Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
  • C25B9/17—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof
  • C25B9/19—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof with diaphragms
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B1/00—Electrolytic production of inorganic compounds or non-metals
  • C25B1/01—Products
  • C25B1/02—Hydrogen or oxygen
  • C25B1/04—Hydrogen or oxygen by electrolysis of water
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
  • C25B9/70—Assemblies comprising two or more cells
  • C25B9/73—Assemblies comprising two or more cells of the filter-press type
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2201/00—Apparatus for treatment of water, waste water or sewage
  • C02F2201/002—Construction details of the apparatus
  • C02F2201/003—Coaxial constructions, e.g. a cartridge located coaxially within another
• • 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
  • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Definitions

• the invention relates to electrolysis of a fluid.
• the invention relates to an electrolysis process and an apparatus for carrying out the process.
• Hydrogen gas produced by electrolysis during the availability of the primary energy has been identified as a viable way to store energy. It can also serve as an energy carrier where hydrogen is produced at the site of the source (nuclear, fossil or renewables) and converted to hydrogen through electrolysis which is then transported to where the energy is required. Hydrogen is further a candidate for fuel for vehicles utilizing high efficient fuel cells.
• the applicant has identified a need for an improved electrolysis cell, and a method of producing gasses by electrolysis, with high current density and efficiency, cheap and simple construction and with high gas purities without the need for subsequent purification.
• an electrolysis apparatus for the production of hydrogen and oxygen, which apparatus includes at least: - two or more tubular electrodes, at least one of which is an inner electrode located in at least one outer electrode; and a separator interposed between the inner and outer electrodes and substantially coextensive therewith.
• One or more of the electrodes may, in use, be an anode.
• One or more of the electrodes may, in use, be a cathode.
• the separator may be positioned between the anode and the cathode so that there is substantially no gap between the separator and the anode, and the separator and the cathode.
• a portion of the separator may be bonded to a support structure associated with the anode and/or the cathode using, for example, an epoxy sealant.
• the electrodes may be made of an apertured conductive material.
• the electrodes may be plated.
• the apertured conductive material may be a sintered body having flow channels extending between the inside and the outside thereof.
• the apertured conductive material may be a single layer mesh.
• the apertured conductive material may be made of two or more layers of mesh.
• the apertured conductive material may be a three dimensional mesh.
• the apertured conductive material may comprise a conductive polymer.
• the polymer may be coated with a conductive material, for example, a metal.
• the apertured conductive material may comprise of silver, nickel, stainless steel or copper.
• the anode and cathode may be substantially concentric.
• a plurality of anodes and cathodes of various diameters may be nested to provide a high electrolysis surface area to electrolysis apparatus volume ratio.
• the cathode and/or anode may be made of one or more first material i.e. the substrate, and plated with a second material or composition of matter which is electrically conductive.
• the anode may be made of a conductive metal, for example, stainless steel mesh.
• the anode may comprise two or more layers of stainless steel mesh.
• the anode may be nickel plated.
• the cathode may be made of a conductive metal, for example, stainless steel mesh.
• the cathode may comprise two or more layers of stainless steel mesh.
• the cathode may be nickel plated.
• the mesh may be nickel plated before or after the layers of stainless steel are placed together.
• One or more of the tubular anode and the cathode may be closed off at one end such that, in use, an overpressure is established within the closed off tubular anode or cathode.
• One or more conductors may be provided in association with the anode and/or the cathode.
• a tubular mesh conductor is provided on the outside of the anode and another on the inside of the cathode.
• the conductors are in the form of one or more conductive strips attached to a portion or portions of the anode and/or the cathode.
• the separator may comprise one or more layers of a fibrous material.
• the separator may comprise one or more layers of a wettable material.
• the separator may comprise one or more layers of a wettable fibrous material.
• the separator may comprise one or more layers of cellulose containing composition.
• the cellulose containing composition may be paper.
• the paper may be a filter paper.
• the filter paper may be chemical resistant filter paper.
• the filter paper may be medium to fast grade filter paper.
• the apparatus may consist of : a tubular apertured stainless steel mesh anode electrode; and a tubular apertured nickel-plated stainless steel cathode electrode, wherein the cathode and anode are substantially concentric and the cathode lies within the anode; and a separator means between the anode and cathode comprising one or more layers of a fibrous material.
• the apparatus may, in use, include an alkaline electrolyte solution.
• the apparatus may, in use, include an acidic electrolyte solution.
