SU1460920A1 - CONTINUOUS LAYERS FOR LIQUID-PHASE CATALYTIC HYDROGENATION OF ORGANIC COMPOUNDS - Google Patents

Description

The invention relates to petrochemistry, in particular the continuous method of liquid-phase catalytic hydride 1

The invention relates to the basic organic and petrochemical synthesis, in which the processes of liquid-phase hydrogenation of hydrocarbons, oxygen-containing and nitrogenous compounds are widely used for the production of mainly saturated hydrocarbons, ketones, carboxylic acids, alcohols and ambs.

The aim of the invention is to simplify the process of continuous liquid-phase catalytic hydrogenation of organic compounds.

The drawing shows a schematic diagram of the reactor site.

The site contains a mixer 1, a liquid distributor 2, a reactor 3, a catalyst 4, a lamp 5, a pump 6 and a refrigerator 7.

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hydrocarbons, oxygen-containing and nitrogenous compounds, which can be used to produce saturated hydrocarbons, ketones, carboxylic acids, alcohols and amines. · The goal is to simplify the process. The latter is carried out at 50-130 ° C and a stationary layer of catalyst. Moreover, the hydrogenation is carried out in film mode in the presence of the reaction mass formed during the hydrogenation. The method allows to simplify the process by conducting it at a pressure of 1-5 MPa without an excess of hydrogen while maintaining 98-100% selectivity, -98-99.9% conversion and feed rate of raw materials with

0.1-1.0 h ^-4 . 1 dw., 3 tab. At the beginning of the process, the final product (or solvent) is supplied to the reactor in an amount necessary for recycling through the reactor 3, lantern 5, refrigerator 7 and pump 6. After that, pump 6 is turned on and the liquid is circulated through reactor 3. Then the initial product is fed ( or its solution) into mixer 1, where it is mixed with the circulating hydrogenation product (or solution). Through the liquid distributor 2, the mixture of the initial and final products (or their solutions) enters the thermally insulated reactor 3 loaded with preformed catalyst 4, where it is evenly distributed over the cross section, forming a thin film of liquid on the surface of the catalyst, through which

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The bones of the catalyst diffuses the hydrogen fed to the reactor. Release of hydrogen in the reactor takes place automatically as it consumes ₅ Nia reaction. When a film of liquid moves from top to bottom, a chemical transformation occurs. Part of the reaction mixture at the level of the liquid in the lantern 5 is taken out of the reactor unit, and another part is sent by pump 6 to recycle. The heat of reaction is removed on a recycle line in a remote cooler 7. Monitoring the operation of the reactor in the film mode is carried out according to .15 the presence of a level in the flashlight. five.

Example 1. Into the reactor, which is a hollow vertical pipe (steel 12ХН1ОТ) 20 with a diameter of 50 mm and a length of 1800 mm, load 3000 cm ’, a pelletized alloyed nickel-aluminum catalyst (TU 59-83-75). Before the start of the hydrogenation, dnmetilfor- 25 mtsd is fed in the amount of 1-2 liters and ςτο is circulated with a flow rate of 30 l / h. A 10% by weight solution of 2,4-dinitroaniline (2,4- 30 DND) in dimethylformamide (DMF) with a flow rate of 6 l / h, which corresponds to a contact load of 2,4-DNA '0.2 g per cm', of a catalyst per hour, and 6.7% by weight of a solution triaminobenzene-35 (TAB) in DMF with a flow rate of 30 l / h. The liquid temperature at the reactor inlet is 60 * С. The fluid is uniformly distributed over the cross section, forming on the surface. catalyst thin film 40

ku, through which hydrogen diffuses to the surface of the catalyst and is fed into the reactor. Hydrogen is fed at a pressure of 1.5 MPa almost at a stoichiometric ratio (when hydrogenating 2.4 — DND by a known method, hydrogen is fed into the reactor with a 500-fold excess relative to stoichiometry), the liquid temperature at the outlet of the reactor 53 ra reaches 100 * C due to the release of heat of reaction. At the outlet of the reactor, 36 l / h of a 6.7% TAK solution in DMF is obtained, of which 6 l / h is removed from the reactor unit, and 30 l / h is sent to recycling. The conversion of 2,4-DNA in this case is 99.9%, ₍ selectivity for TAB is 100%. _.

Analogously to example 1 was carried out the hydrogenation of the compounds shown in table. one.

The hydrogenation was carried out according to the proposed method and for comparison by the method prototype with a recycle of hydrogen. The results are presented in table.

2 (data for hydrogen recycling are shown in brackets).

As can be seen from the table, 2, carrying out the hydrogenation of the proposed method, not only without worsening, but for some compounds even improving such technological parameters as contact load, conversion and selectivity, makes it possible to organize the process of liquid-phase hydrogenation at low pressure and without excess hydrogen. Such an organization of the process makes it possible to simplify the industrial technology of hydrogenation.

In Tile. 3, using the example of three hydrogenated compounds, illustrates the non-obviousness of a positive effect arising from the combination in the proposed method of liquid-phase hydrogenation of such techniques known in the technology of organic synthesis as film mode of fluid flow and recycling of the liquid phase.

Claims (1)

Claim A continuous method of liquid-phase catalytic hydrogenation of organic compounds at elevated temperature on a stationary catalyst bed, characterized in that, in order to simplify the process, hydrogenation is carried out in the regime of film flow of liquid with recycling of the reaction mass obtained by hydrogenation at the exit of the reactor. 1460920 Source ^ pradum ^ - ^! (or its solution The final product (or its solution)