Method for producing catalysts for unsaturated aldehydes and unsaturated carboxylic acids

Abstract

The objective is to provide a catalyst that, when used in the gas-phase catalytic oxidation of olefins with an oxygen-containing gas to synthesize corresponding unsaturated aldehydes and unsaturated carboxylic acids, exhibits excellent conversion rates of raw materials, high selectivity for the target product, high yield production, and improved mechanical strength, even under conditions of high load on the catalyst. [Solution] A method for producing a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids, comprising a molding step in which a carrier is introduced into a granulator, then a first binder, Binder A, is introduced, and further a powder containing catalyst component elements and a second binder, Binder B, are introduced, and the powder containing the catalyst component elements is supported on the carrier to form a catalyst precursor, wherein the catalyst component elements include molybdenum (Mo), bismuth (Bi), and iron (Fe), and the ratio of the introduction rate of Binder A into the granulator to the introduction rate of Binder B (introduction rate of Binder A / introduction rate of Binder B) is greater than 0.1 and less than 1.0.

Description

Technical Field

[0001] The present invention relates to a method for producing a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids. Specifically, it relates to a method for producing a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids, which is used when olefins such as propylene and isobutylene are catalytically oxidized with an oxygen-containing gas in the gas phase to produce unsaturated aldehydes and unsaturated carboxylic acids.

Background Art

[0002] Catalysts for producing unsaturated aldehydes and unsaturated carboxylic acids by catalytically oxidizing olefins such as propylene and isobutylene with an oxygen-containing gas in the gas phase generally use catalysts having molybdenum as an essential component. Specifically, the improvement of the catalysts used for producing acrolein and acrylic acid using propylene etc. as raw materials, and the catalysts used for producing methacrolein and methacrylic acid using isobutylene etc. as raw materials, and the production methods thereof, are being vigorously promoted from various viewpoints.

[0003] The production of unsaturated aldehydes and unsaturated carboxylic acids is carried out by catalytically oxidizing olefins such as propylene and isobutylene with an oxygen-containing gas in the gas phase in a fixed-bed reactor filled with a catalyst.

[0004] The catalyst filled in the fixed-bed reactor has a shape such as a cylinder shape, a ring shape, a tablet shape, a spherical shape, etc. Generally, a catalyst obtained by molding a powder of a catalytic active component, or a catalyst in which a catalytic component element is supported on an inert carrier having the same shape as the above-mentioned shape is used.

[0005] Known catalysts of this type include catalysts with a specific cumulative pore volume (Patent Document 1), supported catalysts having a specific shape, which are obtained by coating an inert support with catalyst powder containing molybdenum as an essential component and which may also contain bismuth, vanadium, etc. (Patent Document 2), and catalysts with sufficient mechanical strength obtained by adding a predetermined amount of binder in a predetermined manner (Patent Documents 3-7). It is known that using these catalysts results in excellent raw material conversion rates, high selectivity for unsaturated aldehydes and unsaturated carboxylic acids, and improved yields. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2017-176931 [Patent Document 2] WO2009 / 147965 pamphlet [Patent Document 3] Japanese Patent Publication No. 2022-067387 [Patent Document 4] Japanese Patent Publication No. 2022-067392 [Patent Document 5] Japanese Patent Publication No. 2022-067415 [Patent Document 6] Japanese Patent Publication No. 2022-067425 [Patent Document 7] Japanese Patent Publication No. 2022-067427 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, conventionally known catalysts for the production of unsaturated aldehydes and unsaturated carboxylic acids have problems when used in a reactor packed with the catalyst to produce the corresponding unsaturated aldehydes and unsaturated carboxylic acids by gas-phase catalytic oxidation of olefins such as propylene and isobutylene. These problems include insufficient mechanical strength of the catalyst, low conversion rates, low selectivity for the corresponding unsaturated aldehydes and unsaturated carboxylic acids, and low yields. In particular, under conditions where the heat transfer medium temperature is low, In other words, under conditions of lower reaction temperatures, the conversion rate decreased, leading to a problem of reduced yields of the corresponding unsaturated aldehydes and unsaturated carboxylic acids.

[0008] The present invention was made to solve the above-mentioned problems. Specifically, the objective is to provide a catalyst that can be used when synthesizing unsaturated aldehydes such as acrolein and methacrolein, and unsaturated carboxylic acids such as acrylic acid and methacrylic acid, by gas-phase catalytic oxidation of olefins such as propylene and isobutylene with an oxygen-containing gas, thereby improving mechanical strength, exhibiting excellent conversion rates of raw materials, high selectivity for unsaturated aldehydes and unsaturated carboxylic acids, ensuring sufficient yield, and enabling stable gas-phase catalytic oxidation reactions over long periods, even under conditions of high catalyst load and low heat medium temperature, i.e., even under conditions of lower reaction temperatures. [Means for solving the problem]

[0009] The present inventors have conducted extensive research to solve the above problems and have found a method for producing a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids, which includes a molding step in which a carrier is introduced into a granulator, then a first binder, Binder A, is introduced, and further a powder containing catalyst component elements and a second binder, Binder B, are introduced, and the powder containing the catalyst component elements is supported on the carrier to form a catalyst precursor, wherein the ratio of the introduction rate of Binder A to the introduction rate of Binder B into the granulator (introduction rate of Binder A / introduction rate of Binder B) is set within a specific range for the catalyst precursor, and the catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids produced can have improved mechanical strength when packed into a reactor, and the unsaturated aldehyde When olefins such as propylene and isobutylene are catalytically oxidized with an oxygen-containing gas using a catalyst for producing aldehydes and unsaturated carboxylic acids, the conversion rate of olefins such as propylene and isobutylene is excellent, even under conditions of high catalyst load, and the selectivity for unsaturated aldehydes such as acrolein and methacrolein, and unsaturated carboxylic acids such as acrylic acid and methacrylic acid is good. As a result, it is possible to improve the yield of unsaturated aldehydes such as acrolein and methacrolein, and unsaturated carboxylic acids such as acrylic acid and methacrylic acid. Furthermore, even under conditions of low reaction temperature, it is possible to achieve excellent conversion rates of the raw materials, high selectivity for unsaturated aldehydes and unsaturated carboxylic acids, and ensure a sufficient yield. This discovery led to the present invention.

[0010] In other words, the gist of this invention is as follows: [1] A method for producing a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids, comprising a molding step of introducing a carrier into a granulator, then introducing a first binder, Binder A, then introducing a powder containing catalyst component elements and a second binder, Binder B, and supporting the powder containing the catalyst component elements on the carrier to form a catalyst precursor, wherein the catalyst component elements include molybdenum (Mo), bismuth (Bi), and iron (Fe), and the ratio of the introduction rate of Binder A into the granulator to the introduction rate of Binder B (introduction rate of Binder A / introduction rate of Binder B) is greater than 0.1 and less than 1.0.

[0011] [2] A method for producing a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids, comprising a molding step of introducing a carrier into a granulator, then introducing a first binder, Binder A, and further introducing a powder containing catalyst component elements and a second binder, Binder B, and supporting the powder containing the catalyst component elements on the carrier to form a catalyst precursor, wherein the catalyst component elements include molybdenum (Mo), bismuth (Bi), and iron (Fe), and the ratio of the introduction rate of Binder A into the granulator to the introduction rate from the start of introduction of Binder B to the end of introduction of 90% by mass of the total amount of Binder B (introduction rate of Binder A / introduction rate from the start of introduction of Binder B to the end of introduction of 90% by mass) is greater than 0.1 and less than 1.0.

[0012] [3] A method for producing a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids, comprising a molding step of introducing a carrier into a granulator, then introducing a first binder, Binder A, and further introducing a powder containing catalyst component elements and a second binder, Binder B, and supporting the powder containing the catalyst component elements on the carrier to form a catalyst precursor, wherein the catalyst component elements include molybdenum (Mo), bismuth (Bi), and iron (Fe), and the ratio of the introduction rate of Binder A into the granulator to the introduction rate from the start of introduction of Binder B to the end of introduction of 80% by mass of the total amount of Binder B (introduction rate of Binder A / introduction rate from the start of introduction of Binder B to the end of introduction of 80% by mass) is greater than 0.1 and less than 1.0.

[0013] [4] A method for producing catalysts for unsaturated aldehydes and unsaturated carboxylic acids according to any one of [1] to [3], wherein the total amount of binder introduced into the granulator is 10% by mass or more and 60% by mass or less relative to the amount of carrier introduced into the granulator. [5] A method for producing catalysts for producing unsaturated aldehydes and unsaturated carboxylic acids according to any one of the claims [1] to [3], wherein the total amount of binder introduced into the granulator is 10% by mass or more and 70% by mass or less relative to the amount of powder containing the catalyst component elements introduced into the granulator.

