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 aque- ous 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 in- terest 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 pA1 of 15 kPa and pA2 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.