Classifications

• • 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
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
  • B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
  • B01J23/56—Platinum group metals
  • B01J23/62—Platinum group metals with gallium, indium, thallium, germanium, tin or lead
  • B01J23/622—Platinum group metals with gallium, indium, thallium, germanium, tin or lead with germanium, tin or lead
  • B01J23/626—Platinum group metals with gallium, indium, thallium, germanium, tin or lead with germanium, tin or lead with tin
• • 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
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/14—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of germanium, tin or lead
• • 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
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
  • B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
  • B01J23/42—Platinum
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C5/00—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
  • C07C5/32—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by dehydrogenation with formation of free hydrogen
  • C07C5/327—Formation of non-aromatic carbon-to-carbon double bonds only
  • C07C5/333—Catalytic processes
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C5/00—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
  • C07C5/32—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by dehydrogenation with formation of free hydrogen
  • C07C5/327—Formation of non-aromatic carbon-to-carbon double bonds only
  • C07C5/333—Catalytic processes
  • C07C5/3335—Catalytic processes with metals
  • C07C5/3337—Catalytic processes with metals of the platinum group
• • 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
  • B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
  • B01J21/02—Boron or aluminium; Oxides or hydroxides thereof
  • B01J21/04—Alumina
• • 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
  • B01J35/00—Catalysts, in general, characterised by their form or physical properties
  • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
  • B01J35/61—Surface area
  • B01J35/612—Surface area less than 10 m2/g
• • 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
  • B01J35/00—Catalysts, in general, characterised by their form or physical properties
  • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
  • B01J35/61—Surface area
  • B01J35/613—10-100 m2/g
• • 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
  • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
  • B01J37/0009—Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2523/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00
  • C07C2523/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00 of noble metals
  • C07C2523/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00 of noble metals combined with metals, oxides or hydroxides provided for in groups C07C2523/02 - C07C2523/36
  • C07C2523/56—Platinum group metals
  • C07C2523/60—Platinum group metals with zinc, cadmium or mercury

Definitions

• the invention relates to a catalyst for the oxidation of hydrogen in a process for the dehydrogenation of hydrocarbons, the catalyst, supported on oc-alumina, 0.01 to 0.1 wt .-% platinum and 0.01 to 0.1 wt. % Tin based on the total weight of the catalyst contains, a process for the oxidation of hydrogen and a process for the dehydrogenation of hydrocarbons with an integrated oxidation process using the said catalyst.
• US Pat. No. 4,418,237 describes a process for the dehydrogenation of hydrocarbons with selective oxidation of the hydrogen formed in a first process step on a dehydrogenation catalyst.
• the oxidation catalyst contains noble metals from Group VIII and a metal cation with an ionic radius> 1.35 Angstrom on a porous aluminum support with a BET surface area of 1 to 500 m 2 / g.
• the noble metal content is between 0.001 and 5% by weight.
• US-A 4 599471 describes a dehydrogenation process in which there is an oxidation zone between two dehydrogenation zones, which is fed with oxygen-rich water vapor.
• the oxidation catalyst contains a noble metal
• Group VIII in an amount of 0.01 to 5 wt .-% and a metal or metal cation with an ionic radius> 1.35 Angstrom.
• EP-A 826418 describes oxidation catalysts and a process for the selective oxidation of hydrogen in the dehydrogenation of ethylbenzene to styrene.
• the catalysts contain 0.01 to 10% by weight of platinum on an aluminum oxide support, the BET surface area of the aluminum oxide being 0.5 to 6 m 2 / g and the aluminum oxide having an ammonia adsorption of at most 5 ⁇ mol / g.
• EP-A 1 229 011 describes a process for the dehydrogenation of ethylbenzene, in which an oxidation zone is integrated between two dehydrogenation stages and in the second dehydrogenation stage a carbon dioxide generation rate of less than 2.1 with respect to the first stage is maintained.
• Oxidation catalysts with platinum, alkali or alkaline earth metals, tin or lead and / or metals of the 4th group, such as germanium, are used.
• the object of the invention was therefore to find a catalyst for the oxidation of hydrogen which has a high selectivity and activity and which is more economical in comparison with the catalysts from the prior art. Furthermore, an improved process for the oxidation of hydrogen, in particular integrated in a dehydrogenation process, should be found.
