• Title, Summary, Keyword: Methane ($CH_4$)

Search Result 665, Processing Time 0.034 seconds

In-situ Fourier Transform Infrared Spectroscopic Study during Thermolysis of Trimethylaluminum and its Adduct (Trimethylaluminum (TMA), $NH_3$ 및 TMA :$NH_3$Adduct의 열분해 반응에 대한 in-situ FTIR 분광학적 연구)

  • Hyang Sook Kim;Seong Han Kim;Jin Soo Hwang;Joong Gill Choi;Paul Joe Chong
    • Journal of the Korean Chemical Society
    • /
    • v.37 no.12
    • /
    • pp.995-1002
    • /
    • 1993
  • The thermal decomposition of trimethylaluminum (TMA) with ammonia has been investigated by in-situ Fourier transform infrared spectroscopy. The spectroscopic reaction cell, which permits heating interna lly up to 1100$^{\circ}C$, consists of stainless-steel hexagonal-port chamber containing two NaCl windows installed in parallel. In this work, the stoichiometric reaction between TMA and $NH_3$ is found to be completed immediately after mixing. FTIR spectra observed in the range of temperature 25∼1100$^{\circ}C$ show that TMA and TMA : $NH_3$ adduct decompose into methane as a predominant product around 500$^{\circ}C$. The assignments of the IR bands due to the gaseous TMA, $NH_3$ and TMA : $NH_3$ adduct are attempted on the basis of the published data. Furthermore, the decomposition of TMA can be described as a first-order reaction. Kinetic data about the decompositon of TMA and TMA : $NH_3$adduct will also be discussed.

  • PDF

Experiment and Simulation of 2-bed PSA for Hydrogen Separation from H2/CH4 Gas Mixture (수소/메탄 혼합 기체로부터 수소 분리를 위한 두 탑 PSA 실험과 전산 모사)

  • Nam, Gi-Moon;Jeong, Byung-Man;Kang, Seok-Hyun;Lee, Chang-Ha;Lee, Byung-Kwon;Choi, Dae-Ki
    • Korean Chemical Engineering Research
    • /
    • v.43 no.2
    • /
    • pp.249-258
    • /
    • 2005
  • A two-column six-step pressure swing adsorption(PSA) process was to study separation of hydrogen from hydrogen and methane($60_{vol}%/40_{vol}%$) binary system onto activated carbon adsorbent. The effects of the feed gas pressure, the feed flowrate and the P/F(purge to feed) ratio on the process performance were evaluated. The cyclic steady-states of PSA process were reached to after 15 cycles. $H_2$ purity increases according as the P/F ratio and pressure increase and the feed flow rate decreases; however, $H_2$ recovery shows an opposite phenomena to the purity. PSA process simulation studied to find optimum operation condition. In the results, 22 LPM feed flowrate, 11 atm adsorption pressure and 0.10 P/F ratio might be optimal values to obtain more than 75% recovery and 99% purity hydrogen. In this study was non-isothermal and non-adiabatic model considering linear driving force(LDF) model and Langmuir-Freundlich adsorption isotherm considered to compare between prediction and experimental data.

Changes in Carbon Amount of Soil and Rice Plant as Influenced by the Cultivation of Different Green Manure Crops (녹비작물 종류에 의한 토양 및 벼 탄소량의 변화)

  • Cho, Hyeoun-Suk;Seong, Ki-Yeung;Park, Tae-Seon;Seo, Myung-Chul;Jeon, Weon-Tai;Yang, Woon-Ho;Kang, Hang-Won;Lee, Hye-Jin
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.45 no.6
    • /
    • pp.1058-1064
    • /
    • 2012
  • A green manure crop were used in many ways, such as for reducing chemical fertilizer, improving physical and chemical properties of soils, protecting soil loss, and creating landscape when it's grown in agricultural land. Experiments were conducted to find out carbon emitted with applying green manure crops in paddy field. Amounts of carbon absorbed in the green manure crops during the winter were 1.22 ton $ha^{-1}$ in hairy vetch, 1,24 ton $ha^{-1}$ in barley, and 1.54 ton $ha^{-1}$ in hairy vetch/barley. The soil carbon content was the highest at days before transplanting of rice and decreased after days after harvesting the plant. Soil carbon contents were higher with hairy vetch or barley treatment than with hairy vetch/barley treatment. The content of emitted methane ($CH_4$) was the highest at 7 days after transplanting rice plant, and was 17 ~ 25 times higher with green manure treatments than with chemical fertilizer application. The $CH_4$ emission was the highest with hairy vetch treatment and than followed by hairy vetch/barley and barley treatments. The content of carbon absorbed in rice plant increased during the cultivation period but was not different with the applications of different green manure crops. The yield amounts of rough rice and rice strow were 5 ~ 13% higher with the green manure treatments than the chemical fertilizer application. In particular, they were the highest with hairy vetch/barley treatment as 14.07 ton $ha^{-1}$.

