CA1043357A - Production of unsaturated nitriles using catalysts promoted with various metals - Google Patents

Abstract

PRODUCTION OF UNSATURATED NITRILES USING
CATALYSTS PROMOTED WITH VARIOUS METALS

ABSTRACT OF THE DISCLOSURE
Certain catalysts containing iron, bismuth and molybdenum plus nickel, cobalt, magnesium, zinc, cadmium or calcium have been found to give especially large volumes of acrylonitrile-or methacrylonitrile in a given time when germanium, tin, copper, silver, chromium, ruthenium, titanium, tungsten, beryllium, boron, gallium, indium, or mixture thereof is incorporated into the catalyst.

Description

BACKGROUND 0~ VENT OM
_ _ A number of very desirable ammoxidation catalvsts are known which represent the base catalysts of the invention.
These catalysts are used to produce acrylonitrile or methacrylonitrile under certain conditions with high per pass conversions. Under these conditions, if the amount of olefin fed over the catalyst in a given time is increased significantly, the per pass conversion tends to drop.
In some instances, the per pass conversion to unsaturated nitriles drops markedly. Since the viability of a commercial operation is significantly affected by the amount of product that can be prepared in a given time, the present invention is directed at the problem in the arl of increasing the production of product in a given time while maintaining high per pass conversions.

(4711) ~4721) ~4756) ~V43~S7 SUMMARY OF THE INV~TION
It has now been discovered in the process for - the preparation of acrylonitrile or methacrylonitrile by the reaction of propylene or isobutylene, molecular oxygen and ammonia at a temperature of about 200C to about 600~C.
in the presence of a catalyst, the improvement comprising using as the catalyst a catalyst having the atomic ratios described by the formula Xa Ab CC Fed Bie M12 x wherein X is Ge, Sn, Cu, Ag, Cr, Ru, Ti, W, Be, B, Ga, In, or mixture thereof;
A is an alkali metal, alkaline earth metal, rare earth metal, Nb, Ta, Tl, P, As or mixture thereof;
C is Ni, Co, Mg, Zn, Cd, Ca or mixture thereof;
and wherein a is 0.01 to about 4;
b is O to about 4;
c and d are 0.01 to about 12;
e is 0.01 to about 6; and x is the number of oxygens required to satisfy the valence requ;rements of the other elements present The process of the present invention provides a commercially feasible process for preparing large quantities of acrylonitrile or methacrylonitrile in a given period of time at high per pass conversions.
The amount of a desirable acrylonitrilc or methacrylonitrile produced in an ammoxidat:~on reaction is essentially a function of 1) the amount of olefin fed to the reactor in a given period of time, and 2) the per (4711) ~4721~
1043357 ~4756) pass conversion to the desired product. As noted above, catalysts useful in ammoxidation reactions have been limited to a certain range of feed rates to provide high per pass conversions. When higher feed rates are attempted, the per pass conversion drops and the reaction becomes less efficient. Whenlower feed rates are employed, less of the desired product is produced. The present invention solves this problem by the discovery of catalysts that can accept a high reactant feed rate while at the same time maintain a high per pass conversion.
The reactant feed rate is normally stated as "WWH"
and is measured according to the following formula:
weight of olefin fed WWH-weight of catalyst x hours It can be seen from the formula that the rate of reactant feed varies directly with the WWH--as the WWH increases, the rate of reactant feed increases.
The second variable is the per pass conversion.
Per pass conversion is usually stated in terms of mole percent of a product formed according to the following formula for acrylonitrile moles of acrylonitrile Mole % = ln reactor effluent 100 p.p.c moles of olefin fed x It i8 seen that the amount of product formed is a direct function of the per pass conversion me central aspect of the present invention is the catalyst employed. me catalyst is suitably any catalyst containing the elements described in the formula above. Broadly, the base catalysts contain at least (4711) ~4721) (4756) iron, molybdenum and bismuth and at least one of nickel, cobalt, magnesium, zinc, cadmium or calcium. In addition to these base elements, there is a large number of optional elements that could be incorporated into the catalyst.
These base catalysts of the invention are known catalysts useful for ammoxidation reactions. Accordingly, the base catalyst and its preparations are not the subject of the present invention even though there are preferred variations in the base catalyst.
The present invention is the incorporation of germanium, tin, copper, silver, chromium, ruthenium, titanium, tungsten, beryllium, boron, gallium, indium, or mixture thereof into the base catalyst to provide higher rates of production at hi~h per pass conversions.
The elements added to the base catalyst can be incorporated into the catalysts in any amount that is effective to obtain improved results of the present invention.
Although this range may vary, a preferred range of 0.01 to about 4 is designated in the general formula. A more preferred range is about 0.1 to about 2.
Although a mixture of the elements added to the base catalyst by the invention could be used, it is preferred to use each of these elements separately in the catalyst.
In the catalyst formula, this is accomplished by separately setting X equal to each of these elements.
The base catalyst to which the promoter elements are added also has preferred embodiments Preferred are catalysts that contain nickel or cobalt or mixtures thereof, (4711) ~47211 ~4756) ~0433S7 i.e. wherein C is nickel, cobalt or mixtures thereof Also preferred are catalysts that contain an alkali metal, especially potassium.
The catalysts of the invention are suitably used in supported or unsupported form. Representative examples of carrier materials include silica, alumina, zirconia, titanium dioxide, boron phosphate and the like.
The reactants, process conditions and other reaction parameters of the reaction are known in the art of the ammoxidation of propylene and isobutylene. The conditions, reactors and the like are not substantially changed from the art. The temperature may range from about 200 to about 600C. with about 300 to about 500C. being preferred. The reaction may be conducted in a fluid or a fixed-bed reactor using atmospheric, subatmospheric or superatmospheric pressure. A feasible commercial application could be use of the present invention in a fluidized-bed reactor at superatmospheric pressure Since the present invention is primarily designed to feed more olefin over a catalyst in a given time, it is understood that the feed rates and composition of the feed could be altered from the art. Expressed in terms of WWH, the feed of olefin over the catalyst is preferably between about 0.05 and about 0 25 Using the present invention, large quantities of acrylonitrile or methacrylonitrile are produced at high olefin feed rates and high per pass conversions.

