M. Shi, A. Mukhopadhyay
Idaho National Laboratory,
United States
Keywords: lithium, brine, CO2 capture, CO2 mineralization, chemical regeneration, electrochemistry
Summary:
Lithium is one of the domestic critical materials for its essential role in energy storage while at a high risk of supply chain disruption. Domestic Li mining focuses on spodumene or clay processing, while the extraction of Li from abundant liquid sources (brines, produced water, mining wastes, etc.) is not so extractive due to low Li concentration and high concentration of competing ions. To concentrate Li for extraction and purification, it is a conventional method to heat the brine pond with an external heating process which is energy and time consuming, resulting in high cost and carbon footprint. Our work has developed a process for Li extraction and concentration that enables domestic sourcing from diluted sources with a carbon-negative management. In conventional carbon capture, utilization, and storage (CCUS), CO2 is captured in an organic solvent, shipped to remote locations, heated to unload CO2, and finally kept underground. It requests transportation and the underground storage cause concerns of environment and human safety. The flowsheet established in this work, including CO2 mineralization and electrochemical processes, utilizes the CO2-saturated solution and brine as the feedstock and will finally produce concentrated Li, mineralize carbon as carbonates, and regenerate the chemical reagent for CO2 capture at room temperature. The produced concentrated Li stream could be a source in downstream R&D or commercial lithium recovery, and this process dramatically reduced the environmental concerns, carbon footprint, and cost in carbon capture and storage.