Single Process for CO2 Capture and Mineralization in Various Alkanolamines Using Calcium Chloride

To replace the thermal regeneration method of absorbent in the CO2 capture system, a novel method of CO2 absorption–mineralization was investigated. In this study, various alkanolamine absorbents, such as monoethanolamine (MEA), diethanolamine (DEA), N-methyldiethanolamine (MDEA), and 2-amino-2-methyl-1-propanol (AMP), were applied to the CO2 absorption–regeneration process with different regeneration methods via thermal treatment and mineralization. Calcium chloride was added as a calcium source in the mineralization process. Integration of absorption and mineralization defined as a single process was proposed in this study to resolve the excessive requirement of energy in a conventional amine regeneration process, leading to enhanced working capacity and desorption rate without increasing the regeneration temperature. This method provides an increment of working capacity 1.3–3 times higher than the conventional thermal amine-scrubbing process. Among the tested amines, MEA exhibited the highest increase of working capacity and AMP showed the highest yield of CaCO3. MEA, DEA, and MDEA favored the formation of calcite, while AMP produced a mixture of calcite and vaterite.