Dry particles for catalyst production, catalyst and method for producing compound

Abstract

A catalyst, wherein, in a SEM image of the catalyst obtained using a scanning electron microscope (SEM) with an acceleration voltage set to 15 kV and at a magnification such that the maximum longitudinal length of one particle in the SEM image accounts for more than 90% of the longitudinal length of the SEM image and the maximum lateral length of one particle in the SEM image accounts for more than 90% of the lateral length of the SEM image, when the SEM image is binarized into a black and white image, the bismuth (Bi) concentration of the white portion is greater than the value obtained by adding 2.5 times the standard deviation σ1 of the Bi concentration of the black portion.

Description

Technical Field

[0001] The present invention relates to a novel catalyst which is highly active and capable of obtaining a target product in high yield, and in particular to a catalyst which can be produced stably and in high yield even in a region of high catalyst activity when producing unsaturated aldehydes, unsaturated carboxylic acids or conjugated dienes by oxidation, and a method for producing the same. Background Art

[0002] Methods for producing corresponding unsaturated aldehydes and unsaturated carboxylic acids using propylene, isobutylene, tert-butyl alcohol, etc. as raw materials, and gas phase catalytic oxidation methods for producing 1,3-butadiene from butenes are widely practiced in industry. In particular, many reports have been made on methods for producing corresponding unsaturated aldehydes and unsaturated carboxylic acids using propylene, isobutylene, tert-butyl alcohol, etc. as raw materials as means for improving their yields (e.g., Patent Documents 1 and 2, etc.).

[0003] According to Patent Document 3, two or more composite metal oxide catalysts of different compositions are prepared, and when the multiple layers are filled in a manner of stacking more than two layers in the tube axis direction, the catalyst is filled in a manner in which the component amount of bismuth relative to molybdenum decreases from the gas inlet side to the gas outlet side and the component amount of iron relative to molybdenum increases from the gas inlet side to the gas outlet side, and the reaction bath temperature is suppressed to a low level even in a reaction under high load. As described above, the following research has not been seen in the prior art: in the process of manufacturing the corresponding unsaturated aldehyde and / or unsaturated carboxylic acid from olefins, the total yield (hereinafter, recorded as "effective yield") of the unsaturated aldehyde and / or unsaturated carboxylic acid itself is increased, and the reaction bath temperature is suppressed to a low level even in a reaction under high load and the effective yield is maintained while the increased effective yield is stably manufactured.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2016 / 136882

[0007] Patent Document 2: Japanese Patent Application Publication No. 2017-024009

[0008] Patent Document 3: International Publication No. 2015 / 008815 Summary of the invention

[0009] Problems to be solved by the invention

[0010] Although improvement is sought by the above means, when utilizing the partial oxidation reaction of olefins such as propylene, isobutylene, tert-butyl alcohol to manufacture corresponding unsaturated aldehydes and / or unsaturated carboxylic acids, and utilizing the oxidative dehydrogenation reaction of butenes to manufacture conjugated dienes, it is required to further improve the yield. For example, the yield of the target product affects the usage of the required olefins such as propylene, isobutylene, tert-butyl alcohol, butenes, and has a great impact on the manufacturing cost. In addition, due to the continuous operation with low yield, a large amount of by-products are generated, and therefore a large load is brought to the purification process, and the time and running cost consumed by the purification process may increase. In addition, according to the type of by-products, these by-products are sometimes accumulated in the gas flow channel near the catalyst surface or the catalyst. Because these by-products cover the necessary reactive sites on the catalyst surface and reduce the activity of the catalyst, it is necessary to forcibly improve the activity and have to increase the reaction bath temperature. Then, the catalyst is subjected to thermal stress, causing the reduction of the life span and the further reduction of the selectivity, and also leading to the reduction of the yield. In addition, it is also conceivable that the pressure in the system increases due to the accumulation of byproducts in the system, thereby reducing the selectivity and resulting in a reduction in yield. It is also conceivable that the rapid increase in internal pressure may cause abnormal temperature and runaway reaction, depending on the situation. In this case, it is assumed that the operation will be stopped for a long time, and the system will need to be cleaned and the catalyst replaced.

[0011] Therefore, an object of the present invention is to provide a catalyst that can produce an unsaturated aldehyde, an unsaturated carboxylic acid and / or a conjugated diene safely and inexpensively and has a high yield of the target product.

[0012] Means used to solve problems

[0013] The inventors of the present application have discovered that a catalyst in which uneven distribution (partial distribution) of a bismuth (Bi) component can be confirmed in evaluation of catalyst particles by SEM has a higher yield of a target product than conventional catalysts, thereby completing the present invention.

[0014] That is, the present invention relates to the following 1) to 11). 1)

[0016] A catalyst, wherein in a SEM image of the catalyst obtained using a scanning electron microscope (SEM) with an accelerating voltage set to 15 kV and at a magnification such that the maximum longitudinal length of one particle in the SEM image occupies 90% or more of the longitudinal length of the SEM image and the maximum lateral length of one particle in the SEM image occupies 90% or more of the lateral length of the SEM image,

[0017] When the SEM image is binarized into a black-and-white image, the bismuth (Bi) concentration of the white portion is greater than the value obtained by adding 2.5 times the standard deviation σ1 of the Bi concentration of the black portion to the Bi concentration of the black portion. 2)

[0019] A catalyst, wherein in a SEM image of the catalyst obtained using a scanning electron microscope (SEM) with an accelerating voltage set to 15 kV and at a magnification such that the maximum longitudinal length of one particle in the SEM image occupies 90% or more of the longitudinal length of the SEM image and the maximum lateral length of one particle in the SEM image occupies 90% or more of the lateral length of the SEM image,

[0020] When arbitrarily 10 straight lines are set on the catalyst in the SEM image, the standard deviation σ2 of the Bi (bismuth) concentration on the catalyst surface corresponding to the straight lines is 0.4 or more. 3)

[0022] A dry particle for catalyst production, wherein in a SEM image of the dry particle obtained using a scanning electron microscope (SEM) with an accelerating voltage set to 15 kV and at a magnification such that the maximum longitudinal length of one particle in the SEM image occupies 90% or more of the longitudinal length of the SEM image and the maximum lateral length of one particle in the SEM image occupies 90% or more of the lateral length of the SEM image,

[0023] When the SEM image is binarized into a black-and-white image, the bismuth (Bi) concentration of the white portion is greater than the value obtained by adding 2.5 times the standard deviation σ1 of the Bi concentration of the black portion to the Bi concentration of the black portion. 4)

[0025] A dry particle for catalyst production, wherein in a SEM image of the dry particle obtained using a scanning electron microscope (SEM) with an accelerating voltage set to 15 kV and at a magnification such that the maximum longitudinal length of one particle in the SEM image occupies 90% or more of the longitudinal length of the SEM image and the maximum lateral length of one particle in the SEM image occupies 90% or more of the lateral length of the SEM image,

[0026] When 10 arbitrary straight lines are set on the dry particles in the SEM image, the standard deviation σ2 of the Bi (bismuth) concentration on the surface of the dry particles corresponding to the straight lines is 0.4 or more. 5)

[0028] A catalyst, wherein the catalyst is produced from the dry particles for producing the catalyst according to 3) or 4). 6)

[0030] The catalyst as described in any one of 1), 2) and 5), wherein the composition of the catalytic active component is represented by the following formula (1):

[0031] Mo a1 Bib1 Ni c1 Co d1 Fe e1 X f1 Y g1 Z h1 O i1 ……(1)

[0032] (wherein, Mo, Bi, Ni, Co and Fe represent molybdenum, bismuth, nickel, cobalt and iron respectively, X represents at least one element selected from tungsten, antimony, tin, zinc, chromium, manganese, magnesium, silicon, aluminum, cerium and titanium, Y represents at least one element selected from sodium, potassium, cesium, rubidium and thallium, Z represents at least one element belonging to Group 1 to Group 16 of the periodic table and selected from elements other than Mo, Bi, Ni, Co, Fe, X and Y, a1, b1, c1, d1, e1, f1, g1, h1 and i1 represent the atomic numbers of molybdenum, bismuth, nickel, cobalt, iron, X, Y, Z and oxygen respectively, when a1=12, 0<b1≤7, 0≤c1≤10, 0<d1≤10, 0<c1+d1≤20, 0≤e1≤5, 0≤f1≤2, 0≤g1≤3, 0≤h1≤5, and i1=a value determined by the oxidation state of each element). 7)

[0034] The catalyst as described in 6), wherein, in the formula (1), c1, b1 and d1 satisfy the following formula (2):

[0035] 0.300≤c1 / (b1+d1)≤0.600 (2). 8)

[0037] The catalyst as described in any one of 1), 2) and 5) to 7), wherein the catalyst is a catalyst in which a catalytically active component is supported on an inert carrier. 9)

[0039] The catalyst according to any one of 1), 2) and 5) to 8), wherein the catalyst is a catalyst for producing an unsaturated aldehyde compound and / or an unsaturated carboxylic acid compound. 10)

[0041] A method for producing an unsaturated aldehyde compound and / or an unsaturated carboxylic acid compound, wherein the method uses the catalyst described in any one of 1), 2), and 5) to 9). 11)

[0043] The production method according to item 10), wherein the unsaturated aldehyde compound is acrolein and the unsaturated carboxylic acid compound is acrylic acid.

