CO2 mineralisation of brines with regenerative hydrotalcites in a cyclical process

CO2 mineralisation is a process that can store the as solid mineral permanently. Brines rich in alkaline earth metals present an opportunity to trap form of insoluble carbonates. Moreover, this be accomplished work, using flue gas concentrations and at near-ambient temperatures, eliminating energy-intensive capture step. Alkali or pH-buffering substances neutralise acidification brines caused by dissolution one primary costs limits technology deployment. Hence, we herein developed remove chloride anions from ion-exchange, namely hydrotalcites (HT), while avoiding addition alkali. These layered double hydroxides release hydroxyl groups exchange for chloride, sufficiently raising pH dechlorination enable precipitation carbonates during mineralisation. HT recyclable multiple usage taking advantage ‘memory effect’ property. Gaseous Na2CO3 solution were tested recharging agents, replace spent interlayers intercalate with HCO3? CO32?, followed calcination produce reusable calcined-HT; approach gaseous regeneration newly proposed. It was found removal efficiency remains over 70% after cycles, calcium utilisation brine carbonation surpass 90%. This unique cyclical closed-loop presents potentially more cost- energy-effective than our previous studies. In addition, precipitated are sufficient quality variety applications reduce cost accelerate progress capture, sequestration.