【作者】 荆磊；

【导师】 金永灿；

【作者基本信息】 南京林业大学 ， 制浆造纸工程， 2010， 硕士

【摘要】 当前,利用资源丰富的木质纤维素转化燃料乙醇已成为世界各国的研究热点,但由于木质纤维原料的生物构造和化学组成等方面的原因,直接酶水解糖化效果很差,必须经过适当的预处理以提高酶水解糖化效率。本文以稻草秸秆为原料,利用制浆造纸工业的工艺和设备,研究了酸法、碱法和亚硫酸盐预处理对其主要化学成分和酶水解性能的影响。结果表明:相对其他预处理方法,绿液和碳酸钠预处理是较为理想的预处理方法,有望实现制浆厂的转型和产品多元化。绿液预处理酶水解糖得率略高于碳酸钠预处理。稻草原料经140℃、4%用碱量绿液预处理,酶水解糖得率(对原料)达到42.1%,即总糖回收率接近80%,在此条件下,木质素脱除39.2%(占原料木质素%),灰分溶出26.6%(占原料灰分%),其中SiO2仅溶出8.4%(占原料SiO2%),高聚糖降解12.8%(占原料总糖%)。相比绿液预处理,Na2SO3-HCHO预处理即可有效脱除木质素,又能避免高聚糖的大量降解,酶解总糖回收率接近80%。在本实验的基础上,可通过进一步的预处理,提高酶水解糖得率,如:氧脱木素、磨浆细纤维化等。另外,还可以通过优化酶组合、二次酶水解、添加表面活性剂等酶水解方法提高酶水解糖得率。更多还原

【Abstract】 Utilization of agricultural straw fiber to produce fuel ethanol offers a great potential for reducing the raw material cost and increasing the alternatives of raw material. Unlike crops which can be easily hydrolyze into the monomeric sugar, pretreatment is required for the utilization of lignocellulosic materials to attain relatively high enzymatic saccharification.This thesis focuses on the effects of chemical composition and enzymatic saccharification of rice straw pretreated by acid, alkali and sulfite with the use of pulping technics and equipments. The results showed that, compared with other pretreatment methods, the green liquor and sodium carbonate pretreatment are desirable pretreatment methods for conversion ethanol from rice straw, which provide a potential way for the repurpose of pulping mill and diversification of products. The enzymatic hydrolysis sugar yield of green liquor pretreatment is higher than sodium carbonate pretreatment. Rice straw pretreated by 4% GL at 140 oC, the enzymatic hydrolysis sugar yield about 42.1% on the basis of original rice straw, or a sugar conversion ratio close to 80% could be expected. In this condition, the removal of lignin occupied 39.2%, ash 26.6%, SiO2 8.4% and saccharification degradation 12.8% (all based on the components in rice straw). Na2SO3-HCHO pretreatment is another choice for enhancing sugar recovery for bioethanol production if the lignin in enzymatic hydrolysis residue could be used. The total sugar recovery in enzymatic hydrolysis is close to 80% while rice straw pretreated by Na2SO3-HCHO.Based on this experiment, other pretreatment method such as oxygen deligninfication, refining and so on also can be applied to enhance the effect of enzymatic sacchrification. Moreover, other methods like optimizing enzyme combinations, twice enzymatic sacchrification and adding surfactant also can raise sugar yield.更多还原