Design and simulation of a petcoke gasification polygeneration plant integrated with a bitumen extraction and upgrading facility and net energy analysis

The in-situ extraction of bitumen from oil sands, particularly steam assisted gravity drainage, has been the fastest growing production technology in the industry. Integrated with upgrading operations to enhance the fuel quality, the process consumes significant amounts of energy, which are currently mostly derived from burning natural gas. On the other hand, considerable amounts of petroleum coke residues are generated in the refineries. This petcoke ends up stockpiled as a waste byproduct with associated environmental concerns. The aim of this study is to evaluate the feasibility of integrating a petroleum coke residue gasification plant to the energy infrastructure of an integrated SAGD/upgrading facility. The petcoke gasification process is specifically designed to fulfill the demands of a facility processing 112,500 barrels per day of Athabasca bitumen. Two plant configurations are compared, one without and one with CO2capture and storage. The gasification-based polygeneration plant is modeled with the Aspen Plus flowsheeting software. Two levels of energy demands (i.e. high and low energy scenarios), reflecting the range of variability in the energy requirements of extraction and upgrading operations (e.g. steam to oil ratio), are considered. The net efficiency for polygeneration plant was determined to be in the range of 48–58%. The gasification of approximately 190 t/h of petroleum coke is required to achieve the power, thermal and hydrogen demands. The incorporation of carbon capture imposes significant energy penalties, which requires the addition of natural gas fueled gas turbines to meet the power requirements.