JP2008036527A - Method of packing solid catalyst, and method of producing unsaturated aldehyde and unsaturated carboxylic acid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of packing a solid catalyst by which a deterioration in the solid catalyst containing organic matter can be reduced, the deterioration arising when the solid catalyst containing organic matter is packed into a reaction tube and then the temperature of the packed solid catalyst is raised, and to provide a method of producing unsaturated aldehyde and unsaturated carboxylic acid by using the hard-to-deteriorate solid catalyst. <P>SOLUTION: The method of packing the solid catalyst comprises packing the solid catalyst containing organic matter into the reaction tube of the temperature x[°C] satisfying a relationship of expression (1) (wherein T is the decomposition temperature [°C] of the organic matter contained in the solid catalyst). The method of producing the corresponding unsaturated aldehyde and unsaturated carboxylic acid comprises: packing the solid catalyst into the reaction tube according to the above-mentioned packing method: removing the organic matter contained in the solid catalyst in the reaction tube; and subjecting propylene, isobutylene, tertiary butanol or methyl tertiary-buthyl ether to vapor phase contact oxidation by using molecular oxygen in the reaction tube. The method of producing (meth)acrylic acid comprises: packing the solid catalyst into the reaction tube according to the above-mentioned packing method; removing the organic matter contained in the solid catalyst in the reaction tube; and subjecting (meth)acrolein to vapor phase contact oxidation by using molecular oxygen in the reaction tube. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for filling a reaction tube with a solid catalyst containing an organic substance, a method for producing an unsaturated aldehyde and an unsaturated carboxylic acid, and a method for producing (meth) acrylic acid.

  As a method of filling a solid catalyst into a reaction tube, Patent Document 1 describes filling the solid catalyst in an atmosphere gas temperature in a temperature range of 10 ° C. to 40 ° C. in a reaction tube of a fixed bed reactor. Patent Document 1 exemplifies solid catalysts for the gas phase catalytic oxidation reaction of propylene, isobutylene and tert-butanol and for the gas phase catalytic oxidation reaction of methacrolein.

  In Patent Document 2, a molded product of a precursor of a catalyst for producing methacrylic acid by vapor-phase catalytic oxidation of methacrolein and containing an organic substance is charged into a reaction tube, and then 300 to 300 in the reaction tube. It is described that a catalyst can be produced by calcining at 500 ° C., and that methacrylic acid can be produced at a reaction temperature of 200 to 450 ° C. using the calcined catalyst.

In Patent Document 3, in a method for producing an unsaturated aldehyde and an unsaturated carboxylic acid by a gas phase catalytic oxidation method, after filling a reaction tube with a catalyst precursor containing an organic substance, gas is circulated through the reaction tube. Thus, a method is described in which the temperature of the catalyst precursor is raised and heat-treated so that the temperature of the catalyst precursor layer outlet is higher than the temperature of the gas catalyst precursor layer inlet.
JP 2005-224661 A JP 2005-187463 A JP 2002-239386 A

  In the case of the methods of Patent Documents 1 and 2, it is necessary to raise the temperature of a catalyst containing an organic substance such as an organic binder from a low temperature of 40 ° C. or lower to a heat treatment temperature or a reaction temperature before the firing step or reaction. According to the study by the present inventors, temperature spots may occur in the solid catalyst during the process, whereby the organic matter is decomposed or vaporized in the high temperature part, and the organic matter is condensed and concentrated in the low temperature part. A portion having a high concentration of is formed. There is a problem that the catalyst deteriorates due to rapid heat generation when the organic matter is decomposed at that portion. In the method of Patent Document 3, it is difficult to cause the above-mentioned problem, but it is not easy to increase the temperature of the reaction tube monotonically from the gas inlet side to the outlet side. Such a problem may occur in the region.

  The present invention relates to a solid catalyst filling method capable of reducing deterioration of a catalyst at the time of temperature rise after filling a solid catalyst containing an organic substance into a reaction tube, and unsaturated aldehyde and unsaturated using a catalyst with little deterioration. It aims at providing the method of manufacturing carboxylic acid.

