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WO2025227115A1 - Utilisation d'oxydants pour la production stable d'hydrogène et de carbone à haute valeur à partir de pyrolyse d'hydrocarbures - Google Patents

Utilisation d'oxydants pour la production stable d'hydrogène et de carbone à haute valeur à partir de pyrolyse d'hydrocarbures

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Publication number
WO2025227115A1
WO2025227115A1 PCT/US2025/026512 US2025026512W WO2025227115A1 WO 2025227115 A1 WO2025227115 A1 WO 2025227115A1 US 2025026512 W US2025026512 W US 2025026512W WO 2025227115 A1 WO2025227115 A1 WO 2025227115A1
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WO
WIPO (PCT)
Prior art keywords
pyrolysis
gas
reactor
hydrocarbon
oxidant
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/US2025/026512
Other languages
English (en)
Inventor
Vasudev Pralhad HARIBAL
Jian Ping SHEN
Andrew Shih TONG
Raghubir Prasad GUPTA
Arun Majumdar
Matteo CARGNELLO
Marco GIGANTINO
Eddie SUN
Henry MOISE
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Leland Stanford Junior University
Susteon Inc
Original Assignee
Leland Stanford Junior University
Susteon Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Leland Stanford Junior University, Susteon Inc filed Critical Leland Stanford Junior University
Publication of WO2025227115A1 publication Critical patent/WO2025227115A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

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    • 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
    • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
    • C01B3/22—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by decomposition of gaseous or liquid organic compounds
    • C01B3/24—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by decomposition of gaseous or liquid organic compounds of hydrocarbons
    • C01B3/26—Production of hydrogen or of gaseous mixtures containing a substantial proportion of 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
    • 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
    • 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
    • B01J23/745—Iron
    • 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
    • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
    • C01B3/22—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by decomposition of gaseous or liquid organic compounds
    • C01B3/24—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by decomposition of gaseous or liquid organic compounds of hydrocarbons
    • C01B3/28—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by decomposition of gaseous or liquid organic compounds of hydrocarbons using moving solid particles
    • C01B3/30—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by decomposition of gaseous or liquid organic compounds of hydrocarbons using moving solid particles using the fluidised bed technique
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
    • 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
    • B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
    • B01J35/56—Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
    • B01J35/57—Honeycombs
    • 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
    • C01B2203/04—Integrated processes for the production of hydrogen or synthesis gas containing a purification step for the hydrogen or the synthesis gas
    • 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
    • C01B2203/04—Integrated processes for the production of hydrogen or synthesis gas containing a purification step for the hydrogen or the synthesis gas
    • C01B2203/042—Purification by adsorption on solids
    • C01B2203/043—Regenerative adsorption process in two or more beds, one for adsorption, the other for regeneration
    • 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
    • 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
    • C01B2203/1082—Composition of support materials
    • 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
    • C01B2203/14—Details of the flowsheet
    • C01B2203/148—Details of the flowsheet involving a recycle stream to the feed of the process for making hydrogen or synthesis gas

Definitions

  • the invention is generally directed to systems and methods for using oxidants in the feed methane or other feed hydrocarbon to obtain a stable production of hydrogen along with high value carbon from hydrocarbon pyrolysis.
  • SMR produces hydrogen at an affordable cost of $1.2 — 1.5 per kilogram of hydrogen (kg-H2) at a natural gas price of ⁇ $3 per million British thermal units (mm BTU); however, this process also produces approximately 10 kg of carbon dioxide per kg of hydrogen, wherein capturing and sequestering this carbon dioxide increases the hydrogen cost to $1.5- 1.8/kg-H 2 .
  • thermocatalytic pyrolysis route allows for (a) an operating temperature lower than thermal pyrolysis, (b) use of designed catalysts for selective hydrogen production and (c) co-production of high value solid carbon.
  • thermocatalytic hydrocarbon pyrolysis for the production of hydrogen and high value solid carbon is avoiding catalyst deactivation due to excessive coke formation, leading to an unstable and decline in production of hydrogen over time.
  • thermocatalytic hydrocarbon pyrolysis for the production of hydrogen and high value solid carbon.
  • the present disclosure generally relates to systems and methods for utilizing oxidants to obtain a stable hydrogen production during thermocatalytic hydrocarbon pyrolysis producing hydrogen and solid carbon as co-products.
  • the disclosure relates to a process for catalytic pyrolysis of hydrocarbon, comprising: catalytically pyrolyzing a gaseous hydrocarbon to produce hydrogen and solid carbon, wherein an oxidant is added to the gaseous hydrocarbon before or during the catalytic pyrolysis.
  • the disclosure relates to a system for catalytic pyrolysis of hydrocarbon, comprising: a pyrolysis reactor containing pyrolysis catalyst effective for pyrolyzing a gaseous hydrocarbon to produce hydrogen and solid carbon, the pyrolysis reactor comprising a gas inlet and a catalytic pyrolysis product outlet; a heat source arranged to supply heat into the pyrolysis reactor for the catalytic pyrolysis; a hydrocarbon feed source containing hydrocarbon and arranged to supply the hydrocarbon to the gas inlet of the pyrolysis reactor for catalytic pyrolysis thereof in the pyrolysis reactor; and an oxidant gas source containing oxidant and arranged to supply the oxidant to the pyrolysis reactor before or during the catalytic pyrolysis.
  • Another aspect of the disclosure relates to the pyrolysis reaction being conducted in the process and system of the disclosure at temperature in a range of from 600°C to 1000°C.
  • the disclosure relates to the use of a pyrolysis reactor in the process and system of the disclosure, comprising a fluidized bed, a packed bed, a moving bed, or any combination thereof.
  • the disclosure relates to conducting the pyrolysis reaction in the process and system of the disclosure for pyrolysis of methane at an operating space velocity in a range of from 75 to 20,000 cm 3 /minute (seem) CH g of active catalyst, at the standard temperature of 0°C and the standard pressure of 1 atm.
  • the disclosure relates to use of a hydrocarbon feedstock in the process and system of the disclosure, in which the hydrocarbon is selected from the group consisting of (a) alkanes with a molecular formula of C n H2n+2, where n is 1 to 4; (b) alkenes with a molecular formula of Cnlhn, wherein n is 2 to 4; (c) alkynes with a molecular formula of C n H2n-2, wherein n is 2 to 4; any isomers thereof; and any combination thereof.
  • the hydrocarbon is selected from the group consisting of (a) alkanes with a molecular formula of C n H2n+2, where n is 1 to 4; (b) alkenes with a molecular formula of Cnlhn, wherein n is 2 to 4; (c) alkynes with a molecular formula of C n H2n-2, wherein n is 2 to 4; any isomers thereof; and any combination thereof.