• the apparatus may include means for supplying and conducting electrical current to the electrodes.
• the apparatus may include means for drawing off the gasses.
• the apparatus may include means for removing vapour from the generated gasses.
• a plurality of anode and cathode sets may be used in parallel.
• a plurality of anode and cathode sets may be used in series.
• the anode and cathode sets and the conductors may be configured in such a way that a plurality of such sets is arranged around a tubular conductor for the anodes, all in a common electrolyte.
• Each cathode may be connected to its own conductor.
• the invention extends to a separator for an electrolysis apparatus, which , separator is interposed between the anode and the cathode of the apparatus, said separator comprising one or more layers of fibrous material.
• the fibrous material may be wettable.
• the wettable material may be a cellulose containing composition.
• the cellulose containing composition may be paper.
• the paper may be a filter paper.
• the filter paper may be chemical resistant filter paper.
• the filter paper may be medium to fast grade filter paper.
• the invention extends to an electrolysis process carried out in an apparatus substantially as described above.
• the process may include: 5 - establishing a potential difference between the anode and the cathode; and contacting the anode and cathode with an electrolyte from which gasses are liberated by electrolysis.
• the process may include contacting the apparatus with an electrolyte solution of between 10% and 50% by mass of electrolytic salts, typically from 20% to 35% by mass.
• the electrolyte solution may be a KOH, NaOH, or other alkaline solution.
• the electrolyte solution may be acidic.
• the process may be carried out at from 40°C to 100°C, typically from 60°C to 90°C. 20
• the electrodes may be submerged in the electrolyte.
• the electrolyte may be pumped through the separator of the apparatus.
• the electrolyte may be drip fed through the separator, thereby maintaining the separator saturated with electrolyte while minimizing the volume of fluid being circulated.
• FIG. 1 A cross section of an electrode pair 10 is shown in Figure 1 (a).
• the electrodes 12, 14 of the electrode pair 10 are made of a stainless steel mesh.
• the nickel plated copper pipe 22 is used as support and electrical connector to the cathode. It serves also to extract the hydrogen gas.
• the top part of the pipe is covered with insulating material 13 to prevent contact with the electrolyte.
• a cylindrical plastic plug 18 serve as support and seal of the inner cathode.
• the cathode, anode and separator are sealed 16 at the bottom and top ends to prevent any mixing of the gasses.
• the inner electrode 12 i.e. the H 2 cathode consists of two layers of fine mesh stainless steel.
• a copper pipe 22 forms the electrical contact.
• the total length is
• the inner electrode 12 is nickel plated to a thickness of about 200 ⁇ m on the mesh.
• Two layers of medium filter paper 20 are wrapped around this mesh and the end points sealed with epoxy 16
• the outer electrode 14, i.e. the O 2 anode consists of two layers of fine mesh stainless steel.
• the anode 14 is not plated with nickel.
• the bottom of the electrode 14 is sealed with a plastic stopper 18.
• An electrical contact is attached to the anode (not shown).
• the electrode pair is immersed in the electrolyte.
• the electrolyte enters the inner pipe by liquid diffusion through the porous separator.
• the generated gasses are prevented from passing through the separator.
• a plastic pipe 22 provides support.
• the demister 40 consists of a 30 cm 22 mm diameter nickel plated copper pipe.
• the lower half 42 of the pipe contains rolled layers of course mesh stainless steel 44 around a plastic bar 46 with 10 mm diameter. The roll fits snugly in the pipe and traps all KOH spray and condenses most of the water vapour.
• the top half 48 is filled with brass curling to trap the remaining water vapour and cool the gasses down to room temperature. The heat is liberated to the atmosphere by normal convection and radiative cooling.
• a reactor which consists of a transparent plastic jar of 10 cm diameter and height 40 cm was used.
• a KOH solution (25% m/m) was placed in the jar.
• the electrolyte was kept at a constant temperature for each experiment by supplying external heating.
• the electrode pair (as described above) was submerged in the electrolyte.
• the generated gasses pass through demisters 40 on top of the reactor. These demisters 40 trap the KOH spray and water vapour at the high temperatures and deliver cooled dry gasses at room temperature.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
• Electrodes For Compound Or Non-Metal Manufacture (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (2)

Family

ID=9942059

Family Applications (1)

Country Status (9)

Cited By (7)

Families Citing this family (20)

Family Cites Families (10)

• 2002
  • 2002-08-12 GB GBGB0218587.4A patent/GB0218587D0/en not_active Ceased
• 2003
  • 2003-08-11 AU AU2003263114A patent/AU2003263114A1/en not_active Abandoned
  • 2003-08-11 RU RU2005105559/15A patent/RU2005105559A/ru not_active Application Discontinuation
  • 2003-08-11 CN CNA038227703A patent/CN1685083A/zh active Pending
  • 2003-08-11 JP JP2004528155A patent/JP2005535783A/ja active Pending
  • 2003-08-11 EP EP03785306A patent/EP1537257A4/de not_active Withdrawn
  • 2003-08-11 WO PCT/ZA2003/000107 patent/WO2004015172A2/en not_active Ceased
• 2005
  • 2005-02-11 ZA ZA200501239A patent/ZA200501239B/en unknown
  • 2005-08-04 US US10/524,327 patent/US20060011489A1/en not_active Abandoned

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