Synthesis of hexyl levulinate as a potential fuel additive from levulinic acid over a solid acid catalyst

Abstract

hexyl levulinate (HL) as a potential fuel additive was synthesized by catalytic esterification of levulinic acid (LA) with hexanol using SBA-15-Pr-SO3H as an efficient solid acid catalyst for the first time. FT-IR, N2 adsorption/desorption, TGA, SEM and TEM methods were used to characterize the SBA-15-Pr-SO3H catalyst and the results confirmed the successful modification of SBA-15 surface. The reaction conditions were optimized and 0.17 g of the catalyst, 140 °C for the reaction temperature, 8 h for the reaction time, and LA to hexanol molar ratio of 1:3 were selected to obtain the maximum yield of HL. The results showed that the SBA-15-Pr-SO3H catalyst had the excellent catalytic performance for esterification of LA and HL was synthesized with 94% yield of HL and 100% conversion of LA under optimum reaction conditions. Also, the reusability tests showed that the SBA-15-Pr-SO3H catalyst was stable and can be reused four times.