BACKGROUND: Nafion ® membranes have found several applications in chemical processes, one of which is 'salt splitting', where a salt is split to produce acid and/or alkali. So, the determination of the behaviour of this membrane in the electrolysis of certain salts is an important issue. The aim of this study is to investigate the performance of Nafion ® 424 membrane in a two-compartment membrane cell for the membrane electrolysis of lithium sulphate (Li 2 SO 4 ), where lithium hydroxide (LiOH) is the target product.
RESULTS: Regression analysis was performed between conductivity and concentration to predict instantaneous electrolyteconcentration. The effects of catholyte concentration (4-8% LiOH), current density (4-16 A dm −2 ) and temperature (30-60 ∘ C) were investigated. 45-70% current efficiency; 6.1-14.6 kWh kg −1 LiOH power consumption and 140-900 g LiOH m −2 membrane h −1 production rate were obtained. A cost estimation revealed that 60 ∘ C, 8% LiOH and 4 A dm −2 are the optimum parameters within the studied range. CONCLUSION: Concentration can be successfully predicted for lithium sulphate and lithium hydroxide with the help of conductivity-concentration regression equations. Current efficiency is affected primarily by LiOH concentration with a direct proportion. Power consumption increases with the increase of current density and the decrease of temperature. Based on production cost estimation, optimum working parameters can be recommended.