The chemistry of organosulphur compound types occurring in heavy oils: 4. the high-temperature reaction of thiophene and tetrahydrothiophene with aqueous solutions of aluminium and first-row transition-metal cations

Abstract

In the reactions of thiophene and tetrahydrothiophene with aqueous solutions of first-row transition-metal and aluminium cations at 240 °C and 3.4 MPa all the metal species accelerated the decomposition of the thiophenes in relation to equivalent reactions with pure water. Al 3+, Sc 3+, VO 2+, Cr 3+, Ni 2+ and Cu 2+ were most reactive towards thiophene and Al 3+, VO 2+, Cr 3+ and Cu 2+ were most reactive towards tetrahydrothiophene. Principal products were H 2S and complex mixtures of organic products. The presence of CO 2 and oxygen-containing organic products revealed that water was involved in direct chemical reaction with the substrates. It is likely that these model reactions parallel more complex processes that occur during the steam-stimulated recovery of oil-sand bitumen and other high-sulphur oils.