Adiponitrile production system

Abstract

The invention relates to an adiponitrile production system which comprises an adipic acid storage tank, a mixer, an adipic acid ammoniation reactor, a cyanation reactor, a separation tower, an ammoniagas cooler, an ammonia gas decarburization tower, a circulating ammonia gas dehydrator and a liquid ring compressor. The adipic acid storage tank is connected to the mixer by a pipeline, a branch fordelivering liquid phosphoric acid is arranged on the pipeline, the mixer is connected to an inlet of the adipic acid ammoniation reactor, an ammonia gas inlet and adipic acid ammoniation product andammonia gas outlets are further formed in the adipic acid ammoniation reactor, the adipic acid ammoniation product and ammonia gas outlets are connected with the cyanation reactor by pipelines, and the cyanation reactor is connected to the separation tower. The adiponitrile production system has the advantage that the shortcomings of decomposition and condensation coking of adipic acid in existingproduction routes at the high temperatures and the like can be overcome by the aid of the adiponitrile production system.

Description

technical field [0001] The invention belongs to the technical field of chemical industry and relates to a production system of adiponitrile. Background technique [0002] Adipic acid catalyzed ammoniation method is that adipic acid and ammonia react to form adiponitrile under the action of dehydration catalyst. According to the different physical states of adipic acid, the process is divided into adipic acid liquid phase method and adipic acid gas phase method. Among them, the reaction temperature of the liquid phase method is generally around 280°C, and the reaction temperature of the gas phase method is 350°C-420°C. Different from the gas-phase method, in order to reduce the generation of by-products and tar in the liquid-phase method, an additional diluent is added to maintain the uniformity of the temperature of the reaction system. In addition, the liquid-phase method is more favored by the industry because of its relatively simple process, less ring-shaped impurities...

AI Technical Summary

Problems solved by technology

Because adipic acid will generate by-products such as decarboxylation, decomposition, and coking at high temperatures, which not only affects the unit consumption; adipic acid generates coke at high temperatures and also affects the operating cycle

[0006] Patent CN201510185122.7 discloses a method for producing adiponitrile by adipic acid liquid phase method. Its main innovation is the use of solid phosphoric acid catalyst. Although it can be stirred, the mixing effect is not very good, and its catalytic performance will also be affected.

[0007] Patent CN201210577924.9 discloses a method for producing adiponitrile with adipic acid and the equipment used. Its main innovation point is that "after the neutralization reaction of adipic acid and gaseous ammonia in the nitrilation reactor, continue to Dehydration reaction in the tubes of the nitrilation reactor", although two reactions can be carried out in the nitrilation reactor and "the reaction temperature is 250‐‐290 ° C", but the molten adipic acid is very easy to Side reactions and cokes occur, which affect the yield and the operating cycle of the device

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