JP2014525942A - Method for producing EDDN and / or EDMN by reaction of FACH and EDA - Google Patents

Abstract

  A method in which formaldehyde cyanohydrin (FACH) and ethylenediamine (EDA) are reacted at a temperature in the range of 20 to 120 ° C. in a reactor in which back-mixing is limited, the residence time in the reactor being 300 A method characterized in that it is less than a second.

Description

  This application includes US provisional application 61/529303, filed on August 31, 2011, by reference.

  The present invention relates to a process for producing EDDN (ethylenediaminediacetonitrile) and / or EDMN (ethylenediaminemonoacetonitrile) by reacting FACH (formaldehyde cyanohydrin) and EDA (ethylenediamine), wherein the reaction is conducted in a reactor. It relates to said process carried out with a short residence time. The invention further relates to the production of TETA (triethylenetetramine) and / or DETA (diethylenetriamine) by reacting the EDDN or EDMN thus produced with hydrogen in the presence of a catalyst. A further subject of the invention is the production of epoxy resins, amides or polyamides from DETA or TETA obtained according to the invention.

  In WO 2008/104579 and the prior art listed in WO 2008/104579, various production methods for EDDN or EDMN are mentioned. In WO 2008/104579, EDDN is produced by the reaction of EDA with formaldehyde (FA) and hydrocyanic acid (HCN), wherein the molar ratio of EDA to FA to HCN is 1: 1.5: 1.5. ~ 1: 2: 2 [mol: mol: mol]. Said preparations include: a) reacting EDA with FACH, wherein the molar ratio of EDA to FACH is from 1: 1.5 to 1: 2, or b) EDDN is converted to an ethylenediamine-formaldehyde adduct (EDFA). ) And hydrocyanic acid, wherein the molar ratio of EDFA to HCN is from 1: 1.5 to 1: 2, or c) EDA is reacted with a mixture of formaldehyde and hydrocyanic acid, The molar ratio of EDA to FA to HCN is 1: 1.5: 1.5 to 1: 2: 2, or d) EDA is reacted simultaneously with formaldehyde and HCN, wherein EDA to FA to HCN The molar ratio is from 1: 1.5: 1.5 to 1: 2: 2. It is disclosed that the reaction is preferably carried out at a temperature of 10 to 90 ° C. and an overpressure slightly elevated from normal pressure. Preferred reactors are described as tubular reactors or stirred tank cascades. The work-up of the reaction effluent produced is preferably carried out by distillation, in which first low boilers, such as hydrocyanic acid, are first separated in the first step and water is removed in the second distillation step. The remaining aminonitrile mixture can still preferably have a residual water content of at least 10% by weight. In WO 2008/104579, in the examples, the residence time for the reaction between EDA and FACH is disclosed in the range of 30 minutes to 2 hours.

  Within the scope of the present invention, it has been found that in particular EDDN or EDMN aqueous solutions are thermally unstable. EDDN and EDMN can form degradation products. Said degradation products can reduce the yield of EDDN or EDMN and can lead to reduced processing quality in subsequent reactions, for example in subsequent hydrogenation to TETA and / or DETA, especially discoloration May increase.

  The object of the present invention is to provide a process for the production of EDDN and / or EDMN, which enables the production of said EDDN and / or EDMN on a large industrial scale with high yield, conversion and selectivity. Was to do. The proportion of unwanted by-products, in particular EDDN and / or EDMN degradation products, should be reduced with respect to the prior art. In addition, EDDN or EDMN should be provided that in a subsequent reaction, for example in hydrogenation to TETA or DETA, results in a lesser degree of product discoloration and allows a longer life of the hydrogenation catalyst. is there.

  The subject is a method of reacting formaldehyde cyanohydrin (FACH) and ethylenediamine (EDA) at a temperature in the range of 20 to 120 ° C. in a reactor in which backmixing is restricted, The problem has been solved by a method characterized in that the residence time is 300 seconds or less.

  EDDN and / or EDMN are produced by the reaction of FACH and EDA.

EDA
EDA can be produced by a reaction of ethylene dichloride (EDC) and ammonia in an aqueous phase according to the EDC (ethylene dichloride) method. Details of the method are given, for example, in Ullmann (item "Amines, aliphatic", Ullmann's Encyclopedia of Industrial Chemistry, Karsten Eller, Erhard Henkes, Roland Rossbacher and Hartmut Hoeke, Published Online: 15 JUN 2000, DOI: 10.1002 / 14356007.a02_001, page 33).

  Another approach for the production of EDA is in the catalytic reaction of monoethanolamine (MEOA) with ammonia (item "Amines, aliphatic", Ullmann's Encyclopedia of Industrial Chemistry, Karsten Eller, Erhard Henkes, Roland Rossbacher and Hartmut Hoeke, Published Online: 15 JUN 2000, DOI: 10.1002 / 14356007.a02_001, page 33 or Hans-Juergen Arpe, Industrielle Organische Chemie, 6. edition (2007), Wiley VCH, 2007).

  EDA can also be obtained by hydrogenation of aminoacetonitrile (AAN). In that case, AAN can be manufactured by reaction of hydrocyanic acid, formaldehyde (FA), and ammonia. Hydrogenation of AAN to EDA is described, for example, in WO 2008/104583.

  Preferably, EDA is used in its free base form, although salts such as dihydrochloride of EDA can optionally be used as starting material. The purity of EDA used in the method is preferably 95% by mass or more, particularly preferably 98% by mass or more, particularly preferably 99% by mass or more, and particularly preferably 99.5% by mass or more. It is.

FACH Production FACH production is described, for example, in Ullmann (item "Formaldehyde", Ullmann's Encyclopedia of Industrial Chemistry, Guenther Reuss, Walter Disteldorf, Armin Otto Gamer and Albrecht Hilt, Published Online: 15 JUN 2000, DOI: 10.1002 / 14356007.a11_619, p.28). Said method can be carried out, for example, by reaction of formaldehyde with aqueous hydrocyanic acid. Formaldehyde and hydrocyanic acid are also commonly commercially available chemicals, as described above. Preferably, formaldehyde is used as a 30-50% aqueous solution as described above. As mentioned above, hydrocyanic acid can be used in the form of a gas or an aqueous solution. A preferred variant for the production of FACH is described in WO 2008/104579. According to it, the production of FACH can be carried out by the reaction of aqueous formaldehyde and hydrocyanic acid. Preferably, formaldehyde is present as a 30-50% aqueous solution and hydrocyanic acid is preferably used in 90-100% purity. These reactions are preferably carried out at a pH value of 5.5, which is preferably adjusted with caustic soda or ammonia. The reaction can be carried out at a temperature of 20 to 70 ° C., for example in a loop reactor and / or a tubular reactor. Instead of purified hydrocyanic acid (HCN), the HCN crude gas can be chemisorbed into FACH in an aqueous formaldehyde solution under the conditions described above. The HCN crude gas is preferably produced by pyrolysis of formamide and contains, in addition to water, a particularly small content of ammonia. Optionally, the resulting aqueous FACH solution can be concentrated by gentle vacuum evaporation, for example using a falling film evaporator or a thin film evaporator. Preferably, concentration to 50-80 mass% FACH aqueous solution is performed. Before concentration, the stabilization of the FACH solution is carried out by reducing the pH value to below 4 and preferably below 3, for example by adding acid, for example by adding phosphoric acid or preferably by adding sulfuric acid. Is preferred. Preferably, in the process according to option a), 50 to 80% by weight of an aqueous solution of FACH is used.

FA
Formaldehyde is used as a starting material for the production of FACH. Formaldehyde is a commercially available chemical. Preferably, formaldehyde is used as a 30-50% aqueous solution.

HCN
In addition, hydrocyanic acid is used for the production of FACH. Cyanic acid is likewise a commercially available chemical. Cyanic acid can be produced industrially according to essentially three different methods. According to the first method, hydrocyanic acid can be obtained by ammoxidation of methane with oxygen and ammonia (Andersov method). According to the second method, hydrocyanic acid can be obtained from methane and ammonia by Ammodehydrierung in the absence of oxygen. Finally, hydrocyanic acid can be produced industrially by dehydration of formamide. The hydrogen cyanide produced according to these methods, in general, acidic stabilizer, for example SO _2, sulfuric acid, phosphoric acid or organic acids such as acetic acid is added, thus autocatalytic polymerization of hydrogen cyanide can lead to blockages in the conduit Is avoided.

  Cyanic acid is liquid or gaseous and can be used in pure form or as an aqueous solution. Preferably, the hydrocyanic acid is used as an aqueous solution of 50 to 95% by weight, particularly preferably 75 to 90% by weight. Cyanic acid is preferably used in a purity of 90% by mass or more. Preferably, HCN without stabilizers is used. When stabilized HCN is used, it is preferred that the stabilizer is an organic acid, especially acetic acid. In a preferred embodiment, the EDDN production is carried out essentially free of cyano salts, such as KCN.

The reaction of water EDA and FACH is preferably carried out in the presence of water. In the reaction of EDA and FACH, one mole of water is generally produced per mole of formaldehyde used. However, it can supply additional water. For example, the starting material is charged in the form of an aqueous solution. In particular, as mentioned above, generally FA and / or HCN are used as an aqueous solution for the production of FACH. The amount of water is generally in the range from 1 to 50 mol, preferably in the range from 2 to 40 mol, particularly preferably in the range from 3 to 30 mol, per mol EDA used.

  If the reaction of EDA and FACH is carried out in an adiabatic reactor, i.e. a reactor that is essentially not cooled and the reaction temperature is increased by the heat of reaction released, before EDA is introduced into the adiabatic reactor. And mixing with water before mixing with another starting material, such as FACH. This is because, when mixing EDA and water, the temperature of the aqueous EDA stream is generally increased by the exothermic reaction of the hydrate that forms. By venting the heat of hydration of EDA before entering the EDA into the reactor, the temperature rise in the adiabatic reactor can be reduced.

  As a device for mixing EDA and water, a static mixer, an empty pipe with turbulent flow, a pump or a heat exchanger is suitable. For the discharge of heat of hydration, water and EDA are preferably mixed in a water to EDA molar ratio of 1: 1 to 6: 1.

Organic solvent The reaction of EDA and FACH is preferably carried out in an organic solvent. The organic solvent is preferably a solvent selected from the group consisting of aliphatic, alicyclic, araliphatic, aromatic hydrocarbons, alcohols and ethers. It is particularly preferred that the organic solvent is stable under the conditions of the subsequent EDDN and / or EDMN hydrogenation. Furthermore, it is preferred that the organic solvent can be condensed in the range of 20-50 ° C. at a pressure in the range of 50-500 mbar, thus allowing normal cooling water to be used for condensation in subsequent EDDN or EDMN subsequent processing. Furthermore, the organic solvent is preferably sufficiently low boiling so that a bottom temperature of less than 100 ° C. can be adjusted during the post-treatment of the reaction effluent during subsequent water separation. Preferred organic solvents are, for example, cyclohexane, methylcyclohexane, toluene, N-methylmorpholine, o-xylene, m-xylene or p-xylene, anisole, n-pentane, n-hexane, n-heptane, n-octane, n- Nonane, diisobutyl ether, light benzine, benzine, benzene, diglyme, tetrahydrofuran, 2- and 3-methyltetrahydrofuran (MeTHF) and cyclohexanol or a mixture of the above compounds. Particularly preferred solvents are cyclohexane, methylcyclohexane, toluene, N-methylmorpholine, o-xylene, m-xylene or p-xylene, anisole, n-pentane, n-hexane, n-heptane, n-octane, n-nonane. , Diisobutyl ether, light benzine, benzine (benzene), diglyme and MeTHF or a mixture of said compounds. The amount of the organic solvent is generally 0.1 to 50 kg, preferably 1 to 30 kg, particularly preferably 3 to 25 kg per kg of EDA used.

  In a particularly preferred variant, an organic solvent having a boiling point between water and EDDN or EDMN is used in the reaction of EDA and FACH, in particular under the conditions of distillative water reduction described below. The As described below, organic solvents having boiling points in this range allow for particularly efficient water separation from the reaction effluent obtained during the reaction of FACH and EDA. Particularly preferred solvents having a boiling point between water and EDDN or EDMN are toluene, N-methylmorpholine, o-xylene, m-xylene or p-xylene, anisole, n-octane, n-nonane, diisobutyl ether and diglyme. Or a mixture thereof.

  Some of the organic solvents described above can form low boiling azeotropes with water. A low-boiling azeotrope corresponds to a substance mixture having a maximum vapor pressure in the p and x diagrams. The boiling point of the mixture has a minimum in the T, x diagram and is below the minimum of the relevant pure substance. Particularly preferred organic solvents having a boiling point between water and EDDN or EDMN and forming a low-boiling azeotrope with water are toluene, N-methylmorpholine, o-xylene, m-xylene or p-xylene. , Anisole, n-octane, n-nonane, diisobutyl ether and diglyme or mixtures thereof. When an organic solvent having a boiling point between water and EDDN and / or EDMN forms a low-boiling azeotrope with water, the organic solvent further has a miscibility gap or is hardly soluble in water. It is even more preferred to have, especially under the conditions of the post-treatment steps described below. This facilitates subsequent separation of water and organic solvent. Preferably, the solubility of such organic solvents is 1% by weight or less, particularly preferably 0.5% by weight or less, particularly preferably 0.1% by weight or less. In particular, toluene is preferred as such an organic solvent.

  In a further preferred embodiment, in the reaction of FACH with EDA, an azeotrope having a boiling point below that of water and having a boiling point below that of water is used, in particular for the distillative water separation described below. Organic solvents that form under conditions are used. Particularly preferred solvents having a boiling point below that of water and forming a low boiling azeotrope with water are n-pentane, n-hexane, n-heptane, tetrahydrofuran, cyclohexane, methylcyclohexane, light benzine, benzine. (Benzene) or a mixture thereof. Such solvents have a boiling point of preferably at least 50 ° C., particularly preferably at least 60 ° C. under standard conditions in order to achieve high condensation temperatures, thus avoiding the use of Sole in the condenser can do. Solvents used having a boiling point below that of water and forming a low-boiling azeotrope with water are low in water under conditions that occur during the reaction of FACH and EDA, or in subsequent work-up. More preferably, it has a solubility or miscibility gap with water. This facilitates subsequent separation of water and organic solvent. Preferably, the solubility of such organic solvents in water is 1% by weight or less, particularly preferably 0.5% by weight or less, particularly preferably 0.1% by weight or less.

  In a particularly preferred embodiment, the reaction of EDA and FACH to EDDN and / or EDMN is carried out in the presence of toluene as solvent and EDDN and / or EDMN to TETA and / or DETA. Subsequent hydrogenation of is carried out in the presence of THF. As will be described below, this makes it possible to prepare a particularly more effective solvent composite, which allows the return of organic solvents to the process. Furthermore, it has been confirmed that the presence of THF during the subsequent hydrogenation can reduce the tendency of the suspension catalyst used to aggregate, especially when the hydrogenation is carried out in suspension mode. Accordingly, one particularly preferred embodiment of the present invention is a process for producing TETA and / or DETA in the presence of a catalyst by hydrogenation of EDDN and / or EDMN with hydrogen, said EDDN and / or EDMN is produced from FACH and EDA in the presence of toluene as solvent and the hydrogenation is carried out in suspension in the presence of THF. THF is fed after the production of EDDN and / or EDMN, and after the production of EDDN and / or EDMN, treatment of EDDN or EDMN with an adsorbent, preferably a solid acidic adsorbent, in the presence of THF. It is particularly preferred to do this.

