Patent ID: 7605296

Claim:
A method for separating and purifying 2,6-dimethylnaphthalene, comprising the steps of: 1) performing melt crystallization to produce 2,6-dimethylnaphthalene crystals using a column melt crystallization process of adding a mixture of dimethylnaphthalene (DMN) isomers containing 2,6-dimethylnaphthalene to a column crystallization apparatus, melting the mixture in the apparatus, and then cooling a molten liquid of the mixture; 2) forming 2,6-dimethylnaphthalene crystal layers by separating the 2,6-dimethylnaphthalene crystals produced in Step 1) from the mother liquor by vacuum suction filtration; 3) performing a sweating operation of partially melting the impurities contained on the surfaces of the 2,6-dimethylnaphthalene crystal layers formed in Step 2) and between the 2,6-dimethylnaphthalene crystal layers, while suction filtering the impurities; and 4) melting the 2,6-dimethylnaphthalene crystals after the sweating operation, and separating and recovering 2,6-dimethylnaphthalene.