JP2005186064A - Production method for catalyst for producing unsaturated aldehyde and unsaturated carboxylic acid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new production method for a catalyst with large mechanical strengths for stably producing corresponding unsaturated aldehyde and unsaturated carboxylic acid at high yield over a long period of time. <P>SOLUTION: The production method for the catalyst for producing unsaturated aldehyde and unsaturated carboxylic acid is a production method for the catalyst containing at least molybdenum, bismuth and iron used when olefin, tert-butyl alcohol or methyl tert-butyl ether are subjected to gas phase catalytic oxidation by a molecular oxygen-containing gas to prepare the corresponding unsaturated aldehyde and unsaturated carboxylic acid respectively. A mixed solution or a water base slurry containing the catalyst component is dried and moisture content of the obtained dried product is adjusted to 0.3-4 wt.% and is subjected to tablet molding. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a catalyst for producing a corresponding unsaturated aldehyde and unsaturated carboxylic acid by vapor-phase catalytic oxidation of olefin, tertiary butyl alcohol, or methyl tertiary butyl ether with a molecular oxygen-containing gas. In addition, the present invention relates to a method for producing a catalyst that can produce an unsaturated aldehyde and an unsaturated carboxylic acid that have high mechanical strength, are stable over a long period of time, and can be produced in a high yield.

  Conventionally, a catalyst for producing acrolein and acrylic acid by vapor-phase catalytic oxidation of propylene with a molecular oxygen-containing gas, and isobutylene, tertiary butyl alcohol, or methyl tertiary butyl ether with a molecular oxygen-containing gas. Various catalysts for producing methacrolein and methacrylic acid by gas phase catalytic oxidation have been proposed.

  These catalysts can of course produce the corresponding unsaturated aldehydes and unsaturated carboxylic acids of interest in high yields, but at the same time have sufficiently high mechanical strength and long-term industrial use. It must be durable enough to withstand use.

  Conventionally, in order to improve the characteristics of the catalyst used in these reactions, it has been proposed to use various organic compounds during catalyst preparation to control the pores of the catalyst. As such examples, Patent Literature 1, Patent Literature 2, Patent Literature 3, and the like are known. According to this method, there is an advantage that the pore diameter of the catalyst can be changed relatively freely by adding an organic compound having a different type or particle size during the production of the catalyst and removing the used organic compound by heat treatment. However, in this method, when the organic compound is removed, the catalyst is sintered due to the combustion of the organic compound and the catalyst is reduced by the organic compound, so that the activation process is complicated and the catalyst performance is reproduced. There is a problem that lacks sex.

  In order to improve the performance and mechanical strength of the catalyst, Patent Document 4 discloses the use of activated carbon at the time of catalyst production. That is, the catalyst component mixture is calcined, activated carbon having a predetermined particle size is mixed with the obtained calcined product, and is molded and heat-treated. However, there is still room for further improvement in the yield of the target unsaturated aldehyde and unsaturated carboxylic acid.

Thus, there is a need for a new method for producing a catalyst that is easy to improve and improve the catalyst performance and is excellent in reproducibility.
JP-A-58-98143 Japanese Patent No. 3-109946 Japanese Patent No. 3278246 Japanese Patent No. 3251642

  In view of the prior art as described above, the object of the present invention is to subject an olefin, tertiary butyl alcohol, or methyl tertiary butyl ether to gas phase catalytic oxidation with a molecular oxygen-containing gas and to the corresponding unsaturated aldehydes and unsaturated aldehydes. An object of the present invention is to provide a method for producing a catalyst which can advantageously produce a saturated carboxylic acid with high yield and good reproducibility, and which has a large mechanical strength and high durability.

  As a result of diligent research to solve the above-mentioned problems, the present inventors have produced a complex oxide catalyst containing at least molybdenum, bismuth, and iron for producing an unsaturated aldehyde and an unsaturated carboxylic acid. In addition, the amount of water contained in the dried product when the mixed solution containing the catalyst component or the slurry thereof is molded by drying is greatly linked to the properties such as the activity and mechanical strength of the catalyst that can be obtained. It has been found that the above-mentioned problems can be solved by controlling within a range.

