Synthesis of High SiO2/Al2O3 Ratio B-NaY Zeolite and its Catalytic Performance in the Diethylbenzene Transalkylation
1. School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China;；
2. State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Shanghai Research Institute of Petrochemical Technology, SINOPEC, Shanghai 201208, China
Abstract：To obtain a well-behaved B-NaY zeolite, a series of heteroatom B-NaY zeolites were synthesized by direct hydrothermal method using the untreated silicon source and that pretreated with oxalic acid, sulfuric acid and aluminum sulfate, respectively. The physical and chemical properties of the synthesized B-NaY zeolites were studied. The results showed that when the silicon source was pretreated by oxalic acid, the well-crystallized B-NaY zeolites with the relative crystallinity 97% and the SiO2/Al2O3 ratio 6.3 were obtained, and the crystallization rate was faster. The pretreatment of silicon source with oxalic acid can not only increase the degree of polymerization of silicate ion in the silicon source, but also increase the active aluminum species in the process of crystallization, because oxalic acid as a complexing agent can form four coordination active aluminum with OH- and Al3+ to promote the dissolution of the gel, making the solution of active aluminum species content increased, which was conducive to accelerated crystallization. The catalytic performance of the synthesized catalysts in the reaction of diethylbenzene with phenylalkyl transfer to ethylbenzene was studied. Under the experimental conditions of the reaction temperature 175 ℃, reaction pressure 3 MPa, mass ratio of benzene to diethylbenzene 2 and mass space velocity of 3.3 h-1, the diethylbenzene conversion was over 50%, and the selectivity of ethylbenzene was up to 99.3%. The method for the B-NaY zeolites synthesis using oxalic acid pretreated silicon source was simple and fast, and the synthesized B-NaY zeolites had excellent performance. There would be a good industrial application prospect in the future.
Cao Feng1,2,Guo Dongdong2 et al. Synthesis of High SiO2/Al2O3 Ratio B-NaY Zeolite and its Catalytic Performance in the Diethylbenzene Transalkylation[J]. 化学反应工程与工艺, 2017, 33(1): 21-28.
