粉煤灰小球协同低温等离子体处理汽车尾气

Purification of Automotive Exhaust by Simultaneously Using Low Temperature Plasma and Fly Ash Pellet Bed

针对汽车尾气防治，自制了介质阻挡放电催化反应器，并以改性粉煤灰小球为催化剂对汽油机尾气进行处理，研究了脉冲电压、脉冲频率、放电间隙及气体流量qv等对NO、HC和CO去除率η的影响。结果表明：NO、HC和CO的η随脉冲电压、脉冲频率的增加而增加，随qv的增加而减小。当放电间隙G在2．5～3．5mm变化时，3种污染物的η变化不大；但G增大到4mm时，污染物η明显下降。当脉冲电压为20kV、脉冲频率为15kHz、G≡3mm、qv＝0．05m^3／h，并以改性粉煤灰小球为催化剂时，NO、HC和C0的η分别能达到84．6％、87．7％和54．5％，比相同条件下不填充时分别增加了12．6％、7．2％和6．2％。研究表明：改性粉煤灰小球作为催化剂，能显著提高汽油机尾气中污染物的η。研究为等离子体催化技术提供了一种新型催化剂。

Dielectric-barrier discharge reactor with catalyst is designed. When treating automotive exhaust by the dielectric-barrier discharge reactor with modified fly ash pellets bed as catalyst, the removal rates of NO, HC and CO under different pulsed voltage, pulsed frequency, discharge space and gas flow are investigated. The results show that the removal rates of NO, HC and CO increase with the addition of pulsed voltage, pulsed frequency and the reducing of gas flow. When discharge space changes from 2.5 mm to 3.5 mm, the removal rates of three pollutants show little differences. When discharge space increases from 3.5 mm to 4 mm, the removal rates of pollutants decrease distinctly. The removal rates of NO, HC and CO are respectively 84.60%, 87.70% and 54.50% in the conditions of pulsed voltage 20 kV, pulsed frequency 15 kHz, discharge space 3 mm and gas flow 0.05 m^3/h with modified fly ash pellet bed as catalyst. They increase respectively by 12.6%, 7.20% and 6.20% comparing with the removal rates in the same condition without catalyst. Research shows that the removal rates of pollutants increase significantly with the synergetic effect of modified fly ash pellet bed. The research provides a new catalyst for plasma catalytic technology.