China Coal Research Institute Corporation Ltd.
National Energy Technology & Equipment Laboratory ofCoal Utilization and Emission Control
Beijing Key Laboratory of Coal Based Carbon Materials
CCTEG Low⁃carbon Technology Institute

2,6-萘二甲酸是合成特种聚酯聚萘二甲酸乙二醇酯(PEN)的重要单体,利用2-甲基萘通过酰化、氧化、纯化工艺可得到2,6-萘二甲酸,工艺中的酰化反应至关重要。目前2-甲基萘酰化反应中的催化剂通常采用Lewis酸AlCl3且催化体系的反应转化率高、选择性好,但反应淬灭过程会产生大量的酸性含铝废水,反应体系对设备的材质要求高。基于分子筛具有择型性高、热稳性好、易与产物分离等优势且在多种酰基化反应中表现出良好的催化活性,以2-甲基萘和丁酸酐为原料经分子筛固体酸催化的酰基化反应制备2-甲基-6-丁酰基萘,采用XRD、BET、SEM、NH3-TPD等方法对催化剂结构物性进行表征,对比研究BEA、MFI、MWW骨架拓扑结构的H-Beta、H-HZSM-5、H-MCM-22分子筛催化性能,探讨反应机理并考察分子筛催化剂的回用性能。研究表明,与具有十元环特征孔道的H-ZSM-5分子筛相比,具有十二元环特征孔道的H-Beta分子筛表现出更好的催化活性,BEA骨架拓扑的分子筛具有较高的选择性;在H-Beta分子筛催化下,反应条件为2-甲基萘与丁酸酐摩尔比1∶1、2-甲基萘0.05mol、催化剂2g、190℃反应10h,丁酸酐转化率为57.42%,其中2,6-位选择性为44.98%,2,7-位选择性为28.62%;H-MCM-22分子筛催化体系下,丁酸酐的转化率为31.66%,但生成产物不以期望的目标物为主;H-MCM-5分子筛由于孔道尺寸小,不适用于该体系,在液相体系中丁酸酐转化率<3%且未生成目标物。分子筛具有优良的回用性能,使用后的H-Beta分子筛通过高温焙烧再生后,催化剂的性能得到恢复,体现沸石分子筛催化剂的可回收和可重复利用的优点,该研究可为以中国丰富的含萘资源为原料制备高端聚酯单体提供颇具潜力的分子筛催化体系。

2, 6⁃Naphthalenedicarboxylic acid is an important monomer for the synthesis of special polyester polyethy⁃lene naphthalate ( PEN ). 2, 6⁃Naphthalenedicarboxylic acid can be obtained by acylation, oxidation and purifica⁃tion of 2⁃methylnaphthalene. The acylation reaction is very important in this process. At present, Lewis acid AlCl isusually used as the catalyst in the 2⁃methylnaphthalene acylation reaction. The catalytic system has high conversionrate and good selectivity, but the reaction quenching process will produce a large amount of acidic aluminum⁃contai⁃ning wastewater, and the reaction system has high requirements for the material of the equipment. Based on the ad⁃vantages of molecular sieves such as high selectivity, good thermal stability, easy separation from products and goodcatalytic activity in various acylation reactions, 2⁃methyl⁃6⁃butyrylnaphthalene was prepared by acylation reaction of2⁃methyl⁃ naphthalene and butyric anhydride catalyzed by molecular sieve solid acid. The structure and properties ofthe catalysts were characterized by XRD, BET, SEM and NH⁃TPD. The catalytic properties of H⁃Beta, H⁃ZSM⁃5and H⁃MCM⁃22 molecular sieves with BEA, MFI and MWW skeleton topologies were compared. The reaction mecha⁃nism was discussed and the reuse performance of molecular sieve catalyst was investigated. The results showed thatcompared with H⁃ZSM⁃5 zeolite with ten⁃membered ring characteristic channel, H⁃Beta zeolite with twelve⁃memberedring characteristic channel showed better catalytic activity, and the zeolite with BEA skeleton topology had higher se⁃lectivity. Under the catalysis of H⁃Beta molecular sieve, the reaction conditions were as follows: the molar ratio of 2⁃methylnaphthalene to butyric anhydride was 1 ∶ 1; 2⁃methylnaphthalene was 0. 05 mol, catalyst was 2 g, reactiontemperature was 190 ℃, reaction time was 10 h, the conversion of butyric anhydride was 57. 42%, the selectivity of2, 6⁃position was 44. 98%, the selectivity of 2, 7⁃position was 28. 62%. The conversion rate of butyric anhydridewas 31. 66% under the catalytic system of H⁃MCM⁃22 molecular sieve, but the product was not dominated by the de⁃sired target. H⁃MCM⁃5 molecular sieve is not suitable for this system due to its small pore size. In this liquid phasesystem, the conversion of butyric anhydride is less than 3%, and no target is formed. Molecular sieve has excellentrecycling performance. After the used H-Beta molecular sieve was regenerated by high temperature calcination, theperformance of the catalyst was restored, which fully reflected the advantages of recyclability and reusability of the ze⁃olite molecular sieve catalyst. This study provides a promising molecular sieve catalytic system for the preparation ofhigh⁃end polyester monomers from China ’s abundant naphthalene⁃containing resources.

中国煤炭科工集团有限公司科技创新创业资金专项项目(2023-2-TD-ZD008)

李军芳.不同拓扑结构分子筛催化2⁃甲基萘酰化反应性能对比研究[J].煤质技术,2024,39(6):79-86.

LI Junfang. Comparative study on the catalytic performance of zeolite catalysts with different topologies in 2⁃methyl⁃naphthalene acylation reaction [J]. Coal Quality Technology, 2024, 39 (6): 79-86.