Separation and Purification of 2,6-dimethylnaphthalene in the Light Cycle Oil(II) - Separation of Individual Isomers of Dimethylnaphthalene -

접촉분해경유에 함유된 2,6-dimethylnaphthalene의 분리, 정제(II) - Dimethylnaphthalene 이성체 성분간 분리 -

  • Kim, Su Jin (Division Chemical Eng., Korea Research Institute of Chemical Technology) ;
  • Kim, Sang Chai (Dept. of Environmental Engineering and Education, Mokpo Nat'l Univ.) ;
  • Kawasaki, Junjiro (Dept. of Chem. Eng., Tokyo Institute of Technology)
  • Received : 1996.03.12
  • Accepted : 1996.08.23
  • Published : 1996.10.10

Abstract

Purification of 2,6-dimethylnaphthalene(2,6-DMNA) from the distillate containing a mixture of dimethylnaphthalene(DMNA) isomers of very high concentration was investigated by crystallization-recrystallization combination as a after-treatment for separation and purification of 2,6-DMNA in the light cycle oil(LCO). The separation of individual isomers of DMNA was studied by crystallization with the distillate as a feed. 2,6-DMNA, 2,7-dimethylnaphthalene(2,7-DMNA) and 2,3-dimethylnaphthalene(2,3-DMNA) were concentrated to crystal, and it was fould that separation between a group of 2,6-, 2,7-, 2,3-DMNA isomers and a group of the other DMNA isomers was possible. However, it was not possible to separate 2,6-, 2,7- and 2,3-DMNA from one another. To select the most suitable recrystallization solvent for purification of 2,6-DMNA, several conventional solvents, which have been employed commercially as recrystallization solvents for high purity performance, were tested, through measurement of solubility of 2,6- and 2,7-DMNA. The solvent used were hexane, iso-propyl ether, ethyl acetate and ethanol. From the solubility results for 2,6- and 2,7-DMNA, ethanol seemed to be the most suitable solvent for purification of 2,6-DMNA. Finally, with crystal recovered by crystallization as a feed and ethanol as a solvent, recrystallization experiments were conducted under various conditions. Purification of 2,6-DMNA was easily done with increasing operating temperature and solvent to feed ratio. These results show that the crystallization-recrystallization combination is an effective one for separation of individual isomers of DMNA.

Keywords

References

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