The impact of the CO2 separation system integration with a 900Â MWe power unit on its thermodynamic and economic indices

This paper presents an analysis of the thermal cycle of a supercritical 900 MWe condensing power plant which meets the “capture ready” requirements. The CO2 separation method selected for the analysis is chemical absorption using MEA (monoethanolamine) or ammonia as sorbent. The indispensable scope of the turbine system upgrade necessitated by the incorporation of the carbon dioxide separation installation is proposed. The change in indices of the power unit operation after integration with the capture installation is presented for different variants of the retrofit. If MEA is used for carbon dioxide separation, the smallest drop in electric power can be observed in the case of hard coal for added stages at the intermediate pressure part outlet. In the case of lignite, the most favourable upgrade solution in terms of the smallest drop in electric power is elimination of one low pressure part and a backpressure turbine is added at the same time. If ammonia is used as sorbent, the best upgrade solution in terms of the smallest drop in electric power is the variant with more stages added at the IP part outlet, regardless of the type of fuel. An economic analysis is conducted for the proposed variants.