Microreactors, ultrasonic waves, and alcoholic solvents have been proven to be efficient techniques for CO2 desorption improvement. In the present study, the simultaneous use of all three methods was proposed. First, a direct-contact sono-microreactor was designed and employed for CO2 desorption from MEA, DEA, and MDEA aqueous solvents. The effect of temperature, flow rate, microchannel diameter, and ultrasound power were evaluated. Since MDEA indicated the highest desorption rate and the minimum regeneration energy demand, it was chosen for preparing hybrid solvents using methanol and ethanol. Aqueous and alcoholic MDEA solutions in terms of desorption efficiency and regeneration energy requirement were compared. The results demonstrated that MDEA-methanol inside the efficiently designed sono-microreactor could desorb 93.3% of CO2 with regeneration energy of 2.26 MJ/kg CO2, indicating 46.1% energy saving compared to 30 wt % MEA benchmark.
