Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G49/00—Compounds of iron
  • C01G49/009—Compounds containing iron, with or without oxygen or hydrogen, and containing two or more other elements
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G49/00—Compounds of iron

Definitions

• the present invention relates to a process for the preparation of a element iron and at least one other elemental constituent different from oxygen in oxidic form containing multielement oxide composition, wherein the sources of the elemental constituents of the Multielementoxidmasse a elementary constituents containing dry mixture containing as precursor material and the Former mass as such or molded into a shaped body thermally treated at elevated temperature, wherein as a source of the elemental constituent iron, an aqueous solution of iron nitrate is also used.
• Multielement oxide compositions containing the element iron and at least one other elemental constituent other than oxygen in oxidic form are known (see, for example, US 2005/0131253 A1, US-A 3,825,600, EP-A 1080781 and DE-A 102005035978). Among others, they are used as active material for catalysts capable of catalyzing heterogeneously catalyzed gas-phase partial oxidations of a wide variety of organic starting compounds (eg from propylene to acolein, from isobutene to methacrolein, from n-butane to maleic anhydride, from propylene to acrylonitrile, or from iso-butene to methacrylonitrile).
• organic starting compounds eg from propylene to acolein, from isobutene to methacrolein, from n-butane to maleic anhydride, from propylene to acrylonitrile, or from iso-butene to methacrylonitrile.
• a complete oxidation of an organic compound with molecular oxygen is understood here to mean that the organic compound is reacted under the reactive action of molecular oxygen in such a way that the carbon contained in the organic compound as a whole is contained in oxides of carbon and in the total amount of hydrogen contained in the organic compound is converted into oxides of hydrogen. All of these differing reactions of an organic compound under the reactive action of molecular oxygen are summarized here as partial oxidations of an organic compound.
• partial reactions are to be understood here as meaning those reactions of organic compounds under the reactive action of molecular oxygen, in which the partially oxidized organic compound contains at least one oxygen atom more chemically bound after completion of the reaction than before the partial oxidation (the term partial oxidation is in this document also the partial ammoxidation, ie, a partial oxidation in the presence of ammonia, include).
• the catalyst bed has the task of causing the desired gas phase partial oxidation to take place. on preferential over the complete oxidation expires.
• the chemical reaction takes place when the reaction gas mixture flows through the catalyst bed during the residence time of the reaction gas mixture in selbigem.
• the reactants in the reaction gas mixture are diluted by a substantially inert diluent gas whose constituents under the conditions of the heterogeneously catalyzed gas phase partial oxidation - each constituent per se - more than 95 mol%, preferably more than 99 mol% chemically unchanged remain.
• the catalytically active oxide composition may contain only one other element or more than another element (multielement oxide masses). Particularly frequently used as catalytically active oxide materials are those which, in addition to iron, comprise at least one other metallic, in particular transitional, metallic element. In this case one speaks of Multimetalloxidmas- sen.
• the multielement oxide compositions are not simple physical mixtures of oxides of the elemental constituents, but heterogeneous and / or homogeneous mixtures of complex polyoxo compounds of these elements.
• Multielementoxidmassen is usually carried out so that with appropriate sources of their elemental constituents (preferably intimately and application technically functional finely divided) of their stoichiometry correspondingly assembled dry mix and this formed as such or to a shaped body at elevated temperature (often 150 to 650 0 C) thermally treated.
• Suitable sources for the elemental constituents of the desired multielement oxide active substance are in principle those compounds which are already oxides and / or compounds which can be converted into oxides by heating (thermal treatment) (at least in the presence of gaseous molecular oxygen).
• the oxygen source may also be e.g. be part of the precursor mixture in the form of a peroxide.
• such sources are, in particular, halides, nitrates, formates, oxalates, citrates, acetates, carbonates, amine complexes, ammonium salts and / or hydroxides.
• Compounds such as NH 4 OH, (NH 4 ) 2 CO 3 , NH 4 NO 3 , NH 4 CHO 2 , CH 3 COOH, NH 4 CH 3 CO 2 and / or ammonium oxalate, which, like the abovementioned constituents, in the thermal treatment to essenli - gaseous escaping compounds can disintegrate and / or decomposed, can be incorporated in the precursor mixture additionally.
• the precursor dry mixture may additionally contain finely divided reinforcing aids such as glass microfibers, asbestos, silicon carbide and / or potassium titanate.
• reinforcing aids such as glass microfibers, asbestos, silicon carbide and / or potassium titanate.
• Forming aids such as boron nitride, graphite, carbon black, polyethylene glycol, stearic acid, starch, polyacrylic acid, mineral or vegetable oil, water, boron trifluoride, glycerol and cellulose ethers can also be added (cf., for example, German specification with the file reference 102005037678.9).
