JPS58140056A - Ammoxidation process - Google Patents

Abstract

PURPOSE:To prevent the lowering of the selectivity and the reaction rate of the objective compound with time in the ammoxidation process using a metallic oxide catalyst free from tellurium, by using the catalyst in contact with metallic tellurium or a tellurium compound and a molybdenum compound. CONSTITUTION:In the ammoxidation of an organic compound using a metallic oxide catalyst essentially free from tellurium, especially a metallic oxide catalyst containing an element selected from Sb, Mo and V, at 300-600 deg.C, metallic tellurium or a tellurium compound and a molybdenum compound are used as an activity-improving agent in an amount of >=0.01wt% based on the catalyst in the state of being contacted with said catalyst (i.e. physical mixing in dry state). It is effective to improve the activity by using a fluidized bed catalyst and reacting under fluidized state. The cativity-improving agent may be mixed with the catalyst before reaction, or adding to the reaction system separately or as a mixture with the calalyst.

Description

[Detailed description of the invention]

The present invention relates to an improvement in the ammoxidation process for shoulder compounds, and more particularly to an improvement in the ammoxidation process using a metal oxide catalyst that is substantially free of tellurium. There are many examples of ammoxidation reactions of organic compounds (although many examples are known, here, the organic compounds targeted for the reaction using a metal oxide catalyst at a temperature of 300C to 600C include olefinic hydrocarbons, alcohols, Examples include aldehydes, alkyl-substituted aromatic hydrocarbons, nitrogen, oxygen, sulfur, etc. as metal oxide catalysts, metal oxide catalysts containing molybdenum, bismuth, etc., antimony and tin, iron, or uranium. Japanese Patent Publication No. 36-5870 discloses that a metal oxide catalyst containing
Special Publication No. 37-1475, Special Publication No. 39-19111
Publication No. 37-13460, Special Publication No. 13460-
24367, JP 49-58100, JP 51-10200, JP 51-33888
This is described in Japanese Patent Publication No. 53-18014, etc. It is stated in Japanese Patent Publication No. 35-15689 and Japanese Patent Application Laid-Open No. 13378-1987 that metal oxide catalysts containing vanadium are useful for ammoxidation of alkyl-substituted aromatic hydrocarbons and alkyl-substituted heterocyclic compounds. It is being In the ammoxidation of these organic compounds, a decrease in activity is often observed after long-term reaction use, although the degree varies depending on the type of catalyst or conditions of use. There are various causes for this, and countermeasures are being considered from various angles. However, in each case, the cause is not necessarily clear, and countermeasures include changing the reaction conditions, partially or completely replacing the catalyst, or removing the deteriorated catalyst from the reactor and regenerating it. However, only complicated and economically costly methods have been proposed. It would be very advantageous if the catalyst performance could be restored while the reaction was progressing. As a result of various studies in this direction, the inventors of the present invention discovered that
No. 6-159703, they proposed an ammoxidation method in which the activity was improved by physically dry-mixing a tellurium-containing solid with a metal oxide catalyst that does not substantially contain tellurium. This method is convenient when carried out in a fluidized bed reaction because it can be carried out during the reaction. It's effective, but it's rarely effective. Therefore, a situation may occur in which the amount of packed catalyst f must be gradually increased in order to obtain a desired reaction rate. In this respect, this proposal was still unsatisfactory. The present invention aims to provide a solution to the above points for ammoxidation using metal oxide catalysts that do not substantially contain tellurium, and aims to solve the above-mentioned problems by using a metal oxide catalyst that is substantially free of tellurium and molybdenum. The objective is to be achieved by bringing the components into contact with the catalyst. Therefore, the ammonia-brewing method according to the present invention is a method of carrying out ammoxidation of an organic compound at a temperature of 300C to 600C using a metal oxide catalyst that does not substantially contain tellurium. In a particularly preferred embodiment of the present invention, the catalyst is and a tellurium-containing solid and a molybdenum-containing solid, or the catalyst and a tellurium-containing solid.
