[go: up one dir, main page]

WO2001014702A1 - Low power compact plasma fuel converter - Google Patents

Low power compact plasma fuel converter Download PDF

Info

Publication number
WO2001014702A1
WO2001014702A1 PCT/US2000/040677 US0040677W WO0114702A1 WO 2001014702 A1 WO2001014702 A1 WO 2001014702A1 US 0040677 W US0040677 W US 0040677W WO 0114702 A1 WO0114702 A1 WO 0114702A1
Authority
WO
WIPO (PCT)
Prior art keywords
plasma
fuel converter
plasma fuel
converter
fuel
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.)
Ceased
Application number
PCT/US2000/040677
Other languages
French (fr)
Inventor
Alexander Rabinovich
Leslie Bromberg
Daniel R. Cohn
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.)
Massachusetts Institute of Technology
Original Assignee
Massachusetts Institute of Technology
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 Massachusetts Institute of Technology filed Critical Massachusetts Institute of Technology
Priority to CA002391851A priority Critical patent/CA2391851A1/en
Priority to JP2001518551A priority patent/JP2003507321A/en
Publication of WO2001014702A1 publication Critical patent/WO2001014702A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/06—Combination of fuel cells with means for production of reactants or for treatment of residues
    • H01M8/0606—Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants
    • H01M8/0612—Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants from carbon-containing material
    • 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
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J19/087—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy
    • B01J19/088—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges
    • 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
    • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
    • C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
    • C01B3/342—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents with the aid of electrical means, electromagnetic or mechanical vibrations, or particle radiations
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B43/00—Engines characterised by operating on gaseous fuels; Plants including such engines
    • F02B43/10—Engines or plants characterised by use of other specific gases, e.g. acetylene, oxyhydrogen
    • 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
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0803—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy
    • B01J2219/0805—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges
    • B01J2219/0807—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges involving electrodes
    • B01J2219/0809—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges involving electrodes employing two or more electrodes
    • 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
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0803—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy
    • B01J2219/0805—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges
    • B01J2219/0807—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges involving electrodes
    • B01J2219/0824—Details relating to the shape of the electrodes
    • B01J2219/0826—Details relating to the shape of the electrodes essentially linear
    • B01J2219/0828—Wires
    • 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
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0873—Materials to be treated
    • B01J2219/0881—Two or more materials
    • B01J2219/0883—Gas-gas
    • 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
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0873—Materials to be treated
    • B01J2219/0892—Materials to be treated involving catalytically active material
    • 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
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0894—Processes carried out in the presence of a plasma
    • 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
    • C01B2203/0205—Processes for making hydrogen or synthesis gas containing a reforming step
    • C01B2203/0227—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step
    • C01B2203/0233—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step the reforming step being a steam reforming 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
    • C01B2203/02—Processes for making hydrogen or synthesis gas
    • C01B2203/025—Processes for making hydrogen or synthesis gas containing a partial oxidation 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
    • C01B2203/02—Processes for making hydrogen or synthesis gas
    • C01B2203/0283—Processes for making hydrogen or synthesis gas containing a CO-shift step, i.e. a water gas shift 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
    • C01B2203/06—Integration with other chemical processes
    • C01B2203/066—Integration with other chemical processes with fuel cells
    • 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
    • C01B2203/08—Methods of heating or cooling
    • C01B2203/0805—Methods of heating the process for making hydrogen or synthesis gas
    • C01B2203/0811—Methods of heating the process for making hydrogen or synthesis gas by combustion of fuel
    • C01B2203/0816—Heating by flames
    • 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
    • C01B2203/08—Methods of heating or cooling
    • C01B2203/0805—Methods of heating the process for making hydrogen or synthesis gas
    • C01B2203/0838—Methods of heating the process for making hydrogen or synthesis gas by heat exchange with exothermic reactions, other than by combustion of fuel
    • C01B2203/0844—Methods of heating the process for making hydrogen or synthesis gas by heat exchange with exothermic reactions, other than by combustion of fuel the non-combustive exothermic reaction being another reforming reaction as defined in groups C01B2203/02 - C01B2203/0294
    • 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
    • C01B2203/08—Methods of heating or cooling
    • C01B2203/0805—Methods of heating the process for making hydrogen or synthesis gas
    • C01B2203/085—Methods of heating the process for making hydrogen or synthesis gas by electric heating
    • 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
    • C01B2203/08—Methods of heating or cooling
    • C01B2203/0805—Methods of heating the process for making hydrogen or synthesis gas
    • C01B2203/0861—Methods of heating the process for making hydrogen or synthesis gas by plasma
    • 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
    • C01B2203/08—Methods of heating or cooling
    • C01B2203/0805—Methods of heating the process for making hydrogen or synthesis gas
    • C01B2203/0866—Methods of heating the process for making hydrogen or synthesis gas by combination of different heating methods
    • 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
    • C01B2203/08—Methods of heating or cooling
    • C01B2203/0872—Methods of cooling
    • C01B2203/0883—Methods of cooling by indirect heat exchange
    • 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
    • C01B2203/1005—Arrangement or shape of catalyst
    • C01B2203/1023—Catalysts in the form of a monolith or honeycomb
    • 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
    • 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
    • C01B2203/12—Feeding the process for making hydrogen or synthesis gas
    • C01B2203/1276—Mixing of different feed components
    • 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
    • C01B2203/16—Controlling the process
    • C01B2203/1604—Starting up the process
    • 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
    • C01B2203/16—Controlling the process
    • C01B2203/1642—Controlling the product
    • C01B2203/1671—Controlling the composition of the product
    • C01B2203/1676—Measuring the composition of the product
    • 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
    • C01B2203/16—Controlling the process
    • C01B2203/1695—Adjusting the feed of the combustion
    • 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
    • C01B2203/80—Aspect of integrated processes for the production of hydrogen or synthesis gas not covered by groups C01B2203/02 - C01B2203/1695
    • C01B2203/82—Several process steps of C01B2203/02 - C01B2203/08 integrated into a single apparatus
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/30—Use of alternative fuels, e.g. biofuels

