JPS5820958B2 - Pyridine Rui no Seizouhou - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing pyridines.

More specifically, it relates to a method for producing pyridines by contacting a saturated or unsaturated hydrocarbon having 2 to 4 carbon atoms, ammonia, and molecular oxygen with a hydrocarbon oxidation catalyst and a catalyst containing a solid acid in the gas phase. It is.

Many attempts have been made to synthesize pyridines, which have conventionally been obtained from coal tar, using raw materials obtained in the petrochemical industry due to the increase in industrial heavy dust.

For example, Japanese Patent Publication No. 40-8356 describes that a picoline mixture is synthesized by bringing acetaldehyde and NH3 gas into contact with silica alumina supporting tin, tungsten, nickel, cobalt, etc. at 300 to 550°C.

Furthermore, Japanese Patent Publication No. 17869/1989 describes a method for synthesizing pyridines by bringing acrolein and ammonia into contact with bismuth, magnesium or zirconium-supported silica alumina.

There are many other synthetic methods (reported) in which saturated and/or unsaturated aldehydes and ammonia are used as the main raw materials, alcohols, ketones, etc. are added thereto, and the mixture is brought into contact with catalysts containing silica and alumina as main components.

In this method, these saturated and/or unsaturated carbonyl compounds are first synthesized from hydrocarbons having the corresponding number of carbon atoms by gas phase contact reaction and/or liquid phase reaction, and then separated and purified by operations such as extraction and distillation. After that, new ammonia is added to this to synthesize pyridines through a gas phase catalytic reaction, which requires a complicated process.

In addition, as an improved method, unsaturated hydrocarbons are catalytically oxidized with molecular oxygen-containing gas in the first stage reactor, and unsaturated carbonyls are then separated and purified from the resulting gas (
, a method in which the required amount of ammonia is added and a catalytic reaction is carried out in the second stage reactor (see Japanese Patent Publication No. 45-26493), and a method in which a mixed gas of unsaturated hydrocarbon, ammonia and air is brought into contact in the first stage reactor. A method is known (see BP 1134163) in which oxidation is carried out and then the reaction product is catalytically condensed in a second stage reactor.

However, in this method, depending on the reaction conditions described in the above patent, the temperature of the second stage reactor is 100 to 20°C higher than that of the first stage reactor.
Since it is necessary to lower the temperature to 0°C, the product gas from the first stage reactor must be cooled by some means before being introduced into the second stage reactor.

Therefore, not only does the reactor itself become complicated, but it is also unfavorable from the standpoint of heat balance.

If the reaction temperature of the second stage reactor is raised to improve the heat balance, this will result in decomposition of the raw materials and oxidation reaction products, increase in the carbonization reaction, and decrease in the production yield of pyridines. This is not a good solution.

As a result of intensive research to overcome the drawbacks of the conventional methods as described above, it was surprisingly possible to oxidize hydrocarbons by simply oxidizing saturated or unsaturated hydrocarbons having 2 to 4 carbon atoms, ammonia, and molecular oxygen in the gas phase. Catalyst.

We have discovered that pyridines can be produced in one step simply by contacting them with a catalyst containing a solid acid.

The present invention has been achieved based on the above findings, and involves the use of saturated or unsaturated hydrocarbons having 2 to 4 carbon atoms, ammonia, and molecular oxygen in a gas phase.

Hydrocarbon oxidation catalysts and aluminum, silicon, phosphorus,
This is a method for producing pyridines, characterized by bringing them into contact with a catalyst containing an oxide of at least one element selected from the group of magnesium, titanium, zinc, gallium, zirconium, and lanthanum.

Conventionally, pyridine bases have been synthesized by a two-step reaction using separate catalysts for aldehyde synthesis reaction by oxidation of unsaturated hydrocarbons and condensation reaction with aldehyde and ammonia, but according to the present invention, 1. , ammonia and molecular oxygen, a pyridine base is synthesized in one step by using the above catalyst, which is an epoch-making method that was not expected from conventional methods.