  The invention according to claim 1 of the present application is a solid catalyst filling method in which a solid catalyst containing an organic substance is filled in a reaction tube having a temperature x [° C.] satisfying the relationship of the following (1).

100 ≦ x and (T−150) ≦ x ≦ (T + 100) (1)
(T represents the decomposition temperature [° C.] of the organic matter in the catalyst.)
Further, the invention according to claim 2 of the present application is directed to vapor-phase catalytic oxidation of propylene, isobutylene, tertiary butanol or methyl tertiary butyl ether with molecular oxygen, and corresponding unsaturated aldehyde and unsaturated carboxylic acid respectively. In the method for producing an acid, a solid catalyst is filled in a reaction tube by the method according to claim 1, and after removing organic substances contained in the solid catalyst in the reaction tube, propylene, isobutylene, In this method, tertiary butanol or methyl tertiary butyl ether is subjected to gas phase catalytic oxidation with molecular oxygen to produce the corresponding unsaturated aldehyde and unsaturated carboxylic acid.

  Furthermore, the invention according to claim 3 of the present application is a method for producing (meth) acrylic acid by vapor-phase catalytic oxidation of (meth) acrolein with molecular oxygen, wherein the solid catalyst is the method according to claim 1. After filling the reaction tube and removing the organic substances contained in the solid catalyst in the reaction tube, (meth) acrylic acid is vapor-phase contact oxidized with molecular oxygen using the reaction tube, and (meth) acrylic acid It is a method of manufacturing.

  In the filling method of the present invention, the solid catalyst containing an organic substance such as an organic binder introduced into the reaction tube is heated simultaneously with the addition by the heat of the reaction tube, and the organic substance is removed without any spots. This makes it difficult to form a high-concentration portion of the organic substance, and as a result, it is possible to prevent the catalyst from deteriorating when the temperature is raised.

  Hereinafter, the present invention will be described in detail.

  The method of the present invention is characterized by filling a reaction tube within a specific temperature range with a solid catalyst containing an organic substance (hereinafter also simply referred to as catalyst). The temperature of the reaction tube when the catalyst is filled in the reaction tube is a temperature x [° C.] that satisfies the following relationship (1).

100 ≦ x and (T−150) ≦ x ≦ (T + 100) (1)
(T represents the decomposition temperature [° C.] of the organic matter in the catalyst.)
The decomposition temperature T of the organic matter in the catalyst is a temperature at which the generation of the decomposition component and / or volatile component of the organic matter becomes the most intense, and can be determined from the D-TG curve obtained by differential thermogravimetric analysis. For example, a catalyst containing an organic substance is subjected to differential thermogravimetric analysis in the range of 25 ° C. to 700 ° C. under a temperature rising rate of 20 ° C./h with a Shimadzu thermogravimetric measuring device TGA-50, and a D-TG curve is measured. The peak top temperature is defined as the decomposition temperature T of the organic substance in the catalyst. In addition, when a plurality of peaks are observed in the D-TG curve, such as when two or more organic substances are included, the lowest temperature peak is used as a reference.

  The lower limit of the temperature x of the reaction tube is 100 ° C or (T-150) ° C, whichever is higher, preferably (T-120) ° C, more preferably (T-100) ° C (both 100 ° C or higher). ). The upper limit of the temperature x of the reaction tube is (T + 100) ° C., preferably (T + 50) ° C., and more preferably (T + 30) ° C.

  The temperature x of the reaction tube is the temperature of the reaction tube itself, but in the case of an externally heated reaction tube using a heat medium, the temperature of the heat medium near the reaction tube is substantially equal to the temperature of the reaction tube. You can also Although it does not specifically limit as a heat medium, Air, steam, etc. can be used in a low temperature range. Further, in a high temperature range, it is preferable to use a nitrate heat medium such as nighter. The heater that heats the heat medium is preferably installed so that temperature spots are unlikely to occur in the heat medium, and preferably has a structure that can be adjusted to an arbitrary temperature. Further, when filling the catalyst, a gas such as air or nitrogen may be circulated through the reaction tube, and the temperature x of the reaction tube can be adjusted by the temperature of the gas.

