EP2751067A1

EP2751067A1 - Method for processing reaction product stemming from the hydrogenation of eddn or edmn

Info

Publication number: EP2751067A1
Application number: EP12751344.8A
Authority: EP
Inventors: Hermann Luyken; Sebastian Ahrens; Gordon Brasche; Jens Baldamus; Robert Baumann; Randolf Hugo; Stephanie JAEGLI; Johann-Peter Melder; Jörg PASTRE; Boris Buschhaus
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2011-08-31
Filing date: 2012-08-30
Publication date: 2014-07-09
Also published as: CN103764614A; JP2014534164A; WO2013030258A1

Abstract

The invention relates to a method for separating a reaction product stemming from the reaction of EDDN or EDMN with hydrogen in the presence of THF and a catalyst that contains TETA or DETA, water and optionally organic compounds that have a higher or lower boiling point than TETA or DETA, characterized by a) adding the reaction product, once hydrogen was separated off, to a distillation column DK1 in which a THF/water azeotrope is separated off via the top, said azeotrope optionally containing other organic compounds having a lower boiling point than TETA or DETA, and in which column a bottom product which contains TETA or DETA is separated off, and ii) guiding the bottom product from stage i) to a distillation column DK2 and separating THF off via the top and removing a TETA- or DETA-containing stream at the bottom of the column, and iii) condensing the stream from stage i) removed at the top of the column DK1 and adding to the condensate or a part of the condensate an organic solvent, which is substantially immiscible with water, in such an amount that a phase decomposition takes place and separating the mixture so obtained in a phase separator, returning the arising organic phase, which contains THF and the organic solvent which is substantially immiscible with water, to the column DK1 and removing the aqueous phase.

Description

Process for the treatment of reaction effluents from the hydrogenation of EDDN or EDM N

Description The present application includes by reference the US Provisional Application 61 / 529,331 filed on August 31, 2011.

The present invention relates to a process for the treatment of reaction effluents from the hydrogenation of EDDN and / or. EDMN. The present invention furthermore relates to the preparation of TETA and / or DETA by reacting EDDN and / or EDM N, the separation of the reaction effluents being carried out according to the invention.

Another object of the present invention is the preparation of epoxy resins, amides or polyamides from the inventively processed DETA or TETA. In WO 2008/104579 and in the state of the art mentioned in WO 2008/104579 various production methods for EDDN or EDMN are mentioned.

It is disclosed that these reactions are preferably carried out at a temperature of 10 to 90 ° C and at normal pressure to slightly elevated pressure. Preferred reactors described are a tubular reactor or a stirred tank cascade. The work-up of the resulting reaction effluent is preferably carried out by distillation, in a first stage firstly low boilers, such as hydrocyanic acid, being separated off, and water being removed in a second distillation step. The remaining Aminonitrilgemisch may still have a residual water content of preferably at least 10 wt .-%. WO 2008/104553 describes the hydrogenation of EDDN or EDM N with hydrogen in the presence of catalysts. After the hydrogenation, the effluent from the hydrogenation may optionally be further purified, for example by separating the organic solvent and / or the catalyst by methods known to those skilled in the art. In particular, the main products (TETA or DETA) can be separated from the reaction product together or individually by methods known to those skilled in the art. If the two main products are isolated together, for example by distillation, they can then be isolated in the two individual products. Ultimately, you will get pure TETA and pure DETA. Other impurities, byproducts or other ethylene amines such as TEPA or PIP can also be separated from the respective product by methods known to those skilled in the art. Optionally, TETA may also be isolated together with diaminoethylpiperazine or piperazinyl ethyl ethylenediamine formed in minor amounts. The workup of the hydrogenation from the hydrogenation of EDDN is carried out according to the disclosure preferably by distillation. The object of the present invention was to provide a process for the separation of reaction effluents incurred in the reaction of EDDN or EDDMN with hydrogen in the presence of catalysts. A further object was to recover the solvent used efficiently and effectively, so that it was returned to the process or incorporated into a process for the preparation of EDDN or EDM N as a solvent. can be set so that a Lösungsleleverbund between the TETA and the EDDN production can be made. The separation of the reaction effluents should result in commercially viable products of high purity and quality. Furthermore, the procedural complexity of the separation should be kept as low as possible

The object was achieved by a process for the separation of a reaction product obtained in the reaction of EDDN or EDMN with hydrogen in the presence of THF and a catalyst containing TETA or DETA, water and possibly higher and lower than TETA or DETA boiling organic compounds containing, characterized in that i) the reaction after removal of hydrogen to a distillation column DK1 leads, in which a THF / water azeotrope is separated overhead, which optionally further organic compounds having a lower boiling point as TETA or DETA contains, and in which a bottom product is separated, which contains TETA or DETA, and

ii) passing the bottom product from stage i) into a distillation column DK2 and separating off THF overhead and condensing a stream containing TETA or DETA at the bottom of the column, and iii) condensing the stream from stage i) withdrawn at the top of the column DK1 and supplying to the condensate or a part of the condensate an organic solvent which is substantially immiscible with water in an amount such that a phase decay occurs and the mixture thus obtained is separated in a phase separator, wherein the organic phase forming, containing THF and recycling the organic solvent, which is substantially immiscible with water, to the column DK1 and discharging the water phase.

Reaction discharge According to the invention, the reaction effluent obtained in the reaction of EDDN or EDMN with hydrogen in the presence of THF and a catalyst which contains TETA or DETA, water and possibly higher and lower than TETA or DETA boiling organic compounds. The reaction effluent contains THF since the production of the reaction effluent is carried out by hydrogenation of EDDN and / or EDMN in the presence of THF, as described below.

THF is preferably used, as described below, already before the hydrogenation of EDDN and / or EDMN for the treatment of EDDN and / or EDM N with adsorbent as organic solvent, wherein the treatment with adsorbent preferably takes place after a water depletion.

The reaction product hydrogenation usually also contains other higher or lower boiling organic substances as by-products, such as methylamine, AEPIP, PIP or TEPA or basic compounds or additives which have been added before or during the hydrogenation, for example alkali metal hydroxides, alcoholates, amides, amines and ammonia.

The hydrogenation product preferably further contains organic solvent which was present during the hydrogenation, preferably the organic solvent which was also present during the treatment with adsorbent, in particular THF.

The reaction effluent further preferably contains distillation agents (as defined below), in particular toluene, which was preferably used in the distillative depletion of water after EDDN or EDMN production, as described below.

The reaction generally also contains small amounts of water.

In general, the amounts of water contained in the hydrogenation effluent correspond to the amounts derived from the EDDN or EDMN preparation and the preferred workup, as described below.

Preferred embodiments for producing a reaction product which is obtained in the reaction of EDDN or EDM N with hydrogen in the presence of THF and a catalyst are described below. Separation of hydrogen

According to the invention, hydrogen is separated from the reaction effluent.

The separation of hydrogen is preferably carried out by lowering the pressure at which the hydrogenation was carried out to a value at which hydrogen is gaseous, but the other components are present in the reaction effluent but in the liquid phase. Preferably, the reaction product is from a hydrogenation pressure of

preferably 60 to 325 bar, more preferably 100 to 280 bar, and most preferably 170 to 240 bar to a pressure of 5 to 50 bar relaxed in a container. At the top of the container are hydrogen and possibly ammonia, and a small amount of evaporated low-boiling components, such as THF obtained. Hydrogen and optionally ammonia can be recycled to the hydrogenation of EDDN or EDM N. For example, THF can be condensed out and recovered. Alternatively, THF may be recovered by scrubbing with a higher boiling solvent such as toluene or TETA. THF separation

The hydrogenation effluent contains TH F and it is preferable to recycle the THF into the process. In particular, it is preferred to use the THF which was present in the hydrogenation again for the treatment of EDDN and / or EDMN described below with adsorbent.

However, it is necessary that the THF be recycled almost anhydrous, since it has been found that small amounts of water in the treatment with adsorbent, the absorptive tion capacity of the adsorbent and in the hydrogenation of EDDN or

EDMN polar impurities can be introduced, which lead to undesirable side reactions. THF and water, however, form a low-boiling azeotrope. According to the invention, after separation of hydrogen, the reaction effluent is fed to a column DK1.

For this purpose, the fraction of the reaction output which has remained liquid after the expansion is preferably passed into a column DK1.

The exact operating conditions of the distillation column can be routinely determined by the skilled person on the basis of the known vapor pressures and evaporation equilibria of the components introduced into the distillation column according to the separation performance of the distillation column according to conventional calculation methods.

The column is preferably designed as a tray column.

In a tray column are located in the interior of the column shelves on which the mass transfer takes place. Examples of different soil types are sieve trays, tunnel trays, dual-flow trays, bubble trays or valve trays.

The column preferably has a stripping section and a reinforcing section. But it can also have only one output part.

The number of theoretical plates is generally in the range of 5 to 30, preferably 10 to 20.

The pressure of the column is preferably chosen so that a bottom temperature in the range of 100 to 250 ° C is established.

Preferably, the top pressure is 1 to 30 bar, more preferably 3 to 25 bar.

In general, the operating temperature of the capacitor is in the range of 30 to 70 ° C, preferably 35 to 50 ° C.

In general, low-boiling components, such as ammonia or methylamine, are not condensed and discharged as a gaseous stream. This stream can subsequently be supplied to combustion.

In the condenser condensate precipitates mainly the separated azeotrope of water and THF.

In the particularly preferred embodiment, the condensate or a part of the condensate is fed to an organic solvent which is substantially immiscible with water and which has a higher boiling point under the distillation conditions in the column DK1 than the forming THF / water azeotrope, which is pulled off at the top of the column.

In the context of the present invention, organic solvents which are essentially immiscible with water are those organic solvents in which less than 500 ppm by weight of water can be dissolved.

Preferred organic solvents which are substantially immiscible with water are toluene, n-heptane, n-octane, n-nonane and the like. Particular preference is given to using those organic solvents which are substantially immiscible with water and which also contain preferred solvents in the case of the EDDN or EDF described below. EDMN production are.

Very particular preference is given to using toluene, since this is already preferably used in EDDN or EDMN production.

The amount of organic solvent fed, which is substantially immiscible with water, is generally chosen to cause phase failure and to separate the phases by conventional engineering means such as separation in a phase separation vessel.

The weight ratio of organic solvent fed, which is substantially immiscible with water, to condensate is preferably 0.1: 1 to 10: 1, more preferably 0.5: 1 to 5: 1, and most preferably 0.8: 1 to 2 : 1.

The resulting mixture of condensate and organic solvent, which is substantially immiscible with water, is preferably passed into a phase separator where it decomposes into an aqueous phase and a phase containing THF and the substantially water immiscible solvent.

Preferably, the phase containing THF and the substantially water-immiscible solvent, in the upper region of the column DK1, preferably recycled to the top of the column DK1.

Preferably, the entire phase, the THF and the organic solvent, which is not substantially miscible with water, recycled, in the upper region of the column DK1.

By separating the water at the top of the column by adding an organic solvent which is essentially immiscible with water, and subsequent phase separation, it is possible to obtain a bottom product which contains only small amounts of water. Preferably, the bottoms discharge contains less than 1 wt .-%, more preferably less than 1000 ppm by weight and more preferably less than 200 ppm by weight of water.

The bottoms discharge from column DK1 also contains TETA or DETA, THF, which is substantially water-immiscible solvent, and optionally further organic solvent (which originates from dewatering and phase separation) and generally organic by-products, such as PIP, AEPIP and TEPA.

In the particularly preferred embodiment, the bottom product from column DK1 is passed into a distillation column DK2, in which THF is removed overhead and at the bottom of the column a stream is withdrawn, the TETA or DETA and the substantially water-immiscible solvent and, if necessary Contains additional toluene.

The exact operating conditions of the distillation column can be routinely determined according to the separation efficiency of the column used by the skilled person on the basis of the known vapor pressures and evaporation equilibria of the introduced into the distillation column components according to conventional calculation methods.

The column is preferably designed as a tray column. In a tray column are located in the interior of the column shelves on which the mass transfer takes place. Examples of different soil types are sieve trays, tunnel trays, dual-flow trays, bubble trays or valve trays.

The column preferably has only one stripping section.

The top pressure is more preferably 200 mbar to 5 bar, particularly preferably 500 mbar to 2 bar.

In the column bottom, preference is given to setting a temperature which is above the evaporation temperature of THF, so that THF is essentially completely converted into the gas phase. Particularly preferably, a temperature is set at the bottom of the column, which is in the range of 100 to 250 ° C.

The condenser of the distillation column DK2 is usually operated at a temperature at which the major part of the THF is condensed at the corresponding top pressure. In general, the operating temperature of the capacitor is in the range of 30 to 70 ° C, preferably 35 to 50 ° C.

In the condenser a condensate accumulates, which essentially contains THF. This THF preferably contains less than 200 ppm by weight, more preferably less than 100 ppm by weight of water, so that it is particularly suitable for recycling to the working up of the reaction effluent or the EDDN or EDMN preparation. Thus, a bond can be created between the EDDN or EDMN hydrogenation and the EDDN or EDMN production, which reduces the amounts of organic solvents required.

Possibly. For example, in addition to THF, the condensate at the top of the column DK2 may also contain traces of the organic solvent, which is substantially immiscible with water. Nevertheless, the condensate can, as described above, be introduced into the EDDN or EDMN

Workup be recycled, since these solvents, as described above, are also a preferred organic solvent in this stage. However, the amount of organic solvent which is essentially immiscible with water is preferably reduced in the condensate by precondensing a precondensator in the top of the column which is in the temperature range from 80 to 150.degree. C., preferably from 100 to 130.degree is operated. Alternatively, the number of trays in the enrichment section of the column DK2 can be increased and / or a portion of the condensate can be added as reflux to the column. However, it is also possible to reduce the proportion of organic solvent which is substantially immiscible with water in the overhead distillate, in which the feed to the column DK2 is cooled and / or the bottom temperature in the column DK2 is adjusted so that only a small amount Amount of water-immiscible organic solvent are transferred to the gas phase.

At the bottom of the column DK2 usually falls to a bottom product, which contains TETA or DETA, toluene, and generally the by-products AEPIP, PIP and TEPA.

In a further particularly preferred embodiment, TH F, which is obtained according to the invention at the top of the column DK 2, before returning to the process, in particular specially dehydrated before recycling in the adsorber stage described below with a molecular sieve. Preferably, the molecular sieve has a pore diameter of less than 4 A, so that only water and ammonia are retained, but not other amines such as methylamine and ethylamine. The absorption capacity of the molecular sieve as adsorbent for the separation of water is thereby increased.

Workup of the bottoms product

This bottoms discharge can be worked up further by conventional methods and separated into the individual constituents.

In a preferred embodiment, the bottom product from column DK2 is passed into a column DK3, in which a stream is withdrawn at the top, which contains predominantly toluene and / or the substantially water-immiscible solvent, and as the bottom product, a stream is withdrawn, the predominantly TETA or DETA, AEPIP and generally contains the by-products PIP, AEPIP and TEPA.

The distillation column preferably has internals for increasing the separation efficiency. The distillative internals may, for example, be in the form of an ordered packing, for example as a sheet-metal package such as Mellapak 250 Y or Montz Pak, type B1 -250. There may also be a pack of lesser or increased specific surface area, or a tissue pack or pack of other geometry such as Mellapak 252Y may be used. The advantage of using these distillative internals is the low pressure loss and the low specific liquid hold-up in comparison to, for example, valve trays. The installations can be in one or more beds.

The column preferably has a stripping and a reinforcing part.

The bottoms discharge from column DK2 is preferably supplied in a spatial range between 30% and 90% of the theoretical plates of the distillation column (counted from below), more preferably in a spatial range between 50% and 80% of the theoretical plates of the distillation column. For example, the feed may be slightly above the center of the theoretical plates. The optimum inlet point can be determined by the skilled person using the usual calculation tools.

The number of theoretical plates is generally in the range of 3 to 25, preferably 5 to 15.

