Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C253/00—Preparation of carboxylic acid nitriles
  • C07C253/08—Preparation of carboxylic acid nitriles by addition of hydrogen cyanide or salts thereof to unsaturated compounds
  • C07C253/10—Preparation of carboxylic acid nitriles by addition of hydrogen cyanide or salts thereof to unsaturated compounds to compounds containing carbon-to-carbon double bonds
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C253/00—Preparation of carboxylic acid nitriles
  • C07C253/32—Separation; Purification; Stabilisation; Use of additives
• • 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
  • C07C255/06—Carboxylic acid nitriles having cyano groups bound to acyclic carbon atoms of an acyclic and unsaturated carbon skeleton
  • C07C255/07—Mononitriles
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/17—Nitrogen containing
  • Y10T436/172307—Cyanide or isocyanide

Definitions

• the present invention relates to a process for the preparation of 3-pentenenitrile by hydrocyanation of 1,3-butadiene in the presence of at least one catalyst.
• Adipodinitrile an important intermediate in nylon production, is produced by double hydrocyanation of 1,3-butadiene.
• 1,3-butadiene is converted to 3-pentenenitrile with hydrogen cyanide in the presence of nickel (O), which is stabilized with phosphorus ligands.
• nickel (O) which is stabilized with phosphorus ligands.
• 3-pentenenitrile is then reacted with hydrogen cyanide to give adiponitrile, likewise on a nickel catalyst, but with the addition of a Lewis acid.
• 1,3-butadiene is used in the hydrocyanation reaction in a stoichiometric excess in relation to the hydrogen cyanide.
• the hydrogen cyanide used reacts almost completely.
• a residual hydrogen cyanide content of 10 to 5,000 ppm by weight generally remains in the reaction discharge from this hydrocyanation.
• unconverted hydrogen cyanide can polymerize at a high content in the process for the production of 3-pentenenitrile under a strongly exothermic reaction and, if appropriate, lead to the container cracking.
• the object of the present invention is accordingly a process for the preparation of 3-pentenenitrile by hydrocyanation of 1,3-butadiene in the presence of at least B03 / 0404 IB / SF / BRD / ewe to provide at least one catalyst that makes it possible to avoid the problems described above and to increase process reliability.
• the solution to this problem is based on a process for the preparation of 3-pentenenitrile by hydrocyanation of 1,3-butadiene in the presence of at least one catalyst.
• the process according to the invention is then characterized in that non-hydrocyanated 1,3-butadiene is removed from the discharge from the hydrocyanation and returned to the process, the hydrogen cyanide content in the recycled 1,3-butadiene stream being determined.
• a determination of the content of cyanide in the recycled stream of 1,3-butadiene is understood to mean that the content is preferably measured at regular intervals, particularly preferably permanently, and that when a limit value is exceeded this excess is indicated and, if necessary, suitable measures are initiated to prevent further exposure of the 1,3-butadiene to hydrogen cyanide.
• a limit value is preferably 10% by weight, particularly preferably 7% by weight, in particular 5% by weight, of hydrogen cyanide, in each case based on the mixture of 1,3-butadiene and hydrogen cyanide.
• a pre-alarm can already be given at values lower than the aforementioned values, for example 2.5% by weight or 1.5% by weight.
• butadiene is understood to mean 1,3-butadiene which contains constituents which are also present in commercially available 1,3-butadiene.
• Pentenenitrile isomers may also be present.
• the content of the pentenenitrile isomers is preferably less than 1% by weight, particularly preferably less than 0.5% by weight, in particular less than 1000 ppm by weight.
• 3-pentenenitrile also means the corresponding isomers, for example 2-methyl-3-butenenitrile.
• Hydrogen cyanide and 1,3-butadiene form a minimum boiling point, so that regardless of the conditions under which the hydrocyanation discharge is partially evaporated, hydrogen cyanide in a mixture with 1, 3 is always present -Butadien goes overhead.
