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CN-121988332-A - Catalyst and preparation method thereof and preparation method of hexamethylenediamine

CN121988332ACN 121988332 ACN121988332 ACN 121988332ACN-121988332-A

Abstract

The invention relates to the technical field of catalysts, in particular to a catalyst and a preparation method thereof as well as a preparation method of hexamethylenediamine. The catalyst provided by the invention comprises a carrier, an active component and an auxiliary agent, wherein the active component comprises Ni, and the auxiliary agent comprises Fe and Cr. The catalyst disclosed by the invention has the advantages that the content of zero-valent Ni is effectively increased by introducing the bimetallic additives Fe and Cr, the hydrogenation activity is promoted, and the reaction process is accelerated, and the catalyst is used in the preparation of hexamethylenediamine by hydrogenating adiponitrile, so that the conversion rate of adiponitrile and the selectivity of hexamethylenediamine under mild conditions are improved.

Inventors

  • LI PENGHUI
  • ZHANG YANLU
  • Lou Changshuan
  • ZENG LE

Assignees

  • 华润化学材料科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241029

Claims (10)

  1. 1. The catalyst is characterized by comprising a carrier, an active component and an auxiliary agent, wherein the active component comprises Ni, and the auxiliary agent comprises Fe and Cr.
  2. 2. The catalyst according to claim 1, wherein in the catalyst, the loading amount of the Ni element is 15% to 40%, the mass of the Fe element is 1% to 5% of the mass of the Ni element, and the mass of the Cr element is 1% to 5% of the mass of the Ni element.
  3. 3. The catalyst of claim 1, wherein the support comprises at least one of SiO 2 , activated carbon, tiO 2 、γ-Al 2 O 3 、α-Al 2 O 3 , and hydrotalcite.
  4. 4. The catalyst of claim 1, wherein the active component and the auxiliary agent form nanoparticles having a particle size of 5-20 nm.
  5. 5. The method for preparing the catalyst according to any one of claims 1 to 4, comprising the steps of: and (3) reacting the carrier, ni salt, fe salt, cr salt and the precipitant in a solvent to obtain a catalyst precursor, and activating the catalyst precursor to obtain the catalyst.
  6. 6. The method for producing a catalyst according to claim 5, characterized by comprising at least one of the following features (1) to (3); (1) The precipitant comprises at least one of NaOH, na 2 CO 3 , KOH and K 2 CO 3 ; (2) The solvent includes at least one of ethanol, water, methanol, and isopropanol; (3) The Ni salt, the Fe salt, and the Cr salt each independently include at least one of a sulfate, a nitrate, a hydrochloride, and an acetylacetonate.
  7. 7. The method for preparing the catalyst according to claim 5, wherein the catalyst precursor is obtained by uniformly mixing a carrier and a solvent to obtain a solution A, adding a Ni salt solution into the solution A to obtain a solution B, adding a Fe salt solution and a Cr salt solution into the solution B to obtain a solution C, and adding a precipitant solution into the solution C until the pH of the system is 8-11.
  8. 8. The method for producing a catalyst according to claim 5, characterized by comprising at least one of the following features (1) to (5); (1) The activation comprises the steps of adding a reaction solvent for liquid sealing after activating the catalyst precursor under reducing gas; (2) The reducing gas comprises hydrogen; (3) The activation temperature is 350-500 ℃; (4) The activation time is 1-3 h; (5) The flow rate of the reducing gas is 40-100 mL/min.
  9. 9. The preparation method of hexamethylenediamine is characterized by comprising the following steps: after reacting adiponitrile, a reaction solvent, an alkali inhibitor, the catalyst of any one of claims 1-4 and hydrogen, obtaining hexamethylenediamine.
  10. 10. The method for producing hexamethylenediamine according to claim 9, comprising at least one of the following features (1) to (5); (1) The alkalinity inhibitor comprises at least one of KOH, naOH and ammonia water; (2) The mass ratio of the adiponitrile to the catalyst is (1-20): 1; (3) The mass ratio of the catalyst to the alkaline inhibitor is (1-20): 1; (4) The reaction temperature is 60-100 ℃; (5) The pressure of the reaction is 1.5-5 MPa.

