GB2038657A - Catalysts for the hydration of olefins - Google Patents

Abstract

Catalysts for the hydration of olefins such as ethylene and propylene in the liquid or vapor phase to the corresponding alkanols comprise a water-insoluble interacted oxide composition of at least one metal oxide having an electronegativity value Xi for the metal ion above 20.0 with at least one different metal oxide having an electronegativity value Xi for its metal ion above 13.0, electronegativity of the metal ion being calculated by the equation Xi = (1 + 2Z) Xo in which Z is the charge on the metal ion and Xo is the electronegativity value of the neutral metal atom.

Description

SPECIFICATION Catalytic hydration of olefins This invention relates to the field of olefin hydra tion processes and more particularly, to such pro cesses employing metallic oxide catalysts, to the catalysts per se and to their production.

The use of metal oxide catalysts in the hydration of olefins to the corresponding alkanols is well known.

Each of U.S. Patent Nos. 1,873,536 and 1,907,317 to Brown metal. discloses olefin hydration catalysts containing one or more oxides of aluminum, thorium, titanium, tungsten and chromium. U.S. Patent No.

1,882,712 to Andrussow et al. discloses the use of oxides of antimony, manganese, tungsten, zinc and/ortin oxides as promotors in metal phosphate ethylene hydration catalysts. U.S. Patent No.

1,977,633 acknowledges that it is known to employ compounds of gold, iron, chromium, vanadium, tung sten, molybdenum and manganese for olefin hydra tion. U.S. Patent No. 2,162,913 to Eversoleetal.

describes an olefin hydration catalyst which is an inorganic complex of a nuclear element such as sili con or boron surrounded by a coordinated group of another metallic oxide or oxides such as the oxides of tungsten, molybdenum, vanadium, chromium and tellurium. U.S. Patent No. 2,769,847 to Robinson describes a binary metal oxide olefin hydration catalyst in which ferric oxide is in intimate admixture with titania. U.S. Patent No. 3,076,036 to Hansen dis closes a catalyst composition forthe hydration of olefins of three to five carbon atoms containing molybdenum oxide in combination with silica and an oxide of at least one metal of groups Ill band IV a of the periodic table such as alumina, hafnia, zir conia, titania and thoria.With the exception of Robinson, none of the foregoing disclose the use of a binary orternary metal oxide olefin hydration catalyst composition, i.e., a catalyst composition in which the component metal oxides are in more inti mate association than that which is attainable through mere mechanical mixing.

It has now been discovered that certain binary, ternary and other interacted metal oxides are active as catalysts for the liquid or vapor phase hydration of olefins. The metal oxides which are useful herein as olefin hydration catalysts comprise interacted oxide compositions of at least one metal oxide hav ing an electronegativity value Xi for the metal ion of at least 20.0 with at least one different metal oxide having an electronegativity value Xi for its metal ion above about 13.0.The electronegativity value as ;herein defined is calculated from the relationship X = (1 + 2Z) X0 in which Z is the charge on the metal ion and X0 is the electronegativity value of the neutral metal atom as assigned by Pauling (and given in such standard reference works as Lange's Handbook of Chemistry, eleventh edition). By con trast, the binary catalyst composition of U.S. Patent 2,769,847 combines two metal oxides, ferric oxide and titania, each of which possesses an elec tronegativity value Xi for the metal ion of not greater than about 14.0 and as such, are less active than the metal oxide hydration catalysts herein.

The expressions "interacted oxide composition" and "interacted relationship" as used herein refer to an association of metal oxides which is closer than that which can be obtained by mechanical mixing of the oxides. One hypothesis holds that in binary oxides such as silica-alumina there is an amorphous substitution of one metal ion for a second metal ion in the oxide lattice of the latter. Another hypothesis holds that the oxide of one of the metals may become a terminal group in the micelle structure of the other with its metal ion becoming coordinated with hydroxyl and water. However, the actual mechanism by which the interacted oxide compositions are formed herein is in no way to be regarded as a limitation upon the invention described.

According to one method for preparing the metal oxide catalysts herein, aqueous solutions of the selected metals in the form of their water soluble salts, e.g., the halides, nitrates, phosphates, etc., are contacted with a base such as ammonia with consequent coprecipitation of the metal oxides. The oxides are separated from the supernatant, dried and if desired, calcined in a nonreducing atmosphere.

