水热协同酸性低共熔溶剂对泡桐物化性质及酶解效率的影响

Effects of Synergistic Hydrothermal-Acid DES Pretreatment on the Physicochemical Properties and Enzymatic Hydrolysis of Paulownia

关键词:  水热预处理  低共熔溶剂预处理  泡桐  木糖  酶水解

Key Words:hydrothermal pretreatment  deep eutectic solvent pretreatment  Paulownia  xylose  enzymatic hydrolysis

摘要:采用水热协同酸性低共熔溶剂两步法处理泡桐以获得高的木糖得率和纤维素酶解效率。首先，采用酒石酸（TA）辅助的水热处理对泡桐进行预处理，探究了温度（120~160oC）、时间（15~120 min）和TA含量（0~10 wt %）对木糖得率的影响。发现在140oC、60 min、4 wt% TA的预处理条件下，木糖得率最高达80.5%。随后，采用低共熔溶剂（DES，氯化胆碱/乳酸，90~150 oC，2~8 h）对水热残渣进行后处理。研究表明，水热协同DES处理能够有效去除半纤维素和木质素，处理后泡桐结晶度、结晶尺寸、表面粗糙度及比表面积均增加；当DES后处理在130oC、6 h条件下，半纤维素和木质素去除率分别达100.0%和89.7%，纤维素保留率为77.3%。添加吐温80后，纤维素酶解效率为85.2%，是原料酶解率的4.6倍。

Abstract:The hydrothermal combined with acidic deep eutectic solvent (DES) treatments were used to pretreat Paulownia to obtain high xylose yield and enzymatic hydrolysis efficiency. Firstly, tartaric acid (TA) assisted hydrothermal pretreatment was utilized to treat Paulownia. The effects of temperature (120-160oC), time (15-120 min), and TA concentration (0-10 wt %) on xylose yield were examined. Result showed that the optimal hydrothermal pretreatment conditions were 140 °C, 60 min and 4 wt% TA, resulting in a maximum xylose yield of 80.5%. Subsequently, the hydrothermal residue was subjected to post-treatment with deep eutectic solvent (DES) composed of choline chloride and lactic acid operated at 90-150 oC for 2-8 h. The study revealed that the combined hydrothermal and DES treatments effectively removed hemicellulose and lignin, leading to increased crystallinity, surface roughness, specific surface area and accessibility of the treated Paulownia. The optimal DES post-treatment conditions were determined to be 130 °C for 6 h. Under the optimal treatment conditions, the removal rates of hemicellulose and lignin reached 100.0% and 89.7%, respectively, with a cellulose retention rate of 77.3% and an enzymatic hydrolysis efficiency of 85.2%, which was 4.6 times higher than that of raw paulownia wood.