Definitions

  • This invention relates to a plasma fuel converter and more particularly to a low power compact plasma fuel converter employing high voltage and low current.
  • Plasma fuel converters such as plasmatrons reform hydrocarbons to produce a hydrogen rich gas.
  • DC arc plasmatrons have received particular attention in the prior art. See, for example, U.S. Patent Nos. 5,425,332 and 5,437,250.
  • DC arc plasmatrons typically operate at low voltage and high current. By operating at high currents and lower voltages, the arc current is high enough that precautions are required to minimize electrode erosion and even melting. High flow rates of cooling water are required to keep the erosion in check. Air flow is required to simultaneously center the discharge on the cathode tip (made of hafnium or other specialized material, embedded in a copper plug) and to move the root of the arc at the anode to minimize erosion at the anode.
  • a constriction is also required to increase the impedance of the discharge (i.e., to operate at high voltages and lower currents than free-flowing arcs).
  • the air flows and the constriction are likely to require operation at elevated pressure (as much as 0.5 bar above ambient pressure), and thus a compressor is likely to be required. Even with these precautions, it is often difficult to extend the lifetime of the electrodes beyond approximately 1,000 hours of operation.
  • DC plasmatrons also require relatively sophisticated power supplies for stabilization of the arc discharge. Further, DC plasmatrons have a limited capability for low power operation. In some reforming applications, the minimum operating power can be significantly greater than needed resulting in unnecessary power loss. DC arc plasmatrons are typically operated at power levels of one kilowatt or more.
  • the plasma fuel converter of the invention includes an electrically conductive structure forming a first electrode A second electrode is disposed to create a gap with respect to the first electrode in a reaction chamber A fuel air mixture is introduced into the gap and a power supply connected to the first and second electrodes provides voltage in the range of approximately 100 volts to 40 kilovolts and current in the range of approximately 10 milhamperes to one ampere to generate a discharge to reform the fuel
  • the discharge can be a "glow type" discharge, a silent discharge and/or a breakdown discharge
  • a preferred range for voltage is 200 volts to 20 kilovolts
  • the plasma fuel converter includes a reaction extension region to increase residence time in a high temperature zone An insert in the reaction extension region and in the reaction chamber is provided to increase the temperature of operation The insert may be metallic or ceramic A heat exchanger may also be provided to decrease power needed from the power supply
  • the power supply be a current controlled, high voltage power supply such as a power supply including a saturable inductor to limit current
  • the saturable inductor power supply may be a neon transformer power supply
  • the fuel-air mixture is selected for operation between stoichiomet ⁇ c partial oxidation and full combustion depending on conditions and applications
  • An additional power supply may be provided for simultaneous operation in a low voltage, high current DC arc mode and a high voltage, low current glow discharge mode
  • the plasma fuel converter may include a plurality of plasma regions to increase hydrogen generation rate
  • the hydrogen rich gas output of the plasma fuel converter may be brought into contact with a catalyst such as for nitrogen oxide catalyst regeneration
  • the plasma fuel converter of the invention reduces or removes the disadvantages associated with DC arc plasmatrons known in the prior art
  • the disadvantages are overcome by the specially controlled high voltage, low current plasma fuel converter operation
  • the voltage and current vary over time in such a manner as to limit the current flowing in the plasma
  • the elect ⁇ cal characteristics of the plasma operation are a voltage range from a few hundred volts and up to 40 kilovolts, and a current range from 10 milhamperes to hundreds of milhamperes
  • the corresponding ranges for DC arc plasmatron fuel reformers are a voltage of around 100 volts and currents starting at 3-5 amperes
  • a representative high voltage, low current discharge of the plasma fuel converters of the invention has "glow discharge" type features Typically, this type of atmospheric pressure, high voltage, low current discharge can be made to operate at tens to hundreds of watts of average power
  • DC arc plasmatrons known m the prior art are typically operated at power levels of one kilowatt or more
  • Neon transformer power supplies use a saturable inductor to limit the current to a relatively low value, on the order of tens to hundreds of milhamps
  • Such power supplies are also capable of producing open circuit voltages of tens of kilovolts
  • the capacitive-based power supply delivers a high voltage, short pulse that breaks down the electrode-to- electrode gap and results in a discharge This breakdown phase is followed by a lower voltage, lower power discharge Most of the energy is delivered during the relatively long low voltage, low power part of the discharge The energy delivered per pulsed discharge is small, on the order of tens of millyoules Average power levels are typically around a few watts which is generally too low for hydrogen production applications
  • the power that is provided by the discharge can be on the order one-tenth of the minimum power of a compact DC arc plasmatron known in the prior art
  • the reformer of the invention is therefore appropriate for low hydrogen production rates where it provides enough power to increase substantially the enthalpy of the reactants Such low rates may be appropriate for some applications, such as catalyst regeneration
  • High hydrogen production rates are possible by using multiple units
  • a further increase in hydrogen production rate is possible by increasing the air/fuel ratio and the fuel throughput
  • the low power, high- voltage low-current plasma is used as an expanded volume igniter and a source of radicals to enhance the partial oxidation reaction with the necessary enthalpy increase provided by other means
  • These other means include air-fuel chemical reactions and/or heat provided by a heat exchanger
  • substantially all of the enthalpy (at least 80% and preferably 90% or more) is provided by these other means This mode of operation makes possible higher hydrogen production rates than would otherwise be allowed by constrain
  • the partial oxidation reaction with additional oxygen (. e , partial oxidation with an oxygen-to-fuel ratio greater than that for stoichiomet ⁇ c partial oxidation)
  • the oxygen is generally provided by additional air
  • the hydrogen yield (defined as the fraction of the hydrogen in the fuel that is released m the process) is reduced, but the elect ⁇ cal power requirement is decreased
  • the partial oxidation reaction is facilitated by fully oxidizing a fraction of the fuel and partially oxidizing the rest of the fuel
  • the additional required fuel does not impact substantially the overall fuel efficiency
  • the reduced power requirements for the plasma coupled with a much longer lifetime of the electrodes and a much simpler overall system reduces the complexity and cost of the
  • the power to the plasmatron is adjusted by changing the frequency of operation of the power supply
  • dielectrics cover one or both of the electrode surfaces so that microdischarges are generated across the gas It is also preferred that the fuel and air be introduced in a region such that the flow carries the reagents to a region close to the discharge.
  • Fig 1 is a cross-sectional view of a high voltage, low current discharge plasma fuel converter according to the invention.
  • Fig. 2 is such a plasma fuel converter including a reaction extension cylinder
  • Fig 3 is a cross-sectional view of a high voltage, low current glow-discharge plasmatron with thermal insulation
  • Fig 4 is a cross-sectional view of a high voltage, low current glow-discharge plasmatron including a heat exchanger.
  • Fig 5 is a cross-sectional view of another glow-discharge plasmatron with a heat exchanger.
  • Fig 6 is a circuit diagram of a high voltage, low current microplasmatron connected to a power supply with one grounded electrode.
  • Fig 7 is a circuit diagram of a high voltage, low current microplasmatron connected to a power supply with both electrodes connected to the microplasmatron.
  • Fig. 8 is a circuit diagram of a high voltage, low current microplasmatron connected to a power supply with a single electrode connected to the microplasmatron.
  • Fig 9 is a cross-sectional view of the a plasmatron of the invention using a conventional spark plug as one of the electrodes.
  • Fig. 10 is a cross-sectional view of an embodiment with dielectric covering on the electrodes.
  • Fig. 11 is a cross-sectional view of an embodiment of the invention employing a f ⁇ t.
  • Figs. 12 and 13 are cross-sectional views of other embodiments of the invention.
  • Fig. 14 is a cross-sectional view of an embodiment of the invention employing a heat exchanger and a water-shift reactor.
  • Figs. 15 and 16 are cross-sectional views of embodiments of the invention with electrically heated reaction extension zones.
  • a plasma fuel converter 10 includes a conductive structure 12 and an electrode 14.
  • the conductive structure 12 and the electrode 14 form a gap 16 within a reaction chamber 18.
  • An air fuel mixture is introduced into the reaction chamber 18 through a conduit 20 which results in a radial introduction.
  • a discharge 22 occurs across the gap 16.
  • the energy in the discharge 22 serves to reform the fuel portion of the air- fuel mixture to generate hydrogen rich gas.
  • the electrode 14 is electrically isolated from the conductive structure 12 by an insulator 24.
  • Figure 2 shows the embodiment of Fig. 1 but including a reaction extension cylinder 26 which increases the residence time of the reactants in the high temperature zone thereby increasing the hydrogen rich gas yields. It is possible to increase yields further by minimizing heat losses downstream from the plasma discharge 22. As shown in Fig. 3, minimizing heat losses can be achieved by the use of a thermal shield 28 in the region immediately downstream from the plasma and in the reaction extension cylinder 26 that is further downstream.
  • the thermal shield 28 may be a thin metallic barrier with low thermal capacity (and therefore short thermal response time) to minimize radiation losses.
