RU2114849C1 - Method of preparing triethylene diamine - Google Patents

Abstract

FIELD: chemistry of polymer. SUBSTANCE: triethylene diamine is product of organic synthesis used as urethane polymerization catalyst. Said triethylene diamine is prepared by contacting combination of monoethanol amine, ethylene diamine, piperazine with zeolite catalyst treated with aqueous solution of complexing agent and activated with stream of air and ammonia. Process is carried out at volumetric feed rate of initial mixture of amino compounds of 0.1-5.0 h h^-1 and initial mixture of amino compounds to diluent molar ratio of 1:(1-10), followed by rectification of catalyst into fractions. Fraction having boiling point of 160-180 C is cooled, the desired product is recovered and mother liquor is recycled to the beginning of process. The latter is carried out in continuous flow isothermal reactor. Process is intensified owing to using secondary products. EFFECT: more efficient preparation method. 4 cl, 1 tbl

Description

 The present invention relates to the field of organic chemistry of heterocyclic compounds, and in particular to a method for producing triethylenediamine, a product of basic organic synthesis, used as a catalyst for the polymerization of urethanes.

 A known method of producing triethylenediamine from ethylene diamine by catalytic contacting it with zeolites of the type "pentasil" [1].

A known method of producing triethylenediamine from an aqueous solution of piperazine on aluminosilicate with a structure of ZSM-5 at a reaction temperature of 340 ^o C and a pressure of 3 bar [2]. The conversion of piperazine in this case is 45%, and the concentration of the target product in the catalysis is 16.56%.

 The disadvantage of these methods is the low yield of the target product to the skipped feedstock due to the formation of by-products along the secondary conversion routes.

 Currently, in the process of obtaining triethylenediamine, the goal is to increase the yield of the target product using cheap and affordable raw materials.

Closest to the claimed is a method for producing triethylenediamine from individual amino compounds (monoethanolamine, ethylenediamine, diethylene triamine, piperazine or triethylenetetramine) by catalytic conversion on crystalline metal silicates of a pentasyl structure or on zeolites of the ZSM-5 type [3]. According to this method, the process is carried out at reaction temperatures of 250-450 ^o C, a contact load of 0.5-20 h ^-1 , gaseous hydrogen, nitrogen, water vapor or hydrocarbons are used as a diluent. Crystalline zeolite of the ZSM-type is used as a catalyst. 5 in the H-form, obtained from the sodium form of ZSM-5 by processing the last 1 N. ammonium sodium solution. In reference to this method for producing triethylenediamine from monoethanolamine, the triethylenediamine selectivity among organic reaction products is 63.5% when the monoethanolamine conversion is 88.7%, which, in terms of the concentration of triethylenediamine in the catalyst taking into account water, corresponds to 11.3 wt.%. When other amino compounds are used as raw materials, the target product selectivity and feed conversion indicate 55.6% and 64% for piperazine and 43.9% and 79.6% for ethylenediamine, respectively.

 The disadvantages of this method for the production of triethylenediamine is the low conversion and unproductive consumption of raw materials along the routes of formation of secondary products, a rather complicated process of isolation of the target product and, as a consequence, insufficiently high yield of the target product.

 The invention solves the problem of increasing the yield of triethylenediamine in the reaction products.

The problem is solved in that in the method for producing triethylenediamine by contacting the starting amino compound in a mixture with a diluent with a high silica zeolite catalyst at a temperature of 350-450 ^o C followed by distillation, a mixture of monoethanolamine (MEA) and ethylene diamine (EDA) or monoethanol is used as the starting amino compound. (PP) or ethylenediamine and piperazine in a molar ratio (1.0-0.1) :( 0.1-1.0) or a mixture of monoethanolamine, ethylenediamine and piperazine in a molar ratio (1.0-0.1) :( 0.1-1.0) :( 0.1-1.0) as dil of Tell use ammonia gas and / or steam, as well as a catalyst - type zeolite "pentasil" with a molar ratio SiO ₂ / Al ₂ O ₃ equal to 40-300, treated with an aqueous solution of a complexing agent and activated air stream at a temperature of 480-520 ^o C for two hours, and then with an ammonia stream at a temperature of 350-450 ^o C for at least two hours with a bulk velocity of 0.1-3.0 hour ^-1 , the process is carried out in a flow isothermal catalytic reactor at a volumetric feed rate of the original mixtures of amino compounds 0.1-5.0 hour ^-1 and molar in relation to the mixture of the starting amino compounds: diluent equal to 1: (1-10), followed by distillation of the catalysis into fractions by boiling points and the precipitation of a solid precipitate of triethylenediamine.