  That is, according to the research of the present inventors, the water content contained in the mixed solution containing the catalyst component or the dried product of the slurry is controlled to 0.3 to 4% by weight as seen in Examples and Comparative Examples described later. It has been found that the desired unsaturated aldehyde and unsaturated carboxylic acid can be produced in a high yield with good reproducibility, and a molded catalyst having high mechanical strength and stability can be obtained. . When the moisture content of the dried product is less than 0.3% by weight, the molding pressure necessary for obtaining good characteristics becomes high, and a molded catalyst having stable characteristics cannot be obtained. On the other hand, in the case of a dried product having a moisture content of more than 4% by weight, the characteristics of the catalyst are changed by the calcination step subsequent to molding, and a molded catalyst having stable characteristics cannot be obtained.

Thus, the present invention is characterized by having the following configuration.
(1) Used in the production of a corresponding unsaturated aldehyde and unsaturated carboxylic acid by vapor phase catalytic oxidation of olefin, tertiary butyl alcohol, or methyl tertiary butyl ether with a molecular oxygen-containing gas, A method for producing a composite oxide catalyst containing at least molybdenum, bismuth, and iron, wherein a mixed solution or an aqueous slurry containing the catalyst component is dried, and a moisture content of the resulting dried product is 0.3 to 4% by weight. A method for producing a catalyst for producing an unsaturated aldehyde and an unsaturated carboxylic acid, wherein the molded product is formed by compression and tableting.
(2) The molded body has an outer diameter of 3 to 10 mm, an inner diameter of 0.1 to 0.7 times the outer diameter, a length of 0.5 to 2 times the outer diameter, and opens in the length direction. The manufacturing method of the catalyst for manufacture of the unsaturated aldehyde and unsaturated carboxylic acid as described in said (1) which is a ring shape.
(3) The manufacturing method of the catalyst for manufacture of the unsaturated aldehyde and unsaturated carboxylic acid as described in said (1) or (2) whose catalyst has the following general formula (1).

MoaBibCocNidFeeXfYgZhQiSijOk (1)

(Wherein X is at least one element selected from the group consisting of Na, K, Rb, Cs and Tl, and Y is at least one element selected from the group consisting of B, P, As and W) Z is at least one element selected from the group consisting of Mg, Ca, Zn, Ce and Sm, Q is a halogen, and a to k represent the atomic ratio of each element. When a = 12, b = 0.5-7, c = 0-10, d = 0-10, c + d = 1-10, e = 0.05-3, f = 0.005-3, g = 0 to 3, h = 0 to 1, i = 0 to 0.5, j = 0 to 40, and k is a numerical value that satisfies the oxidation state of other elements.)
(4) Gas phase contact of olefin, tertiary butyl alcohol, or methyl tertiary butyl ether with molecular oxygen-containing gas using the catalyst obtained by the production method of any one of (1) to (3) above A method for producing an unsaturated aldehyde and an unsaturated carboxylic acid corresponding to oxidation.
(5) The method of (4) above, wherein the olefin is propylene, and the unsaturated aldehyde and unsaturated carboxylic acid are acrolein and acrylic acid, respectively.

  According to the method of the present invention, when producing a composite oxide catalyst containing at least molybdenum, bismuth, and iron, the mixed solution containing the catalyst component or the slurry thereof is contained in the dried product when dried and molded. Olefin and tertiary butyl have high mechanical strength, long-term stability, and high yield by means based on the novel idea of controlling the moisture content to be controlled within a specific range and tableting. There is provided a catalyst capable of producing a corresponding unsaturated aldehyde and unsaturated carboxylic acid by vapor-phase catalytic oxidation of alcohol or methyl tertiary butyl ether with a molecular oxygen-containing gas.

The catalyst produced in the present invention is used for the production of the corresponding unsaturated aldehyde and unsaturated carboxylic acid by gas phase catalytic oxidation of olefin, tertiary butyl alcohol, or methyl tertiary butyl ether with gas containing molecular oxygen. The catalyst is a composite oxide catalyst containing at least molybdenum, bismuth, and iron. The present invention can be applied to any catalyst as long as it is a composite oxide catalyst containing these three components, and among them, a catalyst represented by the following formula (1) can be preferably applied.