  • the thermal shield 28 may be a ceramic barrier having low thermal conductivity but with increased thermal capacity and therefore increased thermal response time.
  • a compact heat exchanger 30 can be used to preheat part of the air and/or part of the fuel in a counter- flow heat exchanger configuration.
  • Fig. 6 shows one circuit arrangement.
  • a saturable core transformer 32 draws power from power mains 34, which can carry either AC or DC current.
  • the AC power can be obtained from a conventional AC power source, or it can be generated from DC (for example, onboard vehicles) by the use of a DC-AC converter.
  • the saturable core transformer has one grounded electrode 36 and another electrode 38 is connected to the electrode 14 of the plasmatron 10.
  • the conductive structure 12 of the plasmatron 10 is also grounded.
  • Another circuit arrangement is shown in Fig. 7 in which both power supply 32 electrodes 36 and 38 are connected to the plasmatron 10.
  • a second method is by operating a number of plasma fuel converter units in either a parallel or a series configuration, increasing the power by increasing the number of units operating.
  • a third method of adjusting the power is by changing the frequency of operation of the power supply.
  • the power to the plasma discharges is time varying. The higher power occurs at the discharge initiation time, when the voltage is very high and the current low, and during which gas breakdown occurs. At this time, the high voltage generates relatively energetic electrons that very efficiently generate radicals and efficiently couple their energy into the gas, with minimal voltage drops (sheaths) near the electrodes. The power decreases as the discharge approaches the glow-like regime. Frequencies as high as 100-200 kHz and even higher can be achieved using state of the art solid state components, such as IGBT's.
  • the frequency of a resonant inverter can be controlled and by simply varying the frequency, the power can be altered.
  • Fig. 9 is a schematic of the experimental plasmatron 10.
  • One electrode of a conventional spark plug 40 was used in these experiments as the electrode 14.
  • the other electrode is a steel tube 42 which is maintained at ground potential (the ground electrode from the spark plug 40 has been removed).
  • This experimental plasmatron was operated with gasoline in the high voltage-low current mode of the invention.
  • the power supply was a saturable transformer (neon transformer). Two such units, of 50 watts each, were connected in parallel.
  • the actual power input into the plasmatron 10 may actually be less than 100 watts.
  • the power supply was AC, operating at line frequency.
  • the plasmatron was connected to a conventional reaction extension cylinder 26 to increase the residence time and increase conversion efficiency.
  • the present invention may also be very useful for operation at higher pressures.
  • High pressure increases the required voltages for both breakdown and for glow discharge sustenance.
  • High pressure operation with low voltage DC arc plasmatrons is very difficult, due to very high electrode wear.
  • the high voltage, low current operation of the plasmatron removes this difficulty.
  • the increased voltage with increasing pressure at some point requires sophisticated high voltage insulators and feedthroughs.
  • a possible application could be hydrogen addition in gas turbines, injecting the hydrogen rich gas downstream from the turbine compressor at or before the main fuel injection. This could have the benefit of extending the lean burn limit of the turbine, further decreasing the emissions and possibly increasing the turbine efficiency.
  • the type of electrical power supply that is being considered can be combined with a conventional DC arc power supply.
  • the neon transformer power supply can be used to stabilize the arc and during transients, such as start up, power variations or variations, in throughput through the plasma of fuel, air or other flows.
  • the requirements on stability that are imposed on the DC power supply can be eliminated, making it cheaper.
  • One possibility is to use a plasmatron that is connected directly to a rotating generating unit (such as an automobile generator) to provide the bulk of the power, and then to utilize the other power supply to provide the stabilization and the turn-on requirements.
  • the plasmatron With either power supply on.
  • the DC plasmatron power When the DC plasmatron power is on, it operates at high power, while when operating in the glow-like mode with the DC plasmatron power supply not providing any electricity, it operates at low power.
  • a large dynamic variation of power from tens of watts to 1-2 kW can be achieved in this manner.
  • This dynamic range can be used for load following of the engine, or for a different mission
  • the gas throughputs required for engine exhaust catalyst regeneration can be substantially lower than the throughputs required for hydrogen additive operation or cold start In this manner, if the momentary hydrogen requirements call for small throughput, the plasma fuel reformer can operate in a glow-like discharge mode, while for higher hydrogen requirements, it can operate in a combination of both modes
  • Each high voltage, low current glow-discharge plasmatron may operate with only about 100 watts It is possible to increase the power by placing several high voltage, low current discharges in the plasma fuel reformer
  • the high voltage, low current glow-discharge plasma sources can be connected to a single power supply, either in a series or in a parallel configuration
  • the preferred embodiment is for each high voltage, low current glow plasmatron to be connected to its own power supply
  • applications include cold start emissions reduction m spark ignition internal combustion engines and nitrogen oxides reduction during the entire driving cycle
  • Other applications include hydrogen production for diesel engines, fuel cells and gas turbines, and for small hydrogen sources for industrial applications
  • the stand alone, low power, low current plasma fuel converter devices may be particularly useful for small power engines (with generated power levels m the 1-40 kW range)
  • oxygen concentration of the reformate is very low, usually less than 1%. Higher concentrations in the reformate indicate poor reforming. Oxygen detection, by the use of conventional oxygen sensors can therefore be used to monitor the reforming process and to control the plasmatron operation (power and oxygen/fuel ratio).
  • the operation of the plasmatron in the high- voltage low current mode allows operation of the fuel reformer at high pressures.
  • upstream air and fuel compressors are needed (which, for the case of a turbine driven by hydrogen-rich gas, are built into the system).
  • mixing downstream from the plasmatron In order to maximize the throughput and the conversion yield of hydrocarbon into hydrogen, it is attractive to introduce mixing downstream from the plasmatron. In this way the size and number of pockets that are either of elevated or reduced (with respect to the average) hydrocarbon content are substantially decreased, allowing for higher yield of hydrogen and decreased energy consumption.
  • a frit 52 or comparable material consisting of increased surface area
  • the frit 52 can be either a conventional frit that is used just to increase the mixing, or it can be made of a material that provides a catalytic reaction. In the latter case, the frit 50 is made of a catalytic material on a substrate, such as nickel catalyst on an alumina substrate (ideal for steam reforming).
  • the preferred method of air injection is to inject some of the air upstream from the plasma. Some of the fuel can be injected into the discharge either prior to the plasma, which is the preferred method for the case of the low power plasma fuel converter (or downstream from the plasma for the high power DC arc plasma fuel converter described in previous patents and patent applications of the present inventors). This is done in order to prevent soot formation across the small cathode- anode gap.
  • the flow is such that the flame propagates in the same direction as the bulk air flows.
  • the flame propagates at least partially against the main direction of the flow. Having the flow be in the same direction as the flame results in more stable reforming.
  • the desired flame and flow pattern in the present invention is achieved by having a small region where some or all of the air, and some, all or none of fuel are introduced, upstream from the discharge, and having a region of expansion where the air/fuel mixture propagates at much reduced velocity because of the increased cross section of the expansion region.
  • the expansion region can be followed by a reaction extension region that increases the residence time in the plasma fuel converter. Both the expansion region as well as the reaction extension region are well insulated thermally to minimize enthalpy loss, increasing the yield of hydrogen rich gas.
  • Figs 12 and 13 illustrate preferred embodiments with respect to air/fuel flow
  • Air and fuel 54 are introduced into the region of the discharge 22 and pass into an expanded region 56
  • air and fuel 54 are introduced alongside the electrode 14 m the vicinity of the discharge 22 and proceeds into the expanded region 56
  • the reaction occurs at oxygen-to-carbon ratios of 1 2-2 5 Under these conditions, the product gas has a substantial water content This water (or steam) can be used to increase the hydrogen production rates by changing (shifting) the carbon monoxide produced in the partial oxidation reaction to hydrogen by a water-gas shift reaction
  • Fig 14 illustrates the addition of a heat exchanger and a water-shift catalytic reactor
  • a heat exchanger 60 is placed downstream from the reaction extension cylinders 26 to decrease the reformate temperature before entry into a water-shift catalytic reactor 62 so as to increase the hydrogen concentration in the reformate
  • the water-shift catalytic reactor includes a suitable catalyst 63 to promote the water-shift reaction
  • the embodiment of Fig 14 both increases hydrogen concentration and decreases unwanted carbon monoxide
  • electrically heated walls 64 are energized through electrical leads 66 and 68 with high temperature insulation 70 provided adjacent to the electrically heated wall 64 Alternatively, as shown in Fig 16, an electrically conducting frit or an electrically conducting honeycomb structure 72 is placed in the reaction extension cylinder 26 The frit or metallic honeycomb 72 is heated by driving electricity through electrical leads 74 and 76
  • the honeycomb structure may have a catalyst on its surface such as the water-shift or steam reforming catalyst as shown in Fig 14

