JPS58170543A - Preparation of catalyst composition - Google Patents

Abstract

PURPOSE:To obtain a catalyst enhanced in strength and flowability, by drying after spraying a mixed slurry consisting of a crystalline composite oxide containing V and P and showing specific X-ray diffraction peak, an aqueous solution containing V and P and silical sol. CONSTITUTION:A tetravalent V-ion containing solution is prepared and reacted with phosphoric acid to prepare a first component being a V-P composite showing X-ray diffraction peak shown by a table I . On the other hand, V2O5 is added to an aqueous solution containing phosphoric acid and oxalic acid to obtain a second component and 10-50wt% silica sol slurry is further prepared separately as a third component. In the next step, the first component and the second component are mixed to form a first slurry which is in turn mixed with the aforementioned third component to form a mixed slurry and the resulting mixed slurry is spray dried at 120-350 deg.C to obtain a catalyst composition. This catalyst composition is especially suitably used as a catalyst for preparing maleic anhydride due to oxidation of n-butane.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for making a catalyst composition. More specifically, the present invention relates to a method for producing a catalyst composition suitable for producing maleic anhydride from the oxidation of n-butane.

In method K for producing maleic anhydride by vapor phase oxidation of hydrocarbons with a carbon number of 411F (n-butane, n-butene, butadiene, etc.), a composite oxide containing panadium and phosphorus as essential components is effective. (U.S. Pat.
It has been reported that O)xPmOγ) is effective as an active ingredient. [E. Bordes. Be Curtain.
Journal of Catalysis
s,'P,Oourtine,. T. Oatal. )z
7,236 (lta 7F)] This compound monocrystalline phase can be identified by exhibiting an x-ray r pattern as shown in Table 1 below.

According to the knowledge of the present inventors, the crystal phase of this compound is . n-butane. As a gas-phase oxidation catalyst for n-butenes, it has considerably higher activity than the amorphous composite oxide catalyst based on Jubei's manufacturing method, and in particular for the oxidation of n-butane, it can be used even in the low temperature range of about 100°F. It has the characteristic that the reaction progresses. Therefore, it is preferable for the process to use a catalytically active species having the X-ray softening peak shown in Table 1 above. The catalyst produced by the present invention also takes the form of an active species having the above-mentioned peak in the reaction system.

on the other hand. The reaction to produce maleic anhydride by gas-phase oxidation from a number of hydrocarbons is a strongly exothermic reaction, including the complete oxidation (i.e., the production of carbon monoxide and carbon dioxide) as a side reaction. Also from the point of view of energy efficiency. It is also because the explosive limit concentration of feedstock hydrocarbons relative to air is low. It has been thought that a fluidized bed catalytic oxidation reaction is suitable. Examples of catalysts developed for this purpose include vanadyl oxalate solutions. phosphoric acid. Silica sol. Furthermore, spray a mixture containing appropriate activity-promoting ingredients. It has been prepared by drying. (British Patent No. 42t↓07j, etc.) The catalyst obtained in this way is n-pute/. It is effective for oxidizing butadiene, etc. The activity is not sufficient for the oxidation of n-butane. Usually, reaction temperature of 200°C or higher is required. Regarding fluidized bed catalysts for the oxidation of n-butane
Some reports have been made. For example, JP-A-Sho Gutter l26
! In issue 17. A complex oxide containing phosphorus and vanadium is formed by contacting a pentavalent vanadium compound with a trivalent phosphorus compound. Then, it is ground into a fine powder. An example of application to a flow reaction is described. Although it is possible to extract crystalline active ingredients using this method, and it is possible to improve the activity. The strength and fluidity of the catalyst are not sufficient.

Regarding the crushed fluidized bed reaction using such fine powder of catalytically active components, %Kaisho jθ-rite. Tokukai Shoj4-
The possibility was also pointed out in cases such as No. 33011. Tokukai ShojG-4
No. J631 also proposes the possibility of producing a fluidized bed catalyst by depositing a composite oxide containing phosphorus and panadium on a carrier.