Another method ("slurry growth") which can be employed herein for preparing the metal oxide catalysts of thins invention calls for heating an aqueous slurry of the selected oxides, precipitating the coreacted oxides from the liquid phase as reported in Batist,etal.J Cat Vol. 12, pp. 45-60 (1968), and calcining the dried precipitated oxides in a nonreducing atmosphere.

Examples of metal oxides having an electronegativity value Xj for the metal ions above about 20 which are useful herein are set forth in Table I as follows: TABLE! Electronegativity Values of Metal lons Above About 20.0 Electronegativity Electronega tivity Charge on the Value ofthe Neutral Value ofthe Metal Oxide Metal Ion, Z Metal Atom, X0 Metal lon, Xi MoO3 6 1.8 23.4 WO3 6 1.7 22.1 W401. 5.5 1.7 20.4 Sb2Os 5 2.05 22.6 TeO2 4 22 20.7 TeO3 6 2.3 29.9 AuO2 4 2.4 21.6 CrO3 6 1.6 20.8 Metal oxides with metal ions having an electronegativity value Xj above about 13.0 which are useful as the other metal oxide component of the catalysts herein include those set forth above in Table las well as the following oxides set forth below in Table II:: TABLET Electronegativity Values of metal lons Above About 13.0 Electronegativity Electronegativity Charge on the Value of the Neutral Value ofthe Metal Oxide Metal lon, Z Metal Atom, X0 Metal lon, Xj TiO2 4 1.6 14 Fe2O3 3 2.0 14 MnO2 4 1.6 14 SnO2 4 1.8 16 SiO2 4 1.9 17 MoO2 4 1.8 16 WO2 4 1.7 15.3 V2Os 5 1.6 17.6 VO2 4 1.6 14.4 Tacos 5 1.3 14 RuO3 4 2.2 20 Rh2O3 3 2.2 15 RhO2 4 2.2 20 ReO2 4 1.9 17 ZnO2 4 1.6 14 CrO2 4 1.6 14 B203 3 2.0 14 Bi203 3 1.9 13 Sb2O3 3 2.05 14 ZrO2 4 1.6 14.4 The proportions of the individual metal oxides can be freely chosen over a fairly wide range of values bearing in mind that as a generality, the higher the Xi value for the oxides selected, the greater the activity of the resultant catalyst for the olefin hydration reaction. Accordingly, the preferred catalysts herein will contain oxides each having an Xi above about 20.0, e.g., combinations of MoO3 and WO3 or MoO3 and Sb2O5, or combinations of an oxide having an XL above about 20.0 and an oxide having an Xi above about 13.0 but below about 20.0 wherein the total number of metal atoms of the oxide of higher Xi is preferably at least equal to the total number of metal atoms of the oxide of lower Xi, e.g., a combination of MoO3 and Sb2Os in a molar ratio of about 2:1.Other preferred combinations of metal oxides in addition to those illustrated in the examples, infra, include the binary oxide MoO3-SnO2 wherein the atomic ratio of Mo Sn + Mo is within the range of about 0.3 tq about 0.6 and the binary oxide MoO3 - V2Os wherein the atomic ratio Mo is within the range V -e Mo of about 0.3 to about 0.6. If desired, the metal oxide catalysts herein can be applied in a known manner to any one of several known or conventional carriers such as silica, alumina, titania, thoria, hafnia, etc., and mixtures thereof.

The catalysts of this invention are useful for effecting the hydration of a wide variety of mono-, di- and polyethylenically unsaturated olefinsto provide the corresponding alkanols and are especially effective for the hydration of the lower monoolefins such as ethylene, propylene, and butene-1. In conducting the hydration reaction, olefin vapor is contacted with the catalyst either continuously or batchwise under suitable conditions of temperature and pressure in the presence of a molar excess of water with respect to olefin. Conditions oftemperature and pressure can be such that the water is partly in the liquid phase or wholly in the vapor phase. Catalytic hydration can be conducted over a wide range of conditions.Usually the temperature employed is within the approximate range of 150 to 3750C and preferably between about 250 and 325"C. The pressure employed depends on the temperature and the reaction phase desired.

Pressures in the approximate range of 250 to 10,000 psig are suitable with a pressure between about 500 and about 5,000 psig being preferred. The water to olefin mole ratio required in the reaction zone varies with the vapor phase and mixed phase operation. In general, the mole ratio of water to olefin reactant will be within the range of 2:1 to 50:1 with a mole ratio of between about 20:1 to 40:1 being preferred.

