Removal of hydrogen sulphide by combusted Rundle oil shale: sulphidation of iron oxides

• Published in: Fuel (Guildford) 1989-12, Vol.68 (12), p.1598-1602
• Main Authors: Killingley, John S., Callaghan, D.Glen, Day, Stuart J.
• Format: Article
• Language: English
• Subjects: Applied sciences; Crude oil, natural gas and petroleum products; Energy; Exact sciences and technology; Fuels; iron; oil shale; Processing of crude oil and oils from shales and tar sands. Processes. Equipment. Refinery and treatment units; sulphur
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/0016-2361(89)90301-3

Oil shale from the Rundle deposit of Queensland, Australia, after retorting and combustion in air, contains haematite and magnetite. Studies of the reactions of hydrogen sulphide with this combusted shale, and with the individual iron oxides, showed the sulphidation kinetics to be first order with respect to hydrogen sulphide, with activation energies of 35 ± 1, 59 ± 3 and 66 ± 2 kJ mol −1 respectively for haematite, magnetite and combusted shale. Under dry conditions the shale trapped 36 mg of hydrogen sulphide per gram of combusted shale. With steam present, the iron oxides did not trap hydrogen sulphide and the combusted shale was also ineffective because, apart from negligible sulphidation of its iron oxide minerals, another sulphur-trapping mineral, calcium oxide, had effectively been removed by silication during combustion. The potential to control hydrogen sulphide (produced during steam retorting of shale) by recycled combusted Rundle shale is therefore poor, but a characteristic of this shale during pyrolysis is that most hydrogen sulphide is released above 500 °C, so that by minimizing retort temperatures, consistent with appropriate oil recovery, substantial control of hydrogen sulphide should be possible.