JPH09249619A - Production of methylamines - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably obtain dimethylamine and monomethylamine while suppressing reduction in catalytic performances and subduing formation of trimethylamine even in a case in which a methanol admixed with formaldehyde, etc., is used as a raw material. SOLUTION: Methanol is reacted with ammonia in the presence of hydrogen and a metal zeolite obtained by replacing a zeolite as a catalyst with an ion of a metal having reducing ability such as copper, silver, gold or nickel to give the objective methylamine. Preferably unreacted methanol recovered from the reaction mixture is used as a part of methanol. In the reaction, the content of formaldehyde is <=2,000ppm based on methanol by weight ratio.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing amines,
More specifically, in the production of methylamines from methanol and ammonia, a method for obtaining a larger amount of mono- and dimethylamine than trimethylamine, and more specifically, a method for suppressing the production of trimethylamine used to accelerate the reaction. The present invention relates to a method for stably producing methylamines from methanol and ammonia, which suppresses a decrease in activity of zeolites containing aluminosilicate as a main component, which is an effective catalyst, maintains high activity and high selectivity for a long time.

[0002]

2. Description of the Related Art Methylamines, that is, monomethylamine, dimethylamine and trimethylamine are produced by a method of reacting methanol or a mixture of methanol and dimethyl ether with ammonia, a method of catalytic reduction of hydrocyanic acid with hydrogen and the like. These methylamines are produced as a mixture of mono, di and trimethylamines,
It has uses corresponding to each. On the other hand, demand for these methylamines is biased toward dimethylamine or monomethylamine, and demand for trimethylamine is extremely small at present.

Methylamines, which are usually obtained by the reaction of methanol and ammonia using a known amorphous silica-alumina as a catalyst, have trimethylamine as the main product in the reaction equilibrium, and the demanded amount of dimethylamine is small. There was a difficulty. In order to overcome these difficulties, when dehydrated crystalline aluminosilicate (zeolite) having a pore size of 5 to 10 Å is used as a catalyst for the reaction of an alcohol having 1 to 18 carbon atoms with ammonia, mono, and It is disclosed that diamines are preferentially produced over triamines. Further, natural zeolite and synthetic zeolite are disclosed as types of zeolite suitable for the above reaction. As natural zeolite, faujasite, analsite, clinoptyllite, ferrierite, chabazite, gmelinite,
Levinite, erionite and mordenite are disclosed as suitable. As a synthetic zeolite, X
Molds, Y-shapes, A-shapes and the like are disclosed as suitable. (U.S. Pat. No. 3,384,667, 1968).

A method in which methanol and ammonia are mixed at a specific ratio and reacted in the presence of a catalyst such as mordenite to obtain a large amount of monomethylamine (JP-A-56-1).
No. 13747) and a crystalline aluminosilicate selected from sodium-type mordenite to disproportionate monomethylamine to obtain dimethylamine with high selectivity (Japanese Patent Laid-Open No. Sho 5)
6-46846) method is also disclosed.

A method of using a naturally occurring mineral for the mordenite used in the same manner as in the above-mentioned US Pat. No. 3,384,667 (Japanese Patent Laid-Open No. 169444/1982), using mordenite ion-exchanged with lanthanum ion as a catalyst. Method (JP-A-58-49340), method using mordenite in which the amount of alkali metal ion exchange is limited to a specific range (JP-A-59-21050), steam-treated mordenite on the catalyst (Japanese Patent Application Laid-Open No. 59-227841) and a method of using A-type zeolite having a low binder content as a catalyst (Japanese Patent Laid-Open No. 58-6)
No. 9846) or a method using Rho type (ZK-5) zeolite as a catalyst is also disclosed. Although the amount of trimethylamine produced can be suppressed by using the zeolite-based catalyst in the above method, the mordenite fine pores of silicon tetrachloride can be formed with the aim of further reducing the amount of trimethylamine produced to zero or substantially zero. CVD (Chemic
There is also known a method of using a catalyst modified by al Vapor Deposition) as a catalyst (JP-A-3-262540; J. Catal., 13).
1, p. 482 (1991); U.S. Pat. No. 5,137,8.
No. 54).

A method in which chabazite, erionite, ZK-5 and Rho type zeolite are deposited and modified with silicon, aluminum, phosphorus or boron as a catalyst and used as a catalyst (JP-A 61-254256, US Pat. No. 4,683). ，
No. 334), a method of reducing the production of trimethylamine is also disclosed. Furthermore, a method of silylating mordenite in a liquid phase using a silylating agent such as ethyl silicate (JP-A-6-179640, JP-A-7-2740).
Are also disclosed. In particular, it is known that the production of trimethylamine is extremely efficiently suppressed by using a mordenite catalyst that has been subjected to a silylation treatment in a liquid phase. Also known is a method of reacting an alcohol with ammonia using a non-zeolitic molecular sieve SAPO as a catalyst to form an alkylamine (JP-A-2-734).

