Reactor for preparing hydroanthraquinone and preparation method of hydroanthraquinone

Abstract

The invention discloses a reactor for preparing hydroanthraquinone and a preparation method of hydroanthraquinone. The reactor comprises a reaction kettle, a circulating pump, a heat exchanger and a Venturi ejector, the Venturi ejector comprises an inlet section, a nozzle, a mixing section and a diffusion section which are communicated in sequence; the inlet section and the nozzle are in a reducing pipe type; the ratio of the inner diameter of an inlet section opening to the inner diameter of a nozzle to the inner diameter of an air chamber closing opening to the length of a mixing section to the length of a diffusion section of the Venturi ejector is 34: (2-5): (3-6): (30-60): (600-1000); and the opening angle of the diffusion section is 10-25 degrees. According to the present invention, the specification and the size of the reactor are optimized, such that the mass transfer process of the reaction is effectively enhanced, the catalyst liquid film thickness is reduced, the conversion from EAQ to EAQH2 can be achieved with low hydrogen partial pressure and low catalyst consumption, the hydrogenation depth is effectively controlled, and the selectivity and the utilization rate of the effective anthraquinone by the catalyst are significantly improved.

Description

technical field [0001] The invention belongs to the field of anthraquinone method for preparing hydrogen peroxide, and in particular relates to a method for catalytically hydrogenating 2-ethylanthraquinone (EAQ) to 2-ethylhydroanthraquinone (EAQH2) by adopting a new type of reactor equipment—a loop reactor method. Background technique [0002] The process of preparing hydrogen peroxide by anthraquinone method is mainly composed of the following steps. First, 2-ethylanthraquinone (EAQ) is dissolved in a specific solvent to form a working fluid. The EAQ dissolved in the solvent has a pressure of 0.3Mpa and a temperature of 40- At 70°C, hydrogenation reaction occurs in the presence of a hydrogenation catalyst to obtain hydroanthraquinone (EAQH 2 ), passing oxygen-containing gas into the hydrogenated working solution can make hydroanthraquinone (EAQH 2 ) is re-oxidized to anthraquinone (EAQ). Meanwhile, during the hydrogenation reaction, EAQH 2 will be further hydrogenated t...

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Problems solved by technology

Usually the hydrogenation reaction occurs at the interface of the gas-liquid-solid three-phase. The supported palladium catalyst is a structure similar to an eggshell. Part of the palladium invades the pores of the carrier and cannot be fully utilized. Only the palladium on the surface of the carrier can Utilization, and the hydrogenation reaction in the form of a fixed bed is subject to the influence of gravity, the velocity of the liquid through the fluidized bed is slow, and the catalyst liquid film is relatively thick, which is not conducive to the full contact reaction of the gas-liquid-solid three-phase, and the catalyst filling in the fixed bed involves catalyst molding and loading Form, easy to form interstitial flow, this kind of fixed-bed hydrogenation in the form of trickle flow has low gas-liquid-solid mass transfer efficiency, and requires a hydrogen-rich environment, which can easily lead to deep hydrogenation of anthraquinone, resulting in serious degradation of anthraquinone and reduced yield ; And increasing the space velocity will inevitably lead to a low conversion rate per pass, which determines the two major shortcomings of the hydrogenation reaction in the form of a fixed bed in the production of hydrogen peroxide by the anthraquinone method:

[0006] 1. A hydrogen-rich environment is required to maintain hydrogenation efficiency, but it is easy to reduce the yield of anthraquinone overhydrogenation, and it is difficult to control the depth of hydrogenation;

[0007] 2. The generated hydroanthraquinone easily leads to an increase in the viscosity of the working fluid, thick catalyst liquid film, and poorer gas-liquid-solid three-phase mass transfer effect, resulting in low catalyst utilization (the quality of anthraquinone converted by a unit catalyst per unit time is expressed in g EAQ / ( g h) meter)

[0009] When using a loop reactor for the preparation of hydroanthraquinone, due to the use of powder catalyst, factors such as catalyst density and liquid injection speed will affect the distribution ratio of the catalyst in the reactor and circulation pipeline, thus affecting the selection of effective hydroanthraquinone sex and utilization

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