Fischer-Tropsch diesel enhances aftertreatment performance in California fleet tests

Diesel Fuel News, Sept 15, 2003

Fischer-Tropsch (FT) Diesel Enhances Aftertreatment Performance in California Fleet Tests: Zero-sulfur, low-aromatics, high-octane FT diesel outperformed an 8%-aromatics, 2-ppm sulfur, 42-cetane crude-based ULSD in California fleet tests, in engine systems optimized for 2007 EPA emissions limits.

This included Cleaire's combination lean-NOx catalyst/DPF, plus EGR/combustion bowl changes (Ricardo's lower-compression ratio design) to work better with high-cetane FT diesel. This allowed 2007 compliance at 4.4% fuel penalty. "The increased EGR plus lean-NOx catalyst plus DPF approach shows potential for meeting 2007 emissions standards," Ricardo researcher Mike May showed here. Separately, Cleaire's Brad Edgar added that straight-chain hydrocarbons typical of FT diesel "may be more selective for NOx reduction" in the lean-NOx cat, compared to a CARB-ULSD fuel.