Reaction of FACH and EDA (general matters)
The reaction method of EDA and FACH in the presence of water is described, for example, in WO 2008/104579, the contents of which are disclosed by reference.

  According to the present invention, the reaction of FACH and EDA is carried out in a reactor with limited backmixing at 20 to 120 ° C. and a short residence time.

  Accordingly, the present invention provides a process for the reaction of formaldehyde cyanohydrin (FACH) and ethylenediamine (EDA) at a temperature in the range of 20-120 ° C. in a reactor with limited backmixing, said reactor It is related with the said method characterized by the residence time in being 300 seconds or less.

として定義され、その際、前記反応器容量は、反応器の入口から反応器の出口までを含む。本発明の範囲においては、反応器入口は、ＦＡＣＨとＥＤＡが接触される混加位置に相当する。本発明の範囲においては、反応器出口は、反応混合物の温度が冷却によって低減される位置に相当する。反応器出口での反応混合物の冷却は、以下に記載されるように、好ましくは、
− 熱交換器による熱の排出か、
− 有機溶剤の供給か、または
− 放圧蒸発か、
のいずれかによって行うことができる。第一の事例では、反応器出口は、反応混合物が冷却のために熱交換器に入る位置に相当する。第二の事例では、反応器出口は、反応器の出口にある最後の混加位置であって、更なる有機溶剤が冷却のために供給される位置に相当する。第三の事例では、反応器出口は、反応混合物が以下に記載されるように部分的に蒸発される放圧弁に相当する。従って、反応器容積は、任意にまた、反応器入口（ＥＤＡとＦＡＣＨが接触される混加位置）と反応器出口（例えば放圧弁、熱交換器への入口または反応器の出口にある最後の混加位置であって、有機溶剤が冷却のために供給される位置）との間にある配管あるいは反応器への供給導管の一部も含む。殊に好ましい実施形態においては、ＦＡＣＨ含有の流れと水性のＥＤＡの流れは、反応器の入口で混合される。前記混合は、スタティックミキサー、好適な内部取付物、例えば充填体、特にラシヒリングまたは混加位置と混加位置の後方での乱流の生成によって行うことができる。例えば、乱流は、出発物質の一方をもう一方の出発物質中に噴入あるいは注入することによって起こすことができる。特に好ましくは、ＥＤＡとＦＡＣＨとの反応は、殊に好ましい実施形態においては、断熱条件下で行われる。すなわち、反応温度は、放出される反応熱によって高められる。本発明によれば、反応温度は１２０℃を超過しないことが必要である。それというのも、本発明の範囲において、前記温度を上回ると、目的生成物であるＥＤＤＮあるいはＥＤＭＮの高められた分解が観察されるからである。反応器中の温度上昇を、２０〜１２０℃の範囲の温度に制限するために、複数の技術的措置を行うことができる、好ましくは
− 出発物質および任意に有機溶剤および任意に水を、反応器への導入の前に、１０〜５０℃の範囲の、好ましくは２０〜４０℃の範囲の、特に好ましくは２５〜３５℃の範囲の温度に冷却することができる；
− 反応器または反応器の一部が冷却装置を備えていてよい；または
− 反応混合物に有機溶剤を供給してよい。また、上述の措置の１つ以上を組み合わせて行うこともできる。 According to the present invention, the reaction of FACH and EDA is carried out in a reactor with limited backmixing. Examples for reactors with limited backmixing are tubular reactors and stirred tank cascades. Particularly preferably, the reaction of FACH and EDA takes place in a tubular reactor (“plug flow reactor”). The ratio of the height of the tubular reactor to the diameter is preferably 1: 1 to 500: 1, particularly preferably 2: 1 to 100: 1, particularly preferably 5: 1 to 50: 1. The tubular reactor includes an internal fitting that resists backmixing. The internal attachment may be a sphere, a blind, a sieve tray or a static mixer, for example. Particularly preferably, an empty tube is used as the tubular reactor. The arrangement of the reactor is not critical. The reactor may be vertical or horizontal, or configured as a spiral or loop. According to the invention, the residence time in the reactor during the reaction of FACH and EDA is 300 seconds or less, preferably 200 seconds or less, particularly preferably 100 seconds or less, particularly advantageous in the required temperature range. For 60 seconds or less. The residence time is preferably in the range from 1 to 300 seconds, particularly preferably in the range from 5 to 200 seconds, particularly preferably in the range from 10 to 100 seconds, particularly preferably from 15 to 60 seconds. It is a range. Within the scope of the present invention, the residence time τ is the quotient from the reactor volume V _R and the outflow volumetric flow rate.

Where the reactor volume includes from the inlet of the reactor to the outlet of the reactor. In the scope of the present invention, the reactor inlet corresponds to the mixing position where FACH and EDA are contacted. Within the scope of the present invention, the reactor outlet corresponds to the position where the temperature of the reaction mixture is reduced by cooling. Cooling of the reaction mixture at the reactor outlet is preferably as described below:
-Heat exhaustion by heat exchangers,
-Supply of organic solvents, or-evaporation under pressure,
Can be done by either. In the first case, the reactor outlet corresponds to the position where the reaction mixture enters the heat exchanger for cooling. In the second case, the reactor outlet corresponds to the last mixing position at the reactor outlet, where additional organic solvent is supplied for cooling. In the third case, the reactor outlet corresponds to a pressure relief valve in which the reaction mixture is partially evaporated as described below. Thus, the reactor volume may optionally also be the last at the reactor inlet (mixing position where EDA and FACH are contacted) and reactor outlet (eg, pressure relief valve, inlet to heat exchanger or reactor outlet). A part of the supply pipe to the reactor or the reactor between the mixing position and the position where the organic solvent is supplied for cooling is also included. In a particularly preferred embodiment, the FACH-containing stream and the aqueous EDA stream are mixed at the reactor inlet. Said mixing can be effected by static mixers, suitable internal fittings, such as fillers, in particular Raschig rings or generation of turbulence behind the mixing position and the mixing position. For example, turbulence can be caused by injecting or injecting one of the starting materials into the other starting material. Particularly preferably, the reaction between EDA and FACH is carried out under adiabatic conditions in a particularly preferred embodiment. That is, the reaction temperature is increased by the released reaction heat. According to the invention, the reaction temperature should not exceed 120 ° C. This is because, within the scope of the present invention, when the temperature is exceeded, enhanced decomposition of the target product EDDN or EDMN is observed. In order to limit the temperature rise in the reactor to a temperature in the range of 20-120 ° C., several technical measures can be taken, preferably: the reaction of starting materials and optionally organic solvents and optionally water Before introduction into the vessel, it can be cooled to a temperature in the range of 10-50 ° C, preferably in the range of 20-40 ° C, particularly preferably in the range of 25-35 ° C;
The reactor or part of the reactor may be equipped with a cooling device; or the organic solvent may be fed to the reaction mixture. Also, one or more of the above measures can be combined.

  The starting material and optionally the organic solvent and water can be introduced into the reactor at a temperature in the range of 10-50 ° C., preferably in the range of 15-40 ° C., particularly preferably in the range of 20-35 ° C. . If the temperature of the starting material should be above the preferred range, the starting material is cooled by a suitable cooling device, for example by a heat exchanger, in particular a plate-type, tube-bundle-type or double-jacket-type heat exchanger. be able to.

  Instead of or in addition to the reactor or part of the reactor, a cooling device may be provided. For example, the reactor may have jacket cooling. There may be an element in the reactor that can dissipate heat, such as an internal heat exchanger. It is also conceivable to pass a part of the reactor contents into a loop in which a heat exchanger is present. However, additional cooling devices generally mean higher equipment and structural effort and costs, which are also suitable for maintaining the temperature in the reactor within the range according to the invention.

  In a further embodiment, the reaction mixture can be cooled by supplying additional organic solvent before or during the reaction. However, the total amount of organic solvent should preferably not exceed 50 kg / kg EDA, preferably not exceed 30 kg / kg EDA, particularly preferably not exceed 25 kg. Preferably, the organic solvent is cooled in the reactor at a temperature in the range from 10 to 50 ° C., preferably at a temperature in the range from 15 to 40 ° C., particularly preferably at a temperature in the range from 20 to 35 ° C. To be introduced.

  By taking the above measures, in particular by adding an organic solvent, the outlet temperature is maintained in the range of 50-120 ° C., preferably in the range of 60-110 ° C., particularly preferably in the range of 70-100 ° C. can do. It is particularly preferable to perform the cooling by adding an organic solvent or by cooling the tubular reactor with a cooling jacket.

  The reaction mixture is additionally cooled at the outlet of the reactor as described. The reaction mixture can be cooled, for example, either by means of a suitable cooling device, by supply of further organic solvents, or by pressureless evaporation. Cooling of the reaction mixture at the outlet of the reactor is described in more detail below.

  Depending on the selection of the corresponding process parameters (for example starting materials, temperature, solvent or pressure), the method varies in the proportion of EDMN in the reaction product and the EDMN is not only as a by-product. It can also be controlled to occur as a second main reaction product.

  Preferably, the ratio of EDDN to EDMN can be influenced by the molar ratio of starting materials as described above in the reaction of FACH and EDA.

  In general, the molar ratio of EDA to FACH is in the range of 1: 1 to 1: 2 [mol / mol] in the reaction of EDA and FACH. Preferably, the molar ratio of EDA to FACH is about 1: 1.8 to 1: 2 [mol / mol], especially about 1: 2 [mol / mol].

  If the EDDN proportion in the reaction mixture is to be increased, the molar ratio of EDA to FACH is preferably 1: 1.5 to 1: 2, particularly preferably 1: 1.8 to 1: 2. A high EDDN proportion in the reaction mixture is preferred when EDDN is to be hydrogenated to TETA in subsequent reactions. If the proportion of EDMN in the reaction mixture is to be increased, the molar ratio of EDA to FACH is preferably 1: 1 to 1: 1.5, particularly preferably 1: 1 to 1: 1.3. A higher EDMN proportion in the reaction mixture is preferred when EDMN is to be hydrogenated to DETA in subsequent reactions.

  Particularly preferably, the reaction is carried out in the presence of one of the organic solvents mentioned above, in particular in the presence of the organic solvents mentioned as being preferred and particularly preferred. As described above, the amount of the solvent used is 0.1 to 50 kg, preferably 1 to 30 kg, particularly preferably 3 to 25 kg per kg of EDA used. Toluene is regarded as a particularly preferred organic solvent, which allows a technically simple and efficient method in the subsequent separation of water.

  The FACH is mixed into the FACH-containing stream, preferably together with an organic solvent and one of the above-mentioned organic solvents, in particular toluene, in which case the new organic solvent or the organic solvent recovered from the subsequent work-up is collected. Either can be used.

  If the EDA is carried out in a reactor operated adiabatically as described above, as described above, the EDA is preferably preferably combined with water into an aqueous EDA stream before being introduced into the reactor. It is mixed. Thus, the heat of hydration that occurs during the mixing of water and EDA can already be discharged before the reactor.

  In a particularly preferred embodiment, in order to reach the limit of the adiabatic temperature rise, the reaction is increased in a reactor operated adiabatically, i.e. essentially not cooled and the reaction temperature is increased by the released reaction heat. When carried out in a reactor, the reaction mixture is fed with an organic solvent prior to introduction into the reactor. The organic solvent used can contribute to the restriction of temperature rise by absorbing heat of reaction according to the heat capacity of the organic solvent and contributing to lower temperature rise. In general, the temperature rise can be more strongly limited as the amount of solvent supplied is increased. Preferably the organic solvent is cooled or added at ambient temperature. Thereby, heat can be absorbed. Preferably, the organic solvent is introduced into the reactor at a temperature in the range of 10-50 ° C., preferably at a temperature in the range of 15-45 ° C., particularly preferably at a temperature in the range of 20-40 ° C. The use of an organic solvent can also promote cooling of the reaction mixture after leaving the reactor, as described below, for example, allowing the solvent-containing reaction mixture to be depressurized and evaporating at least a portion of the organic solvent. Can be promoted by. Additional heat can be removed from the reaction mixture by additional evaporation of the organic solvent.

  Preferably, the reaction mixture is cooled at or after the outlet of the reactor, especially when the reaction is carried out in an adiabatically operated reactor. Cooling of the reaction mixture can be carried out as described above and as described in more detail below.

Reaction effluent The reaction effluent generally comprises a mixture of EDDN and EDMN.

  The ratio of EDDN to EDMN is as described above and can be influenced by the ratio of commonly used starting materials.

  The mass ratio of EDDN to EDMN is generally 30:70 to 95: 5, preferably 50:50 to 95: 5, particularly preferably 75:25 to 90:10.

  The reaction effluent may optionally contain an organic solvent. Preferably, the reaction effluent contains one of the organic solvents mentioned above or as preferred and particularly preferred. In particular, the reaction effluent contains toluene.

  Particularly preferably, the reaction effluent contains 5-30% by weight, particularly preferably 10-20% by weight, particularly preferably 12-18% by weight, of toluene, based on the reaction effluent. Particularly preferably, the reaction effluent contains essentially no further organic solvent in addition to toluene.

  The reaction effluent generally contains water produced as reaction water during the reaction of FACH and EDA, or water supplied together with the starting material or separately.

  The reaction effluent generated in the production of EDDN or EDMN can be further worked up by methods known to those skilled in the art. It relates, for example, to the separation of reaction products from unreacted starting materials as well as optionally present solvents.

Cooling the effluent from the reaction of EDA and FACH In one particularly preferred embodiment, the reaction mixture from the reaction of EDA and FACH is cooled after leaving the reactor and prior to work-up. Accordingly, a particularly preferred embodiment is a process for the preparation of EDDN and / or EDMN by reaction of FACH and EDA, wherein the reaction is carried out in the presence of water, the reaction from the reaction of EDA and FACH. The process is characterized in that the mixture is cooled after leaving the reactor.

  Cooling of the reaction mixture from the reaction of FACH and EDA is particularly preferred when the final step of the reaction is carried out in a reactor operated adiabatically, in particular a tubular reactor. Furthermore, the temperature after cooling is preferably in the range of 20 to 70 ° C., particularly preferably in the range of 20 to 60 ° C., particularly preferably in the range of 30 to 50 ° C. By rapidly cooling to the above-mentioned temperature range, it is possible to further reduce unwanted by-products such as nitrile degradation products. The reaction mixture can be cooled by means of a suitable cooling device, for example by means of a heat exchanger, in particular a plate heat exchanger, a tube bundle heat exchanger or a double jacket heat exchanger. It is also possible to supply further organic solvents for cooling. However, as described above, the total amount of the organic solvent is preferably not more than 50 kg per kg EDA, preferably not more than 30 kg per kg EDA, and particularly preferably not more than 25 kg. Preferably, the organic solvent is cooled in the reactor at a temperature in the range from 10 to 50 ° C., preferably at a temperature in the range from 15 to 40 ° C., particularly preferably at a temperature in the range from 20 to 35 ° C. To be introduced.