According to the method of the present invention, it is possible to shorten the reaction process from a two-step process to a one-step process, so that not only is the separation and purification process of unsaturated/aldehydes unnecessary, but also the oxidation reaction, which is an exothermic reaction, is eliminated. Because the condensation reaction, which is an endothermic reaction, occurs at the same time, the calorific value is small. It is possible to avoid a sudden temperature rise in the catalyst layer or the formation of hot spots inside the catalyst layer.

In addition, it is not only possible to use a fixed bed reactor and reduce losses due to combustion of raw materials and products to a very small extent, but also to increase the concentration of hydrocarbons in the raw materials, making it possible to separate the produced pyridines. , the load on the purification process is significantly reduced.

It is also possible to prevent deterioration of the catalyst due to local temperature increases.

According to the conventional method of synthesizing pyridines from ammonia, which is an aldehyde, in the gas phase, alkylpyridines are the main products, and the amount of pyridine is less than 1/2 of that of alkylpyridines (for example, Japanese Patent Publication No. 8356/1983). Publication No., Special Publication No. 4
1-17869).

Therefore, pyridine synthesis by such a method requires a dealkylation process of alkylpyridines, which is industrially disadvantageous.

This tendency is due to the fact that aldehydes are not separated from the gas phase catalytic reaction products of unsaturated hydrocarbons in the first stage reactor (
There is a method in which ammonia gas is added to this to synthesize pyridines in a second stage reactor (see Japanese Patent Publication No. 45-26493), and a method in which oxidation catalysts and condensation catalysts are separately charged into a multistage reactor to perform different reactions. A method of reacting a mixed gas of unsaturated hydrocarbons, ammonia gas, and air while maintaining the temperature (BP1
This phenomenon is also observed in methods that do not use aldehydes alone, such as (see the specification of No. 134163).

However, according to the present invention, it is not only possible to synthesize pyridines in one step from hydrocarbons, ammonia, and oxygen-containing gases (the amount of pyridine produced can be reduced from several times or more to a fraction of that of picoline using the catalyst used). This method can be changed by changing the method, and is extremely superior to conventional methods.

The present invention will be explained in detail below.

Hydrocarbons used in the present invention include, for example, ethane,
Saturated hydrocarbons having 2 to 4 carbon atoms, such as furopane, n-butane, isobutane, and cyclobutane, and unsaturated carbon atoms having 2 to 4 carbon atoms, such as ethylene, furopylene, 1-7"ten, 2-butene, imbutene, and butadiene. Examples include hydrogen, but propane, butanes, propylene, butene, and isobutyne are preferably used, and propylene is particularly preferably used.

Such hydrocarbons can be used alone, but also in combination with
It may be used as a mixture of more than one species.

The saturated and/or unsaturated hydrocarbons having 2 to 4 carbon atoms used in the present invention may be pure or methane,
It may contain hydrogen, aromatic hydrocarbons, water vapor, carbon monoxide, carbon dioxide, and other substances that do not substantially poison the reaction.

Therefore, naphtha pyrolysis gas, refinery gas, etc. can be used as is or after being subjected to simple processing operations.

In the present invention, the hydrocarbons include alcohols such as methanol, ethanol, and furopanol, formaldehyde, acetaldehyde, acrolein, propionaldehyde,
Favorable results can be obtained by adding aldehydes such as crotonaldehyde, ketones such as acetone, methyl ethyl ketone, diethyl ketone.

The catalysts used in the present invention include catalysts used for the oxidation of hydrocarbons and solids such as oxides of aluminum, silicon, phosphorus, magnesium, titanium, zinc, gallium, zirconium, and lanthanum (at least one element). Contains acid.

Preferred hydrocarbon oxidation catalysts are olefin oxidation catalysts, especially propylene oxidation catalysts.

