The problem of excessive oil stains on liquefied petroleum gas
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Liquefied gas oil stain inspection, as an indicator of liquefied gas, is required by the liquefied gas standard "GB 11174-1997 Liquefied Petroleum Gas". Under normal circumstances, there is no problem with this indicator, but in some cases, the oil stain inspection "fails" occurs. Let's discuss what factors can cause this phenomenon, especially when the residue content is qualified? Recently, I read on the Internet that Dushanzi Petrochemical’s explanation of the problem they encountered was attributed to “After analyzing the oil stains of the liquefied gas, the research team determined that the oil stains were excessive due to the processing of sulfur-containing crude oil, and chose to use adsorption methods to remove the oil stains from the liquefied gas. ”Original link: http://www.dsz.gov.cn/show.aspx?id=8769 Who is familiar with this situation, because it is generally believed that the cause of oil stains is due to some heavy hydrocarbons entering the liquefied gas component. Is it related to the processing of "sulfur-containing crude oil"? In addition, what is the process of "adsorption method"? Thanks!
Dear refinery friends, especially those engaged in liquefied gas refining, please share your views. Participants will receive wealth rewards! :lol
How is the liquefied gas oil stain inspection performed? Can you first introduce it?
As described in the SY/T7509 method, drop 0.3 mL of the solvent residue mixture onto the filter paper in 0.1 mL increments each time. Observe under sunlight after 2 minutes. If there is no persistent oil ring, it is passed. For more details, please refer to GB11174-97 and SY/T 7509.
Dear refinery friends, if your actual central control does not control this indicator, if a problem occurs, how do you adjust it?
Reduce the temperature at the bottom of the tower and increase the pressure at the top of the tower. Is this kind of operation possible?
This post was last edited by lean1986 on 2014-12-22 22:31. Increase the frequency of water changes and alkali changes. The oil stains often appeared unqualified where our plant's No. 2 liquefied gas desulfurization unit was put into use. Later, after forcing the workshop to change the water and alkali, the situation improved significantly, and the oil stains no longer appeared unqualified. Personally, I think the situation may be more obvious in the fiber membrane extraction process. Because of the high concentration of alkali solution, the concentration of colored reactants such as disulfide produced is also relatively high, which can easily form back-extraction with liquefied gas, resulting in unqualified oil stains. It may also be caused by the upstream device. Consider whether the device pipeline has been alkali washed, etc. The liquefied state of liquefied gas is similar to oil. Think about it, this situation will also occur if the system is not clean and can be miscible with liquefied gas. The reasons are multifaceted and the solution depends on the situation.