Roughly 9% diglycol, 1 Yo triglycol, and higher ethylene glycols
are also formed. The total yield is 95 -96%. Purity requirements
vary depending on the application of the glycols; a particularly
high quality is required for the manufacture of polyesters (99.9
wt% purity).
A well-known noncatalytic process developed by Scientific
Design was used in more than 45 plants (1993).
If the proportion of water is lowered in the hydration of ethylene
oxide, di-, tri-, and polyethylene glycols are formed in a stepwise
manner: