Abstract: This paper reported the delignification of bagasse with the supercritical fiuid of CO₂ and the influence of extraction conditions.The pulp yield, holocellulose contents,and Klason lignin contents were obtained by orthogonal experiments to get the delignification rate and the optimal conditions.The experimental results showed that the temperature was the main factor that influenced the efficiency of delignification.Under the condition of 180 ℃,20 MPa,1,4-dioxane 2 mL within 60 min,the delignification rate could reach 79.61%.The GC-MS analysis of the supercritical extraction liquid under different temperature showed that the degradation of lignin not only occured by breaking the aryl-ether bonds of macromolecule,but also led to the fracture of methoxy on the benzene ring.And at high temperature,the other carbohydrates,cellulose,and hemicellulose in bagasse also degraded.

Key words: bagasse, delignification, supercritical CO₂, GC-MS