Continuous Regeneration Of Diesel Particulate Filters Pilot Study

The control of diesel paniculate emission is very important and challenging research field during the present development of diesel. The regeneration of diesel particulate filter (DPF) is the emphasis and difficult hurdle in the research and application of this field.This thesis presents experimental research on Continuous Regeneration of DPF (CR-DPF) using the novel DPF regeneration theory that NO2 has a superior oxidizing ability and it can oxidize the diesel particulate (soot) at rather low temperature of about 250"C.Some systematic analyses are made on the status and the new tendency of diesel pollution aftertreatment technology, mainly on the particulate and NOX.A fundamental research is made on the oxidation reaction of NO-, and diesel particulate (soot) by means of thermogravimetric analysis (TGA) method in the chemistry laboratory. After proof of the superior oxidizing character of NO2 than 02, a research is intensively done on the effects of reaction temperature, NO2 concentration et al. on this oxidation reaction. After that, a kinetic analysis is made with the conclusion that the reaction order is 0.5 and the apparent activation energy is about 22kJ.mol~'.Experimental tests are conducted in the simulating model flow reactor (ex situ situation) and on the 165F diesel engine (in situ situation) respectively in the I.C. engine laboratory. In the former, the superior oxidizing ability of NO, is proved. In the latter, by additional injection of NO, to the exhaust pipe ahead of the DPF, the study is made on the character of continuously regenerating of DPF by NO, in the in-line situation. And it proves the CR-DPF's feasibility. It is found that NO, reacts with diesel particulate under the exhaust temperature range of 275 °C~350°C during the experiments, and that increasing the exhaust temperature and NO, concentration contributes to DPF regeneration to some extent.It is demonstrated that under 300 °C, NO2 can continuously and effectively regenerate the DPF. The effects of NO, concentration, reaction temperature and diesel load on DPF regeneration efficiency are analyzed in detail.The study shows that the continuous regeneration of DPF by N02 is feasible if the catalyst is developed to convert the existing contents of NO exhausted from the engine to NO,.