[0014] [6] A method for producing a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids according to any one of [1] to [3], wherein the binder A and the binder B comprise an organic compound. [7] A method for producing catalysts for producing unsaturated aldehydes and unsaturated carboxylic acids according to any one of the items [1] to [3], wherein the amount of binder A introduced into the granulator is 2% by mass or more and 90% by mass or less of the total amount of binder introduced into the granulator, and the amount of binder B introduced into the granulator is 10% by mass or more and 98% by mass or less of the total amount of binder introduced into the granulator.

[0015] [8] The method for producing a catalyst for producing an unsaturated aldehyde and an unsaturated carboxylic acid according to any one of [1] to [3], wherein the catalyst component elements of the catalyst for producing an unsaturated aldehyde and an unsaturated carboxylic acid are 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 Ti, Y represents at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Mn, and Zn, and 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 ratios of the respective elements, and are in the ranges of 0.5 ≦ a ≦ 7, 0.05 ≦ b ≦ 5, 0 ≦ c ≦ 10, 0 ≦ d ≦ 10, 0 ≦ e ≦ 2, 0 ≦ f ≦ 5, 0 ≦ g ≦ 5, 0 ≦ h ≦ 500, and i is a value that satisfies the oxidation states of the other elements.) [9] A method for producing acrolein and acrylic acid by gas-phase catalytic oxidation of propylene with an oxygen-containing gas using the catalyst for producing an unsaturated aldehyde and an unsaturated carboxylic acid produced by the production method according to any one of [1] to [3].

Advantages of the Invention

[0016] The catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids produced by the manufacturing method of the present invention can improve mechanical strength, and when olefins such as propylene and isobutylene are oxidized in gas phase with an oxygen-containing gas using this catalyst, the conversion rate of olefins such as propylene and isobutylene is excellent even under conditions of high load on the catalyst, and the selectivity for unsaturated aldehydes such as acrolein and methacrolein, and unsaturated carboxylic acids such as acrylic acid and methacrylic acid is good. As a result, the yield of unsaturated aldehydes such as acrolein and methacrolein, and unsaturated carboxylic acids such as acrylic acid and methacrylic acid can be improved, and stable gas phase catalytic oxidation reaction can be performed over a long period of time. This enables the following: In particular, when propylene is catalytically oxidized in the gas phase with an oxygen-containing gas, even under conditions of high catalyst load, the conversion rate of propylene is excellent, and the selectivity for acrolein and acrylic acid is good. As a result, the yield of acrolein and acrylic acid can be improved, and a stable gas-phase catalytic oxidation reaction can be performed over a long period of time. Furthermore, even under low reaction temperature conditions, the conversion rate of the raw materials is excellent, the selectivity for unsaturated aldehydes and unsaturated carboxylic acids is high, and sufficient yield can be ensured. This reduces running costs in commercial plants and allows the reaction process to be kept stable. [Modes for carrying out the invention]

[0017] The embodiments of the present invention will be described in detail below. However, the present invention is not limited to the following description and can be implemented in various modifications within the scope of its gist.

[0018] This invention provides a detailed description of a method for producing catalysts for unsaturated aldehydes and unsaturated carboxylic acids (hereinafter sometimes simply referred to as "catalysts"). The catalyst according to this invention is a catalyst for the synthesis of unsaturated aldehydes and unsaturated carboxylic acids, which uses olefins such as propylene and isobutylene (hereinafter sometimes simply referred to as "olefins") as raw materials and produces unsaturated aldehydes such as acrolein and methacrolein (hereinafter sometimes simply referred to as "unsaturated aldehydes") and unsaturated carboxylic acids such as acrylic acid and methacrylic acid (hereinafter sometimes simply referred to as "unsaturated carboxylic acids") by gas-phase catalytic oxidation with an oxygen-containing gas. In particular, the catalyst uses propylene as a raw material and produces acrolein and acrylic acid particularly efficiently by gas-phase catalytic oxidation with an oxygen-containing gas.

[0019] <Method for manufacturing a catalyst> The catalyst according to the present invention can be manufactured by a method that includes a molding step for manufacturing a catalyst precursor and a calcination step for calcining the catalyst precursor obtained in the molding step.

[0020] <Molding process> The molding process involves introducing a carrier into a granulator, then introducing a portion of the binder, and finally introducing a powder containing catalyst elemental components and the remaining binder to obtain a catalyst precursor. Specifically, first, the carrier is introduced into the granulator. Next, the binder is divided into a first binder (sometimes referred to as "binder A") and a second binder (sometimes referred to as "binder B"), and binder A is introduced into the granulator. Next, powders containing the elements that constitute the catalyst (hereinafter sometimes referred to as "catalyst component elements") and the binder B are introduced as the respective components of the catalyst. This allows the powder containing the catalyst component elements to be supported on the carrier to obtain a catalyst precursor, which can then be used to manufacture a catalyst.

[0021] As for the molding process, for example, a method can be used in which a granulator used in the rolling granulation method (rolling granulator) is used to support a powder containing catalyst elemental components on the surface of a carrier. Specifically, as the granulator, for example, a granulator having a flat or uneven disc at the bottom of the granulator is used, and by rotating the disc of the granulator, the carrier introduced into the granulator is stirred by repeated rotation and revolution motion, then binder A is introduced, followed by the introduction of powder containing catalyst elemental components and binder B, and other additives may be added, thereby supporting the powder on the carrier. Since the powder can be uniformly supported on the carrier, it is preferable to use a rolling granulator as the granulator.

[0022] [carrier] The aforementioned carriers include spherical carriers such as silica, silicon carbide, alumina, mullite, and alundum. Examples include the above. The size of the carrier is preferably such that the long axis diameter is 2.5 mm to 10 mm, and more preferably 2.5 mm to 6 mm. Furthermore, the porosity of the carrier is preferably 20% to 60%, more preferably 30% to 57%, and even more preferably 40% to 55%. The water absorption rate of the carrier is preferably 10% to 60%, more preferably 12% to 50%, and even more preferably 15% to 40%. By setting the porosity and water absorption rate of the carrier within the above ranges, the powder containing the catalyst component elements can be easily supported on the carrier. Furthermore, it is preferable that the support material is inert to the reaction in which the olefin is oxidized by gas-phase catalytic oxidation with an oxygen-containing gas.

[0023] [Powder containing catalytic elemental components] The powder containing the aforementioned catalyst element can be obtained by the following process. First, a compound having a catalytic component element is used as a catalyst source compound (hereinafter referred to as "source compound"), and each of these source compounds having a catalytic component element is added to a solvent or solution to integrate them, and if necessary, heated to obtain a prepared solution (preparation step), and the prepared solution is dried to obtain a powder (drying step), thereby obtaining a powder containing the aforementioned catalytic component element.

[0024] (liquid preparation process) The aforementioned liquid preparation step involves integrating each source compound containing the catalyst component element in an aqueous system and heating it to obtain a prepared liquid. The aforementioned integration in an aqueous system refers to the process of integrating each source compound by adding it to an aqueous solvent or solution. This aqueous solvent is an aqueous medium for dissolving or suspending each source compound, and refers to a solvent consisting of water, an organic solvent that is miscible with water such as methanol or ethanol, or a mixture thereof. Furthermore, the aforementioned aqueous solution refers to a liquid obtained by dissolving, suspending, or integrating one or more source compounds in the aforementioned aqueous solvent.

[0025] The aforementioned integration refers to mixing aqueous solutions or aqueous dispersions of the source compounds for each catalyst element all at once or in stages, and heating as necessary. Specifically, this includes methods such as mixing each source compound all at once, mixing each source compound all at once and then heating, mixing each source compound in stages, repeatedly mixing and heating each source compound in stages, and methods combining these methods. All of these are included in the concept of integration of the source compounds for each catalyst element.

[0026] The aforementioned heating refers to stirring the mixture or mixed dispersion obtained in the integration process at a predetermined temperature for a predetermined time. This heating increases the viscosity of the mixture or mixed dispersion, which in the case of a mixed dispersion reduces the sedimentation of solid components and is particularly effective in suppressing non-uniformity of components in the subsequent drying process, resulting in better catalytic activity of the final product, the catalyst, such as the raw material conversion rate and product selectivity.

[0027] The heating temperature is preferably 60°C to 100°C, more preferably 60°C to 90°C, and even more preferably 60°C to 80°C. A heating temperature within this range may result in good activity of the manufactured catalyst.

[0028] The heating time is preferably 2 to 12 hours, and more preferably 3 to 8 hours. A heating time within this range may result in good activity of the manufactured catalyst. Any method can be used for the stirring method, such as a method using a stirrer with stirring blades or a method using external circulation with a pump.

