WO2015018815A1 - Procédé de conversion sans oxygène de méthane en éthylène sur des catalyseurs à base de zéolithe - Google Patents

Procédé de conversion sans oxygène de méthane en éthylène sur des catalyseurs à base de zéolithe Download PDF

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WO2015018815A1
WO2015018815A1 PCT/EP2014/066788 EP2014066788W WO2015018815A1 WO 2015018815 A1 WO2015018815 A1 WO 2015018815A1 EP 2014066788 W EP2014066788 W EP 2014066788W WO 2015018815 A1 WO2015018815 A1 WO 2015018815A1
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small
preferred
zeolite
pore
metal
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PCT/EP2014/066788
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Mathias Feyen
Ulrich Müller
Xinhe Bao
Weiping Zhang
Dirk De Vos
Hermann Gies
Takashi Tatsumi
Feng-Shou Xiao
Xiaoguang Guo
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Basf Se
Tokyo Institute Of Technology
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2/00—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms
    • C07C2/76—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by condensation of hydrocarbons with partial elimination of hydrogen
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/061—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof containing metallic elements added to the zeolite
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
    • B01J29/72—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 containing iron group metals, noble metals or copper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
    • B01J29/78—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 containing arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
    • B01J29/78—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 containing arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J29/7815—Zeolite Beta
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
    • B01J2229/10—After treatment, characterised by the effect to be obtained
    • B01J2229/18—After treatment, characterised by the effect to be obtained to introduce other elements into or onto the molecular sieve itself
    • B01J2229/186—After treatment, characterised by the effect to be obtained to introduce other elements into or onto the molecular sieve itself not in framework positions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
    • B01J2229/60—Synthesis on support
    • B01J2229/62—Synthesis on support in or on other molecular sieves
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/005—Mixtures of molecular sieves comprising at least one molecular sieve which is not an aluminosilicate zeolite, e.g. from groups B01J29/03 - B01J29/049 or B01J29/82 - B01J29/89
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
    • B01J29/7015—CHA-type, e.g. Chabazite, LZ-218
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/82—Phosphates
    • B01J29/84—Aluminophosphates containing other elements, e.g. metals, boron
    • B01J29/85—Silicoaluminophosphates [SAPO compounds]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/90—Regeneration or reactivation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J38/00—Regeneration or reactivation of catalysts, in general
    • B01J38/04—Gas or vapour treating; Treating by using liquids vaporisable upon contacting spent catalyst
    • B01J38/10—Gas or vapour treating; Treating by using liquids vaporisable upon contacting spent catalyst using elemental hydrogen
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2529/00—Catalysts comprising molecular sieves
    • C07C2529/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites, pillared clays
    • C07C2529/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • C07C2529/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups C07C2529/08 - C07C2529/65
    • C07C2529/72—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups C07C2529/08 - C07C2529/65 containing iron group metals, noble metals or copper
    • C07C2529/74—Noble metals
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2529/00—Catalysts comprising molecular sieves
    • C07C2529/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites, pillared clays
    • C07C2529/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • C07C2529/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups C07C2529/08 - C07C2529/65
    • C07C2529/72—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups C07C2529/08 - C07C2529/65 containing iron group metals, noble metals or copper
    • C07C2529/76—Iron group metals or copper
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2529/00—Catalysts comprising molecular sieves
    • C07C2529/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites, pillared clays
    • C07C2529/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • C07C2529/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups C07C2529/08 - C07C2529/65
    • C07C2529/78—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups C07C2529/08 - C07C2529/65 containing arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2529/00—Catalysts comprising molecular sieves
    • C07C2529/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites, pillared clays
    • C07C2529/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • C07C2529/80—Mixtures of different zeolites
    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/582—Recycling of unreacted starting or intermediate materials
    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/584—Recycling of catalysts

Definitions

  • the present invention relates to a process for the oxygen free conversion of methane to ethylene on zeolite catalysts and catalysts comprising a small-pore zeolite, a metal and a further component.
  • Methane as the key component of natural gas, landfill gas and a by-product from oil refining and chemical, can be utilized as clean fossil energy or as hydrocarbon source for platform molecules in the chemical industry.
  • the know reserves were estimated with 180 trillion cubic meters, which is comparable of that to know crude oil reserves.
  • the methane price in the US has stimulated research efforts in the last years, dealing with oxidative coupling, oxyhalogenation, aromatization and selective oxidation to methanol.
  • the high stability of the C-H bonds remains a major issue to provide economically feasible processes, which can compete with state of the art technology based on crude oil.
  • hydrophilicity describes that no or only few degradation of a zeolite takes place under exposition to high temperatures in combination with the presence of water.
  • a further disadvantage is that using a low O2/CH4 molar ratio in the feed, the selectivity to C2 hydrocarbons is high, but CH4 conversion is rather low.
  • An additional disadvantage is that due to the low concentration of ethylene in the exit stream the cost of its separation is high, thereby rendering its separation uneconomical.
  • the problem has been solved by providing a process comprising the step of converting methane to ethene under non-oxidative conditions in the presence of a catalyst comprising
  • Reaction 1 The conversion of methane to ethylene under non-oxidative conditions is depicted in Reaction 1 : Catalytic reaction: 2 CH 4 -> C2H4 + 2 H 2 (Reaction 1 )
  • nonoxidative means, in relation to the MTE reaction, that the concentration of oxidizing agents such as oxygen or nitrogen oxides in the reactant stream E is below 5% by weight, preferably below 1 % by weight, more preferably below 0.1 % by weight. Most preferably, the mixture is free of oxygen. Likewise particularly preferred is a concentration of oxidizing agents in the mixture E which is equal to or less than the concentration of oxidizing agents in the source from which the methane originates.
  • nonoxidative in the context of the pre- sent invention means that the coke deposits originating from the MTE on the catalyst, to regenerate the catalyst, are not converted to CO and/or CO2 by means of oxidizing agents such as air or oxygen.
  • concentration of oxidizing agents in the mixture H for use for regeneration in step II is below 5% by weight, preferably below 1 % by weight, more preferably below 0.1 % by weight.
  • zeolite based catalysts are applicable at this high temperatures. They combine a high surface area with defined pore structures and well adjustable acidic centers, which can be used to improve the ethylene yield in the product stream. To suppress the deactivation of the catalyst due to coke formation, zeolite based catalysts can be regenerated with H2 formed in Reaction 1 to recover CH4, which can then be reused in the educt stream during catalytic reaction. Regeneration of the catalyst: C (coke) + 2 H2 -> CH4 (Reaction 2)
  • zeolite shall have the following meaning within the frame of the present invention: a zeolite comprising, preferred consisting essentially of, both tetravalent and trivalent structural components Y and X as YO2 and X2O3, respectively, wherein Y is a tetravalent element, and X is a trivalent element; and wherein the Y : X molar ratios of the zeolite is respectively comprised in the range of from 1 to 50, preferably of from 1.5 to 35, more preferably of from 2 to 25, more preferably of from 2.5 to 15, more preferably of from 3 to 10, more preferably of from 3.5 to 7, more preferably of from 4 to 6, and even more preferably in the range of from 4 to 5.
  • the zeolite does not comprise pentavalent structural components Z as Z2O5 wherein Z is a pentavalent element.
  • YO2 and optionally X2O3 comprised in the zeolite framework structure of the zeolite are contained therein as structure building elements, as opposed to non-framework elements which can be present in the pores and cavities formed by the framework structure and typical for zeolites in general.
  • a zeolite may comprise a chemical composition which is selected from the group consisting of [Al-Si-O]-, [B-Si-O]-, [Ga-Si-O]-, [Ti-Si-O]-, Al-rich and pure silica.
  • Y comprised in a zeolite stands for any conceivable tetravalent element, wherein Y is one or more tetravalent elements.
  • Preferred tetravalent elements according to the present invention include Si, Sn, Ti, Zr, and Ge, and combina- tions thereof. More preferably, Y stands for Si, Ti, or Zr, or any combination of said trivalent elements, even more preferably for Si and/or Sn. According to the present invention, it is particularly preferred that Y stands for Si.
  • the framework of a zeolite comprises X2O3, wherein X stands for any conceivable trivalent element, X being one or more trivalent elements.
  • Preferred trivalent elements according to the present invention include Al, B, In, and Ga, and combinations thereof. More preferably, Y stands for Al, B, or In, or any combination of said trivalent ele- merits, even more preferably for Al and/or B. According to the present invention, it is particularly preferred that X stands for Al.
  • any conceivable combination of one or more tetravalent elements Y in YO2 may be comprised in one or more of the zeolites in combination with one or more trivalent elements X in X2O3, wherein the aforementioned elements Y and X respectively refer to constitutive elements of the small-pore framework structure.
  • the one or more tetravalent ele- ments Y comprise Si
  • the one or more trivalent elements X comprise Al
  • even more preferably the one or more of the one or more zeolites comprise S1O2 and AI2O3.
  • a zeolite generally displays molar ratios ranging anywhere from 1 to 50.
  • the Y : X molar ratio of the tetravalent element Y to the trivalent element X ranges from 1 .5 to 35, more preferably of from 2 to 25, more preferably of from 2.5 to 15, more preferably of from 3 to 10, more preferably of from 3.5 to 7, and even more preferably of from 4 to 6.
  • the Y : X molar ratio ranges from 4 to 5.
  • the Si : Al molar ratio displayed by the framework structure is comprised in the range of from 1 to 50, preferably of from 1 .5 to 35, more preferably of from 2 to 25, more preferably of from 2.5 to 15, more preferably of from 3 to 10, more preferably of from 3.5 to 7, more preferably of from 4 to 6, and even more preferably in the range of from 4 to 5.
