Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C253/00—Preparation of carboxylic acid nitriles
  • C07C253/30—Preparation of carboxylic acid nitriles by reactions not involving the formation of cyano groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
  • C07C209/44—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of carboxylic acids or esters thereof in presence of ammonia or amines, or by reduction of nitriles, carboxylic acid amides, imines or imino-ethers
  • C07C209/48—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of carboxylic acids or esters thereof in presence of ammonia or amines, or by reduction of nitriles, carboxylic acid amides, imines or imino-ethers by reduction of nitriles
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C211/00—Compounds containing amino groups bound to a carbon skeleton
  • C07C211/01—Compounds containing amino groups bound to a carbon skeleton having amino groups bound to acyclic carbon atoms
  • C07C211/20—Compounds containing amino groups bound to a carbon skeleton having amino groups bound to acyclic carbon atoms of an acyclic unsaturated carbon skeleton
  • C07C211/21—Monoamines
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C255/00—Carboxylic acid nitriles
  • C07C255/01—Carboxylic acid nitriles having cyano groups bound to acyclic carbon atoms
  • C07C255/24—Carboxylic acid nitriles having cyano groups bound to acyclic carbon atoms containing cyano groups and singly-bound nitrogen atoms, not being further bound to other hetero atoms, bound to the same saturated acyclic carbon skeleton