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Organic Chemistry (AREA)
  • Combustion & Propulsion (AREA)
  • Toxicology (AREA)
  • Mechanical Engineering (AREA)
  • General Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Electromagnetism (AREA)
  • Physics & Mathematics (AREA)
  • Sustainable Energy (AREA)
  • Electrochemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Inorganic Chemistry (AREA)
  • Sustainable Development (AREA)
  • General Engineering & Computer Science (AREA)
  • Hydrogen, Water And Hydrids (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)

Abstract

The plasma fuel converter includes an electrically conductive structure for forming a first electrode and a second electrode is disposed to create a gap with respect to the first electrode in a reaction chamber. A fuel-air mixture is introduced into the gap and the power supply is connected to the first and second electrodes to provide voltage in the range of approximately 100 volts to 40 kilovolts and current in the range of approximately 10 milliamperes to 1 ampere to generate a glow discharge to reform the fuel. The high voltage low current plasmatron of the invention is low cost, has long electrode life, utilizes a simple power supply and control and eliminates the need for an air compressor.

Description

Low Power Compact Plasma Fuel Converter
This application is a continuation-in-part of United States patent application serial number 09/379,004 filed August 23, 1999.
Background of the Invention This invention relates to a plasma fuel converter and more particularly to a low power compact plasma fuel converter employing high voltage and low current.
Plasma fuel converters such as plasmatrons reform hydrocarbons to produce a hydrogen rich gas. DC arc plasmatrons have received particular attention in the prior art. See, for example, U.S. Patent Nos. 5,425,332 and 5,437,250. DC arc plasmatrons typically operate at low voltage and high current. By operating at high currents and lower voltages, the arc current is high enough that precautions are required to minimize electrode erosion and even melting. High flow rates of cooling water are required to keep the erosion in check. Air flow is required to simultaneously center the discharge on the cathode tip (made of hafnium or other specialized material, embedded in a copper plug) and to move the root of the arc at the anode to minimize erosion at the anode. A constriction is also required to increase the impedance of the discharge (i.e., to operate at high voltages and lower currents than free-flowing arcs). The air flows and the constriction are likely to require operation at elevated pressure (as much as 0.5 bar above ambient pressure), and thus a compressor is likely to be required. Even with these precautions, it is often difficult to extend the lifetime of the electrodes beyond approximately 1,000 hours of operation.
DC plasmatrons also require relatively sophisticated power supplies for stabilization of the arc discharge. Further, DC plasmatrons have a limited capability for low power operation. In some reforming applications, the minimum operating power can be significantly greater than needed resulting in unnecessary power loss. DC arc plasmatrons are typically operated at power levels of one kilowatt or more.
It is therefore desirable to have a plasma fuel converter that does not require a compressor or a sophisticated power supply for stabilization of the arc discharge. It is also desirable to have a plasma fuel converter having longer electrode life and with a capability of lower power operation when lower flow rates of hydrogen rich gas are required. Summary of the Invention In one aspect, the plasma fuel converter of the invention includes an electrically conductive structure forming a first electrode A second electrode is disposed to create a gap with respect to the first electrode in a reaction chamber A fuel air mixture is introduced into the gap and a power supply connected to the first and second electrodes provides voltage in the range of approximately 100 volts to 40 kilovolts and current in the range of approximately 10 milhamperes to one ampere to generate a discharge to reform the fuel The discharge can be a "glow type" discharge, a silent discharge and/or a breakdown discharge A preferred range for voltage is 200 volts to 20 kilovolts In a preferred embodiment, the plasma fuel converter includes a reaction extension region to increase residence time in a high temperature zone An insert in the reaction extension region and in the reaction chamber is provided to increase the temperature of operation The insert may be metallic or ceramic A heat exchanger may also be provided to decrease power needed from the power supply
In this embodiment, it is preferred that the power supply be a current controlled, high voltage power supply such as a power supply including a saturable inductor to limit current The saturable inductor power supply may be a neon transformer power supply The fuel-air mixture is selected for operation between stoichiometπc partial oxidation and full combustion depending on conditions and applications An additional power supply may be provided for simultaneous operation in a low voltage, high current DC arc mode and a high voltage, low current glow discharge mode The plasma fuel converter may include a plurality of plasma regions to increase hydrogen generation rate The hydrogen rich gas output of the plasma fuel converter may be brought into contact with a catalyst such as for nitrogen oxide catalyst regeneration
The plasma fuel converter of the invention reduces or removes the disadvantages associated with DC arc plasmatrons known in the prior art The disadvantages are overcome by the specially controlled high voltage, low current plasma fuel converter operation The voltage and current vary over time in such a manner as to limit the current flowing in the plasma The electπcal characteristics of the plasma operation are a voltage range from a few hundred volts and up to 40 kilovolts, and a current range from 10 milhamperes to hundreds of milhamperes In contrast, the corresponding ranges for DC arc plasmatron fuel reformers are a voltage of around 100 volts and currents starting at 3-5 amperes A representative high voltage, low current discharge of the plasma fuel converters of the invention has "glow discharge" type features Typically, this type of atmospheric pressure, high voltage, low current discharge can be made to operate at tens to hundreds of watts of average power In contrast, DC arc plasmatrons known m the prior art are typically operated at power levels of one kilowatt or more
The high voltage, low current operation of the high- voltage low-current discharge is maintained by the use of an appropriate power supply such as a conventional AC neon transformer Neon transformer power supplies use a saturable inductor to limit the current to a relatively low value, on the order of tens to hundreds of milhamps Such power supplies are also capable of producing open circuit voltages of tens of kilovolts These power supplies are inexpensive and can be made for the delivery of tens to hundreds of watts
In contrast, in the case of conventional spark discharges, the capacitive-based power supply delivers a high voltage, short pulse that breaks down the electrode-to- electrode gap and results in a discharge This breakdown phase is followed by a lower voltage, lower power discharge Most of the energy is delivered during the relatively long low voltage, low power part of the discharge The energy delivered per pulsed discharge is small, on the order of tens of millyoules Average power levels are typically around a few watts which is generally too low for hydrogen production applications
Thus, in a plasma fuel converter using high-voltage, low-current operation according to the invention, the power that is provided by the discharge can be on the order one-tenth of the minimum power of a compact DC arc plasmatron known in the prior art The reformer of the invention is therefore appropriate for low hydrogen production rates where it provides enough power to increase substantially the enthalpy of the reactants Such low rates may be appropriate for some applications, such as catalyst regeneration High hydrogen production rates are possible by using multiple units A further increase in hydrogen production rate is possible by increasing the air/fuel ratio and the fuel throughput Alternatively, the low power, high- voltage low-current plasma is used as an expanded volume igniter and a source of radicals to enhance the partial oxidation reaction with the necessary enthalpy increase provided by other means These other means include air-fuel chemical reactions and/or heat provided by a heat exchanger In this mode of operation, substantially all of the enthalpy (at least 80% and preferably 90% or more) is provided by these other means This mode of operation makes possible higher hydrogen production rates than would otherwise be allowed by constrains on plasma power or generator/battery power supply capability
In some cases, it may be useful to operate the partial oxidation reaction with additional oxygen (. e , partial oxidation with an oxygen-to-fuel ratio greater than that for stoichiometπc partial oxidation) The oxygen is generally provided by additional air In this case the hydrogen yield (defined as the fraction of the hydrogen in the fuel that is released m the process) is reduced, but the electπcal power requirement is decreased There is a tradeoff between the electrical power requirement for the plasma and the fuel required in the fuel converter In the case of additional oxygen, the partial oxidation reaction is facilitated by fully oxidizing a fraction of the fuel and partially oxidizing the rest of the fuel Using this approach, it is possible to decrease the required electrical power at the expense of increased fuel flow rate for a given rate of hydrogen flow In some applications where limited amounts of hydrogen are required for a limited amount of time, the additional required fuel does not impact substantially the overall fuel efficiency However, the reduced power requirements for the plasma, coupled with a much longer lifetime of the electrodes and a much simpler overall system reduces the complexity and cost of the plasma fuel converter Alternatively, for the same plasmatron power, an increased air to fuel ratio (as compared to stoichiometπc partial oxidation) can be used to increase the hydrogen generation rate by using increased fuel and air throughputs Thus the hydrogen throughput can be increased without needing to increase the electπcal power to the plasmatron but at conditions that reduce the hydrogen yield It is also possible to inject additional amounts of fuel after the plasma fuel converter and produce a final gas composition close to stoichiometπc at partial oxidation conditions
In another preferred embodiment, the power to the plasmatron is adjusted by changing the frequency of operation of the power supply In yet another embodiment, dielectrics cover one or both of the electrode surfaces so that microdischarges are generated across the gas It is also preferred that the fuel and air be introduced in a region such that the flow carries the reagents to a region close to the discharge.
Bnef Description of the Drawing
Fig 1 is a cross-sectional view of a high voltage, low current discharge plasma fuel converter according to the invention.
Fig. 2 is such a plasma fuel converter including a reaction extension cylinder Fig 3 is a cross-sectional view of a high voltage, low current glow-discharge plasmatron with thermal insulation
