An investigation of solvent stability in amine based systems used to capture CO2

Oxidative degradation in amine based system was investigated in a high temperature/pressure 300-ml autoclave. The investigation was conducted using 2 to 11 kmol/m(3) aqueous monoethanolamine (MEA) solutions under 120degrees to 170degreesC and 241 to 345 kPa of O-2 pressure. To determine the degradation rate, the test solutions were analyzed by a GC/MS equipped with a HP-Innowax column. The analytical results suggested that the oxidative degradation of MEA was a complex reaction of which the reaction order (with respect to MEA concentration) apparently changed from virtually 0 to 3.35 as the initial concentration of MEA increased. It was also found that the degradation was dependent upon temperature, initial MEA concentration, and O-2 pressure. Based on the investigation results, an empirical rate equation for the oxidative degradation of MEA was established.