METHOD FOR SEPARATION OF AROMATIC HYDROCARBONS, USING EXTRACTION DISTILLATION Russian patent published in 2022 - IPC C07C7/08 C07C7/04 C07C15/00 C07C15/04 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for separation of aromatic hydrocarbons by means of extraction distillation. The method includes following stages: (1) introduction of a hydrocarbon mixture containing aromatic hydrocarbons into a middle part of extraction distillation column (8); introduction of an extraction solvent into an upper part of the extraction distillation column. After extraction distillation, the purified product containing benzene is released from the upper part of the column, wherein a benzene content is from 3 to 40 wt.%; and an enriched solvent having a high content of aromatic hydrocarbons is obtained in a lower part of the column. (2) The purified product released from the upper part of the extraction distillation column is directed to the lower part of extraction column (10). The extraction solvent is introduced into the upper part of the extraction column; after liquid-liquid extraction, the purified liquid product not containing aromatic hydrocarbons is released from the upper part of the extraction column; the enriched solvent containing benzene is released from the lower part of the column and introduced into the extraction distillation column between upper and middle parts at a point, which is between positions, in which the extraction solvent and initial material are introduced. The enriched solvent containing benzene is introduced into theoretical plates with numbers from 2 to 9, located upstream relatively to a position, in which the extraction solvent is introduced into the extraction distillation column. (3) The enriched solvent obtained from the lower part of the extraction distillation column is directed to a middle part of solvent regeneration column (17). After vacuum distillation, aromatic hydrocarbons are released from an upper part of the solvent regeneration column, and a depleted solvent is released from a lower part of the solvent regeneration chamber.

EFFECT: method allows for provision of separation of aromatic hydrocarbons with high purity, high extraction coefficient, and significant reduction in energy consumption during extraction and separation.

14 cl, 1 dwg, 3 tbl, 3 ex