Process for the isolation of purified ethylene glycol carbonate (EGC)
AssigneeBayer Aktiengesellschaft
InventorsChristine Mendoza-Frohn, Paul Wagner, Hans-Peter Wirges
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Abstract
Ethylene glycol carbonate (EGC) can be isolated in purified form from contaminated material which contains impurities from the group comprising starting materials, by-products and/or catalysts of the preparation process in that the contaminated EGC is subjected to a fractional melt crystallization and the crystals of the purified EGC formed in this case are mechanically separated off from the remaining impurities dissolved in the residual melt.
Claims7
A process for the isolation of purified ethylene glycol carbonate (EGC) from a contaminated EGC which contains impurities from the group comprising starting materials, by-products and/or catalysts of the preparation process, wherein the contaminated EGC is subjected to a fractional melt crystallization wherein the melt of the EGC to be purified is cooled in range from 38.degree. to 20.degree. C. at a cooling rate of the cooling medium of 40 to 0.1 K/h and is carried out with the aid of a tube-bundle crystallizer, plate heat exchanger or a falling-film crystallizer and the crystals of the purified EGC formed in this case are mechanically separated off from the remaining impurities dissolved in the residual melt.
Dependencies are inferred from the claim text.