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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.

Forthcoming on-highway 2005/2007 European and North American emission regulations will require modern diesel engines to be equipped with Diesel Particulate Filters (DPF) capable of trapping up to 99% of the exhaust particulate matter. Since diesel particulates (soot) accumulate in the filter over time, the overall system needs to be regenerated by attaining the ignition temperature of soot, which in the presence of oxygen is >600 °C. Catalyzed DPFs regenerate at temperatures as low as ∼300 °C. One of the major issues facing OEMs, aftertreatment system manufacturers, and lubricant formulators is the potential effects of the lubricant-derived ash deposits and their impact on a pressure increase across filters, as well as overall filter performance and its service characteristics.

Several previous SAE papers have discussed the direct on-line soot measurement device that uses radio frequency (RF) technology to measure filter soot loads in diesel particulate filters. This paper presents differential pressure measurement data from several different retrofit vehicle applications using various filter geometries. This data is discussed and correlated to laboratory test results. The durability of the system to urban buses is also outlined.