Abstract:
Propylene glycol plants are conventionally linked with partially captive
propylene oxide. The hydrolysis takes place in two serially connected
stirred reactors, operated under pressure. The molar ratio of water to
propylene oxide in the feed to the first reactor is 15 to 1. Following the
glycol formation, unreacted propylene oxide and bulk water are removed from
the reaction mixture. The last traces of water are stripped under vacuum by
the glycol drying column. The propylene glycol product is vacuum distilled
overhead and then pumped to offsite storage tanks.