ZSM-35分子筛的合成与有机酸脱铝改性  

Synthesis and organic acids de-aluminum modification of ZSM-35 zeolites

作　　者：张丹丹 张晓丹 刘仁杰 陈惠莹 韩洪晶[1,2] 张亚男 陈彦广 ZHANG Dandan;ZHANG Xiaodan;LIU Renjie;CHEN Huiying;HAN Hongjing;ZHANG Yanan;CHEN Yanguang(College of Chemistry&Chemical Engineering,Northeast Petroleum University,Daqing 163318,China;Heilongjiang Provincial Key Laboratory of Oil and Gas Chemical Technology,Daqing 163318,China)

机构地区：[1]东北石油大学化学化工学院,黑龙江大庆163318 [2]黑龙江省石油与天然气化工重点实验室,黑龙江大庆163318

出　　处：《化工科技》2023年第5期1-9,共9页Science & Technology in Chemical Industry

基　　金：国家自然科学基金青年基金项目(21908021);中国石油科技创新基金项目(2021DQ02-0701);东北石油大学引导性创新基金项目(2021YDL-03);东北石油大学新能源新领域培育项目(XNYXLY202102)。

摘　　要：采用动态水热合成法制备了ZSM-35分子筛,对其合成条件进行优化,同时通过有机酸处理改性,实现分子筛酸位点的调控,并且对改性前、后的分子筛进行烃类催化裂解性能评价。利用XRD、XRF、BET、Py-IR等方法对ZSM-35分子筛的结构与酸性进行表征,结果表明,t=135℃、t=72 h、n(SiO_(2))∶n(Al_(2)O_(3))=30、合成体系碱度n(OH-)∶n(SiO_(2))=0.31,得到较为纯净的ZSM-35分子筛,结晶度为99.24%。采用柠檬酸处理分子筛的效果明显高于乙酸与草酸,c(柠檬酸)=1 mol/L在保持分子筛具有较高结晶度的同时可以脱除分子筛内的非骨架铝,调控分子筛的孔道结构,降低分子筛的整体酸性;改性ZSM-35分子筛催化油品时,使乙烯/丙烯(双烯)选择性由51.3%提升至56.7%,双烯比由54%提升至56%,具有一定抑制结焦的作用。In this paper,ZSM-35 zeolites were prepared by dynamic hydrothermal synthesis method,and its synthesis conditions were optimized.The acid sites of the zeolites were modulated by organic acid treatment,and the hydrocarbon catalytic cracking performance of the zeolites before and after the modification was evaluated.The structure and acidity of ZSM-35 zeolites were characterized by XRD,XRF,BET and Py-IR,and the results showed that at the crystallization temperature of 135℃,the crystallization time of 72 h,n(SiO_(2))∶n(Al_(2)O_(3))of 30,and the alkalinity of the synthesis system of n(OH-)∶n(SiO_(2))=0.31,a relatively pure ZSM-35 zeolites with 99.24%crystallinity can be obtained.The effect of treating the zeolites with citric acid is significantly higher than that of acetic acid and oxalic acid.1 mol/L citric acid can remove the non-skeletal aluminum in the zeolites while maintaining the high crystallinity of the zeolites,regulate the pore structure of the zeolites,and reduce the overall acidity of the zeolites.When the ZSM-35 zeolites modified with 1 mol/L citric acid was used to catalyze oil,the diene(ethylene/propylene)selectivity increased from 51.3%to 56.7%,and the bis-ene ratio increased from 54%to 56%,as well as a certain effect of coking inhibition.

关 键 词：ZSM-35分子筛 合成调控 有机酸脱铝 催化裂解 抑制结焦 

分 类 号：TQ170.6[化学工程—硅酸盐工业]