• The, preferably intimate, mixing of the starting compounds (sources) for the preparation of the dry precursor composition takes place suitably from an application point of view in wet form.
• the starting compounds are at least partially mixed together in the form of an aqueous solution and / or suspension.
• solvent and / or suspending medium but also liquids other than water such. Methanol, ethanol, iso-butanol, benzene, diethyl ether and other organic solvents into consideration.
• the wet preparation is converted by drying and, if appropriate, subsequent comminution into a dry mixture from which, as such or after shaping into a shaped body, the multilayer oxide active composition is produced by thermal treatment.
• Iron (II) and / or iron (III) nitrate is normally used as the source of the elemental constituent iron in the process of the prior art in the context of the production of multielement oxide compositions of the invention (the Roman numeral indicates the oxidation state of the iron). and, for reasons of intimate wet mixing of the various sources to be used for the preparation of the precursor composition, this is preferably from an application point of view as an aqueous solution (eg US Pat. No. 3,825,600, US-2005/0131253 A1 and EP-A 1080781).
• the preparation of the aqueous solution of iron nitrate takes place in that iron (II) nitrate (Fe (NOs) 2), or iron (III) nitrate (Fe (NOs) 3), or at a temperature of 25 ° C and a pressure of 1 bar solid hydrate of the foregoing iron nitrates (eg Fe (NOs) 2 ⁇ 6H 2 O, or Fe (NOs) 3 ⁇ 6H 2 O, or Fe (NOs) 3 ⁇ 9H 2 O, or Fe (NOs) 2 ⁇ 9H 2 O or a mixture of various aforementioned salts in water, or in an aqueous solution (this may already contain other chemical components dissolved)) is dissolved.
• the object of the present invention was therefore to provide a form of iron nitrate which is more suitable for the industrial production of aqueous iron nitrate solutions, which on the one hand is comparatively easily accessible and on the other hand both easy to convey and precisely metered.
• a process for producing a multielement oxide composition containing the element iron and at least one other elemental constituent other than oxygen in oxidic form comprising producing a constituent element-containing dry mixture precursor composition and sources of the elemental constituents of the multielement oxide composition thermally treated as such or formed into a shaped body at elevated temperature, wherein an aqueous solution of iron nitrate is used as the source of the elemental constituent iron, characterized in that the preparation of the aqueous iron nitrate solution comprises melting one at a temperature of 25 ° C and a pressure of 1 bar in the solid state hydrate of iron nitrate.
• Basis of the procedure according to the invention is the fact that the melting point of located at 25 ° C and a pressure of 1 bar in the solid state hydrates of iron nitrate at atmospheric pressure (1 bar) is comparatively low.
• aqueous solutions of iron nitrate can thus be obtained in a particularly simple manner.
• aqueous solutions are easy to convey and can be metered with pinpoint accuracy.
• they may be directly as such a source of iron nitrate to be used in the present invention.
• water or a water-miscible organic solvent and / or the source of one or more other constituents of the multielement oxide composition (optionally in solution) may also be added at any time prior to use as an iron nitrate source in the process of the invention.
• the water is connected to a hot water circuit.
• the temperature of the circulating water is usually above the melting temperature of the iron nitrate hydrate (preferably> 10 0 C above the melting temperature of the iron nitrate), but normally at a value ⁇ 98 0 C.
• the container containing the melt (aqueous iron nitrate solution) is located on a balance.
• the desired amount of the melt (the aqueous solution) for use in the method according to the invention can be sent out at any time in terms of application technology.
• solid iron nitrate hydrate is added to the remaining melt and melted, so as to replenish the aqueous iron nitrate solution.
• the container containing the iron nitrate melt is substantially closed.
• the pressure in the exhaust air system is preferably> 950 mbar abs., Particularly preferably> 980 mbar abs. and most preferably> 995 mbar abs ..
• this pressure will not be more than 1100 mbar absolute (abs.). Slight negative pressure relative to the atmosphere is preferred.
• inert gases for example, ISb, CO2 and / or noble gases can be used.
• the remelting of solid iron nitrate hydrate in iron-nitrate melt remaining in the double-walled container is effected with stirring.
• the exact Fe content of the solid iron nitrate hydrate is determined by analytical Determine mood on a first melted sample amount. This analytical determination can be carried out, for example, titrimetrically (ie by dimensional analysis).
• the other starting compounds of the various elemental constituents of the desired multielement oxide composition for example in the form of an aqueous solution and / or suspension, are mixed together. Particularly intimate dry mixtures are obtained when it is assumed that only in dissolved form sources of elemental constituents.
• the solvent (or dispersant) is preferably water.
