ABSTRACT
Canada has extensive reserves of high sulphur heavy oils. These heavy oils are recovered primarily by steam injection techniques. As a result, the heavy oils are obtained as emulsions at well-heads. The heavy oils, being high in sulphur and metals, and low in hydrogen to carbon atomic ratio, require upgrading such as desulphurization and hydrocracking before it can be used in conventional refineries. Conventional emulsion treatment and desulphurization technology require multistage processing. Thus, alternative technologies for processing heavy oil emulsions would be attractive.
We have recently developed a novel single stage process for upgrading emulsions via activation of water to provide hydrogen in situ for catalytic desulphurization and hydrocracking. Current work is focused on the desulphurization aspect of upgrading, using benzothiophene as the model 434sulphur compound and molybdic acid as the catalyst. At 340°C and a CO loading pressure of 600 psi, up to 86 % sulphur removal was obtained. As well, in situ generated H2 was found to be more active than externally supplied molecular H2. A likely pathway for desulphurization of benzothiophene was via the initial hydrogenation of benzothiophene to dihydrobenzothiophene followed by hydrogenolysis to give ethylbenzene and H2S.