As described above, the catalyst used in the method for producing methylamines by the reaction of methanol and ammonia, particularly the production method for reducing or suppressing the formation of trimethylamine, is zeolites, particularly metal ion exchange or It is known that a zeolite catalyst such as mordenite treated by the CVD method or the liquid phase silylation method is effective.

[0008]

However, as described in, for example, JP-A-2-63554, methylamine which suppresses the formation of trimethylamine by the reaction of methanol and ammonia in the presence of a zeolite catalyst. In the production method of the class, a considerable amount of aldehyde compound such as formaldehyde is produced in the reaction product. Further, when the method for producing the methylamines is industrially carried out, after the methylamines are separated and obtained from the reaction product, unreacted methanol is separated from water, which is a by-product, and recovered by separation, It needs to be reused. At that time, it is described in the above-mentioned specification that the separation of methanol and the aldehyde compound is not easy and the circulation of a considerable amount of the aldehyde compound into the reaction system is unavoidable. Here, the above-mentioned patent (JP-A-2-63554) discloses that it is necessary to reduce the amount of aldehydes (particularly formaldehyde) introduced into the reaction system. That is, it is disclosed that it is necessary to reduce the amount of aldehydes to the catalyst to a certain amount or less, because the catalyst life is extremely shortened by mixing aldehydes into the reaction system.

However, as described above, in the case of a catalyst for suppressing the formation of trimethylamine, particularly in a usual zeolite, especially a mordenite catalyst ion-exchanged with sodium metal or the like, a considerable amount of aldehyde (particularly formaldehyde) is formed during the reaction. Is unavoidable,
Therefore, avoiding the recycling of a substantial amount of aldehydes to the reaction system in the recycling and reuse of unreacted methanol in industrial practice is difficult in the conventional industrial separation method.

As a solution to this problem, a method of removing aldehydes with a reagent such as sodium sulfite when separating and recovering methanol is known, and further, the metal content of sodium or the like in the catalyst is reduced to remove formaldehyde or the like. A method of suppressing generation and increasing durability against formaldehyde and the like is also disclosed (Japanese Patent Application No. 6-68478).

The former solution complicates the process, and since it uses a reagent such as sodium sulfite, it cannot be said to be advantageous for industrial practice. Furthermore, the reaction between methanol and ammonia in the presence of a zeolite catalyst cannot be a solution for suppressing the formation of aldehydes such as formaldehyde produced in the reaction system. The decrease in the activity of the catalyst by the class is not substantially solved. The latter solution is efficient and highly effective, and is reasonably effective as an industrial production method, but if a method of further extending the life can be found, it can be an extremely effective process as an industrial production method.

The object of the present invention is to formaldehydes produced in the reaction system in the production of methylamines for suppressing or reducing the production of trimethylamine by using a catalyst such as zeolite in the reaction between methanol and ammonia. It is possible to suppress the decrease of the catalytic activity due to, etc., and when carrying out industrially, unreacted methanol is separated by an industrial method such as distillation, and a considerable amount of collected aldehydes such as formaldehyde is recovered. A highly efficient zeolite catalyst of methanol and ammonia that enables suppression of catalyst activity reduction even when the contained methanol is recycled and reused in the reaction without performing a special separation and removal operation of aldehydes and the like. PROBLEM TO BE SOLVED: To provide a method for producing methylamines capable of suppressing the amount of trimethylamine produced in the presence thereof A.

Another object of the present invention is also industrially applicable to a production method which suppresses the formation of trimethylamine in the presence of a zeolite catalyst containing aldehydes such as formaldehyde and having a low degree of purification. It is also to provide a method for producing methylamines that can be carried out.

[0014]

Means for Solving the Problems As a result of intensive investigations by the present inventors to solve the difficulty of being industrially implemented due to performance degradation such as catalyst activity due to aldehydes such as formalin, as a result, methanol and In the method for producing methylamines by reaction with ammonia, a metal ion-exchanged zeolite prepared by exchanging zeolite with a metal ion having a reducing ability is used as a catalyst, and the reaction is carried out in the presence of hydrogen. It was found that the deterioration of the catalyst due to a decrease in the activity thereof can be suppressed very effectively, and the present invention has been completed.