  • Zeolites are divided into categories depending on the largest pore opening in their structures.
  • Small pore the largest pore opening is an 8-ring pore.
  • Medium pore the largest pore opening is a 10-ring pore.
  • Large pore the largest pore opening is a 12-ring pore or a larger pore.
  • a zeolite (a) according to the present invention is a small-pore zeolite.
  • the small-pore molecular zeolite (a) is selected from the Framework Type Codes consisting of: ACO, AEI, AEN, AFN, AFT, AFX, ANA, APC, APD, ATT, CDO, CHA, DDR, DFT, EAB, EDI, EPI, ERI, GIS, GOO, IHW, ITE, ITW, LEV, KFI, MER, MON, NSI, OWE, PAU, PHI, RHO, RTH, SAT, SAV, SFW, SIV, SW, THO, TSC, UEI, UFI, VNI, YUG, and ZON.
  • the small-pore zeolite (a) is selected from the structural group consisting of LEV, CHA , CDO and mixtures thereof.
  • the small-pore zeolite (a) is selected from the group consisting of RUB-37, RUB-50, LEV and mixtures thereof. Table 1 :
  • At least one small-pore zeolite (a) is loaded with at least one metal (b).
  • the metal (b) is selected from the group consisting of Mo, Fe, Co, Ni, Cu, Ag, Mg, W, Re, Ga, Ru, Rh, Pd, Ir, Pt and mixtures thereof, preferred Mo.
  • the loading of the at least one metal is performed by wet chemical or dry chemical means.
  • the metals are applied in the form of aqueous, organic or organic- aqueous solutions of their salts or complexes by impregnating the support with the corresponding solution.
  • the solvent used may also be supercritical CO2.
  • the impregnation can be effected by the incipient wetness method, in which the porous volume of the support is filled by about the same volume of impregnation solution and - if appropriate after maturation - the support is dried. It is also possible to work with an excess of solution, in which case the volume of this solution is greater than the porous volume of the support.
  • the support is mixed with the im- pregnation solution and stirred for a sufficiently long period.
  • Other preparation methods known to those skilled in the art are also possible, such as precipitation of the metal compounds onto the support, spray application of a solution comprising metal compound, sol impregnation, etc.
  • the catalyst is dried at from about 80 to 130°C under reduced pressure or under air, typically for from 4 to 20 hours.
  • the at least one metal can also be applied by dry chemical methods, for example by depositing the metal carbonyls which are gaseous at higher temperatures, such as Mo(CO)6, W(CO)6 and Re2(CO)io, on the support from the gas phase.
  • the deposition of the metal carbonyl compound is performed after the calcination of the support.
  • the metal can be applied by wet chemical means together in one solution, or in different solutions in succession with drying steps between the individual applications.
  • the metal can also be applied in mixed form, i.e. one portion by wet chemical means and another portion by dry chem- ical means. Between the applications of the metal compounds, calcination can be effected if required according to the above description.
  • Preferred is a process wherein the amount of metal (b) is higher than 4 wt%, preferred 5 wt% or more, more preferred 6 wt% or more, based on the total weight of the catalyst.
  • the catalyst comprises
  • the small-pore zeolite (a) is selected from the structural group consisting of LEV, CHA , CDO and mixtures thereof. In a further preferred embodiment of the process, the small-pore zeolite (a) is selected from the group consisting of RUB-37, RUB-50, LEV and mixtures thereof.
  • the metal (b) is selected from the group consisting of Mo, Fe, Co, Ni, Cu, Ag, Mg, W, Re, Ga, Ru, Rh, Pd, Ir, Pt and mixtures thereof, pre- ferred Mo.
  • the amount of metal (b) is higher than 4 wt%, preferred 5 wt% or more, more preferred 6 wt% or more, based on the total weight of the catalyst.
  • the catalyst comprises at least two different metals (b) and (c3) which are selected from the group consisting of Mo, Fe, Co, Ni, Cu, Ag, Mg, W, Re, Ga, Ru, Rh, Pd, Ir, Pt and mixtures thereof, preferred Fe, Co, Ni, Cu and mixtures thereof, more preferred Mo-Fe, Mo-Co and Mo-Ni.
  • the catalyst may comprise a metal (b) in conjunction with at least one metal (c3).
  • the at least one metal (c3) is present in the catalyst, according to the invention, in a concentration of at least 0.1 % by weight, preferably at least 0.2% by weight, most preferably at least 0.5% by weight, based on the total weight of the catalyst.
  • the zeolite is provided from synthesis as opposed to being obtained from natural sources, wherein it is further preferred that the zeolite is obtainable from an organotemplate-free synthetic process. According to particularly preferred embodiments of the present invention, the zeolite is obtained from an organotemplate-free synthetic process.
  • the zeolite is obtainable, and preferably obtained, from an organotemplate-free synthetic process.
  • an organotemplate-free synthetic process there is no particular restriction as to the synthetic procedure which may be used to this effect, provided that it does not employ an or- ganotemplate as structure directing agent.
  • the zeolite is obtainable, and preferably obtained, according to a synthetic process for the organotemplate-free synthesis of a zeolite having a small-pore framework structure, wherein said synthetic process comprises the steps of
  • the mixture according to step (1 ) further comprises one or more sources for X2O3.
  • the mixture provided in step (1 ) and crystallized in step (2) contain more than an impurity of an organic structure directing agent specifically used in the synthesis of the one or more zeolites having a small-pore framework structure, in particular specific tetraacylammonium salts and/or related organotemplates such as tetraethylammonium and/or dibenzylmethylammonium salts, and dibenzyl-1 ,4-diazabicyclo[2,2,2]octane.
  • an impurity can, for example, be caused by organic structure directing agents still present in seed crystals used in the preferred synthesis.
  • Organotemplates contained in seed crystal material may not, however, participate in the crystallization process since they are trapped within the seed crystal framework and therefore may not act structure directing agents within the meaning of the present invention.
  • a zeolite having a small-pore framework structure is crystallized in step (2) of the preferred synthetic method.
  • YO2 can be provided in step (1 ) in any conceivable form, provided that a zeolite having a small-pore framework structure comprising YO2 can be crystallized in step (2).
  • YO2 is provided as such and/or as a compound which comprises YO2 as a chemical moiety and/or as a compound which (partly or entirely) is chemically transformed to YO2 during the inventive process.
  • the source for S1O2 provided in step (1 ) can be any conceivable source.
  • silica and silicates preferably fumed silica, silica hydrosols, reactive amorphous solid silicas, silica gel, silicic acid, water glass, sodium metasilicate hydrate, sesquisilicate or disilicate, colloidal silica, pyrogenic silica, silicic acid esters, or tetraalkoxysilanes, or mixtures of at least two of these compounds.
  • the mixture according to step (1 ) comprises one or more sources for S1O2
  • said source preferably comprises one or more compounds selected from the group consisting of silica and silicates, preferably alkali metal silicates.
  • the one or more sources preferably comprise water glass, more preferably sodium and/or potassium silicate, and more pref- erably sodium silicate.
  • the source for S1O2 is sodium silicate.
  • fumed silica is particularly preferred.
  • X2O3 can be provided in any conceivable form, provided that a zeolite having a small-pore framework structure comprising X2O3 can be crystallized in step (2).
  • X2O3 is provided as such and/or as a compound which com- prises X2O3 as a chemical moiety and/or as a compound which (partly or entirely) is chemically transformed to X2O3 during the inventive process.
  • the source for AI2O3 provided in step (1 ) can be any conceivable source.
  • alumina and aluminates aluminum salts such as, for example, alkali metal aluminates, aluminum alcoholates, such as, for example, aluminum triisopropylate, or hydrated alumina such as, for example, alumina trihydrate, or mixtures thereof.
  • the source for AI2O3 comprises one or more compounds selected from the group consisting of alumina and aluminates, preferably aluminates, more preferably alkali metal aluminates.
  • the one or more sources preferably comprises sodium and/or potassium aluminate, more preferably sodium aluminate.
  • the source for AI2O3 is sodium aluminate.
  • the mixture of step (1 ) further comprises one or more sources for X2O3 including one or more boron compounds, for example free boric acid and/or borates and/or boric esters, such as, for example, triethyl borate or trimethyl borate, can be used as starting materials.
  • the mixture according to step (1 ) comprises one or more silicates as a source for YO2 and one or more aluminates as a source for X2O3, more preferably one or more alkali metal silicates and/or one or more alkali metal aluminates, and even more preferably one or more water glass compounds and/or one or more alkali metal aluminates, wherein the alkali metal of said preferred embodiments preferably comprises sodium and/or potassium, more preferably sodium, and wherein the alkali metal even more preferably is sodium.
  • the mixture according to step (1 ) comprises silica and one or more silicates as a source for YO2 and one or more aluminates as a source for X2O3, more preferably fumed silica and one or more alkali metal silicates and/or one or more alkali metal aluminates, and even more preferably silica and one or more water glass compounds and/or one or more alkali metal aluminates, wherein the alkali metal of said preferred embodiments preferably comprises sodium and/or potassium, more preferably sodium, and wherein the alkali metal even more preferably is sodium.
  • the YO2 : X2O3 molar ratio of the mixture can have any conceivable value, provided that a zeolite having a small-pore framework structure comprising both YO2 and X2O3 is crystallized in step (2).
  • the molar ratio ranges from 1 to 100, preferably from 5 to 75, more preferably from 10 to 50, more preferably from 15 to 40, more preferably from 18 to 35, and particularly preferably from 20 to 33.
