JP2771465B2 - Process for producing alkanolamine and catalyst used therein - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a product to which an alkylene oxide is added in an amount of 2 mol or more when an alkanolamine is produced by aminating an alkylene oxide with ammonia using a catalyst supporting a rare earth element. The present invention relates to a method for producing an alkanolamine for producing a monoalkanolamine selectively and with high productivity while suppressing the addition of 3 mol of the product, and a catalyst used in the method. In particular, it is useful industrially in the production of ethanolamines for aminating ethylene oxide with ammonia.

[0002]

2. Description of the Related Art As a method for producing an alkanolamine by aminating an alkylene oxide with ammonia, industrially, ethylene oxide and aqueous ammonia (20%) are used.
(Ammonia concentration of ４０40% by weight) to produce ethanolamines. In this method, in addition to monoethanolamine, diethanolamine and triethanolamine are by-produced. Among them, the demand for triethanolamine has declined, and thus it is required to suppress the production of triethanolamine.
For this reason, usually, the reaction is carried out with a large excess of ammonia such that the molar ratio of ammonia to ethylene oxide is about 3 to 5, but the selectivity of triethanolamine is still 10 to 2
It is 0% by weight or more, and the selectivity of monoethanolamine is also 50% by weight or less.

On the other hand, in a system in which water does not exist, the alkylene oxide hardly reacts with ammonia. Therefore, the presence of a catalyst is indispensable for such a reaction,
For example, homogeneous catalysts such as organic acids, inorganic acids and ammonium salts have been proposed (Swedish Patent No. 15).
No. 8167). In the case of a homogeneous catalyst, there were difficulties in separating the catalyst, and the performance was not sufficient. As an attempt to immobilize this homogeneous acid catalyst, an ion exchange resin in which sulfonic acid groups are immobilized on the resin has been proposed (Japanese Patent Publication No. 49-4772).
No. 8). This catalyst has relatively high activity and selectivity and is industrially practiced. However, ion exchange resins have a problem that the maximum use temperature is low. The maximum temperature at which commercially available ion-exchange resins can be used is as low as about 120 ° C (“Ion-exchange-guide to theory and application-”
(Translated by Rokuro Kuroda and Masami Shibukawa, published by Maruzen Co., Ltd. in 1981, p. 34) Therefore, when the reaction is carried out with a low molar ratio of ammonia and ethylene oxide, the temperature of the catalyst layer exceeds the heat resistance temperature due to heat of reaction. However, when used under such temperature conditions for a long time, there is a problem that the catalyst is deteriorated. For this reason, it is difficult to make the molar ratio between ammonia and ethylene oxide less than about 20 to 25. Therefore, in order to overcome the drawback of the ion exchange resin having low heat resistance, an inorganic catalyst having excellent thermal stability has been studied.
U.S. Pat. No. 4,438,281 discloses that commonly used silica alumina exhibits activity.
Industrial and Engineering Chemistry, Product Research and Development, 1986, Vol. 25, pp. 424-430, comparing ion exchange resins and various zeolite catalysts, etc., but selectivity to monoalkanolamine In terms of, it was not superior to ion exchange resin. In addition, Japanese Unexamined Patent Publication
225446 discloses an acid activated clay catalyst. In some of these catalysts, the yield of monoethanolamine is as high as 60% by weight or more. However, since the selectivity to monoalkanolamine is not sufficient in all cases, the molar ratio of ammonia to ethylene oxide is set to 20 to
The reaction is performed 30 times or more, and the equipment cost for recovering and circulating ammonia is large, and there are many practical difficulties.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the molar ratio of ammonia to alkylene oxide to a practically advantageous molar ratio, and to selectively produce monoalkanolamine even at that molar ratio. It is an object of the present invention to provide a catalyst having high heat resistance and high selectivity, and a method for producing an alkanolamine using such a catalyst.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that a catalyst in which a rare earth element is supported on an inorganic refractory carrier exhibits excellent performance. The invention has been completed.

