DE2600128A1 - OXYDATION CATALYST AND ITS USE IN THE AMMOXYDATION OF PROPYLENE OR ISOBUTYLENE IN THE GAS PHASE FOR THE PRODUCTION OF ACRYLNITRILE OR METHACRYLNITRILE - Google Patents

Description

The invention relates to a new oxidation catalyst which contains at least one element from group IIA or IIB of the Periodic Table of the Elements or manganese plus chromium, bismuth and molybdenum as necessary elements and optionally can also contain a number of other elements which are suitable for various oxidation reactions , in particular for the ammoxidation of propylene or isobutylene for the production of acrylonitrile or methacrylonitrile, for the oxidation of propylene or isobutylene to acrolein or methacrolein and the oxidative dehydrogenation of olefins with 4 or 5 carbon atoms to the corresponding diolefins.

Oxidation catalysts similar to the subject of the present invention catalysts are already known. The new catalysts forming the subject of the invention differ, however, in terms of their composition from all catalysts known hitherto. The catalysts according to the invention are prepared by processes such as are also generally used for the preparation of the known catalysts.

The oxidation reactions for which the catalysts according to the invention are particularly suitable are known per se.

Generally speaking, these reactions are gas phase reactions in which the solid catalyst according to the invention is used. The reactants are passed over the catalyst in the presence of molecular oxygen at an elevated temperature, the desired product being obtained.

The new oxidation catalysts forming the subject of the invention are characterized by the general formula

A [deep] a C [deep] c D [deep] d Cr [deep] e Bi [deep] f Mo [deep] 12 O [deep] x

where mean:

A is an alkali metal, Tl, In, Ag, Cu, Sn, W, a rare earth metal or a mixture thereof,

C an element of group IIA or IIB of the Periodic Table of the Elements, manganese or a mixture thereof,

D Ni, Co, P, As, Sb, Ge, B or a mixture thereof,

a is a number from 0 to 4,

c is a number from 0.5 to 20, d is a number from 0 to 2,

e and f are each a number from 0.1 to 12 and

x is the number of oxygen atoms required to saturate the valences of the other elements present.

The new oxidation catalysts according to the invention are suitable for a wide variety of oxidation reactions, which are described in more detail below.

The catalysts according to the invention include all those which come under the general formula given above. Those catalysts according to the invention which contain calcium, magnesium, manganese, cadmium, zinc or a mixture thereof are of particular interest. They have the general formula given above, in which C stands for the elements mentioned. Those catalysts according to the invention which contain potassium, copper, tin or a mixture thereof are also of particular interest. These are those of the general formula given above, in which A stands for the elements mentioned and a is a number greater than zero.

The catalysts of the present invention are prepared in a manner similar to the known related catalysts (see e.g. U.S. Patent 3,642,930). Usually the catalysts are made by coprecipitating the soluble salts from an aqueous solution. The precipitate is then dried and heat-treated in air, whereby a catalytic oxide structure is formed.

It can be seen from the general formula given for the catalysts according to the invention that the number of oxygen atoms is identified by “x”. This "x" is variable because, while these oxidation catalysts are in use, the catalysts are constantly absorbing and releasing oxygen and giving an exact number for these catalysts would therefore be imprecise. The value of x is generally within the range of the number of oxygen atoms required in the highest oxidation state to a value greater than 50% of the number of oxygen atoms corresponding to the reduced state.

Although the reactions for which these catalysts are particularly suitable are known per se, some broad parameters within which the reactions are normally carried out are explained in more detail below. For the ammoxidation of propylene and isobutylene, the reaction is carried out in the presence of a catalyst as described above at a temperature of about 200 to about 600.degree. The contact time can range from less than 1 second to 20 seconds or more. The reaction can be carried out with the catalyst according to the invention either in the form of a fixed bed or in the form of a fluidized bed (fluidized bed) at atmospheric pressure, overpressure or underpressure.

The other reactions for which the catalysts of the invention are particularly well suited are the oxidation of other olefins and these are also known per se and the parameters used in the ammoxidation reaction can also be applied to these reactions.

The invention is explained in more detail below with reference to preferred embodiments, but without being restricted thereto.