  As a method of measuring the temperature x of the reaction tube, for example, a method of directly measuring the temperature of the surface of the reaction tube using a temperature sensor such as a thermocouple, or a substantial reaction when a heat medium exists outside the reaction tube. For example, a method of measuring the temperature of the heat medium near the reaction tube equal to the temperature of the tube with a temperature sensor such as a thermocouple. The temperature x of the reaction tube is preferably within ± 10 ° C., more preferably within ± 5 ° C., and particularly preferably uniform without unevenness in the length direction of the reaction tube.

  The length of industrially used reaction tubes may be several meters, and depending on the structure of the reactor including the reaction tubes, temperature spots may occur at the ends of the reaction tubes. In the present invention, it is necessary that the temperature x satisfies the relationship (1) over the entire reaction tube.

  In the present invention, the type of the fixed bed reactor including the reaction tube is not particularly limited, and the present invention can be applied to various reactors. In particular, like multi-tubular fixed bed reactors, the number of reaction tubes is large, ranging from several thousand to several tens of thousands, so that temperature fluctuations occur in the reaction tube in the process of raising the temperature from room temperature to the heat treatment temperature or reaction temperature. This is a very effective means when applied to a reactor that is likely to generate. The material of the reaction tube is not particularly limited, but it is preferable to use a metal material such as stainless steel or carbon steel.

  The catalyst filling operation in the present invention is not particularly limited. However, when the operation is performed manually, it is desirable to perform the operation after taking sufficient heat insulation measures. The filling operation can also be performed using a remotely operable device or the like.

  The rate at which the catalyst is charged into the reaction tube is not particularly limited, but a rate at which the catalysts do not crosslink within the reaction tube is preferable.

  In the present invention, the filling operation may also serve as a heat treatment operation of the catalyst, and after the reaction tube is set to the above temperature, it is preferable to sequentially fill the reaction tube with the catalyst little by little. It is also possible to dilute the catalyst in the reaction tube with an inert substance such as silica, alumina, silica-alumina, silicon carbide, ceramic balls or stainless steel. In this case, an inert substance is charged together with the catalyst.

  The catalyst put into the reaction tube is heated little by little by the heat of the reaction tube, and the organic matter is decomposed without spots. Although this filling operation does not necessarily complete the decomposition of the organic matter, this method can prevent the formation of a high concentration portion of the organic matter. Moreover, since it can be charged at a higher temperature than the conventional method of filling at 40 ° C. or lower and the temperature can be raised from this temperature, the time until the heat treatment temperature is shortened and the reaction is started after the catalyst is charged. The process time can be shortened. Further, the atmosphere of the reaction tube at the time of filling is not particularly specified, and it is not always necessary to circulate a gas such as air or nitrogen. However, in order to remove decomposition products such as an organic binder, a gas such as air or nitrogen is not required. Is preferably distributed. As an example, air is preferably circulated in the range of 5 cm / sec to 80 cm / sec, more preferably in the range of 10 cm / sec to 65 cm / sec, and circulated in the range of 15 cm / sec to 55 cm / sec. More preferably.

  Moreover, it is preferable to remove the remaining organic matter after the catalyst filling operation. As a preferable method for removing the organic substance, for example, a method by heat treatment may be mentioned. The heat treatment conditions are not particularly limited, and known heat treatment conditions can be applied. In the case of a catalyst for the gas phase catalytic oxidation of propylene, isobutylene, tertiary butanol or methyl tertiary butyl ether with molecular oxygen to produce the corresponding unsaturated aldehyde and unsaturated carboxylic acid, 200-600 It is preferable to carry out in the temperature range of ° C. The heat treatment time is appropriately selected. Moreover, it is preferable to distribute | circulate gas, such as air and nitrogen, at the time of heat processing.

  In the present invention, the solid catalyst filled in the reaction tube means not only a catalyst having a catalytic activity but also a catalyst precursor activated by heat treatment in the reaction tube.

  Examples of the solid catalyst containing an organic substance used in the present invention include an oxidation reaction from isobutylene or the like to methacrolein or the like, an oxidation reaction from propylene to acrolein or the like, an oxidation reaction from methacrolein to methacrylic acid, or acrolein to acrylic acid. Examples thereof include catalysts used for the oxidation reaction and the like, and precursors thereof.

