RU2372323C1 - Method of producing high-molecular amines - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to production of high-molecular amines through catalytic hydrogenation of nitriles and can be used in production of fertiliser, biocides for petroleum production, ore mining, pharmaceutical preparations, and surfactants. The method involves catalytic hydrogenation of a reaction mixture containing nitrile, hydrogen, ammonia and catalyst. The catalyst used is an olefinic complex of palladium with formula [Pd(C₂H₄)Cl₂]₂·PdO, taken in volume ratio to nitrile of 1.6:1, and volume ratio to hydrogen of 2.9:1. The nitrile used is a fatty acid nitrile, for example, alkylnitrile of the C₁₀-C₁₈ fraction.

EFFECT: increased output of product, reduced amount of impurities.

3 cl, 1 tbl, 1 ex

Description

The present invention relates to the field of chemistry, in particular to the production of catalytic hydrogenation of nitriles of high molecular weight amines, which can be used in the production of fertilizers, biocides for oil production, mining, as well as an intermediate product in the production of tertiary amines and their derivatives, pharmaceuticals, surface active substances.

A known method of producing a primary amine by hydrogenation of nitriles, in which the conversion reaction proceeds in a reaction mixture containing (a) at least one nitrile, (b) hydrogen, (c) optionally ammonia, and (d) at least one cobalt or a nickel catalyst modified ex situ by adsorption of an alkali metal carbonate or alkali metal hydrogen carbonate, which contains an alkali metal carbonate or hydrogen carbonate in an amount of from 2 to 12 wt.% (RU 2004128337, C07C 209/48, 2006-02-27).

The patent RU 2233266, С07С 209/48, 2003-06-27 describes methods (options) for producing an amine from nitrile by hydrogenation, which include: supplying hydrogen and nitrile to a reactor containing a catalyst, water and an inorganic base, with the formation of a reaction medium; stirring said reaction medium and hydrogenating said nitrile to form an amine. The catalyst used in this method is Raney nickel, with or without metal activator, such as chromium and / or iron.

The method is complicated by the need to control the degree of mixing of the reaction mixture and the introduction into the reaction medium of an inorganic base, which is an alkali metal hydroxide such as sodium, potassium, lithium, rubidium or cesium, which does not allow to obtain high-quality amines without impurities, and requires the operation of them cleaning up.

S. Sakakibara et al., J. Chem. Soc. Japan, Ind. Chem. Sect., 56, 497 (1953) discloses a process for preparing primary amines, for example, dodecylamine, by hydrogenating a nitrile such as lauronitrile with ammonia using Raney nickel catalysts.

The process of catalytic hydrogenation of C ₃ -C ₄₀ aliphatic nitriles is known to produce primary amines by the reaction of nitriles with hydrogen in the presence of Raney cobalt as a catalyst. Hydrogenation is carried out in a liquid medium containing particles of a cobalt-aluminum alloy into which alkali metal hydroxide is introduced. The process is carried out at a hydrogen pressure of 8.5-34 atm at a temperature of 50-170 ° C for 2-30 hours (US 4375003, B01J 25/00, C07C 209/48, 1983-02-22).

This method includes an operation to control the introduced alkali metal hydroxide and the step of washing the hydrogenate from the hydroxide, which complicates the process and increases its time.

US Pat. No. 5,869,653, C07C 209/48, 1999-02-09 describes a process for the catalytic hydrogenation of nitriles to convert a nitrile group to a primary amine. Nitrile in the presence of a sponge cobalt catalyst treated with a catalytically effective amount of lithium hydroxide is contacted with hydrogen in the absence of ammonia in the presence of water. The hydrogenation reaction is carried out at a temperature of 70-130 ° C, a pressure of 25-56 atm for 1.5-4 hours.

Catalysts Raney nickel and Raney cobalt under the conditions of the hydrogenation reaction of the methods described above have a high rate of catalyst deactivation, additional operations for washing the hydrogenate, are long in time the process.

Catalytic hydrogenation on Pt or Pd at a pressure of 0.1-0.3 MPa and 20-50 ° C is most often used to reduce nitriles to produce amines. To suppress the formation of secondary and tertiary amines, NH _{3 is} added.

A method for producing a hydrogenation catalyst containing palladium by hydrogen reduction of divalent palladium from the starting compound to palladium with zero valence, followed by deposition of reduced palladium on a carbon material, is described. Tetraaquapalladium (II) perchlorate is used as the starting compound, and nanocluster soot is used as the carbon material. The recovery of palladium from the starting compound and the deposition of reduced palladium on the carbon material is carried out in separate portions, the method is carried out at room temperature and normal atmospheric pressure (RU 22585617, B01J 23/44, 2005-08-20).