Fig 4 is a cross-sectional view of a high voltage, low current glow-discharge plasmatron including a heat exchanger.
Fig 5 is a cross-sectional view of another glow-discharge plasmatron with a heat exchanger. Fig 6 is a circuit diagram of a high voltage, low current microplasmatron connected to a power supply with one grounded electrode.
Fig 7 is a circuit diagram of a high voltage, low current microplasmatron connected to a power supply with both electrodes connected to the microplasmatron. Fig. 8 is a circuit diagram of a high voltage, low current microplasmatron connected to a power supply with a single electrode connected to the microplasmatron.
Fig 9 is a cross-sectional view of the a plasmatron of the invention using a conventional spark plug as one of the electrodes.
Fig. 10 is a cross-sectional view of an embodiment with dielectric covering on the electrodes.
Fig. 11 is a cross-sectional view of an embodiment of the invention employing a fπt.
Figs. 12 and 13 are cross-sectional views of other embodiments of the invention. Fig. 14 is a cross-sectional view of an embodiment of the invention employing a heat exchanger and a water-shift reactor. Figs. 15 and 16 are cross-sectional views of embodiments of the invention with electrically heated reaction extension zones.
Description of the Preferred Embodiment With reference now to Fig. 1, a plasma fuel converter 10 includes a conductive structure 12 and an electrode 14. The conductive structure 12 and the electrode 14 form a gap 16 within a reaction chamber 18. An air fuel mixture is introduced into the reaction chamber 18 through a conduit 20 which results in a radial introduction. As will be described below, when energized by a suitable power supply, a discharge 22 occurs across the gap 16. The energy in the discharge 22 serves to reform the fuel portion of the air- fuel mixture to generate hydrogen rich gas. The electrode 14 is electrically isolated from the conductive structure 12 by an insulator 24.
Figure 2 shows the embodiment of Fig. 1 but including a reaction extension cylinder 26 which increases the residence time of the reactants in the high temperature zone thereby increasing the hydrogen rich gas yields. It is possible to increase yields further by minimizing heat losses downstream from the plasma discharge 22. As shown in Fig. 3, minimizing heat losses can be achieved by the use of a thermal shield 28 in the region immediately downstream from the plasma and in the reaction extension cylinder 26 that is further downstream. The thermal shield 28 may be a thin metallic barrier with low thermal capacity (and therefore short thermal response time) to minimize radiation losses. Alternatively, the thermal shield 28 may be a ceramic barrier having low thermal conductivity but with increased thermal capacity and therefore increased thermal response time.
As shown in Figs. 4 and 5, instead of a thermal barrier, a compact heat exchanger 30 can be used to preheat part of the air and/or part of the fuel in a counter- flow heat exchanger configuration.
As discussed above, the plasma fuel converters of the invention are energized with a current controlled, high voltage power supply used for driving the glow discharge type of plasmas. Fig. 6 shows one circuit arrangement. A saturable core transformer 32 draws power from power mains 34, which can carry either AC or DC current. The AC power can be obtained from a conventional AC power source, or it can be generated from DC (for example, onboard vehicles) by the use of a DC-AC converter. In this arrangement, the saturable core transformer has one grounded electrode 36 and another electrode 38 is connected to the electrode 14 of the plasmatron 10. The conductive structure 12 of the plasmatron 10 is also grounded. Another circuit arrangement is shown in Fig. 7 in which both power supply 32 electrodes 36 and 38 are connected to the plasmatron 10. This arrangement requires extra safety precautions (additional insulation) but delivers full power to the plasma in the plasmatron 10. Yet another arrangement is shown in Fig. 8 in which the single electrode 38 is connected to the plasmatron 10. In this case the voltage supply requires higher voltage insulation to deliver the same power.
There are several methods of adjusting the power in a low power plasma fuel converter. It can be varied by changing the voltage applied to the saturable inductor (neon transformer or comparable device). A second method is by operating a number of plasma fuel converter units in either a parallel or a series configuration, increasing the power by increasing the number of units operating. A third method of adjusting the power is by changing the frequency of operation of the power supply. As described above, the power to the plasma discharges is time varying. The higher power occurs at the discharge initiation time, when the voltage is very high and the current low, and during which gas breakdown occurs. At this time, the high voltage generates relatively energetic electrons that very efficiently generate radicals and efficiently couple their energy into the gas, with minimal voltage drops (sheaths) near the electrodes. The power decreases as the discharge approaches the glow-like regime. Frequencies as high as 100-200 kHz and even higher can be achieved using state of the art solid state components, such as IGBT's.
By operating at higher frequencies, it is possible to maximize operation at the higher voltage, higher efficiency breakdown-like regime, and minimize operation at the lower voltage, glow-discharge regime. The frequency of a resonant inverter can be controlled and by simply varying the frequency, the power can be altered.
The inventors herein have experimentally achieved plasma fuel converter operation at lower levels of around 50 watts. Although a neon transformer power supply was used in our experiments, it is not the only possible power supply. A current controlled, high voltage power supply can also be used for driving the glow- discharge type of plasmas. Fig. 9 is a schematic of the experimental plasmatron 10. One electrode of a conventional spark plug 40 was used in these experiments as the electrode 14. The other electrode is a steel tube 42 which is maintained at ground potential (the ground electrode from the spark plug 40 has been removed). This experimental plasmatron was operated with gasoline in the high voltage-low current mode of the invention. The power supply was a saturable transformer (neon transformer). Two such units, of 50 watts each, were connected in parallel. It is not known whether the full 100 watts from both units was being applied to the plasmatron. The actual power input into the plasmatron 10 may actually be less than 100 watts. The power supply was AC, operating at line frequency. The plasmatron was connected to a conventional reaction extension cylinder 26 to increase the residence time and increase conversion efficiency.
The results from tests (after optimizing the air/fuel ratio) are shown in Table 1. Energy consumption has been decreased by about one order of magnitude compared with results obtained with conventional low voltage-high current plasma reformers. The electrical energy consumption per hydrogen produced has been decreased by about a factor of 5.
Table 1
Plasma Air g/s 1.1
Gasoline g/s 0.12
Product gas composition (% vol) Hydrogen 10.3 CO 16
C02 6
Nitrogen 70
Methane 0.7
Energy consumption kJ/mol fuel 100
Mj/kg H2 12
Conversion yield
To Hydrogen 54% To CO 87% The electrode 14 showed no signs of degradation leading to the expectation that long electrode life will be possible operating the microplasmatron reformer in the low current high voltage mode of operation according to the invention. In addition, no cooling water was required and air pressure requirements were substantially decreased. It is also expected that performance can be improved with better ways of introducing fuel into the reactor using a nozzle/atomizer.
The present invention may also be very useful for operation at higher pressures. High pressure increases the required voltages for both breakdown and for glow discharge sustenance. High pressure operation with low voltage DC arc plasmatrons is very difficult, due to very high electrode wear. The high voltage, low current operation of the plasmatron removes this difficulty. The increased voltage with increasing pressure at some point requires sophisticated high voltage insulators and feedthroughs. A possible application could be hydrogen addition in gas turbines, injecting the hydrogen rich gas downstream from the turbine compressor at or before the main fuel injection. This could have the benefit of extending the lean burn limit of the turbine, further decreasing the emissions and possibly increasing the turbine efficiency.
In addition, the type of electrical power supply that is being considered can be combined with a conventional DC arc power supply. When connected in a parallel configuration, the neon transformer power supply can be used to stabilize the arc and during transients, such as start up, power variations or variations, in throughput through the plasma of fuel, air or other flows. When connected in parallel, the requirements on stability that are imposed on the DC power supply can be eliminated, making it cheaper. One possibility is to use a plasmatron that is connected directly to a rotating generating unit (such as an automobile generator) to provide the bulk of the power, and then to utilize the other power supply to provide the stabilization and the turn-on requirements.
In addition, it is possible to operate the plasmatron with either power supply on. When the DC plasmatron power is on, it operates at high power, while when operating in the glow-like mode with the DC plasmatron power supply not providing any electricity, it operates at low power. A large dynamic variation of power, from tens of watts to 1-2 kW can be achieved in this manner. This dynamic range can be used for load following of the engine, or for a different mission For example, the gas throughputs required for engine exhaust catalyst regeneration can be substantially lower than the throughputs required for hydrogen additive operation or cold start In this manner, if the momentary hydrogen requirements call for small throughput, the plasma fuel reformer can operate in a glow-like discharge mode, while for higher hydrogen requirements, it can operate in a combination of both modes
These low power plasma fuel converters are particularly attractive for plasma fuel converter-catalyst regeneration applications Low voltage DC arc plasmatrons, with a limited capability of low power operation, need to operate with very low duty cycle for this application, due to the low average demands on hydrogen production By operating the hydrogen generator in a high- voltage, low-current mode, it is possible to decrease the plasmatron power and operate with high duty cycle
Each high voltage, low current glow-discharge plasmatron may operate with only about 100 watts It is possible to increase the power by placing several high voltage, low current discharges in the plasma fuel reformer The high voltage, low current glow-discharge plasma sources can be connected to a single power supply, either in a series or in a parallel configuration However, the preferred embodiment is for each high voltage, low current glow plasmatron to be connected to its own power supply In addition to catalyst regeneration, applications include cold start emissions reduction m spark ignition internal combustion engines and nitrogen oxides reduction during the entire driving cycle Other applications include hydrogen production for diesel engines, fuel cells and gas turbines, and for small hydrogen sources for industrial applications The stand alone, low power, low current plasma fuel converter devices may be particularly useful for small power engines (with generated power levels m the 1-40 kW range)
