The Roles of O2 and SO2 in the Degradation of Monoethanolamine during CO2 Absorption from Industrial Flue Gas Streams

The roles of O₂ and SO₂ in the degradation of aqueous monoethanolamine (MEA) in the concentration range of 5 - 7 kmol/m³ were investigated using simulated flue gas containing O₂ of 6- 100 %, and SO₂ concentration in the range of 10^-11 -11 ppm, as typically present in polished flue gas streams, at degradation temperatures in the range of 328 - 393 K. An analysis of a power law rate expression formulated to represent the degradation process showed that the degradation was most susceptible to O₂ followed by MEA and then SO₂. SO₂ played a significant role by giving rise to additional MEA oxidative degradation. An increase in O₂ and SO₂ concentrations, the initial MEA concentration, and temperature all resulted in an increase of the degradation rate.