The present inventors. In particular, this is the result of intensive research aimed at developing a catalyst for gas-phase oxidation of n-butane using a fluidized bed. A special crystalline oxide containing vanadium and phosphorus as the first components. g An aqueous solution containing vanadium 2 and phosphorus as two components. A slurry is prepared by mixing silica sol as the third component. By spray drying. Discovered that it was possible to produce a catalyst with excellent strength and fluidity.
This completes the present invention.

below. The present invention will be explained in detail.

In the present invention. The first component shows a special X-ray diffraction nail peak. A crystalline composite oxide containing tetravalent panadium and pentavalent phosphorus is used.

prayer The X-ray diffraction peaks and intensity ratios are as follows.

In addition to the above peaks, /I. jt", λ/j", j.
2. ．． A weak peak with an intensity ratio of about IO-CoO is seen at 2''.

The crystalline composite oxide of the first component is well known, and several manufacturing methods have been reported. For example, ■ In a non-oxidizing acidic solution such as hydrochloric acid solution. Pentavalent vanadium such as vanadium pentoxide. Reduce by using a reducing agent such as oxalic acid. After preparing a solution containing tetravalent vanadium ions and reacting with a pentavalent phosphorus compound, e.g. phosphoric acid. The produced soluble panadium-phosphorus complex. Method of precipitation by adding water (%Kaishojf/-tajtatao). ■A pentavalent vanadium compound such as panadium pentoxide and phosphoric acid. React in an aqueous medium in the presence of a reducing agent such as hydrazine [f] or hydroxylamine hydrochloride. Method for obtaining crystals by concentration or evaporation to dryness (Japanese Patent Application Laid-open No. 1983-
≠jllj issue). or ■ reduction of vanadium pentoxide in an organic medium such as ethanol, ingropanol, or glycerol. A method of reacting with phosphoric anhydride and precipitating the crystals by azeotropic dehydration [7] with a solvent such as benzene (US Patent No. IA CofJ, λrt) is known.

By any of the above methods. A crystalline composite oxide having a main Xk1 diffraction peak as shown in Table 11 can be obtained. Crystal purity and operability. From the perspective of waste disposal, etc., method ① is considered preferable. It is not limited to %.

The composite oxide containing vanadium and phosphorus, which is the first component, can be roughly represented by the following compositional formula: (V204)(PzOs)(JH20)<7). Therefore. The ratio of phosphorus to vanadium is the P/V atomic ratio, which is theoretically /. Since Q,
With vanadium compounds. Phosphorus compounds. P/'v atomic ratio o. t-i. It is preferable to carry out the reaction within the range of sz.

Further, the first component used in the present invention may be partially substituted with various metal ions having a small difference in ionic radius from vanadium ions. As such metal ions. Iron, chromium. Aluminum, titanium, cobalt. Examples include ions such as magnesium. When used as a catalyst, a composite oxide converted to -St with such a metal ion. Enhancement of activity and stabilization of activity can bring about significant improvements. The rate of substitution is o.c. as metal per mol of vanadium element. ooz～O. U, more preferably 0.0/-0.
selected in the range of λ moles. Here are some methods for introducing other metal ions into composite oxides. At the stage of manufacturing composite oxide. These metal ions are converted into hydrochloride. sulfate,
nitrate. Free salts such as carbonates. An example is a method of adding it in the form of an organic salt such as oxalate.

The X-ray diffraction pattern of the substituted solid solution complex acid compound thus obtained is as follows. Although it is slightly shifted from the peak shown in Table-C. ．． 2θ° is within ±0.2”.

The first component is added before preparing the slurry. It is best to pulverize it in advance. For example, IQμ or less, more preferably! Grind to a particle size of μ or less (measurable by coater counter method, etc.). Machines well known to those skilled in the art are used for such processing. For example, hammer mill, jet mill, colloid mill. A Zand grinder etc. can be used, and there is no problem whether a wet method or a dry method is used.

The aqueous solution containing vanadium and phosphorus as the second component in the present invention is. Usually contains substantially tetravalent vanadium and pentavalent phosphorus. It is preferable that at least a part of it exists as vanadyl phosphate, Fluidity of fluidized catalyst. Contributes to improved strength. Although the method for producing such an aqueous solution is not very accurate. Some examples are shown below.