The embodiments discussed above indicate the operation with electrodes in direct contact with the plasma This method is most suitable to DC or low frequency AC discharges As the frequency of the discharge increases, it is possible to eliminate the need of direct electrode contact with the discharge As shown in Fig 10, if a dielectric mateπal 50 is placed between the electrode and the gas, microdischarges can be generated across the gas These microdischarges have very short duration (on the order of and less than 1 microsecond), and operate at high voltage and high current The microdischarges are quenched when charge build-up in the dielectric decreases the voltage below that required for current sustenance This type of discharge is called a silent discharge A plasmatron fuel converter using the silent discharge mode of operation minimizes the power loss to a cooled or cold electrode by the use of high temperature operation of the dielectric 50 This mode of operation allows for very long lifetime, since the current on the electrode is small and the dielectric mateπal can be made of high strength, high temperature ceramics It is possible to place the dielectric coating 50 at both electrode surfaces, or on just one of the surfaces The power capabilities of the silent-discharge type of plasmatron is lower than that of the uncovered dielectric plasmatron, but the energy efficiency may be higher The power can be varied, as described above, by changing the frequency of operation of the power supply that drives the discharge The plasma is needed m order to initiate and maintain the partial oxidation reactions m the plasma fuel converter during transients During startup, when the plasma fuel converter surfaces are cold, greater thermal energy may be required to achieve the required temperature During startup it is therefore necessary to operate the plasma fuel converter at relatively high power and/or with oxygen/fuel ratios higher than during normal operation when the surfaces are warm The increased burn-up of the fuel by the higher oxygen/fuel ratios can result in decreased hydrogen rich gas yields (where the yield is the ratio between the hydrogen in the reformate divided by the amount of hydrogen m the fuel) Increased throughput of hydrogen- πch gas for the vehicle startup period can be achieved by increasing the oxygen/fuel ratio simultaneously with the increase m air and fuel flow rates The hydrogen yield decreases, but the hydrogen-rich gas throughput increases The plasma needs to be operational in order to increase the stability of the reaction, both through direct ignition of the gases and by providing radicals that enhance the chemical reactions We have thus demonstrated very fast turn on times for hydrogen rich gas production, with operation of oxygen-to-carbon atomic ratios between 1 2 and 2 5
After warm-up of the plasma fuel converter, operation normally occurs at an oxygen/fuel ratio closer to stoichiometπc partial oxidation (with the oxygen/carbon atomic ratio equal to 1-1.5). It may be possible to turn the plasma on and off, in an intermittent fashion. Intermittent operation of the plasma decreases the electrical energy consumption. The flexibility of the fuel reformer is increased by trading off decreased electrical energy consumption of the plasma by decreased hydrogen yield. It is possible to operate the reformer with the plasma on at oxygen/fuel ratios closer to conditions of stoichiometric partial oxidation than when the plasma is off. The regime of operation (plasma on, increased hydrogen yield vs. plasma off, decreased hydrogen yield) can be determined by optimization of the overall system.
During transients when the throughput of the hydrogen rich gas is altered, operation with the plasma on can provide stability to the fuel reformer. Finally, once the electrical energy consumption by the plasma has decreased to levels substantially lower than the energy loss from the partial oxidation process, then the plasma operation does not affect the overall system efficiency, and can be left operating to provide additional stability to transients. The efficiency of conversion by partial oxidation of hydrocarbon to hydrogen rich gas can vary due to finite heat losses, random transients (for example, generated by vibration, acceleration, sudden changes in flow, fuel contamination, dust in air, etc.) and changing hydrogen rich gas throughput. To compensate for decreased reforming efficiency, it is necessary to either: a) turn on the plasma (in the case of intermittent plasmatron operation); b) increase the plasma power if the plasma is already on; c) increase the oxygen-to-carbon ratio (by increasing the oxygen-to-fuel ratio) to increase the heat generated by the reforming process; or d) a combination of any or all of the above. It is therefore necessary to monitor the reforming process.
During efficient reforming, the oxygen concentration of the reformate is very low, usually less than 1%. Higher concentrations in the reformate indicate poor reforming. Oxygen detection, by the use of conventional oxygen sensors can therefore be used to monitor the reforming process and to control the plasmatron operation (power and oxygen/fuel ratio).
The operation of the plasmatron in the high- voltage low current mode allows operation of the fuel reformer at high pressures. For high-pressure operation, upstream air and fuel compressors are needed (which, for the case of a turbine driven by hydrogen-rich gas, are built into the system). In order to maximize the throughput and the conversion yield of hydrocarbon into hydrogen, it is attractive to introduce mixing downstream from the plasmatron. In this way the size and number of pockets that are either of elevated or reduced (with respect to the average) hydrocarbon content are substantially decreased, allowing for higher yield of hydrogen and decreased energy consumption. As shown in Fig. 11, it is useful to place a frit 52 (or comparable material consisting of increased surface area) downstream from the plasma discharge, to increase the mixing. The frit 52 can be either a conventional frit that is used just to increase the mixing, or it can be made of a material that provides a catalytic reaction. In the latter case, the frit 50 is made of a catalytic material on a substrate, such as nickel catalyst on an alumina substrate (ideal for steam reforming).
The preferred method of air injection is to inject some of the air upstream from the plasma. Some of the fuel can be injected into the discharge either prior to the plasma, which is the preferred method for the case of the low power plasma fuel converter (or downstream from the plasma for the high power DC arc plasma fuel converter described in previous patents and patent applications of the present inventors). This is done in order to prevent soot formation across the small cathode- anode gap.
The flow is such that the flame propagates in the same direction as the bulk air flows. In conventional reformers, even if a spark plug discharge is used to initiate the process, the flame propagates at least partially against the main direction of the flow. Having the flow be in the same direction as the flame results in more stable reforming.
The desired flame and flow pattern in the present invention is achieved by having a small region where some or all of the air, and some, all or none of fuel are introduced, upstream from the discharge, and having a region of expansion where the air/fuel mixture propagates at much reduced velocity because of the increased cross section of the expansion region. The expansion region can be followed by a reaction extension region that increases the residence time in the plasma fuel converter. Both the expansion region as well as the reaction extension region are well insulated thermally to minimize enthalpy loss, increasing the yield of hydrogen rich gas. Although it is best to introduce the air and fuel prior to the discharge, it is not necessary as long as the point of introduction of the air and fuel is near the region of the discharge The fuel and air are best introduced at a region such that all of the reagents introduced upstream from the plasma flow through the electrode gap In this manner, the radicals produced by the electrical discharge, and associated enthalpy generation in the gas, is distributed uniformly among the reagents (air and fuel)
Figs 12 and 13 illustrate preferred embodiments with respect to air/fuel flow Air and fuel 54 are introduced into the region of the discharge 22 and pass into an expanded region 56 As shown in Fig 13, air and fuel 54 are introduced alongside the electrode 14 m the vicinity of the discharge 22 and proceeds into the expanded region 56
Returning now to the partial oxidation operation discussed above, in the suggested process the reaction occurs at oxygen-to-carbon ratios of 1 2-2 5 Under these conditions, the product gas has a substantial water content This water (or steam) can be used to increase the hydrogen production rates by changing (shifting) the carbon monoxide produced in the partial oxidation reaction to hydrogen by a water-gas shift reaction
H20 + CO ^ C0 + H2 The water-gas shift reaction is slightly exothermic, and it can reach near completion at relatively low temperatures (200-700°C) Therefore, there can be a heat exchanger downstream from the reaction extension cylinder to decrease the reformate temperature to that optimal for the catalytic water-shift reaction In this manner, the hydrogen concentration in the reformate can be increased with minimal decrement to the heating value of the hydrogen rich gas
Fig 14 illustrates the addition of a heat exchanger and a water-shift catalytic reactor A heat exchanger 60 is placed downstream from the reaction extension cylinders 26 to decrease the reformate temperature before entry into a water-shift catalytic reactor 62 so as to increase the hydrogen concentration in the reformate The water-shift catalytic reactor includes a suitable catalyst 63 to promote the water-shift reaction Thus, the embodiment of Fig 14 both increases hydrogen concentration and decreases unwanted carbon monoxide
Methods were described earlier in this application to produce the required hydrogen during transients, in particular, the start up transient These methods included increasing the power of the plasmatron, increasing the number of plasmatrons or increasing the oxygen-to-carbon ratio (thereby increasing the fraction of the fuel that is fully combusted) An alternative is to utilize electrical heating of the reaction extension cylinder 26 as shown in Figs 15 and 16 With reference to Fig 15. electrically heated walls 64 are energized through electrical leads 66 and 68 with high temperature insulation 70 provided adjacent to the electrically heated wall 64 Alternatively, as shown in Fig 16, an electrically conducting frit or an electrically conducting honeycomb structure 72 is placed in the reaction extension cylinder 26 The frit or metallic honeycomb 72 is heated by driving electricity through electrical leads 74 and 76 The honeycomb structure may have a catalyst on its surface such as the water-shift or steam reforming catalyst as shown in Fig 14
It is recognized that modifications and variations of the invention disclosed herein will be apparent to those skilled m the art and it is intended that all such modifications and variations be included withm the scope of the appended claims What is claimed is

