JP2023143794A - Production method of catalyst - Google Patents

Abstract

To efficiently provide a catalyst having a high raw material conversion rate and an excellent product yield as a catalyst to be used for a gas phase catalytic oxidation reaction for producing from olefin such as propylene or t-butanol, unsaturated aldehyde such as acrolein and methacrolein, and unsaturated carboxylic acid such as acrylic acid and methacrylic acid.SOLUTION: A method for producing a catalyst for producing unsaturated aldehyde and unsaturated carboxylic acid includes a liquid preparing step of adding a feed source compound of a plurality of catalyst active elements to an aqueous liquid and dissolving or dispersing the product to bring to a prepared solution, wherein the liquid preparing step includes a process of adding nitride as the feed source compound or an aqueous liquid in which the nitride is dissolved or dispersed to an aqueous liquid in which the other feed source compound is dissolved or dispersed followed by dissolving or dispersing the product, an amount of the nitride to be added or a content of nitride contained in an aqueous liquid in which the added nitride is dissolved or dispersed is 2 kg or more, and an addition rate of the added nitride or the aqueous liquid in which the nitride is dissolved or dispersed is 40 kg or less per minute.SELECTED DRAWING: None

Description

This invention relates to a catalyst used in the gas phase catalytic oxidation of olefins such as propylene or tertiary butanol to produce unsaturated aldehydes such as acrolein or methacrolein, and unsaturated carboxylic acids such as acrylic acid or methacrylic acid. Regarding the manufacturing method.

Molybdenum-based catalysts are useful as catalysts used when producing unsaturated aldehydes such as acrolein or methacrolein and unsaturated carboxylic acids such as acrylic acid or methacrylic acid by gas phase catalytic oxidation of olefins or tertiary butanol. This is well known and has been widely put into practical use industrially.

Patent documents such as Patent Document 1 are known regarding the composition and manufacturing method of molybdenum-based catalysts in these various reactions. Patent Document 1 states that in preparing a raw material slurry by mixing catalyst raw materials with hot water or the like, by controlling the slurry temperature, the raw material slurry becomes uniform and the catalyst composition is homogenized.

Japanese Patent Application Publication No. 2018-140326

However, these previously known production methods only control the temperature of the slurry after the catalyst raw materials have been dissolved or dispersed, and the produced catalysts have insufficient raw material conversion rates and unsatisfactory yields. There wasn't. In particular, as the amount of the prepared liquid obtained in the liquid preparation step increased, the raw material conversion rate and the yield decreased significantly.

Therefore, the present invention provides a catalyst for use in a gas phase catalytic oxidation reaction for producing unsaturated aldehydes such as acrolein or methacrolein and unsaturated carboxylic acids such as acrylic acid or methacrylic acid from olefins such as propylene or tertiary butanol. The purpose of this invention is to efficiently provide a catalyst with a high raw material conversion rate and an excellent product yield.

As a result of studies conducted by the present inventors, unsaturated aldehydes and unsaturated carboxylic acids, which include a liquid preparation process in which a plurality of catalytically active element source compounds are added to an aqueous liquid and dissolved or dispersed to prepare a prepared liquid, A method for producing a catalyst for production, in which the liquid preparation step includes adding a nitrate as the source compound or an aqueous liquid in which the nitrate is dissolved or dispersed to an aqueous liquid in which another source compound is dissolved or dispersed. , including the process of dissolving or dispersing, the amount of the nitrate to be added, or the content of the nitrate contained in the aqueous liquid in which the nitrate is dissolved or dispersed, is within a specific range, and the nitrate to be added or the nitrate is dissolved or dispersed. The inventors have discovered that the above problem can be solved by adjusting the addition rate of the dispersed aqueous liquid within a specific range, and have completed the present invention.
That is, the gist of the present invention is as follows.

[1] A method for producing a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids, which includes a liquid preparation step in which a plurality of source compounds of catalytically active elements are added to an aqueous liquid and dissolved or dispersed to obtain a prepared liquid. The liquid preparation step is a process of adding the source compound nitrate or an aqueous liquid in which the nitrate is dissolved or dispersed to an aqueous liquid in which another source compound is dissolved or dispersed, and dissolving or dispersing it. The amount of the nitrate contained or added, or the content of the nitrate contained in the aqueous liquid in which the nitrate to be added is dissolved or dispersed is 2 kg or more, and the nitrate to be added or the aqueous liquid in which the nitrate is dissolved or dispersed is 2 kg or more. A method for producing a catalyst in which the addition rate is 40 kg or less per minute.
[2] The method for producing a catalyst according to [1], wherein the concentration of nitrate in the aqueous liquid in which the nitrate is dissolved or dispersed is in the range of 50 g/L or more and 2000 g/L or less.
[3] The method for producing a catalyst according to [1] or [2], wherein the nitrate is at least one compound selected from the group consisting of bismuth nitrate, iron nitrate, cobalt nitrate, and nickel nitrate.

[4] The method for producing a catalyst according to any one of [1] to [3], wherein the catalyst component element of the catalyst is represented by the following formula (1).
Mo ₁₂ Bi _a Fe _b Co _c Ni _d X _e Y _f Z _g Si _h O _i (1)
(In formula (1), X represents at least one element selected from the group consisting of Na, K, Rb, Cs and Tl, and Y is selected from the group consisting of Mg, Ca, Sr, Ba, Mn and Zn. Z represents at least one element selected from the group consisting of F, Cl, B, P, As, W and Nb. a to i represent the atomic ratio of each element. , 0.5≦
a≦7, 0≦b≦5, 0≦c≦10, 0≦d≦10, 0≦e≦2, 0≦f≦5, 0≦g≦
5, 0≦h≦500, where i is a value that satisfies the oxidation states of other elements. )
[5] In the presence of a catalyst produced by the method for producing a catalyst according to any one of [1] to [4],
A method for producing acrolein and acrylic acid by gas phase catalytic oxidation of a mixed gas containing propylene and an oxygen-containing gas.

