• 제목/요약/키워드: Methane Content

검색결과 248건 처리시간 0.028초

겨자종자와 겨자분의 첨가가 반추위 발효성상과 메탄생성에 미치는 영향 (Effects of Mustard Seeds and Powder on In vitro Ruminal Fermentation Characteristics and Methane Production)

  • 이강연;김경훈;백열창;옥지운;설용주;한기준;박근규;류호태;이상석;전체옥;오영균
    • Journal of Animal Science and Technology
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    • 제55권1호
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    • pp.25-32
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    • 2013
  • 본 연구는 allyl isothiocyanate를 함유한 겨자종자와 겨자분을 이용하여 반추위 발효성상과 메탄 배출에 미치는 영향을 알아보고자 실시하였다. 완충용액과 혼합한 반추위액 30 ml에 겨자종자와 겨자분을 첨가하여 $39^{\circ}C$에서 6, 12, 그리고 24시간 동안 배양하였다. 겨자종자와 겨자분은 각각 0, 3.33, 5.00, 6.67 및 8.34 g/L 첨가하였다. 총 가스 생성량은 모든 처리구에서 유의적으로 증가하였다(P<0.01). 메탄 배출량은 겨자종자를 6.67 g/L 및 8.34 g/L 첨가하였을 때 각각 4.77% 및 11.54% 감소하였다(P<0.05). 겨자분에서는 배양 6시간에 8.34 g/L를 첨가하였을 때를 제외하고 효과가 나타나지 않았다. 반추위 발효성상에 있어, pH는 대조구와 비교하여 모든 처리구에서 낮게 나타났다(P<0.01). 암모니아의 농도는 첨가량이 증가할수록 유의적으로 증가하였다(P<0.01). 총 휘발성 지방산 농도는 모든 처리구가 대조구보다 높았다(P<0.05). 대조구와 비교하여 acetate의 농도는 감소하였고, propionate의 농도는 증가하였다(P<0.05). Acetate와 propionate 변화로 인해 A:P ratio 역시 감소하였다(P<0.05). 본 시험 결과로 보아, allyl isothiocyanate를 함유한 겨자종자를 첨가하였을 때 반추위 발효성상에 영향을 미치지 않고 메탄 생성량을 감소시킬 수 있을 것으로 생각된다.

PHYSICOCHEMICAL CHARACTERIZATION OF UASB GRANULAR SLUDGE WITH DIFFERENT SIZE DISTRIBUTIONS

  • 안영희;송영진;이유진;박성훈
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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    • pp.172-181
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    • 2001
  • Upflow anaerobic sludge blanket (UASB) system employs granular sludge to treat various wastewaters including landfill leachate. CH$_4$ production of the granules determines overall performance of a UASB reactor. Sludge granules are developed by self-granulation of microorganisms and dynamic balance between granule growth and decay results in coexistence of granules with different sizes in the reactor. In this study, granules taken from a laboratory-scale UASB reactor were classified into 4 groups based on their diameters and their Physicochemical characteristics we were investigated. Each group was analyzed for settling ability, specific methanogenic activity (SMA), and elemental content. Settling ability was proportional to granule diameter. suggesting effective detainment of larger granules in the reactor. When acetate or glucose was used as a substrate, all groups showed relatively slight difference in SMA. However SMA with a volatile fatty acid mixture showed significant increase with granule diameter, suggesting better establishment of syntrophic relationship in larger granules. Larger granules showed higher value of SMA upon environmental changes (i.e., PH, temperature, or toxicant concentration). Comparative analysis of elemental contents showed that content (dry weight %) of most tested elements (iron, calcium, phosphorus, zinc, nickel. and manganese) deceased with granule diameter, suggesting importance of these elements for initial granulation. Taken together, this study verified experimentally that Physicochemical Properties of granules are related to granule size distributions. Overall results of physicochemical characterization supports that larger.

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에폭시/PMR-15 폴리이미드 블렌드계의 경화동력학 및 열안정성에 관한 연구 (Studies on Cure Behavior and Thermal Stability of Epoxy/PMR-15 Polyimide Blend System)

  • Lee, Jae-Rock;Lee, Hwa-Young;Park, Soo-Jin
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2002년도 추계학술발표대회 논문집
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    • pp.265-268
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    • 2002
  • In this work, the blend system of epoxy and PMR-15 polyimide is investigated in terms of the cure behaviors and thermal stabilities. The cure behaviors are studied in DSC measurements and thermal stabilities are also carried out by TGA analysis. DDM (4, 4'-diamino diphenyl methane) is used as curing agent for EP and the content of PMR-15 is varied within 0, 5, 10, 35, and 20 phr to neat EP. As a result, the cure activation energy ($E_a$) is increased at 10 phr of PMR-15, compared with that of neat EP. From the TGA results of EP/PMR-15 blend system, the thermal stabilities based in the initial decomposed temperature (IDT) and integral procedural decomposition temperature (IPDT) are increased with increasing the PMR-15 content. The fracture toughness, measured in the context of critical stress intensity factor ($K_{IC}$) and critical strain energy release rate ($G_{IC}$), shows a similar behavior with $E_a$. This result is probably due to the crosslinking developed by the interactions between intermolecules in the polymer chains.