[0044] Effects of the Invention

[0045] The catalyst of the present invention relates to a catalyst for producing unsaturated aldehydes, unsaturated carboxylic acids and / or conjugated dienes by oxidation, and in particular, aims to provide a catalyst capable of producing unsaturated aldehydes and / or unsaturated carboxylic acids safely and inexpensively with a high yield of the target product. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 Examples of SEM images of the surfaces of dried particles used in catalyst preparation.

[0047] Figure 2 To adjust Figure 1 Example of an SEM image of the dried particle surface after toning of the catalyst preparation.

[0048] Figure 3 An example of a SEM image of the surface of dry particles of Catalyst A used for catalyst preparation.

[0049] Figure 4 For the general Figure 3 An example of a SEM image of the surface of dry particles for catalyst production after binarization into a black and white image.

[0050] Figure 5 An example of a SEM image of the surface of dry particles of Catalyst B used for catalyst preparation.

[0051] Figure 6 For the general Figure 5 An example of a SEM image of the surface of dry particles for catalyst production after binarization into a black and white image.

[0052] Figure 7 An example of a SEM image of the surface of dry particles of Catalyst C used for catalyst preparation.

[0053] Figure 8 For the general Figure 7 An example of a SEM image of the surface of dry particles for catalyst production after binarization into a black and white image.

[0054] Fig. 9 This is an example of a SEM image of the surface of dry particles of Catalyst E used in catalyst preparation.

[0055] Fig.10 For the general Fig. 9 An example of a SEM image of the surface of dry particles for catalyst production after binarization into a black and white image. DETAILED DESCRIPTION

[0056] [Uneven distribution of Bi (bismuth)]

[0057] The dry particles and catalyst for catalyst manufacturing of the present invention are characterized in that bismuth (Bi) is unevenly distributed. Although the detailed reason is not clear, the presence of the unevenly distributed parts of bismuth (Bi) can effectively carry out oxidation reaction and oxidative dehydrogenation reaction. It should be noted that in the present invention, bismuth (Bi) includes bismuth itself, compounds of bismuth and other elements contained in the raw materials other than bismuth, and / or all oxides, such as bismuth oxide, bismuth molybdate, bismuth iron molybdate, etc., and its crystal phase can be arbitrary. In addition, bismuth (Bi) is sometimes referred to as bismuth or Bi below.

[0058] In the present application, as a method for confirming the above-mentioned uneven distribution, for example, a method using image analysis using a scanning electron microscope (SEM) can be cited, but as long as the same accuracy and the same purpose, the details are not limited thereto, for example, an electron probe microanalyzer (EPMA) can be cited as another method, and in addition, a method using SEM and EPMA can also be cited. In addition, it is speculated that the uneven distribution of bismuth observed in the dry particles for catalyst manufacture is also observed in the catalyst manufactured using dry particles for catalyst manufacture. This is because, if the observed particles are below a certain particle size, it is necessary to apply extremely strong crushing and other processes in order to crush the particles. In addition, since the dry particles for catalyst manufacture are composite metal oxides, the particles will not melt unless excessive heat is applied.

[0059] [Method for measuring the uneven distribution of Bi (1)]

[0060] Using a scanning electron microscope (SEM), an SEM image of dry particles or catalysts for catalyst manufacture is taken under the conditions of an acceleration voltage of 15kV and a magnification of 1500 times. When shooting, dry particles or catalysts for catalyst manufacture are embedded in resins or the like as needed, and then the surface is sputtered, so that a cross section can be taken. In the case of few unevenly distributed parts, it is preferred to shoot a cross section. In addition, in order to make the image clearer, gold, platinum, etc. can also be evaporated. In the present invention, since the main component of dry particles and catalysts for catalyst manufacture is molybdenum, if the SEM image is taken in the form of a backscattered electron image, Bi with a large atomic number is highlighted as white. In addition, gray is used to represent the non-unevenly distributed part, and the part where the component with a small atomic number is unevenly distributed or the part that becomes a shadow is represented by black. That is, by binarizing the obtained SEM image into a black and white image, the part where Bi with a large atomic number is unevenly distributed can be further highlighted, and the unevenly distributed part can be more accurately determined. When the obtained SEM image is binarized, in order to highlight light and dark, it is further preferred to adjust the contrast and brightness.

[0061] The method for adjusting the SEM image is not particularly specified as long as the uneven distribution of Bi can be determined. As an example, in the present application specification, an SEM image of dry particles for catalyst production is attached as Figure 1 , and attached is an SEM image of the dry particles used for catalyst preparation with adjusted color tone. Figure 2 As in the attached Figure 2 How to adjust the color tone in Figure 2 To obtain the SEM image ( Figure 1 ) An image obtained by adjusting the midtone to -100, the contrast to -100, and the brightness to -50 using the picture manager software manufactured by Microsoft. As another method, the SEM image is opened using the photo software manufactured by Microsoft, the editing operation of setting the light to -80 is repeated three times, and then the obtained image is opened again using the paint software manufactured by Microsoft and saved as a monotone image (monochrome bitmap), thereby enabling binarization into a black and white image.

[0062] The Bi concentration of the white part in the image obtained by the above method is measured by EDS (energy dispersive X-ray spectroscopy). There are no special restrictions on the measurement conditions. It is preferred to select metal components used as catalyst raw materials other than alkaline components in the obtained spectrum, and calculate the relative element ratio. In addition, the measurement range can be appropriately set according to the size of the white part. For example, the measurement points can be set in the form of points, or the size can be set to a setting range within the size of the white part. In the case of local measurement, the Bi concentration of the white part is represented by the average value obtained by measuring at least 10 points. As particles having a white part as a measurement part, it is preferably appropriately judged. If the average particle size is less than 0.1μm, it is difficult to judge using SEM. If the average particle size is more than 1000μm, it is likely that it is not a component of the catalyst but an impurity.

[0063] On the other hand, in order to compare with the uneven distribution site, Figure 2 The black part, that is, the part other than the white part, is measured. As a measurement condition, an area larger than a certain size needs to be set as the measurement range to avoid accurately selecting the unevenly distributed part and measuring it. As the lower limit of the preferred range of the measurement area, there is no special restriction as long as it is within the range that the device cannot measure, but it should be greater than or equal to the area of ​​the photographed part of the unevenly distributed particles. Therefore, the measurement area is preferably 0.01μm 2It is preferred to perform EDS measurement on the entire image to determine the average element ratio within the image, or to set a certain measurement range for the black portion, for example, to set the measurement to a size greater than or equal to the white portion in order to minimize the influence of the white portion. That is, as the lower limit of the preferred range of the measurement area, there is no special restriction as long as it is within the range that the device cannot measure, but it should be greater than or equal to the area of ​​the photographed portion of the unevenly distributed particles. Therefore, the measurement area is preferably 0.01 μm 2 By using the Bi concentration obtained by measuring the entire image and the Bi concentration obtained by measuring more than 10 black parts as data, it is possible to measure the Bi concentration in a wide range while reducing the uneven distribution of the local catalyst component and the measurement deviation of the EDS measurement. In addition, in order to set the measurement range in the above manner, it is necessary to measure more than a certain amount of catalyst particles in the field of view.

[0064] The component ratio measured in this way is used to compare the unevenly distributed part with the part other than the unevenly distributed part to determine whether there is an uneven distribution. That is, the Bi concentration of the white part is greater than the value obtained by adding the average concentration of the Bi concentration of the black part to 2.5 times the standard deviation σ1 of the average concentration to indicate the presence of an uneven distribution. For a part where the concentration is statistically outside the range of the concentration average value ±2.5σ1, it can be determined that the part is composed of different component ratios. As described above, in the present invention, since the main component constituting the dry particles and catalysts for catalyst manufacturing is molybdenum, when the Bi with a large atomic number is binarized into a black and white image, since there may be abundant Bi in the white part, it is considered that in most cases it exceeds the above range. That is, it can be considered that the Bi concentration of the white part is a value greater than the value obtained by adding the average concentration of the Bi concentration of the black part to 2.5 times the standard deviation σ1 of the average concentration.

