Selective separation of vitamin C by reactive extraction using ionic liquid: Experimental and modelling

Vitamin C (ascorbic acid), is an important nutrient widely used as a dietary supplement in the food, beverage, cosmetic and feed industries or as a drug in the pharmaceutical industry. It can be produced by a traditional twostep fermentation or a novel one-step process, but its separation from the fermentation broth still needs improvement. This study investigated a reactive extraction method to selectively separate vitamin C from 2-ketogluconic acid using an ionic liquid as the extracting agent and heptane as diluent. The separation efficiency and selectivity factor, as well as the analysis of extraction conditions (type and ionic liquid concentration, pH of the aqueous phase, contact time, temperature) influence and extraction mechanism were discussed. Heptane as the solvent and 100 g/L [P6,6,6,14][Phos] as the extractant were the optimum mixture for reactive extraction, resulting in an extraction yield of 99.98 % for vitamin C. A maximum selectivity factor of 3.5 was obtained for ascorbic acid for 160 g/L [P6,6,6,14][Phos] and pH 3 of the aqueous phase. The process was modeled and optimized using an Artificial Neural Networks (ANNs) and Differential Evolution (DE) algorithm. Based on the performance parameters evaluated and extraction yields obtained, ionic liquids have great potential for vitamin C separation.