顺酐液相催化加氢的研究

发布时间：2018-07-10 06:00

  本文选题：顺酐加氢 + 丁二酸酐　； 参考：《北京化工大学》2016年硕士论文

【摘要】：顺酐是一种重要的有机合成中间体,可加氢制备丁二酸酐、Y-丁内酯以及1,4-丁二醇等一系列重要的精细化工原料。其中,丁二酸酐因其独特的分子结构故而可发生一系列化学反应。具体来说,丁二酸酐由两个酰基和一个氧原子组成,酰基的吸电子效应和酰基之间的相互作用可增强酰基中碳原子的正电性,进而易于发生水解、醇解、氨解和酯化反应等,因此丁二酸酐在工业上具有广泛的用途。目前丁二酸酐的主要制备方法有顺酐加氢法、生物发酵法以及电化学还原法,其中顺酐加氢法具有产品纯度高、易于生产规模化等竞争优势,而目前对于顺酐加氢的研究,多以γ-丁内酯以及1,4-丁二醇等为主要产物,因此对顺酐加氢制备丁二酸酐,特别是相关催化剂的研究是十分有必要的。本文研究了在顺酐加氢反应中,Pd催化剂对产物丁二酸酐收率的影响。结合XRD、TEM、XPS、TG-DTA等一系列表征方法,考察了催化剂制备条件和反应条件对顺酐转化率以及丁二酸酐选择性的影响。具体内容如下：1.以TiO2、 Al2O3、SiO2为载体时,尽管Al203和SiO2的比表面积比较大,但由于活性组分Pd在Ti02表面的分散性最好、颗粒粒径最小,相对活性位较多,因此Pd/TiO2催化剂的顺酐加氢活性最高,为53.9%；2.前驱体为Pd(NO3)2时,经过煅烧步骤处理的催化剂,其活性组分Pd颗粒明显大,使得催化剂加氢活性较差,顺酐转化率降低10%左右；催化剂还原温度从150℃升至450℃时,活性组分Pd与Ti02之间的相互作用增强,导致催化剂的加氢活性显著降低,还原温度为150℃时,顺酐转化率为87.9%,而还原温度为450℃时,顺酐转化率仅为38.9%；载体经浸渍干燥后于150℃直接还原制得的催化剂的加氢活性最高,为87.9%；3.随着反应温度从100℃升至200℃,顺酐转化率从59.4%提高到100%,温度升至250℃时,顺酐转化率维持100%,但丁二酸酐选择性降低,有副产物γ-丁内酯生成；H2分压和反应时间对顺酐转化率的影响较小；最佳反应条件为150℃-2 MPa H2-1h;另外,发现在溶剂中水的存在会抑制顺酐加氢反应。
[Abstract]:Maleic anhydride is an important intermediate in organic synthesis. It can be hydrogenated to produce succinic anhydride Y- butyrolactone and a series of important fine chemical raw materials. Among them, succinic anhydride can take place a series of chemical reactions because of its unique molecular structure. Specifically, succinic anhydride consists of two acyl groups and one oxygen atom. The electron-absorption effect of acyl groups and the interaction between acyl groups can enhance the positive electrical properties of carbon atoms in acyl groups, which can lead to hydrolysis, alcoholysis, ammonolysis and esterification, etc. Therefore, succinic anhydride is widely used in industry. At present, the main preparation methods of succinic anhydride are maleic anhydride hydrogenation, biological fermentation and electrochemical reduction. Among them, maleic anhydride hydrogenation has the competitive advantages of high purity and easy to produce large-scale. 纬 -butyrolactone and 1-butanediol are the main products, so it is necessary to study the hydrogenation of maleic anhydride to succinic anhydride, especially the related catalysts. The effect of PD catalyst on the yield of succinic anhydride in maleic anhydride hydrogenation was studied. The effects of preparation conditions and reaction conditions on the conversion of maleic anhydride and selectivity of succinic anhydride were investigated by means of a series of characterization methods, such as XRDX, TG-DTA and so on. The details are as follows: 1. With TIO _ 2, Al _ 2O _ 3 and Sio _ 2 as the support, although the specific surface area of Al203 and Sio _ 2 is large, the active component PD has the best dispersion on Ti02 surface, the smallest particle size and more relative active sites, so PD / TIO _ 2 catalyst has the highest maleic anhydride hydrogenation activity (53.9%). When PD (no _ 3) _ 2 is the precursor, the active component PD particles are obviously large, which makes the hydrogenation activity of the catalyst worse, the conversion of maleic anhydride decreases by about 10%, and the reduction temperature increases from 150 鈩，

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