Definitions

• the invention relates to a process for preparing an aminonitrile mixture containing aminoacetonitrile (AAN) and from 5 to 70% by weight of lminodiacetonitrile (IDAN).
• AAN aminoacetonitrile
• IDAN lminodiacetonitrile
• EP-A 1 209 146 relates to a process for the continuous hydrogenation of nitriles to primary amines, wherein from the starting material AAN ethylenediamine (EDA) and from the starting material IDAN diethylenetriamine (DETA) is produced.
• EDA ethylenediamine
• DETA diethylenetriamine
• US-A 5,079,380 relates to a process for the preparation of AAN, wherein ammonia (NH 3), formaldehyde (HCHO) and hydrogen cyanide (HCN) are reacted at at least 100 0 C.
• first formaldehyde and hydrocyanic acid can be converted to formaldehyde cyanohydrin (FACH) as an intermediate, which then reacts further with ammonia to give AAN.
• FACH formaldehyde cyanohydrin
• the molar ratio of ammonia to FACH or to formaldehyde and hydrogen cyanide is 4: 1 [mol / mol].
• the temperatures in the AAN synthesis are 50 to 80 0 C and the pH is about 10.
• IDAN is usually also assumed by ammonia and FACH or ammonia, formaldehyde and hydrocyanic acid.
• the conversion to IDAN is usually carried out at higher temperatures (about 100 to 150 ° C), a lower pH of about 5 to 7 and at a lower ammonia content than in the corresponding synthesis of AAN.
• Such processes for the preparation of IDAN are described, for example, in EP-A 426 394 or US Pat. No. 4,895,971.
• the preparation of IDAN can also be carried out by the reaction of urotropin (hexamethylenetetraamine, HMTA) with hydrocyanic acid and formaldehyde, as described, for example, in US Pat. No. 3,988,360.
• urotropin hexamethylenetetraamine, HMTA
• US-A 2,511,487 relates to a process in which IDAN is prepared starting from AAN.
• AAN is mixed with FACH in a molar ratio of about 1: 0.3 to 1, 5 [mol / mol] and heated in the presence of a mineral acid stabilizer, such as phosphoric acid at 100 to 150 0 C.
• a mineral acid stabilizer such as phosphoric acid
• the reaction preferably takes place at 135 to 150 ° C. and for a maximum of 15 minutes.
• US-A 2,551,1487 it is not mentioned that the mixture of AAN and FACH is passed through a (separate) device, but the reaction takes place in a conventional bulb with cooling device instead.
• AAN or IDAN The above-described process for the preparation of AAN or IDAN has in common that it is always attempted to produce the highest possible degree of purity of the corresponding product (AAN or IDAN).
• processes which can purposefully prepare an aminonitrile mixture which contains (on aminonitriles) mainly AAN and IDAN in a defined composition are not known.
• To prepare a corresponding aminonitrile mixture comprising AAN and IDAN it is possible in principle to mix the two main components AAN and IDAN in the desired ratio.
• a disadvantage of this method is that on the one hand two separate approaches (AAN and IDAN) must be driven.
• the isolation and handling of the solid-state IDAN often causes problems.
• the object underlying the invention is thus to provide an improved process for the preparation of a Aminonitrilgemisches containing defined amounts of AAN and IDAN, wherein the IDAN content in the mixture should be variable.
• the total amount of IDAN contained in the aminonitrile mixture should be from 5 to 70% by weight, based on the total amount of aminonitriles present in the mixture.
• this object is achieved by a process for preparing an aminonitrile mixture containing aminoacetonitrile (AAN) and from 5 to 70% by weight of imidodiacetonitrile (IDAN), crude AAN, which is substantially free of formaldehyde cyanohydrin (FACH-free ) is heated at a temperature of 50 to 150 0 C.
• AAN aminoacetonitrile
• IDAN imidodiacetonitrile
• FACH-free formaldehyde cyanohydrin
• the process according to the invention has the advantage that it is possible to prepare an aminonitrile mixture which contains defined amounts of the two main constituents AAN and IDAN. Rather, a mixture comprising AAN and from 5 to 70% by weight of IDAN can be prepared in a very selective manner. Thus, with the method according to the invention, an IDAN content in the aminonitrile mixture can be adjusted variably. This takes place in a simple way, since only one starting material (AAN) has to be prepared, from which part of the process according to the invention, IDAN, is formed in part.
• AAN starting material
• any type of AAN can generally be used in the process according to the invention. Usually, however, the crude AAN is present as an aqueous or aqueous ammoniacal solution.
• the AAN content in the crude AAN is usually 5 to 100% by weight, preferably 10 to 80% by weight.
• the crude AAN is preferably prepared by reacting an aqueous mixture of ammonia with formaldehyde cyanohydrin (FACH) in a molar ratio of> 4: 1 [mol / mol] at a temperature of 50 to 80 ° C.
• FACH formaldehyde cyanohydrin
• the reaction is carried out at about 70 0 C in the flow reactor at a residence time of about 10-20 minutes.
• the reaction is carried out so that the FACH content is as low as possible in the crude AAN.
• a sufficiently long residence time and / or a not too low reaction temperature is set.
• these reaction parameters are optimized so that virtually no FACH is present in the reaction.
• the crude AAN can also be prepared by other methods known to those skilled in the art, for example by reacting ammonia with formaldehyde and hydrocyanic acid.
• substantially free of formaldehyde cyanohydrin FACH-free
• FACH-free formaldehyde cyanohydrin
• the inventive method can be carried out in principle in any device.
• the process according to the invention can be carried out in the same apparatus as the previous synthesis of the crude AAN, or the process according to the invention is carried out in a separate apparatus.
• the process according to the invention is preferably carried out in the same reactor as the synthesis of the crude AAN.
• a flow tube or a cascade of flow tubes can be used.
• Each flow tube can be subdivided by the impressed reaction conditions into several sections, so that although there is only one apparatus, but this corresponds in the reaction-technical sense, a cascade of flow tubes. In practice, this can be done by different heating or cooling zones, different catalysts or by intermediate feed of reactants or inert components (eg solvents).