Generally, pentavalent phosphorus compounds are used, for example. In an aqueous solution containing phosphoric acid. Obtained by adding and dissolving a reducing agent and vanadium pentoxide. The atomic ratio of phosphorus element to vanadium element in the aqueous solution is preferably 0.3-/0. In general, aqueous solutions containing vanadyl phosphate are unreliable, and it may be difficult to maintain them safely for long periods of time. Oxalic acid may be present for effeminization of the aqueous solution. The amount is expressed as the molar ratio of oxalic acid to vanadium element K.
λ or less, preferably O. It is in the range of λ~/. If the amount of oxalic acid is too high. Mechanical strength of catalyst. The bulk density. Unfavorably affects the active surface. In other words. If the molar ratio of oxalic acid to elemental vanadium is l. The range below λ can be said to be the range in which vanadyl oxalate is not formed.

As specific examples of methods for producing aqueous solutions, there are the following five methods.

/Secondly, in an aqueous solution containing phosphoric acid and oxalic acid.
Vanadium pentoxide is used at a molar ratio of oxalic acid to vanadium element of /,7 or less. and preferably by adding 0.7 or more. This is a method of preparing an aqueous solution containing vanadyl phosphate and oxalic acid. in particular. Oxalic acid is dissolved in an acidic aqueous medium containing phosphorus rII. It is produced by adding vanadium pentate while maintaining the temperature at which reduction proceeds by slight heating. According to this method K, after the reduction is completed. For the element panadium, /,. There will be less than 2 moles of oxalic acid present.

No. 2K. A reducing agent other than oxalic acid is added to an acidic aqueous solution containing ljic acid. Preferred is hydrazine hydrate. Inorganic reducing agents such as hydrazine or hydroxylamine hydrochloride or phosphate. This method involves adding one or a mixture of two or more selected organic reducing agents such as lactic acid, and then reducing by adding vanadium pentoxide to obtain a homogeneous phosphorus-vanadyl-containing aqueous solution. Preferably oxalic acid is added.

Thirdly. Mix vanadium pentoxide, phosphoric acid, and phosphorous acid in an aqueous medium. This method produces tetravalent vanadium ions through the reducing action of phosphorous acid. From the aqueous solution containing vanadyl phosphate obtained by this method, when left to stand, a crystalline solid that exhibits a characteristic X-ray spectra as shown in Table 3 below precipitates.

Such precipitation of crystalline solids is undesirable from the purpose of the present invention, and if it is necessary to keep the aqueous solution stable for a long period of time, it is preferable to add oxalic acid.

Alcohol may be added to the aqueous solution containing vanadium and phosphorus as described above, if necessary. Organic solvents such as ketones and ethers may be used in combination.

In the present invention, the above-mentioned first component and second component. A catalyst composition is produced by mixing the third component, silica sol, to prepare a slurry, and spray drying the slurry. Silica sol is v4 as /0-jO Shigemonchi's @ degree in advance.
Prepare it in advance. Mix and stir the first and second components. Make a uniform slurry. First ingredient. The ratio of the second and third components is dry weight: first component: second component = 20
710-40:20m Two components: Third component =! 0:10~
Ta0:/0 first component: third component = so:jo~ta0:/
Selected within the range of 0. The dry weight of the second component is.
It can be calculated as vanadium and phosphorus ttVz04 and P,O,.

If the amounts of the first and second components are too small relative to the third component, the catalyst strength will improve. Low activity is seen. Also. 1 of the second component is. If the first component falls below the above range, the tlM. Strength tends to decrease.

The slurry thus obtained was spray dried.
A catalyst composition with excellent fluidity and strength is obtained.

The spray drying conditions are normal. Adjust the air volume and liquid supply amount appropriately. It is best to set the gas S degree in the dry area to /20/3jO℃. The inlet temperature of the drying gas at this time is usually 2
00~3j0℃. In addition, the average value of the catalyst particle diameter after spray drying is adjusted to JO-/0 by adjusting the liquid supply site and the take rotation speed.
It should be within the range of ζi chron. A more preferable range of average particle diameter is UO to 70 microns.

The catalyst composition obtained as above is. Da00~6o
It is more preferable to use the catalyst after firing at a temperature in the range of 0.degree. C. in view of the viscosity of the catalyst. At this time, it is preferable to perform the firing in the presence of air such as butane or in an inert gas atmosphere such as argon or nitrogen. As a result, the X plow shown in Table 1/. It changes into a composite oxide with φ line diffraction hahns.

