CRUDE TEREPHTHALIC ACID COMPOSITION AND METHOD OF OBTAINING SAID COMPOSITION Russian patent published in 2010 - IPC C07C63/26 C07C51/235 B01J19/24 

FIELD: chemistry.

SUBSTANCE: invention relates to liquid-phase catalytic oxidation of an aromatic compound and to the obtained crude terephthalic acid. Oxidation is carried out in a bubble column reactor which ensures a highly efficient process at relatively low temperature. Particles of the obtained terephthalic acid, which contains approximately less than 100 parts weight/million of 2,6-dicarboxyfluorenone, have transmission factor at 340 nm (%T₃₄₀) greater than approximately 25%, additionally contains approximately less than 12 parts weight/million of 4,4-dicarboxystilbene and/or contains approximately less than 400 parts weight/million of isophthalic acid. Particles of the obtained terephthalic acid, characterised by average size ranging from approximately 20 to approximately 150 micrometres, are dissolved in tetrahydrofuran for one minute to concentration of a least approximately 500 parts/million and/or is characterised by average BET surface area greater than approximately 0.6 m²/g.

EFFECT: product can be extracted and purified using methods which are cheaper than those which can be used if the acid is obtained via a high-temperature oxidation method.

37 cl, 36 dwg, 5 tbl, 1 ex