JP4809532B2 - Catalyst for catalytic oxidation of propane to acrylic acid, its production and use - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
A novel mixed metal oxide catalyst for the production of acrylic acid through the catalytic gas phase partial oxidation of propane and its use for the single stage selective production of acrylic acid and acrolein at low temperatures.
The catalyst creates a mixture comprising Mo, V, Ga, Pd, Nb and at least one element selected from the group consisting of La, Te, Ge, Zn, Si, In and W, and then drying the mixture, Formed by firing the dried mixture.
[0002]
Related technology
In this application, several publications are cited as references. These documents describe the technical situation related to the present invention, and these documents are incorporated herein by reference.
[0003]
Two-stage gas phase oxidation of propylene to produce acrylic acid is known in the art. However, there is no commercial process for oxidizing propane to produce acrylic acid. Acrylic acid production from propane will be more attractive due to the considerable price difference between propane and propylene.
[0004]
There are few references reported in the literature on the production of acrylic acid from propane. US Pat. No. 5,198,580 discloses a method of partially oxidizing propane to obtain acrylic acid, propylene, acrolein, acetic acid and carbon oxide. This is because propane mixed with molecular oxygen-containing gas is Bi in the reaction zone. _b Mo _c V _v A _a D _d E _e O _x Wherein A is one or more of K, Na, Li, Cs and Tl; D is one or more of Fe, Ni, Co, Zn, Ce and La; E is one or more of W, Nb, Sb, Sn, P, Cu, Pb, B, Mg, Ca and Sr; the values of a, d and e are 0 to 10, b is 0.1 to 10, c is 0.1 to 20, and v is 0.1 to 0.1. 10, c: b is from 2: 1 to 30: 1 and v: b is from 1: 5 to 1: 8]. The yield of acrylic acid achieved using a bismuth molybdate type catalyst is the pressure L4 × 10 ^Five Pa (20 psig) and temperature of 400 ° C., propane conversion of 19% and 5.4%.
[0005]
European Patent EP0608838 A2 by Takashi et al. Discloses a process for the production of unsaturated carboxylic acids. This is an almost explosive preparation of a mixture of propane, air and water at 380 ° C. in the presence of a catalyst containing the mixed metal oxide MoVTeXO. In the formula, X is at least one selected from bismuth, cerium, indium, tantalum, tungsten, titanium, zirconium, chromium, manganese, iron, ruthenium, cobalt, rhodium, nickel, palladium, platinum and antimony, niobium, aluminum and boron. It is an element. The ratio of each essential component is based on the total amount of essential components other than oxygen and satisfies the following formula. That is, 0.25 <V _Mo <0.98, 0.003 <V _v <0.5, 0.003 <V _Te <0.5, 0.003 <V _x <0.5, V _Mo , V _v , V _Te And V _x Is the mole fraction of Mo, V, Te and X.
[0006]
Recently, Takashi et al. In another Japanese Patent Laid-Open No. 10-45643 (98464543, February 1998) _a Mo _b V _c W _d X _e O _n 380 ° C. in the presence of (X = Nb, Ta, Ti, Zr, Sb; when a = 1, b = 1-18, c = 0-4, d = 0-4 and e = 0.05-20) The production of acrylic acid and acrolein is disclosed. This achieves acrolein yield of 0.9% and acrylic acid yield of 3.5% with a propane conversion of 12%.
[0007]
The aforementioned catalysts disclosed in the literature result in low yields of acrylic acid at relatively high temperatures and produce propylene as one of the prominent byproducts. Propylene can be expensive to separate, especially in recycle mode operations.
[0008]
Thus, the prior art does not disclose or suggest any catalyst for the selective production of acrylic acid and acrolein at low temperatures through the propane gas phase partial oxidation process.
[0009]
It would be desirable to provide a catalyst designed so that acrylic acid and acrolein are selectively produced from propane with a single catalyst, producing little intermediate such as propylene.
[0010]
Object of the invention
The object of the present invention is to overcome the aforementioned drawbacks.
Another object of the present invention is to provide an improved catalyst system for the catalytic oxidation of propane to produce acrylic acid.
It is a further object of the present invention to provide an improved catalyst system for the single stage oxidation of propane to produce acrylic acid.
