What are the effects of incomplete passivation of the methanol catalyst?
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What are the effects of incomplete passivation of the methanol catalyst? Recently, methanol catalyst passivation work was carried out at a company in Jiangsu, with a time limit of 36 hours. During time passivation, the oxygen concentration reached up to 6%; a planned water and power cut forced an end to the passivation process. For safety reasons, the catalyst is unloaded under nitrogen protection. No abnormal phenomena occurred throughout the process; however, the unloaded catalyst caught fire on its own.
Since the catalyst needs to be removed, it means it is no longer useful. Inadequate passivation can cause the unloaded catalyst to oxidize, leading to a fire; this can be suppressed by using water immediately after unloading, and flammable materials in the vicinity should be removed.
With nitrogen supply ensured and a professional catalyst removal team available, passivation is not necessary!
It depends on the catalyst you are using; with some catalysts, no matter how thoroughly they are deactivated, they will still catch fire on contact with air once removed. Such as iron molybdenum
What is the purpose of catalyst deactivation? Passivation is intended to ensure the safety of the synthesis tower during catalyst removal, preventing overheating that could damage the components inside the tower.
Based on what you’ve said, the catalyst has not been completely deactivated. Even when passivation is complete, natural phenomena can still occur; it is necessary to identify any flammable materials in the vicinity and use fire-fighting water to cool down and suppress dust. A dedicated person is responsible for observation and reporting
It’s not that exaggerated either; it’s fine to unload directly in a nitrogen environment. After unloading, just take it to an open area where it can self-ignite and undergo passivation, which also saves time on replacing the catalyst.
As long as there are no problems during unloading, even if they are piled up together after being thoroughly passivated, they will still heat up and catch fire; just take them out, spread them out in a spacious area, water them, and they will be fine after a few days
What are the impacts? If spontaneous combustion occurs, then it will happen; as long as it can be controlled, that’s enough. When the catalyst is unloaded, it is placed directly into a barrel, where dry ice is used for protection, and it is then transported away for processing promptly. There’s no problem.
If it is not properly passivated, oxidation releases a large amount of heat; this heat must be prevented from causing caking inside the synthesis tower and blocking the tubes. After being discharged, heat is released leading to spontaneous combustion, so a large amount of water is sprayed to lower the temperature! ! !