JPH0899040A - Catalyst for fluidized bed for use in gas phase catalytic oxidation of aromatic hydrocarbon and production aromatic carboxylic acid anhydride using the same - Google Patents

Abstract

PURPOSE: To provide a catalyst for a fluidized bed which has adequate strength, proper bulk density, high activity, and high selectivity and a method for producing an aromatic carboxylic acid anhydride using the catalyst. CONSTITUTION: A catalyst contains titanium oxide, a vanadium compound, an alkali metal compound, and a sulfuric acid compound as indispensable components and 1-50wt.% crystalline aluminosilicate (zeolite). In addition, at least one kind of silica, boron oxide, phosphorus oxide, and a rare earth metal oxide can be contained. A raw material of an aromatic hydrocarbon and gas containing oxygen is oxidized catalytically in a gas phase by a fluidized bed using the catalyst to produce an aromatic carboxylic acid anhydride.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the production of aromatic carboxylic acid anhydrides.
The present invention relates to a fluidized bed catalyst used for producing phthalic anhydride by subjecting xylene or naphthalene to gas phase catalytic oxidation, and a method for producing an aromatic carboxylic acid anhydride using the catalyst.

[0002]

Aromatic carboxylic acid anhydrides are produced by vapor phase catalytic oxidation of hydrocarbon feedstocks. As an example,
Particular mention may be made of the production of phthalic anhydride by vapor phase catalytic oxidation of o-xylene or naphthalene.

Conventionally, as a catalyst used for producing phthalic anhydride by vapor-phase oxidation of o-xylene in a fixed bed, an inert carrier such as alundum, silicon carbide, quartz, pumice, and α-alumina is used. , Vanadium pentoxide and titanium oxide (anatase type), or vanadium pentoxide and tellurium oxide, molybdenum oxide, tungsten oxide, nickel oxide, niobium oxide, tin oxide, chromium oxide and other active metal oxides, and even potassium, A catalyst supporting an alkali metal salt such as lithium or sodium has been announced (for example, edited by Kimio Tarama, practical catalyst for each reaction, P.35).
8 (1970) Chemical Industry Co., Ltd.).

In the fixed bed, in order to remove the high heat generated in the oxidation reaction, the catalyst is uniformly packed in a pipe-shaped reaction tube having a small diameter of about 1 inch, and the heat is removed outside by using a heat medium for cooling. Although the method is adopted, the labor and cost for uniformly filling the catalyst in each of thousands of reaction tubes is enormous, and the pressure loss of each reaction tube and the equipment cost for keeping the temperature constant, The burden of operation management is heavy. Further, the cost and labor required for replacing the catalyst after deterioration are large.

Further, in the catalyst in which the active ingredient is coated on the inert carrier as described above, due to uneven distribution of the reaction gas, generation of hot spots, increase of pressure loss, etc. due to separation and desorption of the active ingredient during filling and operation. There is a risk of a reaction runaway. In addition, in the fixed bed, since the concentration must be kept within the explosion limit of the reaction gas, it is required to supply the gas at a low concentration, and thus the productivity is poor.

To solve these problems, it is preferable to use a fluidized bed. According to the fluidized bed, heat removal is easy and not only generation of uneven flow and hot spots can be suppressed, but also replacement and replenishment of the catalyst are greatly advantageous as compared with the fixed bed. Furthermore, it is possible to increase the reaction concentration, which is a great advantage from the viewpoint of productivity.

As a fluidized catalyst used for producing phthalic anhydride by gas phase oxidation of o-xylene, silica is used as a carrier, vanadium pentoxide and potassium sulfate, and further, as in the case of using naphthalene as a raw material. Molybdenum oxide,
A catalyst supporting tungsten oxide, phosphorus oxide, boron oxide or the like has been proposed (for example, British Patent No. 9412).
93 (1936); U.S. Pat. No. 3,232,955 (1
966)). However, it is difficult to obtain phthalic anhydride in a high yield due to an excessive oxidation reaction or a side reaction that produces CO or CO ₂ , when the above-mentioned catalyst using silica as a carrier is used, and the yield is improved. Therefore, attempts have been made to mix a halogen gas such as Br ₂ into the reaction gas, but if halogen gas is used, equipment troubles due to corrosion occur (Dutch Patent No. 1144709 (1963);
U.S. Pat. No. 3,455,962 (1969)).

