Desulfurization of Fluid Catalytic Cracking Gasoline by Extractive Distillation Coupled with Hydrodesulfurization of Heavy Fraction

Abstract

Desulfurization of a fluid catalytic cracking (FCC) gasoline by extractive distillation was investigated. A modified Ellis dual-circulating vapor–liquid distiller was used to measure vapor–liquid equilibrium data of the FCC gasoline and various solvents. N-Formyl morpholine (NFM) was selected as the solvent for extractive distillation desulfurization. The desulfurization effect of FCC gasoline was investigated on a continuous extractive distillation column. At the optimal conditions, the distillate yield reached to 64.18 vol %, and sulfur content was 26.03 mg·L–1. After that, the heavy fraction was hydrodesulfurized on a FGH-31 catalyst in a fixed bed reactor. Results showed that the sulfur compounds in the heavy cut could be reduced to 9.5 mg·L–1. Light fraction of the extractive distillation and the hydrodesulfurized heavy cut are of primer blending compounds for producing low sulfur gasoline.