[0029] (source compound) This catalyst preferably contains molybdenum (Mo), bismuth (Bi), and iron (Fe) as catalytic elemental components, and more preferably contains cobalt (Co) and nickel (Ni) as other catalytic elemental components. Furthermore, it may contain one or more of the following components: sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), titanium (Ti), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), manganese (Mn), zinc (Zn), fluorine (F), chlorine (Cl), boron (B), phosphorus (P), arsenic (As), tungsten (W), niobium (Nb), silicon (Si), etc.

[0030] Examples of molybdenum (Mo) source compounds include ammonium paramolybdate, molybdenum trioxide, molybdic acid, ammonium phosphomolybdate, and phosphomolybdic acid.

[0031] Examples of bismuth (Bi) source compounds include bismuth chloride, bismuth nitrate, bismuth oxide, and bismuth subcarbonate. The amount of bismuth added is preferably such that, as an atomic ratio of catalyst component elements, when molybdenum atoms are set to 12, the ratio is 0.5 to 7, more preferably 0.5 to 5, even more preferably 0.5 to 4, and particularly preferably 0.5 to 3. Within this range, the catalyst can be made that exhibits excellent raw material conversion rates and can produce unsaturated aldehydes and unsaturated carboxylic acids with high selectivity.

[0032] Examples of iron (Fe) source compounds include ferric nitrate, ferric sulfate, ferric chloride, and ferric acetate. The amount of iron added is preferably such that, as an atomic ratio of catalyst elemental elements, when molybdenum atoms are set to 12, the ratio is 0.05 to 5, more preferably 0.1 to 4, even more preferably 0.2 to 3, and particularly preferably 0.3 to 3. Within this range, the catalyst can be made that exhibits excellent raw material conversion rates and can produce unsaturated aldehydes and unsaturated carboxylic acids with high selectivity.

[0033] Examples of cobalt (Co) source compounds include cobalt nitrate, cobalt sulfate, cobalt chloride, cobalt carbonate, and cobalt acetate. The amount of cobalt added is preferably such that, as an atomic ratio of catalyst component elements, the amount is 0 to 10 when molybdenum atoms are set to 12, more preferably 0.5 to 9, even more preferably 1 to 8, and particularly preferably 2 to 7. Within this range, the catalyst can be made that exhibits excellent raw material conversion rates and can produce unsaturated aldehydes and unsaturated carboxylic acids with high selectivity.

[0034] Examples of nickel (Ni) source compounds include nickel nitrate, nickel sulfate, nickel chloride, nickel carbonate, and nickel acetate. The amount of nickel added is preferably such that, as an atomic ratio of catalyst elemental components, the amount is between 0 and 10, more preferably between 0.5 and 9, even more preferably between 1 and 8, and particularly preferably between 2 and 7. Within this range, the catalyst can be made that exhibits excellent raw material conversion rates and can produce unsaturated aldehydes and unsaturated carboxylic acids with high selectivity.

[0035] Examples of sodium (Na) source compounds include sodium chloride, sodium carbonate, sodium nitrate, sodium sulfate, sodium acetate, and sodium borate. Examples of potassium (K) source compounds include potassium nitrate, potassium sulfate, and potassium chloride. Examples include potassium carbonate and potassium acetate. Examples of source compounds for rubidium (Rb) include rubidium nitrate, rubidium sulfate, rubidium chloride, rubidium carbonate, and rubidium acetate. Examples of source compounds for cesium (Cs) include cesium nitrate, cesium sulfate, cesium chloride, cesium carbonate, and cesium acetate. Examples of source compounds for titanium (Ti) include titanium oxide and titanium chloride. The amount of at least one element selected from sodium, potassium, rubidium, cesium, and titanium added is preferably such that, with molybdenum atoms set to 12, the amount is between 0 and 2, more preferably between 0.01 and 2, and even more preferably between 0.02 and 2. Within this range, the catalyst can be made that exhibits excellent raw material conversion rates and can produce unsaturated aldehydes and unsaturated carboxylic acids with high selectivity.

[0036] Examples of magnesium (Mg) source compounds include magnesium oxide, magnesium carbonate, or magnesium sulfate. Examples of calcium (Ca) source compounds include calcium oxide, calcium carbonate, or calcium hydroxide. Examples of strontium (Sr) source compounds include strontium oxide, strontium carbonate, strontium hydroxide, or strontium nitrate. Examples of barium (Ba) source compounds include barium oxide, barium carbonate, barium nitrate, barium acetate, or barium sulfate. Examples of manganese (Mn) source compounds include manganese dioxide and manganese carbonate. Examples of zinc (Zn) source compounds include zinc oxide, zinc carbonate, zinc hydroxide, or zinc nitrate. The amount of at least one element selected from the group consisting of magnesium, calcium, strontium, barium, manganese, and zinc added is preferably such that, as an atomic ratio of catalyst elemental elements, the ratio is 0 to 5, more preferably 0 to 4, and even more preferably 0 to 3, when molybdenum atoms are set to 12. Within this range, a catalyst can be obtained that exhibits excellent raw material conversion rates and can produce unsaturated aldehydes and unsaturated carboxylic acids with high selectivity.

[0037] Examples of fluorine (F) source compounds include calcium fluoride and sodium fluoride. Examples of chlorine (Cl) source compounds include sodium chloride and ammonium chloride. Examples of boron (B) source compounds include borax, ammonium borate, and boric acid. Examples of phosphorus (P) source compounds include ammonium phosphomolybdate, ammonium phosphate, phosphoric acid, and phosphorus pentoxide. Examples of arsenic (As) source compounds include ammonium dialseno18-molybdate and ammonium dialseno18-tungstate. Examples of tungsten (W) source compounds include tungstic acid or its salts. Examples of niobium (Nb) source compounds include niobium hydroxide. The amount of at least one element selected from fluorine, chlorine, boron, phosphorus, arsenic, tungsten, and niobium added is preferably between 0 and 5, more preferably between 0 and 4, and even more preferably between 0 and 3, when the molybdenum atom is set to 12. Within this range, the catalyst can be made that exhibits excellent raw material conversion rates and can produce unsaturated aldehydes and unsaturated carboxylic acids with high selectivity.

[0038] Examples of silicon (Si) source compounds include silica, granular silica, colloidal silica, and fumed silica. The amount of silicon added is preferably such that, as an atomic ratio of catalyst component elements, the number of silicon atoms is 0 to 500, more preferably 0 to 400, and even more preferably 0 to 300, when molybdenum atoms are set to 12. Within this range, the catalyst can be made that exhibits excellent raw material conversion rates and can produce unsaturated aldehydes and unsaturated carboxylic acids with high selectivity.

[0039] (Method for adding source compounds) In the aforementioned liquid preparation step, all of the source compounds may be used to make one prepared liquid, or each source compound may be used individually or divided into several groups to make multiple prepared liquids, and these multiple prepared liquids may be mixed at once or sequentially to make one prepared liquid, or one or more prepared liquids may be dried or calcined to make a solid, and this solid may be added to the prepared liquid made from the remaining source compounds to make a new prepared liquid.

[0040] (drying process) The prepared solution is dried in a drying process to obtain a powder containing catalyst elemental components (hereinafter sometimes simply referred to as "powder"). There are no particular limitations on the drying method in this drying process; for example, a conventional spray dryer, slurry dryer, drum dryer, etc., may be used to obtain the powder.

[0041] (Heat treatment) The powder obtained by the drying process may be further heat-treated as needed. This heat treatment is performed in air at a temperature range of 300°C to 600°C, preferably 350°C to 550°C, for a short period of time. There are no particular limitations on the method; for example, the powder may be heated in a fixed state using a conventional box-type heating furnace, tunnel-type heating furnace, etc., or it may be heated while the powder is flowing using a rotary kiln, etc. Furthermore, powders obtained by further processing such as pulverization of dried materials that have undergone drying or heat treatment are also considered powders in this invention.

[0042] (Powder components) Furthermore, the catalyst element components of the powder obtained by the drying process preferably contain molybdenum and bismuth, more preferably iron, and even more preferably represented by the following general formula (1). By keeping the catalyst element components of the powder within the above range, the manufactured catalyst can have improved mechanical strength, exhibit excellent raw material conversion rate even under high load conditions, and have good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, thereby improving the yield of unsaturated aldehydes and unsaturated carboxylic acids.

[0043] Mo 12 Bi a Fe b Co c Ni d X e Y f Z g Si h O i (1) (In equation (1), X represents at least one element selected from the group consisting of Na, K, Rb, Cs, and Ti; Y represents at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Mn, and Zn; and 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 ratios of each element, within the ranges of 0.5 ≤ a ≤ 7, 0.05 ≤ b ≤ 5, 0 ≤ c ≤ 10, 0 ≤ d ≤ 10, 0 ≤ e ≤ 2, 0 ≤ f ≤ 5, 0 ≤ g ≤ 5, and 0 ≤ h ≤ 500, where i is the value that satisfies the oxidation state of the other elements.)