That is, according to the present invention, the general formula (I) having 2 to 4 carbon atoms

[0007]

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(Wherein R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a methyl group or an ethyl group) and ammonia.
In the liquid phase, a catalyst in which a rare earth element is supported on an inorganic refractory carrier, provided that the crystalline medium contains scandium in the lattice.
Reacting in the presence of , except for tallosilicate , characterized by the general formula (II)

[0009]

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(Wherein R ¹ , R ² , R ³ and R 4 are the same as those of the general formula (I)) and a general method having 2 to 4 carbon atoms. Formula (I)

[0011]

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(Wherein R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a methyl group or an ethyl group) and ammonia in a liquid phase. General formula (II)

[0013]

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(Wherein R ¹ , R ² , R ³ and R ⁴ are the same as those of the general formula (I)), wherein the catalyst is used for producing an alkanolamine represented by the formula: Characterized by being supported on an inorganic refractory carrier, provided that the crystalline lattice has scandium incorporated in the lattice.
The present invention relates to a catalyst for producing an alkanolamine , excluding tarosilicate.

The catalyst according to the present invention has better selectivity to monoalkanolamines than conventionally known solid catalysts and has higher heat resistance of the catalyst than ion exchange resins. The ratio can be reduced, and it can be implemented industrially.

Hereinafter, the present invention will be described in detail.

As the active component of the catalyst according to the present invention, a rare earth element is used. As the rare earth element, a lanthanoid group element (lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium), scandium or yttrium is used as the rare earth element.

The rare earth element raw material may be any material which becomes insoluble in the reaction solution after being prepared by heat treatment, and particularly includes nitrates, sulfates, carbonates, acetates, oxalates, heteropolyacid salts, phosphates, and the like. A halide, an oxide, a hydroxide, or the like can be used. The carrier of the catalyst of the present invention may be any of inorganic refractory materials having a specific surface area of 1 to 500 m ² / g, and various known carriers such as natural products (diatomaceous earth, pumice, clay, etc.), and single oxides (Silica, alumina, titania, zirconia, etc.), composite oxides (silica alumina, titania silica, zirconia silica, perovskite, etc.), inorganic refractories (silicon carbide, silicon nitride, graphite, etc.), inorganic ion exchanger (SAP)
O, MeAPO, metallosilicate, layered clay compound, etc.) can be used. However, if the catalytically active component is
In the case of indium, the use of metallosilicate
Excluded from the light.

As a supporting method, an ion exchange method, an impregnation method, a kneading method and the like can be used.

The impregnation method is a method in which a molded carrier is charged into a soluble rare earth element solution, and the carrier is heated to remove the solvent and carried.

The kneading method is a method in which a rare earth element compound carried on a carrier powder is added, and a cake obtained by sufficiently kneading with a kneader using a small amount of a solvent is molded.

The ion exchange method is a method in which a carrier is charged into a soluble rare earth element solution, alkali metal ions at the exchange site of the ion exchanger are ion-exchanged with the rare earth element, and then separated from the solution and supported. The ion exchange method is convenient for uniformly supporting the rare earth element on the carrier.
In the ion exchange method, an inorganic ion exchanger is used as a carrier. Examples of inorganic ion exchangers include SAPO, M
eAPO, metallosilicate, layered clay compound, and the like.

SAPO is a crystalline aluminum phosphate (A
lPO) is a substance in which part of phosphorus is replaced with silicon or a pair of aluminum and phosphorus is replaced with two silicons. M
eAPO is a substance in which aluminum of AlPO is replaced by a metal element other than silicon (such as Co, Mg, Mn, Zn, and Fe). Each has an ion exchange site, SAPO-5, -11, -17, -40, MAPO
(Mg) -5, -11, -36, MnAPO-5, -1
1, CoAPO-5, -36, FAPO (Fe) -3
4, ZAPO (Zn) -34, etc. are known (the-number is the same identification number as AlPO of the corresponding structure).

