The problem of separation between epichlorohydrin and water
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During the production of epoxy resins, alkali is added to the reaction vessel using vacuum azeotropic dehydration. The azeotic water and epichlorohydrin are separated in a phase separator: the chlorohydrin in the lower layer returns to the vessel, while the water in the upper layer goes into the wastewater tank. Our phase separator is equipped with cooling coils that are kept active with chilled water; however, the chlorohydrin in the lower layer remains cloudy and contains a high amount of water. Yet after turning off the chilled water for half an hour, the chlorohydrin in the lower layer becomes clear. What is causing this? I would be grateful for any advice from those who have experience with epoxy resin!
Epichlorohydrin is slightly soluble in water and miscible with alcohols, ethers, carbon tetrachloride, and benzene. At 20°C, the solubility of epichlorohydrin in water is 6.58% (by mass), while the solubility of water in epichlorohydrin is 1.47% (by mass). This product can form an azeotrope with water, with a boiling point of 88°C and 28% water content. You can try by controlling the temperature of the chilled water, and adjust it through trial and error.
I’ve done some research recently and have come up with some ideas of my own: epichlorohydrin belongs to the class of cyclic ethers, and its oxygen atoms can form hydrogen bonds with water. Could extremely low temperatures, that is, when the chilled water is used, accelerate the formation of these hydrogen bonds, resulting in an increase in the amount of water dissolved in the chloropropene layer below the phase separator and thus causing turbidity?
That makes sense. Is there a table showing the solubility of epichlorohydrin in water at different temperatures? Which sage has it?