Examples 1-10

Manufacture of various catalysts

Various catalysts consisting of 80% active material and 20% silica were prepared as described below.

example 1

80% K [deep] 0.1 Mg [deep] 7 Cr [deep] 3 BiP [deep] 0.5 Mo [deep] 12 O [deep] x and 20% SiO [deep] 2

A slurry was prepared composed of water and 63.56 g (NH [deep] 4) [deep] 6 Mo [deep] 7 O [deep] 24 times 4H [deep] 2 O, 48.37 g Nalco (40th % silica sol) and 3.46 g of H [deep] 3 PO [deep] 4 (42.5% solution), and with a solution of 9.00 g of CrO [deep] 3, 53.85 g of Mg ( NO [deep] 3) [deep] 2 times 6H [deep] 2 O, 3.03 g KNO [deep] 3 (10% solution) and 14.55 g Bi (NO [deep] 3) [deep] 3 times 5H [deep] 2 O combined. The slurry was evaporated to dryness and the resulting solid was further dried at 120 ° C overnight. The solid was then heated in air at 290 ° C for 3 hours, 425 ° C for 3 hours and 550 ° C for 16 hours to produce the active catalytic complex.

Example 2

80% K [deep] 0.1 Mg [deep] 7.5 Ni [deep] 0.5 Cr [deep] 3 BiP [deep] 0.5 Mo [deep] 12 O [deep] x and 20% SiO [ deep] 2

This catalyst was prepared in the same manner as in Example 1 using a slurry containing 63.56 g (NH [deep] 4) [deep] 6 Mo [deep] 7 P [deep] 24 times 4H [deep] 2 O, 49.50 g of Nalco (40% silica sol) and 3.46 g of a 42.5% H [deep] 3 PO [deep] 4 solution, and a solution containing 22.24 g of Cr (C [ deep] 2 H [deep] 3 O [deep] 2) [deep] 3 times H [deep] 2 O, 57.70 g Mg (NO [deep] 3) [deep] 2 times 6H [deep] 2 O, 4.36 g Ni (NO [deep] 3) [deep] 2 times 6H [deep] 2 O, 3.03 g of a 10% KNO [deep] 3 solution and 14.55 g Bi (NO [deep] 3) [deep] 3 times 5H [deep] 2 O contained. The separated solid was heat-treated in the above manner.

Example 3

80% K [deep] 0.1 Mn [deep] 7 Cr [deep] 3 BiP [deep] 0.5 Mo [deep] 12 O [deep] x and 20% SiO [deep] 2

This catalyst was prepared in the same manner as in Example 1 using a slurry containing 63.56 g (NH [deep] 4) [deep] 6 Mo [deep] 7 O [deep] 24 times 4H [deep] 2 O , 52.42 g Nalco (40% silica sol) and 3.46 g of a 42.5% H [deep] 3 PO [deep] 4 solution, and a solution containing 9.00 g CrO [deep] 3, 75.18 g Mn (NO [deep] 3) [deep] 2 (50% solution), 3.03 g KNO [deep] 3 (10% solution) and 14.55 g Bi (NO [deep ] 3) [deep] 3 times 5H [deep] 2 O. The separated solid was heat-treated in the same manner as above.

Example 4

80% K [deep] 0.1 Ni [deep] 0.5 Mn [deep] 6.5 Cr [deep] 3 BiP [deep] 0.5 Mo [deep] 12 O [deep] x and 20% SiO [ deep] 2

This catalyst was prepared in the same manner as in Example 1 using a slurry containing 63.56 g (NH [deep] 4) [deep] 6 Mo [deep] 7 O [deep] 24 times 4H [deep] 2 O , 51.13 g Nalco (40% SiO [deep] 2) and 3.46 g H [deep] 3 PO [deep] 4 (42.5% solution), and a solution containing 9.00 g CrO [deep] 3, 69.79 g Mn (NO [deep] 3) [deep] 2 (50% solution), 4.36 g Ni (NO [deep] 3) [deep] 2 times 6H [deep] 2 O, 14.55 g Bi (NO [deep] 3) [deep] 3 times 5H [deep] 2 O and 3.03 g KNO [deep] 3. The separated solid was heat-treated in the same manner as above.

