JPS62152539A - Catalyst for gaseous phase intramolecular dehydrating action of alkanolamines - Google Patents

Abstract

PURPOSE:To prepare objective cyclic amines at high yield, by forming a catalyst of an oxide composition represented by a specific general formula prepared by adding one or more of an element selected from an alkali metal and/or an alkaline earth metal to silicon. CONSTITUTION:A minute amount or equal amount of one or more of an element selected from an alkali meal and/or an alkaline earth metal is added to silicon in a state dissolved or suspended in water and the resulting mixture is heated under stirring, conc., dried and molded to obtain a catalyst for the gaseous phase intramolecular dehydrating reaction of alkanolamines. This catalyst is an oxide composition represented by general formula SiaXbOc (wherein Si is silicon, X is one or more of an element selected from an alkali metal and/or an alkaline earth metal and a, b and c are an atomic ratio of each element and, when a=1, b=0.005-1 and c is a value determined by a and b).

Description

Detailed Description of the Invention [Technical Field] The present invention relates to gas phase molecules used in converting alkanolamines represented by general formula (1) to cyclic amines represented by general formula (I). This invention relates to a catalyst for internal dehydration reaction.

RR (I) (II) (wherein, R
, R' are each selected from the group consisting of hydrogen, methyl group and ethyl group, and n is an integer in the range of 2 to 5. ) Cyclic amines represented by a surface (IF) are generally highly reactive and react with compounds having various functional groups, so that various derivatives having amine groups can be produced. Furthermore, since a ring-retaining reaction is also possible, derivatives having ring-opening reactivity can also be produced. Furthermore, polyamine-based polymers can also be produced by ring-opening polymerization reaction, making it a highly useful compound. Derivatives of cyclic amines are very useful compounds that are widely used in various industries as mN processing agents, antistatic agents, raw materials for pharmaceuticals and agricultural chemicals, and the like. The present invention provides a high-performance catalyst for producing cyclic amines, which are useful compounds, by intramolecular dehydration reaction of alkanolamines in the gas phase, which is extremely advantageous in terms of productivity. It is.

[Prior Art] Methods for converting alkanolamines into cyclic amines by dehydration include a method of intramolecular ring-closing of a halogenated amine with a concentrated alkali (Gabriel method);
A method of ring-closing an alkanolamine sulfate ester with a heated concentrated alkali (Wenker method) is known, but these methods use a large amount of alkali in the form of a concentrated solution, resulting in low productivity, and the cost of alkali is low in raw material costs. There are many problems from an industrial perspective, such as the large unit size and the production of large amounts of inorganic salts with low utilization.

In recent years, attempts have been made to continuously produce the corresponding cyclic amine, ie, ethyleneimine, by using monoethanolamine as the alkanolamine and dehydrating it in the gas phase in the presence of a catalyst, in contrast to the liquid phase method described above. have been reported. As an example of these, for example,
No. 10593 describes a method using a tungsten oxide catalyst, and US Pat. No. 4,301,
No. 036 tIa further describes a method using a catalyst consisting of tungsten oxide and silicon, as disclosed in U.S. Pat.
No. 9,656, No. 4.337.175, No. 4.4
No. 77□591 discloses a method using a niobium or tantalum catalyst. however,
In both of these methods, the conversion rate of monoethanolamine is low, and even when the conversion rate is relatively high, the proportion of products due to side reactions such as deammonization reaction and dispensing reaction is high, so the selectivity of ethyleneimine is low. is low. Furthermore, according to the studies conducted by the present inventors, as far as the life of the catalyst is concerned, the activity decreases significantly in a short period of time in all cases, which is completely unsatisfactory from an industrial point of view.