  Preferably, propylene, isobutylene, tertiary butanol (hereinafter abbreviated as TBA) or methyl tertiary butyl ether (hereinafter abbreviated as MTBE) is subjected to gas phase catalytic oxidation with molecular oxygen, respectively. Examples thereof include Mo, Bi, and Fe-based composite oxide catalysts that are solid catalysts for synthesizing corresponding unsaturated aldehydes and unsaturated carboxylic acids. Among these, a catalyst having a composition represented by the following general formula (I) (excluding organic substances) is preferably used.

Formula _{Mo a Bi b Fe c A d} X e Y f Z g O h (I)
(In the formula (I), Mo, Bi, Fe and O represent molybdenum, bismuth, iron and oxygen, respectively, A is nickel and / or cobalt, X is selected from the group consisting of magnesium, zinc, manganese, tin and lead. At least one element selected from the group consisting of phosphorus, boron, sulfur, tellurium, silicon, selenium, germanium, tungsten and antimony, Z is potassium, sodium, rubidium, cesium and 1 represents at least one element selected from the group consisting of thallium, where a, b, c, d, e, f, g and h represent the atomic ratio of each element, and when a = 12, 0. 1 ≦ b ≦ 5, 0.1 ≦ c ≦ 5, 1 ≦ d ≦ 12, 0 ≦ e ≦ 5, 0 ≦ f ≦ 5, 0.01 ≦ g ≦ 3. Necessary to satisfy the valence It is an atom ratio.)
The method of the present invention can also be suitably used for a solid catalyst used when producing methacrylic acid by vapor-phase catalytic oxidation of methacrolein with molecular oxygen. The catalyst for producing methacrylic acid is not particularly limited as long as it is a composite oxide catalyst containing molybdenum and phosphorus as essential components, but preferably has a composition (excluding organic matter) represented by the following formula (II). is there.

_{P a Mo b V c Cu d} X e Y f Z g O h (II)
(In the formula (II), P, Mo, V, Cu and O represent phosphorus, molybdenum, vanadium, copper and oxygen, respectively, X represents antimony, bismuth, arsenic, germanium, zirconium, tellurium, selenium, silicon, tungsten, Represents at least one element selected from the group consisting of boron and silver, and Y represents at least one element selected from the group consisting of iron, zinc, chromium, magnesium, tantalum, manganese, cobalt, barium, gallium, cerium and lanthanum Z represents at least one element selected from the group consisting of potassium, rubidium, cesium, and thallium, and a, b, c, d, e, f, g, and h represent atoms of each element. The ratio is expressed as follows: when b = 12, a = 0.5-3, c = 0.01-3, d = 0-2, e = 0-3, f = 0-3, g = 0. Is 1 to 3, h is an oxygen atom ratio required for satisfying the valency of each component.)
The raw material of the catalyst component element used in the production of the solid catalyst is not particularly limited, but can be converted into an oxide or an oxide by igniting, for example, chloride, sulfate, nitrate, carbonate, ammonium salt or It is preferable to use a mixture thereof. The method for preparing the catalyst or its precursor need not be limited to a special method, and various methods such as a conventionally known evaporation to dryness method, precipitation method, and oxide mixing method can be used.

  Examples of a method for forming a catalyst obtained by the above preparation method or a precursor thereof into a solid catalyst include a wet molding method and a dry molding method. In the wet molding method, for example, (1) a step of producing a powder containing a catalyst or a precursor component thereof, (2) a step of kneading the obtained powder and an organic substance, and (3) a kneaded product obtained A solid catalyst is produced through a step of extruding and (4) a step of drying and / or heat-treating the obtained extrudate.

  In the dry molding method, for example, a solid catalyst is produced through (1) a step of producing a powder containing a catalyst or a precursor component thereof, and (2) a step of tableting and molding the obtained powder and an organic substance.

  Although organic substance is not specifically limited, For example, what is called an organic binder is mentioned. Preferred organic binders include, for example, polysaccharides and cellulose derivatives.

