Energy-saving CO₂ Capture Process Using Phase Separation Type Solvent by Aqueous (amine + ether) Solution

We have developed the phase separation solvent for CO₂ capture. Our developed solvent consists amine, organic solvent and water and shows single liquid phase before CO₂ absorption though it shows two liquid phases after CO₂ absorption. Feature of phase separation solvent is reducing temperature difference between absorber and stripper. We apply the heat pump system for CO₂ separation and evaluate the energy consumption. Low temperature swing process saves energy requirement for CO₂ capture process with highly-effective reaction-heat recovering. To evaluate the CO₂ capture system with our solvent, screening test for amine and organic solvent combination and CO₂ solubility measurement were examined. In the phase separation test, three types of solvents were obtained by combining amine and ether, that is, no phase separation with CO₂ scrubbing, phase separation with CO₂ scrubbing, and thoroughly immiscible. The phase behaviour depends on the hydrophobicity of amines or organic solvents, and the types of solvents were classified using the hydrophobic parameter.