WO1993013042A1

WO1993013042A1 - Process for producing methacrylic acid and methacrolein

Info

Publication number: WO1993013042A1
Application number: PCT/JP1989/000510
Authority: WO
Inventors: Setsuo Yamamatsu; Tatsuo Yamaguchi
Original assignee: Setsuo Yamamatsu; Tatsuo Yamaguchi
Priority date: 1989-05-22
Filing date: 1989-05-22
Publication date: 1993-07-08

Abstract

The invention relates to a process for producing methacrylic acid and methacrolein, which comprises catalytically oxidizing isobutane in a gas phase in the presence of molecular oxygen to produce methacrylic acid and methacrolein in one step with a high productivity in a high yield using a catalyst containing a heteropoly acid and having a composition of P/As-Mo-V/Cu at temperatures up to 350 °C, preferably up to 320 °C, at which said heteropoly acid difficulty decomoses, to thereby maintain the catalytic activity for a long time.

Description

Incense

Method for producing methacrylic acid and methacrolein

Technical field

TECHNICAL FIELD The present invention relates to a method for producing methacrylic acid and methacryloline in a single step by subjecting isobutane to gas phase catalytic oxidation. More specifically, the present invention relates to isobutane in the presence of molecular oxygen in the presence of a heteropolyacid and a erosion medium having a P / As-Mo-V / Cu system composition in a low temperature gas phase. A method for producing methacrylic acid and methacryloline with high selectivity and high yield in one step by catalytic reaction

Background art

Traditionally, saturated hydrocarbons such as isobutane have been considered inert gases. For example, Japanese Patent Application Laid-Open No. 55-2619 describes that it is used as a diluent for a reaction gas in oxidation of olefins and aldehydes. Since isobutane is poor in reactivity, it is converted to isobutylene using a dehydrogenation catalyst or an oxidative dehydrogenation catalyst, and then oxidized to metacrolein or methanol. In general, a method of converting to lactic acid was used (for example, Japanese Patent Application Laid-Open No. 58-189130).

In recent years, research has been conducted to oxidize isobutane and convert it into useful compounds such as methachlorin or methacrylyl II. British Patent 1,340,891 states that oxides composed of antimony, molybdenum, etc. It has been shown that a mixture of butane and oxygen is brought into contact in the gaseous phase, but with very low yields, methacrolein can be obtained in a single step from isobutane. However, this method does not yield methacrylic acid.

U.S. Pat. No. 4,260,822 is the first to show that methacrylic acid can be produced in a single step from isobutane. According to this, a specific catalyst consisting of oxides of antimony, molybdenum and phosphorus is used, and methacrylic acid is obtained with high selectivity from isobutane in one step. For example, if the isobutane concentration is 10 mol%, 10% of the isobutane will react and 50% of it will be converted to methacrylic acid. However, under these conditions, the content of methacrylic acid in the reaction gas is as low as 0.5 mol%, and the productivity per unit weight of the edible medium is extremely low. Also, when the isobutane strain is increased and the reaction is performed at 28 mol%, the reaction yield tends to decrease. Therefore, it is still insufficient for an industrial production method in terms of productivity per unit weight of the medium.

Then, Japanese Patent Application Laid-Open No. Sho 62-1323282 discloses that heteropolyacid is used as an erosion medium, and isobutane having a low concentration of 30 to 60 mol% is reacted to produce methacrylic acid. Methods have been proposed to produce with high yields and high productivity. In other words, high efficiency is obtained by a very distinctive method, in which a heteropolyacid containing molybdenum is used as a catalyst with phosphorus as the central element, and isobutane and oxygen are alternately brought into contact with the erosion medium. Rate and wealth productivity. However Further, a special reaction apparatus is required to alternately bring isobutane and oxygen into contact with the catalyst, and the operation is complicated. For this reason, an industrial production method may be economically disadvantageous in this point as compared with a normal production method in which a mixed gas containing isobutane and oxygen is simply brought into contact with a catalyst.

It is also known that molybdenum-based heteropolyacids gradually decompose the heteropolyacid structure at temperatures exceeding 350 ° C, albeit gradually. Nevertheless, in this method the reaction is carried out at temperatures between 350 and 370 ° C. This is because if the reaction temperature is lowered because the catalytic performance is not yet sufficient, the reaction yield is greatly reduced. In fact, a catalyst that exhibits an excellent reaction yield at a reaction temperature of preferably 320 ° C or less, because the heteropolyacid is thermally decomposed even at about 330 ° C under the reaction conditions, is required. That is, a mixed gas containing isobutane and oxygen is brought into gaseous phase contact with the catalyst at a reaction temperature of 350 ° C or less, more preferably 320 ° C or less, to stably produce methacrylic acid for a long time. There has been an eager need for a method of producing with high productivity and high yield.

Disclosure of the invention

In the technical background described above, the present inventors provide a gas phase contact of a mixed gas containing isobutane and oxygen with a catalyst at a reaction temperature of 350 ° C or less, more preferably 320 ° C or less. In order to find a catalyst that shows excellent reaction performance just by performing a simple reaction, we conducted intensive research on a heteropoly catalyst and found that many elements and innumerable combinations were obtained. Among the pitting agents, the erosion medium containing a heteropolyacid containing P and / or As as a central element, containing Mo as a coordinating element, and having a P / As-Mo-V / Cu system composition. As will be described later, methacrylic acid and methacrolein can be produced with high selectivity simply by bringing a mixed gas containing isobutane and oxygen into gaseous phase into contact with a catalyst. The combination of at least one of alkali metals, alkaline earth metals, and T 1 as a corrosion medium makes it possible to obtain methacrylic acid and methacrylate even at low reaction temperatures below 320 ° C. It has been found that mouth lanes can be produced with high reaction yields and high productivity. In particular, corrosion media containing at least one of alkali metals, alkaline earth metals, and T 1 have the effect of lowering the reaction temperature, as well as the decrease in activity over time and the selection of methacrylic acid. It has been found that the rate of decrease in the rate over time is extremely small, and that the catalyst becomes a very excellent corrosion medium with a long catalyst life. The present invention has been completed based on these findings.