  • the disclosure relates to the use in the process and system of the disclosure of oxidant selected from the group consisting of CO2, O2, H2O, and any combinations thereof.
  • oxidant selected from the group consisting of CO2, O2, H2O, and any combinations thereof.
  • FIG.l is a schematic representation of a process system for thermocatalytic hydrocarbon pyrolysis producing hydrogen and solid carbon as co-products, according to one embodiment of the present disclosure.
  • FIG.2 demonstrates the effect of temperature (750°C, Test 1 vs 850°C, Test 2) on methane conversion when tested in a laboratory fixed bed reactor using Fe/AhCE for 180 minutes.
  • FIG.3 demonstrates the effect of space velocity at 850°C (200 seem CH g active catalyst, Test 2 vs 200 seem CH g active catalyst, Test 3) on methane conversion when tested in a laboratory fixed bed reactor using Fe/AhCh for 180 minutes.
  • FIG.4 demonstrates the effect of CO2 addition in the feed (Test 4) along with methane as a hydrocarbon at 850°C at 200 seem CH g active catalyst space velocity vs Test 2 on methane conversion when tested in a laboratory fixed bed reactor using Fe/AhCE for 180 minutes.
  • FIG.5 demonstrates the effect of CO2 addition in the feed (Test 5) along with methane as a hydrocarbon at 850°C at 100 seem CH g active catalyst space velocity vs Test 3 on methane conversion when tested in a laboratory fixed bed reactor using Fe/AhCE for 180 minutes.
  • FIG.6 shows the laboratory scale fixed bed reactor multicycle testing schedule using Fe/AhCh incorporating the dislodging and the pre-reaction reduction steps.
  • FIG.7 demonstrates the high methane conversion obtained over 4 cycles in the laboratory fixed bed reactor using Fe/AhCh when tested using the schedule shown in FIG.6.
  • FIG. 8 is a graph of fractional methane conversion as a function of CH4 time-onstream (TOS), in minutes, for each of (i) pure CH4 feed, (ii) CH4 + H2O co-feed, (iii) CH4+ O2 co-feed, and (iv) (iii) CH4 + CO2 co-feed.
  • TOS time-onstream
  • FIG. 9 shows SEM images of carbon removed continuously from a fluidized bed reactor.
  • FIG. 10 is a graph of methane conversion [%], as a function of methane TOS [minutes], for methane conversion in a fluidized bed with cyclic carbon production and removal for co-feed of 5:95 CO2: CH4.
  • FIG. 11 is a graph of methane conversion [%], as a function of methane TOS [minutes], for methane conversion in a fluidized bed with cyclic carbon production and removal for a 0: 100 CO2: CH4 at 750°C.
  • FIG. 12 shows graphs of methane conversion [%], as a function of time [minutes], for fluidized bed methane conversion with cyclic carbon production and removal for 0%, 5%, 10%, and 20% CO 2 co-feed at 850°C.
  • FIG. 13 shows high-magnification SEM images of pyrolysis catalyst beads after pyrolysis experiments with variable CO2 fraction in the reactor gas feed.
  • FIG. 14 shows low-magnification SEM images of carbon from pyrolysis experiments with variable CO2 fraction in the reactor gas feed.
  • FIG. 15 shows high-magnification SEM images of carbon from pyrolysis experiments with variable CO2 fraction in the reactor gas feed.
  • FIG. 16 is a graph of methane conversion [%], as a function of process time [minutes] for sustained and regenerable methane conversion over 10 cycles of operation in a fluidized bed at 750°C with 5 wt.% Fe/AhCE, 5 vol.% CO2 co-feed and use of an 880 pm diameter AI2O3 gas distribution system, in which continuous lines represent pyrolysis steps while the dashed lines represent both production and dislodging steps.
  • FIG. 17 shows SEM images of carbon after experiments performed at 870°C with (left image) and with (right image) the presence of H2O in the gas feed.
  • FIG. 18 shows an SEM image of carbon produced in a fluidized bed with cyclic carbon production and removal for a 285: 15:50: 1.25 CEL: CO2: N2: H2O at 750°C.
  • the present disclosure relates generally to therm ocataly tic hydrocarbon pyrolysis for production of hydrogen and solid carbon, and more particularly to systems and methods for carrying out such therm ocataly tic hydrocarbon pyrolysis utilizing oxidants to produce hydrogen and solid carbon of high quality.
  • the phrase “and any combination thereof’ when referencing members of a group refers to at least two members of the group forming part of a collection. Further, in those instances where a convention analogous to "at least one of A, B and C, etc.” is used, in general such a construction is intended in the sense of one having ordinary skill in the art would understand the convention (for example, "a system having at least one of A, B and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together).
  • a range of carbon numbers will be regarded as specifying a sequence of consecutive alternative carbon-containing moieties, including all moieties containing numbers of carbon atoms intermediate the endpoint values of carbon number in the specific range as well as moieties containing numbers of carbon atoms equal to an endpoint value of the specific range, e.g., Ci-Ce, is inclusive of Ci, C2, C3, C4, C5 and Ce, and each of such broader ranges may be further limitingly specified with reference to carbon numbers within such ranges, as sub-ranges thereof.
  • the range Ci-Ce would be inclusive of and can be further limited by specification of sub-ranges such as C1-C3, C1-C4, C2-C6, C4-C6, etc. within the scope of the broader range.
  • carbon number range is intended to include each of the component carbon number moieties within such range, so that each intervening carbon number and any other stated or intervening carbon number value in that stated range, is encompassed, it being further understood that subranges of carbon number within specified carbon number ranges may independently be included in smaller carbon number ranges, within the scope of the disclosure, and that ranges of carbon numbers specifically excluding a carbon number or numbers are included in the invention, and subranges excluding either or both of carbon number limits of specified ranges are also included in the disclosure. Accordingly, C1-C4 alkyl is intended to include methyl, ethyl, propyl, and butyl, including straight chain as well as branched groups of such types.
  • a carbon number range e.g., Ci-Ce
  • the carbon number range is deemed to affirmatively set forth each of the carbon number species in the range, as to the substituent, moiety, or compound to which such range applies, as a selection group from which specific ones of the members of the selection group may be selected, either as a sequential carbon number subrange, or as specific carbon number species within such selection group.
  • the disclosure may in particular implementations be constituted as comprising, consisting, or consisting essentially of, some or all of such features, aspects and embodiments, as well as elements and components thereof being aggregated to constitute various further implementations of the disclosure.
  • the disclosure is set out herein in various embodiments, and with reference to various features and aspects of the disclosure.
  • the disclosure contemplates such features, aspects and embodiments in various permutations and combinations, as being within the scope of the invention.
