JPS63190877A - Synthesis of pyridine bases - Google Patents

Abstract

PURPOSE:To obtain the titled pyridine base having high commercial value in high yield at a low cost, suppressing deposition of carbon on a catalyst and facilitating the regeneration of the catalyst, by condensing an aliphatic aldehyde, etc., with ammonia in vapor phase in the presence of a specific zeolite catalyst. CONSTITUTION:The objective compound composed mainly of pyridine, etc., can be produced by the vapor-phase condensation reaction of (A) an aliphatic aldehyde (e.g. acetaldehyde, formaldehyde, acrolein, etc.) and/or ketone (e.g. acetone) with (B) ammonia in the presence of (C) a catalyst produced by modifying (a) a zeolite having a ratio of Si to a metal composed of Al, Fe and Ga (excluding the case composed solely of Al) of about 12-,000 and a control index of 0.8-12 with (b) one or more metal ions and/or metal compounds selected from Tl, Pb and Co. The above catalyst can be produced by ion exchange of a zeolite with metallic ion or by the treatment of zeolite with a metallic compound by kneading, impregnation, immersion, precipitation, etc.

Description

Detailed Description of the Invention <Field of Application of the Invention> The present invention relates to a method for producing pyridine bases by reacting aliphatic aldehydes and/or ketones with ammonia in the gas phase using a specific zeolite catalyst. Preferably, it relates to a method for producing pyridine and picolines by reacting acetaldehyde and formaldehyde with ammonia in the gas phase.

<Prior art and problems to be solved by the present invention> Pyridine bases are produced by reacting aliphatic aldehydes and/or ketones with ammonia in the gas phase using a solid acid catalyst such as amorphous silica alumina. The method of
-41546 Publication, Special Publication No. 44-82790)
. These methods are distinguished by the reaction conditions, especially the catalyst.

It is known that crystalline aluminosilicates, so-called zeolites, are used as catalysts for converting aliphatic aldehydes and/or ketones and ammonia into pyridine bases (U.S. Pat.
-88862).

In the method using an amorphous silica alumina catalyst currently practiced industrially, the amount of pyridine bases obtained is stoichiometric (the expected The ratio to hk, that is, the yield, is as low as 50%, and side reactions cause carbon precipitation on the catalyst, resulting in a decrease in activity within a short period of time.Therefore, regeneration by airage is carried out periodically. However, due to repeated reaction (carbon deposition) and regeneration (superheating), catalyst activity and mechanical strength deteriorate.

Even when zeolite is used as a catalyst, for example, U.S. Pat.
-5 has a low pyridine yield of 40% or less. In JP-A-60-13362, using acetaldehyde, formaldehyde and ammonia, the total yield of pyridine and β-picoline was 77.0% in a fixed bed, and viridi, which is economically more expensive than β-picoline, was The rate is 51%. Furthermore, in a fluidized bed with a superior reaction method, when the same catalyst was used for the reaction, the total yield of pyridine and picoline was 88.8%, and the inner pyridine yield was 60.2%.

However, this yield is a value based on acetaldehyde of acetaldehyde and formaldehyde (molar ratio 1:1) used in the reaction, and when converted to a value based on the total carbon number of acetaldehyde and formaldehyde, pyridine, Total yield of picoline 88.8%
is 78.5%, and the pyridine yield of 60.2% is 5,7
%.

<Means for Solving the Problems> As a result of our intensive search for a catalyst that can obtain pyridine bases with even higher efficiency, we were surprised to find that zeolite with a large control index was combined with thallium, lead, and cobalt. The present invention has been achieved based on the discovery that a high pyridine yield can be obtained by using a catalyst modified with one or more metal ions and/or metal compounds selected from the following.

That is, the present invention provides a method for producing pyridine bases by condensing an aliphatic aldehyde and/or ketone with ammonia in the presence of a catalyst in a gas phase, in which the catalyst is composed of AJ, Fe, and/or Ga. The ratio of Si to metal (excluding Al only) is approximately 1
2 to 1000 and a control index of about 0.8 to about 12 modified with one or more metal ions and/or metal compounds selected from thallium, lead, and cobalt. The present invention relates to a method for producing pyridine bases characterized by the following.

Modification methods include, for example, ion exchange of zeolite with thallium, lead and/or cobalt ions, kneading, impregnation, and dipping with compounds of one or more metals selected from thallium, lead, and cobalt. Examples include methods of treating zeolite by a deposition method, an evaporation drying method, or the like. Further, these methods may be used in combination.

