Study On The Removal Of The Exhaust Emissions From Diesel Engine With Dielectric Barrier Discharge NTP

The investigation on the removal of diesel emission by the non-thermal plasma (NTP)technology was carried out. Firstly, the NTP after-treatment experimental equipment wasconsidered and designed based on the dielectric barrier discharge (DBD) theory. Using theNTP after-treatment experimental equipment and the AC power with high-voltage andhigh-frequency, the after-treatment experiments of exhaust emissions from a diesel enginewere carried out. The experimental results showed that the NTP exhaust after-treatmenttechnique was so effective on the removal of particulate matter from diesel engine that theremoval efficiency of particle matters could highly reach 79% (m/m), and the THC(TotalHydrocarbon Compound) removal efficiency was up to 20% simultaneously. NOX was alsoreduced to some extent. Furthermore,by scanning electron microscope (SEM), it wasrevealed that the sizes of most particles diminished after NTP treatment.Secondly, The high sensitive and efficient analysis method was studied, to analyze theorganic compounds in the diesel exhaust particle matters (PM) with the thermal desorption /concentration / GC-MS. To begin with, the thermal desorption / concentration equipmentwas designed. The principle was that the organic compounds were heated andnon-equilibriously desorbed from the PM under a small velocity of carrier flow, and thenwas concentrated inside a cooling section of the GC capillary, and finally was instantlyheated and ejected into the analysis GC capillary. Secondly, using the equipment, thenon-thermal plasma (NTP) after-treatment experiments of exhaust emissions from a smalldiesel generator were carried out. The organic compounds were thermally desorbed andconcentrated from the PM samples, and then directly were determined with GC-MS. Theresults showed that, firstly, the method of the thermal desorption / concentration / GC-MSwas more sensitive and efficient than the Soxhlet extraction to analyze the organiccompounds of the PM. Secondly, with the high sensitive method, the new organiccompounds were found. The GC-MS results indicated that a small quantity of lesser carbonnumber of aldehyde compounds were included in the organic compounds of PM, besidesbiggish carbon number of fatty hydrocarbon and volatilizable aromatic hydrocarbon, such asbenzene, methylbenzene, dimethylbenzene and etc. Lastly, the outlook of NTP technology for application on diesel emission after-treamentwas also discussed in this paper.