It is a further object of the present invention to provide improved methods for making and using the catalyst system.
The foregoing and other objects and advantages of the invention are described below or will be apparent from the following description.
[0011]
Summary of the Invention
The present invention relates to an improved catalyst system for the selective oxidation of propane and its production and use. According to one preferred embodiment of the present invention, propane is selectively oxidized with molecular oxygen to acrylic acid and acrolein in a gas phase reaction at a temperature of 150 ° C. to 450 ° C. and a pressure of 1 to 50 bar. this is, Calcined Composition Mo _a V _b Ga _c Pd _d Nb _e X _f This is achieved by using a novel catalyst having
Where
X = at least one element selected from the group consisting of La, Te, Ge, Zn, Si, In and W;
a is 1;
b is 0.01 to 0.9;
c is> 0 to 0.2;
d is 0.0000001 to 0.2;
e is> 0 to 0.2; and
f is> 0 to 0.5
It is.
[0012]
The numerical values a, b, c, d, e and f represent the relative gram atomic ratios of the elements Mo, V, Ga, Pd, Nb and X in the catalyst, respectively. The element is preferably present in various oxide forms in combination with oxygen.
[0013]
The improved catalyst system is preferably made by the procedure disclosed in the examples.
[0014]
The present invention further relates to a selective low temperature contact process for producing acrylic acid and / or acrolein by vapor phase oxidation of propane, preferably in a non-explosive manner.
[0015]
Other objects, aspects, features and advantages of the present invention will become apparent upon studying this specification, including the claims and specific examples.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
One aspect of the invention relates to an improved catalyst system for the selective oxidation of propane. The catalyst system is preferably a calcined composition Mo _a V _b Ga _c Pd _d Nb _e X _f including.
Where
X = at least one element selected from the group consisting of La, Te, Ge, Zn, Si, In and W;
a is 1;
b is 0.01 to 0.9;
c is> 0 to 0.2;
d is 0.0000001 to 0.2;
e is> 0 to 0.2; and
f is> 0 to 0.5
It is.
[0017]
According to one embodiment of the present invention, the catalyst composition is Mo. _a V _b Ga _c Pd _d Nb _e X _f O _y including. Where y is a number determined by the valence requirements of other elements in the catalyst composition. The catalyst of the present invention can be used with or without a support. Suitable supports for the catalyst are alumina, silica, titania, zirconia, zeolite, silicon carbide, Mo carbide, molecular sieves, and other microporous / nonporous materials, and mixtures thereof. When used with a support, the supported catalyst usually comprises about 10-50% by weight of the catalyst composition, with 50-95% by weight being the support material.
[0018]
Another aspect of the present invention relates to a process for producing an improved catalyst. The choice of compounds used, as well as the specific procedure taken in preparing the catalyst, can have a significant impact on the catalyst performance. The elements of the catalyst composition are preferably combined with oxygen to form oxides.
[0019]
Preferably, the catalyst is prepared from a solution of a soluble compound (salt, complex or other compound) of each metal. The solution is an aqueous system preferably having a pH of 1 to 10, more preferably a pH of 1 to 7 at a temperature of about 30 to about 100 ° C.
[0020]
In general, a mixture of elements-containing compounds dissolves insoluble compounds by dissolving a sufficient amount of soluble compounds to achieve the desired gram atomic ratio of elements in the catalyst composition. Manufactured by. The catalyst composition is then prepared by removing water and / or other solvents from the mixture of compounds in the solution system. By heating the dried catalyst in air or oxygen at a temperature of 250 ° C. to 450 ° C. for 1 hour to 16 hours Calcined To obtain a desired catalyst composition.
[0021]
Preferably, the molybdenum is introduced into the solution in the form of ammonium salts such as ammonium paramolybdate or as organic acid salts of molybdenum such as acetates, oxalates, mandelate salts, and glycolate salts. Other partially water-soluble molybdenum compounds that can be used include molybdenum oxides, molybdic acid, and molybdenum chlorides.
[0022]
Preferably, vanadium is introduced into the solution in the form of ammonium salts such as ammonium metavanadate and ammonium decabanadate, or as organic acid salts of vanadium such as acetates, oxalates, and tartrate salts. Partially water-soluble vanadium compounds such as vanadium oxides and sulfates of vanadium can also be used. An amount of oxalic acid or tartaric acid can also be added to achieve complete solubility.
