Share: Why is it necessary to purge the synthesis tower after depressurizing it during a short-term shutdown of the methanol synthesis system?
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(1) During short-term shutdowns, a small amount of carbon monoxide and methanol remains in the system after the synthesis tower is depressurized. When equipment is under maintenance, this carbon monoxide and methanol can enter the air, and when inhaled by maintenance personnel it can be harmful to their health; therefore, nitrogen must be used to purge the system after the synthesis tower is depressurized； (2) Carbon monoxide in the gas causes carbonyl corrosion to the equipment pipes ； (3) After the synthesis tower is shut down and depressurized, to prevent air from entering the system and oxidizing the catalyst, the system must be purged with nitrogen, maintaining a slight positive pressure to ensure the safety of the catalyst.
Also, when driving, nitrogen should be in the system in order to raise the temperature and prepare for air intake.
The gas synthesized by feeding ammonia at the compressor outlet can also be heated
After the synthesis tower is purged with nitrogen, a large amount of nitrogen remains inside the tower, which can still be harmful to the workers. What should be done before carrying out maintenance?
If maintenance is to be carried out inside the synthesis tower, it is necessary to deactivate the catalyst using instrument air; work can only proceed after the oxygen content and combustible gas levels are found to be within acceptable limits
If you’re not worried about the catalyst being damaged, there’s no need for replacement; it’s better to replace it