METHOD FOR PURIFICATION OF SOLVENT INTENDED FOR SEPARATION OF STYRENE BY MEANS OF EXTRACTION DISTILLATION AND SEPARATION OF STYRENE Russian patent published in 2022 - IPC C07C15/46 C07C7/08 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for purification of a solvent for separation of styrene by means of extraction distillation. The method includes stages, at which: (1) styrene-containing source material is introduced into extraction distillation column (301) from a middle part, and a solvent for extraction distillation is introduced into the extraction distillation column from an upper part; after extraction distillation, raffinate oil is released from the upper part of the extraction distillation column, and the solvent enriched with styrene is released from a lower part of the column; (2) the enriched solvent described at the stage (1) is introduced into solvent regeneration column (302) from a middle part; after vacuum distillation, unpurified styrene is released from an upper part of the solvent regeneration column, and the depleted solvent is released from a lower part of the solvent regeneration column and returned to the upper part of the extraction distillation column; (3) part of the enriched solvent described at the stage (1) is separated and directed to solvent purification zone (303), into which water is introduced; after liquid-liquid extraction, a mixture of styrene polymer and styrene is released from an upper part of the solvent purification zone, and the purified solvent containing water is released from a lower part of the solvent purification zone, while a purifying agent for the solvent is introduced into the solvent purification zone described at the stage (3), wherein the specified purifying agent for the solvent contains styrene and optional alkyl-aromatic compounds, while the styrene content is at least 98 wt.%. The invention also relates to a method for separation of styrene.

EFFECT: method can effectively remove styrene polymer in a solvent for extraction distillation, simplify stages of treatment of a purifying agent for the solvent, provide operational characteristics of the solvent in extraction distillation, and increase the duration of stable operation of a device.

22 cl, 4 tbl, 3 ex, 3 dwg