Hydrolysis of delignified sugarcane bagasse using hydrothermal technique catalyzed by carbonaceous acid catalysts

Carbonaceous catalysts derived from sugarcane bagasse (SCB), cellulose and lignin were synthesized by three different methods using slow pyrolysis and subsequent sulfonation. The synthesized catalysts were used for hydrolysis of lignocellulose and cassava starch. The catalysts synthesized from SCB 100 mesh (type I) and lignin (type II) were highly active for hydrolysis of SCB (70 mesh), cellulose and starch at 140 °C for 3 h yielding 18.0%, 27.6%, 87.6% and 65.0%, 46.0%, 96.5% total reducing sugar (TRS) yields, respectively. Box–Behnken design was applied to investigate the influence of reaction temperature, amount of catalyst and reaction time on hydrolysis yield of delignified SCB in the presence of these two catalysts. The finding demonstrated that the lignin catalyst (type II) prepared by direct sulfonation without pyrolysis had equal or higher catalytic performance than catalysts prepared by pyrolysis and sulfonation.