FIELD: chemistry.
SUBSTANCE: invention relates to methods of producing aromatic carboxylic acids. The method involves the following, for example: bringing material which contains at least one substituted aromatic hydrocarbon, in which the substitutes can be oxidised to carboxyl groups, with oxygen gas in a liquid-phase oxidation reaction mixture which contains monocarboxylic acid as a solvent and water, in the presence of a catalyst composition meant for oxidising the substituted aromatic hydrocarbon to an aromatic carboxylic acid, containing at least one heavy metal, in a reaction section at high temperature and pressure sufficient for preservation of the liquid-phase oxidation reaction mixture and formation of an aromatic carboxylic acid and impurities containing by-products of the reaction, dissolved or suspended in the liquid-phase oxidation reaction mixture and a high-pressure vapour phase which contains a solvent - monocarboxylic acid, water and small quantities of the initial aromatic hydrocarbon and by-products of oxidation of the initial aromatic hydrocarbon and the solvent - monocarboxylic acid; moving the high-pressure vapour phase from the reaction section to a separation section in which the solvent - monocarboxylic acid, water and oxidation by-products are separated into at least one first liquid phase rich in the solvent - monocarboxylic acid and at least one second liquid phase rich in water, and at least one second high-pressure vapour phase stripped of the solvent - monocarboxylic acid, which contains water vapour, so that by-products of oxidation of the initial aromatic hydrocarbon are preferably in the first liquid phase and by-products of oxidation of the solvent - monocarboxylic acid are preferably in the second high-pressure vapour phase; and removal from the separation section in separate streams of the first liquid phase which is rich in the solvent - monocarboxylic acid, and the second liquid phase rich in water, which contains less than 5 wt % solvent - monocarboxylic acid and by-products of its oxidation, and the second high-pressure vapour phase which virtually contains less than 2 wt % by-products of oxidation of the initial aromatic hydrocarbon.
EFFECT: invention relates to an apparatus for producing aromatic carboxylic acids.
45 cl, 2 dwg