That is, the present invention relates to a method for producing methylamines by the reaction of methanol and ammonia, in which a metal ion-exchanged zeolite (hereinafter referred to as a zeolite as a precursor of a catalyst is exchanged with an ion of a metal having a reducing ability). (Abbreviated as catalyst)) and hydrogen in the presence of hydrogen.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The catalyst used in the present invention is a metal ion (cation) capable of reducing part of the cations possessed by zeolite.
It was exchanged in. The zeolite used as the catalyst precursor is not particularly limited in the method of the present invention, and it is known that the production of trimethylamine is suppressed by the reaction of methanol and ammonia, and monomethylamine and dimethylamine are selectively produced. Any zeolite can be used as long as it is a zeolite.
Zeolites such as mordenite, A-type zeolite, clinoptyllite, chabazite, erionite, ZK
-5 and Rho type zeolite are exemplified. Further, those zeolites whose pores are controlled by a treatment method such as a CVD treatment with silicon tetrachloride or the like, a deposition modification treatment of silicon, aluminum, phosphorus or boron, or a silylation treatment with a silylating agent in a liquid phase are also performed in the same manner. It is illustrated. Zeolite is preferably mordenite or clinoptyllite, and liquid phase silylation treatment is recommended as pore control treatment. However, the present invention is not limited to only these zeolites and these zeolite pore control treatment methods.

Most of these synthetic or natural zeolites are usually in the sodium ion form. In the present invention, the zeolite (catalyst precursor) is not particularly limited in its form (ion exchange state), but it is preferable to use one having at least a part of hydrogen ion type. In particular, in the case of zeolite that has been silylated with a silylating agent in the liquid phase, it is recommended to use the hydrogen ion type.

The present invention uses a catalyst in which some or all of the cations (hydrogen ions, sodium ions, etc.) of these zeolites are exchanged by ion exchange treatment with metal ions (cations) having a reducing ability. . In the present invention, the metal having a reducing ability means a metal capable of reducing an organic compound in the presence of hydrogen. Specifically, metals such as copper, silver, gold, nickel, palladium, platinum, cobalt, rhodium, iridium, iron, ruthenium and osmium are exemplified as the most general metal having a reducing ability. Examples of preferable metals include copper and silver. Of course, the invention is not limited to only these metals.

In the method of the present invention, a catalyst in which a part or all of the cations possessed by the zeolite is exchanged with at least one metal ion selected from these groups is used as a catalyst. The method of ion exchange with the ion of the metal having the above-mentioned reducing ability of zeolite is not particularly limited in the present invention, and cations such as hydrogen ions of the catalyst precursor zeolite are exchanged with the cation of the metal. If it is a method that can be exchanged, any method can be exchanged, but if it is specifically exemplified as a method that is easy to carry out, an aqueous solution in which a predetermined amount of a metal compound having a reducing ability is dissolved in a zeolite such as a hydrogen ion type is used. After soaking in
Wash with deionized water, dry and bake. Alternatively, a method of immersing in an aqueous solution in which a metal compound is dissolved, distilling off water, drying and firing, and the like can be mentioned. Of course, the invention is not limited to only these methods. The compound form of the metal having a reducing ability used for ion exchange is not particularly limited, as long as it is a general compound form,
It can be used for ion exchange in the method of the present invention. As a compound form that facilitates ion exchange,
A compound that is soluble in a solvent such as water or alcohol is preferable. Specifically, metal chlorides, nitrates, which have reducing ability,
Examples thereof include organic carboxylic acid salts such as sulfates and acetates.

In the present invention, a part of the cations of the zeolite as the catalyst precursor is exchanged with the ions of the metal having the reducing ability described above, and the amount of exchange with the metal having the reducing ability is changed. Although not particularly limited, it is recommended that at least 0.5% or more, more preferably 1% or more, of the base exchange capacity of zeolite is recommended. In particular, when a hydrogen ion type is used as the precursor zeolite, the exchange amount thereof is 1 to 90%, preferably 3 to 70%, more preferably 5 to 50% of the base exchange capacity of the zeolite, and the exchange capacity is It is recommended to replace with the metal ion that it has. This is because if the amount of exchange is too small, the effect of the present invention may not be remarkably observed, and if the amount of exchange is too large, the reaction rate may decrease. Of course, the present invention is not limited to only these quantitative ranges.

Usually, a metal having a reducing ability as described above has a plurality of valences when forming its compound.
The valence of the metal in the compound of these metals used in the present invention is not particularly limited. Specifically, for example, when the metal having a reducing ability is copper, the ion exchange is carried out using a predetermined amount of a copper compound, but the valence of copper in the copper compound is usually 1 to 2 Value. In the present invention, the compound can be replaced by a copper compound having any of these valences.

The base exchange capacity (cation exchange capacity) of the above-mentioned zeolite in the present invention will be described. The base exchange capacity (cation exchange capacity) of the zeolite referred to in the present invention is the Cation Exchange Capacity.
y (abbreviated as CEC), which is usually represented by the exchange capacity per 100 g of zeolite. This measuring method is described in detail in the literature of Negishi (Clay Science, Vol. 12, No. 1, pages 23 to 30; 1972).