• the object was achieved with the aid of a catalyst for the oxidation of hydrogen in a process for the dehydrogenation of hydrocarbons, the catalyst, supported on ⁇ -aluminum oxide, 0.01 to 0.1% by weight of platinum and 0.01 to 0, Contains 1 wt .-% tin based on the total weight of the catalyst.
• Platinum and tin are advantageously used in a weight ratio of 1: 4 to 1: 0.2, preferably in a ratio of 1: 2 to 1: 0.5, in particular in a ratio of approximately 1: 1.
• the catalyst advantageously contains 0.05 to 0.09% by weight of platinum and 0.05 to 0.09% by weight of tin, based on the total weight of the catalyst.
• alkali and / or alkaline earth metal compounds can optionally be used.
• fertilizers are used in amounts of less than 2% by weight, in particular less than 0.5% by weight.
• alkali metal compounds are preferred, in particular sodium, potassium and / or cesium compounds.
• the aluminum oxide catalyst particularly preferably contains only platinum and tin. If necessary, traces of alkali and alkaline earth metals can be present in an order of magnitude, such as are typically present in commercially available aluminum oxides or entered during the production of shaped articles, for example when using magnesium stearate as a tabletting aid.
• the catalyst support made of ⁇ -aluminum oxide advantageously has a BET surface area of 0.5 to 15 m 2 / g, preferably 2 to 14 m 2 / g, in particular 7 to 11 m 2 / g.
• a shaped body is preferably used as the carrier.
• Preferred geometries are, for example, tablets, ring tablets, balls, cylinders, star strands or gear-shaped strands.
• the diameters of these geometries are advantageously 1 to 10 mm, preferably 2 to 8 mm, the individual diameters being able to scatter with a distribution around the mean diameter mentioned above.
• Balls or cylinders, in particular balls, are particularly preferred.
• the balls essentially have an average diameter of 3 to 7 mm, advantageously not more than 5% by weight of the balls.
• gels have a diameter smaller than 3 mm and not more than 5% by weight of the balls have a diameter larger than 7 mm.
• the catalyst carrier preferably consists exclusively of ⁇ -aluminum oxide.
• the ⁇ -alumina carrier can be prepared by all methods known to the person skilled in the art.
• a cylindrical shaped body is advantageously produced by mixing aluminum oxide hydrate (pseudoboehmite) and optionally ⁇ -aluminum oxide powder and shaping, optionally with the addition of auxiliaries such as graphite, magnesium stearate, potato starch or nitric acid, with the addition of water in an extruder or preferably in one continuously operated extruder. If necessary, the shaped bodies can also be cut to length during the extrusion.
• the extruded strands are advantageously dried at temperatures between 100 and 180 ° C and generally calcined at 400 and 800 ° C, preferably in a belt calciner for 0.5 to 5 hours.
• a final calcination takes place, for example, in a rotary tube, shaft or muffle furnace at temperatures of advantageously 1000 and 1200 ° C.
• the calcination starting from a molded body containing pseudoboehmite, can advantageously be carried out in a single apparatus, for example a muffle furnace, with a temperature control that is graded or continuously increasing over time.
• Mechanical properties and pore structure of the support can be determined by the ratio of pseudoboehmite and ⁇ -Al 2 O 3 can be influenced.
• the shaping is also possible by means of tableting, as described, for example, in EP-A 1 068 009. A preferred embodiment in the case of tableting are dome-shaped ring tablets as described in US Pat. No. 6,518,220.
• the active components of the catalyst are generally applied by impregnation.
• the ⁇ -aluminum oxide support is impregnated, for example, as described in WO 03/092887 A1.
• the impregnation is preferably carried out in two steps, in which the aluminum oxide support is first impregnated with a solution of a platinum compound, preferably with a platinum nitrate solution, the catalyst is dried and then impregnated with a solution of a tin compound, preferably with a tin-H-chloride solution, and then dried and is calcined.
• the catalyst according to the invention advantageously has an abrasion of less than 5%. Furthermore, the catalyst according to the invention advantageously has a breaking hardness of more than 10 N.
• the catalyst advantageously has a shell-like profile.
• the bulk density is advantageously 0.3 to 2 g / cm 3 , in particular 0.6 to 1, 2 g / cm 3 .
