B20-ULSD Blend Cuts PM and NO_x Emissions

21 December 2004

Clean Diesel Technologies (CDT) has created a B20 blend combining ultra low-sulfur diesel (ULSD), biodiesel and its platinum- and cerium-based diesel fuel combustion catalyst (Platinum Plus). Tests on this proprietary blend, which CDT calls “Cleaner Burning Biodiesel” (CBB), show reductions of up to 51% in PM emissions and up to 9% in NO_x compared to conventional #2 Diesel. The testing of CDT’s biodiesel fuel blends were completed at Southwest Research Institute (SwRI) in San Antonio.

“This combination represents a reduction of over 100 lbs. per year of regulated pollutants from a typical school bus and over 200 lbs. per year for a local delivery vehicle,” said [CDT] President and COO James Valentine. “In addition to the more than 50 percent reduction in toxic particulates, the most significant finding was the 9 percent reduction in NO_x—typical biodiesel blends can increase NO_x by two to four percent,” Valentine added.

Testing was conducted over triplicate federal transient test cycles on a 1995 Navistar DT-466 engine typical of school bus, beverage and local delivery service fleets.

The first of two test sequences used a 20% blend of biodiesel with a commercially available ULSD (ultra low-sulfur diesel) combined with Platinum Plus, and an engine equipped with a lightly catalyzed DOC. This configuration produced the largest reductions (table at right).

The testers also found reductions of more than 60% in the NO₂ fraction of exhaust which is a strong lung irritant and can increase with traditional heavily catalyzed aftertreatment devices.

In a second test sequence, a B20 blend with commercial #1D kerosene fuel and the FBC  reduced NO_x emissions 4% and PM emissions 35% when the fuel was used alone without any aftertreatment.

CDT recently received a patent on Cleaner Burning Biodiesel blends in the United Kingdom, and other U.S. and international patents are issued and pending.