Levulinic acid from orange peel waste by hydrothermal carbonization (HTC)

With the awareness of the need for optimal and sustainable use of natural resources, hydrothermal treatment of biomass and biomass waste for energy and resource recovery has received increasing attention. The hydrothermal carbonization (HTC) of a biomass is achieved using water as the reaction medium and applying mild temperatures (180-250 ° C) under saturated pressure (autogenous or provided by a gas) for several hours. The thermochemical process applied to biomass includes simultaneous reactions of hydrolysis, dehydration, decarboxylation, condensation, polymerization and aromatization of the original precursor. The main resulting products are a carbon-rich solid, known as hydrochar, and a water phase containing soluble organic compounds. In this work, an experimental study on HTC process of orange peels to assess the yield of levulinic acid in water phase during the acid-catalyzed hydrolysis is reported. The results are promising, and comparable with other lignocellulosic biomass sources.