Claims

1. Plasma fuel converter comprising: an electrically conductive structure forming a first electrode; a second electrode disposed to create a gap with respect to the first electrode in a reaction chamber; a fuel-air mixture residing in the gap; and a power supply connected to the first and second electrodes to provide voltage in the range of approximately 100 volts to 40 kilovolts and current in the range of approximately 10 milhamperes to 1 ampere to generate a discharge to reform the fuel.
2. The plasma fuel converter of claim 1 further including a reaction extension region to increase residence time in a high temperature zone.
3. The plasma fuel converter of claim 2 further including an insert in the reaction extension region and in the reaction chamber to increase temperature.
4. The plasma fuel converter of claim 3 wherein the insert is metallic.
5. The plasma fuel converter of claim 3 wherein the insert is ceramic.
6. The plasma fuel converter of claim 2 further including a heat exchanger to decrease power from the power supply.
7. The plasma fuel converter of claim 1 wherein the power supply is a current controlled, high voltage power supply.
8. The plasma fuel converter of claim 7 wherein the power supply includes a saturable inductor to limit current.
9. The plasma fuel converter of claim 8 wherein the power supply is a neon transformer power supply.
10. The plasma fuel converter of claim 1 wherein the fuel-air mixture is selected for operation between stoichiometric partial oxidation and full oxidation.
11. The plasma fuel converter of claim 1 further including an additional power supply for simultaneous operation in a low voltage, high current DC arc mode and a high voltage, low current discharge mode.
12. The plasma fuel converter of claim 1 further including a plurality of plasmatron regions to increase hydrogen generation rate.
13. The plasma fuel converter of claim 1 wherein an output of the plasma fuel converter is brought into contact with a catalyst.
14. The plasma fuel converter of claim 13 for nitrogen oxide catalyst regeneration
15. Plasma fuel converter comprising: an electrically conductive structure forming a first electrode; a second electrode disposed to create a gap with respect to the first electrode in a reaction chamber; a fuel-air mixture residing in the gap; and a power supply connected to the first and second electrodes to provide voltage in the range of approximately 100 volts to 40 kilovolts and current in the range of approximately 10 milhamperes to 1 ampere to generate a plasma.
16. The plasma fuel converter of claim 15 wherein average power to the plasma is between 10 and 1000 watts.
17. The plasma fuel converter of claim 15 wherein a partial oxidation reaction of hydrocarbon fuel and oxygen produces reaction products that include hydrogen and carbon monoxide.
18. The plasma fuel converter of claim 16 wherein the plasma sustains the partial oxidation reaction of hydrocarbon fuel and oxygen.
19. The plasma fuel converter of claim 1 wherein the fuel and air mixture is introduced upstream from the plasma and additional air/fuel mixture of possibly different composition is introduced downstream from the plasma.
20. The plasma fuel converter of claim 15 wherein the power supply has a variable frequency, with power being controlled by adjusting the frequency of the power supply.
21. The plasma fuel converter of claim 20 wherein power supply frequency can be adjusted up to 100-200 kHz.
22. The plasma fuel converter of claim 15 wherein at least one of the first and second electrodes is covered with a dielectric coating to produce a discharge in the gap between either the dielectric or the dielectric-electrode.
23. The plasma fuel converter of claim 22 wherein power is controlled by varying frequency of the power supply.
24. The plasma fuel converter of claim 15 wherein oxygen/fuel ratio of the fuel/air mixture is varied during transient conditions.
25. The plasma fuel converter of claim 15 wherein the plasma is operating in an intermittent mode.
26. The plasma fuel converter of claim 24 wherein oxygen to carbon atomic ratio during turn on and normal operation is between 1.2 and 2.5 with or without intermittent operation.
27. The plasma fuel converter of claim 15 further including an oxygen sensor in contact with the reformate to control conversion efficiency.
28. The plasma fuel converter of claim 27, wherein conversion efficiency is controlled by changing either power level or oxygen/fuel ratios or both.
29. The plasma fuel converter of claim 15 operated at pressures up to 500 psi.
30. The plasma fuel converter of claim 17 wherein the plasma is a breakdown, glow discharge or a silent discharge plasma.
31. The plasma fuel converter of claim 17 wherein electrical power consumption is between 0.3% to 10% of the thermal power content of the hydrogen rich gas produced by the converter.
32. The plasma fuel converter of claim 17 wherein an oxygen to carbon ratio is 1.2 to 2.0.
33. The plasma fuel converter of claim 17 wherein substantially all necessary enthalpy increase is provided by means other than the plasma.
34. The plasma fuel converter of claim 19 wherein substantially all necessary enthalpy increase is provided by means other than the plasma.
35. The plasma fuel converter of claim 33 wherein oxygen to carbon ratio is between 1.2 and 2.0.
36. The plasma fuel converter of claim 31 wherein oxygen to carbon ratio is between 1.2 and 2.0.
37. The plasma fuel converter of claim 15 further including a material providing increased surface area downstream from the plasma discharge.
38. The plasma fuel converter of claim 37 wherein the material is inert.
39. The plasma fuel converter of claim 37 wherein the material is a catalyst.
40. The plasma fuel converter of claim 37 wherein the material is a nickel based catalyst on an alumina substrate. 41 The plasma fuel converter of claim 15 wherein the fuel-air mixture is introduced at a region such that flow carries all of the reagents through the electrode gap
42 The plasma fuel converter of claim 17 wherein the partial oxidation reaction operation is between stoichiometric partial oxidation and full combustion and further includes a catalytic water-shift reaction region maintained in the temperature range of approximately 200-700°C
43 The plasma fuel converter of claim 42 further including a heat exchanger prior to the catalytic water-shift reaction region, the heat exchanger adapted to decrease the reformate temperature to that optimal for a water-shift reaction
44 The plasma fuel converter of claim 2 wherein the reaction extension region is electrically heated
45 The plasma fuel converter of claim 44 wherein the reaction extension cylinder includes electrically heated fπt and or electrically conducting honeycomb 46 The plasma fuel converter of claim 45 wherein the electrically conducting honeycomb includes a catalyst on its surface
47 The plasma fuel converter of claim 19 wherein all of the air and fuel mixture introduced upstream from the plasma flows through the electrode gap
PCT/US2000/040677 1999-08-23 2000-08-18 Low power compact plasma fuel converter Ceased WO2001014702A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CA002391851A CA2391851A1 (en) 1999-08-23 2000-08-18 Low power compact plasma fuel converter
JP2001518551A JP2003507321A (en) 1999-08-23 2000-08-18 Low power small plasma fuel converter

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US37900499A 1999-08-23 1999-08-23
US09/379,004 1999-08-23

Publications (1)

Publication Number Publication Date
WO2001014702A1 true WO2001014702A1 (en) 2001-03-01

Family

ID=23495419

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2000/040677 Ceased WO2001014702A1 (en) 1999-08-23 2000-08-18 Low power compact plasma fuel converter

Country Status (3)

Country Link
JP (1) JP2003507321A (en)
CA (1) CA2391851A1 (en)
WO (1) WO2001014702A1 (en)

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002076884A1 (en) * 2001-03-21 2002-10-03 Accentus Plc Production of hydrogen
US6651597B2 (en) 2002-04-23 2003-11-25 Arvin Technologies, Inc. Plasmatron having an air jacket and method for operating the same
WO2004026444A1 (en) * 2002-09-18 2004-04-01 Arvin Technologies, Inc. Apparatus and method for removing nox from the exhaust gas of an internal combustion engine
US6715452B1 (en) 2002-11-13 2004-04-06 Arvin Technologies, Inc. Method and apparatus for shutting down a fuel reformer
US6758035B2 (en) 2002-09-18 2004-07-06 Arvin Technologies, Inc. Method and apparatus for purging SOX from a NOX trap
WO2004027526A3 (en) * 2002-09-17 2004-09-16 Arvin Technologies Inc Fuel reformer control system and method
US6843054B2 (en) 2003-01-16 2005-01-18 Arvin Technologies, Inc. Method and apparatus for removing NOx and soot from engine exhaust gas
US6851398B2 (en) 2003-02-13 2005-02-08 Arvin Technologies, Inc. Method and apparatus for controlling a fuel reformer by use of existing vehicle control signals
US6903259B2 (en) 2002-12-06 2005-06-07 Arvin Technologies, Inc. Thermoelectric device for use with fuel reformer and associated method
US6959542B2 (en) 2002-01-25 2005-11-01 Arvin Technologies, Inc. Apparatus and method for operating a fuel reformer to regenerate a DPNR device
US6976353B2 (en) 2002-01-25 2005-12-20 Arvin Technologies, Inc. Apparatus and method for operating a fuel reformer to provide reformate gas to both a fuel cell and an emission abatement device
US7014930B2 (en) 2002-01-25 2006-03-21 Arvin Technologies, Inc. Apparatus and method for operating a fuel reformer to generate multiple reformate gases
US7021048B2 (en) 2002-01-25 2006-04-04 Arvin Technologies, Inc. Combination emission abatement assembly and method of operating the same
WO2007054571A1 (en) 2005-11-14 2007-05-18 Robert Bosch Gmbh Exhaust gas after-treatment system and method for operating an exhaust gas after-treatment system
WO2007054574A1 (en) 2005-11-14 2007-05-18 Robert Bosch Gmbh Catalyst arrangement in an exhaust gas after-treatment system
DE102006061692A1 (en) 2006-12-28 2008-07-03 Robert Bosch Gmbh Apparatus and method for generating nitric oxide
US7559195B2 (en) 2005-11-14 2009-07-14 Robert Bosch Gmbh Procedure and device to heat a reducing agent generation system
US7614220B2 (en) 2005-11-14 2009-11-10 Robert Bosch Gmbh Procedure for controlling the reducing agent in an exhaust gas post-processing system
US7678352B2 (en) 2005-11-14 2010-03-16 Robert Bosch Gmbh Device and procedure for the production of ammonia
US7690193B2 (en) 2005-11-14 2010-04-06 Robert Bosch Gmbh Procedure and device to control a reducing agent generation system
US7731925B2 (en) 2005-11-14 2010-06-08 Robert Bosch Gmbh Process for reducing agent control in an exhaust gas aftertreatment system
US7776280B2 (en) 2005-05-10 2010-08-17 Emcon Technologies Llc Method and apparatus for selective catalytic reduction of NOx
US8263011B2 (en) 2009-03-18 2012-09-11 Ngk Insulators, Ltd. Reactor
EP3238817A1 (en) * 2016-04-27 2017-11-01 Blueplasma Power, S.L. Process for the partial oxidation of fuels and the device for applying said process

