Hydrodesulfurization and hydroconversion of heavy FCC gasoline on PtPd/H-USY zeolite

Abstract

In the search for catalysts suitable for upgrading fractions of FCC gasoline, PtPd/USY zeolite was investigated. The objectives of the work were to reduce simultaneously the sulfur, nitrogen and aromatic contents of heavy FCC gasoline having various sulfur (30–203 ppmw) and 28 ppmw nitrogen contents. The process conditions were the following: temperature: 200–300 °C; pressure: 30 bar; liquid hourly space velocity: 1.0–3.0 h −1; H 2/hydrocarbon ratio: 500 m 3/m 3. The results indicated that PtPd/H-USY zeolite catalyst can be applied for the desulfurization of heavy FCC gasoline up to 203 ppm sulfur content. When a base heavy FCC gasoline fraction of 30 ppmw sulfur content was used the catalyst was able to reduce the aromatic content by 14 abs.% as well as sulfur and nitrogen contents to <1 ppmw in one step. Blending calculations were made to evaluate the quality of a full range FCC gasoline obtained by mixing the desulfurized heavy FCC gasoline and the untreated light cut.