  • the disclosure may therefore be specified as comprising, consisting or consisting essentially of, any of such combinations and permutations of these specific features, aspects and embodiments, or a selected one or ones thereof.
  • the present disclosure relates in various aspects to a process for catalytic pyrolysis of hydrocarbon, comprising: catalytically pyrolyzing a gaseous hydrocarbon to produce hydrogen and solid carbon, wherein an oxidant is added to the gaseous hydrocarbon before or during the catalytic pyrolysis.
  • the present disclosure relates in various other aspects to a system for catalytic pyrolysis of hydrocarbon, comprising: a pyrolysis reactor containing pyrolysis catalyst effective for pyrolyzing a gaseous hydrocarbon to produce hydrogen and solid carbon, the pyrolysis reactor comprising a gas inlet and a catalytic pyrolysis product outlet; a heat source arranged to supply heat into the pyrolysis reactor for the catalytic pyrolysis; a hydrocarbon feed source containing hydrocarbon and arranged to supply the hydrocarbon to the gas inlet of the pyrolysis reactor for catalytic pyrolysis thereof in the pyrolysis reactor; and an oxidant gas source containing oxidant and arranged to supply the oxidant to the pyrolysis reactor before or during the catalytic pyrolysis.
  • FIG.l is a schematic representation of a process system for thermocatalytic hydrocarbon pyrolysis producing hydrogen and solid carbon as co-products, according to one embodiment of the present disclosure, wherein oxidant(s) may be employed to secure stable hydrogen production during the thermocatalytic pyrolysis process.
  • the process system shown in FIG.l includes a pyrolysis reactor 101, in which is disposed a catalyst bed 101 A of a catalyst for the thermal -catalytic hydrocarbon pyrolysis, with a heat source 10 IB associated with the pyrolysis reactor.
  • the pyrolysis reactor may be of any suitable type, such as for example a packed bed, a fluidized bed, or a moving bed, containing the catalyst.
  • the pyrolysis reactor may include a vessel or housing of appropriate size, shape, orientation, and configuration for carrying out the pyrolysis reaction and other process operations therein.
  • the pyrolysis reactor may include a vertically extending cylindrical vessel containing a packed (fixed) bed of pyrolysis catalyst, or a bed of the pyrolysis catalyst adapted for fluidization during at least part of the process operations, or the pyrolysis reactor may be horizontally arranged, comprising a housing in which a moving bed of the pyrolysis catalyst is disposed for carrying out the pyrolysis and other process operations.
  • the pyrolysis reactor in various fluidizing embodiments may be vertically upwardly extending in conformation, and may be of a progressively upwardly reduced cross-sectional area, e.g., being tapered or upwardly stepwise reduced in cross-sectional area, or equipped with an outlet dip leg construction.
  • the pyrolysis reactor may be formed of any suitable material(s) of construction that are compatible with the pyrolysis reaction and other process operations therein.
  • the pyrolysis catalyst employed in the pyrolysis reactor may be of any suitable type appropriate to the thermocatalytic hydrocarbon pyrolysis and subsequent product recovery operations, and any associated catalyst activation, pre-activation, and reactivation process operations.
  • the pyrolysis catalyst may comprise a catalytic metal, in elemental, compound, or complexed form, such as a catalytic metal selected from the group consisting of iron, copper, molybdenum, nickel, cobalt, and any combination thereof.
  • the pyrolysis catalyst may be provided in a pre-catalyst form that is inactive or less active than the pyrolysis catalyst, and that is activated in situ in the pyrolysis reactor prior to conducting the pyrolysis reaction, or that is otherwise activated ex situ of the pyrolysis reactor prior to introduction or installation of the activated pyrolysis catalyst in the pyrolysis reactor.
  • the pyrolysis catalyst may comprise a supported pyrolysis catalyst, in which the pyrolysis catalyst is on and/or in a support, or otherwise is bound to, or coupled or associated with a support.
  • the support may be in any suitable form, and in various embodiments may for example comprise geometrically regular or irregular particles, plates, platelets, flakes, sheets, blocks, films, rods, cylinders, tubes, bars, layers, monoliths, and any combination thereof.
  • the support may be formed of any appropriate material that is non-deleterious to the pyrolysis catalyst and thermocatalytic pyrolysis operation for which the pyrolysis catalyst is employed, and stable (retaining its structural and functional integrity) at the conditions to which the supported catalyst is exposed in carrying out the thermocatalytic pyrolysis and associated operations to produce hydrogen and solid carbon in the methods of the present disclosure.
  • the support material may for example comprise metals, ceramics, metal oxides, and any combination thereof.
  • the support material may comprise cordierite, mullite, alumina, silica/alumina, silicon carbide (SiC), titania, silica, magnesia, zirconia, metal mesh, carbon, and any combination thereof.
  • the support may for example comprise a ceramic such as cordierite, titania, alumina, mullite, carbon/ceramic composite, SiC, or SiC/ceramic composite in a monolithic form.
  • cordierite comprises a mixture of components, including MgO, AI2O3 and SiCh.
  • the composition of cordierite is represented as MgO AhCh’SSiCh.
  • This cordierite composition MgO AhCh’SSiCh may be suitably tailored to have different molar ratios and starting raw material properties of magnesia, alumina, and silica to meet the performance targets for the substrate. Additionally, components such as talc, clay, kaolin, and raw alumina powder may also be used for cordierite preparation.
  • Monolithic compositions can include advantageous characteristics, such as, for example, wall thickness, porosity and pore size distribution suitable for ease of washcoat application and good washcoat adherence, and compatibility with washcoats, thereby facilitating application of pyrolysis catalysts to monolithic supports so that the pyrolysis catalyst is on and/or in the support monolith. Support monoliths may also be machined or otherwise prepared with fluid flow passages therein in which gas may be contacted with pyrolysis catalyst that is applied to the interior surfaces of such fluid flow passages.
  • the pyrolysis catalyst in various embodiments may be utilized in combination with any suitable catalyst promoters thereof, as appropriate to facilitate and enhance the catalytic pyrolysis, and the pyrolysis catalyst may additionally, or alternatively, be furnished in combination with any other components or compositions beneficial to the pyrolysis catalyst, or the operations of therm ocataly tic pyrolysis and/or recovery of hydrogen and solid carbon products, e.g., for example, release agents that facilitate disengagement of solid carbon from the pyrolysis catalyst (and/or its support, when the pyrolysis catalyst is associated with a support).
  • the heat source 10 IB associated with the pyrolysis reactor may comprise a heater or heat exchanger that is arranged to deliver heat to the pyrolysis catalyst and hydrocarbon feedstock in the interior volume of the pyrolysis reactor.