Here, the exchange rate of the reducing metal with ions in the method of the present invention will be described in detail. As described above, the valence of the compound or ion of these metals is not always monovalent. Therefore, the exchange rate in the present invention means that the valence of the metal ion to be exchanged is n (the metal valence is n) with respect to the base exchange capacity of the catalyst precursor zeolite.
Valuation), the formula (1)

[0024]

## EQU1 ## Y = [(A × 100) × n] / B (1) (where Y is the exchange rate (unit is%), and A is 100 g of the catalyst precursor zeolite and is incorporated into the zeolite by ion exchange treatment). The number of milligram atoms of the metal having the reducing ability, n is the valence of the metal (as a compound) used in the ion exchange treatment, and B is the base exchange ability of the precursor zeolite (measured by the above method ( The unit is milligram equivalent / 100 g)).

The form of the catalyst is not particularly limited, but it is recommended to use it in a granular form or the like. If the zeolite used as a catalyst is in the form of granules or tablets, it can be used as a catalyst as it is.If it is in the form of powder, it can be extruded by a usual method, or molded by a method such as tablet molding. It is preferable from the viewpoint of ease of filling the container.

The present invention is a method for producing methylamines by the reaction of methanol and ammonia using zeolites ion-exchanged with metal ions (cations) having the above-mentioned reducing ability in the presence of hydrogen as a catalyst. The ammonia used here may be of ordinary reagent purity or industrial purity.
In addition, a part or all of the ammonia that is used in the reaction and separated and recovered may be reused.

The methanol used may be of ordinary reagent purity or industrial purity, like ammonia. It is also used as a mixture with dimethyl ether. Furthermore, it is also possible to use those containing aldehydes (particularly formaldehyde) of low purification purity. Naturally, recovered methanol containing formaldehyde produced as a by-product used in the reaction (after separating methylamines from the reaction mixture by distillation from a mixture containing water, which is a by-product of the reaction, naturally also included recovered methanol) .) Can be reused in part or in whole.

Usually, most of aldehydes such as formaldehyde are contained in methanol. The amount of aldehydes such as formaldehyde contained in the methanol used is not particularly limited, but is preferably 2,000 ppm or less in terms of formaldehyde in methanol, and more preferably 1,000 pp.
m or less. If the amount of aldehyde is too large, the effect of extending the catalyst life can be recognized, but it is difficult to bring about a catalyst life that can substantially withstand the industrial production method. The effect of the method of the present invention is to improve the durability of the catalyst. Therefore, basically, the amount of aldehydes such as formaldehyde, which adversely affects the life of the catalyst, is determined by the amount of loading on the catalyst.
The load on the catalyst is also not particularly limited, but the amount of aldehyde per unit weight of the catalyst is preferably 2,000 ppm or less per hour in terms of formaldehyde weight, and more preferably 1,000 ppm or less. Here, even if the amount of aldehyde contained in the methanol is more than the above, the load on the catalyst is 2,000 p.
Although it may be pm or less, in that case, the introduction speed of methanol to the catalyst layer is unavoidably slowed down, and there is a fear that it may not be an economical method when industrially implemented.

However, the aldehydes are not always
Only what is contained in methanol is not necessarily introduced into the reaction system, and it may be contained in one of the reaction raw materials, ammonia, and introduced into the reaction system. In this case, the amount of aldehydes such as formaldehyde is contained in methanol and / or ammonia alone. In this case, the amount of aldehyde introduced is preferably within the above-mentioned loading amount of aldehydes on the zeolite catalyst.

Therefore, in the present invention, of the ammonia used in the reaction, even if aldehydes such as formaldehyde are contained in the ammonia which is unreacted and is separated and recovered by a usual industrial separation method such as distillation, it is recycled. It is also possible to reuse and implement. Of course, the present invention is not essential that these aldehydes are mixed and introduced into the raw material, and can be carried out even if mixed.
It is of course possible to carry out using a raw material containing no aldehydes.

As described above, the reaction raw materials used in the method of the present invention are methanol or a mixture of methanol and dimethyl ether, and ammonia. The introduction ratio of ammonia and methanol to the reaction system is not particularly limited, but is usually 0.5 or more, preferably 1 to 10 and more preferably 1 to 4 in terms of ammonia / methanol molar ratio. Is recommended.

The method of the present invention is a method for producing methylamines which suppresses the formation of trimethylamine in the presence of various zeolite catalysts of methanol and ammonia. Further, the presence of hydrogen in the reaction system or the introduction of hydrogen into the reaction system activates the catalyst. This is a method for producing methylamines that suppresses deterioration such as deterioration. Here, the amount of hydrogen existing or introduced into the reaction system is not particularly limited, but is preferably 1 to 5 relative to the total molar amount of the starting ammonia and methanol.
The amount is 0 mol%, more preferably 2 to 20 mol%. If there is too much hydrogen, the reaction efficiency will decrease,
There is a risk of impeding industrial implementation such as a reduction in distillation efficiency, and if the amount is too small, the effect of the method of the present invention may not be expected so much.

