JP2012130919A - Method for producing catalyst for synthesizing unsaturated aldehyde and unsaturated carboxylic acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a catalyst with which unsaturated aldehyde and unsaturated carboxylic acid corresponding to propylene, isobutylene, tertiary butyl alcohol or methyl tertiary-butyl ether are produced in high yield, and which has excellent mechanical strength.SOLUTION: The method for producing the catalyst for synthesizing unsaturated aldehyde and unsaturated carboxylic acid is provided in which 0.1-3 parts mass of silica gel having an average particle diameter of 1-10 nm in terms of anhydrous silicic acid (SiO), an organic binder which has a viscosity at 20°C of ≥10,000 mPa-s when formed into a 2 mass% aqueous solution, and at least one selected from the group comprising water and alcohol is added to and kneaded with 100 parts mass of spherical particles having an average particle diameter of 40-150μm which is obtained by spray-drying a solution or slurry containing molybdenum, bismuth and iron at the least, then the obtained kneaded material is subjected to extrusion molding, and after that, the extrusion-molded material is dried and heat treated.

Description

  In the present invention, propylene, isobutylene, tertiary butyl alcohol (hereinafter also referred to as “TBA”) or methyl tertiary butyl ether (hereinafter also referred to as “MTBE”) is vapor-phase catalytically oxidized using molecular oxygen. The present invention relates to a method for producing a catalyst having excellent mechanical strength and excellent reactivity used in synthesizing an unsaturated aldehyde and an unsaturated carboxylic acid corresponding to each.

  Conventional catalysts used for producing acrolein and acrylic acid by vapor phase catalytic oxidation of propylene, and catalysts used for producing methacrolein and methacrylic acid by vapor phase catalytic oxidation of isobutylene, TBA or MTBE and production thereof Many proposals have been made for methods.

  Among these proposals, as a method for imparting the mechanical strength of the catalyst, for example, a method of adding whisker to the catalyst component and shaping (Patent Document 1), a silica sol having an average particle diameter of 1 to 10 nm for the catalyst component Of 1 to 10% by weight of silica as anhydrous silicic acid (Patent Document 2) and 1 to 6 parts by weight of silica sol as anhydrous silicic acid and 30 to 300 μm in length are added for shaping. A method (Patent Document 3) has been reported.

  However, although the mechanical strength of the catalyst obtained by the above method is improved, the yield of the target unsaturated aldehyde and unsaturated carboxylic acid is not yet sufficient, and it has higher mechanical strength, and Development of a catalyst capable of obtaining a target product in a high yield and a method for producing the same are desired.

  On the other hand, as a method for obtaining a catalyst capable of obtaining a target product with a high yield, for example, after heat-treating an aqueous slurry containing a catalyst component, the particles of the aqueous slurry are atomized to 0.5 to 10 μm and spray dried. A method of firing and forming spherical particles having an average particle diameter of 10 to 250 μm using a machine (Patent Document 4), at least a high-viscosity organic binder having a viscosity of 5,000 mPa · s to 25,000 mPa · s, and A method for forming a catalyst component using an organic binder containing a low-viscosity organic binder having a viscosity of 10 mPa · s or more and less than 5,000 mPa · s has been proposed (Patent Document 5).

  However, although the yield of the target unsaturated aldehyde and unsaturated carboxylic acid is improved in the catalyst obtained by the above method, the mechanical strength of the catalyst is not yet sufficient, and has higher mechanical strength, In addition, it is desired to develop a catalyst capable of obtaining a target product with high yield and a method for producing the catalyst.

JP 59-183832 A Japanese Patent Laid-Open No. 7-16463 JP-A-9-52053 JP 10-258233 A International Application Publication WO2005 / 058497 A1

  An object of the present invention is to provide a method for producing a catalyst capable of producing an unsaturated aldehyde and an unsaturated carboxylic acid corresponding to propylene, isobutylene, TBA or MTBE in high yield and having excellent mechanical strength. .