  • the zeolite obtained and/or obtainable and/or the inventive material as such according to the preferred synthetic method comprises one or more alkali metals M, preferably sodium and/or potassium, and more preferably sodium.
  • the alkali metal can be added at any conceivable stage of the pre- ferred synthetic method, wherein preferably it is also added in step (1 ). More preferably, the entire quantity of the alkali metal comprised in the zeolite having a small-pore framework structure is added in step (1 ) of the preferred synthetic method.
  • the alkali metal is partly or entirely contained in the one or more sources for YO2 and/or X2O3 provided in step (1 ), wherein preferably, the alkali metal is entirely contained in the one or more sources for YO2 and/or X2O3, and more preferably in both the one or more sources for YO2 and/or X2O3.
  • the alkali metal M can be contained in the mixture according to step (1 ) of the preferred synthetic method in any conceivable amount, provided that a zeolite having a small-pore framework structure is crystallized in step (2).
  • the M : YO2 molar ratio in the mixture according to step (1 ) ranges from 0.1 to 2, more preferably from 0.2 to 1.2, more preferably from 0.3 to 1 , more preferably from 0.4 to 0.85, more preferably from 0.5 to 0.75, and more preferably from 0.55 to 0.7.
  • the M : YO2 molar ratio in the mixture according to step (1 ) ranges from 0.61 to 0.65.
  • the mixture according to step (1 ) comprises one or more sources for X2O3 and one or more alkali metals M.
  • any conceivable amounts of these components can be contained in the mixture provided that a zeolite having a small-pore framework structure is crystallized in step (2).
  • the YO2 : X2O3 : M molar ratios in the mixture according to step (1 ) range from (1 - 100) : 1 : (2 - 90), more preferably from (5 - 75) : 1 : (4 - 60), more preferably from (10 - 50) : 1 : (6 - 40), more preferably from (15 - 40) : 1 : (8 - 30), more preferably from (18 - 35) : 1 : (10 - 25), and even more preferably from (20 - 33) : 1 : (12 - 22).
  • seed crystals are provided in step (1 ), wherein said seed crystals comprise a zeolite having a small-pore framework structure.
  • said seed crystals can comprise any zeolite having a small-pore framework structure, provided that a zeolite having a small-pore framework structure is crystal- lized in step (2).
  • the zeolite having a small-pore framework structure comprised in the seed crystals is a zeolite which is obtainable and preferably obtained according to the preferred synthetic method.
  • the zeolite having a small-pore framework structure comprised in the seed crystals is the same as the zeolite having a small-pore framework struc- ture which is then crystallized in step (2).
  • Particularly preferred are seed crystals comprising zeolite Beta, more preferably zeolite Beta which is obtainable or has preferably been obtained according to the preferred synthetic method.
  • the seed crystals are zeolite Beta crystals, preferably zeolite Beta crystals which are obtainable or have preferably been obtained according to the preferred synthetic method.
  • any suitable amount of seed crystals can be provided in the mixture according to step (1 ), provided that a zeolite having a small-pore framework structure is crystallized in step (2).
  • the amount of seed crystals contained in the mixture according to step (1 ) ranges from 0.1 to 50 wt.-% based on 100 wt.-% of YO2 in the one or more sources for YO2, preferably from 0.5 to 35 wt.-%, more preferably from 1 to 20 wt.-%, more preferably from 1 .5 to 10 wt.-%, more preferably from 2 to 5 wt.-%, and even more preferably from 2.5 to 3.5 wt.-%.
  • the mixture can be prepared by any conceivable means, wherein mixing by agitation is preferred, preferably by means of stirring.
  • the mixture according to step (1 ) further comprises a solvent.
  • a solvent Any conceivable solvent can be used in any conceivable amount, provided that a zeolite having a small-pore framework structure can be crystallized in step (2) of the preferred synthetic method.
  • the solvent comprises water, wherein the H2O : YO2 molar ratio of the mixture ranges from 1 to 100, preferably from 5 to 70, more preferably from 10 to 50, more preferably from 12 to 35, more preferably from 15 to 25, more preferably from 16 to 20, and particularly preferably from 17 to 18.
  • the solvent provided in step (1 ) is distilled water.
  • the single components for providing the mixture of step (1 ) of the preferred synthetic method can be added in any order, provided that a zeolite having a small-pore framework structure is crystallized from the mixture in step (2) of the preferred synthetic method.
  • This may, for example, involve the addition of the optional solvent and the one or more sources for X2O3 followed by the addition of the one or more sources for YO2, wherein the seed crystals are only added to the mixture afterwards.
  • the addition of the optional solvent and the one or more sources for X2O3 may be first followed by the addition of the seed crystals, wherein the one or more sources for YO2 is only added thereafter.
  • step (2) according to the preferred synthetic method can be conducted in any conceivable manner, provided that a zeolite having a small-pore framework structure is crystallized from the mixture according to step (1 ).
  • the mixture can be crystallized in any type of vessel, wherein a means of agitation is optionally employed, said agitation being preferably achieved by rotation of the vessel and/or stirring, and more preferably by stirring the mixture.
  • the mixture is preferably heated during at least a portion of the crystallization process in step (2).
  • the mixture can be heated to any conceivable temperature of crystallization, provided that a zeolite having a small-pore framework structure is crystallized from the mixture.
  • the mixture is heated to a temperature of crystallization ranging from 80 to 200°C, more preferably from 90 to 175°C, more preferably from 95 to 150°C, more preferably from 100 to 140°C, more preferably from 1 10 to 130°C, and even more preferably from 1 15 to 125°C.
  • the preferred heating in step (2) of the preferred synthetic method can be conducted in any conceivable manner suitable for the crystallization of a zeolite having a small-pore framework structure.
  • heating may be conducted at one temperature of crystallization or vary between different temperatures.
  • a heat ramp is used for reaching the temperature of crystallization, wherein, by way of example, the heating rate may range from 10 to 100°C/h, more preferably from 15 to 70°C/h, more preferably from 20 to 50°C/h, more preferably from 25 to 40°C/h, and even more preferably from 30 to 35°C/h.
  • the mixture according to step (1 ) is subjected in step (2) to a pressure which is elevated with regard to normal pressure.
  • normal pressure as used in the context of the present invention relates to a pressure of 101 ,325 Pa in the ideal case.
  • this pressure may vary within boundaries known to the person skilled in the art.
  • this pressure can be in the range of from 95,000 to 106,000 or of from 96,000 to 105,000 or of from 97,000 to 104,000 or of from 98,000 to 103,000 or of from 99,000 to 102,000 Pa.
  • heating in step (2) is conducted under solvothermal conditions, meaning that the mixture is crystallized under autogenous pressure of the solvent which is used, for example by conducting heating in an autoclave or other crystallization vessel suited for generating solvothermal conditions.
  • the solvent comprises or consists of water, preferably of distilled water
  • heating in step (2) is accordingly preferably conducted under hydrothermal conditions.
  • the apparatus which can be used in the preferred synthetic method for crystallization is not particularly restricted, provided that the desired parameters for the crystallization process can be realized, in particular with respect to the preferred embodiments requiring particular crystallization conditions.
  • any type of autoclave or digestion vessel can be used, wherein a Teflon-lined apparatus is preferred.
  • the duration of the crystallization process in step (2) of the preferred synthetic method is not particularly limited.
  • said crystallization process is conducted for a period ranging from 10 to 200 h, more preferably from 30 to 150 h, more preferably from 100 to 140 h, and even more preferably from 1 10 to 130 h.
  • heating may be conducted during the entire crystallization process or during only one or more portions thereof, provided that a zeolite having the small-pore frame- work structure is crystallized.
  • heating is conducted during the entire duration of crystallization.
  • the process of the preferred synthetic method can optionally comprise further steps for the work-up and/or further physical and/or chemical transformation of the zeolite having a small-pore framework structure crystallized in step (2) from the mixture provided in step (1 ).
  • the crystallized material can for example be subject to any sequence of isolation and/or washing procedures, wherein the zeolite obtained from crystallization in step (2) is preferably subject to one or more isolation and one or more washing procedures.
  • Isolation of the crystallized product can be achieved by any conceivable means.
  • isolation of the crystallized product can be achieved by means of filtration, ultrafiltration, diafiltra- tion, centrifugation and/or decantation methods, wherein filtration methods can involve suction and/or pressure filtration steps.
  • washing agents which may be used are, for example, water, alcohols, such as methanol, ethanol or propanol, or mixtures of two or more thereof.
  • mixtures are mixtures of two or more alcohols, such as methanol and ethanol or methanol and propanol or ethanol and propanol or methanol and ethanol and propanol, or mixtures of water and one or more alcohols, such as water and methanol or water and ethanol or water and propanol or water and methanol and ethanol or water and methanol and propanol or water and ethanol and propanol or water and methanol and ethanol and propanol.
  • the separated zeolite is washed until the pH of the washing agent, preferably the washwater, is in the range of from 6 to 8, preferably from 6.5 to 7.5, as determined via a standard glass electrode.
  • the preferred synthetic method can optionally comprise one or more drying steps. In general, any conceivable means of drying can be used. Drying procedures preferably include heating and/or applying vacuum to the zeolite having a small-pore framework structure. In en- visaged embodiments of the preferred synthetic method, one or more drying steps may involve spray drying, preferably spray granulation of the zeolite.
  • the drying temperatures are prefera- bly in the range of from 25°C to 150°C, more preferably of from 60 to 140°C, more preferably of from 70 to 130°C and even more preferably in the range of from 75 to 125°C.
  • the durations of drying are preferably in the range of from 2 to 60 h, more preferably in the range of 6 to 48 hours, and even more preferably of from 12 to 24 h.