A number of catalysts have been proposed in which titanium oxide is used as a carrier and vanadium pentoxide is supported on the carrier (for example, British Patent No. 1067726 (1967); French Patent No. 1537351 (1968)), ammonium thiocyanate. By forming a melt with an alkali compound and an alkali compound, a strong catalyst is obtained.However, the catalysts obtained by these methods have a specific surface area decreased and a pore volume decreased due to the formation of the melt. Because
It is difficult to obtain phthalic anhydride in good yield using the catalyst obtained by this method, because the activity is extremely low and therefore a high reaction temperature is required, and as a result, excessive oxidation and side reactions occur simultaneously.

Further, the formation of the melted material overlaps with the high bulk density of titanium oxide to give only a catalyst having a remarkably large bulk density, and it is difficult to carry out an efficient fluidized bed reaction using these catalysts. is there. For these reasons, the production of phthalic anhydride by vapor phase oxidation of o-xylene using a fluidized bed has not been put to practical use.

[0010]

DISCLOSURE OF THE INVENTION The present invention provides a catalyst for use in a fluidized bed, which is significantly more advantageous than a fixed bed in a reaction for producing an aromatic carboxylic acid anhydride by vapor-phase catalytic oxidation of an aromatic hydrocarbon, And a method for producing an aromatic carboxylic acid anhydride using the catalyst, specifically, a highly active and highly selective fluidized bed having titanium oxide as a carrier and having sufficient strength and an appropriate bulk density. It is an object of the present invention to provide a catalyst for use and a method for producing an aromatic carboxylic acid anhydride using the catalyst.

[0011]

Means for Solving the Problems In order to achieve the above object, the inventors of the present invention have accomplished the present invention as a result of intensive research on a fluidized bed catalyst for producing phthalic anhydride using titanium oxide as a carrier. That is, the present invention comprises titanium oxide, a vanadium compound, an alkali metal compound and a sulfuric acid compound as essential components, and a crystalline aluminosilicate (zeolite) of 1 to 5
The present invention provides a fluidized bed catalyst for vapor phase catalytic oxidation of aromatic hydrocarbons, which is characterized by containing 0% by weight.

The present invention also uses an aromatic hydrocarbon and an oxygen-containing gas as a raw material, the raw material containing titanium oxide, a vanadium compound, an alkali metal compound and a sulfuric acid compound as essential components, and a crystalline aluminosilicate (zeolite) as 1
The present invention provides a method for producing an aromatic carboxylic acid anhydride, characterized in that a gas phase catalytic oxidation is carried out using a fluidized bed catalyst containing ˜50% by weight.

The catalyst of the present invention and the method for producing an aromatic carboxylic acid anhydride according to the present invention are more preferably a method for producing phthalic anhydride from o-xylene and / or naphthalene, and still more preferably a phthalic anhydride from naphthalene. It is preferably applied to a method for producing an acid. Furthermore, the catalyst of the present invention preferably further contains one or more components selected from silica, boron oxide, phosphorus oxides and rare earth metal oxides.

Further, in the gas phase catalytic oxidation fluidized bed catalyst and the method for producing an aromatic carboxylic acid using the same according to the present invention, the following is preferable. The content of each of the titanium oxide, the vanadium compound, the alkali metal compound and the sulfuric acid compound is 20 to 90 as an oxide.
It is preferred that it is wt%, 2 to 13 wt%, 2.0 to 5.0 wt% and 1.0 to 4.5 wt%. Further, the crystallite diameter of the titanium oxide is preferably 300 Å or less. Further, the catalyst preferably further contains at least one component selected from silica, boron oxide, phosphorus oxide and rare earth metal oxide.

The present invention will be described in more detail below. Book
The catalyst of the invention is based on oxide, titanium oxide (TiO 2₂)
20-90 wt%, vanadium compound V₂O_FiveAs
2 to 13% by weight, M is an alkali metal compound₂O (here
M: alkali metal) 2.0 to 5.0% by weight, sulfuric acid
Compound SO ₃In the range of 1.0-4.5% by weight
It is desirable to have a crystalline aluminosilicate
Content (zeolite) in the range of 1 to 50% by weight.
And is desirable. Especially, crystalline aluminosilicate is 1%
When the amount is too small, the effect of suppressing excessive oxidation in gas phase oxidation
Is not obtained, and when it is more than 50% by weight, the catalyst resistance
It is not preferable because abrasion resistance and activity are significantly reduced.

