蒸汽爆破-乙醇蒸煮两步法预处理对麦秆结构的影响  

Effect of Steam Explosion and Ethanol Pulping Pretreatment on Structure of Wheat Straw

作　　者：潘诚[1] 刘忠[1] 惠岚峰[1] 

机构地区：[1]天津科技大学天津市制浆造纸重点实验室,天津300457

出　　处：《林产化学与工业》2016年第6期76-80,共5页Chemistry and Industry of Forest Products

基　　金：国家自然科学基金资助项目(31270631)

摘　　要：对麦秆采用先蒸汽爆破后乙醇蒸煮的两步法进行预处理,研究预处理对麦秆组分及结构变化的影响。蒸汽爆破过程实验条件选取200 g绝干麦秆,压力1.75 MPa和时间3.5 min。乙醇预处理过程选取80 g蒸汽爆破麦秆(绝干),55%乙醇,两者固液比1∶5(g∶mL),温度170℃、时间30 min。通过高效液相色谱法测定,预处理最终产物组分中半纤维素降低89%左右,木质素降低35%左右。采用红外光谱、纤维形态分布分析及SEM分析对预处理过程中麦秆结构变化情况进行研究,结果表明:蒸汽爆破过程破坏了半纤维素酯键连接且半纤维素降解非常明显,但对纤维素链结构影响和降解作用相对较低;麦秆经过蒸汽爆破预处理后,纤维平均长度明显降低,而平均宽度却显著增加;再经乙醇预处理后纤维平均长度基本保持不变,但平均宽度降低;经两步预处理后麦秆纤维的天然物理结构由紧密到蓬松,纤维束呈松散状态且纤维表面基本无碎片附着物,利于后续加工利用。The wheat straw was pretreated by steam explosion and ethanol cooking to investigate the changes of chemical composition and morphology structure. The wheat straw were firstly steam explored under 1. 75 MPa pressure for 3.5 min, then treated by 55% ethanol at 170 ℃ for 50 rain with a 1：5 solid to liquid ratio （g： mL）. The hemicellulose content of the treated product was 89%, and the lignin content was decreased to 42.16%. The morphology structures of the treated wheat straw were analyzed by FT-IR, Fiber Fester and SEM. The results showed that the hemicelluloses were degraded significantly and the ester linkages were also destroyed after steam explosion, but only tiny degradation of cellulose was observed. For the fiber morphology, the average length of steam explored pulp was significantly decreased. However, the average width of the steam explored pulp were increased. After the ethanol pretreatment, there is no negative impact on the average fiber length, but a lower average width was observed. After this two-step pretreatment, a fluffier wheat straw was obtained and very few fragments were attached to the fiber surface.

关 键 词：蒸汽爆破 乙醇预处理 麦草秸秆 纤维形态 

分 类 号：TQ35[化学工程]