PLASMA REACTOR

• US 20100329940A1
• Filed: 06/01/2010
• Published: 12/30/2010
• Est. Priority Date: 06/25/2009
• Status: Abandoned Application

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: SHIMIZU, Naohiro, MIZUNO, Hiroshi, TAKAHASHI, Michio
• Application Number:
  US12/791,157
• Publication Number:
  US 20100329940A1
• Time in Patent Office: Days
• US Class Current: 422/186.04
• CPC Class Codes: B01J 19/088 giving rise to electric discharges for heating purposes H05B7/00; for the production of ozone C01B13/11, H01T19/00
• CPC Class Codes: B01J 2219/0811 employing three electrodes
• CPC Class Codes: B01J 2219/0826 essentially linear
• CPC Class Codes: B01J 2219/083 cylindrical
• CPC Class Codes: B01J 2219/0833 forming part of a full circle
• CPC Class Codes: B01J 2219/0841 Metal
• CPC Class Codes: B01J 2219/0843 Ceramic
• CPC Class Codes: B01J 2219/0883 Gas-gas
• CPC Class Codes: B01J 2219/0892 involving catalytically active material
• CPC Class Codes: B01J 2219/0894 Processes carried out in the presence of a plasma
• CPC Class Codes: C01B 13/11 by electric discharge
• CPC Class Codes: C01B 2203/0233 the reforming step being a steam reforming step
• CPC Class Codes: C01B 2203/0244 the reforming step being an autothermal reforming step, e.g. secondary reforming processes
• CPC Class Codes: C01B 2203/0261 containing a catalytic partial oxidation step [CPO]
• CPC Class Codes: C01B 2203/0861 by plasma
• CPC Class Codes: C01B 2203/1041 Composition of the catalyst
• CPC Class Codes: C01B 2203/1052 Nickel or cobalt catalysts
• CPC Class Codes: C01B 2203/1058 Nickel catalysts
• CPC Class Codes: C01B 2203/1064 Platinum group metal catalysts
• CPC Class Codes: C01B 2203/107 Platinum catalysts
• CPC Class Codes: C01B 2203/1217 : Alcohols
• CPC Class Codes: C01B 2203/1223 : Methanol
• CPC Class Codes: C01B 2203/1229 : Ethanol
• CPC Class Codes: C01B 2203/1235 : Hydrocarbons
• CPC Class Codes: C01B 2203/1241 : Natural gas or methane
• CPC Class Codes: C01B 2203/1247 : Higher hydrocarbons
• CPC Class Codes: C01B 3/342 : with the aid of electrical means, electromagnetic or mechanical vibrations, or particle radiations
• CPC Class Codes: C01B 3/38 : using catalysts
• CPC Class Codes: C01B 3/382 : Multi-step processes
• CPC Class Codes: C01B 3/386 : Catalytic partial combustion
• CPC Class Codes: H05H 1/2406 : using dielectric barrier discharges, i.e. with a dielectric interposed between the electrodes
• CPC Class Codes: H05H 1/245 : the plasma being activated using internal electrodes

Abstract

A plasma reactor includes a reaction container having an inlet 4 for a reforming target gas and an outlet for a reformed gas, a pair of electrodes that generate plasma and are disposed opposite to each other in an inner space of the reaction container, a pulse power supply that applies a voltage between the pair of electrodes, and a catalyst that promotes a reforming reaction of the reforming target gas, one electrode being a honeycomb electrode that is formed of a conductive ceramic and includes a plurality of cells that are defined by a partition wall, the other electrode being disposed opposite to an end face of the honeycomb electrode, the catalyst being supported on the partition wall of the honeycomb electrode, and a concave surface being formed in a center area of the end face of the honeycomb electrode that opposes the opposite electrode.

Claims

1. A plasma reactor comprising a reaction container that has an inlet for a reforming target gas and an outlet for a reformed gas, a pair of electrodes that generate plasma and are disposed opposite to each other in an inner space of the reaction container, a pulse power supply that applies a voltage between the pair of electrodes, and a catalyst that promotes a reforming reaction of the reforming target gas,

one of the pair of electrodes being a honeycomb electrode that is formed of a conductive ceramic and includes a plurality of cells that are defined by a partition wall and serve as a gas passage;

the other of the pair of electrodes being an opposite electrode that is disposed opposite to an end face of the honeycomb electrode;

the catalyst being supported on the partition wall of the honeycomb electrode; and

a concave surface being formed in a center area of the end face of the honeycomb electrode that is opposite to the opposite electrode.