  • the heat source may comprise a thermal heating jacket overlying at least a portion of the exterior surface of the pyrolysis reactor and arranged to heat the pyrolysis reactor and its contents.
  • Such thermal heating jacket may in turn be overlaid with an insulative cover to minimize heat loss from the thermal heating jacket, so that the pyrolysis reactor operates adiabatically or otherwise at greater thermal efficiency.
  • the thermal heating jacket may comprise electrically resistive heating elements therein powered by a source of electrical energy, or the thermal heating jacket may be provided with heating fluid flow passages therein through which heating fluid flows to provide heat to the pyrolysis reactor.
  • the heat source may comprise a thermal heating jacket of the above-described general character that is provided on the interior wall surfaces of the pyrolysis reactor, with the insulative cover in contact with such interior wall surfaces, and with the interior surface of the thermal heating jacket in contact with the interior pyrolysis reaction volume so that the pyrolysis catalyst and hydrocarbon feedstock are heated by the thermal heating jacket.
  • the heat source in other embodiments may comprise electrical heating tapes applied to exterior surfaces of the pyrolysis reactor.
  • the heat source may comprise a heating coil disposed in the bed of pyrolysis catalyst, in which the heating coil provides an extended flow passage therein through which a heat exchange fluid may be introduced to deliver heat to the catalyst and hydrocarbon feedstock.
  • the heat source may comprise an infrared heater that is arranged to deliver infrared radiation to the interior volume of the pyrolysis reactor, or a microwave generator that is arranged to deliver microwave energy to the interior volume of the pyrolysis reactor.
  • the heat source may comprise heat pipes, or solar heating apparatus, or geothermal heat delivery circuitry.
  • the heat source in various other embodiments may comprise any of a wide variety of induction heaters, electrical heaters, gas combustion heaters.
  • the heating by the heat source may variously include conductive, convective, and radiative heating modes, and any combination thereof.
  • the pyrolysis reactor will be of suitable construction to accommodate the specific heat source or sources deployed for heating of the pyrolysis reactor.
  • the hydrocarbon feed is supplied from a hydrocarbon feed source 102 containing the hydrocarbon feedstock.
  • the hydrocarbon feed source 102 may for example comprise a tank, vessel, reservoir, or pipeline containing the hydrocarbon feedstock.
  • the hydrocarbon feedstock is flowed from the hydrocarbon feed source via suitable piping or flow circuitry to the hydrocarbon feedstock pretreatment facility 103, in which the hydrocarbon feedstock may be preliminarily treated for the subsequent pyrolysis operation, e.g., for removal of undesired components of such feedstock by unit operations such as phase separation (precipitation or condensation) of impurities, sorptive removal of undesired components by physical adsorption and/or chemisorption, gas/liquid contacting for impurity removal by a liquid scrubbing medium, etc., utilizing corresponding process apparatus and materials for such unit operations.
  • the hydrocarbon feedstock pretreatment facility additionally or alternatively comprise apparatus arranged to adjust pressure, flow rate, or other characteristics of the hydrocarbon feedstock to prepare it for the subsequent pyrolysis and product recovery operations.
  • the hydrocarbon feedstock is flowed by piping or flow circuitry to the hydrocarbon feed heater 104 to heat the hydrocarbon feedstock to temperature that may for example be in a range of from 20°C to 600°C, preferably in a range of from 100°C to 600°C, more preferably in a range of from 200°C to 600°C, and even more preferably in a range of from 250°C to 600°C, although the disclosure is not limited thereto.
  • the hydrocarbon feedstock as thus preheated is flowed by piping or flow circuitry to the pyrolysis reactor for contacting the pyrolysis catalyst in the catalyst bed 101A.
  • An oxidant gas supplied from oxidant gas source I l l is flowed by piping or flow circuitry to the pyrolysis reactor and is co-fed with the hydrocarbon feedstock to support sustained hydrogen production.
  • the hydrocarbon feedstock may be of any suitable type.
  • the hydrocarbon feedstock is a single hydrocarbon or a mixture of hydrocarbons such that it is in a gas phase at temperatures above 500°C.
  • the hydrocarbon feedstock comprises one or more of (a) an alkane with a molecular formula of C n H2n+2, where n is 1 to 4; (b) an alkene with a molecular formula of C n H2n, wherein n is 2 to 4; (c) an alkyne with a molecular formula of C n H2n-2, wherein n is 2 to 4; and any isomers thereof; and any combination thereof, including any isomers of such hydrocarbons having isomeric forms.
  • the hydrocarbon feedstock is at least predominantly comprised of methane (> 50 mol %), e.g., wherein the mol % of the methane in the hydrocarbon feedstock is at least one of 55, 60, 65, 70, 75, 80, 85, 90, 92, 94, 96, 98 and up to 100 mol % of the hydrocarbon feedstock.
  • the hydrocarbon feedstock is at least predominantly comprised of alkane(s) with a molecular formula of C n H2n+2, where n is 1 to 4, e.g., wherein the mol % of the alkane(s) in the hydrocarbon feedstock is at least one of 55, 60, 65, 70, 75, 80, 85, 90, 92, 94, 96, 98 and up to 100 mol % of the hydrocarbon feedstock.
  • the hydrocarbon feedstock is delivered to the pyrolysis reactor via a hydrocarbon gas feed characterized by a hydrocarbon flow rate.
  • the hydrocarbon gas feed additionally comprises one or more promotors.
  • the promoter is a chemical selected from the group consisting of hydrogen, steam, sulfur-containing compounds (e.g., thiophene), carbon monoxide, another hydrocarbon, and any combination thereof.
  • the promoter is another hydrocarbon
  • such another hydrocarbon is a chemical selected from the group consisting of: an alkane, C n H2n+2, wherein n is 1 to 4; an alkene C n H2n, wherein n is 2 to 4; an alkyne C n H2n-2, wherein n is 2 to 4; and any of isomer thereof; and any combination thereof.
  • the hydrocarbon gas feed comprises the hydrocarbon in the amount ranging from 20% to 100% by volume. In various embodiments, the hydrocarbon gas feed comprises the hydrocarbon in the amount ranging from 50% to 100% by volume. In various embodiments, the hydrocarbon gas feed comprises, in addition to the hydrocarbon, one or more promoters in the amount ranging from 0% to 10% by volume. In various embodiments, the hydrocarbon gas feed comprises, in addition to the hydrocarbon, one or more promoters in the amount ranging from 0% to 2% by volume.
  • the oxidant gas that is co-fed with the hydrocarbon gas to the pyrolysis reactor to extend the catalytic activity and sustain hydrogen production may for example comprise CO2, O2, H2O, and any combination thereof.
