Method for replacing catalyst in formaldehyde reactor during productive process of paraform

Abstract

The present invention discloses a method for replacing catalysts in a formaldehyde reactor during the productive process of paraform, which includes steps as follows: 1) scraping all catalysts on the topside out until shiny white electrolytic silver is exposed when the catalyst is replaced for the first time, and the catalyst is dark gray and the catalytic effect of the catalyst declines obviously; 2) laying new electrolytic silver catalysts on the topside, caulking gaps at the edge of the reactor by using the old catalyst, and compacting. According to the method, the formaldehyde conversion in the formaldehyde reactor is in good condition, and the contents of methanoic acid and methyl alcohol are normal, which indicate that the activated energy of the catalyst is at its best, and the effect of replacing one layer of catalysts is very good. According to the replacement of the catalyst at 40-60 meshes at a time, at least one-day workload can be saved, the preparation time for startup is shortened, and the influence to the startup of formaldehyde preparation caused by environmental factors is reduced.

Description

technical field [0001] The invention relates to a method for replacing a catalyst, in particular to a method for replacing a catalyst in a formaldehyde reactor in a polyoxymethylene production process. Background technique [0002] The product formaldehyde of the formaldehyde unit in the polyoxymethylene production process is produced by oxidation of methanol as a raw material and oxygen in the air. The existing process uses the electrolytic silver process to produce high-concentration formaldehyde. [0003] Electrolytic silver method is under the condition of excess methanol, that is, operates at the upper limit of methanol explosion, which is called "methanol excess method". Electrolytic silver can be regenerated and recycled. In recent years, the production process of electrolytic silver method in my country has been continuously improved, so that various technical and economic indicators have reached the international advanced level. Electrolytic silver method products ...

AI Technical Summary

Problems solved by technology

This method of completely renewing the catalyst has the following disadvantages: ① It takes 2 hours of meticulous work to scrape out the old catalyst, and in the process, a small part of the underlying catalyst will leak from the mesh of the copper mesh, causing Catalyst loss; ②After the catalyst is completely taken out, the bottom 40-mesh copper mesh needs to be replaced. The copper mesh needs to be repurchased and subjected to high-temperature quenching before it can be used. The laying of the copper mesh requires more than two people in the reactor for more than 4 hours. The work can only be completed, which consumes a lot of man

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