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植物中木质素的提取及其氧化降解

时间:2018-04-20 12:34来源:毕业论文
摘要:木质素是自然界中储量仅次于纤维素的可再生资源,其在自然界的数量仅次于纤维素,估计每年全世界由植物生长可产生1500亿吨木质素,仅农作物秸秆每年就有5~6亿吨。过去对木

摘要:木质素是自然界中储量仅次于纤维素的可再生资源,其在自然界的数量仅次于纤维素,估计每年全世界由植物生长可产生1500亿吨木质素,仅农作物秸秆每年就有5~6亿吨。过去对木质素的开发并没实现其实用价值,然而随着石油资源的短缺利用木质素制备高附加值产品已成为当今热点。21499
目前超过95%的木质素仍作为工业制浆的废弃物,随废水直接排入江河或者浓缩后燃烧掉,制浆废水的排放不仅造成资源的浪费,同时又污染环境,对其进行很好的资源化利用对社会经济的发展和环境保护具有现实的意义。
本实验以KOH为提取剂,以粉碎的花生壳为原料,通过提取剂提取木质素并通过正交实验取得最佳反应条件,所得最佳条件为:水浴温度 40℃,恒温时间 2.5 h,碱液用量 20mL / g,碱液浓度为 0.5 mol / L。
用所得木质素进行氧化降解试验。通过以氢氧化钠、双氧水为反应物,五水硫酸铜为催化剂与木质素混合在一系列条件下进行反应并运用不同萃取剂对其进行萃取。所得产物在进行浓缩之后通过红外,紫外以及气质谱图对其进行分析。能够得出某些衍生物转换成了香兰素的结论,因此通过进一步的研究能使得木质素实现其进一步的使用价值。    
另一方面,也可以看出木质素氧化降解之后生成多种芳香族化合物,这为木质素将来代替石油化工原料提供了可能。因此对木质素极其附属衍生物的研究具有非常大的现实意义,同样这也是我们努力的方向。
毕业论文关键词:木质素;提取;氧化降解;应用 源自$六l维,论:文w网)加7位QQ3249^114 www.lwfree.cn

Plant extracts and oxidative degradation of lignin
Abstract: Lignin is nature reserves second only to cellulose, a renewable resource, its second only to cellulose in a number of nature, the estimated annual worldwide growth of the plant can produce 150 billion tons of lignin, crop stalks each year there are only 500 ~ 600 million tons. Past development of lignin did not realize it value, but with the use of oil resources shortage lignin preparation of high value-added products has become a hot spot.
Currently more than 95% of the lignin remains as an industrial waste pulp, with the waste water directly into rivers or burned after concentration, pulp wastewater discharge not only a waste of resources, but also pollute the environment, its good resource utilization has practical significance for the socio-economic development and environmental protection.
In this experiment, KOH as extracting agent to crushed peanut shells as raw material to extract lignin obtained by extracting agent and the optimal reaction conditions by orthogonal experiment, the resulting optimal conditions: water bath temperature of 40 degrees, holding time 2.5 h. Amount 20mL / g, alkali concentration of 0.5 mol / L.
The resulting oxidation of lignin degradation test. By sodium hydroxide, hydrogen peroxide reactant, copper sulfate pentahydrate as a catalyst for the reaction with lignin, and the use of different mixing extractants be extracted under a series of conditions. The resulting product was concentrated after performing its analysis by IR, UV spectra and temperament. Some derivatives can be converted into vanillin draw conclusions, so further research can make further use of lignin to achieve its value.
On the other hand, it can be seen that a variety of aromatic compounds generated after degradation of lignin, lignin which may be provided instead of petrochemical raw materials in future. Thus a very large study of lignin extremely practical significance derivatives subsidiary, which is the same direction of our efforts. 源自$六l维,论:文w网)加7位QQ3249^114 www.lwfree.cn
KeyWords:Lignin;abstract;Oxidative degradation;Application
 目  录
1  引言    1
1.1 研究背景    1
1.2 木质素结构及理化性质    2 植物中木质素的提取及其氧化降解:http://www.lwfree.cn/shengwu/20180420/13732.html
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