2. The plasma reactor according to claim 1, wherein a peripheral area of the end face of the honeycomb electrode that is opposite to the opposite electrode is formed tabularly, and the concave surface is formed in the center area of the end face of the honeycomb electrode.

3. The plasma reactor according to claim 1, wherein the opposite electrode has a convex surface at an end thereof.

4. The plasma reactor according to claim 3, wherein the convex surface of the opposite electrode has the same curvature as that of the concave surface of the honeycomb electrode.

7. The plasma reactor according to claim 1, wherein the opposite electrode is formed of a conductive ceramic.

9. The plasma reactor according to claim 1, wherein the honeycomb electrode is provided with an auxiliary electrode that is formed of a metal or an alloy and protrudes from the center area of the end face of the honeycomb electrode opposite to the opposite electrode toward the opposite electrode, the auxiliary electrode being disposed so that part of the auxiliary electrode is embedded in the honeycomb electrode and a remainder of the auxiliary electrode protrudes from the end face of the honeycomb electrode.

11. The plasma reactor according to claim 9, comprising at least a pair of opposite electrodes that are disposed on either side of the honeycomb electrode as the opposite electrode, and at least a pair of auxiliary electrodes that respectively protrude toward a corresponding opposite electrode of the pair of opposite electrodes as the auxiliary electrode.

13. The plasma reactor according to claim 11, wherein the auxiliary electrode is disposed to pass through the honeycomb electrode so that each end of the auxiliary electrode protrudes respectively from each end face of the honeycomb electrode.

15. The plasma reactor according to claim 1, further comprising a blocking member that is formed of an insulating material and blocks inflow of the reforming target gas that has passed through an area other than a plasma generation area, the blocking member protruding into a space between the opposite electrode and the honeycomb electrode so that an outer circumferential area of a gas-introducing end face of the honeycomb electrode is covered.

17. The plasma reactor according to claim 15, wherein the blocking member is formed of an insulating ceramic.

19. The plasma reactor according to claim 1, wherein the honeycomb electrode is formed of a conductive ceramic that includes silicon carbide.

20. The plasma reactor according to claim 1, wherein the pulse power supply is a high-voltage pulse power supply that utilizes a static induction thyristor.

5. A plasma reactor comprising a reaction container that has an inlet for a reforming target gas and an outlet for a reformed gas, a pair of electrodes that generate plasma and are disposed opposite to each other in an inner space of the reaction container, a pulse power supply that applies a voltage between the pair of electrodes, and a catalyst that promotes a reforming reaction of the reforming target gas,

one of the pair of electrodes being a honeycomb electrode that is formed of a conductive ceramic and includes a plurality of cells that are defined by a partition wall and serve as a gas passage;

the other of the pair of electrodes being an opposite electrode that is disposed opposite to an end face of the honeycomb electrode;

the catalyst being supported on the partition wall of the honeycomb electrode; and

the honeycomb electrode being electrically connected to the pulse power supply through a sheet-like conductive member that is formed of a metal and is disposed to come in contact with an outer circumferential surface of the honeycomb electrode.

6. The plasma reactor according to claim 5, wherein the sheet-like conductive member is formed of Cu or a Cu alloy.

8. The plasma reactor according to claim 5, wherein the opposite electrode is formed of a conductive ceramic.

10. The plasma reactor according to claim 5, wherein the honeycomb electrode is provided with an auxiliary electrode that is formed of a metal or an alloy and protrudes from the center area of the end face of the honeycomb electrode opposite to the opposite electrode toward the opposite electrode, the auxiliary electrode being disposed so that part of the auxiliary electrode is embedded in the honeycomb electrode and a remainder of the auxiliary electrode protrudes from the end face of the honeycomb electrode.

12. The plasma reactor according to claim 10, comprising at least a pair of opposite electrodes that are disposed on either side of the honeycomb electrode as the opposite electrode, and at least a pair of auxiliary electrodes that respectively protrude toward a corresponding opposite electrode of the pair of opposite electrodes as the auxiliary electrode.

14. The plasma reactor according to claim 12, wherein the auxiliary electrode is disposed to pass through the honeycomb electrode so that each end of the auxiliary electrode protrudes respectively from each end face of the honeycomb electrode.

16. The plasma reactor according to claim 5, further comprising a blocking member that is formed of an insulating material and blocks inflow of the reforming target gas that has passed through an area other than a plasma generation area, the blocking member protruding into a space between the opposite electrode and the honeycomb electrode so that an outer circumferential area of a gas-introducing end face of the honeycomb electrode is covered.

18. The plasma reactor according to claim 16, wherein the blocking member is formed of an insulating ceramic.