The complexity of the preparation of the catalyst, deposition on an expensive coal carrier - nanocluster soot increases the cost of the resulting product.

Known palladium hydrogenation catalyst containing a palladium compound and a modifying additive, characterized in that palladium bis-acetylacetonate is used as the initial palladium compound, and white phosphorus (P ₄ ) is used as the modifying additive in the following ratio of components: palladium bis-acetylacetonate / phosphorus = 1: 0.1 to 1: 1 (RU 2006119724, B01J 23/00, 2007-12-27).

The method of obtaining this catalyst by the presence of white phosphorus as a modifying additive complicates the process of its production on an industrial scale.

A prototype of the present invention is a method developed by industry for producing aliphatic amines by hydrogenation of nitriles on an aluminum-nickel catalyst modified with titanium addition at a temperature of 80-230 ° C and a pressure of 20-100 atm (ed. Certificate of the USSR 237159, 1969-11-12).

This method does not provide a high yield of amine and its quality.

The present invention aims to eliminate the disadvantages of the above methods for producing primary amines by catalytic hydrogenation of nitriles and to propose a method with a good yield of the target product of high quality: maximum light color on a Hazen scale <50; mass fraction of primary amines> 98%, with a low amount of impurities.

To achieve this goal with the claimed technical result, a method for producing high molecular weight amines by catalytic hydrogenation of nitriles is proposed, in which the conversion reaction proceeds in a reaction mixture containing nitrile, hydrogen, ammonia and a catalyst, characterized in that the palladium olefinic complex of the formula [Pd ( C ₂ H ₄ ) Cl ₂ ] ₂ · PdO, taken in volume ratio to nitrile 1.6: 1; to hydrogen 2.9: 1.

The palladium olefin complex as a catalyst is capable of regeneration and reusability.

In catalytic hydrogenation, the following reaction takes place:

An example of the method

Through a reactor with a working capacity of 8 l, filled with a stationary fixed catalyst bed in an amount of 7 kg (which at a density of 2.2 kg / dm ³ in volume ratio corresponds to 3.2 l), 2 l of alkyl nitrile fraction C ₁₀ -C _{18 is} pumped with a dosing pump and 4 l of ammonia for 0.5 hours to achieve a pressure of 7-10 atm and reduce selectivity to secondary and tertiary amines. Then 1.1 l of hydrogen is supplied to a pressure in the range of 20-50 atm.

As H ₂ is absorbed, hydrogen is added to the reaction mixture. The process is carried out at a temperature of 100 ° C and a pressure maintained in the system within 20-50 atm.

The resulting thoroughly mixed gas-liquid mixture is sent to a separator system for separating gaseous products. In the first separator, hydrogen and ammonia are separated from the hydrogenate; in the second separator, hydrogen and ammonia are separated.

The hydrogenated product obtained is a light, non-solidifying product with a Hazen color <50, containing> 98% primary amine and <2% secondary amine.

The use of palladium olefin complex as a catalyst can reduce the synthesis time, soften the reaction conditions (pressure up to 20-50 atm, temperature 100 ° С), increase the yield of the product (primary amine) and improve its color.

The data presented in table 1, confirm the receipt of the claimed technical result.

Table 1 Comparative data on the process of catalytic hydrogenation of nitriles Catalyst application Reaction time, h Temperature ° С Pressure, atm Exit, % The presence of impurities,% 1. Spongy cobalt (US Pat. US 5869653) 1,5-4 70-130 25-56 95 There is no data 2. Prototype - Nickel - aluminum, mod. titanium additive (ed. certificate. USSR 237159) 2 80-230 20-100 94.2 5-6 * 3. Cobalt with the addition of oxides of lanthanum, uranium, cerium four 150 60-140 88-92 8-12 *four. Palladium 8 200-300 100-150 92-95 5-8 *5. Cobalt 3 85 105 90 10 6. According to the invention (Palladium olefin complex) one one hundred 20-50 98-99.9 0.1-2.0 * experimental data

Claims (3)

1. A method of producing high molecular weight amines by catalytic hydrogenation of nitriles, in which the hydrogenation reaction is carried out in a reaction mixture containing nitrile, hydrogen, ammonia and a catalyst, characterized in that the catalyst used is an olefinic palladium complex with the formula [Pd (C ₂ H ₄ ) Cl ₂ ] ₂ · PdO, taken in volume ratio to nitrile 1.6: 1, to hydrogen 2.9: 1. 2. The method according to claim 1, characterized in that nitrile of a fatty acid is used as nitrile. 3. The method according to claim 2, characterized in that as nitrile use alkylnitrile fraction C ₁₀ -C ₁₈ .