CS200237B2 - Catalyst for olefin oxydation based on molybden iron and promotor - Google Patents

Description

The present invention relates to an olefin oxidation catalyst.

Catalysts for the oxidation, ammoxidation and oxydehydrogenation of olefins are well known, for example, from U.S. Pat. Nos. 3,642,930 and 3,414,631. Although the catalysts of these patents are very suitable, the catalysts of the invention are more preferably.

The olefin oxidation catalyst of the present invention is based on the discovery that some iron, bismuth and molybdenum oxidation catalysts containing other additional elements specified as promoters are characterized by excellent catalytic activity in various olefin oxidation, ammoxidation, dehydrogenation and oxydehydrogenation. In particular, it has been found that the specific catalyst combinations described below are particularly suitable for the preparation of acrylic nitrile and methacrylic nitrile and ammoxidation of propylene or isobutylene.

In addition to being excellent ammoxidation catalysts in the preparation of acrylic nitrile or methacrylic nitrile, the novel catalysts also exhibit excellent catalytic activity in converting olefins having four or more consecutive carbon atoms to the corresponding diolefins as well as oxydehydrogenating olefins to form diolefins.

WcW12 ° x

200237 '

Accordingly, the present invention provides a catalyst for the oxidation of olefins based on molybdenum, iron, and promoters, characterized in that it consists of a combination of elements corresponding to the general formula.

where it means

J alkali metal, thallium, silver or a mixture thereof,

Q cobalt, nickel, zinc, cadmium, beryllium, magnesium, calcium, strontium, barium, radium or a mixture thereof,

Z a two-element or multi-element system selected from the group consisting of germanium with antimony, tungsten, copper with tin, cerium with tungsten, praseodymium with manganese, tin with manganese, manganese and tungsten, tungsten with antimony, chromium with tin, tungsten with tin, germanium with tin, tin, tungsten, phosphorus, phosphorus, chromium or manganese or copper antimony, manganese with phosphorus or mixtures thereof, where J is other than thallium when Z is manganese with phosphorus,

D vizrnut or tellurium, a number greater than zero to 5, b a number greater than zero to 20, c a number greater than zero to 20, d a number greater than zero to 20, e a number greater than zero to 20, x a number to satisfy the valency the requirements of the other elements for oxygen, each element in the two-element or multi-element system being present in an amount of at least 1% atomic with respect to all elements in the system.

Preferably, the catalysts of the present invention comprise the above elements in the following amounts: a is 0.01 to 0.5, b is 0.1 to 20, 0.1 to 9, d, 0.1 to 20, and 0, 1 to 20.

Optionally, the above elements are present in the following amounts:? Is 0.03 to 0.5, 4 to 10, c 0.5 to 7, d 0.5 to 5 and? 0.5 to 5.

In a particularly preferred embodiment, the aforementioned and most preferred catalysts comprise potassium, rubidium and / or cesium, and optionally nickel and / or cobalt.

It is also desirable that Z be selected such that the ratio of the amount of the first element of each system as described above to the amount of the second element in the system is in the range of 1 to 0.25 to 1 to 0.75.

Of the prior art catalysts, those where component Z is selected from the following combinations of elements are of particular interest: germanium and antimony, copper and tungsten, copper and tin, germanium and tungsten, praseodymium and manganese, tin and manganese as well as manganese and tungsten; Of particular interest are those catalysts wherein the Z component is a combination of germanium with tin, copper with tungsten, copper with tin, germanium with tungsten and praseodymium with manganese.

The catalysts of the present invention may be prepared by any of the well-known and conventional methods, such as the various processes described in the patents and applications discussed herein. For example, the catalyst can be prepared by starting from an aqueous preparation containing degradable salts and / or metal oxides to be introduced into the catalyst, water is distilled off from the aqueous preparation to form a thick paste which is dried and the dry matter is calcined in elevated temperatures in the oxidizing environment. Processes for preparing catalysts of this type are well known to those skilled in the art, so that there can be no difficulty in preparing the catalysts of the present invention.