The reaction form is not particularly limited in the method of the present invention, but preferably, it is recommended as an industrial production method to carry out in a gas phase in a fixed bed or in a fluidized bed as a flow reaction. At this time, the introduction rate of the gas (mainly composed of ammonia, methanol and hydrogen) to be supplied to the filled catalyst layer is not particularly limited, but it is preferably 200 in terms of standard state gas conversion space velocity (SV). ~ 2
The range is 000 / hour. The reaction pressure is not particularly limited, and the reaction can be carried out under any of atmospheric pressure, increased pressure, and reduced pressure, but preferably atmospheric pressure to 30 kg / cm.
² G. And more preferably 5 to 25 kg / cm ² G.I. It is recommended to carry out within the range. The reaction temperature is also not particularly limited, but is preferably 200 to 450 ° C, more preferably 250 to 350 ° C. If it is carried out at too high a temperature, undesired by-products will be produced in large amounts, which is not economical, and if it is carried out at too low temperature, it may be difficult to achieve a substantially favorable reaction conversion rate. .

The reaction apparatus used in the method of the present invention is not particularly limited, but a typical fixed bed or fluidized bed reaction apparatus is given as an example of an apparatus that can be easily implemented. Since the reaction to produce methylamines from methanol and ammonia is an exothermic reaction of about 14 Kcal / mol, care should be taken in removing heat of reaction when using a fixed bed reactor to keep trimethylamine production at a low level. Is important to. For this purpose, it is preferable to employ a multitubular reactor. The tube diameter of the multitubular reactor is generally in the range of 1 to 3 inches. The outlet gas (reaction gas) of the reaction device separates and obtains methylamines by an ordinary separation and purification device, and unreacted methanol and ammonia are also separated and recovered, but the recovered methanol and / or ammonia is the reaction system. It can also be recycled and reused.

[0035]

The present invention will be described in more detail with reference to examples. Catalyst Preparation Catalyst 1 Sodium-type synthetic mordenite 5 obtained by hydrothermal synthesis 5
00 g was put into 2.5 L of a 1 N ammonium nitrate aqueous solution, heated on an oil bath, and refluxed for 8 hours.
The solid-liquid was separated, the solid was washed with deionized water, a new 2N ammonium nitrate aqueous solution was added to the solid, and the mixture was refluxed for 8 hours in the same manner. After solid-liquid separation, the solid was sufficiently washed with deionized water, dried, and then calcined under air flow at 600 ° C. for 5 hours to obtain mordenite as a catalyst precursor. The sodium content in the obtained mordenite was 0.12 w% as Na ₂ O. This was tabletted and molded into a cylindrical shape of 3 mm × 3 mm. Then, the mixture was placed in a 0.1 N aqueous nitric acid solution and left for 30 minutes, and then solid-liquid separated. The solid was dried in air at 140 ° C. for 6 hours, and then left in air at room temperature for 10 hours. In this state, about 10 w% of water and a trace amount of nitric acid were stored in the mordenite. The mordenite containing the above-obtained water was put into 1 L of toluene containing 230 mmol of tetraethoxysilane, and gently shaken at room temperature for 8 hours to carry out the silylation treatment of mordenite. After silylation,
Solid-liquid separation was performed, and the solid was dried under reduced pressure at 140 ° C. for 5 hours and then calcined in an air atmosphere at 600 ° C. for 5 hours to obtain a catalyst 1.

Catalyst 2 100 g of Catalyst 1 and 250 mL of an aqueous solution of copper acetate in which 10% of the amount of base exchange were dissolved in water were placed in 250 mL of an aqueous solution of copper acetate, stirred at room temperature for 8 hours, and then the suspension was evaporated under reduced pressure. After drying,
It was calcined in air at 500 ° C. for 2 hours to obtain mordenite having a copper exchange rate of 10%. This was designated as catalyst 2.

Catalyst 3 The amount of copper acetate used for the ion exchange treatment was adjusted to 20 times the base exchange amount.
% Copper acetate aqueous solution was used to prepare mordenite having a copper exchange rate of 20%, which was used as catalyst 3.

Catalyst 4 500 g of synthetic mordenite used for the preparation of catalyst 1 was treated with ammonium nitrate in the same manner as catalyst 1, and sodium was once thoroughly exchanged for ammonium ion. Then
Pour into 2 L of 0.02N sodium nitrate aqueous solution and
The mixture was gently shaken for a minute, immediately solid-liquid separated, washed with deionized water, dried, and calcined at 600 ° C. to obtain mordenite as a catalyst precursor. The sodium content in the obtained mordenite was 0.75 w% as Na ₂ O. This is 3m
It was molded into a cylindrical shape of m × 3 mm. After that, silylation was performed by the same treatment as that of the catalyst 1 to obtain a catalyst 4.

