Project/Area Number |
06680462
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
エネルギー学一般・原子力学
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Research Institution | Tokyo Institute of Technology |
Principal Investigator |
YOSHIDA Takashi Tokyo Institute of Technology Department of Chemistry, assistant, 理学部, 助手 (50251608)
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Co-Investigator(Kenkyū-buntansha) |
TSUJI Masamichi Tokyo Institute of Technology, Research Center for Carbon Recycling & Utilizatio, 炭素循環素材研究センター, 助教授 (20111643)
TAMAURA Yutaka Tokyo Institute of Technology, Research Center for Carbon Recycling & Utilizatio, 炭素循環素材研究センター, 教授 (00108185)
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Project Period (FY) |
1994 – 1995
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Project Status |
Completed (Fiscal Year 1995)
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Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1995: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1994: ¥1,400,000 (Direct Cost: ¥1,400,000)
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Keywords | Carbon dioxide / Carbon monoxide / Methane / Iron oxide / Hydrogen / Ferrite / Magnetite / Energy / ウスタイト / 廃熱 |
Research Abstract |
An endothermic chemical system has been proposed for an option of mitigation technology of CO_2 emissions. This system consist of two process ; 1) CO_2/CH_4 conversion process (CO_2+4H_4=CH_4+2H_2O), 2) methane reforming process (CH_4+H_2O=2CO+4H_2). The overall reaction can be represented by CO_2+H_2=CO+H_2O. The CO_2/CH_4 conversion process is composed of the following three steps ; i) activation step of Ni (II) ferrite by H_2, ii) decomposition step of CO_2 into carbon iii) methanation of deposited carbon with H_2, The formation of the oxygen-deficient ferrites and decomposition of CO_2 with oxygen-deficient ferrites were studied kinetically. It has been found that oxygen-deficient Ni (II) ferrite possesses the highest reactivity toward the decomposition of CO_2 in comparison with other oxygen-deficient ferrites. The methanation of C was studied with ferrite. A high conversion ratio of about 0.85 was obtained at 0.1 MPa for oxygen-deficient ferrite which had been prepared by passing H_2 gas at 300゚C.The high conversion ratio in the methanation reaction is considered to come from a higher reactivity of the elementary carbon deposited on the surface of the H_2-reduced ferrite at about 0.7 molecule of C per 1nm^2. Effect of Pt impregnated on magnetite and Ni (II)-bearing ferrite was studied for its methanation reactivity in a flow of mixed gas of CO_2 and H_2. Decomposition of CO_2 to CO was enhanced, but methanation of CO_2 did not occur on Pt-magnetite. On the other hand, both yield and selectivity for methanation were improved drastically on Pt-Ni (II)-bearing ferrite ; yield and selectivity for methanation increased from 25% to 80% and from 82% to 99%, respectively. A bench scale test has been performed for methanation system. The present methanation system could be extended to CO_2 sources such as LNG power plant.
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