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
  • C25B15/00—Operating or servicing cells
  • C25B15/08—Supplying or removing reactants or electrolytes; Regeneration of electrolytes
• • 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
  • C25B1/24—Halogens or compounds thereof
  • C25B1/26—Chlorine; Compounds thereof
• • 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
  • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
  • C25B11/02—Electrodes; Manufacture thereof not otherwise provided for characterised by shape or form
  • C25B11/03—Electrodes; Manufacture thereof not otherwise provided for characterised by shape or form perforated or foraminous
  • C25B11/031—Porous electrodes
• • 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

Definitions

• the invention relates to an electrochemical half cell which is particularly suitable for the electrochemical production of chlorine from aqueous solutions of an alkali metal chloride by means of a gas diffusion electrode.
• DE 196 22 744 describes an electrolysis cell for the production of chlorine and sodium hydroxide solution by electrolysis using gas diffusion electrodes when using pressure compensation between the height-dependent pressure of the sodium hydroxide solution before
• Gas diffusion electrode and the constant pressure of the oxygen behind the gas diffusion electrode and the passage of oxygen through gas pockets known.
• the gas diffusion electrode is operated as an oxygen consumption cathode.
• the gas diffusion electrode is an open-pore membrane. This is between electrolyte and
• the . Gas diffusion electrode can e.g. be prepared by the method described in DE-A-37 10 168. However, the tightness of the gas diffusion electrode is only present up to a finite pressure drop between the gas side and the liquid side. Is the
• DE 196 22 744 proposes dividing the gas space into several gas pockets.
• the electrochemical half-cell (Fig. 1 and 2) comprises an electrode chamber 10 is supplied into the 'on a filler neck 12 or the like. Electrolyte. The electrolyte also reaches a liquid space 14 via corresponding connections. The half cell is separated from another half cell via an ion exchange membrane 16. Furthermore, a plurality of gas pockets 18, 20, 22, 24 arranged one above the other are provided. The gas pockets 18, 20, 22, 24 are separated from the electrode space 10 by a gas diffusion electrode 36, which serves as a cathode in DE 196 22 744. The individual gas pockets 18, 20, 22, 24 are via connecting channels
• the gas present in the gas pockets 18, 20, 22, 24 flows through outlet openings 28 into the connecting channels 26 and out of these through inlet openings 30 into the gas pocket lying above.
• the direction of flow of the oxygen, for example, in the gas pockets is shown in FIG. 1 by the dashed arrows 32.
• the lowermost gas pocket 18 is connected to a gas supply device, for example, via a feed connector 34.
• the gas also exits from the upper gas pocket 24 through outlet openings 28 into the rear space 14 of the half cell and is discharged from there together with the electrolyte via a nozzle 11.
• Another disadvantage is that larger amounts of electrolyte get into the gas pocket and have to be removed accordingly. It was found that this. Electrolyte cannot always be completely removed from the gas pocket and therefore accumulates in this gas pocket.
• the electrolyte enrichment in the Gas pocket is favored by the fact that the gas / liquid outlet of the gas pocket is located opposite the gas inlet point. The increased fluid supply is noticeable, for example, by an increase in the electrolysis voltage.
• the object of the invention is to provide an electrochemical half cell with gas pockets in which the risk of electrolyte entering the gas pockets is reduced.
• a retaining element is arranged within the connecting channel through which at least two gas pockets are connected to one another.
• the retention element serves to retain electrolyte located in the connection channel.
• the retaining element can be a retaining element designed like a labyrinth.
• droplets entrained by the gas flow are retained by the retaining element, since they cannot pass through the particularly labyrinthine structure of the retaining element.
• At least the retention element ensures that a large part of the electrolyte does not pass through the retention element.
• a mesh, fabric, braid, fleece or foam is preferably used as the retaining element.
• this is an irregular one
