ABSTRACT
Ethylene glycol was first produced commercially by the hydrolysis of ethylene oxide obtained by the chlorination of ethylene via the chlorohydrin route. Direct oxidation of ethylene to ethylene glycol using a silver catalyst was utilized for a period, but operating problems led to its fall from favour. Research on the synthesis of ethylene glycol from carbon monoxide and hydrogen has been undertaken but yields have been low. Ethylene is directly oxidized in the vapour phase with air or oxygen in the presence of a silver oxide catalyst to ethylene oxide. Where ethylene oxide-glycol processes are carried out on the same site, energy is conserved by utilizing the heat generated by the exothermic oxidation reaction to produce steam for the evaporator unit. Ethylene glycol is a stable, non-corrosive liquid. Resin-coated steel, aluminium or stainless steel are used for storage containers to prevent colour change, which is important for products used in polyester manufacture.
