Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G35/00—Reforming naphtha
  • C10G35/16—Reforming naphtha with electric, electromagnetic, or mechanical vibrations; by particle radiation
• • 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
  • C01B32/00—Carbon; Compounds thereof
  • C01B32/40—Carbon monoxide
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G35/00—Reforming naphtha
  • C10G35/02—Thermal reforming
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
  • F23D14/46—Details, e.g. noise reduction means
  • F23D14/68—Treating the combustion air or gas, e.g. by filtering, or moistening
• • 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
  • B01J2219/083—Details relating to the shape of the electrodes essentially linear cylindrical
• • 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
  • B01J2219/0875—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
  • B01J2219/0894—Processes carried out in the presence of a plasma
  • B01J2219/0896—Cold plasma

Definitions

• the present invention is directed to a plasma system and method and, in particular, to an annular electrode discharge, non-thermal plasma device for the pre- treatment of combustion air and method for operating the same.
• a combustion process is generally initiated and maintained by heating the bulk gas to a temperature (typically in the order of approximately 1000°C) where free radicals such as O, OH, H are formed that can initiate dissociation and oxidation reactions.
• a temperature typically in the order of approximately 1000°C
• free radicals such as O, OH, H
• complete molecular conversion will result in the formation of carbon dioxide and water which can be released directly to the atmosphere.
• the chemical efficiency of the molecular conversion depends on the generation and propagation of free radicals, which effectively break carbon bonds.
• Non-Thermal Plasmas are ionized gases which are far from local thermodynamic equilibrium (LTE) and are characterized by having electron mean energies significantly higher than those of ambient gas molecules. In NTP, it is possible to preferentially direct the electrical energy in order to produce highly energetic electrons with minimal, if any, heating of the ambient gas. Instead, the energy is almost entirely utilized to directly excite, dissociate and ionize the gas via electron impact.
• the arc discharge manifests itself as a narrow high temperature filament. These filaments are only 10 microns in diameter thus treating a limited amount of the reactants.
• the treated reactants are heated to temperatures so high that the energy generated by the chemical reaction is miniscule compared to the electrical energy deposited. Attempts to "spread out this" energy to the whole of the fuel air mixture by enhancing the diffusion process, i.e., by introducing turbulence, or by moving the whole arc filament around bodily, e.g., via an applied magnetic field, proved either ineffective or impractical.
• Non-Thermal Plasma can produce energetic electrons, typically in the range of approximately leV -10 eN, which effectively leads to the creation of free radicals without adding to the bulk gas the enthalpy necessary to reach very high temperatures as recognized by Penetrante et al., in the publication entitled “Non-Thermal Plasma Techniques for Abatement of Volatile Organic Compounds and Nitrogen Oxides", INP Report XIII; B. Muller, Ed., pp. 18-46 (1996) and in the book by Tarnovsky V. and Becker K., Plasma Sources Science and Technology, 4, 307 (1995).
• the present invention solves the aforementioned problems by utilizing self- stabilizing discharge electrodes, namely capillary electrodes (as disclosed in U.S. Patent Application Serial No. 09/738,923) and slot electrodes (as disclosed in U.S. Provisional Patent Application No. 60/358,340).
• the present inventive technique is advantageous over the conventional state-of-the-art plasma generation in at least three ways:
• the invention is directed to an apparatus and method for operating the same for enhancing the combustion process and reducing pollution by-products of combustion using non-thermal atmospheric pressure plasma to pre-treat the combustion air. h particular a capillary electrode or slot electrode configuration may be employed to maintain a sufficient volume of plasma to generate the necessary number of free radicals and distribute them throughout the entire volume of the fuel- air mixture.
• An embodiment of the present invention is a device for the pre-treatment of combustion air by exposure to non-thermal plasma at substantially atmospheric pressure.
• the device includes an inner electrode having a longitudinal channel defined therein to receive a fuel.
• An outer dielectric layer is separated a predetermined distance from the inner electrode so as to form a non-thermal atmospheric pressure plasma region therebetween for receiving the combustion air to be treated.
• the outer dielectric has at least one opening (e.g., capillaries or slots) defined therethrough from which the non-thermal plasma is emitted.
• At least one outer electrode e.g., in the shape of a pin or ring
• the treated combustion air and fuel are combined in a mixing region.
• the pretreatment device may be disposed in an unsealed or a sealed combustion burner.
• the invention also discloses a method for operating the device described above wherein the fluid to be treated (combustion air) is received in the non-thermal atmospheric pressure plasma region in which it is exposed to non-thermal plasma. Fuel is received along a separate path so as not to be subject to non-thermal plasma exposure. The fuel and treated fluid are mixed together in a mixing region prior to passing to a combustion region.
• Yet another embodiment of the invention is a device for the pre-treatment of combustion air by exposure to non-thermal plasma at substantially atmospheric pressure, wherein the device has two separate pathways.
• a first pathway receives the combustion air to be treated,.
• This first pathway is formed or defined by an inner electrode and an outer dielectric layer separated a predetermined distance from the inner electrode so as to form a non-thermal atmospheric pressure plasma region therebetween for receiving the combustion air to be treated.
