This system uses air to burn the carbon in the filter. An additive is dosed into the fuel and passes through the engine to be deposited on the filter. This additive reduces the temperature at which the carbon will react with the air.
Johnson Matthey offers an automatic dosing system (the PIO-CAN-DOSY) for the additive. The additive is held in an on-board reservoir. At each start-up, the system determines whether fuel has been added to the tank and, if so, how much. It then calculates how much additive is needed and meters the exact quantity into the tank.
Advantages: passive device which requires no maintenance between normal services, can run with higher sulphur fuel.
Conditions: >380°C catalyst temperature for at least 50% operating time.
The DPFiS uses the EOLYS™ additive from Rhodia.