US3242059A - Electrolytic process for production of chlorine and caustic - Google Patents

Electrolytic process for production of chlorine and caustic Download PDF

Info

Publication number
US3242059A
US3242059A US123262A US12326261A US3242059A US 3242059 A US3242059 A US 3242059A US 123262 A US123262 A US 123262A US 12326261 A US12326261 A US 12326261A US 3242059 A US3242059 A US 3242059A
Authority
US
United States
Prior art keywords
anode
cathode
diaphragm
cell
chlorine
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.)
Expired - Lifetime
Application number
US123262A
Inventor
Cottam Ronald Geoffrey
Edwards George Ernest
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.)
Imperial Chemical Industries Ltd
Original Assignee
Imperial Chemical Industries Ltd
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 Imperial Chemical Industries Ltd filed Critical Imperial Chemical Industries Ltd
Application granted granted Critical
Publication of US3242059A publication Critical patent/US3242059A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D1/00—Oxides or hydroxides of sodium, potassium or alkali metals in general
    • 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
    • C25B1/34—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis
    • C25B1/46—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis in diaphragm cells
    • 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
    • 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
    • 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

Definitions

  • the present invention relates to improvements in or relating .to electrolytic cells and particularly electrolytic cells for the manufacture of chlorine and caustic akali from aqueous soutions of an alkali metal chloride. Yet more particularly it relates to cells for the manufacture of chlorine and caustic alkali in which a porous diaphragm separates the anodes and cathodes of each unit cell.
  • Cells of the diaphragm type are widely used for the production of chlorine and caustic alkali by the electrolysis of alkali metal chloride solution.
  • the anodes usually of graphite
  • the cathodes usually of iron or steel
  • the anodes usually of graphite
  • the cathodes usually of iron or steel
  • chlorine is evolved at the anode
  • alkali metal ions are discharged at the cathode and react at the cathode face with water from the electrolyte to form caustic alkali and liberate hydrogen.
  • a porous diaphragm is placed in the anode-cathode gap in order to prevent as far as possible mixing of the hydrogen and chlorine and mixing of the caustic alkali with the incoming brine, which is fed .to the anode side of the diaphragm.
  • every effort is made to keep the anode-cathode gap small, since the resistance of the electrolyte in the gap to the passage of the electrolysing current raises significantly the operating voltage of the cell and consequently the energy consumption.
  • the anode-cathode gap cannot be reduced below a certain minimum distance; an average figure for the minimum gap in a commercial installation for example is approximately /2 inch.
  • the diaphragm is commonly constructed of asbestos and is unsupported at least on the anode side, and if the gap between the anode and diaphragm is made too small the diaphragm tends to be disintegrated by the turbulence caused by the chlorine evolved from the anode; furthermore, mixing of the anode and cathode products can then also reach troublesome proportions. If the anode-cathode gap could be reduced, considerable savings in energy consumption would result.
  • the anode-cathode gap can be eliminated except for the thickness of the diaphragm itself and a thin anode-supporting member when a noble metal of the platinum group, namely platinum, rhodium or iridium, or an alloy consisting essentially of one or more of these metals (such metals and alloys being hereinafter called generically a platinum metal) is employed as the working anode surface.
  • a noble metal of the platinum group namely platinum, rhodium or iridium
  • an alloy consisting essentially of one or more of these metals such metals and alloys being hereinafter called generically a platinum metal
  • a cell for the manufacture of chlorine and caustic alkali by the electrolysis of alkali metal chloride solution consists essentially of a non-conducting porous diaphragm held between and in contact with a foraminate sheet metal cathode and a foraminate sheet titanium anode support, and an anode which is a coating of a platinum metal as hereinbefore defined on the said anode support.
  • the anode coating is most suitably applied only to those surfaces of the anode support which are not in contact with the diaphragm.
  • foraminate sheet is intended to mean a perforate or reticulate sheet such as a multi-holed or perforated sheet, a gauze, or a sheet of expanded metal which, if desired, may be flattened.
  • titanium includes a titanium alloy consisting essentially of titanium.
  • the diaphragm is no longer unsupported even on the anode side, so that the effect of turbulence in the electrolyte owing to evolution of chlorine from the anode placed close to the diaphragm in causing mechanical damage to the diaphragm is minimised.
  • both the foraminate titanium anode support and the foraminate cathode are in contact with the diaphragm, we have found surprisingly that very little mixing of anode and cathode products takes place through the diaphragm.
  • the anode and cathode are separated only by a distance approximately equal to the aggregate thickness of the diaphragm and the foraminate titanium anode support, and since the diaphragm and anode support can be quite thin, the resistance of the electrolyte to the passage of the elec trolysing current between anode and cathode is very much lower than in conventional diaphragm cells.
  • a cell according to the invention can be operated at a current density three times greater than conventional diaphragm cells for the same cell voltage.
  • the electrolytic cell of the present invention thus provides a very compact installation for the manufacture of chlorine and caustic alkali at high energy efficiency.
  • the diaphragm may be constructed from a non-conducting porous material which is substantially inert to the electrolyte and the products of electrolysis, for example asbestos or an ion exchange resin.
  • the preferred mate rial is asbestos; for example one or more layers of asbestos paper or asbestos fabric may be employed or a diaphragm may be formed by depositing asbestos fibres from a slurry on to one side of the foraminate metal cathode material before assembling the cell.
  • the cathode may consist of one or more layers of foraminate iron, steel or titanium sheet or it may be a coating of a platinum metal as hereinbefore defined on a foraminate sheet titanium metal support. In order to economise on the use of expensive platinum metal the cathode coating, when used, is most suitably applied only to those surfaces of the titanium sheet which are not in contact with the diaphragm.
