The techno-economics of alternative CO_2 transport systems and their application in the Canadian oil sands industry

摘要

The rise in GHG emissions from the oil sands industry has prompted government and industry to seek ways to reduce its CO_2 output. CCS is currently the leading option in Alberta. A key to making it viable is a system that allows multiple emitters to gather, capture, and transport their CO_2 to the best sinks, efficiently and economically. The oil sands are located in Northern Alberta. Geological formations suitable for CO_2 storage exist in the South-West region, ～400 km from the sources. Implementing CCS will necessitate transporting roughly 30 megatonnes of CO_2 to suitable sinks. One of the best sinks is the underground aquifer in the Redwater Reef near Ft. Saskatchewan, with an estimated preliminary capacity of one gigatonne of CO_2, or 37 years of CO_2 emissions from oil sands, at 2007 rates. In this study, we compare two schemes to transport CO_2 from oil sands operations by capturing CO_2 and: 1) transporting it in its supercritical state to storage in the Redwater Reef and 2) transporting it in solution to Redwater, regenerating the solvent on-site and storing the CO_2 in the Redwater Reef. The fugitive emissions of Case 1 are consistently higher than those of Case 2. This is due to the former's electricity demands and the fact that the emissions associated with energy for solvent regeneration are not captured. Case 1 is more susceptible to electricity cost fluctuations than Case 2, but the latter is more susceptible to changes in the price of fuel. Although the CAPEX is similar for both, Case 2 benefits more from economies of scale than Case 1; the OPEX for Case 1 is 3.5% higher. The avoidance costs of Case 2 are lower on a gross basis (111 vs. 114 $/tonne CO_2) and on a net basis (327 vs. 851 $/tonne CO_2).