Harry Arthur Cikanek

ADVANCED TECHNIQUES FOR THERMAL AND CATALYTIC DIESEL PARTICULATE TRAP REGENERATION

Advanced techniques for regenerating diesel particulate traps are described. A bypassable trap system minimized regeneration thermal energy requirements. Thermal regeneration systems with burners or electric resistance heaters were evaluated. Regeneration emissions and fuel consumption penalties were measured. Catalytic fuel additives consisting of octoate based compounds of copper and nickel, and copper and cerium provided reductions of up to 410/sup 0/F in trap regeneration temperature. Durability tests confirmed frequent self regeneration with fuel additives.

THERMAL AND CATALYTIC REGENERATION OF DIESEL PARTICULATE TRAPS

Thermal and catalytic techniques for regenerating particulate traps were assessed. The thermal technique used a burner which heated engine exhaust to the ignition temperature of the particulates to achieve over 90% regeneration effectiveness. HC, CO and particulate emissions resulting from combustion of particulates and burner exhaust were 25 to 50% of the allowable vehicle emissions for one CVS cycle. The fuel consumed by the burner was 9% of the fuel consumed by a vehicle over one CVS cycle. Problems with burner nozzle clogging, ignition reliability, trap durability and control system requirements were identified. In the catalytic technique, diesel fuel containing .5 gm/gal lead and .25 gm/gal copper lowered the ignition temperature of the particulates by 425 deg F so that periodic regeneration occurred. The trap collected nearly all of the lead and copper resulting in limited trap life, and deposits on the engine fuel nozzles tended to increase HC emissions.