Crystalline aluminosilicate (zeolite)
Is in the catalyst, o-xylene and / or naphthalene, which is a raw material for the gas phase catalytic oxidation reaction of aromatic hydrocarbons,
Furthermore, it acts as an occlusion agent for o-tolualdehyde, which is an intermediate product of this reaction. Also alkali metal,
The exchange cation species of the alkaline earth metal act as a retainer and a supplement for the catalytically active component, and C
It has the effect of strongly suppressing the production of O, CO ₂ , maleic anhydride, and benzoic acid. As the effect of the zeolite, it further acts as a catalyst lightening agent and also exerts an effect of improving the fluidity of the catalyst. It also exhibits excellent effects in terms of maintaining high activity and high selectivity over a long period of time.

Examples of the crystalline aluminosilicate (zeolite) used for the catalyst of the present invention include synthetic or natural zeolites such as Y-type zeolite, mordenite, ZSM-5, erionite, gmelinite, chabazite and offretite. It Ultrastable Y-type zeolite, mordenite and ZSM-5, which do not cause dealumination on the acidic side, are particularly preferable. The exchange cation species of the crystalline aluminosilicate (zeolite) used in the catalyst of the present invention are preferably alkali metals such as potassium, sodium, cesium and rubidium and alkaline earth metals such as Ca, Mg and Ba.

The catalyst of the present invention may contain a third component in addition to the above-mentioned zeolite. As the third component, a component which is usually used in a vapor phase catalytic oxidation reaction of aromatic hydrocarbon can be used, and silica, boron oxide, an oxide of phosphorus and an oxide of a rare earth metal are particularly preferable. The total amount of the third component is preferably in the range of 20 to 60% by weight.

The catalyst of the present invention is prepared by, for example, mixing a titanium oxide source, a vanadium compound, an alkali metal compound, a sulfuric acid compound and a crystalline aluminosilicate (zeolite), and further optionally a precursor of the third component, followed by spray drying, It is manufactured by firing. The mixing order of each raw material may be arbitrary, and a method of simultaneously dissolving two or more raw materials,
A method of dissolving the active ingredient material in the titanium hydroxide dispersion may also be adopted. If necessary, the mixed slurry obtained as described above may be concentrated to an appropriate concentration, and then spray-dried to obtain spherical fine particles. As the spray drying method, a known method can be adopted. In spray drying, the weight average particle diameter of the obtained spherical fine particles is 4
It is preferable to set the spraying conditions so as to be 0 to 150 μm. The spherical particles obtained are preferably 30 in air.
Firing is performed at a temperature of 0 to 700 ° C., more preferably 400 to 600 ° C., preferably 1 to 6 hours, more preferably 2 to 4 hours.

The raw materials used in the production of the gas phase catalytic oxidation catalyst for aromatic hydrocarbons of the present invention include titanium oxide sources, vanadium compounds, alkali metal compounds, sulfuric acid compounds, silica sources,
It is an aqueous solution or suspension containing a boron compound, a phosphoric acid compound, and a rare earth metal compound.

The titanium oxide source used in the present invention is 300
It is desirable that the titanium hydroxide is a titanium hydroxide that produces titanium oxide having a crystallite size of 300 Å or less when dried at ℃. The crystallite size defined in the present invention is X based on the Debye-Scherrer method.
It is a value used in the following formula from the half value width of the diffraction peak at 2θ = 25.3 ° (CuKα anatase type titanium oxide) in the line diffraction diagram. Crystallite diameter (Å) = 81.5 / (B ² -0.0225)
^1/2 (however, B = half width (mm) / 10)

A catalyst containing titanium oxide having a crystallite size of more than 300Å has significantly lower wear resistance (strength) than a catalyst containing titanium oxide having a particle size of 300Å or less, and when used in a fluidized bed, a catalyst powder is used. It becomes uneconomical due to the increase in the size and scattering, and at the same time, it tends to cause the trouble of blocking the cyclone and the heat exchanger. In addition, a large amount of catalyst is mixed into the reaction product, and it becomes difficult to maintain a good fluid state. Furthermore, with a catalyst containing titanium oxide with a crystallite size of more than 300Å, the specific surface area of titanium oxide is small, so that uniform and sufficient loading of the active component is not achieved, and the catalytic activity is remarkably lowered, so a flow with a long contact time is required. Even in the bed, a sufficient phthalic anhydride yield cannot be obtained.