According to the present invention, used in a gas phase catalytic oxidation reaction for producing unsaturated aldehydes such as acrolein or methacrolein and unsaturated carboxylic acids such as acrylic acid or methacrylic acid from olefins such as propylene or tertiary butanol. A catalyst with a high raw material conversion rate and an excellent product yield can be efficiently provided.

The method for producing the catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids (hereinafter sometimes referred to as "catalyst") according to the present invention will be described in detail.
The catalyst uses olefins such as propylene or tertiary butanol as a raw material, and performs gas phase catalytic oxidation using oxygen-containing gas to produce unsaturated aldehydes such as acrolein or methacrolein, and unsaturated carboxylic acids such as acrylic acid or methacrylic acid. It is a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids.

[Catalyst manufacturing method]
In the production of the catalyst of the present invention, as each component constituting the catalyst, a predetermined compound having an element (hereinafter sometimes referred to as a "catalyst component element") is added to a compound (which is a supply source of the catalyst). Hereinafter, it may be referred to as a "source compound"), and includes dissolving or dispersing the source compound of the catalyst component element in an aqueous liquid to prepare a liquid (liquid preparation step).
Note that the prepared liquid is dried to form a powder (drying process), then the powder is molded to form a catalyst precursor (molding process), and the catalyst precursor is fired (calcination process). It can further include and be manufactured.

[Liquid preparation process]
The liquid preparation step is a step of dissolving or dispersing the source compound of the catalyst component element in an aqueous liquid to obtain a preparation liquid.
The aqueous liquid is a liquid containing water and an organic solvent that is compatible with water, and may further dissolve an inorganic acid, an inorganic base, or an inorganic salt. The water content in the aqueous liquid is preferably 40
It is at least 70% by mass, more preferably at least 70% by mass, and even more preferably at least 100% by mass. Examples of organic solvents that are compatible with water include methanol, ethanol, glycerin, (poly)amines, and mixtures thereof.

The liquid preparation process in the production of the catalyst of the present invention is a process in which source compounds of a plurality of catalytically active elements are added to an aqueous liquid and dissolved or dispersed to obtain a prepared liquid, and the source compound nitrate or nitrate is dissolved. or the dispersed aqueous liquid is added to an aqueous liquid in which other source compounds are dissolved or dispersed (hereinafter sometimes referred to as "aqueous liquid"), and the amount of the nitrate to be added or The content of nitrate contained in the aqueous liquid in which the nitrate is dissolved or dispersed is 2 kg or more, and the rate of addition of the nitrate to be added or the aqueous liquid in which the nitrate is dissolved or dispersed (hereinafter referred to as "addition rate") 40 kg or less per minute. The amount of nitrate or the content of nitrate contained in the aqueous liquid in which nitrate is dissolved or decomposed is more preferably 5 kg or more, and even more preferably 10 kg or more. The upper limit is not particularly limited, but is preferably 1000 kg, more preferably 500 kg. By being within the above range, a large amount of the preparation liquid can be prepared at once, and a catalyst with a high raw material conversion rate and an excellent product yield can be efficiently provided. The addition rate is preferably 37 kg or less, more preferably 35 kg or less, and even more preferably 25 kg or less per minute. The lower limit of the addition rate per minute is not particularly limited, but is preferably 1 kg or more, more preferably 2 kg or more, and even more preferably 3 kg or more. By adding the nitrate or the aqueous liquid in which the nitrate is dissolved or dispersed at the above-mentioned addition rate, the dispersibility of the catalyst component element added in the form of nitrate and other catalyst component elements present in the aqueous liquid is promoted. The catalyst thus produced can have a high raw material conversion rate and an excellent product yield.

In addition, the concentration of nitrate in the aqueous liquid in which nitrate is dissolved or dispersed is 50 g/L or more2.
000 g/L or less, the lower limit is more preferably 100 g/L, even more preferably 200 g/L, particularly preferably 300 g/L. The upper limit is more preferably 1700 g/L, and 13
00 g/L is more preferable, and 1000 g/L is particularly preferable. By setting the concentration of nitrate within the above range, the dispersibility of the catalyst component element added in the form of nitrate and other catalyst component elements present in the aqueous liquid is promoted, and the produced catalyst is used for raw material conversion. It is possible to produce a catalyst with high yield and excellent product yield.

The weight of the aqueous liquid is preferably 10 kg or more, more preferably 30 kg or more, even more preferably 50 kg or more. Further, the weight of the aqueous liquid is preferably 5000 kg or less, more preferably 1000 kg or less, still more preferably 500 kg or less. By setting it within the above range, the dispersibility of the catalyst component element added in the form of nitrate and other catalyst component elements present in the aqueous liquid is promoted, and the produced catalyst has a high raw material conversion rate, A catalyst with excellent product yield can be obtained.