  Examples of such cellulose derivatives include methylcellulose, ethylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxybutylmethylcellulose, ethylhydroxyethylcellulose, hydroxypropylcellulose and the like. be able to. Of these, methylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose, and hydroxyethylmethylcellulose are preferable. A cellulose derivative can be used alone or in combination of two or more. Examples of the polysaccharide include curdlan, laminaran, paramylon, callose, pacifican, scleroglucan and the like. A polysaccharide may be used alone or in combination of two or more. These cellulose derivatives and polysaccharides can be mixed and used at an arbitrary ratio.

  The shape and molding method of the solid catalyst used in the present invention are not particularly limited, and examples of the shape of the catalyst include arbitrary shapes such as a spherical shape, a cylindrical shape, a cylindrical shape, and a star shape. Examples of means for obtaining a solid catalyst by molding a catalyst or its precursor powder include a molding method using a molding apparatus such as a tableting molding machine, an extrusion molding machine, and a rolling granulator. Further, the solid catalyst may be a supported molded body in which a catalyst or a precursor thereof is supported on a carrier. Examples of the carrier in that case include carriers such as silica, alumina, silica / alumina, magnesia, titania, and the like. It is done. The present invention is a very effective means in the case of using a solid catalyst obtained by molding a mixture of catalyst or catalyst precursor particles and an organic substance such as an organic binder as a molding aid.

  The reaction conditions using the solid catalyst charged by the method of the present invention and appropriately heat-treated include the following.

  In the case of a solid catalyst for producing a corresponding unsaturated aldehyde and unsaturated carboxylic acid by vapor phase catalytic oxidation of propylene, isobutylene, TBA or MTBE with molecular oxygen, respectively, propylene, isobutylene, TBA or MTBE and The reaction is performed by bringing a raw material gas containing molecular oxygen into contact with the catalyst. As the reaction conditions at that time, the molar ratio of raw material propylene, isobutylene, TBA or MTBE to molecular oxygen is preferably in the range of 1: 0.5-3. It is economical to use a raw material gas containing a raw material and molecular oxygen diluted with an inert gas. The concentration of the raw material in the raw material gas is preferably 2 to 40% by volume. Although it is economical to use air as the molecular oxygen source, air enriched with pure oxygen can also be used if necessary. Water vapor can also be added to the source gas. The reaction pressure is preferably from atmospheric pressure to 3 atmospheres. The reaction temperature is preferably in the range of 200 to 400 ° C, more preferably in the range of 280 to 380 ° C. The contact time between the source gas and the catalyst is preferably 1.5 to 15 seconds, and more preferably 2 to 5 seconds.

  In the case of a solid catalyst for producing methacrylic acid by gas phase catalytic oxidation of methacrolein with molecular oxygen, the reaction is carried out by bringing a raw material gas containing methacrolein and molecular oxygen into contact with the catalyst. In this case, the concentration of methacrolein in the raw material gas can be varied in a wide range, but it is preferably 1 to 20% by volume, particularly 3 to 10% by volume. Although it is economical to use air as the molecular oxygen source, air or the like enriched with pure oxygen can also be used if necessary. The molecular oxygen concentration in the raw material gas is preferably 0.4 to 4 mol, particularly preferably 0.5 to 3 mol, relative to 1 mol of methacrolein. The source gas may be obtained by diluting methacrolein and a molecular oxygen source with an inert gas such as nitrogen or carbon dioxide. Further, water (steam) can be added to the raw material gas. When the reaction is carried out in the presence of water, methacrylic acid is obtained in a higher yield. The concentration of water vapor in the raw material gas is preferably from 0.1 to 50% by volume, more preferably from 1 to 40% by volume. The source gas may contain a small amount of impurities such as lower saturated aldehyde, but the amount is preferably as small as possible. The reaction pressure of the methacrylic acid production reaction is preferably from atmospheric pressure to 3 atmospheres. The reaction temperature is preferably in the range of 230 to 450 ° C, more preferably 250 to 400 ° C. The contact time between the source gas and the catalyst is preferably 1.5 to 15 seconds, and more preferably 2 to 5 seconds.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. “Part” in Examples and Comparative Examples is part by mass, and a kneader equipped with a batch type double-arm type stirring blade was used for kneading. The catalyst precursor powder obtained by drying the slurry containing the catalyst raw material, the heat-treated particles, and the molded extruded product are all referred to as a catalyst.