Either physical dry mixtures with molybdenum-containing solids are used. According to the invention, the target product selectivity of the metal oxide catalyst,
It is also possible to improve the reaction rate, reduce the temporal decline in salmon production, or restore the desired product selectivity and reaction rate of a degraded catalyst. And, although the process of the invention can be applied to both fixed and fluidized beds, it is particularly easy to apply when catalysts are used in fluidized bed reactions. (a) Tellurium alone or a tellurium compound and (b) a molybdenum compound are solid and have appropriate physical properties (
(described later), it can be easily added during the reaction. In a fluidized bed reaction, it is easy to remove a portion of the catalyst or add the catalyst while the reaction is being carried out. This can be done continuously or intermittently,
It is easy to operate and is routinely used industrially. Therefore, the catalyst activity improver according to the present invention and t
Even when using the tellurium-containing solid, molybdenum-containing solid, or tellurium/molybdenum-containing solid in ~, it is possible and easy to add while performing a fluid reaction. This, unlike many conventional catalyst regeneration methods, can be carried out while the reaction is running, so there is no loss due to production stoppages. Of course, even if the catalyst, the tellurium-containing solid, and the molybdenum-containing congener are physically dry-mixed before the reaction starts, or the catalyst and the tellurium/molybdenum-containing solid are physically dry-mixed, and then this dry mixture is subjected to the reaction, the activity can be improved. is similarly accepted. Although the mechanism by which the present invention exerts its effects is not clear, when a tellurium-containing solid and a molybdenum-containing solid or tellurium/molybdenum-containing solid are used, volatile tellurium components and molybdenum components are generated under the reaction conditions. The tellurium component in the vapor phase poisons the active sites on the catalyst that are involved in the production of by-products such as carbon dioxide and carbon oxide, thereby increasing the selectivity of the target product by suppressing the production of these products. At the same time, the molybdenum component in the vapor phase also moves and deposits on the catalyst, increasing the reaction rate by regenerating the active sites or creating active sites that are advantageous for the production of new target products through collaboration with the tellurium component. When using tellurium-containing solids, molybdenum-containing solids, or tellurium-molybdenum-containing solids, the time required for the onset of effects is relatively short. In many cases, the effect is already evident within 1-2 hours. Moreover, the durability of the effect is excellent. Therefore, the scattering rate of the tellurium component and molybdenum component from the tellurium/molybdenum-containing solid is relatively rapid, and the tellurium component and molybdenum component deposited on the catalyst have a strong affinity with the catalyst component, and once bonded to the catalyst, It is thought that the tellurium component and molybdenum component will be difficult to escape. Furthermore, this mechanism is based on propulsion,
The details are still not clear yet. Therefore, Jiga's KC Tellurium is an unexciting metal monster F4J
Jr West VC (a) tellurium annual leave over Vrur compound and (b
) The uninvented means of achieving the objective of contacting the molybdenum compound during the 'kI5L reaction should also be understood from this point of view. Below, we will specifically sing about non-invention. Metal oxide catalysts The metal oxide catalysts used herein are as follows: The method of the invention described above can be equally applied to these known tellurium-free metal oxide catalysts. Mention may be made in particular of metal oxide catalysts containing at least one element from the group consisting of antimony, molybdenum and vanadium. More specifically, the catalyst used in the present invention is selected from the following Fragments 11A. These catalyst components can be used as they are, or silica, silica fist alumina, alumina, silica titania, titania, dino

[It may also be used by being supported on each unit such as Konya. (1) 5bnAaBbCCOX (a ratio group area)A
= Fe, Go, Ni, Mn+ u Ce,
Sn+ Qu, TiB=V, MO, W C= Mg, Cat Sr, Ba, l, a, T
ie Zr, Nb* Ta, Cr, Re, Ru
. Os, Rh, Ir, Pd, Pt, Ag, Z
n, Cd, B, A4 Ga, In. T4 Get Pb, P, A1. BL81S
e. a=1~10 b=o~5 C=0~10 (2) Mo, -Dd Ee Ff Ox (Ji3j
(composition) D = Fe, Ni, Co, kite Cr,
Mg, Ca, Cu, Zn, La, Ce, A
4n E=S rice Bt, As, P, BF=Rb=C5 d=0~10 e=0.1~10 f=0~3 (3) V+@Gg Hh Qx (atomic ratio composition)
G = Li, Na, K, Rtx Cs, T4
Mg, Ca, Sr, Ba. H= La, Ce, Ti, Zr, Nlx Ta
, Cr+ FIIIOI SM Mrb Re, F
e+Ru, Oss Co, Rh, Ir, Ni,
Pd, Pt, Cu, Ag, Zn+Cd, a
