Method and apparatus for preparing palladium carbon catalyst

Abstract

The invention provides a method and an apparatus for preparing a palladium carbon catalyst. The apparatus comprises a palladium chloride dissolving reactor, an active carbon slurry preparing reactor, a hydrogenation reactor, a catalyst storage tank and a catalyst scrubber. The catalyst scrubber is provided with a top nitrogen inlet and a middle nitrogen inlet, and a filtering segment at a middle section. The preparation method comprises steps of: preparing a palladium chloride solution; adding water to prepare a active carbon slurry; adsorbing palladium chloride to active carbon; adding alkali to prepare palladium hydroxide; hydrogenating to reduce into a metal target; and preparing into a crude catalyst; washing the crude catalyst in the catalyst scrubber with stirring by nitrogen; filtering until a chloride ion content in a filtrate is qualified; sending the slurry to a storage tank for preservation. The invention increases catalyst activity by 0.2-0.3(Z0), reduces catalyst loss, lowers production cost, increases economic benefit and reduces labor intensity during catalyst preparation.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and relates to a method and equipment for preparing a metal catalyst for hydrogenation, in particular to the improvement of the method and device for preparing a palladium-carbon catalyst for hydrogenation of benzoic acid. Background technique [0002] The hydrogenation of benzoic acid is an intermediate process in the production of caprolactam by the SNIA method. This reaction uses benzoic acid as a raw material, and the precious metal palladium is used as a catalyst to produce the intermediate product cyclohexanecarboxylic acid. The activity of the palladium-carbon catalyst is the key to the hydrogenation effect of benzoic acid. factor. The palladium-carbon catalyst uses palladium as the active component and activated carbon as the carrier. The preparation process mainly includes the following steps: [0003] (1) Palladium chloride is adsorbed on activated carbon. [0004] PdCl 2...

AI Technical Summary

Problems solved by technology

The deficiencies of the prior art are: (1) palladium-carbon catalyst is easily poisoned in the air, which reduces catalyst activity. Tests show that the activity of the catalyst in the semi-dry state has 1.3 and drops below 0.5 after drying.

Therefore, the catalyst after centrifugal washing and drying, semi-dry catalyst loading into barrels and other operations and storage in barrels exposed to the air are prone to deactivation, reducing the quality of fresh finished catalysts

(2) The operation process is complicated and there are potential safety hazards. During the process of feeding and washing materials, the centrifuge vibrates greatly, causing the machine to move

(3) After the scraping system of the centrifuge scrapes, there is a layer of catalyst on the filter cloth. After the automatic scraping stops, the operator needs to enter the machine to scrape, which is time-consuming and laborious, and it is easy to cause the loss of the catalyst.

(4) Manual barreling and adding catalyst to the reaction system, intermittent operation, high labor intensity

(5) The catalyst is exposed outside, causing environmental pollution

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