METHOD OF EXTRACTION OF THE UNREACTED XYLENE FROM THE ACETIC ACID AT PRODUCTION OF THE TEREPHTHALIC OR ISOPHTHALIC ACID (VERSIONS) Russian patent published in 2007 - IPC C07C51/265 C07C51/46 C07C53/08 

FIELD: chemical industry; petrochemical industry; methods of extraction of the unreacted xylene from the acetic acid at production of the terephthalic or isophthalic acid.

SUBSTANCE: the invention is pertaining to the field of production of the terephthalic or isophthalic acid by oxidation of the corresponding alkyl benzene, in particular, to the stage of separation of the reaction mixture including the acetic acid in the capacity of the dissolvent. The method is intended for extraction of the unreacted para-xylene or meta-xylene at the regeneration of the acetic acid using isobutyl acetate as the azeotropic agent for dehydration of the acetic acid. From the azeotropic distillation column at the temperature of 94-100°С separate the fraction containing the para-xylene or meta-xylene, which is fed into the run-down tank, where separate the aqueous phase from the organic phase. In the azeotropic section of the azeotropic distillation column determine the ratio of the para-xylene or meta-xylene and the isobutyl acetate in the stored fraction of the organic phase and periodically remove the accumulated part of the organic phase until the mass ratio of the concentrations of the para-xylene or meta-xylene and the azeotropic agent attains the interval from 0.5 up to 6. As the version of realization of the method route the circulation of the part of the accumulated fraction of the organic phase from the run-down tank to the azeotropic column. The technical result of the invention is upgrade of the production process of regeneration of the acetic acid and the unreacted alkylbenzene using the phase of the azeotropic distillation of xylenes from the acetic acid.

EFFECT: the invention ensures the upgrade of the production process of regeneration of the acetic acid and the unreacted alkylbenzene using the phase of the azeotropic distillation of xylenes from the acetic acid.

8 cl, 4 tbl, 5 dwg