SO2 effect on degradation of MEA and some other amines

AbstractSO2 is the main acidic impurity in flue gas and will affect amine degradation in CO2 capture process. This work introduced SO2/Na2SO3 in various experiment conditions of MEA (monoethanolamine) oxidative degradation and evaluated the SO2 effect on MEA degradation considering both oxidative and thermal degradation. 60ppm SO2 could inhibit MEA oxidative degradation by scavenging oxidative radicals in absorber condition. Higher concentration of SO2 does not enhance the inhibitory effect, but will increase the corrosivity of the solution. NH3 is promoted by sulfite and becomes significant in MEA thermal degradation. Thiosulfate, the disproportionation product of sulfite, is believed to be the catalyst of SN2reaction. Na2SO3 was used to test SO32- effect on thermal degradation of EDA (ethylenediamine), 2-PE (2-piperidineethanol) and PZ/AMP (piperazine/2-amino-2-methyl-1-propanol) solution. Alkyl structure of amines has important effect on the SN2 reactions