In the examples which follow, the general operational procedure for carrying out each liquid phase ethylene hydration reaction was as described: A stainless steel microreactor having an internal diameter of 5/16 inch, an outside diameter of 9/16 inch and a working pressure of 15,000 psi was placed in a vertical position, charged with 1.0 g binary metal oxide catalyst and 4.5 cc water and sealed. Ethylene at 800 psi and ambient temperature was admitted to the reactor and the reactor was shaken for five minutes priorto initiating heating. The reactor was then heated to 300"C and held at this temperature for the duration of the hydration reaction (approximately 30 minutes) after which the heating was discontinued, the shaker stopped and the reactor quickly cooled to 250C by being covered with powdered CO2.After being placed vertically in a container surrounded with powdered CO2, the temperature was permitted to reach -1"C, whereupon gas was vented from the reactor through 2 cc of methanol cooled with dry ice and thereafter through a wettest meter for volume measurement. After introducing 1.0 cc (.80 g) of n-propanol into the reactor the reactor was inverted, placed in warm water and heated to 300C and then placed on a shaker and shaken for 15 minutes. The reactor was then cooled to 80C in wet ice, opened and the contents thereof including the methanol wash analyzed by gas-liquid.

chromatography for alcohol and ether. The ethanol produced is reported as grams alcohol per gram catalyst per hour.

EXAMPLE 1 An unsupported binary oxide of iron and molybdenum prepared by coprecipitation of ammonium molybdate and ferric chloride with ammonia followed by calcination of the precipitate at 4200 as in U.S. Patent No.3,152,997 relating to methanol oxidation catalysts produced an average of 0.12 g ethanol based on 5 runs. The reclaimed solids produced 0.14 g ethanol in one run, and the blue colored reclaimed supernatant gave 0.02 g ethanol.

EXAMPLE 2 An unsupported binary oxide catalyst comprised of antimony and molybdenum in an atomic ratio (Mo/Mo+Sb)=0.5 was prepared by keeping an aqueous slurry of Sb2Os and MoO3 at 900C for five days ("slurry growth") then drying and calcining at 500 C. The catalyst produced an average of 0.14 g ethanol based on 3 runs. Another binary oxide catalyst of atomic ratio (Sb/Mo 1.0) was prepared by drying an aqueous slurry of Sb2O5 in ammonium molybdate followed by calcining at 500"C. This catalyst produced 0.11 g ethanol.

EXAMPLE 3 An unsupported binary oxide of tin and molybdenum was prepared by slurry growth as in Example 2 using SnO2 and MoO3 for an atomic ratio of Sn/Mo of 1.0. This catalyst produced 0.11 g ethanol.

EXAMPLES4to ii Binary or Ternary Catalyst Ethanol Example Catalyst Preparation Produced 4 Bi2O3(5%) : WO3(95%) Calcination Average of 0.44 g at 700 C based otr two runs 5 Sb3O5(5%) : WO3(95%) .28 g (2 runs) 6 V2Os - MoO3 Slurry growth 0.054 to 0.086 followed by calcination at 500 C (.056 g) 7 Bi2O3 - MoO3 Same as Example 0.054 to 0.086 6 (0.086 g) 8 Bi2O3 - MoO3 Same as Example 7 0.080 g except that nitric acid was present in the aqueous suspension 9 ZrO2:MoO3=3.08 C-precipitation 0.060 g of ZrOCI2 and (before ammonium molybdate washing) followed by calcin ation, before 0.064 g washing, at600 C (after and after washing washing) 10 Bi2O3: Fe2O3: MoO3 Co-precipitated 0.076 g in which atomic ammonium molybdate ratio of Bi : Fe: Mo and bismuth nitrate is 2 : 1 : 3 (with NH3) slurried with precipitated ferric nitrate (with NH3) and heated at 600 C for 17 hours.

11 Bi2O3: Fe2O3: MoO3 Precipitated ammonium 0.054 g in which atomic molybdate mixed as ratio of Bi : Fe: Mo slurry with solution is 1:1:1 of bismuth nitrate which was precipi tated with NH3.

Slurry combined with precipitated (with NH3) iron nitrate and heated as slurry to 70 C for 2 hours, then for 16 hours at 45"C, and finally at 90"C until slurry thickened, dried and solid calcined at 600 C for 3 hours In each of the above examples, the amount of ethanol produced varied from no less than 1.5 to as high as 4 times the amount of ethanol produced by a standard catalyst in which 18.9 weight percent WO3 on titania was reduced with hydrogen at 400 C for 8 hours (WO3 reduced to W401,). The standard catalyst produced only 0.036 g ethanol as an average of 11 runs at 4,000 psi nominal pressure.