The catalysts of the present invention can be used on or without a support, and generally known materials such as silica, alumina, zirconia, titanium dioxide, boron phosphate, antimony phosphate, montmorillonite or the like can be used. The catalysts may be used in a fixed or animal bed arrangement. They are simply replaced by the catalysts previously used and the reaction is simply carried out under substantially the same conditions.

For example, when the catalysts of the present invention are used to ammoxidate propylene or isobutylene to form acrylic nitrile or aethacrylic nitrile, the olefin to be reacted is contacted with oxygen and ammonia in the necessary proportions with the catalyst at elevated temperature, usually about 200 to 600 ° C, in a fixed or swirled bed reactor for a time sufficient to effect the desired reaction. Similarly, when the catalyst of the present invention is used to catalyze other known reactions, reaction conditions that are conventional in such a reaction are used.

Specific execution

Comparative example A ^'80 * ^K 0.1 ^Ni 2.5 ^CO 4.5 ^Fe 3 ^BiP 0.5 ^Mo 12 ° x ^{+ 20} * ^Si0 2

A solution of 127.1 g of ammonium heptamolybdate (NH4gMoyOg4E6gH2O) in water is prepared, and 6.9 g of a 42.5% phosphoric acid solution and 102.7 g of a 40% silica sol (NAlco) are added to form a suspension. separately prepare an aqueous solution containing 72.7 g of ferric nitrate FeGlO3, 91.42, 29.1 g of bismuth nitrate BKMO4.9gHgO, 78.6 g of cobalt nitrate CoCNO4gHgO, 43, b. g of nickel nitrate NiNO4 .mu.g and 6.1 g of a 10% aqueous solution of potassium nitrate. The nitrate mixture solution is slowly added to the above suspension. The final slurry was evaporated to dryness and the solid was heated at 290 ° C for 3 hours, for a further 3 hours at 425 ° C and for 16 hours at 550 ° C.

Examples 1 to 7

In the same manner as discussed in Comparative Example A, the catalysts listed in Table I were prepared. Each of these catalysts, as well as the catalyst of Comparative Example A, were tested for catalytic activity in the amaoxidation of propylene to acrylic nitrile. In such a test, a 5 ml fixed bed reactor is charged with catalyst and a 1.8: 2.2: 3.6: 2.4: 6 mixture of propylene, ammonia, oxygen, nitrogen and water is passed into the reactor so that there is a flow rate of 0.1 g propylene per g catalyst per hour with a contact time of 3 seconds. The reaction temperature is maintained at 420 ° C. The results obtained with both these catalysts and the catalyst of Comparative Example A are shown in Table I below.

Tabulkal

Example Catalyst composition (80% catalyst to 20% silica) Conversion to acrylic nitrile as it passes Selectivity to acrylic nitrile Cf. AND ^K 0.1 ^Ni 2.5 ^CO 4.5 ^Fe 3 ^BiP 0.5 ^Mo 12 ° x 73.1 79.4 1 ^to % 5 ⁽ ^ 1 ^Ni 2.5 ^Co 4.5 ^Fe 2 ^Bi M ^o 12 ⁰ x> 68.5 86.4 2 ^Ge * 0.5 ^(K 0.1 ^Ni 2.5 ^0o 4.5 ^Fe 2 ^Bi “ ^o 12 ⁰ x) 78.4 86.2 3 ^{+ / QeW} 0.5 ^(K 0.1 ^Ni 2.5 ^C ° 4.5 ^Fe 2 ^BUto 12 ° χ) 82.5 85.6 4 ^{+ /} * ^Β * 0.5 ^(Κ 0.1 ^Ν1 2.5 ^0ο 4.5 ^Ρβ 2 ^{Β1Μ <} Ί2 ^Ο χ) 83.3 85.2 5 ^Snlto 0.5 ^(K 0.1 ^Ni 2.5 ^Co 4.5 ^Fe 2 ^BiUo, x 2 ⁰⁾ 76.2 52.8 6 PrMn ₀ 5 ^(to about 1 ^Co 4.5 ^Ni 2.5 ^Fe 2 ^BIMO 12 ° χ) 77.9 78.8 7 % ,, ^OeB 0.5 < ^K 0.1 ^Ni 2.5 ^Co 4.5 ^Fe 2 ^BiMo 12 ° x) 74.0 86.4

00237 ^{+ yZ} Reaction temperature 430 ° C.