 The problem is also solved by the fact that a pentasil-type zeolite treated with an aqueous solution of a complexing agent is used as a catalyst, sulfosalicylic acid or tetramethylmethylammonium base or ethylenediaminetetraacetic acid sodium salt is used as the catalyst.

The problem is also solved by the fact that the fraction with a boiling point of 160-180 ^o C is cooled until precipitation of triethylenediamine, the precipitate is separated, and the mother liquor containing a mixture of unconverted raw materials and by-products is used as the starting amino compound.

Distinctive features of the method are: the use of a combination of mixtures of monoethanolamine, ethylenediamine, piperazine and their ratio, the use of ammonia and / or water vapor as a diluent, the use of a zeolite catalyst with a molar ratio of SiO ₂ / Al ₂ O ₃ equal to 40-300 treated with aqueous complexing agent, and its activation, the process conditions, triethylenediamine selection of fractions with boiling point of 160-180 ^o C by cooling, use of masterbatch of solution as a raw material, carrying out the process in a flow isothermal catalytic reactor.

As a result of the studies, it was found that the use of a pentasil-type zeolite catalyst with a SiO ₂ / Al ₂ O ₃ molar ratio of 40-300 treated with an aqueous solution of a complexing agent makes it possible to increase the selectivity of triethylenediamine formation in the reaction products by creating an optimal ratio of active centers of various nature, responsible for the conversion of the starting amino compound along the routes of formation of the target product or side compounds.

 The use of various combinations of mixtures of monoethanolamine, ethylenediamine and piperazine as feedstock leads to an increase in the yield of triethylenediamine due to the fact that ethylenediamine and piperazine, being intermediate products in the process of formation of triethylenediamine from monoethanolamine, being added in a stoichiometric ratio, lead to a decrease in the formation of by-products and obtaining triethylenediamine in higher yield. It has been experimentally found that the claimed component ratios are the most optimal.

 The use of diluents is due to the fact that to facilitate the removal of synthesis products during desorption from the surface of the catalyst and from the reaction zone. Moreover, the use of ammonia and water vapor is most appropriate, since on the one hand they are inert with respect to the initial amino compounds, and on the other hand, the presence of ammonia creates favorable conditions for long-term operation of the catalyst. The most optimal dilution is 1: (0.1-10). Further dilution is not practical due to the large volumes of reaction mixtures.

The process when feeding raw materials with a bulk velocity of 0.1-5.0 h ^-1 and a temperature of 350-450 ^o C is optimal, as it allows the process with the highest possible conversion of raw materials and high yield of the target product.

After the process, the catalyzate is separated into fractions by distillation at boiling points. A fraction with a boiling point of 160-180 ^o C consists of the target product, unconverted monoethanolamine and impurities of by-products, which are difficult to separate from triethylenediamine by simple distillation due to close boiling points. Using the method of crystallization of a product from a solution at low temperatures allows a more complete separation of the target product from undesirable impurities.

The catalyst after separation of fractions from it with a boiling point of 160-180 ^o C and the mother liquor after separation of the target product can be used as raw materials for additional production of triethylene diamine on the proposed catalyst, as they contain the starting amino compounds for the synthesis of the target product. This allows the disposal of by-products and increases the efficiency of the process.

 To carry out the process, it is possible to use a flow isothermal catalytic reactor. This allows you to ensure a uniform temperature field and to avoid the appearance of superheated zones in the catalyst bed, which can lead to a deterioration in the selectivity of the process and the appearance of undesirable products. This is especially important, since the reaction of the formation of by-products is accompanied by a significant exothermic effect.