[Configuration 1 of the present invention] As a result of intensive research into catalysts for gas-phase intramolecular dehydration reactions of alkanolamines, the present inventors found that a trace amount or an equivalent amount of one kind selected from alkali metals and/or alkaline earth metals is added to silicon. or the general formula SiaXbOc (where Si is silicon, X is one or more elements selected from alkali metals and/or alkaline earth metals, and 0 represents oxygen. Subscript a, b
, c indicates the atomic ratio of each element, and when a = 1, b = 0.005 to 1 (7) range (preferably b = 0.01 to 0.5 range), and C is a It takes a value determined by and b. ) By using the oxide catalyst represented by (), the gas phase intramolecular dehydration reaction of alkanolamines proceeds extremely favorably, and the target cyclic amines can be produced highly selectively and in high yields, and also stably for a long period of time. The present inventors have discovered that it is possible to produce the same, and have completed the present invention.

The catalyst of the present invention effectively acts on gas phase intramolecular dehydration reaction,
The alkanolamines used as reaction raw materials include alkanols represented by (in the formula, R and R- are each selected from hydrogen, methyl group, and ethyl group; n is an integer in the range of 2 to 5); Amines are preferred;
Examples of these include (a) monoethanolamine, (
b) Isopropanolamine, (C) 3-amino-1
-propanol, (d) 5-amino-1-pentanol, (e) 2-amino-1-butanol, and the like, but are not limited to these.

According to the invention, these amines correspond to cyclic amines represented by (wherein R, R' and n are the same as in formula 1), that is, the above compounds,
(a') ethyleneimine, (b12-methyl-ethyleneimine, (a') azetidine, (d') piperidine, (
It is stably converted to e''12-ethyl-ethyleneimine with high conversion rate and high selectivity over a long period of time.

The method for preparing the catalyst according to the present invention is not particularly limited, and a commonly used preparation method can be used.

Examples of the alkali metal and/or alkaline earth metal element source which is component X of the catalyst raw material include their oxides, hydroxides, halides, carbonates, and sulfates.

Silicon sources include silicon oxide, silicon halides, and silicic acid.

Silicates, silicon oxide sols, organosilicon compounds, etc. are used.

An example of the method for preparing a catalyst according to the present invention is to dissolve or suspend various catalyst raw materials in water, heat the mixture under stirring, and heat the mixture.
A method of shrinking, drying, molding, and further calcination to make a catalyst, or dissolving or suspending various catalyst raw materials in water and making a hydroxide by adding ammonia water, followed by filtration,
A method of washing with water, drying, molding, and calcination to form a catalyst, or a method of mixing oxides or hydroxides of various elements in powder form and adding an appropriate molding aid (e.g., water, alcohol, etc.) Examples include a method in which the material is added, molded, dried, and then fired.

Further, the catalyst according to the present invention can also be used by being supported on a known inert carrier (for example, silica, alumina, Celite (trade name), etc. are preferable, but not limited to these).

The firing temperature of the catalyst may vary widely from 300°C to 800°C, preferably from 400°C to 700°C, depending on the type of raw materials used.

[Function] When the catalyst of the present invention is used in the gas phase intramolecular dehydration reaction of alkanolamines, it exhibits extremely high activity compared to conventionally known catalysts, and the selectivity for the target cyclic amine is also extremely high. there were.

Moreover, even if this reaction is carried out continuously for a long time,
No deterioration of catalyst activity was observed and the catalyst remained active.

The yield was extremely stable, and the problem of overcoming short-term deterioration, which is most important for industrialization, could be sufficiently solved.

The catalytic performance was evaluated using a known catalyst for ethyleneimine synthesis from monoethanolamine (for example, Japanese Patent Publication No. 50-105
No. 93, and WO'3-8i 02 and Nb205-Ba shown in U.S. Patent No. 4.337.175
O composition catalyst. ), the performance of the catalyst according to the present invention, both in terms of activity and selectivity, was significantly superior to those catalysts.