The present invention synthesizes an unsaturated aldehyde and an unsaturated carboxylic acid corresponding to a reaction material by subjecting propylene, isobutylene, TBA or MTBE (hereinafter referred to as “reaction material”) to gas phase catalytic oxidation using molecular oxygen. A method for producing an unsaturated aldehyde and unsaturated carboxylic acid synthesis catalyst containing at least molybdenum, bismuth and iron catalyst components used in the process, wherein the solution or slurry containing the catalyst components is spray dried and calcined. Thus, 100 parts by mass of spherical particles having an average particle diameter of 40 to 150 μm are obtained by using silica sol having an average particle diameter of 1 to 10 nm as anhydrous silicic acid (SiO ₂ ), 0.1 to 3 parts by mass , and a 2% by mass aqueous solution. Selected from the group of organic binders and water and alcohols that give a viscosity at 20 ° C. of 10,000 mPa · s or higher. By kneading a material obtained by adding at least one, after extrusion molding, drying and heat treatment unsaturated aldehyde and method for producing an unsaturated carboxylic acid catalyst for synthesizing, characterized by.

  According to the present invention, an unsaturated aldehyde and an unsaturated carboxylic acid corresponding to the reaction raw material can be produced in high yield from the reaction raw material, and a catalyst having excellent mechanical strength can be produced.

  The unsaturated aldehyde and unsaturated carboxylic acid synthesis catalyst produced in the present invention (hereinafter referred to as “catalyst”) is obtained by subjecting a reaction raw material to gas phase catalytic oxidation using molecular oxygen and corresponding to the reaction raw material. And an unsaturated carboxylic acid, that is, used when synthesizing acrolein and acrylic acid from propylene, methacrolein and methacrylic acid from other than propylene, and contains at least molybdenum, bismuth and iron as catalyst components, The thing of the composition shown by following General formula (1) is preferable.

_{Mo a Bi b Fe c M d} X e Y f Z g Si h O i ····· (1)
In the general formula (1), Mo, Bi, Fe, Si and O represent molybdenum, bismuth, iron, silicon and oxygen, respectively. M represents at least one element selected from cobalt and nickel. X represents at least one element selected from chromium, lead, manganese, calcium, magnesium, niobium, silver, barium, tin, tantalum and zinc. Y represents at least one element selected from phosphorus, boron, sulfur, selenium, tellurium, cerium, tungsten, antimony and titanium. Z represents at least one element selected from lithium, sodium, potassium, rubidium, cesium and thallium. a, b, c, d, e, f, g, h, and i represent the atomic ratio of each element. When a = 12, b = 0.01-3, c = 0.01-5, d = 1. -12, e = 0 to 8, f = 0 to 5, g = 0.001 to 2, and h = 0 to 20, i is an oxygen atomic ratio necessary for satisfying the valence of each component. is there.

  Examples of the starting material for the catalyst component include oxides, sulfates, nitrates, carbonates, hydroxides, ammonium salts, halides and the like of each element. For example, examples of the molybdenum raw material include ammonium paramolybdate and molybdenum trioxide. Examples of the bismuth raw material include bismuth oxide, bismuth nitrate, and bismuth carbonate. Examples of the iron raw material include ferric nitrate and nonahydrate.

  As the starting material for the catalyst component, one kind of each element may be used alone, or two or more kinds may be used in combination.

  In the present invention, the catalyst component is made into spherical particles having an average particle diameter of 40 to 150 μm by firing after spray drying a solution or slurry containing the catalyst component.

  As a method for preparing the slurry containing the starting material of the catalyst component, a known method such as a precipitation method or an oxide mixing method can be applied as long as the catalyst component is not significantly unevenly distributed.

  As conditions for spray-drying the solution or slurry containing the catalyst component, the inlet temperature of the spray dryer is preferably 100 to 500 ° C. The outlet temperature is preferably 100 ° C. or higher, more preferably 105 to 200 ° C.

  The spherical particles after spray-drying the solution or slurry containing the catalyst component may contain a salt such as nitrate derived from the starting material of the catalyst component. If the salt remains, the mechanical strength of the catalyst may be lowered. Therefore, after drying, calcination is performed to decompose the salt. As firing conditions, known firing conditions can be applied, and the firing temperature is preferably about 200 to 600 ° C. in an air atmosphere. Further, the calcination time is appropriately selected according to the target catalyst.

  As described above, the average particle size of spherical particles (hereinafter referred to as “fired spherical particles”) obtained by spray drying a solution or slurry containing a catalyst component and then firing is 40 to 150 μm, and preferably 50 μm or more. By increasing the average particle size of the calcined spherical particles, large voids between the calcined spherical particles, that is, large pores are formed in the catalyst, and the selectivity of the target unsaturated aldehyde or unsaturated carboxylic acid tends to be improved. is there.

  The average particle size of the fired spherical particles is preferably 100 μm or less. By reducing the average particle diameter of the calcined spherical particles, the contact point between the calcined spherical particles per unit volume increases, so the mechanical strength of the catalyst tends to be improved.

