Emerging technology for the reduction of sulfur in FCC fuels

Passage of the Clean Air Act of 1990 and new regulations issued in California will set new limits on the sulfur content of gasoline. Because most of the sulfur in the gasoline pool comes from FCC naphtha, there is a strong incentive to reduce the sulfur content of this stream in the most cost efficient manner. This work introduces emerging catalytic technology for the direct reduction of the sulfur content of FCC gasolines, called the GSR[trademark] (Gasoline Sulfur Reduction) technology. Studies of this new technology were carried out using the Davison Circulating Riser pilot unit. The GSR technology is shown to reduce the sulfur in FCC naphtha by 15%, with two feedstocks. It is shown that this technology is selective to sulfur species in the middle of the gasoline boiling range, and converts these species to H[sub 2]S, while preserving most of the base catalyst selectivities. Various other catalytic scenarios for minimizing the gasoline sulfur content are also given.