  • the zeolite crystallized in step (2) can optionally be subject to one or more ion-exchange procedures. In general, any conceivable ion-exchange procedure with all possible ionic elements and/or molecules can be conducted on the zeolite.
  • one or more cation and/or cationic elements are employed which preferably comprise one or more cations and/or cationic elements selected from the group con- sisting of H + , Nh , lithium, potassium, calcium, magnesium, barium, transition metals, and combinations thereof, more preferably from the group consisting of H + , Nh , lithium, potassium, calcium, magnesium, barium, lanthanum, cerium, nickel, platinum, palladium, and combinations thereof, wherein even more preferably the one or more cation and/or cationic elements comprise H + and/or Nh , preferably Nh .
  • the optional washing and/or isolation and/or ion-exchange procedures comprised in the preferred synthetic method can be conducted in any conceivably order and repeated as often as desired. Therefore, according to further preferred embodiments, the preferred synthetic method optionally comprises one or more of the following steps of
  • steps (3) and/or (4) and/or (5) and/or (6) can be conducted in any order, and wherein one or more of said steps is preferably repeated at least once.
  • the preferred synthetic method comprises one or more steps of isolating the zeolite crystallized according to step (2), more preferably by filtration thereof.
  • the zeolite is subject to one or more steps of drying, wherein more preferably the zeolite is subject to one or more steps of washing prior to the one or more drying steps.
  • the zeolite crystallized according to step (2) is subject to one or more steps of isolating, followed by one or more steps of washing, followed by one or more steps of drying.
  • the zeolite crystallized in step (2) is directly subject to one or more steps of drying, preferably to spray drying and or spray granulation, without isolating, washing, or drying of the zeolite beforehand.
  • Directly subjecting the mixture obtained from step (2) of the preferred synthetic method to a spray drying or spray granulation stage has the advantage that isolation and drying is performed in a single stage.
  • the zeolite obtained from crystallization in step (2) is subject to one or more isolating steps prior to being subject to one or more ion-exchange procedures, preferably to one or more isolating steps followed by one or more washing steps, and more preferably to one or more isolating steps followed by one or more washing steps followed by one or more drying steps.
  • the preferred synthetic method preferably does not comprise a calcination step generally involving the heating of the zeolite crystallized according to step (2) above a temperature of 500°C.
  • the preferred synthetic method for the production of a zeolite having a small-pore framework structure which does not comprise a calcination step refers to synthetic methods, wherein the zeolite crystallized according to step (2) is not subject to a temperature exceeding 450°C, more preferably 350°C, more preferably 300°C, more preferably 250°C, more preferably 200°C, more preferably 150°C, and even more preferably 100°C.
  • the one or more zeolites provided in step (i) of the inventive process are preferably obtainable, and even more preferably obtained according to one or more of the aforementioned preferred and particularly preferred synthetic methods.
  • the zeolite preferably does not contain more than an impuri- ty of an organic structure directing agent typically used in the synthesis of zeolites having a small-pore framework structure, in particular specific tetraacylammonium salts and/or related organotemplates such as tetraethylammonium and/or dibenzylmethylammonium salts, and dibenzyl-1 ,4-diazabicyclo[2,2,2]octane.
  • an impurity can, for example, be caused by organic structure directing agents still present in seed crystals used in the preferred synthetic pro- cess.
  • the zeolite is non-calcined, meaning that they have not been subject to a calcination step.
  • a calcination step generally designates a process involving the heating of the one or more zeolites above a temperature of 500°C. More preferably, however, a non-calcined zeolite according to the present invention designates a material not having been subject to a temperature exceeding 450°C, more preferably 350°C, more preferably 300°C, more preferably 250°C, more preferably 200°C, and even more preferably not exceeding 150°C.
  • a calcination step may designate any step which may be employed in the synthesis of the zeolite used in the inventive process.
  • a calcination step preferably only refers to a step conducted after completion of the crystallization of the zeolite from one or more precursor compounds which do not have the wanted framework structure, with the exception of any seeding crystals which may be employed therein.
  • a calcination step only refers to a step which is normally or suitably performed after completed crystallization of the zeolite for the removal of organotemplates from the framework structure.
  • the zeolite is non-calcined.
  • the crystalline structure of the zeolite there is no particular restriction as to the crystalline structure of the zeolite, provided that these display a small-pore framework structure, and, in particular, that the zeolite affords an X-ray diffraction pattern comprising the reflections typical of respec- tive framework structure.
  • the surface area of the zeolite there is no particular restriction as to the surface area of the zeolite provided that the zeolite is suitable for catalyzing the inventive process.
  • the BET surface area of the one or more zeolites determined according to DIN 66135 may from 200 to 700 m 2 /g, wherein preferably the BET surface area is comprised in the range of from 400 to 650 m 2 /g, more preferably of from 475 to 575 m 2 /g, and even more preferably of from 500 to 550 m 2 /g.
  • the BET surface area determined according to DIN 66135 ranges from 510 to 530 m 2 /g.
  • step (ii) at least a portion of the one or more alkali metals M preferably comprised in the one or more zeolites provided in step (i) is exchanged with H + and/or NH 4 + .
  • at least a portion of the one or more alkali metals M are exchanged with NH 4 + .
  • prior to the procedure in step (ii) at least a portion of the alkali metal atoms M contained in the one or more zeolites provided in step (i) is exchanged with H + and/or NH 4 + , preferably with NH 4 + .
  • the substitution or exchange is achieved by ion-exchange.
  • the term "ion- exchange" generally refers to non-framework ionic elements and/or molecules contained in the one or more zeolites.
  • the procedure may in principle be conducted in any suitable fashion using any suitable conditions for achieving the aforementioned substitution of alkali metal atoms M.
  • the procedure is con- ducted in a suitable solvent and preferably in aqueous solution.
  • a solvent which is preferably water
  • the pH employed in said preferred embodiments may range anywhere from 0 to 7, wherein more preferably the pH is comprised in the range of from 1 to 6, more preferably of from 1 to 4, more preferably of from 1 .5 to 3.5, and even more preferably of from 2 to 3.5. According to particularly preferred embodiments, the pH is comprised in the range of from 2.5 to 3.5.
  • the ion-exchange process conducted prior to step (ii) is performed at a pH in the range of from 0 to 7, preferably of from 1 to 6, more preferably of from 1 to 4, more preferably of from 1 .5 to 3.5, more preferably of from 2 to 3.5, and even more preferably of from 2.5 to 3.5.
  • the procedure conducted in step (ii) of the inventive process leads to the removal of at least a portion of the trivalent element X from the small-pore framework structure of the one or more zeolites.
  • the process and conditions which may be used in step (ii) provided that at least a portion of the element X originally present in the small-pore framework as a constituting element thereof is removed.
  • the term "removing" with respect to the removal of at least a portion of the framework element X indicates that said procedure leads to the alteration of the framework such that said portion of X which has been removed is not present in the one or more zeolites provided in step (i) and/or is not contained therein as a framework element.
  • the term "framework element” or “framework ion” defines a constituting element or ion of the small-pore framework structure, and in particular with respect to its coordination in the framework structure.
  • a framework element X preferably refers to X which is comprised in the framework structure in a tetra- hedral coordination.
  • non-framework element or “non-framework” ion, on the other hand, refers to any element or ion contained in the zeolite having a small-pore framework structure which is not a constituting the framework structure, meaning that it is for example contained in the micropores of the structure and/or that it only serves to compensate the structural framework, for example as counter ion or the like. Furthermore, said terms also refer to originally constituting elements or ions of the small-pore framework structure which have been altered from their original coor- dination state.
  • a non-framework element X refers to X originally contained in the framework structure as a constituting element, and in particular as tetrahedrally coordinated X in the small-pore framework, and which has been subsequently removed from the framework structure for example by a change in its original coordination state and/or by being contained in the micropores of the zeolite as opposed to the framework thereof.
  • a non-framework element or ion X refers to X which was originally tetrahedrally coordinated in the small-pore framework structure, and which subsequently displays a different coordination state and preferably a higher coordination state.
  • a non-framework element X refers to originally tetrahedrally coordinated X which after having been subject to step (ii) is contained in the zeolite in a pentahedral and/or octahedral coordination, and preferably in an octahedral coordination state.
  • at least a portion of X is removed from the small-pore framework structure by steam treatment of the one or more zeolites provided in step (i).
  • there are no particular limitations according to the present invention as to the procedure and conditions which may be employed in said preferred procedure used in step (ii), provided that at least a portion of X is removed from the small-pore framework structure.
  • the procedure in step (ii) for removing at least a portion of X from the small-pore framework structure comprises one or more steam-treatment steps (S).
  • any conceivable temperature may be employed in the preferred steam-treatment step (S), provided that at least a portion of X is removed from the small-pore framework structure.
  • the one or more steam-treatment steps may be conducted at any temperature comprised in the range of from 200 to 1 ,000°C, wherein preferably the steam temperature is comprised in the range of from 300 to 900°C, more preferably of from 400 to 800°C, and even more preferably of from 500 to 700°C.
  • the one or more of the one or more steam-treatment steps (S) is conducted at a temperature comprised in the range of from 550 to 650°C.
  • a duration of the steam treatment step ranging anywhere from 0.1 to 48 h may be mentioned by way of example, wherein preferably the duration is comprised in a range of anywhere from 0.2 to 24 h, more preferably of from 0.3 to 12 h, more preferably from 0.35 to 6 h, more preferably of from 0.4 to 4 h, and even more preferably of from 0.45 to 2 h.
  • the preferred steam treatment step (S) is conducted for a period ranging from 0.5 to 1.5 h.
