Separation of Lactic Acid and Acetic Acid through Supported Ionic Liquid Membranes Containing Cyphos IL 101

Abstract

Lactic acid is the raw material for polylactic acid, a biodegradable plastic, which is produced by fermentation. Development of a cost-effective separation technique is still required to extract and purify lactic acid from the broth. We conducted permeation of lactic acid and acetic acid through supported ionic liquid membrane containing Cyphos IL 101 as a carrier. Lactic acid successfully permeated through the membranes against its concentration gradient. By using a feed phase of pH 5 and a receiving phase of 0.01 mol/dm³ NaCl solution prepared at pH 3 with HCl, a higher permeation rate of lactic acid and a higher separation of lactic acid and acetic acid could be achieved than when the receiving phase was a HCl solution.