Method for activating adiponitrile hydrogenation catalyst

Abstract

The invention discloses a method for activating an adiponitrile hydrogenation catalyst. The method is characterized in that the catalyst is a modified raney nickel catalyst and is activated by the method comprising the following steps: preparing a mixing solution from iron, chromium, molybdenum, bismuth, manganese or tungsten soluble salts and NaOH respectively; slowly adding the modified raney nickel catalyst and ammonium salt; heating with microwave and reacting, and then washing; the modified raney nickel catalyst is prepared by the method comprises the following steps: grinding nickel-aluminum alloy into powder; adding to a mixing solution to dissolve part of aluminum, wherein the mixing solution is prepared through NaOH, ammonium salt and ammonium hydroxide in certain ratio; washing with deionized water and absolute ethyl alcohol; adding the powder to the mixing solution consisting of ferric nitrate and a modifier under a microwave condition and reacting to obtain a solid; drying and roasting the solid; and then charging hydrogen and reducing to obtain the modified raney nickel catalyst. With the adoption of the method for activating the adiponitrile hydrogenation catalyst, the prepared catalyst is relatively large in specific surface area, loss of the modifier is small, and high conversion rate of adiponitrile and high selectivity of hexamethylenediamine are achieved in the adiponitrile catalytic hydrogenation process.

Description

technical field [0001] The invention belongs to the technical field of petrochemical catalysis, and in particular relates to an activation method of adiponitrile hydrogenation catalyst. Background technique [0002] Raney catalyst is a widely used reduction catalyst, mainly used in the catalytic hydrogenation of organic compounds. According to the different metal active centers, there are Raney iron, Raney cobalt, Raney nickel, etc. Among them, the Raney nickel catalyst with nickel as the active center is the most widely used. For example, hexamethylenediamine is used as a monomer for the production of nylon-66. At present, adiponitrile is mainly used as a raw material, and Raney nickel catalyst is used to prepare it in a tank reactor or a fluidized bed reactor. At present, the main problems of this catalyst are low activity and selectivity, large amount of catalyst, and serious environmental pollution. Therefore, it is necessary to develop new and more efficient catalyst m...

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Problems solved by technology

[0004] At present, Fe, Cr, Mo, Sn, W, etc. are commonly used as doping elements in the catalyst modification process, while catalyst activation generally uses a strong alkali solution, and the modifiers Cr, Mo, Sn, W in a strong Oxidation and dissolution reaction loss is prone to occur in the medium, especially on the surface of the catalyst, which greatly reduces the activity of the catalyst; at the same time, the sodium hydroxide solution is prone to inhomogeneity in the process of extracting aluminum

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