Three primary and two secondary mono-alkylamines, and a di-alkylamine (3-(Methylamino)propylamine, MAPA) were investigated in blend with a tertiary amine (2-(Diethylamino)ethanol, DEEA). The aim of the study was to understand how structural features of the promoting amine influence CO2 absorption and desorption performances. The blended systems were studied using a screening apparatus followed by quantitative 13C NMR spectroscopy.
Results showed that DEEA/MAPA obtained highest absorption capacity and fastest absorption rate, but also the highest amount of carbamate. Thus, the desorption process may be more energy demanding than for DEEA blended with secondary and sterically hindered alkylamines, which obtained the lowest amount of carbamate and highest amount of (bi)carbonate and amine. Nevertheless, due to high volatility of the alkylamines nonconventional process conditions are needed if they were to be used in an absorption and desorption process.