[0065] The particle size of the dry particles for catalyst production of the present invention is preferably about 0.1 μm to 500 μm, and in this case, it can be directly measured using SEM.

[0066] On the other hand, the catalyst of the present invention is produced by subjecting the above-mentioned dry particles for catalyst production to a molding process. Since the catalyst particle size is relatively large, 2 mm to 10 mm, it is sometimes difficult to measure directly using SEM. Therefore, it is necessary to measure the catalyst after the surface is scraped off, but as long as it is SEM observation of the catalyst, there is no particular limitation on the measurement method, and it may also be a sample obtained by embedding the catalyst in a resin or the like and scraping off the surface by sputtering.

[0067] In addition, in this specification, "to" means more than ... and less than .... That is, it means that the numerical value before and after sandwiching "to" is included.

[0068] [Method for measuring the uneven distribution of Bi (2)]

[0069] Line analysis may also be used as a method for measuring the uneven distribution of Bi.

[0070] Line analysis is a method as follows: a SEM image is obtained in the same manner as the above-mentioned method for measuring the uneven distribution of Bi (1), and then the concentration of Bi is analyzed for any 10 straight lines using EDS. It should be noted that EDS is the same as described above. There is no particular limitation on the number of measurement points on each of the 10 straight lines as long as it is 10 points or more, and preferably it is about 32 points. If the number of measurement points is more than 32 points, the measurement time will also increase accordingly. In addition, it is preferred to measure in a manner where the pixel time (PixelTime) is 200ms and the number of repeated measurements of each point is 3 times. By measuring 10 lines each in the longitudinal, transverse, and oblique directions in each SEM image, stable data can be obtained in one image, so it is preferred.

[0071] The average Bi concentration in each direction and the standard deviation σ2 of the average Bi concentration are obtained from the analysis values ​​obtained from the integrated values ​​of the line analysis in each direction. Then, the average Bi concentration and the standard deviation σ2 of the average Bi concentration are obtained from the data of each of these straight lines.

[0072] In the present invention, σ2 is preferably 0.8 or more, more preferably 1.5 or more, particularly preferably 2.3 or more, and most preferably 2.5 or more.

[0073] [About dry particles for catalyst production]

[0074] The dry particles for catalyst manufacturing of the present invention are particles obtained by mixing raw materials containing various elements constituting the catalyst to obtain a slurry, and granulating the slurry using, for example, drum drying, spray drying, evaporative drying, etc. The particles obtained. For the uneven distribution of Bi as an element constituting the present invention, Bi particles and catalyst particles of a certain size or more are required. Therefore, in order to achieve this condition, it is necessary to prepare particles with a certain particle size or more and a slurry with a certain concentration or more. In addition, a drying method for dry particles with a certain particle size or more is appropriately selected. As a drying method, spray drying that can be dried from a slurry into particles in a short time is particularly preferred. There is no particular restriction on the form of the spray used for spray drying, and a disc-shaped spray nozzle is preferably used.

[0075] The drying temperature is not particularly limited as long as it is a temperature at which moisture can be removed. When the pressure and time are adjusted, it can be room temperature (25° C.), but in order to more reliably remove moisture in a short time, it is preferably 80° C. or higher, and more preferably 90° C. or higher. In addition, when the pressure is not adjusted, it is preferably 100° C. or higher, and more preferably 150° C. or higher.

[0076] As will be described in detail in the description of the manufacturing process, the dried particles for catalyst manufacturing may be further pre-calcined, in which case the calcination is performed at a temperature of about 150°C to about 600°C for about 1 hour to about 12 hours. Regarding the SEM measurement of the above-mentioned uneven distribution of Bi, if it is a catalyst having the pre-calcination step, it is preferably measured after pre-calcination. This is because the pre-calcined particles constitute the catalyst. It should be noted that the pre-calcined particles are sometimes described as pre-calcined powder below.

[0077] [Regarding the composition of the catalyst active component]

[0078] The catalyst of the present invention preferably contains a catalytically active component having a composition represented by the following formula (1).

[0079] Mo a1 Bi b1 Ni c1 Co d1 Fe e1 X f1 Y g1 Z h1 O i1 ……(1)

[0080] (wherein, Mo, Bi, Ni, Co and Fe represent molybdenum, bismuth, nickel, cobalt and iron respectively, X represents at least one element selected from tungsten, antimony, tin, zinc, chromium, manganese, magnesium, silicon, aluminum, cerium and titanium, Y represents at least one element selected from sodium, potassium, cesium, rubidium and thallium, Z represents at least one element belonging to Group 1 to Group 16 of the periodic table and selected from elements other than Mo, Bi, Ni, Co, Fe, X and Y, a1, b1, c1, d1, e1, f1, g1, h1 and i1 represent the atomic numbers of molybdenum, bismuth, nickel, cobalt, iron, X, Y, Z and oxygen respectively, when a1=12, 0<b1≤7, 0≤c1≤10, 0<d1≤10, 0<c1+d1≤20, 0≤e1≤5, 0≤f1≤2, 0≤g1≤3, 0≤h1≤5, and i1=a value determined by the oxidation state of each element).

[0081] In the above formula (1), the preferred ranges of b1 to i1 are as follows.

[0082] 0.2<b1≤2, 1≤c1≤5, 3≤d1≤8, 5≤c1+d1≤15, 0.5≤e1≤4, 0≤f1≤1.5, 0.01≤g1≤1, 0≤h1≤2.

[0083] Furthermore, further preferred ranges are as follows.

[0084] 0.5<b1≤1, 2≤c1≤4, 5≤d1≤7, 7≤c1+d1≤12, 1≤e1≤3, 0≤f1≤1, 0.02≤g1≤0.2, 0≤h1≤1.

[0085] It should be noted that it is preferred to contain two or less types of Y, and it is particularly preferred that Y is one type. In addition, it is particularly preferred that f1 and h1 are 0.

[0086] Regarding the catalyst composition in the catalytically active component, it is preferred that c1 / (b1+d1) in the above formula (1) satisfies the following formula (2).

[0087] 0.300≤c1 / (b1+d1)≤0.600……(2)

[0088] The upper limit of c1 / (b1+d1) is more preferably 0.550, further preferably 0.540, and particularly preferably 0.530. The lower limit of c1 / (b1+d1) is more preferably 0.310. That is, the case where c1 / (b1+d1) is 0.310 or more and 0.540 or less is one of the particularly preferred embodiments.

[0089] [Regarding the shape and particle size of the catalyst]

[0090] Regarding the catalyst of the present invention, there can be listed: a catalyst obtained by molding dry particles for catalyst manufacture, a catalyst obtained by loading dry particles for catalyst manufacture on an inert carrier, a catalyst obtained by molding a pre-calcined powder obtained by pre-calcining dry particles for catalyst manufacture, a catalyst obtained by loading the pre-calcined powder on an inert carrier, etc.

[0091] The shape of the catalyst is not particularly limited, and examples thereof include spherical, cylindrical, and ring-shaped shapes, and a spherical shape is preferred.

[0092] In addition, the particle size of the catalyst is preferably 1mm to 15mm in terms of average particle size. The average particle size is not limited to its details as long as it is the average particle size obtained by measuring a portion of the catalysts randomly sampled, for example, more than 300 catalysts can be measured. It should be noted that as a measurement method, the three-axis average diameter is calculated based on the average value of the length (L), width (B), and thickness (T) of each catalyst ball. As the average particle size, it is further preferably 2mm to 10mm, and particularly preferably 3mm to 8mm.

[0093] [About Load]

[0094] The catalyst of the present invention may be used directly as the above-mentioned dry particles for catalyst production or as a pre-calcined powder obtained by pre-calcining after catalyst preparation. However, when the catalyst is supported on an inert carrier, it has a particularly excellent effect as the catalyst of the present invention.

[0095] As the material of the inert carrier, known materials such as alumina, silica, titania, zirconium oxide, niobium oxide, silica-alumina, silicon carbide, carbide and mixtures thereof can be used. In addition, the particle size, water absorption, mechanical strength, crystallinity of each crystal phase, mixing ratio, etc. of the inert carrier are not particularly limited. The performance, formability, production efficiency, etc. of the final catalyst should be considered to select an appropriate range. The mixing ratio of the carrier and the pre-calcined powder is calculated according to the loading rate by the following formula based on the feed mass of each raw material.

[0096] Supporting rate (mass %) = (mass of dry particles or pre-calcined powder for catalyst production used in molding) / {(mass of dry particles or pre-calcined powder for catalyst production used in molding) + (mass of carrier used in molding)} × 100

[0097] The upper limit of the load factor is preferably 90%, more preferably 80%.