• it has proven difficult to detect hydrogen cyanide directly in the reaction effluent from the first hydrocyanation since the presence of pentenenitriles, catalyst complexes, polymeric hydrogen cyanide and solids overwhelms almost all conceivable analysis methods.
• fouling in the presence of solids precludes a large number of analytical methods that do not have a non-contact measuring principle.
• the cyanohydrogen content in the recycle stream of 1,3-butadiene is determined by at least one method which is selected from the group consisting of: (1) near infrared infrared spectrometry in the liquid phase in transmission; (2) infrared spectrometry in the middle infrared in the gas phase and / or the liquid phase in transmission; (3) infrared spectrometry in the middle infrared in the liquid phase using the ATR measurement method; (4) Liquid phase density measurement based on the difference in the densities of hydrogen cyanide and 1,3-butadiene; (5) measurement of thermal conductivity; (6) measurement of the speed of sound; (7) measurement of dielectric permittivity; (8) measurement of refractive index; (9) Online gas chromatographic determination; (10) measurement of the heat capacity of the liquid phase; (11) Online sampling and titration for hydrogen cyanide according to Vollhardt or Liebig,
• “removed” means that the content of hydrogen cyanide in the recycled 1,3-butadiene can also be determined in flow-through or contactless measuring systems, as described in more detail below.
• online means that there is preferably no interruption of a current in the method for taking samples, since the suitable ones Flow through measuring probes continuously or work contactlessly or an automatic sampling system is used which, if necessary, fills sampling vessels or measuring cuvettes at preferably regular intervals.
• the hydrogen cyanide content in the recycled 1,3-butadiene is particularly preferably monitored by measuring the dielectric permittivity with at least one device for level measurement using a capacitive measuring method.
• the 1,3-butadiene to be monitored is essentially free of solids, since solids generally lead to blockages in online sampling systems and thus reduced availability, which is not advantageous for plant safety, or the use thereof prevent optical methods because the particles prevent or greatly weaken the transmission of light, for example.
• Essentially free from solids means a solids content of at most 500 ppm by weight, particularly preferably at most 100 ppm by weight, in particular at most 10 ppm by weight.
• the methods mentioned above for monitoring the hydrogen cyanide content in the recycled 1,3-butadiene are particularly preferably carried out in product streams which result from the evaporation of a portion of the reaction product, the evaporated portion being able to be condensed again and the analysis in the resulting purified liquid Phase can take place.
• Such suitable measures are e.g. Measures to increase the hydrogen cyanide conversion in the hydrocyanation reaction, for example by increasing the temperature or by metering in additional, preferably fresh, catalyst or switching off the supply of hydrogen cyanide into the system, possibly with the hydrocyanation being completely stopped.
• the recycle stream of 1,3-butadiene is formed by evaporating at least part of the discharge from the hydrocyanation of 1,3-butadiene, the evaporated portion of the discharge from the hydrocyanation optionally condensing again before monitoring for hydrogen cyanide becomes.
• a method which is particularly suitable for this is described in DE-A-102004004724.
• DE-A-102 004 004718 describes a process for reducing the content of hydrogen cyanide in mixtures containing pentenenitrile, the reduction being carried out by a azeotropic distillation of the hydrogen cyanide with 1,3-butadiene is carried out.
• the concentration of hydrogen cyanide in the reactor itself and also the amount of hydrogen cyanide caused by the recycled 1,3-butadiene can be inferred is also driven into the reactors for the regular hydrogen cyanide feed.
• the hydrogen cyanide content is preferably measured in the gas phase of the condensate collection container or in the liquid phase of the condensate collection container or flooded in the pumping circuit of the condensate collection container of the distillation device for obtaining the 1,3-butadiene containing hydrogen cyanide from the discharge from the hydrocyanation.
• the process according to the invention for the hydrocyanation of 1,3-butadiene is preferably carried out in the presence of at least one homogeneously dissolved nickel (0) complex with phosphorus-containing ligands.
