Comparison of Xylene and Ethyl Acetate as Solvent in the Isolation of Levulinic Acid from Conversion Reaction of Cellulose Rice Husk using Hierarchical Mn₃O₄/ZSM-5 Catalyst

Levulinic acid is a platform chemical. This compound can be derived from conversion cellulose in lignocellulosic biomass such as rice husk. Cellulose conversion to levulinic acid can be enhanced with the help of a catalyst. Hierarchical Mn₃O₄/ZSM-5 was used as a catalyst in this study, which was made by wet impregnation of ZSM-5 with Mn (II). Before the conversion reaction, rice husk was pretreated with various chemical and mechanical methods to increase the amount of cellulose. The chemical method used NaOH, while mechanical methods used variations of ball milling and ultrasonication in phosphoric acid. The pretreated rice husk was then converted to levulinic acid at 130°C for 10 h in H₃PO₄ 40% and H₂O₂ 30% using hierarchical Mn₃O₄/ZSM-5 as a catalyst. The highest levulinic acid yield of 11.70% was obtained from the delignification of rice husk. The product was then extracted to obtain pure levulinic acid via solvent extraction using xylene and ethyl acetate as the organic solvents.