  • the platinum metal anode material, and the platinum metal cathode coating if used, may be applied to the supporting titanium metal in any known manner.
  • a layer of platinum metal may be electrolytically deposited on the titanium surface or the platinum metal may be deposited by metal spraying or by painting the titanium structure with a conventional metallising solution and subsequently heating in the manner practised in the ceramic industry. It is preferred to deposit the anode coating of a platinum metal on the titanium by the painting and heating technique, since coatings produced in this manner have a low overvoltage for chlorine evolution.
  • a part of the titanium surface which will be in contact with the cell diaphragm may unavoidably receive a coating of the platinum metal. This is not objectionable but such deposit appears to serve no useful purpose and for reasons of economy we prefer to avoid it as far as possible.
  • FIG. 1 shows schematically a horizontal section through a unit cell according to one embodiment of the invention.
  • 1 is a diaphragm inch thick of asbestos fibres held between anode support 2, which is a sheet of expanded titanium metal, and cathode 3, which suitably may consist of a layer of steel gauze backed by a number of layers of eX- panded sheet steel, the gauze layer being in contact with the diaphragm.
  • anode 4 is the anode, which is a coating of a platinum metal suitably carried on those surfaces of anode support 2 which are not in contact with diaphragm 1
  • the whole electrode and diaphragm assembly is held in carriers of resilient material 5, which together with side members 6 and the base and cover of the cell (not shown) enclose anode compartment 7 and cathode compartment 8.
  • Clamping means (not shown) applied to side members 6 maintain pressure on resilient carriers so that anode support 2 and cathode 3 are in close contact With diaphragm 1 and leakage of electrolyte and product gases between anode compartment 7 and cathode compartment 8 around the edges of the electrode and diaphragm assembly are prevented.
  • alkali metal chloride solution is fed continuously as shown at 9 to anode compartment 7 under sufiicient pressure to maintain anode compartment 7 full of electrolyte and to cause percolation of electrolyte through the electrode assembly and diaphragm into cathode compartment 8.
  • Causticised elecrolyte is withdrawn continuously from cathode compartment 8 as shown at 10.
  • Current of the polarity shown is supplied to the cell through anode support 2 and cathode 3. Exits (not shown) are also provided in or near the top of the cell for the removal of chlorine and hydrogen gas from anode compartment 7 and cathode compartment 8, respectively.
  • Causticised electrolyte may be allowed to drain freely from cathode compartment 8 or this compartment may be maintained full of electrolyte. We prefer to operate with a filled cathode compartment as this ensures the same pressure of electrolyte on all areas of the diaphragm and an even electrolyte percolation rate over the whole area.
  • FIG. 2 shows how any number of unit cells may be combined for feeding in parallel with electric current.
  • 5 unit cells 11 are illustrated in FIG. 2 and it will be seen that these are arranged so that neighbouring pairs have cathodes and anode alternately facing so that cathode and anode compartments are formed alternately between pairs of cells, the neighbouring cells being spaced apart from each other by insulating spacers i2.
  • 1, 2 ,3 and 4 are diaphragms, anode supports, cathodes, and anodes, and 7 and 8 are anode and cathode compartments respectively, as in FIG. 1.
  • Current of the polarity shown is fed to anode supports 2 and cathodes 3.
  • FIGS. 3, 4 and 5 show various ways in which unit cells according to the invention may be combined in a bipolar series arrangement.
  • FIG. 3 shows three unit cells 11, in each of which the component parts 1, 2, 3 and 4 are as in FIG. 1. Neighbouring cells are spaced apart by corrugated titanium sheets 13, which also act as current connections between the cells and provide anode compartments 7 and cathode compartments 8 on opposite sides of each corrugated sheet.
  • FIG. 4 shows a combination of two unit cells 11 spaced apart from each other by insulating spacers 14 and separator 15 to provide anode compartment 7 and cathode compartment 8.
  • Separator 1.5 may be an insulating material such as concrete or very suitably it may be a sheet of titanium metal.
  • FIG. 16 is the current connection from the anode support 2 of one unit cell to the cathode 3 of the next unit cell.
  • the arrangement of FIG. 5 is similar to that of FIG. 4 but has the advantage that the need for the external current connection 16 of FIG. 4 has been eliminated by replacing spacers 14 and separator 15 of FIG. 4 by the combined member 17 which is constructed of titanium so that titanium member 17 new acts as spacer, separator and current connection between the two unit cells 11 shown. it will be understood that any number of unit cells 11 may be combined in a bipolar arrangement in the manner of FIGS. 3, 4or 5.
  • the following table illustrates the high current loading and high energy efiiciency achievable when operating a unit cell according to the invention for the electrolysis of sodium chloride solution.
  • the electrode and diaphragm assembly of this unit cell was constructed in the following manner Anode support: ZO-gauge titanium metal sheet expanded to 62 mesh per foot. and then flattened to 58 mesh per foot.
  • Anode Platinum metal applied by painting on those surfaces of the expanded titanium metal anode support which are not in contact with the diaphragm to give a deposit of 47.4 g. of platinum metal per m
  • Cathode One sheet of 25-gauge steel wire gauze with 24 mesh per inch, in contact with the diaphragm, backed by 5 sheets of 20-gauge steel expanded to 7 mesh per inch.
  • Diaphragm Asbestos fibre layer inch thick deposited on the cathode gauze layer under vacuum from a slurry of asbestos fibre in causticised cell liquor.
  • a process for the manufacture of chlorine and caustic which comprises passing an alkali metal chloride solution into an electrolytic cell from the anode side, electrolyzing said alkali metal chloride solution in said cell, withdrawing caustic solution from the cathode side of said cell and withdrawing chlorine from the anode side of said cell, said cell comprising a non-conducting porous diaphragm held between and in contact with a foraminous sheet metal cathode and a foraminous sheet titanium anode support, and an anode which is a coating of a platinum metal on said anode support.
  • the cathode comprises a coating of a platinum metal on a titanium support.
  • UNITED STATES PATENTS 4 A process according to claim 1 wherein said platinurn metal anode is coated on those surfaces of the fi ig gg z n titanium anode support which are not in contact with the 5 2955999 10/1960 Tine dlaphragm- 3,074,858 1/1963 Riding 204-290 5.
  • FOREIGN PATENTS 6 A process according to claim 1 wherein the cathode 221,757 10/1958 Australia.