CO2 Methanation Characteristics over Ni Catalyst in a Pressurized Bubbling Fluidized Bed Reactor (가압 기포 유동층 반응기에서의 Ni계 촉매 CO2 메탄화 특성 연구)

  • Son, Seong Hye;Seo, Myung Won;Hwang, Byung Wook;Park, Sung Jin;Kim, Jung Hwan;Lee, Do Yeon;Go, Kang Seok;Jeon, Sang Goo;Yoon, Sung Min;Kim, Yong Ku;Kim, Jae Ho;Ryu, Ho Jeong;Rhee, Young Woo
    • Korean Chemical Engineering Research
    • /
    • v.56 no.6
    • /
    • pp.871-877
    • /
    • 2018
  • Storing the surplus energy from renewable energy resource is one of the challenges related to intermittent and fluctuating nature of renewable energy electricity production. $CO_2$ methanation is well known reaction that as a renewable energy storage system. $CO_2$ methanation requires a catalyst to be active at relatively low temperatures ($250-500^{\circ}C$) and selectivity towards methane. In this study, the catalytic performance test was conducted using a pressurized bubbling fluidized bed reactor (Diameter: 0.025 m and Height: 0.35 m) with $Ni/{\gamma}-Al_2O_3$ (Ni70%, and ${\gamma}-Al_2O_3$30%) catalyst. The range of the reaction conditions were $H_2/CO_2$ mole ratio range of 4.0-6.0, temperature of $300-420^{\circ}C$, pressure of 1-9 bar, and gas velocity ($U_0/U_{mf}$) of 1-5. As the $H_2/CO_2$ mole ratio, temperature and pressure increased, $CO_2$ conversion increases at the experimental temperature range. However, $CO_2$ conversion decreases with increasing gas velocity due to poor mixing characteristics in the fluidized bed. The maximum $CO_2$ conversion of 99.6% was obtained with the operating condition as follows; $H_2/CO_2$ ratio of 5, temperature of $400^{\circ}C$, pressure of 9 bar, and $U_0/U_{mf}$ of 1.4-3.

Evaluation of Greenhouse Gas Emissions in Cropland Sector on Local Government Levels based on 2006 IPCC Guideline (2006 IPCC 가이드라인을 적용한 지자체별 경종부문 온실가스 배출량 평가)

  • Jeong, Hyun-Cheol;Kim, Gun-Yeob;Lee, Seul-Bi;Lee, Jong-Sik;Lee, Jung-Hwan;So, Kyu-Ho
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.45 no.5
    • /
    • pp.842-847
    • /
    • 2012
  • This study was conducted to estimate the greenhouse gas emissions on local government levels from 1990 to 2010 using 2006 IPCC guideline methodology. To calculate greenhouse gas emissions based on the 16 local governments, emission factor and scaling factor were used with default value and activity data came from the food, agricultural, forestry and fisheries statistical yearbook of MIFAFF (Ministry for Food, Agriculture, Forestry, and Fisheries). The total emissions in crop sector gradually decreased from 1990 to 2010 due to a decline in agricultural land and nitrogen fertilizer usage. The annual average emission of greenhouse gas was the highest in Jeonnam (JN) with 1,698 Gg $CO_2$-eq and following Chungnam (CN), Gyungbuk (GB), Jeonbuk (JB) and Gyunggi (GG). The sum of top-six locals emission had occupied 83.4% of the total emission in cropland sector. The annual average emissions in 1990 by applying 2006 IPCC guideline were approximately 43% less than the national greenhouse gas inventory by 1996 IPCC guideline. Jeonnam (JN) province occupied also the highest results of greenhouse gas emission estimated by gas types (methane, nitrous oxide and carbon dioxide) and emission sources such as rice cultivation, agricultural soil, field burning of crop residue and urea fertilizer.