Technical optimization and energy analysis of an advanced ammonia-based CO2 capture process for coal-fired power plants

This study proposed an advanced ammonia-based post-combustion CO2 capture process and investigated the technical performance under different operating parameters using rate-based model. The response surface methodology (RSM) was employed to establish the predictive models for CO2 removal efficiency and specific desorption energy, thereby optimizing operational parameters. Furthermore, the energy penalty imposed on a 360 MW coal-fired power plant by the integration of the CO2 capture process was quantified. Results indicated that the CO2-rich solvent split ratio, ammonia concentration, lean CO2 load, and solvent flow rate all significantly affected the capture performance. The predictive models for CO2 removal efficiency and desorption energy demonstrated exceptional accuracy, with correlation coefficients of 0.9973 and 0.9498, respectively. The RSM analysis indicated that setting the CO2 removal efficiency target above 80% was appropriate from a technical and economic standpoint. Compared to the basic process, the advanced process resulted in a lower net efficiency penalty of 9.36% for power plant at a CO2 removal efficiency of 80.22%. This penalty can be further reduced to 6.94% by substituting refrigerator with cooling water for CO2-lean solvent cooling.