As the propylene oxidation catalyst, known catalysts used for the synthesis of acrolein, acrylic acid, acrylonitrile and acetonitrile from propylene can be used.

Specific examples of such known propylene oxidation catalysts include, for example, supervised by Kimio Tarama, Reaction Side Practical Catalyst (published by Kagaku Kogyo Co., Ltd.), 3.
Catalysts such as those described on pages 80-385 and 393-401.

Preferred examples of such oxidation catalysts include oxides of bismuth and molybdenum, antimony and uranium, antimony and tin, and copper, or oxides of these to which phosphorus, iron, cobalt, nickel, vanadium, chromium, tungsten, tellurium, etc. are added. can be mentioned.

Even if such an oxidation catalyst is used as it is, it is possible to synthesize pyridic acid in one step from hydrocarbons, ammonia, and molecular oxygen, but particularly favorable results can be obtained by combining it with the solid acid described below. .

On the other hand, as a specific example of the solid acid used together with the hydrocarbon oxidation catalyst, see 5 solid acids a by Kozo Tanabe.
nd 13ases (Kodansha-Aca
natural products such as acid clay, bentonite, kaolin, hojas zeolite, mortenite, etc., ZnO, Al2O3, Ti
O2, CeO2, As2O3, Y2O7, SiO2, C
Oxides such as r2O3 and MoO3, sulfides such as ZnS and CaS, CaSO4, MnSO4, NiSO4, CuS
O4, CdSO4゜ZnSO4, MgSO4, BaSO
4, KH8O AI 2 (S 04 ) s, Fe
2 Sulfates such as (SO4,)3, Ca(NO3)2, B
i (NO3) 3, Zn(NO3)2, Fe (
NO3) 3 etc. nitrates, Ca3(PO4)2, BPO
4, FePO4, CrPO4, T i 3 (PO4)
4, Z r3 (PO4) 4, Cu a (PO4)
2, AI P 04, Zn3 (PO4) 2, M
phosphates such as g(PO4)2, CaCl2, AgCl,
CuC1,5nC1□, CaF2, BaF2, AlCl
3. TiCl3 etc.... rogens, AgClO4, M
Perchlorate such as g2(ClO2)2, SiO2/Al2
O3, B2O3・Al2O3, cr2o3+ A120
3. Mob3+Al2O3, ZrO2・SiO2, Ga
2O3・SiO2, BeO□・SiO2, MgO・Si
O2, CaO・SiO2, 5rO-8iO2, Y2O3
・SiO□, La2O3・SiO□, 5nO-8iO□
, Pb(lsi02, MoO3・Fe2(MoO4)3
, MgO-B203, TiO2・ZnO1SiO□・A
l2O3・MgO3,5i02・Al2O3・B2O
3,5i02・Al2O3・ZrO2, Si02・C
An oxide of two or more elements such as r2O3.MgO or a solid acid of two or more of the above compounds is used.

The solid acid in the present invention is at least one selected from the group of aluminum, silicon, phosphorus, magnesium, titanium, zinc, gallium, zirconium, and lanthanum.
Oxides of species elements are preferred.

Specific examples of these preferable oxide-based solid acids include Al2O3, fluoride-treated Al2O3, SiO2, T
iO□, synthetic zeolite, S i02・A1□03, S
iO2・MgO, 5i02・Al2O3・MgO, etc. are preferable, and SiO□・A1□03 is particularly preferable, and in that case, the content of silica in the silica alumina is preferably 5 to 95
% by weight, particularly preferably from 50 to 90% by weight.

Such a solid acid can be synthesized by any conventionally known method.

Silica/alumina can also be obtained by any of the conventionally known deposition methods, coprecipitation methods, or mixing methods.

