Central Composite Design Approach for Optimization of Levulinic Acid Separation by Reactive Components

Separation of levulinic acid from the rejected stream and fermentation broth has become the topic of scientific interest or importance due to its variety of applications. In the present paper, the optimization study is carried out to find the maximum separation efficiency using various independent variables like the initial concentration of levulinic acid, concentration of trioctylamine extractant, temperature, and time. The response surface methodology in combination with central composite design (face-centered) was employed involving 30 experimental runs for the separation of levulinic acid. To understand the effect of independent variables on the separation efficiency and equilibrium constant, various experiments were performed. The optimum condition was observed at 0.5 mol·L–1 as the initial concentration of levulinic acid, 30% trioctylamine as the organic phase at a temperature of 27.5 °C for a shaking time of 4 h, which could lead to a separation efficiency 61.92%, and an equilibrium constant of 4.61 and is in close agreement with the predicted values of 62.23% and 4.61, respectively. The optimized conditions were applied, and three stages in series were designed to achieve 90% recovery of levulinic acid, which could reduce the energy requirement and waste generation and lead to an increase in the separation efficiency of levulinic acid. The obtained results can be used for the recovery of levulinic acid from the rejected stream and fermentation broth.