Particularly preferably, a temperature is set at the bottom of the column, which is in the range of 100 to 250 ° C.

The top pressure is preferably 10 mbar to 1 bar, particularly preferably 30 mbar to 500 mbar. The condenser of the distillation column is usually operated at a temperature at which the predominant part of the toluene and / or of the substantially not mixed with water. Baren solvent is condensed at the appropriate top pressure. In general, the operating temperature of the capacitor is in the range of 30 to 70 ° C, preferably 35 to 50 ° C.

In the condenser, a condensate is formed, which contains essentially toluene and / or the substantially water-immiscible organic solvent. The toluene thus obtained and / or the substantially water-immiscible organic solvent can be recycled to the process, for example by feeding it to the condensate from column DK1. However, toluene and / or the substantially water-immiscible organic solvent can also be fed to the EDDN or EDMN work-up, for example before the flash evaporation. In this way it is possible to achieve an economic connection.

At the bottom of the column DK3 usually falls to a stream containing TETA or DETA, and generally the by-products AEPIP, PIP and TEPA. This bottoms discharge can be worked up further by conventional methods and separated into the individual constituents.

In a preferred embodiment, the bottoms discharge from column DK3 is passed into a column DK4, in which a mixture of PIP, AEPIP and DETA is obtained at the top, a mixture of pentamines, such as TEPA and other high boilers is obtained at the bottom and a TETA Stream is withdrawn with a purity of more than 99 wt .-%.

The column preferably has a stripping and a reinforcing part.

The bottoms discharge from column DK3 is preferably supplied in a spatial range between 30% and 90% of the theoretical plates of the distillation column (counted from below), more preferably in a spatial range between 50% and 80% of the theoretical plates of the distillation column. For example, the feed may be slightly above the center of the theoretical plates. The optimum inlet point can be determined by the skilled person using the usual calculation tools.

The number of theoretical plates is generally in the range of 5 to 30, preferably 10 to 20. The top pressure is more preferably 1 mbar to 400 mbar, more preferably 5 mbar to 300 mbar.

In the column bottom, a temperature is preferably set which is above the evaporation temperature of toluene, so that toluene passes substantially completely into the gas phase.

More preferably, a temperature is set at the bottom of the column, which is in the range of 150 to 250 ° C.

The condenser of the distillation column is usually operated at a temperature of preferably 30 to 70 ° C, more preferably 35 to 50 ° C.

The condensate is condensed, which essentially contains a mixture of DETA, PIP and AEPIP.

Part of the condensate can be recycled as reflux into the column DK4. Preferably, 5 to 40 wt .-%, particularly preferably 10 to 25 wt .-% of the condensate are recycled as reflux in the column DK4.

At the bottom of the column DK4 usually falls to a stream which contains substantially en mixture of pentaamines, such as TEPA, and other high boilers.

As a side stream TETA is subtracted. The side stream is preferably drawn off below the feed line of the bottom stream from column DK4, preferably in the range from 10% to 60%, particularly preferably in the range from 15 to 35% of the theoretical plates of the distillation column (counted from below). The sidestream 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 the preferred embodiments generally has a high quality and is thus particularly suitable for further reactions, for example for reaction with epoxy compounds for the production of epoxy resins or for reaction with acids for the production of Amides or polyamides.

Another object of the present invention is therefore also the preparation of epoxy resins or amides or polyamides, characterized in that in a first stage TETA and / or DETA is prepared according to the invention, and in a second stage, the TETA or DETA thus obtained to epoxy resins, Amides or polyamides is implemented.

Production of a Reaction Product According to the invention, a reaction product which is obtained in the reaction of EDDN or EDMN with hydrogen in the presence of THF and a catalyst which contains TETA or DETA, water and optionally higher and lower than TETA or DETA boiling organic compounds used. Hereinafter, preferred embodiments for the preparation of EDDN or EDMN and the subsequent reaction with hydrogen in the presence of a catalyst to TETA or DETA are described. EDDN and / or EDMN is prepared by reacting FA, HCN and EDA in the presence of water. EDA

EDA can be prepared by the EDC (ethylene dichloride) process by reacting ethylene dichloride (EDC) with aqueous ammonia. Details of the method are given, for example, in Ullmann (Article "Amines, aliphatic" in Ullmann's Encyclopedia of Industrial Chemistry, Karsten Eller, Erhard Henkes, Roland Rossbacher and Hartmut Höke, Published Online: 15 JUN 2000, DOI: 10.1002 / 14356007.a02_001, Page 33).

A further possibility for the production of EDA consists in the catalytic conversion of monoethanolamine (MEOA) with ammonia (article "Amines, aliphatic" in Ullmann's Encyclopedia of Industrial Chemistry, Karsten Eller, Erhard Henkes, Roland Rossbacher and Hartmut Höke, Published Online: 15 JUN 2000, DOI: 10.1002 / 14356007.a02_001, page 33 or Hans-Jürgen Arpe, Industrial Organic Chemistry, 6th edition (2007), Wiley VCH, 2007).

EDA can also be obtained by hydrogenation of aminoacetonitrile (AAN), whereby AAN can be prepared by reacting hydrocyanic acid, formaldehyde (FA) and ammonia. The hydrogenation of AAN to EDA is described, for example, in WO 2008/104583.

Preferably, EDA is used in the form of its free base, but if desired, it is also possible to use salts, such as the dihydrochloride of EDA, as starting material.

The purity of the EDA used in the process is preferably 95% by weight and more, more preferably 98% by weight and more, most preferably 99% by weight and more, and most preferably 99.5% by weight or more ,

FA

As a further starting material, formaldehyde is used.

Formaldehyde is a commercially available chemical.

Preferably, formaldehyde is used as a 30 to 50% aqueous solution. HCN

Furthermore, hydrocyanic acid is used for the production of EDDN and / or EDMN.

Hydrocyanic acid is also a commercially available chemical.

Hydrocyanic acid can be produced industrially by essentially three different processes. According to a first method, hydrogen cyanide can be obtained by ammoxidation of methane with oxygen and ammonia (Andrussow method). After a second procedure can hydrocyanic acid from methane and ammonia by Ammondehydrierung in the absence be obtained from oxygen. Finally, hydrocyanic acid can be produced industrially by dehydration of formamide.

The hydrocyanic acid produced by these processes is usually an acidic stabilizer, for example S0 ₂ , sulfuric acid, phosphoric acid or an organic acid, such as acetic acid, added to prevent the autocatalytic polymerization of hydrogen cyanide, which can lead to blockages in pipelines ,

Hydrocyanic acid can be used liquid or gaseous, in pure form or as an aqueous solution.

Preference is given to using hydrocyanic acid as 50 to 95% strength by weight, particularly preferably as 75 to 90% strength by weight, aqueous solution.

Hydrocyanic acid is preferably used in a purity of more than 90% by weight or more. Stabilizer-free HCN is preferably used.

When a stabilized HCN is employed, it is preferred that the stabilizer is an organic acid, especially acetic acid.

In a preferred embodiment, the EDDN preparation is carried out substantially free of cyanogen salts, such as KCN.

water

The reaction of EDA, HCN and FA preferably takes place in the presence of water.

In the reaction of EDA, HCN and FA generally 1 mole of water is formed per mole of formaldehyde used.

However, water can also be supplied additionally, for example by using the educts in the form of their aqueous solutions. In particular, as described above, FA and / or HCN are generally used as the aqueous solution for the production of EDDN or EDMN.

The amount of water used is generally in the range of 1 to 50 moles per mole, preferably in the range of 2 to 40 moles, and more preferably in the range of 3 to 30 moles per mole of EDA used.

If the reaction of HCN, EDA and FA in an adiabatic reactor, i. a reactor which is essentially not cooled and the reaction temperature is raised by the heat of reaction liberated, it is preferred that EDA, prior to introduction into the adiabatic reactor and prior to mixing with the other starting materials, such as FACH or HCN and FA, is mixed with water, since the mixing of EDA and water usually the temperature of the aqueous EDA stream increases by the exotherm of the forming hydrates. By diverting the heat of EDA heat of hydration to the entry of EDA into the reactor, the temperature rise in the adiabatic reactor can be reduced.

As devices for the mixture of EDA and water static mixers, empty lines with turbulent flow, pumps or heat exchangers are suitable. To derive the heat of hydration, water is preferably mixed with EDA in a molar ratio of water to EDA of from 1: 1 to 6: 1.

If the reaction of HCN, EDA and FA in a reactor in which the resulting heat of reaction can be removed, for example in a loop reactor with an external heat exchanger, it is preferred that in addition to the water, usually with the use of aqueous solutions is introduced by FA and HCN in the process, no additional water is supplied. Organic solvent

The reaction of EDA, HCN and FA preferably takes place in the presence of an organic solvent.

Preferred organic solvents are those selected from the group consisting of aliphatic, cycloaliphatic, araliphatic, aromatic hydrocarbons, alcohols and ethers.

It is particularly preferred that the organic solvent is stable under the conditions of subsequent hydrogenation of EDDN and / or EDMN.

In addition, it is preferable that the organic solvent is condensable at a pressure in the range of 50 to 500 mbar in the range of 20 to 50 ° C in order to use normal cooling water in the subsequent workup of EDDN or EDMN for condensing.

Furthermore, it is preferred that the organic solvent boils low enough to adjust a bottom temperature of less than 100 ° C in the subsequent water separation during the work-up of the reaction.

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, mineral spirits, gasoline, benzene, diglyme, tetrahydrofuran, 2- and 3-methyltetrahydrofuran (MeTHF) and cyclohexanol, or mixtures of these 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, Mineral spirits, gasoline (benzene), diglyme and MeTHF, or mixtures of these compounds.

The amount of organic solvent is generally 0.1 to 50 kg per kg, preferably 1 to 30 kg, more preferably 3 to 25 kg per kg of EDA used.

In a particularly preferred process variant, in the reaction of FA, EDA and HCN, an organic solvent is used which has a boiling point which is between water and EDDN or EDMN, in particular under the conditions of the distillative water removal described below. As described below, organic solvents that boil in this range allow a particularly efficient separation of water from the reaction effluent obtained in the reaction of FA, HCN and EDA becomes. 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 Mixtures thereof.

Some of the above-mentioned organic solvents can form a low-boiling azeotrope with water. A low-boiling azeotrope corresponds to the ρ, χ-diagram

Mixture at the maximum of the vapor pressure. The boiling point of this mixture has a minimum in the T, x diagram and is below that of the pure substances involved.

Particularly preferred organic solvents having a boiling point which lies between water and EDDN or EDMN and which form a low-boiling azeotrope with water are toluene, N-methylmorpholine, o-xylene, m-xylene or p-xylene, anisole, Octane, n-nonane, diisobutyl ether and diglyme, or mixtures thereof.

When the organic solvent having a boiling point between water and EDDN and / or EDMN forms a low-boiling azeotrope with water, it is further preferable that the organic solvent has a miscibility in water, particularly among those Conditions of the following work-up steps described. This facilitates the later separation of water and organic solvents. Preferably, the solubility of such an organic solvent is 1 wt% or less, more preferably 0.5 wt% or less, and most preferably 0.1 wt% or less. In particular, toluene is preferred as such organic solvent.

In a further preferred embodiment, in the reaction of FA, EDA and HCN, an organic solvent is used which has a boiling point below the boiling point of water and which forms a low-boiling azeotrope with water, in particular under the conditions of the distillative conditions described below water separation. Particularly preferred solvents which have a boiling point below the boiling point of water and which form a low-boiling azeotrope with water are n-pentane, n-hexane, n-heptane, tetrahydrofuran, cyclohexane, methylcyclohexane, mineral spirits, gasoline (benzene) or mixtures thereof , Under normal conditions, such a solvent should preferably have a boiling point of at least 50.degree. C. and more preferably of at least 60.degree. C. in order to achieve such high condensation temperatures, so that the use of brine on the condenser can be avoided.

It is further preferred that the solvent used, which has a boiling point below the boiling point of water and which forms a low-boiling azeotrope with water, under the prevailing in the reaction of FA, HCN and EDA conditions or the subsequent workup, a low solubility in water or has a miscibility gap with water. This facilitates the later separation of water and organic solvents. Preferably, the solubility of such an organic solvent in water is 1 wt% or less, more preferably 0.5 wt% or less, and most preferably 0.1 wt% or less. In a very particularly preferred embodiment, the reaction of EDA, FA and HCN to EDDN and / or EDMN is carried out in the presence of toluene as solvent and the subsequent hydrogenation of EDDN and / or EDMN to TETA and / or DETA is carried out in the presence of THF , As described below, this makes it possible to set a particularly efficient solvent composite which allows the return of the organic solvents into the process. Furthermore, it was recognized that the presence of THF during the subsequent hydrogenation, especially when the hydrogenation is carried out in suspension mode, can reduce the agglomeration tendency of the suspension catalysts used.

Accordingly, a particularly preferred embodiment of the present invention relates to the preparation of TETA and / or DETA by hydrogenation of EDDN and / or EDMN with hydrogen in the presence of a catalyst, characterized in that the preparation of EDDN and / or EDMN from FA, HCN and EDA in the presence of toluene as solvent and the hydrogenation is carried out in suspension mode in the presence of THF. In particular, it is preferred that THF is supplied after the EDDN and / or EDMN preparation and that after the EDDN and / or EDMN preparation, a treatment of EDDN or EDMN with an adsorbent, preferably a solid, acidic adsorbent, in the presence of THF takes place. Implementation of FA + HCN + EDA (General)

Methods for the reaction of EDA, HCN and FA in the presence of water are described, for example, in WO 2008/104579, the content of which is expressly incorporated by reference. According to the teaching of WO 2008/104579, the reaction of FA, HCN and EDA can be carried out according to the options a) to d) described there, the starting materials generally being converted to mixtures of EDDN and / or EDMN.

The preparation can be carried out, for example, by reacting a) HCN and EDA initially to FACH, which is subsequently reacted with EDA, or b) EDDN by reaction of an ethylenediamine-formaldehyde adduct (EDFA) or

EDMN prepared by reacting an ethylenediamine monoformaldehyde adduct (EDMFA) with hydrocyanic acid, wherein EDFA or EDMFA can be obtained by reacting EDA with FA, or that c) EDA is reacted with a mixture of formaldehyde and hydrogen cyanide, or that d ) EDA is reacted simultaneously with formaldehyde and HCN. The options a) to d)) described in WO 2008/104579 are preferably carried out at a temperature of 10 to 90 ° C, in particular at 30 to 70 ° C. The reaction can be carried out at atmospheric pressure or optionally also at elevated pressure (overpressure). The options a) to d) are preferably carried out in a tube reactor or a stirred tank cascade. Preferably, the reaction of FA, HCN and EDA can also be carried out as a continuous process, in particular as a large-scale process.

Depending on the choice of the corresponding process parameters (for example educt, temperature, solvent or pressure), the process can be controlled such that the proportion of EDMN in the reaction product varies and EDMN is not obtained as a by-product but as the second main reaction product.

Preferably, the ratio of EDDN to EDMN in the reaction of FA, HCN and EDA is influenced by the molar ratio of the starting materials as described below. Hereinafter, further details of the method options a) to d), and possibly preferred embodiments of the respective options will be described.

Option a) EDDN and / or EDMN can be prepared according to option a) from HCN, FA and EDA, whereby first FA is reacted with HCN to FACH and subsequently FACH with EDA.

As described above, EDA can in principle be prepared by methods known to those skilled in the art

FACH production

The production of FACH is described, for example, in Ullmann (Article "Formaldehyde" in Ullmann's Encyclopedia of Industrial Chemistry, Günther Reuss, Walter Disteldorf, Armin Otto Gamer and Albrecht Hilt, Published Online: 15 JUN 2000, DOI: 10.1002 / 14356007.a1 1_619, It can be carried out, for example, by reacting formaldehyde with an aqueous hydrocyanic acid.

Formaldehyde and hydrocyanic acid are also commercially available chemicals, as described above.