The process of obtaining triethylenediamine is as follows. A catalyst with a molar ratio of SiO ₂ / Al ₂ O ₃ equal to 40-300 obtained by crystallization under hydrothermal conditions of a mixture of 30% sol of SiO ₂ , aluminum sulfate, sodium hydroxide and tetrabutylammonium bromide, taken in the ratio in terms of 3-15 Na oxides ₂ O: Al ₂ O ₃ : 30-100 SiO ₂ : 10 R ₂ O, and treated with an aqueous solution of a complexing agent: sulfosalicylic acid or tetramethylammonium base or sodium salt of ethylenediaminetetraacetic acid, is loaded into the reactor with a flowing isothermal catalytic installation, activated by a stream air at 480-520 ^o C for 2 hours and is treated with a stream of ammonia at 350-450 ^o C for at least 2 hours with a bulk velocity of 0.1-3.0 hour ^-1 . The process is carried out by catalytic conversion of an amino compound in an atmosphere of gaseous ammonia and / or water vapor at a temperature of 350-450 ^o C, a volumetric feed rate of liquid raw materials of 0.1-5.0 hour ^-1 and a molar ratio of a mixture of amino compounds: diluent = 1: (1 :ten). The resulting catalyzate by distillation is divided into fractions by boiling point. A fraction with a boiling point of 160-180 ^o C, containing the main amount of the target product, is subjected to cooling to temperatures of 0-10 ^o C in order to isolate a crystalline precipitate of triethylene diamine by crystallization from solution at low temperatures. In this case, the exposure time at low temperatures may be different depending on the content of the target product. The crystalline precipitate is separated from the solution. A solution containing a mixture consisting of monoethanolamine, piperazine and triethylenediamine is used a second time to obtain the desired product. In this case, the use of a mixture of amino compounds as a raw material makes it possible to increase the concentration of the target product in the obtained catalysis to 36.2 wt.%, And in the catalysis obtained as a result of using the mother liquor after separation of the crystalline precipitate of triethylene diamine to 41.8 wt.% . Thus, the proposed method allows to increase the yield of triethylenediamine due to the efficiency of the process and the efficiency of using secondary products.

 Industrial applicability is confirmed by the following examples.

Example 1. Use a catalyst prepared as follows: a mixture of 30% Zola SiO ₂ , aluminum sulfate, sodium hydroxide and tetrabutylammonium bromide is loaded into the autoclave in the ratio in terms of oxides 12 Na ₂ O: Al ₂ O ₃ : 112 SiO ₂ : 14 R ₂ O. Crystallization is carried out at 175 ^o C for 3 days. The precipitate obtained is filtered off and washed with distilled water. The obtained high-silica zeolite with a ratio of SiO ₂ / Al ₂ O ₃ = 90 is treated with an air stream for 2 hours at 520 ^o C, after cooling, ion exchange is carried out with a 0.1 molar solution of ammonium chloride, then filtered, washed with distilled water from chlorine ions, dried and ignite. Part of the initial sample is heated with a 5-fold amount of a 1% solution of sodium salt of ethylenediaminetetraacetic acid to 80 ^o C and kept under stirring for 3 hours, filtered, washed with distilled water, dried at 120 ^o C, tabletted and loaded into the reactor with a flow isothermal catalytic installation. Then it is activated by an air stream for 2 hours at 480 ^° C, cooled to 400 ^° C and kept in a stream of ammonia supplied at a space velocity of 0.1 hour ^-1 for 2 hours. A mixture of MEA and EDA in a ratio of 1.0: 0.1 is added to the ammonia stream in a molar ratio of the feedstock: ammonia equal to 1: 5, and passed over the catalyst with a volumetric feed rate of liquid feed 1 hour ^-1 at 400 ^o C. The resulting catalysis is analyzed on a gas chromatograph. The MEA conversion is 76.7%, the concentration of TEDA in the catalyst is 17.9 wt. % 10 g of the obtained catalyzate is subjected to distillation and a fraction with a boiling point of 160-180 ^° C is isolated, which is then cooled to 10 ^° C and held for a long time for at least 4 hours to more fully isolate TEDA crystals from the solution. The precipitate is filtered off, the mother liquor is used again, the yield of TEDA from the target fraction is 52 wt.%. The resulting product is characterized by a melting point of 158 ^o C, a boiling point of 174 ^o C and according to mass spectrometric analysis, its structure corresponds to triethylenediamine. The experimental and literature data of the analysis are shown in the table.

