Scope of the work presented in this paper is to examine and evaluate the application of the oxyfuel combustion CO2 capture technology in a lignite- fired power plant from an economic point of view. CO2 capture costs and the energy requirements associated with the oxyfuel method affect significantly the cost of electricity. The paper focuses on the analysis of the techno-economic factors that result in the increase of the cost of electricity in comparison with a conventional power plant.
Results from thermodynamic simulations dealing with the most important features for CO2 sequestration are presented, demonstrating the efficiency penalties related to the application of the oxyfuel technology in a greenfield application, with respect to a reference typical Greek lignite power plant. The cycle calculations have been performed using the thermodynamic cycle calculation software ENBIPRO (ENergie-BUIanz-PROgram), a powerful tool for heat and mass balance solving of complex thermodynamic circuits, calculation of efficiency, exergetic and exergoeconomic analysis of power plants. The oxyfuel simulations are performed by adopting measures for the exploitation of heat that would otherwise be wasted. Such measures concern the water/ steam cycle and the gas flows (e.g. the oxygen flow). Heat integration from processes - such as the air separation, the CO: compression and purification and the flue gas treatment - is adopted in order to lower as much as possible the efficiency penalty.
The technical, economic and financial assumptions applied provide a common basis for both power plants (i.e. conventional and oxyfuel) for the assessment of the variation of the cost of electricity and the CO2 capture cost