Jacobs secures Canadian Order

Abstract

The relatively high sulphur content of coke produced during the upgrading of Athabasca bitumen, makes it environmentally unsuitable as a fuel. Using heavy oil or bitumen as a binder, attempts have been made to coagglomerate these cokes with sulphur dioxide capture agents, such as lime, hydrated lime and limestone, to reduce emissions during combustion. By providing an environment in which there is intimate contact between fuel and sorbent, it was hoped that greater utilization of the sorbent could be achieved, compared with the systems in which the sorbent is added separately to the combustion bed. Cokes from both Suncor and Syncrude operations were used in this investigation. The combustion tests on coke-sorbent agglomerates were carried out in a bench scale fluidized bed apparatus at 850 °C. Test results indicated sulphur capture of over 60 wt % for Syncrude coke and over 50 wt % for Suncor coke at a calcium to sulphur molar ratio of 1:1. The presence of moisture did not appear to have any significant effect on sulphur capture. Other variables investigated included: the role of binder, the effect of coke size and calcium to sulphur mole ratio. A comparison was made of the efficiency of the various sulphur sorbents in the reduction of sulphur dioxide emissions.