Example 5

80% K [deep] 0.8 Mg [deep] 3.5 Mn [deep] 3.5 Cr [deep] 3 BiP [deep] 0.5 Mo [deep] 12 O [deep] x and 20% SiO [ deep] 2

This catalyst was prepared in the same manner as in Example 1 using a slurry containing 63.56 g (NH [deep] 4) [deep] 6 Mo [deep] 7 O [deep] 24 times 4H [deep] 2 O , 50.43 g of Nalco (40% silica sol) and 3.46 g of H [deep] 3 PO [deep] 4 (42.5% solution), and a solution that contained 9.00 g of CrO [deep] 3, 26.92 g Mg (NO [deep] 3) [deep] 2 times 6H [deep] 2 O, 37.60 g Mn (NO [deep] 3) [deep] 2 (50% solution), 3 .03 g of a 45% KOH solution and 14.55 g of Bi (NO [deep] 3) [deep] 3 times 5H [deep] 2 O. The separated solid was heat-treated in the same manner as above.

Example 6

80% Cs [deep] 0.1 Co [deep] 0.5 Mg [deep] 6.5 Cr [deep] 3 BiSb [deep] 0.5 Mo [deep] 12 O [deep] x and 20% SiO [ deep] 2

This catalyst was prepared in the same manner as in Example 1 using a slurry containing 63.56 g (NH [deep] 4) [deep] 6 Mo [deep] 7 O [deep] 24 times 4H [deep] 2 O , 48.28 g Nalco (40% SiO [deep] 2), 2.19 g

Sb [deep] 2 O [deep] 3, and a solution that contained 9.00 g CrO [deep] 3, 50.00 g Mg (NO [deep] 3) [deep] 2 times 6H [deep] 2 O , 4.37 g Co (NO [deep] 3) [deep] 2 times 6H [deep] 2 O, 14.55 g Bi (NO [deep] 3) [deep] 3 times 5H [deep] 2 O and 0 , 58 g CsNO [deep] 3 contained. The separated solid was heat-treated in the same manner as above.

Example 7

80% Mg [deep] 7 Cr [deep] 1.5 Cu [deep] 1.5 BiP [deep] 0.5 Mo [deep] 12 O [deep] x and 20% SiO [deep] 2

This catalyst was prepared in the same manner as in Example 1 using a slurry containing 63.56 g (NH [deep] 4) [deep] 6 Mo [deep] 7 O [deep] 24 times 4H [deep] 2 O , 47.78 g of Nalco (40% silica sol) and 3.46 g of H [deep] 3 PO [deep] 4 (42.5% solution), and a solution containing 53.83 g of Mg (NO [ deep] 3) [deep] 2 times 6H [deep] 2 O, 10.88 g Cu (NO [deep] 3) [deep] 2 times 3H [deep] 2 O, 4.50 g CrO [deep] 3 and 14.55 g Bi (NO [deep] 3) [deep] 3 times 5H [deep] 2 O contained. The separated solid was heat-treated in the same manner as above.

Example 8

80% Mg [deep] 7 Cr [deep] 1.5 Sn [deep] 1.5 BiP [deep] 0.5 Mo [deep] 12 O [deep] x and 20% SiO [deep] 2

This catalyst was prepared in the same manner as in Example 1 using a slurry containing 63.56 g (NH [deep] 4) [deep] 6 Mo [deep] 7 O [deep] 24 times 4H [deep] 2 O , 49.78 g of Nalco (40% silica sol) and 3.46 g of a 42.5% H [deep] 3 PO [deep] 4 solution, and a solution containing 53.83 g of Mg (NO [ deep] 3) [deep] 2 times 6H [deep] 2 O, 14.55 g Bi (NO [deep] 3) [deep] 3 times 5H [deep] 2 O, 4.50 g CrO [deep] 3 and Contained 6.78 g of SnO [deep] 2. The separated solid was heat-treated in the same manner as above.

Example 9

80% Ca [deep] 1 Cr [deep] 0.5 Sn [deep] 0.5 Bi [deep] 0.2 Mo [deep] 2 O [deep] x and 20% SiO [deep] 2

This catalyst was prepared in the same manner as in Example 1 using a slurry containing 22.95 g (NH [deep] 4) [deep] 6 Mo [deep] 7 O [deep] 24 times 4H [deep] 2 O , 21.09 g Nalco (40% silica sol) and a solution containing 15.35 g Ca (NO [deep] 3) [deep] 2 times 4H [deep] 2 O, 3.25 g CrO [deep ] 3, 6.31 g Bi (NO [deep] 3) [deep] 3 times 5H [deep] 2 O and 4.90 g SnO [deep] 2. The separated solid was heat-treated in the same manner as above.