  • the oxidant gas comprises CO2.
  • the oxidant gas comprises CO2 and H2O.
  • Other oxidant gases may be employed in other embodiments in broad practice of the present disclosure.
  • Oxidant gas supplied from oxidant gas source 111 is co-fed to the pyrolysis reactor 101 via piping or flow circuitry, concurrently with feeding of the hydrocarbon feed to the pyrolysis reactor, to support the sustained hydrogen production and production of solid carbon product in the therm ocataly tic pyrolysis reaction.
  • Such therm ocataly tic pyrolysis reaction produces hydrogen and solid carbon product, and the process conditions in the pyrolysis reactor are controllably maintained by the gas flow throughput conditions so that a gas/solids product is produced in which solids comprise the solid carbon product in particulate or otherwise finely divided form.
  • the gas/solids product is discharged from the pyrolysis reactor in gas/solids product line 105 in which it flows to the gas/solids separator 106.
  • the gas/solids separator 106 may comprise any suitable gas/solids separation apparatus, such as a cyclone separator, a baghouse, a moving bed conveyor separator, an upflow depressurization chamber with upwardly increasing cross-sectional area so that solid carbon particles gravitationally disengage from the gas and fall to the bottom of the depressurization chamber for collection, an electrostatic separator imposing electrostatic charge on the solid carbon particles to aggregate and separate them from the gas, or any other gas/solids separation apparatus that is effective to recover the pyrolysis reaction product carbon solids from the gas/solids effluent discharged from the pyrolysis reactor.
  • a gas/solids separation apparatus such as a cyclone separator, a baghouse, a moving bed conveyor separator, an upflow depressurization chamber with upwardly increasing cross-sectional area so that solid carbon particles gravitationally disengage from the gas and fall to the bottom of the depressurization chamber for collection, an electrostatic separator imposing electrostatic charge on the solid carbon particles to aggregate and separate them
  • the gas/solids separator 106 separates the solid carbon-based product from the hydrogen-containing product gas, and the separated solid carbon-based product then is collected from the separator, e.g., in a solid carbon product collection vessel 107.
  • the solids-reduced hydrogen-containing product gas flows from the gas/solids separator 106 to the hydrocarbon feed heater, in which the hydrogen-containing product gas is heat exchanged with the hydrocarbon feed being supplied from the hydrocarbon feed source 102 following the hydrocarbon feed pretreatment in the hydrocarbon feed pretreatment apparatus, thereby reclaiming heat from the hydrogen-containing product gas to preheat the hydrocarbon feed in such heat exchange.
  • the heat exchanger may be of any suitable form and type. Alternatively, other types of heat reclamation may be employed in the process system to recover heat from the hydrogen-containing product gas, e.g., comprising thermal accumulators. Alternative, or additional, heating of the hydrocarbon feed may be employed, in which a portion of the hydrogen gas produced by the process system may be combusted to generate heat for heating of the hydrocarbon feed.
  • the hydrogen-containing product gas following the above-described heat exchange or heat recovery then is processed for purification of the hydrogen-containing product gas to yield purified hydrogen product gas.
  • Such purification may for example comprise flowing the hydrogen-containing product gas to a cooler 108 A to reduce temperature of the hydrogen-containing product gas to appropriate temperature for processing in a pressure swing adsorption (PSA) apparatus 108B to produce the purified hydrogen product gas.
  • PSA pressure swing adsorption
  • the PSA apparatus may be of single bed or multi-bed type, preferably comprising two or more adsorber vessels containing adsorbent beds for continuous purification operation, in which one or more of the multiple adsorbent beds is contacted with the hydrogen-containing product gas to remove non-hydrogen component(s) and produce the purified product hydrogen gas, while adsorbent beds previously loaded with adsorbent non-hydrogen component(s) in the cyclic PSA process undergo regeneration to discharge the removed non-hydrogen component(s) as desorbate, thereby renewing the adsorbent bed for subsequently resumed active adsorption duty in the cyclic PSA process.
  • At least one of the multiple adsorber vessels is onstream in active adsorption operation, while other(s) are being regenerated or have been regenerated and are in standby condition awaiting return to active onstream adsorption operation, so that each adsorber vessel undergoes alternating cyclic and repetitive operations of adsorption of non-hydrogen component(s) and subsequent regeneration to remove accumulated non-hydrogen component(s) resulting from preceding onstream adsorption operation.
  • the desorbate generated by the regeneration of the PSA adsorbent beds in the PSA apparatus may be recycled to the pyrolysis reactor to enhance overall system efficiency, while the purified hydrogen product gas is flowed to the high-purity hydrogen product collection vessel 109, or to other disposition or use.
  • the purification of the hydrogen-containing product gas to yield purified hydrogen product gas in other embodiments may involve only cooling in the cooler 108 A without any PSA purification, producing the hydrogen-containing product gas as a suitable low carbon fuel that may be used for applications such as power generation.
  • the hydrogen-containing product gas when purified may be purified by apparatus and processes other than pressure swing adsorption, such as wet scrubbing, dry scrubbing, membrane separation, etc.
  • a dislodging gas can be supplied from the dislodging gas source 110, which is fed to the pyrolysis reactor at sufficient volumetric flowrate together with the flows of gaseous hydrocarbon feed and oxidant gas feed, to achieve such disengagement and dislodge carbon from the pyrolysis catalyst surface.
  • the dislodging gas may be of any suitable type and may for example comprise inert gas selected from the group consisting of argon, nitrogen, helium, and any combination thereof.
  • the flow rate of the dislodging gas may be flow rate associated with a superficial gas velocity in a range of from 3 to 100 times the minimum fluidization velocity of the pyrolysis catalyst, so that the pyrolysis catalyst is fluidized and subjected to impact and shear and abrasion forces of particle-particle interaction in the fluidized state, as well as hydrodynamic entrainment by the fluidizing gases in the pyrolysis reactor.
  • the dislodging gas used to dislodge carbon from the catalyst surface may include inert gas and a dislodging promoter, such as for example a gas selected from the group consisting of hydrogen, steam, carbon monoxide, oxygen, and any combination thereof.
  • the dislodging promoter may comprise up to 20% by volume of the dislodging gas (inert gas + dislodging promoter), and in specific embodiments may be less than 5% of the volume of the dislodging gas, e.g., in a range of from 0.5% to 5% by volume of the dislodging gas.
  • the dislodging agent may comprise argon and steam, wherein steam comprises less than 3.1% by volume of the dislodging agent, e.g., 2.5% by volume of the dislodging agent.