In the above-mentioned catalyst containing a hydrocarbon oxidation catalyst and a solid acid, the ratio of the oxidation catalyst to the solid acid is such that the metal in the oxidation catalyst is 0.001 to 100 parts by weight per 1 part by weight of the solid acid. , preferably in the range of 0.01 to 10 parts by weight.

If too much of the oxidation catalyst is used relative to the solid acid, the products will mainly be acrolein, acrylonitrile, acetonitrile, etc., the amount of pyridines produced will be reduced, and the oxidation catalyst will be used in an extremely small amount. The amount of pyridines produced also decreases when

Therefore, if a catalyst containing an appropriate amount of oxidation catalyst for the solid acid is used, pyridines can be obtained in good yield.

If desired, the oxidation catalyst and the solids may be physically mixed, and such a mixed catalyst may be charged to the same reaction temperature and used under the same reaction conditions, i.e., the hydrocarbon, ammonia and oxygen containing gases may be It is also possible to contact the solid acid catalyst and the solid acid catalyst under substantially the same reaction conditions, without contacting them under separate reaction conditions.

The hydrocarbon oxidation catalyst may be supported on the solid acid by any method such as an impregnation method, a deposition method, or a kneading method.

In addition, methods such as a method of uniformly mixing an aqueous solution of metal-containing salts, an aqueous solution of solid acid component-containing salts, and an aqueous precipitant solution in a short period of time to obtain a solid phase chemical mixture of both components with extremely high dispersion are also used. be able to.

In short, any method may be used as long as it can remove a catalyst containing a solid acid and an oxidation catalyst.

The catalyst thus obtained does not necessarily need to be calcined before use; however, calcining can activate the catalyst,
It is generally preferable to perform calcination because it removes impurities and imparts mechanical strength through thermal decomposition or oxidative decomposition.

Firing is carried out at 100 to 1500°C, preferably 300 to 100°C, in a molecular oxygen-containing gas or an inert gas such as nitrogen to prevent sintering.

Ammonia in the raw material is preferably 0.01 to 100 mol, particularly preferably 0.1 to 10 mol, per mol of raw material hydrocarbon, and oxygen gas is preferably o, oi to 1 mol per mol of hydrocarbon.
0.1 to 10 moles per 100 mils are used.

In the present invention, a hydrocarbon, ammonia, or oxygen-containing gas alone can be used, but preferably a diluent is used.

The diluent may be any of inert gases such as nitrogen, helium, and argon, or components contained in the reaction product such as carbon dioxide gas and water vapor, but water vapor is preferred.

These gases serve to lower the partial pressure of the reaction mixture, improve catalyst activity, and extend catalyst life.

The reaction temperature is 200-800°C, especially 300°C-600°C.
°C is preferred.

If the reaction temperature is too low, the reaction rate will be extremely slow (which is industrially disadvantageous).

On the other hand, if it is too high, excessive decomposition of the raw material or carbonization reaction will progress significantly, which is not preferable.

The reaction pressure is preferably normal pressure, but may be reduced pressure or increased pressure.

The reaction may be carried out either batchwise or continuously.

In batch operation, the reactants and catalyst are introduced into the reaction zone.

The reaction zone is equipped with suitable equipment for bringing the catalyst and reactants into intimate contact.

In the reaction zone, the catalyst and the reactants are maintained at a desired temperature and pressure for a certain period of time by appropriate means to carry out the reaction.

In the case of continuous operation, any of fixed bed type, moving bed type, fluidized bed type, etc. may be used.

If a fixed bed system is used, the catalyst is packed into the reaction zone and the reactants are passed upwardly or downwardly into contact with the catalyst at the desired temperature.

In the moving bed type, unused or regenerated catalyst is generally continuously or intermittently introduced from the upper part of the reaction zone, and used catalyst is continuously or intermittently extracted from the lower part of the reaction zone and recycled to the regeneration system.

The reactants are brought into contact with the catalyst by passing in countercurrent or cocurrent with the catalyst.

