ASPEN Plus® reassessment of efficiency penalties associated with a pulverised coal oxy-combustion power plant-A case study

The ASPEN Plus V8.4 was used to model air- and oxy-combustion plants and determine the thermal efficiency penalty associated with retrofits, which was then compared to the thermal efficiency penalty established in the literature. Additionally, this paper investigates the feasibility of offsetting the efficiency penalty through the use of reaction heat from flue gas desulphurization (FGD), as all previous research on the subject has ignored both the reaction heat generated by the FGD unit and the chemical exergy of the FGD wastewater. Finally, a heat integration study is done to determine the feasibility of preheating boiler feed water during the steam cycle utilizing compression heat generated by the air separation unit (ASU) and CPU (compression and purification unit) compressors. Thermal efficiency penalty was determined to be 9.24% in this study, while the theoretically bare minimum efficiency penalty was determined to be 3%. Additionally, it was determined that by combining the compression and steam cycles, net thermal efficiency may be increased by 0.679%.