Simultaneous absorption of CO₂ and SO₂ into aqueous AMP/NH₃ solutions in binary composite absorption system

Abstract

To enhance the absorption rate for CO₂ and SO₂, aqueous ammonia (NH₃) solution was added to an aqueous 2-amino-2-methyl-1-propanol (AMP) solution. The simultaneous absorption rates of AMP and a blend of AMP+ NH₃ for CO₂ and SO₂ were measured by using a stirred-cell reactor at 303 K. The process operating parameters of interest in this study were the solvent and concentration, and the partial pressures of CO₂ and SO₂. As a result, the addition of NH₃ solution into aqueous AMP solution increased the reaction rate constants of CO₂ and SO₂ by 144 and 109%, respectively, compared to that of AMP solution alone. The simultaneous absorption rate of CO₂/SO₂ on the addition of 1 wt% NH₃ into 10 wt% AMP at a p _A1 of 15 kPa and p _A2 of 1 kPa was 5.50×10⁻⁶ kmol m⁻² s⁻¹, with an increase of 15.5% compared to 10 wt% AMP alone. Consequently, the addition of NH₃ solution into an aqueous AMP solution would be expected to be an excellent absorbent for the simultaneous removal of CO₂/SO₂ from the composition of flue gas emitted from thermoelectric power plants.