The titanium oxide source (titanium hydroxide) used in the present invention is a raw material for obtaining titanium oxide having a crystallite size of 300 Å or less, preferably 200 Å or less in powder dried at 300 ° C. The preparation method does not matter.

Examples of these titanium oxide sources (titanium hydroxide) include titanic acid obtained by a thermal hydrolysis method obtained in the intermediate step of producing pigment titanium oxide, and titania sol obtained by adding an acid thereto. Further examples include titanium hydroxide, titania sol, etc. obtained by neutralizing and hydrolyzing titanium sulfate, titanyl sulfate, titanium tetrachloride and the like, or by deoxidizing and hydrolyzing by an ion exchange method. In particular, titanium hydroxide obtained by neutralizing and hydrolyzing a solution of titanyl sulfate or the like at a low temperature of 40 ° C. or less is several tens of times after drying.
It shows a crystallite diameter of Å and is preferable. The content of titanium oxide in the catalyst is preferably 20 to 90% by weight, and more preferably 20 to 75% by weight in terms of TiO ₂ .

As the raw material of the vanadium compound used in the present invention, those which are soluble in water and produce vanadium pentoxide upon firing in air, such as ammonium metavanadate, vanadyl sulfate (vanadium oxysulfate), vanadium formate, Examples thereof include vanadium acetate, vanadyl oxalate, vanadyl ammonium oxalate, vanadyl phosphate, and vanadium oxyhalide. Of these, vanadyl sulfate, ammonium metavanadate, vanadyl oxalate and the like are preferably used. The content of the vanadium compound in the catalyst is 2-1 as an oxide (V ₂ O ₅ ).
It is preferably 3% by weight.

As the raw material of the alkali metal compound used in the present invention, hydroxides, sulfates, carbonates, chlorides, nitrates, oxyhalides, thiosulfates, nitrites of potassium, cesium, rubidium and the like are used. , Sulfite, hydrogen sulfite, hydrogen sulfate, oxalate, hydrogen oxalate and the like. Of these, hydroxides, sulfates, carbonates and the like are preferably used. The content of the alkali metal compound in the catalyst is preferably 2.0 to 5.0% by weight as an oxide (M ₂ O, where M is an alkali metal).

Examples of the raw material of the sulfuric acid compound include those which are soluble in water and produce sulfur trioxide by firing in air, such as sulfuric acid, ammonium sulfate and ammonium hydrogensulfate. Of these, sulfuric acid and ammonium sulfate are preferably used. The content of the sulfuric acid compound in the catalyst is preferably 1.0 to 4.5% by weight as SO ₃ .

Further, the silica source used as the raw material of the present invention is used as a lightening agent (low bulk density agent) and a binder. The silica source in the present invention is preferably a raw material having good dispersibility such as a solution or silica sol. For example, an organic silicon compound such as silicic acid or ethyl silicate obtained by neutralizing sodium silicate or potassium silicate, or cation exchange and its acidic hydrolyzate, quaternary ammonium silicate and its acidic hydrolysis. It is desirable to use a material, colloidal silica or the like. Colloidal silica which is stable at a high concentration for a long time is particularly preferable, and among these, those containing sodium as a stabilizer are preferably used after removing sodium by means such as cation exchange or ultrafiltration in advance. Among colloidal silica, those having a particle size of 50 μm or more are effective for lightening, but are inferior in binder strength, which is not preferable. As a silica source, for example, white carbon, aerosil, etc. are not preferable because they are not well dispersed and the binder strength is poor, and the effect of the boron compound (boron oxide) added at the same time is reduced.

As the boron compound used as the raw material of the present invention, soluble compounds such as boron oxide, boric acid, potassium tetraborate, potassium pentaborate, potassium metaborate, ammonium metaborate and ammonium tetraborate are used. Boric acid, ammonium metaborate, and the like, which have relatively high solubility, are suitable. The boron compound (boron oxide) not only significantly improves the wear resistance (strength), but also has the effect of improving the reaction selectivity (formation of phthalic anhydride).

