【摘要】 用氯化锌/甘油低共熔溶剂(DES)对棉花秸秆(棉杆)进行预处理及酶解,并对回收DES进行重复利用。通过组分分析、粘度分析、FTIR和XRD研究了DES预处理对棉秆各组分含量、结构和酶解效果的影响。结果表明,80℃、DES含水5 m L时,木质素、半纤维素和纤维素的去除率分别为75.81%、15.59%和14.40%,实现了木质素与纤维素、半纤维素的较好分离。预处理后纤维素的I型晶体结构保持不变。由于木质素和半纤维素的去除,预处理所得残渣的结晶度(30.4%～48.3%)均高于原棉秆的结晶度(27.9%)。DES的回收率为76.19%～80.02%。棉秆中纤维素的转化率随着木质素和半纤维素去除率的增加而增加,80℃、DES含水5m L时达到了80%。在此条件下DES重复利用4次时,残渣中纤维素的转化率高于76%,重复利用效果良好。更多还原

【Abstract】 Cotton straw was pretreated with aqueous zinc chloride/glycerin deep eutectic solvent(DES),then enzymatically hydrolyzed,DESs were recovered and recycled. The effect of DES pretreatments on cotton straw’s component contents,structures and enzymatic hydrolysis efficiency were studied by component analysis,viscosity analysis,FTIR and XRD. The results demonstrated that the removals of lignin,hemicellulose and cellulose were 75. 81%,15. 59%and 14. 40%,respectively,when it was pretreated at 80℃ with the DES containing 5 m L of water,effective separation of lignin from cellulose and hemicellulose was achieved. The I-type crystal structure of cellulose remains unchanged after pretreatment. Due to the removal of lignin and hemicellulose,the crystallinity of the residues(30. 4% ～48. 3%)were higher than that of the original cotton straw(27. 9%). Recoveries of DESs were 76. 19% ～80. 02%. The cellulose conversions of cotton straw were reached to 80%when it was pretreated at 80 ℃ with the DES containing 5m L of water,which increased with the increase of lignin removal and hemicellulose removal. The conversions of cellulose in the residues were higher than 76%,when the DES was being recycled for 4 times at 80 ℃ with the DES containing 5 m L of water,indicating good recycling effect.更多还原