In addition, the method of adding nitrate or an aqueous liquid in which nitrate is dissolved or dispersed to an aqueous liquid in which other source compounds are dissolved or dispersed can be carried out either by adding the desired amount continuously or by adding it intermittently. Good too. If the additive is a nitrate, the rate of addition can be determined by dividing the amount of nitrate added by the time of addition. Further, when the additive is an aqueous liquid in which nitrate is dissolved or dispersed, the addition rate can be determined by dividing the amount of the aqueous liquid in which the added nitrate is dissolved or dispersed by the addition time.

It is considered necessary to set the amount of the nitrate or the content of the aqueous liquid in which the nitrate is dissolved or dispersed within a specific range, and to control the addition rate as follows. In the production of catalysts, in recent years there has been a demand for uniform mass production of catalysts having high catalytic performance. In mass production, there are cases where catalysts manufactured using multiple small-sized manufacturing equipment are combined, but it is difficult to suppress the occurrence of non-uniformity in the manufactured catalysts due to differences in manufacturing equipment. Ta. On the other hand, attempts have been made to mass-produce catalysts using large-scale production equipment, but it has not been possible to obtain a large quantity of catalysts having uniformly high catalytic performance. The present inventors have intensively investigated the problems in mass production of catalysts using large-scale production equipment, and found that in the liquid preparation process, if the addition rate of nitrate or an aqueous liquid in which nitrate is dissolved or dispersed is high, the inside of the aqueous liquid after addition , it takes time to mix the areas where nitrates are present in high concentrations with the areas where nitrates are present at low concentrations, and there is a long period of time when the concentration is uneven in the aqueous liquid, that is, a non-uniform state exists, and the nitrates are This adversely affects the dispersibility of the catalyst component elements added in the form of catalyst components and the catalyst component elements existing inside the aqueous liquid.
It was revealed that this was the cause of the non-uniformity of the produced catalyst. The present invention suppresses local non-uniformity of the catalyst by controlling the addition rate when producing a large amount of catalyst,
The dispersibility of the catalyst component element added in the form of nitrate with other catalyst component elements present in the aqueous liquid is promoted, and the produced catalyst has a high raw material conversion rate and an excellent product yield. It can be done.

The nitrate or the aqueous liquid in which the nitrate is dissolved or dispersed may be added to the aqueous liquid by adding the desired total amount of the nitrate continuously or intermittently. In any case,
The addition rate is the value obtained by dividing the total addition amount by the addition time, regardless of the increase or decrease in the addition amount per hour. Furthermore, even if the nitrate is added to the aqueous liquid at multiple locations, the amount added is calculated based on the total amount added at each location.
As mentioned above, dissolving nitrate in an aqueous liquid is accompanied by endotherm, so a device for dissolving nitrate into a prepared liquid (hereinafter sometimes referred to as a "liquid preparation device") uses heating to compensate for endotherm. It is preferable to have ancillary equipment that can efficiently perform this.

[Source compound]
The catalyst preferably contains molybdenum (Mo) and bismuth (Bi) as catalyst component elements, and other catalyst component elements such as iron (Fe), cobalt (Co), and nickel (
It is more preferable to contain Ni), and further preferably contains sodium (Na), potassium (K),
Rubidium (Rb), cesium (Cs), titanium (Ti), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), manganese (Mn), zinc (Zn), fluorine (F), It may contain one or more components such as chlorine (Cl), boron (B), phosphorus (P), arsenic (As), tungsten (W), niobium (Nb), and silicon (Si).

Examples of the molybdenum (Mo) source compound include ammonium paramolybdate, molybdenum trioxide, molybdic acid, ammonium phosphomolybdate, phosphomolybdic acid, and the like.

Examples of the bismuth (Bi) source compound include bismuth chloride, bismuth nitrate, bismuth oxide, bismuth subcarbonate, and the like. The amount of bismuth added is preferably such that the atomic ratio of the catalyst component elements is 0.5 or more and 7 or less, more preferably 0.5 or more and 5 or less, and more preferably 0.5 or more and 5 or less, when molybdenum atoms are 12. It is preferably added in an amount of 0.5 or more and 4 or less, particularly preferably 0.5 or more and 3 or less. By falling within this range, the catalyst can have a high raw material conversion rate and can produce unsaturated aldehydes and unsaturated carboxylic acids in high yields.

Examples of the iron (Fe) source compound include ferric nitrate, ferric sulfate, ferric chloride, and ferric acetate. The amount of iron added is preferably such that the atomic ratio of the catalyst component elements is from 0 to 5, more preferably from 0.1 to 4, even more preferably from 0.1 to 4. It is added in an amount of 0.2 or more and 3 or less, particularly preferably 0.3 or more and 3 or less. By falling within this range, the catalyst can have a high raw material conversion rate and can produce unsaturated aldehydes and unsaturated carboxylic acids in high yields.

Examples of the source compound of cobalt (Co) include cobalt nitrate, cobalt sulfate, cobalt chloride, cobalt carbonate, and cobalt acetate. The amount of cobalt added is preferably such that the atomic ratio of the catalyst component elements is 0 or more and 10 or less, more preferably 0.5 or more and 9 or less, and even more preferably 0.5 or more and 9 or less, when molybdenum atoms are 12. It is added in an amount of 1 or more and 8 or less, particularly preferably 2 or more and 7 or less. By falling within this range, the catalyst can have a high raw material conversion rate and can produce unsaturated aldehydes and unsaturated carboxylic acids in high yields.