The catalyst composition obtained as described above is. ! 51! Mobility. A hydrocarbon with excellent strength and activity, and a carbon number of μ. Especially n
- It is suitably used as a catalyst for producing maleic anhydride by oxidizing butane.

below. The present invention will be explained by examples.

Example 1 (Synthesis of first component A-/) Lin Shun (1j Chi, reagent special grade) Ta. j2kg, hydrazine hydrochloride t. jokg, after dissolving hydrazine monohydrochloridejjO9 in demineralized water μ01. Warmed. After raising the temperature to 7j℃. 7.2 Ikg of vanadium pentoxide was added little by little with stirring. After adding all the ingredients, the mixture was further boiled for 1 hour to complete the reduction. After concentrating this liquid under reduced pressure using a rotary evaporator to a liquid volume of approximately 2. The mixture was placed in an evaporating dish and evaporated to dryness at 170°C. After confirming that the constant weight has been reached. Coarsely grind. The solid was boiled and washed with water to completely remove residual hydrochloric acid. After washing with P. It was dried again in a dryer at 70°C and finely ground in a hammer mill to obtain the 1st component (A-/) having an atomic ratio of φ=l. The average particle diameter is z. It was jμ. The X-ray diffraction spectrum of this product matched that shown in Table 1 λ.

Example 2 (Synthesis of first component A) Phosphate t/, Ig, hydrazine hydrochloride IO≠. 7 g, hydrazine monohydrochloride 3 o. og into demineralized water l. De! dissolved in
Warmed. After raising the temperature to 7j℃. Vanadium pentoxide ir.
Add ug little by little while stirring, and after adding the entire amount. Boiling was further performed for 1 hour to complete the reduction. Allow to cool, then add ferric chloride (II'eO13.AH20) r/. 011 water/0
A solution of 0 g was added. Approximately 273 ml of this liquid as it is
Concentrate to a liquid volume of /70°C. Evaporated to dryness in evaporated blood. Confirm that the constant weight has been reached. Through the same process as in Example 1, P/V/IF●=i7'o. Ta/0. A first component (A-1) having an atomic ratio of / was obtained. This thing's X
The line recovery spectrum was within a range of 10 U'' from the position of each peak shown in Table 1.

Examples 3 to 7 (Synthesis of first component A-3 to A-7) In place of ferric chloride, which is the promoting component in Example 2. Chromium chloride, aluminum chloride. Using titanium oxalate, cobalt chloride, and magnesium chloride, oxides mA-3 to A-7 having the element ratios shown in Table 3 below were produced according to the method of Example λ. In addition, according to the change in atomic ratio. The amount of chemicals used in Example 1 was also adjusted. Note that A-/ and ▲11 are also listed in Table-3.

Example t (Synthesis of second component B-/) Phosphoric acid (rt chronic solution) in demineralized water zooy/63! g, and oxalic acid/! 00fi was dissolved and the solution was warmed to goC. Then, panadium pentoxide/Orcog was added little by little and dissolved. The P/V atomic ratio of the solution is l. The resulting solution was viscous and a true color homogeneous solution. By slightly concentrating (V*04+PzOs'll converted oxide concentration was 11% by weight), the molar ratio of residual oxalic acid and panadium element was reduced to 1 mol per 1 mol of vanadium pentafluoride due to the reduction reaction. Since oxalic acid was used, o
．． It becomes r.

Example (Synthesis of second component B) The amount of oxalic acid used is /l! The procedure was the same as in Example r except that g was changed. Converted oxide concentration i. tr. A blue homogeneous solution B-2 of heavy wrinkles was obtained.

In this solution, P/'v=/. It is Ko. The molar ratio of residual oxalic acid to elemental vanadium is O. Ko! It is.

Example IO The same procedure as Example ♂ was carried out except that the amount of phosphoric acid used was 22JOg. Converted oxide concentration aZ. Solution B-J of O weight
I got it.