  • the dislodging of the solid carbon from the pyrolysis catalyst may alternatively be carried out by disposing an array of impact targets in the pyrolysis reactor so that fluidized catalyst particles impact such targets so that solid carbon formed on the pyrolysis catalyst particles is dislodged by such impacts in the upward flow of the pyrolysis catalyst particles in the interior volume of the pyrolysis reactor.
  • Such impact targets may be of relatively small size and positioned in relation to one another so that multiple dislodgment impacts are achieved to release solid carbon from the pyrolysis catalyst particles.
  • the size, positioning, and configurational density of the impact targets is preferably of such character as to not significantly change the pressure drop characteristics of the pyrolysis reactor.
  • the impact targets may be of any suitable size, shape, and composition to provide the desired extent of impacts of pyrolysis catalyst thereon.
  • the impact targets may be in the form of spaced-apart wires extending between interior wall surfaces across the crosssection of the pyrolysis reactor, with such wires being provided at various elevational levels in the pyrolysis reactor interior volume, with wires in the respective elevational levels being offset or otherwise arranged in relation to one another to increase the extent of successive collisions in the various elevational levels.
  • the wires may be of sufficient diameter and spacing in relation to other wires so that negligible pressure drop is created by the successive elevational layers, and the wires may additionally be provided as electrical resistance heating wires, by connection to appropriate electrical circuitry and electrical power supply, so that such wires provide the dual function of enhancing the dislodgment of solid carbon from the pyrolysis catalyst particles and concurrently introducing heat in the interior volume of the pyrolysis reactor.
  • the impact targets may include bars, blocks, sheets, or other target forms.
  • the hydrocarbon pyrolysis process may be conducted so that hydrocarbon pyrolysis and solid carbon dislodging are continuously carried out.
  • the hydrocarbon pyrolysis may be carried out for a predetermined first time period or until solid carbon buildup of sufficient character occurs, followed by solid carbon dislodging operation in which a dislodging gas is introduced.
  • the hydrocarbon gas is fed to the pyrolysis reactor and catalytically pyrolyzed to produce a solid carbon product and hydrogen gas.
  • an oxidant is also co-fed with the hydrocarbon gas to extend the catalytic activity and sustain hydrogen production.
  • the flow rate of the hydrocarbon feed in the pyrolysis operation can be between 75 and 20,000 seem CH g of active catalyst, at the standard temperature of 0°C and the standard pressure of 1 atm.
  • the operating temperature of the pyrolysis reactor in the pyrolysis operation can be between 600 and l,000°C, although the disclosure is not limited thereto.
  • the previously described carbon dislodging operation may be conducted as a separate processing operation from the therm ocataly tic pyrolysis of the hydrocarbon gas, to clear the carbon from the active catalyst and to regain catalytic activity, e.g., by high velocity nonreactive gas introduction to facilitate the solid carbon dislodging from the active catalyst via mechanical shearing or abrasion.
  • high velocity refers to introducing a gas flow rate greater than 7 times the minimum fluidization velocity of the catalyst particles to promoter turbulent fluidization.
  • an oxidant such as O2, CO2, and H2O may also be introduced with the nonreactive gas to promote carbon dislodgement.
  • the previously described carbon dislodging operation may be conducted concurrently with therm ocataly tic pyrolysis of the hydrocarbon gas, either during the full extent of the therm ocataly tic pyrolysis operation, or otherwise in an intermittent or periodic manner during the therm ocataly tic pyrolysis operation.
  • the pyrolysis reactor is operated as a gas-solid fluidized bed where the pyrolysis catalyst can be solid fluidizable particles and the hydrocarbon and oxidant feed and product hydrogen are the fluidizing gas.
  • the particle size can be of any suitable character, e.g., in a range of from 20 microns to 3,000 microns, with a particle density in a range of from 100 to 4,000 kg/m 3 , and with a particle fluidization Geldart classification of Group A, B, or D.
  • Fluidized bed operation refers to the design of the reactor, and the flow rate of the gases flowed through the pyrolysis reactor, e.g., reactant gas, product gas, oxidant gas, dislodging gas, etc., being such that the pyrolysis catalyst particles in the pyrolysis reactor are subject to a gas velocity that is at or greater than the minimum fluidization velocity.
  • the fluidizing gas is fed from the bottom, or a lower portion, of the pyrolysis reactor, and the gas outlet is located generally above the fluidized bed of catalyst particles.
  • the cross-sectional area of the fluidized bed pyrolysis reactor decreases from the bottom to the top of the pyrolysis reactor in order for the reactor to increase the gas velocity to support solid carbon product entrainment in the gas stream that ultimately is discharged from the pyrolysis reactor outlet.
  • the change in cross-sectional area can be a gradual variation so that the pyrolysis reactor vessel wall is continuously upwardly tapered, or the pyrolysis reactor vessel wall may be configured with one or more step change(s), or a combination of such confirmations may be employed.
  • the cross- sectional area reduction can be achieved by utilizing a dip leg connected to the reactor gas outlet.
  • additional entrainment gas can be fed to the pyrolysis reactor to support the entrainment of solid carbon in the gas stream that ultimately is discharged from the pyrolysis reactor outlet.
  • the entrainment gas can consist of hydrocarbon reactant gas, oxidant, recycled product hydrogen, inert or noble gases, and any combination thereof.
  • the entrainment gas can be introduced at an elevation that is higher than that of the reactant gas stream fed to the pyrolysis reactor at a bottom portion thereof, but lower than the product gas outlet of the reactor.
  • the particle size and density of the pyrolysis catalyst are such that the catalyst particles can be categorized as Geldart Group B particles, and the associated gas velocity in the pyrolysis reactor may be between 3-7 times the minimum fluidization velocity of the catalyst particles during the pyrolysis operation.
  • the catalyst particles by way of example may be spherical in shape and comprise iron impregnated on an alumina support.
  • the reactant gas for the pyrolysis operation may comprise natural gas, primarily methane, with 1-10 vol% carbon dioxide as the oxidant.
  • the pyrolysis catalyst may comprise active catalyst metal selected from the group consisting of Fe, Ni, Mn, Gd, Mo, W, and any combination thereof.
  • the catalyst in various embodiments may be a supported catalyst, in which the support may comprise a ceramic, e.g., metal oxide, metal silicate, metal carbide, metal aluminate, and any combination thereof, and the support in various embodiments may contain an element selected from the group consisting of Al, Ca, Si, Ti, Mg, and any combination thereof.
  • the gas/solids separation of the gas/solids product discharged from the pyrolysis reactor may be performed using particulate filters comprised of ceramic, cloth, and/or high temperature polymers.
  • the gas/solids separation may be achieved using one or a series of cyclones, expansion/disengagement separators, or in combination with other methods for gas/solids separation.