Description

arch 22, 1966 COTTAM ETAL 3,242,059
ELECTROLYTIC PROCESS FOR PRODUCTION OF CHLORINE AND CAUSTIC Filed July 11 1961 I2 Sheets-Sheet l FIG.I
L FD :j I I tIZIH 'T\ J T W T Q I I 11 I2 H II II II uvunvrans Row/710 a onwe corr/m FI 2 GEORGE ERA/57 50mm:
March 22, 19 66 R. G. COTTAM ETAL 3,242,059
ELECTROLYTIC PROCESS FOR PRODUCTION OF CHLORINE AND CAUSTIC 2 Sheets-Sheet 2 Filed July 11, 1961 FIG. 3
FIG.5
FIG.4
Fan/A10 GEOFFREY GOTTA/'4 GEORGE ERNEST 5014 0805 M f :ZWJZZLLM 5y M flTTOR/VEVS United States Patent 3,242,059 ELECTRQLYTIC PROCESS FUR PRODUCTION 0F CHLORHNE AND CAUSTIC Ronald Geoifrey Cottam and George Ernest Edwards,
both of Widnes, England, assignors to Imperial Chemical Industries Limited, Millbank, London, England, a corporation of Great Britain Filed July 11,1961, Ser. No. 123,262 Claims priority, application Great Britain, July 11, 1960, 24,082/60 7 Claims. (Cl. 204-98) "The present invention relates to improvements in or relating .to electrolytic cells and particularly electrolytic cells for the manufacture of chlorine and caustic akali from aqueous soutions of an alkali metal chloride. Yet more particularly it relates to cells for the manufacture of chlorine and caustic alkali in which a porous diaphragm separates the anodes and cathodes of each unit cell.
Cells of the diaphragm type are widely used for the production of chlorine and caustic alkali by the electrolysis of alkali metal chloride solution. In such cells the anodes, usually of graphite, and the cathodes, usually of iron or steel, are fixed and are spaced apart in the alkali metal chloride electrolyte. As current is passed through the electrolyte between anode and cathode, chlorine is evolved at the anode and alkali metal ions are discharged at the cathode and react at the cathode face with water from the electrolyte to form caustic alkali and liberate hydrogen. A porous diaphragm is placed in the anode-cathode gap in order to prevent as far as possible mixing of the hydrogen and chlorine and mixing of the caustic alkali with the incoming brine, which is fed .to the anode side of the diaphragm. In operating cells of this type every effort is made to keep the anode-cathode gap small, since the resistance of the electrolyte in the gap to the passage of the electrolysing current raises significantly the operating voltage of the cell and consequently the energy consumption. In all known types of diaphragm cell, however, the anode-cathode gap cannot be reduced below a certain minimum distance; an average figure for the minimum gap in a commercial installation for example is approximately /2 inch. The diaphragm is commonly constructed of asbestos and is unsupported at least on the anode side, and if the gap between the anode and diaphragm is made too small the diaphragm tends to be disintegrated by the turbulence caused by the chlorine evolved from the anode; furthermore, mixing of the anode and cathode products can then also reach troublesome proportions. If the anode-cathode gap could be reduced, considerable savings in energy consumption would result. We have now found surprisingly that in a diaphragm cell for the production of chlorine and caustic alkali the anode-cathode gap can be eliminated except for the thickness of the diaphragm itself and a thin anode-supporting member when a noble metal of the platinum group, namely platinum, rhodium or iridium, or an alloy consisting essentially of one or more of these metals (such metals and alloys being hereinafter called generically a platinum metal) is employed as the working anode surface. In selecting alloys consisting essentially of one or more of the metals platinum, rhodium and iridium we do not exelude alloys which contain a small proportion of other metals, for instance the remaining metals of the platinum group.
According to the present invention, a cell for the manufacture of chlorine and caustic alkali by the electrolysis of alkali metal chloride solution consists essentially of a non-conducting porous diaphragm held between and in contact with a foraminate sheet metal cathode and a foraminate sheet titanium anode support, and an anode which is a coating of a platinum metal as hereinbefore defined on the said anode support. In order to economise on the use of expensive platinum metal, the anode coating is most suitably applied only to those surfaces of the anode support which are not in contact with the diaphragm.
The term foraminate sheet is intended to mean a perforate or reticulate sheet such as a multi-holed or perforated sheet, a gauze, or a sheet of expanded metal which, if desired, may be flattened. The term titanium includes a titanium alloy consisting essentially of titanium.