The present invention will be specifically explained. The aliphatic aldehydes used in the present invention include saturated aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde, as well as acrolein,
Unsaturated aldehydes such as methacrolein and crotonaldehyde are used. Further, as the aliphatic ketone, acetone, methyl ethyl ketone, etc. are used. The main compound of the pyridine bases to be produced is determined by the combination of aliphatic aldehyde and/or aliphatic ketone as raw materials.

Representative examples of these are shown in Table 1.

The "control index" mentioned here is, for example, Fr1llett
Journal of Catalysis 67
213-222 (1981). Although this value varies slightly depending on the measurement method, Table 2 shows the results of measurements by Fr1llette and others.

As the zeolite having a control index of about 0.8 to 12 before Table 2, for example, crystalline iron silicate, gallium silicate, iron aluminosilicate, gallium aluminosilicate, iron gallium silicate, or iron gallium aluminosilicate can be used. can. In particular, ZSM-5
Iron silicate or gallium silicate having a ZSM-11 type or ZSM-11 type crystal structure is preferable. Metals consisting of kl, Fe, and/or Ga in zeolites consisting of these heterosilicates (excluding only Al)
Zeolite with a control index of about 0.8 to about 12 used in the present invention exhibits high performance when the ratio of Si to Si is about 12 to 1000, particularly preferably about 15 to 500. , ammonium ion type or proton type can be used. However, if alkali ions ultimately remain in the catalyst, they will reduce the activity of the catalyst and are therefore undesirable. It is desirable to carry out an operation to remove alkali ions either after the modification or after the modification. In addition, using zeolite that has been ion-exchanged in advance with ions of one or more metals selected from thallium, lead, and cobalt, kneading method, impregnation method, Treatment may be performed by the immersion method, deposition method, or evaporation to dryness method. Metal compounds can be converted into oxides, halides, sulfates, and phosphates after normal treatment such as calcination. Alternatively, it is a compound that becomes a composite oxide of these.Calcination is usually carried out at 350 to 800°C for several hours in the air or other gases such as nitrogen or carbon dioxide, but since the temperature of the catalyst is raised in the reaction tube, , calcination of the catalyst is not necessarily required.

Specifically, for example, in the ion exchange method, the zeolite to be ion-exchanged can be of the alkali ion type, ammonium ion type, or proton type, and preferably the ammonium ion type. ammonium chloride, ammonium nitrate,
It is desirable to ion-exchange the material into ammonium ion form by repeating dipping, dipping, and filtering several times in an aqueous solution of ammonium salt such as ammonium acetate. Ion exchange to thallium, lead and/or cobalt ion type is 0.01
- zeolite of the alkali ion type, ammonium ion type or proton type, preferably ammonium ion type, into an aqueous solution of chloride, nitrate or acetate containing thallium, lead and/or cobalt ions at a concentration of 2 g ions/j. This is done by repeating the steps of immersion, stirring at a predetermined temperature, and filtration, and finally washing with water.

Alternatively, 1 g or more of a metal compound such as a metal oxide selected from thallium, lead, and cobalt is mixed or kneaded with zeolite, preferably ammonium ion type or proton type zeolite, either as a powder or with water, and then calcined. . Alternatively, a hydroxide obtained by neutralizing a metal compound such as nitrate or acetate of one or more metals selected from thallium, lead, and cobalt with aqueous ammonia may be used as a zeolite, preferably an ammonium ion type or proton type zeolite. After cross-wiring, fire.

Furthermore, by adding tR of zeolite, preferably ammonium ion type or proton type zeolite, to an aqueous solution of metal compounds such as nitrates and acetates, and adding aqueous ammonia or the like to this, metal oxides etc. can be formed on the surface of the zeolite. is deposited, washed with water, and fired. In addition, zeolite, preferably ammonium ion type or proton type zeolite, is added to an aqueous solution of one or more metal compounds selected from thallium, lead, and cobalt, and after evaporation to dryness,
Fire.

Through these modifications, the JJ (JJ) of thallium, lead and/or cobalt contained in the zeolite is approximately 0.005 to 0 m?equivalent/
It is g.