A4 G & In, Qe, Sn, P b, P
, As, Sb, Bl. 8, Se g = Q ~ 5 h = o ~ 20 Note that 0 stands for sane, and the subtractor X stands for water on the rk purple number corresponding to the oxide produced by combining each component element. (
(1) to (3) co-traced above) The shape of the catalyst is also arbitrary,
For fixed reactions, use a few pellets 1. Catalysts of various shapes, such as poles, can be used. In the case of fE, moving bed JX tail, catalyst particles with particle sizes ranging from 5 to 20 microns are used. As the oiliness improver used in the present invention, (a) tellurium alone or tellurium, and (b) molybtenized sogan,
It could be something like each yuzu. In a preferred embodiment of the present invention, the catalyst to be improved in activity is for a fluidized bed and ↓r, -, and the stream 1jjl 1*
Because it improves activity while performing inverse comparison,
In the case of the MjJ alignment improving agent, it is preferable that the particles are fluidizable under reaction conditions. When using finely divided particulate activity enhancers, it is desirable to carefully feed these finely divided particles from the bottom of the fluidized bed reactor so that they are well distributed throughout the catalyst. l) Specific examples of tellurium-containing solids used according to the type and manufacture are simple tellurium, tellurium oxide, tellurium dioxide, tellurium trioxide, tellurous acid, telluric acid, or organic tellurium compounds as they are, or these compounds. Silica, alumina, silica・
Examples include those supported on inert supports such as alumina, titania, silica/titania, and zirconia, and physical catalysts. As tellurium metal, tellurium dioxide, tellurium trioxide, tellurite acid, telluric acid, organic tellurium compounds, etc., commercially available reagents or those prepared from various tellurium raw materials by known methods may be used. When using the tellurium component supported on various carriers, various means can be applied as the supporting method. For example, tellurium raw materials include metallic tellurium, tellurium dioxide, tellurite acid,
Tellurium butyrate, tellurium nitrate, basic tellurium nitrate, tellurium halide, tellurium sulfate, organic tellurium compounds, etc. can be used, and carrier materials such as silica sol,
It is produced by mixing with alumina sol, titania sol, etc. and then spray-drying it, or by impregnating and supporting a previously prepared carrier with a solution in which these raw materials are dissolved. Further, when a tellurium-enriched fluidized bed catalyst is used for this purpose, any known catalyst manufacturing method can be used. Furthermore (2. After using the catalyst prepared by any known method as it is or using it in the reaction ζ binary,
This: It is also possible to impregnate it with a liquid containing a niterulium component, dry it, and sinter it. When baking these, 9
It is preferable to bake at a temperature of 0.0C or less for 0.5 to 1 hour. Examples of molybdenum compounds include molybdenum dioxide, molybdenum trioxide, molybdic acid, ammonium paramolybdate, ammonium molybdophosphate, and molybdophosphoric acid as they are, or those supported on the above-mentioned inert carrier, or molybdenum-enriched compounds. Examples include metal oxide catalysts. The methods for preparing these molybdenum-containing solids are similar to those for preparing the tellurium-containing solids described above. The tellurium-molybdenum-containing solid differs from the former two only in that it contains a tellurium component and a molybdenum component within the same particle. Using the above-mentioned tellurium component raw material and molybdenum component raw material, both are mixed and molded. It can be prepared using any known method, such as a method for producing a moving catalyst. These tellurium-containing solids, molybten-containing solids, tellurium/molybten-containing solids may necessarily contain a certain amount of elements in addition to the tellurium and/or molybdenum components. Namely, alkali metals, alkaline earth metals, lanthanum, cerium, vanadium, niobium, chromium, tungsten, manganese, iron, cobalt, nickel, copper, zinc,
Cadmium, boron, luminium, potassium, germanium, tin, lead, phosphorus, arsenic, antimony, bismuth,
It may contain at least one element selected from the group consisting of yellow and selenium. However, tellurium-containing solids and molybdenum-containing solids containing these elements are permissible insofar as they do not adversely affect the selectivity of the desired product when the reaction is carried out by mixing them with the target catalyst. When these solids alone carry out the desired reaction, even if they have activity and the selectivity of the desired product is somewhat poor, if the reaction rate is about the same or lower than that of the catalyst, the amount added A positive effect will be recognized as long as it is not completely excessive (Example 4 PCj 50chi or more). When a catalyst completely enriched with tellurium and molybdenum is used for the purpose of the invention, as long as its reaction rate and selectivity for the target product are within a range not significantly different from that of the catalyst used,