Said cooling is particularly preferably effected by pressureless evaporation. For this purpose, usually the reaction mixture from the EDDN production or EDMN production is released via a valve at the outlet of the last reactor where the EDDN production or EDMN production takes place into a vessel with reduced pressure. Is done. The reduced pressure preferably converts the starting material such as EDDN or EDMN and water by changing some of the water used and some of the components having lower boiling points than EDDN or EDMN in the reaction effluent to the gas phase. And optionally adjusting the organic solvent in a liquid phase. By pressure evaporation, some of the water from the reaction mixture is gently removed. By extracting the heat of vaporization, the liquid phase containing EDDN or EDMN is cooled. The contained EDDN or EDMN is generally stabilized by two effects, cooling and lowering the water concentration. Side reactions are generally reduced thereby. Preferably 10 to 80% by weight, particularly preferably 20 to 70% by weight, particularly preferably 30 to 60% by weight, of the water present in the reaction mixture is evaporated during the pressure-release and is evaporated into the gas phase. be changed. Preferably, the reduced pressure is 1000 mbar or less, particularly preferably 300 mbar or less, particularly preferably 200 mbar or less. In a preferred embodiment, the reduced pressure is 10 to 1000 mbar, preferably 50 to 300 mbar, particularly preferably 100 to 200 mbar. The proportion of components present in gaseous form after the pressure-release evaporation is preferably partially condensed in the cooler, wherein the condensation is preferably essentially complete with water and optionally used solvent. To be condensed. Lower boiling components, the components such as ammonia, HCN, such as methanol or CO _2, preferably not condensed, can be supplied either be removed in gaseous form, or in combustion.

  The workup of the condensed phase can depend on whether the reaction of EDA and FACH was carried out in the presence of an organic solvent and which organic solvent was used. If no organic solvent is used in the production of EDDN or EDMN, the aqueous condensate can be fed to the column K2 described below, where the low boilers and water are separated. It is also possible to supply the water for waste treatment, for example for waste water treatment.

  If an organic solvent is used that is miscible with water or does not have a miscibility gap with water, the organic solvent and water are generally distilled from the condensed mixture to form an aqueous stream and a solvent. The solvent-containing stream is preferably returned to the process or introduced into the column K1 described below. Said aqueous stream can generally be introduced into water treatment.

  In a preferred embodiment, when an organic solvent is used that has a miscibility gap with water or is essentially insoluble in water, the condensed mixture is preferably fed to the phase separator. Thus, the condensed phase can be separated into a phase containing an organic solvent and an aqueous phase. By using an organic solvent that has a miscibility gap with water or is essentially insoluble in water, the separation of the organic solvent and water can generally be carried out without additional distillation. In addition, the separated water can then be introduced generally directly into the purifier after phase separation, or it can be returned to the process, for example to return for mixing EDA and water. In this respect, organic solvents with very little (preferably less than 5000 ppm) amount of solvent dissolved in the aqueous phase are particularly preferred. Examples for this are toluene, cyclohexane, methylcyclohexane, octane, heptane and xylene. The aqueous phase obtained after phase separation may be introduced into the distillation apparatus K2, where water is separated from the lower boiling organic solvent as the bottom product. The water thus separated can be returned to the process, for example as a solvent (for example for the production of an aqueous EDA solution) or fed to a purification device or biological wastewater treatment. Organic low boilers separated via the top during distillation in column K2 (eg organic solvents having a boiling point lower than water or solvents forming an azeotropic mixture with water, HCN or toluene) are preferably process To be sent back to. For example, the organic low boilers can be supplied to a condenser that is connected after the pressure evaporation. The organic phase obtained after phase separation is preferably introduced into the column K1 described below or returned to the process as an organic solvent.

  Reaction effluents containing EDDN or EDMN, which are present in the liquid phase after pressure-evaporation into a vessel with reduced pressure, preferably have water as described below. EDDN or EDMN is fed to the distillation column K1, which is reduced. EDDN production or EDMN production when an EDDN production or EDMN production uses an organic solvent that has a miscibility gap with water under the conditions of EDDN production or EDMN production, or has only a slight solubility in water. In the container in which the discharge from the vessel is released, usually two liquid phases are formed, namely an aqueous phase of EDDN or EDMN and a phase containing an organic solvent. Preferably, the two phases are separated as described below or fed together to column K1. Furthermore, when the column K1 contains a packing, it is preferable to lead the two liquid phases separately from each other into separate liquid distributors.

  After cooling, the reaction effluent produced in the production of EDDN or EDMN is further worked up by methods known to those skilled in the art. It relates, for example, to the separation of reaction products from unreacted starting materials as well as optionally present solvents.

Post-treatment of reaction effluent from EDDN production or EDMN production As mentioned above, the reaction effluent produced in the production of EDDN or EDMN is further post-treated by methods known to those skilled in the art. It relates, for example, to the separation of reaction products from unreacted starting materials as well as optionally present solvents.

  Preferably, the reaction effluent from EDDN production or EDMN production is worked up, where i) low boilers are first separated, followed by ii) water reduction.

Reduction of low boilers Reduction of low boilers is preferably done by stripping. Here, for example, reaction effluents from EDDN production or EDMN production can be stripped with nitrogen, thus removing traces of hydrocyanic acid, which can be produced, for example, as FACH decomposition products. However, low boilers can also be separated by distillation. When the low-boiling substances are separated by distillation, it is preferable to keep the residence time during the distillation short. For example, the distillation is carried out in a falling film evaporator or a wipe film evaporator (Wischfilmverdampfer). Is done. Preferably, the low boilers are separated by pressure evaporation as described above. Said release pressure evaporation has the advantage that the low boilers can be separated and the reaction effluent cooled in one process step.

Reduction of water The reduction of water after the reduction of low boilers is preferably carried out in the distillation column K1.

  The column is generally operated so that an aqueous stream is removed at the top of the column while a stream containing EDDN or EDMM is removed at the bottom of the column.

  The effluent from the EDDN production or EDMN production is preferably fed in the upper region of the distillation column K1, preferably at the top, together with a destillations mittel (see definition below). When effluent from EDDN production or EDMN production is cooled by pressure evaporation, and EDDN production or EDMN production has a miscibility gap with water under the conditions of the EDDN production or EDMN production, or in water When an organic solvent with only a slight solubility is used, as described above, two liquid phases are formed in the container in which the effluent from the EDDN production or EDMN production is released. In this case, it is preferable that the formed aqueous phase of EDDN or EDMN and the organic solvent as the distilling agent are supplied separately to the column K1. Furthermore, when the column K1 contains a packing, it is preferable to lead the two liquid phases to separate liquid distributors. At that time, it is preferable to return the organic solvent as a distilling agent to the recovery section of the column, preferably to the lower region of the column, particularly preferably to the bottom of the column. It has the advantage that HCN contained in the returned organic solvent can react with EDMN to become EDDN. Thereby, the amount of HCN discharged can be reduced.

  Preferably, the distillation column K1 has an internal attachment for improving the separation performance. Said internal attachment for distillation may be present, for example, as a regular packing, for example as a plate-shaped packing, such as Mellapak 250 Y or Montz Pak, Typ B1-250. There may also be a filler with a lower or higher specific surface area, or a filler with a woven or other shape, such as Mellapak 252 Y can be used. In the use of the distillation inner attachment, for example, a low pressure drop and a low liquid hold-up rate are preferred compared to a valve tray. The internal fixture may be present on one or more floors. The number of theoretical plates is generally in the range of 3-25, preferably 5-15. The top pressure in the column K1 is preferably adjusted so that the bottom temperature is in the range given below. The bottom temperature is preferably 100 ° C. or lower. This is because, within the scope of the present invention, it has been found that EDMN or EDDN is unstable at higher temperatures in the presence of water and decomposes into unwanted by-products. Preferably, the bottom temperature is adjusted to a range below 100 ° C., particularly preferably below 80 ° C., particularly preferably below 60 ° C. The bottom temperature is particularly preferably in the range from 20 to 100 ° C., particularly preferably in the range from 30 to 80 ° C., particularly preferably in the range from 40 to 60 ° C. The top pressure is preferably from 10 mbar to 1 bar, particularly preferably from 30 mbar to 700 mbar, particularly preferably from 50 to 500 mbar. In one particular embodiment, the top pressure in the column K1 is less than 300 mbar, particularly preferably 100 to 200 mbar, particularly preferably 130 to 180 mbar. Within the scope of the present invention, it has been determined that the temperature adjusted in the column at the top pressure can essentially reduce the formation of deposits in the column internals, particularly the column packing.

  In a particularly preferred embodiment, the distillation is an organic solvent having a boiling point between water and EDDN and / or EDMN at the distillation pressure occupying the column or forming a low-boiling azeotrope with water. Carried out in the presence of

  Thus, the preferred embodiment is a process for producing EDDN and / or EDMN by reaction of FACH and EDA, wherein the reaction is carried out in the presence of water and after the reaction water is distilled from the reaction mixture to the distillation column. Wherein the distillation is carried out with an organic solvent having a boiling point between water and EDDN and / or EDMN at the distillation pressure occupying the column or forming an azeotrope with water and a low boiling point. It is carried out in the presence of the method.

  Organic solvents that have a boiling point between water and EDDN and / or EDMN at the distillation pressure occupying the column or that form a low-boiling azeotrope with water are referred to below as distilling agents. Preferred distilling agents are the organic solvents listed at the beginning, which have a boiling point between water and EDDN and / or EDMN, or form a low-boiling azeotrope with water. Particularly preferably, toluene is used as the distilling agent. It is preferred that the distilling agent is already supplied before or during the reaction between FACH and EDA. The amount of the above-mentioned organic solvent is generally 0.1 to 50 kg, preferably 1 to 30 kg, particularly preferably 3 to 25 kg per kg of EDA used. The amount of distilling agent is generally particularly preferably in the bottom of the distillation column K1, as described above, preferably in the range of less than 100 ° C., particularly preferably less than 80 ° C., particularly preferably less than 70 ° C. Is preferably metered to be adjusted to a bottom temperature in the range of less than 60 ° C. Preferably, the bottom temperature is in the range of 20-100 ° C., particularly preferably in the range of 30-80 ° C., particularly preferably in the range of 40-60 ° C. The bottom temperature is preferably 100 ° C. or lower. This is because, within the scope of the present invention, it has been found that EDMN or EDDN is unstable at higher temperatures in the presence of water and decomposes into unwanted by-products. If the distilling agent forms a low boiling azeotrope with water, the amount of distilling agent needs to be that which is “on the side” of the appropriate azeotrope. That is, the amount of distilling agent must be such that a low boiling aqueous azeotrope is produced at the top of the column and essentially no more water is produced at the bottom of the column. The amount of solvent required can routinely be determined by those skilled in the art from the tables and encyclopedias for commonly known azeotropes depending on the distilling agent selected.

  As mentioned above, the top pressure in the column K1 is preferably from 10 mbar to 1 bar, particularly preferably from 30 mbar to 700 mbar, particularly preferably from 50 to 500 mbar. In one particular embodiment, the top pressure in the column K1 is less than 300 mbar, particularly preferably 100 to 200 mbar, particularly preferably 130 to 180 mbar. Within the scope of the present invention, it has been determined that the temperature adjusted in the column at the top pressure can essentially reduce the formation of deposits in the column internals, particularly the column packing.

  The condenser of the distillation column K1 is generally operated at a temperature at which most of the water or water azeotrope is condensed at a corresponding top pressure. Generally, the operating temperature of the condenser is in the range of 20-70 ° C, preferably in the range of 25-50 ° C. In the condenser, a condensate is generally formed which essentially contains water or a low boiling water azeotrope.

  The condensate in column K1 may be discharged or returned to the process. Optionally, the condensate can be separated into water and a distilling agent, for example by distillation, before returning or discharging. For example, the distillation of water can be carried out in the column K2. When the distilling agent has a miscibility gap with water, the separation of water and the distilling agent can also be performed by phase separation. In a preferred embodiment, the exhaust vapor from the top of the column K1 is fed to a condenser where the discharge vapor generated during the pressure evaporation is condensed. That is, the vapor discharged from the column K1 and the vapor from the discharge evaporation are preferably sent to a common condenser.

Reaction effluent from column K1 At the bottom of column K1, preferably a mixture containing EDDN or EDMN as bottom product is withdrawn. The mixture containing EDDN or EDMN preferably contains a distilling agent used in the reduction by distillation of water. When toluene is used as the distilling agent, the mixture containing EDDN or EDMN from the bottom of column K1 is preferably 5 to 30% by weight, particularly preferably 10 to 10%, based on the bottoms discharged. It contains 20% by weight, particularly preferably 12-18% by weight, of toluene.

  In a preferred embodiment, the mixture comprising EDDN or EDMN from the bottom of the column K1 is preferably less than 3% by weight, particularly preferably 1% by weight, relative to the amount greater than 10% by weight described in the prior art. Less than, particularly preferably less than 0.5% by weight, particularly preferably less than 0.3% by weight of water.

  The resulting mixture containing EDDN or EDMN can be hydrogenated directly to DETA or TETA in the subsequent reaction with hydrogen and in the presence of a catalyst.

Treatment with Adsorbent In a further particularly preferred embodiment, the mixture comprising EDDN or EDMN is EDDN or EDMN after hydrogen reduction but prior to hydrogenation of EDDN or EDMN to TETA or DETA. It is purified by treating the containing mixture with an adsorbent.

In a particularly preferred embodiment, the treatment is carried out with a solid acidic adsorbent. Within the scope of the present invention, it has been found that solid acidic adsorbents can be used to extend the life of the hydrogenation catalyst in subsequent hydrogenation to DETA or TETA. Furthermore, it has been found that the formation of by-product aminoethylpiperazine (AEPIP), generally associated with a loss of activity of the catalyst, during the hydrogenation of EDDN or EDMN can be reduced. Thus, said further particularly preferred embodiment is a method for producing EDDN and / or EDMN comprising:
a) reacting FACH with EDA;
In this case, the reaction is performed in the presence of water.
b) reducing water from the reaction mixture obtained in step a);
c) treating the mixture from step b) with an adsorbent in the presence of an organic solvent;
The method according to claim 1, wherein the adsorbent is a solid acidic adsorbent.

Step a)
The reaction method of FACH and EDN in the presence of water (step a)) has been described previously.

Step b)
The reduction of water from the reaction effluent of the production of EDDN or EDMN is likewise described above. Preferably, low reaction products such as HCN or methanol are first separated from the reaction effluent from EDDN production or EDMN production, for example by stripping or pressure evaporation, and EDDN or EDMN containing water is then distilled. Feed and reduce water there. Particularly preferably, the distillation is carried out in the presence of a distilling agent (see above for definition) as described above.

Specifications: Introduction of step c) The EDDN or EDMN from step b) is subtracted from the EDDN mixture by the distilling agent and / or organic solvent contained in the EDDN mixture ("without distilling agent and without solvent"). Preferably 95% by weight or more, particularly preferably 97% by weight or more, particularly preferably 99% by weight or more of EDDN and / or EDMN.

  As mentioned above, the mixture obtained from step b) preferably contains the distilling agent used in the reduction of water. If toluene is used as the distilling agent, the EDDN or EDMN mixture from step b) is preferably from 5 to 30% by weight of toluene, particularly preferably from 10 to 20% by weight of toluene, particularly preferably from 12 to Contains 18% by weight toluene.

  If a distiller that does not have a miscibility gap with EDDN is used, the EDDN or EDMN mixture from step b) is preferably 5 to 50% by weight of EDDN and / or EDMN, particularly preferably 8 to 30% by weight of EDDN and / or EDMN, particularly preferably 10-20% by weight of EDDN and / or EDMN.