• Fabrics such as a felt-like material, preferably made of metal, plastic or ceramic. In a cost-effective embodiment, this can be a ball of metal wire.
• Another essential element of the invention is the preferred arrangement of the
• Retaining element in the connecting channel An arrangement is preferred here of the retaining element in the area of the inlet opening. This has the advantage that no or at most extremely small amounts of electrolyte can pass through the retaining element.
• the retaining element is preferably arranged in the part of the connecting channel which is filled with gas, the retaining element being arranged closer to the inlet opening than to the electrolyte surface.
• the arrangement of the retaining element in the upper third is particularly preferred.
• the connecting channel or the gas bell particularly advantageously extends over two gas pocket heights. At the lower edge of the lower gas pocket, the gas comes out of the gas pocket and is collected directly through the connecting channel acting as a gas collection device and to the gas inlet opening of the one above it
• the gas inlet opening is preferably located at the upper edge of the gas pocket.
• a corresponding liquid level is established in the connecting channel.
• the retaining element is arranged above this liquid level.
• FIG. 1 shows a schematic cross section through the half cell according to the invention parallel to the gas diffusion electrode according to the prior art.
• Fig. 2 shows a section of a schematic sectional view along the
• FIG. 1 shows a schematic sectional view of a preferred embodiment of the invention, corresponding in principle to the sectional view shown in FIG. 2.
• the structure of the electrochemical half-cell according to the invention corresponds fundamentally to that shown in FIGS. 1 and 2 described structure.
• the same or similar components are therefore designated with the same reference numerals in FIG. 3.
• a retaining element 40 is arranged in the connecting channel 26, which connects the two gas pockets 20, 22 as shown in FIG. 3 as an example.
• the retaining element 40 is, for example, glued into the connecting channel 26 or held in it due to friction. Gas emerges from the lower gas pocket 20 in FIG. 3 through the outlet opening 28 arranged in the lower region of the gas pocket 20. The gas is collected by the connecting channel 26, which is open at the bottom, and rises in this.
• Connection channel 26 is located depending on the pressure of electrolyte 42.
• the height of an electrolyte surface 44 depends on the pressure conditions.
• the gas emerging from the outlet opening 28 flows upward in the direction of the arrow 46 and, at the electrolyte surface 44, enters an area 48 of the connecting channel 26 filled with gas.
• Electrolyte 42 is entrained by the gas bubbles 50 into the area 48 filled with gas.
• the entrained electrolyte is then retained or separated by the retaining element 40, so that no or only small amounts of electrolyte reach the area 52 above the retaining element 40.
• the gas After passing through the retaining element 40, the gas then passes into the gas pocket 22 lying above it through the in the upper region of the
• Corresponding connecting channels 26 described with reference to FIG. 3 with retaining elements 40 provided and arranged according to the invention are also arranged in the connecting channels 26 connecting the other gas pockets 18, 20, 22, 24 (FIG. 1).

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• 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)
• Water Treatment By Electricity Or Magnetism (AREA)
• Hybrid Cells (AREA)

Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

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Family Cites Families (5)

• 2001
  • 2001-10-25 DE DE10152791A patent/DE10152791A1/de not_active Withdrawn
• 2002
  • 2002-10-22 WO PCT/EP2002/011787 patent/WO2003035939A2/de active Application Filing
  • 2002-10-22 AU AU2002350591A patent/AU2002350591A1/en not_active Abandoned
  • 2002-10-22 EP EP02785267A patent/EP1442158A2/de not_active Withdrawn
  • 2002-10-22 KR KR10-2004-7006032A patent/KR20040062953A/ko not_active Application Discontinuation
  • 2002-10-22 CN CNA028210026A patent/CN1575354A/zh active Pending
  • 2002-10-22 JP JP2003538433A patent/JP2005506455A/ja active Pending
  • 2002-10-22 CA CA002464638A patent/CA2464638A1/en not_active Abandoned
  • 2002-10-22 HU HU0401580A patent/HUP0401580A3/hu unknown
  • 2002-10-22 US US10/493,441 patent/US20040262153A1/en not_active Abandoned

Non-Patent Citations (1)

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