Example 2. A portion of a zeolite catalyst with a ratio of SiO ₂ / Al ₂ O ₃ = 60, prepared and activated, as in example 1, is loaded into the reactor flow isothermal catalytic installation. Then, an initial mixture of the composition MEA: EDA = 3: 1 was added to the ammonia stream in the ratio: feed: ammonia = 1: 1 and passed over the catalyst with a bulk velocity of 0.5 h ⁻¹ at 380 ^° C. The resulting catalysis was analyzed on a gas chromatograph. The MEA conversion is 96.7%, the EDA conversion is 100%, the concentration of TEDA in the catalyst is 23.4 wt.%. The yield of TEDA after rectification of the catalysis and cooling of the target fraction is 77 wt.%.

Example 3. A portion of a zeolite catalyst with a ratio of SiO ₂ / Al ₂ O ₃ = 120, prepared as in example 1, but treated with an aqueous solution of sulfosalicylic acid, is loaded into the reactor of a flowing isothermal catalytic installation, activated, as in example 1. The initial mixture of the composition MEA: EDA = 2: 1 with a ratio of feed: ammonia = 1: 2 is passed over the catalyst with a bulk velocity of 0.5 hour ^-1 at 380 ^o C. The conversion of MEA is 87.9%, the conversion of EDA is 100%, the concentration of TEDA in catalysis - 25.2 wt.%.

Example 4. A portion of a zeolite catalyst with a ratio of SiO ₂ / Al ₂ O ₃ = 90, treated with an aqueous solution of sulfosilicylic acid, is loaded into the reactor of a flow isothermal catalytic installation and activated, as in example 1. The initial mixture of the composition MEA: EDA = 1: 1 at a dilution of ammonia equal to 1: 3 is passed over the catalyst with a space velocity of 1.5 h ^-1 at a temperature of 410 ^o C. The conversion of MEA is 87.9%, the conversion of EDA is 100%, the concentration of TEDA in the catalyst is 34.3 wt. %

Example 5. A portion of a zeolite catalyst with a ratio of SiO ₂ / Al ₂ O ₃ = 87, obtained as in example 1, but treated with an aqueous solution of tetramethylammonium base, is loaded into the reactor of a flow isothermal catalytic installation. The activation conditions of the sample, as in example 1. As a raw material, use the initial mixture of the MEA composition: EDA = 1: 2 in proportion to diluents 1: 3. The process is carried out at a volumetric feed rate of 0.7 hour ^-1 and a temperature of 420 ^o C. The conversion of MEA is 87.9%, EDA is 100%, the concentration of TEDA in the catalyst is 36.2 wt.%.

Example 6. Use a sample of a zeolite catalyst with a ratio of SiO ₂ / Al ₂ O ₃ = 44. The conditions for activation of the catalyst, as in example 1. As a raw material, take a mixture of MEA: EDA in the ratio of 0.1: 1.0 when diluted with ammonia equal to 1: 5. The process is conducted at a volumetric feed rate of 2.0 hour ^-1 and a temperature of 400 ^o C. EDA conversion of 75%, the concentration of TEDA in the catalysis is 25.2 wt.%.

Example 7. Use a sample of a zeolite catalyst with a ratio of SiO ₂ / Al ₂ O ₃ = 90, the processing and activation conditions of the catalyst, as in example 1, only as raw materials use an aqueous mixture of an amine solution obtained after separation of a crystalline precipitate TEDA containing 55, 8 wt.% MEA, 2.4 wt.% PP and 12.2 wt.% TEDA, the rest is water, in the ratio of raw materials: ammonia = 1: 5. The volumetric feed rate of 1.0 hour ^-1 at a temperature of 400 ^o C. The conversion of TEDA in the catalysis is 24.2 wt.%.

Example 8. Use a sample of a zeolite catalyst with a ratio of SiO ₂ / Al ₂ O ₃ = 90, the processing and activation conditions of the catalyst, as in example 3, only as a raw material use an aqueous mixture of an amine solution obtained after separation of the crystalline precipitate TEDA containing 50, 3 wt.% MEA, 10.9 wt.% PP and 28.1 wt.% TEDA, in the ratio of raw materials: ammonia = 1: 3. The volumetric feed rate of 5.0 hours ^-1 , the reaction temperature of 450 ^o C. the Conversion of the MEA - 100%, the concentration of TEDA in the catalysis - 41.8 wt.%.