  The EDDN or EDMN mixture obtained from step b) preferably contains less than 3% by weight, particularly preferably less than 1% by weight, particularly preferably less than 0.5% by weight, based on EDDN and EDMN. Particularly preferably, it contains less than 0.3% by weight of water.

Step c)
In a particularly preferred embodiment, in step c), the EDDN or EDMN obtained from step b) is treated with a solid acidic adsorbent in the presence of an organic solvent.

  Any organic solvent that can be used for the reaction of EDDN or EDMN is suitable as the solvent. As mentioned above, the organic solvent used is preferably stable under the conditions of EDDN hydrogenation or EDMN hydrogenation. Preferably, the organic solvent is supplied prior to treatment of the EDDN or EDMN mixture from step b) with the adsorbent. Preferably, the organic solvent has a concentration of EDDN and / or EDMN in the mixture to be treated with the adsorbent of 5-50% by weight, particularly preferably 8-30% by weight, particularly preferably 10-20% by weight. Supplied in an amount that is in the range of More preferably, the water content of the organic solvent supplied after EDDN production and / or EDMN production and before or during treatment with the adsorbent of EDDN and / or EDMN has a low water content. This is because small amounts of water during treatment with the adsorbent can reduce the absorption capacity of the adsorbent, and polar impurities that can lead to unwanted side reactions during subsequent EDDN or EDMN hydrogenation. It is because it may bring in. Particularly preferably, the organic solvent supplied is less than 0.5% by weight of water, particularly preferably less than 0.3% by weight of water, particularly preferably less than 0.1% by weight of water, particularly preferably 0%. Contains less than 0.03 wt% water. In a particularly preferred embodiment, THF is supplied as the organic solvent. A particularly good catalyst life can be achieved in the subsequent hydrogenation when THF is used. If the subsequent hydrogenation is carried out in suspension mode, the tendency of the suspension catalyst to agglomerate can be reduced during the hydrogenation by using THF.

Solid acidic adsorbent In the scope of the present invention, a solid acidic adsorbent is a water-insoluble porous material that can bind water or other molecules by physical or chemical forces based on its large surface area. Represents. Acidic adsorbents generally have functional groups that behave as Bronsted or Lewis acids under the conditions of adsorption. In particular, the acidic adsorbent makes it possible to suppress preferred basic substances compared to lower basic substances.

Preferred solid acidic adsorbents are acidic metal oxides such as silicon dioxide, titanium dioxide, aluminum oxide, boron oxide (B ₂ O ₃ ), zirconium dioxide, silicates, aluminosilicates, borosilicates, zeolites (especially H-form), acidic ion exchangers and silica gels, for example Sorbead WS from BASF SE or a mixture of said substances. Particularly preferred solid acidic adsorbents are silicon dioxide and silica gel. Particularly preferred are silica gels which can be prepared, for example, by acidification of aqueous soda water glass solutions and drying of the silica sol obtained first, such as Hollemann-Wiberg (Lehrbuch der Anorganischen Chemie, 102nd edition, Walter der Gruyter publication, 2007). Year, page 962). Examples for particularly preferred silica gels are Sorbead WA from BASF SE and Silikagel KG 60 from Merck KGaA. In a preferred embodiment, the solid acidic adsorbent is silicon dioxide, titanium dioxide, aluminum oxide, boron oxide (B ₂ O ₃ ), zirconium dioxide, silicate, aluminosilicate, borosilicate, zeolite. (Especially H-type), a substance selected from the group consisting of an acidic ion exchanger and silica gel.

  Within the scope of the present invention, the invention specific matter of solid acidic adsorbent does not include activated carbon or non-acidic (basic) ion exchangers.

  The treatment of the EDDN or EDMN mixture obtained in step b) with an organic solvent can be carried out continuously, semi-continuously or intermittently.

  The treatment can be performed intermittently, for example, by bringing an adsorbent and EDDN or EDMN into contact with each other in the presence of an organic solvent. Said treatment can be carried out by suspending the adsorbent in the mixture to be purified, for example by stirring in a suitable container. The treatment time in the intermittent treatment is generally in the range from 1 minute to 48 hours, preferably from 5 minutes to 24 hours, particularly preferably from 1 hour to 16 hours, particularly preferably from 2 to 8 hours. The amount of adsorbent is in the range from 0.1 to 25% by weight, particularly preferably in the range from 0.5 to 20% by weight, particularly preferably from 1 to 10% by weight, based on the total of EDDN, EDMN and organic solvent. Range. The pressure is generally not critical. Preferably, however, the pressure to be purified should be adjusted to the pressure at which the mixture to be purified exists. The pressure is generally from 1 to 10 bar. The treatment is generally carried out at temperatures below 150 ° C., preferably at temperatures below 100 ° C., particularly preferably at temperatures below 80 ° C., particularly preferably at temperatures below 60 ° C. The intermittent treatment with the adsorbent can be carried out under an inert gas atmosphere, for example under nitrogen or argon. After said treatment, the adsorbent can be separated from EDDN or EDMN by suitable methods, for example by filtration, centrifugation or precipitation.

  Preferably, the processing of the mixture to be purified is carried out continuously.

  Particularly preferably, the mixture to be purified is passed to one or more fixed or packed beds of absorbent. The adsorbent may be arranged in the form of a fluidized bed. Said fixed bed or packed bed is preferably arranged in a tube or in a heat exchanger. Said fixed bed or packed bed is generally flowed through by the mixture to be purified. The loading is 0.01 to 20 kg, particularly preferably 0.05 to 15 kg, particularly preferably 0.1 to 10 kg of the mixture to be purified per kg of adsorbent per hour. The fixed bed volume and adsorbent particle size can be varied over a wide range and can be adapted to the chosen reaction conditions and the given circumstances of the process.

  However, the particle size of the solid acidic adsorbent used is preferably from 0.1 to 10 mm, particularly preferably from 0.5 to 6 mm, particularly preferably from 1 to 4 mm. This is because it has been found that particles that are too large exhibit an adverse diffusion effect, and particles that are too small can lead to blockages in the adsorber. Preferably, the particles are spherical.

  In a preferred variant, the adsorbent is present in a fixed bed in a carousel arrangement, in particular with regeneration. That is, since two or more fixed beds flow alternately, it is possible to regenerate a fixed bed that is not used. The pressure is generally not critical. Preferably, however, the pressure to be purified should be adjusted to the pressure at which the mixture to be purified exists. The pressure is generally from 1 to 10 bar. As already mentioned above, the treatment is generally carried out at temperatures below 150 ° C., preferably at temperatures below 100 ° C., particularly preferably at temperatures below 80 ° C., particularly preferably at temperatures below 60 ° C. . The continuous treatment with the adsorbent can be carried out under an inert gas atmosphere, for example under nitrogen or argon. If necessary, after continuous treatment, the adsorbent or part of the adsorbent, such as wear, can be separated from the EDDN or EDMN by suitable methods, for example by filtration, centrifugation or precipitation.

  It may be necessary to regenerate the adsorbent after a predetermined operating period if the action of the adsorbent decreases as the operating period elapses.

  The regeneration of the adsorbent can be carried out by washing with water, preferably by washing with diluted aqueous acid, particularly preferably by first washing with water and subsequently with diluted aqueous acid. Preferably, diluted organic acids, particularly preferably acetic acid, are used for washing. Preferably, the concentration of acid in the diluted aqueous acid is 10% by weight or less. Preferably, the adsorbent is dried after treatment with water and / or aqueous acid by passing a drying gas, such as air or nitrogen. Preferably, the adsorbent and / or gas is heated during drying with the drying gas.

  In a particularly preferred variant, the adsorbent is dried by passing an anhydrous organic solvent. Particular preference is given to using the same organic solvent that is used in the subsequent hydrogenation or already added during the treatment with the adsorbent. Preferably, the anhydrous organic solvent is not more than 1% by weight of water, particularly preferably not more than 0.5% by weight of water, particularly preferably not more than 0.1% by weight of water, particularly preferably 0.05% by weight. Contains up to mass% water. The anhydrous organic solvent can be conducted to the adsorbent in either liquid or vapor form.

  Preferably, the mixture from step c) comprises EDDN and / or EDMN with an organic solvent, a solvent which has been treated with an adsorbent in the presence thereof and optionally a distilling agent added preferably in the reduction of water. Contains together. Optionally, the mixture from step c) may still contain further organic solvents.

  The water content of the mixture from step c) is preferably lower than the water content of the EDDN or EDMN mixture before treatment with the adsorbent. This is because the adsorbent also has a drying effect. Preferably, the water content of the mixture from step c) is preferably not more than 0.1% by weight, particularly preferably not more than 0.03% by weight.

  The EDDN or EDMN mixture obtained from step c) may be further purified, for example, the optionally added organic solvent can be separated from the EDDN or EDMN.

  Preferably, however, the mixture resulting from step c) is fed directly (without further workup) to the hydrogenation.

  The hydrogenation can be performed as described below.

Hydrogenation of EDDN or EDMN to TETA or DETA The hydrogenation of EDDN or EDMN to TETA or DETA is generally carried out by the reaction of EDDN or EDMN and hydrogen in the presence of a catalyst and an organic solvent.

  The production of EDDN or EDMN is preferably carried out according to one of the above options a) to d), in particular according to the preferred embodiments described therein, as described above.

  Furthermore, it is preferred that the reaction mixture from the EDDN production or EDMN production is cooled, preferably by pressure-release evaporation. Furthermore, the reaction mixture from EDDN production or EDMN production is preferably, as described, reduced by low boilers, preferably by pressure evaporation and for the reduction of water, preferably in the presence of a distilling agent. Further purification by distillation at is preferred. Further, it is preferred that the EDDN or EDMN mixture be treated with an adsorbent after water reduction, preferably with a solid acidic adsorbent as described.

  Preferably, the mixture introduced into the hydrogenation contains EDDN and / or EDMN. The proportion of EDDN and / or EDDN in the mixture fed to the hydrogenation is preferably in the range from 5 to 50% by weight, particularly preferably from 8 to 30% by weight, particularly preferably from 10 to 20% by weight. is there.

  Preferably, the mixture introduced into the hydrogenation contains an organic solvent added upon treatment with the adsorbent.

  Furthermore, the mixture introduced into the hydrogenation contains a distilling agent which is preferably used in reducing water by distillation.

Hydrogen TETA or DETA is produced in the presence of hydrogen. Hydrogen is generally used in industrial purity. Hydrogen can also be used in the form of a hydrogen-containing gas, i.e. in the form of a gas with the addition of other inert gases such as nitrogen, helium, neon, argon or carbon dioxide. As the hydrogen-containing gas, for example, reformer exhaust gas, raffinate gas and the like can be used only when these gases do not contain a catalyst poison for the hydrogenation catalyst used, such as CO. Preferably, however, pure hydrogen or essentially pure hydrogen is used in the process, for example hydrogen having a hydrogen content of more than 99% by weight, preferably hydrogen having a hydrogen content of more than 99.9% by weight, in particular Preferably hydrogen having a hydrogen content of more than 99.99% by weight, in particular hydrogen having a hydrogen content of more than 99.999% by weight, is used.

Organic solvent The production of TETA or DETA is preferably carried out in the presence of an organic solvent. The organic solvent is preferably the same solvent that was added during the treatment with the adsorbent. However, it is also possible to add other solvents or to separate the solvent added during the treatment with the adsorbent and add a new solvent. As the organic solvent, any organic solvent that can be used in the production of EDDN or EDMN can be used, and the organic solvents mentioned as being particularly preferable can be used. The mass ratio of organic solvent to EDDN or EDMN during hydrogenation is preferably 0.01: 1 to 99: 1, particularly preferably 0.05: 1 to 19: 1, particularly preferably 0.5: 1. ~ 9: 1. However, it is particularly preferred to carry out the hydrogenation in the presence of THF. This is because the tendency of the catalyst to aggregate in THF can be reduced in suspension mode. Particularly preferably, the hydrogenation has a content during the hydrogenation of EDDN and / or EDMN of preferably 5 to 50% by weight, particularly preferably 8 to 30% by weight, particularly preferably 10 to 20% by weight. In the presence of an amount of THF such that it is in the range of%. The production of EDDN and / or EDMN is more preferably performed in the presence of toluene as described above.

Hydrogenation of water EDDN or EDMN can also be carried out in the presence of water. However, further water supply is not preferred. This is because both EDDN and EDMN tend to decompose in the presence of water. Preferably, EDDN or EDMN, less than 3% by weight, preferably less than 1% by weight, particularly preferably less than 0.5% by weight, particularly preferably 0%, based on the EDDN or EDMN. Those containing less than 3% by weight of water are used. Particular preference is given to using EDDN or EDMN which contains less than 0.1% by weight, particularly preferably less than 0.03% by weight of water, based on the EDDN or EDMN. In particular, EDDN and / or EDMN are preferably obtained with a low water content by treatment with an adsorbent of EDDN and / or EDMN.

Additives: In the basic compound further preferred one variant, the hydrogenation is a basic compound, preferably suitable solvent, for example an alkanol, for example C ₁ -C ₄ - alkanol, for example methanol or ethanol, or ethers For example, in the presence of a basic compound mixed in the reaction mixture in a cyclic ether such as THF or dioxane. Particularly preferably, a solution in which an alkali metal or alkaline earth metal hydroxide or a rare earth metal hydroxide is dissolved in water, particularly preferably a solution of LiOH, NaOH, KOH and / or CsOH is added. Preferably, the alkali metal hydroxide and / or alkaline earth metal hydroxide is less than 0. 0% relative to the mixture in which the concentration of alkali metal hydroxide and / or alkaline earth metal hydroxide is to be hydrogenated. It is supplied in such an amount that it is in the range of 005 to 1% by weight, particularly preferably in the range of 0.01 to 0.5% by weight, particularly preferably in the range of 0.03 to 0.1% by weight. However, it is also possible to use amides and / or amines such as ammonia and EDA as basic compounds. By adding such basic additives, the amount of by-products formed, for example AEPIP, can be reduced during hydrogenation. Preferred examples for such additives are ammonia and ethylenediamine. The amount of the additive is 0.01 to 10 mol per mol of EDDN + EDMN. Said basic additives can generally be supplied intermittently or continuously and before and / or during hydrogenation.

Catalyst As a catalyst for hydrogenating a nitrile functional group to an amine, one or more of the eighth subgroup of periodic system (Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt) as active species Catalysts containing these elements, preferably Fe, Co, Ni, Ru or Rh, particularly preferably Co or Ni can be used. Included therein is a so-called oxide catalyst, which is a catalyst containing one or more active species in the form of its oxygen-containing compound, and a so-called skeleton catalyst (also known as Raney (registered trademark)). ) Type; hereinafter referred to as Raney catalyst), said catalyst being obtained by alkaline leaching (activation) of an alloy comprising a hydrogenation active metal and a further component (preferably Al). The catalyst may additionally contain one or more promoters.

  In a particularly preferred embodiment, in the hydrogenation of EDDN and / or EDMN, a Raney catalyst, preferably a Raney cobalt catalyst or a Raney nickel catalyst, particularly preferably a Raney doped with at least one of the elements Cr, Ni or Fe. A cobalt catalyst or a Raney nickel catalyst doped with one of the elements Mo, Cr or Fe is used.

The catalyst can be used as a total catalyst (Vollkatalysator) or as a supported type. As the support, metal oxides such as Al ₂ O ₃ , SiO ₂ , ZrO ₂ , TiO ₂ , a mixture of metal oxides or carbon (activated carbon, carbon black, graphite) are preferably used.

