Chemical absorption method is an effective way to capture CO_2 from flue gas of coal burning. Compared with conventional organic amine absorbents

two-phase absorbent can significantly reduce the regenerative energy consumption and the capture cost. A new type of two-phase sorbent is developed

which uses the physical solvent diethylene glycol dimethyl ether as split-phase agent

ethanolamine and hydroxyethyl ethylenediamine as the main agent

and its absorption regeneration performance

viscosity

water phase proportion and phase separation interval is tested. Moreover

nuclear magnetic resonance(NMR) spectroscopy is carried out for the two phases in the sorbent to determine the composition and phase splitting mechanism. The organic amine composition in the formulation is optimized

and the results show that

the absorption and regeneration performance of the optimized absorbent is better than that of the conventional 5 mol/L ethanolamine absorbent. The cyclic absorption capacity can reach 2.086 mol/kg

more than 99% of CO_2 is enriched in water phase

and the flow of the absorbent entering into the regenerator can be reduced by about 40%. The viscosity of the water-rich phase is lower than 10 m Pa·s

the theoretical regeneration energy consumption is 2.688 GJ/t(calculated in CO_2)

indicating the new two-phase sorbent has a good industrial application prospect.