That is, the present invention contains a heteropolyacid containing P and / or As as a central element and containing Mo as a coordinating element, and has the following formula (1):

A aM o ₁₂ B bC cD dO e-(1)

(Wherein A represents P and / or As, Mo represents molybdenum, B represents V and Z or Cu. C represents an alkali metal, alkaline It represents at least one of the earth metals, T 1. D is Ag, Zn, T i, Z r, b. T a, C r, W, M n, F e, C o NB, A 1, G e,

R h, S n, S b B S e, T e, Y, L a .C e

It represents at least one of Pr and Nd. 〇 stands for oxygen. a, b, c, d, and e represent the atomic ratio of each element, a = 0.5-3. b = 0.01-3, c = 0-3, and d = 0-3. e is a numerical value determined by the valence and atomic ratio of each element. (B) contacting a mixed gas containing isobutane and molecular oxygen at 240 to 350 ° C in the gas phase with a catalyst having the composition represented by the formula (1). It relates to the method of manufacturing the Kuguchi Rain.

In the present invention, it is important to use the catalyst having the above composition as a catalyst, and high productivity can be achieved by bringing a mixed gas containing isobutane and oxygen into gas phase contact with the catalyst of the present invention. Methacrylic acid and methacrolein can be obtained with high yield and high yield. Lack of essential components in the above composition, that is, P / As-Mo-V / Cu If the composition deviates from the above range, as will be apparent from Comparative Examples 1 to 14, the reaction method in which a mixed gas containing isobutane and oxygen is brought into gaseous phase contact with the catalyst. The selectivity for methacrylic acid is significantly reduced.

According to Japanese Unexamined Patent Publication No. Sho 62-132328, in a reaction in the presence of oxygen, oxygen species that cause excessive oxidation are generated on the surface of the erosion medium. This further oxidizes methacrylic acid and methacrolein, reducing their selectivity. Here is the book It has been found that in the eclipse medium of the invention, methacrylic acid can be unexpectedly obtained with a high selectivity by a reaction in the presence of oxygen. There are many disadvantages about why this unexpected effect can be obtained, but the combination of V and / or Cu with a catalyst containing a heteropolyacid and having a P / As-Mo system composition is , V or Cu forms a stable salt with the heteropolyacid or replaces a part of the coordination element of the heteropolyacid, resulting in excessive oxidation of methacrylic acid and methacrylone. It is considered that the formation of oxygen species on the catalyst, which may cause the occurrence of oxidization, is specifically suppressed.

Further, when the edible medium of the present invention is used, the reaction temperature can be lowered, and the reaction can be carried out at a temperature at which thermal decomposition of the heteropolyacid is difficult to occur. Further increase the activity at low temperatures, 320. In order to carry out the reaction at a temperature of not more than C, it is preferable that the catalyst contains at least one of an alkali metal, an alkaline earth metal and T 1. In this case, the effect of improving the thermal stability of the catalyst can also be obtained, and when combined with the effect of lowering the reaction temperature, at least one of the alkali metals, the alkaline earth metals, and T 1 is used. A catalyst containing one or more catalysts is an erosion medium with a long catalyst life and low durability. Thus, the use of at least one of the alkali metals, argali earth metals, and T1 in combination with vanadium and Z or saw increases the selectivity of metaacrylic acid. While maintaining the above values, excellent effects such as a high isobutane conversion and a low reaction temperature can be obtained. In addition, by lowering the reaction temperature, the reaction products such as methacrylic acid and methacryloline are sequentially oxidized to be effectively suppressed from being oxidized to carbon dioxide. There is also a secondary effect of improving the selectivity of combining methacrylic acid with the methacrylic acid lane. In particular, when this reaction is carried out in a fluidized-bed reactor, the reaction product is generally liable to be further excessively oxidized, and the selectivity of methacrylic acid is reduced as compared with a fixed-bed reaction. Often. However, in the method of the present invention, the reaction can be carried out at a low temperature, so that dimethacrylic acid selectivity can be obtained even in a fluidized bed reactor.

Hereinafter, the present invention will be described in more detail. The catalyst used in the present invention contains P and Z or As as a central element, contains heteropolyacid containing Mo as a coordinating element, and contains V and V as catalyst constituent elements. Or contain Cu. The atomic ratio of the catalyst constituent elements to each other is Mo: 12, P and / or As is 0.5 to 3, V and Z or Cu are 0.01 to 3, preferably 0.05 to 2.0. It is. More favorable results can be obtained by using at least one of alkali metal, alkaline earth metal and T1 in the above composition.

In this case, at least one kind selected from Li, Na, K, Rb and Cs can be used as the alkali metal. Or at least one selected from Mg, C a, S r, and B a. These Al metal, Al earth metal and T1 are 0.01 to 3, Preferably, it is added in the range of 0.1 to 2. Also, Ag, Zn, Cd, Ti, Zr, N "b, Ta, Cr, W, Mn, Fe, Co, Ni, Rh, Sn, Bi, When at least one selected from the group consisting of Se, Te, Y, La, Ce, Pr, and Nd is added as a catalyst element, the value should be 0.01 to 3. It is particularly preferred that the value be 0.05 to 1.

Heteropolyacids containing P and Z or As as central elements and containing Mo as a coordinating element include linmolybdic acid, arsenic molybdic acid, and linsenic molybdic acid. It is known to adopt various structures (Chemistry, Vol. 29, No. 853, Sasaki, Matsumoto), and the ratio of central element to coordinating element is 1/12, 1/11, 1 / Various structures such as 10, 1/9, 2/17, and 2/18 are known. Among them, those having a 1/12 structure called a Keggin structure are particularly suitable.

Vanadium preferably substitutes a part of the coordinating element of linmolybdic acid, arsenic molybdic acid, and arsenic molybdic acid. As such, it may exist in a state outside the heteropolyacid.鋦 may be present as a metal salt of heteropoly acid or in the form of an oxide or oxyacid, although the chemical state is extremely complicated and the details are not clear. It may exist in a state other than heteropolyacid. Further, the constituent elements of the heteropolyacid may be partially substituted. Preferably, the oxide or heteropolyacid gold is used. It should be present as a genus salt. Alkali metals, alkaline earth metals, and T 1 exist mainly in the form of heteropolyacid salts. Also, A g, Z n, C d, T i, Z r, N b, T a,

C r, W, M n, F e, C o, N R h, S n, B i,

Se, Te, Y, La, Ce, Pr and Nd may be present as a metal salt of a heteropolyacid like Cu, or may be an oxide or oxyacid. Thus, it may exist in a state other than the heteropolyacid. Further, the constituent elements of the heteropolyacid may be partially substituted.

