Particulate matter (PM) from internal combustion engines such as direct injection petrol engines and diesel engines has generate negative impacts on human health and environment. Diesel particulate filters (DPF), as the most successful technology of removing PM in engine exhaust, encounter the regeneration problems of decreasing engine backpressure in order to keep high fuel economy of internal combustion engines. However, the exhaust temperature of internal combustion engines, especially the diesel engines is lower than PM oxidation temperature under most of the real driving conditions. Usually, more fuel is delivered into the cylinders by post injection to increase the exhaust temperature, which leads to high fuel consumption. In order to keep high fuel economy of internal combustion engines, catalyst is applied to decrease the PM oxidation temperature, achieving DPF regeneration. There are two ways to provide the catalyst to achieve DPF regeneration (1) fossil fuel additives and (2) catalyst coating on filters. Catalyst additives are homogeneously dispersed in the fossil fuel; during the PM formation process, catalyst additives as one of the ingredients will be in the PM, which continuously oxides the PM in the process of formation and captured in the filters. The backpressure caused by PM capture is kept at a low level. However, the ash generation after PM oxidation is increased by the additives, which to some extend increases the frequency of DPF clean. Catalyst coating on the filters will not generate more ash, however, the catalyst may be aging and inactivated because of long time remaining in the high temperature conditions such as long distance uphill journey.
- High efficiency catalyst helps to achieve continuous regeneration of diesel particulate filters to improve the fuel economy of internal combustion engines.
- Catalyst used for the regeneration of diesel particulate filters can be coated in the filters or be additives of fossil fuels.
- Finding the proper catalyst in terms of price, performance, and, coating technology for diesel particulate filters regeneration is important to keep high fuel economy of internal combustion engines.