Highly integrated post-combustion carbon capture process in a coal-fired power plant with solar repowering

Abstract

While post-combustion carbon capture (PCC) technology has been considered as the ready-to-retrofit carbon capture solution, the implementation of the technology remains hampered by high costs associated with the large energy penalty incurred by solvent regeneration. This paper presents a highly integrated PCC process for a coal-fired power plant with solar repowering that features significantly enhanced energy efficiency. Validated process models are developed for the power, capture, and solar thermal plants and simulated in a model superstructure to evaluate the possible improvements in power plant energy efficiency and power output penalty reductions. A 660-MW power plant is taken as the case study. Three cases are used in this simulation analysis: (a) base case consisting of 660-MW power plant integrated with a PCC plant, (b) the base case extended to incorporate solar repowering, and (c) a highly integrated case that extends on the previous case to include CO2 gas compression unit heat integration. This study also highlights and discusses the role and interaction of various PCC and solar plant variables (e.g., solar field size, steam extraction flow rate, and twin LP turbine pressures) in the integration with power plant parameters. In particular, the power plant deaerator conditions play an important role in determining the total solar thermal energy required from the solar plant, thus dictating the solar field size. Copyright © 2015 John Wiley & Sons, Ltd.