Catalyst 5 200 g of Catalyst 4 and 500 mL of an aqueous solution of copper acetate in which 10% of the amount of base exchange were dissolved in water were put into 500 mL of water and stirred at room temperature for 8 hours, and then the suspension was evaporated under reduced pressure. After drying,
It was calcined in air at 500 ° C. for 2 hours to obtain mordenite having a copper exchange rate of 10%. This was designated as catalyst 5.

Catalyst 6 500 g of naturally-occurring clinoptyllite (clinoptyllite content 74%, particle size 2.5 to 3.5 mm) was added to 2.5 L of 4N hydrochloric acid, and gently shaken at room temperature for 8 hours. . After solid-liquid separation, use 2.5 L of new 4N hydrochloric acid,
The same treatment was further performed for 15 hours, solid-liquid separation, deionized water washing, drying and baking at 600 ° C. to prepare a catalyst precursor (N
a ₂ O content 0.1 w%). This was subjected to silylation treatment with tetraethoxysilane in the same manner as in Catalyst 1 to obtain Catalyst 6.

Catalyst 7 200 g of catalyst 6 was placed in 500 mL of an aqueous solution of copper acetate in which 10% of the amount of base exchange was dissolved in water, stirred for 8 hours at room temperature, and then the suspension was evaporated under reduced pressure. After drying,
It was calcined in air at 500 ° C. for 2 hours to obtain mordenite having a copper exchange rate of 10%. This was designated as catalyst 7.

Catalyst 8 220 g of natural zeolite having a particle size of 2 to 3 mm (mordenite content: about 70%) was put into 2 L of 2N hydrochloric acid, and 50 ° C.
I shook it for 10 hours. After solid-liquid separation, the same operation was repeated using 2 L of new 1N hydrochloric acid as a solid. The zeolite was separated by filtration, washed with deionized water, dried and calcined at 600 ° C. to obtain H-mordenite (catalyst precursor). The obtained mordenite was almost completely H type, and the content of Na was 0.19%. This catalyst precursor was subjected to silylation treatment with tetraethoxysilane in the same manner as catalyst 1 to obtain catalyst 8.

Catalyst 9 100 g of catalyst 8 was placed in 250 mL of an aqueous solution of copper acetate in which 10% of the amount of base exchange was dissolved in water, and the mixture was shaken at room temperature for 15 hours, and then the suspension was decompressed. After evaporating to dryness, calcination in air at 500 ℃ for 2 hours, copper exchange rate 10%
Mordenite was obtained. This was designated as catalyst 9.

Catalyst 10 Catalyst 2 was prepared in the same manner as in Catalyst 2 except that silver acetate was used in place of copper acetate in an amount of 10% of the amount of base exchange. Obtained mordenite. This was designated as catalyst 10.

Catalyst 11 In the same manner as in the preparation method of the catalyst 2, except that palladium acetate (divalent) was used in place of copper acetate in an amount of 10% of the base exchange amount in the preparation method of the catalyst 2, the palladium exchange was performed. Mordenite having a rate of 10% was obtained. This was used as catalyst 11.

Comparative Example 1 50 g of catalyst 1 prepared by the above-mentioned preparation method, having an inner diameter of 2
It was filled in a 5 mm stainless steel reaction tube and heated from the outside to 290 ° C. in a sand fluidized bath. Industrial methanol 3 per hour
0 g and 36 g of ammonia per hour were pressed into the catalyst layer to carry out a methylamine production reaction at a pressure of 20 kg / cm ² G. The maximum temperature of the catalyst layer was 294 to 296 ° C. The reaction results after 100 hours, 2000 hours and 4000 hours have been listed in Table 1.

COMPARATIVE EXAMPLE 2 In Comparative Example 1, 100 mL / min (20 mL) of nitrogen was further added.
The reaction between methanol and ammonia was carried out under the same conditions as in Comparative Example 1 except that the introduction was carried out at a temperature of 1 ° C.). The reaction results after each elapsed time are shown in Table 1. As shown in Table 1, the reaction results showed that the methanol conversion rate was slightly lowered, but the degree of catalyst performance deterioration was the same as in Comparative Example 1.

Comparative Example 3 In Comparative Example 2, the reaction was carried out under the same conditions as in Comparative Example 2 except that 50 g of Catalyst 2 was used instead of Catalyst 1.
As shown in Table 1, when the catalyst is partially exchanged with copper ions and hydrogen is not added, the deterioration of the catalyst is accelerated.

Comparative Example 4 In Comparative Example 2, 100 m / min of hydrogen was used instead of nitrogen.
All were carried out under the same conditions as in Comparative Example 2 except that L (20 ° C., 1 atm conversion) was introduced. The results are shown in Table 2.

Example 1 The procedure of Comparative Example 4 was repeated except that the catalyst 1 was replaced by the catalyst 2 and the catalyst filling amount and reaction conditions were the same as those of Comparative Example 4. As shown in Table 2, the results showed that the reduction in the activity of the catalyst was significantly suppressed.

