Studies of catalytic CO₂ absorption and desorption were completed in two well-performed tertiary amines: diethylmonoethanolamine (DEEA) and 1-dimethylamino-2-propanol (1DMA-2P), with the aid of CaCO₃ and MgCO₃ in the absorption process, and with the aid of γ-Al₂O₃ and H-ZSM-5 in the desorption process. The batch process was used for CO₂ absorption with solid alkalis, and the recirculation process was used for CO₂ desorption with solid acid catalysts. The CO₂ equilibrium solubility and pKa were also measured at 293 K with results comparable to the literature. The catalytic tests discovered that the heterogeneous catalysis of tertiary amines on both absorption and desorption sides were quite different from monoethanolamine (MEA) and diethanolamine (DEA). These results were illustrative as a start-up to further study of the kinetics of heterogeneous catalysis of CO₂ to tertiary amines based on their special reaction schemes and base-catalyzed hydration mechanism.
Keywords: CO2 absorption; CO2 desorption; energy cost; equilibrium; solubility; tertiary amines.