Methyl‐diethanolamine degradation — Mechanism and kinetics

Methyl‐diethanolamine (MDEA) degradation reactions between aqueous solutions of MDEA and CO 2 have been carried out in a 600 mL stirred autoclave under the following conditions: initial MDEA solution concentration 20‐50 mass%, solution temperature 100‐200°C, CO 2 partial pressure 1.38‐4.24 MPa. It was found that MDEA degrades quite rapidly (although more slowly than diethanolamine under comparable conditions) at elevated temperatures and CO 2 partial pressures. Degradation products are identified by gas chromatography and mass spectrometry (GC/MS). An MDEA degradation reaction mechanism and kinetic model predicting concentration changes is proposed and verified.