Impact of carbon capture technologies on GHG emissions from oil sands in-situ facilities: A system prospective

Abstract

The Canadian in-situ bitumen extraction is one of the most energy-intensive processes and a large GHG producer. In an increasingly carbon-constrained environment, industry and technology developers aim towards decarbonization of their operations by considering several design strategies. Post-combustion carbon capture (PCC) and heat integration are available solutions that can significantly reduce GHG emissions produced by in-situ extraction plants such as steam-assisted gravity drainage (SAGD) facilities. An important challenge that currently limits the use of carbon capture in SAGD facilities, apart from the capital cost, is the large quantity of energy needed and the associated GHG emissions. In this work, the energy performance of two typical SAGD configurations was optimized with and without PCC technologies. Aspen HYSYS® was used to model each configuration for a standard capacity and CanmetENERGY’s INTEGRATION software was used to optimize heat recovery. First, it was shown that SAGD facilities’ energy consumption and GHG emissions could be reduced by up to 8% through optimized heat recovery leading to a significant increase in the boiler feedwater and combustion air temperatures. Then, two PCC technologies were integrated into the SAGD configurations. Several energy integration strategies were considered to provide part of the regeneration energy required in the PCC units by using the excess heat in the SAGD and PCC plants. The analysis revealed that, depending on the SAGD process configuration, the PCC technology considered and the level of heat integration within the SAGD plant, 13–47% of the regeneration energy could be provided by heat recovery. Additionally, the techno-economic analysis results showed a capture cost of US$34.6–55.3/t-CO2 for different studied scenarios.