氯化铁基乙烷氧氯化催化剂的助剂效应与载体效应研究

发布时间：2018-02-01 23:06

  本文关键词： 乙烷氧氯化 氯化铁 助剂作用 载体效应 氯乙烯时空产率　出处：《内蒙古大学》2017年硕士论文　论文类型：学位论文

【摘要】：聚氯乙烯是世界五大通用塑料之一,被广泛应用于许多领域。氯乙烯作为聚氯乙烯的单体,可以通过乙炔氢氯化,乙烯氧氯化,乙烷氧氯化三种工艺生产。乙炔氢氯化最明显的缺点是高能耗,高污染。在发达国家,乙炔氢氯化已经被乙烯氧氯化取代。虽然乙烯氧氯化在石油资源丰富的国家有一定的优势,但世界范围内的石油资源日渐紧缺,也导致乙烯氧氯化的成本在不断的攀升。乙烷氧氯化采用乙烷为原料,生产工艺简单。乙烷氧氯化是最经济,最环保的生产工艺。但缺乏高性能催化剂限制了乙烷氧氯化在工业上的应用。因而乙烷氧氯化催化剂的研究十分重要。本论文以氯化铁为活性组分,采用浸渍法制备了一系列氯化铁基乙烷氧氯化催化剂。对常见的碱金属和碱土金属进行筛选,从中选出最好的碱金属/碱土金属助剂。详细研究了氯化钾助剂的助剂效应以及不同混合载体对氯化铁基乙烷氧氯化催化剂的载体效应。利用正交试验研究了不同反应条件对催化剂性能的影响。结合X射线粉末衍射(XRD)、氮气物理吸附、X射线光电子能谱(XPS)、氢气程序升温还原(H2-TPR)、穆斯堡尔谱(Mossbauer spectrum)、拉曼光谱(Raman spectrum)等表征手段的测试结果,得到以下结论:1.对常见的碱金属和碱土金属进行筛选,从中选出最好的碱金属/碱土金属助剂。发现碱金属盐/碱土金属盐助剂对氯化铁基乙烷氧氯化催化剂有显著的影响。添加助剂后的催化剂乙烷转化率明显提高,氯乙烯选择性同样明显升高。并且,氯化钾助剂的助剂作用最为明显。2.详细研究了氯化钾助剂对氯化铁基乙烷氧氯化催化剂的助剂效应。发现催化剂的乙烷转化率和氯乙烯选择性均随着钾铁摩尔比x(0≤x≤2)的增加而增加。催化剂的活性明显提高以及各种表征手段的结果证明了催化剂活性组分的变化(FeCl3→KFeCl4)。在此基础上,本文尝试提出部分反应机理,认为KFeCl4比FeCl3具有更高的氯气释放能力,最终导致了催化剂性能的提高。3.详细研究了不同载体混合对氯化铁基乙烷氧氯化催化剂的载体效应。发现二氧化铈/二氧化锆-氧化铝混合载体催化剂中,二氧化锆-氧化铝混合载体催化剂表现更佳。多种表征手段,如XRD、XPS、拉曼光谱等,证明了二氧化锆和氧化铝之间发生相互作用,部分Al3+进入二氧化锆晶格,导致二氧化锆晶胞塌缩。这种相互作用有利于乙烷氧氯化活性的提高。4.对催化性能最好的FeK2和Zr50催化剂进行了正交试验。发现不同乙烷流量、不同进料比和不同温度对乙烷转化率和氯乙烯选择性都有影响,并最终影响氯乙烯时空产率。其中,乙烷流量与HC1流量之比对乙烷转化率、氯乙烯选择性和时空产率都有明显影响。氯化氢过量与否、过量多少对乙烷氧氯化反应十分重要。
[Abstract]:Polyvinyl chloride (PVC) is one of the five universal plastics in the world and has been widely used in many fields. As a monomer of PVC, it can be chlorinated by hydrogen acetylene and oxychlorination of ethylene. Ethane oxychlorination is produced by three processes. The most obvious disadvantages of acetylene hydrochlorination are high energy consumption, high pollution. In developed countries. Hydrogen chlorination of acetylene has been replaced by ethylene oxychlorination. Although ethylene oxychlorination has some advantages in oil-rich countries, oil resources in the world are increasingly scarce. It also leads to the rising cost of ethane oxychlorination. Ethane oxychlorination using ethane as raw material, the production process is simple. Ethane oxychlorination is the most economical. The most environmentally friendly production process. However, the lack of high performance catalyst limits the industrial application of ethane oxychlorination. Therefore, the study of ethane oxychlorination catalyst is very important. In this paper, ferric chloride is used as the active component. A series of ferric chloride ethane oxychlorination catalysts were prepared by impregnation method. The common alkali metals and alkaline earth metals were screened. The best alkali metal / alkali earth metal promoter was selected. The promoter effect of potassium chloride promoter and the support effect of different mixed support on ferric chloride ethoxy chlorination catalyst were studied in detail. Effect of the same reaction conditions on the performance of the catalyst-combined X-ray powder diffraction (XRD). XRD). Nitrogen is physically adsorbed by X-ray photoelectron spectroscopy (XPS), hydrogen temperature programmed reduction (H2-TPRN), Mossbauer spectrum (Mossbauer spectrum). The results of Raman spectroscopy and other characterization methods obtained the following conclusions: 1. Screening of common alkali metals and alkaline earth metals. The best alkali metal / alkali earth metal promoter was selected. It was found that the alkali metal salt / alkali earth metal additive had a significant effect on the catalyst of ferric chloride ethane oxygen chlorination. . Vinyl chloride selectivity was also significantly increased. And. The promoter effect of potassium chloride promoter on ferric chloride ethane oxychlorination catalyst was studied in detail. It was found that the conversion of ethane and the selectivity of vinyl chloride of the catalyst were with potassium iron friction. Erbix (. The increase of 0 鈮，

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