Comprehensive monitoring of MEA degradation in a post-combustion CO2 capture pilot plant with identification of novel degradation products in gaseous effluents

A pilot plant campaign was performed to study MEA degradation in CO2 capture conditions and anticipate potential degradation products emissions to the atmosphere in industrial case. Aqueous 30% wt MEA was cycled between absorption and regeneration steps during 1700 h in the presence of a synthetic flue gas containing 81% of N2, 14% of CO2, 5% of O2, 97 ppm of NO, 9 ppm of SO2 and 5 ppm of NO2. Specific methods (sampling, sample conditioning and analysis) were developed to improve degradation products identification and to provide a quantification of targeted compounds in liquid phase and above all in absorber and stripper gas effluents. Especially, trace elements were detected in liquid phase thanks to Head Space-Solid Phase MicroExtraction (HS-SPME) and liquid-liquid extraction with ChemElut cartridges and in gas phase thanks to adsorbent tubes of different type: Sep-Pak® for aldehydes and ketones, Orbo 60 for N-nitrosodimethylamine, Tenax and active charcoal for non-specific adsorption. 32 degradation products were identified in liquid phase and 38 in gas phase, 17 of which for the first time, especially derivatives of pyridine and oxazolidine, 1H-pyrrole and a new nitrosamine, the N-nitroso-2-methyl-oxazolidine.