Experimental study on CO capture by MEA/-butanol/HO phase change absorbent.

Monoethanolamines (MEAs) are widely used for CO capture, but their regeneration energy consumption is very high. CO Phase change absorbents (CPCAs) can be converted into CO-rich and CO-lean phases after absorbing CO, and the regeneration energy consumption can be reduced because only the CO-rich phase is thermally desorbed. In this paper, a novel CPCA with the composition "MEA/-butanol/HO (MNBH)" is proposed. Compared with the reported MEA phase change absorbent, the MNBH absorbent has higher CO absorption capacity, smaller absorbent viscosity and CO-rich phase volume. The MNBH absorbent has the highest CO absorption capacity of 2.5227 mol CO per mol amine at a mass ratio of 3 : 4 : 3. The CO desorption efficiency reaches 89.96% at 120 °C, and the CO regeneration energy consumption is 2.6 GJ tCO, which is about 35% lower than that of the 30 wt% MEA absorbent. When the mass ratio of MNBH absorbent was 3 : 6 : 1, the CO recycling capacity was 4.1918 mol CO L, which is 76% higher than that of the conventional 30 wt% MEA absorbent. The phase change absorbent developed in this paper can reduce the desorbent volume by about 50% and has good absorption performance for CO in flue gas.