[0098] In addition, the lower limit of the load factor is preferably 20%, and more preferably 30%.

[0099] It should be noted that the inert carrier is preferably silica and / or alumina, and particularly preferably a mixture of silica and alumina.

[0100] It should be noted that a binder is preferably used when loading. As specific examples of binders that can be used, water or ethanol, methanol, propanol, polyols, polyvinyl alcohol as a polymer binder, silica sol aqueous solution as an inorganic binder, etc., preferably ethanol, methanol, propanol, polyols, preferably diols such as ethylene glycol, triols such as glycerol, etc., preferably an aqueous solution with a concentration of glycerol of 5% by mass or more. By using an appropriate amount of glycerol aqueous solution, the moldability becomes good, and a catalyst with high mechanical strength and high performance can be obtained. Relative to 100 parts by mass of pre-calcined powder, the amount of these binders used is usually 2 parts by mass to 60 parts by mass, and in the case of glycerol aqueous solution, it is preferably 10 parts by mass to 30 parts by mass. When loaded, the binder and the pre-calcined powder can be supplied to the molding machine alternately, or they can be supplied to the molding machine at the same time.

[0101] [Regarding the method for producing the catalyst, etc.]

[0102] There are no particular restrictions on the starting raw materials of the elements that constitute the dry particles, pre-calcined powder or catalyst for catalyst manufacturing of the present invention. For example, as the raw material of the molybdenum component, molybdenum oxides such as molybdenum trioxide; molybdic acids or their salts such as molybdic acid, ammonium paramolybdate, and ammonium metamolybdate; molybdenum-containing heteropoly acids such as phosphomolybdic acid and silicomolybdic acid or their salts can be used.

[0103] As the raw material of the bismuth component, bismuth salts such as bismuth nitrate, bismuth carbonate, bismuth sulfate, bismuth acetate, and basic bismuth nitrate can be used; bismuth trioxide, metallic bismuth, etc. These raw materials can be used directly in a solid state or in the form of an aqueous solution, a nitric acid solution, or a slurry of a bismuth compound generated from these aqueous solutions. Preferably, a nitrate, or a solution thereof, or a slurry generated from a solution thereof is used.

[0104] As starting materials for other component elements, ammonium salts, nitrates, nitrites, carbonates, subcarbonates, acetates, chlorides, inorganic acids, salts of inorganic acids, heteropoly acids, salts of heteropoly acids, sulfates, hydroxides, organic acid salts, oxides or mixtures thereof of metal elements commonly used for such catalysts can be used in combination, with ammonium salts and nitrates being preferred.

[0105] These compounds containing active ingredients can be used alone or in combination of two or more. Slurry can be obtained by uniformly mixing various compounds containing active ingredients with water. The amount of water used in the slurry is not particularly limited as long as it can completely dissolve the entire amount of the used compound or the amount that can be uniformly mixed. Considering the drying method and drying conditions, the amount of water used can be appropriately determined. Generally, the amount of water used is 100 mass parts or more and 2000 mass parts or less relative to the total mass of 100 mass parts of the compound for preparing the slurry. When the amount of water is too much, not only can dry particles with a certain particle size or more not be obtained, but also the energy cost of the drying process becomes high, and there is also a situation where it cannot be completely dried, etc., and there are many disadvantages.

[0106] The slurry of the source compounds of the above-mentioned component elements is preferably prepared by the following methods: (a) a method of mixing the above-mentioned source compounds at once, (b) a method of mixing the above-mentioned source compounds at once and then subjecting them to aging treatment, (c) a method of mixing the above-mentioned source compounds in steps, (d) a method of repeatedly subjecting the above-mentioned source compounds to step-by-step mixing and aging treatment, and a method of combining (a) to (d). Here, the above-mentioned aging refers to "processing industrial raw materials or semi-finished products under specific conditions such as a certain time and a certain temperature to achieve the acquisition or improvement of the desired physical properties, chemical properties, or the progress of a specified reaction". It should be noted that in the present invention, the above-mentioned certain time refers to a range of more than 5 minutes and less than 24 hours, and the above-mentioned certain temperature refers to a range of more than room temperature and less than the boiling point of the aqueous solution or aqueous dispersion. Among them, from the perspective of the activity and yield of the catalyst finally obtained, the method (c) of mixing the above-mentioned supply source compounds step by step is preferred, and the method of preparing a solution by completely dissolving the raw materials mixed with the mother liquor step by step is further preferred, and the method of mixing various mixed solutions of alkali metal solutions and nitrates in the mother liquor prepared as a prepared solution or slurry of the molybdenum raw material is most preferred. However, it is not necessary to mix all the catalyst constituent elements in this step, and some of the elements or some of the amounts thereof may be added in the subsequent steps.

[0107] In the present invention, the shape of the stirring blade of the stirrer used when mixing the necessary active ingredients is not particularly limited, and any stirring blade such as a propeller blade, a turbine blade, a paddle blade, a pitched paddle blade, a spiral blade, an anchor blade, a belt blade, a large grille blade, etc. can be used, or two or more stages of the same blade or different types of blades can be used in the up and down directions. In addition, a baffle (dam) can be set in the reaction tank as needed.

[0108] Next, the slurry obtained in the above manner is dried. The drying method is not particularly limited as long as it is a method that can completely dry the slurry, and examples thereof include: drum drying, freeze drying, spray drying, evaporative drying, etc. Among them, in the present invention, spray drying that can dry the slurry into powder or granules in a short time is particularly preferred. The drying temperature of spray drying varies according to the concentration of the slurry, the liquid delivery rate, etc., and the temperature of the inlet air usually used in the drying is preferably above 200°C and below 300°C, and the temperature of the air at the outlet of the dryer is preferably above 70°C and below 150°C. In addition, the sprayer (atomizer) of the slurry in the spray drying is not limited as long as it is a method known to those skilled in the art, for example, a disc-type atomizer, a two-fluid atomizer, and an ultrasonic atomizer are preferred, and a disc-type atomizer is most preferred, and the disc rotation speed is 5000rpm to 30000rpm. In addition, it is preferred to dry so that the average particle size of the dried slurry (catalyst precursor) obtained at this time is 1μm to 1000μm. As one of the methods for achieving the non-uniform distribution of Bi in the present invention, a method of optimizing the preparation conditions and spraying conditions of the slurry can be exemplified.

[0109] For example, a particularly effective method is to optimize the rotation speed of the sprayer (atomizer) when spray drying is used. The rotation speed of the atomizer varies according to the composition of the catalyst precursor, preferably more than 10000rpm and less than 20000rpm. The upper limit of the more preferred atomizer rotation speed is 18000pm, particularly preferably 17000rpm, and most preferably 16000rpm. In addition, the lower limit of the more preferred atomizer rotation speed is 11000rpm, the particularly preferred lower limit is 12000rpm, and the most preferred lower limit is 13000rpm. That is, the range of the most preferred atomizer rotation speed is more than 13000rpm and less than 16000rpm.

[0110] By pre-calcining, molding and finally calcining the catalyst precursor obtained in the above manner, the molding shape can be controlled and maintained, and a catalyst having particularly excellent mechanical strength for industrial use can be obtained, and stable catalyst performance can be exhibited.

[0111] About molding, as mentioned above, any molding method in the load molding supported on carriers such as silica and non-load molding without carriers can be adopted. As a specific molding method, for example, tablet molding, compression molding, extrusion molding, granulation molding, etc. can be cited. As the shape of the molded product, for example, cylindrical, annular, spherical, etc. can be appropriately selected considering the operating conditions, and it can be a spherical carrier, especially on an inert carrier such as silica or alumina, a catalyst active component is loaded and preferably the average particle size is 1.0 mm or more and 15.0 mm or less, more preferably the average particle size is 2.0 mm or more and 10.0 mm or less, and particularly preferably the average particle size is 3.0 mm or more and 8.0 mm or less. The loaded catalyst. As a loading method, rotary granulation, a method using a centrifugal flow coating device, a wash coating method, etc. are well known, as long as the method that the pre-calcined powder can be uniformly loaded on the carrier is not particularly limited, and in the case of considering the manufacturing efficiency of the catalyst, the rotary granulation method is preferred. Specifically, the method is as follows: in a device having a flat or concave-convex disc at the bottom of a fixed cylindrical container, the disc is rotated at high speed, thereby utilizing the repeated rotation and revolution of the carrier itself to vigorously stir the carrier loaded in the container, and adding pre-calcined powder thereto, thereby loading the powder component on the carrier.