Examples of the nickel (Ni) source compound include nickel nitrate, nickel sulfate, nickel chloride, nickel carbonate, and nickel acetate. The amount of nickel added is preferably 0 or more and 10 or less, more preferably 0.5 or more and 9 or less, and even more preferably 0.5 or more and 9 or less, as the atomic ratio of the catalyst component elements when molybdenum atoms are 12. It is added in an amount of 1 or more and 8 or less, particularly preferably 2 or more and 7 or less. By falling within this range, the catalyst can have a high raw material conversion rate and can produce unsaturated aldehydes and unsaturated carboxylic acids in high yields.

The sodium (Na) source compounds include sodium chloride, sodium carbonate,
Examples include sodium nitrate, sodium sulfate, sodium acetate, and sodium borate.
Examples of the potassium (K) source compound include potassium nitrate, potassium sulfate, potassium chloride, potassium carbonate, potassium acetate, and the like. Examples of the rubidium (Rb) source compound include rubidium nitrate, rubidium sulfate, rubidium chloride, rubidium carbonate, rubidium acetate, and the like. Examples of the cesium (Cs) source compound include cesium nitrate, cesium sulfate, cesium chloride, cesium carbonate, and cesium acetate. Examples of the titanium (Ti) source compound include titanium oxide, titanium chloride, and the like.

The amount of at least one element selected from sodium, potassium, rubidium, cesium, and titanium added is preferably 0 or more and 2 or less when molybdenum is 12, more preferably 0.01 or more and 2 or less. , more preferably in a range of 0.02 or more and 2 or less. By falling within this range, the catalyst can have a high raw material conversion rate and can produce unsaturated aldehydes and unsaturated carboxylic acids in high yields.

Examples of the magnesium (Mg) source compound include magnesium oxide, magnesium carbonate, and magnesium sulfate. Examples of the calcium (Ca) source compound include calcium oxide, calcium carbonate, and calcium hydroxide.
Examples of the strontium (Sr) source compound include strontium oxide, strontium carbonate, strontium hydroxide, and strontium nitrate. Examples of the barium (Ba) source compound include barium oxide, barium carbonate, barium nitrate, barium acetate, and barium sulfate. Examples of the manganese (Mn) source compound include manganese dioxide, manganese carbonate, and the like. Examples of the zinc (Zn) source compound include zinc oxide, zinc carbonate, zinc hydroxide, and zinc nitrate.

The amount of at least one element selected from the group consisting of magnesium, calcium, strontium, barium, manganese, and zinc is added such that the atomic ratio of the catalyst component elements is 0 or more and 5 or less when molybdenum is 12. It is preferable to add the amount, more preferably 0 or more and 4 or less, and even more preferably 0 or more and 3 or less. By falling within this range, the catalyst can have a high raw material conversion rate and can produce unsaturated aldehydes and unsaturated carboxylic acids in high yields.

Examples of the fluorine (F) source compound include calcium fluoride, sodium fluoride, and the like. Examples of the chlorine (Cl) source compound include sodium chloride, ammonium chloride, and the like. Examples of the boron (B) source compound include borax, ammonium borate, and boric acid. Examples of the phosphorus (P) source compound include ammonium phosphomolybdate, ammonium phosphate, phosphoric acid, and phosphorus pentoxide. Examples of source compounds for arsenic (As) include ammonium dialseno-18 molybdate and ammonium dialseno-18 tungstate. Examples of the tungsten (W) source compound include tungstic acid, a salt thereof, and the like. Examples of the niobium (Nb) source compound include niobium hydroxide.

When molybdenum is 12, the amount of at least one element selected from fluorine, chlorine, boron, phosphorus, arsenic, tungsten, and niobium is preferably 0 or more and 5 or less, more preferably 0 or more. It is added so that the number is 4 or less, more preferably 0 or more and 3 or less. By falling within this range, the catalyst can have a high raw material conversion rate and can produce unsaturated aldehydes and unsaturated carboxylic acids in high yields.

Examples of the silicon (Si) source compound include silica, granular silica, colloidal silica, fumed silica, and the like. The amount of silicon added is preferably such that the atomic ratio of the catalyst component elements is 0 or more and 500 or less, more preferably 0 or more and 400 or less, and even more preferably 0 or more. Add so that it becomes 300 or less. By falling within this range, the catalyst can have a high raw material conversion rate and can produce unsaturated aldehydes and unsaturated carboxylic acids in high yields.

In the method for producing a catalyst of the present invention, the source compound contains a nitrate, and the nitrate is preferably at least one compound selected from the group consisting of bismuth nitrate, iron nitrate, cobalt nitrate, and nickel nitrate; More preferably, it is at least one compound selected from the group consisting of iron, cobalt nitrate, and nickel nitrate. By using the nitrate, it is possible to obtain a catalyst that has a high raw material conversion rate and can produce unsaturated aldehydes and unsaturated carboxylic acids in high yields.

[Method of adding source compound]
In the liquid preparation step, all of the source compounds may be made into one preparation liquid, or each source compound may be made into a plurality of preparation liquids individually or divided into several groups, and the plurality of preparation liquids may be made into a plurality of preparation liquids. It may be mixed all at once or sequentially to form a single preparation, or one or more preparations may be dried or even calcined to form a solid, which is then mixed into a preparation with the remaining source compounds. It is also possible to add it to a new preparation solution.

[Drying process]
The obtained preparation liquid is dried in a drying process to obtain a powder. There are no particular limitations on the drying method in this drying step, and for example, a powder may be obtained using an ordinary spray dryer, slurry dryer, drum dryer, or the like. Incidentally, the powder may be appropriately pulverized.

