桉木热磨与高温热水协同预处理对酶解效果的影响及工艺优化  

Effects of Combination of Thermo-mechanical and Liquid Hot Water Pretreatment on the Efficiency of the Enzymatic Hydrolysis of Eucalyptus and Its Process Optimization

作　　者：徐绍华[1] 武书彬[1] 李霄虹 

机构地区：[1]华南理工大学制浆造纸工程国家重点实验室,广东广州510640

出　　处：《林产化学与工业》2014年第4期30-36,共7页Chemistry and Industry of Forest Products

基　　金：国家863计划资助(2012AA101806);国家自然科学基金项目资助(31270635);广东省科技计划项目(2011A090200006)

摘　　要：为提高桉木原料的酶解糖化效果,降低原料处理成本,采用热磨与高温热水法联合对桉木原料进行预处理,并对高温热水预处理后样品进行纤维素酶酶解糖化。通过对预处理液和酶解液中木糖和葡萄糖得率的测定,来研究预处理条件对糖得率的影响。以预处理液和酶解液中的总糖得率作为预处理工艺条件的评价指标,得到最优的预处理条件为:预处理温度180℃、保温时间40 min、固液比1∶20(g∶mL)。在此条件下,桉木热磨后原料经预处理、酶解后总木糖得率为11.78%,木糖的转化率为82.67%;总葡萄糖得率为36.33%,葡萄糖的转化率为78.90%。采用傅立叶红外光谱(FT-IR)、扫描电镜(SEM)等分析预处理样的理化特性,结果表明:桉木原料热磨后颗粒变小,呈丝状,纤维形态和表面结构基本不变;而高温热水预处理后物料的纤维结构松散、碎化,断裂明显,改善了纤维素酶的可及度,提高了酶解效率。Combination of thermo-mechanical pulping （TMP） process and liquid hot water pretreatment method had been adopted to improve the enzymatic saccharification efficiency and reduce the processing costs of eucalyptus. The pretreated sample was then hydrolyzed by cellulase. The pretreatment conditions on the influence of sugars yield had been discussed by measuring the yield of xylose and glucose in the pretreated hydrolyzate and enzymatic hydrolyzate. The optimal pretreatment condition was 180 ℃ （cooking temperature）, 40 min（ residence time） and 5 % （substrate concentration）. It was obtained by using the total sugars in the pretrcated hydrolyzate and enzymatic hydrolyzate as the evaluation index. Under this pretreatment condition, the conversion of xylose and glucose reached 82.70 % and 78.90 %, respectively. The physics and chemical properties of pretreated residue were characterized using FF-IR, SEM so as to analyse effect of two pretreatment methods. The results showed that the particle of raw eucalyptus was diminished, the shape was filiform, but the fibre morphology was maintained. However, the structure of fibre was loose and smashed after the hot water pretreatment, and this improved the accessibility of cellulase and efficiency of enzymolysis.

关 键 词：桉木 热磨 高温热水预处理 酶解 FT-IR SEM 

分 类 号：TQ35[化学工程]