PTA (Pure Terephthalic Acid) energy-saving and consumption-reducing device and homogeneous pre-mixing method before CTA (Crude Terephthalic Acid) oxidation reaction

Abstract

The invention discloses a PTA (Pure Terephthalic Acid) energy-saving and consumption-reducing device and a homogeneous pre-mixing method before a CTA (Crude Terephthalic Acid) oxidation reaction. A super-gravity homogeneous premixing reactor is added between a feed mixing device and an oxidation reactor, and the super-gravity homogeneous premixing reactor comprises a motor, a housing, an end cap,a rotating shaft, a rotor, a stationary ring, and a feed nozzle. The rotor comprises a rotating disc and a moving ring; the moving ring comprises an inner moving ring, an intermediate moving ring andan outer moving ring which coaxially sleeve the periphery of the rotating shaft from the inside to the outside. Adding the super-gravity homogeneous premixing reactor has two effects on the oxidationreaction process: 1, homogeneously mixing p-xylene, an acetic acid solvent, a catalyst (cobalt acetate, manganese acetate, and an accelerator tetrabromoethane) mixture again, to improve the mixing uniformity; 2, initiating an oxidation reaction by introducing air, to increase the oxidation reaction rate in the oxidation reactor, and to increase the main reaction yield. The heat removal time is shortened, and the evaporation of the acetic acid solvent is reduced.

Description

technical field [0001] The invention relates to a PTA production device and a production process, in particular to a PTA energy saving device and a homogeneous premixing method before CTA oxidation reaction. Background technique [0002] In the oxidation reaction unit of the existing purified terephthalic acid industrial plant, prior to the oxidation reaction of crude terephthalic acid, the homogeneous premixing of p-xylene, acetic acid and catalyst adopts the traditional mixing technology of "in-tank mixing or static mixer" , see the flowchart figure 1 . In the present invention, purified terephthalic acid is collectively referred to as PTA, crude terephthalic acid is collectively referred to as CTA, and p-xylene is collectively referred to as PX. [0003] In the oxidation reaction unit of the PTA industrial plant, such as figure 1 Shown, raw material p-xylene, solvent acetic acid, catalyzer (cobalt acetate, manganese acetate, promotor tetrabromoethane) enter in the feed...

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Problems solved by technology

[0006] When the raw material p-xylene, solvent acetic acid, and catalyst (cobalt acetate, manganese acetate, accelerator tetrabromoethane) are mixed in a certain proportion by using a feed mixing device, the mixing time is short, the homogeneous mixing effect is poor, and the oxidation reaction is entered Side reactions are prone to occur after the reactor, producing carbon monoxide, carbon dioxide and water, which affects the yield of the main reaction; at the same time, because the main reaction and the side reaction process are all exothermic processes, and the heat removal in the reaction process is mainly taken away by the vaporization of acetic acid. Larger solvent consumption

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