( 1~711 ) ~4721) ~4756~
~43357 SPECIFIC EMBODIMENTS
Comparative Examples A & B and Examples 1-27 - Comparison of catalyst containing promoters of invention with base catalyst.
A 5 cc. fixed-bed reactor was constructed of an 8 mm. inside diameter stainless steel tube. Catalysts prepared as described below were charged to the reactor and heated to 420~C. under a flow of air. At the reaction temperature for Comparative Example B and Examples 1-27, a reactant composition of propylene/ammonia/oxygen/nitrogen/
steam of 1.8/2.2/3.6/2.4/6 was fed over the catalyst at a contact time of 3 seconds. me WWH for the reaction was O .10.
For Comparative Example A, a reactant feed of propylene/ammonia/oxygen/nitrogen/steam in the ratio of 1/1.1/2.1/7.9/4 was used at a temperature of 420C. A
contact time of 6 seconds was used. m e WWH was O.03. m is example is included to show a base catalyst operating under normal operating conditions at a low WWH.
The catalysts were prepared as follows:

Comparative Examples A and B
80~ Ko lNi2~5C4~sFe3BiPo~sMol2ox + 20% SiO2 -A solution of 127.1 g. ammonium heptamolybdate (NH4)6Mo7024.4H20 and water was prepared To thls solution was added 6.9 g. of a 42.5% solution of H3P04 and 102.7 g.
of Nalco 40% silica sol to form a slurry. Separately, an aqueous solution containing 72.7 g., ferric nitrate, Fe(N03)3-9H20; 29.1 g. bismuth nitrate, Bi(N03)3-5H20;
78.6 g. cobalt nitrate Co(N03)2-6H20; 43.6 g. nickel nitrate (4711) ~4721 ~4756 1~43357 Ni(N03)2 6H20; and 6.1 g. of a 10~ potassium nitrate solution was prepared. The solution of metal nitrates was slowly added to the slurry. The resulting slurry was evaporated to dryness, and the solid obtained was heat treated at 290C. for three hours, at 425C. for three hours and at 550C. for 16 hours.