Description

Catalyst and preparation method thereof and preparation method of hexamethylenediamine Technical Field The invention relates to the technical field of catalysts, in particular to a catalyst and a preparation method thereof as well as a preparation method of hexamethylenediamine. Background Hexamethylenediamine is an important chemical intermediate and is widely used for synthesizing polyamide (such as nylon 66, nylon 6-10 and the like) and hexamethylene-1, 6-diisocyanate (HDI). Nylon 66 materials obtained by polymerizing hexamethylenediamine and adipic acid have high strength, high toughness and excellent creep resistance and wear resistance, and nylon and modified materials thereof are widely used in the fields of engineering members, electronic and electric fields, medical sanitation and the like, which increases the demand for upstream monomer hexamethylenediamine. The preparation method of the hexamethylenediamine comprises a hexanediol method, an adipic acid method, a caprolactam method, a butadiene method and an adiponitrile hydrogenation method. At present, adiponitrile catalytic hydrogenation technology is mainly adopted in industry to prepare hexamethylenediamine. The hydrogenation technology of adiponitrile is divided into a high-pressure method and a low-pressure method, wherein the DuPont company in the United states adopts a high-pressure method technology, and the technology adopts an iron-based catalyst, so that the hexamethylenediamine selectivity of 90% -95% can be realized at the reaction temperature of 100-180 ℃ under the pressure of 30-35 MPa H 2. The high-pressure method has harsh reaction conditions, high equipment requirements and high operation safety risk, so the low-pressure method is easier to be adopted in large-scale production. The low-pressure method is industrially carried out under the reaction temperature of 60-100 ℃ by adopting a skeletal nickel catalyst and the pressure of 1-3 MPa H 2. However, the skeletal nickel catalyst has poor mechanical strength, is extremely easy to break and deactivate in the reaction process, and is prepared from nickel-aluminum alloy through the multi-step operations of cooling, breaking, naOH activation, washing liquid sealing and the like, and has complex preparation process and easy spontaneous combustion. At present, the adiponitrile hydrogenation catalyst has the problems of poor selectivity to hexamethylenediamine, low yield of hexamethylenediamine, further separation and purification of the reacted product, harsh required reaction conditions and the like. In view of this, the present invention has been made. Disclosure of Invention A first object of the present invention is to provide a catalyst having improved hydrogen activation capacity, improved adiponitrile conversion and improved hexamethylenediamine selectivity. The second object of the present invention is to provide a method for preparing the above catalyst, which has simple steps and can prepare a uniformly dispersed supported catalyst. The third aim of the invention is to provide a preparation method of hexamethylenediamine, which can realize the efficient hydrogenation of adiponitrile to prepare hexamethylenediamine under the condition of mild reaction conditions and low catalyst consumption. In order to achieve the above object of the present invention, the following technical solutions are specifically adopted: In a first aspect, the present invention provides a catalyst comprising a support, an active component comprising Ni, and an adjunct comprising Fe and Cr. Further, in the catalyst, the loading amount of the Ni element is 15% -40%, the mass of the Fe element is 1% -5% of the mass of the Ni element, and the mass of the Cr element is 1% -5% of the mass of the Ni element. Further, the carrier comprises at least one of SiO 2, activated carbon, tiO 2、γ-Al2O3、α-Al2O3, and hydrotalcite. Further, the particle size of the nano particles formed by the active component and the auxiliary agent is 5-20 nm. In a second aspect, the present invention also provides a method for preparing the catalyst as described above, comprising the steps of: and (3) reacting the carrier, ni salt, fe salt, cr salt and the precipitant in a solvent to obtain a catalyst precursor, and activating the catalyst precursor to obtain the catalyst. Further, at least one of the following features (1) to (3) is included; (1) The precipitant comprises at least one of NaOH, na 2CO3, KOH and K 2CO3; (2) The solvent includes at least one of ethanol, water, methanol, and isopropanol; (3) The Ni salt, the Fe salt, and the Cr salt each independently include at least one of a sulfate, a nitrate, a hydrochloride, and an acetylacetonate. Further, uniformly mixing a carrier and a solvent to obtain a solution A, adding a Ni salt solution into the solution A to obtain a solution B, adding a Fe salt solution and a Cr salt solution into the solution B to obtain a solution C, adding a precipitant solution into the solution C un