Ethylene Glycol Production Process

1. Chloroethanol method
Chloroethanol is hydrolyzed in an alkaline medium as a raw material. The reaction is carried out at 100°C.
2. Ethylene oxide hydration method
Ethylene oxide hydration method includes direct hydration method and catalytic hydration method. The hydration process can be carried out under normal pressure or under pressure. Normal pressure hydration method generally uses a small amount of inorganic acid as a catalyst and reacts at 50-70°C. Ethylene oxide direct hydration method is a relatively mature production method for industrial-scale production of ethylene glycol. Ethylene oxide and water are directly liquid-phase hydrated in a tubular reactor under pressure (2.23MPa) and 190-200°C to produce ethylene glycol, while diethylene glycol, triethylene glycol and polyethylene glycol are produced as byproducts.
① Direct hydration method;
② Catalytic hydration method;
③ Pressurized hydration method: The molar ratio of ethylene oxide to water should be higher, above 1:6, to reduce the side reaction of ether formation. The reaction temperature is 150℃ and the pressure is 147kPa. Hydration to obtain ethylene glycol.
3. Gas phase catalytic hydration method: silver oxide is used as a catalyst and aluminum oxide is used as a carrier. The reaction is carried out at 150-240℃ to produce ethylene glycol.
4. Ethylene direct hydration method: ethylene is oxidized in acetic acid solution in the presence of a catalyst (such as antimony oxide TeO2, palladium catalyst) to produce monoacetate or diacetate, and further hydrolysis to obtain ethylene glycol.
5. Ethylene oxide and water are hydrated under the action of sulfuric acid catalyst, and the reaction liquid is neutralized with alkali, evaporated, and distilled to obtain the finished product. Or ethylene oxide and water are used to produce ethylene glycol at a certain temperature and pressure, and diethylene glycol, triethylene glycol and polyethylene glycol are produced as by-products. The reaction liquid is evaporated, concentrated, dehydrated and refined to obtain qualified products and by-products.
6. Formaldehyde method;
7. Take industrial ethylene glycol as raw material, distill under reduced pressure, and collect the intermediate fraction at 1333Pa.
8. Vacuum distill ethylene glycol, dry the main fraction with anhydrous sodium sulfate for a long time, and then re-vacuum distill with a good fractionating column.