1. Introduction - Firenze University Press

Figure 6a. Impact of CCE on PCU Figure 6b. Effect of CCR on the power plant
performance for the two purification methods. for the two purification methods.
For low CCE the flash separation method has positive effect on energy balance as the PCU
produces electrical power instead of consuming (Figure 6a). This is owed to the expansion of the
CO2-rich stream. However, the combustibles are not recovered as effectively as in the case of the
distillation column method and therefore the latter is exergetically more efficient. As the CCE
approaches 100%, energy duties for both methods tend to be equal and the divergence of the
corresponding exergy efficiency increases. The effect of CCR on the overall plant efficiency and the
corresponding SPECCA (Figure 6b) is the same for both combustibles separation options
(especially for CCR