• 제목/요약/키워드: Methane Energy-based Society

검색결과 104건 처리시간 0.034초

메탄의 수증기/이산화탄소 복합 개질 반응용 니켈 촉매의 루테늄 증진 효과 (Promotion effect of Ru in Ni-based catalyst for combined $H_{2}O$ and $CO_{2}$ reforming of methane)

  • 장원진;서유택;노현석;구기영;서동주;서용석;이영우;윤왕래
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 춘계학술대회
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    • pp.53-56
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    • 2007
  • 미량의 Ru을 증진제로 첨가하여 니켈 촉매의 반응 활성을 증진시킴으로써, 저온 환원성과 장시간 반응에 대한 안정성을 확보하고자 하였다. Ni의 담지량은 12 wt%로 고정하였으며 이에 Ru을 각각 0.1, 0.3, 0.5 wt%로 변화시켜 2차 담지하였다. 메탄의 수증기/이산화탄소 복합 개질 반응에 있어 니켈 촉매에 Ru을 2차 담지 한 촉매는 800 $^{\circ}C$, GHSV(gas hourly space velocity) 265,000 $h^{-1}$ 하에서 100 %에 가까운 $CH_{4}$ 전환율을 보였으며, GHSV 1,060,000 $h^{-1}$ 일 때에도 10시간 동안 90 %의 $CH_{4}$ 전환율을 기록하였다. 또한 이 중 0.3 wt%의 Ru를 담지한 경우가 1,060,000 $h^{-1}$의 조건하에서도 95 %이상으로 가장 높은 $CH_{4}$ 전환율로 유지되었다. $H_{2}-TPR$ 분석 결과, Ni(12)/$MgAl_{2}O_{4}$ 와 비교해 볼 때 Ru(0.5)/Ni(12)/$MgAl_{2}O_{4}$와 Ru(0.3)/Ni(12)/$MgAl_{2}O_{4}$ 촉매의 경우 150 $^{\circ}C$에서 저온 환원이 가능한 $RuO_{2}$의 존재를 확인할 수 있었다.

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Evaluation of Biogas Production Performance and Dynamics of the Microbial Community in Different Straws

  • Li, Xue;Liu, Yan-Hua;Zhang, Xin;Ge, Chang-Ming;Piao, Ren-Zhe;Wang, Wei-Dong;Cui, Zong-Jun;Zhao, Hong-Yan
    • Journal of Microbiology and Biotechnology
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    • 제27권3호
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    • pp.524-534
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    • 2017
  • The development and utilization of crop straw biogas resources can effectively alleviate the shortage of energy, environmental pollution, and other issues. This study performed a continuous batch test at $35^{\circ}C$ to assess the methane production potential and volatile organic acid contents using the modified Gompertz equation. Illumina MiSeq platform sequencing, which is a sequencing method based on sequencing-by-synthesis, was used to compare the archaeal community diversity, and denaturing gradient gel electrophoresis (DGGE) was used to analyze the bacterial community diversity in rice straw, dry maize straw, silage maize straw, and tobacco straw. The results showed that cumulative gas production values for silage maize straw, rice straw, dry maize straw, and tobacco straw were 4,870, 4,032.5, 3,907.5, and $3,628.3ml/g{\cdot}VS$, respectively, after 24 days. Maximum daily gas production values of silage maize straw and rice straw were 1,025 and $904.17ml/g{\cdot}VS$, respectively, followed by tobacco straw and dry maize straw. The methane content of all four kinds of straws was > 60%, particularly that of silage maize straw, which peaked at 67.3%. Biogas production from the four kinds of straw was in the order silage maize straw > rice straw > dry maize straw > tobacco straw, and the values were 1,166.7, 1,048.4, 890, and $637.4ml/g{\cdot}VS$, respectively. The microbial community analysis showed that metabolism was mainly carried out by acetate-utilizing methanogens, and that Methanosarcina was the dominant archaeal genus in the four kinds of straw, and the DGGE bands belonged to the phyla Firmicutes, Bacteroidetes, and Chloroflexi. Silage maize is useful for biogas production because it contains four kinds of straw.

