FIELD: industrial organic synthesis.
SUBSTANCE: aromatic carboxylic acid is obtained via liquid-phase oxygen-mediated oxidation of initial aromatic mix containing benzene bearing two or three oxidizable substituents in its ring or naphthalene bearing at least one oxidizable substituent in its ring in reaction medium containing initial aromatics, promoter, heavy metal-based catalyst, and solvent containing benzoic acid and about 5 to about 60 wt % water, percentage of solvent in reaction medium ranging from 1 to 40 wt %. Oxidation proceeds in reaction zone of double-phase stream reactor under reaction conditions to produce high-pressure emission gas at 160-230°C in first part of reaction zone and at 180-260°C in second part of reaction zone, while at least part of aromatic acid produced crystallizes from reaction medium in reaction zone. According to second embodiment of invention, aromatic carboxylic acid production process comprises (i) providing reaction mixture containing initial aromatic compound, heavy metal-based catalyst, bromine source, and solvent containing benzoic acid and water, initial aromatic compound being benzene bearing two oxidizable alkyl substituents in m- and/or p-positions of its ring or naphthalene bearing oxidizable alkyl substituents in its ring, percentage of solvent in reaction medium ranging from 1 to 40 wt %; (ii) bringing at least part of reaction medium into contact with oxygen-containing gas in first continuously stirred mixing reactor at 160-230°C to form first high-pressure gas stream and product containing crystalline aromatic dicarboxylic acid in liquid medium containing the same, heavy metal-based catalyst, bromine, water, benzoic acid, intermediate oxidation products, and by-products; and (iii) sending thus obtained product to second continuously stirred mixing reactor, wherein second high-pressure gas stream is formed and at least part thereof contacts with oxygen-containing gas at 180 to 260°C to produce aromatic dicarboxylic acid.
EFFECT: minimized toxic methyl bromide formation.
26 cl, 2 dwg