• Ni (0) complexes which contain phosphorus-containing ligands and / or free phosphorus-containing ligands, are preferably homogeneously dissolved nickel (O) complexes.
• the phosphorus-containing ligands of the nickel (0) complexes and the free phosphorus-containing ligands are preferably selected from mono- or bidentate phosphines, phosphites, phosphinites and phosphonites.
• These phosphorus-containing ligands preferably have the formula I: P (X 1 R 1 ) (X 2 R 2 ) (X 3 R 3 ) (I)
• compound I is understood to mean a single compound or a mixture of different compounds of the abovementioned formula.
• X 1 , X 2 , X 3 are independently oxygen or a single bond. If all of the groups X 1 , X 2 and X 3 are individual bonds, compound I is a phosphine of the formula P (R 1 R 2 R 3 ) with the meanings given for R 1 , R 2 and R 3 in this description ,
• compound I is a phosphinite of the formula P (OR 1 ) (R 2 ) (R 3 ) or P (R 1 ) (OR 2 ) (R 3 ) or P (R 1 ) (R 2 ) (OR 3 ) with the meanings given below for R 2 and R 3 .
• compound I represents a phosphonite of the formula P (OR 1 ) (OR 2 ) (R 3 ) or P (R 1 ) (OR 2 ) (OR 3 ) or P (OR 1 ) (R 2 ) (OR 3 ) with the meanings given for R 1 , R 2 and R 3 in this description.
• all of the groups X 1 , X 2 and X 3 should stand for oxygen, so that compound I is advantageously a phosphite of the formula P (OR 1 ) (OR 2 ) (OR 3 ) with those for R 1 , R 2 and R 3 represents meanings mentioned below.
• R 2 , R 3 independently of one another represent identical or different organic radicals.
• R 1 , R 2 and R 3 are, independently of one another, alkyl radicals, preferably having 1 to 10 carbon atoms, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, Aryl groups, such as phenyl, o-tolyl, m-tolyl, p-tolyl, 1-naphthyl, 2-naphthyl, or hydrocarbyl, preferably having 1 to 20 carbon atoms, such as 1,1'-biphenol, 1,1'- Binaphthol into consideration.
• the groups R 1 , R 2 and R 3 can be connected to one another directly, that is to say not only via the central phosphorus atom.
• the groups R 1 , R 2 and R 3 are preferably not directly connected to one another
• groups R 1 , R 2 and R 3 are selected from the group consisting of phenyl, o-tolyl, m-tolyl and p-tolyl. In a particularly preferred embodiment, a maximum of two of the groups R 1 , R 2 and R 3 should be phenyl groups.
• a maximum of two of the groups R 1 , R 2 and R 3 should be o-tolyl groups.
• Particularly preferred compounds I are those of the formula I a (o-tolyl-O-) w (m-tolyl-O-) ⁇ (p-tolyl-O-) y (phenyl-O-) z P (I a)
• Such compounds I a are, for example, (p-tolyl-O -) (phenyl-O-) 2 P, (m-tolyl-O -) (phenyl-O-) 2 P, (o-tolyl-O-) (phenyl -O-) 2 P, (p-toiyl-O-) 2 (phenyl-O-) P, (m-tolyl-O-) 2 (phenyl-O-) P, (o-tolyl-O-) 2 (Phenyl-O-) P, (m-tolyl-O -) (p-tolyl-O) (phenyl-O-) P, (o-tolyl-O -) (p-tolyl-O -) (phenyl-O-) (phenyl- O-) P, (o-tolyl-O -) (m-tolyl-O -) (phenyl-O-) P, (p-tolyl-O-) 3
• Mixtures containing (m-tolyl-O-) 3 P, (m-tolyl-O-) 2 (p-tolyl-O-) P, (m-tolyl-O -) (p-tolyl-O-) 2 P and (p-tolyl-O-) 3 P can be obtained, for example, by reacting a mixture containing m-cresol and p-cresol, in particular in a molar ratio of 2: 1, as is obtained in the working up of petroleum by distillation, with a phosphorus trihalide, such as phosphorus trichloride , receive.