[0044] (Amount of powder relative to the amount of carrier) The amount of powder containing the catalyst component elements relative to the amount of carrier introduced into the granulator is preferably 20% by mass or more and 300% by mass or less. The lower limit is more preferably 30% by mass and even more preferably 40% by mass. The upper limit is more preferably 250% by mass and even more preferably 200% by mass. By keeping the amount within this range, the manufactured catalyst can have improved mechanical strength, exhibit excellent raw material conversion rate even under high load conditions, and have good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, thereby improving the yield of unsaturated aldehydes and unsaturated carboxylic acids.

[0045] [binder] The binder is used to hold the powder in the carrier, and as described above, It is used in two separate binders: Binder 1 (Binder A) and Binder 2 (Binder B). Binder A is a binder that is introduced into the granulator after the carrier has been introduced and before the powder containing the catalyst element is introduced into the granulator. The binder A may be introduced into the granulator in a desired amount continuously, or it may be divided into multiple portions and introduced with time intervals between portions, but from the viewpoint of uniformity, it is preferable to introduce it continuously.

[0046] Furthermore, the binder B is a binder that is introduced into the granulator at the same time as the powder containing the catalyst element, or after the powder containing the catalyst element has been introduced. The following methods can be used to introduce the powder containing the catalyst element and the binder B into the granulator. (1) A method of preparing a homogeneous mixture by mixing a powder containing catalyst element elements with binder B, and introducing the homogeneous mixture into a granulator. (2) A method of introducing the powder containing the catalyst element and binder B into the granulator simultaneously in separate states. (3) A method of introducing a powder containing catalyst elemental components into a granulator, and then introducing binder B into the granulator. (4) A method of adding binder B to a powder containing catalyst element elements to form a heterogeneous mixture, and introducing the heterogeneous mixture into a granulator. (5) A method of introducing the powder containing the catalyst element and binder B into a granulator in separate states, divided into portions, simultaneously, alternately, or in any order. These are some examples.

[0047] In the present invention, methods such as adding the entire amount by appropriately combining (1) to (5) can be arbitrarily adopted. Of these, in (5), it is preferable to adjust the addition rate using an auto feeder or the like so that a predetermined amount is supported on the carrier without, for example, the powder containing the catalyst component element adhering to the inner wall of the granulator or the like, or the powder containing the catalyst component element agglomerating with each other.

[0048] In the method for producing the catalyst of the present invention, the methods described above (1) to (5) can be appropriately combined, but from the viewpoint of uniformly supporting the powder containing the catalyst component elements and binder B on the carrier, it is preferable to adopt methods (2) or (5). Method (5) is preferred because the produced catalyst can have improved mechanical strength, has excellent raw material conversion rate even under high load conditions, and has good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, making it easier to improve the yield of unsaturated aldehydes and unsaturated carboxylic acids. Furthermore, in method (5), if a binder is introduced into the granulator before the powder containing the catalyst element, that binder corresponds to binder A.

[0049] Examples of the aforementioned binders include inorganic compounds such as water, sulfuric acid, ammonium sulfate, nitric acid, ammonium nitrate, and ammonium carbonate, and organic compounds such as ethylene glycol, glycerin, propionic acid, maleic acid, benzyl alcohol, propyl alcohol, butyl alcohol, polyvinyl alcohol, stearic acid, or phenol.

[0050] The binder preferably contains an organic compound, more preferably an organic compound having a hydroxyl group, and even more preferably glycerin and / or polyvinyl alcohol. By including the above compounds as the binder (binder A or binder B), the manufactured catalyst can have improved mechanical strength, exhibit excellent raw material conversion rate even under high load conditions, and have good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, and yield of unsaturated aldehydes and unsaturated carboxylic acids. This makes it possible to improve the situation. Furthermore, even under conditions where the heat transfer medium temperature during the reaction is low, i.e., under conditions where the reaction temperature is low, the conversion rate of the olefin raw material is excellent, the selectivity for unsaturated aldehydes and unsaturated carboxylic acids is high, and a sufficient yield can be ensured. When the binder is introduced into the granulator, it is preferably in the form of an aqueous solution, and the concentration of the aqueous solution is preferably 2% by mass or more and 50% by mass or less. The lower limit is more preferably 3% by mass, and the upper limit is more preferably 40% by mass. This range makes it possible to uniformly disperse the binder into the carrier or powder within the granulator.

[0051] The types of binders used in Binder A and Binder B may be the same or different, but it is preferable that they be the same from the viewpoint of uniformity. Furthermore, both Binder A and Binder B may use one type of binder or multiple types, and if multiple types are used, they may be introduced into the granulator separately or mixed and introduced into the granulator.

[0052] The amount of binder A introduced into the granulator is preferably 2% by mass or more and 90% by mass or less of the total amount of binder introduced into the granulator, and the amount of binder B introduced into the granulator is preferably 10% by mass or more and 98% by mass or less of the total amount of binder introduced into the granulator. The upper limit of the amount of binder A is preferably 85% by mass, more preferably 80% by mass, even more preferably 75% by mass, and particularly preferably 70% by mass. The lower limit of the amount of binder A is preferably 3% by mass, more preferably 4% by mass, and even more preferably 5% by mass.

[0053] Accordingly, the upper limit of the amount of binder B is preferably 97% by mass, more preferably 96% by mass, and even more preferably 95% by mass. The lower limit of the amount of binder B is preferably 15% by mass, more preferably 20% by mass, even more preferably 25% by mass, and particularly preferably 30% by mass. As long as the conditions are within the aforementioned range, the manufactured catalyst can improve mechanical strength, exhibit excellent raw material conversion rates even under high load conditions, and have good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, thereby improving the yield of unsaturated aldehydes and unsaturated carboxylic acids. Furthermore, even under conditions where the heat transfer medium temperature during the reaction is low, i.e., under conditions where the reaction temperature is low, the conversion rate of the olefin raw material is excellent, the selectivity for unsaturated aldehydes and unsaturated carboxylic acids is high, and a sufficient yield can be ensured.

[0054] Furthermore, the introduction speed of binders A and B into the granulator can be adjusted to achieve the effects of the present invention. The relationship between the introduction speed of binder A and the introduction speed of binder B is preferably as follows:

[0055] Regarding the introduction of binder A into the granulator, the value obtained by dividing the total amount of binder A introduced by the time from the start of introduction of binder A to the start of introduction of the powder containing the catalyst element is referred to as the "introduction rate of binder A," and its abbreviation is referred to as "VA." Furthermore, regarding the introduction of binder B into the granulator, the value obtained by dividing the total amount of binder B introduced by the time from the start of introduction of binder B to the end of introduction of a predetermined amount of binder B is referred to as the "introduction rate of binder B." Furthermore, the abbreviation for the introduction speed from the start of introducing the binder B into the granulator until 80% by mass of the total amount of binder B has been introduced is referred to as "VB80", the abbreviation for the introduction speed from the start of introducing the binder B into the granulator until 90% by mass of the total amount of binder B has been introduced is referred to as "VB90", and the abbreviation for the introduction speed from the start of introducing the binder B into the granulator until the entire amount of binder B has been introduced is referred to as "VB100".

[0056] The ratio of VA to VB80 (VA / VB80) is greater than 0.1 and less than 1.0, preferably greater than 0.1 and 0.9 or less, more preferably greater than 0.1 and 0.8 or less, and even more preferably greater than 0.1 and 0.7 or less. Because it is within the above range, the manufactured catalyst can improve mechanical strength, exhibit excellent raw material conversion rate even under high load conditions, and have good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, making it possible to improve the yield of unsaturated aldehydes and unsaturated carboxylic acids. Furthermore, even under conditions where the heat transfer medium temperature during the reaction is low, i.e., under conditions where the reaction temperature is low, the conversion rate of the olefin raw material is excellent, the selectivity for unsaturated aldehydes and unsaturated carboxylic acids is high, and a sufficient yield can be ensured.

[0057] Furthermore, the ratio of VA to VB90 (VA / VB90) is greater than 0.1 and less than 1.0, preferably greater than 0.1 and 0.9 or less, more preferably greater than 0.1 and 0.8 or less, and even more preferably greater than 0.1 and 0.7 or less. Because it is within the above range, the manufactured catalyst can improve mechanical strength, exhibit excellent raw material conversion rate even under high load conditions, and have good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, making it possible to improve the yield of unsaturated aldehydes and unsaturated carboxylic acids. Furthermore, even under conditions where the heat transfer medium temperature during the reaction is low, i.e., under conditions where the reaction temperature is low, the conversion rate of the olefin raw material is excellent, the selectivity for unsaturated aldehydes and unsaturated carboxylic acids is high, and a sufficient yield can be ensured.