Example 10

80% K [deep] 0.5 Cd [deep] 3.5 Mg [deep] 3.5 Cr [deep] 3 BiP [deep] 0.5 Mo [deep] 12 O [deep] x and 20% SiO [ deep] 2

This catalyst was prepared in the same manner as in Example 1 using a slurry containing 63.56 g (NH [deep] 4) [deep] 6 Mo [deep] 7 O [deep] 24 times 4H [deep] 2 O , 53.20 g of Nalco (40% SiO [deep] 2) and 3.46 g of a 42.5% H [deep] 3 PO [deep] 4 solution, and a solution that contained 9.00 g CrO [deep] 3, 14.55 g Bi (NO [deep] 3) [deep] 3 times 5H [deep] 2 O, 32.39 g Cd (NO [deep] 3) [deep] 2 times 4H [deep ] 2 O, 26.92 g Mg (NO [deep] 3) [deep] 2 times 6H [deep] 2 O and 1.52 g KNO [deep] 3. The separated solid was heat-treated in the same manner as above.

Example 10-a

80% K [deep] 1.5 Zn [deep] 3 Ni [deep] 0.5 Cr [deep] 3 Bi [deep] 3 P [deep] 0.5 Mo [deep] 12 O [deep] x and 20 % SiO [deep] 2

This catalyst was prepared in the same manner as in Example 1 using a slurry containing 63 56 g (NH [deep] 4) [deep] 6 Mo [deep] 7 O [deep] 24 times 4H [deep] 2 O, 57.03 g of Nalco (40% SiO [deep] 2) and 3.46 g of a 42.5% H [deep] 3 PO [deep] 4 solution and a solution containing 9.00 g of CrO [deep] 3, 43.65 g Bi (NO [deep] 3) [deep] 3 times 5H [deep] 2 O, 7.32 g ZnO,

Contained 4.36 g Ni (NO [deep] 3) [deep] 2 times 6H [deep] 2 O and 4.55 g KNO [deep] 3. The slurry was evaporated to dryness and heat treated in the same manner as above.

Example 11

Manufacture of a catalyst without silica

The preparation of the catalyst Ca [deep] 2 SnO [deep] 0.5 Cr [deep] 0.5 BiMo [deep] 2 O [deep] x was carried out as follows:

In 20 ccm of water, 24.93 g Ca (NO [deep] 3) [deep] 2 times 4H [deep] 2 O were dissolved and 2.65 g CrO [deep] 3 and 3.99 g SnO [deep] 2 added. A solution of 18.72 g (NH [deep] 4) [deep] 6 Mo [deep] 7 O [deep] 24 times 4H [deep] 2 O, dissolved in 50 ccm of a 9.3% strength, was added to this mixture Ammonia solution, added dropwise and then 25.36 g Bi (NO [deep] 3) [deep] 3 times 5H [deep] 2 O, dissolved in 40 cc of a 13.8% HNO [deep] 3 solution, was added. The pH of the mixture was brought to 4.0-4.5 with about 10 cc ammonium hydroxide. The mixture was stirred for 30 minutes and allowed to stand for 48 hours. The catalyst was washed with 1440 ml of water, filtered and dried at 120.degree. The catalyst was heat treated at 540 ° C for 16 hours. Due to the leaching of calcium during the wash, the final composition of the catalyst was Ca [deep] 1.8 Sn [deep] 3 Cr [deep] 3 Bi [deep] 6 Mo [deep] 12 O [deep] x.

Examples 12-30

Manufacture of acrylonitrile

The catalysts used in Examples 1 to 10 were tested in the ammoxidation of propylene. The feed used had a propylene / ammonia / air / water vapor ratio of 1/1, 1/10/4. The catalyst in each of the reactions was milled and sieved and transferred to a 5 cc reaction zone of a tubular reactor made of stainless steel with an inner diameter of 1 cm. Table I below shows the catalyst used, the reaction time and contact time used, and the results obtained when using the respective catalysts. The results were expressed as follows:

Table I.

