Electrodesalination of crude oil with high acid value
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I once read a passage in a book that said more or less the following: When the level of naphthenic acid in crude oil is high, and if the electrodialysis system is alkaline, emulsification easily occurs during the desalination process, as naphthenate salts are strong surfactants (while naphthenic acid is less effective as a surfactant). This makes it difficult to separate oil from water, and both the water containing oil after desalination and the oil-containing wastewater fail to meet the specified standards. Therefore, it is recommended that the pH value of the electrodialysis system be maintained around 5.5 – this is presumably the pH value at which water separation occurs. Now I’ve gone through the books I’ve read several times, but I still can’t find that passage. . . . . {:3_54:} Do you know any experts, masters, or friends who are familiar with this area? 1. Do you know which book this passage is from? (OCD; can’t find the source of discomfort.) 2: Will crude oil with a high acid value exhibit more pronounced difficulties in separating oil from water? 3. Generally, electrodesalination is carried out under weakly alkaline conditions; then, when the acid value is high, is it better to maintain the pH at around 5.5 for better demulsification effects?
This post was last edited by ai444099439 on 2019-6-25 11:25. 1. Do you know which book this passage is from? (OCD; it’s hard to find information on this.) It’s probably not easy to locate such information, but one could look through relevant research papers. However, I think there’s a problem with a pH of 5.5, as such a low pH can cause severe corrosion of the equipment. 2. Will crude oil with a high acid value experience more difficulties in separating oil from water? The principle is correct; in other words, it’s due to factors such as their surface activity that desalination and dehydration become difficult. However, there are many factors that influence this process – if the acid value changes, other properties of the oil also change significantly, making it hard to determine exactly what causes these issues. 3. Generally, electrodesalination is carried out under weakly alkaline conditions. So, when the acid value is high, would maintaining a pH level of around 5.5 yield better demulsification results? How do I do this? It is theoretically feasible, but how can the pH value of the electrodialysis tank be reduced forcibly? Can’t inject more acid, right? The pH of crude oil certainly cannot drop to such a low level, which results in very poor operability in actual processing
This post was last edited by qhhqhh on 2019-6-25 at 14:20. Thank you. So, if dealing with crude oil with a high acid value, do you know what adjustments and measures would be taken? I also saw in an old post on a forum where some friends mentioned that their electrodialysis pH level was between 5.5 and 6.5.
What technology do they use? What methods are used to maintain such a low pH value in electrodialysis? I don’t know much about this area; could you give me some information? High acid number crude oil has not been processed, but we have dealt with heavy crude oil – oil with a density of around 0.95–0.96. It is difficult to treat such oil using conventional electrodesalination; instead, high-efficiency electrodesalination methods were used (you can look up more information on this topic)
Do you mean the pH of the water being added, or the pH in the electrodialysis tank? The most practical solution lies in using injectables; demulsifiers and degreasing agents are also available.
It’s an old post; it only mentions the PH range. I’ll check later to see if I can find it; please leave a message for advice. For oils with high density, one approach seems to be to circulate atmospheric-pressure diesel and mix it with crude oil before subjecting it to electrical desalting, in order to increase the density difference.
PH usually refers to water, right? It doesn’t hydrolyze in oil either