Techno-economic evaluation of amine-reclamation technologies and combined CO2/SO2 capture for Australian coal-fired plants

CSIRO's patented CS-Cap process aims at reducing the costs of amine-based post-combustion capture by combining SO2 and CO2 capture using one absorbent in a single absorber column. By avoiding the need for a separate flue gas desulfurization unit, the process offers potential savings for power plants requiring CO2 capture. High-level cost estimates based on lab and pilot data are presented for two amine reclamation techniques i.e. thermal reclamation and reactive crystallisation. Only regeneration via reactive crystallisation reduces CS-Cap costs below base case FGD/SCR-PCC. Cost estimations suggest a potential reduction of 38-44% in the total plant cost when using the CS-Cap process compared to base case. However, the amine reclaimer operating cost governs the overall cost of the CS-Cap process and is highly sensitive to sulfur content. A 50% reduction is observed when SO2 levels reduce from 700 to 200 ppm. Comparing levelised cost of electricity and CO2 avoided costs for CS-Cap against our base case, low sulfur brown coal has a slight (5-7%) cost advantage; however, confirmation requires pilot data on amine recovery.