In the following two examples the operational procedure for carrying out the liquid phase ethylene hydration reaction was modified in that ethylene at 1,500 psi was admitted to the reactor and that the internal standard for analysis used was ethyl acetate instead of n-propanol. The standard catalyst produced 0.20 grams ethanol under these conditions.

EXAMPLE 12 The catalyst comprised of interacted Sb2Os and WO3 in ratio of 45% WO3: 55% Sb2Os was prepared as follows: 1.8 g ammonium metatungstate [(NH4)2W4O,3 8H2Qj dissolved in 5.0 ml H2Owas added to a solution of 2.0 ml SbCI3 (4.67 g) in 10% HCI solution. Anhydrous NH3 was added until the pH reached 10.0 to co-precipitate the oxides. The precipitates were aged overnight, then the mixture evaporated over the steam bath to dryness. The catalyst produced 0.28 grams alcohol.

EXAMPLE 13 The catalyst comprised 9% By203: 91% W4O11 prepared as follows: 43.5 g ammonium metatungstate [(NH4)2W4O,3 8H3O] and 3.48 g Bi(NO3)3 5H2O were placed in a 200 cc glass beaker with 100ml distilled water. Six (6) drops of concentrated HNO3 were added and the preparation was stirred until solution was effected after which the water was evaporated to dryness at 115 C. The solid was then reduced with flowing hydrogen at 400"C for eight (8) hours after which it was calcined at 700"C under helium. The catalyst produced 0.30 g alcohol.

Claims (20)

1. An olefin hydration catalyst comprising a water-insoluble interacted oxide composition of at least one metal oxide whose metal ion has an electronegativity value as herein defined of at least 20 and at least one different metal oxide whose metal ion has an electronegativity value as herein defined of above 13.

2. A catalyst according to claim 1 wherein each of the said metal ions has an electronegativity value as herein defined of at least 20.

3. A catalyst according to claim 1 wherein the metal ion of the said different metal oxide has an electronegativityvalue as herein defined of from 13 to 20, with the total number of metal ions of higher electronegativity value being at least equal to the total number of metal ions of the said different metal oxide.

4. A catalyst according to any of claims 1 to 3 comprising a water-insoluble interacted oxide composition of at least two metal oxides selected from Table 1 herein.

5. A catalyst according to any of claims 1 to 4 comprising a water-insoluble interacted oxide composition of at least one metal oxide selected from Table 1 herein and at least one metal oxide selected from Table II herein.

6. A catalyst according to claim 5 comprising a water-insoluble interacted oxide composition of MoO3 and at least one of Sb3O5, Foe203, V3O5, By203, ZrO3andZnO2.

7. A catalyst according to any of claims 1 to 6 on a support.

8. A catalyst according to claim 7 in which the support comprises at least one of silica, alumina, titania and thoria.

9. A method of making a catalyst according to claim 1 in which the interacted oxide composition is formed by coprecipitating the said metal oxides from an aqueous solution of water-soluble salts of the metals.

10. A method of making a catalyst according to claim 1 wherein the interacted oxide composition is formed by heating an aqueous slurry of the said metal oxides.

11. A method according to claim 9 or 10 wherein the resulting interacted oxide composition is recovered, dried and calcined in a non-reducing atmosphere.

12. An olefin hydration catalyst obtained by a method according to any of claims 9 to 11.

13. A process for the catalytic hydration of an olefin which employs a catalyst according to any of claims 1 to 8 and 12.

14. A process according to claim 13 in which the hydration reaction is conducted in the liquid phase.

15. A process according to claim 13 in which the hydration reaction is conducted in the vapour phase.

16. A process according to any of claims 13 to 15 in which the olefin is ethylene, propylene or butene-1.

17. An olefin hydration catalyst comprising a water-insoluble interacted metal oxide composition of at least two metal oxides and substantially as herein before described in any one of Examples 1 to 13.

18. A method of making an olefin hydration catalyst comprising a water-insoluble interacted oxide composition of at least two metal oxides, the method being substantially as hereinbefore described in any one of Examples 1 to 13.

19. A process for the catalytic hydration of an olefin using as catalyst a water-insoluble interacted metal oxide composition of at least two metal oxides, the process being substantially as hereinbefore described in any one of Examples 1 to 13.

20. An alcohol obtained by a process according to any of claims 13 to 16 and 19.