METHODS, PROCESSES AND SYSTEMS FOR PROCESSING AND PURIFICATION OF RAW TEREPHTHALIC ACID AND PROCESS ASSOCIATED FLOWS Russian patent published in 2014 - IPC C07C51/43 C07C63/26 

FIELD: chemistry.

SUBSTANCE: invention relates to versions of method of para-toluylic and terephthalic acid regeneration. One of versions includes obtaining flow of mother liquor, which has temperature from 140°C to 170°C under pressure from 3.5 bar to 8 bar, with flow of mother liquor representing saturated solution, which includes terephthalic acid and para-toluylic acid in water and contains less than 1 % wt/wt of fine solid particles of terephthalic acid; supply of mother liquor flow into evaporation tank, pressure in which equals atmospheric pressure, and in which from mother liquor flow formed is vapour, discharged from evaporation tank; supply of mother liquor flow into cooling device by first tube, and in the point of mixing, before mother liquor enters cooling device, mother liquor flow is mixed with secondary mother liquor flow at temperature from 40°C to 60°C, which results in formation by mixture of mother liquor flow and secondary mother liquor flow of mother liquor mixture, temperature of which constitutes from 60°C to 80°C after mixing mother liquor flow and secondary mother liquor flow, with part of terephthalic acis and para-toluylic acid being precipitated from mother liquor mixture before supply into cooling device; cooling mother liquor mixture to temperature from 40°C to 60°C in cooling device; output of mother liquor mixture from cooling device towards filter; supply of first portion of mother liquor mixture into filter; and supply of second portion of mother liquor mixture, called secondary mother liquor flow, into circulation tube, with circulation tube intersecting first tube in point of mixing.

EFFECT: providing regeneration of para-toluylic and terephthalic acid.

13 cl, 1 tbl, 4 dwg, 1 ex