秸秆纤维素的一步快速提取和水解

研究了秸秆纤维素的一步快速提取方法, 在醋酸和硝酸溶液体系中, 选择10种不同的反应条件, 进行了提取条件优选, 然后对提取的纤维素样品分别进行了水解. 结果发现, 纤维素提取的最佳条件为120 ℃, 固液比为1∶25, 在体积分数为80%的醋酸和10%的硝酸混合溶液中反应20 min, 纤维素的产率为38%. 纤维素样品的水解实验发现, 在最佳条件下提取样品的葡萄糖含量都大于90%, 水解率达到94%. 13C NMR和FTIR分析结果表明, 纤维素的分子结构未被破坏, 但纤维素Ⅰβ含量较高, 木质素和半纤维素的去除率都很高, 表明此方法是比较理想的制备高纯度纤维素的方法.

One-step Rapid Extraction and Hydrolysis of Straw Cellulose

One-step extraction method was studied for the rapid extraction of pure celluloses from the corn stalk, in acetic acid-nitric acid mixture under 10 different reaction conditions, and then the extracted cellulo-sic samples were hydrolyzed. The experimental results show that the optimized parameters for isolation of celluloses are reaction temperature at 120 ℃, 1∶25 of the solid-liquid ratio, 80% acetic acid and 10% nitric acid, reaction duration for 20 min, and the yield of cellulose is 38%. Hydrolysis of cellulosic samples show that the content of glucose is above 90% in preparations obtained under the optimized condition, and hydrolysis rate arrived to 94%. 13C NMR and FTIR indicate that the structure of cellulose is not damaged, and the content of cellulose Iβ is the highest, and the high degree of both lignin and hemicellulose degradation and removal is achieved in acetic acid-nitric acid mixture. The result shows a remarkable potential for pure cellulose production.