The zeolite thus modified with one or more metal ions and/or metal compounds can be shaped into cylinders on a tablet machine, either as is or with the addition of silica, silica, kaolin, bentonite, alumina and/or silica-alumina. It can be molded into a cylindrical shape, or it can be kneaded with water, polyvinyl alcohol, or vinyl acetate, and then molded using an extruder.

In addition, as a catalyst for a fluidized bed as described later, silica,
Diatomaceous earth, kaolin, bentonite, alumina and/or silica-alumina and water are added to form a slurry, which is spray dried to form spherical microbeads. In either method, baking is performed at 350 to 800°C for several hours in the air or other gases such as nitrogen or carbon dioxide.
Adds strength to molded products and removes volatile components contained in binders, etc. However, since the temperature of the catalyst is raised within the reaction tube, calcination of the catalyst is not necessarily required.

The reaction of the invention may be carried out in a fixed bed, fluidized bed or moving bed.

The molar ratio of ammonia to aliphatic aldehyde, ketone or mixture thereof is approximately 0.5 to 5 mo.
o 1. Space velocity (SV) is 100-10000
Hr, preferably 800 to 3000 Hr-' is used. The reaction temperature is preferably 850°C to 600°C. The pressure of the reaction gas can range from below atmospheric pressure to several atmospheres, but it is usually most convenient to use atmospheric pressure to around 2 atmospheres.

A particularly preferred combination of aliphatic aldehydes or ketones for synthesizing pyridine or β-picoline is a combination of acetaldehyde and formaldehyde, with a molar ratio of acetaldehyde and formaldehyde of 1.
:0.8 to l:3. In particular, when using the catalyst of the present invention, pyridine, which is more expensive than β-picoline, is produced predominantly.

Furthermore, in order to synthesize α-picoline or γ-picoline, it is desirable to use only acetaldehyde as the combination of aliphatic aldehydes or ketones. The reaction can also be carried out without any particular problem by including water, methanol, etc. in the raw material gas. The methanol content (11t) is usually 0.5 mol or less per 1 mol of acetaldehyde. Formaldehyde can be supplied in the form of formalin. Further, as the aliphatic aldehyde or ketone, it is also possible to use dimers, trimers, other oligomers, or polymers that generate heptamers of aliphatic aldehydes or ketones in the evaporator or reactor.

During the reaction, carbon deposits are observed on the catalyst, but this is a natural consequence of the higher yield of pyridine bases compared to conventional methods.

Therefore, regeneration of the catalyst is easy. The catalyst is regenerated by a conventional method, that is, by passing air through the catalyst layer at a temperature of 450 to 550 DEG C. to burn off the carbon deposited on the catalyst.

<Effects of the Invention> By using the catalyst of the present invention, for example, as shown in Examples, the pyridine yield is 54% or more based on the total number of carbon atoms in the aldehyde and ketone raw materials, and the yield of pyridine and picoline is The total yield is 75% or more, and compared to the conventional method (according to a comparative example, the highest pyridine yield and total yield are 43% and 61%, respectively), it is possible to increase the cost of pyridine, which is economically more expensive. It can be obtained in high yield. Further, there is little carbon deposition on the catalyst, and the catalyst can be easily regenerated.

<Examples> In order to explain the present invention in more detail, specific examples will be given below, but the present invention is based on the total number of carbon atoms limited to these, and was based on the following formula.

Total number of C atoms in generated pyridine Pyridine yield = X100
(%) Total number of C atoms in raw material aldehydes and ketones Production α, β, γ- Total number of C atoms in picoline α, β, γ-
Picoline yield =
x-100 (%) scale 14 aldehydes and ketones 7
Example 1 of EC atomic attack I Crystalline iron silicate zeolite was synthesized by the following method.

An aqueous solution of Fe(NO3)3-9H2034y, tetra-n-propylammonium bromide 84f, and distilled water 150F is defined as A solution. Fuyumushiri Power 70f1 Distilled Water 7
Let the suspension of 002 be liquid B.

Solution C is a solution of 7.4F NaOH and 50F distilled water.

Add liquid A and liquid B to liquid C, and heat in an autoclave for 16 minutes.
The mixture was heated and stirred at 0°C for 60 hours. pH is 12.4 to 1,
It changed to 4. The obtained solid was washed with water at a pH of 7.3.
The solid was washed with water until it became 72.7y, giving a white solid of 72.7y. This product was confirmed to have a ZSM-5 crystal structure by X-ray diffraction analysis.

