JPS587622B2 - Pyridine enkylinoseizohouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for forming an acrylic layer using Ti02-Si02-Al.
The present invention relates to an improvement in a method for producing pyridine bases, mainly pyridine and β-picoline, in high yield through a catalytic reaction with ammonia in a high-temperature gas phase in the presence of a 203-based catalyst.

Conventionally, there is a known method for producing pyridine bases by catalytically reacting ammonia with ammonia in the presence of a catalyst in the gas phase at high temperature. car alumina catalyst is used.

For example, Japanese Patent Publication No. 47-44743 describes a catalyst in which cadmium or zinc is added to silica alumina, and it is said that when cadmium was added, pyridine bases were obtained with a yield of 72.4%. Description (the same publication, Example 1
).

However, in this case, since cadmium, a highly toxic element, is used, there is a drawback that special equipment and treatment methods are required for preparing the catalyst and treating the deteriorated catalyst.

In addition, Canadian Patent No. 836592 describes a silica-alumina catalyst or a silica-alumina containing 1 to 20% by weight of oxides of zirconium, zinc, thorium, copper, iron, cobalt, titanium, lead, cadmium, chromium, etc. A catalyst to which titanium oxide was added is described, and Examples 26 to 28 thereof describe examples in which titanium oxide was added, but the yield of pyridine bases is less than 50%.

Furthermore, Japanese Patent Publication No. 46-8305 describes a silica alumina catalyst impregnated with a fluoride.

However, the yield of pyridine bases is at most 61% (see Example 2 of Japanese Patent Publication No. 46-8305).

As a result of these inventors incorporating copper oxide into the silica alumina described in Canadian Patent No. 836592,
The yield of pyridine bases reaches a peak at an addition amount of ~7% by weight (
When as much as 20 parts by weight of copper oxide was added, the yield of pyridine bases was extremely low (about 51%).

The inventors have developed a method for producing pyridine bases with the aim of developing a catalyst that does not contain highly toxic elements and can produce pyridine and β-picoline, which are highly useful, in high yield. I conducted extensive research.

As a result, silicon, aluminum, and titanium were selected from among a large number of element and oxide combinations, and ? When a combination of liquor alumina and titanium dioxide and a composition containing a large amount of titanium dioxide in silica alumina are used as a catalyst, the yield of pyridine base exceeds 70%, which cannot be predicted with conventionally known titanium oxide containing catalysts. It has been found that the object of this invention can be achieved.

This invention provides improved TiO-SiO2-Al20,
This article relates to a method for producing pyridine bases from Akuchirein in high yield using a system catalyst.In detail, Akuchirein is catalytically reacted with ammonia in the presence of a catalyst in a high-temperature gas phase to produce pyridine bases. In the method of manufacturing
This invention relates to a method for producing pyridine bases, characterized in that a composition consisting of silicon, aluminum, titanium, and oxygen, comprising 30 to 70 parts by weight of titanium dioxide and 70 to 30 parts by weight of silica alumina, is used as a catalyst. .

The catalyst used in this invention is composed of silicon, aluminum, titanium and oxygen, which are Ti02
, A403 and Si02 in the catalyst,
There is no problem even if a small amount of compounds such as Tie, Ti203, Al (AASi05), etc. are contained.

Quantity ratio of silica alumina, i.e. SiOz:A120
, is A72O3 for 95 to 70 parts by weight of Si02.
A suitable proportion is 5 to 30 parts by weight.

In this invention, it is important to use a catalyst containing titanium dioxide, that is, Ti02, in a much larger amount than that added to conventional silica alumina. Ti02)
30-70 weight factor and silica alumina (Si02-Al
203) Use one consisting of 70 to 30 weight ratio.

According to this research by the inventors, Ti02-Si02-
In the Al203 system, the yield of pyridine bases is greatly influenced by the content of Ti02 in the catalyst, although it is slightly affected by the quantitative ratio of Si02 and Al20.
It shows a peak in terms of weight, and outside this range the yield of pyridine and β-picoline decreases, making it difficult to produce pyridine bases mainly consisting of pyridine and β-picoline with a yield exceeding 70%. Become.

The catalyst suitably used in this invention can be prepared, for example, as follows.

A predetermined amount of powdered titanium dioxide (Ti02), silica sol, and alumina sol or aluminum nitrate is mixed and crushed while heating until it becomes mud-like.