가축분뇨 및 음식물쓰레기의 혐기성 소화 병합처리 시 VS 제거효율과 메탄 발생량의 관한 연구 (A Study on VS Removal Efficiency and Methane Emission in Combined Anaerobic Digestion of Livestock Manure and Food Waste)

  • 최영익;지현조;정진희;정병길;김정권
    • 한국환경과학회지
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    • 제27권9호
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    • pp.737-742
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    • 2018
  • Livestock manure treatments have become a more serious problem because massive environmental pollutions such as green and red tides caused by non-point pollution sources from livestock manures have emerged as a serious social issue. In addition, more food wastes are being produced due to population growth and increased income level. Since the London Convention has banned the ocean dumping of wastes, some other waste treatment methods for land disposal had to be developed and applied. At the same time, researches have been conducted to develop alternative energy sources from various types of wastes. As a result, anaerobic digestion as a waste treatment method has become an attractive solution. In this study has three objectives: first, to identify the physical properties of the mixture of livestock wastewater and food waste when combining food waste treatment with the conventional livestock manure treatment based on anaerobic mesophilic digestion; second, to find the ideal ratio of waste mixture that could maximize the collection efficiency of methane ($CH_4$) from the anaerobic digestion process; and third, to promote $CH_4$ production by comparing the biodegradability. As a result of comparing the reactors R1, R2, and R3, each containing a mixture of food waste and livestock manure at the ratio of 5:5, 7:3, and 3:7, respectively, R2 showed the optimum treatment efficiencies for the removal of Total Solids (TS) and Volatile Solids (VS), $CH_4$ production, and biodegradability.

저온열탈착기술을 이용한 에틸렌 및 저분자 탄화수소 분석방법 연구 (A Study of Analytical Method for Ethylene and Low Weight Hydrocarbons (LWHC) using Thermal Desorption and Gas Chromatography-Flame Ionization Detector with (TD-GC-FID))

  • 김보원;김기현;김용현;안정현
    • 한국대기환경학회지
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    • 제30권1호
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    • pp.77-87
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    • 2014
  • In this study, an experimental approach to measure a suite of low weight hydrocarbons was investigated with an emphasis on ethylene (EL) along with many others (ethane (EA), propane (PA), propylene (PL), n-butane (BA), acetylene (AL), methyl acetylene (ML)). Their concentrations were quantified using GC-FID system equipped with thermal desorption (TD) system. The TD-based analysis was conducted using both Link Tube/Thermal Desorber (LT/TD) method and Modified Injection through a Thermal Desorption (MITD) method. The results of these analyses were evaluated in a number of respects. The system allowed the detection of all compounds except methane with the mean response factor (RF) of 10.28 (EA) to 11.94 (PL). The method detection limits of target compounds were seen in the range of 0.027 (ML) to 0.146 ng (BA). The emission flux of some environmental samples (fruits), when measured using a small flux chamber system, fell in the range of 0.14 (AL: Kiwi) to $181ng{\cdot}g^{-1}{\cdot}hr^{-1}$ (EL: Apple Peel). The results of this study confirm that the experimental approach developed in this study allows to accurately measure emissions of low weight hydrocarbons (LWHC) like ethylene from various natural and man-made source processes.

쓰레기 매립지 MGT 발전 및 유리온실 설계기술개발 (Development of Land Fill Gas(LFG)-MGT Power Generation and Green House Design Technology)

  • 허광범;박정극;이정빈
    • 에너지공학
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    • 제20권1호
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    • pp.13-20
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    • 2011
  • 마이크로 가스터빈의 높은 연료 다양성은 광범위한 범위의 적용처에 적용할 수 있도록 설계되었다. 최근에는 가스터빈 발전시스템의 연료로서, 유기성폐기물의 소화가스와 쓰레기 매립지로부터 발생되는 바이오 가스에 대한 수요가 증가하고 있다. 우리는 매립지 가스를 이용하여 마이크로 가스터빈 열병합 발전시스템의 성능특성 및 운전 특성에 대한 영향을 연구하고 있다. 메탄과 이산화탄소를 동시에 회수하는 공정을 개발하여 현장 실증 플랜트 규모로 시험을 수행하였으며, 유리온실에 농작물의 이산화탄소 고농도 집적을 목적으로 철-킬레이트 화합물을 기본으로 하는 액상촉매를 이용하여 매립지 가스내에 있는 불순물을 저렴한 비용으로 제거하고자 한다. Fe-EDTA(철-킬레이트)를 이용한 내부순환 다판식 기포탑 반응기에 의하여 농축정제와 이산화탄소 제거가 매립지 가스의 최적화 연료화를 추진하였다. 매립지가스의 유량은 0.207 $m^3$/min이고 5.5 kg/$cm^2$의 압력으로 공급되며 메탄농도 70%, 이산화탄소 27%로 공급되도록 농축반응기를 설계하였고 황화수소 99% 제거를 목표로 한다. 유리온실은 마이크로 가스터빈 배가스와 온수를 이용하여 대기중의 이산화탄소 농도에서 1500 ppm의 농도범위로 공급되도록 설계되었다.

