Glycol

In the industrial preparation of ethylene glycol, ethylene (IUPAC name: ethene) is oxidized to ethylene oxide (IUPAC name: oxirane) using oxygen and a silver catalyst. Ethylene oxide is then reacted with water at high temperature or in the presence of an acid catalyst to produce ethylene glycol. Diethylene glycol is a useful by-product of this process (Figure 3).

Alternative methods of preparing ethylene glycol that avoid the use of toxic ethylene oxide are currently being investigated.