| Project/Area Number |
11218202
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| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
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| Allocation Type | Single-year Grants |
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| Review Section |
Science and Engineering
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| Research Institution | Tohoku University |
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Principal Investigator |
OHTSUKA Yasuo Tohoku University, IMRAM, Professor, 多元物質研究所, 教授 (20091663)
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| Co-Investigator(Kenkyū-buntansha) |
KIKUCHI Takemitsu Tohoku Univ., IMRAM, Research Associate, 多元物質研究所, 助手 (30169825)
TSUBOUCHI Naoto Tohoku Univ., IMRAM, Research Associate, 多元物質研究所, 助手 (90333898)
王 野 東北大学, 反応化学研究所, 助手 (40292304)
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| Project Period (FY) |
1999 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥31,600,000 (Direct Cost: ¥31,600,000)
Fiscal Year 2002: ¥5,200,000 (Direct Cost: ¥5,200,000)
Fiscal Year 2001: ¥7,800,000 (Direct Cost: ¥7,800,000)
Fiscal Year 2000: ¥9,600,000 (Direct Cost: ¥9,600,000)
Fiscal Year 1999: ¥9,000,000 (Direct Cost: ¥9,000,000)
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| Keywords | Nanoparticles / Carbon composites / Nitrogen removal / Sulfur removal / Hot gas cleanup / ナノ微粒子複合体 / 石炭 |
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| Research Abstract |
This project has been performed to develop a novel method of removing nitrogen and sulfur by using nanoparticles containing composites, which are produced from inexpensive raw materials, from a viewpoint of hot gas cleanup for an integrated gasification combined cycle process. The main achievements are summarized as follows :
(1) Nanoscale Fe particles on coal chars, prepared by carbonizing brown coals with externally added Fe ions, show higher activity in the catalytic decomposition of NH_3 to N_2 than Fe catalyst loaded on a commercial activated carbon, when 2000 ppm NH_3 diluted with He is fed at a high space velocity of 45000 1/h.
(2) The TEM, XRD and TPD measurements strongly suggest that the highly dispersed Fe particles play the crucial role in NH_3 decomposition and catalyze this reaction through a cycle mechanism involving α-Fe and the nitride species
(3) Some chars, prepared by simply pyrolyzing low rank coals with significant amounts of Fe and Ca cations naturally present as minerals, also work efficiently as the catalysts, and there is a strong correlation between NH_3 conversion and Fe content in char.
(4) The char with the largest content (2 wt%) of inherent Fe provides the stable conversion of 80% during 25 h reaction at 750℃ and achieves complete decomposition of NH_3 at 850℃.
(5) When NH_3 decomposition is carried out in the presence of 2000 ppm H_2S, CaO in the char is completely deactivated to form CaS, but Fe particles in it are still active, showing that the char can realize the removal of sulfur compounds and the catalytic decomposition of NH_3 simultaneously.
(6) The coexistence of syngas, a mixture of CO and H_2 with the molar ratio of 2 : 1, lowers the activity of the Fe catalyst, whereas the addition of C0_2 to syngas restores the performance to the original state without syngas, which suggests that some chars can be utilized in an actual hot gas cleanup process.
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