Thermal Degradation of Ethanolamine in CO2 Capture with SO2

Amine degradation in the absorption / stripping process is one of the concerns in this technology. SO2 is reported to promote amine degradation in both bench scale and pilot scale. This work investigates the impact of SO2 on thermal degradation of MEA by preloading additives, which are Na2SO3, SO2 and H2SO4. 7 m (mol / kg H2O) MEA with 0.4 CO2 loading (mol CO2 / mol MEA) at 135 degrees C is the baseline condition. Initial sulfer concentration is 0.4 m in the experiments with additives. The experiment temperature varied from 120 degrees C to 150 degrees C. Neither sulfite nor sulfate has significant impact on MEA degradation rate in thermal condition. There is no different cation product in the samples with additives compared to the baseline experiment. The main process of MEA thermal degradation is still carbamate polymerizing. Ammonium was induced by sulfite. The main organic acid product is formate for all the experiment conditions, while there are new anion products with sulfite. Formate formation was promoted by H2SO4. Ammonium and formate formation were promoted at higher temperature.