JPS63126553A - Catalyst for vapor phase intramolecular dehydration reaction of alkanol amines - Google Patents

Abstract

PURPOSE:To stably produce desired cyclic amines selectively at a high yield for a long period of time by effecting the vapor phase intramolecular dehydration reaction of alkanol amines by using a catalyst consisting of group Ib-VIII transition metals and specific bond of P, O. CONSTITUTION:The titled catalyst is constituted of the catalyst compsn. expressed by the formula XaPbOc (X denotes 1 or more kinds of elements selected from the group Ib-VIII transition metal elements of periodic table, a, b, c denote atomic ratios of the respective elements, b=0.01-6 when a=1, c is the numerical value determined by the bonding condition of a, b and various constituting elements). The alkanol amines expressed by formula I (R, R' are selected from H, methyl group and ethyl groups, n is an integer in a 2-5 range) are converted to the cyclic amines expressed by formula II (R, R' are the same as in formula I). As a result, the desired cyclic amines are highly are highly selectively produced at a high yield stably for a long period of time.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a novel method for converting alkanolamines represented by the general formula (I) into cyclic amines represented by the general formula (I). This invention relates to a catalyst for gas phase intramolecular dehydration reaction.

(In the formula, R and R' are each selected from the group consisting of hydrogen, methyl group, and ethyl group, and n is an integer of 2 to 5 in the @ bracket.) The cyclic amines represented by (IF) above are Generally, since it is highly reactive and reacts with compounds having various functional groups, various derivatives having amino 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 extremely useful compounds that are widely used in various industries as textile processing agents, antistatic agents, pharmaceuticals, agricultural chemicals, and the like. The present invention provides a high-performance catalyst for use in producing cyclic amines, which are such useful compounds, by intramolecular dehydration reaction of alkanolamines in the gas phase, which is extremely advantageous in terms of productivity. It is something.

[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 (Q abriel 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, in contrast to the liquid phase method described above, monoethanolamine has been used as the alkanolamine and dehydrated in the gas phase in the presence of a catalyst to continuously produce the corresponding cyclic amine, ie, ethyleneimine. Several attempts 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 describes a method using a catalyst made of tungsten oxide and silicon, and is further described in US Pat. No. 4,289.
No. 656, No. 4.337.175, No. 4.477
, No. 591 IIm discloses a method using a niobium or tantalum catalyst.

[Problems to be Solved by the Invention] However, in any of the methods using the above-mentioned catalysts, the conversion rate of monoethanolamine is low, and even when the conversion rate is relatively high, deammonification reactions, dimerization reactions, etc. The selectivity for ethyleneimine is low because the proportion of products resulting from side reactions is low. Furthermore, according to the studies conducted by the present inventors, when it comes to the life of the catalyst, in any case, the activity decreases significantly in a short period of time, and from an industrial point of view,
It's not completely satisfying.

The present invention is intended to produce target cyclic amines with high selectivity and yield, and moreover, stably over a long period of time when performing a gas phase intramolecular dehydration reaction of alkanolamines.

[Means for Solving the Problems] As a result of intensive research on catalysts for gas-phase intramolecular dehydration reactions of alkanolamines, the present inventors found that the general formula: XaP, O
c (wherein, X is one or more elements selected from group Ib to group II transition metal elements in the periodic table, P represents phosphorus, and 0 represents oxygen. Subscripts a, b, and c are respectively indicates the atomic ratio of the elements, and when a-1, b-
It takes a value in the extreme range of 0.01 to 6 (preferably: 1 or 0.05 to 3), and C is a numerical value determined by the bonding state of a, b and various constituent elements. ) 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 inventors have discovered a scale that can be manufactured in the following manner, and have completed the present invention.

X is one or more elements selected from group Ib to group II transition metal elements in the periodic table, and examples of such elements include Cu.

Zn, Cd, Sc, Y, Ti, Zr, Nb
, Ta.

Examples include elements such as Mo, W, Mn, Fe, and Ni.

The alkanolamines used as reaction raw materials have the general formula (
Alkanolamines represented by I) are preferred;
According to the present invention, these amines are stably converted into cyclic amines represented by general formula (n) with high conversion and selectivity over a long period of time. Examples of the alkanolamines 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. The cyclic amines obtained corresponding to these amines are each (a
-) ethyleneimine, (b”) 2-methyl-ethyleneimine, (C-) azetidine, (d-) piperidine, (e
') 2-ethyl-ethyleneimine.

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

Raw materials for the X component include various oxides, hydroxides, halides, salts (carbonate, sulfur MMA1 nitrate, etc.), metals, etc., and phosphorus sources include orthophosphoric acid, birophosphoric acid, metaphosphoric acid, and phosphorous acid. Various phosphoric acids such as phosphoric acid and polyphosphoric acid, phosphorus pentoxide, and salts of the above phosphoric acids (ammonium phosphate, potassium phosphate, sodium phosphate, etc.)
etc. are used. Note that phosphates of the X component may be used as the X component source and the phosphorus source.