[0112] It should be noted that a binder is preferably used when loading. As specific examples of binders that can be used, water or ethanol, methanol, propanol, polyols, polyvinyl alcohol as a polymer binder, silica sol aqueous solution as an inorganic binder, etc., preferably ethanol, methanol, propanol, polyols, more preferably diols such as ethylene glycol, triols such as glycerol, etc., and further preferably an aqueous solution in which the concentration of glycerol is 5% by mass or more. By using an appropriate amount of glycerol aqueous solution, the moldability becomes good, and a catalyst with high mechanical strength and high performance can be obtained. Relative to 100 parts by mass of pre-calcined powder, the amount of these binders used is usually 2 parts by mass to 60 parts by mass, and in the case of glycerol aqueous solution, it is preferably 15 parts by mass to 50 parts by mass. When loaded, the binder and the pre-calcined powder can be alternately supplied to the molding machine, or they can be supplied to the molding machine at the same time. In addition, during molding, a small amount of known additives such as graphite, talc, etc. can be added. It should be noted that, regardless of whether or not there is activity in the sense of converting the raw materials into some other products, the molding aids, pore formers, and carriers added during molding are not considered as constituent elements of the active ingredients in the present invention.

[0113] There is no particular restriction on the pre-calcination method, pre-calcination conditions or formal calcination method, formal calcination conditions, and known treatment methods and conditions can be applied. Pre-calcination and formal calcination are usually carried out for more than 0.5 hours, preferably more than 1 hour and less than 40 hours, under the circulation of oxygen-containing gas such as air or the circulation of inert gas at 150°C or above and 600°C or below, preferably at 200°C or above and 550°C or below. Here, the inert gas refers to a gas that does not reduce the reaction activity of the catalyst, specifically, nitrogen, carbon dioxide, helium, argon, etc. It should be noted that according to the reaction conditions when using the catalyst to manufacture unsaturated aldehydes and / or unsaturated carboxylic acids, conjugated dienes, etc., especially the optimal conditions in the formal calcination, the process parameters of the formal calcination process, i.e., the oxygen content in the atmosphere, the maximum reached temperature, the calcination time, etc. are changed, which is well known to those skilled in the art, and therefore falls within the scope of the invention of this application. In addition, the main calcination step is implemented after the above-mentioned pre-calcination step, and the highest temperature reached in the main calcination step (main calcination temperature) is higher than the highest temperature reached in the above-mentioned pre-calcination step (pre-calcination temperature). The calcination method is not particularly limited to a fluidized bed, a rotary kiln, a muffle furnace, a tunnel calcination furnace, etc., and an appropriate range should be selected in consideration of the performance, mechanical strength, formability, production efficiency, etc. of the final catalyst.

[0114] The catalyst of the present invention is preferably used as a catalyst for producing unsaturated aldehyde compounds, unsaturated carboxylic acid compounds and conjugated dienes, more preferably as a first-stage catalyst for producing unsaturated aldehyde compounds, and particularly preferably as a catalyst for producing acrolein from propylene.

[0115] [About the catalyst in the second paragraph]

[0116] When the catalyst of the present invention is used as a catalyst for producing an unsaturated aldehyde compound, the second-stage oxidation reaction can be performed to obtain an unsaturated carboxylic acid compound.

[0117] In this case, as the catalyst of the second stage, the catalyst of the present invention can be used, and preferably a catalyst containing a catalytically active component represented by the following formula (3).

[0118] Mo 12 V a2 W b2 Cu c2 Sb d2 X e2 Y f2 Z g2 O h2 (3)

[0119] (In the formula, Mo, V, W, Cu, Sb and O represent molybdenum, vanadium, tungsten, copper, antimony and oxygen, respectively, X represents at least one element selected from the group consisting of alkali metals and thallium, Y represents at least one element selected from the group consisting of magnesium, calcium, strontium, barium and zinc, and Z represents at least one element selected from the group consisting of niobium, cerium, tin, chromium, manganese, iron, cobalt, samarium, germanium, titanium and arsenic. In addition, a2, b2, c2, d2, e2, f2, g2 and h2 represent the atomic ratio of each element. Relative to 12 molybdenum atoms, a2 represents 0<a2≤10, b2 represents 0≤b2≤10, c2 represents 0<c2≤6, d2 represents 0<d2≤10, e2 represents 0≤e2≤0.5, f2 represents 0≤f2≤1, and g2 represents 0≤g2<6. In addition, h2 is the number of oxygen atoms required to satisfy the valence of the above-mentioned components).

[0120] When manufacturing a catalyst containing a catalytically active component represented by the above formula (3), a method generally known as a method for preparing such a catalyst, such as an oxide catalyst, a catalyst having a structure of a heteropolyacid or a salt thereof can be used. There is no particular restriction on the raw materials that can be used when manufacturing the catalyst, and various raw materials can be used. For example, molybdenum oxides such as molybdenum trioxide; molybdic acids such as molybdic acid and ammonium molybdate or their salts; molybdenum-containing heteropolyacids such as phosphomolybdic acid and silicomolybdic acid or their salts, etc. can be used. As the raw material of the antimony component, there is no particular restriction, preferably antimony trioxide or antimony acetate. As raw materials for other elements such as vanadium, tungsten, and copper, respective nitrates, sulfates, carbonates, phosphates, organic acid salts, halides, hydroxides, oxides, metals, etc. can be used.

[0121] These compounds containing active ingredients may be used alone or in combination of two or more.

[0122] Next, the slurry obtained above is dried to prepare a solid catalyst active component. The drying method is not particularly limited as long as the slurry can be completely dried. For example, drum drying, freeze drying, spray drying, evaporative drying, etc. are listed. Preferably, the slurry can be dried into powder or granules in a short time by spray drying. The drying temperature of spray drying varies according to the concentration of the slurry, the liquid delivery speed, etc., and the temperature at the outlet of the dryer is usually 70°C to 150°C. In addition, it is preferred to dry so that the average particle size of the dried slurry obtained at this time is 1μm to 1000μm.

[0123] The solid of the catalyst active component of the second stage obtained in the above manner can be directly used for the coating mixture, but if calcined, the moldability is sometimes improved, which is preferred. There are no particular restrictions on the calcination method and calcination conditions, and known treatment methods and conditions can be applied. The optimal conditions for calcination vary depending on the catalyst raw materials, catalyst composition, preparation method, etc. used. The calcination temperature is usually 100°C to 350°C, preferably 150°C to 300°C, and the calcination time is 1 hour to 20 hours. It should be noted that calcination is usually carried out in an air atmosphere, but it can also be carried out in an inert gas atmosphere such as nitrogen, carbon dioxide, helium, argon, etc., and it can also be calcined in an inert gas atmosphere and then further calcined in an air atmosphere as needed. The calcined solid obtained in this way is preferably crushed before molding. As a crushing method, there is no particular restriction, and a ball mill can be used.

[0124] In addition, the compound containing the active ingredient when preparing the second-stage slurry does not necessarily need to contain all the active ingredients, and a part of the ingredients may be used before the molding step described below.

[0125] The shape of the catalyst of the above-mentioned second section is not particularly limited. In order to reduce the pressure loss of the reaction gas in the oxidation reaction, it is formed into a columnar object, a small piece, a ring, a sphere, etc. and used. Among them, from the aspect of being able to expect to improve selectivity and remove the heat of reaction, it is particularly preferred to load the catalyst active component solid on an inert carrier and make a loaded catalyst. The load is preferably the rotary granulation method described below. The method is, for example, the following method: in a device having a flat or concave-convex disc at the bottom in a fixed container, the disc is rotated at a high speed, thereby utilizing repeated rotation and revolution motion to violently stir the carrier in the container, add a binder and a catalyst active component solid, and add other additives, such as a molding aid, a strength enhancer, thereto as needed to obtain a loaded mixture, and the loaded mixture is loaded on the carrier. The binder can be added by any of the following methods: 1) premixed in the above-mentioned loading mixture; 2) added while adding the loading mixture to the fixed container; 3) added after adding the loading mixture to the fixed container; 4) added before adding the loading mixture to the fixed container; 5) adding the loading mixture and the binder in batches and appropriately combining the methods 2) to 4) to add the entire amount; etc. Among them, in 5), it is preferred to adjust the addition speed using an automatic feeder or the like so that a predetermined amount of the loading mixture is loaded on the carrier without causing, for example, the loading mixture to adhere to the wall of the fixed container or the loading mixture to agglomerate with each other.

