Barium carbonate precipitation as a method to fix and utilize carbon dioxide

This study focuses on a carbon capture and utilization (CCU) technology to fix carbon dioxide (CO₂), with an emphasis on producing a useable product while lowering the energy consumed in the process. The amines monoethanolamine, diethanolamine, and methyl diethanolamine were employed to rapidly convert gaseous CO₂ to aqueous CO₂, and BaCl₂ was added as a source of metal ions to react with the aqueous CO₂ and rapidly form a precipitate. We repeated this absorption-conversion-precipitation-separation-desorption sequence twice. All experiments were conducted at 303.15K and 1atm, except for the desorption process that was used to assess the residual CO₂ in the solution. We measured the amount of fixed CO₂ and the characteristics of the BaCO₃ precipitates. By X-ray diffractometry and scanning electron microscopy analyses, the precipitates exhibited the witherite morphology. The particle sizes of the second-batch precipitates were larger than those from the first batch. These results confirmed that the concentration of the supplied metal ions was important for controlling the precipitation. Finally, we showed that the particle size of the carbonate precipitates, which are used in various industries, can be controlled during their formation. Barium showed a similar potential to magnesium and calcium for fixing CO₂.