Carbon dioxide chemical sequestration from industrial emissions by carbonation

A process for sequestering carbon dioxide from a carbon dioxide containing gas, the process comprising:

• contacting the carbon dioxide containing gas with an aqueous slurry comprising an alkaline earth metal containing material in a carbonation unit for carbonation of at least a portion of an alkaline earth metal to produce a carbon dioxide depleted gas and a carbonate loaded slurry comprising precipitable carbonates and substantially exempt of precipitated alkaline earth metal carbonates;
• removing the carbonate loaded slurry from the carbonation unit and separating the carbonate loaded slurry into an aqueous phase comprising the precipitable carbonates and a solid phase;
• and
• supplying the aqueous phase to a precipitation unit and precipitating alkaline earth metal carbonates in the precipitation unit to produce a precipitation slurry.

A carbon dioxide sequestration system for sequestering carbon dioxide from a carbon dioxide containing gas, the system comprising:

• at least one carbonation unit having:
• a gas inlet for receiving the carbon dioxide containing gas,
• a slurry inlet for receiving an aqueous slurry comprising an alkaline earth metal containing material,
• a carbonation vessel for the carbonation of at least a portion of an alkaline earth metal of the aqueous slurry with carbon dioxide to produce a carbon dioxide depleted gas and a carbonate loaded slurry comprising precipitable carbonates and substantially exempt of precipitated alkaline earth metal carbonates,
• a slurry outlet for releasing the carbonate loaded slurry comprising precipitable carbonates, and
• a gas outlet for releasing the carbon dioxide depleted gas;
• a separation unit having:
• a slurry inlet for receiving the carbonate loaded slurry comprising precipitable carbonates from the slurry outlet of the at least one carbonation unit,
• a separation chamber for separation of the carbonate loaded slurry comprising precipitable carbonates into a solid phase and an aqueous phase comprising the precipitable carbonates and substantially exempt of precipitated alkaline earth metal carbonates,
• a liquid outlet for releasing the aqueous phase, and
• a solid outlet for releasing the solid phase;
• and
• a precipitation unit having:
• a slurry inlet for receiving the aqueous phase comprising the precipitable carbonates from he liquid outlet of the separation unit,
• a precipitation chamber for precipitation of the alkaline earth metal carbonates and formation of a precipitation slurry, and
• a liquid outlet for releasing the precipitation slurry.