In an electrolytic cell according to the present invention .the diaphragm is no longer unsupported even on the anode side, so that the effect of turbulence in the electrolyte owing to evolution of chlorine from the anode placed close to the diaphragm in causing mechanical damage to the diaphragm is minimised. Although both the foraminate titanium anode support and the foraminate cathode are in contact with the diaphragm, we have found surprisingly that very little mixing of anode and cathode products takes place through the diaphragm. Furthermore, since the anode and cathode are separated only by a distance approximately equal to the aggregate thickness of the diaphragm and the foraminate titanium anode support, and since the diaphragm and anode support can be quite thin, the resistance of the electrolyte to the passage of the elec trolysing current between anode and cathode is very much lower than in conventional diaphragm cells. We have in fact found that a cell according to the invention can be operated at a current density three times greater than conventional diaphragm cells for the same cell voltage. The electrolytic cell of the present invention thus provides a very compact installation for the manufacture of chlorine and caustic alkali at high energy efficiency.
In an electrolytic cell according to the invention the diaphragm may be constructed from a non-conducting porous material which is substantially inert to the electrolyte and the products of electrolysis, for example asbestos or an ion exchange resin. The preferred mate rial is asbestos; for example one or more layers of asbestos paper or asbestos fabric may be employed or a diaphragm may be formed by depositing asbestos fibres from a slurry on to one side of the foraminate metal cathode material before assembling the cell. The cathode may consist of one or more layers of foraminate iron, steel or titanium sheet or it may be a coating of a platinum metal as hereinbefore defined on a foraminate sheet titanium metal support. In order to economise on the use of expensive platinum metal the cathode coating, when used, is most suitably applied only to those surfaces of the titanium sheet which are not in contact with the diaphragm.
The platinum metal anode material, and the platinum metal cathode coating if used, may be applied to the supporting titanium metal in any known manner. For example a layer of platinum metal may be electrolytically deposited on the titanium surface or the platinum metal may be deposited by metal spraying or by painting the titanium structure with a conventional metallising solution and subsequently heating in the manner practised in the ceramic industry. It is preferred to deposit the anode coating of a platinum metal on the titanium by the painting and heating technique, since coatings produced in this manner have a low overvoltage for chlorine evolution. With certain methods of deposition a part of the titanium surface which will be in contact with the cell diaphragm may unavoidably receive a coating of the platinum metal. This is not objectionable but such deposit appears to serve no useful purpose and for reasons of economy we prefer to avoid it as far as possible.
An electrolytic cell according to the present invention may be operated as a unit cell or may be combined in various ways in a multi-cell arrangement. The construction of the unit cell and some useful multi-cell arrangemerits will be discussed with reference to the drawings accompanying the provisional specification, which are schematic representations not to scale. FIG. 1 shows schematically a horizontal section through a unit cell according to one embodiment of the invention. 1 is a diaphragm inch thick of asbestos fibres held between anode support 2, which is a sheet of expanded titanium metal, and cathode 3, which suitably may consist of a layer of steel gauze backed by a number of layers of eX- panded sheet steel, the gauze layer being in contact with the diaphragm. 4 is the anode, which is a coating of a platinum metal suitably carried on those surfaces of anode support 2 which are not in contact with diaphragm 1 The whole electrode and diaphragm assembly is held in carriers of resilient material 5, which together with side members 6 and the base and cover of the cell (not shown) enclose anode compartment 7 and cathode compartment 8. Clamping means (not shown) applied to side members 6 maintain pressure on resilient carriers so that anode support 2 and cathode 3 are in close contact With diaphragm 1 and leakage of electrolyte and product gases between anode compartment 7 and cathode compartment 8 around the edges of the electrode and diaphragm assembly are prevented. In operation, alkali metal chloride solution is fed continuously as shown at 9 to anode compartment 7 under sufiicient pressure to maintain anode compartment 7 full of electrolyte and to cause percolation of electrolyte through the electrode assembly and diaphragm into cathode compartment 8. Causticised elecrolyte is withdrawn continuously from cathode compartment 8 as shown at 10. Current of the polarity shown is supplied to the cell through anode support 2 and cathode 3. Exits (not shown) are also provided in or near the top of the cell for the removal of chlorine and hydrogen gas from anode compartment 7 and cathode compartment 8, respectively. Causticised electrolyte may be allowed to drain freely from cathode compartment 8 or this compartment may be maintained full of electrolyte. We prefer to operate with a filled cathode compartment as this ensures the same pressure of electrolyte on all areas of the diaphragm and an even electrolyte percolation rate over the whole area.