  • a pressure swing adsorption (PSA) apparatus may be employed to purify the hydrogen product for use in downstream applications.
  • the off gas discharged from the PSA can be processed and recycled as the oxidant feed to the pyrolysis reactor.
  • CO X species and PF in the off gas can subjected to methanation reaction, and the resulting methane product stream can be circulated to the pyrolysis reactor to be pyrolyzed to H2 and solid carbon product to avoid potential gaseous carbon emissions.
  • the oxidant used during the hydrocarbon pyrolysis step is premixed with the gaseous hydrocarbon in the hydrocarbon feed pretreatment apparatus (103 in FIG. 1) and the resulting gaseous hydrocarbon/oxidant gas mixture is fed into the pyrolysis reactor.
  • the hydrocarbon to oxidant molar ratio in such pre-mixing pretreatment can be in a range of from 2 to 1000, but the disclosure is not limited thereto.
  • the oxidant serves to maintain the activity of the catalyst and thereby sustain hydrogen production during the pyrolysis step.
  • the oxidant can for example comprise CO2, H2O, O2, and any combination thereof.
  • the oxidant can be fed to the pyrolysis reactor as a separate, discrete stream as a point injection, or alternatively may be distributed axially and/or radially throughout the interior volume of the pyrolysis reactor.
  • the hydrocarbon to oxidant molar ratio for the total flow of oxidant can be in a range of from 2 to 1000, but the disclosure is not limited thereto.
  • the oxidant can be fed intermittently throughout the therm ocataly tic pyrolysis operation.
  • the average flow of oxidant in the therm ocataly tic pyrolysis operation maintains the hydrocarbon to oxidant molar ratio in a range of from 2 to 1000, but the disclosure is not limited thereto.
  • the pyrolysis reactor operates as a fixed bed reactor with the gas velocity being lower than the minimum fluidization velocity and/or the reactor being configured so that the reactant gas is delivered to the reactor at the top or upper portion thereof, and so that the gas outlet is located on the bottom or lower portion of the reactor.
  • the gas does not agitate the catalyst to create gas/solid fluidized bed behavior.
  • the oxidant in such embodiments can be co-fed with the hydrocarbon reactant in a combined stream, or the oxidant can be fed separately into the reactor. Similar to the oxidant feed, the reactant feed can be distributed radially and/or axially in the interior volume of the fixed bed pyrolysis reactor.
  • the heat required for the pyrolysis step in the pyrolysis reactor can be transferred from heat source (10 IB in FIG. 1).
  • the heat source comprises an external electric heating j acket that can heat the pyrolysis reactor to temperature in a range of from 500°C to 1000°C.
  • external thermal insulation comprising porous metal oxide ceramics can be used to reduce, and preferably eliminate, heat loss from the pyrolysis reactor.
  • the heat source can comprise an electric heating element placed inside the pyrolysis reactor to provide heat to the catalyst particles while minimizing heating the walls of the reactor. Internal thermal insulation comprising porous ceramic metal oxides can be used to minimize, and preferably eliminate, heat loss from the pyrolysis reactor.
  • the heat source can be a heat exchanger in which high temperature fluid is used to heat the pyrolysis reactor.
  • the high temperature fluid can comprise a combustion product of hydrogen, methane, and/or other hydrocarbons and air species such as oxygen and nitrogen.
  • the hydrocarbon or hydrogen combustion can occur directly in the heat source to provide additional radiative heat transfer to the pyrolysis reactor.
  • the heat exchanger for the heat source can be placed around the pyrolysis reactor, in the pyrolysis reactor, or a combination thereof.
  • the heat source and thermal insulation can be placed externally around the pyrolysis reactor.
  • the pyrolysis reactor material of construction can for example comprise high nickel metal alloy capable of sustaining a 600-1000°C operating temperature of the pyrolysis reactor.
  • the thermal insulation and heat source can be placed internally in the pyrolysis reactor, and the reactor material of construction can comprise lower grade iron alloys such as various types of carbon steel.
  • Methane pyrolysis was performed using Fe/AhCE as the catalyst.
  • a high porosity cordierite monolith with 400 cells per square inch (CPSI) and 3 mils wall thickness was used as the substrate for the catalyst.
  • Small cylindrical cores (approximately 1.5 in. length and 0.75 in. diameter) were extracted from the full-sized monolith. Cores were pre-dried at 120°C in air for at least 12 hours. Each core was then washcoated with a layer of Fe/AhCE. The washcoated cores were cured overnight at 120°C in air to thermoset the washcoated material and then the washcoated cores were calcined at 550°C.
  • the catalyst was tested in a laboratory fixed bed reactor system for methane pyrolysis at two different temperatures: (a) 750°C (Test 1) and (b) 850°C (Test 2). Feed consisted of 34 seem of methane, with the balance being argon. The reaction was run for 180 minutes, with a space velocity of 200 seem CH g Fe, using 10% Fe/ALCE (wt.%).
  • Test 3 was performed at 850°C, using a lower space velocity.
  • Feed consisted of 40 seem of methane, with balance being argon. The reaction was run for 180 minutes, with a space velocity of 100 seem CH g Fe, using 23% Fe/ALCE (wt.%). [00117] The results are shown in FIG. 3. A decrease in space velocity led to a drastic increase in methane conversion. Both Tests 2 and 3 showed a drop in methane conversion after 80 minutes of operation, signifying catalyst deactivation. After 180 minutes, Test 3 showed higher methane conversion than Test 2.
  • Test 4 was performed at 850°C like Tests 2 and 3. Feed for Test 4 consisted of 27 seem of methane, 5 seem of CO2, with the balance being argon. The reaction was run for 180 minutes, with a space velocity of 200 seem CH g Fe, using 10% Fe/AhCh (wt.%).
  • Test 5 was performed at 850°C like Tests 2, 3 and 4. Feed for Test 5 consisted of 43 seem of methane, 8 seem of CO2, with the balance being argon. The reaction was run for 180 minutes, with a space velocity of 100 seem CH g Fe, using 25% Fe/AhCh (wt.%).
  • Test 5 was performed for 4 cycles using the schedule shown in FIG. 6. Methane conversion was unchanged for the 4 cycles as shown in FIG. 7.
  • Example 5 Methane Conversion in Fluidized Bed with In-Situ Carbon Removal
  • the addition of CO2, O2, and H2O to the CH4 feed was tested to determine corresponding methane conversion, and the amount and quality of solid carbon that was produced.
  • FIGS. 10 and 11 show the results of a 5% CO2 co-feed on cyclic operation in the fluidized bed, although the same benefits were also seen with the monolith reactor.
