微波辅助木质素催化酸解制备酚类物质的研究

 2021-12-11 07:12

论文总字数:30021字

摘 要

:木质素因其特殊的化学结构,能够制备具有高附加值的酚类化合物。并且木质素储量极为丰富,有望替代石油生产化学化工产品,具有巨大的潜在价值。微波加热较传统加热方式具有加热快、效率高的优点,因此本文采用微波加热法研究黑液木质素在甲酸溶剂中深度解聚制备酚类物质的过程。

整个实验过程主要根据有无催化剂参与分为两部分进行。首先,研究了无催化条件下微波加热辅助甲酸溶剂中木质素的降解,通过控制变量法对比分析不同反应条件(反应温度、反应时间、微波功率和溶剂与样品液固配比)对液体产率和单酚类物质分布的影响。然后实验研究了黑夜木质素在四种不同分子筛催化剂催化条件下的液相降解,通过BET,SEM, NH3-TPD等手段表征分析了四种分子筛催化剂(HUSY、HY、HZSM-5和SBA-15分子筛),并分析了不同条件下木质素降解产物的分布规律。

最后综合整个实验的分析研究结果,探索出微波辅助黑液木质素催化酸解的一般规律,进而获得黑液木质素降解最佳工艺条件,为实现造纸黑液的综合利用,制备具有高附加值的化学品提供实验和理论参考。

关键词:微波; 木质素; 催化剂; 酸解; 酚类物质

Microwave-assisted Acidolysis of Lignin for Phenolic Compounds

Abstract:In view of the special chemical structure of lignin, lignin can provide us with valuable phenolic compounds. And considering the rich lignin reserves in the world, it is expected to use ligin to take the place of oil in producing chemical chemical products. So lignin has great potential value. Compared to traditional electrical heating methods, the microwave heating has advantages of fast heating rate and high heating efficiency. In this thesis, the process of acidolysis of lignin in formic acid was investigated by microwave heating.

The experiment is divided into two parts depending on whether with the addition of catalyst. Firstly, the process of microwave-assisted acidolysis of lignin in formic acid was studied without catalyst, to analyze the influence on the product yield and distribution of phenolic compounds under the different conditions (reaction temperature, reaction time, microwave power, and liquid-solid ratio) by comparison. Then, the experiments of microwave-assisted acidolysis of lignin in formic acid was carried under the different types of catalytic conditions. The chemical structure of four molecular sieve catalyst (HUSY, HY, HZDM-5 and SBA-15) was analyzed by BET, SEM, NH3-TPD, and the distribution of products degraded from lignin under different conditions was also investigated.

Finally, on the basis of the results and analysis of the whole experiment, the regular pattern of the microwave-assisted acidolysis of lignin in formic acid was explored evidently, and the optimum reaction conditions to the lignin’s degradation process was acquired as well. Consequently, the efficient utilization of lignin may be realized not too long after.

KEY WORDS: microwave; lignin; catalyst; acidolysis; phenolic compounds

目 录

摘要 I

Abstract II

第一章 绪论 1

1.1 引言 1

1.2 木质素的结构及性质 1

1.2.1 木质素的组成和结构 1

1.2.2 木质素的性质 2

1.3 木质素利用现状及研究进展 3

1.3.1 木质素的应用前景 3

1.3.2 木质素的解聚方法 3

1.3.3 木质素的液化工艺研究 3

1.4 本文的研究目的和主要研究内容 5

1.4.1 研究目的 5

1.4.2 主要研究内容 5

第二章 实验方法 6

2.1 实验准备 6

2.1.1 实验材料和试剂 6

2.1.2 实验仪器 6

2.2 黑液木质素的制备 6

2.3 黑液木质素的组成分析和结构表征 7

2.3.1 组分分析和结构表征方法 7

2.3.2 黑液木质素样品分析结果 7

2.4 实验主要步骤和流程 8

2.5 木质素降解产物表征方法 9

2.5.1 油1相产物表征方法 9

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