Study on Aromatization Reaction of n-Hexane Coupled Methanol Catalyzed by HZSM-5 with Different Si/Al Ratios
1. Engineering Research Center of Large Scale Reactor Engineering and Technology, East China University of Science and Technology, Shanghai 200237, China;
2. Petro China Institute for Research of Urumqi Petrochemical Company, Urumqi 830019, China
Abstract：Aromatization reaction of n-hexane coupled methanol catalyzed by five ZSM-5 zeolites with different Si/Al ratios was investigated in a 50 mL fixed bed reactor under temperature of 400 ℃，pressure of 0.50 MPa, weight hourly space velocity of 1.0 h-1 and 7/3 mass ratio of n-hexane to methanol. The ZSM-5 zeolites were characterized by X-ray diffraction (XRD), N2 adsorption-desorption, NH3 temperature programmed desorption (NH3-TPD)，scanning electron microscope (SEM) and pyridine adsorption Fourier-transform infrared (Py-IR). The results showed that the aromatics selectivity was higher when the coupling reaction of n-hexane and methanol was catalyzed by HZSM-5 zeolites with lower Si/Al ratio, and the catalytic performance of HZSM-5 zeolites with higher Si/Al ratio was more stable. The aromatic selectivity was 49.7% and the lifetime of catalyst was 144 h when Si/Al ratio of HZSM-5 was 15, while the aromatic selectivity was 27.7% and the lifetime was 384 h when Si/Al ratio of HZSM-5 was 75. The characterization results demonstrated that the HZSM-5 zeolites with different Si/Al ratios were composed of nano-sized particles with MFI crystal structure and similar specific surface area and pore volume. The amount of middle, strong and Br?nsted acid were lower for HZSM-5 zeolites with higher Si/Al ratio, and the reaction was mild and the catalyst stability was better. The different acid amounts might be the main reason for the different catalytic performance of HZSM-5 zeolites with different Si/Al ratios.
WEI Shumei1,2,XU Yarong1 et al. Study on Aromatization Reaction of n-Hexane Coupled Methanol Catalyzed by HZSM-5 with Different Si/Al Ratios [J]. 化学反应工程与工艺, 2021, 37(1): 8-14.