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8044319B2 (en) 2005-02-07 2011-10-25 Pratt & Whitney Canada Corp. Variable arc gap plasma igniter
US8568662B2 (en) * 2005-10-10 2013-10-29 Korea Institute Of Machinery And Materials Plasma reaction apparatus, plasma reaction method using the same, plasma reaction method of persistent gas, and apparatus for decreasing NOx by occlusion catalyst
KR101581235B1 (en) * 2015-04-14 2015-12-30 고천일 Apparatus and method for manufacturing reforming fuel

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3992277A (en) * 1974-01-22 1976-11-16 Basf Aktiengesellschaft Process and apparatus for the manufacture of a gas mixture containing acetylene, ethylene, methane and hydrogen, by thermal cracking of liquid hydrocarbons
US4059416A (en) * 1972-07-13 1977-11-22 Thagard Technology Company Chemical reaction process utilizing fluid-wall reactors
US5425332A (en) 1993-08-20 1995-06-20 Massachusetts Institute Of Technology Plasmatron-internal combustion engine system
US5437250A (en) 1993-08-20 1995-08-01 Massachusetts Institute Of Technology Plasmatron-internal combustion engine system
US5887554A (en) * 1996-01-19 1999-03-30 Cohn; Daniel R. Rapid response plasma fuel converter systems
DE19757936A1 (en) * 1997-12-27 1999-07-08 Abb Research Ltd Production of synthesis gas with given hydrogen to carbon monoxide ratio in silent discharge

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4059416A (en) * 1972-07-13 1977-11-22 Thagard Technology Company Chemical reaction process utilizing fluid-wall reactors
US3992277A (en) * 1974-01-22 1976-11-16 Basf Aktiengesellschaft Process and apparatus for the manufacture of a gas mixture containing acetylene, ethylene, methane and hydrogen, by thermal cracking of liquid hydrocarbons
US5425332A (en) 1993-08-20 1995-06-20 Massachusetts Institute Of Technology Plasmatron-internal combustion engine system
US5437250A (en) 1993-08-20 1995-08-01 Massachusetts Institute Of Technology Plasmatron-internal combustion engine system
US5887554A (en) * 1996-01-19 1999-03-30 Cohn; Daniel R. Rapid response plasma fuel converter systems
DE19757936A1 (en) * 1997-12-27 1999-07-08 Abb Research Ltd Production of synthesis gas with given hydrogen to carbon monoxide ratio in silent discharge

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002076884A1 (en) * 2001-03-21 2002-10-03 Accentus Plc Production of hydrogen
US7014930B2 (en) 2002-01-25 2006-03-21 Arvin Technologies, Inc. Apparatus and method for operating a fuel reformer to generate multiple reformate gases
US7021048B2 (en) 2002-01-25 2006-04-04 Arvin Technologies, Inc. Combination emission abatement assembly and method of operating the same
US6959542B2 (en) 2002-01-25 2005-11-01 Arvin Technologies, Inc. Apparatus and method for operating a fuel reformer to regenerate a DPNR device
US6976353B2 (en) 2002-01-25 2005-12-20 Arvin Technologies, Inc. Apparatus and method for operating a fuel reformer to provide reformate gas to both a fuel cell and an emission abatement device
US6651597B2 (en) 2002-04-23 2003-11-25 Arvin Technologies, Inc. Plasmatron having an air jacket and method for operating the same
WO2004027526A3 (en) * 2002-09-17 2004-09-16 Arvin Technologies Inc Fuel reformer control system and method
WO2004026444A1 (en) * 2002-09-18 2004-04-01 Arvin Technologies, Inc. Apparatus and method for removing nox from the exhaust gas of an internal combustion engine
US6758035B2 (en) 2002-09-18 2004-07-06 Arvin Technologies, Inc. Method and apparatus for purging SOX from a NOX trap
US6715452B1 (en) 2002-11-13 2004-04-06 Arvin Technologies, Inc. Method and apparatus for shutting down a fuel reformer
US6903259B2 (en) 2002-12-06 2005-06-07 Arvin Technologies, Inc. Thermoelectric device for use with fuel reformer and associated method
US6843054B2 (en) 2003-01-16 2005-01-18 Arvin Technologies, Inc. Method and apparatus for removing NOx and soot from engine exhaust gas
US6851398B2 (en) 2003-02-13 2005-02-08 Arvin Technologies, Inc. Method and apparatus for controlling a fuel reformer by use of existing vehicle control signals
US7776280B2 (en) 2005-05-10 2010-08-17 Emcon Technologies Llc Method and apparatus for selective catalytic reduction of NOx
US7678352B2 (en) 2005-11-14 2010-03-16 Robert Bosch Gmbh Device and procedure for the production of ammonia
US7559195B2 (en) 2005-11-14 2009-07-14 Robert Bosch Gmbh Procedure and device to heat a reducing agent generation system
US7614220B2 (en) 2005-11-14 2009-11-10 Robert Bosch Gmbh Procedure for controlling the reducing agent in an exhaust gas post-processing system
WO2007054574A1 (en) 2005-11-14 2007-05-18 Robert Bosch Gmbh Catalyst arrangement in an exhaust gas after-treatment system
US7690193B2 (en) 2005-11-14 2010-04-06 Robert Bosch Gmbh Procedure and device to control a reducing agent generation system
US7731925B2 (en) 2005-11-14 2010-06-08 Robert Bosch Gmbh Process for reducing agent control in an exhaust gas aftertreatment system
WO2007054571A1 (en) 2005-11-14 2007-05-18 Robert Bosch Gmbh Exhaust gas after-treatment system and method for operating an exhaust gas after-treatment system
USRE44753E1 (en) 2005-11-14 2014-02-11 Robert Bosch Gmbh Procedure and device to heat a reducing agent generation system
DE102006061692A1 (en) 2006-12-28 2008-07-03 Robert Bosch Gmbh Apparatus and method for generating nitric oxide
US8263011B2 (en) 2009-03-18 2012-09-11 Ngk Insulators, Ltd. Reactor
EP3238817A1 (en) * 2016-04-27 2017-11-01 Blueplasma Power, S.L. Process for the partial oxidation of fuels and the device for applying said process
US11013098B2 (en) 2016-04-27 2021-05-18 Blueplasma Power, S.L. Process for the partial oxidation of fuels and the device for applying said process

Also Published As

Publication number Publication date
JP2003507321A (en) 2003-02-25
CA2391851A1 (en) 2001-03-01

Similar Documents

Publication Publication Date Title
US6322757B1 (en) Low power compact plasma fuel converter
WO2001014702A1 (en) Low power compact plasma fuel converter
US6881386B2 (en) Low current plasmatron fuel converter having enlarged volume discharges
US6245309B1 (en) Method and devices for producing hydrogen by plasma reformer
US5887554A (en) Rapid response plasma fuel converter systems
EP0715683B1 (en) Plasmatron-internal combustion engine system
US5852927A (en) Integrated plasmatron-turbine system for the production and utilization of hydrogen-rich gas
US6651597B2 (en) Plasmatron having an air jacket and method for operating the same
US7591242B2 (en) Plasma reformer and internal combustion engine system having the same
US7407634B2 (en) Plasmatron fuel converter having decoupled air flow control
Bromberg et al. Hydrogen manufacturing using low current, non-thermal plasma boosted fuel converters
KR101405543B1 (en) Non-thermal Plasma Device for Activating Reaction in the Gasification and Combustion
KR20040029388A (en) Chemical processing using non-thermal discharge plasma
WO2007084335A2 (en) Plasma reformer with extended volume discharge
Gallagher Jr Partial oxidation and autothermal reforming of heavy hydrocarbon fuels with non-equilibrium gliding arc plasma for fuel cell applications
Khoobroo et al. On the efficiency of the fuel cell vehicles with onboard hydrogen generation
CN101209815B (en) Plasma reformer and internal combustion engine system having the plasma reformer
RU2769172C1 (en) Steam plasma burner device with in-cycle gasification of fuel
RU205967U1 (en) STEAM PLASMA BURNER WITH INTERNAL CYCLE GASIFICATION OF FUEL
KR100998918B1 (en) Reforming Device and Reforming Method
Majidi et al. Boosting CO₂ utilization in dry methane reforming using a two-stage DC-pulsed spark cold plasma reactor
Akbiyik et al. Hydrogen Application of Plasmatron Technology in Fuel Preparation and Mitigation of Exhaust Emissions
JP2001055907A (en) Closed-cycle power system and moving body
MXPA99006005A (en) Method and devices for producing hydrogen by plasma reformer

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA JP

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AM AZ BY KG KZ MD RU TJ TM

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 2391851

Country of ref document: CA