• Title, Summary, Keyword: Methane

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Control of Rumen Microbial Fermentation for Mitigating Methane Emissions from the Rumen

  • Mitsumori, Makoto;Sun, Weibin
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.1
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    • pp.144-154
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    • 2008
  • The rumen microbial ecosystem produces methane as a result of anaerobic fermentation. Methanogenesis in the rumen is thought to represent a 2-12% loss of energy intake and is estimated to be about 15% of total atmospheric methane emissions. While methanogenesis in the rumen is conducted by methanogens, PCR-based techniques have recently detected many uncultured methanogens which have a broader phylogenetic range than cultured strains isolated from the rumen. Strategies for reduction of methane emissions from the rumen have been proposed. These include 1) control of components in feed, 2) application of feed additives and 3) biological control of rumen fermentation. In any case, although it could be possible that repression of hydrogen-producing reactions leads to abatement of methane production, repression of hydrogen-producing reactions means repression of the activity of rumen fermentation and leads to restrained digestibility of carbohydrates and suppression of microbial growth. Thus, in order to reduce the flow of hydrogen into methane production, hydrogen should be diverted into propionate production via lactate or fumarate.

Characteristics of methane sorption in surface modified activated carbon (표면개질 된 활성탄의 메탄흡장 특성)

  • Yun, Seok-Min;Kim, Ju-Wan;Jo, Won-Jun;Kim, Young-Ho;Lee, Young-Seak
    • 한국신재생에너지학회:학술대회논문집
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    • pp.73-76
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    • 2007
  • In this study, methane gas adsorption ability of activated carbon (AC) with surface functional group effect, adsorbed methane amount was evaluated after nitric acid and ureatreatment of AC surface. Specific surface area and pore distribution of AC were studied though nitrogen adsorption isotherm at 77 K. Micro pore volume was calculated through H-K method. Adsorbed methane amount was evaluated through volume method at room temperature by using auto adsorption apparatus. Adsorbed methane amount of AC was found to increase with to specific surface area increase.Correlation proposed between the methane adsorption amount and surface nature indicates that the surface nature plays an important role on the adsorption amount at a given temperature.

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Continuous methanol synthesis directly from methane and steam over Cu(II)-exchanged mordenite

  • Lee, Sae Ha;Kang, Jong Kyu;Park, Eun Duck
    • The Korean Journal of Chemical Engineering
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    • v.35 no.11
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    • pp.2145-2149
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    • 2018
  • The formation of methanol directly from methane and steam was observed over Cu ion-exchanged mordenite. Furthermore, the continuous production of methanol was achieved by co-feeding methane and steam over Cumordenite. The methanol production rate was comparable to that reported in the stepwise process in which activation, methane reaction, and extraction of methanol were carried out separately.

Comparison of the Combustion Characteristics of Methane-Air and Gasoline-Air Mixtures (가솔린.메탄의 연소특성 비교)

  • Park, M.H.
    • Journal of ILASS-Korea
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    • v.7 no.3
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    • pp.7-11
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    • 2002
  • Comparison of the combustion characteristics of methane-air and gasoline-air mixtures has been conducted experimentally by a spherical bomb technique. The results indicate 1) the burning velocity of gasoline is slightly higher than that of methane, but their basic behavior of combustion characteristics, positive dependence on temperature and negative one on pressure, are the same, and 2) 20 vol.% addition of hydrogen to methane enhances the burning velocity by about 30%, but does not come to reverse the tendency of pressure dependence to that of pure hydrogen.

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When Methane is decomposed on the CRT Manufacturing Process

  • Lee, Byoung-Joo;Hong, Sang-Pyo;Ko, Byoung-Doo;Hwang, Cheol-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.1051-1052
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    • 2002
  • Vacuum surroundings in Cathode Ray Tubes (CRT) are very important factor for CRT lifetime, especially cathode & getter's. A getter is a very good vacuum pump; unfortunately, it cannot absorb an inert gas and hydrocarbons. There are only argon and helium in CRT after $1^{st}$ emission test because other active gases are absorbed by getter and methane is decomposed during CRT working. It is also very important to know exactly where and when methane is decomposed during the CRT manufacturing process, because methane is known to be harmful to cathode when its amount is high, and getter can't absorb the methane.