MoaBibCocNidFeeXfYgZhQiSijOk (1)

In the formula (1), Mo is molybdenum, Bi is bismuth, Co is cobalt, Ni is nickel, Fe is iron, Si is silicon, O is oxygen, and X, Y, Z, Q, a ~ K and k are as defined above. Especially, the catalyst manufactured by this invention WHEREIN: It is preferable that Q is a chlorine atom in the said Formula (1), and when a = 12, b = 0.5-7, c = 0-10. , D = 0 to 10, c + d = 1 to 10, e = 0.05 to 3, f = 0.0005 to 3, g = 0 to 3, h = 0 to 1, i = 0 to 0.05, j A range of 0 to 40 is particularly preferable.

  In the production method of the present invention, the raw material compound containing each elemental component of the catalyst is mixed with the catalyst component by appropriately dissolving or dispersing a necessary amount in an aqueous medium according to the composition of the catalyst to be produced. A solution or an aqueous slurry thereof is produced. As raw materials for each catalyst component, nitrates, ammonium salts, hydroxides, oxides, sulfates, carbonates, halides, acetates, and the like containing the respective elements are used. For example, as molybdenum, ammonium paramolybdate, molybdenum trioxide, molybdenum chloride, or the like is used. A non-aqueous solvent such as alcohol can be added to the aqueous medium in order to adjust the viscosity as necessary.

  The mixed solution or aqueous slurry containing the catalyst component is preferably sufficiently stirred and mixed in order to prevent uneven distribution of each component. Next, the mixed solution or aqueous slurry containing the catalyst component is dried, and the drying can be carried out by various methods. For example, a powdery dried product may be obtained using a normal spray dryer, slurry dryer, drum dryer, or the like, but drying with a spray dryer is particularly preferable.

  In the present invention, it is important to control the moisture content in the dry product, preferably in the form of a powder, containing the catalyst component subjected to molding, and as described above, the moisture content of the dry product is 0.3 to 4% by weight. The moisture content of the dried product is defined as in equation (2).

In Formula (2), W1 is the weight when the dried product is evaporated to dryness at 150 ° C. for 10 hours, and W2 is the weight of the dried product.

Moisture content = (W2-W1) / W1 × 100 (2)

In the present invention, the method for controlling the moisture content of the dried product to be molded within the above range may be carried out by controlling the conditions when drying the mixed solution or aqueous slurry containing the catalyst component, Moreover, you may carry out by performing appropriate humidification by means, such as spraying a water | moisture content, to the dried material once manufactured. In any case, it is necessary to control the moisture content of the dried product within the above range. Especially, in this invention, the moisture content of a dried material becomes like this. Preferably it is 0.4 to 3 weight%.

  As a method for molding the dried product, tableting molding is adopted in view of ease of molding and properties of the molded body. The shape of the molded body may be any of a spherical shape, a cylindrical shape, and a ring shape, and various sizes can be selected as appropriate. However, the molded body has a ring shape, the outer diameter is 3 to 10 mm, the inner diameter is 0.1 to 0.7 times the outer diameter, and the length (height) is 0.5 of the outer diameter. A shape having an opening in the length (height) direction is preferable from the viewpoint that the pressure loss is small.

  In the above molding, inorganic fibers such as glass fibers, various whiskers and the like that are generally known for improving the mechanical strength and the degree of pulverization of the molded product may be used. In order to control the physical properties of the catalyst with good reproducibility, additives generally known as binders such as ammonium nitrate, cellulose, starch, polyvinyl alcohol and stearic acid can also be used.

  In the present invention, the dried product containing the catalyst components obtained as described above is subsequently calcined. Firing is preferably performed in the presence of an oxygen-containing gas at 400 to 650 ° C., particularly preferably at 450 to 600 ° C., preferably for 1 to 15 hours, particularly preferably for 3 to 12 hours. For the firing, an atmosphere firing furnace can be used. As the atmosphere firing furnace, for example, a method in which a fixed bed reactor is filled with a catalyst and heated from the outside under the circulation of the atmosphere gas, a method in which the fixed bed reactor is a heat exchange type, and an atmosphere gas is circulated inside the muffle furnace A method of circulating the atmosphere gas inside the tunnel furnace, a method of circulating the atmosphere gas inside the kiln furnace, and the like can be used. In view of the ease of control of the atmospheric gas flow rate in the calcination, the catalyst is preferably filled in the fixed bed reactor and heated from the outside under the circulation of the atmospheric gas, more preferably the catalyst is added to the heat exchange type fixed bed reactor. A method of filling and heating from the outside under a flow of atmospheric gas can be used. As the atmospheric gas, in addition to air, a mixed gas of air and an inert gas such as nitrogen can be used. Air is preferably used because it is economically advantageous.