디젤 자열개질 가스 내 포함된 $C_2H_4$ 제거를 위한 후개질기 촉매 활성 실험 (Activity test of post-reforming catalyst for removing the ethylene in diesel ATR reformate)

  • 윤상호;배중면;이상호
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 추계학술대회 논문집
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    • pp.218-221
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    • 2009
  • Solid oxide fuel cells (SOFCs), as high-temperature fuel cells, have various advantages. In some merits of SOFCs, high temperature operation can lead to the capability for internal reforming, providing fuel flexibility. SOFCs can directly use CH4 and CO as fuels with sufficient steam feeds. However, hydrocarbons heavier than CH4, such as ethylene, ethane, and propane, induce carbon deposition on the Ni-based anodes of SOFCs. In the case of the ethylene steam reforming reaction on a Ni-based catalyst, the rate of carbon deposition is faster than among other hydrocarbons, even aromatics. In the reformates of heavy hydrocarbons (diesel, gasoline, kerosene and JP-8), the concentration of ethylene is usually higher than other low hydrocarbons such as methane, propane and butane. It is importatnt that ethylene in the reformate is removed for stlable operation of SOFCs. A new methodology, termed post-reforming was introduced for removing low hydrocarbons from the reformate gas stream. In this work, activity tests of some post-reforming catalysts, such as CGO-Ru, CGO-Ni, and CGO-Pt, are investigated. CGO-Pt catalyst is not good for removing ethylene due to low conversion of ethylene and low selectivity of ethylene dehydrogenation. The other hand, CGO-Ru and CGO-Ni catalysts show good ethylene conversion, and CGO-Ni catalyst shows the best reaction selectivity of ethylene dehydrogenation.

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우드칩 반탄화와 부생가스의 특성 분석 (The Characterization of Woodchip Torrefaction and Byproduct Gas)

  • 강구;왕용;홍성구
    • 한국농공학회논문집
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    • 제56권6호
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    • pp.55-62
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    • 2014
  • Torrefaction is considered as a promising pre-treatment for thermochemical utilization of biomass. Torrefaction temperature and time are the critical operation parameters. In this study, investigated were the effects of reaction temperature and time on product composition of torrefaction. scanning electron microscope (SEM) images and thermo gravimetric analyzer (TGA) results were also compared for the effects of the operating parameters. SEM images showed that the pores were observed at the temperature of $250^{\circ}C$ for 30 minutes. Rapid decreases in weight were observed the temperature between 200 and$400^{\circ}C$. Higher heating value of the torrefied biomass was over 5,000 kcal/kg at the temperature of $250^{\circ}C$ for 45 minutes. Energy density, which is defined as the ratio of the energy yield over the mass yield was 1.36 at the temperature of $250^{\circ}C$ for 45 minutes. The energy density was higher up to 1.6 at the temperature of $280^{\circ}C$, which indicates greater loss in mass. The major components of the gas produced in the torrefaction were $CO_2$ and CO, with traces of methane. The total amount of gas was 31.54 l/kg and the calorific value of the gas was $1,164.4Kcal/Nm^3$ at the temperature of $250^{\circ}C$ for 30 minute reaction time. Based on the results of this study, the temperature of effective torrefaction is about $250^{\circ}C$ for 30 to 45 minutes of reaction time. Considering the heating value, it is desirable to utilize the gas for efficient process of torrefaction.

육성기 거세한우의 유지에너지 요구량 결정에 관한 연구 (Determination of Maintenance Energy Requirements for Growing Hanwoo Steers)

  • 설용주;김경훈;백열창;이상철;옥지운;이강연;홍성구;장선식;최창원;송만강;이성실;오영균
    • Journal of Animal Science and Technology
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    • 제53권2호
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    • pp.155-160
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    • 2011
  • 본 시험은 생후 6개월 령의 육성기 거세한우 6두($180.6{\pm}3.1$ kg)를 공시하여 옥수수 위주의 농후사료 60%와 티모시 건초 40% 비율로 급여하였고 TDN 함량은 71.4%, CP는 14.6%이었다. 시험은 Korean Feeding Standard for Hanwoo (2007)에 따라 일당 증체량 0 kg, 0.4 kg, 0.7 kg/일에 필요한 각각의 TDN 함량 1.70 kg (Low), 2.05 kg (Medium), 2.80 kg (High)의 공시사료를 섭취할 수 있도록 하는 duplicated 3 ${\times}$ 3 Latin square design으로 수행하였다. 에너지 수준에 따른 급여사료는 전량 섭취하였고, 일반적으로 건물섭취량의 증가가 반추위 통과속도를 높이기 때문에 소화율이 낮아지지만 본 실험에서는 건물, 조단백질, 조지방, 조섬유의 소화율은 차이가 없었다 (P>0.05). 섭취 에너지 수준별 평균 대사 체중 당 총에너지 섭취량은 180.2, 292.7와 337.2 kcal/$BW^{0.75}$이었다(P<0.001). 처리구별 총 에너지섭취량이 증가하면서 분으로 손실된 에너지도 51.1에서 99.71kcal/$BW^{0.75}$로 유의적으로 증가함(P<0.001)에 따라 가소화에너지는 약 70%로 처리 간 차이가 없었다. 뇨로 손실된 에너지는 3.5에서 7.9 kcal/$BW^{0.75}$로 유의적으로 증가하였고(P<0.03), 반추위 발효과정에서 발생되는 메탄가스에 의한 에너지 손실도 15.0에서 20.5 kcal/$BW^{0.75}$로 증가하는 경향을 보였다(P=0.06). 체열에 의한 손실량은 수준별로 차이가 없었지만, 총에너지섭취량(GE)에 대한 비율은 60.4, 41.2와 34.1%로 에너지 섭취량이 높아질수록 감소하였다. 대사에너지 섭취량 수준 110.6, 186.3, 209.1 kcal/$BW^{0.75}$와 각각의 체 축적 에너지 1.67, 65.76, 94.25 kcal/$BW^{0.75}$의 관계식을 통해 구한 X축 절편 값, 즉 유지를 위한 에너지 요구량은 109.8 kcal/$BW^{0.75}$로 나타났다.