A metallosilicate is a substance in which silicon in crystalline silicon oxide is replaced with a metal, has very uniform pores, and the charge balance is lost by the amount of the metal replaced, so that ion exchange is performed. Site exists. As the metallosilicate, specifically, a crystalline aluminosilicate known as zeolite is often used. As zeolites, A type, X type, Y type, L type, pentasil type (ZSM-
5, ZSM-11, etc.), mordenite, ferrierite and the like can be generally used. As other metallosilicates, iron silicate, nickel silicate and the like can be used.

As the layered clay compound, smectite clay is known, and specifically, montmorillonite, saponite, hectorite, nontronite and the like are used.
These clay compounds also have an ion exchange site, and usually an alkali metal ion such as sodium occupies this site, and often exhibits basicity.

In preparation methods other than the kneading method, a soluble salt (nitrate, halide, heteropolyacid salt, etc.) can be used as the catalyst raw material.

The loading ratio varies depending on the surface area of the carrier and the type of the rare earth element, but is in the range of 0.5 to 50% by weight, preferably 1 to 30% by weight.

When supported by an ion exchange method, it can be used without high-temperature treatment.
The catalyst is subjected to a high temperature treatment in the range described above. The high-temperature treatment is usually performed in the air, but when the oxidation treatment is not particularly required, the catalyst material can be thermally decomposed in an atmosphere of an inert gas such as nitrogen or in a vacuum.

In order to make effective use of expensive rare earth elements and to facilitate preparation of the catalyst, another metal element having a valence of 2 or more can be added simultaneously. The element that can be added may be any element that does not impair the activity and selectivity. For example, a group IVB element (such as Ti), a group VB element (such as Nb), a group VIB element (such as W), a group VIIB element (such as Mn), a group VIII element (such as Fe), III of the periodic table
Group A elements (such as Al) and Group IVA elements (such as Sn). Trivalent metals such as Fe and Al have the same valence as the rare earth elements, and thus often provide favorable results.
The amount to be added is not particularly limited as long as the effect of the rare earth element is not impaired, but a range of 0 to 10 in atomic ratio to the rare earth element is usually used.

Although the reason why the catalyst is effective in the present reaction is not completely clear, the found effects are described below.

A conventional acid catalyst cannot activate ammonia, which is a relatively weak inorganic base, and the reactivity of monoethanolamine, which is an amine having organic active hydrogen, is 5 to 20 times greater than that of ammonia, and is sequential. And diethanolamine and triethanolamine were formed. By using a catalyst supporting a rare earth element, it was possible to activate inorganic ammonia, thereby increasing the reactivity of ammonia and consequently suppressing the sequential reaction.

It is considered that the carrier effectively utilizes an expensive rare earth element, so that the effect of increasing the surface area and the activity selectivity of the supported rare earth element are controlled by the properties of the acid base contained in the carrier. SAPO, Me as carrier
When a material having pores of a molecular order such as APO or metallosilicate is used, the pore size is 0.45 to 0.7.
The use of a compound having a thickness of nm can suppress the formation of triethanolamine having a particularly branched structure due to so-called shape selectivity. Examples of the carrier having such a pore size include ZSM-5, ZSM-11, mordenite, ferrierite, and SAPO-40.

The starting material alkylene oxide according to the present invention is an alkylene oxide having 2 to 4 carbon atoms and represented by the general formula (I), and examples thereof include ethylene oxide and propylene oxide. The alkanolamine represented by the general formula (II) is obtained corresponding to these raw materials. Specific examples include monoethanolamine,
Examples thereof include diethanolamine, triethanolamine, and propanolamines.

Since the reaction must be carried out in the liquid phase, the reaction pressure must be kept higher than the vapor pressure of the reaction solution at the highest temperature in the reactor.

