growth of R. sphaeroides, however, not less efficient in the hydrogen production. In the co-culture system with glucose, hydrogen could be steadily produced without any lag-phase. There were distinguishable inflection points in the accumulation of hydrogen production graph that resulted from the dynamic production of VFAs or consumption of it by the interaction between the dark and photo fermentation bacteria. Lastly, the hydrogen production rate of a repeated fed-batch run was $15.9mL-H_2/L/h$, which was achievable in the sustainable hydrogen production.

Feasibility of fermentative bio-hydrogen production from different organic wastes (다양한 유기성 폐자원에서 바이오 수소 생성 연구)

  • Hwang, Jae-Hoon;Choi, Jeong-A;Abou-Shanab, R.A.I.;Jeon, Byong-Hun
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.506-510
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    • 2009
  • The effects of various organic wastes on anaerobic fermentative hydrogen production were studied using enriched mixed microflora in batch tests. Rotten fruit, corn powder and organic wastewater enriched with sulfate (up to 1,000 mg/L) were used for experiments. Maximum hydrogen production (547.1 mL) was observed from rotten apple with initial substrate concentration of 132.2 g COD/L. The experimental result on sulfate enriched organic wastewater indicated that hydrogen production is not adversely influenced by relatively high sulfate concentration. Residual sulfate content remained at 96-98 % after 75 hours of reaction, which showed that no major sulfate reduction was occurred at pH 5.3-5.5 in the reactor. The volatile fatty acid (VFA) fractions produced during the reaction was in the order of butyrate > acetate > propionate in all experiments. The results of this study would be useful for controlling the conditions on fermentative hydrogen production using different feedstocks.

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Effect of Limited Oxygen Supply on Coenzyme $Q_{10}$ Production and Its Relation to Limited Electron Transfer and Oxidative Stress in Rhizobium radiobacter T6102

  • Seo, Myung-Ji;Kim, Soon-Ok
    • Journal of Microbiology and Biotechnology
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    • v.20 no.2
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    • pp.346-349
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    • 2010
  • Coenzyme $Q_{10}$ ($CoQ_{10}$) production from Rhizobium radiobacter T6102 was monitored under various oxygen supply conditions by controlling the agitation speeds, aeration rates, and dissolved oxygen levels. As the results, the $CoQ_{10}$ production was enhanced by limited oxygen supply. To investigate whether the $CoQ_{10}$ production is associated with its physiological functions of electron carrier and antioxidant, the effects of sodium azide and hydrogen peroxide on the $CoQ_{10}$ production were studied, showing that the $CoQ_{10}$ contents were slightly enhanced with increasing sodium azide (up to 0.4 mM) and hydrogen peroxide (up to $10\;{\mu}M$) concentrations. These results suggest the plausible mechanism where the limited electron transfer stimulating the environments of limited oxygen supply and oxidative stress could accumulate the $CoQ_{10}$, providing the relationship between the $CoQ_{10}$ physiological functions and its regulation system.

Research Trends of Ni-based Catalysts on Steam Reforming of Bio-oils for H2 Production: A Review (수소 생산을 위한 바이오오일 수증기 개질 반응에서의 니켈계 촉매 연구동향)

  • Da Hae Lee;Hyeon Myeong Seo;Yun Ha Song;Jaekyoung Lee
    • Clean Technology
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    • v.29 no.3
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    • pp.163-171
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    • 2023
  • Hydrogen has been gaining a lot of attention as a possible clean energy source that can aid in reaching carbon neutrality. Currently, hydrogen production has relied on the steam reforming of fossil fuels. However, due to the carbon dioxide emissions caused by this process, hydrogen production based on the steam reforming of bio-oil derived from biomass has been proposed as an alternative approach. In order to use this alternative approach efficiently, one of the key issues that must be overcome is that the complexity of bio-oil, which has a large molecular weight and diverse functional groups of hydrocarbons, promotes the catalytic deactivation of nickel-based catalysts. In this review, research efforts to improve nickel-based catalysts for the steam reforming of bio-oil have been discussed in terms of the active phase, support, and promoters. The active phases are involved in activating C-C and C-H bonds of high-molecular-weight hydrocarbons, and noble and transition metals can be utilized. In terms of the support and promoters, the catalytic deactivation of Ni-based catalysts can be inhibited by utilizing reactive lattice oxygen for support or by suppressing the acidity. The development of active and stable Ni-based reforming catalysts plays a critical role in clean hydrogen production based on bio-oils.