Ammoxidation of propylene

Example 31

Manufacture of acrylonitrile using a 100% active catalyst

The catalyst used in Example 10 was used to make acrylonitrile, but this time using a different reactant feed of propylene / ammonia / air / steam in a ratio of 1/1/8/2. A reaction temperature of 450 ° C and an apparent contact time of 3 seconds were used. This reaction gave a one-pass yield of acrylonitrile of 68.4% with a selectivity of 79%.

Examples 32-36

Ammoxidation of isobutylene

Several of the above catalysts were tested in the ammoxidation of isobutylene using a contact time of 3 seconds and a reactant charge of isobutylene / ammonia / air / water vapor in a ratio of 1 / 1.1 / 10/4. The results obtained in these experiments are given in Table II below.

Table II

Ammoxidation of isobutylene

* Contact time was 6 seconds, starting charge: isobutylene / ammonia / air / steam = 1/2/15/4. Example 37 Oxydehydrogenation of butene-1 The catalyst of Example 2 was used for the oxydehydrogenation of butene-1 using a butene-1 / air ratio of 1/14. The reaction was carried out at 400 ° C using a contact time of 3 seconds. The single pass yield of butadiene was 77.6%, the conversion of 1-butene was 86.9% and the selectivity to butadiene was 90%. Example 38 Oxydehydrogenation of butene-2 Using the catalyst of Example 5, butene-2 was converted to butadiene using a reactant ratio of cis / trans-butene-2 (42.5% cis and 57.5% trans) / air of 1/11. A reaction temperature of 490 ° C and an apparent contact time of 3 seconds were used. The single pass yield of butadiene was 68.1%, the conversion of 2-butene was 73.1% and the selectivity was 93%. In the same manner as above, other catalysts of the present invention can be prepared and used in ammoxidation, oxydehydrogenation and oxidation reactions.

Claims (7)

1. Oxidation catalyst, characterized by the general formula A [deep] a C [deep] c D [deep] d Cr [deep] e Bi [deep] f Mo [deep] 12 O [deep] x where mean: A is an alkali metal, Tl, In, Ag, Cu, Sn, W, a rare earth metal or a mixture thereof, C an element of group IIA or IIB of the Periodic Table of the Elements, manganese or a mixture thereof, D Ni, Co, P, As, Sb, Ge, B or a mixture thereof, a is a number from 0 to 4, c is a number from 0.5 to 20, d is a number from 0 to 2, e and f are each a number from 0.1 to 12 and x is the number of oxygen atoms required to saturate the valences of the other elements present. 2. Oxidation catalyst according to claim 1, characterized in that in the general formula C is calcium, magnesium, manganese, cadmium, zinc or a mixture thereof. 3. Oxidation catalyst according to claim 1 and / or 2, characterized in that in the general formula A is potassium, copper, tin or a mixture thereof and a is a number greater than zero. 4. Process for the preparation of acrylonitrile or methacrylonitrile by ammoxidation of propylene or isobutylene in the gas phase, in which propylene or isobutylene, ammonia and molecular oxygen are brought into contact with a catalyst at a temperature of about 200 to about 600 ° C., characterized in that that the catalyst used is one of the general formula A [deep] a C [deep] c D [deep] d Cr [deep] e Bi [deep] f Mo [deep] 12 O [deep] x where mean: A is an alkali metal, Tl, In, Ag, Cu, Sn, W, a rare earth metal or a mixture thereof, C an element of group IIA or IIB of the Periodic Table of the Elements, manganese or a mixture thereof, D Ni, Co, P, As, Sb, Ge, B or a mixture thereof, a is a number from 0 to 4, c is a number from 0.5 to 20, d is a number from 0 to 2, e and f are each a number from 0.1 to 12 and x is the number of oxygen atoms required to saturate the valences of the other elements present. 5. The method according to claim 4, characterized in that one uses a catalyst of the general formula given in claim 4, in which C is calcium, magnesium, manganese, cadmium, zinc or a mixture thereof. 6. The method according to claim 4 and / or 5, characterized in that a catalyst of the general formula given in claim 4, in which A is potassium, copper, tin or a mixture thereof and a is a number greater than 0 is used. 7. The method according to claim 4, characterized in that acrylonitrile is produced.