  • step (ii) of the inventive process includes one or more steam-treatment step (S)
  • either pure steam may be used or one or more further gases may be additionally present in the steam.
  • the steam includes further gases
  • one or more additional gases to steam be used which do not chemically react with the one or more zeolites.
  • one or more inert gases and preferably nitrogen is used as a further gas in addition to steam in the one or more steam-treatment steps (S).
  • the steam used in the preferred steam-treatment step (S) comprises one or more further gases, preferably one or more further inert gases and more preferably nitrogen
  • the content of steam in the resulting gas mixture may, by way of example, range anywhere from 5 to 75 vol.-%, wherein preferably the steam content is comprised in the range of from 10 to 50 vol.-%, and even more preferably of from 15 to 25 vol.-%.
  • the the one or more steam-treatment steps (S) employed in step (ii) are conducted using a steam concentration of from 5 to 75 vol.-%, preferably of from 10 to 50 vol.-%, and more preferably of from 15 to 25 vol.-%, wherein the remaining volume is preferably an inert gas, more preferably nitrogen.
  • a steam concentration of from 5 to 75 vol.-%, preferably of from 10 to 50 vol.-%, and more preferably of from 15 to 25 vol.-%, wherein the remaining volume is preferably an inert gas, more preferably nitrogen.
  • one or more steam-treatment steps (S) employed in step (ii) are followed by one or more acid-treatment steps (A).
  • the procedure, and the conditions which may be employed in said particularly preferred embodiments of the inventive process no particular limitation applies provided that said one or more acid-treatment steps do not interfere with the removal of at least a portion of X from the small-pore framework structure in step (ii).
  • the procedure is chosen such that the small-pore framework structure of the treated zeolite is retained as least in part, wherein it is preferred that the small-pore framework structure is not deteriorated or partly destroyed during the acid-treatment step compared the its condition prior thereto.
  • the procedure in step (ii) further comprises subjecting the one or more zeolites obtained from the one or more steam-treatment steps (S) to one or more acid-treatment steps (A).
  • the procedure may be conducted under any suitable conditions leading to the contacting of the steam-treated zeolite with one or more acids or acidic compounds, wherein the procedure is preferably conducted in a suitable solvent and preferably in aqueous solution.
  • a suitable solvent and preferably in aqueous solution there is no particular restriction as to the pH of the solution, provided that it is acidic.
  • the one or more particularly preferred acid-treatment steps may be conducted at a pH of 4 or less, wherein a pH of 3.5 or less is preferred.
  • the pH is comprised in the range of from -1 .5 to 3, more preferably of from -1 to 2.5, more prefera- bly of from -0.5 to 2, and even more preferably of from -0.5 to 1 , wherein it is yet further preferred according to said embodiments that the pH is comprised in the range of from -0.5 to 0.5.
  • the one or more acid-treatment steps (A) involve contacting the one or more zeolites with an acidic solution having a pH of 4 or less, preferably of 3.5 or less, wherein preferably the pH is in the range of from -1 .5 to 3, more preferably of from -1 to 2.5, more preferably of from -0.5 to 2, more preferably of from -0.5 to 1 , and even more preferably of from -0.5 to 0.5.
  • the procedure may be conducted at ambient temperature or, preferably, under heating.
  • the acid-treatment step (A) is conducted at temperatures which are elevated with respect to ambient conditions
  • the acid-treatment is con- ducted at a temperature comprised in the range of from 50 to 100°C, wherein more preferably the temperature employed for the acid-treatment step is comprised in the range of from 60 to 95°C, more preferably of from 70 to 90°C, and even more preferably of from 75 to 85 °C.
  • the particularly preferred acid- treatment step (A) as concerns the duration thereof, provided that the small-pore framework structure of the treated zeolite is retained as least in part, and that the small-pore framework structure is preferably not deteriorated or partly destroyed due to the particular duration of the acid-treatment step compared the zeolite's condition prior thereto.
  • the duration of the acid-treatment step (A) is comprised in the range of from 0.25 to 5 h, and more preferably of from 0.5 to 4.5 h, more preferably of from 1 to 4 h, more preferably of from 1 to 3.5 h, wherein even more preferably the duration of the acid-treatment step (A) is comprised in the range of from 1.5 to 3.5 h.
  • said one or more acid-treatment steps (A) involve contacting the one or more zeolites with an acidic solution at a temperature of from 50 to 100°C, preferably of from 60 to 95°C, more preferably of from 70 to 90°C, and even more preferably of from 75 to 85 °C.
  • the one or more acid-treatment steps (A) involve contacting the one or more zeolites with an acidic solution for a period of from 0.25 to 5 h, preferably of from 0.5 to 4.5 h, more preferably of from 1 to 4 h, more preferably of from 1 to 3.5 h, and even more preferably of from 1 .5 to 3.5 h.
  • the procedure in step (ii) for removing at least a portion of X from the small-pore framework structure comprises one or more calcination steps (C).
  • the procedure and conditions which may be employed in the alternatively preferred calcniation step for the removal of X from the small-pore framework structure provided that that the small-pore framework struc- ture of the calcinated zeolite is retained as least in part, wherein it is preferred that the small- pore framework structure is not deteriorated or partly destroyed during the preferred calcination step compared the its condition prior thereto.
  • temperatures comprised in the range of from 450 to 800°C may be mentioned by way of example, wherein preferably the calcination temperature is comprised in the range of from 550 to 750°C, and more preferably of from 600 to 720°C. According to particularly preferred embodiments, calcination temperatures are employed which are comprised in the range of from 620 to 700°C. Furthermore, concerning the duration of calcination, there is again no particular limitation in this respect, wherein it is preferred that the duration be comprised in the range of from 0.5 to 10 h, more preferably of from 1 to 6 h, and even more preferably of from 1 .5 to 3 h.
  • the one or more calcination steps (C) are conducted at a temperature of from 450 to 800°C, preferably of from 550 to 750°C, more preferably of from 600 to 720°C, and even more preferably of from 620 to 700°C. Furthermore and preferably in addition thereto, the one or more calcination steps (C) are conducted for a period ranging from 0.5 to 10 h, preferably of from 1 to 6 h, and even more preferably of from 1.5 to 3 h.
  • step (ii) of subjecting the one or more zeolites provided in step (i) to a procedure for removing at least a portion of X may be repeated.
  • the number of repetitions provided that the zeolite is retained as least in part, and preferably that the small-pore framework structure is not deteriorated or partly destroyed as a result of excessive repetition of step (ii).
  • step (ii) of the inventive process my be repeated anywhere from once to 5 times, wherein preferably step (ii) is repeated 1 to 5 times, more preferably 1 to 3 times, and even more preferably once or twice.
  • step (ii) is repeated twice.
  • step (ii) it is yet further preferred that said repetition comprises the repetition of one or more of the one or more calcination steps (C).
  • said repetition comprises the repetition of one or more of the one or more calcination steps (C).
  • the specific type of the one or more calcination steps (C) according to the preferred embodiments of the inventive process as outlined above which may be repeated wherein it is particularly preferred that in those embodiments involving the repetition of the one or more calcination steps in step (ii), the calcination steps according to the particularly preferred embodiments of the present invention as outlined in the foregoing are repeated therein.
  • step (ii) is repeated one or more times, preferably 1 to 5 times, more preferably 1 to 3 times, more preferably 1 or 2 times, and even more preferably 2 times, wherein it is particularly preferred that the repetition of step (ii) comprises the repetition of one or more of the one or more calcination steps (C) accord- ing to preferred embodiments and in particular according to particularly preferred embodiments as outlined in the foregoing.
  • step (ii) involving one or more calcination steps (C) it is particularly preferred according to said embodiments that prior to at least one of said repetitions, and preferably prior to each of said repetitions, the one or more zeolites are subject at least one ion-exchange procedure.
  • at least part of the non- framework element X which has been removed from the small-pore framework in step (ii) is first removed from the zeolite prior to a repetition of the one or more calcination steps (C) in a further step (ii).
  • step (ii) there is no particular restriction as to the specific type of ion-exchange procedure which is employed prior to the repetition of step (ii), provided that at least a portion and preferably all of the non-framework X which has been removed from the small-pore framework structure in the initial and/or preceding step (ii) may be exchanged with one or more cations and/or cationic elements, wherein the non- framework X preferably comprises octahedrally coordinated non-framework X.
  • the non-framework X comprised in the one or more zeolites obtained from an initial and/or preceding step (ii) is exchanged with H + and/or Nh , and more preferably with Nh prior to the repetition of step (ii), and in particular to the one or more calcination steps (C).
  • the non-framework ions respectively present in the one or more zeolites are exchanged with one or more cations and/or cationic elements prior to repeating step (ii), wherein the one or more cation and/or cationic elements preferably comprise H + and/or Nh , wherein even more preferably at least part of the non-framework ions are exchange with Nh .
  • the non- framework ions comprise X, preferably X which has been removed from the small-pore framework structure in a previous step (ii).
  • the zeolite may in principle be used in any suitable form, provided that it is capable of catalyzing the reaction.
  • the zeolite can be employed as such, such as by way of example in the form of a powder, a spray powder or a spray granulate.
  • the inventive process is employed on an industrial scale, it is however preferable not to employ the zeolite as powder or sprayed material but rather in the form of a molding. Therefore, according to preferred embodiments of the inventive process, the zeolite is provided in the form of a molding.
  • the powder or sprayed material can be shaped to form a molding without any other compounds, such as for example by suitable compacting, to obtain moldings of a desired geometry, such as in the form of tablets, cylinders, and/or spheres.
  • the molding may however comprise all conceivable further compounds in addition to the zeolite, provided that it is ensured that the resulting molding is capable of catalyzing the inventive process.
