CO2 absorption and microwave regeneration with high‐concentration TETA nonaqueous absorbents

While nonaqueous organic‐amine absorbents have great potential in reducing energy consumption of CO2 capture, their absorption/desorption behaviors are still poorly understood when high‐concentration polyamines are used. On the other hand, large scale CO2 capture demands the use of high‐concentration polyamines absorbents. Therefore, we investigated the absorption and microwave regeneration behavior of high‐concentration triethylenetetramine (TETA) in three typical organic solvents, including polyethylene glycol 200 (PEG200), diethylene glycol (DEG), and ethylene glycol (EG). The results showed that high‐concentration TETA nonaqueous absorbents demonstrate advantages in absorption rate and regeneration energy consumption. The average absorption rate of 2.0 and 5.0 mol/L TETA/EG was 2.84 and 4.70 times that of 0.6 mol/L, respectively. The energy consumption of TETA/EG and TETA/DEG decreased by 29.4 and 25.6% as the concentration increased from 0.6 to 5.0 mol/L. In addition, the high‐concentration TETA/PEG200 absorbent demonstrated observable tolerance for water vapor, which usually exists in flue gas. Results also showed that microwave regeneration was superior to conventional conduction heating especially when high‐concentration TETA/PEG200 absorbent were used. The energy consumption of microwave regeneration of the absorbent with a concentration of 0.6, 2.0, and 5.0 mol/L was reduced by 65.9, 81.2, and 86.0%, respectively when compared with conduction heating. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.