[0023]
Preferably, gallium is introduced into the catalyst slurry in the form of gallium salts, such as oxides, chlorides, nitrates, and the like.
[0024]
Preferably, the palladium is introduced into the catalyst slurry in the form of Pd-supported activated carbon or alumina or as a solution of palladium salts such as acetates, chlorides, nitrates and the like.
[0025]
Preferably, other metals are introduced into the catalyst slurry in the form of salts such as oxides, acetates, chlorides, nitrates and the like.
[0026]
Preferably, niobium is used in the form of oxalates or hydrated oxides. Other sources of the soluble form of the metal include compounds in which the metal is coordinated, bound or complexed to a beta-diketonate, carboxylic acid, amine, alcohol, or alkanolamine.
[0027]
According to one preferred embodiment, the catalyst is prepared according to the following general procedure. An aqueous solution of vanadium and molybdenum is produced separately. The vanadium solution is mixed with the molybdenum solution at a specific temperature and pH. The remaining necessary ingredients are slowly added to the combined gel solution. After mixing, the resulting gel is dried to initial wetness with continuous stirring.
[0028]
After the resulting gel mixture is dried at 120 ° C. for 16 hours, the resulting catalyst is heated to about 350 ° C. at a rate of 2 ° C. per minute and is kept in air at this temperature for 4 hours Calcined Thus, a desired oxide composition is obtained.
[0029]
Another aspect of the present invention is the use of the catalyst system of the present invention to selectively oxidize propane to produce acrylic acid.
[0030]
The feedstock used as a source of propane can be a gas stream containing at least 3% by volume propane or a propylene / propane mixture. The gas flow is C ₂ Or C ₈ May contain alkanes. Preferably the gas flow is C ₂ Or C _Four Contains less than 30% by volume of each of alkanes and alkenes, such as ethane, isobutane, n-butane, or mixtures thereof. The gas stream may also include a large amount, greater than 5% by volume, of a diluent such as nitrogen / argon, carbon dioxide, and water in the form of water vapor.
[0031]
In carrying out the manufacturing process, the reaction mixture is generally 1 mole of propane, 0.01 to 2.0 moles of molecular oxygen (as pure oxygen or in the form of air), and 0 to 4.0 moles of water (water vapor). In the form).
[0032]
The molecular oxygen source as the feed is purified oxygen, air and air enriched with oxygen, etc., depending on the economics of separation and the hydrocarbon conversion achieved. The ratio of propane to oxygen varies depending on the desired conversion and catalyst selectivity, but is generally in the range of 1/5 to 5/1.
[0033]
By taking appropriate measures to avoid explosion problems, the oxygen concentration in the feed gas mixture can vary greatly, which is 0.1-50% or more of the feed mixture. Air is suitable as a source of oxygen in the feed. The amount of oxygen present will be less than the stoichiometric amount of hydrocarbons in the feed.
[0034]
The reaction can be affected especially in the presence of diluents such as argon, nitrogen or water vapor. The ratio of propane to diluent can range from 1/5 to 1/1.
[0035]
Water vapor can be used for the reaction as a reaction diluent and as a heat modifier 0-60 wt%. It can also act as a desorption accelerator for reaction products in the gas phase oxidation reaction. Other gases such as helium, nitrogen and carbon dioxide may be used as reaction diluent or thermal modifier.
[0036]
The liquid product of the reaction can be separated from unreacted feed hydrocarbons by condensation or purification, usually using water or dilute acid.
[0037]
The gaseous components of the reaction mixture are preferably propane, oxygen or oxygen and diluent, etc., but these components are preferably mixed homogeneously and then introduced into the reaction zone. The components may be preheated individually or after mixing prior to introduction to the reaction zone where the temperature should be from about 150 ° C to about 450 ° C.
[0038]
The reaction zone generally has a pressure of 1 to 50 bar, preferably 1 to 30 bar; a temperature of about 150 ° C. to about 450 ° C., preferably 200 to 300 ° C .; a contact time of the reaction mixture with the catalyst of about 0.01 to 100 seconds, preferably 0.1 to 10 seconds; and hourly space velocity of about 50 to about 50,000 h ^-1 , Preferably 100-10,000h ^-1 , Most preferably 200-3,000h ^-1 Have
[0039]
The contact time is defined on the basis of the ratio between the apparent volume of the catalyst bed and the volume of the gaseous reaction mixture fed to the catalyst bed under a given reaction condition, in unit time.
