The vapor‐phase catalytic hydration of ethylene oxide to glycols

The vapor‐phase reaction between ethylene oxide and water to form glycols has been carried out under a wide range of conditions with particles of polystyrene–sulfonic acid ion exchange resins used as catalysts. The rates observed appeared to be directly proportional to the product of the partial pressure of ethylene oxide and the amount of water sorbed by the resin. By use of the Brunauer, Emmett, and Teller equation to describe the amount of water sorbed by the resin, the experimental data were correlated over a sixty‐fold range of reaction rates with a mean deviation of 15%. To obtain data of value in elucidating reaction mechanisms, the reactor was usually run under “differential” conditions, that is low conversions. However in a few runs conversions of as high as 54% were obtained for a contact time of 0.02 sec. The ratio of ethylene glycol to higher glycols (selectivity) obtained varied between 73 and 99% but was usually above 80% under conditions of high conversion. However it could also be reduced forcibly to produce higher glycols as the major product, if desired.