[0126] As the binder, water or ethanol, polyol, polyvinyl alcohol as a polymer binder, crystalline cellulose, methyl cellulose, ethyl cellulose and other celluloses, silica sol aqueous solution as an inorganic binder, etc., preferably monohydric alcohols such as ethanol, dihydric alcohols such as ethylene glycol, trihydric alcohols such as glycerol, celluloses and other polyhydric alcohols, particularly preferably using an aqueous solution of a trihydric alcohol or less at a concentration of 5% by weight or more. Relative to 100 parts by weight of the load mixture, the amount of these binders used is usually 2 parts by weight to 60 parts by weight, preferably 10 parts by weight to 50 parts by weight.

[0127] As specific examples of the carrier in the above-mentioned load, there can be cited: spherical carriers with a diameter of 1mm to 15mm, preferably 2mm to 10mm, such as silicon carbide, alumina, silica-alumina, mullite, and alundum. For these carriers, a carrier with a porosity of 10% to 70% is generally used. Regarding the ratio of the carrier to the mixture for loading, the amount of the loading mixture / (loading mixture + carrier) = 10% to 75% by mass, preferably 15% to 60% by mass, is generally used. In the case where the proportion of the loading mixture is large, although the reaction activity of the loaded catalyst increases, there is a tendency for the mechanical strength to decrease. On the contrary, in the case where the proportion of the loading mixture is small, although the mechanical strength is large, there is a tendency for the reaction activity to decrease. It should be noted that, in the above, as a molding aid used as needed, there can be cited: silica gel, diatomaceous earth, alumina powder, etc. Relative to 100 parts by mass of the catalyst active component solid, the amount of the molding aid used is generally 1 part by mass to 60 parts by mass. In addition, inorganic fibers (e.g., ceramic fibers or whiskers, etc.) that are inert to the catalyst active component solid and the reaction gas are further used as strength reinforcing agents as needed, which are useful for improving the mechanical strength of the catalyst, preferably glass fibers. The amount of these fibers used is usually 1 to 30 parts by mass relative to 100 parts by mass of the catalyst active component solid. It should be noted that in the molding of the catalyst in the first section, regardless of whether there is activity in the sense of converting the raw material into some other product, the added molding aids, pore formers, and carriers are not considered as constituent elements of the active component in the present invention.

[0128] The supported catalyst obtained in the above manner can be directly used as a catalyst for gas-phase catalytic oxidation reaction, but if calcined, the catalyst activity is sometimes improved, which is preferred. There is no particular restriction on the calcination method and calcination conditions, and known treatment methods and conditions can be applied. The optimal conditions for calcination vary depending on the catalyst raw material, catalyst composition, preparation method, etc. used. The calcination temperature is usually 100°C to 450°C, preferably 270°C to 420°C, and the calcination time is 1 hour to 20 hours. It should be noted that calcination is usually carried out in an air atmosphere, but it can also be carried out in an inert gas atmosphere such as nitrogen, carbon dioxide, helium, argon, etc., and it can also be calcined in an inert gas atmosphere and then further calcined in an air atmosphere as needed.

[0129] When the catalyst of the present invention is used in the reaction of producing corresponding unsaturated aldehydes, unsaturated carboxylic acids, and conjugated dienes using propylene, isobutylene, tert-butyl alcohol, butene, etc. as raw materials, especially in the case of producing acrolein and acrylic acid by gas-phase catalytic oxidation of propylene using molecular oxygen or a gas containing molecular oxygen, the catalyst activity and yield can be improved, which is very effective in improving the price competitiveness of the product compared with the known methods. In addition, the effect of improving the process stability of the exothermic partial oxidation reaction, such as the reduction of the hot spot temperature, can also be expected. In addition, the catalyst of the present invention is also effective in reducing byproducts that have adverse effects on the environment and the quality of the final product, such as carbon monoxide (CO), carbon dioxide (CO2), acetaldehyde, acetic acid, and formaldehyde.

[0130] In the method for producing acrolein and / or acrylic acid of the present invention, the circulation method of the raw material gas may be a conventional one-way circulation method or a circulation method, and may be implemented under commonly used conditions without particular limitation. For example, a mixed gas containing 1% to 10% by volume, preferably 4% to 9% by volume of propylene at room temperature as a starting raw material; 3% to 20% by volume, preferably 4% to 18% by volume of molecular oxygen; 0% to 60% by volume, preferably 4% to 50% by volume of water vapor; 20% to 80% by volume, preferably 30% to 60% by volume of inert gases such as carbon dioxide and nitrogen is heated at 250°C to 450°C and at a pressure of normal pressure to 10 atmospheres for 300 hours. -1 ~5000 hours -1 The reaction is carried out by introducing the catalyst of the present invention into the reaction tube at a space velocity of .

[0131] In the present invention, unless otherwise specified, an improvement in catalyst activity means that the raw material conversion rate is high when the catalytic reaction is carried out at the same reaction bath temperature and compared.

[0132] In the present invention, unless otherwise specified, high yield means that when propylene, isobutylene, tert-butyl alcohol, butene, etc. are used as raw materials for oxidation reaction, the total yield of the corresponding unsaturated aldehyde and / or unsaturated carboxylic acid and conjugated diene is high.

[0133] In the present invention, unless otherwise specified, the constituent elements of the catalyst active component refer to all elements used in the above-mentioned catalyst manufacturing process, but the raw materials and their constituent elements that disappear, sublimate, volatilize, or burn at a temperature below the highest temperature of the main calcination process are not included in the constituent elements of the catalyst active component. In addition, silicon contained in the molding aid and the carrier in the molding process and elements constituting other inorganic materials are also not included in the constituent elements of the catalyst active component.

[0134] In the present invention, the hot spot temperature refers to the highest temperature of the temperature distribution in the catalyst packing layer measured by setting a thermocouple in the long axis direction in the multi-tubular reaction tube, and the reaction bath temperature refers to the set temperature of the heat medium used to cool the heat released by the reaction tube. There is no particular restriction on the number of points for measuring the above temperature distribution, for example, the catalyst packing length is evenly divided into 10 to 1000 points.

[0135] In the present invention, unsaturated aldehydes and unsaturated aldehyde compounds refer to organic compounds having at least one double bond and at least one aldehyde group in the molecule, such as acrolein and methacrolein. In the present invention, unsaturated carboxylic acids and unsaturated carboxylic acid compounds refer to organic compounds having at least one double bond and at least one carboxyl group or its ester group in the molecule, such as acrylic acid, methacrylic acid, and methyl methacrylate.

[0136] [Example]

[0137] Hereinafter, although specific examples are given to explain the embodiments, the present invention is not limited to the embodiments unless it deviates from the gist of the invention.

[0138] [Catalyst Preparation Example 1]

[0139] 800 parts by weight of ammonium heptamolybdate tetrahydrate are completely dissolved in 3040 parts by weight of pure water heated to 60°C. Next, 5.59 parts by weight of potassium nitrate are dissolved in 55 mL of pure water and added to the above solution. Next, 274.6 parts by weight of iron nitrate nonahydrate, 571.5 parts by weight of cobalt nitrate hexahydrate and 307.4 parts by weight of nickel nitrate hexahydrate are dissolved in 611 mL of pure water heated to 60°C. These solutions are slowly mixed while stirring. Next, 311.4 parts by weight of bismuth nitrate are added to the nitric acid aqueous solution obtained by adding 79.3 parts by weight of nitric acid (60% by weight) to 330 mL of pure water, and the solution obtained by completely dissolving it is added to the above solution and stirred and mixed. The slurry is dried by disc spray drying, and the obtained dry powder is pre-calcined in a manner that is maintained at a maximum temperature of 440°C for 4 hours. 5 wt% of crystalline cellulose was added to the pre-calcined powder, mixed thoroughly, and then loaded on a 4.5 mm inert spherical carrier at a loading rate of 50 wt% using a rotary granulation method using a 30 wt% glycerol solution as a binder. Then, calcination was performed at a maximum temperature of 530°C for 4 hours to obtain a spherical catalyst A with an average particle size of 5.2 mm. The catalyst active component calculated from the input raw materials was a composite metal oxide having the following atomic ratio.

[0140] Mo: Bi: Fe: Co: Ni: K=12: 1.7: 2.0: 5.2: 2.8: 0.15

[0141] In addition, the drying conditions of spray drying are as follows.