[0040]
The space velocity is calculated by dividing the total reactor outlet gas equal to the number of liters of total effluent generated over one hour by the number of liters of catalyst in the reaction vessel. This room temperature volume is converted to a volume of 0 bar and 1 bar.
[0041]
The reaction pressure is initially provided by the supply of gaseous reactants and diluent, but after the reaction has begun, the reaction pressure can be maintained by a suitable back pressure controller located above the flow at the reaction vessel outlet.
[0042]
The reaction temperature is provided by placing the catalyst bed in a tubular converter having walls in a furnace heated to the desired reaction temperature.
[0043]
One surprising advantage of the catalyst system of the present invention is that high yields of acrylic acid are achieved. Preferably, at least a 30% yield of acrylic acid is obtained by oxidation.
[0044]
The oxidation carried out according to the present invention preferably provides a selectivity of at least 50%, more preferably at least 70%, with respect to acrylic acid per pass through the reaction zone.
The catalyst system and process of the present invention provides 80% selectivity for the oxygenated products acrylic acid, acrolein and acetic acid.
[0045]
Preferably, less than 1% propylene is produced when the catalyst system is used. More preferably, no detectable propylene is produced as a by-product.
In accordance with the present invention, at least one reactant in the fluid phase is contacted with the aforementioned catalyst system of the present invention to initiate a fluid phase catalytic chemical reaction. This reaction converts the fluid phase reactant to one or more fluid phase products. The fluid phase reactant is C ₂ -C ₈ It can be an alkane or alkene, which is oxidized to the corresponding acid. Preferably, the fluid phase reactant comprises an alpha-beta unsaturated aliphatic aldehyde and oxygen and the fluid phase product comprises an alpha-beta unsaturated carboxylic acid. More preferably, the fluid phase reactant comprises propane and oxygen and the fluid phase product comprises acrylic acid.
[0046]
The production process is generally carried out in a single stage where all oxygen and reactants are supplied as a single feed, and unreacted initial reactants are not recycled. However, to improve the total productivity and / or yield of the desired product, oxygen or hydrocarbons can also be added to the reaction vessel in a multi-stage manner and / or the unreacted gas is recycled in purge mode. You can also.
This production method can be carried out in a reaction vessel. The reaction zone within the reaction vessel is in the form of either a fixed bed or a fluidized bed or a solid bed.
[0047]
The use of the catalyst of the present invention is not limited to the oxidation of propane to acrylic acid and acrolein. The catalyst can also be used to oxidize n / iso C4, C5 with molecular oxygen in the gas phase to produce the corresponding alpha-beta unsaturated carboxylic acid.
[0048]
【Example】
The following examples illustrate some of the products that are within the scope of the present invention and how to make them. It should be understood that these examples do not limit the invention in any way. Various modifications and changes can be made with respect to the present invention.
The catalyst samples produced in the examples were evaluated by the following methods.
[0049]
Catalyst test:
Catalyst evaluation was performed in a stainless steel fixed bed tubular reaction vessel under standard manufacturing conditions. The gas feed composition used for the evaluation of the catalyst contained propane, oxygen and nitrogen. The reaction is at a temperature of 300 ° C. and a pressure of 1.0 × 10 ^Five Pa (15 psig) and space velocity about 1,090 h ^-1 It carried out in.
[0050]
The reaction product was analyzed online by gas chromatography. Oxygen, argon, and carbon monoxide were analyzed using a 2.5 × 3 mm column with 13 × molecular sieve. Carbon dioxide, propane and propylene were analyzed using a 2m x 3mm column packed with materials sold under the trade name HAYESEP Q (R). Liquid products (acrylic acid, acrolein, acetic acid and water) were collected over a period of time with a cold trap and analyzed using a 2m x 3mm column packed with materials sold under the trademark PORAPAK Q®. In all cases, conversion and selectivity calculations were based on reaction stoichiometry.
