超临界CO2萃取脱除甘蔗渣木质素的研究

采用超临界CO₂萃取技术,研究了萃取条件对甘蔗渣木质素脱除规律的影响,设计正交试验方案得出纸浆得率、综纤素维含量、Klason木质素含量,进一步得出脱木质素率,以确定最优条件.结果表明,温度是影响超临界CO₂脱除木质素的最主要因素.在180 ℃、 20 MPa下,用1,4-二氧六环2 mL作夹带剂反应60 min,脱木质素率达到79.61%.用GC-MS 对不同温度下超临界CO₂萃取液的分析以研究在超临界CO₂下甘蔗渣中木质素的溶出规律,结果表明,木质素的降解不仅发生在芳基醚键这种大分子的断裂,还导致了苯环上甲氧基的断裂.且在高温作用下,还会导致甘蔗渣中其它碳水化合物、纤维素和半纤维素的降解.

Delignification of Bagasse with CO2 Supercritical Fluid Extraction

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.