FIG. 2 shows how any number of unit cells may be combined for feeding in parallel with electric current. 5 unit cells 11 are illustrated in FIG. 2 and it will be seen that these are arranged so that neighbouring pairs have cathodes and anode alternately facing so that cathode and anode compartments are formed alternately between pairs of cells, the neighbouring cells being spaced apart from each other by insulating spacers i2. 1, 2 ,3 and 4 are diaphragms, anode supports, cathodes, and anodes, and 7 and 8 are anode and cathode compartments respectively, as in FIG. 1. Current of the polarity shown is fed to anode supports 2 and cathodes 3.
FIGS. 3, 4 and 5 show various ways in which unit cells according to the invention may be combined in a bipolar series arrangement. FIG. 3 shows three unit cells 11, in each of which the component parts 1, 2, 3 and 4 are as in FIG. 1. Neighbouring cells are spaced apart by corrugated titanium sheets 13, which also act as current connections between the cells and provide anode compartments 7 and cathode compartments 8 on opposite sides of each corrugated sheet. FIG. 4 shows a combination of two unit cells 11 spaced apart from each other by insulating spacers 14 and separator 15 to provide anode compartment 7 and cathode compartment 8. Separator 1.5 may be an insulating material such as concrete or very suitably it may be a sheet of titanium metal. 16 is the current connection from the anode support 2 of one unit cell to the cathode 3 of the next unit cell. The arrangement of FIG. 5 is similar to that of FIG. 4 but has the advantage that the need for the external current connection 16 of FIG. 4 has been eliminated by replacing spacers 14 and separator 15 of FIG. 4 by the combined member 17 which is constructed of titanium so that titanium member 17 new acts as spacer, separator and current connection between the two unit cells 11 shown. it will be understood that any number of unit cells 11 may be combined in a bipolar arrangement in the manner of FIGS. 3, 4or 5.
By way of further illustrating the usefulness of the invention the following table illustrates the high current loading and high energy efiiciency achievable when operating a unit cell according to the invention for the electrolysis of sodium chloride solution.
Cell voltage (average) 3.85 volts. Anode current density 4ka./m Sodium chloride feed concentration 305 g./1.NaCl (approx.). Catholyte concentration (average) 141.1 g./1.NaOH. Chlorine current efficiency 95.5%. Chlorine gas analysisna z: Energy consumption per ton of chlorine 3,096 kWh.
The electrode and diaphragm assembly of this unit cell was constructed in the following manner Anode support: ZO-gauge titanium metal sheet expanded to 62 mesh per foot. and then flattened to 58 mesh per foot.
Anode: Platinum metal applied by painting on those surfaces of the expanded titanium metal anode support which are not in contact with the diaphragm to give a deposit of 47.4 g. of platinum metal per m Cathode: One sheet of 25-gauge steel wire gauze with 24 mesh per inch, in contact with the diaphragm, backed by 5 sheets of 20-gauge steel expanded to 7 mesh per inch.
Diaphragm: Asbestos fibre layer inch thick deposited on the cathode gauze layer under vacuum from a slurry of asbestos fibre in causticised cell liquor.
What we claim is:
1. A process for the manufacture of chlorine and caustic which comprises passing an alkali metal chloride solution into an electrolytic cell from the anode side, electrolyzing said alkali metal chloride solution in said cell, withdrawing caustic solution from the cathode side of said cell and withdrawing chlorine from the anode side of said cell, said cell comprising a non-conducting porous diaphragm held between and in contact with a foraminous sheet metal cathode and a foraminous sheet titanium anode support, and an anode which is a coating of a platinum metal on said anode support.
2. A process according to claim 1 wherein the cathode comprises a coating of a platinum metal on a titanium support.
3. A process according to claim 2 wherein the platinum metal cathode is coated on those surfaces of the titanium References Cited by the Examiner support which are not in contact with the diaphragm. UNITED STATES PATENTS 4. A process according to claim 1 wherein said platinurn metal anode is coated on those surfaces of the fi ig gg z n titanium anode support which are not in contact with the 5 2955999 10/1960 Tine dlaphragm- 3,074,858 1/1963 Riding 204-290 5. A process accordmg to claim 1 whereln the diaphragm comprises asbestos. FOREIGN PATENTS 6. A process according to claim 1 wherein the cathode 221,757 10/1958 Australia.
comprises a member of the group consisting of iron and 10 679,334 9/1952 Great Britain. steel.
7. A process according to claim 1 wherein the cathode JOHN MACK Pnmm? Examl'lercomprises titanium. D. R. JORDAN, Assistant Examiner.