[0051]
Example 1: [Mo ₁ V _0.398 Ga _1.0E-05 Pd _1.90E-04 Nb _0.125 Te _0.23 ]
An amount of 7.6 g ammonium metavanadate (Aldrich Chemicals, assay = 99.0%) was added to 80 ml distilled water and heated to 90 ° C. with stirring. 3.4 g of niobium oxide (80% Nb ₂ O _Five ), 28 g of oxalic acid, and 28.8 g of ammonium paramolybdate tetrahydrate (Aldrich Chemicals AC 12054-85-2) were added to the vanadate solution to form a gel mixture. The required amount of palladium, then telluric acid and gallium oxide were slowly added to the gel mixture. The gel mixture was vigorously stirred to a uniform gel mixture, which was then slowly dried with continuous stirring to the initial dryness.
The resulting solid was placed in a porcelain dish and further dried in an oven at 120 ° C. The dried material is cooled to room temperature and placed in a furnace where the catalyst is placed at 350 ° C. for 4-16 hours Calcined did. The temperature was increased from room temperature to 350 ° C. at a rate of 2 ° / min, and then maintained at 350 ° C. for 4 hours.
Calcined The prepared catalyst was prepared into uniform particles of 0.25 to 0.42 mm (40 to 60 mesh size) and evaluated for the propane oxidation reaction. The catalyst was evaluated at a temperature of 300 ° C. using a feed mixture containing propane: oxygen: nitrogen (20:10:70). The reaction product showed the following results:
Propane conversion (%): 26.45
Acrylic acid selectivity (%): 31
Acrolein selectivity (%): 1
Acetic acid selectivity (%): 21
CO _x Selectivity (%): 47
The overall reaction product was 53% oxygenated product and 47% total oxidation product.
[0052]
Example 2: [Mo ₁ V _0.398 Ga _1.0E-05 Pd _1.90E-04 Nb _0.125 Te _0.23 La _1.0E-05 ]
The production procedure was the same as Example 1 except that the required amount of lanthanum nitrate was also added in the final production step.
Calcined The prepared catalyst was prepared into uniform particles of 0.25 to 0.42 mm (40 to 60 mesh size) and evaluated for the propane oxidation reaction. The catalyst was evaluated at a temperature of 300 ° C. using a feed mixture containing propane: oxygen: nitrogen (20:10:70). The reaction product showed the following results:
Propane conversion (%): 21.21
Acrylic acid selectivity (%): 21
Acrolein selectivity (%): 1
Acetic acid selectivity (%): 13
COx selectivity (%): 65
The overall reaction product was 35% oxygenated product and 65% total oxidation product.
[0053]
Example 3: [Mo ₁ V _0.398 Ga _1.0E-05 Pd _1.90E-04 Nb _0.125 Te _0.23 La _1.0E-05 ]
Lanthanum nitrate was added and the catalyst was prepared according to the procedure of Example 1. The catalyst was evaluated at 320 ° C. using a feed mixture containing propane and oxygen (80:20). The reaction product has a selectivity to acrylic acid of 65%, acetic acid 10%, propylene 5% and CO under 10.4% propane conversion. _x 20% product was shown. The overall reaction product showed a selectivity of about 75% over the oxygenated value added product.
[0054]
Example 4: [Mo ₁ V _0.398 Ga _1.0E-05 Pd _1.90E-04 Nb _0.125 Te _0.23 Zn _1.0E-05 ]
The production procedure was the same as that described in Example 1 except that the required amounts of zinc nitrate and telluric acid were also added in the final step of production. Calcined The prepared catalyst was prepared into uniform particles of 0.25 to 0.42 mm (40 to 60 mesh size) and evaluated for the propane oxidation reaction. The catalyst was evaluated at a temperature of 300 ° C. using a feed mixture containing propane: oxygen: nitrogen (20:10:70). The reaction product showed the following results: Propane conversion (%): 20
Oxygen conversion rate (%): 100
Acrylic acid selectivity (%): 26
Acrolein selectivity (%): 1
Acetic acid selectivity (%): 15
COx selectivity (%): 58
The overall reaction product was 42% oxygenated product and 58% total oxidation product.