[0058] Furthermore, the ratio of VA to VB100 (VA / VB100) is greater than 0.1 and less than 1.0, preferably greater than 0.1 and 0.9 or less, more preferably greater than 0.1 and 0.8 or less, and even more preferably greater than 0.1 and 0.7 or less. Because it is within the above range, the manufactured catalyst can improve mechanical strength, exhibit excellent raw material conversion rate even under high load conditions, and have good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, making it possible to improve the yield of unsaturated aldehydes and unsaturated carboxylic acids. Furthermore, even under conditions where the heat transfer medium temperature during the reaction is low, i.e., under conditions where the reaction temperature is low, the conversion rate of the olefin raw material is excellent, the selectivity for unsaturated aldehydes and unsaturated carboxylic acids is high, and a sufficient yield can be ensured.

[0059] The introduction rate of binder A is calculated by dividing the total amount of binder A introduced into the granulator by the time elapsed from the start of binder A introduction to the start of the introduction of the powder containing the catalyst elements. In other words, even if there is a period of time when binder A is not introduced between the start of binder A introduction and the start of the introduction of the powder containing the catalyst elements, that time is not subtracted. Similarly, the introduction rate of binder B is calculated by dividing the total amount of binder B introduced into the granulator by the time elapsed from the start of binder B introduction to the end of binder B introduction. In other words, even if there is a period of time when binder B is not introduced between the start of binder B introduction and the end of binder B introduction, that time is not subtracted.

[0060] The total amount of the binder relative to the amount of the carrier introduced into the granulator is preferably 10% by mass or more and 60% by mass or less. The lower limit is more preferably 13% by mass, and even more preferably 15% by mass. The upper limit is more preferably 58% by mass, and even more preferably 55% by mass. By keeping it within the above range, the manufactured catalyst can have improved mechanical strength, excellent raw material conversion rate even under high load conditions, good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, and an improved yield of unsaturated aldehydes and unsaturated carboxylic acids. Furthermore, even under conditions where the heat transfer medium temperature during the reaction is low, i.e., under conditions where the reaction temperature is low, the conversion rate of the olefin raw material is excellent, the selectivity for unsaturated aldehydes and unsaturated carboxylic acids is high, and a sufficient yield can be ensured.

[0061] The introduction rate of the binder A into the granulator with respect to the amount of carrier is preferably 0.39 g / min to 8.8 g / min when the amount of carrier is 0.1 kg to 1 kg. The lower limit is more preferably 0.45 g / min, and even more preferably 0.50 g / min. The upper limit is more preferably 8.5 g / min, and even more preferably 8.3 g / min. When the amount of carrier is 1 kg to 10 kg, it is preferably 2.6 g / min to 59.5 g / min. The lower limit is more preferably 2.7 g / min, and even more preferably 2.8 g / min. The upper limit is more preferably 59.0 g / min, and even more preferably 58.5 g / min. When the amount of carrier is 10 kg to 1000 kg, it is preferably 18.0 g / min to 2740 g / min. The lower limit is more preferably 20.0 g / min, and even more preferably 22.0 g / min. The upper limit is more preferably 2720g / min, and even more preferably 2700g / min. By keeping the range within the aforementioned range, the manufactured catalyst can have improved mechanical strength, excellent raw material conversion rate even under high load conditions, good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, and an improved yield of unsaturated aldehydes and unsaturated carboxylic acids. Furthermore, even under conditions where the heat transfer medium temperature during the reaction is low, i.e., under conditions where the reaction temperature is low, the conversion rate of the olefin raw material is excellent, the selectivity for unsaturated aldehydes and unsaturated carboxylic acids is high, and a sufficient yield can be ensured.

[0062] Furthermore, the introduction rate of the binder A into the granulator for the powder is preferably 0.39 g / min to 8.8 g / min when the amount of powder is 0.1 kg to 1 kg. The lower limit is more preferably 0.45 g / min, and even more preferably 0.50 g / min. The upper limit is more preferably 8.5 g / min, and even more preferably 8.3 g / min. Furthermore, when the amount of powder is 1 kg to 10 kg, it is preferably 2.6 g / min to 59.5 g / min. The lower limit is more preferably 2.7 g / min, and even more preferably 2.8 g / min. The upper limit is more preferably 59.0 g / min, and even more preferably 58.5 g / min. Furthermore, when the amount of powder is 10 kg to 1000 kg, it is preferably 18.0 g / min to 2740 g / min. The lower limit is more preferably 20.0 g / min, and even more preferably 22.0 g / min. The upper limit is more preferably 2720g / min, and even more preferably 2700g / min. By keeping the range within the aforementioned range, the manufactured catalyst can have improved mechanical strength, excellent raw material conversion rate even under high load conditions, good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, and an improved yield of unsaturated aldehydes and unsaturated carboxylic acids. Furthermore, even under conditions where the heat transfer medium temperature during the reaction is low, i.e., under conditions where the reaction temperature is low, the conversion rate of the olefin raw material is excellent, the selectivity for unsaturated aldehydes and unsaturated carboxylic acids is high, and a sufficient yield can be ensured.

[0063] The total amount of the binder relative to the amount of the powder containing the catalyst element introduced into the granulator is preferably 10% by mass or more and 70% by mass or less. The lower limit is more preferably 13% by mass, and even more preferably 15% by mass. The upper limit is more preferably 67% by mass, and even more preferably 64% by mass. By keeping the amount within this range, the manufactured catalyst can have improved mechanical strength, exhibit excellent raw material conversion rate even under high load conditions, and have good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, thereby improving the yield of unsaturated aldehydes and unsaturated carboxylic acids. Furthermore, even under conditions where the heat transfer medium temperature during the reaction is low, i.e., under conditions where the reaction temperature is low, the conversion rate of the olefin raw material is excellent, the selectivity for unsaturated aldehydes and unsaturated carboxylic acids is high, and a sufficient yield can be ensured.

[0064] [Forming aid] In the molding process, other molding aids may be added in addition to the carrier, powder, and binder described above. Examples of other molding aids include silica, alumina, glass, silicon carbide, silicon nitride, graphite, cellulose, methylcellulose, and starch.

[0065] <Firing Process> The catalyst precursor obtained in the molding process can be converted into a catalyst by calcining the catalyst precursor (calcination process). The calcination process is carried out by calcining the catalyst precursor in a suitable oxygen atmosphere at a temperature of preferably 400°C to 600°C, more preferably 450°C to 550°C, for about 1 to 16 hours. The calcination method can be the same as the heat treatment method used in the drying process. As described above, a catalyst can be obtained that has improved mechanical strength, is highly active, and exhibits excellent yields of the desired unsaturated aldehydes and unsaturated carboxylic acids.

[0066] <Catalyst> The resulting catalyst preferably contains molybdenum and bismuth as catalytic elemental components, more preferably iron, and even more preferably represented by the following general formula (1). By keeping the catalytic elemental components of the catalyst within the above range, the manufactured catalyst can have improved mechanical strength, exhibit excellent raw material conversion rate even under high load conditions, and have good selectivity for unsaturated aldehydes and unsaturated carboxylic acids, thereby improving the yield of unsaturated aldehydes and unsaturated carboxylic acids.

[0067] Mo 12 Bi a Fe b Co c Nid X e Y f Z g Si h O i (1) (In equation (1), X represents at least one element selected from the group consisting of Na, K, Rb, Cs, and Ti; Y represents at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Mn, and Zn; and 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 ratios of each element, within the ranges of 0.5 ≤ a ≤ 7, 0.05 ≤ b ≤ 5, 0 ≤ c ≤ 10, 0 ≤ d ≤ 10, 0 ≤ e ≤ 2, 0 ≤ f ≤ 5, 0 ≤ g ≤ 5, and 0 ≤ h ≤ 500, where i is the value that satisfies the oxidation state of the other elements.) Furthermore, the catalytic elemental components of a catalyst are those remaining after removing the support from the catalyst.

[0068] [Gas-phase catalytic oxidation reaction] The gas-phase catalytic oxidation reaction using this catalyst can be carried out by the following method. First, a predetermined amount of the catalyst is packed into a reaction tube of a predetermined size. Next, the reaction tube is heated with a heat transfer medium to adjust the temperature inside the tube to a predetermined reaction temperature. Then, a raw material mixture gas containing olefins such as propylene and isobutylene and oxygen gas is introduced into the inlet of the reaction tube, and the reaction is carried out by passing it through the catalyst at a predetermined space velocity. The reaction gas is then recovered from the outlet of the reaction tube. The size of the reaction tube at this time can be any size, and the space velocity and heat transfer medium temperature are adjusted to obtain an appropriate raw material conversion rate, appropriate selectivity for unsaturated aldehydes and unsaturated carboxylic acids, and an appropriate yield.

