Separation of ethylene glycol from water
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The ethylene glycol content is about 80%, the water content is about 19%, and the rest consists of some impurities! Currently, I am using a rotary evaporator with an oil bath to remove water, but tests still show that 6% water remains! May I ask everyone if there’s a way to purify ethylene glycol to 99%? Any advice would be greatly appreciated!
With a rotary evaporator, water and ethylene glycol will form an azeotrope; of course, water will be carried away as well. A distillation tower is needed for this purpose
Thank you for your reply, @ttm_F5z5c. According to the information available online, ethylene glycol and water do not have an azeotrope. With a distillation tower, might the efficiency be a bit low? I have to process 100 liters of mixed material every day!
Ethylene glycol and water do not form an azeotrope. Primarily, a small amount of decomposition (condensation and dehydration) occurs at high temperatures, resulting in the ethylene glycol vapor exiting the tower being contaminated with water. Therefore, a vacuum distillation process is required. Ethylene glycol product is withdrawn as a side stream from the upper part of the column; after condensation, part of the overhead vapor serves as reflux, while the remaining portion is withdrawn as a by-product—water-containing ethylene glycol for antifreeze use.