Preferably, formaldehyde, as described above, used as a 30 to 50% aqueous solution.

Hydrocyanic acid can, as described above, be used in gaseous form or as an aqueous solution.

A preferred variant for the production of FACH is described in WO 2008/104579. Accordingly, the preparation of FACH can be carried out by reacting aqueous formaldehyde with hydrocyanic acid. Preferably, formaldehyde is present as a 30 to 50% aqueous solution, hydrocyanic acid is preferably used in 90 to 100% purity. This implementation takes place preferably at a pH of 5.5, which is preferably adjusted with sodium hydroxide or ammonia. The reaction can be carried out at temperatures of 20 to 70 ° C, for example in the loop and / or tubular reactor. Instead of purified hydrocyanic acid (HCN) and HCN crude gas can be chemisobiert in aqueous formaldehyde solution under the above conditions to FACH. The crude HCN gas is preferably prepared by pyrolysis of formamide and, in addition to water, contains in particular small amounts of ammonia. If appropriate, the resulting aqueous FACH solution can be concentrated by careful vacuum evaporation, for example with a falling-film or thin-film evaporator. Preferably, a concentration is carried out on a 50-80 wt .-% aqueous FACH solution. Before concentration, stabilization of the FACH solution by lowering the pH to <4, preferably to <3, is advantageous, for example by addition of acid, for example by addition of phosphoric acid or preferably of sulfuric acid.

A 50 to 80% by weight aqueous solution of FACH is preferably used in the process according to option a).

EDDN / EDMN from EDA and FACH

In general, the molar ratio of EDA to FACH according to option a) in the reaction of EDA with FACH is in the range from 1: 1 to 1: 2 [mol / mol].

In option a), the molar ratio of EDA to FACH is preferably about 1: 1, 8 to 1: 2 [mol / mol], in particular about 1: 2 [mol / mol].

If the EDDN content in the reaction mixture is to be increased, the molar ratio of EDA to FACH is preferably 1: 1.5 to 1: 2, more preferably 1: 1.8 to 1: 2. A high EDDN content in the reaction mixture advantageous if EDDN is to be hydrogenated in a subsequent reaction to TETA.

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, more preferably 1: 1 to 1: 1.3. A higher EDMN content in the reaction mixture is advantageous when EDM N is to be hydrogenated in a subsequent reaction to DETA.

In general, the reaction of FACH and EDA can be carried out according to the general process conditions described above.

In particular, the reaction is carried out in the presence of one of the abovementioned organic solvents, in particular the preferred and particularly preferred organic solvents mentioned. The amount of solvent used is generally 0.1 to 50 kg per kg, preferably 1 to 30 kg, more preferably 3 to 25 kg per kg of EDA used, as described above.

As a particularly advantageous organic solvent, toluene has proven to be a technically simple and efficient method in a subsequent separation of water. The educts and optionally the organic solvent (s) used, and optionally water, can be mixed before being introduced into the reactor or first in the reactor itself.

FACH is preferably mixed with an organic solvent, one of the above-mentioned organic solvents, in particular toluene, to a FACH-containing stream, either fresh organic solvent or organic solvent, which is recovered from the subsequent workup can be used. EDA, as described above, is also preferably mixed with water to form an aqueous EDA stream before being introduced into the reactor when the subsequent reaction with FACH is carried out in an adiabatically operated reactor. Thus, the heat of hydration arising during the mixing of water and EDA can already be removed before the reactor.

However, it is also possible that the educts and optionally solvents are fed separately or partially separated and the mixture is carried out in the reactor, for example by means of suitable internals. In a particularly preferred embodiment, an organic solvent is added to the reaction mixture prior to introduction into the reactor in order to limit adiabatic temperature increase when the reaction is carried out in an adiabatically operated reactor, i. in a reactor which is substantially not cooled and in which the reaction temperature is raised by the heat of reaction liberated. The organic solvents used can help to limit the rise in temperature by absorbing heat of reaction according to their heat capacity and contributing to a lower increase in temperature. In general, the higher the amount of supplied solvent, the more the temperature rise can be limited.

Preferably, the organic solvent is cooled or added at ambient temperature so that it can absorb heat. The organic solvent is preferably introduced into the reactor at a temperature in the range from 10 to 50.degree. C., preferably from 15 to 45.degree. C. and more preferably from 20 to 40.degree

The use of organic solvents can, as described below, also accelerate cooling of the reaction mixture after leaving the reactor, for example by depressurizing the solvent-containing reaction mixture so that at least part of the organic solvent evaporates. Due to the additional evaporation of the organic solvent, the reaction mixture can be additionally deprived of heat.

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. The cooling of the reaction mixture can be carried out as described above and in more detail below.

In a most preferred variant, the reaction of FACH and EDA takes place in a reactor with limited backmixing at a temperature in the range from 20 to 120 ° C., and a short residence time. Accordingly, this particularly preferred embodiment relates to the reaction of formaldehyde cyanohydrin (FACH) with ethylenediamine (EDA) in a reactor with limited back-mixing at a temperature in the range from 20 to 120 ° C, characterized in that the residence time in the reactor is 300 seconds or less.

In this most preferred embodiment, the implementation of FACH and

EDA carried out in a reactor with limited backmixing.

Examples of a reactor with limited backmixing are a tubular reactor and a

Stirred tank battery.

The reaction of FACH and EDA is particularly preferably carried out in a tubular reactor ("plug flow reactor").

The ratio of height to diameter of the tubular reactor is preferably 1: 1 to 500: 1, more preferably 2: 1 to 100: 1, and most preferably 5: 1 to 50: 1.

The tubular reactor may contain internal internals that counteract backmixing. The internals may be, for example, balls, diaphragms, sieve plates or static mixers.

Most preferably, an empty tube is used as tube reactor.

The location of the reactor is insignificant. It can be vertical or horizontal, or run as a spiral or sly.

In this most preferred embodiment, the residence time in the reaction of FACH with EDA in the reactor in the claimed temperature range is 300 seconds or less, preferably 200 seconds or less, more preferably 100 seconds or less, and most preferably 60 seconds or less.

In a particular embodiment, the residence time is in the range from 1 to 300 seconds, particularly preferably 5 to 200 seconds, very particularly preferably 10 to 100 seconds and particularly preferably 15 to 60 seconds. In the context of the present invention is the

Dwell time τ defined as the quotient of reactor volume VR and outgoing volumetric flow V

(T =), where the reactor volume is the volume from the reactor inlet to the reactor

includes output.

In the context of the present invention, the reactor inlet corresponds to the mixing point at which FACH and EDA are brought into contact.

In the context of the present invention, the reactor outlet corresponds to the point at which the temperature of the reaction mixture is lowered by cooling.

The cooling of the reaction mixture at the reactor outlet, as described below, preferably by

Removal of heat by means of a heat exchanger,

- Supply of an organic solvent, or

Relaxation evaporation take place.

In the first case, the reactor outlet corresponds to the point at which the reaction mixture enters the heat exchanger for cooling. In the second case, the reactor outlet corresponds to the last mixing point at the outlet of the reactor, at which further organic solvent is supplied for cooling.

In the third case, the reactor outlet corresponds to the expansion valve, through which the reaction mixture is partially evaporated as described below.

Thus, if necessary, the reactor volume also includes the parts of the pipe or supply lines to the reactor, which are brought into contact between the reactor inlet (mixing point, at the EDA and FACH) and the reactor outlet (eg expansion valve, inlet to the heat exchanger or the last mixing point at the Outlet of the reactor to which organic solvent is supplied for cooling).

In the most preferred embodiment, the FACH-containing stream and the aqueous EDA stream are mixed at the input of the reactor. The mixing can take place by means of static mixers, suitable internals, such as packing, in particular Raschig rings, or by generating a turbulent flow on and after the mixing point. For example, a turbulent flow can be effected by injection or injection of one of the educts into the other educt.

In the most preferred embodiment, the reaction of EDA with FACH takes place in the temperature range from 20 to 120 ° C, preferably 25 to 100 ° C and particularly preferably in the range of 30 to 90 ° C.

Particularly preferably, the reaction of EDA with FACH in the very particularly preferred embodiment takes place under adiabatic conditions, ie. the reaction temperature is increased by the released heat of reaction.

In the very particularly preferred embodiment, it is necessary that the reaction temperature does not exceed 120 ° C, since in the context of this invention, above this temperature, an increased decomposition of the target products EDDN or EDMN was observed.

In order to limit the temperature increase in the reactor to temperatures in the range of 20 to 120 ° C, several technical measures can be carried out, preferably:

- The starting materials and optionally organic solvent and optionally water can be cooled to temperatures in the range of 10 to 50 ° C, preferably 20 to 40 ° C and particularly preferably 25 to 35 ° C before being introduced into the reactor;

the reactor or a part of the reactor can be provided with cooling devices; or

- The reaction mixture, an organic solvent can be supplied.

One or more of the above measures may be combined.

The educts, and optionally organic solvent and water can be introduced at a temperature in the range of 10 to 50 ° C, preferably 15 to 40 ° C and particularly preferably 20 to 35 ° C in the reactor. If the temperature of the educts are above these preferred ranges, then the starting materials can be cooled down with suitable cooling devices, For example, heat exchangers, in particular plate, tube bundle or double-jacket heat exchangers.

The reactor or part of the reactor may alternatively or additionally be provided with cooling devices. For example, the reactor may have a jacket cooling. It is also possible that there are elements in the reactor, which can dissipate heat, such as internal heat exchangers. Furthermore, it is also conceivable that a part of the reactor contents is passed through a loop in which a heat exchanger is located. However, additional cooling devices usually mean a higher apparatus and design effort, but these are also suitable to keep the temperature in the reactor in the range of the most preferred embodiment.

In a further embodiment, the reaction mixture may be cooled by adding further organic solvent before or during the reaction. However, the total amount of organic solvent should preferably not be above 50 kg per kg of EDA, preferably 30 and more preferably 25 kg per kg of EDA. Preferably, the organic solvent for cooling at a temperature in the range of 10 to 50 ° C, preferably 15 to 40 ° C and particularly preferably 20 to 35 ° C is introduced into the reactor. By carrying out the above-mentioned measures, in particular by the addition of organic solvent, the outlet temperatures in the range of 50 to 120 ° C, preferably maintained in the range of 60 to 1 10 ° C and more preferably in the range of 70 to 100 ° C. become. In particular, it is preferred if the cooling takes place both by adding organic solvent and by cooling the tubular reactor via a cooling jacket.

In the most preferred embodiment, the reaction mixture is additionally cooled at the outlet of the reactor. The cooling of the reaction mixture can, for example, by cooling by means of suitable cooling devices, supply of additional organic see solvent or by flash evaporation. The cooling of the reaction mixture at the outlet of the reactor will be described in more detail below.

Option b) The preparation of EDDN and / or EDMN from EDFA or EDMFA can also be carried out according to option b) by reacting FA with EDA to give EDFA and / or EDMFA, which can then react further with HCN to give EDDN or EDMN.

EDFA / EDMFA production

According to option b), EDA is first converted with FA to EDFA or EDMFA. In a preferred embodiment, no organic solvent is added to EDFA or EDMFA before or during the reaction of EDA with FA.

The reaction preferably takes place in the presence of water, since FA, as described above, is preferably used in the form of aqueous solutions.

The conversion of EDA (I) with FA to EDFA (II) or EDMFA (III) usually proceeds so fast that generally no catalyst is needed.

EDA EDMFA EDFA

(III)

(I) (II)

EDFA (II) is formally presented as a seminal for clarity. The preparation of EDFA generally proceeds via the intermediate EDMFA (III), which is formed from one mole of EDA and one mole of formaldehyde.

The reaction of EDA with formaldehyde to EDFA is generally highly exothermic. The enthalpy of reaction is between 100 and 120 kJ per mole of EDA. In addition, EDA generally forms a hydrate with water in an exothermic reaction. The amount of heat produced by hydrate formation, at about 25 kJ per mole of EDA, is usually about 20% of the total heat liberated.

The molar ratio of EDA to formaldehyde is 1 to 1.8 to 1 to 2.2, preferably 1 to 1.9 to 1 to 2.1, more preferably 1 to 2 to 1 to 2.1.

If the proportion of EDFA in the reaction mixture is to be increased, the molar ratio of EDA to FA is preferably 1: 1, 8 to 1: 2.2, more preferably 1: 1 .9 to 1: 2.1. A high EDFA content in the reaction mixture is advantageous when EDFA is reacted in a subsequent reaction with HCN to EDDN, which is to be further hydrogenated to TETA.

If the proportion of EDMFA in the reaction mixture is to be increased, the molar ratio of EDA to FA is preferably 1: 0.8 to 1: 1, 5, more preferably 1: 1 to 1: 1, 3. A higher EDMFA content in the reaction mixture is advantageous when EDMFA is reacted in a subsequent reaction with HCN to EDMN, which is to be further hydrogenated to DETA.

The pressure maintained in the reaction of EDA with FA is not critical and generally needs to be high enough that the reactor contents are liquid. It is not limited to the top and is preferably 1 to 10 bar, more preferably 2 to 5 bar.

The reaction of FA with EDA is preferably carried out continuously. For the continuous reaction of EDA with formaldehyde, all reactors suitable for liquid phase reactions can be used.

The process according to option b) is preferably carried out in a tubular reactor or a stirred tank reactor or a loop reactor, in particular a loop reactor.

A loop reactor is to be understood below as a reactor in which the reactor contents are circulated. The reaction entry can, after flowing through the reactor in a cooling device such as. B. a heat exchanger cooled, a partial stream of the cooled stream fed back into the reactor and the residual stream are passed to the next stage of the process. It can be an internal or an external cycle. Preferably, the external circuit in a cooling device, such as. B. a heat exchanger, in particular plate, tube bundle or double-jacket heat exchanger can be cooled.

By dissipating the heat of reaction, which results, for example, in the hydration of EDA or in the reaction of FA with EDA, the temperature rise in the reactor can be well controlled.

The residence time in the loop reactor is preferably 5 seconds to 60 minutes, more preferably 30 seconds to 20 minutes.

If the conversion to EDFA or EDM FA takes place in a loop reactor in which backmixing occurs, the conversion is generally not complete. It is generally in the range of 50 to 99%. In a very particularly preferred embodiment, therefore, a combination of loop reactor and downstream tubular reactor is used as the reactor.

As a result, the conversion, which can be in the range from 50 to 99% after leaving the loop reactor, as described above, can be further increased.

The downstream tubular reactor is preferably operated under the conditions of the loop reactor, preferably at the same pressure and temperature as the loop reactor

The starting materials can be mixed before being introduced into the reactor or only in the reactor itself.

It is possible, for example, for the educts and, if appropriate, organic solvents to be fed separately or partly separately and the mixture to be carried out in the reactor, for example with the aid of suitable internals.

As a mixing device, static mixers, turbulent flow piping, pumps or heat exchangers are generally suitable.

In a preferred embodiment, the mixture obtained by mixing EDA and FA is introduced into the loop of the loop reactor.

In a particularly preferred embodiment, a mixing device is contained in the reactor circuit, so that EDA and FA are introduced into the reactor cycle via separate lines. can be passed and in the circulation, before the introduction into the reactor area, are mixed in the mixing devices.

The temperature in the conversion of FA and EDA to EDFA or EDMFA is generally in the range from 0 to 100 ° C.

In a particularly preferred embodiment, the reaction of EDA and FA takes place in a narrow temperature range.

Accordingly, the particularly preferred embodiment relates to the reaction of ethylenediamine (EDA) with formaldehyde to ethylenediamine-formaldehyde adduct (EDFA) and / or ethylenediamine-monoformaldehyde adduct (EDMFA), characterized in that the reaction of FA with EDA at a temperature in the range of 20 to 50 ° C is performed.

In the temperature range of the preferred embodiment of only 20 to 50 ° C, the EDFA or EDMFA synthesis runs fast enough without a catalyst. The formation of two by-products, which lead to yield losses at temperatures of> 50 ° C, surprisingly occurs at the synthesis temperatures only to a minor extent. These are compounds IV and V, which are identified after reaction with HCN.