[0069] By keeping the ratio of the introduction rate of binder A to the introduction rate of binder B into the granulator (introduction rate of binder A / introduction rate of binder B) within the aforementioned range, even under conditions of low heat transfer temperature, the raw material conversion rate is excellent, and the selectivity of unsaturated aldehydes and unsaturated carboxylic acids is good. This makes it possible to improve the yield of bonic acid.

[0070] [Powdering rate] The catalyst must have sufficient strength. If the catalyst strength is low, when it is packed into a reaction tube or similar device used to produce unsaturated aldehydes and unsaturated carboxylic acids by gas-phase catalytic oxidation of olefins with an oxygen-containing gas, the catalyst may pulverize or crack, which can lead to a large differential pressure (the pressure difference between the inlet and outlet of the reaction tube). A large differential pressure can place a heavy load on the compressor and other equipment that blows the raw material mixture gas containing olefins and oxygen-containing gas into the reaction tube filled with the catalyst. Furthermore, if the catalyst strength is low, the pulverization of the catalyst may accelerate in proportion to the progress of gas-phase catalytic oxidation, and the differential pressure may increase further over time. Therefore, the catalyst pulverization rate, which serves as an indicator of catalyst strength, is preferably 5.0% or less, more preferably 3.0% or less, and even more preferably 2.0% or less. The pulverization rate refers to the ratio of the weight of fine particles to the weight of the catalyst sample when the catalyst is dropped from a height of 1 m, and the measurement method will be described later.

[0071] [Application] By using the catalyst produced by the manufacturing method of the present invention, mechanical strength can be improved, catalytic performance such as raw material conversion rate and product selectivity can be further enhanced, and olefins such as propylene and isobutylene can be catalytically oxidized in the gas phase with an oxygen-containing gas to produce corresponding unsaturated aldehydes such as acrolein and methacrolein, and unsaturated carboxylic acids such as acrylic acid and methacrolein in high yield. Among these, acrolein and acrylic acid can be produced in particularly high yields by catalytically oxidizing propylene with an oxygen-containing gas. [Examples]

[0072] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way to the following examples as long as it does not exceed the gist of the invention. The propylene conversion rate, the selectivity for acrolein and acrylic acid, and the yield of acrolein and acrylic acid are defined as shown in the following formulas (1) to (5). (1) Propylene conversion rate (mol%) = 100 × (moles of propylene reacted) / (moles of propylene supplied) (2) Acrolein selectivity (mol %) = 100 × (moles of acrolein produced) / (moles of propylene converted) (3) Acrylic acid selectivity (mol%) = 100 × (moles of acrylic acid produced) / (moles of propylene converted) (4) Acrolein yield (mol%) = 100 × (moles of acrolein produced) / (moles of propylene supplied) (5) Acrylic acid yield (mol%) = 100 × (moles of acrylic acid produced) / (moles of propylene supplied)

[0073] <Gas-phase catalytic oxidation reaction of propylene> A reaction tube with an inner diameter of 21.4 mm was filled with 13.3 ml of the catalyst prepared in each of the following examples and comparative examples. A raw material mixture gas with the following composition was introduced into the inlet of the reaction tube, and the reaction was evaluated at a space velocity of 3064 / hr. The heat transfer medium temperature was set to 370°C and 380°C, respectively. The reaction evaluation results are shown in Table 1. The composition of the raw material mixture gas used is as follows: • Propylene: 10% by volume, Steam: 17% by volume, Oxygen: 15% by volume, (Nitrogen-containing inert gas + other gases): 58% by volume

[0074] <Measurement of catalyst pulverization rate> The catalysts produced in each of the following examples and comparative examples were sieved using a sieve with a mesh size of 2.36 mm, and the sieved material was used as the sample for measuring the pulverization rate. A funnel (conical upper opening diameter 150 mm, conical lower opening diameter 25 mm) was inserted into the top of an acrylic cylinder (φ66 mm) that was 1 m high, and a receiving tray was placed at the bottom of the cylinder. Approximately 20 g of the pulverization rate measurement sample was accurately weighed and poured into the conical upper part of the funnel, falling through the cylinder into the receiving tray. The pulverization rate measurement sample that fell was collected from the receiving tray, and the weight of the fine particles (pulverized weight) sieved using the sieve with a mesh size of 2.36 mm was measured, and the pulverization rate was calculated using the following formula. Powdering rate (%) = (Weight of powdered material / Weight of sample used for powdering) × 100

[0075] (Example 1) 12,000 ml of warm water was placed in a container, and 3,121.0 g of ammonium molybdate was added and dissolved. Next, 9.4 g of potassium nitrate was added and dissolved. Then, 7.9 g of ammonium chloride was added and dissolved to obtain a solution (hereinafter referred to as "Solution A"). Next, a solution prepared by dissolving 1062.6g of iron nitrate, 1487.6g of cobalt nitrate, and 1147.3g of nickel nitrate in 2500ml of warm water was added to solution A and mixed for 1 hour until homogeneous (hereinafter referred to as "solution B"). Then, a solution prepared by dissolving 145.9g of nitric acid and 637.9g ​​of bismuth nitrate in 690ml of pure water at room temperature was added to solution B and mixed for 2 hours until homogeneous to obtain a starting material mixture. This starting material mixture was spray-dried at 150°C, and then heat-treated in air at a heating temperature of 440°C for 6 hours to obtain a dried product.

[0076] This dried material was ground to a particle size of 200 μm or less using a stirring blade type pulverizer to obtain a pulverized material. This pulverized material was used as the support powder. 1.4 g of flake glass and 4.7 g of cellulose were added to 93.9 g of this support powder and mixed until uniform to obtain a support mixed powder. 100 g of spherical inert carriers with a diameter of 4.5 mm, mainly composed of alumina-silica, were introduced into a rolling granulator, and then 7.5 g of binder A was introduced into the granulator at an introduction rate of 0.5 g / min. Binder A consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. Furthermore, the supporting mixed powder and 37.5 g of binder B were each divided, and the divided supporting mixed powder was introduced alternately first to support the catalyst precursor, which was a molded body. At this time, the ratio of the introduction rate of binder A to the introduction rate of binder B until the entire amount of binder B was introduced was 0.2, the ratio of the introduction rate of binder A to the introduction rate until 90% by mass of binder B was introduced was 0.2, and the ratio of the introduction rate until 80% by mass of binder B was introduced was 0.2. Binder B consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. This catalyst precursor was calcined in an air atmosphere at 510°C for 2 hours to obtain a catalyst. The composition ratio of the catalytic elemental components of this catalyst (excluding oxygen) was as follows. Mo 12 Bi 0.9 Fe 1.8 Co 5.8 Ni 2.7 K 0.07 Cl 0.1 Table 1 shows the results of the gas-phase catalytic oxidation reaction of propylene using the manufactured catalyst.

[0077] (Example 2) A dried product was obtained in the same manner as in Example 1. This dried material was ground to a particle size of 200 μm or less using a stirring blade type pulverizer to obtain a pulverized material. This pulverized material was used as the support powder. 1.4 g of flake glass and 4.7 g of cellulose were added to 93.9 g of this support powder and mixed until uniform to obtain a support mixed powder. 100 g of spherical inert carriers with a diameter of 4.5 mm, mainly composed of alumina-silica, were introduced into a rolling granulator, and then 7.5 g of binder A was introduced into the granulator at an introduction rate of 0.75 g / min. Binder A consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. Furthermore, the supporting mixed powder and 37.5 g of binder B were each divided, and the divided supporting mixed powder was introduced alternately first to support the catalyst precursor, which was a molded body. At this time, the ratio of the introduction rate of binder A to the introduction rate of binder B until the entire amount of binder B was introduced was 0.4, the ratio of the introduction rate of binder A to the introduction rate until 90% by mass of binder B was introduced was 0.4, and the ratio of the introduction rate until 80% by mass of binder B was introduced was 0.4. Binder B consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. This catalyst precursor was calcined in an air atmosphere at 510°C for 2 hours to obtain a catalyst. The composition ratio of the catalytic elemental components of this catalyst (excluding oxygen) was as follows. Mo 12 Bi 0.9 Fe 1.8 Co 5.8 Ni 2.7 K 0.07 Cl 0.1 Table 1 shows the results of the gas-phase catalytic oxidation reaction of propylene using the manufactured catalyst.