  The oxide-based catalyst is activated prior to use by reducing the metal oxide at an elevated temperature in a hydrogen-containing gas stream either outside or in the reactor. When reducing the catalyst outside the reactor, to avoid uncontrolled oxidation in the air and to allow safe handling, it is subsequently passivated by an oxygen-containing gas stream or into an inert material Can be buried. As inert materials, it is also possible to use organic solvents such as alcohols, but also water or amines, preferably the reaction products. An exception to activation is the skeleton catalyst, which can be activated by alkaline treatment with an aqueous base, for example as described in EP-A 1 209 146.

  Depending on the method carried out (suspension hydrogenation, fluidized bed method, fixed bed hydrogenation), the catalyst is used as a powder, as a Splitt or as a shaped body (preferably extrudate or tablet). .

  A particularly preferred fixed bed catalyst is the cobalt total catalyst disclosed in EP-A1 742 045, which is doped with Mn, P and alkali metals (Li, Na, K, Rb, Cs). The catalytically active material of the catalyst, calculated as an oxide, respectively before reduction with hydrogen, is 55 to 98% by weight, in particular 75 to 95% by weight cobalt, 0.2 to 15% by weight phosphorus,. It consists of 2-15% by weight of manganese and 0.05-5% by weight of alkali metals, in particular sodium.

Further suitable catalysts are those disclosed in EP-A 963 975, whose catalytically active material is calculated to be 22-40% by weight of ZrO ₂ before treatment with hydrogen, calculated as CuO 1 30 mass% copper oxygen-containing compound, 15-50 mass% nickel oxygen-containing compound calculated as NiO (Ni: Cu molar ratio value is greater than 1), 15% calculated as CoO Contains 50% by weight cobalt oxygen-containing compound and 0-10% by weight calculated as Al ₂ O ₃ or MnO ₂ aluminum and / or manganese oxygen-containing compound, but includes molybdenum oxygen-containing compound is no catalyst, for example, catalyst a which is disclosed in the literature, and calculates and 33 wt% Zr as ZrO _2, and calculates and 28 wt% of Ni as NiO, calculated as CuO and 11% by weight It has a u, a composition of calculated on 28 wt% of Co as CoO.

Furthermore, the catalyst disclosed in EP-A 696 572, wherein the catalytically active material is 20 to 85% by weight of ZrO ₂ before reduction with hydrogen and 1 to 30% by weight of copper oxygen calculated as CuO. A compound containing 30 to 70% by weight of nickel, calculated as NiO, 0.1 to 5% by weight of oxygen containing compound calculated as MoO ₃ , and Al ₂ O ₃ or MnO ₂ The catalyst contains 0 to 10% by mass of aluminum and / or an oxygen-containing compound of manganese. For example, the catalyst specifically disclosed in the above literature has a composition of 31.5% by weight of ZrO ₂ , 50% by weight of NiO, 17% by weight of CuO and 1.5% by weight of MoO ₃ . Similarly, a catalyst as described in WO-A-99 / 44984, comprising (a) iron or an iron-based compound or mixture thereof and (b) (a) 0.001 to 0.00. 3% by weight of a co-catalyst based on 2, 3, 4 or 5 elements selected from the group of Al, Si, Zr, Ti, V and (c) 0 to 0. A catalyst containing 3% by weight of an alkali metal and / or alkaline earth metal based compound and 0.001 to 1% by weight of manganese with respect to (d) (a) is suitable.

  For the suspension process, Raney catalysts are preferably used. In the case of Raney catalysts, active catalysts as "metal sponges" are produced from binary alloys (nickel, iron, cobalt and aluminum or silicon) by elution with one partner acid or alkali. The rest of the original alloy partner is often synergistic.

  The Raney catalyst used for the hydrogenation of EDDN and / or EDMN is preferably produced starting from an alloy consisting of cobalt or nickel, particularly preferably cobalt and other alloy components soluble in alkali. In the case of the aforementioned soluble alloy components, preferably aluminum is used, but other components such as zinc and silicon or mixtures of such components can also be used.

  For the activation of the Raney catalyst, the soluble alloy components are extracted completely or partly with alkali, for which, for example, an aqueous caustic soda solution can be used. The catalyst can then be washed, for example with water or an organic solvent.

  In the catalyst, one or more additional elements may be present as a cocatalyst. Examples for cocatalysts are metals of the IB subgroup, VIB subgroup and / or VIII subgroup of the periodic system, for example metals such as chromium, iron, molybdenum, nickel, copper.

  Activation of the catalyst by alkaline leaching of soluble components (generally aluminum) can also take place in the reactor or before filling into the reactor. The preactivated catalyst is air-sensitive and natural and thus generally of a medium such as water, an organic solvent or a substance (solvent, starting material, product) added in a subsequent hydrogenation. Stored and handled originally, or embedded in organic compounds that are solid at room temperature.

  In one preferred embodiment, a Raney cobalt skeleton catalyst, obtained from a Co / Al alloy by alkaline treatment with an aqueous alkali metal hydroxide solution, such as caustic soda, followed by washing with water, and preferably assisting. A catalyst containing at least one of the elements Fe, Ni or Cr is used as the catalyst.

  Such preferred Raney cobalt catalysts are generally, in addition to cobalt, 1-30% by weight Al, in particular 2-12% by weight Al, in particular 3-6% by weight Al, 0-10% by weight Cr, In particular 0.1 to 7% by weight of Cr, in particular 0.5 to 5% by weight of Cr, in particular 1.5 to 3.5% by weight of Cr, 0 to 10% by weight of Fe, in particular 0.1 to 3%. % By weight Fe, in particular 0.2-1% by weight Fe, and / or 0-10% by weight Ni, in particular 0.1-7% by weight Ni, in particular 0.5-5% by weight Ni. In particular, it contains 1 to 4% by weight of Ni, with the mass indications being relative to the total mass of the catalyst, respectively.

  As a catalyst for the hydrogenation, for example, a cobalt skeleton catalyst “Raney 2724” manufactured by W. R. Grace & Co. can be preferably used. This catalyst has the following composition: Al: 2 to 6% by mass, Co: ≧ 86% by mass, Fe: 0 to 1% by mass, Ni: 1 to 4% by mass, Cr: 1.5 to 3.5% by mass Have

Regeneration-General Matters Catalysts used in the reaction of EDDN or EDMN with hydrogen are optionally cited by methods known to those skilled in the art when activity and / or selectivity is reduced, such as WO 99/33561. Can be reproduced by methods published in published literature.

  From EP 892777 it is known to regenerate a deactivated Raney catalyst with hydrogen at a temperature of 150 to 400 ° C. and a pressure of 0.1 to 30 MPa for 2 to 48 hours, in which case the catalyst is Before the original regeneration, it is preferable to wash with a solvent contained in the system, particularly ammonia.

  In WO 2008/104553 it is disclosed that the catalyst used for the hydrogenation of TETA or DETA can be regenerated. For regeneration, it is desirable to use the method according to WO 99/33561. WO 99/33561 is a method for regenerating a Raney catalyst, first separating the catalyst and the reaction medium, treating the separated catalyst with a basic aqueous solution, and the aqueous solution is more than 0.01 mol / kg. Disclosed is a process as described above having a concentration of basic ions, wherein the mixture is kept at a temperature below 130 ° C., optionally in the presence of hydrogen, for 1 to 10 hours. Subsequently, the catalyst is washed with water or a basic solution until the wash water has a pH value in the range of 12-13.

  The regeneration of the catalyst can be carried out in the original reactor (in situ) or with the removed catalyst (ex situ). In the fixed bed method, it is preferably regenerated in situ. In the suspension method, it is likewise preferably regenerated in situ. At that time, the entire catalyst is generally regenerated. The regeneration is usually performed during a short interruption.

Regeneration with liquid ammonia and hydrogen In one particularly preferred embodiment, the Raney catalyst is regenerated by treating the Raney catalyst with liquid ammonia and hydrogen. In this case, it is desirable that the reproduction can be performed by simple technical means. Furthermore, it is desirable that the regeneration be performed with as little time consumption as possible in order to shorten the downtime due to regeneration of the catalyst. Furthermore, it is desirable that the regeneration allows a fully complete recovery of the activity of the catalyst used. Therefore, a particularly preferred embodiment is a method for regenerating a Raney catalyst used in the reaction of EDDN or EDMN with hydrogen, the catalyst having a water content of less than 5% by weight and 0.1 to 0.1%. The method relates to the treatment with liquid ammonia with hydrogen at a partial pressure of 40 MPa in the temperature range of 50 to 200 ° C. for at least 0.1 hour.

  In the preferred embodiment, the doped and undoped Raney catalysts described above are regenerated. Particular preference is given to using such Raney catalysts which are used in the reaction of EDDN or EDMN with hydrogen. Particularly preferably, Raney cobalt is regenerated by the preferred embodiment described above.

  For regeneration, the Raney catalyst is treated with ammonia. The ammonia used contains less than 5% by weight, preferably less than 3% by weight, particularly preferably less than 1% by weight of water in the particularly preferred embodiments described above. Such “water-free” ammonia is a commercially available product.

  Said regeneration can be carried out in any of the reactors described below and above which can be used for the hydrogenation of EDDN or EDMN to TETA or DETA. For example, the hydrogenation may be carried out in stirred reactors, jet loop reactors, jet nozzle reactors, bubble column reactors, tubular reactors, but in tube bundle reactors or cascades of such same or different reactors. It can also be implemented. The hydrogenation can be carried out continuously or intermittently.

  In an intermittent manner, preferably the reactor is first evacuated before treatment with ammonia, for example by first removing the reactor contents from the reactor, for example by pumping or discharging. It is desirable that emptying the reactor be sufficiently complete. Preferably, it is desirable to discharge or pump out more than 80% by weight of the reactor contents, particularly preferably more than 90% by weight, particularly preferably more than 95% by weight.

  In a continuous manner, the supply of starting material is preferably interrupted and replaced with liquid ammonia. In a continuous manner, liquid ammonia can also come from the condensation reaction in the reactor, for example from the condensation of EDA to AEPIP.

  In the particularly preferred embodiment, the treatment of the catalyst with liquid ammonia is carried out at a temperature of 50 to 350 ° C., preferably 150 to 300 ° C., particularly preferably 200 to 250 ° C. The duration of the treatment is preferably 0.1 to 100 hours, preferably 0.1 to 10 hours, particularly preferably 0.5 to 5 hours.

  The mass ratio of the amount of ammonia supplied to the catalyst is preferably in the range from 1: 1 to 1000: 1, particularly preferably in the range from 50: 1 to 200: 1. Furthermore, it is preferred to recirculate ammonia during the treatment with ammonia, for example by pump circulation or preferably by stirring.

  Treatment of the catalyst with ammonia is carried out in the presence of hydrogen in certain preferred embodiments. The hydrogen partial pressure during the treatment with ammonia is preferably 1 to 400 bar, particularly preferably 5 to 300 bar. In a particularly preferred embodiment, the concentration of anions in liquid ammonia is less than 0.01 mol / kg, particularly preferably less than 0.0099 mol / kg, particularly preferably less than 0.005 mol / kg. .

  After treatment with ammonia, the ammonia can be separated from the catalyst. This can be done, for example, by emptying the reactor and / or by interrupting the ammonia feed.

  Before and after treatment of the Raney catalyst with liquid ammonia, the Raney catalyst may be rinsed one or more times with an organic solvent and / or water.

  Treatment of the catalyst with an organic solvent and / or water, however, is always necessary after the separation of ammonia or after interruption of the ammonia supply. This is because ammonia cannot be disturbed in the subsequent hydrogenation process and can be continuously discharged from the reactor.

Reaction conditions for hydrogenation The production of TETA or DETA is generally carried out by the reaction of EDDN or EDMN with hydrogen in the presence of a hydrogenation catalyst and an organic solvent.

  The temperature is generally in the range from 60 to 150 ° C., preferably from 80 to 140 ° C., in particular from 100 to 130 ° C.

  The pressure maintained during the hydrogenation is generally from 5 to 400 bar, preferably from 60 to 325 bar, particularly preferably from 100 to 280 bar, particularly preferably from 170 to 240 bar.

  In a particularly preferred embodiment, the pressure in the hydrogenation when using a Raney catalyst is in the range from 170 to 240 bar. This is because the formation of AEPIP can be reduced in the above pressure range. The formation of AEPIP can accelerate catalyst deactivation. Accordingly, a particularly preferred embodiment is a process for the production of TETA and / or DETA by reaction of EDDN and / or EDMN and hydrogen in the presence of a catalyst, using Raney-type catalyst as catalyst and hydrogen The process is characterized in that the pressure during the conversion is in the range from 170 to 240 bar.

  In one preferred embodiment, EDDN or an amino nitrile mixture comprising EDDN is fed at a hydrogenation rate that is no higher than the rate at which EDDN and optionally other components of the amino nitrile mixture react with hydrogen during hydrogenation.

  In the hydrogenation of EDDN to TETA, generally at least 4 moles of hydrogen are required per mole of EDDN.

  In the hydrogenation of EDMN to DETA, generally at least 2 moles of hydrogen are required per mole of EDMN.

Reactor The reaction of EDDN or EDMN and hydrogen in the presence of a catalyst is carried out in a conventional reaction vessel suitable for said catalyst, in a fixed bed mode, fluidized bed mode, suspension mode, continuously, semi-continuously. Or intermittently. For carrying out the hydrogenation, EDDN or EDMN and reaction vessels which allow contact between the catalyst and hydrogen under pressure are suitable.

  Hydrogenation in suspension mode can be carried out in stirred reactors, jet loop reactors, jet nozzle reactors, bubble column reactors, or cascades of such same or different reactors.

  Hydrogenation with a fixed bed catalyst is preferably carried out in one or more tubular reactors, but also in a bundle reactor.

  Nitrile group hydrogenation is carried out with heat dissipation and the heat must generally be discharged. Waste heat can be generated by heat conducting surfaces, cooling jackets or external heat conductors mounted to circulate around the reactor. The hydrogenation reactor or hydrogenation reactor cascade may be connected by a straight path. On the other hand, a circulation mode is also possible, in which part of the reactor effluent is returned to the reactor inlet, preferably without prior post-treatment of the circulation stream.

  In particular, the circulating flow can be cooled in a simple and inexpensive manner by an external heat conductor and thus the heat of reaction can be discharged. The reactor can also be operated adiabatically. During adiabatic operation of the reactor, the temperature rise in the reaction mixture can be limited by cooling the feed or by feeding a “cold” organic solvent. Since the reactor itself does not need to be cooled at that time, a simple and inexpensive structural type is possible. One option is a tube bundle reactor that is cooled (only in the case of a fixed bed). A combination of both styles is also conceivable. In this case, a fixed bed reactor is preferably connected afterwards to the suspension reactor.

Catalyst Placement The catalyst may be placed in a fixed bed (fixed bed mode) or suspended in the reaction mixture (suspension mode).

Suspension mode In a particularly preferred embodiment, the catalyst is suspended in the reaction mixture to be hydrogenated.

  The precipitation rate of the hydrogenation catalyst in the selected solvent is desirably low so that the catalyst can be well retained in suspension.

  The particle size of the catalyst used is therefore preferably from 0.1 to 500 μm, in particular from 1 to 100 μm, in the suspension mode.

  If the hydrogenation of EDDN or EDMN is carried out continuously in suspension mode, EDDN or EDMN is preferably continuously fed to the reactor and continuously from the reactor the hydrogenated product TETA. Alternatively, a stream containing DETA is taken.

