Energy harvesting from amine-based CO2 capture: proof-of-concept based on mono-ethanolamine

Amine-based processes are the leading technology for CO2 capture, but their commercial deployment is hindered by their large energy requirement. In practice, the energy consumption of this CO2 capture process is a result of an inability to offset the energy required for CO2 desorption against the enthalpy released in CO2 absorption. Here, we propose a metal-mediated CO2-regenerative amine-based battery (CRAB) to directly convert the CO2-reaction enthalpy into electrical energy. Using the benchmark mono-ethanolamine (MEA) absorbent, we developed and validated a CRAB process model that is used to predict the energy harvesting performance. We then harvested an electrical energy of 8.3 kJe/mol CO2 from the lab-scale flow battery, demonstrating the proof-of-concept of energy harvesting from amine-based CO2 capture. Techno-economic analysis indicates that the CRAB energy harvesting system improved the power generation efficiency by 1.75% and decreased the CO2 avoided cost when integrated with a coal-fired power station, suggesting its potential to improve the techno-economic competitiveness of amine-based CO2 capture process.