[0078] (Example 3) A dried product was obtained in the same manner as in Example 1. This dried material was ground to a particle size of 200 μm or less using a stirring blade type pulverizer to obtain a pulverized material. This pulverized material was used as the support powder. 1.4 g of flake glass and 4.7 g of cellulose were added to 93.9 g of this support powder and mixed until uniform to obtain a support mixed powder. 100 g of spherical inert carriers with a diameter of 4.5 mm, mainly composed of alumina-silica, were introduced into a rolling granulator, and then 7.5 g of binder A was introduced into the granulator at an introduction rate of 1.07 g / min. Binder A consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. Furthermore, the supporting mixed powder and 37.5 g of binder B were each divided, and the divided supporting mixed powder was introduced alternately first to support the catalyst precursor, which was a molded body. At this time, the ratio of the introduction rate of binder A to the introduction rate of binder B until the entire amount of binder B was introduced was 0.7, the ratio of the introduction rate of binder A to the introduction rate until 90% by mass of binder B was introduced was 0.7, and the ratio of the introduction rate until 80% by mass of binder B was introduced was 0.7. Binder B consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. This catalyst precursor was calcined in an air atmosphere at 510°C for 2 hours to obtain a catalyst. The composition ratio of the catalytic elemental components of this catalyst (excluding oxygen) was as follows. Mo 12 Bi 0.9 Fe 1.8 Co 5.8 Ni 2.7 K 0.07 Cl 0.1 Table 1 shows the results of the gas-phase catalytic oxidation reaction of propylene using the manufactured catalyst.

[0079] (Example 4) A dried product was obtained in the same manner as in Example 1. This dried material was ground to a particle size of 200 μm or less using a stirring blade type pulverizer to obtain a pulverized material. This pulverized material was used as the support powder. 1.4 g of flake glass and 4.7 g of cellulose were added to 93.9 g of this support powder and mixed until uniform to obtain a support mixed powder. 100 g of spherical inert carriers with a diameter of 4.5 mm, mainly composed of alumina-silica, were introduced into a rolling granulator, and then 7.5 g of binder A was introduced into the granulator at an introduction rate of 1.36 g / min. Binder A consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. Furthermore, the supporting mixed powder and 37.5 g of binder B were each divided, and the divided supporting mixed powder was introduced alternately first to support the catalyst precursor, which was a molded body. At this time, the ratio of the introduction rate of binder A to the introduction rate of binder B until the entire amount of binder B was introduced was 0.9, the ratio of the introduction rate of binder A to the introduction rate until 90% by mass of binder B was introduced was 0.9, and the ratio of the introduction rate until 80% by mass of binder B was introduced was 0.9. Binder B consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. This catalyst precursor was calcined in an air atmosphere at 510°C for 2 hours to obtain the catalyst. The composition ratio of the elemental components (excluding oxygen) was as follows: Mo 12 Bi 0.9 Fe 1.8 Co 5.8 Ni 2.7 K 0.07 Cl 0.1 Table 1 shows the results of the gas-phase catalytic oxidation reaction of propylene using the manufactured catalyst.

[0080] (Example 5) A dried product was obtained in the same manner as in Example 1. This dried material was ground to a particle size of 200 μm or less using a stirring blade type pulverizer to obtain a pulverized material. This pulverized material was used as the support powder. 1.4 g of flake glass and 4.7 g of cellulose were added to 93.9 g of this support powder and mixed until uniform to obtain a support mixed powder. 100 g of spherical inert carriers with a diameter of 4.5 mm, mainly composed of alumina-silica, were introduced into a rolling granulator, and then 7.5 g of binder A was introduced into the granulator at an introduction rate of 0.75 g / min. Binder A consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. Furthermore, the supporting mixed powder and 37.5 g of binder B were introduced simultaneously in separate states to support the catalyst precursor, which was a molded body. At this time, the ratio of the introduction rate of binder A to the introduction rate of binder B until the entire amount of binder B was introduced was 0.4, the ratio of the introduction rate of binder A to the introduction rate until 90% by mass of binder B was introduced was 0.4, and the ratio of the introduction rate until 80% by mass of binder B was introduced was 0.4. Binder B consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. This catalyst precursor was calcined in an air atmosphere at 510°C for 2 hours to obtain a catalyst. The composition ratio of the catalytic elemental components of this catalyst (excluding oxygen) was as follows. Mo 12 Bi 0.9 Fe 1.8 Co 5.8 Ni 2.7 K 0.07 Cl 0.1 Table 1 shows the results of the gas-phase catalytic oxidation reaction of propylene using the manufactured catalyst.

[0081] (Comparative Example 1) A dried product was obtained in the same manner as in Example 1. This dried material was ground to a particle size of 200 μm or less using a stirring blade type pulverizer to obtain a pulverized material. This pulverized material was used as the support powder. 1.4 g of flake glass and 4.7 g of cellulose were added to 93.9 g of this support powder and mixed until uniform to obtain a support mixed powder. 100 g of spherical inert carriers with a diameter of 4.5 mm, mainly composed of alumina-silica, were introduced into a rolling granulator, and then 7.5 g of binder A was introduced into the granulator at an introduction rate of 0.38 g / min. Binder A consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. Furthermore, the supporting mixed powder and 37.5 g of binder B were each divided, and the divided supporting mixed powder was introduced alternately first to support the catalyst precursor, which was a molded body. At this time, the ratio of the introduction rate of binder A to the introduction rate of binder B until the entire amount of binder B was introduced was 0.1, the ratio of the introduction rate of binder A to the introduction rate until 90% by mass of binder B was introduced was 0.1, and the ratio of the introduction rate until 80% by mass of binder B was introduced was 0.1. Binder B consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. This catalyst precursor was calcined in an air atmosphere at 510°C for 2 hours to obtain a catalyst. The composition ratio of the catalytic elemental components of this catalyst (excluding oxygen) was as follows. Mo 12 Bi 0.9 Fe 1.8 Co 5.8 Ni 2.7 K 0.07 Cl 0.1 Table 1 shows the results of the gas-phase catalytic oxidation reaction of propylene using the manufactured catalyst.

[0082] (Comparative Example 2) A dried product was obtained in the same manner as in Example 1. This dried material was ground to a particle size of 200 μm or less using a stirring blade type pulverizer to obtain a pulverized material. This pulverized material was used as the support powder. 1.4 g of flake glass was added to 93.9 g of this support powder. 4.7g of cellulose was added and mixed until uniform to obtain a support powder mixture. 100 g of spherical inert carriers with a diameter of 4.5 mm, mainly composed of alumina-silica, were introduced into a rolling granulator, and then 7.5 g of binder A was introduced into the granulator at an introduction rate of 1.50 g / min. Binder A consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. Furthermore, the supporting mixed powder and 37.5 g of binder B were each divided, and the divided supporting mixed powder was introduced alternately first to support the catalyst precursor, which was a molded body. At this time, the ratio of the introduction rate of binder A to the introduction rate of binder B until the entire amount of binder B was introduced was 1.0, the ratio of the introduction rate of binder A to the introduction rate until 90% by mass of binder B was introduced was 1.0, and the ratio of the introduction rate until 80% by mass of binder B was introduced was 1.0. Binder B consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. This catalyst precursor was calcined in an air atmosphere at 510°C for 2 hours to obtain a catalyst. The composition ratio of the catalytic elemental components of this catalyst (excluding oxygen) was as follows. Mo 12 Bi 0.9 Fe 1.8 Co 5.8 Ni 2.7 K 0.07 Cl 0.1 Table 1 shows the results of the gas-phase catalytic oxidation reaction of propylene using the manufactured catalyst.

[0083] (Comparative Example 3) A dried product was obtained in the same manner as in Example 1. This dried material was ground to a particle size of 200 μm or less using a stirring blade type pulverizer to obtain a pulverized material. This pulverized material was used as the support powder. 1.4 g of flake glass and 4.7 g of cellulose were added to 93.9 g of this support powder and mixed until uniform to obtain a support mixed powder. 100 g of spherical inert carriers with a diameter of 4.5 mm, mainly composed of alumina-silica, were introduced into a rolling granulator, and then 7.5 g of binder A was introduced into the granulator at an introduction rate of 0.38 g / min. Binder A consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. Furthermore, the supporting mixed powder and 37.5 g of binder B were introduced simultaneously in separate states to support the catalyst precursor, which was a molded body. At this time, binder B was introduced such that the ratio of the introduction rate of binder A to the introduction rate of binder B until the entire amount of binder B was introduced was 0.1, the ratio of the introduction rate of binder A to the introduction rate until 90% by mass of binder B was introduced was 0.1, and the ratio of the introduction rate until 80% by mass of binder B was introduced was 0.1. Binder B consisted of glycerin and water, specifically a 10% by mass aqueous solution of glycerin. This catalyst precursor was calcined in an air atmosphere at 510°C for 2 hours to obtain a catalyst. The composition ratio of the catalytic elemental components of this catalyst (excluding oxygen) was as follows. Mo 12 Bi 0.9 Fe 1.8 Co 5.8 Ni 2.7 K 0.07 Cl 0.1 Table 1 shows the results of the gas-phase catalytic oxidation reaction of propylene using the manufactured catalyst.