  In an intermittent suspension mode, EDDN or EDMN is optionally charged with an organic solvent.

  The amount of catalyst in the intermittent suspension mode is preferably from 1 to 60% by weight, particularly preferably from 5 to 40% by weight, particularly preferably from 20 to 30% by weight, based on the total reaction mixture.

  The residence time in the reactor is preferably 0.1 to 6 hours, particularly preferably 0.5 to 2 hours in the case of an intermittent suspension mode.

  The residence time in the reactor is preferably 0.1 to 6 hours, particularly preferably 0.5 to 2 hours, in the case of a continuous suspension mode.

  The catalyst loading is preferably 0.1 to 10 kg, preferably 0.5 to 5 kg EDDN + EDMN per hour with 1 kg of catalyst in a continuous suspension mode.

In one particularly preferred embodiment, the catalyst loading relative to the catalyst surface area is preferably 10 ⁻⁶ to 10 ⁻⁴ kg EDDN + EDMN per 1 m ^{2 of} catalyst surface area and 1 hour, wherein said catalyst surface area is BET Measured according to the method (DIN 66131). Particularly preferably, the catalyst loading for the catalyst surface area, the catalyst surface area and per hour of 1 m ^2, a EDDN + EDMN of ^{0.25 · 10 -5 ~5 · 10 -5} kg, particularly preferably from 1 m ² catalyst 0.5 · 10 ⁻⁵ to 2 · 10 ⁻⁵ kg EDDN + EDMN per hour and surface area.

Accordingly, a particularly preferred embodiment is a process for producing TETA and / or DETA by reacting EDDN and / or EDMN and hydrogen in the presence of a catalyst in suspension, the catalyst loading on the catalyst surface area. The amount is from 10 ⁻⁶ to 10 ⁻⁴ kg of EDDN + EDMN per hour of catalyst surface area of 1 m ² , wherein said catalyst surface area is measured according to the BET method.

When the reaction is carried out in a stirred reactor in a suspension mode, the input for the stirrer is preferably 0.1 to 10 KW per m ³ .

  The spent catalyst can be separated by filtration, centrifugation or cross flow filtration. In doing so, the initial loss of catalyst amount due to wear and / or deactivation may need to be compensated by the addition of new catalyst.

Fixed bed mode In a further embodiment, which is less preferred, the catalyst is placed in a catalyst fixed bed.

  The catalyst loading is preferably 0.1 to 10 kg per hour with 1 kg of catalyst in the case of hydrogenation in a continuous fixed bed reactor, for example in a tubular reactor or a bundle reactor. , Preferably 0.5 to 5 kg of EDDN + EDMN.

In one particularly preferred embodiment, the catalyst loading relative to the catalyst surface area is preferably 10 ⁻⁶ to 10 ⁻⁴ kg EDDN + EDMN per 1 m ^{2 of} catalyst surface area and 1 hour, wherein said catalyst surface area is BET Measured according to the method (DIN 66131). Particularly preferably, the catalyst loading for the catalyst surface area, the catalyst surface area and per hour of 1 m ^2, a EDDN + EDMN of ^{0.25 · 10 -5 ~5 · 10 -5} kg, particularly preferably from 1 m ² catalyst 0.5 · 10 ⁻⁵ to 2 · 10 ⁻⁵ kg EDDN + EDMN per hour and surface area.

Accordingly, a particularly preferred embodiment is a process for producing TETA and / or DETA by reacting EDDN and / or EDMN and hydrogen in the presence of a catalyst in a fixed bed, the catalyst loading relative to the catalyst surface area. Relates to the process, characterized in that the catalyst surface area is 10 ⁻⁶ to 10 ⁻⁴ kg of EDDN + EDMN per 1 m ^{2 of} catalyst surface and per hour, wherein the catalyst surface area is measured according to the BET method.

  In the case of a fixed bed catalyst, EDDN or EDMN is generally added to the catalyst in an upflow manner or a downflow manner.

Reaction effluents The reaction effluents from hydrogenation are generally prior to or prior to other higher or lower boiling organic substances such as methylamine, AEPIP, PIP or TEPA or basic compounds or hydrogenation as by-products. It also contains additives supplied in between, such as alkali metal hydroxides, alcoholates, amides, amines and ammonia. The hydrogenation effluent more preferably contains an organic solvent added during the hydrogenation, preferably an organic solvent added during treatment with the adsorbent, in particular THF.

  The reaction effluent more preferably contains a distilling agent, particularly toluene, preferably used in the distillative reduction of water after EDDN production or EDMN production.

  The reaction effluent generally still contains a small amount of water. In general, the amount of water contained in the effluent from the hydrogenation corresponds to the amount derived from EDDN production or EDMN production and preferably subsequent work-up.

Further purification (general matters)
Subsequent to hydrogenation, the effluent from hydrogenation may optionally be further purified. The catalyst can be separated according to methods known to those skilled in the art. Generally, after separation of the catalyst, the hydrogen present during the hydrogenation is separated.

Hydrogen Separation Hydrogen separation is preferably performed by reducing the pressure at which the hydrogenation was performed to a value where hydrogen is gaseous but other components in the reaction effluent are present in the liquid phase. Is called. Preferably, the reaction effluent is from a hydrogenation pressure of preferably 60 to 325 bar, particularly preferably of 100 to 280 bar, particularly preferably of 170 to 240 bar, to a pressure of 5 to 50 bar in the vessel. Is released. At the top of the vessel, hydrogen and optionally ammonia and a small amount of evaporated low boilers such as THF are obtained. Hydrogen and optionally ammonia can be returned to the EDDN or EDMN hydrogenation. For example, THF can be condensed and recovered. On the other hand, THF can be recovered by exhaust gas cleaning with higher boiling solvents such as toluene or TETA.

Separation of organic solvent The organic solvent present in the reaction effluent is generally separated by distillation as well. In particular, the main products (TETA or DETA) can be isolated from the reaction products together or individually by methods known to those skilled in the art. If both main products are isolated together, for example by distillation, they can subsequently be separated into two separate products. Finally, pure TETA and pure DETA are thus obtained. Other impurities, by-products or other ethyleneamines such as TEPA or PIP can likewise be separated from the respective products by methods known to those skilled in the art. Optionally, TETA can be isolated together with diaminoethylpiperazine or piperazinyl-ethyl-ethylenediamine formed in small amounts. The post-treatment of the hydrogenation effluent from the hydrogenation of EDDN is preferably carried out by distillation.

THF separation When the hydrogenation effluent contains THF, it is preferred that the THF be returned to the process. In particular, the THF added during the hydrogenation is preferably used again for the treatment with the adsorbent of EDDN and / or EDMN. In this case, however, it is necessary to return THF almost free of water. This is because a small amount of water can reduce the adsorption capacity of the adsorbent upon treatment with the adsorbent, and can introduce polar impurities that lead to undesirable side reactions during the hydrogenation of EDDN or EDMN. It was because it became clear. THF and water, however, form a low boiling azeotrope. When the hydrogenation effluent contains THF, the separation of water and THF can be performed, for example, as a two-pressure distillation.

In one particularly preferred embodiment, the separation of THF occurs during the reaction of EDDN or EDMN with hydrogen in the presence of THF and a catalyst, which has higher and lower boiling points than TETA or DETA, water and optionally TETA or DETA. A method for the separation of reaction effluents containing organic compounds, comprising:
i) Feeding the reaction effluent to the distillation column DK1 after separation of hydrogen, where it is a THF / water azeotrope, optionally containing further organic compounds having a boiling point lower than TETA or DETA Separating the azeotrope from the top and separating the bottom product containing TETA or DETA therein;
ii) introducing the bottom product from step i) into the distillation column DK2 and separating the THF through the top and taking out a stream containing TETA or DETA at the bottom of the column;
iii) condensing the stream taken off at the top of the column DK1 from step i), thus obtaining an organic solvent which is essentially immiscible with water in this condensate or part of the condensate thus The resulting mixture is fed in an amount to be separated in a phase separator, wherein the formed organic phase containing THF and an organic solvent which is essentially immiscible with water is returned to column DK1, and the aqueous phase is Discharging process;
Is done by.

  In a particularly preferred embodiment, hydrogen is first separated from the reaction effluent. As described above, the hydrogen separation preferably reduces the pressure at which the hydrogenation was carried out to a pressure at which hydrogen is gaseous but other components in the reaction effluent are present in the liquid phase. Is done by. Preferably, the reaction effluent is from a hydrogenation pressure of preferably 60 to 325 bar, particularly preferably of 100 to 280 bar, particularly preferably of 170 to 240 bar, to a pressure of 5 to 50 bar in the vessel. Is released. At the top of the vessel, hydrogen and optionally ammonia and a small amount of evaporated low boilers such as THF are obtained. Hydrogen and optionally ammonia can be returned to the EDDN or EDMN hydrogenation. THF can be condensed and recovered. On the other hand, THF can be recovered by exhaust gas cleaning with higher boiling solvents such as toluene or TETA.

  In one particularly preferred embodiment, the reaction effluent is fed to column DK1 after the separation of hydrogen. For this purpose, preferably the proportion of reaction effluent that remains liquid after release is introduced into the column DK1. The exact operating conditions of the distillation column are customary according to conventional calculation methods by the person skilled in the art according to the separation capacity of the column used and based on the known vapor pressure and evaporation equilibrium of the components introduced into the distillation column. Can be determined. The tower is preferably configured as a plate tower. In the column tower, there is an intervening tray in which mass exchange is performed. Examples for various tray types are sieve tray, tunnel tray, dual flow tray, bubble bell tray or valve tray. The tower preferably has a recovery part and a concentration part. However, the tower may have only a recovery part. The number of theoretical plates is generally in the range of 5-30, preferably 10-20. The column pressure is preferably selected such that a bottom pressure in the range of 100 to 250 ° C. occurs. Preferably, the top pressure is 1 to 30 bar, particularly preferably 3 to 25 bar. In general, the operating temperature of the condenser is in the range of 30-70 ° C, preferably in the range of 35-50 ° C. Generally, low boilers such as ammonia or methylamine are not condensed and are discharged as a gaseous stream. This stream can later be fed to incineration. In the condenser, an azeotropic mixture composed of separated water and THF is mainly produced as a condensate. In a particularly preferred embodiment, the condensate or part of the condensate is essentially not miscible with water and formed THF / water formed at the top of the column under distillation conditions in column DK1. An organic solvent having a boiling point higher than that of the azeotrope is supplied.

  An organic solvent that is essentially not miscible with water means within the scope of the invention an organic solvent that can only dissolve less than 500 ppm by weight of water. Preferred organic solvents that are essentially immiscible with water are toluene, n-heptane, n-octane, n-nonane, and the like. Particular preference is given to using organic solvents that are essentially immiscible with water, which are also preferred solvents for the production of EDDN or EDMN. Particular preference is given to using toluene. This is because the solvent is already preferably used in EDDN production or EDMN production. The amount of organic solvent supplied, which is essentially immiscible with water, is generally selected such that phase separation occurs and the phases can be separated by conventional technical measures such as separation in a phase separation vessel. Is done. The mass ratio of the organic solvent fed to the condensate which is essentially immiscible with water is preferably 0.1: 1 to 10: 1, particularly preferably 0.5: 1 to 5: 1, very particularly preferably. 0.8: 1 to 2: 1. A mixture of the condensate thus obtained and an organic solvent that is essentially immiscible with water is preferably introduced into a phase separator, where the aqueous phase and the solvent that is essentially immiscible with water and THF are removed. Divided into containing phases. Preferably, a phase comprising THF and a solvent that is essentially not miscible in water is returned to the upper region of column DK1, preferably to the top of column DK1. Preferably, the entire phase containing THF and an organic solvent that is essentially immiscible with water is returned to the upper region of column DK1. By separating the water at the top of the column by the addition of an organic solvent which is essentially immiscible with water, and subsequent phase separation, a bottom discharge still containing small amounts of water can be obtained. Preferably, the bottom effluent contains less than 1% by weight of water, particularly preferably less than 1000 ppm by weight, particularly advantageously less than 200 ppm by weight.

  The bottom discharge from column DK1 is further fed with TETA or DETA, THF, solvents that are essentially immiscible with water and optionally other organic solvents (derived from dehydration and phase separation) and generally organic by-products such as PIP , AEPIP and TEPA.

  In a particularly preferred embodiment, the bottom product from column DK1 is introduced into distillation column DK2, where THF is separated via the top and at the bottom of the column is miscible with TETA or DETA and essentially water. A stream containing non-solvent and optionally additional toluene is removed. The exact operating conditions of the distillation column are customary according to conventional calculation methods by the person skilled in the art according to the separation capacity of the column used and based on the known vapor pressure and evaporation equilibrium of the components introduced into the distillation column. Can be determined. The tower is preferably configured as a plate tower. In the column tower, there is an intervening tray in which mass exchange is performed. Examples for various tray types are sieve tray, tunnel tray, dual flow tray, bubble bell tray or valve tray. The tower preferably has only a recovery part. The number of theoretical plates is generally in the range of 5-30, preferably 10-20. The top pressure is particularly preferably from 200 mbar to 5 bar, particularly preferably from 500 mbar to 2 bar. At the bottom of the column, it is preferably adjusted to a temperature higher than the evaporation temperature of THF, so that the THF is essentially completely converted into the gas phase. Particularly preferably, the temperature in the range from 100 to 250 ° C. is adjusted at the bottom of the column. The condenser of the distillation column DK2 is generally operated at a temperature at which most of the THF is condensed at a corresponding top pressure. In general, the operating temperature of the condenser is in the range of 30-70 ° C, preferably in the range of 35-50 ° C. In the condenser, a condensate containing essentially THF is produced. Preferably, this THF contains less than 200 ppm by weight of water, particularly preferably less than 100 ppm by weight, so it is particularly suitable for return to the reaction effluent or post-treatment of EDDN production or EDMN production. Here, a connection may be provided between EDDN hydrogenation or EDMN hydrogenation and EDDN production or EDMN production that reduces the amount of organic solvent required. Optionally, the condensate at the top of column DK2 may contain traces of organic solvents that are essentially not miscible with water in addition to THF. However, the condensate can nevertheless be returned to EDDN post-treatment or EDMN post-treatment as described above. This is because the solvent is also a preferred organic solvent in this step as described above. Preferably, however, the amount of organic solvent in the condensate that is essentially not miscible with water is preliminarily provided at the top of the column with a precondenser operating in the temperature range of 80-150 ° C, preferably 100-130 ° C. Reduced by being connected. On the other hand, the number of trays in the concentrating part of the column DK2 may be increased and / or a part of the condensate may be introduced into the column as reflux. However, the proportion of organic solvent that is essentially immiscible with water in the top distillate may also be used to cool the feed to column DK2 and / or lower the bottom temperature in column DK2 of organic solvent that is not miscible with water. It can also be lowered by adjusting so that only a small amount is converted to the gas phase. At the bottom of column DK2, there is generally a bottom product containing TETA or DETA, toluene and generally by-products AEPIP, PIP and TEPA.

  In a further particularly preferred embodiment, the THF obtained by two-pressure distillation or in the particularly preferred embodiment at the top of the column DK2 is obtained before returning to the process, in particular before returning to the adsorber stage. Further dehydration. Preferably, the molecular sieve has a pore size of less than 4 mm so that only water and ammonia remain, and other amines such as methylamine and ethylamine do not. The absorption capacity of the molecular sieve as adsorbent for the separation of water is thereby increased.