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모사 SNG 연료를 적용한 모델 가스터빈 연소기의 연소 불안정성에 관한 실험적 연구 (An Experimental Study on Combustion Instability in Model Gas Turbine Combustor using Simulated SNG Fuel)

  • 최인찬;이기만
    • 한국연소학회지
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    • 제20권1호
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    • pp.32-42
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    • 2015
  • The combustion instability was experimentally investigated in model gas turbine combustor with dual swirl burner. When such instability occurs, a strong coupling between pressure oscillation and unsteady heat release excites a self-sustained acoustic wave which results in a loud sound, and can even cause fatal damage to the combustor and entire system. In present study, to understand the combustion instability with a premixed mixture, the detailed periods of pressure and heat release data in unstable flame mode were investigated by various measurement methods at relatively rich condition and lean condition near flammable limits. Also, to prepare the utilization of synthetic natural gas (SNG) fuel in gas turbine system, an investigation was conducted using a simulated SNG including methane as a reference fuel to examine the effects of $H_2$ content on flame stability. These results provide that the instability due to flash-back behaviour like CIVB phenomenon occurred at rich condition, while the repetition of relighting and extinction caused the oscillation of lean condition near flammable limit. From the analysis of $H_2$ content effects, it is also confirmed that the instability frequency is proportional to the laminar burning velocity at both rich and lean condition.

양파 음료 제조를 위한 기능성 성분 추출 최적화 (Extractive Optimization of Functional Components for Processing of Onion Health Promotion Drink)

  • 허원녕;고은경
    • 한국식품과학회지
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    • 제36권3호
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    • pp.403-409
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    • 2004
  • 복합음료의 재료인 양파, 솔잎, 뽕잎, 당귀, 감초, 대추를 물과 methanol로 상온에서 각각 추출하여 전자공여능, thiosulfinate함량, ascorbic acid 함량, SOD유사황성 및 pH 1.2와 3.0에서 아질산 소거능 등을 조사하였다. SOD 유사활성은 모든 시료에서 methanol 추출이 우수하였고, 아질산 소거능은 물 추출이 우수하였고 다른 기능성 항목은 재료에 따라 추출방법에 대한 우열의 일정한 경향을 보이지 않았다. 그러나 3 hr동안 hard boil한 물추출이 thiosulfinate의 함량을 제외한 모든 기능성을 상온에서 물추출보다 증가 시켰고, 특히 상온에서 methane이 물 추출보다 높은 값을 보였던 양파, 뽕잎, 대추의 전자공여능과 당귀의 ascorbic acid 함량은 methanol 추출보다도 높은 추출 효율을 보였으므로 hard boil에 의한 물추출이 효과적인 것으로 나타났다. 단 휘발성인 thiosulfinate는 온도의 상승에 따라 그 함량이 급격한 감소를 보였으므로 이 성분은 저온에서 추출하여 혼합하는 방법을 모색해야 할 것으로 여겨진다. 아울러 hard boil에 의한 적정한 추출시간을 조사한 결과, 6 hr이면 thiosulfinate를 제외한 기능성분은 거의 용출 되어지는 것으로 밝혀졌다. 저장중의 변화를 조사한 결과, 저온저장시 ascorbic acid만이 약간의 손실이 더 있는 편이고 다른 기능성 성분은 상온 저장과 거의 같거나 저온저장이 유리하였다. 이상의 결과로 양파의 기능성 강화 복합음료의 제조는 thiosulfinate를 제외하고 6 hr 물로 고와서 추출하고 저온 저장하여야 한다는 것을 알 수 있었다.

침출수 재순환에 따른 매립가스 변화특성 연구 (Effect of Leachate Recirculation LFG Generation Characteristics)

  • 원승현;박대원
    • 유기물자원화
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    • 제26권2호
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    • pp.19-32
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    • 2018
  • 본 연구는 침출수 재순환에 의한 매립가스에 대한 메탄가스 농도에 어떠한 영향이 있는지 분석하였다. 실험대상 매립장 지역의 2010~2016년간 월평균 총강수량은 130.9mm, 2017년 6월 총강수량 73.7mm 이었다. 이러한 기상청 자료를 근거로 실험대상 매립장의 수분함수율은 낮을 것으로 예상되었다. 실험대상 매립장에 10개의 포집공을 선정하여 5톤의 침출수를 나누어서 투입하면서 매립가스 변화특성을 조사하였다. 침출수 투입하기 전 10개의 메탄가스 농도(평균) 투입전 30.14%, 투입후 메탄가스 농도(평균) 24.66%(6월 21일), 31.51%(6월 24일), 36.68%(7월 1일), 52.47%(7월 25일)로 메탄가스 농도가 증가하였다. 본 실험대상 매립장의 경우 5톤의 침출수를 투입한 결과 매립지의 유기물질 분해에 필요한 최적 함수율 50~65% 범위를 유지하는 것으로 판단된다.