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Small Methane Detection System using Optical Spectrum Characteristics (분광특성을 이용한 소형의 메탄 가스 감지 시스템)

  • Jo, Kyung-Hwa;Lyu, Geun-Jun;Kim, Eung-Soo
    • Journal of Sensor Science and Technology
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    • v.20 no.1
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    • pp.53-57
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    • 2011
  • We developed a small methane detection system because methane gas is used in many areas and is dangerous. The developed system consisted of LD(Laser Diode) tuned a wavelength of $1.65\;{\mu}m$, two mirrors to collect a laser beam, photo detector. It could detect methane gas at a long range and its sensitivity was 1.98 V/$CH_4%$.

A Method for the Measurement of Methane Gas Based on Multi-beam Interferometry

  • Ye, Jiansen;Li, Zhuo
    • Journal of the Optical Society of Korea
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    • v.17 no.6
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    • pp.481-485
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    • 2013
  • A method for the measurement of the concentration of methane is experimentally demonstrated. The wavelength filter and gas cell are combined by using one Fabry-Perot etalon, which is filmed with the reflectivity of 96%. The optical broadband source is not only filtered to match the absorption wavelength of methane, but also absorbed by the methane in the same Fabry-Perot etalon. The concentration of the methane can be detected directly by measuring the transmission intensity. Compared with the conventional method, the proposed method possesses low costand high stability.

Correlation between Methane (CH4) Emissions and Root Aerenchyma of Rice Varieties

  • Kim, Woo-Jae;Bui, Liem T.;Chun, Jae-Buhm;McClung, Anna M.;Barnaby, Jinyoung Y.
    • Plant Breeding and Biotechnology
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    • v.6 no.4
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    • pp.381-390
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    • 2018
  • Percentage of aerenchyma area has been closely linked with amounts of methane emitted by rice. A diversity panel of 39 global rice varieties were examined to determine genetic variation for root transverse section (RTS), aerenchyma area, and % aerenchyma. RTS and aerenchyma area showed a strong positive correlation while there existed no significant correlation between RTS area and % aerenchyma. Five varieties previously shown to differ in methane emissions under field conditions were found to encompass the variation found in the diversity panel for RTS and aerenchyma area. These five varieties were evaluated in a greenhouse study to determine the relationship of RTS, aerenchyma area, and % aerenchyma with methane emissions. Methane emissions at physiological maturity were the highest for 'Rondo', followed by 'Jupiter', while 'Sabine', 'Francis' and 'CLXL745' emitted the least. The same varietal rank, 'Rondo' being the largest and 'CLXL745' the smallest, was observed with RTS and aerenchyma areas. RTS and aerenchyma area were significantly correlated with methane emissions, r = 0.61 and r = 0.57, respectively (P < 0.001); however, there was no relationship with % aerenchyma. Our results demonstrated that varieties with a larger root area also developed a larger aerenchyma area, which serves as a gas conduit, and as a result, methane emissions were increased. This study suggests that root transverse section area could be used as a means of selecting germplasm with reduced $CH_4$ emissions.

메탄 하이드레이트의 부존 가능성과 평형조건

  • 류병재;허대기;선우돈;정태진;김현태;김세준;이호섭
    • 한국석유지질학회:학술대회논문집
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    • pp.56-65
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    • 1998
  • Methane hydrate is ice-like solid compound consisting of mainly methane and water, and is stable under specific low temperature and high pressure conditions (HSZ : methane hydrate stability zone) that occurs in permafrost regions and in the ocean floor sediments. Geophysical survey was implemented in the southern area of the East Sea, and the HSZ of the study area is determined by the temperature, pressure and local heat flow obtained from the survey and well data. In the study area, methane hydrates could exist in the sediments below the water depths of about $300{\cal}m$, and the base of HSZ is about 600m beneath the seafloor. The acoustically blanking zones in the sediment and phenomena of gas seepage were detected from the seismic section. These sediments have the sufficient physical condition for the formation of methane hydrate. The temperature and pressure conditions were experimentally measured for the dissociation of methane and propane hydrates in Pure water. Equilibrium conditions of methane and propane hydrates were obtained in the pressure range up to 19050Kpa and 401.3Kpa. Under same temperature condition, propane hydrate was dissociated at lower pressure than that of methane hydrate.

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