“…In flexible operation, on the other hand, some of the variables can be varied dynamically in response to fluctuating electricity market price in order to meet the electricity demand and improve the overall profit. This can be done, for example, either by reducing the capture level (CO 2 venting, by-passing a part of the flue gas, CO 2 capture level reduction) (Chalmers, 2010;Chalmers et al, 2009aChalmers et al, ,b, 2011Chalmers and Jon, 2007;Cohen et al, 2011bCohen et al, , 2012Fyffe et al, 2011;Khalilpour, 2014a,b;Qixin et al, 2010;Wiley et al, 2011;Ziaii et al, 2009), or by reducing the rate of spent solvent regeneration (e.g., by storing a part or all of the CO 2 rich solvent in a tank and using the already regenerated solvent stored in another tank (Arce et al, 2012;Bui et al, 2014;Chalmers, 2010;Chalmers et al, 2009aChalmers et al, ,b, 2011Chalmers and Jon, 2007;Cohen et al, 2011bCohen et al, , 2012Domenichini et al, 2013;Husebye et al, 2011;Khalilpour, 2014b;Patiño-Echeverri and Hoppock, 2012;Qixin et al, 2010;Ziaii et al, 2009)) during times of high electricity price/demand. These two operation modes are illustrated in Figs.…”