Application of a continuous twin screw-driven process for dilute acid pretreatment of rape straw

Rape straw, a processing residue generated from the bio-oil industry, was used as a model biomass for application of continuous twin screw-driven dilute acid pretreatment. The screw rotation speed and feeding rate were adjusted to 19.7 rpm and 0.5 g/min, respectively to maintain a residence time of 7.2 min in the reaction zone, respectively. The sulfuric acid concentration was 3.5 wt% and the reaction temperature was 165 °C. The enzymatic digestibility of the glucan in the pretreated solids was 70.9%. The continuous process routinely gave around 28.8% higher yield for glucan digestibility than did the batch processing method.