Since the market introduction of the Diesel Particle Filter (DPF) system in serial applications in May 2000, more than 500,000 vehicles have been DPF-equipped. Tracking the serial production current situation, several themes for improvement have been identified, including system simplification to limit its total cost as well as proposition to optimize maintenance. The paper presents those upgrades that will be proposed in serial applications.
Based on a DPF regeneration assisted by engine management systems in combination with the use of a Ceria-based fuel-borne catalyst, the first improvement is to limit the ash build up phenomenon of fuel-borne catalyst and then to limit the DPF clogging effect.
In the first stage, catalytic activity of Ceria-based fuel-borne catalyst has been improved, by introducing Iron as a catalytic promoter. Targeting the “fit for life” DPF application (and thus “zero maintenance” on the DPF), it is necessary to find a compromise between the catalytic activity (reduction in the temperature of soot burn-off and kinetics of DPF regeneration), the temperature peak generated during the DPF regeneration (exotherms of regeneration) and the density of the inorganic ash arising from the fuel-borne catalyst (ash build-up speed). A good compromise is proposed in this way, based on the use of the Iron-doped Ceria nanoparticules as active catalytic ingredient.
In parallel, a dosing strategy of a fuel-borne catalyst is being developed to match with the proposed evolution in the Ceria-based fuel-borne catalyst for serial applications. New designs of the automatic on-board dosing system have been developed to ensure the global accuracy in the Diesel fuel treatment. On the other hand, the maintenance operation for fuel-borne catalyst tank refilling is integrated in the design of the dosing systems, which is adapted to the platform of the vehicle and the car makers' specifications. In the paper, the following approaches are developed, and the data obtained on a demonstrator are proposed.