H

, CN

NC N

I

CH ₃

IV

V

It is believed that these by-products are due to reactions with formaldehyde and formic acid produced by Cannizzaro reaction. Their occurrence would be associated with value product losses and would lead to a reduction in the yields and selectivities, also in the subsequent reactions of EDFA or EDMFA. In addition, the N-methylated by-products are difficult to separate from the main product, so they are usually unwanted impurities.

The product of the reaction of FA and EDA prepared in the temperature range of 20 to 50 ° C has a small proportion of the minor components (IV) and (V), so that the yield of EDFA and / or EDMFA can be increased.

In the particularly preferred embodiment of the process according to option b), the temperature in the conversion of EDA with FA to EDFA and / or EDMFA is in the range from 20 to 50 ° C, preferably in the range from 25 to 45 ° C. It is further preferred that the reaction, as described above, is carried out in a loop reactor, more preferably in the previously described combination of loop reactor and tubular reactor. EDDN / EDMN from EDFA or EDMFA

In variant b) EDFA or EDMFA is subsequently further reacted with HCN to give EDDN or EDMN after its preparation.

EDFA or EDMFA is preferably reacted with HCN without further work-up.

The molar ratio of EDFA to hydrocyanic acid (HCN) is preferably 1: 1, 8 to 1: 2.2, more preferably 1: 1, 9 to 1: 2.0.

The molar ratio of EDMFA to hydrocyanic acid is preferably 1: 1 to 1: 1, 3, more preferably 1: 1 to 1: 1.2.

In general, the reaction of EDFA and / or EDMFA and HCN can be carried out according to the general process conditions described above. In particular, the reaction of EDFA or EDMFA with HCN is carried out in the presence of one of the abovementioned organic solvents, in particular the preferred and particularly preferred organic solvents mentioned. The amount of solvent used is, as described above, generally from 0.5 to 50 kg per kg, preferably from 1 to 30 kg, more preferably from 3 to 25 kg per kg of EDA used. Particular preference is also given to the reaction of EDFA or EDMFA with HCN in the presence of toluene.

The reaction pressure in the reaction of HCN with EDFA or EDMFA is generally not critical. Preference is given to setting a pressure at which the educts and any solvent used are present in the liquid phase. The pressure is therefore preferably 1 bar to 10 bar, particularly preferably 1 to 5 bar and particularly preferably 1 to 3 bar. The pressure preferably corresponds to the pressure which was set during the optionally previous conversion of FA with EDA to EDFA or EDMFA.

EDFA and / or EDM FA and HCN and, if appropriate, the organic solvent (s) used and if appropriate water may be mixed before being introduced into the reactor or first in the reactor itself.

The reaction preferably takes place in a tubular reactor or a stirred tank cascade under adiabatic conditions, ie in a reactor which is essentially not cooled and the reaction temperature is raised by the heat of reaction liberated. Due to the exothermic nature of the reaction between EDFA or EDMFA and HCN, the reaction mixture generally exits the reactor at a temperature above the inlet temperature. Preferably, the reaction mixture is cooled at the outlet of the reactor. The cooling of the reaction mixture can be carried out as described above and in more detail below.

In a particularly preferred embodiment, the reaction of EDFA or EDM-FA with HCN takes place in a reactor with limited backmixing at a temperature in the range from 20 to 120 ° C. and a short residence time.

Accordingly, this particularly preferred embodiment relates to the reaction of ethylene diamine-formaldehyde adduct (EDFA) and / or ethylenediamine monoformaldehyde adduct (EDMFA) with hydrocyanic acid (HCN) in a limited backmixed reactor at a temperature in the region of 20 to 120 ° C, characterized in that the residence time in the reactor is 300 seconds or less.

Examples of a reactor with limited backmixing are a tube reactor and a stirred tank cascade.

The reaction is particularly preferably carried out in a tubular reactor ("plug flow reactor").

The tube reactor may contain internal internals which counteract backmixing in the longitudinal direction. The internals may be, for example, balls, diaphragms, sieve plates or static mixers.

Most preferably, an empty tube is used as tube reactor.

In the preferred embodiment for reacting EDFA or EDMFA with HCN, the residence time in the reactor in the claimed temperature range is 300 seconds or less, preferably 200 seconds or less, more preferably 100 seconds or less, and most preferably 60 seconds or less.

In a particular embodiment, the residence time is in the range from 1 to 300 seconds, particularly preferably 5 to 200 seconds, very particularly preferably 10 to 100 seconds and particularly preferably 15 to 60 seconds.

In the context of the present invention, the residence time τ is defined as the quotient of the reactor volume VR and the exiting volume flow V (T =), the reactor volume being the

Includes volume from the reactor inlet to the reactor outlet. In the context of the present invention, the reactor inlet corresponds to the mixing-in point at which EDFA or EDMFA are brought into contact with HCN.

Removal of heat by means of a heat exchanger,

- Supply of an organic solvent, or

Relaxation evaporation take place.

In the first case, the reactor outlet corresponds to the point at which the reaction mixture enters the heat exchanger for cooling.

In the second case, the reactor outlet corresponds to the last mixing point at the outlet of the

Reactor, is supplied to the additional organic solvent for cooling.

In the third case, the reactor outlet corresponds to the expansion valve, after which the reaction mixture is partially evaporated, as described below.

Thus, the reactor volume also includes the parts of the pipe or supply lines to the reactor, which are brought between the reactor inlet (mixing point, contacted at the EDFA or EDMFA with HCN) and the reactor outlet (eg expansion valve, input to the heat exchanger or the last mixing point at the exit where organic solvent is supplied for cooling).

The EDFA or FACH-containing stream and the HCN stream are mixed in the particularly preferred embodiment at the entrance of the reactor. The mixing can take place by means of static mixers, suitable internals, such as packing, in particular Raschig rings, or by generating a turbulent flow on and after the mixing point.

The reaction of EDFA or EDMFA with HCN in this particularly preferred embodiment is in the temperature range from 20 to 120 ° C., preferably from 25 to 100 ° C. and particularly preferably in the range from 30 to 90 ° C.

Particularly preferably, the reaction of EDFA or EDMFA with HCN is carried out in the particularly preferred embodiment under adiabatic conditions, i. the reaction temperature in the reactor is increased by the liberated heat of reaction.

In the context of the preferred embodiment, it should be noted that the reaction temperature does not exceed 120 ° C, since in the context of this invention, above this temperature, an increased decomposition of the target products EDDN or EDMN was observed.

In order to limit the temperature rise in the reactor, several technical measures can be carried out: the starting materials and, if appropriate, organic solvent and optionally water, before being introduced into the reactor at temperatures in the range of 10 to 50 ° C, preferably 20 to 40 ° C and more preferably 25 to 35 ° C are cooled; the reactor or a part of the reactor can be provided with cooling devices; or

- The reaction mixture, an organic solvent can be supplied

One or more of the above measures may be combined.

The educts, and optionally organic solvent and water can be introduced at a temperature in the range of 10 to 50 ° C, preferably 15 to 40 ° C and particularly preferably 20 to 35 ° C in the reactor. If the temperature of the educts are above these preferred ranges, then the starting materials can be cooled down with suitable cooling devices, for example heat exchangers, in particular plate, tube bundle or double-jacket heat exchangers.

The reactor or part of the reactor may alternatively or additionally be provided with cooling devices. For example, the reactor may have a jacket cooling. It is also possible that there are elements in the reactor, which can dissipate heat, such as internal heat exchangers. Furthermore, it is also conceivable that a part of the reactor contents is passed through a loop in which a heat exchanger is located. However, additional cooling devices usually mean a higher expenditure on equipment and construction, but these are also suitable for keeping the temperature in the reactor in the range of the particularly preferred embodiment. In a further embodiment, the reaction mixture may be cooled by adding further organic solvent before or during the reaction. However, the total amount of organic solvent should preferably not be above 50 kg per kg of EDA, preferably 30 and more preferably 25 kg per kg of EDA. Preferably, the organic solvent for cooling at a temperature in the range of 10 to 50 ° C, preferably 15 to 40 ° C and particularly preferably 20 to 35 ° C is introduced into the reactor.

Due to the exothermic nature of the reaction between EDFA or EDMFA and HCN, the reaction mixture generally exits the reactor at a temperature above the inlet temperature.

By carrying out the above-mentioned measures, in particular by the addition of organic solvent, the outlet temperatures in the range of 50 to 120 ° C, preferably maintained in the range of 60 to 1 10 ° C and more preferably in the range of 70 to 100 ° C. become. In particular, it is preferred if the cooling takes place both by adding organic solvent and by cooling the tubular reactor via a cooling jacket. In the most preferred embodiment, the reaction mixture is additionally cooled at the outlet of the reactor. The cooling of the reaction mixture can be carried out, for example, by cooling by means of suitable cooling devices, addition of further organic solvent or by flash evaporation. The cooling of the reaction mixture at the outlet of the reactor is described in more detail below.

Option c)

The production of EDDN and / or EDMN can furthermore be carried out according to option c) by reacting EDA with a mixture of formaldehyde and hydrocyanic acid (GFB).

In general, the reaction of EDA with a mixture of formaldehyde and hydrogen cyanide can be carried out according to the general process conditions described above.

In particular, the reaction is carried out in the presence of one of the abovementioned organic solvents, in particular the preferred and particularly preferred organic solvents mentioned. The amount of solvent used is generally 0.5 to 50 kg per kg, preferably 1 to 30 kg, more preferably 3 to 25 kg per kg of EDA used, as described above.

In particular, the reaction is preferably carried out in the presence of water, as also described above. The molar ratio of FA and hydrocyanic acid in the GFB is generally in the range of 0.5: 1 to 1.5: 1.

The molar ratio of EDA to GFB is preferably 1: 1.5 to 1: 2 [mol / mol]. Preferably, the molar ratio of EDA to GFB is 1: 1, 8 to 1: 2 [mol / mol]. Preferably, the GFB is prepared by mixing approximately equimolar amounts of formaldehyde and hydrocyanic acid.

Preferably, the reaction mixture is cooled at the outlet of the reactor. The cooling of the reaction mixture can be carried out as described above and in more detail below

Option d)

Another variant for the production of EDDN or EDMN according to option d) is that EDA with formaldehyde and hydrogen cyanide (HCN) is reacted simultaneously (in parallel). In general, the simultaneous (parallel) reaction of EDA with formaldehyde and hydrogen cyanide (HCN) can be carried out according to the general process conditions described above. The molar ratio of EDA to formaldehyde to HCN is usually 1: 1, 5: 1, 5 to 1: 2: 2 [mol / mol / mol]. The molar ratio of EDA to formaldehyde to HCN is preferably 1: 1, 8: 1, 8 to 1: 2: 2 [mol / mol / mol]. Preferably, in this embodiment, the three reactant components are added to the reaction vessel at the same time or stepwise in equal molar amounts, based on the respective total amount of starting material.

In general, the simultaneous (parallel) reaction of EDA with formaldehyde and hydrogen cyanide (HCN) can be carried out according to the general process conditions described above. In particular, the reaction is carried out in the presence of one of the abovementioned organic solvents, in particular the preferred and particularly preferred organic solvents mentioned. The amount of solvent used is, as described above, generally from 0.5 to 50 kg per kg, preferably from 1 to 30 kg, more preferably from 3 to 25 kg per kg of EDA used.

As the reaction discharge, a mixture of EDDN and EDMN generally occurs in the previously described process variants a) to d) and their preferred embodiments. The ratio of EDDN to EDMN, as described above, can generally be influenced by the ratio of the educts used.

The weight ratio of EDDN to EDMN is generally from 30:70 to 95: 5, preferably from 50:50 to 95: 5, more preferably from 75:25 to 90:10

The reaction may optionally contain organic solvent.

The reaction product preferably contains one of the abovementioned or preferred and particularly preferred organic solvents. In particular, the reaction effluent contains toluene.

The reaction discharge particularly preferably contains 5 to 30% by weight and very particularly preferably 10 to 20% by weight and more preferably 12 to 18% by weight of toluene, based on the reaction output. With particular preference, the reaction discharge contains essentially no further organic solvents in addition to toluene.

The reaction effluent generally contains water which is formed in the reaction of FA, HCN and EDA as reaction water or which was fed together with the educts or separately.

The reaction product which is obtained in the preparation of EDDN or EDMN can

be further worked up by methods known in the art. This concerns, for example, the separation of the reaction product from unreacted educt and any solvent present.

Cooling of the effluent from the reaction of EDA, HCN and FA In a particularly preferred embodiment, the reaction mixture from the reaction of EDA, HCN and FA after leaving the reactor and cooled before working up. Accordingly, the particularly preferred embodiment relates to the preparation of EDDN and / or EDMN by reacting FA, HCN and EDA, wherein the reaction is carried out in the presence of water, characterized in that the reaction mixture from the reaction of EDA, HCN and FA after leaving the reactor is cooled.

Cooling of the reaction mixture from the reaction of FA, EDA and HCN is particularly preferred when the last stage of the reaction was carried out in an adiabatically operated reactor, in particular a tubular reactor.

It is further preferred that the temperature after cooling in the range of 20 to 70 ° C, more preferably in the range of 20 to 60 ° C and particularly preferably in the range of 30 to 50 ° C. By rapid cooling to the temperature range mentioned, it is possible that undesired by-products, for example decomposition products of nitriles, are further reduced.

The cooling of the reaction mixture can be carried out by means of suitable cooling devices, such as heat exchangers, in particular plate, tube bundle or double-shell heat exchangers.

It is also possible that further organic solvent is supplied for cooling. However, as previously mentioned, the total amount of organic solvent should preferably not be above 50 kg per kg of EDA, preferably 30 and more preferably 25 kg per kg of EDA. Preferably, the organic solvent is used for cooling at a temperature in the range of 10 to 50 ° C, preferably 15 to 40 ° C and more preferably 20 to 35 ° C introduced into the reactor.

The cooling is most preferably carried out by flash evaporation.

For this purpose, the reaction mixture from the EDDN or EDM N preparation is usually expanded into a container under reduced pressure via a valve at the outlet of the last reactor in which EDDN or EDMN production takes place. The reduced pressure is preferred adjusted so that a part of the water used and the easier than EDDN or EDMN boiling components are transferred in the reaction in the gas phase and the Eduk- te, such as EDMN or EDDN, and a portion of the water, and optionally organic solvent in the liquid phase remain.

By flash evaporation, a portion of the water is removed from the reaction mixture in a gentle manner. The withdrawn heat of vaporization, the liquid EDDN or EDMN-containing phase is cooled. By both effects, cooling and reduction of the water concentration, the contained EDDN or EDMN is stabilized in the rule. Side reactions are generally reduced by this.

Preferably, 10 to 80 wt .-%, particularly preferably 20 to 70 wt .-% and most preferably 30 to 60 wt .-% of the water present in the reaction mixture is evaporated in the flash evaporation and transferred to the gas phase.

Preferably, the reduced pressure is 1000 mbar and less, more preferably 300 mbar and less and most preferably 200 mbar and less.

In a preferred embodiment, the reduced pressure is 10 to 1000 mbar, preferably 50 to 300 mbar and particularly preferably 100 to 200 mbar.

The proportion of the components present in gaseous form after the flash evaporation is preferably partially condensed in a cooler, the condensation preferably being operated in such a way that water and any solvent used are substantially completely condensed. Lighter boiling components, e.g. Ammonia, HCN, methanol or CO2 are preferably not condensed and can be removed in gaseous form or supplied to combustion.

The work-up of the condensed phase may depend on whether the reaction of EDA with HCN and FA was carried out in the presence of an organic solvent and then which organic solvent was used.

If no organic solvent is used in the production of EDDN or EDMN, then the aqueous condensate can be fed to the column K2 described below, in which low boilers are separated from water. It is also possible to supply the water for disposal, for example, a wastewater treatment.

