JPS59204163A - Production of unsaturated nitrile - Google Patents

Abstract

PURPOSE:To obtain the titled compound in high yield, by ammoxidation of propylene, isobutene or a compound capable of giving isobutene under reaction conditions in the presence of oxides of elements at a specific composition ratio as a catalyst. CONSTITUTION:Propylene, isobutene or a compound capable of giving isobutene under reaction conditions, e.g. tert-butanol, is subjected to ammoxidation to give an unsaturated nitrile. In the process, the reaction is carried out in the presence of a catalyst containing (A) an oxide of Mo, Bi, P or Si, (B) two or more oxides of two or more elements of the group consisting of Fe, Co, Ni, Cu, Zr and K and (C) an oxide of one or more elements of the group consisting of Mn, Ce, Th, Y, La and T1. Preferably, the catalyst composition is usually withing the range of the formula [the atomic ratio, m is wt%; X1 is element belonging to the component (A); X2 is element belonging to the component (C); a is 2-15; b is 0.5-10; n is 20-100].

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an unsaturated nitrile, and more particularly to a catalyst used when producing an unsaturated nitrile by mixing KH propylene and isobutyne with ammonoxychloride.

The production of unsaturated nitriles by ammoxidation of olefins has been carried out industrially for some time, and in particular, the production of acrylonitrile by ammoxidation of propylene is the most extensive. It has been reported that the yield when acrylonitrile is produced by ammoxidation of propylene is usually about 75% and a high value of 780%. In the production of methacrylonitrile using ammooxythione of -4, isobutyne, the yield is even lower, at a level of 60 to 65, or at most 70.

In other words, there are still many points to be improved in terms of yield in the method for producing unsaturated nitriles by ammoxidation of olefins.

Since the production of unsaturated nitriles by ammoxidation of olefins is a large-scale industry, the improvement in unit consumption associated with the improvement in yield has great industrial significance.

It is an object of the present invention to provide a method for producing unsaturated nitriles in high yield by anomooxidation of propylene and isobutyne.

The present inventors have conducted various studies on a method for producing unsaturated nitriles using ammoxylation of olefins, and in particular on catalysts for ammoxylation. As a result, the present inventors have discovered a catalyst that can produce 14f of the target compound in a higher yield than conventionally known catalysts. 7'ζ0 That is, the gist of the present invention is that the ammoxylation of propylene, isobutene or inobutene under the reaction conditions is When producing a saturated nitrile, (1) M□, Bi.

P, Si oxide, and (2) "e' + cO+
NI + cIJ.

oxides of two or more elements selected from the group consisting of Zr, K, and (6) Mn + Ce + TI]
The purpose of the present invention is to carry out the reaction in the presence of a catalyst containing an oxide of one or more elements selected from the group consisting of: +Y+''a+T1.

Therefore, when the ammoxidation of propylene/hone is carried out using the catalyst according to the method of the present invention, the desired acrylonitrile can be obtained in high yield compared to conventionally known catalysts, and the same In addition, methacrylonitrile is obtained from isobutyne.

The reaction raw material in the method of the present invention is propylene or isobutyne, and in place of isobutyne, compounds that easily give inobutene under the reaction conditions, such as tert-buquinol or methyl-tert-butyl ether, may also be used. It can be used.

Air is usually used as the oxygen source. If necessary, nitric acid gas, water vapor, etc. may be mixed as a diluting gas. Gas i'! supplied to the reactor! ,oxygen/
Molar ratios of olefins of 1 to 5, especially 2 to 4 are suitable. The ammonia/olefin molar ratio is preferably 1-5, particularly 1-2. Although water vapor can be added during the reaction, in many cases in the present invention, there is no need to add water vapor.

The content ratio of the constituent elements of the catalyst in the method of the present invention can vary over a wide range, but usually.

It is preferable that the catalyst composition (atomic ratio, where m is a weight factor) is within the range shown by the following formula.

”0□2Bio5~2Po6, Yaz(X1')acX2
)b On” (SiO2)m plus, Xl is 'e +
It is an oxide of two or more elements selected from the group consisting of CO + Nl + OLl + Zr + K, and
2B Mll + ”e + Th + Y+ La +
Indicates an oxide of one or more elements apart from the group consisting of TI.

It is a trace,] If it is begging in the range of 2 to 15), it is in the range of 05 to 10, and N is the range of 20 to 100.

