ULSD/DPF combo claims to compete with diesel-water emulsions for NOx/PM control

Diesel Fuel News, March 3, 2003

Clean Diesel Technologies (CDT) cites standard tests at Southwest Research Institute showing that low-aromatics ULSD, mixed with a platinum/cerium additive, can achieve NOx reductions of 13%, similar to those of diesel-water emulsions. The CDT additive improves combustion and promotes the oxidation of soot in a diesel particulate filter (DPF).

While the additive adds several cents/gallon to the cost of diesel fuel--and ULSD is itself several cents more expensive than ordinary diesel fuel--fuel-economy gains partly offset these costs. In contrast, water emulsions "can increase costs by up to 30 cents per gallon, as well as rob an engine of power and fuel economy performance by diluting the fuel with up to 20% water," CDT president Jim Valentine said. CDT cited tests of its additive with Valero's low-aromatics ULSD in Texas; BP's "ECD" ULSD in California, and the ULSD marketed by Sprague Energy in New England. The latest tests incl ude results on a 1998 DDC Series 60 heavy-duty engine, but CDT also has over 100 test results from an older, 1990 engine, with similarly low-NOx/PM results. Once CDT achieves final US EPA and CARB "verification" of its emissions technology claims, then states can start earning "state implementation plan" (SIP) emissions credits for fleets adopting low-emissions retrofit technologies. CDT also touts its wire-mesh "flow-through filter" (FTF) that achieves about 50-60% PM reduction at less than one-quarter the cost of a catalyzed DPF. Bonus: The FTF tolerates non-ULSD fuel, unlike catalyzed DPFs.