When a fluidized bed system is used, the reactant and/or one or more other gases are blown into the lower part of the reaction zone, and the catalyst is suspended in the gas to bring the catalyst into contact.

The catalyst may be regenerated simultaneously with the reaction by a portion of the gas blown in from the lower part of the reaction zone, or a portion of the catalyst may be continuously extracted to the regeneration system and then returned to the reaction zone.

The alkylation reaction product can be obtained by separating unreacted substances and intermediate products convertible into pyridines by an appropriate method such as distillation or solvent extraction, and then converting the product to its fufu or by subjecting it to an appropriate treatment for post-reaction. It is recycled to the belt, mixed with new raw materials and reacted again.

As detailed above, the method of the present invention not only eliminates the need for separation of unsaturated aldehydes and a refining plant, but also reduces losses due to combustion of raw materials and products, separates products, and imposes a burden on the refining process. It is possible to measure the reduction of

The present invention method will be explained in more detail below with reference to Examples.

The method of the present invention is not limited in any way by these Examples.

In the examples, unless otherwise specified, parts are by weight.

Example 1 A silica alumina catalyst containing molybdenum and bismuth was prepared as follows.

Aluminum nitrate (AI (NOs)3.9H20)
Molybdenum trioxide (Mo0
3) Add 22 parts.

While stirring vigorously, add bismuth nitrate (Bi(NO3)3
・5H20) 57 parts of nitric acid.

(specific gravity 1.38) dissolved in a solution consisting of 4.3 parts and 32 parts of ion-exchanged water, 129 parts of water glass, and
A solution prepared by dissolving 163 parts of sodium hydroxide solution in 770 parts of ion-exchanged water is added all at once, the pH is maintained at 8, and the mixture is aged.

After filtration, at 110℃. dry.

The sodium ions are removed by washing several times with 500 parts of a 5% hot aqueous ammonium nitrate solution and dried at 110°C.

After baking at 430° C. for 8 hours under air circulation, the mixture was subjected to reaction.

Evaporator, preheater and U-shaped stem with inner diameter of 20mm.

A flow-through reactor consisting of a waterless reactor was used.

The stainless steel reactor was heated with a salt pass using nitrate.

A thermocouple was inserted into the center of the reaction tube to measure the temperature distribution in the axial direction of the reaction tube.

A predetermined amount of water using a Milton Roy pump.

The mixture was sent to an evaporator heated to 150° C., and the generated steam was mixed with ammonia, propylene, and air, and then introduced into a reaction tube.

The upper part of the reaction tube was filled with quartz glass wool, and the reaction gas was preheated to the reaction temperature and brought into contact with the catalyst.

The reaction gas was cooled to water temperature in a condenser, and the condensate was collected in a cooling trap using two stages of water cooling and one stage of dry ice methanol, and then purged.

The trap liquid was mixed uniformly and then analyzed and quantified by gas chromatography.

200 parts of the catalyst prepared above was charged into a reactor, the reaction temperature was 430°C, propylene, ammonia and air were each 25.25.276 parts/min by volume, and water was 13.5 parts/min.
When fed in parts by weight/hour, 0.07272 volumes of pyridine and 0.01111 volumes of β- and α-picolines were obtained.

Example 2 226 parts of stannous chloride (SnC12-2H20) was added to 50
Dissolve in 0 parts of ion-exchanged water and add ammonia water to make P.
The H content was 8 and the resulting precipitate was separated.

Add 15.7 parts of antimony pentachloride (SbC15) to 500 parts of ion-exchanged water, add aqueous ammonia to adjust the pH to 8, and distribute the resulting precipitate from house to house.

(Add 300 parts of ion-exchanged water to the resulting precipitate,
Filter the powder using a ball mill for 24 hours and dry at 110°C.

This was heated to 300℃ for 6 hours, 600℃ for 6 hours, and 900℃.
Bake under air circulation for 6 hours.

