• Title, Summary, Keyword: reforming

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

  • Yoon, Sang-Ho;Bae, Joong-Myeon;Lee, Sang-Ho
    • 한국신재생에너지학회:학술대회논문집
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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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Hydrogen Gas Production from Methane Reforming Using Oxygen Enriched Compression Ignition Engine (산소부화 압축착화기관을 이용한 메탄으로부터 수소 생산)

  • Lim, Mun-Sup;Hong, Sung-In;Hong, Myung-Seok;Chun, Young-Nam
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.5
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    • pp.557-562
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    • 2007
  • The purpose of this paper is to investigate the reforming characteristics and maximum operating condition for the hydrogen production by methane reforming using the compression ignition engine induced partial oxidation. An dedicated compression engine used for methane reforming was decided operating range. The partial oxidation reforming was investigated with oxygen enrichment which can improve hydrogen production, compared to general reforming. Parametric screening studies were achieved as $O_2/CH_4$ ratio, total flow rate, and intake temperature. When the variations of $O_2/CH_4$ ratio, total flow rate, and intake temperature were 1.24, 208.4 L/min, and $400^{\circ}C$, respectively, the maximum operating conditions were produced hydrogen and carbon monoxide. Under the condition mentioned above, synthetic gas were $H_2\;22.77{\sim}29.22%,\;CO\;21.11{\sim}23.59%$.

A Study on the Suppression of Carbon Deposition in Solid Oxide Fuel Cells Through Methane Internal Reforming (메탄 내부개질 반응을 통한 고체산화물 연료전지의 탄소침적 억제에 관한 연구)

  • Kang, Yun-Hyeok;Lim, Sung-Kwang;Yoo, Yung-Sung;Park, Jin-Woo;Bae, Joong-Myeon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.5
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    • pp.473-481
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    • 2007
  • Compared to other types of fuel cells, SOFC has advantages like a wide output range and the direct use of hydrocarbon fuel without the process of external reforming. Particularly because the direct use of fuel without reforming reaction is closely linked to overall system efficiency, it is a very attractive advantage. We tried the operation with methane. However, although methane has a small number of carbons compared to other hydrocarbon fuels, our experiment found the deposition of carbon on the surface of the SOFC electrode. To overcome the problem, we tried the operation through activating internal reforming. The reason that internal reforming was possible was that SOFC runs at high temperature compared to other fuel cells and its electrode is made of Ni, which functions as a catalyst favorable for steam reforming.

Characteristics of LPG Fuel Reforming using Plasma Technology (플라즈마를 이용한 LPG연료 개질 특성연구)

  • Kim, Changup
    • Transactions of the Korean hydrogen and new energy society
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    • v.26 no.1
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    • pp.1-7
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    • 2015
  • In this study, characteristics of reforming process of automotive liquefied petroleum gas (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 $O_2/C$ ratios, reactant flow rate and metal form on the process were investigated. In the test of varying $O_2/C$ ratio from partial oxidation to stoichiometry combustion, 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 around 1.0 for 20~50 lpm, and 1.35 for 100 lpm. Specific energy density (SED) was major factor in reforming process and higher SED leads to higher $H_2$ yield. And metal form in the reformer increased $H_2$ yield of about 34 % as compared to the case of no metal form. The result can be a guide to map optimal condition of reforming process.

Numerical Study on Correlation between Operating Parameters and Reforming Efficiency for a Methane Autothermal Reformer (천연가스 자열개질기를 위한 작동조건과 개질효율의 상관관계에 대한 수치해석 연구)

  • Park, Joon-Guen;Lee, Shin-Ku;Lim, Sung-Kwang;Bae, Joong-Myeon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.8
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    • pp.636-644
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    • 2008
  • The objective of this paper is to investigate characteristics of an autothermal reformer at various operating conditions. Numerical method has been used, and simulation model has been developed for the analysis. Pseudo-homogeneous model is incorporated because the reactor is filled with catalysts of a packed-bed type. Dominant chemical reactions are Full Combustion reaction, Steam Reforming(SR) reaction, Water-Gas Shift(WGS) reaction, and Direct Steam Reforming(DSR) reaction. Simulation results are compared with experimental results for code validation. Operating parameters of the autothermal reformer are inlet temperature, Oxygen to Carbon Ratio(OCR), Steam to Carbon Ratio(SCR), and Gas Hourly Space Velocity(GHSV). Temperature at the reactor center, fuel conversion, species at the reformer outlet, and reforming efficiency are shown as simulation results. SR reaction rate is improved by increased inlet temperature. Reforming efficiency and fuel conversion reached the maximum at 0.7 of OCR. SR reaction and WGS reaction are activated as SCR increases. When GHSV is increased, reforming efficiency increases but pressure drop from the increased GHSV may decrease the system efficiency.

Influence of Discharge Voltage-Current Characteristics on CO2 Reforming of Methane using an Elongated Arc Reactor (신장 아크 반응기를 이용한 메탄 CO2 개질반응에서 방전 전압-전류특성의 영향)

  • Kim, Kwan-Tae;Hwang, Na-Kyung;Lee, Jae-Ok;Lee, Dae-Hoon;Hur, Min;Song, Young-Hoon
    • Journal of Korean Society for Atmospheric Environment
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    • v.26 no.6
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    • pp.683-689
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    • 2010
  • Reforming of methane with carbon dioxide has been carried out using a bipolar pulse driven elongated arc reactor operating at atmospheric pressure and non-equilibrium regime. This plasma reactor is driven by two kinds of power supply, characterized by different voltage-current characteristics under the same operating power and frequency. Varying the $CO_2/CH_4$ ratio and the discharge power, the conversion rate, yield, and reforming efficiency for the two power supplies are investigated in conjunction with the static and dynamic behaviors of voltage and current. It is found that not only the values of voltage and current but also their shapes give an influence on the reforming performances. Finally, a better electrical operation regime for the efficient plasma reforming is proposed based on the relationship between the voltage-current characteristics and the reforming performance.