• the obtained, for example, aqueous mass is dried, wherein the drying process is industrially advantageous by spray drying of eg aqueous mixture with eg outlet temperatures of 100 to 150 0 C. In principle, however, the drying can also be carried out by freeze-drying, by conventional evaporation or by filtration and subsequent heating of the filter cake, for example in a rotary kiln.
• the stoichiometry of the desired multielement oxide composition may be e.g. those of the general formula I, as described in EP-A 1080781, e.g. as an active composition for a heterogeneously catalyzed partial gas phase oxidation of propylene to acrolein,
• X 2 K, Na, Rb, Cs and / or Tl
• X 3 P, Nb, Mn, Ce, Te, W, Sb and / or Pb
• X 4 Si, Al, Zr and / or Ti
• b 0.1 to 10
• c 0.1 to 10
• d 2 to 20
• e 0.001 to 5
• f 0 to 5
• g 0 to 30, and
• n a number which is determined by the valence and frequency of the elements other than oxygen in I.
• the stoichiometry of the desired multielement oxide composition may also be that of the general formula II, as described generally in US 2005/0131253.
• tive mass for the heterogeneously catalyzed partial oxidation of an olefin to an unsaturated aldehyde recommends:
• X 1 K, Na, Rb, Cs and / or Tl
• X 2 P, B, As and / or W
• X 3 Mg, Ca, Zn, Ce and / or Sm
• X 4 F, Cl, Br and / or J
• b 0.5 to 7
• c 0 to 10
• d 0 to 10
• e 0.05 to 3
• f 0.0005 to 3
• g 0 to 3
• h 0 to 1
• i 0 to 0.5
• j 0 to 40
• n a number which is determined by the valency and frequency of the elements other than oxygen in II.
• the process according to the invention also encompasses the preparation of all multielement oxide compositions described in the document with the file reference 102005037678.9 and in Research Disclosure 2005, 09, 497 (RD 2005-497012, 20050820), which contain the element iron.
• These include, in particular, all multielement oxide materials of general stoichiometry III,
• X 1 Ni and / or Co
• X 2 thallium, an alkali metal and / or an alkaline earth metal
• X 3 Zn, P, As, B, Sb, Sn, Ce, Pb and / or W,
• the process according to the invention is suitable for the preparation of multielement oxide compositions which, in addition to oxygen and iron, in particular also contain the elements Bi and Mo.
• multielement oxide compositions which, in addition to oxygen and iron, in particular also contain the elements Bi and Mo.
• These also include in particular the multimetal oxide active compositions which are described in DE-A 100 46 957, DE-A 44 07 020, EP-A 835, EP-A 575 897 and DE-C 33 38 380.
• the process according to the invention is suitable for the preparation of multimetal oxide compositions which, in addition to oxygen and iron, in particular also contain the elements V and P and are suitable as an active composition for the heterogeneously catalyzed partial oxidation of n-butane to maleic anhydride.
• the stoichiometry of the multielement oxide mass may then be e.g. be one of the general formula IV,
• X 1 Mo, Bi, Co, Ni, Si, Zn, Hf, Zr, Ti, Cr, Mn, Cu, B, Sn and / or Nb,
• X 2 K, Na, Rb, Cs and / or Tl
• b 0.9 to 1.5
• c 0.005 to 0.1
• d 0 to 0.1
• e 0 to 0.1
• n a number determined by the valence and frequency of the elements other than oxygen in IV.
• thermal treatment of the dry precursor composition and the drying of the wet mixture of the elemental constituents of the desired multielement oxide composition can blend seamlessly into one another.
• the dried precursor composition Prior to the thermal treatment, the dried precursor composition can be comminuted if necessary or formed into a shaped body.
• the thermal treatment (calcination), within which the desired mutant oxide active mass is formed from the precursor composition, can in principle be carried out under an inert gas atmosphere (eg H2O, N2, CO2, noble gas or mixtures thereof) or under an oxidizing atmosphere (eg under a pure molecular weight) Oxygen, or under a mixture of molecular oxygen and inert gases (eg air), as well as under a reducing atmosphere (eg mixture of inert gas, NH3, CO and / or H2).
• an inert gas atmosphere eg H2O, N2, CO2, noble gas or mixtures thereof
• an oxidizing atmosphere eg under a pure molecular weight
• Oxygen eg under a pure molecular weight
• a mixture of molecular oxygen and inert gases eg air
• a reducing atmosphere eg mixture of inert gas, NH3, CO and / or H2
• the multielement oxide active masses resulting in the calcination can be shaped both in powder form and in shaped bodies of any desired geometry (cf., for example, WO 02/062737) as catalysts for gas phase partial oxidations (for example propylene to acrolein, isobutene to methacrolein, propylene to acrylonitrile, isobutene to methacrylonitrile, n-butane to maleic anhydride, butadiene to maleic anhydride, propane to acrolein and / or acrylic acid, isobutane to methacrolein and / or methacrylic acid).