  The bulk specific gravity of the fired spherical particles is preferably 0.5 kg / L or more, more preferably 0.8 kg / L or more from the viewpoint of handleability. The bulk specific gravity of the calcined spherical particles is preferably 1.8 kg / L or less, more preferably 1.2 kg / L or less from the viewpoint of performance.

In the present invention, the calcined spherical particles have a viscosity at 10 ° C. of 10 to 100 parts by mass of silica sol (SiO ₂ ) of 0.1 to 3 parts by mass of silica sol and 2% by mass aqueous solution at 10, An organic binder giving 000 mPa · s or more and at least one selected from the group of water and alcohol are added, and after being kneaded as described later, extrusion molding is performed.

The addition amount of the silica sol is 0.1 to 4 parts by mass as silicic anhydride (SiO ₂ ) with respect to 100 parts by mass of the fired spherical particles, and preferably 0.5 parts by mass or more. The amount of silica sol added is preferably 3 parts by mass or less. When the addition amount is 0.1 parts by mass or more, sufficient mechanical strength is obtained when the catalyst is used, and when it is 4 parts by mass or less, the activity of the catalyst is hardly lowered. The average particle size of the silica sol is preferably 1 to 10 nm.

  As the organic binder, those giving a viscosity at 20 ° C. of 10,000 mPa · s or more when used as a 2 mass% aqueous solution are used. When the viscosity is 10,000 mPa · s or more, the moldability at the time of extrusion molding described later is good and sufficient mechanical strength is obtained when the catalyst is used. The viscosity can be measured using, for example, a viscometer such as a B-type viscometer.

  Examples of such an organic binder include β-1,3-glucan derived from microorganisms and cellulose derivatives such as methylcellulose, ethylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, and hydroxyethyl. Mention may be made of methylcellulose, hydroxybutylmethylcellulose, ethylhydroxyethylcellulose and hydroxypropylcellulose.

  These organic binders may be used alone or in combination of two or more.

  The amount of the organic binder added is preferably 0.1 parts by mass or more and more preferably 2 parts by mass or more with respect to 100 parts by mass of the fired spherical particles from the viewpoint of improving moldability. In addition, the amount of the organic binder added is preferably 10 parts by mass or less and more preferably 6 parts by mass or less with respect to 100 parts by mass of the fired spherical particles from the viewpoint that post-treatment such as heat treatment after molding becomes simple.

  Water or alcohol is used as a liquid (hereinafter referred to as “liquid”) used for kneading and extrusion molding described later. Examples of the alcohol include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, and butyl alcohol. As the liquid, water is preferable from the viewpoints of economy and handleability.

  In addition, a liquid may be used individually by 1 type and may be used in combination of 2 or more type.

  The amount of the liquid is appropriately selected depending on the kind and size of the fired spherical particles, the kind of the liquid, and the like, but is preferably 10 to 70 parts by weight with respect to 100 parts by weight of the fired spherical particles. The amount of the liquid is more preferably 20 parts by mass or more, still more preferably 30 parts by mass or more, and particularly preferably 35 parts by mass or more with respect to 100 parts by mass of the sintered spherical particles. When the amount of the liquid is increased, large voids or large pores are formed in the obtained catalyst, and the selectivity of the target unsaturated aldehyde or unsaturated carboxylic acid tends to be improved. The amount of the liquid is more preferably 60 parts by mass or less, still more preferably 50 parts by mass or less, and particularly preferably 45 parts by mass or less with respect to 100 parts by mass of the spherical particles. When the amount of the liquid is reduced, the adhesion of the fired spherical particles at the time of molding is reduced, the handleability is improved, and the resulting catalyst becomes denser, and the mechanical strength of the catalyst tends to be improved.

  The kneading machine used for kneading the calcined spherical particles, the silica sol, the organic binder defined in the present invention, and further the molding aid such as a lubricant and a plasticizer is not particularly limited. For example, a double-arm type stirring blade is used. A batch type kneading machine or a continuous kneading machine such as a shaft rotation reciprocating type or a self-cleaning type can be used. Among these, the batch type is preferable because kneading can be performed while checking the state of the kneaded product.

  When extruding by adding at least one selected from the group consisting of fired spherical particles, silica sol, the organic binder defined in the present invention, and water and alcohol, ring-shaped, cylindrical, star-shaped, honeycomb-shaped, etc. Can be shaped into any shape.