  • at least one suitable binder material is used in the production of the molding.
  • more preferably a mixture of the zeolite and the one or more binders is prepared.
  • Suitable binders are in general all compounds which impart adhesion and/or cohesion between the one or more zeolites which are to be bound, in particular beyond the physisorption which may be present without a binder.
  • binders are metal oxides, such as S1O2, AI2O3, T1O2, Zr02 or MgO, or clays or mixtures of two or more of these compounds.
  • AI2O3 binders clay minerals and naturally occurring or synthetic aluminas, for example alpha-, beta-, gamma-, delta-, eta-, kappa-, chi- or theta-alumina and the inorganic or organometallic precursor compounds thereof, such as gibbs- ite, bayerite, boehmite, pseudoboehmite or trialkoxyaluminates, such as aluminum triisopropy- late are preferred in particular.
  • Further preferred binders are amphiphilic compounds having a polar and a nonpolar moiety, and graphite.
  • Further binders are, for example, clays, such as montmorillonites, kaolins, bentonites, halloysites, dickites, nacrites or anaxites.
  • the binders can be used as such for the production of a molding.
  • compounds from which the binder is formed in at least one further step in the production of the moldings are tetraalkoxysilanes, tetraalkoxytitanates, tetraalkoxyzir- conates or a mixture of two or more different tetraalkoxysilanes or a mixture of two or more different tetraalkoxytitanates or a mixture of two or more different tetraalkoxyzirconates or a mixture of at least one tetraalkoxysilane and at least one tetraalkoxytitanate or of at least one tetraalkoxysilane and at least one tetraalkoxyzirconate or of at least one tetraalkoxytitanate and at least one tetraalkoxyzirconate or of at least one tetraalkoxytitanate and at least one te
  • binders which either completely or partly consist of S1O2 or are a precursor of S1O2, from which S1O2 is formed in at least one further step in the production of the moldings are to be mentioned.
  • colloidal silica and "wet process” silica as well as “dry process” silica can be used. These are very particularly preferably amorphous silica, the size of the silica particles being, for example, in the range of from 5 to 100 nm and the surface of the silica particles being in the range of from 50 to 500 m 2 /g.
  • Colloidal silica preferably in the form of an alkaline and/or ammoniacal solution, more preferably in the form of an ammoniacal solution, is, for example, commercially available as, inter alia, Ludox®, Syton®, Nalco® or Snowtex®.
  • "Wet process” silica is, for example, commercially available, inter alia, as Hi-Sil®, Ultrasil®, Vulcasil®, Santocel®, Valron-Estersil®, Tokusil® or Nipsil®.
  • “Dry process” silica is, for example, commercially available, inter alia, as Aerosil®, Reolosil®, Cab-O-Sil®, Fransil® or ArcSilica®.
  • the binders are pref- erably used in an amount which leads to the finally resulting moldings whose binder content is up to 80 % by weight, more preferably in the range of from 5 to 80 % by weight, more preferably in the range of from 10 to 70 % by weight, more preferably in the range of from 10 to 60 % by weight, more preferably in the range of from 15 to 50 % by weight, more preferably in the range of from 15 to 45 % by weight, particularly preferably in the range of from 15 to 40 % by weight, based in each case on the total weight of the finally resulting molding.
  • the molding comprising the zeolite may be obtained according to any suitable procedure, provided that the molding may catalyze the inventive process.
  • the molding is obtainable and preferably obtained according to a process for the production of a molding comprising the steps of
  • finally resulting molding as used in the context of the present invention relates to a molding as obtainable and preferably obtained from the optional drying and/or calcining steps (IV) and/or (V), particularly preferably as obtainable and preferably obtained from step (IV).
  • the mixture of binder or precursor of a binder and the zeolite can be mixed with at least one further compound for further processing and for the formation of a plastic material.
  • pore formers may preferably be mentioned.
  • all compounds which, with regard to the finished molding, provide a certain pore size and/or a certain pore size distribution and/or certain pore volumes can be used as pore formers.
  • pore formers in the process of the present invention are polymers which are dispersible, suspendable or emulsifiable in water or in aqueous solvent mixtures.
  • Preferred polymers here are polymeric vinyl compounds, for example polyacylene oxides, such as polyeth- ylene oxides, polystyrene, polyacrylates, polymethacrylates, polyolefins, polyamides and polyesters, carbohydrates, such as cellulose or cellulose derivatives, for example methylcellulose, or sugars or natural fibers.
  • polyacylene oxides such as polyeth- ylene oxides, polystyrene, polyacrylates, polymethacrylates, polyolefins, polyamides and polyesters
  • carbohydrates such as cellulose or cellulose derivatives, for example methylcellulose, or sugars or natural fibers.
  • Further suitable pore formers are, for example, pulp or graphite.
  • the pore former content, preferably the polymer content of the mixture according to (I) is preferably in the range of from 5 to 90 % by weight, preferably in the range of from 15 to 75 % by weight, and particularly preferably in the range of from 25 to 55 % by weight, based in each case on the amount of the one or more zeolites in the mixture according to (I).
  • a mixture of two or more pore formers may also be used.
  • the pore formers are removed in a step (V) by calcina- tion to give the porous molding.
  • the molding obtained in step (III) is subsequently not subject to a calcination step.
  • the term "calcination” refers to a calcination step as defined in the foregoing with respect to the one or more zeolites.
  • step (III) wherein the molding obtained in step (III) is subsequently not subject to a calcination step, it is accordingly preferred according to said embodiments either not to employ a pore former or, alternatively, to use one or more pore formers which may be suitably removed either by a heat- ing step which is not a calcination step within the meaning of the present invention and/or which may be removed by other means than by suitable heating of the preferred molding containing one or more pore formers.
  • Pasting agents which may be used are all compounds suitable for this purpose. These are preferably organic, in particular hydrophilic polymers, for example cellulose, cellulose derivatives, such as methylcellulose, starch, such as potato starch, wallpaper paste, polyacrylates, polymethacrylates, polyvinyl alcohol, polyvinylpyrrolidone, polyisobutene or polytetrahydrofuran. Accordingly, particular com- pounds which also act as pore formers can be used as pasting agents.
  • these pasting agents are removed in a step (V) by calcination to give the porous molding.
  • the molding obtained in step (III) is subsequently not subject to a calcination step.
  • step (III) wherein the molding obtained in step (III) is subsequently not subject to a calcination step, it is accordingly preferred according to said embodiments either not to employ a pasting agent or, alternatively, to use one or more pasting agents which may be suitably removed either by a heating step which is not a calcination step within the meaning of the present invention and/or which may be removed by other means than by suita- ble heating of the preferred molding containing one or more pasting agents.
  • At least one acidic additive may added during the preparation of the mixture according to (I).
  • organic acidic compounds are preferred which can be removed in an optional calcination step (V).
  • Carboxylic acids for example formic acid, oxalic acid and/or citric acid, are particularly preferred. It is also possible to use two or more of these acidic compounds.
  • one or more acidic aditives and preferably one or more organic acidic compounds which may be removed either by a heating step which is not a calcination step within the meaning of the present invention and/or which may be removed by other means than by suitable heating of the preferred molding containing one or more acidic additives, preferably one or more organic acidic compounds.
  • the order of addition of the components of the mixture according to (I) which contains the zeolite is not critical. In particular is both possible first to add the at least one binder, then the at least one pore former and the at least one acidic compound and finally the at least one pasting agent and to interchange the sequence with regard to the at least one binder, the at least one pore former, the at least one acidic compound and the at least one pasting agent.
  • the mixture according to (I) is normally homogenized for from 10 to 180 minutes.
  • kneaders, edge mills or extruders are particularly preferably used for the homogenization.
  • the mixture is preferably kneaded.
  • treatment in an edge mill is preferably employed for the homogenization.
  • the homogenization is carried out as a rule at temperatures in the range of from about 10 °C to the boiling point of the pasting agent and normal pressure or slightly superatmospheric pressure. Thereafter, if appropriate, at least one of the compounds described above can be added.
  • the mixture thus obtained is homogenized, preferably kneaded, until an extrudable plastic material has formed.
  • the homogenized mixture is subsequently molded.
  • those processes in which the molding is effected by extrusion in conventional extruders for example to give extrudates having a diameter of preferably from 1 to 10 mm, particularly preferably from 2 to 5 mm, are preferred for the shaping processes.
  • extrusion apparatuses are described, for example, in Ullmann's Enzyklopadie der Technischen Chemie, 4th Edition, Vol. 2, page 295 et seq., 1972.
  • a plunger-type extruder is also preferably used for the molding.
  • kneading and molding apparatuses and processes may be used for the shaping.
  • these are inter alia: briquetting, i.e. mechanical compression with or without addition of additional binder material; pelleting, i.e. compacting by circular and/or rotational movements; sintering, i.e. the material to be molded is subjected to a thermal treatment.
  • the shape of the moldings produced according to the invention can be chosen as desired. In particular, inter alia spheres, oval shapes, cyl- inders or tablets are possible.
  • step (III) is preferably followed by at least one drying step.
  • any suitable drying step may be used, provided that a dry molding is provided.
  • the drying step does not involve temperatures used in a calcination step within the meaning of the present invention.
  • an optional drying step (IV) is optionally followed by at least one calcination step (V).
  • a calcination step (V) is directly carried out after the molding step (III).
  • the preferred molding containing the acylation catalyst comprising the one or more zeolites having the small-pore framework structure is not subject to a calcination step (V) subsequently to the optional drying step (IV), wherein according to said particularly preferred embodiments not involving a calcination step (V) it is preferred that the production process comprises one or more drying steps (IV) subsequently to the molding step (III).