If an organic solvent is used which is miscible with water or has no miscibility gap with water, the condensed mixture of organic solvent and water is usually separated by distillation into an aqueous stream and a solvent-containing stream, the solvent-containing stream being preferred is returned to the process or can be introduced into a column K1 described below. The aqueous stream can generally be introduced into a water treatment.

If, in a preferred embodiment, a solvent is used as organic solvent which has a miscibility gap with water or which is essentially insoluble in water, the condensed mixture preferably becomes a phase separator so that the condensed phase can be separated into a phase containing the organic solvent and an aqueous phase.

By using an organic solvent which has a miscibility with water or is substantially insoluble in water, the separation of organic solvent and water can generally be carried out without additional distillation. In addition, the separated water after phase separation can then generally be introduced directly into a sewage treatment plant or returned to the process, for example for mixing EDA with water.

In this regard, organic solvents in which the amount of solvent dissolved in the aqueous phase is very low (less than 5000 ppm) are particularly preferred. Examples include toluene, cyclohexane, Metyhlcyclohexan, octane, heptane and xylenes.

The aqueous phase obtained after the phase separation can also be introduced into a distillation apparatus K2, in which water is separated off as the bottom product from lower-boiling organic components. The water thus separated off can be recycled, for example, as a solvent into the process (for example for the production of an aqueous EDA solution) or fed to a sewage treatment plant or to a biological wastewater treatment. The organic low boilers separated off by distillation during the distillation in the column K2 (for example organic solvents which are lighter than water or solvents which form a low-boiling azeotrope with water, HCN or toluene) are preferably recycled to the process. For example, the organic low-boiling components can be fed to the condenser connected downstream of the flash evaporation.

The organic phase obtained after the phase separation is preferably passed into the column K1 described below or recycled as organic solvent in the process.

The EDDN- or EDMN-containing reaction effluent present in the liquid phase reduced pressure vessel after flash evaporation is preferably fed to a distillation column K1, as described below, in which water is depleted of EDDN and EDMN, respectively.

If an organic solvent was used in EDDN or EDM N production, which has a miscibility gap with water or a low solubility in water under the conditions of the EDDN or EDMN preparation, the formation in the container in which the discharge from the EDDN or EDMN preparation was expanded, usually two liquid phases, namely an aqueous EDDN or EDMN phase and a phase containing the organic solvent.

Preferably, the two phases, as described below, separately or together fed to a column K1. It is further preferred that when the column contains K1 packing, both liquid phases separated from each other to lead to separate liquid distributor.

After cooling, the reaction product used in the production of EDDN or

EDMN accumulates, be further worked up by methods known in the art. This For example, concerns the separation of the reaction product of unreacted starting material and any solvent present.

Working up of the reaction product from EDDN or EDMN production

As mentioned above, the reaction product obtained in the production of EDDN or EDMN can be worked up further by methods known to those skilled in the art. This relates for example to the separation of the reaction product from unreacted starting material and any solvent present.

The reaction discharge from the EDDN or EDMN preparation is preferably worked up by firstly i) carrying out a low boiler separation and then ii) carrying out a water depletion. Leichtsiederabreicherung

The depletion of the low boilers is preferably carried out by stripping. Thus, for example, the reaction effluent from EDDN or EDMN production can be stripped with nitrogen in order to remove traces of hydrocyanic acid, which can occur, for example, as a decomposition product of FACH.

However, the separation of low-boiling components can also be effected by distillation. When the separation of low boilers is carried out by distillation, it is preferred that the residence time in the distillation be kept short, for example by carrying out the distillation in a falling film evaporator or wiped film evaporator.

Preferably, the low boiler removal, as described above, by flash evaporation. The flash evaporation has the advantage that the low boiler removal and the cooling of the reaction can be carried out in one process step.

Wasserabreicherung

The water depletion after the depletion of low boilers preferably takes place in a distillation column K1.

The column is generally operated so that an aqueous stream is withdrawn at the top of the column, while at the bottom of the column an EDDN or EDMN-containing stream is withdrawn.

The discharge from the EDDN or EDMN preparation is preferably fed together with the distillation agent into the upper region, preferably at the top, to a distillation column K1.

When the discharge from the EDDN or EDMN preparation was cooled by flash evaporation and when an organic solvent in the EDDN or EDM N production was used, which under the conditions of EDDN or EDMN production has a miscibility gap with water or in water a low solubility, so form as described above, in the container in which the discharge from the EDDN or EDMN- Production was relaxed, two liquid phases. In this case, it is preferable that the aqueous EDDN or EDMN aqueous phase and the organic solvent are separately supplied to the column K1 as a distillation agent. It is further preferred that when the column contains K1 packing, both liquid phases to lead to separate liquid distributor. In this case, it is preferable to recycle the organic solvent as distillation agent into the stripping section of the column, preferably into the lower section of the column, and more preferably into the bottom of the column. This has the advantage that HCN, which may be contained in the recycled organic solvent, can react with EDMN to EDDN. This can reduce the amount of HCN removed.

The distillation column K1 preferably has internals for increasing the separation efficiency. The distillative internals may, for example, be in the form of an ordered packing, for example as a sheet-metal package such as Mellapak 250 Y or Montz Pak, type B1 -250. There may also be a package of lesser or increased specific surface area, or a fabric packing or other geometry package such as Mellapak 252Y may be used. The advantage of using these distillative internals is the low pressure loss and the low specific liquid hold-up in comparison to, for example, valve trays. The installations can be in one or more beds.

The top pressure in the column K1 is preferably adjusted so that the bottom temperature is in the range specified below.

It is preferred that the bottom temperature is 100 ° C or less because it has been found in the present invention that EDMN or EDDN is unstable in the presence of water at higher temperatures and decomposes to undesirable by-products. Preferably, a bottom temperature in the range of less than 100 ° C, more preferably less than 80 ° C and most preferably less than 60 ° C is set. More preferably, the bottom temperature is in the range of 20 to 100 ° C, more preferably in the range of 30 to 80 ° C and most preferably in the range of 40 to 60 ° C.

The top pressure is preferably 10 mbar to 1 bar, more preferably 30 mbar to 700 mbar and most preferably 50 to 500 mbar.

In a very particular embodiment, the top pressure in the column K1 is less than 300 mbar, more preferably 100 to 200 mbar and most preferably 130 to 180 mbar. In the context of this invention, it has been recognized that at the temperatures which are established at these top pressures in the column, the formation of deposits in the column internals, in particular the column packs, can be substantially reduced. In a very particularly preferred embodiment, the distillation is carried out in the presence of an organic solvent which has a boiling point between water and EDDN and / or EDM N at the distillation pressure prevailing in the column or which forms a low-boiling azeotrope with water.

This particularly preferred embodiment thus relates to the preparation of EDDN and / or EDMN by reacting FA, HCN and EDA, wherein the reaction is carried out in the presence of water, and depleted after the reaction water from the reaction mixture in a distillation column, characterized in that the distillation is carried out in the presence of an organic solvent which has a boiling point between water and EDDN and / or EDMN at the distillation pressure prevailing in the column or which forms a low-boiling azeotrope with water.

The organic solvent which has a boiling point between water and EDDN and / or EDM N at the distillation pressure prevailing in the column or which forms a low-boiling azeotrope with water is hereinafter referred to as a distillation medium.

Preferred distillers are the organic solvents mentioned at the beginning which have a boiling point between water and EDDN and / or EDMN or which form a low-boiling azeotrope with water.

Very particular preference is given to using toluene as the distillation agent.

It is preferred that the distillation agent is already supplied before or during the reaction of FA, HCN and EDA. As mentioned above, the amount of organic solvent is generally 0.1 to 50 kg per kg, preferably 1 to 30 kg, more preferably 3 to 25 kg per kg of EDA used.

The amount of distillation agent should generally be such that in the column bottom of the distillation column K1 - as described above, preferably a bottom temperature in the range of less than 100 ° C, more preferably less than 80 ° C and most preferably less than 60 ° C is set. Preferably, the bottom temperature is in the range of 20 to 100 ° C, more preferably in the range of 30 to 80 ° C and most preferably in the range of 40 to 60 ° C.

It is preferred that the bottom temperature is 100 ° C or less because it has been found in the present invention that EDMN or EDDN is unstable in the presence of water at higher temperatures and decomposes to undesirable by-products.

If the distillation medium forms a low-boiling azeotrope with water, then it is necessary that the amount of distillation agent be sufficient to be on the correct "side" of the azeotrope, ie that the amount of distillation agent must be sufficient to maintain the azeotrope At the top of the column, the low-boiling, aqueous azeotrope and essentially no more water are obtained in the bottom of the column The required amount of solvent can be determined routinely by the person skilled in the art, depending on the chosen distillation agent, from generally known tables and reference books for azeotropes. The top pressure in the column K1 is, as described above, preferably 10 mbar to 1 bar, more preferably 30 mbar to 700 mbar and most preferably 50 to 500 mbar. In a very particular embodiment, the top pressure in the column K1 is less than 200 mbar, more preferably 100 to 200 mbar and most preferably 130 to 180 mbar. In the context of this invention, it has been recognized that at the temperatures set at these head pressures in the column, the formation of deposits in the column internals, in particular the column packs, can be substantially reduced.

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 the corresponding top pressure. In general, the operating temperature of the capacitor is in the range of 20 to 70 ° C, preferably 25 to 50 ° C.

In the condenser, a condensate generally accumulates, which contains essentially water or a low-boiling water azeotrope.

The condensate of the column K1 can either be discharged or returned to the process. Possibly. the condensate can be separated before recirculation or discharge in water and distillation, for example by distillation. For example, the distillation of water in the previously described column K2 can be carried out.

If the distillation medium has a miscibility gap with water, then the separation of water and distillation agent can also be effected by means of phase separation.

In a preferred embodiment, the vapors from the top of the column K1 are fed to the condenser, at which the vapors which are formed in the flash vaporization, ie. that the vapors from the column K1 and from the flash evaporation are driven onto a common condenser.

Reaction output from the column K1 In the bottom of the column K1, a mixture which contains EDDN or EDMN is preferably withdrawn as the bottom product.

The EDDN or. EDMN-containing mixture preferably contains the distillate used in the distillative removal of water.

If toluene is used as the distillation agent, then the EDDN or. EDMN-containing mixture from the bottom of the column K1 preferably 5 to 30 wt .-% toluene and most preferably 10 to 20 wt .-% and particularly preferably 12 to 18 wt .-%, based on the discharged sump.

The EDDN or. In the preferred embodiment, EDMN-containing mixture from the bottom of column K1 contains-in contrast to the amounts of more than 10% by weight described in the prior art-preferably less than 3% by weight, more preferably less than 1 Wt .-% water, most preferably less than 0.5 wt .-% and particularly preferably less than 0.3 wt .-% water.

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

Treatment with Adsorbent In a further particularly preferred embodiment, however, the EDDN- or EDMN-containing mixture after the water depletion is purified before the hydrogenation of the EDDN or EDMN to form TETA or DETA, in which the EDDN- or EDMN-containing mixture treated with an adsorbent. In a very particularly preferred embodiment, the treatment is carried out with a solid, acidic adsorbent. In the context of the present invention, it has been found that with solid, acidic adsorbents, the service life of hydrogenation catalysts in the subsequent hydrogenation can be extended to DETA or TETA. Furthermore, it has been found that the formation of the by-products aminoethylpiperazine (AEPIP) which occur in the hydrogenation of EDDN or EDMN, which are generally associated with the loss of activity of the catalyst, can be reduced.

Thus, this further particularly preferred embodiment relates to the production of EDDN and / or EDMN by

a) reaction of FA, HCN and EDA, the reaction being carried out in the presence of water, b) depleted of water from the reaction mixture obtained in step a), and

c) the mixture from stage b) is treated with an adsorbent in the presence of an organic solvent,

characterized in that the adsorbent is a solid, acidic adsorbent. Stage a)

Methods for reacting FA, HCN and EDN in the presence of water (step a)) have been described above. For example, the reaction according to the options a) to d) described above, in particular according to the embodiments described as preferred.

Stage b)

The depletion of water from the reaction of EDDN or EDM N production is also described above.

Preferably, low-boiling components, such as HCN or methanol, are separated from the reaction discharge from the EDDN or EDMN preparation, for example by stripping or decanting. evaporation, and the water-containing EDDN or EDMN subsequently fed to a distillation in which water is depleted. Most preferably, the distillation is carried out as described above in the presence of a distillation agent (definition see above). Specification: entry level c)

The EDDN or EDMN mixture from stage b) preferably contains 95% by weight EDDN and / or EDMN and more, particularly preferably 97% by weight and more, very particularly preferably 99% by weight and more, based on the EDDN mixture minus the distillation agent contained in the EDDN mixture (calculated as "distillate-free").

As described above, the mixture obtained from stage b) preferably contains the distillate used in the depletion of water.

Was used as the distillation agent toluene, the EDDN or EDMN mixture from step b) preferably contains 5 to 30 wt .-% toluene, particularly preferably 10 to 20 wt .-% toluene, and most preferably 12 to 18 wt. -%.

If distillation agents are used which have no miscibility gap with EDDN, then the EDDN or EDMN mixture from stage b) contains preferably 5 to 50 Gew. -% EDDN and / or EDMN, particularly prefers 8 to 30 Gew. -% EDDN and / or EDMN, and most preferably 10 to 20 wt .-% EDDN and / or EDMN.

The EDDN or EDM N mixture obtained from stage b) preferably contains less than

3% by weight, particularly preferably less than 1% by weight, very particularly preferably less than 0.5% by weight of water and particularly preferably less than 0.3% by weight of water, based on EDDN and EDMN.

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

Suitable solvents are all organic solvents which can be used for the reaction of EDDN or EDMN. As mentioned above, it is preferred that the organic solvents used are stable under the conditions of EDDN and EDMN hydrogenation, respectively.

Preferably, the organic solvent is fed before the treatment of the EDDN or EDMN mixture from step b) with the adsorbent.

Preferably, enough organic solvent is added so that the concentration of EDDN and / or EDM N in the mixture which is treated with the adsorbent, in the range of 5 to 50 wt .-%, particularly preferably 8 to 30 wt .-% and very particularly preferably 10 to 20 wt .-% is.

It is further preferred that the water content of organic solvents fed after EDDN and / or EDMN preparation and before or during the treatment of the EDDN and / or EDM N with adsorbent, have a low water content, since it was found that small amounts of water in the treatment with adsorbent can reduce the absorbency of the adsorbent and in the subsequent hydrogenation of EDDN or EDM N polar impurities can be introduced, which lead to undesirable side reactions.

The organic solvent fed in more preferably contains less than 0.5% by weight of water, more preferably less than 0.3% by weight of water, very preferably less than 0.1% by weight of water and particularly preferably less than 0 , 03 wt .-% water. In a most preferred embodiment, THF is supplied as organic solvent. When THF was used, particularly good catalyst service lives could be achieved in the subsequent hydrogenation. If the subsequent hydrogenation is carried out in suspension mode, the use of THF can reduce the agglomeration tendency of suspension catalysts during the hydrogenation.

Solid, acid adsorbents

In the context of the present invention, solid, acidic adsorbent is understood as meaning a water-insoluble porous material which, because of its large surface area, can bind water or other molecules to it by physical or chemical forces

An acidic adsorbent usually has functional groups that behave under the conditions of adsorption as Bronsted or Lewis acids. In particular, an acidic sorbent is able to retain preferred basic substances compared to less basic substances.

Preferred solid, acidic adsorbents are acidic metal oxides, such as silica, titania, alumina, boria (B ₂ 0 ₃ ), zirconia, silicates, aluminosilicates, borosilicates, zeolites (in particular in the H form), acid ion exchangers, and silica gel, eg sorbead WS of BASF SE, or mixtures of these substances.

Very particularly preferred solid, acidic adsorbents are silicon dioxide and silica gel.