• gas phase partial oxidations for example propylene to acrolein, isobutene to methacrolein, propylene to acrylonitrile, isobutene to methacrylonitrile, n-butane to maleic anhydride, butadiene to maleic anhydride, propane to acrolein
• spherical, solid cylindrical or annular unsupported catalysts may be prepared by compacting to the desired catalyst geometry (e.g., by extrusion or tableting), optionally with adjuvants such as e.g. Graphite or stearic acid as lubricants and / or molding aids and reinforcing agents such as microfibers of glass, asbestos, silicon carbide or potassium titanate can be added.
• adjuvants such as e.g. Graphite or stearic acid as lubricants and / or molding aids and reinforcing agents such as microfibers of glass, asbestos, silicon carbide or potassium titanate can be added.
• the shaping can also be carried out by applying the powder form of the multimetal oxide active composition or its uncalcined and / or partially calcined finely divided precursor composition to an inert carrier (eg spherical, cylindrical or annular), the application suitably in terms of application with the concomitant use of a liquid binder (eg water , or a mixture of water and glycerol) takes place.
• a liquid binder eg water , or a mixture of water and glycerol
• the longest extent (longest direct connecting line of two points located on the surface of the shaped catalyst body) of the resulting shaped catalyst bodies is generally 1 to 12 mm, often 2 to 10 mm.
• Typical calcination temperatures are from 150 to 650 ° C., frequently from 250 to 550 ° C.
• the calcination temperature will vary over the duration of the calcination.
• the melting of iron (III) nitrate hydrates are preferred according to comprise (in particular (of Fe NO3) 3 ⁇ 6H2O and Fe (NOs) 3 ⁇ 9HbO; the latter is particularly preferred due to its less pronounced hygroscopicity).
• a melting point depression can be effected by melting a mixture of different iron nitrate hydrates.
• exclusively an aqueous solution of iron nitrate is used as the source of the elemental constituent iron, the preparation of which comprises melting a hydrate of iron nitrate (at 25 ° C., 1 bar) in the solid state.
• the melt of the iron nitrate hydrate was easy to keep liquid and could be precisely metered in the context of the large-scale production of Fe-containing multielement oxide masses by discharging precalculated amounts by weight (the double-walled vessel was on a mass scale). Significant decomposition of Fe (NO 3 ) 3 ⁇ 9H 2 O during the melting process was not observed.
• a second aqueous solution Il was prepared by adding, with stirring, to 500.6 kg of an aqueous cobalt (II) nitrate solution (12.4 wt .-% Co) at 6O 0 C 179.4 kg of a 60.5 ° C (NO 3) (13.8 wt .-% Fe) were aqueous having Fe 3 ⁇ 9H2 ⁇ melt. After complete addition, the mixture was stirred for 30 min at 6O 0 C again. Thereafter, at 6O 0 C 168.5 kg of a 20 0 C-containing aqueous bismuth nitrate solution (11 wt .-% Bi 2) is stirred to obtain the aqueous solution Il.
• II aqueous cobalt
• the resulting slurry was spray dried in a countercurrent process (gas inlet temperature: 400 ⁇ 10 0 C, gas outlet temperature: C 140 ⁇ 5 °) with a spray-dried powder was obtained as a dry precursor material, the loss on ignition (3 h at 600 ° C under air) for 30% of its weight amounted to.
• the grain size of the spray powder was substantially uniformly 30 ⁇ m.
• TIMREX T44 graphite from Timcal AG (CH-Bodio)
• the precursor material became annular unsupported catalyst precursor bodies of the annular geometry 5 mm ⁇ 3 mm ⁇ 2 mm (outer diameter ⁇ height ⁇ inner diameter ) shaped. These were then calcined in air at 500 ° C. (9 h) to give the desired multimetal oxide catalyst.
• This is suitable as a catalyst for the heterogeneously catalyzed gas phase partial oxidation of propylene to acrolein.

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• Catalysts (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
• Compounds Of Iron (AREA)
• Oxygen, Ozone, And Oxides In General (AREA)

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• 2007
  • 2007-01-16 DE DE102007003076A patent/DE102007003076A1/de not_active Withdrawn
• 2008
  • 2008-01-14 CN CN200880002381XA patent/CN101583569B/zh not_active Expired - Fee Related
  • 2008-01-14 WO PCT/EP2008/050341 patent/WO2008087115A2/de not_active Ceased
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  • 2008-01-14 JP JP2009545195A patent/JP5562038B2/ja active Active
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