Deactivation and Regeneration of Catalyst from Toluene and Methanol to Xylene
State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Shanghai Research Institute of Petrochemical Technology, SINOPEC, Shanghai 201208, China
Abstract：In view of the rapid deactivation problem of catalyst for methylation of toluene with methanol, the methylation reaction was investigated in detail over ZSM-5 zeolite, and the deactivated catalyst and deposited carbon species were characterized by using X-ray diffraction (XRD), N2 adsorption-desorption, Fourier infrared spectroscopy (FT-IR) and pyridine absorption infrared spectroscopy (Py-IR). The results showed that the catalyst experienced a stable period and a rapid deactivation in the fixed-bed reactor, and the selectivity of xylene kept rising with toluene disproportionation reaction being inhibited. The deposited carbon species on the deactivated catalyst were mainly composed with carbonyl and hydroxyl compounds, alkylaromatic, polycyclic aromatic hydrocarbons. Carbon deposition could block the pore channels of ZSM-5 zeolite and cover its surface acid sites, and the blockage of the active site was the mainly reason for the catalyst deactivation. Furthermore, a simple regeneration method was proposed by a temperature programmed coke burning-off, and the structure and performance of the catalyst could be recovered efficiently.
LI Huaying,DONG Qian,SHI Zhangping et al. Deactivation and Regeneration of Catalyst from Toluene and Methanol to Xylene[J]. 化学反应工程与工艺, 2019, 35(5): 402-409.
