This paper details the development of Cool Particulate Regeneration™, CPR™, an ultra-efficient non-thermal active particulate filter regeneration technology for gasoline and diesel particulate filters. In the technologies simplest form, mechanical two-way regeneration valves are sequentially and in rapid succession pneumatically actuated to induce a reverse flow filter cleaning. Their operation generates exhaust pressure by sealing off the exhaust system preventing filtered engine exhaust from exiting the tailpipe. The filtered and pressurized gases are then released to a separate low pressure particulate matter (PM) reservoir upstream of the filter. The reverse flow of high pressure filtered exhaust gases pass back though the filter physically dislodging the particulate and transporting it to the low pressure storage chamber. Innovative utilization of the particulate matter is discussed.
CPR has undergone bench testing and two generations of research and development. Demonstration projects utilizing a 2002 GMC C6500 7.2l 3126B and a 1999 Onan 7.5kW IDI NA Tier 0 high PM emitting genset were performed. The demonstration applications were chosen to prove the technologies scalability and applicability to legacy and high PM emitting small engine designs. Both demonstration projects utilized bare cordierite filters, did not require engine down time for regeneration, and were controlled independent of the engine. The 2nd generation design achieved ultra-efficient 2 seconds regeneration and operated for only 0.06% of the time that the engine was operating.
In addition to particulate matter reduction, CPR enables the use of high sulfur fuels and B100 straight biodiesel. High sulfur tolerant SCR technologies, such as proven Vanadium Pentoxide, that are incapable of high temperature operation [1,2,6], can be directly coated to the filter substrate for a SCR/CPR solution that will allow compliance with stringent emissions regulations for developing and developed countries.