Pretreatment is a key step in the conversion of lignocellulosic biomass to bioethanol. The development of efficient pretreatment technologies is of great significance for biomass valorization. Herein, an integrated pretreatment was proposed for enhancing the enzymatic hydrolysis of poplar and improving the isolation of hemicelluloses by coordinating microwave radiation (MW) in hydrothermal and alkali (HT-AL) pretreatment. Results showed that the cooperation of MW with HT-AL (MW-HT-AL) effectively enhanced the enzymatic digestibility of poplar and a maximum glucose yield of 89.4 % was achieved under optimum condition, which was significantly higher than that of the HT-AL treated and untreated residues (71.6 % and 28.4 %). Additionally, substantial amounts of hemicelluloses (72.4 %) were also separated during the integrated pretreatment as compared with the HT-AL pretreatment alone (54.4 %). Structural analysis revealed that the poplar hemicelluloses were typical O-acetyl-4-O-methylglucuronoxylan and the water-soluble hemicellulosic fractions were substituted with more branches than the alkali-soluble hemicellulosic fractions.

预处理是将木质纤维素生物质转化为生物乙醇的关键步骤。开发高效的预处理技术对生物质资源化具有重要意义。在此，提出了一种综合预处理，通过在水热和碱 (HT-AL) 预处理中协调微波辐射 (MW) 来增强杨树的酶水解和改善半纤维素的分离。结果表明，MW与HT-AL（MW-HT-AL）协同作用有效提高了杨树的酶消化率，最佳条件下葡萄糖产率最高可达89.4%，明显高于HT-AL处理和未处理的残留物（71.6 % 和 28.4 %）。此外，大量的半纤维素（72。与单独的 HT-AL 预处理 (54.4%) 相比，在集成预处理期间也分离了 4%)。结构分析表明，杨树半纤维素是典型的O-乙酰基-4- O-甲基葡糖醛酸木聚糖和水溶性半纤维素组分比碱溶性半纤维素组分被更多的支链取代。