- Ethylene oxide hydration method
There are two methods for the hydration of ethylene oxide: direct hydration and catalytic hydration. The hydration process can be carried out under normal pressure or pressure. Atmospheric pressure hydration usually uses a small number of inorganic acids as catalysts and reacts at 50-70 ℃. Direct hydration of ethylene oxide is a more mature production method for ethylene glycol in current industrial planning. Ethylene oxide and water are directly hydrated in the liquid phase under pressure (2.23MPa) and 190-200 ℃ in a tubular reactor to produce ethylene glycol, One byproduct is diethylene glycol, triethylene glycol, and polyethylene glycol
① Direct water method;
② Catalytic hydration method;
③ The molar ratio of ethylene oxide to water in the pressurized water method is higher, above 1:6, to reduce the side reaction of ether formation. The reaction temperature is 150 ℃ and the pressure is 147 kPa. Hydration yields ethylene glycol
- Gas phase catalytic hydration method
Using silver oxide as a catalyst and alumina as a carrier, ethylene glycol is generated by reaction at 150~240 ℃
- Ethylene direct hydration method
Ethylene is oxidized in acetic acid solution in the presence of catalysts such as antimony oxide TeO2 and palladium to form monoacetate or diacetate, which is further hydrolyzed to obtain ethylene glycol
- Effect of ethylene oxide and water on sulfuric acid catalyst
Ethylene oxide and water undergo hydration reaction under the effect of sulfuric acid catalyst, and the reaction liquid is neutralized by alkali, evaporated, and distilled to obtain the product. Perhaps ethylene glycol is produced from ethylene oxide and water at a certain temperature and pressure, and together they produce diethylene glycol, triethylene glycol, and polyethylene glycol. The reaction liquid is concentrated, dehydrated, and refined by evaporation to obtain qualified products and by-products