CO2 capture by a highly-efficient aqueous blend of monoethanolamine and a hydrophilic amino acid ionic liquid [C2OHmim][Gly]

A hydrophilic amino acid ionic liquid [C(2)OHmim][Gly] synthesized by our laboratory was utilized to enhance the process of MEA for CO2 capture from low-pressure flue gas. The optimum proportion of the mixed solution was chosen as 0.7 mol L-1 MEA and 0.3 mol L-1 [C(2)OHmim][Gly]. The absorption capacity of the new absorbent was 0.534 mol CO2/mol absorbent under 3% O-2, and was higher than that of MEA (0.430 mol CO2/mol amine). The capacity of MEA/[C(2)OHmim][Gly] solution was maintained at 0.50 mol CO2/mol absorbent even with 8% of O-2. Only 12.6% of decrease in the absorption capacity was noticed compared with that in the absence of O-2. Furthermore, it was well recycled with a regeneration efficiency, of 90.2% by thermal regeneration after fourth-cycle experiments in 3% O-2. The new absorbent is proved to have a reduced degradation and evaporation rate, an enhanced absorption capacity and a high stability and regeneration efficiency for the CO2 capture. (C) 2015 Elsevier B.V. All rights reserved.