Abstract:
The depleting primary energy sources and increasing greenhouse gas emissions have driven initiatives to develop clean technologies for chemical transformations from renewable feedstocks. Currently, extensive studies are being carried out to investigate the conversion of renewable biomass into biofuels and other chemical feedstocks. In particular, levulinic acid (LA) derived from biomass has been recognized as a versatile building block for the production of various platform chemicals. Esterification of LA with alcohols produce levulinate esters which have extensive application either in the flavoring and fragrance industries or fuel additives. Till date, the catalyst employed in the reported literatures for LA esterification suffered from either poor catalytic activity or lack of reusability properties. Herein, the esterification of LA with ethanol for ethyl levulinate (EL) production was conducted using iron modified HY zeolite (Fe/HY) at reflux condition. The effect of reaction time (1 – 7 h) , Fe/HY loading (10 – 35% Fe/HY to LA), and molar ratio of LA to ethanol (1:4 – 1:24), on LA conversion and EL yield were investigated. The experimental results revealed the optimum LA conversion and EL yield were obtained from LA esterification conducted at reflux condition for 6 h, 10% Fe/HY loading, and 1:16 of LA to ethanol molar ratio. The reusability of Fe/HY for EL production was also examined. In addition, Fe/HY catalyst was employed in the esterification of LA with methanol and butanol for methyl levulinate (ML) and butyl levulinate (BL) productions, respectively, with good performance. This study demonstrated the potential of Fe/HY catalyst for esterification of LA to levulinate esters at mild process conditions
