Ultrasonic-Assisted Dilute Acid Pretreatment of Poplar Wood Biomass for Biofuel Manufacturing: A Preliminary Study

For the first time, this study demonstrated that the efficiency of enzymatic hydrolysis of poplar wood biomass was drastically enhanced after being pretreated with ultrasonic-assisted dilute acid pretreatment comparing to dilute acid pretreatment only. Three levels of ultrasonic power (0%, 30%, and 70%) were used in pretreatment. Approximately 10–40% improvement in the sugar yield was attained by using ultrasound-assisted dilute acid pretreatment for 15 min. XRD analysis revealed that poplar wood biomass pretreated ultrasonically had lower biomass crystallinity than that pretreated with dilute acid only. The combination of ultrasound irradiation and dilute acid can be a key factor in the disruption of rigid cellulose structures and contributes to the improvement of cellulose saccharification in enzymatic hydrolysis.