CO2 capture retrofit options for a gasification-based integrated bitumen extraction and upgrading facility

Abstract

Abstract We have modelled a gasification-based bitumen extraction and upgrading plant, based on the Long Lake project in Alberta, Canada. The process is energy self-sufficient, featuring gasification of upgrading residue (asphaltene) and subsequent H2 extraction. The H2-lean syngas is used as fuel in a co-generation unit to provide power for the complex and steam for bitumen extraction. This study involves retrofitting the proposed process to capture CO 2 produced in the gasifier. Two CO 2 capture retrofit cases are considered: integrating pre-combustion CO 2 removal to the existing gasification process or adding a postcombustion CO 2 capture plant as a tail-end process. Both options feature a CO 2 capture efficiency of 90%. After CO 2 retrofit, natural gas supplementation is required and the power output drops, in both cases. The CO 2 reductions achieved by the retrofits are roughly 72% with respect to the original process. The net CO 2 emissions of the pre- and postcombustion capture cases are essentially the same. From a performance perspective, no option offers a clear advantage; the precombustion case has lower steam and natural gas requirements and yields less compressed CO 2 than the post-combustion case. However, the post-combustion retrofit is likely less disruptive to the process, it preserves a greater portion of the power production potential of the co-gen plant, and generates a purer CO 2 stream than the pre-combustion option.