Regeneration method for catalyst used for methylation of toluene

[0034] [Example 1]

[0035] The deactivated JSM-03 catalyst was used for the regeneration test. The JSM-03 catalyst includes the following components in weight percentage: 69.27% ​​hydrogen type ZSM-5 molecular sieve with a silicon to aluminum ratio of 280, 30.68% Al 2 O 3 , 0.05% La 2 O 3.

[0036] The regeneration process is: stop feeding methylating reagents and toluene raw materials, and circulate hydrogen for 5 hours under the conditions of constant reaction temperature and pressure; gradually unload the system pressure to normal pressure and drop the temperature below 100°C; stop introducing hydrogen , Disconnect the liquid-phase feed system and product separation system to isolate the reactor system from the liquid-phase feed system and product separation system; replace the reaction system with nitrogen, and purge the system with nitrogen to make the total hydrogen and hydrocarbons in the system The concentration is less than 0.2% by volume; at the same time, raise the temperature of the reactor so that the catalyst bed temperature is 300°C, and adjust the system pressure to 0.3MPa; pass in air and observe the temperature rise of the catalyst bed. Once there is a temperature rise, immediately reduce the amount of injected air And reduce the temperature of the reaction system, wait for the temperature to stabilize, and then slowly pass in air, control the maximum bed temperature not to exceed 480℃, and the oxygen content in the system not to exceed 0.5% by volume; make the catalyst bed temperature constant at 480℃, increase air injection The oxygen content in the system reaches 0.5% by volume. After maintaining for 2 hours, the air is stopped, the system is gradually unloaded to normal pressure, the temperature drops to room temperature, and the regeneration process is ended.

[0037]

[0038] [Example 2]

[0039] The deactivated JSM-03 catalyst was used for the regeneration test.

[0040] The regeneration process is: stop feeding methylating reagents and toluene raw materials, and circulate water vapor for 3 hours under the conditions of constant reaction temperature and pressure; gradually unload the system pressure to normal pressure, and the temperature drops below 100°C; stop introducing water Steam shuts off the liquid-phase feed system and product separation system to isolate the reactor system from the liquid-phase feed system and product separation system; replace the reaction system with nitrogen and purge the system with nitrogen to make the hydrogen and hydrocarbons in the system separate The total concentration is less than 0.2% by volume; at the same time, raise the temperature of the reactor so that the temperature of the catalyst bed is 100℃, and adjust the system pressure to 1.0MPa; let in air and observe the temperature rise of the catalyst bed, once there is a temperature rise, immediately reduce the injected air The temperature of the reaction system is reduced, and the air is slowly introduced after the temperature is stable. The maximum temperature of the bed does not exceed 510℃, and the oxygen content in the system does not exceed 0.2% by volume; the temperature of the catalyst bed is kept constant at 510℃, and the air is increased The amount of injection is such that the oxygen content in the system reaches 0.45% by volume. After maintaining for 4 hours, the air is stopped, the system is gradually unloaded to normal pressure, and the temperature is lowered to room temperature to end the regeneration process.

[0041]

[0042] [Example 3]

[0043] The deactivated JSM-03 catalyst was used for the regeneration test.

[0044] The regeneration process is as follows: stop feeding methylating reagent and toluene raw materials, and circulate nitrogen for 2 hours under the condition of constant reaction temperature and pressure; gradually unload the system pressure to normal pressure, and drop the temperature below 100°C; stop introducing nitrogen , Disconnect the liquid-phase feed system and product separation system to isolate the reactor system from the liquid-phase feed system and product separation system; replace the reaction system with nitrogen, and purge the system with nitrogen to make the total hydrogen and hydrocarbons in the system The concentration is less than 0.2% by volume; at the same time, raise the temperature of the reactor to make the catalyst bed temperature 250℃, and adjust the system pressure to 0.6MPa; let air in, observe the temperature rise of the catalyst bed, once there is a temperature rise, immediately reduce the amount of air injected And lower the temperature of the reaction system, wait for the temperature to stabilize, and then slowly pass in air, control the maximum bed temperature not to exceed 490℃, and the oxygen content in the system not to exceed 0.1% by volume; make the catalyst bed temperature constant at 490℃, increase air injection The oxygen content in the system reaches 0.55% by volume. After maintaining for 1 hour, the air is stopped, the system is gradually unloaded to normal pressure, the temperature drops to room temperature, and the regeneration process is ended.

[0045]