CO$_2$ Conversion to Methane using Bio-hydrogen (바이오 수소를 이용한 이산화탄소의 메탄 전환 연구)

  • Lee, Jun-Cheol;Kim, Jae-Hyung;Choi, Kwang-Keun;Pak, Dae-Won
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.9
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    • pp.933-938
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    • 2008
  • In the present study, carbon dioxide was converted to methane, using bio-hydrogen. Here, the bio-hydrogen was produced from organic waste. The anaerobic microorganism was cultured using only carbon dioxide and hydrogen for duration of 3 months. Therefore methane was not produced with acetogenotrophs. During methane production, carbon dioxide and hydrogen are taken in different ratios; among which 1 : 5 ratio has shown the highest methane yield. Carbon dioxide and hydrogen were introduced into the reactor at the rate of 8 mL/min and 40 mL/min, respectively. In this case, 92% of carbon dioxide was reduced and 2.2 m$^3$/m$^3$ day amount of methane was produced. Thus, the process has been successful in conversion of carbon dioxide into methane by purging it into methane fermentation reactor with bio-hydrogen using batch process.

Optimization of Hydrogen Production using Clostridium beijerinckii KCTC 1785 (Clostridium beijerinckii KCTC 1785를 이용한 수소생산 최적화 조건 탐색)

  • Kim, Jung-Kon;Nhat, Le;Kim, Seong-Jun;Kim, Si-Wouk
    • KSBB Journal
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    • v.20 no.6
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    • pp.401-407
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    • 2005
  • Optimum culture conditions and medium composition for hydrogen production by Clostridium beijerinckii KCTC 1785 were investigated. Initial pH and temperature for growth were 7.0 and $35^{\circ}C$, respectively. Agitation accelerated the hydrogen production. Although C. beijerinckii KCTC 1785 could grow up to 6%(w/v) glucose in the medium, the optimum glucose concentration for hydrogen production was 4% and hydrogen content in the biogas was 37%(v/v). However, the economical glucose concentration for hydrogen production was 1% regarding to the residual glucose which was not used in the medium. During hydrogen fermentation, acetic and butyric acid were produced simultaneously. High concentrations of acetic(>5,000 mg/L) or butyric(>3,000 mg/L) acid inhibited hydrogen production. When pH was maintained at 5.5 in the batch fermentation, 1,728 mL of hydrogen was produced from 0.5% glucose within 15 hr. $H_2$ yield was estimated to be 1.23 mol $H_2/mol$ glucose. It was found that yeast extract or tryptose in the medium was essential for hydrogen production.

Studies on the Production of Hydrogen by the Steam Reforming of Glycerol Over NI Based Catalysts (NI계 촉매상에서 글리세롤의 수증기 개질반응(Steam Reforming)에 의한 수소제조 연구)

  • Hur, Eun;Moon, Dong-Ju
    • Transactions of the Korean hydrogen and new energy society
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    • v.21 no.6
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    • pp.493-499
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    • 2010
  • Steam reforming (SR) of glycerol, a main by-product of manufacturing process of bio-diesel, for the production of hydrogen was investigated over the Ni-based catalysts. The Ni-based catalysts were prepared by an impregnation method, and characterized by $N_2$ physisorption, CO chemisorption, XRD and TEM techniques. It was found that the Ni/${\gamma}-Al_2O_3$ catalyst showed higher conversion and catalytic stability for the carbon formation than the other catalysts in the steam reforming of glycerol under the tested conditions. The results suggest that the steam reforming of glycerol over modified Ni/${\gamma}-Al_2O_3$ catalyst minimized carbon formation can be applied in hydrogen station for fuel-cell powered vehicles and fuel processor for stationary and portable fuel cells.

