摘 要:植物秸秆资源丰富,含有大量的纤维素、半纤维素,利用植物秸秆生产燃料乙醇具有广阔的应用前景。本次实验选用了芒草、小麦秸秆作为实验材料,经过 H2SO4 法预处 理后,探究不同材料细胞壁成分对预处理和酶解的产糖效率的影响。67581
实验测定了秸秆纤维素、半纤维素、木质素含量,芒草细胞壁总成分(75%、81%), 显著高于小麦(51%、55%),其中纤维素差异较大,半纤维素、木质素差异较小。H2SO4 预处理可以水解半纤维素,溶解少量木质素,暴露纤维素链,使得纤维素酶可以有效解除 底物,提高酶解效率。预处理液中含有大量五碳糖,纤维素酶水解液中主要为六碳糖,4% H2SO4预处理酶解六碳糖产率接近最大值;芒草五碳糖产率高于六碳糖,小麦结果相反; 两者总糖产率都在50%,单位质量芒草总糖产量高出小麦10%左右。
Abstract: Plant straw which contains large amounts of cellulose, hemicellulose has broad application prospect to produce bioethanol. This experiment chose Miscanthus, wheat straw as the experimental material, to explore the cell walls of different material composition on the efficiency of the pretreatment of H2SO4 and enzymatic hydrolysis of sugar .
The plant cell walls are composed of cellulose, hemicelluloses, lignins and pectins. The results showed that total lignin contents of Miscanthus (75%, 81%) was significantly higher than wheat straw (51%, 55%), and cellulose was most varied among the tested samples. H2SO4 pretreatment can dissolve most hemicellulose, a small amount of lignin, and hydrolyzed very little cellulose, makes the cellulose enzyme can effectively remove the substrate, improve the efficiency of enzymatic hydrolysis. Pretreatment fluid contains a large number of five-carbon sugar, mainly six carbon sugar in cellulase hydrolysate, 4% H2SO4 pretreatment enzymolysis six carbon sugar yield close to the maximum; Miscanthus five-carbon sugar yield is higher than six carbon sugar, wheat instead; Both production rate are 50% of total sugar, unit mass miscanthus total sugar yield about 10% higher than that of wheat straw.
Keywords: Bioenergy, Miscanthus, Wheat straw, H2SO4 pretreatment
目 录
1 绪论 3
1.1 生物质能 3
1.2 植物细胞壁 4
1.3 细胞壁化学组成 4
1.4 生物质降解转化 7
1.5 本研究目的与意义 9
2 材料与方法 10
2.1 实验材料 10
2.2 实验方法 10
2.2.1 材料收集 10
2.2.2 细胞壁成分测定 10
2.2.3 比色法测定六碳糖、五碳糖 12
2.2.4 H2SO4 梯度预处理 13
3 结果与分析 14
3.1 细胞壁成分测定 14
3.1.1 C6、C5 标准曲线 14
3.2 H2SO4 预处理降解转化效率 15
3.2.1 纤维素降解效率 15
3.2.2 酶浓度预实验