• Title/Summary/Keyword: Reforming

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Effect of discontinuous mixture gas feeding on effective hydrogen production in a steam reformer frommethane (효율적 수소 생산을 위한 메탄 수증기 개질 반응기에서의 불연속적 가스 유입의 영향)

  • Lee, Shin-Ku;Park, Joon-Guen;Lim, Sung-Kwang;Bae, Joong-Myeon
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.10a
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    • pp.25-28
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    • 2008
  • Steam reforming reaction is a matured technology to get hydrogen from hydrocarbon fuels compared with other reforming reactions such as partial oxidation(POX), autothermal reforming(ATR). It is so endothermic that it needs heat source to activate the reaction. Due to the reaction characteristics, heat transfer limitation phenomena generally occur in the steam reformer. As one of new ideas, the effect of discontinuous gas feeding is investigated based on heat transfer characteristics. The new operating method is usually favorable at high GHSV region(i.e. over $10,000h^{-1}$). In order to numerically simulate the physical issues, numerical approach is adopted based on heterogeneous reaction model, two-equation model in energy equation, and other constitutive models in porous media.

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GASIFICATION OF CARBONEOUS WASTES USING THE HIGH TEMPERATURE REFORMER

  • Lee, Dong-Jin
    • Environmental Engineering Research
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    • v.10 no.3
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    • pp.122-130
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    • 2005
  • Gasification of carbonaceous wastes such as shredded tire, waste lubricating oil, plastics, and powdered coal initiates a single-stage reforming reactor(reformer) Without catalyst and a syngas burner. Syngas is combusted with $O_2$ gas in the syngas burner to produce $H_2O\;{and}\;CO_2$ gas with exothermic heat. Reaction products are introduced into the reforming reactor, reaction heat from syngas burner elevates the temperature of reactor above $1,200^{\circ}C$, and hydrogen gas fraction reaches 65% of the product gas output. Reactants and heat necessary for the reaction are provided through the syngas burner only. Neither $O_2$ gas nor steam is injected into the reforming reactor. Multiple syngas burners may be connected to the reforming reactor in order to increase the syngas output, and the product syngas is recycled into syngas burner.

Characteristics of LPG Fuel Reforming Utilizing Plasma Reformer (LPG 연료의 플라즈마 개질 특성연구)

  • Park, Yunhwan;Lee, Deahoon;Kim, Changup;Kang, Kernyoung;Cho, Yongseok
    • Journal of the Korean Institute of Gas
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    • v.16 no.6
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    • pp.17-22
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    • 2012
  • In this study, characteristics of reforming process of Automotive LPG fuel using plasma reactor are investigated. Because plasma reformer technology has advantages of a fast start-up and wide fuel/oxidizer ratio of operation, and reactor size is smaller and more simple compared to typical combustor and catalytic reactor, plasma reforming is suitable to the on-board vehicle reformer. To evaluate the characteristics of the reforming process, parametric effect of $O_2$/C ratio, reactant flow rate and plasma power on the process were investigated. In the test of varying $O_2$/C ratio from partial oxidation stoichiometry to combustion stoichiometry, conversion of LPG was increased but selectivity of $H_2$ decreased. The optimum condition of $O_2$/C ratio for the highest $H_2$ yield was determined to be 0.8~0.9 for 20~50 lpm. The result can be a guide to map optimal condition of reforming process.

Numerical Study of Heat and Mass Transfer Characteristics in Microchannel Steam Methane Reforming Reactor (마이크로채널 메탄 수증기 개질 반응기의 열 및 물질 전달 특성에 관한 수치해석 연구)

  • Jeon, Seung-Won;Lee, Kyu-Jung;Cho, Yeon-Hwa;Moon, Dong-Ju
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.9
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    • pp.885-894
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    • 2012
  • A numerical study of a microchannel steam methane reforming reactor has been performed to understand the characteristics of heat and mass transfer. The integration of Rh-catalyzed steam methane reforming and Pt-catalyzed methane combustion has been simulated. The reaction rates for chemical reactions have been incorporated into the simulation. This study investigated the effect of contact time, flow pattern (parallel or counter), and channel size on the reforming performance and temperature distribution. The parallel and counter flow have opposite temperature distribution, and they show a different type of reaction rate and species mole fraction. As the contact time decreases and channel size increases, mass transfer between the catalyst layer and the flow is limited, and the reforming performance is decreased.

A Study on Reaction Kinetics in Steam Reforming of Natural Gas and Methane over Nickel Catalyst (니켈촉매 상에서 천연가스와 메탄의 수증기 개질 반응에 관한 Kinetics 연구)

  • Seong, Minjun;Lee, Young-Chul;Park, Young-Kwon;Jeon, Jong-Ki
    • Applied Chemistry for Engineering
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    • v.24 no.4
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    • pp.375-381
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    • 2013
  • Kinetics data were obtained for steam reforming of methane and natural gas over the commercial nickel catalyst. Variables for the steam reforming were the reaction temperature and partial pressure of reactants. Parameters for the Power law rate model and the Langmuir-Hinshelwood model were obtained from the kinetic data. As a result of the reforming reaction using pure methane as a reactant, the reaction rate could be determined by the Power law rate model as well as the Langmuir-Hinshelwood model. In the case of methane in natural gas, however, the Langmuir-Hinshelwood model is much more suitable than the Power law rate model in terms of explaining methane reforming reaction. This behavior can be attributed to the competitive adsorption of methane, ethane, propane and butane in natural gas over the same catalyst sites.