Lactic acid extraction using environmentally benign Green emulsion ionic liquid membrane

The environmentally benign green emulsion ionic liquid membrane (GEILM) is a new development in the field of emulsion liquid membrane (ELM) which will help in reducing both environmental as well as economic problems caused by the use of petroleum-based solvents. An experimental study on the lactic acid (LA) extraction through GEILM has been carried out. The main constituents of GEILM includes diluents (rice bran oil (RBO, 70%, v/v) as a green solvent and hexane (30%, v/v) as an organic solvent), ionic liquid (tri-n-octylmethylammonium chloride (TOMAC (0.2%, v/v of diluents solution)), emulsifying agent (span 80 (2.66%, v/v of diluents solution)), and stripping agent (sodium hydroxide (NaOH)). The effects of several process parameters (such as LA concentration, NaOH concentration, phase ratio, treat ratio, temperature, stirring speed, and stirring time) on the LA extraction efficiency (%) and visual static stability (min) have been studied. The LA extraction efficiency of 90 ± 2% with the visual static stability of 90 ± 2 min has been obtained under the optimum conditions of various process parameters viz. LA concentration- 0.05 [M], NaOH concentration- 0.25 [M], phase ratio- 0.40 (v/v), treat ratio- 2:1 (v/v), temperature- 25 ± 1 (°C), stirring speed- 400 (rpm), and stirring time- 20 (min). Thus, the present investigation has shown that RBO as a green solvent has very high potential to be applied in the various existing ELM processes for the efficient extraction of low concentrated solutes.