Aluminum nitrate (A
Suspended in an aqueous solution consisting of 220 parts of I (NOa)s・9H20) and 2500 parts of ion-exchanged water,
A solution consisting of 40 parts of 6N sodium hydroxide, 250 parts of an aqueous solution, and 600 parts of ion-exchanged water was added thereto, and the pH was adjusted to 6 for ripening.

After filtering, it is dried at 110°C, sodium ions are removed with a 5% ammonium nitrate hot aqueous solution, and then dried at 110°C.

It is used for the reaction after being calcined at 500° C. for 8 hours under air circulation.

200 parts of the catalyst obtained above were charged into a reactor, and the reaction temperature was 430°C. Propylene, ammonia and air were each fed at a rate of 25.25.276 parts by volume/min, and water at a rate of 13.5 parts by weight/hour. where pyridine is 0.04040 volume β-
and 0.01010 volumes of γ-picoline.

Example 3 200 parts of activated alumina (3 mm x 5 mm molded product) was immersed in 400 parts of a 9.5% aqueous solution of copper nitrate (Cu (NOs) 2 .3H20), and the water was slowly evaporated on a water bath at 80°C. , dry at 100°C.

A reactor was filled with 200 parts of the catalyst thus obtained, and the reaction was carried out at a reaction temperature of 400°C and a flow rate of propylene, ammonia, and air of 142.40.188 parts by volume/min, respectively, resulting in 0.03333 parts by volume of pyridine. However, the amount of picolines was very small.

Example 4 Antimony acetate (Sb (CH3COO)3) 110
of nitric acid (1,38) is added to 500 parts of nitric acid (1,38) and heated until the generation of nitrogen oxides stops.

To this, uranyl nitrate (UO2(NOs) 2.6H
20] Dissolve 48 parts in 400 parts of water and add.

Add 200 parts of 28% ammonia water, filter out the formed precipitate, and wash the cake with 200 parts of ion-exchanged water.

After drying at 120°C overnight, drying at 500°C for 8 hours, then at 700°C for 8 hours.
Carry out firing in air for an hour.

(50 parts of the catalyst obtained by
0 parts (128 parts as Sin2) and 300 parts of alumina hydrogel (22 parts as A1203) and mix in a ball mill for 24 hours.

After filtering, dry at 110°C and remove sodium with an aqueous ammonium nitrate solution.

After drying at 110°C, it is fired at 500°C for 8 hours.

Charge 200 parts of catalyst into the reactor. Reaction temperature: 450°C, flow rates of propylene, isobutyne, ammonia and air: 100.32.37.174 parts by volume/min, water 1
When fed at 0 parts by weight/hour, 0.04242 volumes of pyridine, a total of 0.00404 volumes of β- and γ-picolines, and 0.01212 volumes of lutidines were produced.

Example 5 5 parts of phosphoric acid and 30 parts of ammonium molybdate ((NH4) a NO7024.4H20) are dissolved in 30 parts of ion-exchanged water.

60 parts of bismuth nitrate (Bi(NO3)3.5H20),
Dissolve 5 parts of nitric acid (1,38) in 40 parts of ion exchange water.

Both are mixed and the precipitate is separated and dried at 110°C.

Bake at 450° C. for 8 hours under air flow. Such a catalyst 10
Silica/alumina 1 with 0 parts and silica content of 85% by weight
00 parts are mixed and charged into the reactor.

The reaction temperature was 430°C, and the flow rates of propane, propylene, ammonia, and air were 10.25.25.276, respectively.
, 7 minutes by volume, water was supplied at 11.7 parts by weight/hour,
A total of 0.0033 parts/h of β- and γ-picoline was obtained at 0.0639 L' hours of pyridine.

Example 6 (6-a) Preparation of tellurium oxide In a suspension of 1 part of tellurium dioxide (Te02) and 30 parts of water, 6
Add 30 parts of 0% by weight concentrated nitric acid and dissolve completely.

