Techno-economic analysis of water-based CO2 capture method based on adiabatic compressed air energy storage: Comparison with monoethanolamine-based CO2 capture method

Abstract

Carbon dioxide (CO2) capture and storage is considered an effective measure to mitigate climate change, used to reduce CO2 emissions from industrial sectors, especially for coal-fired power plants. In our previous work, a novel water-based CO2 capture (WCC) method based on adiabatic compressed air energy storage (A-CAES) was developed. This method is simple and environmentally friendly. However, unlike the widely used monoethanolamine (MEA)-based CO2 capture (MCC) technology, which consumes low-grade thermal energy, the WCC technology consumes high-grade electrical energy. Therefore, in this work, a comprehensive techno-economic analysis of the WCC technology is conducted and compared with the MCC technology from the perspective of carbon emission reduction. A universal economic assessment criterion of CO2 capture cost based on electricity prices is proposed, and the techno-economic analysis is based on the cost in 2022 USD ($). The result shows that the CO2 capture cost of the WCC system ranges from 53.74 to 71.70 $/tonne CO2 due to the different factors considered in computational models, taking 63.57%–84.81% of the MCC system under the same capture rate (85%). The dynamic payback period of the WCC system ranges from 7.14 years to 20.52 years, while the MCC system failed to recover capital throughout the entire lifecycle. Moreover, the CO2 capture cost of the WCC system can be reduced to below carbon tax (43 $/tonne CO2) when the CO2 concentration in the feed flue gas is above 18 vol%, achieving positive benefits with no carbon trading required, which means the WCC system can achieve positive profitability for higher CO2 concentration emission sectors. The results provide significant guidance for developing and promoting the WCC technology.