Economic Optimization of Carbon Capture Processes Using Ionic Liquids: Toward Flexibility in Capture Rate and Feed Composition

Aprotic heterocyclic anion ionic liquids (AHA ILs) have received significant recent attention as potential absorbents for next-generation carbon capture processes. In this paper, we describe a rate-based model of an AHA IL-based carbon capture process. We use the model to perform economic optimization, minimizing a total cost function (annual operating cost plus annualized capital cost). Process-level decisions, including equipment design and operating parameters, are considered simultaneously with the material-level decision of the CO2 reactive absorption enthalpy in the AHA IL being a tunable molecular parameter. We study how the optimal design changes with flexible flue gas compositions, with a focus on cases arising in the context of partial oxy-combustion. We also study the variation in the optimal design as the CO2 capture level changes. Flexibility in this regard is important as power plants increasingly need to account for time-varying power demand due to the market penetration of variable renewable energy sources such as wind and solar power.

Automated summary

The paper presents a rate-based model of an AHA IL-based carbon capture process and conducts economic optimization using the model. The study shows how the optimal design changes with flexible flue gas compositions and CO2 capture levels, emphasizing the importance of flexibility in power plants facing time-varying power demand.