Usually, the production of alkanolamines is 5
It can be carried out in a temperature range of 0 to 300 ° C. The preferred range is 80-200 ° C. Operating pressure is 1-2
0 MPa.

The molar ratio of ammonia to alkylene oxide is from 1: 1 to 40: 1, preferably from 1: 1 to 20: 1,
More preferably, it is in the range of 1: 1 to 15: 1.

Under the above conditions, the hourly space velocity (LH
Conditions with an SV) of 4 to 15 or more are particularly advantageous for the quantitative conversion of alkylene oxides.

[0038]

The catalyst of the present invention has a high selectivity for the production of monoalkanolamines, so that even if the ratio of ammonia to alkylene oxide is lower than that of other solid catalysts, the production ratio of alkanolamines becomes the same, so that the unreacted catalyst is not reacted. Ammonia recovery cost is reduced. At the same time, since the total amount of the feedstock is reduced, the size of the reaction system and the recovery system can be reduced, and the equipment cost is reduced.

[0039]

The examples which follow show examples of the production of ethanolamines mainly from ethylene oxide and ammonia. The examples are intended for illustrative purposes and do not limit the invention.

The LHSV, the conversion of ethylene oxide and the selectivity of monoethanolamine are defined as follows. It should be noted that almost no products other than ethanolamines were formed, and thus the conversion (mol%) of ethylene oxide was (mono, di, tri) based on ethylene oxide.
It is almost equal to the total yield (mol%) of ethanolamine.

[0041]

(Equation 1)

[0042]

(Equation 2)

[0043]

(Equation 3)

[Catalyst Preparation Example] Catalyst A This is an example using lanthanum as an active ingredient and ZSM-5 as a carrier.

1 mol / dm ³ lanthanum nitrate aqueous solution 5
50 g of ZSM-5 was added to 00 cm ³ with stirring,
After stirring at room temperature for 1 day, the mixture was filtered and washed with 2 dm ³ of pure water. After drying this cake at 100 ° C. for 1 day,
The catalyst was pulverized to a particle size of 0.2 mm to obtain a catalyst. At this time, the amount of lanthanum carried (in terms of element) was 10% by weight.

Catalyst B This is an example using yttrium as an active ingredient and silica as a carrier.

In an 18% by weight aqueous solution of yttrium nitrate, silica (CAR, manufactured by Fuji Silysia Chemical Ltd.)
A sample filled with 50 g of iACT-50 (sphere of 8 mesh or more) is immersed for 5 hours. 1 after withdrawing from solution
It was dried at 20 ° C. for 1 day and treated at 500 ° C. for 5 hours under high air flow. This was pulverized to a particle size of 0.1 to 0.2 mm to obtain a catalyst. At this time, the supported amount of yttrium was 7.8% by weight.

Catalyst C This is an example using yttrium as an active ingredient and silica alumina as a carrier. In a 30% by weight yttrium nitrate aqueous solution, 50 g of silica alumina (N631HN manufactured by Nikki Chemical Co., Ltd., containing 25% of Al ₂ O ₃ ) is filled in a basket-shaped container, and the basket is immersed for 5 hours. 1 after withdrawing from solution
It was dried at 20 ° C. for 1 day and treated at 500 ° C. for 5 hours under high air flow. This was pulverized to a particle size of 0.1 to 0.2 mm to obtain a catalyst. At this time, the supported amount of yttrium was 7.8% by weight.

Catalyst D This is an example using lanthanum (heteropolyacid salt) as an active ingredient and silica as a carrier.

7.2 g of lanthanum nitrate hexahydrate and 42.7 g of phosphotungstic acid are dissolved in 300 cm ₃ of pure water.
Silica (CARiACT- manufactured by Fuji Silysia Chemical Ltd.)
100 g (500.1-0.2 mm crushed) was put into this solution and evaporated to dryness on a hot water bath. This was dried at 120 ° C. for 1 day and subjected to a high temperature treatment at 300 ° C. for 5 hours while flowing air. At this time, the amount of lanthanum carried was 1.6% by weight.