The powder obtained by the drying treatment may be further subjected to a heat treatment, if necessary. This heat treatment is preferably carried out in air from 200°C to 470°C, more preferably from 250°C to 450°C.
This process is carried out in a short period of time in a temperature range of There are no particular limitations on the method; for example,
The powder may be heated in a fixed state using an ordinary box-type heating furnace, tunnel-type heating furnace, etc., or may be heated while flowing the powder using a rotary kiln or the like.
In addition, it is preferable that the powder obtained by this drying process contains molybdenum and bismuth, and it is especially preferable that it is the powder represented by the following general formula (1).

Mo ₁₂ Bi _a Fe _b Co _c Ni _d X _e Y _f Z _g Si _h O _i (1)
(In formula (1), X represents at least one element selected from the group consisting of Na, K, Rb, Cs and Tl, and Y is selected from the group consisting of Mg, Ca, Sr, Ba, Mn and Zn. Z represents at least one element selected from the group consisting of F, Cl, B, P, As, W and Nb. a to i represent the atomic ratio of each element. , 0.5≦
a≦7, 0≦b≦5, 0≦c≦10, 0≦d≦10, 0≦e≦2, 0≦f≦5, 0≦g≦
5, 0≦h≦500, where i is a value that satisfies the oxidation states of other elements. )

[Molding process]
The molding step is a step in which the powder obtained in the drying step is molded into a catalyst precursor. The molding method may be any conventionally known method; for example, there are the following two methods. While a carrier, one of which is inert to the reaction for producing unsaturated aldehydes and unsaturated carboxylic acids, is fluidized, the powder is supplied to the fluidized carrier, the powder is supported on the surface of the carrier, and the powder is granulated. A method of molding and forming a catalyst precursor (hereinafter sometimes referred to as "rolling granulation method"). Another method is to place the powder in a mold and apply mechanical pressure to granulate it and mold it into a catalyst precursor (hereinafter sometimes referred to as "tablet molding method"). A rolling granulation method is preferred.

Examples of the carrier used in the rolling granulation method include spherical carriers having a long axis diameter of preferably 2.5 mm to 10 mm, more preferably 2.5 mm to 6 mm, such as silica, silicon carbide, alumina, mullite, and alundum. . Among these, the porosity of the carrier is preferably 20% to 60%, more preferably 30% to 57%, even more preferably 40% to 55%. Further, the water absorption rate of the carrier is preferably 10% to 60%, more preferably 12% to 50%, even more preferably 15% to 60%.
It is 40%. By setting the porosity and water absorption rate of the carrier within the above range, the powder containing the catalyst component element can be easily supported on the carrier.

The rolling granulation method is, for example, in a granulator that has a flat or uneven disk at the bottom of a fixed container, and by rotating the disk at high speed, the carrier in the container is rotated and revolved. In this method, the powder is stirred vigorously by repeated motions, and the powder containing the catalyst component elements and additives are added thereto, thereby supporting the powder on the carrier. Methods for adding additives include (1) a method of preparing a homogeneous mixture by mixing the powder etc. containing the catalyst component element and the additive, and charging the homogeneous mixture into a granulator and stirring; 2) A method in which powder, etc. containing catalyst component elements and additives are simultaneously charged into a granulator and stirred; (3) Powder, etc. containing catalyst component elements are stirred in a granulator, and then the powder, etc. (4) Prepare a heterogeneous mixture by adding additives to powder containing catalyst component elements, and then add the heterogeneous mixture to a granulator and stir. how to,(
5) A method may be mentioned in which the powder containing the catalytic component element and the additive are divided into separate parts and simultaneously, alternately, or in random order, and are charged into a granulator while being stirred. A method such as adding the entire amount of a suitable combination of (1) to (5) can be arbitrarily adopted. For (5), for example, an auto feeder or the like is used to ensure that a predetermined amount of powder containing catalyst elements is supported on the carrier without adhesion to the walls of fixed containers or aggregation of powders containing catalyst elements. It is preferable to adjust the addition rate by using

In the molding step, it is preferable to add an organic compound and mold the molded product from the viewpoint of improving the strength of the molded product. Organic compounds include ethylene glycol, glycerin, propionic acid,
Examples include maleic acid, benzyl alcohol, propyl alcohol, butyl alcohol, cellulose, methyl cellulose, starch, polyvinyl alcohol, stearic acid, and phenol, but glycerin is more preferable because it has excellent raw material conversion rate and product yield. The amount of the organic compound added is preferably 0.3 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the powder. The lower limit is more preferably 0.4 parts by weight, still more preferably 0.5 parts by weight, particularly preferably 0.6 parts by weight. The upper limit is more preferably 13 parts by weight, still more preferably 11 parts by weight, and particularly preferably 9 parts by weight. When the amount of the organic compound added is within the above range, the raw material conversion rate may be high and the product yield may be good. The organic compound added is preferably in the form of an aqueous solution, and its concentration is preferably 2% by weight or more and 40% by weight or less. The lower limit is more preferably 3% by weight. The upper limit is more preferably 30% by weight. By being within the above range, the organic compound can be well dispersed in the solution.

In addition, in the molding process, a molding aid other than the above-mentioned organic compound may be added. Examples of molding aids other than the organic compounds include silica, alumina, glass fiber, silicon carbide, silicon nitride, and graphite.