The value of nl can be prepared by the central valve 4 "catalyst preparation" method described on page 67, when the weight percentage of 8102 in the catalyst is 60 to 60 years. As raw materials for catalyst preparation, for example, as starting materials for molybdenum, molybdic acid, molybdenum trioxide, ammonium molybdate, etc. are often used.

Bismuth oxide, bismuth nitrate, etc. are used as raw materials for the bismuth component. As the raw material for the phosphorus component, phosphoric acid, ammonium phosphate, etc. are used. Iron, cobalt, copper, zirconium, potassium, manganese, cerium,
Oxides, hydroxides, nitrates, etc. are used as raw materials for thorium, yttrium, lanthanum, and thallium components. As the silicon oxide component, colloidal silica, silica sol, etc. are used.

A catalyst is produced by mixing, drying, and calcining each of the above-mentioned catalyst components to a desired composition ratio. The firing is
Usually, it is heated at 500° C. to 800° C. for 1.1 hours to 30 hours in the presence of air. The catalyst is often used in a fluidized bed reactor in the form of fine particles, but it can also be shaped into tablets and used in a fixed bed reactor.

The reactor was filled with the above catalyst, and the catalyst bed temperature was 650-55.
It is preferable to carry out the reaction at 0°C, particularly at 380 to 470°C.

The reaction pressure is normal pressure to slightly increased pressure, and the contact time is 0.5 seconds to 1.
5 seconds is sufficient.

The present invention will be explained below with reference to Examples.

Example-1 Silica sol (5io220 wt%) 2500 f!
An aqueous solution in which ammonium dihydrogen phosphate 67 and ammonium para-molybdate 2407 were dissolved was added. Next, potassium nitrate 12, cobalt nitrate 1307,
Ferric nitrate 1201, nickel nitrate 72.5'if, manganese nitrate 60 and cerium nitrate filter5. P− was added and dissolved. Next, bismuth nitrate 497 was added for 1 month. 1.Heat the 2nd solution while stirring well. Evaporated to dryness. The dried product was filtered at 250° C. for 4 hours and then calcined at 450° C. for 4 hours, then pulverized into a fine powder for use in a fluidized bed, and then calcined at 650° C. for 4 hours to prepare a catalyst.

The above catalyst 4007 was packed in a fluidized bed reactor with an inner diameter of 50:++mφ, and dipropylene, ammonia, and air were added in a volume of 1Q'.
=J was supplied at a ratio of 1.2:105, and the reaction was carried out at a catalyst bed C crystallinity of 420° C. for a contact time of 75 seconds.

As a result of analyzing one cogas for the reactor by gas chromatography using a conventional method, the conversion rate of propylene was 97% and the selectivity of acrylonitrile was 85 mo1%.

Examples 2 to 5 Using the same method as in Example 1, using various catalysts Example 6 In the same reaction method as in Example 1, metaacrylonitrile was synthesized by changing the reaction raw material from propyleno to isobutyne. The catalyst used was the same as that used in Example 1, and the reaction was carried out at a catalyst bed temperature of 400°C. The results obtained were a conversion of inobutene l<99% and a selectivity of methacrylonitrile of 7 mol.

Example 7 The same reaction as in Example 6 was carried out, the catalyst used was changed to the catalyst of Example 2, and isobutyne was reacted.

The conversion rate of isobutyne was 99%, and the selectivity of acrylonitrile was 75 moA%.

Example 8 A sample was immersed in an aqueous solution containing Rum 127 and heated to dryness. This was calcined at 250°C for 4 hours and at 650°C for 4 hours to prepare a catalyst. Using this catalyst, a reaction was carried out in the same manner as in Example 1 to obtain a propylene conversion rate of 96-fiber acrylonitrile selectivity of 88%.

Example? It was immersed in an aqueous solution containing 10 g of lamb and heated to dryness. This was calcined at 250°C for 4 hours and at 660°C for 5 hours to prepare a catalyst. Using this catalyst, a reaction was carried out in the same manner as in Example 1, resulting in a propylene conversion of 96% and an acrylonitrile selectivity of 19%.

patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1) When producing unsaturated nitriles by ammoxylation of propylene, isobutyne or a compound that gives isobutyne under reaction conditions, (1) M<), 1
3i, P, Si oxide, and (2) 'e
1. A method for producing an unsaturated nitrile, characterized in that the reaction is carried out in the presence of a catalyst containing an oxide of one or more elements selected from the group consisting of +COrN++.