Corrosion issues in methanol-water separation towers
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The wash water from the exhaust gas washing tower in our plant is sent to the flange of the methanol-water separation tower, where corrosion has occurred and the wall thickness has decreased. Has anyone encountered a similar problem? How was it dealt with? Is it necessary to replace the methanol-water separation tower with one made of stainless steel?
It is necessary to switch to SC. But check whether the H2S content of the medium is within the standard range. Corrosion will occur once it exceeds the specified limit.
Upgrade the materials, and prepare the appropriate materials accordingly based on the medium
Indeed, the problem of corrosion does occur
This issue has occurred in my installation; the reason is that the CO2 removed through the exhaust gas scrubber ends up in the methanol-water separation tower. The temporary solution is to cut out the affected part and weld it back together, while the long-term solution involves adding alkali again
There’s no need to switch to stainless steel! 1. Simply apply stainless steel inside the area where corrosion occurs – Cause of corrosion: The temperature of the recycled wastewater is much lower than the designed value (115°C); corrosive effects due to the alkalinity of the wastewater ； 2. Pay attention to controlling the operating temperature regularly.
Corrosion also occurs in our plant, mainly caused by hydrocyanic acid generated in the gas processing section
Thank you, expert – it’s obvious you’re a true professional. Just to confirm, are you saying that it’s because the temperature of the wastewater flowing to the methanol-water separation tower is lower than the designed value that this issue occurs?
During operation, the temperature of the wastewater flowing to the methanol removal water separation tower was much lower than the designed value of 115°C, resulting in carbonation corrosion.
The temperature of our fluid is actually 130 degrees Celsius; will corrosion be that severe?
If the temperature of this water exceeds 100°C, carbonation corrosion no longer occurs; after all, it contains only carbon dioxide, so there will be no problem with corrosion due to pressure. The key point is that in actual production, there are periods of low temperature for this water; the longer such periods last, the more corrosion accumulates.