Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen; Reversible storage of hydrogen
  • C01B3/02—Production of hydrogen; Production of gaseous mixtures containing hydrogen
  • C01B3/22—Production of hydrogen; Production of gaseous mixtures containing hydrogen by decomposition of gaseous or liquid organic compounds
  • C01B3/24—Production of hydrogen; Production of gaseous mixtures containing hydrogen by decomposition of gaseous or liquid organic compounds of hydrocarbons
  • C01B3/26—Production of hydrogen; Production of gaseous mixtures containing hydrogen by decomposition of gaseous or liquid organic compounds of hydrocarbons using catalysts
• • 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
  • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
  • B01J23/74—Iron group metals
  • B01J23/755—Nickel
• • 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
  • B01J37/02—Impregnation, coating or precipitation
  • B01J37/0201—Impregnation
  • B01J37/0205—Impregnation in several steps
• • 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
  • B01J37/08—Heat treatment
• • 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
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
  • C01B2203/02—Processes for making hydrogen or synthesis gas
  • C01B2203/0266—Processes for making hydrogen or synthesis gas containing a decomposition step
  • C01B2203/0277—Processes for making hydrogen or synthesis gas containing a decomposition step containing a catalytic decomposition step
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
  • C01B2203/10—Catalysts for performing the hydrogen forming reactions
  • C01B2203/1041—Composition of the catalyst
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
  • C01B2203/10—Catalysts for performing the hydrogen forming reactions
  • C01B2203/1041—Composition of the catalyst
  • C01B2203/1047—Group VIII metal catalysts
  • C01B2203/1052—Nickel or cobalt catalysts
  • C01B2203/1058—Nickel catalysts
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
  • C01B2203/12—Feeding the process for making hydrogen or synthesis gas
  • C01B2203/1205—Composition of the feed
  • C01B2203/1211—Organic compounds or organic mixtures used in the process for making hydrogen or synthesis gas
  • C01B2203/1235—Hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
  • C01B2203/12—Feeding the process for making hydrogen or synthesis gas
  • C01B2203/1205—Composition of the feed
  • C01B2203/1211—Organic compounds or organic mixtures used in the process for making hydrogen or synthesis gas
  • C01B2203/1235—Hydrocarbons
  • C01B2203/1241—Natural gas or methane