Very particularly preferred are silica gels, e.g. by acidification of aqueous Natronwas- serglas solutions and drying of the initially obtained silica sols can be prepared, as described for example in Hollemann-Wiberg (Textbook of Inorganic Chemistry, 102nd edition, Verlag Walter Gruyter, 2007, page 962). Examples of 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 a substance selected from the group consisting of silica, titania, alumina, boria (B2O3), zirconia, silicates, aluminosilicates, borosilicates, zeolites (especially in the H form), acidic ion exchangers and silica gel. In the context of the present invention, the feature solid acidic adsorbent comprises neither activated carbon nor non-acidic (basic) ion exchangers. The treatment of the obtained in step b) EDDN or EDM N mixture with organic solvent can be carried out either continuously, semi-continuously or discontinuously.

The treatment can be carried out batchwise, for example by bringing the adsorbent into contact with the EDDN or EDMN in the presence of an organic solvent. The treatment may be carried out by suspending the adsorbent in the mixture to be purified, e.g. by stirring in a suitable container.

The treatment time in the batchwise treatment is generally in the range of 1 minute to 48 hours, preferably 5 minutes to 24 hours, more preferably 1 hour to 16 hours and particularly preferably 2 to 8 hours.

The amount of adsorbent is preferably in the range of 0.1 to 25 wt .-%, more preferably in the range of 0.5 to 20 wt .-% and most preferably in the range of 1 to 10 wt .-%, based on the sum of EDDN, EDMN and organic solvent.

The pressure is usually not critical. However, it is preferred to set a pressure at which the mixture to be purified is liquid. The pressure is usually 1 to 10 bar. The treatment is generally carried out at temperatures of less than 150 ° C, preferably less than 100 ° C, more preferably less than 80 ° C and most preferably less than 60 ° C.

The discontinuous treatment with adsorbent can be carried out under an inert gas atmosphere, for example under nitrogen or argon.

After the treatment, the adsorbent can be separated by suitable methods of EDDN or EDMN, for example by filtration, centrifugation or sedimentation.

Preferably, the treatment of the mixture to be purified takes place continuously.

Particularly preferably, the mixture to be purified is passed over one or more fixed beds or beds of the adsorbent. The adsorbent may also be arranged in the form of a fluidized bed

The fixed bed or the bed is preferably arranged in a tube or a heat exchanger.

The fixed bed or bed is generally passed through by the mixture to be cleaned.

The load is preferably 0.01 to 20, more preferably 0.05 to 15 and most preferably 0.1 to 10 kg to be purified mixture per kg of adsorbent per hour. The fixed bed volume and the size of the adsorbent particles can be varied within wide limits and thus adapted to the selected reaction conditions and the process conditions.

However, the particle size of the solid, acidic adsorbents used is preferably 0.1 to 10, particularly preferably 0.5 to 6 and very particularly preferably 1 to 4 mm, since was that too large particles have negative diffusion effects and too small particles 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 carousel arrangement, in particular with regeneration, i. Two or more fixed beds are alternatively flowed through, so that the unused fixed beds can be regenerated.

The pressure is usually not critical. However, it is preferred to set a pressure at which the mixture to be purified is liquid. The pressure is usually 1 to 10 bar. As already described above, the treatment is generally carried out at temperatures of less than 150.degree. C., preferably less than 100.degree. C., more preferably less than 80.degree. C. and particularly preferably less than 60.degree.

The continuous treatment with adsorbent can be carried out under an inert gas atmosphere, for example under nitrogen or argon.

If necessary, after the continuous treatment, the adsorbent or parts of the adsorbent, e.g. Abrieb, be separated by suitable methods of EDDN or EDMN, for example by filtration, centrifugation or sedimentation.

It may be necessary that the adsorbent must be regenerated after a certain period of operation, if the effect of the adsorbent decreases with increasing operating time.

The regeneration of the adsorbent can be carried out by washing with water, preferably by washing with dilute aqueous acids, more preferably first by washing with water and then by washing with dilute aqueous acids. For washing, dilute, organic acids are preferably used, more preferably

Acetic acid.

Preferably, the concentration of acids in the dilute aqueous acids is 10% by weight or less.

Preferably, after treatment with water and / or aqueous acid, the sorbent is dried by introducing a dry gas such as air or nitrogen. Preferably, when drying with a dry gas, the sorbent and / or the gas is warmed up.

In a particularly preferred process variant, the sorbent is dried by passing a dry organic solvent over it. Particularly preferred is the same organic solvent that is used in the subsequent hydrogenation or that is already present in the treatment with adsorbent. The dry organic solvent preferably contains 1% by weight of water or less, particularly preferably 0.5% by weight or less, very particularly preferably 0.1% by weight or less and especially preferably 0.05% by weight or fewer. The dry organic solvent can be passed either liquid or vapor over the adsorbent. The mixture from stage c) preferably comprises EDDN and / or EDMN together with the organic solvent in the presence of which the treatment with adsorbents has been carried out and, if appropriate, distillation agent which was preferably present during the water depletion. Possibly. the mixture obtained from stage c) may contain further organic solvents.

The water content of the mixture from stage c) is preferably lower than the water content of the EDDN or EDMN mixture before the treatment with adsorbent, since the adsorbent also has a drying effect.

The water content of the mixture from stage c) is preferably 0.1% by weight or less, more preferably 0.03% by weight or less.

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

However, the mixture obtained from c) is preferably fed directly to the hydrogenation without further work-up.

The hydrogenation can, as described below, carried out hydrogenation of EDDN or EDMN to TETA or DETA

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

The production of EDDN or EDMN preferably takes place-as described above-in accordance with one of the options a) to d) described above, in particular of the preferred embodiments described therein.

Furthermore, it is preferred that the reaction mixture from the EDDN or EDMN production is cooled, preferably by flash evaporation.

Furthermore, it is preferred that the reaction mixture from the EDDN or EDMN preparation is purified, preferably, as described, by depletion of low boilers, preferably by flash evaporation, and subsequent distillation to deplete water, preferably in the presence of a distillation agent.

It is further preferred that the EDDN or EDMN mixture after depletion of water is treated with an adsorbent, preferably as described with a solid, acidic adorbent.

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

Preferably, the mixture introduced into the hydrogenation contains the organic solvent present in the treatment with adsorbent.

Furthermore, the mixture which is introduced into the hydrogenation, distillation medium, which was preferably used in the distillative Wasserabreicherung.

hydrogen

The preparation of TETA or DETA takes place in the presence of hydrogen.

The hydrogen is generally used technically pure. The hydrogen may also be in the form of a hydrogen-containing gas, i. with admixtures of other inert gases, such as nitrogen, helium, neon, argon or carbon dioxide are used. For example, reformer effluents, refinery gases, etc. can be used as the hydrogen-containing gases, if and insofar as these gases do not contain any contact poisons for the hydrogenation catalysts used, for example CO. However, preference is given to using pure hydrogen or essentially pure hydrogen in the process, for example hydrogen having a content of more than 99% by weight of hydrogen, preferably more than 99.9% by weight of hydrogen, particularly preferably more than 99.99 Wt .-% hydrogen, in particular more than 99.999 wt .-% hydrogen. Organic solvent

The hydrogenation takes place in the presence of THF, since in THF the agglomeration tendency of catalysts, in particular in the suspension mode of operation, can be reduced.

Particularly preferably, the hydrogenation takes place in the presence of so much THF that the content of EDDN and / or EDMN during the hydrogenation preferably in the range of 5 to 50

Wt .-%, particularly preferably 8 to 30 wt .-% and most preferably 10 to 20% by weight.

It is further preferred that the preparation of EDDN and / or EDMN, as described above, takes place in the presence of toluene.

water

The hydrogenation of EDDN or EDMN can also be carried out in the presence of water.

However, it is preferred to add no further water since both EDDN and EDMN tend to decompose in the presence of water. Preference is given to using an EDDN or EDMN which contains less than 3% by weight, preferably less than 1% by weight, particularly preferably less than 0.5% by weight of water and particularly preferably less than 0.3% by weight. , based on EDDN or EDMN contains.

Very particular preference is given to using an EDDN or EDMN which contains less than 0.1% by weight and more preferably less than 0.03% by weight of water, based on EDDN or EDMN.

In particular, it is preferred that EDDN and / or EDMN having a low water content is obtained by treating the EDDN and / or EDMN with adsorbent. Additive: Basic compounds

In a further preferred process variant, the hydrogenation takes place in the presence of basic compounds which are preferably in suitable solvents, such as alkanols, such as C 1 -C 4 -alkanols, e.g. Methanol or ethanol, or ethers, such as cyclic ethers, e.g. THF or dioxane are added to the reaction mixture.

Particular preference is given to adding solutions of alkali metal or alkaline earth metal hydroxides or of hydroxides of the rare earth metals in water, particularly preferably solutions of LiOH, NaOH, KOH and / or CsOH.

It is preferably fed so much alkali and / or alkaline earth metal hydroxide, that the concentration of alkali and / or alkaline earth metal hydroxide based on the mixture to be hydrogenated in the range of 0.005 to 1 wt .-%, particularly preferably 0.01 to 0.5 wt .-% and most preferably 0.03 to 0.1 wt .-% is.

As basic compounds but can also be used preferably amides and / or amines, such as ammonia and EDA.

By adding such basic additives, the amount of by-products formed, such as AEPIP, can be reduced in the hydrogenation.

Preferred examples of such additives are ammonia and ethylenediamine.

The amount of these additives is 0.01 to 10 moles per mole EDDN + EDM N.

The basic additives can generally be fed batchwise or continuously and before and / or during the hydrogenation.

catalysts

As catalysts for the hydrogenation of the nitrile function to the amine catalysts can be used, which as active species one or more elements of the 8th subgroup of the periodic table (Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt), preferred Fe, Co, Ni, Ru or Rh, more preferably Co or Ni.

This includes so-called oxidic catalysts containing the one or more active species in the form of their oxygen-containing compounds and so-called skeletal catalysts (also known as Raney® type, hereinafter also: Raney catalyst), which by leaching (activation) an alloy of hydrogenation-active metal and another Component (preferably Al) are obtained. The catalysts may additionally contain one or more promoters.

In a particularly preferred embodiment, hydrogenation of EDDN and / or EDMN uses Raney catalysts, preferably Raney cobalt or Raney nickel catalysts.

Catalysts and particularly preferably with at least one of the elements Cr, Ni or Fe doped Raney cobalt or doped with one of the elements Mo, Cr or Fe Raney nickel catalysts. The catalysts can be used as unsupported catalysts or supported. The preferred carriers are metal oxides such as Al 2 O 3, SiO 2, ZrO 2, Z 2, mixtures of metal oxides or carbon (activated carbons, carbon blacks, graphite).

The oxide catalysts are activated before use outside the reactor or in the reactor by reduction of the metal oxides in a hydrogen-containing gas stream at elevated temperature. If the catalysts are reduced outside the reactor, then passivation by an oxygen-containing gas stream or embedding in an inert material can be done to avoid uncontrolled oxidation in air and to allow safe handling. Organic solvents such as alcohols but also water or an amine, preferably the reaction product, can be used as the inert material. An exception in the activation are the skeletal catalysts, which are prepared by leaching with aqueous base, such. As described in EP-A 1 209 146, can be activated.

Depending on the process carried out (suspension hydrogenation, fluidized bed process, fixed-bed hydrogenation), the catalysts are used as powder, grit or shaped body (preferably extrudates or tablets).

Particularly preferred fixed bed catalysts are the full cobalt contacts disclosed in EP-A1 742 045, doped with Mn, P, and alkali metal (Li, Na, K, Rb, Cs). The catalytically active composition of these catalysts before reduction with hydrogen from 55 to 98 wt .-%, in particular 75 to 95 wt .-%, cobalt, 0.2 to 15 wt .-% phosphorus, 0.2 to 15 wt. -% manganese and 0.05 to 5 wt .-% alkali metal, especially sodium, each calculated as the oxide.

Further suitable catalysts are the catalysts disclosed in EP-A 963 975, whose catalytically active composition before treatment with hydrogen contains 22 to 40% by weight ZrO ₂ , 1 to 30% by weight of oxygen-containing compounds of copper, calculated as CuO, 15 to 50% by weight of oxygen-containing compounds of nickel, calculated as NiO, the molar Ni: Cu ratio being greater than 1, 15 to 50% by weight of oxygen-containing compounds of cobalt, calculated as CoO, 0 to 10% by weight oxygen-containing compounds of aluminum and / or manganese, calculated as Al 2 O 3 or MnO 2, and contain no oxygen-containing compounds of molybdenum, for example the catalyst A disclosed in this document with the addition of composition 33% by weight Zr, calculated as ZrO ₂ , 28% by weight Ni, calculated as NiO, 1 1% by weight Cu, calculated as CuO and 28% by weight Co, calculated as CoO.

Also suitable are the catalysts disclosed in EP-A 696 572, whose catalytically active composition prior to reduction with hydrogen contains 20 to 85% by weight ZrO ₂ , 1 to 30% by weight of oxygen-containing compounds of copper, calculated as CuO, 30 to 70 wt .-% oxygen-containing compounds of nickel, calculated as NiO, 0.1 to 5 wt .-% oxygen-containing compounds of molybdenum, calculated as M0O3, and 0 to 10 wt .-% oxygen-containing compounds of aluminum and / or manganese, calculated as Al ₂ 0 ₃ or Mn0 ₂ contains. For example, the specifically disclosed in this document catalyst having the composition 31, 5 wt .-% Zr0 ₂ , 50 wt .-% NiO, 17 wt .-% CuO and 1, 5 wt .-% M0O3. Also suitable are the catalysts described in WO-A-99/44984 comprising (a) iron or a compound based on iron or mixtures thereof, (b) from 0.001 to 0.3% by weight, based on (a) of Promoters based on 2, 3, 4 or 5 elements selected from the group AI, Si, Zr, Ti, V, (c) from 0 to 0.3 wt .-% based on (a) a compound based on an alkali and / or alkaline earth metal, and (d) from 0.001 to 1 wt .-% based on (a) manganese.

For suspension processes Raney catalysts are preferably used. In the Raney catalysts, the active catalyst is prepared as a 'metal sponge' from a binary alloy (nickel, iron, cobalt, with aluminum or silicon) by dissolving a partner with acid or alkali. Residues of the original alloying partner often act synergistically.

The Raney catalysts used for the hydrogenation of EDDN and / or EDMN are preferably prepared starting from an alloy of cobalt or nickel, more preferably cobalt, and another alloying component which is soluble in alkalis. In this soluble alloy component, aluminum is preferably used, but other components such as zinc and silicon or mixtures of such components may be used.

To activate the Raney catalyst, the soluble alloying component is wholly or partly extracted with alkali, for which example aqueous sodium hydroxide solution can be used. The catalyst can then z. B. be washed with water or organic solvents.

In the catalyst, one or more other elements may be present as promoters. Examples of promoters are metals of subgroups IB, VIB and / or VIII of the Periodic Table, such as chromium, iron, molybdenum, nickel, copper, etc.

The activation of the catalysts by leaching the soluble component (typically aluminum) can either be in the reactor itself or before it is charged to the reactor. The preactivated catalysts are sensitive to air and pyrophoric and are therefore usually under a medium such. As water, an organic solvent or a substance, the in the subsequent hydrogenation (solvent, educt, product) is stored and handled or embedded in an organic compound which is solid at room temperature.

In a preferred embodiment, a Raney cobalt skeletal catalyst is used consisting of a Co / Al alloy by leaching with aqueous alkali metal hydroxide solution, e.g. Sodium hydroxide solution, and subsequent washing with water was obtained, and preferably contains as promoters at least one of the elements Fe, Ni or Cr.