Example 2 The reaction was carried out under the same conditions as in Example 1, except that the catalyst 2 was replaced by the catalyst 3 and the catalyst loading and reaction conditions were the same. As shown in Table 2, the effect of suppressing the deterioration of the catalyst was clearly recognized even if the amount of ion exchange was changed, as shown in Table 2.

[0052]

[Table 1]

[0053]

[Table 2]

Comparative Example 5 The reaction was carried out under the same conditions as in Comparative Example 2 except that 50 g of the catalyst 4 was used instead of the catalyst 1 in Comparative Example 2.
The results of 100 hours, 2000 hours and 4000 hours after the start of the reaction are shown in Table 3.

Comparative Example 6 In Comparative Example 5, hydrogen was replaced by 100 m / min instead of nitrogen.
All were carried out under the same conditions as in Comparative Example 5 except that L (20 ° C., 1 atm conversion) was introduced. The results show that, as shown in Table 3, the introduction of hydrogen suppressed the deterioration of the catalyst performance.

Example 3 The reaction was carried out under the same conditions as in Comparative Example 6 except that 50 g of the catalyst 5 was used instead of the catalyst 4 in Comparative Example 6. The results are shown in Table 3.

[0057]

[Table 3]

COMPARATIVE EXAMPLE 7 The procedure of Comparative Example 2 was repeated except that the amount of the catalyst 8 was 50 g instead of the amount of the catalyst 1. Table 4 shows the reaction results at 100 hours, 2000 hours and 4000 hours after the start of the reaction.

Comparative Example 8 The same procedure as in Comparative Example 4 was carried out except that the amount of the catalyst 8 was changed to 50 g instead of the catalyst 1 in Comparative Example 4. Table 4 shows the reaction results at 100 hours, 2000 hours and 4000 hours after the start of the reaction.

Example 4 The reaction was carried out under the same conditions as in Comparative Example 8 except that 50 g of the catalyst 9 was used instead of the catalyst 8 in Comparative Example 8. The results are shown in Table 4.

[0061]

[Table 4]

Example 5 The reaction was carried out under the same conditions as in Example 1 except that 50 g of the catalyst 10 was used instead of the catalyst 2 in Example 1.
The reaction results are shown in Table 5.

Example 6 The reaction was carried out under the same conditions as in Example 1 except that 50 g of the catalyst 11 was used instead of the catalyst 2 in Example 1.
The reaction results are shown in Table 5. From the results of Examples 5 and 6,
It can be seen that the silver or palladium exchanged zeolite catalyst also has the effect of suppressing catalyst deterioration.

[0064]

[Table 5]

Comparative Example 9 The procedure of Comparative Example 2 was repeated except that the methanol used was replaced with methanol containing 670 ppm of formaldehyde. At this time, the amount of formaldehyde fed corresponds to 0.4 g per hour for 1 kg of the catalyst. 100 hours and 300 after starting the reaction
Table 6 shows the reaction results after 0 hours.

Comparative Example 10 The procedure of Comparative Example 4 was repeated except that the methanol used was replaced with methanol containing 670 ppm of formaldehyde. At this time, the amount of formaldehyde fed corresponds to 0.4 g per hour for 1 kg of the catalyst. 100 hours and 300 after starting the reaction
Table 6 shows the reaction results after 0 hours.

Example 7 The reaction was carried out under the same conditions as in Comparative Example 10 except that 50 g of Catalyst 2 was used instead of Catalyst 1 in Comparative Example 10. As a result, as shown in Table 6, even when methanol containing a considerable amount of formaldehyde was used, the effect of suppressing the deterioration of the catalyst performance was recognized.

[0068]

[Table 6]

Comparative Example 11 The reaction was carried out under the same conditions as in Comparative Example 9 except that 50 g of the catalyst 4 was used instead of the catalyst 1.
Table 7 shows the reaction results 100 hours and 2000 hours after the start of the reaction.

Comparative Example 12 In Comparative Example 10, 50 g of catalyst 4 was used instead of catalyst 1.
The reaction was carried out under the same conditions as in Comparative Example 10 except for the above. Table 7 shows the reaction results 100 hours and 2000 hours after the start of the reaction.

Example 8 The reaction was carried out under the same conditions as in Comparative Example 12 except that 50 g of the catalyst 5 was used instead of the catalyst 4 in Comparative Example 12. Table 7 shows the reaction results 100 hours and 2000 hours after the start of the reaction. Similar to the result confirmed in Example 7, the effect of suppressing the catalyst deterioration of the copper ion, which is the metal ion having the reducing ability, is recognized.

[0072]

[Table 7]

Comparative Example 13 The reaction was carried out under the same conditions as in Comparative Example 11 except that 50 g of the catalyst 6 was used instead of the catalyst 4 in Comparative Example 11. Table 8 shows the reaction results 100 hours and 2000 hours after the start of the reaction.

