Simultaneous design and operational optimization for flexible carbon capture process using ionic liquids

Abstract

Carbon capture and storage is an effective way to abate CO2 emissions during the transition to zero-carbon power generation technologies. As renewable electricity sources such as wind and solar photovoltaics become more prevalent, conventional power generation systems are increasingly required to operate at highly variable rates in order to balance intermittent renewable power supply. As a result, post-combustion carbon capture systems integrated with fossil fuel power plants must also operate at variable load. In addition, the solvent regeneration and CO2 compression in capture plants requires substantial amounts of energy and such flexible operation can present an opportunity for operators to take advantage of fluctuating electricity prices, potentially offsetting the cost of carbon capture. This can be achieved through, among others, variable capture rates and utilization of solvent storage. In this paper, we consider a carbon capture system using ionic liquids as a chemical absorption solvent. We study the optimal flexible operation of this system when connected to a natural gas combined cycle power plant under high variable renewable power generation rates. The results show significant cost savings relative to the case of inflexible capture system operation.