木质素的提取、改性及其综合利用

【作者】 王磊；

【导师】 辛寅昌；

【作者基本信息】 山东师范大学 ， 物理化学， 2012， 硕士

【摘要】 木质素是一类天然多羟基芳香族化合物，在植物体内作为纤维素和半纤维素的粘结物质，增强植物体机械强度。木质素的来源十分广泛，可以直接从各种植物的芯材中分离提取，也可以从造纸制浆废液中回收利用。造纸制浆废液给环境造成很大的负荷，其主要污染成分就是其中被废弃的木质素，因此，分离提取造纸制浆废液中的木质素，并对其进行化学改性，合成具有工业应用价值的产品，不仅具有环保意义，更具有经济意义。本论文选用难处理的造纸制浆黑液作为原料，对其中木质素的提取、改性及其改性产品在油田钻井方面的应用进行了较为系统的实验研究。本文在第一章对木质素这类天然聚集体进行了概述，介绍了其在自然界的存在、分布以及基本的分子结构和理化性质，同时对已有的木质素的提纯方法进行了介绍，并综述了钻井液降粘剂及降滤失剂的应用研究现状及未来发展趋势。本文在第二章对造纸制浆黑液中的木质素进行分离提纯。通过实验粗略确定了所用造纸制浆黑液的主要化学成分，采用了物理和化学两种提纯方法并对两种方法提纯后的木质素纯度进行了对比。物理方法是将酸化后的制浆黑液经板框式压滤机压滤来得到粗品木质素滤饼，但此法耗酸量大，处理后的滤液酸度高，对环境仍然存在很大的危害；本文采用的化学方法是利用支型耐盐活性剂DM-5522与有机絮凝剂CPAM的协同作用得到高纯度的木质素，讨论了支型耐盐活性剂使用的最佳pH值，并研究了在最佳pH值下，支型耐盐活性剂及絮凝剂的加量对木质素析出率的影响，并对相关作用机理进行了阐述。本文研究的提纯木质素的化学方法的优势在于：（1）耗酸量少，大大降低了处理成本而且不会产生二次污水；（2）不会产生因引入金属离子导致污泥难处理的问题；（3）提纯后的木质素纯度高，达到较高的脱盐率。本文在第三章以化学方法提纯得到的木质素为原料，对其进行化学改性合成了两种钻井液处理剂，即降粘剂铁铬木质素磺酸钠（FCLS）和降滤失剂磺化木质素磺甲基化酚醛树脂（SLSP）。对两大改性产品红外光谱中主要特征峰进行了解析，同时讨论了改性反应过程中的主要影响因素。本文在第四章里对上述木质素改性产品进行了室内性能评价，分别研究讨论了FCLS和SLSP的最佳使用量，并在最佳使用量条件下分别考察了其抗温、抗盐及抗钙性能。实验结果表明，本文制备的木质素改性产品性能优良，符合钻井要求，而且原料来源广泛，价格低廉，可以解决油田化学品用量大的问题。更多还原

【Abstract】 Lignin is a kind of natural aromatic compound with much hydroxyl, whichenhances mechanical strength of the plant as cellulose and hemicellulose bondingmaterial in plant body. The source of lignin is a very wide range, which can beextracted directly from the core material of all kinds of plants and also can be recycledfrom waste pulp of paper making. Waste pulp of paper making brings a big load to theenvironment, in which the main pollution composition is the abandoned lignin.Therefore, extracting the lignin in waste pulp and synthesising it to the products ofindustrial application value by the chemical modification not only have theenvironmental protection sense and more economic significance.This thesis chooses the black liquor as raw materials which is difficult to betreated and carries out a system of experiments about the extraction and modificationof lignin and the application of lignin’s modified products in oilfield drilling.The first chapter of this paper includes the summarisation of this kind of naturalaggregate lignin, in which introducing the existence and distribution of lignin innature and lignin’s basic molecular structure as well as the physical and chemicalproperties of lignin. At the same time, the first chapter also introduces the lignin’spurification methods existed and summarizes present situation of application andfuture development trend about the thinnervisbreaker and filtrate reducer for drillingfluid .The second chapter of this paper introduces the purification of lignin from theblack liquor. The main chemical composition of the black liquor has be determinedroughly through the experiment. Two kind of purification methods which is physicaland chemical methods are used to purify the lignin. The purity of lignin with the twomethods are compared. Physical method is that the black liquor is acidified and thentreated through the plate frame type filter press, which can get filter cake of crudeproducts lignin. But large amount of acid is consumed by this method and the filtratestill exists great harm on the environment because of high acidity. The chemicalmethod used in this article is that using synergy of subordinate structure salt resisting surfactant DM-5522 and organic flocculants CPAM to get lignin of high purity. Thebest pH value about using DM-5522 is determined. The amountofusage of DM-5522and CPAM on the influence of lignin’s extraction efficiency is studied and and therelevant mechanism is discussed in this paper. The adbantages of the chemical methodused to purify lignin in this paper are: (1) consumption of acid is little, the processingcost is greatly reduced and it can’t produce secondary sewage; (2) it can’t cause theproblem of sludge difficult to deal with because of the introduction of metal ions; (3)lignin has high purity and high desalination rate after the process.In the third chapter of this paper, lignin purified by above chemical method asraw materials is synthesized to two kind of drilling fluid additive by chemicalmodification. They are thinnervisbreaker—chromium iron lignin sulfonic acid sodium(FCLS) and filtrate reducer for drilling fluid—sulfited lignin sulfomethylatedphenolaldehyde resin (SLSP). It makes an analysis for main characteristic peaks of thetwo modified products in infrared spectrum, and discusses the main influence factorsin the modifing progeess. In the fourth chapter of this paper, it makes the indoorperformance evaluation of the modified lignin product and discusses the best usage ofSLSP and FCLS respectively, and investigates their performance of temperatureendurance, salt resistance and calcium resistance. The results of experiments showthat the modified lignin products prepared in this paper have good performance andcan meet the need of oilfield drilling, and can solve the problem of large usage ofoilfield chemicals because the wide sources of the raw materials and low price.更多还原