The phosphoric acid compound used as the raw material of the present invention is phosphoric acid, ammonium phosphate, ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, sodium phosphate, sodium monohydrogen phosphate, sodium dihydrogen phosphate, phosphorus. Examples thereof include potassium acid salt, sodium monohydrogen phosphate, sodium dihydrogen phosphate and the like, and phosphoric acid, ammonium phosphate, ammonium monohydrogen phosphate and ammonium dihydrogen phosphate are preferable. The phosphoric acid compound (phosphorus oxide) is not only effective as a lightening agent (lowering the bulk density), but also has the effect of improving the reaction selectivity like the boron compound.

As the rare earth metal compound used as the raw material of the present invention, scandium, yttrium and lanthanide metal compounds, particularly lanthanide metal compounds represented by lanthanum and cerium (atomic numbers 57 to 71) are preferable. Illustrative examples of lanthanum include lanthanum chloride, lanthanum bromide, lanthanum iodide, lanthanum sulfate, lanthanum nitrate, lanthanum carbonate, ammonium lanthanum sulfate and lanthanum acetate. Of these, lanthanum nitrate, lanthanum carbonate, lanthanum acetate and the like are preferable. The lanthanum compound has an effect of preventing crystallization of titanium oxide and rutile conversion of anatase type titanium oxide, and as a result, suppressing thermal deterioration of the catalyst.

Oxidation of silica, boron oxide and phosphorus mentioned above
At least one selected from oxides and rare earth metal oxides
Component oxides (SiO₂, B₂O₃, P₂O_Five, RE
₂O ₃, Where RE: rare earth metal) in the catalyst as
The content is preferably 20 to 60% by weight. Including
If the content is less than 20% by weight, wear resistance is low (powdering rate
Large), at the same time, the appropriate bulk density cannot be obtained, and 60
If the amount exceeds%, the specific surface area will increase dramatically (> 150 m²/ G)
However, the excessive oxidation is promoted.

The catalyst of the present invention can be used to vapor-phase catalytically oxidize aromatic hydrocarbons in a fluidized bed to obtain the corresponding carboxylic anhydride. Representative examples of suitable aromatic hydrocarbons include:
Includes benzene, xylene, pseudocumene, durene, naphthalene and mixtures thereof. Thus, the catalysts of the present invention can be used in reactions to convert benzene to maleic anhydride; pseudocumene to trimellitic anhydride; durene to pyromellitic anhydride; and o-xylene and / or naphthalene to phthalic anhydride.

The catalyst of the present invention can be preferably used in a reaction for converting o-xylene and / or naphthalene into phthalic anhydride, and more preferably used in a reaction for converting naphthalene into phthalic anhydride. This is a method for producing an aromatic carboxylic acid anhydride by catalytic gas phase oxidation of a fluidized bed of aromatic hydrocarbon using the catalyst of the present invention,
This is because in the case of producing phthalic anhydride from o-xylene or naphthalene, the yield of phthalic anhydride is particularly large when naphthalene is used as a raw material.

Preferred reaction conditions in the method for producing an aromatic carboxylic acid anhydride by catalytic gas phase oxidation using a fluidized bed of aromatic hydrocarbon of the present invention, particularly in the method for producing phthalic anhydride from o-xylene or naphthalene are as follows. It is as follows. The reaction temperature is preferably 200 to 500 ° C, more preferably 250 to 400 ° C, further preferably 280 to 280 ° C.
The range of 360 ° C is preferred. When the reaction temperature is lower than 200 ° C, the conversion of o-xylene and naphthalene is low and the productivity is lowered, and when it is higher than 500 ° C, the yield of phthalic anhydride is lowered due to excessive oxidation.

W / F defined by the following equation is 5 to 40 h
A range of r ^-1 is preferred. W: catalyst weight (kg), F: o-xylene and / or naphthalene feed rate (kg / hr) When W / F is less than 5 hr ^-1 , the conversion rate of o-xylene and naphthalene is low and productivity is lowered. And W / F is 40hr
If it exceeds ^-1, the yield of phthalic anhydride decreases due to excessive oxidation.