Claims (1)

1. A PROCESS FOR THE MANUFACTURE OF CHLORINE AND CAUSTIC WHICH COMPRISES PASSING AN ALKALI METAL CHLORIDE SOLUTION INTO AN ELECTROLYTIC CELL FROM THE ANODE SIDE, ELECTROLYZING SAID ALKALI METAL CHLORIDE SOLUTION IN SAID CELL, WITHDRAWING CAUSTIC SOLUTION FROM THE CATHODE SIDE OF SAID CELL AND WITHDRAWING CHLORINE FROMTHE ANODE SIDE OF SAID CELL, SAID CELL COMPRISING A NON-CONDUCTING POROUS DIAPHRAGM HELD BETWEEN AND IN CONTACT WITH A FORAMINOUS SHEET METAL CATHODE AND A FORAMINOUS SHEET TITANIUM ANODE SUPPORT, AND AN ANODE WHICH IS A COATING OF A PLATINUM METAL OF SAID ANODE SUPPORT.
US123262A 1960-07-11 1961-07-11 Electrolytic process for production of chlorine and caustic Expired - Lifetime US3242059A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB24082/60A GB905141A (en) 1960-07-11 1960-07-11 Improvements in or relating to electrolytic cells

Publications (1)

Publication Number Publication Date
US3242059A true US3242059A (en) 1966-03-22

Family

ID=10206076

Family Applications (1)

Application Number Title Priority Date Filing Date
US123262A Expired - Lifetime US3242059A (en) 1960-07-11 1961-07-11 Electrolytic process for production of chlorine and caustic

Country Status (7)

Country Link
US (1) US3242059A (en)
CH (1) CH433210A (en)
DE (1) DE1252643B (en)
ES (1) ES268960A1 (en)
FI (1) FI42952B (en)
GB (1) GB905141A (en)
NL (2) NL128257C (en)