• a phosphorus trihalide such as phosphorus trichloride
• phosphites of the formula Ib described in more detail in DE-A 19953 058 are suitable as phosphorus-containing ligands:
• R 1 aromatic radical with a CrC 18 alkyl substituent in the o-position to the oxygen atom that connects the phosphorus atom to the aromatic system, or with an aromatic substituent in the o-position to the oxygen atom that connects the phosphorus atom to the aromatic system, or with an aromatic system fused in the o-position to the oxygen atom which connects the phosphorus atom to the aromatic system,
• R 2 aromatic radical with a dC-i ⁇ -alkyl substituent in the m-position to the oxygen atom that connects the phosphorus atom with the aromatic system, or with an aromatic substituent in the m-position to the oxygen atom that connects the phosphorus atom with the aromatic system , or with an aromatic system fused in the m-position to the oxygen atom, which connects the phosphorus atom with the aromatic system, whereby the aromatic matic radical in the o-position to the oxygen atom that connects the phosphorus atom to the aromatic system carries a hydrogen atom,
• R 3 aromatic radical with a C 18 -C 18 -alkyl substituent in the p-position to the oxygen atom that connects the phosphorus atom to the aromatic system, or with an aromatic substituent in the p-position to the oxygen atom that connects the phosphorus atom with the aromatic system connects, the aromatic radical in the o-position to the oxygen atom which connects the phosphorus atom to the aromatic system carries a hydrogen atom,
• R 4 aromatic radical which, in the o-, m- and p-position to the oxygen atom which connects the phosphorus atom to the aromatic system, bears other substituents than those defined for R 1 , R 2 and R 3 , the aromatic radical bears a hydrogen atom in the o-position to the oxygen atom that connects the phosphorus atom to the aromatic system,
• Preferred phosphites of the formula I b can be found in DE-A 199 53058.
• the radical R 1 advantageously includes o-tolyl, o-ethyl-phenyl, on-propyl-phenyl, o-isopropyl-phenyl, on-butyl-phenyl, o-sec-butyl-phenyl, o- tert-Butyl-phenyl, (o-phenyl) -phenyl or 1-naphthyl groups into consideration.
• the radical R 2 is m-tolyl, m-ethyl-phenyl, mn-propyl-phenyl, m-isopropyl-phenyl, mn-butyl-phenyl, m-sec-butyl-phenyl, m-tert -Butyl-phenyl, (m-phenyl) -phenyl or 2-naphthyl groups preferred.
• the radical R 3 is advantageously p-tolyl, p-ethyl-phenyl, pn-propyl-phenyl, p-
• R 4 is preferably phenyl.
• P is preferably zero.
• Preferred phosphites of the formula Ib are those in which p is zero and R 1 , R 2 and R 3 are selected independently of one another from o-isopropylphenyl, m-tolyl and p-tolyl, and R 4 is phenyl.
• Particularly preferred phosphites of the formula Ib are those in which R 1 is the o-isopropylphenyl radical, R 2 is the m-tolyl radical and R 3 is the p-tolyl radical with the indices mentioned in the table above; also those in which R 1 is the o-tolyl radical, R 2 is the m-tolyl radical and R 3 is the p-tolyl radical with the indices specified in the table; furthermore those in which R 1 is the 1-naphthyl radical, R 2 is the m-tolyl radical and R 3 is the p-tolyl radical with the indices specified in the table; also those in which R 1 is the o-tolyl radical, R 2 is the 2-naphthyl radical and R 3 is the p-tolyl radical with the indices specified in the table; and finally those in which R 1 is the o-isopropylphenyl radical, R 2 is the 2-naphthyl
• Phosphites of formula I b can be obtained by
• the said dihalophosphoric acid monoester is reacted with an alcohol selected from the group consisting of R 1 OH, R 2 OH, R 3 OH and R 4 OH or mixtures thereof to obtain a monohalophosphoric acid diester and
• the implementation can be carried out in three separate steps. Two of the three steps can also be combined, i.e. a) with b) or b) with c). Alternatively, all of steps a), b) and c) can be combined with one another.
