PRODUCTION OF DICARBOXYLIC ACID WITH MINIMAL FORMATION OF SEWAGE WATERS Russian patent published in 2016 - IPC C07C51/265 C07C63/26 C07C63/15 C07C63/24 C07C63/16 C07C51/44 B01D3/00 

FIELD: chemistry.

SUBSTANCE: invention relates to method for obtaining aromatic dicarboxylic acid in equipment for production of aromatic dicarboxylic acid, in which water is formed as by-product and/or is added into oxidation apparatus, which includes (a) oxidation of aromatic compound in at least one oxidation apparatus of said production equipment to form in this way off-gas of oxidation apparatus and product of oxidation apparatus, which contains aromatic dicarboxylic acid; and (b) ventilation of said water in form of steam from production equipment into the environment, wherein quantity of water, released in form of steam into the environment from said production equipment is, at least 0.3 kg/kg of aromatic compound, supplied into said oxidation apparatus. The invention also relates to method, which includes obtaining terephthalic acid (TPA) in equipment for TPA production, in which water is formed as by-product and/or is added into oxidation apparatus, which includes (a) oxidation of p-xylene at least in one oxidation apparatus in said production equipment, where in the course of operation of said TPA production equipment in stable mode p-xylene is supplied into said TPA production equipment at rate at least 500 kilograms per hour to obtain in this way off-gas of oxidation apparatus and product of oxidation apparatus, which contains terephthalic acid; and (b) ventilation of said water in form of steam from production equipment into the environment, wherein quantity of water, released in form of steam into the environment from said production equipment is, at least 0.3 kg/kg of paraxylene, supplied into said oxidation apparatus, and where in the course of operation of said TPSA production equipment in stable mode liquid wastes are output from said TPA production equipment into equipment for liquid sewage water processing with ratio less than 0.4 kg/kg of p-xylene, supplied into said TPA production equipment. With application of off-gas larger power than required for bringing main air compressor into action, even with preferable relatively low oxidation temperatures, is obtained on shaft.

EFFECT: invention provides improved energy resource in production of power on shaft from off-gas from xylene oxidation reactions, with simultaneous minimisation of expenditures for sewage water processing.

30 cl, 1 dwg