The catalyst used in the present invention can be easily prepared by a known method (preparation operation). Generally, linmolybdenic acid, limbana domolybdic acid, arsenic molybdic acid, arsenic acid When a heteropolyacid or salt thereof, such as nadomolibdenic acid, is in solution or slurry, or under conditions where these polyhedral polyacids are formed, Oxides, hydroxides, carbonates, nitrates, chlorides, oxyacids, phosphates, oxalates, acetates, organic compounds containing compounds containing the necessary elements as catalyst constituent elements After adding in the form of a compound or metal, evaporate to dryness. The obtained catalyst is calcined at 250 to 500 ° C. for 2 to 24 hours in an air atmosphere to obtain a target catalyst. However, the catalyst preparation method and starting materials for catalyst preparation are not limited to those described above, and other preparation methods and starting materials may be used. For example, salts of various nitrogen-containing compounds of heteropolyacid as starting materials Can be used. Useful ^ include ammonium salts or organic amine salts with pyridine, quinoline, piperazine and the like. In the process of preparing the catalyst, such various nitrogen-containing compounds may be added.In the case of an ammonium salt, a water-soluble ammonium salt such as ammonia water, ammonium chloride, or ammonium nitrate is used as an ammonium ion source. Can be added. These ammonium salts or organic amine salts are used as an etchant after baking at 300 to 600 ° C. to remove one or all of the nitrogen-containing compounds. Firing in an inert gas is more preferable. After calcination in an inert gas, calcination with an oxygen-containing gas can also be performed.

These erosion media can be used in the form of being supported on a carrier or diluted and mixed. Examples of the carrier include silica, α-alumina, silicon carbide, titania, zircon air, silica earth, silica alumina, water-soluble silica sol, and silicon carbide. A high porosity inert carrier with a large number of macropores is preferred. In the presence or absence of water on these carriers, usually up to the same weight as the carrier! : Adhere or mix.

The shape of the erosion medium is preferably formed into an arbitrary size and shape, such as a pellet or a granule, depending on the use state, and the erosion medium is preferably used with a certain mechanical strength. For molding, a tableting machine, an extrusion molding machine, a Malmerizer (trade name of Fuji Padal Co., Japan), a rolling granulator, etc. are used. It is not clear how much the catalyst used in the present invention works in the reduced state under the reaction conditions, but the catalyst in the high reducing state shows a yellow-green color over the reaction time. The color often changes to a color close to that of a heteropolyacid, and it does not exhibit the navy blue color known as heteropoly blue. It is presumed to be in the following low reduction state. However, the degree of reduction is not limited to this range, since the reduction state changes greatly depending on the catalyst composition, reaction gas composition, reaction temperature, and the like.

As a source gas to be supplied to the reaction, a mixed gas containing isobutane and oxygen is used. The appropriate degree of isobutane is from 10 to 80 mol. If the concentration of isobutane is less than 10 moles, the production of methacrylic acid per reactor becomes extremely small, and the economics that can be implemented industrially cannot be obtained. . More preferably, it is in the range of 20 to 60 mol. Isobutane used for the corrosion reaction does not need to be particularly high-purity, so paraffin-based hydrocarbons that do not affect the reaction coexist at about twice the molar amount with isobutane. Can be used. Preferably, isobutane in LPG butane, FCC butane or n-butane isomerization reaction product is isolated by distillation and used. When the olefin is mixed in about 0.1 times or more with respect to isobutane, by-products and the like are increased. Therefore, the mixing of olefins other than isobutylene should be avoided. The molar ratio of oxygen to isobutane used in the present invention is preferably 0.05 to 1 to 1 to 1, more preferably 0.1 to 1 to 0.6 to 1. If the oxygen molar ratio is high, complete oxidation proceeds too much, and the generation of carbon dioxide increases. Conversely, when the oxygen molar ratio is small, a sufficient amount of oxygen is not supplied for isobutane oxidation, so that the conversion ratio of isobutane decreases. Further, if the oxygen molar ratio is too small, the catalyst is excessively reduced as the reaction proceeds, which is not preferable.

When selecting the oxygen concentration and isobutane concentration, it is preferable to consider that the mixed gas composition does not enter the explosion range. The molecular oxygen used for the corrosion reaction may be pure oxygen gas, but it is generally economical to use air because it does not need to be particularly high in purity. In addition to nitrogen, inert gases such as helium, argon, and carbon dioxide, which do not adversely affect the reaction, are used as diluents for the source gas to prevent the gas composition from entering the explosion range. Can be prevented. In this case, these inert gases are often selected in a molar ratio of 1/10 to 10/1 with respect to isobutane.

In addition, in order to prevent the reaction product, methacrylic acid, from being further oxidized on the corrosion medium to form carbon dioxide, etc., together with molecular oxygen and isobutane, water vapor is applied to isobutane. Therefore, it is effective to add them in a molar ratio of 1/5 to 5/1, and the selectivity of methacrylic acid is increased. It is preferably in a molar ratio of 1/3 to 3/1. The reaction temperature is selected from the range of 240 to 350 ° C. A range of 270 to 320 ° C is particularly preferred. If the reaction temperature is high, decomposition of the catalyst and complete oxidation of the reaction product are likely to occur. In particular, when a catalyst containing at least one of alkali metal, alkaline earth metal, and T1 as a catalyst constituent element is used, even if the reaction temperature is 320 ° C or less, the methacrylic acid can be obtained. Can be produced with high reaction yield and high productivity. The reaction pressure can be set widely from decompression to pressurization, but it is industrially advantageous from atmospheric pressure to about 1 MPa.

The contact time between the feed gas and the catalyst (the value obtained by dividing the bulk volume of the catalyst by the reaction temperature of the feed gas and the volumetric gas flow rate at the reaction pressure) varies depending on the isobutane roughness or the reaction temperature. 1 to 10 seconds, preferably 0.5 to 5 seconds is suitable. In carrying out the present invention, a fixed bed, a fluidized bed, a moving bed and other types of reactors can be appropriately selected as a reactor to be used. Ind is separated from other oxidation products by a known series of methods such as cooling, extraction, and distillation, and can be purified by any known method. When unreacted isobutane is recovered and recycled to the reactor, carbon monoxide, carbon dioxide, and other reaction products may be mixed as long as the reaction is not affected. In particular, the supply of methacrolein together with a feed gas containing isobutane to the reactor can effectively convert methacrolein to methacrylic acid. it can BEST MODE FOR CARRYING OUT THE INVENTION

EXAMPLES The present invention will be described in more detail with reference to examples, but the scope of the present invention is not limited to these examples.