There is no need to think strictly about the upper limit of the mixing ratio. When these activity improvers contain the aforementioned various elements in addition to tellurium and/or molybdenum, the expression of the effects of the present invention may be affected to some extent. These can also be used to increase or decrease the transfer rate of the tellurium component and/or molybdenum component to the catalyst. It can also be used to adjust the physical properties of these activity enhancers. The mixing ratio of the activity enhancer should be selected taking these points into consideration. 2) Tellurium content and molybdenum content As mentioned above, under the reaction conditions, the tellurium component and (tomolybdenum component) It is thought that the effect is enhanced by converting into a volatile or volatile )41 compound, and if the tellurium component and molyne component that come into contact with the catalyst at 17 DEG C. are too small, the effect will be reduced. <C1 lurium and molybten are used directly on an inert carrier, or when these components are fully enriched, Pft) When burning, tellurium and/or molyi ・') If there are too few government buildings, use large amounts of these (force) and λ can also cause situations where there is no power. However, since these do not inherently have the catalyst for the desired reaction, it may be necessary to dilute the catalyst in some cases, and the reactor volume may not be sufficient for the reaction to proceed sufficiently. )O Taking these things into consideration, the tellurium content t! of the tellurium-containing solid, molybdenum-containing solid, or tellurium/molybdenum-containing solid! 0.531% or more, preferably 11it- or more, molybdenum content 0.1% or more, preferably 0
．． It is desirable that there be 5 or more layers. tellurium-containing solid and molybdenum-containing solid to be mixed with the catalyst,
Alternatively, the molybdenum/tellurium (atomic ratio) of the tellurium/molybdenum-containing solid is preferably 0.05 to 10. 3) Form (a) Tellurium alone or tellurium compound and (b)
When the molybdenum compound is used as it is, it may enter the reactor as a powder from outside the reactor, or it may be physically dry mixed with the catalyst before the reaction and then provided to the reaction system. When the tellurium component and molybdenum component are used in a completely solid state, their physical properties become a problem. In the case of a fixed bed reaction, the strength must be less than 1 U, and the tellurium or molybdenum component must not volatilize and become powder, increasing the pressure drop of the reaction gas at the catalyst bed. When applying to fluidized bed reactions, these activity enhancers themselves must be fluidized,
It is preferable to mix well with the catalyst. Moreover, in order for the tellurium and molybdenum components to be used effectively, the activity enhancer must be present in the reactor for a sufficient period of time to allow sufficient transfer of these components to the catalyst. From this point of view, when used in a fluidized bed reaction, the particle size of the activity enhancer should be relatively close to that of PBi, and the value of (bulk density of activity enhancer)/(bulk density of catalyst) should be 0.05 or more. 8, preferably 0.2 to 0.6. In addition, the target fluidized bed catalyst when carrying out the invention in this way has a bulk density of 0.1 to 3[/+a
g), preferably having a particle size of about 5 to 200 microns. Activity Improvement Treatment In the ammoxidation reaction according to the present invention, the activity improvement treatment of the catalyst is simultaneously carried out by bringing the gold m oxide catalyst into contact with (a) tellurium alone or a tellurium compound and (bl molybdenum compound). It is preferable that both the target catalyst and the activity improver are in a fluidized state.The method of the present invention can also be used in a fixed bed reaction by physically dry mixing the target catalyst and the activity improver. However, the effect of improving the activity is particularly large when a fluidized bed catalyst is used and the reaction is carried out in a fluidized state.In a fluidized state, the movement of the activity improver is large along with the movement of the catalyst, so the tellurium component and the molybdenum component It is believed that the transfer to the catalyst occurs without any wobbling, which improves the effectiveness.When the activity improver is a solid, the sum of the tellurium-containing solid and the molybdenum-containing solid, t o, o for tellurium-molybdenum-containing solids or tellurium-containing metal oxide catalysts.
