Effects of Direct Non-thermal Plasma on Polycyclic Aromatic Hydrocarbons Emissions in Diesel Engine

Non-thermal plasma (NTP) technology has a good application prospect in diesel after-treatment field, but few studies on the effects of NTP on PAHs emissions had been carried out. In this paper, the concentrations of PAHs at different loads before and after the treatment of DNTP were studied, combined the GC/MS analysis with external standard method. The results indicate that total concentrations of PAHs were 149.46, 102.44, 107.34 and139.69 mu g/m(-3) at 25%, 50%, 75%, 100% load, 2000r/min respectively before the treatment of DNTP and reduced to 88.96, 77.31, 88.51 and 138.22 mu g/m(-3) after the treatment of DNTP, with the largest decline up to 40.48%. The main components of PAHs were naphthalene, anthracene, phenanthrene, fluoranthene, and pyrene, etc. Before the treatment of DNTP, the concentrations of PAHs decreased firstly and then increased with the increase of load. The average concentrations of PAHs with different rings after the treatment of DNTP were decreased by 21.2%, 22.4%, 20.5% and 6.9%.