JPS5814429B2 - Production method of saturated nitrile - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing saturated nitriles.

Conventionally, a method for selectively obtaining a saturated nitrile by hydrogenating an aliphatic unsaturated nitrile in a liquid phase under pressure is known.

However, this manufacturing method requires complicated operations such as the use of high-pressure hydrogen and the removal of solvents such as acetic acid, and there are problems with equipment and safety due to the use of high pressure.
This cannot necessarily be said to be an economical method.

The yield is also not satisfactory.

The present inventors have completed the present invention as a result of intensive studies to eliminate these conventional drawbacks.

The present invention provides an aliphatic unsaturated nitrile as a catalyst containing palladium and X (X represents at least one element selected from phosphorus, arsenic, antimony, and bismuth).

) in the presence of hydrogen in the gas phase using molecular hydrogen.

As described above, the reaction of the present invention is carried out in the gas phase, and by carrying out the reaction in the gas phase, the reaction time is significantly shortened.
Moreover, the gas phase reaction product can be made into a product as it is by simply cooling and condensing, and the desolvation step, which is indispensable in the liquid phase method, can be omitted.

Furthermore, the saturated phase nitrile obtained by the method of the present invention has significantly less coloring of the product due to catalysts and by-product amines, and is also very superior in this respect when compared to the liquid phase method.

Taking these points into consideration, and because it can be operated at normal pressure, the method of the present invention can be said to be an extremely excellent industrial method.

Further, by using the catalyst used in the present invention, a saturated nitrile can be obtained in high yield in the present invention.

Among the catalysts used in the present invention, preferred are catalysts in which the ratio of the number of atoms of palladium and the X component contained in the catalyst is .

The catalyst used in the present invention can be prepared by a generally known method.

For example, by mixing compounds of each constituent element and a carrier if necessary in the presence of water, calcining the mixture preferably at 200 to 700°C, particularly preferably 300 to 600°C, and further reducing with hydrogen if necessary, the catalyst can be catalyzed. can be prepared.

The raw material compounds used to prepare the catalyst, that is, the compounds of each constituent element, are not limited to specific compounds; palladium compounds include, for example, palladium chloride, palladium nitrate, palladium oxide, and phosphorus compounds include, for example, phosphoric acid. and its salts, phosphorous acid and its salts, hypophosphorous acid and its salts, phosphorus pentoxide, etc. Arsenic compounds include arsenic acid, arsenous acid, and their anhydrides, and antimony compounds include antimony trioxide. , antimony pentoxide, antimony trichloride, tartrates such as antimony pentachloride tartarite, and bismuth compounds such as bismuth oxide and bismuth nitrate are often used.

Although it is generally preferable to use a carrier, it is also possible to use it without a carrier.

As the carrier, silica gel, alumina, activated carbon, magnesia, beryllia, carborundum, titania, sintered glass, aluminum sponge, titanium sponge, etc. can be used.

Preferable results can be obtained even when the amount of catalyst relative to the carrier is as small as 0.5% by weight.

The aliphatic unsaturated nitrile used in the present invention is not limited to any special one, but α/β monounsaturated nitrile directly obtained by the ammoxidation reaction of olefin, especially acrylonitrile, methacrylonitrile, etc. Industrially advantageous.

Further, the hydrogen used may be pure hydrogen, or may be a mixture with a gas inert to the reaction, such as nitrogen, carbon dioxide, or carbon monoxide.

Further, water vapor, alcohols, etc. can be optionally used to dilute the reaction gas.

The reaction can be carried out either in a fixed bed or in a fluidized bed.

The reaction materials may be mixed before entering the reaction zone, or may be introduced separately into the reaction zone.

Also, diluents such as nitrogen can be mixed with the feedstock at this time.

The reaction temperature may be any temperature as long as the reactants and reaction products are in a gaseous state, but 85°C to 200°C is particularly preferable.

Furthermore, one of the features of the present invention is that the reaction can be carried out under atmospheric pressure, but the reaction also proceeds normally under increased pressure or reduced pressure.

The concentration of aliphatic unsaturated nitrile contained in the feed gas is not particularly limited, but is particularly preferably 1 to 10%.

Further, the contact time is preferably short, but when carrying out this reaction, 0.5 seconds to 10 seconds is appropriate.

Further, the ratio of aliphatic unsaturated nitrile and hydrogen used is not particularly limited, but in particular unsaturated nitrile: hydrogen = 1:1 ~
It is preferable that it is 10 (molar ratio).

The saturated nitrile produced by the method of the present invention is important as an intermediate in organic synthesis, particularly as a raw material for agricultural chemicals.

Next, the present invention will be explained in detail with reference to Examples.

The reaction was carried out under atmospheric pressure and a U-tube fixed bed reactor was used.

The center of this reaction tube was filled with 10 ml of catalyst.

The reaction raw material gas consisted of unsaturated nitrile, hydrogen, and nitrogen, and was previously made into a gas in a preheating layer before being introduced into the reaction layer.