It is preferable to set it to 1xts or more. If the amount added is less than this, the effect will be very small and the sustainability of the effect will be poor. The upper limit of the amount added can be determined in various cases. This point has already been described in the section on types and production of activity enhancers. The effect of the activity enhancer is discovered by the transfer of tellurium and molybdenum components to the catalyst. Therefore, from this point of view, is it an activity enhancer? 2. The apparent tellurium content of the packed catalyst increases from 0.001 to 15% by weight, preferably from 0.01 to 10% by weight, and the apparent molybdenum content increases from 0.002 to 10% by weight due to physical dry mixing with the catalyst. 11% to 103, favorable 1 t, <
tfO, o 1 Ny L5] [fi-% is desirable. However, the increment in the apparent tellurium content and the increment in the apparent molybdenum content are determined as follows. Apparent Tellurium Content Increment [H] Apparent Molybdenum Content Increment [H] The preferred amount of the activity enhancer to be added also varies depending on the properties of the activity enhancer. If the tellurium and molybdenum components migrate quickly, use an amount of activity enhancer calculated from the desired tellurium and molybdenum contents; if the components migrate slowly, use a slightly larger amount of activity enhancer. Good to use. The activity enhancer may be physically dry mixed with the catalyst before the start of the reaction, or may be added alone or physically dry mixed with the catalyst during the reaction. In the case of a fluid reaction, there is no problem because the catalyst can be removed and the addition port can be safely removed while the reaction is being carried out. The activity enhancer can be added many times depending on the reaction conditions. However, the contact between the catalyst and the tellurium component and the molybdenum component does not have to be carried out at exactly the same time;
The catalyst may be brought into contact with the tellurium component, or vice versa. However, if only the molybdenum component is added first, the selectivity of the target product will temporarily deteriorate, so it is better to avoid this if possible. When tellurium alone or a tellurium compound is physically dry mixed with a catalyst, it is effective in improving the selectivity of the target product, but the reaction rate remains the same or even decreases in some cases. . Therefore, the yield of the desired product is often not sufficiently improved. ◇ When only a molybdenum compound is physically dry mixed with a catalyst, the selectivity of by-products is often increased, resulting in The selectivity of the target product is reduced. As mentioned above, the activity enhancer can be added in various ways, but it is necessary that both the tellurium component and the molybdenum component are added. Ammoxidation Conditions The conditions for carrying out the ammoxidation method according to the present invention may be the same as those commonly used for ammoxidation of organic compounds. That is, the molar ratio of the supplied gas is organic compound/oxygen/ammonia (molar ratio) of 170.3 to 1070 to 5, and the reaction temperature is selected in the range of 300 to 600°C. The reaction pressure is from normal pressure to about 15 IG for 3 powders. The supply gas may be diluted with nitrogen, water vapor, carbon dioxide, carbon oxide, helium, or the like. ]''11 The effects of the non-invention IIl are shown below through Examples and Comparative Examples. Note that the yield and selectivity of the target product in this specification are based on the following definitions. The activity test conditions are as follows. (1) A propylene ammoxidation catalyst is filled into a fluidized reactor with an inner diameter of 2 inches and a height of 2 m, with a catalyst appropriately selected between 120Of and 1800LI above the catalyst. Inject a gas with the following composition into this reactor at an apparent linear velocity of 15
