Effects of the MMT® Fuel Additive on a Catalyzed Diesel Particulate Filter

Emissions regulations for 2007 will likely require engine manufacturers to use a diesel particulate filter (DPF) to meet particulate matter (PM) emission requirements. With the lower operating temperatures of light-duty diesel engines, some form of catalyst will be required to facilitate oxidation of accumulated soot PM to regenerate the DPF. This catalyst can either be permanently applied to the filter substrate in the manufacturing process, or be continuously delivered via the diesel fuel. In this study we examined the impact of using both forms of catalyst. A recently published study of the fuel-borne catalyst additive MMT [1] (Methylcyclopentadienyl Manganese Tricarbonyl), reviewed the performance of MMT in conjunction with an uncatalyzed DPF [2]. This paper summarizes testing with the MMT additive using a MY1998 Cummins M11 engine, and the combination of a MY2002 light-duty Cummins 5.9L diesel engine and catalyzed diesel particulate filter (CDPF) supplied to Ethyl Corp. by Cummins Inc. The MMT fuel-borne catalyst reduced the rate of PM generation, reduced the rate of exhaust backpressure increase during low-temperature operation, and reduced the balance point temperature.