Exergy Analysis on the System of Superheated Steam (700℃, 3 atm) Production for the Reversible Electrolysis: Based Hydrogen Production (양방향수전해 기반 수소제조용 초고온스팀 생산시스템의 엑서지 분석)

  • HAN, DANBEE;PARK, SENGRYONG;CHO, CHONGPYO;BAEK, YOUNGSOON
    • Transactions of the Korean hydrogen and new energy society
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    • v.29 no.3
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    • pp.235-242
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    • 2018
  • Hydrogen can be produced by reforming reaction of natural gas (NG) and biogas, or by water electrolysis. In this study, hydrogen production through water-electrolysis needs superheated steam above $700^{\circ}C$ for high efficiency. The production method of hydrogen like this was recommended for the 4-type processes for superheated steam ($700^{\circ}C$, 3 atm) by Bio-SRF combustion furnace. The 4-type processes to produce superheated steam at $700^{\circ}C$ from the heat source of SRF combustion furnace was simulated using PRO II. The optimum process was selected through exergy analysis. The difference of process 1 and 2 is to the order of depressure and heating process to change $180^{\circ}C$ and 7 atm to $700^{\circ}C$ and 3 atm. Process 3 and 4 is to utilize 25% of steam to generate superheated steam and remaining to use for the power generation by steam generator.

Hydrogen Production by Steam Reforming of Aqueous Bio-Oil from Marine Algae (수소생산을 위한 해조류 유래 수용액 상 바이오오일의 수증기 개질 반응)

  • Park, Yong Beom;Lim, Hankwon;Woo, Hee-Chul
    • Korean Chemical Engineering Research
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    • v.54 no.1
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    • pp.94-100
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    • 2016
  • Hydrogen production via steam reforming of bio-oil from algal biomass over fast pyrolysis with commercial catalysts was carried out. Aqueous bio-oil obtained by phase separation from a crude oil over fast pyrolysis was used as a reactant and comparison studies for activity over different catalysts (FCR-4-02, POS-7, Cat. A, RUA), reaction temperature, and steam/carbon (S/C) ratios were performed. Experimental results showed that different catalytic activities were observed with different S/C ratios and catalyst composition and the highest hydrogen yield of 70% was obtained with a POS-7 catalyst at a S/C ratio of 10 and 1073 K.

Hydrogen Evolution from Biological Protein Photosystem I and Semiconductor BiVO4 Driven by Z-Schematic Electron Transfer

  • Shin, Seonae;Kim, Younghye;Nam, Ki Tae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.251.2-251.2
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    • 2013
  • Natural photosynthesis utilizes two proteins, photosystem I and photosystem II, to efficiently oxidize water and reduce NADP+ to NADPH. Artificial photosynthesis which mimics this process achieve water splitting through a two-step Z-schematic water splitting process using man-made synthetic materials for hydrogen fuel production. In this study, Z-scheme system was achieved from the hybrid materials which composed of hydrogen production part as photosystem I protein and water oxidizing part as semiconductor BiVO4. Utilizing photosystem I as the hydrogen evolving part overcomes the problems of existing hydrogen evolving p-type semiconductors such as water instability, expensive cost, few available choices and poor red light (>600 nm) absorbance. Some problems of photosystem II, oxygen evolving part of natural photosynthesis, such as demanding isolation process and D1 photo-damage can also be solved by utilizing BiVO4 as the oxygen evolving part. Preceding research has not suggested any protein-inorganic-hybrid Z-scheme composed of both materials from natural photosynthesis and artificial photosynthesis. In this study, to realize this Z-schematic electron transfer, diffusion step of electron carrier, which usually degrades natural photosynthesis efficiency, was eliminated. Instead, BiVO4 and Pt-photosystem I were all linked together by the mediator gold. Synthesized all-solid-state hybrid materials show enhanced hydrogen evolution ability directly from water when illuminated with visible light.

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