Definitions

• the present invention relates to producing hydrogen in the petrochemistry field, particularly from natural gas or LPG (Liquefied Petroleum Gas) or from other gas mixtures containing the C 1 -C 4 hydrocarbons.
• the hydrogen production approach according to the present invention is achieved by making use of Ni-Fe/ ⁇ -AI 2 O 3 type catalysts with a higher activity and a special preparation method.
• Both of such methods are conducted at temperatures ranging from 750 0 C to 800 0 C and under low pressure levels. Both such methods bring about the following significant drawbacks: conducting the process at high temperatures; formation of CO besides H 2 in the process; provision of a special catalytic conversion system to completely convert CO to CO 2 .
• the approach of the background art closest to the present invention is the process whereby methane is catalytically decomposed directly to hydrogen and carbon.
• the basic drawback of this process is the high temperature (700-750 0 C) requirement to provide a high CH 4 conversion yield, whereas the others may be listed as following: - higher energy costs; material selection difficulty for the reactor; an increase in the amount of coke that forms and a decrease in the fixed working period without oxidative regeneration of the catalysts; shortening of the general working life of catalysts.
• the present invention provides a high-yield hydrogen production approach at relatively lower temperatures by means of direct decomposition of natural gas, LPG, or other gas mixtures having a C r C 4 -hydrocarbon content.
• This approach is achieved by making use of Ni-Fe/ ⁇ - AI 2 O 3 type catalysts with a higher activity and a special preparation method.
• the subject process is as following.
• the catalyst for the direct decomposition of methane is prepared according to the subject process.
• industrial-type Y-AI 2 O 3 is used as the catalyst carrier, and Ni and Fe are employed as active metals.
• concentrations of Ni and Fe each vary between 5% and 20% on the catalyst's surface.
• the catalysts are prepared by adsorbing on the carrier surface the aqueous solutions of metal salts (typically the nitrate salts) in a multi-step method.
• the adsorption phase is conducted at the room temperature.
• the carrier is subjected to adsorption, the solution is evaporated and the catalyst dried under air.
• the calcination of catalyst is carried out in an oven under air.
• Ni-Fe/ ⁇ -AI 2 O 3 catalyst used in this invention has the following advantages as compared to known catalysts used for the direct decomposition of natural gas (or methane): the aqueous solutions of Ni and Fe salts are adsorbed in a multi-step manner on the carrier in order to have a more homogeneous distribution of such active metals on the carrier surface;
• Ni and Fe salts are adsorbed together onto the carrier surface; and the catalyst is subjected to calcination after each interim adsorption step conducted on the carrier surface.
• Any such prepared catalysts are used in the direct decomposition process of natural gas or LPG according to the present invention.
• the process is conducted under atmosphere pressure and at 550-650 0 C temperature.
• the volumetric flow rate of natural gas or LPG used as raw materials in this process varies between 720 hour “1 and 4320 hour “1 .
• the conversion rate of methane in the natural gas to hydrogen varies between 66 to 91% according to the conditions of this process.
• the contents of the natural gas and LPG used as inputs in the process, and the gaseous products as the output of the process are analyzed by means of Gas Chromatography.
• the amount and character of the coke formed on the catalyst surface as a result of directly decomposing CH 4 according to this process are studied by the Differential Thermal-Gravimetric Analysis method.
• Ni + 5% Fe/ ⁇ -AI 2 O 3 catalyst is prepared for use in the subject process. For this reason, 3.12 g Ni(NO 3 ) 2 .6H 2 O and 4.56 g Fe(NO 3 ) 3 .9H 2 O salts are dissolved in 10 ml distilled water and the resulting solution is adsorbed in two steps under mixing for 12 hours on the surface of Y-AI 2 O 3 (10 g), which is previously dried under 150 0 C for 4 hours.
• the solution is evaporated and the catalyst is dried under air at 150 0 C for 6 hours and subjected to calcination at 500°C for 4 hours, then in the second step following adsorption, the solution is evaporated again and the catalyst dried under air at 15O 0 C. Then, the catalyst is subjected to the final calcination step under air at 75O 0 C for 4 hours. In the calcination steps, the temperature is raised by 150°C/hour "1 starting from 150°C.
• a 2.5 g aliquot is taken from the prepared catalyst and used for directly decomposing the natural gas.
• the content of the natural gas used as raw material in this process is as following (% by volume): H 2 - 0.14, CH 4 - 87.84, C 2 H 6 - 4.16, C 3 - 1.19, C 4 -C 5 - 0.03, N 2 - 5.6, O 2 - 0.51 , CO 2 - 0.43.
• the process is conducted in a continuous experiment system with a fixed bed quarts reactor under atmosphere pressure at 65O 0 C and 30 ml/min gas flow rate (720 hour "1 ).
• the reactor's inner diameter and length are 2.2 cm and 20 cm, respectively. After the gaseous products are put out of the reactor, they are cooled in a water cooler and analyzed by means of GC. The result is as following:
• Ni + 10% Fe/ ⁇ -AI 2 O 3 catalyst is prepared for use in this process. Respectively 6.24 g and 9.12 g of Ni(NO 3 ) 2 .6H 2 O and Fe(NO 3 ) 3 .9H 2 O salts are used in the catalyst's synthesis. The adsorption of aqueous solutions of metal salts on the catalyst surface is conducted at three steps.
• Ni + 20% Fe/ ⁇ -AI 2 O 3 catalyst is prepared for use in this process. Respectively 12.48 g and 18.24 g of Ni(NO 3 ) 2 .6H 2 O and Fe(NO 3 ) 3 .9H 2 O salts are used in the catalyst's synthesis. The adsorption of aqueous solutions of metal salts on the catalyst surface is conducted at four steps in the preparation of the catalyst.
• 20% Ni + 20% Fe/ ⁇ -Al 2 O 3 catalyst is prepared for use in this process.
• the preparation of the catalyst is conducted by means of a 4-step adsorption method.
• the direct decomposition process is conducted at 550°C temperature.
• 20% Ni + 20% Fe/ ⁇ -AI 2 O 3 catalyst is prepared for use in the subject process.
• LPG with the following content (% by volume) is used as the raw material in this process: H 2 - 0.2, CH 4 - 0.6, C 2 H 6 - 15.99, C 3 - 50.98, C 4 - 29.15, C 5 - 0.19, N 2 - 1.78, O 2 - 1.11.
• the temperature of the direct decomposition process is 650 0 C and the flow rate of the natural gas is 30 ml/min (720 hour "1 ).

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• 2006
  • 2006-10-19 TR TR2006/05865A patent/TR200605865A2/xx unknown
• 2007
  • 2007-10-18 EP EP07826782A patent/EP2076332A1/de not_active Ceased
  • 2007-10-18 WO PCT/IB2007/054240 patent/WO2008047321A1/en not_active Ceased
  • 2007-10-18 RU RU2009118631/04A patent/RU2446010C2/ru active

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