Carbon fixation using calcium oxide by an aqueous approach at moderate conditions

This research deals with carbon fixation with a precipitation reaction utilizing 5. wt% and 30. wt% alkanolamine absorbents in an aqueous calcium oxide solution. Unlike carbon fixation operated at high temperature and pressure that consumes a lot of energy, we conducted experiments at moderate temperature (303.15. K) and pressure (1. atm). Since loading capacity or absorption capacity of the amine solution depends on the order of amines, 5. wt% and 10. wt% of monoethanolamine, diethanolamine and N-methyldiethanolamine were used as primary, secondary, and tertiary amines. By adding 20. wt% calcium oxide solution into the carbon dioxide saturated solution, precipitated calcium carbonate (PCC) was formed. To verify the physical properties of PCC, XRD analysis was performed and SEM images were obtained. Formed PCC was proven to exhibit three different crystal structures. Also, by converting absorbed CO2 into solid PCC, solution regeneration energy, which accounts for 50-80% of the total energy consumption in the CCS process, can be reduced.