• Suitable parameters and amounts of the alcohols selected from the group consisting of R 1 OH, R 2 OH, R 3 OH and R 4 OH or their mixtures can easily be determined by a few simple preliminary tests.
• Suitable phosphorus trihalides are in principle all phosphorus trihalides, preferably those in which Cl, Br, I, in particular Cl, is used as the halide, and mixtures thereof. Mixtures of different identical or different halogen-substituted phosphines can also be used as the phosphorus trihalide. PCI 3 is particularly preferred. Further details on the reaction conditions in the preparation of the phosphites Ib and on the workup can be found in DE-A 199 53 058.
• the phosphites Ib can also be used as a ligand in the form of a mixture of different phosphites Ib. Such a mixture can occur, for example, in the production of the phosphites Ib.
• the phosphorus-containing ligand is multidentate, in particular bidentate.
• the ligand used therefore preferably has the formula II
• R 11 , R 12 independently of one another the same or different, individual or bridged organic radicals
• R 21 , R 22 independently of one another are identical or different, individual or bridged organic radicals, Y bridge group
• compound II is understood to mean a single compound or a mixture of different compounds of the abovementioned formula.
• X 11 , X 12 , X 13 , X 21 , X 22 , X 23 can represent oxygen.
• the bridging group Y is linked to phosphite groups.
• X 11 and X 12 oxygen and X 13 can be a single bond or X 11 and X 13 oxygen and X 12 can be a single bond, so that the phosphorus atom surrounded by X 11 , X 12 and X 13 is the central atom of a phosphonite.
• X 21 , X 22 and X 23 oxygen or X 21 and X 22 oxygen and X 23 a single bond or X 21 and X 23 oxygen and X 22 a single bond or X 23 oxygen and X 21 and X 22 a single bond or X 21 oxygen and X 22 and X 23 represent a single bond or X 21 , X 22 and X 23 represent a single bond, so that the phosphorus atom surrounded by X 21 , X 22 and X 23 represents the central atom of a phosphite, phosphonite, phosphinite or phosphine, preferably one Phosphonites.
• X 13 oxygen and X 11 and X 12 can be a single bond or X 11 oxygen and X 12 and X 13 can be a single bond, so that the phosphorus atom surrounded by X 11 , X 12 and X 13 is the central atom of a phosphonite.
• X 21 , X 22 and X 23 can be oxygen or X 23
• Oxygen and X 21 and X 22 is a single bond, or X 21 is oxygen and X 22 and X 23 is a single bond or X 21, X 22 and X 23 is a single bond, so that X 21, X 22 and X 23 phosphorus atom surrounded by the central atom of a phosphite , Phosphinite or phosphine, preferably a phosphinite.
• X 11 , X 12 and X 13 can represent a single bond, so that the phosphorus atom surrounded by X 11 , X 12 and X 13 is the central atom of a phosphine.
• X 21 , X 22 and X 23 oxygen or X 21 , X 22 and X 23 represent a single bond, so that the phosphorus atom surrounded by X 21 , X 22 and X 23 is the central atom of a phosphite or phosphine, preferably a phosphine , can be.
• Suitable bridging groups Y are preferably substituted, for example with CC 4 -alkyl, halogen, such as fluorine, chlorine, bromine, halogenated alkyl, such as trifluoromethyl, aryl, such as phenyl, or unsubstituted aryl groups, preferably those with 6 to 20 carbon atoms in the aromatic system, in particular pyrocatechol, bis (phenol) or bis (naphthol).