Cited By (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3379634A (en) * 1965-05-24 1968-04-23 Air Force Usa Zero gravity electrolysis apparatus
US3431193A (en) * 1965-04-30 1969-03-04 Ceskoslovenska Akademie Ved Electrolyzer for a simultaneous production of chlorine and alkaline carbonates
US3464912A (en) * 1966-05-16 1969-09-02 Hooker Chemical Corp Cathode assembly for electrolytic cell
US3506493A (en) * 1964-08-05 1970-04-14 Electrochimica Corp Electrochemical cell having barrier with microporous openings
US3976556A (en) * 1974-12-05 1976-08-24 Oronzio De Nora Impianti Elettrochimici S.P.A. Electrolysis cell
US4046654A (en) * 1976-04-06 1977-09-06 Marc Cole Process for desalination with chlor-alkali production in a mercury diaphragm cell
US4085028A (en) * 1974-11-21 1978-04-18 Electro-Chlor Corporation Electrolytic chlorination device
US4105514A (en) * 1977-06-27 1978-08-08 Olin Corporation Process for electrolysis in a membrane cell employing pressure actuated uniform spacing
US4108742A (en) * 1974-03-09 1978-08-22 Asahi Kasei Kogyo Kabushiki Kaisha Electrolysis
US4108752A (en) * 1977-05-31 1978-08-22 Diamond Shamrock Corporation Electrolytic cell bank having spring loaded intercell connectors
US4110181A (en) * 1975-10-08 1978-08-29 Solvay & Cie Method of handling aqueous solutions of alkali metal hydroxides that are concentrated in respect of alkali metal halides
FR2404056A1 (en) * 1977-09-22 1979-04-20 Kanegafuchi Chemical Ind NEW PROCESS FOR THE ELECTROLYSIS OF AN ALKALINE METAL CHLORIDE SOLUTION USING A CATIONIC EXCHANGER MEMBRANE
US4204920A (en) * 1978-12-06 1980-05-27 Allied Chemical Corporation Electrolytic production of chlorine and caustic soda
US4265719A (en) * 1980-03-26 1981-05-05 The Dow Chemical Company Electrolysis of aqueous solutions of alkali-metal halides employing a flexible polymeric hydraulically-impermeable membrane disposed against a roughened surface cathode
US4276145A (en) * 1980-01-31 1981-06-30 Skala Stephen F Electrolytic anolyte dehydration of castner cells
USRE30864E (en) * 1977-06-27 1982-02-09 Olin Corporation Process for electrolysis in a membrane cell employing pressure actuated uniform spacing
US4315805A (en) * 1979-11-08 1982-02-16 Ppg Industries, Inc. Solid polymer electrolyte chlor-alkali process
US4342629A (en) * 1979-11-08 1982-08-03 Ppg Industries, Inc. Solid polymer electrolyte chlor-alkali process
US4345986A (en) * 1980-06-02 1982-08-24 Ppg Industries, Inc. Cathode element for solid polymer electrolyte
US4364815A (en) * 1979-11-08 1982-12-21 Ppg Industries, Inc. Solid polymer electrolyte chlor-alkali process and electrolytic cell
US4402809A (en) * 1981-09-03 1983-09-06 Ppg Industries, Inc. Bipolar electrolyzer
US4409074A (en) * 1980-07-28 1983-10-11 Kanegafuchi Kagaku Kogyo Kabushiki Kaisha Process for electrolysis of an aqueous alkali metal chloride solution
US4477321A (en) * 1981-01-16 1984-10-16 E. I. Du Pont De Nemours And Company Sacrificial reinforcements in cation exchange membrane
US4489025A (en) * 1973-01-17 1984-12-18 Diamond Shamrock Chemicals Company Preparation of dimensionally stable asbestos diaphragms
US4536263A (en) * 1978-07-27 1985-08-20 Oronzio Denora Impianti Elettrochimici S.P.A. Process for generating halogen using novel electrolysis cell
EP0021625B1 (en) * 1979-06-01 1985-08-28 Asahi Glass Company Ltd. Electrolytic membrane cell
US4560443A (en) * 1983-05-31 1985-12-24 Chevron Research Company Gas diffusion anode
US4569735A (en) * 1977-12-09 1986-02-11 Oronzio De Nora Impianti Elletrochimici, S.P.A. Production of halogens by electrolysis of alkali metal halides in an electrolysis cell having catalytic electrodes bonded to the surface of a solid polymer electrolyte membrane
US4701250A (en) * 1973-01-17 1987-10-20 Eltech Systems Corporation Dimensionally stable asbestos diaphragm coated foraminous cathode
US4749452A (en) * 1981-12-30 1988-06-07 Oronzio De Nora Impianti Elettrochimici S.P.A. Multi-layer electrode membrane-assembly and electrolysis process using same
US4755272A (en) * 1986-05-02 1988-07-05 The Dow Chemical Company Bipolar electrochemical cell having novel means for electrically connecting anode and cathode of adjacent cell units
EP1201609A1 (en) * 1999-05-06 2002-05-02 Japan Science and Technology Corporation Apparatus for oxidatively destructing trace injurious substance
US20100140092A1 (en) * 2008-12-04 2010-06-10 Palo Alto Research Center Incorporated Flow de-ionization using independently controlled voltages
US20110053052A1 (en) * 2009-08-28 2011-03-03 Enerfuel, Inc. Fuel cell composite flow field element and method of forming the same
WO2015200147A1 (en) 2014-06-24 2015-12-30 Chemetics Inc. Narrow gap, undivided electrolysis cell

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4370209A (en) * 1979-02-23 1983-01-25 Ppg Industries, Inc. Electrolytic process including recovery and condensation of high pressure chlorine gas
JPS5693883A (en) * 1979-12-27 1981-07-29 Permelec Electrode Ltd Electrolytic apparatus using solid polymer electrolyte diaphragm and preparation thereof
US4417959A (en) * 1980-10-29 1983-11-29 Olin Corporation Electrolytic cell having a composite electrode-membrane structure
DE3132947A1 (en) * 1981-08-20 1983-03-03 Uhde Gmbh, 4600 Dortmund ELECTROLYSIS CELL
DE3420483A1 (en) * 1984-06-01 1985-12-05 Hoechst Ag, 6230 Frankfurt BIPOLAR ELECTROLYSIS WITH GAS DIFFUSION CATHODE

