Production of ethyl levulinate from oil palm fronds using heteropoly acid as catalyst

Abstract

Ethyl levulinate is a versatile chemical with numerous industrial applications. The production of ethyl levulinate from glucose and oil palm fronds (OPF) were investigated. The optimization of the effects of parameters was conducted by response surface methodology (RSM), and the data obtained was performed the regression analysis. In this study, three different heteropoly acids (HPAs) were screened and tested for glucose conversion to ethyl levulinate. The heteropoly acids; phosphomolybdic acid (H3PMo12O40), silicotungstic acid (H4SiW12O40) and phosphotungstic acid (H3PW12O40) were tested and the experimental results shown that phosphotungstic acid produced highest ethyl levulinate yield. Optimization of ethyl levulinate was conducted using the potential heteropoly acid catalyst meanwhile glucose was used as model compound. The conducted experiment for glucose conversion to ethyl levulinate produced 19.01% ethyl levulinate yield at 183 °C in 200 min and 5.66 wt% of reaction temperature, time and catalyst loading, respectively. The optimization of the OPF for producing ethyl levulinate at the optimum conditions at 198 °C in 166 min and 1.44 wt% of reaction temperature, time and catalyst loading, respectively, was established wherein 4.65% of ethyl levulinate yield was produced from OPF. Additionally, the high acidity of phosphotungstic acid was significantly can increase the ethyl levulinate yield with increase the amount of catalyst load and reduce the reaction temperature for the OPF conversion into ethyl levulinate. This study demonstrated that the heteropoly acid has potential to be applied in biomass conversion to ethyl levulinate under adequate process conditions