• the catalyst according to the invention can advantageously be used as an oxidation catalyst.
• a gas mixture containing hydrogen and hydrocarbon is reacted with an oxygen-containing gas in the presence of the oxidation catalyst according to the invention.
• the oxygen-containing gas preferably contains at least 80% by volume of oxygen, preferably at least 90% by volume, in particular at least 95% by volume of oxygen, in each case based on an oxygen-containing gas which is gaseous under normal conditions, ie regardless of any additional dilution with water vapor. If necessary, air can also be used.
• the oxidation reaction is usually carried out at a temperature of 400 to 700 degrees Celsius, in particular 500 to 650 degrees Celsius and a pressure of 0.3 to 10 bar, in particular 0.4 to 1 bar.
• the molar ratio of oxygen to hydrogen is generally 0.1: 1 to 1: 1, preferably 0.2: 1 to 0.6: 1, in particular 0.3: 1 to 0.45: 1.
• the molar ratio of hydrogen and hydrocarbons is advantageously between 0.01: 1 and 0.5: 1, in particular between 0.1: 1 and 0.3: 1.
• One method in which the catalyst according to the invention and the oxidation method according to the invention can advantageously be used is the method for the dehydrogenation of hydrocarbons, in particular alkylaromatics, particularly advantageously the dehydrogenation of ethylbenzene to styrene.
• the dehydrogenation reaction is advantageously carried out in a plurality of reactors arranged in series, at least one oxidation process according to the invention being interposed between two dehydrogenation reactors or integrated in at least one dehydrogenation reactor.
• the volume ratio of the beds of oxidation catalyst and dehydrogenation catalyst per reactor is generally 0.1: 1 to 1: 1, preferably 0.15: 1 to 0.6: 1, in particular 0.2: 1 to 0.4: 1.
• an integrated oxidation catalyst it is preferably arranged upstream of the dehydrogenation catalysts, ie that the reaction gas in the respective reactor first flows through the oxidation catalysts and then through the dehydrogenation catalysts.
• Radial flow reactors are preferably used in which the beds (catalyst beds) of oxidation and dehydrogenation catalysts are arranged concentrically one inside the other and are optionally separated from one another by cylindrical screens (screens).
• the oxidation catalyst is then used as the inner of the two concentrically arranged approximately hollow cylindrical beds.
• the dehydrogenation of hydrocarbons can be carried out by all processes known to the person skilled in the art.
• the dehydrogenation of alkyl aromatics to alkenyl aromatics is preferably carried out in adiabatic or isothermal processes, in particular in adiabatic processes.
• the reaction is generally distributed over several reactors connected in series, preferably radial flow reactors (R). Two to four reactors are preferably connected in series. There is a fixed bed with dehydrogenation catalysts in each reactor.
• the dehydrogenation catalysts are generally catalysts containing iron oxide. These are known to the person skilled in the art and are described, for example, in DE-A 101 54 718.
• the dehydrogenation catalysts (DK) are preferably used in the form of full cylinders, star strands or gear-shaped strands, as described for example in EP-A 1 027 928 or EP-A 423 694.
• Strands (solid cylinders) with a diameter of approximately 2 to 6 mm (cross section), in particular 2.5 to 4 mm, star strands with a diameter of 3 to 5 mm or gear-shaped strands with a diameter of 2.5 to 4 mm are particularly preferred.
• ethylbenzene In the dehydrogenation of ethylbenzene to styrene, typically ethylbenzene (EB) is heated together with water vapor (H 2 O), advantageously in an amount of less than 15% by weight based on ethylbenzene, to temperatures around 500 ° C. by means of a heat exchanger (WT) and mixed directly before entering the first reactor (R ⁇ with superheated steam from a steam superheater (DÜH), so that the desired entry temperature in the first reactor is usually between 600 and 650 ° C.
• WT heat exchanger
• DÜH steam superheater
• the mass ratio of water vapor (total water vapor) to When entering the bed of the dehydrogenation catalyst in the first reactor, ethylbenzene is advantageously 0.7: 1 to 2.5: 1.
• a steam / ethylbenzene ratio of 0.75: 1 to 1.8: 1 is preferred, in particular 0.8: 1 to 1.5: 1.
