Effects of concentration and viscosity on the absorption of CO2 in [N1111][Gly] promoted MDEA (methyldiethanolamine) aqueous solution

•Absorption capacity, absorption rate of CO2 and viscosity were measured.•Temperature slightly influences the absorption rate of CO2.•Competitive effects of concentration and viscosity on absorption rate were illustrated.•Effects of temperature, concentration and CO2 loading on viscosity were demonstrated.

The absorption of CO2 in tetramethylammonium glycinate ([N1111][Gly]) promotedMDEA (methyldiethanolamine) aqueous solution was investigated. The temperature ranged from 303.2 K to 323.2 K. The mass fractions of MDEA and [N1111][Gly] respectively ranged from 0.3 to 0.45 and 0.05 to 0.15. The influences of temperature and concentration on the absorption capacity of CO2 were determined. The viscosities of CO2-unloaded and CO2-loaded MDEA-[N1111][Gly] aqueous solutions were measured and correlated. The experiments showed that the absorption rate of CO2 obviously increased when the MDEA aqueous solution was promoted by [N1111][Gly]. The effects of temperature, concentration and solution viscosity on the absorption rate were illustrated.