It is fed so that it becomes cm/sec. The reaction pressure is normal pressure. 0 Snow (supplied with air)/Propylene-2.10 (molar ratio) NH*/Propylene 1.15 (molar ratio) However, the contact time is defined as follows. *Criteria for bulk density of catalyst (2) Ammoxidation of toluene Using the same reactor as used for the ammoxidation of propylene in the previous section, feed the toluene so that the apparent linear velocity is 15 an/Bee. The reaction pressure is normal pressure. Can (supplied with air)/toluene = 2.5 (mole ratio) NH,
/) Luene = 1.5 (mol 1) Steam/toluene = 2.5 (mole ratio) The definition of contact time is also the same as in the case of ammoxidation of propylene in the previous section. The activity test was carried out using a gold bed catalyst and the test conditions (υ). The acrylonitrile yield was 74.2%, to which tellurium containing 3B, 3% molybdenum, 47.84f silicon dioxide, 2.9% molybdenum was added.・When the reaction was continued by mixing 1.0% molybdenum-containing solid with respect to the catalyst, the yield of acrylonitrile was 78.1% after 2 hours. I
〇Example 2 Empirical formula b” W, -* Co I Fen Sbm5
Using a fluidized bed catalyst that is On, s (Stow) so,
Test Conditions (1) The acid activity test was carried out. The yield of acrylonitrile was initially 74.1%, but after a long reaction period, the yield became 70.2%. A tellurium/molybdenum organic solid containing 35.2% tellurium, 7.9% molybdenum, and 44.0% silicon dioxide was added to the mixture and mixed in an amount equivalent to 1.1% based on the catalyst while reacting. After 2 hours of mixing the tellurium-molybdenum-containing solid, the acrylonitrile yield was 73.9%. An activity test was conducted under the same test conditions (1) by adding the above-mentioned tellurium/molybdenum-containing solid in an amount equivalent to 1.1 h per catalyst to a new catalyst. 2 hours later,
The acrylonitrile yield was 76.3%. Example 3 All activity tests were carried out under test conditions (1) using a fluidized bed catalyst with a Sift function of Sn+・sb snow, oma・(Sift)s@, and the loacrylonitrile yield was 68.9%. Met. Tellurium'k 20. 0% of tellurium-containing solid (consisting of silicon and 11! elements other than tellurium) to the catalyst of 1.596. A molybdenum-containing solid containing 66.7% molybdenum (other than molybdenum consists of oxygen) t-1 was also mixed at a ratio of 0.15% to the catalyst and reacted. After 2 hours, the yield of acrylonitrile was was 74.3%. An activity test was conducted under the activity test conditions (1). The acrylonitrile yield was initially 69.5%, but
The activity of the catalyst decreased due to long-term reaction use and became 66.8 inches. When this was mixed with the same tellurium/molybdenum-containing solid used in Example 2 at a ratio of 0.85% to the catalyst and reacted, the acrylonitrile yield was 72% after 2 hours.
．． It became 2chi. Example 5 The empirical formula is pHKe** pes Ni*, s CO4,
An activity test was conducted under test conditions (1) using a fluidized bed catalyst of I Bll MOteOn-a(SjOt)a-. The acrylonitrile yield was initially 75.3%, but the activity of the catalyst decreased due to prolonged reaction use, resulting in a yield of 72%.
It became 0chi. When this was mixed with the same tellurium/molybdenum-containing solid used in Example 2 at a ratio of 0.3% to the catalyst and reacted, the acrylonitrile yield was 76% after 3 hours.
．． It became 3%. Example 6 Using a fluidized bed catalyst with the experimental formula P-VatO.-, -(SiOs)@., an activity test was conducted under test conditions (2). The benzonitrile yield was 75.2%. When this was mixed and reacted with the same tellurium/molybdenum-containing solid catalyst used in Example 1 for 0.261 seconds, the benzonitrile yield was 77.5% after 2 hours. . Comparative Example 1 The tellurium-containing solid used in Example 3 was mixed with the catalyst of Example 2 in an amount equivalent to 1.5% of the catalyst, and a propylene ammoxidation reaction was carried out under test conditions (1).