• the water vapor / ethylbenzene ratio can also increase in the direction of the subsequent reactor stages when the oxygen fed in is diluted with water vapor preferably operated at reduced pressure, typical reactor pressures are in the range from 300 to 1000 mbar.
• the preferably hollow cylindrical catalyst beds (radial flow reactors) are flowed through from the inside to the outside.
• the molar ratio of oxygen (O 2 ) used in relation to the hydrogen discharged from the previous reactor (R-,) is generally 0.1: 1 to 0.6: 1, preferably 0.2: 1 to 0.5 : 1, in particular 0.3: 1 to 0.45: 1, in order to advantageously achieve a temperature increase of 50-150 ° C, in particular 70 to 130 ° C, over the oxidation catalyst (OK) in the second reactor (R 2 ).
• Oxygen can be fed in the form of non-air or preferably in an enriched form diluted with water vapor (H 2 O) to avoid explosive mixtures.
• Oxygen with a content of at least 80% by volume, particularly preferably at least 90% by volume and in particular at least 95% by volume, based on an oxygen-containing gas which is gaseous under normal conditions, is preferably used without consideration of any water vapor dilution.
• the reaction mixture Before entering the third reactor (R 3 ), the reaction mixture is advantageously brought to temperatures of usually 600 and 650 ° C. again using a heat exchanger (WT) by means of superheated steam.
• WT heat exchanger
• the pressure at the outlet of the third reactor (R 3 ) should preferably not be more than 700 mbar, particularly preferably not more than
• a further bed of the oxidation catalyst according to the invention with analog oxygen supply can also be set up analogously to the heat input at the input of R 2 .
• the proportion of carbon dioxide in the exhaust gas of the process (dehydrogenation gas) after extensive condensation of the water vapor and the liquid hydrocarbons is preferably not more than 20% by volume, preferably not more than 15% by volume and in particular not more than 10% by volume.
• the product stream is cooled and the gaseous products and the aqueous phase are separated off in order to separate the residual stream by distillation in styrene (ST) as a valuable product, ethylbenzene as an unreacted starting material, and benzene, toluene and high boilers as by-products. Unreacted ethylbenzene can be recycled after working up the reaction product.
• ST styrene
• the styrene selectivities are usually around 95 to 98%.
• the main by-products are toluene and benzene, as well as hydrogen, carbon dioxide, carbon monoxide, methane, ethane and ethene.
• FIG. 1 The apparatus structure of a preferred embodiment is shown schematically in FIG. 1.
• the number and connection of the heat exchangers are shown in simplified form, the processing of the product mixture is not shown.
• An ⁇ -aluminum oxide carrier in the form of solid cylindrical strands with a 4 mm end face diameter, a water absorption of 0.38 cm 3 / g and a cutting hardness of 60 N was obtained by extrusion of a mixture of ⁇ - analogous to the example for carrier production from EP 1 068009 B1 Alumina and pseudoboehmite and then calcined to a BET surface area of 7 m 2 / g. 225 g (250 cm 3 ) of the carrier were impregnated with 86 ml of a solution of 0.3134 g of platinum nitrate (57.52% platinum content). After 2 hours the impregnated catalyst support was dried at 120 ° C. The catalyst was then impregnated with 77 ml of a solution of 0.3427 g of stannous chloride dihydrate. The catalyst was then dried at 120 ° C. and calcined at 500 ° C. for 3 hours.

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• 2004
  • 2004-03-29 DE DE102004015800A patent/DE102004015800A1/de not_active Withdrawn
• 2005
  • 2005-03-22 EP EP05716274A patent/EP1732867A1/de not_active Withdrawn
  • 2005-03-22 US US11/547,500 patent/US20080262281A1/en not_active Abandoned
  • 2005-03-22 WO PCT/EP2005/003010 patent/WO2005097715A1/de active Search and Examination
  • 2005-03-22 KR KR1020067021400A patent/KR20070004845A/ko not_active Application Discontinuation
  • 2005-03-22 RU RU2006137946/04A patent/RU2006137946A/ru unknown
  • 2005-03-22 CA CA002558547A patent/CA2558547A1/en not_active Abandoned
  • 2005-03-22 CN CNA2005800106306A patent/CN1938246A/zh active Pending
  • 2005-03-22 JP JP2007505446A patent/JP2007537029A/ja active Pending

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