After neutralizing the solution to pH 6 with aqueous ammonia, the resulting white precipitate is distributed from house to house.

The precipitate was washed twice with water, dried and dried in air for 390 min.
After baking at ℃ for 4 hours, about 6 times as much water was added and the mixture was ground for 15 hours using a magnetic ball mill to obtain tellurium oxide.

(6-b) Preparation of catalyst 6 parts of aluminum nitrate and 200 parts of ethyl silicate (Si (OCH2CH3)4) were added with 1800 parts of a 1% nitric acid aqueous solution, and after hydrolysis at 30°C for 2 hours, aqueous ammonia was added. The pH was adjusted to 7 and stirred for 1 hour.

This hydrogel was added to 48 parts of SiO2 as described above (
Add 6.67 parts of the tellurium oxide obtained as in 6-a), mix with stirring, filter through a sieve, wash twice with water, and heat at 110°C.
After ring rotation, the mixture was calcined at 500° C. for 1 hour to obtain a catalyst.

(6-c) The catalyst 15f obtained in the synthesis of pyridines (6-b) was packed into a stainless steel reactor with an inner diameter of 8 mm, and propylene, air, ammonia, and water vapor were each kept under standard conditions at a reaction temperature of 390°C. Standard 9.41 CC7min, 104CC/min, 9.41 QC
/';), and the reaction was carried out at a rate of 104 cc/min.

The reaction gas was cooled with a water cooler, then passed through a water trap cooled with ice water, and the condensate was collected and purged.

After the trap liquid was mixed uniformly, pyridine, picolines, and acrylonitrile were analyzed and quantified by gas chromatography.

In addition, the gas purged after collecting the condensate is made to absorb ammonia in a dilute hydrochloric acid aqueous solution, absorb carbon dioxide gas in a caustic potassium aqueous solution, absorb oxygen in a Pyrogal caustic potassium solution, and then absorb unreacted propylene in concentrated sulfuric acid. The volume percentage of each gas was determined.

This reaction thus produces 0.12 P/hr of pyridine;
β- and γ-picolines were obtained at 0.020 f/hr.

Note that the conversion rate of propylene was 35.1%.

Example 7 Titanium tetrachloride (T
After adding 272 parts of iC1,) to make a transparent solution, the solution was heated to 90°C.
The mixture was heated in a hot water bath to form a white precipitate.

After soaking in a hot water bath for 50 minutes in this manner, it is allowed to cool and neutralized to pH 7 with aqueous ammonia.

To 48 parts of the thus obtained gel in terms of TiO2, 6.67 parts of the tellurium oxide obtained in the manner described in Example (6-a) was added and mixed with stirring. 2
The catalyst was washed twice, dried at 110°C, and further calcined at 500°C for 4 hours.

Using the catalyst, a reaction was carried out in the same manner as in Example (6-C) above, and 0.020 P/hour of pyridine, β- and γ-
- 0.022 P/h of picoline was obtained.

Note that the conversion rate of propylene was 39.4%.

Example 8 168 parts of zinc nitrate (ZnCN03)2.6H20) was dissolved in 1000 parts of water, and then neutralized with aqueous ammonia to a pH of 7 and stirred for 1 hour.

48 parts of the obtained hydrogel in terms of ZnO were mixed with 6.67 parts of the tellurium oxide obtained in (6-a) above in a mixer.

Next, it was filtered, washed twice with water, dried at 110°C, and then calcined at 500°C for 4 hours.

When the synthesis reaction of pyridine was carried out in the same manner as in Example (6-c) using the catalyst obtained in this manner, pyridine was 0.021 P/hour, and β- and γ-picoline were 0.02 P/hour.
2P/hour was obtained.

Note that the conversion rate of propylene was 22.4%.

