Method for continuously maintaining performance of catalyst for cyclohexene production

Abstract

The invention discloses a method for continuously maintaining the performance of a catalyst for cyclohexene production. The method comprises steps: firstly, the feeding amount of a reactor is reduced,a certain amount of a low-activity catalyst is discharged, meanwhile, a corresponding amount of zinc sulfate is added to maintain the concentration of a slurry in the hydrogenation reactor, then a proper amount of a new catalyst is added in batches, the overall activity of the catalyst in the reactor is adjusted, wherein the low-activity catalyst is an old catalyst which operates in the reactor for a long time which is close to the service life. According to the method, two years are taken as a replacement period, the catalyst in the reactor is quantitatively replaced, and the total replacement amount is 30-60Wt% of the total amount of the catalyst in the reactor. According to the method disclosed by the invention, the unit consumption of the new catalyst is reduced, the catalyst adjusting time is shortened, the cost is effectively reduced, and the continuity of a production system is maintained.

Description

technical field [0001] The invention belongs to the field of cyclohexene production, in particular to a method for continuously maintaining the performance of a catalyst for cyclohexene production. Background technique [0002] For catalysts used in traditional hydrogenation reactors, in continuous operation, the activity of the catalyst in the reactor is affected by its strength, the high flow of hydrogen during the reaction, violent collisions, the precipitation of some skeleton metals during the chemical reaction, mechanical transportation after catalyst regeneration, and Partial wear, fragmentation, aging, deactivation and other phenomena will occur under the influence of factors such as grain size change and catalyst poisoning, which will eventually lead to poor catalyst activity in the hydrogenation reactor and a significant reduction in the yield of cyclohexene in the reaction. And it will affect the subsequent separation system and increase the operating cost. [00...

AI Technical Summary

Problems solved by technology

[0007] (1) When the catalyst in the reactor is close to its service life, the reaction activity is obviously deteriorated. Even if the fresh catalyst is added regularly, the effective contact area between the new catalyst and the benzene and hydrogen used for the reaction will be blocked by the old catalyst in the reactor due to the newly added catalyst. As a result, the overall reaction activity of the catalyst in the system is still poor, and the unit consumption of the catalyst increases and the production cost increases;

[0008] (2) Shut down and exit the catalyst for replacement, which affects the stability of the system, and the replacement takes a long time, usually about 10 days, and the new catalyst is highly active and the yield of cyclohexene is unstable;

[0009] (3) Replacing all the old catalysts after shutdown requires a large amount of fresh catalysts, and all the mother liquor in the reactor is discharged, so it cannot continue to be used

Images