After hours, the acrylonitrile yield was 75.8 To. The total propylene conversion rate was 96.0%. Comparative Example 2 The catalyst of Example 2 was mixed with the molybdenum-containing solid sound used in Example 3, in an amount equivalent to 0.3% of the catalyst, and an ammoxidation reaction of propylene was carried out under test conditions (1). , after 2 hours, the acrylonitrile yield was 73.8
%, the total propylene conversion rate was 98.0%. The yields of carbon dioxide and hydrocyanic acid were increased. The contents of Examples 1 to 6 and Comparative Examples 1 to 2 described above can be summarized as follows.

Claims (1)

[Scope of Claims] (1) A method for ammoxidizing an organic compound at a temperature of 300 to 600 C using a metal oxide catalyst that does not substantially contain tellurium, the ammoxidation being carried out using a sulfur catalyst. An ammoxidation method characterized in that it is carried out in the presence of (1) tellurium alone or a tellurium compound and (b) a molybdenum compound in contact with each other. (The ammoxidation reaction is carried out in the presence of a physical dry mixture of two catalysts and a tellurium-containing solid and a molybdenum-containing solid, or a physical dry mixture of the catalyst and a tellurium/molybdenum-containing solid. (3) Sum of tellurium-containing solid and molybdenum-containing solid,
The method according to claim 2, wherein the tellurium-molybdenum-containing solid is present in a ratio of 0.01 or more by weight to the metal oxide catalyst. (4) The method according to claim 2 or 3, wherein the tellurium content of the tellurium-containing solid or the tellurium/molybdenum-containing solid is 1 part by weight or more. (5) The method according to claim 2 or 3, wherein the molybdenum content of the molybdenum-containing solid or the tellurium-molybdenum-containing solid is 0.5 kg or more. (6) The metal oxide catalyst is a fluidized bed catalyst with a particle size ranging from 5 to 200 microns, and in its fluidized state,
6. A method according to any one of claims 2 to 5, wherein the tellurium-containing solid and the molybdenum-containing solid are mixed together or with a tellurium-solibdenum-containing solid. (7) Any of claims 2 to 6, wherein the tellurium-containing solid, molybdenum-containing solid, or tellurium/molybdenum-containing solid is one in which a tellurium component and/or a molybdenum component is supported on an inert carrier. Method described in Crab. (8) The method according to claim 7, wherein the inert carrier is at least one selected from the group consisting of silica, alumina, silica-alumina, titania, silica-titania, and zirconia. (9) At least one of the tellurium-containing solid, the molybdenum-containing solid, and the tellurium/molybdenum-containing solid is enriched with a tellurium component and/or a molybdenum component in the metal oxide catalyst or the used metal oxide catalyst. Claims 2 to 8 are
The method described in any of the paragraphs. (10) Tellurium-containing solid, molybdenum-containing solid, or tellurium/molybdenum-containing solid is tellurium, molybdenum,
Or in addition to tellurium and molybdenum, alkali metals, alkaline earth metals, lanthanum, cerium, vanadium, niobium, chromium, tungsten, manganese, iron, cobalt,
Compounds that also contain at least one element selected from the group consisting of nickel, copper, zinc, cadmium, boron, aluminum, gallium, germanium, tin, lead, phosphorus, arsenic, antimony, bismuth, sulfur, and selenium, or 10. The method according to any one of claims 2 to 9, which comprises a mixture of compounds, supported or unsupported on an inert carrier. (11) The increase in the apparent tellurium content of the packed catalyst observed by physically dry mixing the metal oxide catalyst with a tellurium-containing solid and a molybdenum-containing solid or a tellurium-molybdenum-containing solid as an activity enhancer is 0.001.
The increment in apparent molybdenum content is between 15 and 15 kg by weight,
Claim 2 which is from 0,002 to 10 kg by weight
The method according to any one of Items 1 to 10. However, the increase in apparent tellurium content and the increase in apparent molybdenum content are defined as follows. Apparent tellurium content increment [information] Total weight of packed catalyst [t] Apparent molybdenum content increment [悌] Total weight of packed catalyst [? ]