[0084] (Comparative Example 4) Table 1 shows the results of the evaluation of the gas-phase catalytic oxidation reaction of propylene using a catalyst produced by the method described in Example 1 of Japanese Patent Publication No. 2022-67387. Specifically, the experiment was conducted using the following method. 1700 ml of warm water was placed in a container, and 447.2 g of ammonium molybdate was added and dissolved. Next, 2.1 g of potassium nitrate was added and dissolved. Then, 1.1 g of ammonium chloride was added and dissolved to obtain a solution (hereinafter referred to as "Solution A1"). Next, a solution prepared by dissolving 159.8g of iron nitrate, 376.2g of cobalt nitrate, and 174.1g of nickel nitrate in 376ml of warm water was added to solution A1 and mixed for 1 hour until homogeneous (hereinafter referred to as "solution B1"). Then, a solution prepared by dissolving 22.1g of nitric acid and 96.5g of bismuth nitrate in 104.8ml of pure water at room temperature was added to solution B1 and mixed for 2 hours until homogeneous to obtain a starting material mixture. This starting material mixture was spray-dried at 150 °C and then heat-treated in the atmosphere at a heating temperature of 440 °C for 6 hours to obtain a dried product.

[0085] This dried product was pulverized to 200 μm or less using a stirring blade mill to obtain a pulverized product. This pulverized product was used as the powder for loading. To 81.8 g of this powder for loading, 4.1 g of flake glass and 4.1 g of cellulose were added and mixed uniformly to obtain a mixed powder for loading. 100 g of spherical inert carriers with a diameter of 4.5 mm having alumina-silica as the main component were introduced into a rolling granulator, and then 16.0 mass% of binder A out of a total of 47.0 g of the binder introduced into the granulator was introduced. Incidentally, binder A is glycerin and water, and it was made into an aqueous solution of 10 mass% glycerin. Furthermore, the mixed powder for loading and 84.0 mass% of binder B out of a total of 47.0 g of the binder introduced into the granulator were each divided, and they were supported by alternately introducing them first from the divided mixed powder for loading to obtain a catalyst precursor which is a molded body. Incidentally, binder B is glycerin and water, and it was made into an aqueous solution of 10 mass% glycerin. This catalyst precursor was calcined in an air atmosphere at 510 °C for 2 hours to obtain a catalyst. The composition ratio (excluding oxygen) of the catalyst component elements of this catalyst was as follows. Mo 12 Bi 0.94 Fe 1.87 Co 6.30 Ni 2.84 K 0.1 Cl 0.1

[0086] Incidentally, although not described in Example 1 of JP-A-2022-67387, the ratio of the introduction rate of binder A to the introduction rate of binder B until the introduction of the total amount of binder B is completed is 1.0, the ratio of the introduction rate of binder A to the introduction rate until the introduction of 90 mass% of the total amount of binder B is completed is 1.0, and binder B was introduced so that the ratio of the introduction rate until the introduction of 80 mass% of the total amount of binder B is completed is 1.0. Table 1 shows the results of the gas-phase catalytic oxidation reaction evaluation of propylene using the produced catalyst.

[0087] [Table 1]

[0088] As described above, the catalyst obtained by the catalyst manufacturing method of the present invention has high mechanical strength, resulting in a low pulverization rate. Furthermore, when propylene is oxidized in gas phase with an oxygen-containing gas using this catalyst, it exhibits excellent propylene conversion rates even under low heat transfer temperature conditions, and produces acrolein and ammonium compounds. The selectivity for lylic acid is high in both cases, indicating that acrolein and acrylic acid can be produced in high yield. On the other hand, when the ratio (rate ratio) of the introduction rate of binder A (VA) to the introduction rate of binder B (VB80, VB90, VB100) is 0.1 or less, it was found that the pulverization rate is high due to low mechanical strength, making it difficult to use as a practical catalyst. Furthermore, it was found that when the ratio (rate ratio) of the introduction rate of binder A (VA) to the introduction rate of binder B (VB80, VB90, VB100) was 1.0 or higher, the propylene conversion rate was poor under low heat transfer fluid temperature conditions, and both the acrolein yield and acrylic acid yield were not very high.

Claims

1. A method for producing catalysts for unsaturated aldehydes and unsaturated carboxylic acids, comprising a molding step in which a carrier is introduced into a granulator, then a first binder A is introduced, then a powder containing catalyst component elements and a second binder B is introduced, and the powder containing the catalyst component elements is supported on the carrier to form a catalyst precursor, wherein The catalyst component elements include molybdenum (Mo), bismuth (Bi), and iron (Fe), A method for producing catalysts for unsaturated aldehydes and unsaturated carboxylic acids, wherein the ratio of the introduction rate of binder A into the granulator to the introduction rate of binder B (introduction rate of binder A / introduction rate of binder B) is greater than 0.1 and less than 1.

0.

2. A method for producing catalysts for unsaturated aldehydes and unsaturated carboxylic acids, comprising a molding step in which a carrier is introduced into a granulator, then a first binder A is introduced, then a powder containing catalyst component elements and a second binder B is introduced, and the powder containing the catalyst component elements is supported on the carrier to form a catalyst precursor, wherein The catalyst component elements include molybdenum (Mo), bismuth (Bi), and iron (Fe), A method for producing catalysts for unsaturated aldehydes and unsaturated carboxylic acids, wherein the ratio of the introduction rate of binder A into the granulator to the introduction rate from the start of introduction of binder B to the completion of introduction of 90% by mass of the total amount of binder B (introduction rate of binder A / introduction rate from the start of introduction of binder B to the completion of introduction of 90% by mass) is greater than 0.1 and less than 1.

0.

3. A method for producing catalysts for unsaturated aldehydes and unsaturated carboxylic acids, comprising a molding step in which a carrier is introduced into a granulator, then a first binder A is introduced, then a powder containing catalyst component elements and a second binder B is introduced, and the powder containing the catalyst component elements is supported on the carrier to form a catalyst precursor, wherein The catalyst component elements include molybdenum (Mo), bismuth (Bi), and iron (Fe), A method for producing catalysts for unsaturated aldehydes and unsaturated carboxylic acids, wherein the ratio of the introduction rate of binder A into the granulator to the introduction rate from the start of introduction of binder B to the completion of introduction of 80% by mass of the total amount of binder B (introduction rate of binder A / introduction rate from the start of introduction of binder B to the completion of introduction of 80% by mass) is greater than 0.1 and less than 1.

0.

4. A method for producing catalysts for unsaturated aldehydes and unsaturated carboxylic acids according to any one of claims 1 to 3, wherein the total amount of binder introduced into the granulator is 10% by mass or more and 60% by mass or less relative to the amount of carrier introduced into the granulator.

5. A method for producing catalysts for unsaturated aldehydes and unsaturated carboxylic acids according to any one of claims 1 to 3, wherein the total amount of binder introduced into the granulator is 10% by mass or more and 70% by mass or less relative to the amount of powder containing the catalyst component elements introduced into the granulator.

6. A method for producing a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids according to any one of claims 1 to 3, wherein the binder A and the binder B contain an organic compound.

7. Claim 1, wherein the amount of binder A introduced into the granulator is 2% by mass or more and 90% by mass or less of the total amount of binder introduced into the granulator, and the amount of binder B introduced into the granulator is 10% by mass or more and 98% by mass or less of the total amount of binder introduced into the granulator. A method for producing catalysts for unsaturated aldehydes and unsaturated carboxylic acids as described in any one of paragraphs 1 through 3.

8. A method for producing an unsaturated aldehyde and unsaturated carboxylic acid catalyst according to any one of claims 1 to 3, wherein the catalytic component element of the catalyst for producing the unsaturated aldehyde and unsaturated carboxylic acid 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 Ti; Y represents at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Mn, and Zn; and 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 ratios of each element, within the ranges of 0.5 ≤ a ≤ 7, 0.05 ≤ b ≤ 5, 0 ≤ c ≤ 10, 0 ≤ d ≤ 10, 0 ≤ e ≤ 2, 0 ≤ f ≤ 5, 0 ≤ g ≤ 5, and 0 ≤ h ≤ 500, where i is a value that satisfies the oxidation state of the other elements.)

9. A method for producing acrolein and acrylic acid, comprising using a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids produced by the manufacturing method described in any one of claims 1 to 3, and gas-phase catalytic oxidation of propylene with an oxygen-containing gas.

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