[Implementation 钶]

Example 1

144.0 g of molybdenum trioxide, 8.27 g of vanadium pentoxide and 12.5 g of phosphoric acid (85 double S!) Were added together with 1000 ml of water to a pyrex three-necked flask, and the mixture was heated under reflux for 24 hours. The insoluble components of the aqueous solution were concentrated by extraction and concentrated to give reddish-brown crystals, which were analyzed by X-ray diffraction, atomic absorption analysis and ³¹ P-NMR. The ratio was 1: 11: 1 Molybdovanadolinic acid (PM o „V) The crystal water of the obtained crystal was about 30. The crystal 23.2ε and the chloride First, O.lg was dissolved in 200 ml of water heated to 80 ° C. Then, 2.0 g of cesium nitrate dissolved in 50 ml of water was added, and 23.8 g of pyridine dissolved in water were added. The resulting slurry solution was concentrated and dried for 12 hours at 120 ° C. The obtained solid was pulverized to select particles of 10 to 20 mesh. . Was calcined for 3 hours in a nitrogen stream ^{450 e C P 1. iM o izV} 1. iC u D. llC s 1. 1; is斂媒having the composition (atomic ratio excluding oxygen hereinafter the same) was obtained .

5 g of this medium was filled into a U-tube made of Pyrex having an inner diameter of 6 mia, and set in a thermostat. Set the temperature of the water bath to 320 ° C and Butane 30 mol. /. A mixed gas of 15 mol% of oxygen, 20 mol% of steam and 35 mol% of nitrogen was supplied with a contact time of 3.6 seconds. After 100 hours, the reaction gas was analyzed by gas chromatography and found that 10.3% of the isobutane was converted, the selectivity for methacrylic acid was 55.7%, and the metachlorin Was 16.3%. Isobutylene was not detected. The reaction was performed under the same conditions for 1000 hours. 10.1% of the isobutane was converted, the selectivity for methacrylic acid was 56.3%, and the selectivity for methacrylic acid was 15.9%.

Example 2

By the same catalyst preparation method as in Example 1, a catalyst having a composition of PLiMowV ^: was obtained. Of the starting materials described in Example 1, -II chloride and cesium nitrate were not used. A contact reaction was performed under the same reaction conditions as in Example 1. After 20 hours, the reaction gas was analyzed by gas chromatography. As a result, 5.3% of isobutane was converted, the selectivity of methacrylic acid was 41.1%, and Was 19.2%.

Example 3

Ρ the same catalyst preparation method as in Example 1 to obtain a catalyst having the composition _{_{_{Μ ο 12 C u 0. 5}}} . ! PM o as a starting material; to Ri I or ₃ V to 12-mode Li blanking drill down acid (H ₃ PM 0 ₁₂ 〇 _4-neck · 30Η ₂ ○: Nippon Muki Kagaku) was used. Of the starting materials described in Example 1, cesium nitrate was not used. The contact reaction was carried out under the same reaction conditions as in Example 1. After 20 hours, the reaction gas is supplied to the gas chromatograph. As a result, 5.4% of isobutane was converted, the selectivity for methacrylic acid was 42.1%, and the selectivity for methacoline was 22.5%.

Example 4

The same catalyst preparation method as in Example 1 was used.

A catalyst having a composition of P ₃ M 0 ₁₂ V _G - ₅ AsiCu u j- ₂ was obtained. Na us, starting materials used for catalyst preparation in other than those described in Example 1 12 mode Li blanking de-phosphate _{_{_{(H 3 PM o 12 0 4D}}} -30H 2 0: manufactured by Nippon No machine Chemical) using arsenate CH ₃ a s 0 _4). The corrosion reaction was performed under the same reaction conditions as in Example 1 except that the reaction temperature was 340 ° C. After 20 hours, the reaction gas was analyzed by gas chromatography.It was found that 10.0% of the isobutane was converted, the selectivity for methacrylic acid was 47.2%, and the selectivity for the methanol mouth lane was 19.3. %.

Comparative Example 1

Dissolve 23.2 g of _12- molybdolinic acid (H ₃ PMo ₁₂ (U. '30ii ₂₀ : Nippon Inorganic Chemical)) in 100 ml of water, and treat as in Example 1 without using other components. A medium was made of cocoon, and the reaction was carried out under the same conditions as in Example 1. After 20 hours, the reaction gas was analyzed by gas chromatography, and 4.3% of isobutane was converted. The selectivity for lylic acid was 18.3%, and the selectivity for methacrolein was 21.1%. Comparative Examples 2 to 14 By the same catalyst preparation method as in Example 1, a catalyst having a composition shown in Table 1 having a catalyst composition outside the scope of the present invention was produced, and a part of the reaction temperature was shown in Table 1. The contact reaction was carried out under the same reaction conditions as in Example 1 except that the temperature was changed to the described temperature. Table 1 shows the reaction growth after the reaction for 20 hours.

0

Specific reaction isophthalane methacrylic acid

Catalyst composition ΐιπι degree Conversion rate Selectivity Selectivity example ° c%%%

2 P 340 10.5 18.3 21.1

3 P-ι.3M012K2 340 7.3 34.3 15.3

4 340 8.0 30.2 17.2

5 Ρ: ι.3M012 i 1 340 6.9 27.2 25.3

6 Ρ: I.3MO12AS0.2Mgi 340 8.3 32.5 18.9

7 Ρ] 340 6.2 29.6 18.2

8 Ρ: .3Moi2Cro.5 340 7.8 26.2 23.2

9 Ρ] 340 7.4 31.3 16.3

10 Mo. ₃ Mo ₁₂ Sn _0.4 340 7.6 32.2 18.3

11 story _: .3 Moi ₂ Te _D. ₂ Sr _D .5 340 8.4 34.5 18.9

12 Ρ] .3Moi2Vo. ODJCS 1 320 5.9 38.2 19.3

13 Ρ] .3M0 i2Cua.iK 1 320 6.2 36.3 20.1

14 Ρ ₃ Moi2R j 320 5.8 30.1 24.5 Example 5

12 mode Li blanking de-phosphate _{_{_{(Η 3 ΡΜο 12 0 4 ·}}} 30Η 2 0:. Nippon Muki Kagaku) crystal 23,6G, chloride first鋦O.lg and arsenate 0.85g (H ₃ As0 ₄₎ Was dissolved in 200 m: i of water, and to this solution was added 8.Og of pyridine and 100 ml of water, and the mixture was stirred well. The resulting slurry solution was compressed, then dried at 120 ° C. for 12 hours, and then pulverized to select particles of 10 to 20 mesh. This was calcined at 450 ° C for 3 hours in a nitrogen stream and for 2 hours at 350 ° C in air. An erosion medium having a composition of PM o _{12 As} ci-sC uc ^: was obtained.

