固体酸催化合成2-戊基蒽醌的研究

发布时间：2018-11-13 18:16

【摘要】：烷基蒽醌是重要的精细化工中间体,是合成蒽醌系染料的主要原料,也用作合成过氧化氢的催化剂。它在国民经济中占有举足轻重的位置,具有重要的工业价值。其中,2-戊基蒽醌(2-AAQ)因在过氧化氢生产中稳定性高、工作液相容性好、催化效能高而表现出更优的性能。2-AAQ还是生产超纯双氧水(H_2O_2)、降解树脂、染料和感光化合物的主要中间体和原料。传统2-AAQ的生产采用工艺是:Lewis酸(AlCl3)催化2-戊基苯和苯酐的Friedel-Crafts酰基化反应合成中间体2-(4′-戊基苯甲酰基)苯甲酸(ABB),再以浓硫酸或发烟硫酸催化ABB脱水闭环合成2-AAQ。但该工艺产生大量废酸,不仅腐蚀设备,还污染环境。因此,开发出一条新型的催化工艺路线,实现2-AAQ的绿色合成具有广阔的应用前景。本课题采用环境友好的固体酸催化剂—沸石分子筛,替代传统的浓硫酸催化剂催化ABB脱水缩合反应合成2-AAQ。通过不同类型固体酸催化剂催化性能的筛选结果表明H-Beta沸石分子筛更利于反应的进行,通过对其改性和工艺条件的优化,使2-AAQ的选择性达到99.2%,ABB的转化率达到98.5%。以上解决了催化剂无法再使用、反应后催化剂与产物分离困难等问题,为2-AAQ的生产开辟了一条新的绿色工艺。此外,我们尝试用负载型催化剂替代传统的Lewis酸催化剂来催化戊基苯和苯酐的Friedel-Crafts酰基化反应合成ABB,结果表明该酰基化反应合成出的ABB产量较低,生产工艺还有待于进一步优化。具体研究内容如下:1.使用廉价的硅藻土为硅源和铝源通过水热合成法合成催化剂Beta沸石分子筛。考察了凝胶组成、H_2O用量、晶化时间、晶化温度等对合成Beta沸石分子筛的影响,并将其应用于催化ABB的脱水环合反应中合成2-AAQ。2.H-Y、H-ZSM-5、H-Beta、磷钨酸、磷钼酸、蒙脱土等固体酸催化剂的催化性能对比实验结果表明,H-Beta沸石分子筛在ABB脱水闭环合成2-AAQ工艺中表现出更优的催化性能,ABB的转化率及2-AAQ的选择性均大于其他类型的固体酸催化剂。3.有机酸(柠檬酸)改性的H-Beta沸石分子筛作催化剂对ABB脱水环合合成2-AAQ反应的催化效果优于以CeCl_3·7H_2O和ZrOCl_2·8H_2O改性作催化剂时的催化效果。经柠檬酸改性后的H-Beta沸石分子筛的催化性能受离子交换次数的影响,随着交换次数的增多,总酸量减少,弱酸的相对含量减少,强酸的相对含量增加,催化性能得到提高,以交换2次效果最佳。通过单因素实验工艺优化得到最佳的反应条件是:催化剂用量为原料量的28.6%,反应温度280℃,反应时间1.5h,采用高效液相色谱面积归一化法计算得到ABB的转化率达到98.5%,2-AAQ选择性达到99.2%。4.催化剂的活性稳定性实验结果表明,催化剂重复使用3次后催化效果明显下降。催化剂经高温焙烧再生后ABB的转化率能达到97.7%,2-AAQ的选择性也在84.3%以上,可使催化性能得到恢复。5.改性后的Beta沸石分子筛催化剂经XRD、SEM、TG、IR、NH3-TPD、BET等手段进行表征。6.水洗酸洗工艺得到中间体ABB,柱层析分离得到产物2-AAQ,经IR、1H NMR、13C NMR测定证实是中间体ABB及目的产物2-AAQ。
[Abstract]:Alkyl peroxide is an important fine chemical intermediate, and is the main raw material for the synthesis of the sulfur-based dye. It is also used as a catalyst for the synthesis of hydrogen peroxide. It occupies an important position in the national economy and has important industrial value. 2-AAQ is the main intermediate and raw material for producing ultra-pure hydrogen peroxide (H _ 2O _ 2), degrading resin, dye and photosensitive compound because of high stability, good working fluid compatibility and high catalytic efficiency in the production of hydrogen peroxide. The conventional 2-AAQ production process is as follows: Lewis acid (AlCl3) is used to catalyze the Friedel-Crafts of 2-pentylbenzene and benzene to synthesize the intermediate 2-(4-pentylphenyl) benzoic acid (ABB), and then the 2-AAQ is synthesized with concentrated sulfuric acid or fuming sulfuric acid for ABB dehydration closed-loop synthesis. but the process produces a large amount of waste acid, not only the equipment but also the environment. Therefore, a new catalytic process is developed, and the green synthesis of 2-AAQ has a wide application prospect. In this paper, the environment-friendly solid acid catalyst is used as the zeolite molecular sieve, and the traditional concentrated sulfuric acid catalyst is used to catalyze the synthesis of 2-AAQ by the reaction of the ABB dehydration condensation reaction. The results of the catalytic performance of different types of solid acid catalysts show that the H-Beta zeolite molecular sieve is more favorable for the reaction, and the selectivity of 2-AAQ is 99.2% by the optimization of the modification and the process conditions, and the conversion rate of the ABB reaches 95.8%. The invention