• the outer dielectric has at least one opening defined therethrough through which the non-thermal plasma is emitted, hi addition the device further includes at least one outer electrode disposed in fluid communication with the at least one opening.
• a second pathway receives fuel. The second pathway is separate from the first pathway with the two pathways disposed so that respective outputs thereof form a mixing region for receiving the treated combustion air and fuel.
• Figure 1 is a cross-sectional view of a first exemplary burner arrangement in accordance with the present invention
• Figure 2a is a cross-sectional view of a second exemplary burner arrangement in accordance with the present invention
• Figure 2b is a cross-sectional view of a third exemplary burner arrangement embodiment wherein the solid inner electrode is replaced with a hollow inner electrode, which provides another path to the mixing region that bypasses the plasma treatment region;
• Figure 3 is a cross-sectional view showing the placement of a Segmented Electrode Capillary Discharge system in accordance with the present invention into the air intake of an internal combustion chamber;
• Figure 4a is a perspective view of a section of a cylindrically shaped burner in accordance with the present invention having a slot electrode discharge plasma generation configuration
• Figure 4b is a cross-sectional view of the burner of Figure 4a.
• the segmented electrode capillary discharge, non-thermal plasma reactor in accordance with the present invention is designed so that a fluid being treated, e.g., a gas or a vapor gas mixture, containing one or more chemical agents necessary for combustion (i.e., combustion air, combustible fuel, or some admixture of the two) is subjected to a high density plasma prior to the actual combustion process.
• a fluid being treated e.g., a gas or a vapor gas mixture
• one or more chemical agents necessary for combustion i.e., combustion air, combustible fuel, or some admixture of the two
• the exposure of the fluid to the plasma results in the creation of free radicals that lower the activation energy of combustion and result in lower overall combustion temperature. It is desirable to vary the plasma characteristics so as to be able to specifically tailor chemical reactions to take place by using conditions that effectively initiate or promote desired chemical reactions with minimal, if any, heating of the fluid being treated.
• Figure 1 is a cross-sectional view of a single exemplary annular, segmented electrode plasma pre-treatment burner system in accordance with the present invention.
• the system includes a cylindrical hollow outer dielectric layer 145 and a hollow inner electrode 110 disposed therein.
• the inner electrode 110 is disposed substantially concentric with the outer dielectric layer 145 and separated by a predetermined distance to form a non-thermal atmospheric plasma region 130 therebetween.
• a combustion air inlet port 100 is in fluid communication with non-thermal atmospheric pressure plasma region 130.
• Inner electrode 110 has a channel defined therethrough so as to permit the passage of fuel received through a fuel inlet port 105 without being exposed to plasma. Any combustible material in either a liquid or gaseous state may be used as a fuel source.
• Inner electrode 110 is preferably encased in a dielectric coating or layer 115.
• a plurality of capillaries 125 are preferably defined radially outward in the outer dielectric layer 145. Embedded partially in each capillary is a segmented electrode pin 120.
• combustion air to be treated is received in the combustion air inlet port 100 and enters the non-thermal atmospheric pressure plasma region 130 where it is subject to non-thermal plasma emitted from the capillaries 125 upon applying a voltage differential between the inner electrode 110 and segmented pin electrodes 120.
• the treated combustion air advances through the non-thermal atmospheric pressure plasma region 130 and mixes with fuel received through the hollow channel of the inner electrode 110 in a mixing region 135.
• FIG. 2a A cross-sectional view of a second embodiment of a single annular capillary electrode plasma pre-treatment burner system in accordance with the present invention is shown in Figure 2a.
• Figure 1 A cross-sectional view of a second embodiment of a single annular capillary electrode plasma pre-treatment burner system in accordance with the present invention is shown in Figure 2a.
• Figure 2a A cross-sectional view of a second embodiment of a single annular capillary electrode plasma pre-treatment burner system in accordance with the present invention is shown in Figure 2a.
• Figure 1 A cross-sectional view of a second embodiment of a single annular capillary electrode plasma pre-treatment burner system in accordance with the present invention is shown in Figure 2a.
• Combustion air flows through combustion air pre-treatment unit 200 for plasma treatment prior to mixing with the fuel flowing through fuel port 205.
• the combustion air pre-treatment unit 200 includes a solid inner electrode 210, which preferably has a dielectric outer coating 215.
• a plurality of capillaries 220 are preferably defined radially outward through an outer dielectric 245, some or all of the capillaries 220 may have an electrode pin 225 embedded therein.
• combustion air flows through the passageway or non- thermal atmospheric pressure plasma region 230 defined between the outer dielectric 245 and the inner electrode 210.
• the combustion air is subject to non-thermal plasma emitted from the capillaries 220.
• the combustion air after having been treated by the plasma mixes with the fuel from the fuel port 205 in a mixing region 235 and then the mixture proceeds to a combustion region 240.
• FIG. 2b is a variation of the embodiment shown in Figure 2a.
