Statistical approach for the optimization of levulinic acid production from orange peel as agricultural waste

Abstract

BackgroundAcid‐catalyzed hydrothermal conversion can be considered one of the most effective methods for converting agricultural wastes into sustainable and renewable fuels and value‐added chemicals. Orange wastes are a potential renewable and sustainable resource for the synthesis of value‐added compounds because of their high organic matter content. In this study, acid‐catalyzed hydrothermal conversion of orange peel was applied to produce levulinic acid (LA) using a statistical experimental approach.ResultsThe reaction conditions for LA synthesis by sulfuric acid‐catalyzed hydrothermal conversion of orange peel was optimized at middle‐to‐high temperatures, low catalyst concentrations, and prolonged reaction times within the tested ranges. As a result, an LA yield of 17.13 wt% (biomass weight basis) or 60.77% (glucan content basis) was achieved under the condition of 185 °C, 10% biomass, 0.3 mol L−1 sulfuric acid, and 30 min. In the relationship between combined severity (CS) and LA yield, LA yield increased moderately with increasing CS value until CS 3.2, then remained stable. The highest LA yield was observed under the CS 3.7 condition.ConclusionThe findings of this study demonstrated the potential value of orange peel as a renewable agricultural waste for the manufacture of valuable chemicals and materials. © 2023 Society of Industrial Chemistry and John Wiley & Sons Ltd.