Example 9 Ethyl silicate (Si (OCR2CH3)4) 2
00 parts, magnesium nitrate (Mg(NO3)2.6H2
0) 2.5 parts of a 1% by weight nitric acid aqueous solution (g) was added to 1,800 parts and hydrolyzed at 30°C for 2 hours.

Next, the pH was adjusted to 7 with aqueous ammonia, and the mixture was stirred for 1 hour.

48 parts of the obtained hydrogel as SiO2 and 6.67 parts of the tellurium oxide obtained in (6-a) above were mixed in a mixer, then separated, washed twice with water, and heated at 110°C.
The catalyst was dried and further calcined at 500° C. for 1 hour to obtain a catalyst.

Using the catalyst thus obtained, a reaction was carried out in the same manner as in Example (6-c), and pyridine was 0.02:111.
At 7 hours, 0.021 g/hr of β- and γ-picoline was obtained.

Example 10 When a reaction was carried out in the same manner as in Example 9 using 4.2 parts of lanthanium nitrate (La(NO3)3-6H20) instead of magnesium nitrate, pyridine was 0.021f? /h, β- and γ-picoline are 0
．． 020 S'/hour was obtained.

Incidentally, the conversion rate of propylene was 321%.

Example 11 In Example 9, 3.8 parts of gallium nitrate (Ga(NO3)3.8H20) was used instead of magnesium nitrate, and the reaction was carried out in the same manner as in Example 9. /h, β- and γ-picoline 0.0
13P/hour was obtained.

Example 12 Zyl nitrate-t=ru(ZrQ (NO3)2 ・2H
20) Dissolve 83.1 parts in 1250 parts of water and add 2 parts of water to this.
Phosphoric acid-hydrogen ammonia (NH4) dissolved in 250 parts
) 27.4 parts of 2HPO4) were added dropwise.

After washing the obtained precipitate with water, phosphoric acid/zirconia was obtained.

200 parts of ethyl silicate (Si(OCH2CH3)4) was added to 1,800 parts of a 1% by weight nitric acid aqueous solution and hydrolyzed at 30° C. for 2 hours.

Then, aqueous ammonia was added to adjust the pH to 7, and the mixture was stirred for 1 hour.

38.4 parts of the obtained hydrogel as SiO2, 9.6 parts of the phosphoric acid/zirconia obtained above as 3ZrO2.2P205 and the (6-
6.67 parts of the tellurium oxide obtained in step a) was dissolved in the presence of a small amount of water.

The obtained precipitate was dried at 110°C and further dried at 500°C for 3
A catalyst was obtained by firing for a period of time.

Using the catalyst thus obtained, a pyridine synthesis reaction was carried out in the same manner as in Example (6-c) above, yielding 0.00% pyridine.
0.049 P/h, β- and γ-picoline 0.012 P/h.

Note that the conversion rate of propylene was 10.5%.

Example 13 65.2 parts of titanium tetrachloride (TiC14) was added dropwise to 590 parts of water, and then phosphoric acid (H,...
63.4 parts of PO4) were added dropwise, and the resulting precipitate was washed three times.

For 48 parts as 3TiO2・2P205, the above (6
6.67 parts of the tellurium oxide obtained in -a) were mixed in a mixer.

After filtering, it was dried at 110°C and then calcined at 500°C for 3 hours to prepare a catalyst.

Using the catalyst thus obtained, a pyridine synthesis reaction was carried out in the same manner as in Example (6-c), and pyridine 0.06
9 P/h, β- and γ-picolines 0.008 P/h.

Claims (1)

[Claims] 1 A saturated or unsaturated hydrocarbon having 2 to 4 carbon atoms, ammonia, and molecular oxygen are mixed in the gas phase with a hydrocarbon acid catalyst and aluminum, silicon, phosphorus, magne, sium,
A method for producing pyridines, which comprises bringing them into contact with a catalyst containing an oxide of at least one element selected from the group of titanium, zinc, gallium, zirconium, and lanthanum.