  • the catalyst for the fluidized bed reactor was prepared by incipient wetness impregnation, and consisted of 4.8 wt.% Fe on 9-alumina 300pm-diameter beads.
  • FIG. 13 SEM images of the beads after the 3-cycles experiments with CO2 co-feed are shown in FIG. 13.
  • the surface of the beads with 0% CO2 co-feed appeared free of carbon, while a considerable amount of carbon was present in all the other cases, likely due to the larger amount produced.
  • Enlarged images of the beads are additionally shown in FIG. 13, where it is also possible to observe the carbon layer peeling off from the beads.
  • FIGS. 14 and 15 include SEM images of the carbon with increasing magnifications. In all cases, bamboo-like carbon fibers of various diameters appear to be the prevailing product.
  • Example 6 Dislodging Flowrate and Use of Alumina Beads for Gas Distribution
  • a smaller dislodging flowrate was used, namely a maximum ⁇ 1.5 standard liters per minute (slm) Ar rather than 3 slm Ar, and SSO-pm-dia.-AhCE beads were used for the gas distribution instead of SiC grit.
  • slm standard liters per minute
  • SSO-pm-dia.-AhCE beads were used for the gas distribution instead of SiC grit.
  • FIG. 16 for fluidized bed operation at 750°C with 5 wt.% Fe/AhCE, 5 vol.
  • a 3 -cycles experiment with water in the reactor co-feed was conducted to determine if results could be obtained favorable to those achieved in production of carbon nanotubes (CNTs) by chemical vapor deposition in the presence of water.
  • the 3 -cycle experiment was performed at 850°C with ⁇ 2 vol. % H2O co-feed during pyrolysis and compared to corresponding operation without the presence of water.
  • the catalyst was 4.8 wt.% Fe on 9- alumina 300pm-dia. beads, and the following conditions were used: reduction in 500 seem H2 for 10 minutes; pyrolysis reaction in 300 seem CH4, 50 seem N2 and variable amount of H2O for 14 minutes; carbon dislodging in 3000 seem Ar and 80 seem H2O for 10 minutes.
  • the material in the filter was shown to be 69% carbon through TGA, a 9% increase from the case of only carbon dioxide co-feed.
  • the material collected on the reactor walls was measured to be 81% carbon, and possibly unable to fluidize from the reactor due to wall effects. It was also observed in the fluidized bed reactor operation that small amounts of carbon were able to be conveyed out of the reactor on their own during the pyrolysis phase with the dual co-feed, further signifying a shift in the carbon morphology and fluidization properties.
  • the carbon collected was of very high quality compared to carbon produced from a pure methane feed or a 5% CO2 co-feed.
  • PSA pressure swing adsorption
  • the process and apparatus of the present disclosure are advantageously employed to catalytically pyrolyze gaseous hydrocarbon to produce hydrogen and solid carbon, utilizing oxidant addition to the gaseous hydrocarbon before or during catalytic pyrolysis.
  • the oxidant may be or include CO2, O2, H2O and combinations thereof.
  • the pyrolysis catalyst can be provided on a support, for use in reactors such as bed reactors, fluidized bed reactors, or moving bed reactors, to carry out the catalytic pyrolysis reaction in an efficient and cost-effective manner.
  • the gaseous hydrocarbon may be or comprise an alkane, alkene, or alkyne, and may for example comprise methane in various implementations.
  • the catalytic pyrolysis can be carried out with solid carbon depositing on the pyrolysis catalyst being dislodged with dislodging gas, e.g., inert gas containing a dislodging promoter such as hydrogen, steam, carbon monoxide, oxygen, or any combination thereof.
  • dislodging gas e.g., inert gas containing a dislodging promoter such as hydrogen, steam, carbon monoxide, oxygen, or any combination thereof.

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Abstract

Un processus est décrit pour la pyrolyse catalytique d'hydrocarbures, dans lequel un hydrocarbure gazeux est pyrolysé catalytiquement pour produire de l'hydrogène et du carbone solide, un oxydant étant ajouté à l'hydrocarbure gazeux avant ou pendant la pyrolyse catalytique. Le procédé peut être mis en œuvre dans un système comprenant un réacteur de pyrolyse contenant un catalyseur de pyrolyse efficace pour la pyrolyse d'hydrocarbures et comprenant une entrée de gaz et une sortie de produit de pyrolyse catalytique, avec une source de chaleur de réacteur, une source d'alimentation en hydrocarbures et des composants de source de gaz oxydant associés, pour produire de l'hydrogène et du carbone solide en tant que gaz contenant de l'hydrogène contenant des particules de carbone solide à l'intérieur de celui-ci, qui peut être traité pour récupérer les particules de carbone solide et fournir de l'hydrogène purifié à utiliser.
PCT/US2025/026512 2024-04-26 2025-04-25 Utilisation d'oxydants pour la production stable d'hydrogène et de carbone à haute valeur à partir de pyrolyse d'hydrocarbures Pending WO2025227115A1 (fr)

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Citations (6)

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Publication number Priority date Publication date Assignee Title
US2749287A (en) * 1952-10-03 1956-06-05 Exxon Research Engineering Co Reactivation of hydroforming catalysts using dry air
US4064018A (en) * 1976-06-25 1977-12-20 Occidental Petroleum Corporation Internally circulating fast fluidized bed flash pyrolysis reactor
US4637995A (en) * 1985-03-18 1987-01-20 Corning Glass Works Preparation of monolithic catalyst supports having an integrated high surface area phase
US20120279522A1 (en) * 2010-01-26 2012-11-08 Varrin Jr Robert D Method and composition for removing deposits
US20160016794A1 (en) * 2013-03-15 2016-01-21 Seerstone Llc Methods of producing hydrogen and solid carbon
US20190055173A1 (en) * 2017-08-21 2019-02-21 Palo Alto Research Center Incorporated System and method for pyrolysis using a liquid metal catalyst

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2749287A (en) * 1952-10-03 1956-06-05 Exxon Research Engineering Co Reactivation of hydroforming catalysts using dry air
US4064018A (en) * 1976-06-25 1977-12-20 Occidental Petroleum Corporation Internally circulating fast fluidized bed flash pyrolysis reactor
US4637995A (en) * 1985-03-18 1987-01-20 Corning Glass Works Preparation of monolithic catalyst supports having an integrated high surface area phase
US20120279522A1 (en) * 2010-01-26 2012-11-08 Varrin Jr Robert D Method and composition for removing deposits
US20160016794A1 (en) * 2013-03-15 2016-01-21 Seerstone Llc Methods of producing hydrogen and solid carbon
US20190055173A1 (en) * 2017-08-21 2019-02-21 Palo Alto Research Center Incorporated System and method for pyrolysis using a liquid metal catalyst

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