Impact of liquid absorption process development on the costs of post-combustion capture in Australian coal-fired power stations

▶ This paper describes the results of solvent sensitivity analysis and a techno-economic evaluation of liquid absorption based post-combustion capture (PCC) processes for both existing and new pulverised coal-fired power stations in Australia where presently limited emission controls exist. ▶ Both air and water cooled power plant operations with continuous CO2 capture and with the flexibility to switch a CO2 capture plant on or off are considered. ▶ The techno-economic analysis shows that if the post combustion capture becomes mandatory in future, then the ultra-supercritical single reheat design of power plants will become a preferred option for new plants in Australia due to their potential to generate electricity at lowest cost with the lowest cost of CO2 avoidance. However, roughly 70% of the cost of electricity generation will be due to the capital amortisation charges associated with these plants. ▶ The solvent sensitivity analysis indicates that a novel solvent, that is 50% better than 30% (w/w) aqueous MEA in terms of its heat of reaction, the sensible heat requirement and the stripping steam requirement for regeneration, has potential to reduce the net power plant efficiency penalty from 10 absolute percentage points to less than 7 absolute percentage points, total water consumption by 170 tonnes/h, the cost of electricity generation by Aus $8/MWh of net power output and the cost of CO2 avoidance by Aus $13/tonne of CO2 for an existing mechanical draft water cooled black coal-fired subcritical power plant which has 90% CO2 capture plant retrofitted to operate ON and OFF on demand for maximum flexibility of power generation.