Such preferred Raney co-catalysts typically contain, in addition to cobalt, 1 to 30% by weight Al, especially 2 to 12% by weight Al, very particularly 3 to 6% by weight Al, 0 to 10% by weight Cr , especially 0.1-7 wt.% Cr, especially 0.5-5 wt.% Cr, in particular 1.5- 3.5 wt.% Cr, 0-10 wt.% Fe, especially 0.1 to 3 wt.% Fe, more particularly 0.2 to 1 wt.% Fe, and / or 0 to 10 wt.% Ni, especially 0.1 to 7 wt.% Ni, especially 0.5 to 5 wt .-% Ni, in particular 1 to 4 wt .-% Ni, wherein the weights are based in each case on the total catalyst weight.

For example, a cobalt skeletal catalyst "Raney 2724" from W. R. Grace & Co. can be used as catalyst in the hydrogenation, this catalyst having the following composition:

Al: 2-6 wt.%, Co:> 86 wt.%, Fe: 0-1 wt.%, Ni: 1-4 wt.%, Cr: 1.5- 3.5 wt. -%.

Regeneration - General

The catalysts which are used in the reaction of EDDN or EDMN with hydrogen can, if appropriate, be regenerated with decreasing activity and / or selectivity by methods known to the person skilled in the art, for example in WO 99/33561 and the publications cited therein ,

From EP 892777 is known to regenerate deactivated Raney catalysts at temperatures of 150 to 400 ° C and pressures of 0.1 to 30 MPa for 2 to 48 hours with hydrogen, wherein it is advantageous to the catalyst before the actual regeneration with in the System contained solvent, especially with ammonia, wash.

WO 2008/104553 discloses that catalysts which are used for the hydrogenation of TETA or DETA can be regenerated. For regeneration, a method according to WO 99/33561 should be used.

WO 99/33561 discloses a process for the regeneration of Raney catalysts, wherein initially the separation of the catalysts from the reaction medium takes place and the separated catalyst is treated with an aqueous basic solution which has a concentration of basic ions of more than 0.01 mol / kg and the mixture at temperatures of less than 130 ° C for 1 to 10 hours, if necessary, in the presence of hydrogen holds. Subsequently, will the catalyst is washed with water or a basic solution until the wash water has a pH in the range of 12 to 13.

The regeneration of the catalyst can be carried out in the actual reactor (in situ) or on the finished catalyst (ex situ). In the case of fixed-bed processes, regeneration is preferably carried out in situ.

In the suspension process is also preferably regenerated in situ.

In general, the entire catalyst is regenerated.

The regeneration usually takes place during a short-term shutdown.

Regeneration with liquid ammonia and hydrogen

In a particularly preferred embodiment, Raney catalysts are regenerated by treating the Raney catalysts with liquid ammonia and hydrogen. Regeneration should be possible with simple technical means. In addition, the regeneration should be done with as little time as possible in order to reduce breastfeeding as a result of the catalyst regeneration. Furthermore, the regeneration should allow for the most complete recovery of the activity of the catalysts used.

Accordingly, this particularly preferred embodiment relates to the regeneration of Raney catalysts, which are used in the reaction of EDDN or EDMN with hydrogen, in which the catalyst with liquid ammonia having a water content of less than 5 wt.% And hydrogen at a partial pressure from 0.1 to 40 M Pa in the temperature range of 50 to 200 ° C for at least 0.1 hours. In this preferred embodiment, the previously described doped and undoped Raney catalysts are regenerated.

It is particularly preferred to use those Raney catalysts which are used in the reaction of EDDN or EDM N with hydrogen.

In particular, Raney-Co is regenerated by means of this preferred embodiment.

For regeneration, the Raney catalyst is treated with ammonia.

The ammonia used in this particularly preferred embodiment contains less than 5 wt .-%, preferably less than 3 wt .-% and most preferably less than 1 wt .-% water. Such "anhydrous" ammonia is a commercially available product.

The regeneration can be carried out in all reactors which can be used for the hydrogenation of EDDN or EDMN to TETA or DETA, and which are described below and above. For example, the hydrogenation in a stirred reactor, jet loop reactor, jet nozzle reactor, bubble column reactor, tubular reactor but also Rohbündelreaktor or be carried out in a cascade of such identical or different reactors. The hydrogenation can be continuous or discontinuous.

In the batch mode, the preferred reactor is first emptied prior to treatment with ammonia thereto, for example, by removing the reactor contents from the reactor, e.g. by pumping or draining. The emptying of the reactor should be largely complete. Preferably more than 80% by weight, more preferably more than 90% by weight and most preferably more than 95% by weight of the reactor contents should be drained or pumped off.

In the continuous mode of operation, it is preferable to interrupt the supply of educts and instead to supply liquid ammonia.

In the continuous mode of operation, the liquid ammonia may also be due to condensation reactions within the reactor, for example from the condensation of EDA to AEPIP.

The treatment of the catalyst with liquid ammonia takes place in this particularly preferred embodiment 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 and more preferably 0.5 to 5 hours.

The weight ratio of amount of ammonia fed to catalyst is preferably in the range from 1: 1 to 1000: 1, more preferably in the range from 50: 1 to 200: 1.

It is further preferred that the ammonia is circulated during the treatment with ammonia, for example by pumping over, or preferably by stirring.

The treatment of the catalyst with ammonia takes place in the most preferred embodiment in the presence of hydrogen. The hydrogen partial pressure in the treatment with ammonia is preferably in the range from 1 to 400 bar, more preferably at 5 to 300 bar.

In a particularly preferred embodiment, the concentration of anions in the liquid ammonia is less than 0.01 mol / kg, very particularly preferably less than 0.0099 mol / kg and particularly preferably less than 0.005 mol / kg. After treatment with ammonia, ammonia can be separated from the catalyst. This is done for example by emptying the reactor and / or stopping the ammonia feed.

Before and after the treatment of the Raney catalyst with liquid ammonia, the Raney catalyst can be rinsed one or more times with organic solvent and / or water. However, the treatment of the catalyst with organic solvent and / or water after the separation of ammonia or after termination of the ammonia feed is not absolutely necessary because the ammonia does not interfere with the subsequent hydrogenation and can be continuously discharged from the reactor.

Reaction conditions in the hydrogenation

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

The temperatures are generally in a range of 60 to 150 ° C, preferably from 80 to 140 ° C, especially at 100 to 130 ° C. The pressure prevailing in the hydrogenation is generally from 5 to 400 bar, preferably from 60 to 325 bar, particularly preferably from 100 to 280 bar and particularly preferably from 170 to 240 bar.

In a particularly preferred embodiment, the pressure in the hydrogenation using Raney catalysts in the range of 170 to 240 bar, since in this pressure range, the formation of AEPIP can be reduced. The formation of AEPIP can accelerate the deactivation of the catalyst.

Accordingly, the particularly preferred embodiment relates to the preparation of TETA and / or DETA by reacting EDDN and / or EDMN with hydrogen in the presence of a catalyst, characterized in that a catalyst of Raney type is used as the catalyst and the pressure at hydrogenation in the range from 170 to 240 bar.

In a preferred embodiment, EDDN or the aminonitrile mixture containing EDDN is fed at a rate of hydrogenation which is not greater than the rate at which EDDN and optionally the other components of the aminonitrile mixture react with hydrogen in the hydrogenation.

Hydrogenation of EDDN to TETA generally requires at least four moles of hydrogen per mole of EDDN.

Hydrogenation of EDMN to DETA generally requires at least two moles of hydrogen per mole of EDMN.

reactor

The reaction of EDDN or EDMN with hydrogen in the presence of catalysts can be carried out in conventional reaction vessels suitable for catalysis in a fixed bed, fluidized bed, Suspension mode continuously, semicontinuously or discontinuously carried out. Reaction vessels are suitable for carrying out the hydrogenation, in which it is possible to contact the EDDN or EDMN and the catalyst with the hydrogen under pressure.

The hydrogenation in suspension mode can be carried out in a stirred reactor, jet loop reactor, jet nozzle reactor, bubble column reactor, or in a cascade of such identical or different reactors. The hydrogenation on a fixed bed catalyst preferably takes place in one or more tube reactors but also tube bundle reactors.

The hydrogenation of the nitrile groups takes place with the release of heat, which usually has to be removed. The heat dissipation can be done by built-in heat exchanger surfaces, cooling jackets or external heat transfer in a loop around the reactor. The hydrogenation reactor or a hydrogenation reactor cascade can be run in straight passage. Alternatively, a circulation procedure is possible in which a part of the reactor discharge is returned to the reactor inlet, preferably without prior workup of the circulation stream.

In particular, the circulation stream can be cooled by means of an external heat exchanger in a simple and cost-effective manner and thus the heat of reaction can be dissipated.

The reactor can also be operated adiabatically. With adiabatic operation of the reactor, the temperature rise in the reaction mixture can be limited by cooling the feeds or by supplying "cold" organic solvent.

Since the reactor does not have to be cooled even then, a simple and cost-effective design is possible. An alternative is a cooled tube bundle reactor (only in the case of the fixed bed). A combination of the two modes is conceivable. Here, preferably a fixed bed is followed by a suspension reactor. Arrangement of the catalyst

The catalyst can be arranged in a fixed bed (fixed-bed mode) or suspended in the reaction mixture (suspension mode). Suspension procedure

In a particularly preferred embodiment, the catalyst is suspended in the reaction mixture to be hydrogenated. The settling rate of the hydrogenation catalyst in the chosen solvent should be low in order to keep the catalyst well in suspension. The particle size of the catalysts used in the suspension mode is therefore preferably between 0.1 and 500 μπΊ, in particular 1 and 100 μηι.

If the hydrogenation of EDDN or EDM N is carried out continuously in suspension mode, EDDN or EDM N are preferably fed continuously into the reactor and a stream which contains the hydrogenation products TETA or DETA is continuously removed from the reactor.

In the discontinuous suspension procedure, EDDN or EDMN are initially charged together with organic solvent.

The amount of catalyst in the batchwise batchwise process is preferably from 1 to 60% by weight, more preferably from 5 to 40% by weight, and most 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, more preferably 0.5 to 2 hours, in the case of a discontinuous suspension procedure.

The residence time in the reactor is preferably 0.1 to 6 hours, more preferably 0.5 to 2 hours, in a continuous suspension procedure.

The catalyst loading in the continuous suspension procedure is preferably 0.1 to 10 kg, preferably 0.5 to 5 kg EDDN + EDMN per kg catalyst and hour. In a particularly preferred embodiment, the catalyst loading, based on the catalyst surface preferably 10 ^"6 to 10 ^ kg EDDN + EDMN per m ² of catalyst surface area and per hour, wherein the catalyst surface area is determined according to the BET method (DIN 66131). Particularly preferred are is the catalyst loading, based on the catalyst surface 0,25-10- ⁵ to ⁵ kg 5-10- EDDN + EDMN per m ² of catalyst surface area and per hour, and most preferably ⁵ to 0,5-10- 2-10 ⁵ kg EDDN + EDMN per m ^{2 of} catalyst surface and hour.

Accordingly, the particularly preferred embodiment relates to the production of TETA and / or DETA by reacting EDDN and / or EDMN with hydrogen in the presence of a catalyst in the suspension, characterized in that the catalyst loading, based on the catalyst surface 10- ⁶ to 10- ⁴ kg EDDN + EDMN per m ² catalyst surface and hour, wherein the catalyst surface is determined according to the BET method. If the reaction is carried out in a suspension reactor in a stirred reactor, the power input via the stirrer is preferably 0.1 to 100 KW per m ³ . Used catalyst can be separated by filtration, centrifugation or cross-flow filtration. It may be necessary to compensate for losses of original amount of catalyst by attrition and / or deactivation by adding fresh catalyst. Fixed-bed mode

In a further, less preferred embodiment, the catalyst is disposed in a fixed catalyst bed. The catalyst loading in the continuous hydrogenation in the fixed bed reactor, for example a tube reactor or tube bundle reactor, is preferably 0.1 to 10 kg, preferably 0.5 to 5 kg EDDN + EDMN per kg of catalyst and hour.

In a particularly preferred embodiment, the catalyst loading, based on the catalyst surface preferably 10 ^"6 to 10 ^ kg EDDN + EDMN per m ² of catalyst surface area and per hour, wherein the catalyst surface in accordance with the B ET method (DIN 66131). Particularly preferably, the catalyst loading, based on the catalyst surface 0,25-10- ⁵ to ⁵ kg 5-10- EDDN + EDMN per m ² of catalyst surface area and per hour, and most preferably is 0.5-10 ^"5 to ^{2-10" 5} kg EDDN + EDMN per m ² catalyst surface area and hour.

Accordingly, the particularly preferred embodiment relates to the production of TETA and / or DETA by reacting EDDN and / or EDMN with hydrogen in the presence of a catalyst in a fixed bed, characterized in that the catalyst load, gene bezo- on the catalyst surface 10- ⁶ to 10- ⁴ kg EDDN + EDMN per m ² of catalyst surface area and per hour is, the catalyst surface area is determined according to the BET method.

In the case of a fixed-bed catalyst, this is generally applied to the bottom or trickle mode with EDDN or EDM N.

Reaction discharge from the hydrogenation

The reaction effluent from the hydrogenation usually also contains other higher or lower boiling organic substances as by-products, such as methylamine, AEPIP, PIP or TEPA or basic compounds or additives which were added before or during the hydrogenation, for example alkali metal hydroxides, alcoholates , Amides, amines and ammonia. The hydrogenation output also contains THF.

Such a reaction can, as described above, be processed according to the invention. The accompanying drawings show preferred embodiments of the invention.

FIG. 1 shows the production of EDDN or EDMN from EDA (1) and FACH (5). The preferred process parameters can be taken from the above description. First, EDA (1) is mixed with water (2) in a mixer (I) to form an aqueous EDA stream (3). The mixture of EDA with water releases heat of hydration, which is dissipated in a heat exchanger (II). An FACH-containing stream (5) is mixed with toluene (6). The toluene-containing FACH stream is mixed at a mixing point with the aqueous EDA solution (3) and introduced into an adiabatically operated tubular reactor (III). At the outlet of the tubular reactor (III), the exiting reaction mixture (7) is expanded at a pressure relief valve. The forming gaseous phase (8), which contains water, toluene and low-boiling compounds, is condensed on a condenser (V). Uncondensed components (9), such as ammonia, HCN, methanol or CO2, are discharged from the process. The condensate (10) condensed on 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 recycled to the process, for example, for the preparation of an aqueous EDA solution in mixer (I) or in a biological wastewater treatment can be initiated (not shown). The aqueous phase (14) can also be introduced into a column K2 (VIII), in which water as the bottom product (16) is separated off from low-boiling components (15). The low-boiling components (15), for example solvents which are lighter than water or low-boiling water azeotropes or HCN, can be passed directly to the condenser (V), on which the gaseous phase from the flash evaporation is also condensed. Non-condensable components are discharged as stream (9) from the process.

The toluene-containing phase (11) can be recycled as an organic solvent in the process and mixed with the FACH-containing stream from the FACH production. Optionally, losses of toluene can be supplemented by a toluene supplement. However, the toluene-containing phase (11) can preferably be introduced together with the liquid phase (12) from the flash template (IV) into a column K1 (VII).

The liquid which has remained liquid during the flash evaporation is taken from the flash receiver (flash tank) (IV) and likewise, if appropriate together with the toluene-containing phase (11), to the top of the column K1 (VII). led to deplete water.

In the column K1 (VII), a gaseous, substantially aqueous top product is withdrawn, which is passed directly to the condenser (V) and passed into the phase separation vessel (VI). In the phase separation vessel, as described above, forming aqueous phase (15) is discharged, passed into the mixer (I), or the column K2 (VIII) are supplied. At the bottom (17) of the column K1, a mixture of EDDN or EDM N and toluene is withdrawn.

The mixture (17) of toluene and EDDN or EDMN is diluted with THF (18) and treated in an adsorber (IX) with adsorbent, preferably with a solid, acidic adsorbent. Out the adsorber is a mixture of EDDN and / or EDMN with toluene and THF (20), which contains only small amounts of water. The EDDN or EDMN mixture can be passed into a hydrogenation in which EDDN or EDMN is hydrogenated to TETA or DETA. FIG. 2 shows the preparation of EDDN or EDMN from FA (1), EDA (2) and HCN (5), wherein first FA (1) and EDA (2) are converted to EDFA and / or EDMFA (4) , which then reacts with HCN (5) to EDDN or EDMN.

