Modeling the Formation of Degradation Compounds during Thermal Degradation of MEA

A kinetic model has been developed to predict thermal degradation of aqueous solutions of monoethanolamine (MEA) in carbon capture. The model focusses on both the degradation rate of the amine and the formation rates of selected degradation products as a function of time, temperature, and loading. Experimental literature data on thermal degradation of MEA were used to develop, fit, and evaluate the model. The model was found to have an average relative deviation of 17.5%, most of which was caused by uncertainty in experimental data. The degradation model was also compared to a cyclic degradation campaign. The concentration of 1-(2-hydroxyethyl)-2-imidazolidinone (HEIA), one of the more stable thermal degradation products, is well-predicted with the thermal degradation model. However, the results also indicate that oxidative and thermal degradation mechanisms interact and that this interaction influences the concentration of several thermal degradation products.