A Comparison with CFD Simulation and Experiment for Steam-methane Reforming Reaction in Double pipe Continuous Reactor (이중관형 연속 반응기에서 수증기-메탄 개질반응의 실험 및 CFD 시뮬레이션)

  • Shin, Dong-Woo;Kim, Lae Hyun
    • Journal of Energy Engineering
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    • v.22 no.2
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    • pp.226-236
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    • 2013
  • The heat distribution and internal flow from the efficiency of actual reformer and specification variation, using the computer simulation and experiment about the steam methane reforming reaction which uses the high temperature reformer. Reaction model from steam refoemer uses the steam response model developed by Xu & Froment.As result we supposed the chemical react Steam Reforming(SR), Water Gas Shift(WGS), and Direct Steam Reforming(DSR) from the inner high temperature reformer dominates the response has dissimilar response. According to result of steam methane reforming reaction exam using high temperature reformer, we figured out when Steam Carbon Ratio(SCR) increase, number of hydrogen yield increases but methane decreases. When comparing and examining between design with one inlet and two inlet, result came out one inlet design is more outstanding at thermal distribution and internal flow, hydrogen yield in one inlet design than two inlet design.

Experimental Study of Hydrogen and Syngas Production over Ni/Ce-ZrO2/Al2O3 Catalysts with Additives (Ni/Ce-ZrO2/Al2O3 촉매의 첨가제에 따른 수소 및 합성가스 생성에 대한 실험적 연구)

  • Cho, Wonjun;Yu, Hyejin;Mo, Yonggi;Ahn, Whaseung
    • Transactions of the Korean hydrogen and new energy society
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    • v.25 no.2
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    • pp.105-113
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    • 2014
  • Performance tests on $Ni/Ce-ZrO_2/Al_2O_3$ catalysts with additives (MgO, $La_2O_3$) were investigated in the combined reforming processes (SCR, ATR, TRM) in order to produce hydrogen and carbon monoxide (it is called "syngas".). The catalyst characterization was conducted using the BET surface analyzer, X-ray diffraction (XRD), SEM, TPR and TGA. The combined reforming process was developed to adjust the syngas ratio depending on the synthetic fuel (methanol, DME and GTL) manufacturing processes. Ni-based catalysts supported on alumina has been generally recommended as a combined reforming reaction catalyst. It was found that both free NiO and complexed NiO species were responsible for the catalytic activity in the combined reforming of methane conversion, and the $Ce-ZrO_2$ binary support employed had improved the oxygen storage capacity and thermal stability. The additives, MgO and $La_2O_3$, also seemed to play an important role to prevent the formation of the carbon deposition over the catalysts. The experimental results were compared with the equilibrium data using a commercial simulation tool (PRO/II).

A study on the adaptive predictive control of steam-reforming plant using bilinear model (쌍일차 모델을 이용한 스팀개질 플랜트의 적응예측제어에 관한 연구)

  • 오세천;여영구
    • 제어로봇시스템학회:학술대회논문집
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    • pp.156-159
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    • 1996
  • An adaptive predictive control for steam-reforming plant which consist of a steam-gas reformer and a waste heat steam-boiler was studied by using MIMO bilinear model. The simulation experiments of the process identification were performed by using linear and bilinear models. From the simulation results it was found that the bilinear model represented the dynamic behavior of a steam-reforming plant very well. ARMA model was used in the process identification and the adaptive predictive control. To verify the performance and effectiveness of the adaptive predictive controller proposed in this study the simulation results of steam-reforming plant control based on bilinear model were compared to those of linear model. The simulation results showed that the adaptive predictive controller based on bilinear model provides better performance than those of linear model.

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Study on n-Butane Autothermal Reforming for Portable Fuel Cell (휴대용 연료전지를 위한 부탄 자열개질에 관한 연구)

  • Bae, Gyu-Jong;Kang, In-Young;Lim, Sung-Kwang;Bae, Joong-Myeon;Kim, Ju-Yong;Lee, Chan-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.11
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    • pp.1123-1130
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    • 2006
  • This study discusses about research efforts of hydrogen generation from hydrocarbon(e.g., diesel, gasoline, natural gas, and LPG), especially, butane reforming by using Autothermal Reforming Reaction (ATR) technology. Several catalysts were selected for butane ATR. Thermodynamic reactor conditions (temperature, $O_2$/C, S/C) are varied and reforming characteristics of 2 catalysts (Pt and Rh on ceramic supports) and 1 commercial catalyst (FCR-HC35) have been examined. To understand reaction behaviors in an ATR reactor comprehensively, temperature profiles of reactor were observed. By mass transfer limitation, fuel conversion decreases when GHSV increases. Significant temperature variation along the reactor was observed and it was mainly due reaction kinetics difference between exothermic oxidation and endothermic reforming reaction.