Absorption of carbon dioxide into aqueous blend of monoethanolamine and 1-butyl-3-methylimidazolium tetrafluoroborate

A mixed absorbent composed of MEA and [Bmim]BF4 was used to improve MEA-based process, one of the most extensively used techniques for CO2 capture from flue gas. The optimum mole ratio of MEA to [Bmim]BF4 was found to be 7:3. The absorption capacity of the mixed absorbent was significantly higher than pure MEA aqueous, approaching 0.638 mol of CO2 per mol of MEA. Some factors, e.g., the concentration of the mixed absorbent and O2, temperature was investigated respectively at 15 kPa CO2 partial pressure. The mixed absorbent quality owns higher stability and antioxidant activity compared with aqueous MEA solution in the present of 8% O2. Additionally, the absorbent could be well recycled by thermal regeneration after multi-cycle experiment. All the results indicated that the mixed absorbent employed in this CO2 capture process can help to improve the stability and reliability of the system, possesses great potential for making up the deficiencies of aqueous MEA, which is beneficial to industrial applications.