| 摘要 |
PROBLEM TO BE SOLVED: To produceε-caprolactam (abbreviated as CL) of high purity efficiently by subjecting crudeε-CL to extraction purification with a specific solvent mixture. SOLUTION: Thisε-CL of high purity is obtained by mixing crude CL, which is obtained by catalytic rearrangement of cyclohexanone oxime and contains octahydrophenazine, etc., as by-products in the purification process, with a hydrocarbon-based solvent, preferably cyclohexane, etc., and polyhydric alcohol, preferably butane triol, glycerol or the like, separating the polyhydric alcohol layer, and recovering the CL from the polyhydric alcohol layer by distillation, crystallization, etc., thus removing impurities, such as octahydrophenazine. For the purification, the hydrocarbon-based solvent is used in a quantity of 2-40 pts.wt., preferably 5-20 pts.wt., to 1 pts.wt. of the crude CL, and the polyhydric alcohol is used in a quantity of 0.1-30 pts.wt., preferably 0.5-10 pts.wt., to 1 pts.wt. of the crude CL.
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