• reactors can be used individually or as a cascade. In particular, it is also possible to connect different reactor types or apparatuses into a cascade. Possible reactor types are, in addition to the flow tube, loop reactors, stirred tanks, falling film evaporators, thin-film evaporators or other types of heat exchangers. These apparatuses or reactors can each be operated with or without external circulation, wherein the outer circulation can serve for backmixing or for simple heat supply or removal via an external heat transfer medium.
• a single reactor or a single apparatus is preferably used in which the individual steps described (crude AAN preparation, NH 3 removal, partial conversion of AAN to IDAN) are carried out in succession.
• the desired reaction conditions for each step are set in succession.
• Suitable reactor types are, for example, stirred tank loop reactor, boiler or stirred tank with attached distillation column, each with or without external circulation, wherein the outer circulation is used for temperature control, or the reaction takes place wholly or partly in the outer heat exchanger.
• the combination of reaction and distillation in a continuous or discontinuous reactive distillation column is possible.
• the process according to the invention is preferably carried out in a device selected from a tubular reactor, a flow tube, a falling-film evaporator or a thin-film evaporator.
• reactors can be used singly or as a cascade of the same or different reactors.
• a Reactor cascade can also be realized by sections different reaction conditions in a single reactor or a single apparatus.
• ammonia liberated from the apparatus can also be removed when adjusting the desired aminonitrile mixture, for example by distilling NH 3 off.
• a simultaneous removal of ammonia and aminonitrile mixture synthesis are carried out in a kettle or stirred tank with attached distillation column or in a reactive distillation column.
• the molar ratio of ammonia to AAN is set to be ⁇ 2.5: 1 [mol / mol].
• the crude AAN is heated at a temperature of 50 to 150 0 C, preferably, the temperature is 60 to 130 0 C.
• the crude AAN is prepared in a device and subsequently passed through a separate device (V1).
• the crude AAN is heated at a temperature of 70 to 150 0 C for a maximum of 30 minutes.
• the temperature is preferably 80 to 130 ° C.
• the device (V1) is in principle suitable for all devices through which the AAN can be passed in the specified temperature range.
• the device (V1) is a tubular reactor, a flow tube, a falling-film evaporator or a thin-film evaporator. These reactor types can be operated individually or connected in cascade. By partially impressed reaction conditions, a reactor cascade can also be realized in a single apparatus, for example in a flow tube with different temperature zones.
• the process according to the invention it is possible with the process according to the invention to prepare aminonitrile mixtures which comprise AAN as main components and 5 to 70% by weight of IDAN.
• the IDAN content is 5 to 50% by weight, more preferably 10 to 40% by weight, particularly preferably 10 to 25% by weight.
• the AAN content is usually 30 to 95 wt .-%, preferably 50 to 95 wt .-%, particularly preferably 75 to 90% by weight.
• the above percentages by weight of AAN and IDAN refer to the total amount of aminonitriles present in the mixture.
• any solvent or other by-products, such as other aminonitriles or other impurities are not included in these quantities.
• an aminonitrile mixture which contains the highest possible proportion of IDAN (based on the range from 5 to 70% by weight)
• the following parameters can be changed independently of one another:
• a higher temperature is selected.
• the higher the selected temperature the higher the IDAN content in the aminonitrile mixture;
• a maximum time is selected during which the crude AAN is heated.
• the longer the time during which the crude AAN is exposed to an elevated temperature the higher the IDAN content in the aminonitrile mixture; or iii) the NH 3 content in the device is reduced.
• the lower the NH 3 content in the device the higher the IDAN content in the aminonitrile mixture.
• a temperature increase favors the NH 3 removal and thus leads according to i) and iii) to a higher IDAN content.
• the aminonitrile mixture obtained in the process according to the invention can then be further processed.
• the aminonitrile mixture is then preferably subjected to catalytic hydrogenation by methods known to the person skilled in the art to obtain an ethylene amine mixture.
• the Ethylenamingemisch obtained in the catalytic hydrogenation contains in particular EDA and DETA.
• the individual components of the ethylene amine mixture obtained after the hydrogenation can be isolated, preferably these are EDA and / or DETA.
• Another object of the present invention is thus the use of the amino nitrile mixture prepared by the process according to the invention for the production of ethyleneamine by catalytic hydrogenation, wherein optionally EDA and / or DETA can be isolated from the ethylene amine mixture.
• the individual components of the aminonitrile mixture in particular AAN and IDAN, can also be isolated from the aminonitrile mixture.
• the process according to the invention can be carried out both as a (semi) -batch or preferably as a continuous process.
• the preparation of the aminonitrile mixture takes place directly in the Final synthesis of the crude AAN.
• the crude AAN is prepared by reacting ammonia with FACH.
• the two reactants are mixed prior to entering the tube by means of a static mixer.
• the product mixture contains the following approximate composition:
• VWZ residence time in the flow tube selectivity (AAN + IDAN): in all cases> 98%

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

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• 2008
  • 2008-02-28 KR KR1020097018179A patent/KR20090121293A/ko not_active Withdrawn
  • 2008-02-28 JP JP2009551209A patent/JP2010520169A/ja active Pending
  • 2008-02-28 US US12/529,096 patent/US8153845B2/en not_active Expired - Fee Related
  • 2008-02-28 WO PCT/EP2008/052412 patent/WO2008104581A1/de not_active Ceased
  • 2008-02-28 EP EP08717209A patent/EP2132164A1/de not_active Withdrawn
  • 2008-02-28 CN CN200880006358A patent/CN101627005A/zh active Pending

Non-Patent Citations (1)

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