  In order to quantitatively compare the presence and degree of deterioration after temperature rise, the solid catalyst filled in the reaction tube is calcined after the completion of filling and reacted with the raw material gas, and the conversion rate of the raw material varies depending on the type of reaction. The temperature of the reaction tube necessary for maintaining the temperature was measured as the reaction temperature. That is, when the reaction is carried out under the same catalyst and conditions, if the reaction temperature is relatively high, the catalyst has deteriorated or the degree of deterioration is large, so that it is necessary to convert a certain proportion of the raw material. It can be determined that the temperature is high. Further, qualitatively, it was judged by visually confirming the presence or absence of a black-colored portion indicating that the catalyst was deteriorated to be extracted from the reaction tube.

Example 1
As a catalyst 1 for synthesizing methacrolein by gas phase catalytic oxidation of isobutylene, a slurry containing a catalyst raw material was dried to prepare a powder having the following composition.

Mo ₁₂ Bi _0.6 Fe ₂ Ni ₄ Co ₂ Mg ₂ Sb _0.7 Cs _0.6 O _z
(In the formula, Mo, Bi, Fe, Ni, Co, Mg, Sb, Cs, and O represent molybdenum, bismuth, iron, nickel, cobalt, magnesium, antimony, cesium, and oxygen, respectively. Is the atomic ratio of each element, and z is the oxygen atomic ratio necessary to satisfy the valence of each component (the same applies hereinafter).
The obtained powder was heat-treated at 300 ° C. for 1 hour and at 510 ° C. for 3 hours to obtain a catalyst powder. To 500 parts of the catalyst powder thus obtained, 25 parts of methylcellulose (Metroses 60SH-4000: manufactured by Shin-Etsu Chemical Co., Ltd.) and 5 parts of curdlan (Biopoly P-103: manufactured by Takeda Pharmaceutical Co., Ltd.) were added. In addition, dry mixing. This was mixed with 160 parts of pure water and kneaded with a kneader until it became clayy. The kneaded product in the form of clay was extruded into a cylindrical shape having an outer diameter of 5 mm and an inner diameter of 2 mm using an auger type extruder, and cut into an average length of 5 mm to obtain a ring-shaped extruded product. The obtained extruded product was dried at 110 ° C. using a hot air dryer.

  The obtained solid catalyst containing methylcellulose and curdlan was brown. This catalyst was subjected to differential thermogravimetric analysis in the range of 25 ° C. to 700 ° C. under the condition of a temperature rising rate of 20 ° C./h with a Shimadzu thermogravimetric measuring apparatus TGA-50, and a D-TG curve was measured. The peak top temperature was 250 ° C. and the peak top temperature attributed to curdlan was 308 ° C., so the decomposition temperature T of the organic matter in the catalyst was 250 ° C.

  Based on the results of this analysis, the solid catalyst thus obtained was adjusted so that the temperature of the reaction tube was maintained at 200 ° C. (T-50 ° C.) over its entire length. The stainless steel reaction tube was dropped little by little from the top and filled. The temperature of the reaction tube was the temperature of the heat medium in the vicinity thereof. Further, while filling the catalyst, air was supplied from the upper part to the lower part of the reaction tube at a linear velocity of 18.8 cm / sec.

  Thereafter, the temperature of the reaction tube was increased to 340 ° C. at a temperature increase rate of 25 ° C./hr with air being supplied, and then held at 340 ° C. for 12 hours.

  Thereafter, the air flowing through the reaction tube was stopped, and a raw material gas consisting of 5% by volume of isobutylene, 12% by volume of oxygen, 10% by volume of water vapor, and 73% by volume of nitrogen was added to the reaction tube at the reaction temperature (reaction temperature). (Temperature of tube) The reaction was started by passing at 310 ° C. and a contact time of 3.6 seconds. Thereafter, the temperature of the reaction tube was increased until the conversion of isobutylene reached 95%. As a result, the reaction temperature was 317.0 ° C. When the reaction was stopped 72 hours after the start of the reaction and the catalyst was extracted from the reaction tube, it was confirmed that the catalyst had a dark brown color before filling but no black discoloration and no deterioration.