Although the details of the reason why the catalyst of the present invention exhibits extremely excellent performance in the gas-phase dehydration reaction from alkanolamines to cyclic amines are not clear, the present inventors have discovered that the essential component alkali It is surmised that metals and/or alkaline earth metal elements have a large effect. In other words, oxides of alkali metals and alkaline earth metals have basicity due to bridging oxygen atoms or surface hydroxyl groups, and the basic sites facilitate the rapid detachment of the 1M amine produced from the catalyst surface, leading to sequential polymerization. Inhibit reactions or decomposition reactions. (2) Appropriately control the properties of acid sites in silicon, which is an acidic component, to suppress side reactions such as deammonia or intermolecular condensation reactions caused by too strong acid sites. ■It is thought that the basic site promotes hydrogen withdrawal (friend-reaction) from amino groups and improves activity. Therefore, on the catalyst of the present invention, the reaction is more effective due to acid-base cooperation. At the same time, the desorption of the product is smooth, and deactivation due to poisoning of the strongly adsorbed substance on the catalyst is suppressed, resulting in a high conversion rate and high selectivity, as well as a stable long-term production of the target cyclic product. It is thought to be a source of amine production.

In carrying out the present invention, the reactor is of a fixed bed flow type.

Any fluidized bed type can be used. The raw material alkanolamines are diluted with an inert gas such as nitrogen, helium, or argon at a concentration of 1 to 80% by volume, preferably 2 to 50% by volume, if necessary. Further, in some cases, ammonia, water, or the like may be supplied together with alkanolamines for the purpose of suppressing side reactions. The reaction is usually carried out at normal pressure, but it can also be carried out under increased or reduced pressure if necessary. The reaction temperature varies depending on the type of raw material.
The space velocity of the raw material gas varies depending on the type of raw material and the concentration of the raw material gas, but it is in the range of 100 to 500 °C.
000 hr", preferably in the range of 500 to 3000 hr-1.

The present invention will be specifically described in Examples below, and the conversion rate 2 selectivity and single flow yield in the Examples shall comply with the following definitions.

Conversion rate (mol %) = Number of moles of alkanolamine fed Selectivity (mol %) = Number of moles of alkanolamine consumed Single stream yield (mol %) = Number of moles of alkanolamine fed Number of moles Example 1゜Magnesium hydroxide 0.581J and silicon oxide 301J
was suspended in 100 d of water, and heated and concentrated at 90° C. with sufficient stirring to obtain a white slurry-like mixture. After drying this in the air at 120°C overnight, it was crushed into 3.5 mesh pieces.
It was calcined at 600°C for 2 hours to obtain a catalyst.

After filling this catalyst 20- into a stainless steel reaction tube with an inner diameter of 16 mm, it was immersed in a molten salt bath at 370°C, and a raw material gas of monoethanolamine:nitrogen = 5:95 was charged into the tube at a space velocity of 1500 hours. -' and the reaction was carried out.

The reaction products were quantified by gas chromatography and are shown in Table 1.
The results shown are obtained.

Example 2 A catalyst was prepared in the same manner as in Example 1, except that 1.11 g of calcium hydroxide and 300 g of silicon oxide were used as catalyst raw materials. Using this catalyst, monoethanolamine and isopropanolamine were reacted based on the reaction conditions of Example 1. The results are shown in Table 1.

Example 3 Strontium hydroxide (octahydrate) as catalyst raw material
A catalyst was prepared in the same manner as in Example 1, except that 13.28 (J, rubidium hydroxide 1.02 ()) and silicon oxide 30 (L) were used, and monoethanolamine and 3-amino-1-propanol were used. When the reaction was carried out according to Example 1, the results shown in Table 1 were obtained.

Example 4 Barium hydroxide (octahydrate) 63.1 as catalyst raw material
A catalyst was prepared in the same manner as in Example 1, except that g and silicon oxide 30 (l) were used, and a continuous reaction of monoethanolamine was carried out based on the reaction conditions of Example 1. The results are shown in Table 1. I got it.

Comparative Example 1 A catalyst was prepared in the same manner as in Example 1 using only silicon oxide 30 (7) as a catalyst raw material. Using this catalyst, reactions were carried out under the reaction conditions of Example 1 at various temperatures. −
The results shown in 2 were obtained.