• halogen such as fluorine, chlorine, bromine
• halogenated alkyl such as trifluoromethyl
• aryl such as phenyl
• unsubstituted aryl groups preferably those with 6 to 20 carbon atoms in the aromatic system, in particular pyrocatechol, bis (phenol) or bis (naphthol).
• R 11 and R 12 can independently represent the same or different organic radicals.
• R 11 and R 12 are advantageously aryl radicals, preferably those having 6 to 10 carbon atoms, which may be unsubstituted or mono- or polysubstituted, in particular by C 1 -C 4 -alkyl, halogen, such as fluorine, chlorine, bromine, halogenated alkyl such as trifluoromethyl, aryl such as phenyl or unsubstituted aryl groups.
• R 21 and R 22 can independently represent the same or different organic radicals.
• R 21 and R 22 are advantageously aryl radicals, preferably those having 6 to 10 carbon atoms, which may be unsubstituted or mono- or polysubstituted, in particular by CC 4 alkyl, halogen, such as fluorine, chlorine, bromine, halogenated alkyl such as trifluoromethyl, aryl such as phenyl or unsubstituted aryl groups.
• the radicals R 11 and R 12 can be individually or bridged.
• the radicals R 21 and R 22 can also be individual or bridged.
• the radicals R 11 , R 12 , R 21 and R 22 can all be individually, two bridged and two individually or all four bridged in the manner described.
• the compounds of the formula I, II, III, IV and V mentioned in US Pat. No. 5,723,641 are suitable.
• the compounds of the formula I, II, III, IV, V, VI and VII mentioned in US Pat. No. 5,512,696, in particular the compounds used there in Examples 1 to 31, come into consideration.
• the compounds mentioned in US Pat. No. 6,127,567 and the compounds used there in Examples 1 to 29 come into consideration.
• the compounds of the formula I, II, III, IV, V, VI, VII, VIII, IX and X mentioned in US Pat. No. 6,020,516, in particular the compounds used there in Examples 1 to 33 come into consideration.
• the compounds mentioned in US Pat. No. 5,959,135 and the compounds used there in Examples 1 to 13 are suitable.
• the compounds of the formula I, II and III mentioned in US Pat. No. 5,847,191 are suitable.
• the compounds mentioned in WO 98/27054 are suitable.
• the compounds mentioned in WO 99/13983 are suitable.
• the compounds mentioned in WO 99/64155 come into consideration.
• the compounds mentioned in German patent application DE 100380 37 come into consideration.
• the compounds mentioned in German patent application DE 10046025 come into consideration.
• the compounds mentioned in German patent application DE 101 50285 come into consideration.
• the compounds mentioned in German patent application DE 101 502 86 come into consideration.
• the compounds mentioned in German patent application DE 102 071 65 come into consideration.
• the phosphorus-containing chelate ligands mentioned in US 2003/0100442 A1 come into consideration.
• the phosphorus-containing chelate ligands mentioned in the unpublished German patent application file number DE 103 50 999.2 from October 30, 2003 come into consideration.
• the compounds I, I a, I b and II described and their preparation are known per se. Mixtures containing at least two of the compounds I, I a, I b and II can also be used as the phosphorus-containing ligand.
• the phosphorus-containing ligand of the nickel (0) complex and / or the free phosphorus-containing ligand is selected from tritolylphosphite, bidentate phosphorus-containing chelate ligands, and the phosphites of the formula Ib
• the hydrocyanation can be carried out in any suitable device known to the person skilled in the art.
• Conventional devices are considered for the reaction, as described, for example, in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed. Vol. 20, John Wiley & Sons, New York 1996, pages 1040 to 1055, such as stirred tank reactors, loop reactors, gas circulation reactors, bubble column reactors or tubular reactors, each optionally with devices for dissipating heat of reaction.
• the reaction can be carried out in several, such as two or three, devices.
• reactors with backmixing characteristics or cascades of reactors with backmixing characteristics have proven to be advantageous.
• Cascades from reactors with backmixing characteristics have been found to be particularly advantageous which are operated in cross-flow mode with respect to the metering of hydrogen cyanide.
