Abstract
Sugars released from alkali-pretreated SCB (sugarcane bagasse) were used for biofuel (bioethanol and biogas) production based on a high-solids fed-batch SSF (simultaneous saccharification and fermentation) process with delayed inoculation (DSSF). A DSSF process with 24 h delayed inoculation increased the ethanol production rate by eliminating glucose inhibition in the early stages of fermentation, and shortened the duration of the process. Increasing solids loading from 18 to 36% (w/v) enhanced glucose concentration, while ethanol conversion efficiency was decreased. Gradual feeding of the hydrolyzed medium could improve the DSSF process. DSSF, with batch feeding mode, achieved as high as 68.047 g/L (74.13% of theoretical yield) ethanol concentration with 30% (w/v) solids loading at 96 h. After evaporation, the residual stillage obtained 306.974 mL/g volatile solids (VS) methane through anaerobic digestion. Sequential bioethanol and biogas production improved the yield of utilized biomass.