What is the purpose of the compressed air pipeline at the converter inlet?
Thread Content
The coal-to-methanol plant uses partial shift process and Co-Mo-based wide-range shift catalysts; electric heaters are employed for temperature elevation during sulfidation, with CS2 as the sulfiding agent. The current issue is that there is a compressed air pipeline connected to both the shift reactor and the electric heater – what is the purpose of this pipeline?
It was designed by the design institute for the passivation of sulfur-resistant shift catalysts. In fact, sulfur-resistant shift catalysts based on cobalt and molybdenum do not require passivation when being replaced; it is sufficient to cool them with nitrogen to below 40 degrees Celsius, and once the concentration of CO+H2 is less than 0.5%, the catalyst can be removed. This is due to the lack of professionalism of the design institute in this area. Friend, you haven’t worked in sulfur-resistant shift operations, have you? Trust me – it’s right!
Compressed air should be used to treat the catalyst while it is still fresh; by introducing air, impurities such as tar adhering to the surface of the catalyst are burned off.
No way, how would the gas system dare to allow air in?
We have connected a DN20 compressed air pipe at the inlet of the converter; it is used for catalyst passivation, but it hasn’t been put into use yet. As for cooling with nitrogen, I’ve never heard of it!
Reply to 4# sxtblo: What is mentioned on the 3rd floor refers to \"burning carbon\"; when there is severe carbon buildup in the converter, it is necessary to burn carbon by introducing air
Reply to 2# 654262293: I’d like to ask the moderator who handles this topic – will this sulfided cobalt-molybdenum catalyst undergo rapid oxidation when exposed to air at temperatures below 40 degrees? Haven’t tried it, want to know too? ?
Flammability hazards: Not flammable; toxic fumes containing cobalt compounds and sulfur oxides are produced in case of a fire. Storage and transportation requirements: The storage area should be well-ventilated, cool, and dry. Based on the above information, it is possible to determine whether the statement on the second floor is correct or not.
The last edit to this post was made by 654262293 on 2010-9-6 at 11:04. Reply to 7# Kuju Kaisshi: Generally, the catalyst’s activity is already very low by the time it needs to be replaced. Of course, there are some catalysts that still retain a certain level of activity; they can catch fire when exposed to oxygen, but this issue can be resolved by pouring water on them, and no problems will arise. We have been using cobalt-molybdenum-based sulfur-resistant shift catalysts since 1995; that’s what we’ve always done, and there have been no problems.
Compressed air is used at the inlet of the converter for passivation; the catalyst that has been removed contains sulfur, and it will react naturally when exposed to air. There is also a compressed air pipeline connected to the regeneration steam of the converter, which is used for catalyst regeneration and coking.
We have some too; we haven’t used them. The design indicates they are for passivation or carbonization!