  Using the catalyst produced in the present invention, olefin, tertiary butyl alcohol, or methyl tertiary butyl ether is subjected to gas phase catalytic oxidation with a molecular oxygen-containing gas, and the corresponding unsaturated aldehyde and unsaturated carboxylic acid are respectively obtained. The manufacturing method can be performed by an existing method. For example, a fixed bed tube reactor is used as the reactor. In this case, the reaction may be a single flow method or a recycle method through the reactor, and can be carried out under conditions generally used for this type of reaction.

For example, a mixed gas composed of 1 to 15% by volume of propylene, 3 to 30% by volume of molecular oxygen, 0 to 60% by volume of water vapor, 20 to 80% by volume of an inert gas such as nitrogen or carbon dioxide, It introduce | transduces by the space velocity (SV) 300-5000hr < ^-1 > under the pressurization of 250-450 degreeC and 0.1-1 MPa to the catalyst layer with which each 15-50 mm reaction tube was filled. Moreover, in this invention, in order to raise productivity more, it can also drive | operate also on high load reaction conditions, for example, the conditions of higher raw material concentration or high space velocity.

  The present invention will be described more specifically with reference to examples of the present invention. However, the present invention should not be construed as being limited to such examples. In the following, the conversion rate, selectivity, and yield are calculated by the following equations. Further, the drop strength of the catalyst is determined by the following.

Conversion (mol%): (number of moles of reacted propylene / number of moles of supplied propylene) × 100
Selectivity (mol%): ((moles of acrolein produced + moles of acrylic acid produced) / moles of reacted propylene) × 100
Yield (mol%): ((number of moles of produced acrolein + number of moles of produced acrylic acid) / number of moles of supplied propylene) × 100
-Drop strength: 20 g of catalyst is dropped from the upper part of a stainless steel pipe with an inner diameter of 25 mm and a length of 1 m, which is set up vertically, and received by a stainless steel plate with a thickness of 2 mm. Measured and sieved with a 10-mesh sieve, and the drop strength was determined by the following formula.

Drop strength (%) = (weight of catalyst remaining on sieve / weight of dropped catalyst) × 100

Example 1
155.6 g of ammonium paramolybdate was dissolved in 500 ml of heated pure water. Next, 29.7 g of ferric nitrate, 85.5 g of cobalt nitrate, and 42.7 g of nickel nitrate were dissolved in 150 ml of heated pure water. These solutions were gradually mixed with sufficient stirring to prepare a slurry. Next, 1.4 g of borax and 0.74 g of potassium nitrate were dissolved in 40 ml of pure water under heating and added to the slurry. Next, 66.2 g of silica was added and stirred thoroughly. Subsequently, 3.0 ml of nitric acid was added to 20 ml of pure water, and 35.6 g of bismuth nitrate was further added, followed by stirring and mixing.

The slurry was heat-dried and then subjected to a heat treatment at 300 ° C./1 hour in an air atmosphere. Pure water was added to the obtained granular solid and wet pulverized, and the resulting slurry was dried with a spray dryer under conditions of an inlet temperature of 300 ° C. and an outlet temperature of 125 ° C. It was 1.5 weight% when the moisture content of the obtained dried material was measured.
1.5% by weight of graphite was added to the dried product and molded into a tablet having an outer diameter of 6 mm, an inner diameter of 3 mm, and a height of 4 mm using a tableting machine.

Next, the tablet-molded product was placed in a firing container and fired at 510 ° C. for 4 hours with a small amount of air flowing to produce a composite oxide catalyst.
The catalyst calculated from the charged raw materials is a complex oxide having the following atomic ratio.