  The molded body formed into these arbitrary shapes is then usually dried at room temperature to 150 ° C., and then heat-treated at about 300 to 600 ° C. in an air atmosphere or the like to be used as a catalyst.

  In the presence of the catalyst produced by the method of the present invention, a gas phase catalytic oxidation reaction is performed using the reaction raw material and molecular oxygen. At this time, the molar ratio of the reaction raw material to molecular oxygen is preferably 1: 0.5 to 1: 3. It is economical to use the reaction raw material gas diluted with an inert gas. Although it is economical to use air as the molecular oxygen, air enriched with pure oxygen can also be used if necessary.

  The reaction pressure is preferably from atmospheric pressure to several atmospheres. As reaction temperature, 200-450 degreeC is preferable and 250-400 degreeC is more preferable. The contact time is preferably 1.5 to 15 seconds.

  The catalyst in the reactor can be used by diluting with an inert substance such as silica, alumina, silica-alumina, silicon carbide, ceramic balls and stainless steel.

  Hereinafter, the present invention will be described using examples. In the following, “parts” indicates parts by mass, and the raw material gas and the product were analyzed by gas chromatography.

  Moreover, the reaction rate of the olefin, TBA or MTBE in Examples and Comparative Examples, the selectivity of the unsaturated aldehyde and unsaturated carboxylic acid produced, the total yield of the unsaturated aldehyde and unsaturated carboxylic acid produced (hereinafter, “ The total yield was calculated by the following formula.

Reaction rate (%) = (A / B) × 100
Selectivity of unsaturated aldehyde (%) = (C / A) × 100
Selectivity of unsaturated carboxylic acid (%) = (D / A) × 100
Total yield (%) = {(C + D) / B} × 100
Here, A is the number of moles of the reacted reaction material, B is the number of moles of the supplied reaction material, C is the number of moles of the generated unsaturated aldehyde, and D is the number of moles of the generated unsaturated carboxylic acid.

  Moreover, the packing powdering rate of the catalyst is defined as follows.

The catalyst a part is filled from the upper part of the stainless steel pipe into a stainless steel pipe having an inner diameter of 30 mmφ and a length of 5 m installed vertically with respect to the horizontal direction, and is recovered from the lower part of the stainless steel pipe after filling. When the catalyst that does not pass through the 8-mesh sieve among the recovered catalysts is part b, the packing powdering rate is expressed by the following equation.

Filling powder rate (%) = {(ab) / a} × 100
The crushing strength was measured by the following method.

Crushing strength: Measured with a micro compression tester (manufactured by Shimadzu Corporation, MCTM-200), and the average crushing strength is an average value obtained by measuring 30 particles.

Example 1
To 2000 parts of pure water, 500 parts of ammonium paramolybdate, 12.4 parts of ammonium paratungstate, 23.0 parts of cesium nitrate, 27.4 parts of antimony trioxide and 33.0 parts of bismuth trioxide are added and heated and stirred. did. Further, 209.8 parts of ferric nitrate, 75.5 parts of nickel nitrate, 453.3 parts of cobalt nitrate, 31.3 parts of lead nitrate and 5.6 parts of 85% phosphoric acid were added in that order, and the mixture was heated and stirred. Slurry. Thereafter, the aqueous slurry was spray-dried using a spray dryer equipped with a rotating disk centrifugal atomizer to obtain spherical dry particles having an average particle diameter of 80 μm. At this time, the rotation speed of the atomizer of the spray dryer was 11,000 rpm, the inlet temperature of the spray dryer was 165 ° C., and the outlet temperature was 125 ° C. Next, the dried spherical particles were calcined at 300 ° C. for 1 hour and at 510 ° C. for 3 hours to obtain calcined spherical particles. The crushing strength of the fired spherical particles thus obtained was 1.3 × 10 −2 N.

  5 parts of hydroxypropylmethylcellulose having a viscosity of 10,000 mPa · s at 20 ° C. when made into a 2% by mass aqueous solution was added to 100 parts of the calcined spherical particles thus obtained and dry-mixed. To this mixture, 36 parts of pure water and 0.8 part of silica sol having an average particle diameter of 7 to 9 nm as silica are added and kneaded using a batch type kneader having a double-arm type stirring blade, followed by extrusion molding. A ring-shaped product having an outer diameter of 5 mm, an inner diameter of 2 mm, and a length of 5 mm was formed by a machine.