The data in brackets, as used in Table 1 and as will be used in Table 11, have no other purpose than to define the exact differences between the different catalysts. The composition in brackets therefore does not change.

Examples 8 to 10

Using the various catalysts prepared as described above, further examples of propylene amoxidation to acrylic acid nitrile were carried out, in accordance with Examples 8 to 7, except that a reaction temperature of 430 ° C was used, 6 seconds and the catalyst is supported on 50% silica. The results are shown in Table II below.

Table II

Example Catalyst composition 80% catalyst to 20% silica Through-conversion to acrylic nitrile Selectivity to acrylic acid nitrile Cf. AND ^K 0.1 ^Ni 2.5 ^Co 4.5 ^Pe 3 ^BiP 0.5 ^Mo 12 ° x 76.4 79.2 Cf. A ^{+ // K} 0.1 ^Ni 2.5 ^Co 4.5 ^Pe 3 ^BiP 0.5 ^Mo 12 ° x 76.0 77.6 8 ^SnMn 0.5 ^K 0.2 ^(µl 2.5 ° ^C 4.5 ^Pe 2 ^Mo 12 ^) 77.0 77.4 9 ° ® * 0.5 ^K 0.3 ^(Ki 2.5 ^Co 4.5 ^Fe 2 ^Mo 12 ° χ> 80.0 81.1 10 ^{+ /} GeSbTe _{0, Κ} θ _{5 (3} (Si ₂ ^F 5 ^Co 4.5 ^Mo ®2 ° i2 ^χ} 80.9 82.0 ^+/- contact 9 seconds

OBJECT OF WINE

Claims (4)

Catalyst for the oxidation of olefins based on molybdenum, iron and promoters, characterized in that it consists of a combination of elements corresponding to the general formula J Q.Z Fe.D sorry, "0 ab c d e" 12 x where means J alkali metal, thallium, silver or a mixture thereof, Q cobalt, nickel, zinc, cadmium, beryllium, magnesium, calcium, strontium, barium, radium or mixtures thereof, From a two-element or multi-element system selected from the group consisting of germanium with antimony, tungsten, tin, cerium with tungsten, praseodymium with manganese, tin with manganese, manganese with tungsten, tungsten with antimony, chromium with tin, tungsten with tin, germanium with tin, antimony and tin, tungsten with phosphorus, antimony with phosphorus, chromium with copper, manganese with copper, antimony with copper, manganese phosphorus or mixtures thereof, where in the case where Z is manganese with phosphorus, J has a meaning other than thalliym, D bismuth or tellurium, a number greater than zero to 5, b greater than zero to 20, c greater than zero to 20, d greater than zero to 20, e greater than zero to 20, x number k Compliance with the valency requirements of other elements for oxygen, wherein each element in the two-element or multi-element system is present in an amount of at least 1% atomic with respect to all elements in the system. 2. Catalyst according to claim 1, characterized in that it is and number sentences than zero to 5, b number sentences than zero to 20, C number sentences than zero to 9, and number sentences than zero to 20 a E number sentences than zero to 20 May 3. Catalyst according to claim 2, characterized in that it contains bismuth as component D and Z as germanium with antimony, has tungsten, has tin, cerium with tungsten, praseodymium 8 manganese, tin with manganese, manganese with tungsten, tungsten with antimony, tin chromium, tungsten with tin, germanium with tin, tin with antimony, tungsten with phosphorus, antimony with phosphorus, chromium with copper, manganese with copper, antimony with copper or manganese with phosphorus. 4. Catalyst according to claim 3, characterized in that it comprises at least one element of. the group comprising potassium, rubidium, cesium and cobalt or nickel.