Absorption of carbon dioxide into aqueous colloidal silica solution with diisopropanolamine

Carbon dioxide was absorbed into the aqueous nanometer-sized colloidal silica solution of 0–31 wt% and diisopropanolamine of 0–2 kmol/m3 in a flat-stirred vessel with the impeller of various sizes and speeds at 25 °C and 0.101 MPa to measure the absorption rate of CO2. The volumetric liquid-side mass transfer coefficient (kLa) of CO2 was used to obtain the empirical correlation formula containing the rheological behavior of the aqueous colloidal silica solution. Reduction of the measured kLa was explained by the viscoelastic properties of the aqueous colloidal silica solution. The theoretical value of the absorption rate of CO2 was estimated from the model based on the film theory accompanied by chemical reaction and compared with the measured value.