High Porosity DPF Design for Integrated SCR Functions 2012-01-0843
Diesel engines are more fuel efficient due to their high thermal efficiency, compared to gasoline engines and therefore, have a higher potential to reduce CO2 emissions. Since diesel engines emit higher amounts of Particulate Matter (PM), DPF systems have been introduced. Today, DPF systems have become a standard technology. Nevertheless, with more stringent NOx emission limits and CO2 targets, additional NOx emission control is needed. For high NOx conversion efficiency, SCR catalysts technology shows high potential. Due to higher temperature at the close coupled position and space restrictions, an integrated SCR concept on the DPFs is preferred. A high SCR catalyst loading will be required to have high conversion efficiency over a wide range of engine operations which causes high pressure for conventional DPF materials. Therefore, a high porosity DPF design has been developed to overcome the trade off between high pressure drop, high wash coat loadings, and sufficient filtration efficiency. Furthermore, the DPF design has been adjusted to a high ash capacity concept. This paper will describe the high porosity DPF material development, including test results and future outlook.