Forward-osmosis technology concentrates lithium chloride, enabling recovery from geothermal brine

Alert
COVID-19 Updates and Resources COVID-19 Updates and Resources
Draw Solution In (All concentrations in ppm): Simulated spent geothermal brine (Li-399; Na- 72253; Ca-35982; K-24021; Mn-2173)
Draw Solution In (All concentrations in ppm): Simulated spent geothermal brine (Li-399; Na- 72253; Ca-35982; K-24021; Mn-2173) 

CMI scientists at Oak Ridge National Laboratory conducted this research.

Achievement

Energy-efficient concentration of LiCl recovered from geothermal brine has been achieved, where LiCl concentration increases from 35 g/L to 175 g/L

Significance and impact

The technology concentrates high-purity LiCl for efficient conversion into Li2CO3 or Li(OH), feedstocks for fabrication of lithium ion batteries. Energy savings of >90% vs thermal evaporation or > $60/m3 of water removal can be obtained. 

Details and next steps

  • Stable performance for >500 hours
  • No cation transfer from draw solution
  • LiCl purity: >99.99 wt%
  • Hot operating temperature: 75–80°C
  • Optimize process to increase water flux
  • Work with partner to scale up for demonstration and commercialization
Increase in LiCl concentration as water diffuses across the membrane into the draw solution.
Increase in LiCl concentration as water diffuses across the membrane into the draw solution.