The slurry is dried in an air atmosphere at a temperature of 100 to 200°C, crushed to the extent that it can pass through a 14 mesh (Tyler standard sieve), and molded to a size of 500 to 70.
Calcinate in an air atmosphere at a temperature of 0° C. for 3 to 5 hours to obtain a catalyst.

The catalyst used in this invention is not limited to the catalyst prepared in this way, for example, by adding a small amount of water to commercially available silica alumina and mixing powdered titanium dioxide,
It can also be prepared by baking at 500 to 700°C after drying.

Most of the catalysts prepared in this way are made of Ti.
02, Si02 and Al20, but compounds of titanium, silicon and aluminum other than those represented by this chemical formula may be present in trace amounts in the catalyst.

In this invention, the amount of ammonia supplied to the catalyst layer is 0.5 mol or more, preferably 1 mol or more, per 1 mol of aqueduct.
More than mol is better.

However, it is not economical to supply ammonia in too large a quantity, and the upper limit is about 10 moles.

In carrying out this invention, both acuturein and ammonia are in a completely gaseous state because, due to its chemical properties, acuturein easily polymerizes when it comes into contact with a basic substance in a liquid or solution state. Mixing is preferred.

The reaction can be carried out under normal pressure, reduced pressure, increased pressure, etc., but it is generally convenient to carry out the reaction under normal pressure or slightly increased pressure.

Further, in carrying out the reaction, a diluent gas can be used in addition to aqueous chloride and ammonia.

Diluent gases include gases that are inert to this reaction, such as nitrogen, carbon dioxide, and water vapor.

Among these, water vapor is preferred since it has the effect of sustaining the catalyst activity and increasing the yield of pyridine bases.

The amount of water vapor added is equal to or more than the same mole, preferably 3 to 10 moles, per mole of water vapor.

The reaction temperature is 300-600°C, preferably 380-50°C.
The contact time required for the reaction at 0°C varies somewhat depending on the reaction conditions, but generally 1 to 10 seconds is sufficient.

Example 1 50 parts by weight of titanium dioxide powder [manufactured by Wako Pure Chemical Industries, Ltd.], 44 parts by weight of SiO2 silica sol [manufactured by Nissan Chemical Industries, Ltd.: Snowtex 0; Si02 content 20]
After mixing and crushing 6 parts by weight of alumina sol [manufactured by Nissan Chemical Industries, Ltd.: Al203 content IO weight] as A1203 and A1203 while heating until it becomes muddy,
It was dried in air at 120° C. for 10 hours, and then crushed so as to pass through a 14 mesh (Tyler standard sieve) sieve.

The obtained crushed product was formed into a tablet of approximately 4 mmφ×4 mm using a tablet press, and calcined at 550° C. for 4 hours in an air atmosphere to obtain a catalyst.

40 m of the catalyst prepared in this way was filled into a glass reaction tube with an inner diameter of 20 mmφ,
mol/hr1 ammonia 0.58 mol/hr nitrogen 0.1
The reaction was carried out at 450° C. under normal pressure by supplying water at a rate of 34 mol/hr and steam at a rate of 0,987 mol/hr.

The gas that exited the reaction tube was cooled with a condenser, and the condensed liquid product was analyzed using gas chromatography.
0.35 pyridine per 2 moles of supplied Akuchirein
8 mol of pyridine bases, 0.381 mol of β-picoline and 0.010 mol of 3,5-lutidine were produced.

Examples 2 and 3 Catalysts with the composition ratios listed in Table 1 were prepared using the same preparation method as in Example 1, changing the proportions of titanium dioxide, silica sol, and alumina sol, and pyridine was prepared under the same reaction conditions as in Example 1. Bases were produced.

The results are shown in Table 1.

The number of moles of pyridine bases produced is 2
Per mole.

Comparative Example 1 Tie 220 parts by weight, Sl
A catalyst consisting of 0270.4 parts by weight and 9.6 parts by weight Al20 was prepared, and pyridine bases were produced under the same reaction conditions as in Example 1.

The results are shown in Table 1.

The number of moles of pyridine bases produced is 2
Per mole.

Claims (1)

[Claims] 1. A method for producing pyridine bases by catalytically reacting ammonia with ammonia in the presence of a catalyst in a high-temperature gas phase, comprising 30 to 70 parts by weight of titanium dioxide and 70 to 30 parts by weight of silica alumina as catalysts. A method for producing pyridine bases, which comprises using a composition comprising silicon, aluminum, titanium, and oxygen.