Palladium-carbon filtering and recycling system and method

Abstract

The invention discloses a palladium-carbon filtering and recycling system and method, the palladium-carbon filtering and recycling system comprises a hydrogenation reaction kettle (1), a filter (2) connected with the hydrogenation reaction kettle (1), a nitrogen back flushing mechanism, a drainage system and a cyclohexanecarboxylic acid crude product tank (3) which are connected with the filter (2), a palladium-carbon suction filter (4) connected with the filter (2), and a pure water pipe and a tail gas buffer tank (5) which are communicated with the filter (2), the palladium-carbon filteringand recycling method comprises the following steps: after the reaction is finished, replacing residual gas in the hydrogenation reaction kettle (1) with nitrogen, and conveying crude product cyclohexanecarboxylic acid obtained by the reaction to the cyclohexanecarboxylic acid crude product tank (3); when the activity of a catalyst becomes low and the catalyst cannot be continuously used, discharging filter residues from the filter (2) after the filter residues are filtered by the filter (2), starting pure water flushing until no palladium-carbon and cyclohexanecarboxylic acid residues exist ina pipeline and the filter (2), and enabling the filter residues and cleaning water to enter the palladium-carbon suction filter (4); and recycling the filter residues after vacuum filtration and dehydration through the palladium-carbon suction filter (4).

Description

technical field [0001] The invention relates to the technical field of cyclohexanecarboxylic acid production, in particular to a palladium carbon filtration recovery system applied in the production process of cyclohexanecarboxylic acid produced by reacting benzoic acid and hydrogen, and the invention also relates to a palladium carbon filtration recovery method. Background technique [0002] Cyclohexanecarboxylic acid can be used to synthesize anti-pregnancy 392 drugs and praziquantel, a new drug for the treatment of schistosomiasis; it can also be used as a vulcanized rubber compatibilizer, petroleum clarifier, pesticide, dye and other organic compounds. There are more than 20 methods for the preparation of cyclohexanecarboxylic acid, among which Grignard reagent method, benzoic acid catalytic hydrogenation method, cyclohexene carbon monoxide addition method and cyclohexanone as raw material method are the best. The catalytic hydrogenation of benzoic acid to cyclohexanecar...

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Problems solved by technology

[0004] In the prior art, the catalyst in the palladium-carbon filter is returned to the reactor by backflushing the filtrate and nitrogen, the recovery process is complicated, the efficiency is low, and it is easy to cause accidents (such as palladium-carbon spontaneous combustion)

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