Development of Passive / Active DPF System Utilizing Syngas Regeneration Strategy - Retrofit, Real Life Optimization and Performance Experience 2010-01-0560

Active regeneration of diesel particulate filters is becoming essential for performance longevity given the diversity of duty cycles and engines' operating behaviors for existing and newer engines. The Syngas containing hydrogen and carbon monoxide from diesel fuel and air produced by the non-catalytic Syngas Generator is potential candidate to actively enhance the regeneration efficiency of diesel particulate filters. The Syngas is utilized to create an exothermic condition over a pre-catalyst to the DPF to bring exhaust gas temperature from as low as 200°C to 650°C to enable a sustained DPF regeneration process. The Syngas is introduced to an inlet assembly which is divided into 4 quadrants so the full Syngas is mixing with a quarter of the exhaust flow and regenerating one DPF quadrant at a time.

The Syngas DPF system is designed to operate seamlessly and is transparent to the vehicle operator. A wall-flow base metal catalyzed DPF is used to remove particulate matter from the exhaust stream at all operating conditions. System sensors monitor the DPF differential pressure, system temperature gradients and exhaust gas temperature. The DPF regeneration is triggered by the time interval between regenerations and/or sufficient elevation in the DPF differential pressure at all exhaust gas temperatures, however, the lowest starting exhaust temperature is determined by the Pre-Catalyst light-off temperature and the system overall temperature gradients. The Syngas Generator operates in two modes; lean mode which is the "Standby" state ready to produce Syngas on demand and the rich mode "Syngas Production" or the regeneration mode. During the passive DPF operation, the Syngas Generator can either be operated in a "Standby" lean mode or off to minimize fuel consumption.

The goal of this work is to demonstrate the performance and durability of the developed Syngas DPF system. This paper will discuss; system optimization, integration, retrofit aspects, emissions and temperature gradient during the regeneration process over FTP/steady state protocols and field system performance under usual operating conditions highlighting component durability.