Heating reduction method of radial synthesis tower catalyst

Abstract

The invention relates to a heating reduction method of a radial synthesis tower catalyst, which combines high-concentration hydrogen reduction and intermittent low-concentration hydrogen reduction. In the initial reduction stage, high-concentration reducing gas is used for reduction, and the hydrogen addition heating rate and the bed temperature are adjusted; in the middle stage of reduction, catalysts in low-airspeed areas at the upper end and the lower end of the radial reaction tower start reduction, the concentration of H2 in gas entering the tower is intermittently adjusted, and the heating rate and the bed temperature are controlled; at the final stage of reduction, along with multiple hydrogen supplement operations, the temperature of the low airspeed zone gradually tends to be consistent with that of the main reaction zone, the reduction reaction is weakened, hydrogen begins to accumulate, the temperature of the bed is increased, the permeability of the hydrogen is increased, the catalyst is subjected to deep reduction until the temperature of the bed is increased to the required temperature, and the heating reduction process is finished at the moment. According to the method, the reduction time of the catalyst is shortened, the highest hot-spot temperature of a catalyst bed layer is reduced, the grain size of active components is reduced, and the performance of the catalyst is improved compared with that of the catalyst reduced by a traditional method.

Description

technical field [0001] The invention belongs to the field of catalyst application, and in particular relates to a method for reducing the temperature of a catalyst in a radial synthesis tower. Background technique [0002] The methanol synthesis reaction is a surface contact reaction, and the structure of the active center of the catalyst used has a great influence on its performance. A suitable active center is conducive to the distribution of the active center on the surface, so that the catalyst has higher activity and longer service life. [0003] At present, the catalysts used in industrial methanol production are basically copper-zinc-aluminum catalysts. Copper-based catalysts are heat-sensitive catalysts. Before leaving the factory, the active components of these catalysts are in the state of metal oxides, and must be reduced before use. CuO and ZnO are reacted to generate Cu-ZnO active centers, and different reduction conditions will generate different Cu-ZnO active...

AI Technical Summary

Problems solved by technology

[0011] There are no less than dozens of sets of radial methanol synthesis reactors in China, mainly including DAVY process, Casali radial process and Japan Toyo process. When these reactors use the traditional heating and reduction method, the space velocity in the main reaction zone is controlled at 2000-4000h -1 , but the airspeed at the upper and lower ends is only 300-600h -1 , so the traditional reduction method is very prone to overheating in the region of low space velocity, that is, the apparent hot spot temperature exceeds 240 ° C, which in turn affects the performance of the catalyst

[0012] At the same time, the traditional reduction reaction method uses pure N 2 As the carrier gas, the concentration of hydrogen is controlled at about 1% during the reduction in the main reaction zone, the reduction speed is slow, and it takes a lot of time

Images