[0142] Atomizer speed: 14000rpm

[0143] Raw material supply: 14kg / hour

[0144] [Catalyst Preparation Example 2]

[0145] 800 parts by weight of ammonium heptamolybdate tetrahydrate are completely dissolved in 3040 parts by weight of pure water heated to 60°C. Next, 11.0 parts by weight of cesium nitrate are dissolved in 100 mL of pure water and added to the above solution. Next, 259.3 parts by weight of iron nitrate nonahydrate, 791.3 parts by weight of cobalt nitrate hexahydrate and 109.8 parts by weight of nickel nitrate hexahydrate are dissolved in 615 mL of pure water heated to 60°C. These solutions are slowly mixed while stirring. Next, 311.4 parts by weight of bismuth nitrate are added to the nitric acid aqueous solution obtained by adding 79.3 parts by weight of nitric acid (60% by weight) to 330 mL of pure water, and the solution obtained by completely dissolving it is added to the above solution and stirred and mixed. The slurry is dried by disc spray drying, and the obtained dry powder is pre-calcined in a manner that is maintained at a maximum temperature of 440°C for 4 hours. 5 wt% of crystalline cellulose was added to the pre-calcined powder, mixed thoroughly, and then loaded on a 4.0 mm inert spherical carrier at a loading rate of 40 wt% using a rotary granulation method using a 30 wt% glycerol solution as a binder. Then, calcination was performed at a maximum temperature of 520°C for 4 hours to obtain a spherical catalyst B with an average particle size of 4.4 mm. The catalyst active component calculated from the input raw materials was a composite metal oxide having the following atomic ratio.

[0146] Mo:Bi:Fe:Co:Ni:Cs=12:1.7:1.7:7.2:1.0:0.15

[0147] In addition, the drying conditions of spray drying are as follows.

[0148] Atomizer speed: 14000rpm

[0149] Raw material supply: 14kg / hour

[0150] [Catalyst Preparation Example 3]

[0151] 800 parts by weight of ammonium heptamolybdate tetrahydrate are completely dissolved in 3040 parts by weight of pure water heated to 60°C. Next, 11.0 parts by weight of cesium nitrate are dissolved in 100 mL of pure water and added to the above solution. Next, 259.3 parts by weight of iron nitrate nonahydrate, 769.3 parts by weight of cobalt nitrate hexahydrate and 109.8 parts by weight of nickel nitrate hexahydrate are dissolved in 615 mL of pure water heated to 60°C. These solutions are slowly mixed while stirring. Next, 274.8 parts by weight of bismuth nitrate are added to the nitric acid aqueous solution obtained by adding 70.0 parts by weight of nitric acid (60% by weight) to 300 mL of pure water, and the solution obtained by completely dissolving it is added to the above solution and stirred and mixed. The slurry is dried by disc spray drying, and the obtained dry powder is pre-calcined in a manner that is maintained at a maximum temperature of 440°C for 4 hours. 5 wt% of crystalline cellulose was added to the pre-calcined powder, mixed thoroughly, and then loaded on a 3.8 mm inert spherical carrier at a loading rate of 50 wt% using a rotary granulation method using a 30 wt% glycerol solution as a binder. Then, calcination was performed at a maximum temperature of 520°C for 4 hours to obtain a spherical catalyst C with an average particle size of 4.5 mm. The catalyst active component calculated from the input raw materials was a composite metal oxide having the following atomic ratio.

[0152] Mo: Bi: Fe: Co: Ni: Cs=12: 1.5: 1.7: 7.0: 1.0: 0.15

[0153] In addition, the drying conditions of spray drying are as follows.

[0154] Atomizer speed: 11000rpm

[0155] Raw material supply: 14kg / hour

[0156] [Catalyst Preparation Example 4]

[0157] 800 parts by weight of ammonium heptamolybdate tetrahydrate are completely dissolved in 3040 parts by weight of pure water heated to 60°C. Next, 3.68 parts by weight of cesium nitrate are dissolved in 33 mL of pure water and added to the above solution. Next, 305.1 parts by weight of iron nitrate nonahydrate, 714.4 parts by weight of cobalt nitrate hexahydrate and 274.5 parts by weight of nickel nitrate hexahydrate are dissolved in 686 mL of pure water heated to 60°C. These solutions are slowly mixed while stirring. Next, 183.2 parts by weight of bismuth nitrate are added to the nitric acid aqueous solution obtained by adding 46.6 parts by weight of nitric acid (60% by weight) to 194 mL of pure water, and the solution obtained by completely dissolving it is added to the above solution and stirred and mixed. The slurry is dried by disc spray drying, and the obtained dry powder is pre-calcined in a manner that is maintained at a maximum temperature of 440°C for 4 hours. 5 wt% of crystalline cellulose was added to the pre-calcined powder, mixed thoroughly, and then loaded on a 3.8 mm inert spherical carrier at a loading rate of 50 wt% using a rotary granulation method using a 30 wt% glycerol solution as a binder. Then, calcination was performed at a maximum temperature of 540°C for 4 hours to obtain a spherical catalyst D with an average particle size of 4.5 mm. The catalyst active component calculated from the input raw materials was a composite metal oxide having the following atomic ratio.

[0158] Mo:Bi:Fe:Co:Ni:Cs=12:1.0:2.0:6.5:2.5:0.05

[0159] In addition, the drying conditions of spray drying are as follows.

[0160] Atomizer speed: 11000rpm

[0161] Raw material supply: 14kg / hour

[0162] [Catalyst Preparation Example 5]

[0163] Catalyst E was obtained by preparing in the same manner as Catalyst A except that spray drying was performed using a two-fluid nozzle.

[0164] In addition, the drying conditions using the two-fluid nozzle are as follows.

[0165] Raw material supply: 5.0kg / hour

[0166] Atomizing air supply: 46Nm 3 / Hour

[0167] Pressure: 0.3MPa

[0168] [Example 1]

[0169] (Propylene oxidation reaction test)

[0170] A stainless steel reactor with an inner diameter of 28.4 mm and a jacket for flowing alumina powder as a heat medium with air and a thermocouple for measuring the temperature of the catalyst layer was filled with 35 mL of catalyst A, and the reaction bath temperature was set to 320° C. Here, the supply amount of propylene, air, and water was set so that the raw material molar ratio was propylene: oxygen: nitrogen: water = 1: 2.0: 10.8: 1.5, and the reaction was continued for 2110 hours. -1 The catalyst was introduced into the oxidation reactor at a space velocity of 1.50 g / cm2, and the reactor outlet pressure was set to 0 kPaG. The catalyst performance was evaluated 20 hours after the reaction started. Then, the reaction bath temperature was set to 330°C, and the catalyst performance was evaluated again 24 hours after the reaction started. The effective yield was 67.1% when the feed conversion rate was 70%, and the heat release in the reactor (the value obtained by subtracting the reaction bath temperature from the hot spot temperature) was 82°C (Table 1).

[0171] [Comparative Example 1]

[0172] The catalyst performance was evaluated in the same manner as in Example 1 except that the molded catalyst E was used. The effective yield was 66.7% when the raw material conversion rate was 70%, and the heat release in the reactor was 88°C (Table 1).

[0173] [Example 2]

[0174] (Isobutylene oxidation reaction test)

[0175] 35 mL of the molded catalyst B was placed in a stainless steel reactor with an inner diameter of 22 mm and provided with a jacket for flowing alumina powder as a heat medium with air and a thermocouple for measuring the temperature of the catalyst layer on the tube axis, and the reaction bath temperature was set to 350° C. Here, the supply amounts of isobutylene, air, water, and nitrogen were set so that the raw material molar ratio was isobutylene: oxygen: nitrogen: water = 1:2.2:12.5:1.0, and the reaction was continued for 1200 hours. -1 The space velocity was introduced into the oxidation reactor, and the reactor inlet pressure was set to 0.05 MPaG. The catalyst performance was evaluated 20 hours after the reaction started. The feed conversion rate was 99.3%, and the effective yield was 82.7%. The heat release in the reactor was 61°C (Table 1).

[0176] [Example 3]

[0177] (1-Butene Oxidative Dehydrogenation Reaction Test)

[0178] A stainless steel reactor with an inner diameter of 28.4 mm and a jacket for flowing alumina powder as a heat medium with air and a thermocouple for measuring the temperature of the catalyst layer was filled with 53 mL of the molded catalyst C, and the reaction bath temperature was set to 340° C. Here, the supply amount of 1-butene, air, water, and nitrogen was set so that the raw material molar ratio was 1-butene: oxygen: nitrogen: water = 1:1:7:1, and the reaction was continued for 1440 hours. -1 The space velocity was introduced into the oxidation reactor, and the reactor outlet pressure was set to 0 kPaG. The catalyst performance was evaluated 15 hours after the reaction started. The feed conversion rate was 93.4%, and the effective yield was 81.5%. The heat release in the reactor was 46°C (Table 1).

[0179] [Example 4]

[0180] The catalyst performance was evaluated in the same manner as in Example 3 except that molded catalyst D was used and the reaction bath temperature was set to 320° C. The feed conversion was 96.1%, the effective yield was 80.6%, and the heat release in the reactor was 83° C. (Table 1).

