Can methyl diethanolamine freeze?
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Hello everyone, I would like to ask whether a methyl diethanolamine solution used in coking or catalytic processes can freeze in winter without heating
In normal winters, it does not freeze; the freezing point of pure MDEA is around minus 30 degrees
Sure! The concentration of MDEA that we use is usually a little over 20%. We have several desulfurization towers, and one or two of them are often out of service; at temperatures as low as minus 7 degrees, ice crystals can be seen on the glass surfaces. To this end, when forecasts indicate temperatures dropping below minus 6 degrees, the towers that are not in use have a small amount of amine solution circulated through them.
At what concentration does an MDEA solution stop freezing? Does 30% freeze?
We haven’t considered this issue, as our solvents are recycled. You can take samples and have a laboratory determine their freezing point; that way you’ll know the answer. If the freezing point is high, then we can consider measures to prevent freezing in the pipes
I haven’t thought about it; it probably won’t freeze. We keep cycling.
The ethanolamine concentration is generally set at around 25%, which prevents freezing.