Improvement of Hydrolysis of Eucalyptus urophylla Fiber through Hydrothermal Pretreatment and Alkali Fractionation

Pretreatment is an essential step to lessen recalcitrance of biomass for bioethanol production. In the study of Run-Cang Sun of the Beijing Forest University and South China University of Technology, a two-step hydrothermal pretreatment and alkali fractionation was performed on eucalyptus fiber. The characteristics and morphology of the pretreated fibers were then evaluated.

Compared to the hydrothermal pretreatment alone, the combination of hydrothermal and alkali treatments removed hemicelluloses and lignin, resulting in increased hydrolysis rate. An optimum pretreatment condition was found to be at 180°C for 30 min and alkali fractionation with 2% NaOH at 90°C for 2.5 h, in which 66.3% of the cellulose was converted into glucose.

The combination of hydrothermal pretreatment and alkali fractionation is a promising method in overcoming the biomass recalcitrance of eucalyptus fiber.