Comparative Example 2 40 g of silicon carbide with a diameter of 5 m was immersed in 65.2 g of ammonium metatungstate aqueous solution (50 wt% based on W03), evaporated to dryness on a hot water bath, and then evaporated to dryness in air.
The mixture was dried at 50°C for 1 hour and further calcined in air at 715°C for 4 hours to obtain a catalyst precursor. This was immersed in 50 m of 10% silicon oxide colloidal solution, evaporated to dryness on a hot water bath, and then heated to 150 m in air.
℃ for 1 hour, followed by calcination in air at 715℃ for 4 hours to obtain 25.4% by weight of tungsten oxide and 3% by weight of silicon oxide.
．． Supported catalyst containing 3% by weight (atomic ratio WtoSio
, 504.1) was obtained. Using this catalyst, monoethanolamine was reacted based on the reaction conditions of Example 1, and the results shown in Table 2 were obtained.

Note that this catalyst was prepared according to Example 4 described in US Pat. No. 4,301,036.

Comparative Example 3 Niobium pentachloride S, og was completely dissolved in 50 ttdl of water while heating at 60°C, and aqueous ammonia was added to adjust the pH of the solution to 1.0. Thereafter, the solid obtained through filtration and water washing was dissolved in 80 ml of a 10% by weight aqueous oxalic acid solution, and further 0.2 g of barium hydroxide (octahydrate) was added. Soak 60cc of silicon carbide in this solution,
After evaporating to dryness at 0°C, it was calcined in air at 500°C for 3 hours to obtain a supported catalyst containing 3.7% by weight of niobium pentoxide and 0.5% by weight of barium oxide (Nb to BaO in atomic ratio).
102.6) is 19. Using this catalyst, a reaction was carried out based on Example 1, and the results shown in Table 2 were obtained.

This catalyst was prepared according to Example 3 described in US Pat. No. 4,477,591.

Example 5 A catalyst was prepared in the same manner as in Example 1 using 0.28 (l) of potassium hydroxide and 30 (l) of silicon oxide as catalyst raw materials. Using this catalyst, monoethanolamine and 2-amino The reaction of -1-butanol was carried out based on the reaction conditions of Example 1, and the results shown in Table 1 were obtained.

Example 6゜ 0.58 g of magnesium hydroxide as a catalyst raw material.

A catalyst was prepared in the same manner as in Example 1 using 0.20 g of sodium hydroxide and 30 g of silicon oxide. Using this catalyst, monoethanolamine and 5-amino-1-
The reaction of pentanol was carried out based on the reaction conditions of Example 1, and the results shown in Table 1 were obtained.

Example 7゜ Calcium hydroxide 0.37 (l and water,
A catalyst was prepared in the same manner as in Example 1 using barium oxide (octahydrate) 3.94 (7) and silicon oxide 301J. Using this catalyst, monoethanolamine J: and isopropylamine The reaction was carried out based on the reaction conditions of Example 1, and the results shown in Table 1 were obtained.

Example 8 A catalyst was prepared in the same manner as in Example 1 using 0.75 (J) of cesium hydroxide, 4.73 (J of barium hydroxide (octahydrate) and 30 g of silicon oxide as catalyst raw materials). Using this catalyst, a continuous reaction of monoethanolamine was carried out based on the reaction conditions of Example 1, and the results are shown in Table 1.

Claims (1)

[Claims] (1) General formula SiaXbOc (where Si is silicon, X is an alkali metal and/or One or more elements selected from alkaline earth metals, O
represents oxygen. Subscripts a, b, and c indicate the atomic ratio of each element, and when a = 1, b = 0.005 to 1 (preferably b = 0.01 to 0.5), and c
takes a value determined by a and b. ) General formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (R and R' in the formula are hydrogen, methyl group, and ethyl group, respectively) (n is an integer in the range of 2 to 5.)
Alkanolamines represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) (In the formula, R, R' and n are the same as in the above formula (I).) Cyclic amines represented by the general formula Catalyst for gas phase intramolecular dehydration reaction that converts into