[Firing process]
The catalyst precursor is preferably heated at a temperature of 300°C to 600°C, more preferably 350°C to 550°C.
It is baked for about 1 hour to 16 hours at a temperature of ℃. As the firing method, the method used in the heat treatment described above can be adopted.
In the manner described above, a highly active catalyst can be obtained.
The catalyst component elements constituting the catalyst of the obtained catalyst are preferably represented by the following general formula (2).

Mo ₁₂ Bi _a Fe _b Co _c Ni _d X _e Y _f Z _g Si _h O _i (1)
(In formula (1), X represents at least one element selected from the group consisting of Na, K, Rb, Cs and Tl, and Y is selected from the group consisting of Mg, Ca, Sr, Ba, Mn and Zn. Z represents at least one element selected from the group consisting of F, Cl, B, P, As, W and Nb. a to i represent the atomic ratio of each element. , 0.5≦
a≦7, 0≦b≦5, 0≦c≦10, 0≦d≦10, 0≦e≦2, 0≦f≦5, 0≦g≦
5, 0≦h≦500, where i is a value that satisfies the oxidation states of other elements. )

[Application]
By using the catalyst produced by the production method of the present invention, it is possible to obtain high raw material conversion rates and excellent product yields, and to convert olefins such as propylene or tertiary butanol into a gas phase using an oxygen-containing gas. Catalytic oxidation can produce the corresponding unsaturated aldehydes such as acrolein or methacrolein and unsaturated carboxylic acids such as acrylic acid or methacrylic acid in high yields.

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

<Measurement of loading rate>
Thirty catalyst particles were collected and the total weight was measured (weight A). Thirty particles of carrier were collected and the total weight was measured (weight B). The loading rate was calculated using the following formula.
Support rate (%) = (weight A - weight B) / weight A x 100

<Conversion rate, selectivity, yield>
The definitions of propylene conversion rate, (acrolein + acrylic acid) selectivity, and (acrolein + acrylic acid) yield are as follows.
・Propylene conversion rate (mol%) = (number of moles of propylene reacted/number of moles of propylene supplied) x 100
・(Acrolein + acrylic acid) selectivity (mol%) = ((number of moles of acrolein produced + number of moles of acrylic acid produced) / number of moles of reacted propylene) x 100
・(Acrolein + acrylic acid) yield (mol%) = (acrolein + acrylic acid) conversion rate x (acrolein + acrylic acid) selectivity/100

<Gas-phase catalytic oxidation reaction of propylene>
Using the catalysts obtained in each example and comparative example, a gas phase catalytic oxidation reaction of propylene was carried out under the following conditions.
A jacketed reaction tube (inner diameter 21 mm) containing a nighter was filled with a mixture of 40 ml of the catalyst and 52 ml of mullite poles having a diameter of 5 mm. Raw material gases (10% by volume of pyrene, 17% by volume of steam, 73% by volume of air) were introduced, and an oxidation reaction of pyrene was carried out at a gauge pressure of 70 kPa. The space velocity of propylene was 100/h. still,
The reaction tube was heated with a nighter bath, and the bath temperature was 320°C. The reaction product was collected from the outlet of the reaction tube and analyzed by gas chromatography.

(Example 1)
<Preparation of catalyst>
400 kg of 80° C. hot water was placed in a container (1) with a jacket (80° C.) equipped with a temperature sensor at the bottom to measure the temperature. Then, ammonium paramolybdate tetrahydrate 6
3.8 kg was added and dissolved to form a solution. After dissolution, the liquid temperature reached 78℃, but it soon became 8℃.
The temperature returned to 0°C. Next, 109.8 kg of an aqueous fumed silica dispersion was added to the solution and stirred to form a suspension, thereby obtaining Solution A. The fumed silica aqueous dispersion is fumed silica 3.
After adding 0 kg (specific surface area 200 m ² /g) to 120 kg of ion-exchanged water to make a fumed silica suspension, the fumed silica suspension was passed through a homogenizer, ULTRA-TURRAX T.
115KT (manufactured by IKA) for 60 minutes to form an aqueous dispersion, which is a silicon source compound.

Pour 98% pure water into a jacketed container (2) equipped with a temperature sensor at the bottom to measure the temperature.
I put 3 kg. After the liquid temperature reached 80° C., 12.9 kg of iron nitrate nonahydrate was added and dissolved. After dissolution, after the liquid temperature returned to 80°C, 38.8 kg of cobalt nitrate hexahydrate was added to 1
Dissolution was achieved by continuous addition at an addition rate of approximately 16 kg per minute. After the cobalt nitrate has completely dissolved and the liquid temperature has returned to 80°C, 39.5 kg of nickel nitrate hexahydrate is further added continuously at a rate of about 16 kg per minute to dissolve B. I got the liquid.
Next, the B solution was continuously added to the A solution heated to 80° C. at an addition rate of about 35 kg per minute, mixed, and stirred uniformly to obtain a slurry C solution. Ta. The temperature of liquid C was about 80°C. Thereafter, the mixture was stirred for about 5 hours while maintaining the temperature. Water was removed from the liquid C by heating to obtain a dry product A, and the dry product A was then ground to obtain a powder A.

Pure water 21 is placed in a jacketed container (3) equipped with a temperature sensor at the bottom that can measure the temperature.
6 kg was added, and the liquid temperature was set to 30°C. Next, 8.2 kg of aqueous ammonia and 16.4 kg of ammonium paramolybdate tetrahydrate were sequentially added and dissolved, and further, 0.0 kg of sodium carbonate was added.
37 kg and 0.31 kg of potassium carbonate were added and dissolved to obtain Solution D.
79.2 kg of powder A was added to the D solution and suspended to obtain a solution E. Next, 24.3 kg of bismuth subcarbonate containing 0.53% Na as a solid solution was added to Solution E and mixed for 30 minutes to obtain a mixture containing catalyst component elements.