Example 2
The reaction was performed in the same manner as in Example 1 except that the temperature of the reaction tube held in advance was 140 ° C. (T-110 ° C.). The reaction temperature at which the conversion of isobutylene was 95% was 317.0 ° C. there were. The catalyst extracted from the reaction tube was dark brown before filling, but it was confirmed that there was no black discoloration and no deterioration.

Example 3
The reaction was carried out in the same manner as in Example 1 except that the temperature of the reaction tube held in advance was 180 ° C. (T-70 ° C.). The reaction temperature at which the conversion of isobutylene was 95% was 314.0 ° C. there were. The catalyst extracted from the reaction tube was dark brown before filling, but it was confirmed that there was no black discoloration and no deterioration.

Comparative Example 1
The reaction was carried out in the same manner as in Example 1 except that the temperature of the reaction tube held in advance was 25 ° C. (T-225 ° C.). The reaction temperature at which the conversion of isobutylene was 95% was 323.0 ° C. there were. It was confirmed that the catalyst extracted from the reaction tube was deteriorated with dark brown and partly blackened before filling.

Example 4
As a catalyst 2 for synthesizing methacrolein by gas phase catalytic oxidation of isobutylene, a slurry containing a catalyst raw material was dried to prepare a powder having the following composition.

Mo ₁₂ Bi ₁ Fe _3.2 Co ₆ Rb _0.4 O _z
(In the formula, Mo, Bi, Fe, Co, Rb and O represent molybdenum, bismuth, iron, cobalt, rubidium and oxygen, respectively.)
The same procedure as in Example 1 was conducted except that the obtained powder was used. As a result, T was 250 ° C., and the reaction temperature at which the conversion of isobutylene was 95% was 315.0 ° C. The catalyst extracted from the reaction tube was dark brown before filling, but it was confirmed that there was no black discoloration and no deterioration.

Comparative Example 2
The reaction was performed in the same manner as in Example 4 except that the temperature of the reaction tube held in advance was 25 ° C. (T-225 ° C.). The reaction temperature at which the conversion of isobutylene was 95% was 324.5 ° C. there were. It was confirmed that the catalyst extracted from the reaction tube was deteriorated with dark brown and partly blackened before filling.

Example 5
As catalyst 3 for synthesizing methacrolein by gas phase catalytic oxidation of isobutylene, the slurry containing the catalyst raw material was dried to prepare a powder having the following composition.

Mo ₁₂ Bi _0.5 Fe ₃ Ni ₉ Mg ₁ Mn _0.3 B _0.2 Te _0.1 Si _0.4 K _0.1 Cs _0.3 O _z
(In the formula, Mo, Bi, Fe, Ni, Mg, Mn, B, Te, Si, K, Cs and O are molybdenum, bismuth, iron, nickel, magnesium, manganese, boron, tellurium, silicon, potassium, cesium, respectively. And oxygen.)
The same procedure as in Example 1 was conducted except that the obtained powder was used. As a result, T was 250 ° C., and the reaction temperature at which the conversion of isobutylene was 95% was 315.0 ° C. The catalyst extracted from the reaction tube was dark brown before filling, but it was confirmed that there was no black discoloration and no deterioration.

Comparative Example 3
The reaction was performed in the same manner as in Example 5 except that the temperature of the reaction tube held in advance was 25 ° C. (T-225 ° C.). The reaction temperature at which the conversion of isobutylene was 95% was 322.5 ° C. there were. It was confirmed that the catalyst extracted from the reaction tube was deteriorated with dark brown and partly blackened before filling.

Example 6
As a catalyst for synthesizing methacrylic acid by gas-phase catalytic oxidation of methacrolein, the slurry containing the catalyst raw material is dried, and a powder of catalyst for synthesizing methacrylic acid by gas-phase catalytic oxidation of methacrolein of the following composition (excluding oxygen) is prepared did.

