AM-02-37 CATALYTIC REDUCTION OF SULFUR AND OLEFINS IN THE FCCU: COMMERCIAL PERFORMANCE OF DAVISON CATALYSTS AND ADDITIVES FOR CLEAN FUELS

Description:

Gasoline vapors and tailpipe emissions contain NOx and VOC’s, which can react in the atmosphere to produce ozone, a major component of smog. Toxic compounds (e.g., benzene, a known carcinogen) are also emitted by vehicles. In the United States, Federal Reformulated Gasoline (RFG) Phase 2 specifications went into effect in 2000, requiring reductions in tailpipe emissions of these pollutants as calculated by the Environmental Protection Agency’s (EPA) Complex Model. Gasoline RVP, sulfur, olefins, and aromatics content all play important roles in meeting RFG Phase 2 requirements. Sulfur recently has come under even further scrutiny. It is well known that sulfur in gasoline degrades the performance of catalytic converters by poisoning the active sites. In order to improve catalytic converter performance and meet lower tailpipe emissions standards, the US EPA has determined that gasoline sulfur levels must be reduced. The US EPA’s Tier 2 specifications require that gasoline sulfur average 30 ppm at the refinery level by 2006 with a per-gallon cap of no more than 80 ppm. The 30 ppm requirement represents a greater than 90% reduction in gasoline sulfur from baseline levels. The California Air Resources Board (CARB) has gone even further. Current CaRFG-2 specifications already require an average gasoline sulfur level of 30 ppm and proposals for CaRFG-3 would lower average gasoline sulfur to 15 ppm.