How to Remove Xylene From Methanol

A few things, how is the xylene accumulating in your recovery system?....

Do not know what volume you have on your through put, but it sounds like further refining through distillation is required

You need a chemical process engineer to evaluate and tweak your process....

https://books.google.com/books?

Please advise the forum how far each operational parameter is outside its "as commissioned" record.

Please give further info.

Especially as to how xylene, a low polarity solvent that has no potential to disassociate to form a conventional acid or sites to act as a Lewis acid, can increase acidity. Or is your reaction oxidizing the Xylene and then reacting with your hydroxide?

Do you mean BDO Butanediol? A butane molecule with an -OH on each end?

What type of Methanol recovery system are you using? process? chemicals? temps? etc.

What is the acceptable level of Xylene? Not acidity but per cent, molarity or normality.

What quantities are you talking about?

Are there any other contaminates? Are there any waste or unwanted catalysts present in the mix?

Is the process such that you could drain or decant the high concentration mix off at a particular point? This might then be able to be reprocessed or recycled when the levels are lower than the highest acceptable spec?

Good Luck, Old Salt

As mentioned above, xylenes can't affect acidity directly. You might want to verify that it's actually xylenes that are causing this problem.

If you are absolutely certain that there is xylene contamination, where are they coming from? If they are used in the upstream processes, you need to determine what changed to suddenly allow them to migrate downstream into the methanol recovery process.

Methanol has a much higher vapor pressure than all three xylenes at any temperature. (Or a much lower boiling point at any pressure, if that's easier to visualize). It wouldn't require much of a distillation column to perform this separation. Of course, that would be reacting to a symptom... It's generally preferable to find and fix the cause of the contamination.

A few more details would be helpful.