Post-treatment of the bottom product The bottom discharge can be further worked up according to conventional methods and can be separated into individual components.

  In a preferred embodiment, the bottom product from column DK2 is introduced into column DK3, at the top a stream containing mainly toluene and / or a solvent that is essentially not miscible with water is removed and the bottom As product, a stream containing mainly TETA or DETA, AEPIP and generally the by-products PIP, AEPIP and TEPA is withdrawn. The exact operating conditions of the distillation column are customary according to conventional calculation methods by the person skilled in the art according to the separation capacity of the column used and based on the known vapor pressure and evaporation equilibrium of the components introduced into the distillation column. Can be determined. Preferably, the distillation column has an internal fixture for improved separation performance. Said internal attachment for distillation may be present, for example, as a regular packing, for example as a plate-shaped packing, such as Mellapak 250 Y or Montz Pak, Typ B1-250. There may also be a filler with a lower or higher specific surface area, or a filler with a woven or other shape, such as Mellapak 252 Y can be used. When using the internal attachment for distillation, for example, a low pressure loss and a low liquid hold-up ratio are preferable compared to a valve tray. The internal fixture may be present on one or more floors. The tower preferably has a recovery part and a concentration part. The bottom discharge from the column DK2 is preferably in the spatial region between 30% and 90% of the theoretical column of the distillation column (counting from the bottom), particularly preferably 50% to 80% of the theoretical column of the distillation column. Supplied to the space area between. For example, the feeding takes place somewhat above the center of the theoretical plate. The optimal supply location can be determined by one of ordinary skill in the art using conventional computing tools. The number of theoretical plates is generally in the range of 3-25, preferably 5-15. Particularly preferably, the temperature in the range from 100 to 250 ° C. is adjusted at the bottom of the column. The top pressure is preferably from 10 mbar to 1 bar, particularly preferably from 30 mbar to 500 mbar. Distillation column condensers are generally operated at temperatures at which the majority of toluene and / or the majority of solvents that are essentially immiscible with water are condensed at a corresponding top pressure. In general, the operating temperature of the condenser is in the range of 30-70 ° C, preferably in the range of 35-50 ° C. In the condenser, a condensate is produced containing an organic solvent that is essentially toluene and / or essentially not miscible with water. The toluene and / or organic solvent which is essentially immiscible with water can be returned to the process, for example by feeding it to the condensate from column DK1. Toluene and / or organic solvents that are essentially not miscible with water can also be fed into the EDDN or EDMN workup, for example, prior to pressure evaporation. In this way, an economical connection can be achieved. At the bottom of column DK3, a stream generally containing TETA or DETA and generally by-products AEPIP, PIP and TEPA is produced. The bottom effluent can be further worked up according to conventional methods and separated into individual components.

  In a preferred embodiment, the bottom effluent from column DK3 is introduced into the column (DK4) to obtain a mixture consisting of PIP, AEPIP and DETA at the top and pentaamine such as TEPA and other highs at the bottom. A mixture of boilers is produced and a TETA stream having a purity of more than 99% by weight is withdrawn as a side draw. The exact operating conditions of the distillation column are customary according to conventional calculation methods by the person skilled in the art according to the separation capacity of the column used and based on the known vapor pressure and evaporation equilibrium of the components introduced into the distillation column. Can be determined. Preferably, the distillation column has an internal fixture for improved separation performance. Said internal attachment for distillation may be present, for example, as a regular packing, for example as a plate-shaped packing, such as Mellapak 250 Y or Montz Pak, Typ B1-250. There may also be a filler with a lower or higher specific surface area, or a filler with a woven or other shape, such as Mellapak 252 Y can be used. When using the internal attachment for distillation, for example, a low pressure loss and a low liquid hold-up ratio are preferable compared to a valve tray. The internal fixture may be present on one or more floors. The tower preferably has a recovery part and a concentration part. The bottom discharge from the column DK3 is preferably in the spatial region between 30% and 90% of the theoretical column of the distillation column (counting from the bottom), particularly preferably 50% to 80% of the theoretical column of the distillation column. Supplied to the space area between. For example, the feeding takes place somewhat above the center of the theoretical plate. The optimal supply location can be determined by one of ordinary skill in the art using conventional computing tools. The number of theoretical plates is generally in the range of 5-30, preferably 10-20. The top pressure is particularly preferably from 1 mbar to 400 mbar, particularly preferably from 5 mbar to 300 mbar. At the bottom of the column, it is preferably adjusted to a temperature higher than the evaporation temperature of toluene, so that the toluene is essentially completely converted into the gas phase. Particularly preferably, the temperature in the range from 150 to 250 ° C. is adjusted at the bottom. The condenser of the distillation column is generally operated preferably at a temperature of 30 to 70 ° C, particularly preferably at a temperature of 35 to 50 ° C. In the condenser, a condensate is produced which essentially contains a mixture of DETA, PIP and AEPIP. Part of the condensate can be returned as reflux to the column (DK4). Preferably, 5 to 40% by weight, particularly preferably 10 to 25% by weight, of the condensate is returned to the column (DK4) as reflux. At the bottom of the column (DK4), a stream is produced which generally contains a mixture consisting essentially of pentaamine, such as TEPA and other high boilers. TETA is extracted as a side stream. Said side stream is preferably below the introduction of the bottom stream from the column (DK4), preferably in the range of 10% to 60% of the theoretical stage of the distillation column, particularly preferably in the range of 15% to 35%. (Counted from the bottom). Said side stream preferably contains more than 99% by weight, particularly preferably more than 99.5% by weight of TETA.

  The TETA or DETA produced by the process according to the invention, as well as by the preferred embodiments, generally has a high quality and is therefore particularly suitable for further reactions, for example reaction with epoxy compounds for the production of epoxy resins. Or for reaction with acids for the preparation of amides or polyamides. A further subject of the invention is therefore a process for the production of epoxy resins or amides or polyamides, wherein TETA and / or DETA are produced according to the invention in the first step and thus obtained in the second step. The above-mentioned method is characterized in that TETA or DETA is reacted to form an epoxy resin, amide or polyamide.

  In the accompanying drawings, preferred embodiments of the invention are described.

FIG. 1 shows the production of EDDN or EDMN from EDA (1) and FACH (5). FIG. 2 shows the production of TETA or DETA from EDDN or EDMN. FIG. 3 shows the production of TETA or DETA from EDDN or EDMN followed by post-processing.

FIG. 1 shows the production of EDDN or EDMN from EDA (1) and FACH (5). Preferred process parameters can be derived from the foregoing detailed description of the invention. First, EDA (1) and water (2) are mixed in mixer (I) to form an aqueous EDA stream (3). By mixing EDA and water, the heat of hydration is released and that heat is derived in the heat exchanger (II). The FACH containing stream (5) is mixed with toluene (6). The toluene-containing FACH stream is mixed with the EDA aqueous solution (3) at the mixing point and introduced into a tubular reactor (III) operated adiabatically. At the outlet of the tubular reactor (III), the flowing-out reaction mixture (7) is released with a release valve. The formed gaseous phase (8) containing water, toluene and low-boiling compounds is condensed in a condenser (V). Non-condensed components (9) such as ammonia, HCN, methanol or CO ₂ are discharged from the process. The condensate (10) condensed in the condenser (V) is introduced into a phase separation vessel (VI) and separated into an aqueous phase (14) and a toluene-containing phase (11). The aqueous phase (14) from the phase separation vessel (VI) can be returned to the process, eg introduced into a mixer (I) or biological wastewater treatment for the production of an aqueous EDA solution (not shown). Said aqueous phase (14) may be introduced into column K2 (VIII), where water is separated from the low boilers (15) as bottom product (16). Low boilers (15), such as solvents having a boiling point lower than water or water boiling azeotropes or HCN, may be fed directly to the condenser (V) where the gaseous phase from the pressure evaporation is also Condensed. The components that cannot be condensed are discharged from the process as stream (9). The toluene-containing phase (11) is returned to the process as an organic solvent and can be mixed with the FACH-containing stream from FACH production. Optionally, toluene loss can be compensated by toluene replenishment. However, the toluene-containing phase (11) can preferably be introduced into the column K1 (VII) together with the liquid phase (12) from the flash vessel (IV). The phase (12) which remains in the liquid state during the pressure-release evaporation is from the flash vessel (pressure-release vessel) (IV) to the top of the column K1 (VII), optionally together with the toluene-containing phase (11), Supplied for reduction. In column K1 (VII), an essentially aqueous gaseous top product is withdrawn, which is fed directly to the condenser (V) and introduced into the phase separation vessel (VI). In the phase separation vessel, the aqueous phase (15) formed can be discharged as described above, introduced into the mixer (I) or fed to the column K2 (VIII). At the bottom (17) of column K1, EDDN or a mixture of EDMN and toluene is withdrawn. A mixture of toluene and EDDN or EDMN (17) is diluted with THF (18) and treated with an adsorbent, preferably a solid acidic adsorbent, in an adsorber (IX). From said adsorber, a mixture (20) is obtained which consists of EDDN and / or EDMN and toluene and THF, which no longer contains a small amount of water. The EDDN or EDMN mixture can be introduced into the hydrogenation, where the EDDN or EDMN is hydrogenated to TETA or DETA.

  FIG. 2 shows the production of TETA or DETA from EDDN or EDMN. Preferred process parameters can be derived from the foregoing detailed description of the invention. EDDN or EDMN that can be prepared according to one of the options a) to d) mentioned in the detailed description of the invention by reaction of FACH and EDA, preferably i) stripping, e.g. Or separation by distillation and ii) the presence of an organic solvent having a boiling point between water and EDDN or EDMN or forming an azeotrope of low boiling point with water under the conditions of water distillation, preferably water separation The EDDN or EDMN worked up by distilling off the water below is referred to in FIG. 3 as “unpurified” EDDN. Such “raw” EDDN or EDMN is mixed with THF (18) and treated in the adsorber with an adsorbent, preferably a solid acidic adsorbent. Stream (1) exiting the adsorber is introduced into the hydrogenation reactor (I) where EDDN or EDMN “purified” by adsorption is hydrogenated to TETA or DETA in the presence of hydrogen (2).

  FIG. 3 shows the production of TETA or DETA from EDDN or EDMN followed by post-processing. Preferred process parameters can be derived from the foregoing detailed description of the invention. EDDN or EDMN can be produced by the reaction of FACH and EDA. Said post-treatment preferably comprises i) separation of low boilers, for example by stripping, pressure evaporation or distillation, and ii) reduction of water, preferably between water and EDDN or EDMN under conditions of water separation. This is done by the reduction of water in the presence of an organic solvent having a boiling point or forming a low boiling azeotrope with water. The dehydrated EDDN is preferably mixed with THF and treated with an adsorbent, preferably a solid acidic adsorbent. The mixture (1) of EDDN or EDMN and THF is hydrogenated to TETA or DETA in the presence of hydrogen (2) fed in the hydrogenation reactor (I). The reaction effluent from hydrogenation (3) is depressurized into the pressure relief vessel (II). Gaseous components (4) such as hydrogen, a portion of THF, HCN, methanol or methylamine can be discharged from the process or can be partially or fully recovered. The phase (5) which remains in a liquid state after being released is introduced into a column K1 having a recovery part and a concentration part. At the top of the column, a low boiling THF / water azeotrope (6) is withdrawn and condensed. The condensed stream is mixed with toluene (7) in a phase separation vessel. In the phase separation vessel, an aqueous phase (8) and a THF / toluene phase (9) are formed and the phase (9) is returned to the column K1. From the bottom of column K1, a stream (10) containing TETA, DETA, THF, toluene and organic compounds such as PIP, AEPIP and TEPA is withdrawn. Said stream (10) is introduced into column K2, where THF is withdrawn as top product (11). This THF (11) can be returned directly to the process, preferably for treatment with EDDN or EDMN adsorbent. Prior to introduction into the adsorber stage, THF (11) can be contacted with the molecular sieve for further water reduction. At the bottom of column K2, a stream (12) containing TETA, DETA, toluene and organic compounds such as PIP, AEPIP and TEPA is withdrawn. Said stream (12) is introduced into column K3, where toluene is withdrawn as top product (13). The extracted toluene (13) can be introduced into the phase separation vessel via conduit (7) for the dehydration of THF, where the toluene is combined with the condensate from column K1. The withdrawn toluene (13) can also be discharged from the process via conduit (14) or preferably used as a solvent in EDDN production and / or EDMN production. The bottom product (16) of column K3 contains TETA, DETA, toluene and organic compounds such as PIP, AEPIP and TEPA. The mixture can be further separated in the column (K4). For example, low boilers such as PIP, AEPIP and DETA can be withdrawn via the top (17) and TETA can be withdrawn as a side extract (18). High boilers such as TEPA can be withdrawn at the bottom (19). The top or bottom stream can be separated into its individual components in a subsequent distillation stage.

Abbreviation ethylenediamine (EDA)
Ethylenediamine-formaldehyde-bis adduct (EDFA)
Ethylenediamine-formaldehyde-monoadduct (EDMFA)
Ethylenediamine diacetonitrile (EDDN)
Ethylenediamine monoacetonitrile (EDMN)
Diethylenetriamine (DETA)
Triethylenetetramine (TETA)
Tetraethylenepentamine (TEPA)
Formaldehyde (FA)
Formaldehyde cyanohydrin (FACH)
Piperazine (PIP)
Aminoethylpiperazine (AEPIP)
Mixture consisting of formaldehyde and hydrocyanic acid (GFB)
2- and 3-methyltetrahydrofuran (MeTHF)
Aminoacetonitrile (AAN)

  The method according to the invention is explained in more detail on the basis of the examples given below.

Analysis Formaldehyde cyanohydrin (FACH) conversion and hydrocyanic acid conversion were measured by Forhardt titration (measurement of free cyanide) and Liebig titration (measurement of bound cyanide). Both methods titrated with silver nitrate. The yield of useful product was determined by quantitative HPLC analysis (stationary phase: 3 × Atlantis T3, 5μ, 4.6 × 250 mm, Waters; mobile phase: 50% by volume water with 0.5 g / L ammonium formate, 50 The volume of acetonitrile was measured using a reaction product or a comparative substance present as a pure substance. Usefuls include the sum of the α-amino nitriles ethylenediaminediacetonitrile (EDDN), ethylenediaminemonoacetonitrile (EDMN), biscyanomethylimidazoline (BCMI) and ethylenediaminetriacetonitrile (EDTriN). When measuring the Hazen color number (APHA) and iodine color number (Roempp, Lexikon Chemie, 10th edition, G. Thieme publication, 1997, pages 1285-1286), the aqueous part of the reaction effluent, respectively. Was optionally measured after phase separation.

General production instructions for the production of formaldehyde cyanohydrin (FACH) in a stirred tank In a 10 l reaction vessel with a propeller-type stirrer, formaldehyde (4880 g, 48.8 mol, 30% by weight in water) is charged. And a pH value of 6.5 with caustic soda solution (1 mol / L in water). Within 2 hours, hydrocyanic acid (1295 g, 47.6 mol, 99% by weight) was metered in gaseous form under a stirrer via a heated U-shaped tube. At that time, the reaction temperature was 30 ° C., and the pH value was maintained at 5.5 by the addition of caustic soda solution. After a further stirring time of 45 minutes, the pH value was adjusted to 2.5 with sulfuric acid (50% by weight in water). The cyanide conversion and formaldehyde cyanohydrin content were measured via the Forhardt titration method and the Liebig titration method. In the case of complete conversion, the formaldehyde cyanohydrin content was 44% by weight. This solution (concentration approximately 950 g / L) was used for EDDN production.