The mixture containing the catalytic component elements was heated to remove moisture to obtain a dried product B, and then the dried product B was pulverized to obtain a powder B.
Crystalline cellulose corresponding to 5% by weight based on powder B was added to powder B to form a mixture. A supported molded body was prepared by a rolling granulation method using a spherical carrier containing the mixture, a 30% aqueous glycerin solution, alumina, and silica as main components. Incidentally, the diameter of the supporting molded body was 5 mm. The supported molded body was fired at 515° C. for 2 hours in an air atmosphere to obtain catalyst A.
Catalyst A was spherical, had a diameter of 5 mm, and had a supporting rate of 50%. Further, the composition ratio (molar ratio) of catalyst component elements of catalyst A was as follows.
Mo/Bi/Co/Ni/Fe=12/2.9/3.4/3.4/0.8

(Comparative example 1)
<Preparation of catalyst>
480 kg of 80° C. hot water was placed in a container (1) with a jacket (80° C.) equipped with a temperature sensor at the bottom to measure the temperature. Then, ammonium paramolybdate tetrahydrate 7
6.6 kg was added and dissolved to form a solution. After dissolution, the liquid temperature reached 77°C, but soon returned to 80°C. Next, 132 kg of a fumed silica aqueous dispersion was added to the solution and stirred to form a suspension, thereby obtaining Solution F. In addition, the fumed silica aqueous dispersion is fumed silica 30k.
g (specific surface area 200 m ² /g) to 120 kg of ion-exchanged water to make a fumed silica suspension.
This is an aqueous dispersion obtained by performing a dispersion treatment using T (manufactured by IKA) for 60 minutes, and is a silicon source compound.

Pure water 118 is placed in a jacketed container (2) equipped with a temperature sensor at the bottom that can measure the temperature.
I put kg. After the liquid temperature reached 80° C., 15.5 kg of iron nitrate nonahydrate was added and dissolved. After the solution temperature returned to 80° C., 46.6 kg of cobalt nitrate hexahydrate was continuously added over about 1 minute to dissolve the solution. After the cobalt nitrate was completely dissolved and the liquid temperature returned to 80 ° C., 47.4 kg of nickel nitrate hexahydrate was further added and dissolved over about 1 minute,
Liquid G was obtained.
Next, the G solution was added to the F solution heated to 80° C. over about 1 minute, and the mixture was stirred uniformly to obtain a slurry H solution. The temperature of the H solution was about 80°C. Thereafter, the mixture was stirred for about 5 hours while maintaining the temperature. Water was removed from the H solution by heating to obtain a dry product C, and the dry product C was then ground to obtain a powder C.

Add 25 liters of pure water to a jacketed container (3) equipped with a temperature sensor at the bottom to measure the temperature.
9 kg was added, and the liquid temperature was set to 30°C. Next, 9.8 kg of aqueous ammonia and 19.7 kg of ammonium paramolybdate tetrahydrate were sequentially added and dissolved, and further, 0.0 kg of sodium carbonate was added.
44 kg and 0.37 kg of potassium carbonate were added and dissolved to obtain liquid I.
95.0 kg of Powder C was added to the I solution and suspended to obtain a J solution. Next, 29.1 kg of bismuth subcarbonate containing 0.53% Na as a solid solution was added to Solution J and mixed for 30 minutes to obtain a mixture containing catalyst component elements.

The mixture containing the catalyst component elements was heated to remove water to obtain a dry product D, and then the dry product D was pulverized to obtain a powder D.
Crystalline cellulose corresponding to 5% by weight of powder D was added to powder D to form a mixture. A supported molded body was prepared by a rolling granulation method using a spherical carrier containing the mixture, a 30% aqueous glycerin solution, alumina, and silica as main components. Incidentally, the diameter of the supporting molded body was 5 mm. The supported molded body was fired at 515° C. for 2 hours in an air atmosphere to obtain catalyst B.
Catalyst B was spherical, had a diameter of 5 mm, and had a supporting rate of 50%. Further, the composition ratio (molar ratio) of the catalyst component elements of catalyst B was as follows.
Mo/Bi/Co/Ni/Fe=12/2.9/3.4/3.4/0.8

(Example 2)
<Preparation of catalyst>
400 kg of 80° C. hot water was placed in a container (1) with a jacket (80° C.) equipped with a temperature sensor at the bottom to measure the temperature. Then, ammonium paramolybdate tetrahydrate 6
3.8 kg was added and dissolved to form a solution. After dissolution, the liquid temperature reached 74℃, but it soon became 8℃.
The temperature returned to 0°C. Next, 109.8 kg of an aqueous fumed silica dispersion was added to the solution and stirred to form a suspension to obtain liquid K. The fumed silica aqueous dispersion is fumed silica 3.
After adding 0 kg (specific surface area 200 m2/g) to 120 kg of ion-exchanged water to make a fumed silica suspension, the fumed silica suspension was passed through a homogenizer, ULTRA-TURRAX T.
115KT (manufactured by IKA) for 60 minutes to form an aqueous dispersion, which is a silicon source compound.