Example 1 80% GeO 6Ko~lNi2~5C04 5Fe3BiPo~5Mol2ox + 20% sio2 63.56 Grams of ammonium heptamolybdate was dissolved in 60 cc. of warm water. This solution was added to 53.25 g.
of Nalco 40% silica sol. The mixture was heated at low heat with constant stirring for about 5 minutes. To the slurry formed, 3.46 g. of H3P04 as a 42 5% solution was added, and the mixture was heated for 2 minutes.
Separately, 36.36 g. of ferric nitrate was mixed with 10 cc. of water and melted on a hot plate with constant stirring. Sequentially 14.55 g. bismuth nitrate, 39 29 g cobalt nitrate, 21.80 g. of nickel nitrate were added, always waiting until the previous metal nitrate had melted 3.03 Grams of KN03 added as a 10% solution was combined, and 1.88 e. of GeO2 was added and melted.
m e solution containing metal nitrates was added 810wly to the slurry and heating was increased until the mixture started to thicken. The mixture was dried in an oven at 120C. with occasional stirring. The dried catalyst was calcined at 550C. for 16 hours.

. .

1~43357 4756 Examples 2-27 The other catalysts of the examples were made in an identical manner to the catalysts of Example 1. Germanium, tin, chromium and titanium were added to the catalysts as the oxides. Copper and silver were added to the catalysts as the nitrates. Ruthe~ium and beryllium were added to the catalysts as the chlorides. Tungsten was incorporated into the catalyst as ammonium tungstate added along with the ammonium heptamolybdate. Although different anions were used, the particular anion of the catalytic component is not deemed to be critical.
In those catalysts not containing phosphorus, the promoter elements of the invention were added to the catalyst through the molybdenum-containing slurry.

Example 28 80% Bo 5Ko, lNi2~5C4 sFe3BiMol2ox + 20% SiO2 The catalyst was prepared in the same manner as Comparative Examples A and B except that a half recipe was used, 0.93 g. H3B03 was added to the molybdenum solution and no phosphoric acid was added.

Example 29 80% Bl OKo~lNi2~sco4~sFe3Bipo~sMol2ox + 20% sio2 This catalyst was prepared in exactly the same way as Comparative Examples A and B except that a half recipe was used and 1.86 g. H3B03 was added to the metal nitrate solution.

(4711) ~4756~

~()4;~357 Example 30 80% Gal oKo lNi2 sCo4 sFe3BiPo sMol40x + 20~ SiO2 In the same manner as described in the examples -above, a catalyst was prepared using a first slurry containing 24.7 g. ammonium heptamolybdate, 19.4 g. Nalco 40% silica and 1.15 g. of a 42.5% solution of H3P04 The second slurry contained 12.1 g. ferric nitrate, 4.8 g. bismuth nitrate, 13.1 g. cobalt nitrate, 7.3 g. nickel nitrate, 1 0 g. of a 10% solution of potassium nitrate and 2 5 g. of gallium nitrate, Ga(N03)3.3H20. The slurries were combined, evaporated and heat treated as shown above.

Example 31 80% Inl oKo~lNi2~sCO4 sFe3BiPo~sMol3~sox + 20% sio2 A first slurry containing 71.6 g ammonium heptamolybdate, 58.o g. of Nalco 40% silica sol and 3.4 g.
of a 42.5% solution of phosphoric acid was prepared. A
second slurry containing 36.4 g. of ferric nitrate, 14.6 g.
bismuth nitrate, 39.3 g. cobalt nitrate, 21.ô g. nickel nitrate, 3.0 g. of a 10% solution of potassium nitrate and 4.5 g. of indium chloride was prepared. me slurries were combined, and the solid catalyst was heat treated as described abo~e.