The obtained Na-type iron silicate zeolite was added to 5% of 11.
After 8 times of ion exchange for 50~b hours with an aqueous ammonium chloride solution of 530 more parts
It was calcined in air for 4 hours at ℃ to obtain H-type iron silicate zeolite.

20ml of aqueous solution containing 0.15f of thallium(I) nitrate
71 was neutralized by adding ammonia water, and the resulting precipitate was washed with water to obtain paste-like thallium hydroxide. This and H
Type iron silicate zeolite 42 was uniformly kneaded in a mortar, dried at 110°C for 14 hours, and calcined in air at 530°C for 4 hours to prepare H-type iron silicate (Th0CT120 content: 2.8%).

A mixture of 2 moles of hydrogen and 1 mole of formaldehyde (40% aqueous solution) was vaporized, mixed with 4 moles of preheated ammonia gas, and passed through a reaction vessel kept at 450° C. at 5V, 1000 hours. After the reaction product was absorbed into water, it was analyzed by FID gas chromatography. The average results for 3 hours from the start of the reaction were pyridine 55%, α
- Picoline 6%, β-picoline 12%, γ-picoline 6
%, the total yield was 79%.

Example 2 The NH4+ type iron silicate zeolite 42 prepared in Example 1 was subjected to ion exchange with 40 ml of 0.1 M lead nitrate aqueous solution at 80°C for 2 hours, and washed in several portions with 20 times the amount of distilled water. . 110CX 16 hours dry, 53 in air
Pb type iron silicate) (Pb content, 5%) was prepared by firing at 0°C for 4 hours.

Using this as a catalyst, the same reaction as in Example 1 was carried out and the results are shown in Table 3.

Example 3 In the same manner as in Example 1, Fe (NOs)s ・
9 H20 (1) Substitute Ni Ga (NO3)! -9H
204,87y and has a ZSM-5 crystal structure.
A-type gallium silicate zeolite was synthesized. After ion-exchanging this into NH, + type gallium silicate zeolite, CO type gallium silicate zeolite (C) was prepared using the same method as in Example 1, using cobalt nitrate instead of lead nitrate.

ffO, 08%] was prepared.

Using this as a catalyst, the same reaction as in Example 1 was carried out and the results are shown in Table 3.

Examples 4 and 5 In the same manner as in Example 8, using thallium nitrate or lead nitrate instead of cobalt nitrate, TI type gallium silicate zeolite (TI content 2.9%) or PB type gallium silicate zeolite (PB content , 8%) was prepared.

Table 3 shows the results of a reaction similar to that of Example 1 using these catalysts.

Comparative Example I ZSM-5 zeolite by Hejima method (Takumi, Gen (8), 2B
2 (1981)), it was synthesized by the method shown below.

Distilled water 438.4 y, aluminum sulfate 4.6 f
, Tetoh 7-n-propylammonium bromide 55
82°C and 402°C of sulfuric acid were mixed to obtain liquid A. Distilled water 82
0? , and No. 8 sodium silicate 453y were mixed to obtain liquid B. Distilled water '154fj' and common salt 139F were mixed to obtain liquid C. Pour liquid C into the stainless steel autoclave No. 31, and while stirring vigorously.

Both solutions B were mixed dropwise. The pH of the mixture was adjusted to remain between 9.5 and 11. Seal the autoclave and
The temperature was raised to 60° C., stirring was continued, and hydrothermal synthesis was carried out in this state for 20 hours. This gauge pressure is 5-6 Kg/Cr
It showed A. After the reaction was completed, the mixture was cooled to room temperature and the product was filtered off. After repeating washing and filtration until CI- in the filtrate was 1ppm or less, it was dried at 110°C for 16 hours and calcined in air at 530°C for 4 hours to obtain Na type 28M-5 white crystals 1122. . The X-ray diffraction spectrum of this white crystal is Z
It was confirmed that the spectrum matched the XFi1 diffraction spectrum of SM-5. The obtained Na type 28M-5 zeolite was
After 50-b ion exchange with 5% ammonium chloride aqueous solution three times, C1- of the washing water was lpp.
m or less, and dried at 110° C. for 16 hours to obtain NH4+ type ZSM-5 crystal 1062. Further, a part of it was calcined in air for 5 aoc for 4 hours to obtain H-type ZSM-5.
Got 5.

Using this as a catalyst, the same reaction as in Example 1 was carried out and the results are shown in Table 4.