• the combustion air treatment unit 250 in the embodiment shown in Figure 2b employs a hollow (as opposed to a solid) inner elecfrode 255, which is preferably coated with a dielectric layer 260. Electrically this electrode behaves identically to the solid, inner electrode 210 shown in Figure 2a.
• the hollow channel of the inner electrode 255 serves as an additive port 265 for introducing another substance, e.g., non-treated air or fuel additive, into the mixing region 235, thereby circumventing the non-thermal atmospheric pressure plasma region 230 and preventing mixing of the fuel until reaching the mixing region 235.
• FIG. 1 shows an exemplary plasma pre-treatment unit in accordance with the present invention for use in a non- sealed burner arrangement.
• Figure 3 shows an exemplary plasma pre-treatment unit 300 that may be used, for example, in a sealed burner arrangement like that which may be found on a boiler or employed with an internal combustion chamber such as the cylinder of a car engine.
• the pre-treatment unit may use a fuel in a solid, liquid, gaseous, or any combination of states thereof.
• the device may treat a gaseous fuel-air combination prior to entering the combustion chamber.
• the plasma pre-treatment unit 300 is arranged upstream of the an air intake 305 of a sealed burner/internal combustion chamber represented genetically by the box identified as reference element number 310.
• Plasma pre-treatment unit 300 is similar to the combustion air treatment unit 200 of Figure 2a.
• plasma pre-treatment unit 300 includes an inner electrode 315, which is shown in Figure 3 as being solid but may alternatively have a channel defined therethrough. If a hollow inner electrode is used another chemical additive may be introduced therethrough thereby bypassing the non-thermal atmospheric pressure plasma region 335 and mixing only with the plasma treated air.
• inner electrode 315 has a dielectric coating or layer 320.
• a plurality of electrode pins 330 are partially embedded in respective capillaries defined radially outward through outer dielectric 340.
• Combustion air flows through the non-thermal atmospheric pressure plasma region 335 defined between the inner electrode 315 and the outer dielectric 340 and is subject to the non-thermal plasma emitted from the capillaries 325.
• the plasma treated air which may or may not be mixed with an additive, then proceeds through the air intake 305 into the sealed burner/internal combustion chamber 310.
• the non-thermal plasma is generated using an exemplary segmented capillary discharge configuration wherein the electrodes are pins embedded partially into respective capillaries defined radially therethrough the outer dielectric.
• the electrode pins may be substantially flush with the outer perimeter of the outer dielectric, hi addition, the capillaries need not be defined radially therethrough the outer dielectric but instead may be arranged at any desired angle.
• the shape of the electrode may be modified to be a ring or disk disposed proximate or in contact with the entrance to the capillary. Any geometric configuration of the electrode is contemplated and within the scope of the invention so long as it is in fluid communication with an associated capillary. Alternative configurations, although not exhaustive, are shown and described in U.S. Patent
• FIG. 4a is a perspective view of yet another embodiment of a plasma treatment unit in accordance with the present invention in which the non- thermal plasma is generated using a slot electrode discharge configuration, as disclosed in U.S. Provisional Patent Application No. 60/358,340.
• the slot electrode discharge configuration includes an inner electrode 405, which may be hollow or solid, and is preferably coated with a dielectric layer or coating 410.
• An outer dielectric 415 is disposed preferably concentrically about and separated a predetermined distance from the inner electrode 405 to form a non-thermal atmospheric pressure plasma region 420 therebetween.
• a plurality of slots 400 are defined in the outer dielectric 415 to form a slot electrode discharge. As shown in Figure 4a, the slots 400 are arranged in a longitudinal direction. Alternatively, the slots may be arranged, for example, substantially perpendicular to the longitudinal axis or spirally.
• a power supply (not shown) is connected between the inner electrode 405 and the slot electrode.
• An electrode is embedded in or proximate to the respective slots 400. For example, an electrode in the shape of a tapered blade that is partially inserted or proximate a respective slot.
• FIG. 4b is a cross-sectional view of the plasma treatment unit of Figure 4a employed in an open burner arrangement similar to the one shown in Figure 1.
• the combustion air flows through and is treated in the non-thermal plasma region 420 between the outer dielectric 415 and the inner electrode 405 (which is hollow in this example) by the non-thermal plasma emitted from the slots 400.
• the treated combustion air then enters the mixing region 425 where it mixes with fuel flowing through the hollow channel extending through the inner electrode 405. Thereafter, the mixture enters the combustion region 430.
• the plasma treatment units shown and described above all have an annular shape configuration. It is to be understood that the size and shape of the plasma treatment and, in particular, to the size and shape of the inner and outer electrodes and dielectrics need not necessarily be annular. Any shaped geometry may be used, as desired.

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• 2002
  • 2002-08-02 CA CA002456198A patent/CA2456198A1/en not_active Abandoned
  • 2002-08-02 WO PCT/US2002/024476 patent/WO2003041854A1/en not_active Application Discontinuation
  • 2002-08-02 JP JP2003543732A patent/JP2005508738A/ja active Pending
  • 2002-08-02 EP EP02803143A patent/EP1427522A1/en not_active Withdrawn

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