The reaction was carried out in the same manner as in Example 1 except that the reaction temperature was 340 ° C. Six hours later, the reaction gas was analyzed by gas chromatography, and it was found that 8.8% of isobutane was converted, the selectivity for methacrylic acid was 46.2%, and the selectivity for methanol mouth lane was 25.1%. %Met. After the reaction, the catalyst was yellowish blue.

Example 6

In Example 5, instead of adding arsenic acid, add antimony trioxide and, instead of adding pyridine, add 13 g of quinoline.

The蝕媒having the composition _{_{_{P 3 M o 32 C u α}}} . 5 S b D _ 5 was prepared.

The reaction was carried out in the same manner as in Example 1 except that the reaction temperature was set to 340 ° C using this etching medium. As a result, 9.1% of isobutane was converted, and the selectivity for methacrylic acid was 42.3%, and the selectivity for methacrolein was 19.4%.

Example 7 12 mode Li blanking de-phosphate 236.5G, 3 a _{_{A s 2 O 5 · 5 H}} 2 〇 11.5g was dissolved in water, the total volume mixed oysters 12 hours at 60 ° C was 1000 ml. To 150 ml of this solution, 14.5 g of the crystals of molybdovanadic acid prepared in Example 1, 0.18 g of an aqueous solution of 85 phosphoric acid, and 100 ml of water were added and stirred for 2 hours. Next, 100 g of a 6.4 wt% aqueous ammonium nitrate solution was added, and the obtained slurry was concentrated. Then, after drying at 120 ° C for 12 hours, the particles were pulverized, and particles of 10 to 20 mesh were selected. This was calcined at 450 ° C for 3 hours in a nitrogen stream and for 2 hours at 350 ^eC in air. A catalyst having a composition of PuM o ^ sV 0.3D S84 was obtained. The reaction was carried out in the same manner as in Example 1 except that the reaction temperature was set to 340 ° C using this catalyst. Six hours later, the reaction gas was analyzed by gas chromatography.It was found that 8.3% of isobutane was converted, the selectivity of methacrylic acid was 46.8%, and the The selectivity was 22.5%.

Examples 8 to 26

Catalysts having the catalyst composition shown in Table 2 were prepared in the same manner as in Example 1 except that the reaction temperature was 340 ° C, and the reaction was carried out in the same manner as in Example 1. The reaction cable after a reaction for 20 hours is shown. No.

Isophthalene methacrylic acid Methac-Brain application Catalyst composition Conversion rate Selectivity Selectivity example%%% 8 Pi. SrioiaVo. EAgQ. 7.5 48.3 22.3

9 Pi.sno J2 D. sZno.i 7.6 50.2 15.6 10 PiMo ₁₂ Vi. ₅ Fe _D. 7.0 46.0 15.0 11 P2H012V1C00. 7.0 46.8 14.5 12 Pi. ₃ Hoi ₂ ViNio. 7.1 48.2 10.5 13 D.2 6.8 46.2 9.5 14 Pi.sMoisViGea.sFeo. 8.0 49.3 16.4 15 Ρϊ.3Μοι ₂ νιΖΓ _0. 7.1 8.2 12.9 16 PiHoizCuo.5W0.8.9 40.3 16.1 17 Pi.3M012CU0-】 Taa.7.4 42.2 12.5 18 8.1 43.2 14.3 19 PiMoi ₂ Cu _D .iRho ISea. 6.9 46.3 13.5 21 PjMoi ₂ Cu _D .iHn _a .3 7.4 41.5 16.3 22 PjHdsAso.eCuo.iNba.s 7.7 46.3 15.4 23 PIMOI ₂ VICUD.iCeo.5 9.2 54.6 17.1 24 P1M012V1. _{_{9 Cu D. iNdo. 8.6 55.6}} 18.2 25 PiMoizViCua. iAs D. 3 B D .1 8.8 56.2 19.2 26 PiMoi 2 ViCuo. jBia. 8.2 51.1 18.3 Example 2 7

Water 200ral warmed to 80 ° C, this 12 - motor Li Bed preparative '-phosphate (H ₃ PM o ₁₂ 〇 _4α · _30Η ₂ ○: Nippon Muki Kagaku) was dissolved 23.5 g, oyster this While mixing, add potassium nitrate to 1.Og and copper nitrate.

A solution prepared by dissolving 0.48 g in 20 ml of water was added, and 1.17 g of ammonium metavanadate was further added. Next, an aqueous solution in which 6.4 g of ammonium nitrate was dissolved in 100 ml of water was added to the solution, and the resulting slurry solution was heated, shrunk while stirring, and then evaporated to dryness on an evaporating dish. The solidified product was further dried at 120 ° C. for 12 hours to obtain a solid. This solid was pulverized to select particles of 10 to 20 mesh. This was calcined at 450 ° C for 3 hours in a nitrogen stream to obtain a catalyst. The composition of this catalyst was P] _{M o 12 V Ϊ C u Q.} 2 K 1.

5 g of this catalyst was filled into a U-tube made of Pyrex having an inner diameter of 6 ram, and set in a thermostat. The temperature of the thermostat was set at 300 ° C, and a mixed gas of 25 mol% of isobutane, 55 mol% of air, and 20 mol% of steam was supplied for a contact time of 3.6 seconds. After 100 hours, the reaction gas was analyzed by gas chromatography. As a result, 7.8% of isobutane was degraded, the selectivity of methacrylic acid was 53.4%, and the selectivity of methacrolein was Was 20.8%. Isobutylene was not detected. The reaction was carried out for 1000 hours under the same conditions; 7.5% of isobutane was converted, the selectivity for methacrylic acid was 54.4%, and the selectivity for methacrylate was 21.1%. .

