LPG desulfurization
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Desulfurization during liquefied gas purification is an essential step in the processing of liquefied gas. My current problem is that the liquefied gas contains high levels of sulfur, which results in high consumption of alkali solutions. Additionally, the oil obtained through back-extraction has a very high content of dimethyldisulfide; this oil is then fed into the crude gasoline tank. However, gasoline hydrogenation processes cannot handle gasoline with such high levels of dimethyldisulfide. At present, there is no way to dispose of this gasoline； Switching to a lift pipe resulted in high sulfur content in the liquefied gas, and alkali washing could not remove the sulfur. Guys, does anyone have any good tips?
Do you test dimethyldisulfide separately? What is the total sulfur content in the oil after back-extraction? Here it’s around 0.5%
My alternative route is to go to the oil-gas separator at the top of the fractionation tower
We send it directly to the diesel hydrotreating unit for desulfurization
The anti-extraction oil contains 4,000 ppm of sulfur, mainly as dimethyldisulfide.
Just like the original poster mentioned, its scientific name is a fractionator overhead vapor separator, while its common name is a crude gasoline tank: lol
Does the liquefied gas system use the alcohol amine method along with a catalyst-based alkaline desulfurization process? After normal amine washing, the hydrogen sulfide level should be 0. The problem with back-extraction of oil is that gasoline desulfurization is no longer carried out; by going straight to naphtha hydrogenation, it seems possible to convert gasoline into diesel, though the results will be less good compared to using gasoline. My previous unit had a total sulfur content in the liquefied gas of nearly 20,000, but it was still within acceptable limits after purification.
Dimethyldisulfide is generally not used on its own, right? We just need to ensure that the total sulfur content is within the acceptable range