木质素催化热裂解制备高附加值化学品工艺研究

论文总字数：25578字

摘 要

本论文以香茅草为原料，采用固定床反应器，在氮气氛围下进行香茅草催化热裂解实验。选用硝酸镍、硝酸铝作为原料，以MCM-41分子筛为载体，采用共沉淀法制备分子筛负载镍铝复合氧化物Ni₂Al-LDO/MCM-41，并对制备的催化剂进行了XRD，N₂吸附脱附分析，探究不同催化剂载体对生物油产率及组成的影响。结果表明，Ni₂Al-LDO/MCM-41制备得到生物油的产率（12.507%）高于其他催化剂制备得到的产物。根据生物油组成的结果可知，Ni₂Al-LDO/MCM-41比其他对照催化剂具有更好的促进芳香族生成效果（可高达90%以上），生物油具有很高的附加价值。

以香茅草为反应原料，Ni₂Al-LDO/MCM-41为催化剂，采用固定床反应器，在氮气氛围下进行香茅草催化热裂解实验。通过产物各组分分布情况以及生物油品质探究催化剂对香茅草催化热裂解的影响，此外还考察了热解温度，升温速率，载气流速对香茅草催化热裂解反应的影响。发现裂解温度、升温速率及载气流速对热裂解产物分布影响较大，并发现香茅草催化热裂解的最佳工艺条件：催化剂Ni₂Al-LDO/ MCM-41，催化剂与香茅草的质量比为1：1，反应温度为450 ℃，升温速率10 ℃/min，扫气速度 20 mL/min。香茅草热裂解生成的生物油产率达到最大值，为15.366%。与其他催化剂相比，Ni₂Al-LDO/MCM-41在氮气氛围下得到的生物油明显增加，且液相产物中芳香族产物比例明显上升，酸性物质明显减少。

关键词：香茅草，分子筛负载镍铝复合氧化物，催化热裂解，生物油

ABSTRACT

In this thesis, we use the citronella grass as raw material, using a fixed-bed reactor, under the nitrogen atmosphere to carry on citronella grass catalytic pyrolysis experiments. Nickel nitrate and aluminum nitrate were selected as raw materials for catalysts. The molecular sieves of MCM-41 were used as the carrier to prepare the molecular sieve-supported nickel-aluminum composite oxide Ni₂Al-LDO/MCM-41 by co-precipitation method. The prepared catalysts were analyzed by XRD and N2 adsorption-desorption experiment to explore the effect of different catalyst carriers on bio-oil yield and composition. The results showed that the yield of bio-oil produced by Ni2Al-LDO/MCM-41 (12.507%) was higher than that of other catalysts. According to the results of bio-oil composition, Ni2Al-LDO/MCM-41 has better effect of promoting aromatic formation (up to 90% or more) than other control catalysts, and bio-oil has high added value.

We used citronella as the reaction raw material, Ni2Al-LDO/MCM-41 as the catalyst, using a fixed-bed reactor, under the nitrogen atmosphere of the citronella grass catalytic pyrolysis experiment. The influence of the catalyst on the catalytic pyrolysis of citronella was explored through the analysis of the distribution of each component of the product and the quality of the bio-oil. In addition, the influence of the pyrolysis temperature, heating rate, and carrier gas flow rate on the catalytic pyrolysis reaction of citronella grass was investigated. We found that the pyrolysis temperature, heating rate, and carrier gas flow rate have a great influence on the distribution of pyrolysis products, and found that the best process conditions for the catalytic pyrolysis of citronella cataract: using the catalyst Ni2Al-LDO/MCM-41, the mass ratio of catalyst to citronella grass is 1:1, the reaction temperature is 450 °C, the heating rate is 10 °C/min, and the scavenging speed is 20 mL/min. Under this condition, the yield of bio-oil produced by thermal decomposition of citronella reached a maximum of 15.366%. Compared with other catalysts, the bio-oil of Ni2Al-LDO/MCM-41 obtained under the nitrogen atmosphere increased significantly, and the proportion of aromatic products in the liquid phase product increased significantly, and the amount of acidic substances decreased significantly.

Key words: Lemongrass, molecular sieve loaded nickel-aluminum composite oxide, catalytic pyrolysis, bio-oil.

目录

摘要

ABSTRACT

第一章 绪论

1.1 生物质能源开发的研究意义

1.2 生物质介绍

1.3 生物质热化学转化

1.4 课题研究目的及内容

第二章 实验部分

2.1 实验试剂及仪器

2.2 催化剂的制备

2.3 香茅草热化学转化实验研究

第三章 结果与讨论

3.1 催化剂的表征

3.2产物分析

3.2 工艺条件对反应结果的影响

第四章 结论与展望

4.1 结论

4.2 展望

参考文献

绪论

生物质能源开发的研究意义

随着能源的消耗量和需求量日益增加，所造成的环境污染也日趋严重，因此发展一种环境友好型可再生新能源已迫在眉睫^[1]。

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