An example of the method for preparing a catalyst according to the present invention is as follows: (1) Dissolving or suspending various catalyst raw materials of component X and phosphorus in water, heating and concentrating with stirring, drying and shaping, and further calcination to form a catalyst. Method: ■Dissolve the raw material of component X in water,
A method of adding various phosphoric acids or various phosphates, adjusting the pH as necessary to obtain a phosphate of component ■Alternatively, various phosphoric acids or various phosphates are added and mixed to the oxides or hydroxides of each component element of X component and phosphorus, and after adding an appropriate molding aid (e.g. water, alcohol, etc.), molding and drying. The method includes a method in which the catalyst is further calcined to form a catalyst.

Further, the catalyst according to the present invention may be supported on a known inert carrier such as Celite (trade name), silica gel, silicon carbide, alumina, etc., but is not limited thereto. can.

The firing temperature of the catalyst of the present invention may vary widely from 300°C to 1500°C, preferably from 400°C to 1200°C, although it depends on the type of raw materials used.

In carrying out the present invention, either a fixed bed flow type reactor or a fluidized bed type reactor can be used. The raw material alkanolamines are used after being diluted with an inert gas such as nitrogen, helium, or argon to a concentration of 1 to 80% by volume, preferably 2 to 50% by volume, if necessary. Furthermore, depending on Wa, 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 and ranges from 250 to 60℃.
It is in the range of 0°C. 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 is between 100 and 40.0 O.
Ohr (STP), preferably 500-20.
A range of 000hr"" (STP) is appropriate.

[Operations and Effects of the Invention] 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 has a high selectivity to the target cyclic amine. was also significantly high.

Moreover, even if this reaction is carried out continuously for a long time,
No deterioration in the activity of the catalyst was observed, and both activity and yield were extremely stable, and the problem of overcoming short-term deterioration, which is most important for industrialization, could be fully solved.

The catalytic performance was evaluated using a known catalyst for ethyleneimine synthesis from monoethanolamine (for example, Japanese Patent Publication No. 50-105
WO3-3i 02 and Nb2O'5-Ba shown in Japanese Patent No. 93 and U.S. Pat.
When compared with the composition catalyst 0), the performance of the catalyst according to the present invention was significantly superior to those catalysts in terms of both activity and selectivity.

Although the details of the reason why the catalyst of the present invention exhibits excellent performance in the gas-phase dehydration reaction from alkanolamines to cyclic amines are not clear, there are acidic points and basic points on the catalyst surface. This is thought to be due to their concerted action. It is believed that the X component increases the acid strength of the acidic site by υ3111 due to phosphoric acid and also generates basic sites, forming a surface condition of the catalyst suitable for this reaction. The reaction progresses effectively through acid-base cooperation, and at the same time, the desorption of products is smooth, and deactivation due to poisoning of strongly adsorbed substances on the catalyst is suppressed, which is the same as in conventional catalysts. It is believed that this method solves the phenomenon of decrease in selectivity due to improvement in conversion rate, and can produce the target cyclic amine with high conversion rate and high selectivity, and extremely stably over a long period of time.

[Examples] Hereinafter, the present invention will be specifically described in Examples, and the conversion rate, selectivity, and single flow yield in the Examples shall comply with the following definitions.

Conversion rate (mol %) - Number of moles of alkanolamine consumed Selectivity (mol %) - Number of moles Single stream yield (mol %) - Number of moles Example 1 48.8 g of zinc oxide was mixed with 100 ad of water! Suspended in 85
Weight% orthophosphoric acid 34. The mixture was heated and concentrated with sufficient stirring, and evaporated to dryness on a hot bath. After drying this in air at 120°C overnight, it was crushed into 9 to 5 meshes and calcined at 600°C for 2 hours to obtain a catalyst.

After filling a stainless steel reaction tube with an inner diameter of 16 mm with this catalyst, it was immersed in a 420°C molten salt bath, and a raw material gas with a volume ratio of monoethanolamine:nitrogen of 5:95 was charged into the tube at a space velocity of 1500 hr. (STP) and
The reaction was carried out. The reaction is carried out continuously, and after the start of the reaction 2
Table 1 shows the results of constant analysis of the product at 50 hours and 50 hours by gas chromatography.

Example 2゜Yttrium oxide 3 was used instead of zinc oxide as a catalyst raw material.
A catalyst was prepared in the same manner as in Example 1 except that 3.9 (J was used. Using this catalyst, a reaction was carried out in the same manner as in Example 1 for monoethanolamine and isopropanolamine. The reaction conditions and results are shown in Table-1.