In the oxidation of o-xylene or naphthalene to phthalic anhydride, air is preferable as a source of oxygen, but a mixed gas of oxygen and a diluent such as nitrogen or carbon dioxide and air rich in oxygen are also included. Can be used.
The oxygen-containing gas source (eg air) is preferably preheated (eg 100 to 100%) before it is introduced into the reactor.
300 ° C). The reaction can be carried out at atmospheric pressure, above atmospheric pressure or below atmospheric pressure. Generally, 0.5 to 3.0 atm is suitable.

In the present invention, the wear rate is measured by
ACC method (American Cyanamid Company; "Test Method f
or Synthetic Fluid Cracking Catalyst ") [separate volume Chemical Industry 31-12 Fluidized Bed Reactor Chemical Industry Co., Ltd., The Chemical Industry Association, October 15, 1987, p.33].

[0039]

EXAMPLES The present invention will be specifically described below based on examples. The following examples provide a specific description of the invention as claimed, but the invention is not limited to the particular details described in the examples.

(Example 1) 800 kg of a titanyl sulfate aqueous solution containing 5% by weight of TiO ₂ was stirred well in a 2 m ³ stainless steel tank while stirring 15% by weight of ammonia water 1
5.5 kg was added over 4 hours for neutralization to obtain a titanium hydroxide gel. The pH of this gel was 7.1 and the temperature was 32 ° C. The gel obtained by taking 40 kg of this gel slurry and dewatering under reduced pressure with a flat plate filter was added with 200 L of 6
Hot water of 0 ° C. was gradually poured to remove ammonium sulfate generated by neutralization. Pure water was added to the titanium hydroxide gel obtained by repeating washing, and the mixture was stirred to prepare a gel having a TiO ₂ concentration of 9.3% by weight. The crystallite size of the anatase type titanium oxide determined from the diffraction peak at 2θ = 25.3 ° of the X-ray diffraction pattern of the powder obtained by drying this gel at 300 ° C. was 5
It was 2Å.

91 kg of the above gel (TiO 2₂8.46k
g) and 20 kg of pure water are added and well stirred, and TiO 2 is added.₂concentration
It was 7.6% by weight. Seal the tank at 60 ° C for 2 hours
Titanium hydroxide was sufficiently dispersed by heating and stirring. pH is
At 7.3, add 63% nitric acid to adjust the pH to 2.1.
It was SiO₂Na-free silica sol 4 with a concentration of 15.1% by weight
7.8 kg (SiO₂7.22 kg), ammonium sulfate binding
Crystal 0.7 kg (SO₃0.42 kg), boric acid aqueous solution
(H₃BO₃Concentration 2.0% by weight) 80 kg (B₂O
₃0.98 kg) was added. Then lanthanum nitrate crystal
(La₂O₃Concentration 37.6% by weight) 1.35 kg (La
₂O₃0.51kg), 85% phosphoric acid aqueous solution 0.63k
g (P₂O_Five0.39 kg), vanadyl sulfate aqueous solution (V
₂O_FiveConcentration 19.75% by weight) 5.5 kg (V₂O
_Five1.09 kg) is added and finally cesium sulfate aqueous solution is added.
(Cs₂SO_FourConcentration 50% by weight) 1.7 kg (Cs₂S
O_Four0.85 kg) was added. Enough of the resulting slurry
While stirring, heat to evaporate the water (TiO 2₂+
SiO₂+ V₂O_Five+ Cs₂O + SO₃+ B₂O₃+ L
a₂O₃+ P₂O_Five) To a concentration of 18.6% by weight
Contracted.

Next, potassium-exchanged K- was added to this slurry.
Mordenite (K exchange rate 100%, SiO ₂ / Al ₂ O
₃ (molar ratio) = 30) slurry (K-mordenite concentration 25% by weight) 4.2 kg (K-mordenite 1.05)
kg) was added and mixed well. The slurry was dispersed by a homogenizer and spray-dried by a spray dryer to obtain a powder, which was dried at 150 ° C. for one day and then calcined at 550 ° C. to obtain a catalyst A containing 5% by weight of K-mordenite. Table 1 shows the chemical composition and physical properties of catalyst A.

Example 2 In the same manner as for catalyst A, K-
A catalyst B containing 10% by weight of mordenite was obtained. Table 1 shows the chemical composition and physical properties of catalyst B.