Comparative Example 14 The reaction was carried out under the same conditions as in Comparative Example 12 except that 50 g of the catalyst 6 was used instead of the catalyst 4 in Comparative Example 12. Table 8 shows the reaction results 100 hours and 2000 hours after the start of the reaction.

Example 9 The reaction was carried out under the same conditions as in Comparative Example 14 except that 50 g of Catalyst 7 was used instead of Catalyst 6 in Comparative Example 14. Table 8 shows the reaction results 100 hours and 2000 hours after the start of the reaction.

[0076]

[Table 8]

Comparative Example 15 Methanol was mixed with 2 parts by weight of methanol recovered by distillation separation from the reaction solution of Comparative Example 5 and 8 parts by weight of industrial methanol (the amount of aldehydes converted to formaldehyde was about 400 ppm). The reaction was carried out under the same conditions as in Comparative Example 2 except that it was replaced. The results are shown in Table 9.

Comparative Example 16 Methanol was mixed with 2 parts by weight of methanol recovered by distillation separation from the reaction solution of Comparative Example 5 and 8 parts by weight of industrial methanol (the amount of aldehydes converted to formaldehyde was about 400 ppm). The reaction was carried out under the same conditions as in Comparative Example 4 except that it was replaced. The results are shown in Table 9.

Example 10 The reaction was carried out under the same conditions as in Comparative Example 16 except that 50 g of Catalyst 2 was used instead of Catalyst 1 in Comparative Example 16. As shown in Table 9, the effect of suppressing deterioration of the catalyst in the present invention was recognized even when methanol recovered from the reaction was used as a raw material.

[0080]

[Table 9]

[0081]

INDUSTRIAL APPLICABILITY In a method for producing methylamines in which methanol and ammonia are reacted in the presence of a zeolite catalyst to suppress the amount of trimethylamine produced, by carrying out the method of the present invention, conventional methylamines can be produced. Not only high-purity methanol that contains almost no aldehydes such as formaldehyde used, but also when using methanol mixed with aldehydes such as formaldehyde as a raw material, it is possible to suppress deterioration of catalyst performance and It is possible to stably suppress the amount of trimethylamine produced and mainly produce dimethylamine and monomethylamine. Furthermore, by carrying out the method of the present invention using high-purity methanol as a raw material, it is possible to suppress the deterioration of the performance of the catalyst in the same manner and to produce methylamines extremely stably for a long period of time. Thus, when methanol and ammonia are reacted in the presence of a zeolite catalyst to produce methylamines, unreacted methanol after the reaction is recovered only by a normal separation method such as distillation, and then used again in the reaction. Thus, a method for producing methylamines which is extremely economical is provided.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuaki Matsui 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Shuichi Tokumoto 1190 Kasama-cho, Sakae-ku, Yokohama, Kanagawa (72) Inventor Kaoru Inoue 1190, Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd.

Claims (11)

[Claims] 1. A method for producing methylamines by the reaction of methanol and ammonia, wherein the reaction is carried out in the presence of hydrogen and a metal ion-exchanged zeolite obtained by exchanging zeolite as a catalyst precursor with an ion of a metal having a reducing ability. A method for producing methylamines, which comprises: 2. The method according to claim 1, wherein the methanol contains formaldehyde. 3. A reaction mixture for producing methylamines by reacting a part of methanol with a metal ion-exchanged zeolite obtained by exchanging methanol and ammonia with a metal ion having a reducing ability and a hydrogen catalyst. The method according to claim 1 or 2, which is unreacted methanol recovered further. 4. The method according to claim 2 or 3, wherein the content of formaldehyde is 2,000 ppm or less in weight ratio to methanol. 5. The method according to claim 1, wherein the zeolite as the catalyst precursor is at least one selected from the group consisting of clinoptyllite and mordenite. 6. The recovered unreacted methanol is methanol recovered by distillation from a mixture containing water, which is a reaction by-product, after separating methylamines from the reaction mixture. The method described. 7. The method according to claim 1, wherein the zeolite as a precursor of the catalyst is a zeolite silylated with a silylating agent in a liquid phase. 8. The method according to claim 1, 5 or 7, wherein the zeolite as a catalyst precursor is a hydrogen ion type zeolite. 9. The method according to claim 1, wherein the amount of ion exchange of the metal ion-exchanged zeolite by the metal ion having a reducing ability is 1 to 90% of the total amount of base exchange ability of the metal ion-exchanged zeolite. 10. A metal having a reducing ability is copper, silver, gold,
10. The method according to claim 1, which is at least one selected from the group consisting of nickel, palladium, platinum, cobalt, rhodium, iridium, iron, ruthenium and osmium. 11. The method according to claim 1, wherein the metal having a reducing ability is at least one selected from the group consisting of copper and silver.