Foaming problem in the cyclic hydrogen desulfurization tower of gasoline hydrogenation units
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In our facility, the cyclic hydrogen desulfurization tower of the gasoline hydrogenation unit suffers from severe foaming – this occurs 3 to 6 times per day. Each time foaming takes place, we activate the bypass line of the cyclic hydrogen desulfurization tower, which helps to reduce the foaming. We then proceed with amine regeneration and the use of antifoam agents, which temporarily resolves the problem; however, foaming reoccurs after a short while. At present, there is no effective solution to this issue. I would like to ask those who have experience with similar problems: how did you resolve them?
Ask the foam suppressant manufacturer; also check if there have been any changes in the past. It seems that this is caused by insufficient foam-suppressing performance of the foam suppressant
Has the concentration of the solution changed? Has it been tested?
Enhance the liquid cutting at the inlet liquid separation tank of the desulfurization tower to ensure that the temperature of the lean amine solution is at least 5°C higher than that of the circulating hydrogen.
It’s possible that the temperature you are controlling is a bit too low. An excessively low temperature can cause some of the hydrocarbons in the feed gas to condense inside the tower, which in turn leads to foaming of the MDEA and affects its absorption efficiency. The temperature in the absorption tower should be maintained around 38 degrees, while the temperature of the MDEA should be 4–5 degrees higher than that of the feed gas. To prevent foaming of the solution at the bottom of the tower, its temperature is kept below 50 degrees.