[0055]
Example 5: [Mo ₁ V _0.398 Ga _1.0E-05 Pd _1.90E-04 Nb _0.125 Te _0.23 ]
The catalyst is the same as described in Example 1. Calcined The prepared catalyst was prepared into uniform particles of 0.25-0.42 mm (40-60 mesh size) and evaluated at a temperature of 300 ° C. using a feed mixture containing propane: oxygen (95.25: 4.75). did. The reaction product showed the following results:
Propane conversion (%): 4.22
Oxygen conversion rate (%): 100
Acrylic acid selectivity (%): 45.5
Acrolein selectivity (%): 5.5
Acetic acid selectivity (%): 12
COx selectivity (%): 37
The overall reaction product was 63% oxygenated product and 37% total oxidation product.
[0056]
Example 6: [Mo ₁ V _0.398 Ga _1.0E-05 Pd _1.90E-04 Nb _0.125 Te _0.23 ]
The catalyst used in this example is the same as in Example 1. Calcined The prepared catalyst was prepared into uniform particles of 0.25 to 0.42 mm (40 to 60 mesh size) and evaluated for the propane oxidation reaction. The catalyst was evaluated at a temperature of 300 ° C. using a feed mixture containing propane: oxygen (90:10).
The reaction product showed the following results:
Propane conversion (%): 9
Oxygen conversion rate (%): 100
Acrylic acid selectivity (%): 35.5
Acrolein selectivity (%): 3.5
Acetic acid selectivity (%): 10
COx selectivity (%): 51
The overall reaction product was 49% oxygenated product and 51% total oxidation product.
[0057]
Example 7: [Mo ₁ V _0.398 Ga _1.0E-05 Pd _1.15E-04 Nb _0.125 Te _0.30 ]
The production procedure of the catalyst is the same as that described in Example 1 except that different amounts of Pd and tellurium are added. Calcined The prepared catalyst was prepared into uniform particles of 0.25 to 0.42 mm (40 to 60 mesh size) and evaluated for the propane oxidation reaction. The catalyst was evaluated at a temperature of 300 ° C. using a feed mixture containing propane: oxygen: nitrogen (20:10:70). The reaction product showed the following results:
Propane conversion (%): 17.14
Oxygen conversion rate (%): 100
Acrylic acid selectivity (%): 13
Acrolein selectivity (%): 1
Acetic acid selectivity (%): 10
COx selectivity (%): 76
The overall reaction product was 24% oxygenated product and 76% total oxidation product.
The BET surface area of the catalysts described in Examples 1-6 above is 20-35 m. ² It fluctuated in the range of / g.
[0058]
The XRD pattern of the catalyst according to one embodiment of the present invention is shown in FIG. The catalyst disclosed in the present invention preferably has a diffuse or poorly crystallized pattern with two theta values, a strong reflection peak at 22 (4.00 angstroms) and a very broad peak at 27 (3.57 angstroms). It has the structure which produces. In general, to obtain this structure, the catalyst must be prepared by the method described above. The very broad peak at 3.57 angstroms is a kind of diffuse peak that is difficult to assign to any one phase. However, this type of catalyst at higher temperatures Calcined Then, another very clear reflection appears. These are not active for activating alkanes to oxygenate products as shown in Example 8 (below).
[0059]
The catalyst of the present invention exhibits an optimal redox reaction, thereby being highly active and highly selective for partial oxidation products. Based on the catalyst data, the general characteristics for the catalysts disclosed herein can be concluded below.
1. The catalyst is highly selective for acrylic acid at low temperatures.
2. Propane oxidation exhibits a low ΔT of 10-15 ° C. Low ΔT can have a positive impact on reaction vessel design.
3. The relative selectivity for oxygenated products (acrylic acid, acrolein and acetic acid) depends on the catalyst composition, reaction temperature, space velocity, pressure and feed composition (alkane, oxygen, water vapor, nitrogen).
[0060]
Comparative Example 8: [Mo ₁ V _0.39 Nb _0.125 Te _0.23 ]
The catalyst composition and procedure are identical to those described in EP Patent Publication No. 0608838 for comparison. The catalyst is at 600 ° C. as described in the EP patent publication. Calcined did. The XRD pattern of the catalyst (FIG. 2) shows very clear reflections at 22.1, 28.2, 36.2, 45.2 and 50 at 2-theta values as described in the EP patent publication. Yes. Calcined The prepared catalyst was prepared into uniform particles of 0.25-0.42 mm (40-60 mesh size) and temperatures 300 and 380 ° C. using a feed mixture containing propane: oxygen: nitrogen (20:10:70). The propane oxidation reaction was evaluated in The catalyst was inert at both temperatures.
