Oxidative Desulfurization of Gasoline by Ionic Liquids Coupled with Extraction by Organic Solvents

Rashid Abro,Guangren Yu,Shurong Gao,Salem S Al-Deyab,Xiaochun Chen,Ahmed A Abdeltawab

doi:10.5935/0103-5053.20150355

Abstract

In this work, desulfurization of real fluidized catalytic cracking (FCC) gasoline was investigated in dual steps; first in oxidative desulfurization (ODS) using imidazolium and pyrrolidonium based Bronsted acidic ionic liquids (ILs) as solvent and catalyst and hydrogen peroxide as oxidant. In second step, extractive desulfurization took place using organic solvents of furfural, furfural alcohol and ethylene glycol. Variety of factors such as temperature, time, mass ratio of oil/ILs and regeneration and recycling of ILs, multiple-step desulfurization of ILs and organic solvents and solvent/oil ratio were also investigated. The S-content was significantly decreased to ca. 18 ppm from initial S-content of 260 ppm with a total S-removal of ca. 95% in one-step ODS using pyrrolidonium based ILs coupled with five-step extraction desulfurization (EDS) using furfural alcohol as extractant. This work shows that oxidative desulfurization using ionic liquids coupled with extractive desulfurization using organic solvents is a potential method to produce clean gasoline.

Highlights

The emission of sulfur (S) during combustion from light fuel oils, coupled with increasing automobiles has heightened concern on environmental pollution
We synthesized four Brønsted acidic ionic liquids (ILs) namely [Hnmp]HSO4, [Hnmp]H2PO4, [Bmim]H2PO4 and [Bmim]HSO4 and investigated the desulfurization of real fluidized catalytic cracking (FCC) gasoline in two steps: the first in oxidative desulfurization (ODS) using above ILs as extractant and catalyst and H2O2 as oxidant; the second in extraction desulfurization (EDS) using different organic solvents of furfural, furfural alcohol and ethylene glycol, involving a variety of factors such as temperature, time, and regeneration of ILs, multiple-step desulfurization and solvent/oil mass ratio
Four hours are enough to reach the equilibrium of desulfurization when the S-removal efficiencies are 25.4 and 23.7% for [Hnmp]HSO4 and [Hnmp]H2PO4, respectively, at 60 °C, IL/oil = 1 and O/S = 16 after single step, while S-removal are only slightly increased to 25.6 and 24.1%, respectively, after 6 h

Summary

Introduction

The emission of sulfur (S) during combustion from light fuel oils, coupled with increasing automobiles has heightened concern on environmental pollution. We synthesized four Brønsted acidic ILs namely [Hnmp]HSO4, [Hnmp]H2PO4, [Bmim]H2PO4 and [Bmim]HSO4 and investigated the desulfurization of real fluidized catalytic cracking (FCC) gasoline in two steps: the first in ODS using above ILs as extractant and catalyst and H2O2 as oxidant; the second in EDS using different organic solvents of furfural, furfural alcohol and ethylene glycol (the ILs, organic solvents, used in this work are illustrated in Figure 3), involving a variety of factors such as temperature, time, and regeneration of ILs, multiple-step desulfurization and solvent/oil mass ratio.

H Furfural

Results and Discussion

Conclusions