Example 9. Use a sample of a zeolite catalyst with a ratio of SiO ₂ / Al ₂ O ₃ = 90, the processing and activation conditions of the catalyst, as in example 1, only as raw materials use MEA and PP, taken in a molar ratio of 1: 1, in a vapor atmosphere water at a ratio of raw materials: water vapor equal to 1: 5. The process is carried out at a volumetric feed rate of 0.7 hour ^-1 and a temperature of 450 ^o C. The conversion of MEA 100%, the concentration of TEDA - 33.7 wt.%.

Example 10. Use a sample of a zeolite catalyst with a ratio of SiO ₂ / Al ₂ O ₃ = 280, the processing and activation conditions of the catalyst, as in example 3. As a raw material, a mixture of MEA and PP taken in a molar ratio of 1: 2, the ratio of the mixture of amines : water vapor = 1:10. The process is carried out at a volumetric feed rate of 0.5 hour ^-1 and a temperature of 450 ^o C, the conversion of MEA - 100%, the concentration of TEDA - 35.9 wt.%.

Example 11. Use a sample of a zeolite catalyst with a ratio of SiO ₂ / Al ₂ O ₃ = 150, the processing and activation conditions of the catalyst, as in example 1. As a raw material, a mixture of EDA and PP taken in a molar ratio of 1: 1, the ratio of the mixture of amines : water vapor = 1:10. The process is carried out at a volumetric feed rate of 0.5 hour ^-1 and a temperature of 420 ^o C, the conversion of EDA is 100%, the conversion of PP is 76.0%, the concentration of TEDA is 30.3 wt.%.

Example 12. Use a sample of a zeolite catalyst with a ratio of SiO ₂ / Al ₂ O ₃ = 187, the processing and activation conditions of the catalyst, as in example 5. As a raw material, a mixture of MEA, EDA and PP taken in a molar ratio of 1: 1: 1 the ratio of the mixture of amines: water vapor = 1:10. The process is carried out at a volumetric feed rate of 0.5 h ^-1 and a temperature of 420 ^o C, the conversion of MEA - 100%, the conversion of EDA - 100%, the conversion of PP - 67.0%, the concentration of TEDA - 25.3 wt.%.

Claims (4)

1. The method of producing triethylenediamine by contacting the starting amino compound in a mixture with a diluent with a high silica zeolite catalyst at temperatures of 350-450 ^° C followed by distillation, characterized in that the mixture of monoethanolamine and ethylene diamine, or monoethanolamine and piperazine or piperazine or piperazine or ethylene diamine is used as the starting amino compound. in a molar ratio (1.0 - 0.1): (0.1 - 1.0), or a mixture of monoethanolamine, ethylenediamine and piperazine in a molar ratio (0.1 - 1.0): (0.1 - 1, 0): (0.1 - 1.0), as a diluent using ammonia and / or steam, as well as a catalyst - type zeolite of pentasil with a molar ratio SiO ₂ / Al ₂ O ₃ equal to 40 - 300 is treated with an aqueous solution of a complexing agent and activated air stream at a temperature of 480 - 520 ^o C for 2 hours, and then with a stream of ammonia at a temperature of 350 - 450 ^o C for at least 2 hours with a space velocity of 0.1 - 3.0 h ^-1 , the process is carried out in a flow isothermal catalytic reactor at a volumetric feed rate of the initial mixture of amino compounds 0, 1 - 5.0 h ^-1 and a molar ratio of the mixture of the starting amino distinctions: a diluent equal to 1: (1 - 10), followed by rectification of the catalysis into fractions according to the boiling points and the precipitation of a solid precipitate of triethylene diamine.  2. The method according to claim 1, characterized in that the sodium salt of ethylenediaminetetraacetic acid, or sulfosalicylic acid, or tetramethylammonium base is used as a complexing agent. 3. The method according to claims 1 and 2, characterized in that the fraction with a boiling point of 160 - 180 ^o C is cooled until precipitation of triethylenediamine.  4. The method according to PP. 1 to 3, characterized in that the precipitated precipitate of triethylenediamine is separated, and the mother liquor is returned to the beginning of the process as the starting amino compound.

Images