혐기성 BAC 유동층 반응기에서 Start-up 방법 및 미생물 부착 특성 연구 (A Study on the Start-up Method and Characteristics of Microorganisms Attachment in an Anaerobic BAC FluidizedBed Reactor)

  • 박동일;신승훈;안재동;최석규
    • 한국환경보건학회지
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    • 제22권1호
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    • pp.82-90
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    • 1996
  • The objectives of this study were to examine the start-up method and characteristics of biomass attachment on the media in an anaerobic fluidized bed reactor(AFBR). The media adopted was the granular activated carbon which was successfully capable of adsorbing organics and biomass. The reactor was operated at 5 kg $COD/m^3\cdot day$ and 24hr of HRT. There were important problems in the AFBR's start-up, which has been reported very long and unstable. Therefore, this research was to solve the problem of the start-up and it was performed, comparing two start-up ways that were initial fluidized system and initial static-fluidized system. The results were summarized as follows: (1) On the whole initial static-fluidized system was superior to initial fluidized system in the aspects of biogas production rate, methane content and COD removal efficiency etc. (2) At the steady state methane production rate and recoverable bioenergy of initial static-fluidized system were $2.074 m^3CH_4/m^3\cdot day$, $0.488 m^3CH_4/kgCOD_{removed}\cdot day$, and 81.3kcal/day, respectively. (3) Thickness of biofilm was about $5.11 \mu m$, $\rho_{bw}$ and $\rho_{bd}$ were $1.022 g/cm^3, 0.0953g/cm^3$ respectively. (4) Biomass concentration of fluidized state was about 35 mg/g GAC. In conclusion the efficient method on the start-up of the AFBR using GAC as media was initial static-fluidized system and the period of static state needed to reach steady state was considered about twenty days.

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Mechanical Strength Evaluation of A53B Carbon Steel Subjected to High Temperature Hydrogen Attack

  • Kim, Maan-Won;Lee, Joon-Won;Yoon, Kee-Bong;Park, Jai-Hak
    • International Journal of Safety
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    • 제6권2호
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    • pp.1-7
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    • 2007
  • In this study mechanical strength of A53B carbon steel was analyzed using several types of test specimens directly machined from oil recycling pipe experienced a failure due to hydrogen attack in chemical plants. High temperature hydrogen attack (HTHA) is the damage process of grain boundary facets due to a chemical reaction of carbides with hydrogen, thus forming cavities with high pressure methane gas. Driven by the methane gas pressure, the cavities grow on grain boundaries forming intergranular micro cracks. Microscopic optical examination, tensile test, Charpy impact test, hardness measurement, and small punch (SP) test were performed. Carbon content of the hydrogen attacked specimens was dramatically reduced compared with that of standard specification of A53B. Traces of decarburization and micro-cracks were observed by optical and scanning electron microscopy. Charpy impact energy in hydrogen attacked part of the pipe exhibited very low values due to the decarburization and micro fissure formation by HTHA, on the other hand, data tested from the sound part of the pipe showed high and scattered impact energy. Maximum reaction forces and ductility in SP test were decreased at hydrogen attacked part of the pipe compared with sound part of the pipe. Finite element analyses for SP test were performed to estimate tensile properties for untested part of the pipe in tensile test. And fracture toughness was calculated using an equivalent strain concept with SP test and finite element analysis results.

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.

세리아가 첨가된 니켈/칼슘 하이드록시 아파타이트 촉매 상의 부탄 부분산화 연구 (Partial oxidation of n-butane over ceria-promoted nickel/calcium hydroxyapatite)

  • 곽정훈;이상엽;김미소;남석우;임태훈;홍성안;윤기준
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 추계학술대회 논문집
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    • pp.89-92
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    • 2007
  • Partail oxidation(POX) of n-butane was investigated in this research by employing ceria-promoted Ni/calcium hydroxyapatite catalysts ($Ce_xNi_{2.5}Ca_{10}(OH)_2(PO_4)_6$ ; x = $0.1{\sim}0.3$) which had recently been reported to exhibit good catalytic performance in POX of methane and propane. The experiments were carried out with changing ceria content, $O_2/n-C_4H_{10}$ ratio and temperature. As the $O_2/n-C_4H_{10}$ feed ratio increased up to 2.75, n-$C_4H_{10}$ conversion and $H_2$ yield increased and the selectivity of methane and other hydrocarbons decreased. But with $O_2/n-C_4H_{10}$ = 3.0, $n-C_4H_{10}$ conversion and $H_2$ yield decreased. This is considered due to that too much oxygen may inhibit the reduction of Ni or induce the oxidation of Ni, which results in poor catalytic activity. The optimum $O_2/n-C_4H_{10}$ ratio lay between 2.50 and 2.75. $Ce_{0.1}Ni_{2.5}Ca_{10}(OH)_2(PO_4)_6$ showed the highest $n-C_4H_{10}$ conversion and $H-2$ yield on the whole. In durability tests, higher hydrogen yield and better catalyst stability were obtained with the $O_2/n-C_4H_{10}$ ratio of 2.75 than with the ratio of 2.5.

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