Optimizing levulinic acid from cellulose catalyzed by HY-zeolite immobilized ionic liquid (HY-IL) using response surface methodology

Levulinic acid (LA) is an ideal platform chemical with various applications. Ionic liquid,1,4-methyl sulfonic acid imidazolium tetrachloroaluminate ([MSIM][AlCl4]) has been immobilized into HY zeolite and tested for the conversion of cellulose to LA. Response surface methodology (RSM), based on Box-Behnken design (BBD), was employed to identify the optimum conditions for LA production. Experimental results indicate that the second-order model was sufficient for all independent variables with R² = 0.90. The optimum temperature, reaction time, catalyst dosage, and feedstock loading for cellulose conversion are 200 °C, 7 h, 0.6 g, and 0.3 g, respectively with LA yield of 27.2%. Meanwhile, the LA yield from oil palm frond (OPF) and empty fruit bunch (EFB) at the optimum condition is 24.1% and 21.3%, respectively. The efficiency of OPF and EFB for LA production is 75% and 72%, respectively. This study demonstrates the potential of HY-IL for biomass conversion to levulinic acid under mild condition.