Example 32 80% B2~4wo~6Ko~lNi2~5co4.sFe3Bipo~sMolo~8ox + 20% SiO2 A slurry of 57.2 g. ammonium heptamolybdate, 4.8 g - ammonium heptatungslate, (NH4)6W7024.6H2o, 4.5 g. boric acid 3 5 g of a 42.5% solution of phosphoric acid and 52.3 g of Nalco 40% silica sol was prepared. To this slurry was added * Trademark _ g _ rAa (4711) (4721) ~4756~
1~43357 a solution of 36.4 g. ferric nitrate, 14.6 g bismuth nitrat~
39.3 cobalt nitrate, 21.8 g. nickel nitrate and 3.0 g. of a 10% solution of potassium nitrate. The resulting slurry was evaporated and the solid was heat treated as described above.

Example 33 80% Bl.OKO.lNi2.5C4 5Fe3BiP0 sMl2x + 20% SiO2 (Aerosil) This catalyst was prepared in exactly the same way as the catalyst of Example 29except that Aerosil silica was used instead of Nalco 40% silica sol.
The results of the experiments in the ammoxidation of propylene to produce acrylonitrile are shown in the Table.
The parentheses used in the Table have no significance other than to emphasize the differences in the catalysts.

Table I

Preparation of Acrylonitrile Comparison of Catalysts of Invention with Base Catalyst Molar Per Pass 20Example Active Ingredients of Catalyst Conversion, Comp. A (Ko~lNi2~sco4~sFe3Bipo~5Mol2ox) 80.1*
Comp. B ( " ) 73.1 1 Geo 6( ) 80.7

2 Gel o( ) 76 4

3 n.5( ) 75.7

4 Snl.0( ) 75.0 CuO.l( " ) 77.9 6 Ago~l( 74.2 7 CrO 5(Ko lNi2~5co4~5Fe3Bipo~5Mol2ox) 78.3 8 RUO.l( ) 76.4 * Trademark y~v (4711) ~4721) ~4756) 1~343357 Molar Per Pass Example Active Ingredients of CatalystConversion, %
g Tio 5(Ko.lNi2.sco4.sFe3Bipo.5Mol2ox)74~3 3el.0( ) 75.0 11 Cuo.lGeo.6( 76.2 12 AgO.lGeO.6( ) 75-4 13 RUO.lGeO.6( ) 79 3 14 CuO lBl 0( " ) 76.7 Ago.lBl.o( ) 7~.8 16 Ruo.lBl.o( ) 76.5 17 cro.6wo.6(Ko.lNi2.5co4.5Fe3Bipo-sMolo 8ox) 73-7 - 18 Gel o(Ko lNi2.sco4.5Fe2Bipo.5Mol2ox) 79.1 19 CrO 5Gel 0( " ) 79.2 Snl.0( ) 76.6 21 W0.5Gel.O(KO.lNi2.sC04 5Fe2BiMol2ox) 78.4 22 cro.5(Ko.lNi2.sco4.sFe3BiMol2ox) 79 5 23 W0 5( ) 81.6 24 Tio.5( ) 78.6 CuO lBo 5( " ) 80.2 26 SnO.5( ) 80.6 27 GeO 5( ) 79.1 28 Bo.5Ko.lNi2~5co4~5Fe3BiMol2ox 76.5 29 Bl oKo lNi2~5co4~5Fe3BiPO~5Mol2ox 80.4 Gal oKo lNi2~5co4~5Fe3BiPO~5Mol4ox 76.1 31 Inl oKo lNi2,5Co4,5Fe3BiPo,5Ml3.50x 76.1 32 B2 4Wo 6Ko.lNi2.5co4.5Fe3BiPO.5Molo.8ox 75-7 33 Bl oKo lNl2~5co4~5Fe3BiPo.5Mol2ox 82.8 *WWH is 0.03 ~V4;~ 7 Thus, it is seen from the examples above that high per pass conversions at high WWH values are obtained using the catalysts of the invention.

