The effect of hierarchical treatment by dilute sulfuric acid solution on USY zeolite was studied. The molecular sieve products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), N2 adsorption-desorption, temperature programmed desorption of ammonia (NH3-TPD), pyridine adsorption Fourier-transform infrared (Py-IR) spectroscopy, 27Al magic angle spinning nuclear magnetic resonance (27Al MAS NMR) spectroscopy, and other necessary analysis methods. The results showed that the obtained H-USY sample maintained a high level of relative crystallinity, while the external specific surface area and mesoporous volume reached 187 m2/g and 0.20 cm3/g, which increased by 175% and 150% compared to the reference parent USY sample, which was very beneficial for slowing down the deactivation rate of macromolecular catalytic reactions. At the same time, acid treatment could regulate the distribution of active acid centers and aluminum atom coordination of the zeolite surface, which could effectively reduce strong acid centers while promoting much more abundant medium-strong acid centers, the Bronsted/Lewis distribution was also more reasonable, which helps to suppress the generation of heavy components. In the catalytic reformates deolefinization reaction, the catalytic performance of CH-USY catalyst on the removal of trace olefins in aromatic hydrocarbons was significantly superior than that of the reference CUSY catalyst. Under the conditions of feed space velocity of 6 h-1 and reaction pressure of 2.2 MPa, the CH-USY catalyst maintained almost 90% deolefinization activity after 80 h reaction, and due to the optimization of mass transfer pore structure and acid properties, the CH-USY catalyst exhibited excellent olefin removal performance, light product (middle distillate oil) selectivity, and synergistic catalytic effect under the high temperature (220 ℃) conditions."/>
USY分子筛酸处理对催化脱烯烃性能的影响
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Acid Treatment of USY Zeolite and Its Effect on Catalytic Performance in Deolefinization
WANG Yuemei, LI Wei, TONG Weiyi, ZHOU Yaxin
SINOPEC Shanghai Research Institute of Petrochemical Technology Company Limited, State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Shanghai 201208, China
Abstract：The effect of hierarchical treatment by dilute sulfuric acid solution on USY zeolite was studied. The molecular sieve products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), N2 adsorption-desorption, temperature programmed desorption of ammonia (NH3-TPD), pyridine adsorption Fourier-transform infrared (Py-IR) spectroscopy, 27Al magic angle spinning nuclear magnetic resonance (27Al MAS NMR) spectroscopy, and other necessary analysis methods. The results showed that the obtained H-USY sample maintained a high level of relative crystallinity, while the external specific surface area and mesoporous volume reached 187 m2/g and 0.20 cm3/g, which increased by 175% and 150% compared to the reference parent USY sample, which was very beneficial for slowing down the deactivation rate of macromolecular catalytic reactions. At the same time, acid treatment could regulate the distribution of active acid centers and aluminum atom coordination of the zeolite surface, which could effectively reduce strong acid centers while promoting much more abundant medium-strong acid centers, the Bronsted/Lewis distribution was also more reasonable, which helps to suppress the generation of heavy components. In the catalytic reformates deolefinization reaction, the catalytic performance of CH-USY catalyst on the removal of trace olefins in aromatic hydrocarbons was significantly superior than that of the reference CUSY catalyst. Under the conditions of feed space velocity of 6 h-1 and reaction pressure of 2.2 MPa, the CH-USY catalyst maintained almost 90% deolefinization activity after 80 h reaction, and due to the optimization of mass transfer pore structure and acid properties, the CH-USY catalyst exhibited excellent olefin removal performance, light product (middle distillate oil) selectivity, and synergistic catalytic effect under the high temperature (220 ℃) conditions.
WANG Yuemei,LI Wei,TONG Weiyi et al. Acid Treatment of USY Zeolite and Its Effect on Catalytic Performance in Deolefinization[J]. Chemical Reaction Engineering and Technology, 2023, 39(4): 319-326.
