Direct Synthesis of Ethylene Glycol from Carbon Monoxide and Hydrogen by the Use of Cobalt Catalyst

Abstract

The direct synthesis of ethylene glycol from carbon monoxide and hydrogen with a cobalt catalyst is described. The reactions were carried out in toluene varying the pressure from 600 to 1800 kg/cm². The major products observed were ethylene glycol, methyl form ate, methyl alcohol and ethyl alcohol. The yield and selectivity of ethylene glycol increased as the reaction pressure increased. It was found that an increase in the partial pressure of carbon monoxide and hydrogen increased the yield and selectivity of ethylene glycol. The glycol formation at 1800 kg/cm² (H₂/CO=-1) showed maximum at about 250°C. Above 250°C the formation of methyl alcohol and ethyl alcohol increased with the increase of temperature. The selectivity of ethylene glycol increased as the amount of the catalyst increased and show ed a maximum at a catalyst concentration of about 180 mmol/l. At higher catalyst concentrations the selectivity of methyl alcohol increased. The rate of ethylene glycol formation decreased with time. It was found that an accumulation of ethylene glycol in the catalyst system diminished the rate of glycol formation.
Phenol was found to be a good solvent for ethylene glycol formation. The reaction mechanism by which the production of the major products can be explained is discussed.