메탄 산소 연소에 있어서 화염 소화에 대한 연구 (A Study on Flame Extinction in Oxymethane Combustion)

  • 김태형;권오붕;박정;길상인;윤진한;박종호
    • 한국연소학회지
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    • 제20권4호
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    • pp.34-41
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    • 2015
  • Oxy-methane nonpremixed flames diluted with $CO_2$ were investigated to clarify impact of radiation heat loss and chemical effects of additional $CO_2$ to oxidizer stream on flame extinction. Flame stability maps were presented with functional dependencies of critical diluents mole fraction upon global strain rate at several oxidizer stream temperatures in $CH_4-O_2/N_2$, $CH_4-O_2/CO_2$, and $CH_4-O_2/CO_2/N_2$ counterflow flames. The effects of radiation heat loss on the critical diluent mole fractions for flame extinction are not significant even at low strain rate in nonpremixed $CH_4-O_2/N_2$ diffusion flame, whereas those are significant at low strain rate and are negligible at high strain rate (> $200s^{-1}$) in $CH_4-O_2/CO_2$ and $CH_4-O_2/CO_2/N_2$ counterflow flames. Chemical effects of additional $CO_2$ to oxidizer stream on the flame extinction curves were appreciable in both $CH_4-O_2/CO_2$ and $CH_4-O_2/CO_2/N_2$ flames. A scaling analysis based on asymptotic solution of stretched flame extinction was applied. A specific radical index, which could reflect the OH population in main reaction zone via controlling the mixture composition in the oxidizer stream, was identified to quantify the chemical kinetic contribution to flame extinction. A good correlation of predicted extinction limits to those calculated numerically were obtained via the ratio between radical indices and oxidizer Lewis numbers for the target and baseline flames. This offered an effective approach to estimate extinction strain rate of nonpremixed oxy-methane flames permitting air infiltration when the baseline flame was taken to nonpremixed $CH_4-O_2/N_2$ flame.

5MW 바이오가스 터빈의 바이오가스와 도시가스 혼합용 정적 혼합기의 성능에 관한 수치해석 및 실증 연구 (Numerical Analysis and Demonstration Test on the Performance of a Static Mixer for mixing Biogas and Town Gas for the 5MW Biogas Turbine)

  • 차효석;송순호;박종연;김영일;문성영
    • 에너지공학
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    • 제24권1호
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    • pp.51-57
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    • 2015
  • 본 연구에서는 바이오가스의 공급이 부족한 환경에서 5MW급 바이오 가스터빈을 운전하기 위한 바이오가스와 도시가스의 혼합용 혼합챔버의 성능에 대한 수치해석 및 실증 시험을 수행한 것이다. 혼합챔버의 성능에 대한 수치해석으로 혼합챔버 출구부분에서의 불균일도와 압력강하를 계산하였다. 그 결과, 불균일도는 최소 0.05%에서 최대 0.16%로 이는 99%이상 바이오가스와 도시가스가 혼합되는 것을 의미한다. 압력강하는 입구압력 5bar대비 최소 0.07%에서 0.17%로 0.2%미만으로 나타났다. 이를 통해 현장에서 실증 시험을 수행한 결과 외기온도 $15^{\circ}C$조건에서 바이오가스를 $20.0Nm^3/min$, 도시가스를 $12.0Nm^3/min$ 공급할 경우 5MW급 바이오 가스터빈의 정상적인 운전이 가능함을 확인하였다.