The preferred process parameters can be taken from the above description. First, FA (1) is mixed with EDA (2) in the loop of a loop reactor (I). In the loop reactor, FA (1) is reacted with EDA (2) to EDFA and / or EDMFA. Part of the reactor contents of the loop reactor is discharged (3) and passed into a tubular reactor (II). The discharge (4) from the tubular reactor (II) is mixed at the inlet of a tubular reactor (III) at a mixing point with HCN (5) and toluene (6) and passed through the tubular reactor (III).

At the outlet of the tubular reactor (III), the exiting reaction mixture (7) is expanded at a pressure relief valve. The forming gaseous phase (8), which contains predominantly water and toluene, is condensed on a condenser (V). Uncondensed components (9), such as ammonia, HCN, methanol or CO2, are removed from the process. The condensate (10) condensed on 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 recycled to the process, for example, for the preparation of an aqueous EDA solution in mixer (I) or in a biological wastewater treatment can be initiated (not shown). The aqueous phase (14) can also be introduced into a column K2 (VIII), in which water as the bottom product (16) is separated off from low-boiling components (15). The low boilers (15), for example lighter than water-boiling solvents or low-boiling water azeotropes or HCN, can be passed directly to the condenser (V). Non-condensable components are discharged as stream (9) from the process.

The toluene-containing phase (11) can be recycled to the process as an organic solvent and mixed with the EDFA-containing stream from the EDFA preparation. Optionally, losses of toluene can be supplemented by a toluene supplement. However, the toluene-containing phase (11) can also be introduced into a column K1 (VII) together with the liquid phase (12) from the flash template (IV).

In the column K1 (VII), a gaseous, substantially aqueous overhead product is passed directly to the condenser (V) and passed into the phase separation vessel (VI), where the aqueous phase (15), as described above, discharged into the mixer (I) passed, or the column K2 (VIII) can be supplied.

At the bottom (17) of the column K1, a mixture of EDDN or EDM N and toluene is obtained. The mixture of toluene and EDDN or EDMN (17) is diluted with THF (18) and treated in an adsorber (IX) with adsorbent, preferably with a solid, acidic adsorbent. From the adsorber, a mixture of EDDN and / or EDMN with toluene and THF is obtained, which contains only small amounts of water. The EDDN or EDMN mixture can be passed into a hydrogenation, in which EDDN or EDM N is hydrogenated to TETA or DETA.

FIG. 3 shows the production of TETA or DETA from EDDN or EDMN.

The preferred process parameters can be taken from the above description.

EDDN or EDM N, which can be prepared by reacting FA, HCN and EDA according to one of the options mentioned in the description a) to d), and which has been worked up, preferably by i) removal of low boilers, for example by stripping, flash evaporation or distillation and ii) distilling off water, preferably in the presence of an organic solvent which under the conditions of water separation has a boiling point between water and EDDN or EDMN or which forms a water-boiling azeotrope, is shown in FIG Such EDDN "EDDN" or EDMN is mixed with THF (18) and treated in an adsorber with adsorbent, preferably solid, acidic adsorbent. The stream (1) leaving the adsorber is passed into a hydrogenation reactor (I) in which the adsorbed "purified" EDDN or EDMN in the presence of hydrogen (2) is hydrogenated to TETA or DETA.

FIG. 4 shows the production of TETA or DETA from EDDN or EDMN with subsequent workup.

The preferred process parameters can be taken from the above description.

EDDN or EDM N can be prepared by reacting FA, HCN and EDA according to one of the options a) to d) mentioned in the description. The workup is carried out, preferably by i) removal of low boilers, for example by stripping, flash evaporation or distillation and ii) depletion of water, preferably in the presence of an organic solvent which, under the conditions of water separation, has a boiling point between water and EDDN or EDMN or which forms a water-boiling azeotrope with water.

The dewatered EDDN is preferably mixed with THF and treated with adsorbent, preferably solid, acidic adsorbent. The mixture (1) of EDDN or EDM N and THF is hydrogenated in a hydrogenation reactor (I) in the presence of supplied hydrogen (2) to TETA or DETA. The reaction product from the hydrogenation (3) is expanded into a flash tank (II). The gaseous constituents (4), such as hydrogen, parts of the THF, HCN, methanol or methylamine, can be discharged from the process or recovered partially or completely.

The liquid remaining after the expansion phase (5) is passed into a column K1, which has a stripping and a rectifying section. At the top of the column, a light deducted THF / water azeotrope (6), 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) is formed, which is recycled to the column K1.

From the bottom of the column K1, a stream (10) is withdrawn containing TETA, DETA, THF, toluene and organic compounds such as PIP, AEPIP and TEPA.

This stream (10) is passed into a column K2, in which THF is taken off as top product (1 1). This THF (11) can be recycled directly to the process, preferably in the treatment of EDDN or EDMN with adsorbent. Prior to introduction into the adsorber stage, the THF (11) may be contacted with a molecular sieve to further deplete water.

At the bottom of the column K2, a stream (12) is withdrawn containing TETA, DETA, toluene and organic compounds such as PIP, AEPIP and TEPA.

This stream (12) is introduced into a column K3 in which toluene is drawn off at the top (13). The withdrawn toluene (13) can be passed to dehydration of THF via line (7) in a phase separation vessel in which it is combined with the condensate (6) from column K1. The withdrawn toluene (13) can also be discharged from the process via line (14) or preferably be used as a solvent in EDDN and / or EDMN production.

The bottom product of the column K3 (16) contains TETA, DETA, toluene and organic compounds such as PIP, AEPIP and TEPA. This mixture can be further separated in the column K4. For example, low boilers such as PIP, AEPIP and DETA can be withdrawn overhead (17) and TETA taken off as side draw (18). High boilers, such as TEPA, can be withdrawn at the sump (19). The overhead or bottom stream can be separated into its individual constituents in subsequent distillation stages.

Abbreviations

Ethylenediamine (EDA)

Ethylenediamine-formaldehyde bisadduct (EDFA)

Ethylenediamine-Formaldehyde Monoadduct (EDMFA)

Ethylenediaminediacetonitrile (EDDN)

Ethylenediamine monoacetonitrile (EDMN)

Diethylenetriamine (DETA)

Triethylenetetramine (TETA)

Tetraethylenepentamine (TEPA)

Formaldehyde (FA)

Formaldehyde cyanohydrin (FACH)

Piperazine (PIP)

Aminoethylpiperazine (AEPIP)

Mixture of formaldehyde and hydrocyanic acid (GFB)

2- and 3-methyltetrahydrofuran (MeTHF)

Aminoacetonitrile (AAN) The process according to the invention is explained in more detail with reference to the examples listed below.

Analytics for EDDN:

The formaldehyde cyanohydrin (FACH) and the hydrocyanic acid conversion were determined by Volhard titration (determination of free cyanide) and Liebig titration (determination of bound cyanide). Both methods titrated with silver nitrate. The yield of products of value was determined by quantitative HPLC analysis (solid phase: Atlantis T3, 5 ×, 4.6 × 250 mm, Waters; mobile phase: 50% by volume water with 0.5 g / L ammonium formate, 50% by volume). % Acetonitrile) with the reaction products or comparative substances present in each case as pure substance. The desired product is the sum of the .alpha.-aminonitriles ethylenediaminediacetonitrile (EDDN), ethylenediaminemonoacetonitrile (EDM.sub.N), biscyanomethylimidazoline (BCMI) and ethylenediaminetriacetonitrile (EDTriN). In the determination of the Hazen (APHA) - and iodine color number (Römpp, Lexikon Chemie, 10th edition, G. Thieme Verlag, 1997, pages 1285 to 1286) each of the aqueous portion of the reaction was measured, if necessary, after phase separation. GC analysis:

Column: RTX-5 amine, 30 m, 0.32 mm, 1 .5 μηη

Temperature program: 60 ° C - 5 minutes isothermal - 15 ° C / min - 280 ° C

Internal standard: DEGDME (diethylene glycol dimethyl ether)

Separation of the reaction effluent:

The experimental set-up shown in FIG. 4 was used.

The effluent (stream 3) from the hydrogenation reactor I, by hydrogenation of EDDN to TETA, was vented to a vessel II to a pressure of 30 bar. The resulting sparging gas (stream 4), consisting in part of dissolved hydrogen, was passed through a dephlegmator and cooled to a temperature of 5 ° C. The resulting by the cooling condensate was returned to the container II.

After relaxation of the reactor effluent the stream contained 5 0.4% piperazine, 6.0% DETA, 1 .8% N-methylated DETA's, 6.2% AEPIP, 76.7% TETA and 7.9% N-methylated TETA's. The rest were unknown minor components.

The liquid discharge from the container II (stream 5) was passed into a column DK1. The column DK1 consisted of a reinforcement piece with 720 mm packing of the type Montz A3-500 and an output part with a 2160 mm Montz A3-500 packing. The pressure at the top of the column was 6 bar _a bs. At the top of the column, a temperature of 121.5 ° C was measured at the bottom 138.5 ° C. The vapors (stream 6) of the column were condensed in a condenser. The condensate from this condenser was treated with 120 g / h of toluene (stream 7), which were recycled from the top of the column DK3 (see below). The resulting mixture was passed through a 4 mm internal diameter static mixer (supplied by Kenics) and placed vertically from top to bottom. After the static mixer, the mixture was run in a phase separator. The upper phase (stream 9), 140 g / h consisting of 85% toluene and 14% THF (remainder water and other low boilers), was returned as reflux to the column DK1. The lower phase (stream 8), average 2 g / h consisting of 3% THF, 12% methylamine and 8800 ppm toluene (remainder water and other minor components in low concentration) was discharged discontinuously.

The bottoms discharge (stream 10) from the column DK1, containing 104 ppm of water, was passed into a column DK2. Column DK2 contained 1440 mm Montz A3-500 packing. The pressure at the top of the column DK2 was atmospheric. The head discharge (stream 11) from the column DK2 contained 0.4% ammonia, 104 ppm water, 0.2% monomethylamine, 0.22% dimethylamine, 0.2% trimethylamine, 0.1% n-ethylamine, 98.3% THF and 0.3% toluene. The rest were unknown minor components. This stream was collected in a receiver and then admixed with the bottom product of column VII (FIG. 2). The admixed THF amount was 2.8 kg / h. A small amount of fresh THF of less than 50 g / hr was passed into the receiver to compensate for THF losses.

The head temperature at the column DK2 was 62 ° C, the bottom temperature 1 17 ° C. In the bottom of the column DK2 180 g / h of toluene (stream 15) were recycled from the head of the subsequent column DK3. The bottoms discharge (stream 12) from column DK2 was 934 g / h. The bottom effluent contained 0.3% THF, 65.4% toluene, 0.12% piperazine, 2.1% DETA, 0.68% N-methylated DETAs, 2.1% AEPIP, 26.1% TETA and 1.5% N-methylated TETA's. The rest were unknown minor components.

The bottoms discharge (stream 12) from column DK2 was moved to a further column DK3, which consisted of a reinforcement section with 1000 mm packing of the type Sulzer DYM and a drive section with 1000 mm packing of the type Sulzer DYM. The pressure at the top of the column was 80 mbar. The vapors (stream 13) from the top of the column at a temperature of 42 ° C were condensed and the condensate, consisting mainly of toluene, collected in a container. At the top of the column 200 g / h of condensate were run as reflux from the container. Another 180 g / h (stream 15) from the condensate were returned to the bottom of the column DK2. Another 120 g / h (stream 7) were returned to the condensate from the condenser of the column DK1. An amount of 72 g / h (stream 14) remained as overhead discharge, which was returned to the separator VI of the column VII (FIG. 2). The head discharge (stream 1 1) from the column DK2 contained 0.8% THF and 98.8% toluene. The rest were unknown minor components.

The bottoms discharge (stream 16) from the column DK3 with a quantity of 935 g / h contained no THF (below the detection limit) and 2.8% toluene. Also included were 0.3%

Piperazine, 5.7% DETA, 1 .9% N-methylated DETA's, 5.5% AEPIP, 74.8% TETA and 6.7% N-methylated TETA's. The rest were unknown minor components.

This stream was passed to another column DK4.

The column DK4 contained a reinforcing part with a 1000 mm packing of the type Sulzer Romobopak 9M and a stripping part with a 1700 mm packing of the Sulzer Rombopak 9M type. The diameter of the column was 30 mm. In the column DK4 an amount of 78 g / h was withdrawn overhead (stream 17). This stream contained the light ends DETA and AEPIP containing 1.1% TETA and 2.0% NMTETA. In addition, a reflux rate of 170 g / h was moved to the top of the column. About the bottom (stream 19) was discharged 17 g / h. This stream contained about 50% TETA, the rest were high boilers.

The product (stream 18) was withdrawn from a vapor side draw at 840 g / hr directly above the bottom. The stream contained 180 ppm DETA, 60 ppm AEPIP, 90.9% TETA and 7.5% N-methylated TETA's. The rest were unidentified minor components.

At the column DK4 the head temperature was 1 10 ° C, the bottom temperature 165 ° C and the temperature at the side draw 159 ° C.

Claims

claims

1 . A process for the separation of a Reaktionsaustrags obtained in the reaction of EDDN or EDMN with hydrogen in the presence of THF and a catalyst containing TETA or DETA, water and optionally higher and lower than TETA or DETA boiling organic compounds characterized marked that one

i) the reaction after separation of hydrogen feeds a distillation column DK1, in which a THF / water azeotrope is separated overhead, which may also contain other organic compounds having a lower boiling point than TETA or DETA, and separated in a bottom product which contains TETA or DETA, and

ii) passing the bottom product of step i) into a distillation column DK2 and separating THF overhead and withdrawing a stream containing TETA or DETA at the bottom of the column, and

iii) condensing the stream of stage i) withdrawn at the top of the column DK1 and adding to the condensate or a part of the condensate an organic solvent which is substantially immiscible with water in such an amount that a phase decay occurs and the resulting product Separates mixture in a phase separator, wherein the forming organic phase containing THF and the organic solvent, which is not substantially miscible with water, returns to the column DK1 and discharges the water phase.

2. The method according to claim 1, characterized in that the production of EDDN

and / or EDMN by reaction of EDA, FA and HCN.

3. The method according to at least one of claims 1 to 2, characterized in that the bottom product from column DK1 has a water content of less than 1 wt .-%.

4. The method according to claim 3, characterized in that the water content in the bottom discharge from column DK1 has a water content of less than 300 ppm by weight.

5. The method according to at least one of claims 1 to 4, characterized in that the bottom product from the distillation column DK2 in stage ii) is passed into a distillation column DK3, is withdrawn in the toluene overhead and as the bottom product, a stream is withdrawn, the predominantly TETA or contains DETA or AEPIP.

6. The method according to claim 5, characterized in that the pressure in the entire distillation Kol3 DK3 is less than 300 mbar.

7. The method according to at least one of claims 1 to 6, characterized in that the bottom product from column DK3 is passed into a column DK 4, in the head on

4 Fig. Mixture of PIP, AEPIP and DETA is obtained at the bottom of a mixture of pentamines nen, such as TEPA and other high boilers obtained and deducted as side of a TETA stream with a purity of more than 99 wt .-%.

A method according to claim 7, characterized in that the pressure in the entire distillation column DK4 is less than 100 mbar.

A process for the preparation of TETA and / or DETA by reacting EDDN and / or EDMN with hydrogen in the presence of THF and a catalyst, characterized in that the separation of the reaction effluent according to one of claims 1 to 8 takes place.

Process for the preparation of epoxy resins, amides or polyamides, characterized in that in a first stage TETA or DETA is prepared according to a process of claim 9, and in a second stage, the TETA or DETA thus obtained to epoxy resins, amides or polyamides.