芦苇半纤维素水解生产低聚木糖技术及工艺研究

发布时间：2018-04-01 11:03

  本文选题：芦苇　切入点：蒸汽爆破　出处：《南京理工大学》2016年硕士论文

【摘要】：为探索芦苇资源化利用——生成低聚木糖的方法,本文研究了水解芦苇原料制备低聚木糖的工艺流程,其具体内容包括芦苇原料预处理提取木聚糖工艺、爆破芦苇酶法水解工艺、低聚木糖脱色工艺,以及采用柱层析法分离纯化低聚木糖液的研究。芦苇预处理工艺研究结果表明：碱蒸煮法、酸蒸煮法和蒸汽爆破法均能够从芦苇中提取出木聚糖,酸法的木聚糖提取量较少；另外,蒸汽爆破还会爆出少许低聚木糖；蒸汽爆破法中木聚糖的爆出量随着汽爆压力增大而增加,且相同压力下,加碱爆破物料木聚糖爆出量较高；相同的酶解条件下,1.40Mpa加碱爆破的芦苇物料酶解效果最好,最适合作为芦苇酶解生产低聚木糖的前处理方式。木聚糖酶水解爆破芦苇制备低聚木糖的工艺研究结果表明：当加碱爆破芦苇原料与去离子水比(固液比)为1：10、木聚糖酶添加量为5%(对芦苇干物质量)、pH值4.8、酶解温度45℃、酶解时间24h时,可获得较好的酶解效果；水解液中可溶性总糖量达到6.39mg/ml,还原糖含量达到3.51mg/ml；高效液相色谱分析计算酶解液中低聚木糖含量为14.00%(对芦苇干物质量),其主要成分为木二糖和木三糖,含量分别为12.29%和1.71%(对芦苇干物质量)；最佳酶解条件下,低聚木糖中木二糖、木三糖分别在24h、18h达到最大值。对低聚木糖液脱色的研究中得到以下结论：酸析具有一定的脱色效果,在条件pH3.0、50℃脱色30min,脱色率达到45.79%；采用氨水改性后的粉末状活性炭具有更好的脱色效果,其优化的脱色条件为pH值3、脱色温度70℃、活性炭添加量30%(对固形物)、振荡频率为170r/min、脱色时间70min,此时的脱色率达到90.31%；酸析结合活性炭联合脱色,活性炭添加量20%(对固形物)的脱色率能达到88.60%。最后,采用颗粒状活性炭柱层析分离提纯脱色后的低聚木糖液,用30%乙醇溶液作为洗脱液,蒸发浓缩后得到木二糖、木三糖的低聚木糖产品,低聚木糖提取率达到62.9%。
[Abstract]:In order to explore the method of utilizing reeds to produce xylooligosaccharides, the technological process of preparing xylooligosaccharides from Reed raw materials was studied in this paper. The specific contents of this process include extraction of xylan from Reed raw materials and enzymatic hydrolysis of Reed by blasting. Studies on decolorization of xylose oligosaccharides and separation and purification of xylooligosaccharide solution by column chromatography. The results of pretreatment of Reed showed that xylan could be extracted from Reed by alkali cooking, acid cooking and steam explosion. The amount of xylan extracted by acid method is less, in addition, a little xylooligosaccharide is produced by steam blasting, and the amount of xylan explosion increases with the increase of steam explosion pressure, and under the same pressure, the amount of xylan explosion of alkali blasting material is higher. Under the same enzymatic hydrolysis condition, the Reed material with 1.40Mpa added alkali blasting has the best enzymatic hydrolysis effect. The results showed that the ratio of raw material to deionized water (solid / liquid ratio) was 1: 10 when the ratio of raw material to deionized water was 1: 10. Xylanase addition was 5% (pH 4. 8 for Reed dry matter, enzymatic hydrolysis temperature 45 鈩，

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