  • the calcination may be generally carried out at any temperature as defined within the meaning of the present invention, wherein it is preferably carried out at temperatures in the range of from 300 to 700 °C, and more preferably from 400 to 600 °C.
  • the calcination can be effected under any suitable gas atmosphere, air and/or lean air being preferred.
  • the calcination is preferably car- ried out in a muffle furnace, a rotary kiln and/or a belt calcination oven. It is possible for the temperatures during a calcination step to remain constant or to be changed continuously or dis- continuously. If calcination is effected twice or more often, the calcination temperatures can be different or identical in the individual steps.
  • the at least one molding can, if appropriate, be treated with a concentrated or dilute Broenstedt acid or a mixture of two or more Broenstedt acids.
  • Suitable acids are, for example, hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid or carboxylic acids, dicarboxylic acids or oligo- or polycarboxylic acids, such as nitrilotriacetic acid, sulfosalicylic acid or eth- ylenediaminetetraacetic acid.
  • this at least one treatment with at least one Broenstedt acid is followed by at least one drying step (IV) and/or at least one calcination step (V).
  • the moldings preferably provided in step (a) and used in step (b) can, for better hardening, be subject to a water steam treatment, after which preferably drying is effected at least once again and/or calcination is effected at least once again.
  • a water steam treatment after at least one drying step and at least one subsequent calcination step, the calcined molding is subjected to the steam treatment and is then dried at least once again and/or calcined at least once again.
  • zeolite analogous material shall have the following meaning within the frame of the present invention: a material exhibiting a zeolite structure and comprising tetravalent, trivalent and pentavalent structural components Y, X and Z as YO2, X2O3, and Z2O5 respectively, wherein Y is a tetravalent element, X is a trivalent element and Z is a pentavalent element.
  • Y and X have the same meaning as described for zeolites.
  • Preferred Z is phosphor.
  • zeolite analogous materials comprise materials that are known as SAPO.
  • SAPO-34 A particular preferred zeolite analogous material is SAPO-34.
  • a small-pore zeolite (a) and the at least one small-pore zeolite analogous material (c2) can be used as physical mixtures comprising particles which either comprise the small-pore zeolite or the small-pore analogous material.
  • They can also be used as mixtures comprising particles which comprise both the zeolite and the zeolite-analogous material.
  • a preferred material is a material
  • the core-portion comprises one or more zeolites selected from the group consisting of (Ni(deta) 2 )-UT-6, Chabazite,
  • the shell-portion comprises a material selected from the group consisting of [Al-As-O]- CHA, [AI-Co-P-0]-CHA, [Co-AI-P-0]-CHA, [Mg-AI-P-0]-CHA, [Zn-AI-P-0]-CHA, AIPO-34, CoAPO-44, CoAPO-47, GaPO-34, MeAPO-47, MeAPSO-47, SAPO-34, SAPO-47, ZYT-6, and combinations of two or more thereof, preferably from the group consisting of MeAPSO-47, SAPO-34, SAPO-47, ZYT-6, and combinations of two or more thereof, wherein even more preferably the shell-portion comprises SAPO-34.
  • the at least one metal is impregnated with a solution of a respective precursor.
  • the solution is an aqueous solution.
  • the precursor is a metal salt.
  • Mo a preferred salt is ( ⁇ 4 )6 ⁇ 7 ⁇ 24-4 ⁇ 2 0.
  • Fe a preferred salt is Fe(N03)3-9H?0.
  • Co a preferred salt is Co(N03)3-6H?0.
  • the concentration of the solution is from 0.1 wt% to 30 wt% (calculated as metal per solvent), preferred from 1 wt% to 20 wt%, more preferred 1 .5 wt% to 15 wt%, even more preferred 2 wt% to 10 wt%. Particularly preferred is a concentration of 3 wt% to 8 wt%.
  • the impregnated small-pore zeolite and/or small-pore zeolite material is then dried.
  • the drying is performed in two steps.
  • a first drying is performed at a temperature which is lower than the temperature in the second drying step, preferred the first drying is performed at room temperature, i.e. a temperature of 20°C.
  • a second drying is performed at an elevated temperature, which in particular is higher than the temperature in the first drying step.
  • the temperature in the second drying step is from 50 to 200°C, preferred from 80 to 150°C, more preferred from 90 to 120 °C.
  • Particularly preferred is a temperature in the second drying step of 100°C.
  • the catalyst is calcined.
  • Preferred the calcination is performed under air.
  • the calcination temperature is from 300 to 1000°C, preferred from 400 to 800°C, more preferred from 450 to 600°C, even more preferred from 480 to 550°C.
  • Most preferred the calcination temperature is 500°C.
  • the conversion methane to ethene is performed in the presence of a catalyst at temperatures of from 400 to 1000°C, preferably from 500 to 900°C, more preferably from 600 to 800°C, especially from 700 to 800°C, at a pressure of from 0.5 to 100 bar, preferably from 1 to 30 bar, more preferably from 1 to 10 bar, especially from 1 to 5 bar.
  • the reaction is performed at a GHSV (Gas Hourly Space Velocity) of from 100 to 10 000 h- 1 , preferably from 200 to 3000 hr 1 .
  • a suitable reactor form is the fixed bed reactor, radial flow reactor, tubular reactor or tube bundle reactor.
  • the catalyst is present as a fixed bed in one reaction tube or in a bundle of reaction tubes.
  • the catalysts may likewise be used as a fluidized bed or moving bed in the corresponding reactor types suitable for this purpose, and the process according to the invention may be carried out with the catalysts present in such a form.
  • the process further comprises a regeneration step.
  • the regeneration step is performed at temperatures of from 600°C to 1000°C and more preferably from 700°C to 900°C, and pressures of from 1 bar to 30 bar, preferably from 1 bar to 15 bar and more preferably from 1 to 10 bar.
  • the regeneration step is in the presence of hydrogen.
  • coke is reacted to volatile organic compounds, preferred methane.
  • the process comprising a regeneration step is performed in parallel reactors.
  • the step of converting methane to ethane is performed in at least one reactor and the regeneration step is performed simultaneously in at least one other reactor.
  • the catalyst used for the conversion of methane to ethene is regular- ly regenerated with the hydrogen present in a gas stream H. This converts at least a portion of the deposited coke to methane.
  • at least a portion of the methane formed in the regeneration is fed to a reaction zone. After removal from the gas stream M, the methane can be fed to a reaction zone.
  • At least a portion of the methane-containing gas stream M formed in the regeneration is fed to a reaction zone.
  • the gas stream M can be fed to a reaction zone without preceding removal of one or more constituents, but it is also possible for one or more constituents to be removed before the recycling of gas stream M. This allows the CH4/H2 ratio on entry to a reaction zone to be adjusted in a controlled manner.
  • the methane or the methane-containing gas stream M formed during the regeneration can be fed directly to a reaction zone or can be supplied to reactant stream E by addition of the methane or of the gas stream M.
  • Reaction zone and regeneration zone can be interconverted to one another by altering the gas streams.
  • a reaction zone is converted to a regeneration zone by reducing reactant stream E and supplying gas stream H.
  • Reducing reactant stream E means that the reactant stream E makes up at most 10% by volume of the gases fed to the reaction zone, preferably at most 5% by volume and more preferably at most 1 % by volume.
  • the complete closure of supply of reactant stream E is especially preferred.
  • a regeneration zone is converted to a reaction zone by reducing gas stream H and supplying reactant stream E.
  • Reducing gas stream H means that gas stream H forms at most 10% by volume of the gases fed to a regeneration zone, preferably at most 5% by volume and more preferably at most 1 % by volume, based on the total volume of the gas supply. More preferably, the supply of gas stream H is closed completely.
  • reactant stream E does not comprise any hydrogen; in that case, the supply of gas stream H, when a regeneration zone is converted to a reaction zone, can also be throttled only to such an extent that a content of hydrogen which has a positive effect on the coking is established in a reaction zone.
  • the conversion of a reaction zone to a regeneration zone and the conversion of a regeneration zone to a reaction zone are carried out coupled to one another in alternation, such that a reaction zone is present at time intervals alternatingly as a reaction zone in which the conversion of methane to ethene (MTE) takes place and as a regeneration zone in which at least a portion of the coke deposited is converted to methane with the aid of hydrogen.
  • MTE methane to ethene
  • the other reaction zone is present as a regeneration zone and as a reaction zone.
  • one reaction zone is present as a reaction zone (NTE) for from 5 minutes to 5 hours and as a regeneration zone (regeneration) for from 5 minutes to 5 hours.
  • more than one reaction zone and more than one regeneration zone may be present; it is merely necessary in each case for at least one reaction zone and at least one regeneration zone to be present. It is also possible for reaction zones which are in the phase of conversion from a reaction zone to a regeneration zone to be present; in addition, it is possible for reaction zones in which the catalyst is regenerated by other methods to be present, for example by means of oxygen or steam, in which case a recarbidization step possibly becomes necessary. According to the invention, preferably only reaction zone and regeneration zones are present.
  • the catalyst is transferred from a reaction zone to a regeneration zone and regenerated there with the aid of the hydrogen-comprising gas stream H.
  • the regenerated catalyst is then recycled back into a reaction zone.
  • a reaction zone as described above, is converted to a regeneration zone by reducing the supply of reactant stream E and supplying gas stream H, the deactivated catalyst is regenerated and a regeneration zone is then converted back to a reaction zone as described above.
  • the inventive catalyst consists essentially of
  • the inventive catalyst consists of
  • the catalyst comprises
  • the catalyst comprises
  • the small-pore zeolite (a) is selected from the structural group consisting of LEV, CHA , CDO and mixtures thereof.