Mo: Bi: Co: Ni: Fe: Na: B: K: Si = 12: 1: 4: 2: 1: 0.1: 0.2: 0.1: 15

When the drop strength of this catalyst was measured, it was 98.5%.
30 ml of this catalyst was filled in a stainless steel nighter jacketed reaction tube with an inner diameter of 20 mm, and a mixed gas of 8% by volume of propylene, 67% by volume of air and 25% by volume of water vapor was introduced at SV1800 (hr ⁻¹ ) When propylene was oxidized at 310 ° C., a propylene conversion rate of 98.3%, a selectivity of 95.2%, and a yield of 93.7% were obtained.

Comparative Example 1
A catalyst was prepared in the same manner as in Example 1 except that the outlet temperature of the spray dryer was 160 ° C. The water content of the dried product was 0.2% by weight. The drop strength of this catalyst was measured and found to be 90.1%.
When an oxidation reaction of propylene was carried out in the same manner as in Example 1, the propylene conversion was 97.9%, the selectivity was 95.0%, and the yield was 93.0%.

Comparative Example 2
A catalyst was prepared in the same manner as in Example 1 except that the outlet temperature of the spray dryer was 95 ° C. The water content of the obtained dried product was 5.0% by weight.
When the drop strength of this catalyst was measured, it was 91.5%.
When an oxidation reaction of propylene was carried out in the same manner as in Example 1, the propylene conversion was 97.8%, the selectivity was 94.8%, and the yield was 92.7%.

  The catalyst produced by the method of the present invention is obtained by subjecting olefin, tertiary butyl alcohol, or methyl tertiary butyl ether to gas phase catalytic oxidation with a molecular oxygen-containing gas to give the corresponding unsaturated aldehyde and unsaturated carboxylic acid, respectively. Used for manufacturing. The produced unsaturated aldehydes and unsaturated carboxylic acids are used in a wide range of applications as raw materials for various chemicals, monomers for general-purpose resins, monomers for functional resins such as water-absorbing resins, flocculants, and thickeners. The

Claims (5)

  Molybdenum and bismuth used in the production of the corresponding unsaturated aldehyde and unsaturated carboxylic acid by gas phase catalytic oxidation of olefin, tertiary butyl alcohol or methyl tertiary butyl ether with gas containing molecular oxygen. And a method for producing a composite oxide catalyst containing at least iron, wherein the mixed solution or aqueous slurry containing the catalyst component is dried, and the moisture content of the resulting dried product is adjusted to 0.3 to 4% by weight, A method for producing a catalyst for producing an unsaturated aldehyde and an unsaturated carboxylic acid, wherein the molded product is formed by tableting.   The molded body has an outer diameter of 3 to 10 mm, an inner diameter of 0.1 to 0.7 times the outer diameter, a length of 0.5 to 2 times the outer diameter, and an opening in the length direction. The manufacturing method of the catalyst for manufacture of the unsaturated aldehyde and unsaturated carboxylic acid of Claim 1 which is the shape. The method for producing a catalyst for producing an unsaturated aldehyde and an unsaturated carboxylic acid according to claim 1 or 2, wherein the composite oxide catalyst has the following formula (1).

MoaBibCocNidFeeXfYgZhQiSijOk (1)

(Wherein X is at least one element selected from the group consisting of Na, K, Rb, Cs and Tl, and Y is at least one element selected from the group consisting of B, P, As and W) Z is at least one element selected from the group consisting of Mg, Ca, Zn, Ce and Sm, Q is a halogen, and a to k represent the atomic ratio of each element. When a = 12, b = 0.5-7, c = 0-10, d = 0-10, c + d = 1-10, e = 0.05-3, f = 0.005-3, g = 0-3, h = 0-1, i = 0-0.5, j = 0-40, and k is a numerical value that satisfies the oxidation state of other elements.)   Gas phase catalytic oxidation of olefin, tertiary butyl alcohol, or methyl tertiary butyl ether with molecular oxygen-containing gas using the catalyst obtained by the production method according to claim 1, respectively. Process for producing corresponding unsaturated aldehydes and unsaturated carboxylic acids.   The process of claim 4 wherein the olefin is propylene and the unsaturated aldehyde and unsaturated carboxylic acid are acrolein and acrylic acid, respectively.