A hierarchical MnOx/ZSM-5 heterogeneous catalyst for the conversion of cellulose from mahogany wood to levulinic acid

At present, lignocellulose holds significant potential as a renewable biomass resource. Lignocellulose can be converted to levulinic acid, one of the most important platform chemicals used in several applications. The forestry of mahogany wood produces abundant waste in the urban areas of Indonesia. This waste is a source of biomass, containing the major chemical constituents of holocellulose, α-cellulose, and lignin in proportions of 53.37%, 33.05%, and 31.82%, respectively. Pretreatment processes of mahogany wood were conducted through dewaxing processes followed by delignification using NaOH and NaOCl to pre-concentrate the cellulose substrate. The delignification processes using NaOH and NaOCl reduced the lignin content to 15.58% and 6.40%, respectively, from 31.82% of dewaxed-mahogany wood. The cellulose conversion from mahogany wood to levulinic acid was performed using the MnOx/Hi_ZSM-5 heterogeneous catalyst in the presence of H₂O₂, and H₃PO₄ solutions. The parameters of cellulose conversion, including conversion time and concentration of H₃PO₄ and H₂O₂, were also studied, and HPLC analysis revealed the highest cellulose conversion to levulinic acid to be 2.44% with 20% H₂O₂, (v/v) and 30% H₃PO₄. (v/v) after 8 h of reaction time. (paper)