Thangasamy, P., Venkatramanan, R., Vo, T.-G., Ng, Y.-T., Gao, J., & Liu, Y. (2024). A simulation-based approach for understanding CO2 capture and mineralization dynamics in desalination brine. Desalination, 583, 117713. https://doi.org/10.1016/j.desal.2024.117713
Abstract:
In the pursuit of sustainability, it is crucial to repurpose waste resources into valuable chemicals. One promising avenue is sequential CO2 mineralization using natural seawater or desalination brine solution, which concurrently removes CO2 from the atmosphere while recovering valuable minerals. To realize this approach, it is paramount to grasp the influencing factors governing the process efficiency and product composition. Here, we present a simulation approach using the visual MINTEQ v3.1 and PHREEQC v3.7.0 models to investigate the impact of CO2 concentration and OH- (as an alkaline source) on the mineral recovery process. The findings reveal that both CO2 concentration and OH- significantly influence the mineral phase composition. Specifically, higher CO2 flow rates or elevated OH- levels promote calcite formation while suppressing the brucite phase, with limited hydromagnesite formation. Moreover, an interactive effect between OH- and CO2 is observed, with OH- essential for carbonate formation. We further validated these insights through preliminary experiments employing electrochemical methods as a source of OH-, wherein aqueous CO2 and applied current density (proportional to OH- concentration) regulated mineral phase composition. Notably, the weight percentage of the brucite phase in the precipitates ranged from 67% to 73%, while the calcite phase varied from 20% to 26% with alterations to the applied electric currents. The present study not only provides valuable insights into the recovery of potential elements and efficient capture of CO2 in non-synthesized brine solution with a combined theoretical and experimental approach but also demonstrates the viability of employing electrochemical-driven methods as a greener alkaline source for CO2 capture and mineral recovery.
License type:
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Funding Info:
This research / project is supported by the National Research Foundation, Singapore and PUB - Competitive funding for water research
Grant Reference no. : CWR 2101-0029