Thiophene Extraction from Liquid Fuel using Ionic Liquid

Crude petroleum contains numerous sulphurous compounds that cause pollution if not removed from crude oil. Desulphurisation techniques such as hydrodesulphurisation are used to remove these compounds, in which expensive and highly inflammable hydrogen is used. However, this technique is not that efficient for organic non-reacting sulphur compounds like thiophene, dibenzothiophene, alkyl substituted dibenzothiophene, etc. In this study, aqueous solution of an ionic liquid, namely, [BMIM][Cl] has been used to extract thiophene from a model fuel (iso-octane). Various parameters that affect the extractability have been studied. These parameters include contact time, varying thiophene concentration, varying [BMIM][Cl] concentration and temperature. Maximum possible extraction achieved was >99% for a 1000 ppm of thiophene in iso-octane in 1 hr at 40°C, when aqueous [BMIM][Cl] ionic liquid concentration was 1.5 M.