Integration of Ambient Formic Acid Process and Alkaline Hydrogen Peroxide Post-Treatment of Furfural Residue To Enhance Enzymatic Hydrolysis

A novel integrated process with ambient formic acid combining alkaline hydrogen peroxide was developed to achieve efficient delignification of furfural residue. Furfural residue was treated with 88% formic acid at room temperature for 0.5 h followed by post-treatment with 1% alkaline hydrogen peroxide at 80 °C for 1.5 h. Results showed that 87.9% of the original lignin was removed and the solid residue obtained contained 84.6% cellulose. The glucose yield of the solid residue increased to 83.7% after 96 h enzymatic hydrolysis under a low enzymatic loading of 7 FPU/g cellulose. The analysis of the physicochemical property of the solid residue and lignin fractions indicated that there was an unapparent effect on formylation of cellulose during the ambient formic acid treatment, and the lignin rich in phenolic and carboxylic OH was easily removed. The insoluble-formsovl lignin in solid residue was effectively removed by alkaline hydrogen peroxide treatment.