[0181] <About the method of measuring the uneven distribution of Bi (1)>

[0182] The measurement (1) of the non-uniform distribution of Bi of each dry particle for catalyst production was performed as follows.

[0183] I) The dried particles for production of each catalyst were observed using SEM at the following magnifications.

[0184] Catalyst A: 4500 times

[0185] Catalyst B: 3300 times

[0186] Catalyst C: 3200 times

[0187] Catalyst D: 4100 times

[0188] Catalyst E: 7200 times

[0189] Figure 3 , Figure 5 , Figure 7 and Fig. 9 : are SEM images of dry particles used for production corresponding to Catalyst A, Catalyst B, Catalyst C and Catalyst E, respectively.

[0190] II) The SEM image saved in the bitmap format was opened using the photo software manufactured by Microsoft, and the editing operation of setting the light to -80 was repeated 3 times. The image obtained by the above operation was opened again using the paint software manufactured by Microsoft, and saved in the form of a monotone image (monochrome bitmap), thereby binarizing it into a black and white image. Figure 4 , Figure 6 , Figure 8 and Fig.10 3 and 4 are binarized SEM images of dry particles for production corresponding to Catalyst A, Catalyst B, Catalyst C, and Catalyst E, respectively.

[0191] III) EDS measurement was performed at 10 points on the surface of the dry particles corresponding to the white and black parts of the binarized image, and the average value of the Bi concentration (%) was calculated. The average values ​​of the Bi concentration in the white and black parts are shown in Table 1. In addition, the standard deviation σ1 of the Bi concentration in the black part was calculated. The results are shown in Table 1.

[0192] <About the method of measuring the uneven distribution of Bi (2)>

[0193] I) SEM images were obtained using the same method as in (1) above.

[0194] II) Lines were drawn vertically, horizontally, and obliquely on the dry particles in the SEM image, and EDS measurements were performed on multiple points on the lines under the following conditions to determine the average value of the Bi concentration (%) at each point. The results are shown in Table 1. In addition, the standard deviation σ2 of the Bi concentration at each point was determined. The results are shown in Table 1.

[0195] Pixel Time: 200ms

[0196] Number of data points per line: 32 points

[0197] Repeated measurement times for each point: 3 times

[0198] Table 1

[0199]

[0200] From the results in Table 1, it was confirmed that when acrolein was produced by oxidation reaction of propylene, Example 1, in which the Bi concentration of the white part measured by EDS was greater than the value obtained by adding the Bi concentration of the black part to 2.5 times the standard deviation σ1 of the Bi concentration of the black part (4.84+2.08), had a high yield and a low heat release. On the other hand, Comparative Example 1, in which the Bi concentration of the white part was less than or equal to the value obtained by adding the Bi concentration of the black part to 2.5 times the standard deviation σ1 of the Bi concentration of the black part (7.55+1.38), had a poor yield and a large heat release.

[0201] In Example 1, the standard deviation σ2 of the Bi concentration obtained by line analysis was 0.4 or more, whereas in Comparative Example 1, the standard deviation σ2 of the Bi concentration obtained by line analysis was less than 0.4.

[0202] Similarly, when methacrolein was produced by oxidation reaction of isobutylene (Example 2) and butadiene was produced by oxidative dehydrogenation reaction of 1-butene (Examples 3 and 4), high yield and low heat release were also confirmed for the catalyst in which the non-uniform distribution of Bi was confirmed. It should be noted that the heat release is the difference between the maximum temperature in the reaction tube observed by a thermocouple and the reaction bath temperature.

[0203] While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention.

[0204] It should be noted that this application is based on Japanese patent application (Japanese patent application No. 2019-065495) filed on March 29, 2019, the entire contents of which are cited by reference. In addition, all references cited are incorporated in their entirety into this application.

[0205] Industrial Applicability

[0206] By using the catalyst of the present invention, in the case of oxidation manufacturing unsaturated aldehyde compound, unsaturated carboxylic acid compound or conjugated diene compound, the above-mentioned compound can be obtained with high yield. In addition, because the temperature of hot spot (exothermic position in catalyst layer) is low, the life of catalyst is extended, so the target product can be stably manufactured for a long time.

Claims

1. A catalyst, wherein In a SEM image of the catalyst obtained using a scanning electron microscope (SEM), with the acceleration voltage set to 15 kV and at a magnification such that the maximum longitudinal length of one particle in the SEM image occupies 90% or more of the longitudinal length of the SEM image and the maximum lateral length of one particle in the SEM image occupies 90% or more of the lateral length of the SEM image, When the SEM image is binarized into a black-and-white image, the bismuth (Bi) concentration of the white portion is greater than the value obtained by adding 2.5 times the standard deviation σ1 of the Bi concentration of the black portion to the Bi concentration of the black portion.

2. A catalyst, wherein In a SEM image of the catalyst obtained using a scanning electron microscope (SEM), with the acceleration voltage set to 15 kV and at a magnification such that the maximum longitudinal length of one particle in the SEM image occupies 90% or more of the longitudinal length of the SEM image and the maximum lateral length of one particle in the SEM image occupies 90% or more of the lateral length of the SEM image, When arbitrarily 10 straight lines are set on the catalyst in the SEM image, the standard deviation σ2 of the Bi (bismuth) concentration on the catalyst surface corresponding to the straight lines is 0.4 or more.

3. A dry particle for catalyst production, wherein: In an SEM image of dry particles obtained using a scanning electron microscope (SEM), with the acceleration voltage set to 15 kV and at a magnification such that the maximum longitudinal length of one particle in the SEM image occupies 90% or more of the longitudinal length of the SEM image and the maximum lateral length of one particle in the SEM image occupies 90% or more of the lateral length of the SEM image, When the SEM image is binarized into a black-and-white image, the bismuth (Bi) concentration of the white portion is greater than the value obtained by adding 2.5 times the standard deviation σ1 of the Bi concentration of the black portion to the Bi concentration of the black portion.

4. A dry particle for catalyst production, wherein: In an SEM image of dry particles obtained using a scanning electron microscope (SEM), with the acceleration voltage set to 15 kV and at a magnification such that the maximum longitudinal length of one particle in the SEM image occupies 90% or more of the longitudinal length of the SEM image and the maximum lateral length of one particle in the SEM image occupies 90% or more of the lateral length of the SEM image, When 10 arbitrary straight lines are set on the dry particles in the SEM image, the standard deviation σ2 of the Bi (bismuth) concentration on the surface of the dry particles corresponding to the straight lines is 0.4 or more.

5. A catalyst, wherein The catalyst is produced from the dry particles for producing the catalyst according to claim 3 or 4.

6. The catalyst according to any one of claims 1 and 2, wherein The composition of the catalyst active component is represented by the following formula (1): Mo a1 Bi b1 Ni c1 Co d1 Feb e1 X f1 Y g1 Z h1 O i1 ……(1) In formula (1), Mo, Bi, Ni, Co and Fe represent molybdenum, bismuth, nickel, cobalt and iron, respectively; X represents at least one element selected from tungsten, antimony, tin, zinc, chromium, manganese, magnesium, silicon, aluminum, cerium and titanium; Y represents at least one element selected from sodium, potassium, cesium, rubidium and thallium; and Z represents at least one element selected from Groups 1 to 16 of the periodic table and selected from elements other than Mo, Bi, Ni, Co, Fe, X and Y. at least one element, a1, b1, c1, d1, e1, f1, g1, h1 and i1 represent the atomic number of molybdenum, bismuth, nickel, cobalt, iron, X, Y, Z and oxygen respectively, when a1=12, 0<b1≤7, 0≤c1≤10, 0<d1≤10, 0<c1+d1≤20, 0≤e1≤5, 0≤f1≤2, 0≤g1≤3, 0≤h1≤5, and i1=a value determined by the oxidation state of each element.

7. The catalyst according to claim 6, wherein In the formula (1), c1, b1 and d1 satisfy the following formula (2): 0.300≤c1 / (b1+d1)≤0.600 (2).

8. The catalyst according to any one of claims 1 and 2, wherein The catalyst is a catalyst in which a catalyst active component is supported on an inert carrier.

9. The catalyst according to claim 6, wherein The catalyst is a catalyst in which a catalyst active component is supported on an inert carrier.

10. The catalyst according to claim 6, wherein The catalyst is a catalyst for producing an unsaturated aldehyde compound and / or an unsaturated carboxylic acid compound.

11. A method for producing an unsaturated aldehyde compound and / or an unsaturated carboxylic acid compound, wherein: The production method uses the catalyst according to claim 6.

12. The manufacturing method according to claim 11, wherein: The unsaturated aldehyde compound is acrolein, and the unsaturated carboxylic acid compound is acrylic acid.

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