Characteristics of Absorbent Loss and CO₂-Selective Absorption of CO₂/SO₂ Gas into Aqueous 2-Amino-2-methyl-1-propanol/Ammonia Solution

Abstract

The effect of SO2 on the loss of 2-amino-2-methyl-1-propanol (AMP)/ammonia (NH3) solution and simultaneous removal of CO2 and SO2 into aqueous AMP/NH3 solution was investigated. Solvent loss and selectivity of CO2 were studied using a reactor constructed of stainless steel and a wetted wall column. The losses of NH3 from solution containing 1 wt % NH3, 30 wt % AMP + 1 wt % NH3, and 30 wt % AMP + 1 wt % NH3 loaded with 0.5 mol of CO2/mol at 313 K were 0.0179, 0.013, and 0.010, respectively. The initial degradation rate constants for the CO2/SO2-loaded AMP solution were 0.000 21–0.003 186 h–1, higher than those for the CO2-loaded solution of 0.000 9–0.000 95 h–1. Selective absorption of CO2 into aqueous AMP/NH3 solution decreased from 0.99 to 1.48 as a function of SO2 partial pressure (1, 3, 5, 10, and 15 kPa).