External micro-interface unit enhanced oxidation system for producing PTA from PX

Abstract

The invention provides an external micro-interface unit enhanced oxidation system for producing PTA from PX. The external micro-interface unit enhanced oxidation system comprises a reactor, a circulating heat exchange device and a micro-interface unit, wherein the reactor comprises a shell and an inner barrel concentrically arranged in the shell; the circulating heat exchange device is arranged outside the reactor, is separately connected with the shell and the inner barrel, and is used for adjusting the reaction temperatures of a first reaction zone, a second reaction zone and a third reaction zone in the reactor in the reaction process; and the micro-interface unit is arranged between and connected with the reactor and the circulating heat exchange device and is connected with an external feeding pipeline of the reactor. The system of the invention overcomes the problems that a large amount of a reaction solvent, namely acetic acid is wasted at high temperature and high pressure anda product TA cannot be taken out in time in the existing process of producing PTA from PX, so energy consumption is greatly reduced, the acetic acid solvent is saved, and reaction efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to an enhanced oxidation system of an external micro-interface unit for PX production of PTA. Background technique [0002] The oxidation reaction process of PX (p-xylene) to produce TA (terephthalic acid) is very complicated, mainly including 4 steps, namely p-xylene (PX) → p-tolualdehyde (TALD) → p-toluic acid ( p-TA) → p-carboxybenzaldehyde (4-CBA) → terephthalic acid (TA), the four oxidation reactions in this reaction process are series reactions, which generally use acetic acid as solvent, cobalt acetate, manganese acetate and Hydrobromic acid (or tetrabromomethane) is the catalyst. [0003] At present, in the existing PTA production technology, the four main steps in the oxidation reaction process are all carried out in the same reactor. Although the reaction rate constants of the above four steps differ by more than ten times, the mixed reaction process is adopted,...

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Problems solved by technology

[0004] In view of this, the present invention proposes an external micro-interface unit enhanced oxidation system for PX production of PTA, which aims to solve the problem that the reaction solvent acetic acid is wasted in large quantities under high temperature and high pressure in the existing PX production PTA process, and the product cannot be taken out in time TA's question

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