Example 3 In the same manner as for catalyst A, K-
A catalyst C containing 20% by weight of mordenite was obtained. Table 1 shows the chemical composition and physical properties of catalyst C.

(Example 4) Instead of K-mordenite, KY type zeolite (K exchange rate 95%, SiO ₂ / Al) was used.
₂ O ₃ (molar ratio) = 18) was used in the same manner as for catalyst A to obtain catalyst D containing 10% by weight of KY type zeolite. Table 1 shows the chemical composition and physical properties of catalyst D.

Example 5 Instead of K-mordenite, K-ZSM-5 (K exchange rate 100%, SiO ₂ / Al ₂
O ₃ (molar ratio) = 70) was used and a catalyst E containing 510% by weight of K-ZSM-510 was obtained in the same manner as the catalyst A. Table 1 shows the chemical composition and physical properties of the catalyst E.

(Comparative Example 1) A catalyst F containing no crystalline aluminosilicate was obtained in the same manner as the catalyst A.
Table 1 shows the chemical composition and physical properties of the catalyst F.

Example 6 In the same manner as for catalyst A, K-
A catalyst G containing 45% by weight of mordenite was obtained. Table 1 shows the chemical composition and physical properties of the catalyst G.

Example 7 In the same manner as for catalyst A, Cs
A catalyst H containing 10% by weight of mordenite was obtained. Catalyst H
Table 1 shows the chemical composition and physical properties of.

Comparative Example 2 In the same manner as for catalyst A, K-
A catalyst I containing 60% by weight of mordenite was obtained. Table 1 shows the chemical composition and physical properties of catalyst I.

(Example 8) TiO used in Example 1₂
79.6 kg (TiO 2) of 9.3 wt% concentration of titania gel
₂7.40 kg) and pure water 18 kg are added and well stirred,
TiO₂The concentration was 7.6% by weight. Seal the tank, 6
Warm and stir at 0 ° C for 2 hours to fully disperse titanium hydroxide
Let Nitric acid was added to this to adjust the pH to 3.3.
Next, 0.32 kg of ammonium sulfate crystals (SO₃0.19
kg), vanadyl sulfate aqueous solution (V₂O_FiveConcentration 19.75
% By weight 2.89 kg (V₂O_Five0.57 kg) added
And finally, cesium sulfate aqueous solution (Cs₂SO_FourConcentration 50
% By weight) 0.86 kg (Cs ₂SO_Four0.43 kg)
added. Heat the resulting slurry with sufficient stirring
To evaporate water (TiO₂+ V₂O_Five+ Cs₂O + S
O₃) Was concentrated to a concentration of 17.2% by weight. Next
Potassium-exchanged K-mordenite (K
100% conversion rate, SiO₂/ Al₂O₃(Molar ratio) = 3
0) dry powder 1.57 kg (K-mordenite 1.4
1 kg) was added and well mixed and dispersed. This slurry
After further dispersing with a homogenizer, spray dry
Dry the powder obtained by spray-drying at 150 ° C for one day
Then, it is baked at 550 ° C. to give 14.1% by weight of K-mordenite.
A catalyst J containing was obtained. Shows the chemical composition and physical properties of Catalyst J
Shown in 1.

(Example 9) A catalyst K was obtained in the same manner as in Example 8 except that the aqueous potassium sulfate solution was used. Table 1 shows the chemical composition and physical properties of the catalyst K.

(Example 10) Examples 1 to 9 and Comparative Examples 1 to 1
For the catalysts A to K obtained in 2 above, the reaction results when a production experiment of phthalic anhydride by vapor phase catalytic oxidation of o-xylene was performed using a fluidized bed reactor (SUS-304, 83 mmφ × 3400 mmL). It shows in Table 2. The conversion rate of o-xylene and the yield of phthalic anhydride were calculated from the formulas shown in Table 2. The reaction conditions are as follows.

<Reaction conditions> o-xylene supply rate 230 g / hr (o-xylene: sulfur-containing concentration 1000 ppm, nitrogen-containing concentration 500 ppm) Air amount 2200 Nl / hr Linear velocity (empty column standard) 17 cm / sec Air / o-xylene Ratio 12.2 kg / kg Pressure 0.9 kg / cm ² -G Reaction temperature 340 ° C. Catalyst amount 5 L

Example 11 Examples 1 to 9 and Comparative Examples 1 to 1
Table 2 shows the reaction results when an experiment for producing phthalic anhydride by vapor-phase catalytic oxidation of naphthalene was carried out using the same fluidized bed reactor as in Example 10 for the catalysts A to K obtained in No. 2. The conversion of naphthalene and the yield of phthalic anhydride are shown in Table 2.
It was calculated according to the calculation formula described in the above. The reaction conditions are as follows.