Example 3 Niobium pentoxide 399 instead of zinc oxide as a catalyst raw material
A catalyst was prepared in the same manner as in Example 1, except that g was used. Using this catalyst, monoethanolamine and 3
-Amino-1-propatool was reacted in the same manner as in Example 1. The reaction conditions and results are shown in Table-1.

Example 4 40.1 g of zirconyl nitrate was dissolved in 300 d of water, and a solution of 44.7 Q of triammonium phosphate dissolved in 300 d of water was added thereto with stirring. The obtained precipitate was filtered, washed with water, dried in air at 120°C overnight, crushed into 9 to 5 meshes, and calcined at 1200°C for 2 hours to obtain a catalyst. Using this catalyst, monoethanolamine and
A reaction was carried out in the same manner as in Example 1 using 2-amino-1-butanol. The reaction conditions and results are shown in Table-1.

Example 5 Manganese hydroxide 26.7g, ferrous oxide 21. h and ammonium birophosphate (36.91; l) were mixed in powder form, then kneaded well with a little water to form a powder with a diameter of 3 mm and a length of 3 mm.
The pellet was molded into a pellet of m111, dried in air at 120°C overnight, and then calcined in a nitrogen stream at 800°C for 4 hours to obtain a catalyst. Example 1 for monoethanolamine and 5-amino-1-pentanol using this catalyst.
The reaction was carried out in the same manner. Table 1 shows reaction conditions and results.
It was shown to.

Example 6゜ Titanium oxide 75.9 instead of zinc oxide as catalyst raw material
Q. A catalyst was prepared in the same manner as in Example 1 except that 3.6 g of cuprous oxide was used. Using this catalyst, monoethanolamine was reacted in the same manner as in Example 1. The reaction conditions and results are shown in Table-1.

Example 7゜Phosphortungsten i! 1 (29 hydrate) 102.1
15.49 cadmium oxide was added to a solution of 1 J dissolved in 100 IIr1 water, and the mixture was evaporated to dryness on a hot water bath. After drying this in air at 120°C overnight, it was crushed into 9 to 5 meshes and calcined at 600°C for 2 hours to obtain a catalyst. Using this catalyst, monoethanolamine was reacted in the same manner as in Example 1. The reaction conditions and results are shown in Table-1.

Comparative Example 1 A 601 silicon carbide carrier was added to 10g of an aqueous solution of 30% orthophosphoric acid and evaporated to support it on a hot water bath. This was dried in air at 120°C overnight and then calcined at 450°C for 2 hours to obtain a catalyst.

Using this catalyst, monoethanolamine and 2-
A reaction was carried out in the same manner as in Example 1 using amino-1-butanol. Reaction condition f [and the results are shown in Table 2].

Comparative Example 2 A silicon carbide 40 (J) with a diameter of 51 was immersed in 65.2 l of ammonium metatungstate aqueous solution (50% by weight based on W03 standard) and evaporated to dryness on a hot bath. After drying for 1 hour, it was calcined at 715°C for 4 hours to obtain a catalyst precursor.This was immersed in 10% silicon oxide colloidal solution 501 and evaporated to dryness on a hot bath.Furthermore, it was heated at 150°C in air for 1 hour. After drying, it was baked at 715°C for 4 hours to form tungsten oxide 25.4%, silicon oxide 3.3%.
Supported catalyst containing % by weight (in atomic ratio W to Si o, s
04.1> was obtained. Using this catalyst, monoethanolamine was reacted in the same manner as in Example 1.

The reaction conditions and results are shown in Table-2.

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

Comparative example 3゜niobium pentoxide 5. Completely dissolve Og in water 501 while heating it at 60℃, add ammonium water, and reduce the pH of the solution.
H was set to 7.0. After filtering the generated precipitate and washing with water,
It was dissolved in a 10% oxalic acid aqueous solution aoni+, and 0.217 g of barium hydroxide (octahydrate) was added thereto. 60 cc of silicon carbide was immersed in this solution, evaporated to dryness at 80°C, and then calcined in air at 500°C for 311 J to obtain 3.1% by weight of niobium pentoxide and 0.5ff of barium oxide.
Supported catalyst containing l ffi% (Ntz, in atomic ratio.

3a, o, 102.6) was obtained. Using this catalyst, monoethanolamine was reacted in the same manner as in Example 1. The reaction conditions and results are shown in Table-2.

The catalyst was prepared in accordance with Example 3 of U.S. Pat. No. 4,477,591-Distribution.

Claims (1)

[Claims] (1) General formula , b, and c indicate the atomic ratio of each element, and when a=1, b=0.01 to 6, and c is a numerical value determined by the bonding state of a, b, and various constituent elements. There are general formulas ▲mathematical formulas, chemical formulas, tables, etc.▼(I) (in the formula, R and R' are hydrogen, methyl group, and ethyl group, respectively). selected from among them, and n takes an integer value 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 Catalyst for gas phase intramolecular dehydration reaction that converts into