氢气还原元明粉制硫化钠粗产物的纯化及催化机理初探

发布时间：2018-04-14 17:23

本文选题：氢还原 + 流化床　；参考：《内蒙古大学》2017年硕士论文

【摘要】：硫化钠作为一种强还原性、强碱性的无机化合物,在很多领域具有重要应用。目前,我国的硫化钠工业品大多采用煤粉还原法制备,环境负荷大且产物杂质含量高,限制了硫化钠高附加值产品的进一步开发利用。特别是硫化钠作为近年兴起的新型树脂聚苯硫醚的生产原料,对其纯度品相要求很高。因此,开发新工艺制备高纯硫化钠具有重要意义。气体一步法还原工业硫酸钠制硫化钠的研究已经取得了很大进展,其工艺简单,硫化钠产物纯度高。本实验室对该工艺过程及催化剂进行了多年探索,但固相产物的纯化及催化剂的分离仍是十分棘手的问题。本论文首先用固相法制备了两种不同的a-Fe203催化剂,研究其流化床中催化氢气还原元明粉制高纯硫化钠粗产物反应的催化性能,并提取粗产物中的催化剂进行循环使用及催化机理初步探索。其次,分别以水和无水乙醇为溶剂对硫化钠粗产物进行纯化实验探究,寻求高效的纯化实验方案。最后,对乙醇提纯法纯化硫化钠粗产物的实验条件进行正交实验设计及优化,得出最佳的纯化实验条件。结果表明,反应的催化机理可能为铁氧化物混合相的共同催化作用,G-900-1型α-Fe203催化剂的催化性能最好,制得的硫化钠粗产物中Na2S含量可高达95.2%。以无水乙醇为溶剂对硫化钠粗产物进行减压旋蒸提纯的效果远远优于以水为溶剂的提纯效果。对乙醇提纯法进行正交试验优化,得到了最佳的实验条件,在此条件下获得的纯化产物为纯相的Na2S·5H20,含量可达98.3%,杂质Na2S03和Na2S203含量之和为1.4%,Fe含量0.0023%,均满足国家标准要求。本工作基本解决了固相产物中催化剂的分离问题,产品满足生产聚苯硫醚所需高纯硫化钠原料的要求。
[Abstract]:Sodium sulphide, as an inorganic compound with strong reducibility and alkalinity, has important applications in many fields.At present, most of the industrial products of sodium sulfide in China are prepared by pulverized coal reduction method. The heavy environmental load and high impurity content limit the further development and utilization of high added value sodium sulfide products.Especially, sodium sulfide, as the raw material for the production of new resin polyphenylene sulfide (PPS) in recent years, requires high purity.Therefore, it is of great significance to develop a new process for the preparation of high purity sodium sulfide.Great progress has been made in the reduction of industrial sodium sulfate to sodium sulfide by one step gas reduction. The process is simple and the purity of sodium sulfide product is high.The process and catalyst have been explored in our laboratory for many years, but the purification of solid products and the separation of catalyst are still very difficult problems.In this paper, two kinds of a-Fe203 catalysts were prepared by solid phase method, and the catalytic performance of the catalyst in fluidized bed to produce high purity sodium sulphide was studied.The catalyst was extracted from the crude product for recycling and the mechanism of the catalyst was preliminarily explored.Secondly, the crude product of sodium sulfide was purified with water and anhydrous ethanol, respectively.Finally, the orthogonal design and optimization of the experimental conditions for the purification of crude sodium sulfide by ethanol purification method were carried out, and the optimum purification conditions were obtained.The results showed that the catalytic mechanism of the reaction was probably due to the co-catalysis of iron oxide mixed phase. The catalytic activity of G-900-1 伪 -Fe203 catalyst was the best, and the Na2S content in the crude product of sodium sulphide could be up to 95.2%.The purification of crude product of sodium sulfide with anhydrous ethanol as solvent is much better than that with water as solvent.The orthogonal experiment was carried out to optimize the ethanol purification method, and the optimum experimental conditions were obtained. Under this condition, the purified product was pure phase Na2S 5H20, the content of the purified product was 98.3 and the sum of the impurity Na2S03 and Na2S203 content was 1.4g Fe 0.0023, which met the requirements of the national standard.This work basically solves the problem of catalyst separation in solid product, and the product meets the requirement of high purity sodium sulfide raw material for the production of polyphenylene sulfide.
【学位授予单位】：内蒙古大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ131.12

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