• the hydrocyanation can be carried out in batch mode, continuously or in semi-batch mode.
• the hydrocyanation is preferably carried out continuously in one or more stirred process steps. If a plurality of method steps are used, it is preferred that the method steps are connected in series.
• the product is transferred from one process step directly to the next transferred step.
• the hydrogen cyanide can be fed directly into the first process step or between the individual process steps.
• the catalyst components and 1,3-butadiene are introduced into the reactor while hydrogen cyanide is metered into the reaction mixture over the reaction time.
• the hydrocyanation can be carried out in the presence or absence of a solvent. If a solvent is used, the solvent should be liquid at the given reaction temperature and the given reaction pressure and inert to the unsaturated compounds and the at least one catalyst.
• a solvent for example benzene or xylene, or nitrites, for example acetonitrile or benzonitrile, are used as solvents.
• a ligand is preferably used as the solvent.
• the hydrocyanation reaction can be carried out by loading all reactants into the device. However, it is preferred if the device is filled with the at least one catalyst, 1, 3-butadiene and optionally the solvent.
• the gaseous hydrogen cyanide preferably hovers over the surface of the reaction mixture or is preferably passed through the reaction mixture.
• a further procedure for equipping the device is filling the device with the at least one catalyst, hydrogen cyanide and, if appropriate, the solvent and slowly feeding the 1,3-butadiene into the reaction mixture.
• the reactants to be introduced into the reactor and for the reaction mixture to be brought to the reaction temperature at which the hydrogen cyanide is added to the mixture in liquid form.
• the hydrogen cyanide can also be added before heating to the reaction temperature.
• the reaction is carried out under conventional hydrocyanation conditions for temperature, atmosphere, reaction time, etc.
• the hydrocyanation is preferably carried out at pressures of 0.1 to 500 MPa, particularly preferably 0.5 to 50 MPa, in particular 1 to 5 MPa.
• the reaction is preferably carried out at temperatures from 273 to 473 K, particularly preferably 313 to 423 K, in particular at 333 to 393 K.
• Average residence times of the liquid reactor phase in the range from 0.001 to 100 hours, preferably 0.05 to 20 hours, particularly preferably 0.1 to 5 hours, in each case per reactor, have proven advantageous.
• the hydrocyanation can be carried out in the liquid phase in the presence of a gas phase and, if appropriate, a solid suspended phase.
• the starting materials hydrogen cyanide and 1,3-butadiene can each be metered in in liquid or gaseous form.
• the hydrocyanation can be carried out in the liquid phase, the pressure in the reactor being such that all starting materials, such as 1,3-butadiene, hydrogen cyanide and the at least one catalyst, are metered in liquid and are present in the reaction mixture in the liquid phase.
• a solid suspended phase can be present in the reaction mixture, which can also be metered in together with the at least one catalyst, for example consisting of degradation products of the catalyst system containing, inter alia, nickel (II) compounds.
• the present invention further relates to the use of at least one method which is selected from the group consisting of:
• infrared spectrometry in the near infrared in the liquid phase in transmission (2) infrared spectrometry in the middle infrared in the gas phase and / or the liquid phase in transmission; (3) infrared spectrometry in the middle infrared in the liquid phase using the ATR measurement method; (4) Liquid phase density measurement based on the difference in the densities of hydrogen cyanide and 1,3-butadiene; (5) measurement of thermal conductivity; (6) measurement of the speed of sound; (7) measurement of dielectric permittivity; (8) measurement of refractive index; (9) Online gas chromatographic determination; (10) measurement of the heat capacity of the liquid phase; (11) Online sampling and titration for hydrogen cyanide according to Vollhardt or Liebig,
• Measuring methods according to methods 1, optionally 2, 3 to 5 and 8 to 11 are preferably carried out by flowing through a suitable sampling system which doses samples, for example at preferably regular intervals, onto the respective devices. These methods can also be carried out by direct flow through a suitable measuring apparatus, so that no sampling system is necessary.