- Example 34 and Comparative Examples C and D - Ammoxidation of Isobutylene.
Fresh catalyst of Comparative Example A was used to prepare methacrylonitrile using isobutylene in the feed.
In Comparative Example C, a feed of isobutylene~ammonia/air/
H20 of 1/1.2/11/~ was used to show normal operating conditions, and in Comparative Example D, a feed of isobutylene/ammonia/
oxygen/nitrogen/H20 of 1 8/2 2/3.6/2.4/6 shows operation at high WWH. In Example 34 , the catalyst of Example 23 was run under the same conditions as Comparative Example D. The per pass conversion to methacrylonitrile for Comparative Example C was 67.1~; for Comparative Example D, 59.3~;and for Example 34, 68.1%. Thus, high yields of methacrylonitrile are obtained using the catalysts of the invention at a high WWH.

Examples 35-37 and Comparative Exa~.ple E _ Add6tOo~ncal calcinatlon Fresh catalyst of Comparative Example A was calcined at 600C. for an additional thre-e hours and run as Comparative Example E under the conditions of high WWH of Comparative Example D. Fresh catalyst of Examples 22, 23 and 26 were also calcined at 600 C. for three additional hours and used to prepare methacrylonitrile under the same conditions These results are given in Table IV

1~43;~57 Table IV

Ammoxidation of Isobutylene to Methacrylonitrile at High WWH

- Per Pass Conversion Example Catalyst + 3 hr at 600C to MAN %
Comp E Comparative Example A 59.9 35 Example 22 62.1 36 Example 23 65.4 37 Example 26 67.o Examples 38-39 - Ammoxidation of isobutylene at low WWH
m e catalysts of Examples 23 and 26 were run under the conditions of low I~WH of Comparative Example C. The catalyst of Example 23 gave a per pass conversion to methacrylonitrile of 71.1%, and the catalyst of Example 26 gave a per pass conversion to methacrylonitrile of 74.0%.

In the same manner as shown above, other catalysts of the invention, for example, those without an alkali metal or those with thallium, are employed in ammoxidation reactions.

Claims (12)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In the prccess for the preparation of acrylonitrile or methacrylonitrile by the reaction of propylene or isobutylene, molecular oxygen and ammonia at a temperature of about 200°C.
to about 600°C. in the presence of a catalyst, the improvement comprising using as the catalyst a catalyst having the atomic ratios described by the formula Xa Ab Cc Fed Bie Mo12 Ox wherein X is Ge, Cu, Ag, Cr, Ru, Ti, W, Be, B, Ga, In, or mixture thereof;
A is an alkali metal, alkaline earth metal, rare earth metal, Nb, Ta, Tl, P, As, or mixture thereof;
C is Ni, Co, Mg, Zn, Cd, Ca or mixture thereof;
and wherein a is 0.01 to about 4;
b is 0 to about 4;
c and d are 0.01 to about 12;
e is 0.01 to about 6; and x is the number of oxygens required to satisfy the valence requirements of the other elements present.

2. The process of Claim 1 wherein X is germanium.

3. The process of Claim 1 wherein X is copper.

4. The process of Claim 1 wherein X is silver.

5. The process of Claim 1 wherein X is chromium.

6. The process of Claim 1 wherein X is ruthenium.

7. The process of Claim 1 wherein X is titanium.

8. The process of Claim 1 wherein X is beryllium.

9. The process of Claim 1 wherein X is tungsten.

10. The process of Claim 1 wherein X is boron.

11. The process of Claim 1 wherein X is gallium.

12. The process of Claim 1 wherein X is indium.