The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Karl T Chuang - One of the best experts on this subject based on the ideXlab platform.
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Carbon Deposition on Vanadium-Based Anode Catalyst for SOFC Using Syngas as Fuel
Journal of The Electrochemical Society, 2010Co-Authors: Jing-li Luo, Karl T ChuangAbstract:Carbon Deposition from synthesis gas (syngas) fueling solid oxide fuel cells led to decreased performance with time on stream. Although higher temperatures improved the fuel cell performance, the trade-off was a faster Carbon Deposition. Auger electron spectroscopy and X-ray photoelectron spectroscopy data showed that the Carbon Deposition was more severe in CO than in syngas condition and the Boudouard reaction was the major cause for Carbon Deposition in syngas. The Carbon distribution on the catalysts was also different. In CO, the Carbon deposited mostly on edges of the catalyst, whereas in syngas, Carbon deposited more evenly on the surface, suggesting different mechanisms taking effect. Cofeeding water vapor with the anode feed suppressed Carbon Deposition. However, the presence of water vapor reduced the fuel cell performance.
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Carbon Deposition during propane dehydrogenation in a fuel cell
Journal of Power Sources, 2007Co-Authors: Yu Feng, Karl T ChuangAbstract:Abstract Carbon Deposition in a high temperature proton-conducting fuel cell for selective propane dehydrogenation to propylene with co-generation of electrical power was investigated. Comparison of Carbon Deposition was made for catalytic propane dehydrogenation under an open circuit condition and electro-catalytic conversion of propane to propylene on the anode catalyst of synthesized chromium(III) oxide during fuel cell operation conditions with current flow. Carbon Deposition under the fuel cell operating conditions was much less than that under the open circuit conditions. Chromium(III) oxide catalyst modified by potassium showed a better resistance to Carbon formation under the open circuit conditions but was similar to the unmodified catalyst under current flow conditions.
Jingyu Ran - One of the best experts on this subject based on the ideXlab platform.
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Inhibition effect of methanol addition on Carbon Deposition in propane pyrolysis
Fuel, 2021Co-Authors: Jun Shi, Hui Yan, Qi Huang, Jingyu RanAbstract:Abstract Methanol-mixed fuels consisting of methanol, propane, and a small amount of auxiliary solvent are widely used as inexpensive industrial fuels, but the Carbon Deposition in the pyrolysis of this fuel seriously restrains its popularization. This paper studied the characteristics of gaseous products and Carbon Deposition in the pure propane and methanol-propane mixture pyrolysis experimentally, analyzed the effect of methanol addition on the reaction path of propane pyrolysis and production rate of key species by using detailed reaction mechanism. Results show that methanol addition can restrain C2H4 converting to C2H2 in the later stage of pyrolysis. The Carbon Deposition rate and particle diameter increase exponentially with the increase of reaction temperature in both pure propane and methanol-propane blend pyrolysis. Methanol addition can significantly reduce the Carbon Deposition rate and particle diameter. The reaction path analysis indicates that the main reaction paths forming benzene are C3H3 → A1 and C4H4 → I-C6H6 → A1, and C3H3 is a key specie to form benzene. The pyrolysis of methanol-propane mixture generates more H2 and H than that of pure propane pyrolysis, which makes most C3H6 convert to C2H4, reduces the amount of C3H3 and suppresses the conversion of C2H4 to C2H2. And then the amount of benzene is reduced significantly and the generation of subsequent PAHs and Carbon Deposition is inhibited. Lots of H2 also restrains the hydrogen abstraction from benzene resulting in the delay of the formation of PAHs and Carbon Deposition. This study is of great significance to research the soot formation in hydroCarbon combustion with alcohol fuel.
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Thermodynamic Analysis of Temperature and Pressure on Carbon Deposition for Methane Reforming at Low Temperature in Micro-Combustor
ASME 2010 8th International Conference on Nanochannels Microchannels and Minichannels: Parts A and B, 2010Co-Authors: Jingyu Ran, Liu-jie ZhaoAbstract:Aimed at problems caused by Carbon Deposition in the micro-combustor, such as catalyst deactivation and channel block, based on the technology of methane-wet air autothermal reforming and the effects of hydrogen and methane conversion, the influences of temperature and pressure on Carbon Deposition below 973K are discussed with thermodynamic analysis method in this paper. Results show that for a definite feed gas composition, Carbon Deposition adds with increasing temperature firstly, and then decreases. Reaction pressure is suitable to maintain at 1atm. Moreover, the increasing methane mass flow, decreasing air and steam mass flow can lead to expansion of Carbon Deposition temperature region exists, also lead to the amount of Carbon Deposition increase and the temperature peak of Carbon Deposition shift to higher temperature segment. Under the research conditions that methane mass flow is 6.6g/h, reaction pressure is 1atm, air-methane ratio and steam-methane ratio are respectively 2 and 1 in the micro-combustor, the temperature range of Carbon Deposition production is at 680∼850K. The largest Carbon Deposition is occurred and its mass fraction is 0.66% when the reaction temperature is at 785K, also the methane conversion rate and the mass fraction of hydrogen are approximately 53.43% and 2.37% respectively.© 2010 ASME
P.j. Jackson - One of the best experts on this subject based on the ideXlab platform.
