1999 Fiscal Year Final Research Report Summary
Development of non-thermal plasma reactors for mobile emission sources
| Project/Area Number |
10555087
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
電力工学・電気機器工学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
SHIMIZU Kazuo The University of Tokyo, School of Engineering, Research Associate, 大学院・工学系研究科, 助手 (90282681)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIOKA Masateru The University of Tokyo, School of Engineering, Research Associate., 大学院・工学系研究科, 助手 (00282575)
ODA Tetsuji The University of Tokyo, School of Engineering, Professor, 大学院・工学系研究科, 教授 (90107532)
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| Project Period (FY) |
1998 – 1999
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| Keywords | non-thermal plasma / catalyst / NOx / pulse discharge |
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| Research Abstract |
In order to control air pollution, several researchers have applied atmospheric pressure, non-thermal plasma processing to polluted gases and reported its effectiveness in removing NOx. We have already studied the feasibility of combining non-thermal plasma with catalysts to improve energy efficiency.
The removal of NOx by non-thermal plasma with catalysts was investigated in the presence of water vapor and hydrocarbons. Catalysts tested in this paper were copper- and sodium-coated zeolite (CuZSM-5, NaZSM-5) and a conventional 3-way catalyst (Pt-Rh, alumina cordierite). The simulated flue-gases had from zero to 15% water vapor. Seventy percent (70%) NO removal was achieved with NaZSM-5 catalyst at 200-500 ℃, with 10% moisture and the power to the reactor turned off. High temperature removal of NOx was the result of plasma chemical reactions and adsorption in the catalyst. However, non-thermal plasma degrades the NOx removal with CuZSM-5 catalyst, when the gas temperature is 300℃ or above. When the gas temperature was 100℃, the non-thermal plasma process was enhanced by the combination of non-thermal plasma with any type of catalyst. The catalysts investigated in this paper do not work at lower temperatures by themselves. Adsorption characteristics were also investigated and only NaZSM-5 catalyst showed significant adsorption.
Also, to improve NOx removal reactions, hydrocarbons were added where real exhaust gas contains hydrocarbons from incomplete combustion. However some catalysts have shown NOx adsorption. In order to overcome these difficulties, mesh electrode-plate dielectric barrier reactors have newly developed to increase NOx removal efficiency. It has superiority over wire-cylinder reactors we have used formally. These superior points are shown below.
1) A use of small quantity of catalyst (0.8-1g) coated on plate surface
2) Law pressure loss (without any pellets or honeycomb catalysts)
3) High electric field achieved by narrow gap (2-3 mm).
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