Investigation on the Phase-Change Absorbent System MEA plus Solvent A (SA) + H2O Used for the CO2 Capture from Flue Gas

Amine-based CO2 postcombustion capture is a commercialized technology for recovery CO2 from flue gas, and the energy consumption is concentrated in the regenerative stage. The phase-change solvent system, monoethanolamine (MEA, absorbent) + solvent A (SA, solvent) + water (solvent), was investigated on the performances of CO2 absorption and desorption. CO2-rich solvent can be continuously separated for the feeding flow of the regeneration tower; thereby, it significantly reduces the energy of regeneration. The results show that the solvent with suitable composition can easily separate the CO2-rich phase from the solvent, and the CO2-rich phase accounts for more than 98% of the total CO2. At 293-333 K, the temperature has no significant effect on the absorption rate and phase equilibrium. The estimation of energy consumption shows that the reboiler work can be reduced by 43.6% compared with that using 20 wt % MEA aqueous solution.