Mo ₁₂ P ₁ Cu _0.2 V _0.5 Ge _0.2 Bi _0.2 Cs ₁
(In the formula, Mo, P, Cu, V, Ge, Bi, and Cs represent molybdenum, phosphorus, copper, vanadium, germanium, bismuth, and cesium, respectively.)
The obtained powder was molded in the same manner as in Example 1 except that the catalyst powder was obtained by baking at 380 ° C. for 5 hours to obtain a ring-shaped extruded product. The obtained extruded product was dried at 110 ° C. using a hot air dryer. The resulting solid catalyst containing methylcellulose and curdlan was green. The decomposition temperature T of the organic matter in the catalyst was measured in the same manner as in Example 1. As a result, it was 250 ° C.

  Based on the results of this analysis, the obtained solid catalyst was placed in a small amount from the top in a stainless steel reaction tube having an inner diameter of 26 mm and a length of 5 m, which was previously maintained at 200 ° C. (T-50 ° C.) as the reaction tube temperature. It was dropped and filled one by one.

  After charging the catalyst, the temperature of the reaction tube was increased to 377 ° C. at a temperature increase rate of 25 ° C./hr and then held at 377 ° C. for 12 hours. Further, while filling the catalyst, air was supplied from the upper part to the lower part in the reactor at a linear velocity of 18.8 cm / sec.

  Thereafter, the air flowing in the reaction tube was stopped, and a raw material mixed gas consisting of 5% methacrolein, 12% oxygen, 10% water vapor and 73% nitrogen was added to the reaction tube at a reaction temperature (reaction tube temperature) of 290 ° C. The reaction was started with a contact time of 4.5 seconds. Thereafter, the temperature of the reaction tube was increased until the methacrolein conversion rate became 75%. As a result, the reaction temperature was 291.0 ° C. When the reaction was stopped 72 hours after the start of the reaction and the catalyst was extracted from the reaction tube, it was confirmed that the catalyst had a darker green color than before the charge, but there was no black discoloration and no deterioration.

Example 7
The reaction was carried out in the same manner as in Example 6 except that the temperature of the reaction tube held in advance was 140 ° C. (T-110 ° C.). The reaction temperature at which methacrolein conversion was 75% was 291.5 ° C. Met. The catalyst extracted from the reaction tube was darker green than before filling, but it was confirmed that there was no black discoloration and no deterioration.

Example 8
The reaction was performed in the same manner as in Example 6 except that the temperature of the reaction tube held in advance was 180 ° C. (T-70 ° C.). The reaction temperature at which methacrolein conversion was 75% was 290.5 ° C. Met. The catalyst extracted from the reaction tube was darker green than before filling, but it was confirmed that there was no black discoloration and no deterioration.

Comparative Example 4
The reaction was carried out in the same manner as in Example 6 except that the temperature of the reaction tube held in advance was 25 ° C. (T-225 ° C.). The reaction temperature at which methacrolein conversion was 75% was 298.0 ° C. Met. It was confirmed that the catalyst extracted from the reaction tube was deteriorated with a dark green part and a black discolored part before filling.

Claims (3)

A solid catalyst filling method in which a solid catalyst containing an organic substance is filled in a reaction tube having a temperature x [° C.] that satisfies the relationship (1) below.
100 ≦ x and (T−150) ≦ x ≦ (T + 100) (1)
(T represents the decomposition temperature [° C.] of the organic matter in the catalyst.) A solid catalyst is used in the process for producing a corresponding unsaturated aldehyde and unsaturated carboxylic acid by vapor phase catalytic oxidation of propylene, isobutylene, tertiary butanol or methyl tertiary butyl ether with molecular oxygen, respectively. After filling the reaction tube by the method described and removing organic substances contained in the solid catalyst in the reaction tube, the reaction tube is used to form propylene, isobutylene, tertiary butanol or methyl tertiary butyl ether in molecular form. A method for producing an unsaturated aldehyde and an unsaturated carboxylic acid corresponding to each of them by gas phase catalytic oxidation with oxygen. In a method for producing (meth) acrylic acid by vapor-phase catalytic oxidation of (meth) acrolein with molecular oxygen, a solid catalyst is filled in the reaction tube by the method according to claim 1, and the solid catalyst is contained in the reaction tube (Meth) acrylic acid is produced by removing the organic substances contained in the product and then subjecting (meth) acrolein to gas phase catalytic oxidation with molecular oxygen using the reaction tube.