Energy-efficient CO2 capture using potassium prolinate/ethanol solution as a phase-changing absorbent

High energy consumption for aqueous amine-based CO 2 capture process is still a major drawback limiting its commercial deployment. Most of heat is used for water vaporization during solvent regeneration for CO 2 stripping. Development of phase-changing solvents is an attractive energy-efficient method to reduce energy requirement. In this work, we have proposed potassium prolinate (ProK)/ethanol solution as a novel non-aqueous absorbent. Its physical properties and the rate of CO 2 absorption were investigated and compared with the aqueous ProK systems. Phase behaviours during CO 2 absorption and partition of CO 2 absorbed between liquid and solid phases were characterized. The main species in solid precipitates were identified as bicarbonate and proline salts by 13 C NMR and XRD. Moreover, the regenerated absorbents can remain relatively stable after absorption-desorption cycles.