Post-combustion CO2 capture retrofit from diesel-powered Arctic mines – Techno-economic and environmental assessment

Abstract

This study evaluates the economic feasibility and environmental impacts of retrofitting a diesel-based powerhouse in the Canadian Arctic with a post-combustion carbon capture process at an active gold mining site isolated from cheaper or cleaner electrical grids. A techno-economic analysis was conducted to determine the total annualized cost (TAC) of implementing a monoethanolamine (MEA) chemical absorption process to mitigate carbon dioxide emissions. The calculated cost per tonne of CO₂ captured of $420 reflects the challenges of operating northern sites reliant on diesel fuel. Electricity generation costs, estimated at 0.44 $/kWh, are found to explain most of the variance in cost per tonne compared to other studies. A profitability model, comparing the additional annual expenditure to the current carbon tax exposure (CTE), suggests that carbon pricing alone is insufficient to incentivize investment in energy-intensive carbon capture technologies such as amine-based absorption processes. The sensitivity analysis, which evaluates profitability relative to variations in key variables, highlights the significant impact of the solvent regeneration heat demand. This major cost driver also contributes substantially to the carbon footprint of 0.55 tonnes emitted per tonne captured, as determined by a complementary life cycle assessment.