Separation Characteristic and Selectivity of Lithium from Geothermal Brine Using Forward Osmosis

Abstract

The need for lithium as a raw material for battery production in electric vehicles has triggered the growth of the lithium industry throughout the world, resulting in massive competition for the exploitation of lithium. Responding to these challenges, lithium recovery technology continues to be developed, one of which is membrane technology. This research focuses on the use of forward osmosis (FO) technology. The search for the best operating condition parameters for the process highlights a major concern. The condition parameters include temperature, draw solution concentration, and flow rate. The temperature varied from 30, 33, 36, 39 to 42 °C, the draw solution concentration varied from 1, 2 to 5 M, while the flow rate varied by 2, 3 and 4 L h−1. The best conditions were obtained at a temperature of 42 °C, a concentration of 5 M draw solution, a flow rate of 4 L h−1 with a flux of 68.47 L m−2 h−1, a normalized concentration ratio of 3.31, and an average solute rejection of 79.25%. Meanwhile, the most suitable osmotic pressure model to explain the phenomenon in the FO process is the Extended Pitzer.