Capture of CO2 in the form of thermally stable solid compounds is an interesting alternative for CO2 sequestration and utilization. In this study, CO2 capture using ammonia base absorbent in a bubble column reactor with various parameters (NaCl concentration, reaction temperature, CO2 flow rate, and ammonia concentration) was investigated. The precipitated products mainly consisted of thermally unstable [ammonia salts; e.g. NH4HCO3, (NH4)2CO3] and stable solid [NaHCO3, Na2CO3] products. The results revealed that increasing NaCl concentration and/or ammonia concentration or decreasing reaction temperature and/or CO2 flow rate increased CO2 capture capacity and the amount of the stable solid products. Operating conditions set at 3.0 M of NaCl with 43 wt% of ammonia solution, a reaction temperature of 20 °C, and a CO2 flow rate of 100 mL/min were found to provide the maximum NaHCO3 and Na2CO3 amounts of 20.67 wt% and 39.41 wt%, respectively. The stable solid products were also characterized by SEM/EDS and XRD.