Catalyst E This is an example using lanthanum as an active ingredient and montmorillonite as a carrier.

[0052] was added with stirring Montmorillonite 200g lanthanum nitrate aqueous solution 10 dm ³ of 0.05 mol / dm ^3, stirring is carried out for 1 day at room temperature, filtered, 10 dm
Washed with ³ pure water. The cake was dried at 100 ° C. for 1 day, and then pulverized to 200 mesh or less to obtain a raw material powder of a catalyst.

Pure water was added again to 100 g of the powder in the same amount as the powder, kneaded with a kneader, and dried at 100 ° C. for one day. Thereafter, high temperature treatment was carried out at 500 ° C. for 5 hours under air flow. The obtained solid was pulverized to a particle size of 0.1 to 0.2 mm to obtain a catalyst. At this time, the supported amount of lanthanum was 14% by weight.

Catalyst F is an example in which yttrium is used as an active component and montmorillonite is used as a carrier.

[0055] was added with stirring montmorillonite 100g yttrium nitrate aqueous solution 5 dm ³ of 0.05 mol / dm ^3, stirring is carried out for 1 day at room temperature, filtered, 5 dm
Washed with ³ pure water. This cake was dried at 100 ° C. for 1 day, and then subjected to a high temperature treatment at 400 ° C. for 4 hours under air flow. The obtained solid was pulverized to a particle size of 0.1 to 0.2 mm to obtain a catalyst. At this time, the supported amount of yttrium was 10% by weight.

Catalyst G This is an example using ytterbium as an active ingredient and saponite as a carrier.

A catalyst was prepared in the same manner as the catalyst F except that an aqueous solution of 0.05 mol / dm ³ of ytterbium nitrate was used as a raw material of the rare earth element and saponite was used as a carrier.
At this time, the carried amount of ytterbium was 18% by weight.

Catalyst H This is an example using cerium as an active ingredient and montmorillonite as a carrier.

Cerium nitrate 0.1 as a raw material of the rare earth element.
A catalyst was prepared in the same manner as for the catalyst F, except that an aqueous solution of 05 mol / dm ³ was used. At this time, the supported amount of cerium is 18
% By weight.

Catalyst I This is an example using lanthanum and yttrium as active components and montmorillonite as a carrier.

As a raw material of the rare earth element, 0.025 mol of lanthanum nitrate and 0.1 mol of yttrium nitrate in 1 dm ³ were used.
A catalyst was prepared in the same manner as for the catalyst F, except that a mixed aqueous solution containing 025 mol was used. At this time, the supported amounts of lanthanum and yttrium were 7.5% by weight and 5% by weight, respectively.

Catalyst J This is an example using lanthanum as an active ingredient and montmorillonite as a carrier.

[0063] Besides the use of lanthanum chloride solution 10 dm ³ of 0.05 mol / dm ³ in place as raw material of lanthanum nitrate solution of lanthanum, A catalyst was prepared in the same manner as catalyst E. At this time, the supported amount of lanthanum was 14% by weight.

Catalyst K This is an example using lanthanum as an active ingredient, iron as an additional metal, and montmorillonite as a carrier.

[0065] Lanthanum ingredients as lanthanum nitrate 0.025mol in 1 dm ^3, except that an aqueous solution 10 dm ³ comprising iron nitrate 0.025mol, A catalyst was prepared in the same manner as catalyst E. The amount of lanthanum carried at this time was about 7% by weight.

Catalyst L This is an example using yttrium as an active ingredient, aluminum as an additive metal, and montmorillonite as a carrier.

[0067] Yttrium ingredients as yttrium nitrate 0.025mol in 1 dm ^3, except that an aqueous solution 10 dm ³ containing aluminum nitrate 0.025mol, A catalyst was prepared in the same manner as catalyst E. At this time, the supported amount of yttrium was about 5% by weight.

