Catalyst for preparing cyclohexanediamine by phenylenediamine hydrogenation under ammonia reaction conditions

Abstract

The invention discloses a catalyst for preparing cyclohexanediamine by phenylenediamine hydrogenation under ammonia reaction conditions. The catalyst realizes the transformation of phenylenediamine and hydrogen into cyclohexanediamine under ammonia reaction conditions and comprises a main active component, one or more auxiliary agents and a carrier. The main active component is a precious metal Ru or Pd. The one or more auxiliary agents are selected from Re, Co, Ni, Fe and their oxides. The carrier is active carbon, Al2O3 or SiO2. In a slurry-bed reactor, at a certain temperature, under the action of ammonia and catalyst, the high activity and high selectivity transformation of phenylenediamine and hydrogen into a plurality of amine products comprising cyclohexanediamine as a main product is realized.

Description

technical field [0001] The present invention relates to a catalyst for preparing cyclohexanediamine by hydrogenation of phenylenediamine under the condition of ammonia, and relates in detail to a catalyst for p-phenylenediamine, m-phenylenediamine or o-phenylenediamine and hydrogen under the condition of ammonia. Catalyst for converting 1,4-cyclohexanediamine, 1,3-cyclohexanediamine or 1,2-cyclohexanediamine under ammonia conditions. technical background [0002] Cyclohexanediamine is an important curing agent for epoxy resins, among which 1,2-cyclohexanediamine, 1,4-cyclohexanediamine and 1,3-cyclohexanediamine are the most widely used. It is a colorless transparent liquid and a white solid-liquid mixture. It is widely used in the fields of textile, paper, artificial leather and plastics. It can be used as raw materials for dyes, pharmaceutical intermediates, carbamates and polyamide resins. [0003] Industrially, 1,2-cyclohexanediamine, as a by-product of the production ...

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Problems solved by technology

U.S. Patent Nos. 3,450,759 and 5,973,207 found that hydrogenation of toluenediamine to the corresponding methylcyclohexanediamine is very difficult, and the yield of the target product is low, especially m-toluenediamine, which can be improved only after m-toluenediamine is separated. Yield of target product

Because in the hydrogenation process of o-phenylenediamine and p-phenylenediamine, on the one hand, it is easy to remove an amine group to become cyclohexylamine; Not only lead to catalyst deactivation, but also reduce the selectivity of the target product

[0004] US Patent 5,072,044 describes the dehydrogenation of 1,2-cyclohexanediamine to phenylenediamine, and found that the process of dehydrogenation of cyclohexylamine to aniline at 360-380 ° C on Li-doped Pd catalyst is accompanied by a large number of by-products

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