Example 2 8 Water 200 ml 12-Mo Li Budo-phosphate _{_{_{(H 3 PM o 12 0 4}}} D'30H 2 0: Nippon Muki Kagaku) was dissolved 23.5 g, while stirring this, main Tabanajin Sanna Application Benefits um 0.37g and 3 A s ₂ 〇 5 · 5H ₂ 0 1.15g was added, and the mixture was stirred for 12 hours at 60 ° C. Further, a solution obtained by dissolving 0.5 g of rubidium nitrate and 1.33 g of sodium nitrate in 20 ml of water was added, and then an aqueous solution of 12.8 g of ammonium nitrate dissolved in 100 ml of water was added and stirred. . The resulting slurry solution was concentrated while heating and stirring, then evaporated to dryness on an evaporating dish, and further dried at 120 ° C. for 12 hours to obtain a solid. The solid was formed into a pellet at a pressure of about 100 kg / cm ² and crushed to select particles of 10 to 20 mesh. This was fired at 450 ° C for 3 hours in a nitrogen stream to obtain a bowing medium. The composition of this erosion medium is

_{_{P iM oi 2 V 3 A s}} 64- b D. 5 T 1 D. 5 a was the ₀

5 g of this erosion medium was filled into a P-shaped U-shaped tube having an inner diameter of 6 mm, and set in a thermostat. The temperature of the thermostat was set to 340 ° C, and a mixed gas of 30 mol% of isobutane, 50 mol% of air, and 20 mol% of steam was supplied at 3.6 W for corrosion. After 100 hours, when the reaction gas was analyzed by gas chromatography, 10.8% of isobutane was converted, and the selectivity of methacrylic acid was 45.8% and the selectivity of methacrylone was It was 1δ.2%. Isobutylene was not detected. After 500 hours of reaction under the same conditions, 9.9% of isobutane was converted, the selectivity for methacrylic acid was 47.2%, and the selectivity for methacrylate was 19.3%. Example 2 9

Water 200Pai 12-mode Li blanking de-phosphate: dissolving (Η ₃ Ρ Μ ο ₁₂ 〇 ₄ · _30Η ₂ 〇. Nippon Muki Kagaku) 23.5 g, arsenic acid (H ₃ A s 〇 ₄₎ 0.85 g And stirred at 60 ° C for 12 hours. Then, after adding 0.24 g of copper nitrate, a solution of 2.66 g of sodium nitrate and 1.31 g of barium nitrate dissolved in 40 ml of water was added. Further, an aqueous solution in which 13.7 g of pyridine was dissolved in 100 ml of water was added and stirred. The obtained slurry was heated and shrunk while stirring, then evaporated to dryness on an evaporating dish, and further dried at 120 ° C for 12 hours to obtain a solid. The solid was formed into a pellet at a pressure of about 100 kg / cm ² and crushed to select particles of 10 to 20 mesh. This was calcined at 450 for 3 hours in a nitrogen stream to obtain a catalyst. The composition of the catalyst was P] M o] _{2 A s a. EC u o} . I 1 ] B a _0. _5.

5 g of this catalyst was filled in a pipe-shaped U-shaped tube having an inner diameter of 6 JIDI, and set in a thermostat. The temperature of the thermostat was set to 340 ° C, and a mixed gas of 60 mol% of isobutane, 20 mol% of oxygen, and 20 mol% of steam was supplied for a contact time of 3.6 seconds. After 100 hours, the reaction gas was analyzed by gas chromatography.As a result, 9.5% of isobutane was converted, the selectivity for methacrylic acid was 44.2%, and the The selectivity was 17.4%. Isobutylene was not detected. When the reaction was carried out under the same conditions for 500 hours, 9.4% of isobutane was converted, and the selectivity of methacrylic acid was 43.3% and the selectivity of methacrylate was 17.1%. Examples 30 to 4

Using the same method for preparing the convergent medium as in Example 1, the erosion medium having the catalyst composition shown in Table 3 was prepared, and the reaction was carried out in the same manner as in Example 1 except that the reaction temperature was 340 ° C. The reaction growth after 100 hours of reaction is shown.

Table 3

N, N-Frothane tantacrylate Catalyst composition Degree of selectivity Selectivity Selectivity Example%%%

?. 30 Pi.3 1012V0 Zti 11.2 45.8 15.4 31 Pi 5 Mo 12 Va.5 Mr s mouth -. 2 9.5 47.4 18.2 32 P1M012V 1.5Mga.3 9.2 47.2 19.3 32 Ρ2Μ0 Interview iRbi- 5Sra_ 1 10.9 46.2 17.3 33 Pi . sMoisViCsjNao.11.6 44.3 14.8 34 Pi.2KO12 1.sCS2 9.0 46.8 16.3 35 Pi.3MOi2Cu _D .iRb 12.4 44.8 17.6 36 Pi.3MO I2CUD.2TI0.sCao.5 丄 1-6 42.3 15.3 37 P IMO IZCUO.SCSQ.iRb _D. ₅ 10.0 44.3 18.9 38 Pi.3M012CU iLi _D. IRbo.3 13.7 41.2 12.5 39 10.6 44.5 19.8 40 Pi.3M012CU0.3 Asa.2CS1 10.8 46.2 17.2 41 Pi.3M012CU0.sMgo.sBao.5 8-4 42.3 15.5 Example 4 2 to 5 5

A catalyst having the composition shown in Table 4 was prepared and reacted in the same manner as in Example 1. Table 4 shows the reaction after 100 hours.

Table 4

Nisocrolein methacrylate Natacrolein Application Catalyst composition Degree of selectivity Selectivity Selectivity Example%%%

42 Pi. ₂ M0l ₂ VjAg _D. ₂₅ K: 8.6 44.6 16.2 43 Po ₁₂ Vi. ₅ Ag _D .IASO.25K 1 10.2 46.5 18.2 44 Pi-3Moi ₂ V】 Sbd- iCs _; 7.8 50.2 22.2 45 PH012VD.eZra .sCs 7.2 48.9 16.6 46 PMoi ₂ ViTe _D .zsK 7.6 50.2 18.2 47 PMo ₁₂ ViTa Bo.:Rb; 8.5 50.6 22.3 48 PzMoisViGeo.5 8.2 45.6 19.8 49 Rb- 7.0 45.6 17.2 50 PMo 12CUD.2Cro.iCs 7.1 44.3 20.2 _{51 PMoisCu 5 TID. IKD. 5} 6.9 43.8 21,2 52 PMo 1 zCu a _ 2Fe D. iSr D _ 2 K a 6.8 46.2 19.8

Cs _D.