Example // (Production of fluidized catalyst by spray drying) Example 1
Crystalline active ingredient fine powder (first ingredient) obtained in steps 7 to 7. The uniform background color solution obtained in Example 1-/0 (second component) and silica sol (third component) were mixed at a ratio of 1 gf:S. After sufficiently uniform mixing using a homogenizer, a fluidized catalyst (catalyst A/-4) was produced by spray drying. The results are summarized in Table 1μ. In the same table. Catalyst strength is 100℃. For those fired under a nitrogen stream for one hour. Catalyst particles were collided with an 8US metal plate in a fluid state. The amount of crushing loss within one hour is measured and displayed as an index of mechanical strength. This value becomes smaller for stronger catalysts.

Example 12 (Reaction Example) A fluidized bed catalyst obtained by blow drying was heated at 100°C. It was calcined under a nitrogen stream for several hours, and then the particle size portion of 21-rfμ was sieved. Take the catalyst amount λod. An air mixture gas with a n-butane concentration of μm is passed through at a flow rate of G}{eVj00. The reaction was carried out. The product is absorbed into water. The yield t was determined by potentiometric titration and compositional analysis of the waste gas. The results are in Table 1j
Shown in ^ Example/J (Reaction example) Using the catalyst obtained in Example//. The influence of reaction conditions was investigated.

Assume that GHBV is constant at 300. The reaction was carried out in the same manner as in Example 1λ except that only the degree of n-butane was changed. The reaction results were investigated. The results are shown in Table B.

Implementation/μ (synthesis of second component Bu) V2,/. 3
3kg, gjqb phosphoric acid o. Rugyu, Nitric acid (7.6%) o. l, Aokg and water 4t. Mix jl to make a slurry. The mixture was boiled and heated under reflux for IQ hours while blowing in a small amount of nitrogen and stirring.

The entire amount of v205 was dissolved to obtain a uniform blue solution, which was diluted to /Ql to prepare the second component solution CB-4') vA. The equivalent oxide concentration of this product is approximately. /I. heavy it
9&tefipl. Kono solution (7) P/V=1.0! Yes. Stored in a cool dark place. To adjust the phosphorescence during use. Add desired amount of phosphoric acid.

Example 1j (Creation of fluidized catalyst by spray drying) Middle Example 1
The first component obtained from /,/Ichiyu. The aqueous solution of the second component obtained in Example/q was purified by J. JIl, as the third component. 20%
Silica sol solution. Cocoyu, and rz% phosphoric acid 77
Then, mixing and stirring were continued for 40 minutes using a homogenizer to obtain a homogeneous gel slurry at ℃. The oxide concentration was 30 t%. The fluidized catalyst (A?) was separated by spray drying this slurry. After fluidized firing for λ hours at jOO°C under a nitrogen stream, particles of uj to tJrμ were sieved and used for the reaction.

Example/4 (Production of fluidized catalyst by spray drying) The amount of phosphoric acid was /. A catalyst was produced in the same manner as in Example i6 except that the amount was 30 g. (Catalyst shop io) Example/7 (Reaction example) Catalyst amount λOralt taken. An air mixture gas containing 1 mole of n-butane lII was passed through at a flow rate of GHBVj00.
A flow reaction was performed. As in Example 1, the main product was absorbed in water, and the yield was determined by potentiometric droplet analysis and compositional analysis of the waste gas. The results are shown in Table 7.

Claims (1)

[Scope of Claims] (1) A crystalline composite oxide containing vanadium and phosphorus as a first component and exhibiting the following characteristic X-ray rotation peak. Aqueous solution containing vanadium and phosphorus as second components. and silica sol as a third component to prepare a slurry and spray drying the catalyst composition coe0(±O..2”)(Anticathode Ou-Kα)l!.7 lta.Otsu2hiro.2 λ7, / λl.t 30.l (2) The method according to claim 1, characterized in that the 114 two components are an aqueous solution containing vanadyl phosphate ( 3) The mixing ratio of the first component, second component, and third component is .Dry weight: First component: @ Two components: = 20: Iθ ~ t0: KoO Second component: Third component = jO: 10 ~ta0:/0 first component: third component = zo:.to~deO:/0 ft
(4) The method according to claim 1, wherein the first component vanadium is substantially tetravalent.(5) The second method The method according to claim 1 or λ, characterized in that the component vanadium is substantially tetravalent.