[Production Example of Alkanolamine] Example 1 Catalyst A was charged into a stainless steel tube reactor (inner diameter: 10.7 mm) having an internal volume of 5.5 cm ³ . Ammonia and ethylene oxide were fed into the reaction vessel at a constant rate using a high-pressure pump by an ascending method, and the reaction vessel was heated in an oil bath. Reaction pressure was maintained at 14 MPa. The reaction solution was collected and analyzed by gas chromatography. Table 1 shows the results.

Examples 2 to 12 Reactions were carried out in the same manner as in Example 1 except that the catalyst and reaction conditions were changed. Table 1 shows the catalyst used, the reaction conditions, and the reaction results.

In order to show how the product distribution changes depending on the ammonia / EO molar ratio, the results obtained by reacting the same catalysts in Examples 5, 6 and 7 while changing the molar ratio are shown in Table 1. .

[0071]

[Table 1]

The following comparative examples are examples of heat-resistant inorganic catalysts, in which only the silica-alumina, the acid-activated clay and the carrier free of the rare earth element as the active component disclosed in the prior art are used.

Comparative Example 1 Instead of the catalyst A, silica-alumina (N-631L, manufactured by JGC Corporation, containing 0.1% by weight of Al ₂ O ₃ , 0.1%)
The reaction was carried out in the same manner as in Example 1 except that ０．２0.2 mm crushing) was used. Silica-alumina is a typical so-called solid acid catalyst. Table 2 shows the reaction conditions and results. Despite being a strong solid acid, the activity / selectivity was low, and particularly, a large amount of triethanolamine was produced.

Comparative Examples 2-3 The reaction was carried out in the same manner as in Example 1 except that activated clay powder (manufactured by Wako Pure Chemical Industries, Ltd.) was used in place of the catalyst A. Activated clay is clay that has been subjected to acid treatment and its raw material is clay containing montmorillonite as a main component, so-called acid clay.
It is also a typical solid acid. Table 2 shows the reaction conditions and results.

Comparative Example 4 A reaction was carried out in the same procedure as in Example 5 except that only montmorillonite not carrying a rare earth element was used instead of catalyst E. Due to the very low activity, the reaction temperature was greatly increased to achieve comparable ethylene oxide conversion. The untreated montmorillonite contained sodium ions in the ion exchange site and was not treated with an acid, etc., and thus showed basicity when touched with wet pH test paper. The reaction conditions and results are shown in Table 2 below. The selectivity is very poor compared to Example 5 due to the carrier alone without the active ingredient.

[0076]

[Table 2]

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-33718 (JP, A) JP-A-6-49000 (JP, A) JP-A-2-225446 (JP, A) JP-A-61- 44848 (JP, A) U.S. Pat. No. 4,438,281 (US, A) European Patent Application Publication 375267 (EP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C07C 215/08 C07C 213/04 CA ( STN)

Claims (2)

(57) [Claims] 1. A compound of the general formula (I) having 2 to 4 carbon atoms (Wherein, R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a methyl group or an ethyl group) and ammonia in a liquid phase, wherein the rare earth element is an inorganic refractory metal. Catalyst supported on a porous support, but in a lattice
Crystalline metallosilicate containing scandium
Wherein the reaction is carried out in the presence of a compound represented by the general formula (II): (Wherein R ¹ , R ² , R ³ and R4 are the same as those in the general formula (I)). 2. A compound of the general formula (I) having 2 to 4 carbon atoms. (Wherein R ¹ , R ² , R ³ and R 4 each independently represent a hydrogen atom, a methyl group or an ethyl group), and reacting the alkylene oxide represented by the general formula (II) ) (Wherein R ¹ , R ² , R ³ and R ⁴ are the same as those of the general formula (I)), wherein the rare earth element is an inorganic refractory metal. characterized in that it is supported on a carrier, but rated
Crystalline metallosilicate with scandium incorporated
Catalysts for alkanolamine production , excluding