53 PMoi ₂ Cuo.iNi _D .sCaiTlo.5 6.9 43.2 18.3 54 PMoi ₂ Cua. 1C00.IYQ.iCsi 7.2 45.6 19.6 55 Pi.2Mo _i2 Cu _D- iSno.iRbo.2S 7.8 46.3 18.6 Example 5 6-7 0

An erosion medium having the composition shown in Table 5 was prepared, and an erosion reaction was performed under the same conditions as in Example 1. Table 5 shows the reaction after 100 hours.

Table 5

W ,, methacrylic acid Nutachlorage

2 & Eating medium composition Conversion rate Selectivity Selectivity example%%%

56 PHO! ZV! CUQ. _Z T1 _d . ₅ Rb. _{_{. 5 11.8 56.2 15.4 57 PliOj 2}} V a -..... 5 Cu D 2 Zn D Interview K co _{_{10.9 52.4 16.8 58 PMoi2Vi 5 Cu D}} E RhQ iCsi 9.8 53.2 14.9 59 PH012V1Cuo.5Nb1Mno.5Tl- 10.1 53.8 17.2 60 PMOI ₂ VICUD. ₂ ¥ D.i ₅ 9.7 49.3 16.8 61 PHoi ₂ Vi. ECUD.iBia. ₂ T1 _D. ₅ Ki 10.3 50.2 16.3 62 Pl-3M0l2VlCUD.2Seo.lKl.5 10.2 51.1 17.3

_{.... 64 PMo ie ViCuo.zAs} D iB D iRb D 5 12.8 50.3 14.2 65 10.6 57.8 14.2 66 Pi 5 Hoi 2 V] Cu D 2 Ndo.5CS:... 12.8 53.8 15.9 67 PMo 12 VaCuD 2 Lao sCsa .sTla.5 11.9 54.4 15.3 68 P 012V1CU0. s ao.5R o. δΤΙα. s 10.8 53.4 16.9 9 PMo a2 ViCu D. iCe D. 5 Cs D. 5 T1 D .5 11.2 54.9 15.6 0 PHoi 2 ViCu D. ₂ Co _a .iRb _D. ₅ 9.7 50.0 18.2 Example 7 1

Example 6 The catalyst prepared in _{9 (PM o:...} I2 V; l C u CI; I C e 0 5 C s □ 5 1 5) Use, 1000 under the same reaction conditions as in Example 1 The catalytic reaction was continued for a continuous time, but no catalyst deterioration was observed. At that time, the conversion of isobutane was 10.9 $, the selectivity for methacrylic acid was 56.3, and the The selectivity of the application was 15.3.

Example 7 2

The catalyst prepared in Example 5 4 (Ρ Μ ο:. .. 2 V a C u 0. 2 A s □ i B D jR b o 5) , and was charged into a SUS U-shaped tube having an inner diameter of 6 mm, the reaction At a pressure of 0.3 MPa and a reaction temperature of 280 ° C, a mixed gas of 25 mol% of isobutane, 55 mol% of air, and 20 mol% of steam was reacted with a contact time of 3.6 seconds. After 100 hours, when the reaction gas was analyzed by gas chromatography, 6.2% of the isobutane was converted, the selectivity for methacrylic acid was 50.3%, and the selectivity for methacrolein. Was 22.4%. The catalytic reaction was carried out continuously for 1000 hours under the same conditions, but no deterioration of the catalyst was observed. At that time, the conversion of isobutane was 6.1, the selectivity of methacrylic acid was 51.1, The selectivity of tacrolein was 20.9 <<.

Example 7 3

The catalyst prepared in Example 51 (PMOVUCUQ .:

Using the _{_{B i 0. 2 T 1 S K}} -J, it was subjected to catalytic reaction in the same reaction conditions as in Example 7 2. After 100 hours, the reaction gas is Analysis by matlabi revealed that 6.0% of the isobutane was converted, the selectivity for methacrylic acid was 48.2%, and the selectivity for methacrolein was 24.5%. The corrosion reaction was carried out continuously for 3000 hours under the same conditions, but no catalyst deterioration was observed. At that time, the conversion of isobutane was 6.0, the selectivity of methacrylic acid was 47.1, and the The selectivity of Lorain was 23.8.

Example 74

To the aqueous solution of molybdovanadolinic acid, primary chloride, potassium nitrate, and rubidium nitrate were added to obtain a slurry, which was concentrated and dried. Further, after drying at 130 ° C for 10 hours, the mixture was pulverized and subjected to MO3sVl to obtain a powder having a composition of UD-2T1Rb0.5. On the other hand, 100-200 mesh spherical silica (Fuji Devison: Microbeads Silicon Age 1000A) is calcined at 700 ° C for 3 hours and then impregnated with boric acid and arsenic acid. This was calcined at 500 ° C for 2 hours to prepare a cocoon in advance with a silica carrier in which B and As were each loaded with 0.03 double babies. A small amount of water was added to this silica carrier to form a carrier. Wet. 100 g of the moistened carrier was placed in a rotating dish of a tumbling granulator, and 100 g of the powder was sprayed and mixed for one hour. In the state where the powdery composition had penetrated deep into the pores of the carrier, a carrier supported on the pores was obtained. Absorb pyridine and dry at 120 ° C. Then, it was calcined in a nitrogen stream at 450 ° C for 3 hours and further in air at 35 ° C for 1 hour. This edible medium was reacted at 320 ° C in a fluidized bed reactor with a 400 ml internal volume. I let you. A mixed gas of 30 mol% of isobutane, 50 mol% of air and 20 mol% of steam was supplied at a gas linear velocity of 20 cm / sec and a contact time of 3.6 seconds.

After 20 hours, the reaction gas was analyzed by gas chromatography.As a result, 9.8% of isobutane was degraded, the selectivity of methacrylic acid was 4δ.3%, and the The selectivity for lorain was 17.5%.

