Solubilities of CO2 capture absorbents 2-ethoxyethyl ether, 2-butoxyethyl acetate and 2-(2-ethoxyethoxy)ethyl acetate

•Measured solubility data of CO2 in 2-ethoxyethyl ether, 2-butoxyethyl acetate and 2-(2-ethoxyethoxy)ethyl acetate.•Calculated Henry's law constants and thermodynamic properties of high boiling absorbents.•Carbonyl and ether group in the absorbents can improve absorption capacity of CO2.•Concluded that 2-(2-ethoxyethoxy)ethyl acetate has potential research value for CO2 capture.

The isothermal synthetic method was used to measure CO2 solubilities in three high-boiling-point absorbents, such as 2-ethoxyethyl ether, 2-butoxyethyl acetate and 2-(2-ethoxyethoxy)ethyl acetate under pressures ranging from 0 to 1.3 MPa and temperatures ranging from 293.15 to 333.15 K. Henry's law constants and thermodynamic properties (solution of Gibbs energy, solution of enthalpy, and solution of entropy) of selected systems were calculated. Results showed that carbonyl and ether groups in the absorbents improved CO2 solubility and the carbonyl group was more effective than the ether group. 2-(2-Ethoxyethoxy)ethyl acetate which is rich in carbonyl and ether groups, was found to be the most excellent absorbent for CO2.