After S removal from the liquefied gas in the gas processing unit, the total sulfur content is within acceptable limits; however, severe corrosion renders it unacceptable
Thread Content
After desulfurization of the liquefied gas in our gas treatment unit, the total sulfur content is within the acceptable range of 10–2; however, the corrosion level is severe, resulting in a grade of 4 that is not acceptable. The concentration of the alkaline solution is also between 15–9, and the wash water is neutral. What’s going on? Is corrosion related to anything else? Thank you
This may be related to the form of sulfur in the feed; although the total sulfur content is low, the presence of some reactive sulfur renders the corrosion unacceptable.
It would be best to conduct a sulfur type analysis of the liquefied gas; some believe that elemental sulfur is also a significant cause of failed corrosion tests. Also, although the concentration of the alkaline solution is 9–15%, the presence of this alkaline solution in the liquefied gas can potentially cause corrosion issues.
Corrosion failure is closely related to hydrogen sulfide. It is recommended to analyze the hydrogen sulfide content.
I think it is caused by elemental sulfur present in the alkaline solution; the extraction alkaline solution should be completely replaced, and then an alkaline wash should be carried out in the amine solution section for hydrogen sulfide removal and deodorization. During the alkaline oxidation regeneration process, Na2S produces elemental sulfur, which is then carried back into the liquid hydrocarbons. Alkali can also cause corrosion, but the copper sheet will develop spots.