Optimisation of post-combustion CO2 capture for flexible operation

In order to accommodate the increasing penetration of intermittent renewable electricity generation capacity, it is becoming increasingly clear that decarbonized fossil-fired power plants will have to operate in a highly flexible fashion. In this study, using detailed mathematical models of a coal-fired power plant integrated with a MEA-based post-combustion CO2 capture plant, we present a technical and economic analysis of several distinct modes of flexible operation. Using multi-period dynamic optimization techniques, we evaluate solvent storage, exhaust gas venting and time-varying solvent regeneration using average carbon intensity and profitability as key constraints and objective functions, respectively. Load following operation of the power plant with a tightly integrated capture plant is used as our base case scenario. We find that solvent storage is 4% more profitable than the base case, whereas exhaust gas venting is 17% more costly and appears incapable of meeting our decarbonisation targets. Time varying solvent regeneration is 16% more profitable than the base case and the electricity generated has an average carbon intensity which is approximately 5.5% lower than that of the base case. (C) 2014 The Authors. Published by Elsevier Ltd.