  Subsequently, the obtained molded product was dried at 110 ° C. using a hot air dryer, and further calcined at 400 ° C. for 3 hours to obtain a catalyst.

The composition of elements other than oxygen in the obtained catalyst was Mo ₁₂ W _0.2 Bi _0.6 Fe _2.2 Sb _0.8 Ni _1.1 Co _6.6 Pb _0.4 P _0.2 Cs _0. It was ₅ .

  This catalyst was filled in a stainless steel reaction tube, and a reaction time of 3.6 seconds under normal pressure and a contact time of 3.6 seconds using a mixed gas of 5% isobutylene, 12% oxygen, 10% water vapor and 73% nitrogen (volume% each). The reaction was performed at a temperature of 340 ° C. As a result of the reaction, the reaction rate of isobutylene was 97.1%, the selectivity of methacrolein was 89.9%, and the selectivity of methacrylic acid was 4.0%. The filling powdering rate was 0.04%. These results are shown in Table 1.

(Example 2)
In Example 1, 3 parts of silica sol having an average particle diameter of 7 to 10 nm was added as silicic anhydride when the ring-shaped product was molded. Otherwise, the catalyst was obtained in the same manner as in Example 1 and reacted with isobutylene. As a result, the reaction rate of isobutylene was 96.5%, the selectivity of methacrolein was 90.0%, and the selectivity of methacrylic acid was 4.0%. The filling powdering rate was 0.02%. These results are shown in Table 1.

Example 3
In Example 1, 5 parts of a hydroxypropyl methylcellulose having a viscosity of 30,000 mPa · s at 20 ° C. when a 2 mass% aqueous solution was formed when a ring-shaped product was formed was added. Otherwise, the catalyst was obtained in the same manner as in Example 1 and reacted with isobutylene. As a result, the reaction rate of isobutylene was 97.2%, the selectivity of methacrolein was 89.7%, and the selectivity of methacrylic acid was 3.8%. The filling powdering rate was 0.04%. These results are shown in Table 1.

(Comparative Example 1)
In Example 1, no silica sol was added when the ring-shaped product was molded. Otherwise, the catalyst was obtained in the same manner as in Example 1 and reacted with isobutylene. As a result, the reaction rate of isobutylene was 96.1%, the selectivity of methacrolein was 89.9%, and the selectivity of methacrylic acid was 4.0%. The filling powder ratio was 0.87%. These results are shown in Table 1.

(Comparative Example 2)
In Example 1, 5 parts of hydroxypropylmethylcellulose having a viscosity of 4,000 mPa · s at 20 ° C. when a 2% by mass aqueous solution was formed when the ring-shaped product was formed was added, and no silica sol was added. Otherwise, the catalyst was obtained in the same manner as in Example 1 and reacted with isobutylene. As a result, the reaction rate of isobutylene was 97.1%, the selectivity of methacrolein was 89.6%, and the selectivity of methacrylic acid was 3.5%. The filling powdering rate was 1.24%. These results are shown in Table 1.

(Comparative Example 3)
In Example 1, 10 parts of silica sol having an average particle diameter of 7 to 10 nm as silicic anhydride was added when the ring-shaped product was molded. Otherwise, the catalyst was obtained in the same manner as in Example 1 and reacted with isobutylene. As a result, the reaction rate of isobutylene was 95.4%, the selectivity of methacrolein was 86.5%, and the selectivity of methacrylic acid was 4.7%. The filling powdering rate was 0.04%. These results are shown in Table 1.

Claims (1)

Used in the synthesis of unsaturated aldehydes and carboxylic acids corresponding to propylene, isobutylene, tertiary butyl alcohol or methyl tertiary butyl ether by vapor phase catalytic oxidation with molecular oxygen. , A method for producing an unsaturated aldehyde and unsaturated carboxylic acid synthesis catalyst containing at least molybdenum, bismuth and iron catalyst components, wherein the average particles obtained by spray drying a solution or slurry containing the catalyst components Viscosity at 20 ° C. when 100 parts by mass of spherical particles having a diameter of 40 to 150 μm and silica sol having an average particle diameter of 1 to 10 nm as an anhydrous silicic acid (SiO ₂ ) are 0.1 to 3 parts by mass and a 2% by mass aqueous solution. Selected from the group consisting of an organic binder that gives 10,000 mPa · s or more, and water and alcohol At least one by kneading a material obtained by adding, after the extrusion, drying and heat treatment unsaturated aldehyde and method for producing an unsaturated carboxylic acid catalyst for synthesizing, characterized by that.