solves the problems of no re-use of the catalyst, difficult separation of the catalyst and the product after the reaction, and opens up a new green process for the production of 2-AAQ. In addition, we try to replace the traditional Lewis acid catalyst with the supported catalyst to catalyze the Friedel-Crafts-based reaction of the pentylbenzene and the benzene to synthesize the ABB. The results show that the yield of ABB is low and the production process needs to be further optimized. The specific content of the study is as follows: 1. the catalyst Beta zeolite molecular sieve is synthesized by using cheap kieselguhr as a silicon source and an aluminum source through a hydrothermal synthesis method. The effect of the gel composition, the amount of H _ 2O, the crystallization time, the crystallization temperature and the like on the synthetic Beta zeolite molecular sieve was investigated, and it was applied to the synthesis of 2-AAQ. 2.H-Y, H-ZSM-5, H-Beta, phosphotungstic acid, and P-The catalytic performance of the solid acid catalyst such as montmorillonite and other solid acid catalysts shows that the H-Beta zeolite molecular sieve exhibits better catalytic performance in the 2-AAQ process of the ABB dehydration closed-loop synthesis, and the conversion rate of ABB and the selectivity of 2-AAQ are all higher than that of other types of solid acid catalysts. The catalytic effect of the H-Beta zeolite molecular sieve modified by organic acid (citric acid) on the synthesis of 2-AAQ by the dehydration of ABB was better than the catalytic effect when the catalyst was modified with CeCl _ 3 路 7H _ 2O and ZrOCl _ 2 路 8H _ 2O. The catalytic performance of the H-Beta zeolite molecular sieve modified by citric acid is affected by the number of ion exchange, with the increase of the exchange times, the total acid amount is reduced, the relative content of the weak acid is reduced, the relative content of the strong acid is increased, the catalytic performance is improved, and the exchange of the two effects is optimal. The optimum reaction conditions were as follows: the amount of the catalyst was 28. 6% of the raw material, the reaction temperature was 280.degree. C., the reaction time was 1. 5 h, the conversion of ABB was obtained by the high performance liquid chromatography area normalization method, and the selectivity of 2-AAQ was 99.2%. The experimental results of the activity stability of the catalyst show that the catalytic effect of the catalyst is obviously reduced after 3 times of repeated use of the catalyst. and the conversion rate of the catalyst after high-temperature roasting regeneration can reach 97. 7%, the selectivity of the 2-AAQ is more than 84.3%, and the catalytic performance can be recovered. The modified Beta zeolite molecular sieve catalyst was characterized by XRD, SEM, TG, IR, NH3-TPD and BET. The intermediate ABB and the product 2-AAQ were obtained by the water-washing and acid-washing process, and the intermediate ABB and the target product 2-AAQ were confirmed by IR, 1H NMR and 13C NMR.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TQ244.63

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