摘要:生物质在地球上数量庞大,种类颇多,是全球运用最普遍的可再生能源。生物质资源的主要成分是纤维素、半纤维素和木质素。废弃的木质素通过氧化降解可以得到三种主要的有用途的芳香醛类产品:对羟基苯甲醛、香草醛和丁香醛,但其分离也有一定的困难。独特的加工方法使X-5大孔吸附树脂具有相当大的表面积和适当的孔隙度,物理化学性质稳定,不溶于酸、碱及有机溶剂,再生简便,性能高效等优点。本论文采用X-5树脂对木质素芳香醛进行吸附,以这三种芳香醛产品为模型物,采用大孔树脂吸附分离工艺,通过改变吸附时间、底物浓度、吸附温度等条件,结合吸附过程的动力学及等温线分析,探讨得出了当温度一定时,溶液浓度越高时,越有利于大孔吸附树脂吸附;当溶液浓度一定时,温度在20℃时最有利于大孔吸附树脂吸附。68099
毕业论文关键词:大孔吸附树脂,木质素,芳香醛,吸附分离
Abstract: Biomass can serve as a sustainable source of renewable fuels and chemicals to meet the growing demand for energy due to the particularity of its chemical structure which is composed of three main polymeric constituents: lignin, cellulose and hemicellulose. Lignin represents the largest renewable source of the threearomaticaldehydes vanillin, syringaldehyde and p-hydroxybenzaldehyde.Macroporous resins have been applied toseparatebenzaldehydes due to characteristics including high mechanicalstrength, various functional groups, porous ability, and longlifetimesThe aim of thepresent work was to investigate the adsorptionbehaviors of aromatic aldehydes on X-5 macroporousresin and to develop an efficient process for enrichment and purificationof aromatic aldehydes using X-5. The experimental results showed that the higher of the initial concentrations of the aromatic aldehydes, the greater of the adsorption capacities. The optimized temperature was20 ℃.
Keywords: macroporous adsorption resin, lignin, aromatic aldehyde, adsorption separation
目录
1绪论 4
1.1生物质资源利用的意义 4
1.2木质素的综合利用 4
1.3大孔吸附树脂在化学分离中的应用 5
2X-5大孔吸附树脂对木质素基芳香醛的吸附动力学分析 5
2.1实验材料 6
2.2实验方法与步骤 6
2.2.1香草醛、丁香醛、对羟基苯甲醛、标准曲线的绘制 6
2.2.2HPLC检测条件 7
2.2.3最大吸附量计算 8
2.2.4动力学实验步骤 8
2.3 结果与讨论 10
2.3.1分析动力学 10
结论 22
参考文献 23
致谢 24
1 绪论
1.1 生物质资源利用的意义
能源的开发与生产为人类物质文明和精神文明提供了重要的物质保障,成为满足人类生活和保障,国民经济发展的重要基础工业。我国近年由于能源的过度开发与消费累计的效应,出现了与能源有关的诸多问题。但生物质在地球上数量庞大,种类颇多,是全球运用最普遍的可再生能源[1]。因此生物质极有可能成为新世纪主要能源之一,它能为社会带来良好的社会效益、环境效益、经济效益、对人类的贡献很大。