Forward Osmosis to Concentrate Lithium from Brine: The Effect of Operating Conditions (pH and Temperature)

Abstract

The development of battery technology is the driving force behind the increasing demand for lithium, which has resulted in a decreased supply of lithium in the market and continues to be a challenge for the industry. In response to these conditions, the development of lithium recovery technology continues, and there is a search for sources of lithium that are easier to recover. One source of lithium that has the potential to be processed is geothermal brine using forward osmosis technology. The aim of this study was to determine the best operating conditions for forward osmosis as a substitute for conventional evaporation methods. The parameters to be optimized included pH and operating temperature. The flow rate in the forward osmosis process was controlled by two litres per hour (LPH), while the concentration of the draw solution was 6M. The operating temperature variations used were 40oC, 35oC, and 30oC, while the pH variations used were 7, 6, and 5. The best results were achieved at a pH of 5 with a temperature of 40oC. Apart from these operating conditions, the activity model (the Pitzer equation) showed superior results compared to the simple model (the Van’t Hoff equation), explaining the forward osmosis phenomenon.

Keywords

• battery
• forward osmosis
• geothermal brine
• lithium
• optimization