论文总字数：18462字

摘 要

木质素是自然界中仅次于纤维素的可再生复杂天然高分子化合物原料，因其产量巨大，长期以来被视为有发展前途的生物质材料，但由于木质素本身结构的复杂性，导致其在降解的过程中存在诸多问题与困难。新兴发展起来的固体酸催化剂具有催化能力强，易分离，非常安全，甚至可以放在人的手心，可有效抑制有害物的生成，避免污染环境，有些还具有选择性催化能力，提高反应产率等诸多优点，越来越受到人们的欢迎。本课题采用浸渍共沉降法制备固体酸，与通过预处理后的半纤维素甘蔗渣反应，以求得最大水解率的最优条件，并对经过固体酸处理后的甘蔗渣结构进行分析。

关键字：半纤维素 木糖 固体酸催化剂 降解

Solid base-catalyzed degradation of lignin

Abstract

Second only to cellulose, lignin is the nature of complex natural polymer renewable raw material, because of its huge production, has long been regarded as promising biomass materials, but because of the complexity of the lignin structure itself, leading to its many problems and difficulties in the process of degradation of. Develop new solid acid catalyst having a catalytic ability, easy to separate, very safe, even in the human hands, which can effectively inhibit the formation of harmful substances and avoid environmental pollution, and some selective catalytic ability to increase the reaction yield and many other advantages, more and more people are welcome. The issue of settlement prepared by the impregnation of solid acid method, and by the reaction of bagasse hemicellulose after pretreatment, in order to achieve optimal conditions for the maximum rate of hydrolysis, and the structure of the solid bagasse after acid treatment were analyzed.

Keyword: hemicellulose xylose solid acid catalyst degradation

目 录

摘要.............................................................................................................................Ⅰ

ABSTRACT.............................................................................................................Ⅱ

1. 文献综述.....................................................................................................1
   1. 选题背景与意义......................................................................................................1

1.2半纤维素概述..........................................................................................................2

1.2.1 半纤维素的化学结构.......................................................................................3

1.2.2半纤维素稀酸水解机理...................................................................................3

1.3 木糖简介..................................................................................................................4

1.3.1定义...................................................................................................................4

1.3.2生产原料...........................................................................................................4

1.3.3常见木糖中多缩戊糖含量...............................................................................4

1.3.4 木糖在生产生活中的应用...............................................................................5

1.4固体酸概述..............................................................................................................5

1.4.1固体酸催化剂产生背景...................................................................................5

1.4.2固体酸催化剂分类...........................................................................................6

1.4.3固体酸催化剂优点...........................................................................................6

1.4.4本课题应用的固体酸催化机理.......................................................................7

1.5本课题研究意义......................................................................................................7

第二章 实验材料与方法......................................................................................8

2.1实验材料..................................................................................................................8

2.1.1主要试剂与仪器...............................................................................................8

2.2 试验方法..................................................................................................................9

2.2.1甘蔗渣预处理及组分测定...............................................................................9

2.2.2木糖标准曲线...................................................................................................9

2.2.3 固体酸的制备...................................................................................................9

2.2.4.不同固体酸效果.............................................................................................10

2.2.5 固体酸的再次利用........................................................................................10

2.2.6 甘蔗渣水解单因素实验设计........................................................................10

2.2.7甘蔗渣的响应面优化实验设计.....................................................................10

第三章 结果与讨论..............................................................................................10

3.1单因素试验结果

3.1.1 反应温度对催化水解的影响.........................................................................11

3.1.2油浴时间对催化水解的影响.........................................................................11

3.1.3 固体酸的量对催化水解的影响.....................................................................12

3.1.4 甘蔗渣的量对催化水解的影响.....................................................................12

3.1.5响应面法优化试验.........................................................................................12

3.2二次响应面回归模型的建立与分析....................................................................13

3.3两因素间交互作用的分析....................................................................................16

3.3.1固体酸的量和反应温度的交互作用.................................................................16

3.3.2甘蔗渣的量和固体酸量交互作用.....................................................................17

3.3.3固体酸量和油浴时间交互作用.........................................................................18

第四章 总结.............................................................................................................18

第五章 展望............................................................................................................19

参考文献...................................................................................................................19

1. 文献综述

1.1选题背景及意义

木质纤维素类生物质主要包括农业生物质和林业生物质，如农作物秸 秆、玉米芯、蔗渣、果核和木屑等，它们主要由半纤维素、纤维素、木质素 和一定量的其它组分组成。其中，半纤维素是指那些以非共价键方式与纤维 素连接的糖具有高度的分支机构，主要是由聚戊糖、聚己糖及聚糖醛酸组成，其含量占到木质纤维素原料的19%-35%。半纤维素经水解可以得到 木糖、阿拉伯糖和半糖。我国每年形成的农业废弃物高达7亿吨，其中大部分被焚烧或抛弃处理，浪费了大量有用资源^[1]，又造成环境污染。这些生物质原料中的半纤维素组分可以转化为木糖和阿拉伯糖，纤维素组分可以水 解得到葡萄糖，酶解得到燃料乙醇，木质素原料可以用于制备木质素-酚共 聚物等化工产品，这些产品可以进一步用于制备木糖醇、糠醛、羟甲基糠醛、 乙酰丙酸等下游化工产品。^[2]充分利用木质生物质资源可以提高广大农业劳动 者的经济收入，减轻环境污染，缓解我国对化石原料的依耐，对我国的循环 经济和可持续发展具有重大意义。

请支付后下载全文，论文总字数：18462字