An electric furnace was used for heating, and uniformity of heating was maintained using an alumina fluidized bath.

The reaction product was rapidly cooled at the outlet of the reactor, and the condensate was quantified using gas chromatography.

The reaction rate and yield were calculated using the following formula.

Example 1 16.6 parts by weight of silica gel (Aerosil 380) is suspended in 300 parts by weight of water and evaporated to dryness.

Separately, 0.44 parts by weight of palladium chloride is suspended in 300 parts by weight of water, and 5 parts by weight of concentrated aqueous ammonia is added to dissolve it.

The silica gel was immersed in this palladium ammine complex ion solution, and left to stand for 3 hours while stirring occasionally.
Pass it in your mouth and rinse thoroughly with water.

This was calcined at 450°C for 5 hours, and further reduced with hydrogen at 450°C for 1 hour.

This reduced product was added to an aqueous solution containing 0.33 parts by weight of phosphorous acid, evaporated to dryness, and then calcined at 450°C for 5 hours. The resulting silica-supported palladium-phosphorous catalyst was reduced with hydrogen, and then reacted. used for.

This catalyst has a composition of Pd1P2, with a ratio of 1.0% to the support.
Contains 4% by weight of palladium atoms.

10 ml of this catalyst was filled into a reaction tube, and the reaction temperature was 110
The reaction raw material gas was supplied at a temperature of 3.6 seconds at a temperature of 3.6 seconds.

The reaction raw material gas is 3 mol% methacrylonitrile, 12
% hydrogen and 85 mole % nitrogen.

As a result of gas chromatographic analysis of the reaction product, the reaction rate of methacrylonitrile was 100% and the yield of isobutyronitrile was 33.8%.

Example 2 16.6 parts by weight of silica gel (Aerosil 380) and 0
．． 4 parts by weight of antimony trioxide are suspended in 300 parts by weight of water and evaporated to dryness.

The silica gel containing antimony trioxide obtained here was immersed in palladium ammine complex ions in the same manner as in Example 1, and calcined at 450° C. for 5 hours.

The composition of this catalyst is Pd1Sb1.

This catalyst was reduced with hydrogen at 450° C. for 1 hour and used in the reaction.

The reaction was carried out under the same conditions as in Example 1.

The results are shown in Table 1. Examples 3 to 5 Catalysts were prepared in exactly the same manner as in Example 2, except that the amount of antimony trioxide used was changed, and the reaction was carried out under the same conditions as in Example 1.

The catalyst composition and reaction results are shown in Table-1.

Example 6 A catalyst was prepared in the same manner as in GL Example 2, except that 0.27 parts by weight of triarsenic dioxide was used instead of 0.4 parts by weight of antimony trioxide, and the reaction was carried out under the same conditions as in Example 1. Ta.

The catalyst composition and reaction results are shown in Table-1.

Example 7 A catalyst was prepared in the same manner as in Example 2, except that 1.6 parts by weight of bismuth nitrate was used instead of 0.4 parts by weight of antimony trioxide, and the reaction was carried out under the same conditions as in Example 1. Ta.

The catalyst composition and reaction results are shown in Table I.

Example 8 The catalyst obtained in Example 2 is added to an aqueous solution containing 1.15 parts by weight of phosphorous acid and evaporated to dryness.

This was calcined at 450°C for 5 hours, further reduced with hydrogen at 450°C for 1 hour, and used for the reaction.

The composition of the catalyst is PdISb1P7.

A reaction was carried out under the same conditions as in Example 1 using this catalyst.

The results are shown in Table-2.

Examples 9 to 11 Catalysts were prepared in the same manner as in Example 8, except that the amounts of antimony trioxide and phosphorous acid used were changed, and the reaction was carried out under the same conditions as in Example 1.

The catalyst composition and reaction results are shown in Table-2.

Example 12 Using the catalyst used in Example 1l, a reaction was carried out using a reaction gas containing 3 mol % of acrylonitrile instead of 3 mol % of methacrylonitrile.

Other reaction conditions are the same as in Example 1.

The reaction rate of acrylonitrile was 100.0%, and the yield of propionitrile obtained was 85.3%.

Comparative Example 1 A catalyst was prepared in the same manner as in Example 1, except that phosphorous acid was not added, and a palladium catalyst with a palladium content of 1.4% by weight was obtained.

When a reaction was carried out using this catalyst under the same conditions as in Example 1, the reaction rate of methachronitrile was 100.0% and the yield of isobutyronitrile was 23.3%.

Examples 13 to 18 Catalysts shown in Table 3 were prepared in the same manner, and the reaction was carried out under the same conditions as in Example 1.

The results are shown in Table 3.

Claims (1)

[Claims] 1. Aliphatic unsaturated nitrile is prepared using molecular hydrogen in the presence of a catalyst containing palladium and X (X represents at least one element selected from phosphorus, arsenic, antimony, and bismuth). A method for producing saturated nitrile characterized by hydrogenation in the gas phase.