Pure water 13. is placed in a jacketed container (2) equipped with a temperature sensor at the bottom that can measure the temperature.
I put 6 kg. After the liquid temperature reached 80° C., 12.9 kg of iron nitrate nonahydrate was added and dissolved to form an aqueous solution. After the temperature of the aqueous solution reached 80°C again, 1 liter of cobalt nitrate aqueous solution was added to the aqueous solution by dissolving 38.8 kg of cobalt nitrate hexahydrate in 42.4 kg of pure water to bring the temperature to 80°C. Continuous addition and mixing was performed at an addition rate of approximately 22 kg per minute. Immediately after the addition was completed, the liquid temperature reached 78°C. After the temperature of the aqueous solution after mixing reached 80°C again, 39.5 kg of nickel nitrate hexahydrate was dissolved in 43.3 kg of pure water to bring the temperature to 80°C, and the nickel nitrate aqueous solution was heated for 1 minute. It was continuously added and mixed at an addition rate of about 22 kg/kg. Immediately after the addition was completed, the liquid temperature reached 79°C. After mixing, the temperature of the aqueous solution became 80° C. again, and L solution was obtained.
Next, the L solution was continuously added to the K solution heated to 80° C. at an addition rate of about 25 kg per minute, and the mixture was stirred uniformly to obtain a slurry M solution. The liquid temperature of M liquid is about 8
It was 0°C. Thereafter, the mixture was stirred for about 5 hours while maintaining the temperature. Water was removed from the liquid M by heating to obtain a dry product E, and the dry product E was then ground to obtain a powder E.

Pure water 21 is placed in a jacketed container (3) equipped with a temperature sensor at the bottom that can measure the temperature.
6 kg was added, and the liquid temperature was set to 30°C. Next, 8.2 kg of aqueous ammonia and 16.4 kg of ammonium paramolybdate tetrahydrate were sequentially added and dissolved, and further, 0.0 kg of sodium carbonate was added.
37 kg and 0.31 kg of potassium carbonate were added and dissolved to obtain an N solution.
79.2 kg of Powder E was added to the N solution and suspended to obtain an O solution. Next, 24.3 kg of bismuth subcarbonate containing 0.53% Na as a solid solution was added to the O solution and mixed for 30 minutes to obtain a mixture containing catalyst component elements.

The mixture containing the catalyst component elements was heated to remove water to obtain a dry product F, and then the dry product F was pulverized to obtain a powder F.
Crystalline cellulose corresponding to 5% by weight based on powder F was added to powder F to form a mixture. A supported molded body was prepared by a rolling granulation method using a spherical carrier containing the mixture, a 30% aqueous glycerin solution, alumina, and silica as main components. Incidentally, the diameter of the supporting molded body was 5 mm. The supported molded body was fired at 515° C. for 2 hours in an air atmosphere to obtain catalyst C.
Catalyst C was spherical, had a diameter of 5 mm, and had a supporting ratio of 50%. Further, the composition ratio (molar ratio) of the catalyst component elements of catalyst C was as follows.
Mo/Bi/Co/Ni/Fe=12/2.9/3.4/3.4/0.8

From the above, the catalyst obtained by the catalyst production method of the present invention has an excellent conversion rate of propylene and a total selectivity of acrolein and acrylic acid when the catalyst is used to oxidize propylene with an oxygen-containing gas in a gas phase. It can be seen that acrolein and acrylic acid can be produced in high yield. Furthermore, the selectivity of the final product, acrylic acid, is high.

Claims (5)

A method for producing a catalyst for producing an unsaturated aldehyde and an unsaturated carboxylic acid, comprising a liquid preparation step of adding a plurality of source compounds of catalytically active elements to an aqueous liquid and dissolving or dispersing them to obtain a prepared liquid, the method comprising:
The liquid preparation step includes a process of adding the source compound nitrate or an aqueous liquid in which the nitrate is dissolved or dispersed to an aqueous liquid in which another source compound is dissolved or dispersed. The amount of the nitrate to be added, or the content of the nitrate contained in the aqueous liquid in which the nitrate is dissolved or dispersed is 2 kg or more, and the rate of addition of the nitrate to be added or the aqueous liquid in which the nitrate is dissolved or dispersed is A method for producing a catalyst that produces 40 kg or less per minute. The concentration of nitrate in the aqueous liquid in which the nitrate is dissolved or dispersed is 50 g/L or more.
The method for producing a catalyst according to claim 1, wherein the amount is within the range of 00 g/L or less. 3. The method for producing a catalyst according to claim 1, wherein the nitrate is at least one compound selected from the group consisting of bismuth nitrate, iron nitrate, cobalt nitrate, and nickel nitrate. The method for producing a catalyst according to claim 1 or 2, wherein a catalyst component element of the catalyst is represented by the following formula (1).
Mo ₁₂ Bi _a Fe _b Co _c Ni _d X _e Y _f Z _g Si _h O _i (1)
(In formula (1), X represents at least one element selected from the group consisting of Na, K, Rb, Cs and Tl, and Y is selected from the group consisting of Mg, Ca, Sr, Ba, Mn and Zn. Z represents at least one element selected from the group consisting of F, Cl, B, P, As, W and Nb. a to i represent the atomic ratio of each element. , 0.5≦
a≦7, 0≦b≦5, 0≦c≦10, 0≦d≦10, 0≦e≦2, 0≦f≦5, 0≦g≦
5, 0≦h≦500, where i is a value that satisfies the oxidation states of other elements. ) A method for producing acrolein and acrylic acid, which comprises subjecting a mixed gas containing propylene and an oxygen-containing gas to gas phase catalytic oxidation in the presence of a catalyst produced by the method for producing a catalyst according to claim 1 or 2.