Gasoline sulfur control may be required. Gasoline production and sulfur content

An analysis of the comparative costs for reducing the sulfur content of current unleaded gasoline supplies in the U.S. to avoid sulfate pollution in use with three-way exhaust-gas catalysts, indicates that hydrodesulfurization of the fluid catalytic cracker (FCC) feed, which is mainly 316/sup 0/-538/sup 0/C straight-run gas oil containing 1000-4000 ppm sulfur, would cost a total of $3-$5 billion and would reduce the sulfur content of the product by 400-700 ppm. Hydrotreating of the heavy (intermediate) fraction of the FCC product gasoline to 1 ppm sulfur, followed by reforming to raise the octane rating, would cost about $48 million but would reduce total gasoline production by 5.Vertical Bar3<. Desulfurization of the 21/sup 0/-93/sup 0/C straight-run light naphtha fraction would cost $11 million, with no loss of gasoline production but with an over-all sulfur-content reduction of only 10-30 ppm. The cost of desulfurization is thus $0.04-$0.06/gal/1000 ppm sulfur reduction for the FCC feed or the FCC product gasoline, and $0.10-$0.30/gal/1000 ppm for the light naphtha. Finished unleaded gasoline with 200 ppm sulfur should be obtainable from FCC gasoline for $3-$5 billion; a similar fuel with 100 ppm sulfur should be obtainable from FCC gasoline and light naphtha for $4-$6 billion.