氯化胆碱/1,4-丁二醇/AlCl_(3)三元低共熔体系提高毛竹预处理效率的研究

Improving Pretreatment Efficiency of Moso Bamboo with Ternary Deep Eutectic Solvent of Choline Chloride/1,4-Butanediol/AlCl_(3)

以毛竹为原料,采用氯化胆碱(ChCl)/1,4-丁二醇(BDO)/AlCl_(3)低共熔溶剂(DES)体系,在90~130℃和固液比1∶4(g∶g)条件下对毛竹进行预处理,探讨了木质纤维高原料装锅量的DES反应体系在不同温度下对毛竹化学组分、酶水解效率和木质素回收率的影响。研究结果表明:随着预处理温度的增加,预处理物料木聚糖和木质素质量分数逐渐降低,葡聚糖质量分数升高,酶水解效率显著提高。温度为110℃时,预处理效果最佳,此时预处理物料回收率为59.24%,葡聚糖、木聚糖回收率分别为91.38%和27.03%,木质素脱除率为69.72%,葡聚糖酶水解得率几乎接近100%,表明ChCl/BDO/AlCl_(3)三元低共熔溶剂体系可以极大提高对毛竹的预处理效率。进一步研究表明:通过有机溶剂溶解及沉淀再生的方法,可回收预处理液中90%以上的木质素,且回收的木质素纯度可达99.26%。通过物料衡算发现毛竹各组分可有效分离与转化。

Bamboo was pretreated by choline chloride(ChCl)/1,4-butanediol(BDO)/AlCl_(3) deep eutectic solvent(DES)system with a solid to liquid ratio of 1∶4(g∶g)at 90-130℃.The effects of DES reaction system with high loading capacity of lignocellulose on chemical composition,enzymatic hydrolysis efficiency,and lignin recovery of moso bamboo were investigated at different temperatures.The results of the research showed that the mass fractions of xylan and lignin in the pretreated substrates decreased gradually with the increase of pretreatment temperature,while the mass fraction of glucan increased,and the enzymatic hydrolysis efficiency increased significantly.When conducting pretreatment at the optimal condition of 110℃,the recovery rate of pretreated substrates was 59.24%,and the recovery rate of glucan and xylan were 91.38%and 27.03%,respectively.The lignin removal ratio was 69.72%,and the glucan enzymatic hydrolysis yield reached almost 100%,indicating that the ChCl/BDO/AlCl_(3) ternary DES system could greatly improve the pretreatment efficiency of moso bamboo.Further research showed that more than 90%lignin in the pretreatment liquid could be recovered by sequential organic solvent dissolution and reprecipitation,and the purity of the recovered lignin had high value of 99.26%.From the mass balance,it was found that each component of moso bamboo could be separated and transformed effectively.