• the measuring methods 6 and 7 are preferably carried out with measuring probes which are not in contact with the product and are therefore preferably located outside of flow-through apparatus. These measurements are preferably carried out on an apparatus or a pipeline, particularly preferably a pipeline in the pumping circuit of the condensate collection container at the head of the distillation device for obtaining the 1,3-butadiene containing hydrogen cyanide or a storage container for 1,3-butadiene containing hydrogen cyanide ,
• the measuring point is preferably free of gas phase, particularly preferably it is a flooded pipeline.
• the measurement probes are calibrated by introducing preferably several test mixtures of known content and / or known measurement variables, such as the speed of sound or dielectric permittivity, one after the other into the measuring point, with the inclusion of calibration curves.
• the content of hydrogen cyanide in the returned 1,3-butadiene is particularly preferably monitored by measuring the dielectric permittivity using a device for level measurement using a capacitive measuring method.
• Suitable measuring probes for determining the dielectric permittivity are, for example, level measuring probes from the Endress + Hauser Multicap DC16 or Vega EL21 brands.
• Suitable test mixtures are used to calibrate the appropriate measuring probes.
• the hydrogen cyanide content in the stream which contains 1,3-butadiene and is returned to the hydrocyanation is measured by measuring the relative die- electrical permittivity with a device for level measurement with capacitive measuring method.
• the example describes measurements with probes for capacitive level measurement from two manufacturers (Endress + Hauser, model Multicap DC16; Vega, model EL21).
• the probes were alternately installed in a thermostattable DN50 pipe, which was filled with mixtures of butadiene and hydrogen cyanide.
• the signals of the probes in the temperature range 0 to 10 ° C. and hydrogen cyanide concentration range 0 to 5% by weight were determined.
• unstabilized, distilled hydrogen cyanide and dried butadiene over aluminum oxide from F200 from Almatis according to examples from DE-A-102 004 004 684 were used.
• Butadiene was circulated within the apparatus.
• a container B1 designed as a double jacket pipe DN50 x 500 mm
• the container B1 was cooled via the double jacket with a cryostat.
• Butadiene was removed from container B1 via a gear pump P1 (working range 0.5 to 5 l / min) and conveyed back into container B1 by means of a liquid gas sampling valve.
• the pump head was cooled to approx. -5 ° C by accompanying cooling.
• B1 was driven flooded. A sight glass in the ventilation line served as the air boiler.
• Example 2 After this calibration, a 5 mL sample from the circle described in Example 1 was flushed back into the empty bomb, with which the stock solution of hydrogen cyanide in butadiene had also been introduced into the circle. A sufficient sample volume was pressed from this bomb into the cuvette by applying nitrogen at a pressure of 5 bar. The circle from which the sample was taken had 1.5% by weight of hydrogen cyanide at the time of removal (calculation from the metered amount of stock solution). The absorption determined in the IR device was 0.51.

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• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

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• 2004
  • 2004-01-29 DE DE102004004672A patent/DE102004004672A1/de not_active Withdrawn
• 2005
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  • 2005-01-26 KR KR1020067015350A patent/KR20070011283A/ko not_active Application Discontinuation
  • 2005-01-26 US US10/586,473 patent/US20080227214A1/en not_active Abandoned
  • 2005-01-26 WO PCT/EP2005/000725 patent/WO2005073169A1/de active Application Filing
  • 2005-01-26 TW TW094102237A patent/TW200538428A/zh unknown
  • 2005-01-26 CA CA002553241A patent/CA2553241A1/en not_active Abandoned
  • 2005-01-26 JP JP2006550082A patent/JP4443573B2/ja not_active Expired - Fee Related
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  • 2005-01-26 EP EP05715210A patent/EP1716107A1/de not_active Withdrawn
  • 2005-01-26 CN CNB2005800036411A patent/CN100513388C/zh not_active Expired - Fee Related

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