General production instructions for the production of ethylenediaminediacetonitrile (EDDN) from FACH and ethylenediamine (EDA) in an adiabatic tubular reactor:
Examples 1-5 described below for the preparation of EDDN from EDA and FACH are tubular reactors (length 430 mm, outer diameter: 8 mm, inner diameter: 6 mm, the upper half of the reactor is electrically heated, The cooling coil was connected afterwards). The reactor was filled with glass beads (diameter 0.4-0.6 mm). The volume was 5.2 mL taking into account the glass beads.

Example 1
Anhydrous ethylenediamine (233 g / h, 3.88 mol / h, 100 wt%) conditioned to room temperature and formaldehyde cyanohydrin (988 g / h, 7.57 mol / h, 44 wt%) cooled to 2 ° C. %) Was metered into the above adiabatic tubular reactor via two separate pumps. The residence time was 16 seconds at this metering rate. At the reactor outlet there was a temperature of 117 ° C. (trace heating 85 ° C., pressure 10 bar). The aqueous reaction effluent was cooled to 0 ° C. in a connected chiller and immediately analyzed by Forhardt and Liebig titrations, HPLC and color number measurement. The conversion rate of formaldehyde cyanohydrin was 99.3% according to the Forhardt titration method and the Liebig titration method. The total aminonitrile yield was determined by HPLC to be 96.1% based on the formaldehyde cyanohydrin used. The color number of the aqueous solution was 75 Hazen (Table 1).

Table 1:

Example 2
Anhydrous ethylenediamine (140 g / h, 2.33 mol / h, 100 wt%) conditioned to room temperature and formaldehyde cyanohydrin (593 g / h, 4.54 mol / h, 44 wt%) cooled to 2 ° C. %) Was metered into the above adiabatic tubular reactor via two separate pumps. The residence time at this metering rate was 26 seconds. At the reactor outlet there was a temperature of 117 ° C. (trace heating 85 ° C., pressure 10 bar). The aqueous reaction effluent was cooled to 0 ° C. in a connected chiller and immediately analyzed by Forhardt and Liebig titrations, HPLC and color number measurement. The conversion rate of formaldehyde cyanohydrin was 99.2% according to the Forhardt titration method and the Liebig titration method. The total aminonitrile yield was determined by HPLC to be 96.4% based on the formaldehyde cyanohydrin used. The number of colors of the aqueous solution was 149 Hazen (Table 2).

Table 2:

Example 3
Ethylenediamine was diluted with water at a ratio of 3: 1 (g / g) (corresponding to 1: 1.1 mol / mol) and the mixture was warmed to room temperature. An aqueous ethylenediamine solution (98 g / h, 1.22 mol / h) and formaldehyde cyanohydrin (310 g / h, 2.37 mol / h, 44 wt%) cooled to 2 ° C. were passed through two separate pumps. Were metered into the adiabatic tubular reactor described above. The residence time at this metering rate was 47 seconds. At the reactor outlet there was a temperature of 98 ° C. (trace heating 85 ° C., pressure 10 bar). The aqueous reaction effluent was cooled to 0 ° C. in a connected chiller and immediately analyzed by Forhardt and Liebig titrations, HPLC and color number measurement. The conversion rate of formaldehyde cyanohydrin was 98.8% according to the Forhardt titration method and the Liebig titration method. The total aminonitrile yield was determined by HPLC to be 93.5% based on the formaldehyde cyanohydrin used. The color number of the aqueous solution was 72 Hazen (Table 3).

Table 3:

Example 4
Ethylenediamine was diluted with water at a ratio of 3: 1 (g / g) (corresponding to 1: 1.1 mol / mol) and the mixture was warmed to room temperature. Aqueous ethylenediamine (59 g / h, 0.73 mol / h) and formaldehyde cyanohydrin (186 g / h, 1.43 mol / h, 44 wt%) cooled to 2 ° C. were passed through two separate pumps. Were metered into the adiabatic tubular reactor described above. At this metering rate, the residence time was 78 seconds. At the reactor outlet there was a temperature of 95 ° C. (trace heating 85 ° C., pressure 10 bar). The aqueous reaction effluent was cooled to 0 ° C. in a connected chiller and immediately analyzed by Forhardt and Liebig titrations, HPLC and color number measurement. The conversion rate of formaldehyde cyanohydrin was 98.3% according to the Forhardt titration method and the Liebig titration method. The total aminonitrile yield was determined by HPLC to be 93.2% based on the formaldehyde cyanohydrin used. The number of colors of the aqueous solution was 247 Hazen (Table 4).

Table 4:

Example 5
Ethylenediamine was diluted with toluene at a ratio of 3: 1 (g / g) (corresponding to 4.6: 1 mol / mol) and the mixture was warmed to room temperature. A toluene-containing solution of ethylenediamine (81 g / h, 1.01 mol / h) and formaldehyde cyanohydrin (257 g / h, 1.97 mol / h, 44% by weight) cooled to 2 ° C. It was metered into the above adiabatic tubular reactor via a pump. The residence time at this metering rate was 63 seconds. At the reactor outlet there was a temperature of 104 ° C. (trace heating 85 ° C., pressure 10 bar). The aqueous reaction effluent was cooled to 0 ° C. in a later connected cooling device and received in an ice-cooled sample container. In order to separate the toluene and most of the water, the reaction mixture is subsequently pumped continuously into a Sambay evaporator (jacket temperature: 75 ° C., pressure: 50-60 mbar, feed rate: 13 mL / min). I put it in. The bottom product was analyzed by Karl Fischer titration, HPLC and color number measurement. The water content was 3.3% by mass according to Karl Fischer titration. The total aminonitrile yield was determined by HPLC to be 90.5% based on the formaldehyde cyanohydrin used. The color number of a 30% by weight solution diluted with water was 396 hazen (Table 5).

Table 5:

Example 6
In a 250 mL reaction vessel, ethylenediamine (12 g, 0.20 mol) was charged and formaldehyde cyanohydrin (51 g, 0.39 mol) cooled to 0 ° C. was added dropwise over 60 seconds. The temperature then rose from 41 ° C. to 70 ° C. Immediately after the addition, the mixture was heated to 80-85 ° C. in a preheated oil bath. After a reaction time including a total of 120 seconds (Table 6), 180 seconds (Table 7), 300 seconds (Table 8) and 600 seconds (Table 9) FACH addition time, the solution was subjected to Forhardt titration. And the Liebig titration method, HPLC and color number measurement (Tables 6-9).

Table 6: 120 seconds

Table 7: 180 seconds

Table 8: 300 seconds

Table 9: 600 seconds

Example 7: Follow-up of Example 2 from WO 2008/104582 In a 2 L reaction vessel charged with ethylenediamine (132 g, 2.2 mol) and with ice cooling at a temperature of up to 30 ° C. for 2 hours over 2 hours Phosphorus (563 g, 4.29 mol) was added dropwise. After an additional 4.5 hours of stirring, the solution was analyzed by Forhardt and Liebig titrations, HPLC and color number measurement. The conversion rate of formaldehyde cyanohydrin was 99.8% according to the Forhardt titration method and the Liebig titration method. The total aminonitrile yield was determined by HPLC to be 97.6% based on the formaldehyde cyanohydrin used. The number of colors of the aqueous solution was 10.1 [iodine]. The Hazen color number could no longer be measured (Table 10).

Table 10:

Example 8
700 g / h formaldehyde (30% by weight in water) and 205 g / h HCN (90% by weight in water), consisting of a circulating reactor having a capacity of 138 mL and a tubular reactor having a capacity of 19 mL, connected afterwards. Conducted to the device. The pH value in the circulating reactor was kept constant at 5.5 by the addition of 28 g / h NaOH (0.4 wt% in water). The amount of pump circulation in the circulation reactor was 48 kg / h. The temperature in the circulation reactor was adjusted to 30 ° C. The pressure was 3.2 bar. The temperature at the outlet of the tubular reactor was 37 ° C.

  The FACH thus produced (stream (5), about 42% by weight in water, concentration about 950 g / L) is immediately transferred to 207 g / h ethylenediamine (stream (4), pure) and 1.2 kg / h toluene or organic The phase (stream (6)) was passed through a tubular reactor (III) having a capacity of 18 mL (device structure, flow and device code as in FIG. 1). At the outlet of the tubular reactor, the temperature was 93 ° C. and the pressure was 1.5 bar.

  The effluent from the tubular reactor (III) (stream (7)) was released directly to the flash vessel (IV) to 0.2 bar. The stream was then cooled to 49 ° C. The exhaust steam (stream (8)) was entrained to the condenser (V) and the liquid portion (stream (12)) was entrained at the top of the distillation column (VII). The column (VII) contained a packing Montz A3-500 having a diameter of 42 mm, 960 mm. The height of the packing corresponds to about 4 separation stages. The temperature at the top of the column was 52 ° C. The exhaust vapor (stream (13)) of the column (VII) was likewise condensed in the condenser (V). The condensate (stream (10)) was then separated into an aqueous phase (stream (14)) and an organic phase (stream (11)) and separated in a phase separator (VI). The amount of aqueous phase (stream (14)) was 657 g / h. The aqueous phase was completely discharged. A total of 4.2 kg / h (stream (11)) of the organic phase was returned. The 1.2 kg / h (stream (21)) was again used for cooling the tubular reactor (III) and the remainder was returned to the top of the column (VII) for water separation. Toluene loss was compensated by the addition of fresh toluene. The temperature was adjusted to 74 ° C. at the bottom of the column (VII), and an amount of 558 g / h (stream (17)) was withdrawn.

  The bottom effluent (stream (17)) has the following composition: 15.99 wt% toluene, 3.17 wt% EDMN, 69.92 wt% EDDN, 8.92 wt% BCMI, 0.31 It has wt% EDTriN and 0.15 wt% water. An iodine color number of 10.9 was measured.

  For the ethylenediamine used, the following yields were obtained throughout the above process: 5.2% EDMN, 82.0% EDDN, 9.6% BCMI, relative to the ethylenediamine used, 0.3% EDTriN, 97.1% useful yield overall yield.

  The above examples show that the process according to the invention makes it possible to carry out the reaction between FACH and EDA with high conversion and yield. A reaction effluent with low discoloration and only by-products is obtained. The short residence time in the tubular reactor allows the reaction to be carried out in a relatively small reactor, the temperature of which is simple to monitor and the rise in reaction temperature can be controlled. To do.

Example 9: Stability of EDDN aqueous solution Analysis Useful HPLC analysis (stationary phase: 3 x Atlantis T3, 5μ, 4.6 x 250 mm, Waters; mobile phase: 50 with 0.5 g / L ammonium formate Volume% water, 50 volume% acetonitrile), respectively, using the reaction products or comparative substances present as pure substances.

Stability of 40 wt% EDDN in water at 40 ° C, 60 ° C, 80 ° C and 100 ° C for up to 600 seconds:
EDDN (30 g, pure) was dissolved in water (45 g) in a 250 mL round bottom flask equipped with a thermometer, reflux condenser and KPG stirrer. The solution was heated to the temperature shown in Table 11 using a preheated oil bath. Samples were taken at t = 0, 300 and 600 seconds. From all samples, the EDDN content was determined by HPLC and the color of the mixture was determined by color number measurement.

Table 11:

Stability of 40 wt% EDDN in water at 40 ° C, 60 ° C, 80 ° C and 100 ° C for up to 120 minutes:
EDDN (30 g, pure) was dissolved in water (45 g) in a 250 mL round bottom flask equipped with a thermometer, reflux condenser and KPG stirrer. The solution was heated to the temperature shown in Table 12 below using a preheated oil bath. Samples were removed at time points t = 0 min, 5 min, 10 min, 30 min, 60 min, 90 min and 120 min. From all samples, the EDDN content was determined by HPLC and the color of the mixture was determined by color number measurement (Table 12).

Table 12:

Stability of EDDN in 5%, 20% and 40% by weight water at 80 ° C. for up to 120 minutes EDDN (pure) in a 250 mL round bottom flask equipped with a thermometer, reflux condenser and KPG-type stirrer The indicated amount of water was added. The solution was heated to 80 ° C. using a preheated oil bath. Samples were removed at t = 0 and 120 minutes. From all samples, the color of the mixture was determined by color number measurement (Table 13).

Table 13:

  1 EDA, 2 water, 3 aqueous EDA stream, 4 gaseous component, 5 FACH, 6 toluene, 7 reaction mixture, 8 gaseous phase, 9 non-condensed component, 10 condensate, 11 toluene-containing phase, 12 liquid phase, 13 top product, 14 aqueous phase, 15 low boiler, 16 bottom product, 17 top product, 18 THF, 19 bottom product, 20 EDDN and / or EDMN with toluene and THF, no longer containing a small amount of water, 21 Flow

Claims (16)

  A method in which formaldehyde cyanohydrin (FACH) and ethylenediamine (EDA) are reacted at a temperature in the range of 20 to 120 ° C. in a reactor in which back-mixing is limited, the residence time in the reactor being 300 Said method, wherein the method is less than a second.   The method of claim 1, wherein the residence time in the reactor is less than 60 seconds.   3. The method according to claim 1 or 2, wherein the reactor is a tubular reactor.   The process according to any one of claims 1 to 3, characterized in that the temperature of introduction of the starting material into the reactor is in the range of 10-50 ° C.   The method according to any one of claims 1 to 4, wherein the reaction is carried out in the presence of one or more organic solvents.   6. The method according to any one of claims 1 to 5, wherein the reaction is carried out in the presence of water.   7. The method of claim 6, wherein at least a portion of the water is mixed with EDA prior to introduction into the reactor, and the resulting mixture is subsequently cooled.   8. A method according to any one of claims 1 to 7, characterized in that the reaction mixture is cooled after leaving the reactor.   9. The method according to any one of claims 1 to 8, characterized in that the reaction mixture is cooled by pressureless evaporation.   10. The method according to claim 9, wherein the pressure in the pressure evaporation step is less than 300 mbar.   11. The method according to any one of claims 5 to 10, wherein the organic solvent has a miscibility gap with water.   12. The method according to claim 11, wherein the organic solvent having a miscibility gap with water is toluene.   13. A method according to any one of claims 1 to 12, characterized in that the tubular reactor is additionally cooled via a cooling jacket.   13. The method according to any one of claims 9, 11 or 12, wherein the gaseous components are condensed after pressure-pressure evaporation and separated into an aqueous phase and an organic phase in a phase separator, wherein the The organic phase is fed to the evaporator together with the components which remain in the liquid state during the pressure evaporation, wherein ethylenediaminediacetonitrile (EDDN) or ethylenediaminemonoacetonitrile (EDMN) is withdrawn as bottom product. Method.   A process for producing diethylenetriamine or triethylenetetramine, wherein EDDN or EDMN is obtained in the first step by reaction of EDA and FACH according to any one of claims 1 to 14, wherein said first A process as described above, wherein the EDDN or EDMN obtained in the step is hydrogenated with hydrogen in the presence of a catalyst.   A process for producing an epoxy resin, amide or polyamide, wherein TETA or DETA is produced according to the method of claim 15 in a first step, and the TETA or DETA thus obtained in the second step is converted into an epoxy resin. To obtain an amide or polyamide.

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