Enhanced Bioethanol Production from Waste Paper Through Separate Hydrolysis and Fermentation

The effect of various pretreatments for efficient hydrolysis of waste office paper and newspaper into fermentable sugars and subsequent production of bioethanol through fermentation was investigated. Pretreatment with H₂O₂ (0.5% v/v) at 121 °C for 30 min was considered as the most effective method for this kind of soft biomass like waste paper due to the considerable increase in available cellulose and sugar yield in addition to efficient delignification. Under optimized conditions, enzymatic hydrolysis of pretreated office paper and newspaper resulted the sugar yield of 24.5 and 13.26 g/L with hydrolysis efficiency of 91.8 and 79.6%, respectively. Further, ethanol production using the hydrolysate by Saccharomyces cerevisiae was about 11.15 and 6.65 g/L with the productivity of 0.32 and 0.28 (g ethanol/L/h), respectively. The improved yields achieved through the pretreatment and subsequent ethanol production suggested that the waste paper could be a potential feedstock for the production of bioethanol.