Example 7 5

The catalyst prepared in Example 6 9 (Ρ Μ θ ν, Ο ιΐ ο. Ο β ο ^ C s D. 5 Τ 1 D. 5) as same, press Catering diameter lmm ų in molding machine length After adjusting the diameter to 5 mm, it was packed in a SUS fixed-bed reactor with an inner diameter of 15 mm and a height of 1.8π. A heating medium of 320 ° C was circulated in the jacket of the reactor. A mixed gas of 30 mol% of isobutane, 15 mol% of oxygen, 20 mol% of water vapor, and 35 mol% of nitrogen was supplied to the reactor with a contact time of 3.6 seconds. The reaction pressure was maintained at 0.4 MPa. After 100 hours, the reaction gas was analyzed by gas chromatography and found that 10.3% of the isobutane was converted, the selectivity for methacrylic acid was 55.2%, and the The selectivity was 17.3%. Then, a mixed gas of 30 mol% of isobutane, 0.6 mol% of methacrolein, 15 mol% of oxygen, 20 mol% of steam, and 34.4 mol% of nitrogen was reacted. It should be noted that the methacrolein guides the product gas obtained by this reaction to a quenching tower and then to a methachlorine absorption tower, and from the obtained condensate and absorption liquid to a mechano-rerain area. Was purified by separation and used. Although the conversion of isobutane was reduced to 9.0% compared to the case where no methanol mouth lane was supplied, the selection of methacrylic acid was 65.2%. Approximately 60 of methacrolein have been converted to methacrylic acid.

Industrial applicability

The process of the present invention uses abundant and inexpensive isobutane as a raw material, can produce methacrylic acid and methacrylone from isobutane in a single step at low cost, and furthermore, the catalytic activity of the catalyst used is high This is an industrially superior method for producing methacrylic acid because it can be maintained for a long period of time.

Claims

The scope of the claims

1. It contains a heteropolyacid containing P and / or As as a central element and containing Mo as a coordinating element, and has the following formula (1):

(Where A represents P and ノ or As, Mo represents molybdenum, B represents V and / or Cu, and C represents an alkali metal. , Alkaline earth metals, and at least one of T 1. D is Ag, Zn, Ti, Zr, Nb,

Ta, Cr, W, Mn, Fe, Co, Ni, B, A1, Ge, Rh, Sn, Sb, Bi, Se, Te, Y,: L a, C e,

It represents at least one of Pr and Nd. 0 represents oxygen. a, b, c, d, and e represent the atomic ratios of the respective elements, where a = 0.5-3, b = 0.01-3, c = 0-3, and d = 0-3. e is a numerical value determined by the valence and atomic ratio of each element. A) a gas mixture containing isobutane and molecular oxygen at 240 to 350 ° C in a gas phase with a catalyst having a composition represented by the formula: Manufacturing method for tuck mouth lanes.

2. The method for producing methacrylic acid and methacrolein according to claim 1, wherein in formula (1), c = 0.01-3.

3. The method for producing methacrylic acid and methacrylic acid lane according to claim 1 or 2, wherein d = 0.01-3 in the formula (1).

4. Claims 1 to 4 in which B is V in equation (1). 3. A method for producing methacrylic acid and a metallophthalate according to any one of paragraphs 3 to 4.

5. The method for producing a methacrylic acid and a methacrylic acid lane according to any one of claims 1 to 4, wherein B in the formula (1) is Cu.

6. The method according to any one of claims 1 to 5, wherein the alkali metal is at least one selected from Li, Na, K, Rb, and Cs. A method for producing methacrylic acid and methacrylic acid lane.

7. The method according to any one of claims 1 to 6, wherein the alkaline earth metal is at least one selected from Mg, Ca, Sr, and Ba. A method for the production of acrylic acid and metal mouth lane.

8. The method for producing methacrylic acid and methacrylic acid lane according to any one of claims 1 to 7, wherein b = 0.05 -2 in the formula (1).

9. The process for producing a methacrylic acid and a methacrylic acid line according to any one of claims 2 to 8, wherein c = 0.1-2 in the formula (1).

10. Production of the methacrylic acid and the methacrylic acid line according to any one of claims 3 to 9 wherein d = (K05-1) in the formula (1). Law.

Γ 1. The claim 2 to claim 2, wherein the reaction temperature is 270 to 320 ° C. 10. The method for producing methacrylic acid and the methacrylate mouth line according to any one of the paragraphs 10 to 10.

12. The methacrylic acid and methacrylate according to any one of claims 1 to 11, wherein the concentration of isobutane in the raw material gas is 10 to 80 mol%. The manufacturing method of Lorain.

13. The process for producing methacrylic acid and methacrylic acid lay according to claim 12, wherein the filtration rate of isobutane in the raw material gas is 20 to 60 mol%.

14. The method according to any one of claims 1 to 13, wherein the molar ratio of oxygen to isobutane in the raw material gas is 0.05 to 1 to 1 to 1. A method for producing lylic acid and methacrolein.

15. The methacrylic acid and the metal according to claim 14, wherein the molar ratio of oxygen to isobutane in the raw material gas is from 0.1: 1 to 0.6: 1. Manufacturing method of Lorain.

16. The method for producing methacrylic acid and methachlorine according to any one of claims 1 to 15, wherein water vapor is present in the feed gas.

17. The methacrylic acid and methacrylic acid lantern according to claim 16, wherein the molar ratio of water vapor to isobutane in the feed gas is from 1 to 5 to 5 to 1. Manufacturing method.

18. The method of claim 17, wherein the molar ratio of water vapor to isobutane in the feed gas is from 1: 3 to 3: 1. Manufacturing method.

19. The methacrylic acid and metal according to any one of claims 1 to 18 wherein the contact time of the feed gas with the erosion medium is 1 to 10 seconds. Mouth ray manufacturing method.

20. The method for producing methacrylic acid and methacrolein according to claim 19, wherein the contact time of the feed gas with the erosion medium is 0.5 to 5 seconds.

2 1. The method for producing methacrylic acid and methachlorine according to any one of claims 1 to 20, wherein an inert gas is present in the feed gas.

2 2. Methacrylic acid and inert gas are separated from the reaction product gas, and the resulting methacrylone is introduced into the reactor together with unreacted isobutane! A method for producing the methacrylic acid and the methacrylate mouth lane according to any one of claims 1 to 21 which is a cycle.