| Summary: | Ethyl levulinate can be synthesized by the esterification reaction of levulinic acid with ethanol in the presence of a solid acid catalyst. In this research, the catalyst was prepared from lignin as a carbon precursor at 400 °C for 2 h and modified via sulfonation in a hydrothermal reactor to produce a modified lignin-based carbon catalyst. Acidic DES, which acted as a co-catalyst, was prepared from a choline chloride-sulfanilic acid mixture. The catalyst and acidic DES were characterized to study their chemical and physical characteristics. The catalytic activity was evaluated in the levulinic acid esterification by the effect of parameters such as ethanol to levulinic acid molar ratio (3–15), catalyst loading (5–25 wt%), and reaction time (1–5 h). The reaction performance was further investigated over the catalyst and acidic DES at optimum reaction conditions. The results demonstrated that the catalyst has good thermal stability up to 400 °C with a large surface area of 368.92 m2/g to facilitate the reaction. The optimum conditions of levulinic acid esterification obtained over a modified lignin-based carbon catalyst were a 6 molar ratio of ethanol to levulinic acid, 10 wt% catalyst loading, and 3 h at 80 °C, to give 62.51 mol% of ethyl levulinate yield. The reaction performance was further improved when acidic DES was introduced with 81.65 mol% of ethyl levulinate yield. The catalyst and acidic DES have shown their potential for levulinic acid esterification and further catalyst modifications must consider obtaining better product yield. © 2024, Malaysian Society of Analytical Sciences. All rights reserved.
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