直接低温等离子体技术降低柴油机醛酮类污染物排放

为了研究直接低温等离子体（DNTP）技术去除柴油机排气中醛、酮类污染物的效率，采用2,4-二硝基苯肼（DNPH）衍生法和高效液相色谱（HPLC）分析技术，分析了柴油机4种工况原机和DNTP技术处理后醛、酮类污染物比排放量的变化规律。结果表明，DNTP处理前，醛、酮类污染物比排放量随负荷的增加呈先减少后增加的趋势；DNTP处理后，柴油机醛、酮类污染物比排放量显著降低，醛、酮类污染物在75%负荷时的总去除率可达93.8%，25%负荷、50%负荷、75%负荷时，丙烯醛和丙酮、丁醛和丁酮去除率达到100%。

Direct non-thermal plasma technology reduces emission of aldehyde and ketone in diesel engine exhaust

Abstract: A non-thermal plasma (NTP) technique has currently been investigated intensively as a promising technology for a diesel engine after treatment to abate PM, HC and NOx. However, there is little research about NTP technique treating the aldehyde and ketone emissions of a diesel engine. In this study, Direct Non-thermal Plasma (DNTP) technique is employed to treat the single cylinder diesel exhaust. The variation of the specific aldehyde and ketone emissions of a diesel engine at four loads before and after the treatment of DNTP is studied with 2, 4-dinitrophenylhydrazine (DNPH) derivatization method and a high performance liquid chromatography (HPLC) analysis technique. The results show that 13 kinds of aldehyde and ketone emissions could be detected under this experimental condition. Before the treatment of DNTP, with the growth of the diesel load, the specific aldehyde and ketone emissions decrease first and then increase. The specific emissions of formaldehyde are 83.22, 15.26, 25.06, 27.58 mg/(kW·h) and at each load are the largest. The specific emissions of acetaldehyde are 12.03, 3.47, 8.92, 19.97 mg/(kW·h). The minimum specific emissions of acrolein and acetone, propionaldehyde, crotonaldehyde, butyraldehyde and butanone, methacrolein, benzaldehyde, valeraldehyde are 0.43, 0.78, 0.96, 0, 0.25, 0.28, 0.23 mg/(kW·h) respectively at 50% load. The minimum specific emissions of p-tolualdehyde and hexaldehyde are 0.08, 0.04 mg/(kW·h) respectively at 75% load. After the treatment of DNTP, the specific aldehyde and ketone emissions decreases first and then increases with the growth of the diesel load, but the trend becomes mild and the specific aldehyde and ketone emissions reduce remarkably. Total removal efficiency of aldehyde and ketone emissions could reach 93.8% at 25% load, 50% load, and 75% load. Removal efficiency of acrolein and acetone, butyraldehyde and 2-butanone could reach almost 100%. At the same time, total ozone formation potentials decrease dramatically. These results provide a reference for reducing the diesel engine exhaust emissions with a DNTP technique.