Diesel Particulate Trap Regeneration Using Ceramic Wall-Flow Traps, Fuel Additives, and Supplemental Electrical Igniters

Diesel particulate traps, when heavily loaded with soot to assure complete incineration, are susceptible to thermal stress failure when regenerated under conditions of high exhaust temperature followed by low exhaust flow. The regeneration characteristics of supplemental electrical igniters, operated by automatic regeneration controls and aided by organometallic fuel additives, have been evaluated on cordierite monoliths and several alternative ceramic trap materials. These regeneration systems were evaluated in an attempt to increase trap durability without the use of invasive engine controls, which can cause performance and fuel economy losses. The regeneration and engine exhaust emission characteristics of cerium and manganese fuel additive mixtures are presented. A discussion of a method of dispensing the additive, and its fuel-stability characteristics, are given, along with a means of predicting trap plugging due to additive ash accumulation on the trap walls.