OXIDATION SYSTEM HAVING SECONDARY REACTOR FOR SIDE STREAM Russian patent published in 2012 - IPC C07C51/265 B01J8/18 B01J8/22 B01J10/00 C07C63/26 C08G63/183 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing a composition of aromatic dicarboxylic acid, involving (a) oxidation of a multiphase reaction medium in a primary oxidation reactor to obtain a first suspension; (b) further oxidation of at least a portion of said first suspension in a secondary oxidation reactor which is of the bubble column type, wherein the method further involves feeding an aromatic compound into said primary oxidation reactor, where at least about 80 wt % of said aromatic compound fed into said primary oxidation reactor is oxidised therein, wherein head gases are moved from the top of the secondary oxidation reactor into the primary oxidation reactor. Disclosed are an optimised process and equipment for more efficient and cheaper liquid-phase oxidation. Such liquid-phase oxidation is carried out in a bubble column type reactor which ensures a highly efficient reaction at relatively low temperatures. When the oxidised compound is para-xylene and the oxidation reaction product is crude terephthalic acid (TPA), such a product, TPA, can e purified and extracted using cheaper methods than when TPA is obtained using the conventional high-temperature oxidation process.

EFFECT: improved method of producing a composition of aromatic dicarboxylic acid.

30 cl, 4 tbl, 31 dwg