Does steam react with ethylene glycol? Reasons for coking in steam measurements
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Using ethylene glycol as a separating fluid for steam measurement can lead to occasional coking and blockages; some systems remain functional for decades, while others fail after just one or two years. Upon disassembly, it is found that the coking is extremely hard and cannot even be broken apart. What is the underlying reaction mechanism, and is it possible to avoid this issue?
Damn, waiting for an expert. By the way, in the most extreme cases, after how many times of using ethylene glycol does it get clogged? Has anyone experienced this?
Is it really that black kind of char? Are there any pictures?
Is the steam pure? For example, the dilution steam used in our pyrolysis furnaces contains sulfur injection agents; over time, emulsification occurs followed by coking, and eventually hard masses similar to amber are formed, which are very difficult to remove... Generally, ethylene glycol serves as a separator fluid quite well.
The steam should be pure; there have also been issues with the liquid level in some steam drums. Recently I read on Baidu that ethylene glycol can carbonize at high temperatures; I’m not sure if this is true
Is it necessary to use an isolation tank for steam? Just use a condensation tank to add water, or even add nothing and let it condense on its own. It shouldn’t happen either; it seems like the isolation fluid is reacting with the steam. This causes it to turn black.
It’s not necessary to use a condensation tank; most installations on site have been converted to top-mounted systems. However, as maintenance personnel, having ethylene glycol makes maintenance easier. In terms of the incidence of coking, this is conditional; it’s just a matter of finding ways to reduce the difficulty of maintenance
I’ve seen that in oil refining plants, the instrument isolation tanks also use ethylene glycol as the isolation fluid. The temperature of the medium being measured is already quite high, and steam coils are used for heating; as a result, these instruments remain stable during long-term operation. Logically, coking shouldn’t occur, but could it be due to a different ratio of ethylene glycol?
Using ethylene glycol as a separator isn’t very appropriate; ethylene glycol dissolves in water, and over time it becomes impossible to determine what percentage of the solution is actually ethylene glycol water. As a result, the density cannot be determined. If pressure measurement is involved, the error is not significant. However, with orifice plates, this can lead to errors. Why not use silicone oil instead? What is the steam temperature? High temperature can lead to coking.