Chemical Absorption of Carbon Dioxide into Aqueous Colloidal Silica Solution with Triethanolamine

Abstract

Carbon dioxide was absorbed into an aqueous nanometer sized colloidal silica solution of 0–31 wt% and triethanolamine of 0–2 kmol/m³ in a flat-stirred vessel with an impeller size of 0.05 m and speed of 50 rpm at 25°C and 101.3 kPa to measure the absorption rate of CO₂. The measured rate of CO₂ absorption was compared with the values estimated from the model based on the film theory accompanied by chemical reaction. The volumetric liquid-side mass transfer coefficient (k_La_L) of CO₂ decreased with increasing silica concentration and was expressed as an empirical correlation formula presenting the relationship between k_La_L and the rheological behavior of the aqueous colloidal silica solution. Reduction of the measured k_La_L was explained by the viscoelastic properties of the aqueous colloidal silica solution.