<Reaction Conditions> Naphthalene supply rate 275 g / hr (naphthalene: sulfur-containing concentration 1000 ppm, nitrogen-containing concentration 500 ppm) Air amount 2200 Nl / hr Linear velocity (empty column standard) 17 cm / sec Air / naphthalene ratio 10.4 kg / kg Pressure 0.9 kg / cm ² -G Reaction temperature 320 ° C Catalyst amount 5L

[0057]

[Table 1]

[0058]

[Table 2]

[0059]

[Equation 1]

[0060]

[Equation 2]

[0061]

[Equation 3]

[0062]

[Equation 4]

[0063]

[Effects of the Invention] By containing a certain amount of crystalline aluminosilicate (zeolite) in addition to the essential components such as titanium oxide, it has sufficient strength and moderate bulk density, high activity and high selectivity. A fluidized bed catalyst is obtained, which can be effectively used for vapor phase catalytic oxidation of aromatic hydrocarbons (particularly o-xylene and naphthalene) to produce phthalic anhydride.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi, etc. 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Inside the Chiba Works, Kawasaki Steel Co., Ltd. (72) Noboru Hirooka 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Address Kawasaki Steel Co., Ltd., Chiba Works (72) Inventor Hiroshi Fujishima 13-2, Kitaminato-cho, Wakamatsu-ku, Kitakyushu-shi, Fukuoka Prefecture Catalytic Chemicals Co., Ltd. Wakamatsu factory (72) Inventor Susumu Fujii Wakamatsu-ku, Kitakyushu, Fukuoka Prefecture 13-2 Kitaminato-machi Catalyst Wakamatsu Factory of Kasei Co., Ltd.

Claims (8)

[Claims] 1. A gas phase contact of aromatic hydrocarbons containing titanium oxide, a vanadium compound, an alkali metal compound and a sulfuric acid compound as essential components, and containing 1 to 50% by weight of a crystalline aluminosilicate (zeolite). Fluidized bed catalyst for oxidation. 2. A gas phase catalytic oxidation of an aromatic hydrocarbon according to claim 1, further comprising at least one component selected from silica, boron oxide, and an oxide of phosphorus and an oxide of a rare earth metal. Fluidized bed catalyst. 3. The contents of titanium oxide, vanadium compound, alkali metal compound and sulfuric acid compound are 20 to 90% by weight, 2 to 13% by weight and 2.0 to respectively as oxides.
The fluidized bed catalyst for vapor phase catalytic oxidation of aromatic hydrocarbons according to claim 1 or 2, which is 5.0% by weight and 1.0 to 4.5% by weight. 4. The fluidized bed catalyst for vapor phase catalytic oxidation of aromatic hydrocarbons according to claim 1, wherein the crystallite size of titanium oxide is 300 Å or less. 5. A raw material comprising an aromatic hydrocarbon and an oxygen-containing gas, the raw material comprising titanium oxide, a vanadium compound, an alkali metal compound and a sulfuric acid compound as essential components, and 1 to 50% by weight of a crystalline aluminosilicate (zeolite). A process for producing an aromatic carboxylic acid anhydride, characterized by performing a gas phase catalytic oxidation using a fluidized bed catalyst contained therein. 6. The catalyst further comprises silica, boron oxide,
The method for producing an aromatic carboxylic acid anhydride according to claim 5, which contains at least one component selected from phosphorus oxides and rare earth metal oxides. 7. The content of the titanium oxide, vanadium compound, alkali metal compound and sulfuric acid compound as an oxide is 20 to 90% by weight, 2 to 13% by weight, and 2.
The method for producing an aromatic carboxylic acid anhydride according to claim 5 or 6, which is 0 to 5.0% by weight and 1.0 to 4.5% by weight. 8. The method for producing an aromatic carboxylic acid anhydride according to claim 5, wherein the crystallite size of the titanium oxide is 300 Å or less.