Comparative Example 2 In Comparative Example 1, NH4+ type ZSM-549 was used.
at 80°C with 40ml of 0.1M cadmium nitrate aqueous solution
Ion exchange was performed for 2 hours, and the sample was washed several times with 20 times the amount of distilled water. It was dried at 110° C. for 16 hours and fired in air at 530° C. for 4 hours to prepare Cd type Z SM-5 (Cd content 0.16%).

Table 4 shows the results of a reaction similar to Example 1 using this as a catalyst.

Comparative Example 3 Y-type zeolite (manufactured by Toyo Soda Kogyo Co., Ltd.: TSZJ30
Table 4 shows the results of the same anti-Lc test as in Example 1 using HOA (HOA) as a catalyst.

Ratio Example 4 Using ucc% silicalite (S-115) as a catalyst,
Table 4 shows the results of the same reaction as in Example 1.

Comparative example 5 Silica alumina (manufactured by JGC Chemical C Co., Ltd.): N-681L・O
Table 4 shows the results of a reaction similar to that in Example 1 using the following as a catalyst.

Claims (17)

[Claims] (1) In a method for producing pyridine bases by condensing an aliphatic aldehyde and/or ketone with ammonia in the presence of a catalyst in the gas phase, the catalyst may include Al, Fe,
and/or a zeolite having a ratio of Si to a metal consisting of Ga (excluding only Al) of about 12 to 1000 and a control index of about 0.8 to about 12 selected from thallium, lead, and cobalt. 1. A method for producing pyridine bases, which comprises using a catalyst modified with one or more metal ions and/or metal compounds. (2) The method according to claim 1, wherein acetaldehyde and formaldehyde are used as the aliphatic aldehydes, and the main product is pyridine. (3) The method of claim 2, wherein the molar ratio of acetaldehyde:formaldehyde:ammonia is about 1:0.3 to 3:0.5 to 5. (4) 0 per mole of acetaldehyde in the reaction raw material
．． 3. The method according to claim 2, comprising 5 moles or less of methanol. (5) A catalyst according to claim 1, 2 or 3, characterized in that a catalyst is used which is obtained by ion-exchanging zeolite with one or more metal ions selected from thallium ions, lead ions and cobalt ions. Method. (6) It is characterized by using a catalyst obtained by treating zeolite with one or more metal compounds selected from thallium compounds, lead compounds, and cobalt compounds by a kneading method, an impregnation method, a dipping method, a deposition method, or an evaporation-drying method. A method according to claim 1, 2 or 3. (7) The method according to claim 6, wherein the metal compound is one or more metal compounds selected from oxides, halides, sulfates, phosphates, nitrates, and organic carboxylates. (8) The method according to claim 7, wherein the metal compound of thallium, lead and/or cobalt is an oxide. (9) The method according to claim 6, wherein the modification method with a metal compound comprises kneading the oxide or hydroxide with zeolite. (10) The metal content of thallium, lead and/or cobalt is 0.005 to 0.1 m relative to zeolite
g equivalent/g. (11) The method according to claim 1, wherein acetaldehyde is used as the aliphatic aldehyde and α-picoline and γ-picoline are the main products. (12) using acrolein as the aliphatic aldehyde,
A method according to claim 1, wherein the main products are β-picoline and pyridine. (13) The method according to claim 1, wherein formaldehyde is used as the aliphatic aldehyde, acetone is used as the aliphatic ketone, and 2,6-lutidine is the main product. (14) Al, Fe, and/or G in zeolite
S for metals consisting of a (excluding Al only)
Claims 1, 2, 3, 5, 6, 7, 8, 9, 1, wherein the ratio of i is about 15 to 500.
0, 11, 12 or 13. (15) Zeolite is ZSM-5 type or ZSM-1
Claims 1, 2, 3, 5, 6, 7, 8, which are gallium silicate having type 1 crystal structure.
The method according to item 9, 10, 11, 12 or 13. (16) Zeolite is ZSM-5 type or ZSM-1
Claims 1, 2, 3, 5, 6, 7, 8, 9, which are iron silicate having type 1 crystal structure.
The method according to item 10, 11, 12 or 13. (17) Claims 1, 2, 3, 11, 12, 13, 14, 15, in which the catalyst contains silica, diatomaceous earth, kaolin, bentonite, alumina and/or silica alumina. , or the method according to paragraph 16.