Technical and economic assessment of ammonia-based post-combustion CO2 capture

Abstract

The performance and cost of two ammonia-based post-combustion CO2 capture systems operating at a new supercritical coal-fired power plant were modeled and compared to an amine-based CO2 capture system operating at a similar plant. This assessment showed that for a fixed coal input, the plant derating of a CO2 capture system operating with high ammonia concentrations (HighNH3) was found to be 2 percentage points lower than a plant with the amine-based system. The plant derating of a CO2 capture system operating with low ammonia concentrations (LowNH3) was substantially higher. Preliminary estimates of the revenue requirement of the plants with HighNH3 and LowNH3 systems are $US 117/MWh and $US 148/MWh respectively, compared to $US 119/MWh for a plant with an amine-based system. The results from this performance assessment and preliminary cost analysis suggest that the LowNH3 system will not be competitive and that the HighNH3 system may have a slight energy and cost advantage over the amine system. Furthermore, a preliminary uncertainty analysis explores the critical factors that may affect the performance and cost estimates of these systems, including the potential for slow reaction kinetics to increase absorber costs, and these results are presented.