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Carbon Deposition in the catalytic partial oxidation of methane to synthesis gas
Studies in Surface Science and Catalysis, 1994Co-Authors: P.j. Fleming, W. Cossutta, P.j. JacksonAbstract:Publisher Summary The process of catalytic partial oxidation (CPO) of natural gas to produce synthesis gas has the potential to replace conventional steam reforming, with a substantial reduction in plant size. The process has recently been demonstrated in a fixed bed monolithic reactor (Davy McKee/Engelhard), and in a fluidized bed reactor (Exxon Research & Engineering). Both versions use steam as well as oxygen (1.0 and 0.5 steam/methane respectively). The avoidance of Carbon Deposition is paramount to the fixed bed process. In achieving this, the use of steam has the penalty of leading to high CO 2 selectivity from the water gas shift reaction, correspondingly restricting the CO selectivity achievable. It has long been considered that partial oxidation catalysts based on nickel lead to Carbon Deposition, while catalysts based on rhodium have a unique ability to avoid it. More recently, the extent of Carbon Deposition over the highly active ruthenium pyrochlores developed by Oxford University has been questioned. This chapter reports the work done to assess the conditions under which Carbon Deposition can be minimized over CPO catalysts with steam-free CH 4 /O 2 feeds.
Masanobu Aizawa - One of the best experts on this subject based on the ideXlab platform.
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study on steam reforming of ch4 and c2 hydroCarbons and Carbon Deposition on ni ysz cermets
Journal of Power Sources, 2002Co-Authors: Tatsuya Takeguchi, Y. Uchida, Yukimune Kani, Tatsuya Yano, Ryuji Kikuchi, Koichi Eguchi, Keigo Tsujimoto, Akira Ueno, Koiji Omoshiki, Masanobu AizawaAbstract:Abstract Equilibrium partial pressure of oxygen and the boundary of Carbon Deposition region were calculated in the CHO phase diagram at temperatures ranging from 400 to 1000 °C. The open circuit voltage for the solid oxide fuel cell (SOFC) was directly connected to the calculated partial pressure of oxygen at higher temperatures. These calculations suggested that the development of the anode catalyst without Carbon Deposition was one of the most promising ways to achieve high efficiency in SOFC because the amount of added water could be reduced. The characteristics of steam reforming of methane and Carbon Deposition on Ni-Y2O3-stabilized zirconia (Ni-YSZ) cermets anodes were examined. The effect of MgO, CaO, SrO and CeO2 addition to Ni-YSZ cermets on their catalytic activity and Carbon Deposition was investigated. Although, the CaO addition slightly deteriorated the electrochemical activity as anode, the CaO addition was effective in suppressing Carbon Deposition and promoted steam reforming of CH4.
Liwu Lin - One of the best experts on this subject based on the ideXlab platform.
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Carbon Deposition and migration on Pt and Pt-Sn catalysts
Studies in Surface Science and Catalysis, 1997Co-Authors: Tao Zhang, Yining Fang, Liwu LinAbstract:Carbon Deposition and migration, as well as their influence on the performances of Pt/Al2O3 and Pt-Sn/Al2O3 dehydrogenation catalysts, were investigated by catalytic reaction, hydrogen and ammonia chemisorption, NH3-TPD and TPO. The results showed that Carbonaceous precursors first adsorbed at the active metal sites, and then migrated onto the acidic support surface. It was also found that the rate of Carbon Deposition on the Pt/Al2O3 was quicker than that on the Pt-Sn/Al2O3 at the initial period during butane dehydrogenation. The coking rate on the Pt catalyst increased slowly with continual reaction, while that on the Pt-Sn catalyst increased linearly, and finally overtook the Pt catalyst. However, the amount of Carbonaceous material migrated from the metal to the support was larger on the Pt-Sn catalyst than on the Pt catalyst. For the same amount of Carbon Deposition, e.g. 8wt%, on the catalyst surface, 50% of the metal surface on the Pt-Sn catalyst remained uncovered, whereas only 25% of the metal surface of the platinum catalyst was bare. Hence, addition of tin into the Pt/Al2O3 catalyst could increase its catalytic activity and stability for paraffin dehydrogenation.