OXIDATION SYSTEM WITH SECONDARY REACTOR FOR SIDE STREAM Russian patent published in 2016 - IPC C07C51/265 C07C63/26 B01J8/22 B01J10/00 

FIELD: chemistry.

SUBSTANCE: invention relates to improved system for production of terephthalic acid, in particular, by contact of paraxylene-containing suspension with gas-phase air-containing oxidant, with said system including primary oxidation reactor, which includes first suspension output, secondary suspention output, normally lower oxidant input, and normally upper oxidant input, in which said suspension input is downstream in hydraulic connection with said first suspension output; in which said secondary oxidation reactor represents secondary reaction zone, which has maximal length Ls and maximal diameter Ds, in which distance to said normally lower oxidant input from the bottom of said secondary reaction zone constitutes less than 0.5 Ls, in which distance to said normally upper oxidant input from the bottom of said secondary reaction zone constitutes at least 0.5 Ls, in which distance to said input from the bottom of said secondary reaction zone is in the interval from 0.3 Ls to 0.9 Ls; with said primary oxidation reactor representing bubble column reactor, and where said secondary oxidation reactor represents bubble column reactor. The invention also relates to method for production of terephthalic acid composition, with said method including: (a) supply of first multiphase reaction medium, containing compound to be oxidised to oxidation in primary reaction zone, located in primary oxidation reactor, which results in obtaining first suspension, with compound to be oxidised containing paraxylene; and (b) contact of at least part of said first suspension with gas-phase oxidiser in secondary reaction zone, which is located in secondary oxidation reactor, which results in obtaining second suspension, with gas-phase oxidiser containing air, in which said secondary reaction zone has maximal length Ls and maximal diameter Ds, in which part of said gas-phase oxidant is supplied into secondary reaction zone in first area of oxidant input at distance from the bottom of said secondary reaction zone, constituting at least 0.5 Ls, in which said first part of said gas-phase oxidant constitutes from approximately 5 to approximately 49% of the total volume of said gas-phase oxidant, introduced into said secondary reaction zone, in which at least part of said first suspension is supplied into said secondary reaction zone in area of suspension input at distance from the bottom of said secondary reaction zone in interval from 0.3 Ls to 0.9 Ls, with said primary oxidation reactor representing bubble column reactor, and where said secondary oxidation reactor represents bubble column reactor; and where said secondary oxidation reactor contains normally lower oxidant input.

EFFECT: devices and method can contribute to reduction of oxygen content in the entire reactor of additional oxidation.

15 cl, 6 dwg