  • the small-pore zeolite (a) is selected from the group consisting of RUB-37, RUB-50, LEV and mixtures thereof.
  • the metal (b) is selected from the group consisting of Mo, Fe, Co, Ni, Cu, Ag, Mg, W, Re, Ga, Ru, Rh, Pd, Ir, Pt and mixtures thereof, preferred selected from the group consisting of Mo, Fe, Co, Ni, Cu and mixtures thereof, more preferred Mo.
  • the amount of metal (b) is higher than 4 wt%, preferred 5 wt% or more, more preferred 6 wt% or more, based on the total weight of the catalyst.
  • the catalyst metal (b) and an at least one further metal (c3) different from (b) are selected from the group consisting of Mo, Fe, Co, Ni, Cu, Ag, Mg, W, Re, Ga, Ru, Rh, Pd, Ir, Pt and mixtures thereof, preferred Fe, Co, Ni, Cu and mixtures thereof, more preferred Mo-Fe, Mo-Co and Mo-Ni.
  • the obtained white solid was separated from the reaction mixture by filtration and subsequent washing with Dl H2O until a pH of 7 was reached in the washing fraction. Finally the solid was dried under N2 at 120°C for 10h.
  • 0.40kg AI-RUB-50 are dispersed in an ammonium nitrate solution (0.32kg NH4NO3 in 2.2 I Dl H2O) and stirred at 80°C for 2h. Afterwards, the solid is filtered and washed with H2O to re- move residual nitrate ions. The described ion exchange step is then repeated one more time. Finally, the obtained white solid is dried under air at 120°C for 10h.
  • TF-BEA For the removal of Na + from the zeolite framework, 0.65kg TF-BEA are dispersed in an ammonium ni- trate solution (0.65kg NH4NO3 in 5.8 I Dl H 2 0) in H 2 0 and stirring at 80°C for 2h. Afterwards, the solid is filtered and washed with H2O to remove residual nitrate ions. Finally, the obtained white solid is dried under air at 120°C for 10h.
  • RUB-36 is calcined at 600°C for 10h (heating rate 1 K/min) transforming to obtain RUB-37 through interlayer condensation.
  • To remove Na + from the zeolite framework 0.21 kg RUB-37 are dispersed in an ammonium nitrate solution (0.44kg dissolved in 3.9 I Dl H2O) and heated under stirring to 80°C for 2h. Afterwards, the solid is filtered and washed with H2O to remove residual nitrate ions. The described ion exchange step is then repeated one more time. Finally, the ob- tained white solid is dried under air at 120°C for 10h.
  • Example 4 Preparation of CHA + SAPO-34 (this example is identical with Example 1 of WO 2013/038372):
  • Step 1 Preparation of the Chabazite seed crystals
  • the autoclave was then sealed and heated to a temperature of 170 °C and maintained at that temperature for 20 hours under stirring at 200 rpm.
  • the pressure within the autoclave was 7.8 bar, and the pH was 13.4 at the beginning of the reaction.
  • the autoclave was then cooled to 35 °C, thus obtaining a suspension having a pH of 1 1 .9.
  • Per 1 kg of reactor content 168 g of diluted acid were added. About 80% of the calculated total amount of premixed nitric acid (10 wt.-% aqueous solution) was fed into the reactor under agitation. About 20% were slowly added in smaller portions until pH reached about 7-7.5.
  • the resulting mixture was then filtrated with a filter press, and the filter cake was washed with deionized water to a conductivity of 200 mi- croSiemens/cm.
  • the wet product was heated to a temperature of 120 °C in air within 30 min and dried at that temperature for 4 hours.
  • the dried product was then heated to a temperature of 600 °C within 4 hours and calcined in air at 600 °C for 5 hours to afford zeolite crystals having a CHA framework as observed by XRD.
  • ammonium nitrate solution was prepared by mixing 55.6 g of 54 wt.-% ammonium nitrate with 530 g of deionized water at 80 °C. 300 g of the calcined zeolitic material was then added to this solution. The ion-exchange reaction between the Na/H-form of the zeolitic material and the ammonium ions was carried out by agitating the slurry at 60 °C for 1 hour. The pH was between 2.7 and 2.4 during the reaction. The resulting mixture was then filtered, washed until the filtrate had a conductivity of ⁇ 200 mi- croSiemens/cm, and the washed sample finally air dried.
  • the Si : Al molar ratio of the Chabazite seed crystals amounted to 16.7 as measured by inductively coupled plasma (ICP).
  • Step 2 Synthesis of a Chabazite/SAPO-34 core-shell zeolite
  • the concentration of the respective metal solution is calculated as metal per solvent and indicated as wt.%.
  • 6 wt-% Mo/RUB-37 was prepared as follows: 1 .0g dried RUB-37 (H-form) was incipient impregnated by 1 .2ml 4.6 wt.% Mo water solution of and firstly dried under vacuum at room temperature, then dried at 100°C in an oven for 12h in air. Finally, the catalyst was calcined under air at 500°C for 6h.
  • 6 wt-% Mo-0.5wt% Fe/CHA+SAPO-34 was prepared as follows: 1.0g dried CHA/SAPO was incipient impregnated by 1 .2ml 4.6 wt.% Mo water solution of ( ⁇ 4) ⁇ / ⁇ 2 ⁇ 4 ⁇ 2 ⁇ and 1 ml 3.6 wt% Fe water solution of Fe(NOs)3-9H 2 0, and firstly dried under vacuum at room temperature, then dried at 100°C in an oven for 12h in air. Finally, the catalyst was calcined under air at 500°C for 6h.
  • 6 wt-% Mo-0.5wt% Ni/RUB-37 was prepared as follows: 1.0g dried RUB-37 was incipient impregnated by 1 .2ml 4.6 wt.% Mo water solution of ( ⁇ 4 )6 ⁇ 7 ⁇ 24-4 ⁇ 2 0 and 1 mi 2.5 wt% Ni water solution of Ni(N03)3-6H20, and firstly dried under vacuum at room temperature, then dried at 100°C in an oven for 12h in air. Finally, the catalyst was calcined under air at 500°C for 6h. The other Mo-Ni catalysts have been prepared accordingly.
  • Table 2 Loadings of Mo/zeolite (based on the amount of zeolite)
  • the supported Mo catalyst was pelleted to 40-60 mesh at 2Mpa, and then loaded into single pass fix-bed catalytical evaluation device with a transparent and visible tube furnace. Subsequently, the catalysts were activated at 600 °C with CH4 (30ml/min) for 30min, and further elevated with 10°C/min to ca 750°C, and then reaction gas was switched to the evaluation device.
  • the catalytic reaction was conducted under 0.1 Mpa (N2 as internal standard) with a gas space hour velocity 2400 r 1 .
  • the reaction and regeneration process is a periodic CH4/H2 switching, e.g. after reaction gas (CH4/N2) was conducted into the device for 10min, regeneration gas (25ml/min, H2) switched into the device for 30min.
  • the interval of entry 1 and 2 is 30min, which is a regeneration process

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Abstract

L'invention concerne un procédé de conversion sans oxygène de méthane en éthylène sur des catalyseurs à base de zéolithe, ainsi que des catalyseurs comprenant un zéolithe à pores de petite dimension, un métal et un autre constituant.
PCT/EP2014/066788 2013-08-09 2014-08-05 Procédé de conversion sans oxygène de méthane en éthylène sur des catalyseurs à base de zéolithe WO2015018815A1 (fr)

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WO2016134196A1 (fr) * 2015-02-20 2016-08-25 Johnson Matthey Public Limited Company Catalyseurs à tamis moléculaire bimétallique
US9902665B2 (en) 2015-06-12 2018-02-27 Sabic Global Technologies, B.V. Method for producing hydrocarbons by non-oxidative coupling of methane
US10202324B2 (en) 2015-05-04 2019-02-12 Basf Se Process for the preparation of melonal
US10202323B2 (en) 2015-07-15 2019-02-12 Basf Se Process for preparing an arylpropene
US10556801B2 (en) 2015-02-12 2020-02-11 Basf Se Process for the preparation of a dealuminated zeolitic material having the BEA framework structure
CN113156812A (zh) * 2021-01-28 2021-07-23 淮阴工学院 基于未知输入观测器的二级化学反应器故障检测方法

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WO2008132452A2 (fr) * 2007-04-26 2008-11-06 Johnson Matthey Public Limited Company Catalyseurs de scr en métal de transition/zéolite

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10556801B2 (en) 2015-02-12 2020-02-11 Basf Se Process for the preparation of a dealuminated zeolitic material having the BEA framework structure
WO2016134196A1 (fr) * 2015-02-20 2016-08-25 Johnson Matthey Public Limited Company Catalyseurs à tamis moléculaire bimétallique
GB2540832A (en) * 2015-02-20 2017-02-01 Johnson Matthey Plc Bi-metal molecular sieve catalysts
GB2540832B (en) * 2015-02-20 2019-04-17 Johnson Matthey Plc Bi-metal molecular sieve catalysts
US10202324B2 (en) 2015-05-04 2019-02-12 Basf Se Process for the preparation of melonal
US9902665B2 (en) 2015-06-12 2018-02-27 Sabic Global Technologies, B.V. Method for producing hydrocarbons by non-oxidative coupling of methane
US10202323B2 (en) 2015-07-15 2019-02-12 Basf Se Process for preparing an arylpropene
CN113156812A (zh) * 2021-01-28 2021-07-23 淮阴工学院 基于未知输入观测器的二级化学反应器故障检测方法

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