| 摘要 |
PROBLEM TO BE SOLVED: To obtain highly pure monoethylene glycol excellent in quality at an excellent production cost by using a simple operation and apparatus by subjecting a liquid containing the recovered ethylene glycol to heat treatment in the presence of an alkaline material, roughly distilling the resultant liquid, and purifying the distillate. SOLUTION: (A) A liquid comprising recovered ethylene glycol is subjected to heat treatment in the presence of (B) an alkaline material (e.g. potassium hydroxide), preferably one or more kinds of hydroxide and the like of an alkali metal, preferably at 120-200 deg.C for >=1 hr, and the resultant liquid is subjected to rough distillation. The obtained distillate is purified to provide the objective highly pure monoethylene glycol from the component A as a raw material. Preferably, the component A comprises the crude glycol formed at a recovering and purifying step of ethylene oxide when producing ethylene oxide by a catalytic vapor phase oxidation of ethylene. The amount of the used component B is preferably >=0.01 wt.% based on the component A. |