[0061]
The above description of the present invention is intended to be illustrative and not restrictive. Those skilled in the art will envision many variations or modifications to the described embodiments. These can also be made without departing from the scope of the present invention.
[Brief description of the drawings]
FIG. 1 is an XRD pattern diagram of a catalyst according to an embodiment of the present invention.
FIG. 2 is an XRD pattern diagram of a comparative catalyst.

Claims (19)

Propane, a catalyst for selective oxidation to oxygenated products including acrylic acid, acrolein and acetic acid, said catalyst system containing a catalyst composition comprising _{Mo a V b Ga c Pd d} Nb e X f And
Where
At least one element selected from X = Te and optionally La and Zn;
a is 1;
b is 0.01 to 0.9;
c is> 0 to 0.2;
d is 0.0000001 to 0.2;
e is> 0 to 0.2;
f is> 0 to 0.5; and the numbers a, b, c, d, e and f represent the relative gram atomic ratios of the elements Mo, V, Ga, Pd, Nb and X in the catalyst, respectively. The catalyst for selective oxidation of propane, wherein the element is present in combination with oxygen.   The catalyst according to claim 1, formed by combining the elements to form a mixture and calcining the mixture.   Catalyst according to claim 1 or 2, wherein the catalyst composition exhibits two X-ray diffraction peaks at the following two theta values: a strong peak at 22 and a very broad peak at 27.   The catalyst according to any one of claims 1 to 3, wherein the catalyst is a supported catalyst including a carrier.   5. The catalyst of claim 4, wherein the support comprises alumina, silica, titania, zirconia, silicon carbide, Mo-carbide, zeolite, molecular sieve, or other porous material.   The catalyst according to claim 4 or 5, wherein the supported catalyst comprises 10 to 50 wt% of the catalyst composition and the remaining wt% of the support material.   Propane in a reaction mixture comprising the direct conversion of propane to acrylic acid and acrolein by oxidation of propane, comprising (i) propane or propane / propylene and (ii) oxygen or a compound capable of providing oxygen Is oxidized in a reaction zone in the presence of a catalyst according to any one of claims 1-6. The reaction mixture further comprises a C ₂ -C ₈ alkane, The method of claim 7.   9. The method of claim 8, wherein the alkane is ethane, propane, isobutane, n-butane or a mixture thereof. 8. A process according to claim 7, wherein the catalyst is in the form of a fixed bed and the oxidation is carried out by a feed comprising propane fed to the reaction zone. The process according to claim 7, wherein the catalyst is in the form of a fluidized bed and the oxidation is carried out by a feed comprising propane fed to the reaction zone. 12. A method according to claim 10 or 11 , wherein the feed comprises air . 12. A method according to claim 10 or 11 , wherein the feed comprises oxygen. 12. A method according to claim 10 or 11 , wherein the feed comprises molecular oxygen in the range of 0.1-50% by volume. 12. A process according to claim 10 or 11 , wherein the feed is diluted with an amount of water vapor in the range of 0-60% by volume. The oxidation temperature of 100 to 450 ° C. in the gas phase, 1-50 under a pressure of bar, and the achieved during operation of a contact time of 0.1 to 10 seconds of the reaction mixture and the catalyst, wherein Item 11. The method according to Item 10. Alpha by oxidation of beta unsaturated aliphatic aldehydes - - C ₂ -C ₈ alkanes or alkenes corresponding contact oxidation and alpha to acids in the fluidized phase A method for producing a beta-unsaturated carboxylic acids, flow 7. A process comprising contacting at least one reactant in a phase under suitable reaction conditions with a catalyst according to any one of claims 1-6. A method of forming a catalyst according to any one of claims 1-6,
a) forming a mixture containing Mo, V, Ga, Pd, Nb, and X in the solution;
b) drying the mixture to form a dry solid material; and c) calcining the dry solid material to form the catalyst. 19. The method of claim 18 , wherein the calcination comprises heating the dry solid material in air or oxygen to a calcination temperature of about 250-450 [deg.] C. for 1-16 hours .

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