Fluidization reaction device and method for producing chlorothalonil by using same

Abstract

The invention provides a fluidization reaction device and a method for producing chlorothalonil by using the fluidization reaction device. The fluidization reaction device comprises a first heat exchange tube group, a second heat exchange tube group and a third heat exchange tube group which are independent of one another and are sequentially arranged in a reactor main body from top to bottom, the ratio of the heights of the first heat exchange tube group, the second heat exchange tube group and the third heat exchange tube group to the height of the reactor main body is (0.05-0.2): 1 independently, so that the reaction temperatures of the reactor main body at different axial heights can be well controlled, the temperature distribution in the reactor main body is uniform, no local overheating area exists, and the heat exchange efficiency is improved. The catalyst is prevented from coking in the reactor main body; according to the method for producing chlorothalonil by using the fluidization reaction device, the service life of a single batch of catalysts can be prolonged, and the proportion of chlorothalonil with hexachlorobenzene lower than 10ppm in the product is increased.

Description

technical field [0001] The invention relates to the technical field of fluidized reaction devices, in particular to a fluidized reaction device and a method for producing chlorothalonil. Background technique [0002] Chlorothalonil is a high-efficiency, low-toxicity, low-residue protective fungicide, which is widely used in the control of fungal diseases in agriculture and forestry, especially in economic crops such as vegetables and fruits. Twelve kinds of diseases have control effects. In addition, chlorothalonil also has important uses in the anti-mold industry, such as the manufacture of anti-mold paint and anti-mold wallpaper. The production scale of chlorothalonil in China is constantly expanding, and it has become one of the high-quality large-tonnage pesticide varieties in the world. [0003] The fluidized bed is the most critical equipment in the production of chlorothalonil, which is directly related to the output and product quality of chlorothalonil production....

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Problems solved by technology

[0004] CN101985089B discloses a tubular fluidized bed reactor in the production of chlorothalonil. The fluidized bed of the reactor includes a serpentine tube heat exchanger and a tubular heat exchanger, and the serpentine tube heat exchanger It is arranged under the lower head of the fluidized bed, and the tube-and-tube heat exchanger is arranged between the serpentine tube heat exchanger and the fluidized bed cylinder, but only contains a section of heat exchange tube, which is prone to local overheating areas

[0005] CN100404500C discloses a kind of production method of chlorothalonil with low hexachlorobenzene content, after isophthalonitrile is completely vaporized, it is taken out of the vaporizer with nitrogen, then mixed with chlorine and then entered into the fluidized bed for the first step reaction, the reaction product It is mixed with chlorine gas again, enters the fixed bed for chlorination, and the output mixed gas is condensed and collected to obtain chlorothalonil product, but does not involve the removal of heat in the fluidized bed

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