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1620052A (en) * 1924-09-13 1927-03-08 Farley G Clark Electrolytic apparatus and electrode therefor
US1771091A (en) * 1924-09-01 1930-07-22 Firm Lawaczeck Gmbh Electrolytic cell
GB679334A (en) * 1949-11-30 1952-09-17 Lonza Ag Improvements relating to pressure-operated water electrolyzers
US2955999A (en) * 1957-09-04 1960-10-11 Ionics Self-rectifying electrodialysis unit
US3074858A (en) * 1959-04-15 1963-01-22 Ici Ltd Method for the production of assemblies comprising titanium

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1771091A (en) * 1924-09-01 1930-07-22 Firm Lawaczeck Gmbh Electrolytic cell
US1620052A (en) * 1924-09-13 1927-03-08 Farley G Clark Electrolytic apparatus and electrode therefor
GB679334A (en) * 1949-11-30 1952-09-17 Lonza Ag Improvements relating to pressure-operated water electrolyzers
US2955999A (en) * 1957-09-04 1960-10-11 Ionics Self-rectifying electrodialysis unit
US3074858A (en) * 1959-04-15 1963-01-22 Ici Ltd Method for the production of assemblies comprising titanium

Cited By (42)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3506493A (en) * 1964-08-05 1970-04-14 Electrochimica Corp Electrochemical cell having barrier with microporous openings
US3431193A (en) * 1965-04-30 1969-03-04 Ceskoslovenska Akademie Ved Electrolyzer for a simultaneous production of chlorine and alkaline carbonates
US3379634A (en) * 1965-05-24 1968-04-23 Air Force Usa Zero gravity electrolysis apparatus
US3464912A (en) * 1966-05-16 1969-09-02 Hooker Chemical Corp Cathode assembly for electrolytic cell
US4489025A (en) * 1973-01-17 1984-12-18 Diamond Shamrock Chemicals Company Preparation of dimensionally stable asbestos diaphragms
US4701250A (en) * 1973-01-17 1987-10-20 Eltech Systems Corporation Dimensionally stable asbestos diaphragm coated foraminous cathode
US4108742A (en) * 1974-03-09 1978-08-22 Asahi Kasei Kogyo Kabushiki Kaisha Electrolysis
US4085028A (en) * 1974-11-21 1978-04-18 Electro-Chlor Corporation Electrolytic chlorination device
US3976556A (en) * 1974-12-05 1976-08-24 Oronzio De Nora Impianti Elettrochimici S.P.A. Electrolysis cell
US4110181A (en) * 1975-10-08 1978-08-29 Solvay & Cie Method of handling aqueous solutions of alkali metal hydroxides that are concentrated in respect of alkali metal halides
US4046654A (en) * 1976-04-06 1977-09-06 Marc Cole Process for desalination with chlor-alkali production in a mercury diaphragm cell
US4108752A (en) * 1977-05-31 1978-08-22 Diamond Shamrock Corporation Electrolytic cell bank having spring loaded intercell connectors
US4105514A (en) * 1977-06-27 1978-08-08 Olin Corporation Process for electrolysis in a membrane cell employing pressure actuated uniform spacing
USRE30864E (en) * 1977-06-27 1982-02-09 Olin Corporation Process for electrolysis in a membrane cell employing pressure actuated uniform spacing
FR2404056A1 (en) * 1977-09-22 1979-04-20 Kanegafuchi Chemical Ind NEW PROCESS FOR THE ELECTROLYSIS OF AN ALKALINE METAL CHLORIDE SOLUTION USING A CATIONIC EXCHANGER MEMBRANE
US4268365A (en) * 1977-09-22 1981-05-19 Kanegafuchi Kagaku Kogyo Kabushiki Kaisha Method of electrolysis of an alkali metal chloride
US4569735A (en) * 1977-12-09 1986-02-11 Oronzio De Nora Impianti Elletrochimici, S.P.A. Production of halogens by electrolysis of alkali metal halides in an electrolysis cell having catalytic electrodes bonded to the surface of a solid polymer electrolyte membrane
US4663003A (en) * 1978-07-27 1987-05-05 Oronzio Denora Impianti Elettrochimici S.P.A. Electrolysis cell
US4789443A (en) * 1978-07-27 1988-12-06 Oronzio Denora Impianti Elettrochimici S.P.A. Novel electrolysis cell
US4592822A (en) * 1978-07-27 1986-06-03 Oronzio Denora Impianti Elettrochimici S.P.A. Electrolysis cell
US4536263A (en) * 1978-07-27 1985-08-20 Oronzio Denora Impianti Elettrochimici S.P.A. Process for generating halogen using novel electrolysis cell
US4204920A (en) * 1978-12-06 1980-05-27 Allied Chemical Corporation Electrolytic production of chlorine and caustic soda
EP0021625B1 (en) * 1979-06-01 1985-08-28 Asahi Glass Company Ltd. Electrolytic membrane cell
US4364815A (en) * 1979-11-08 1982-12-21 Ppg Industries, Inc. Solid polymer electrolyte chlor-alkali process and electrolytic cell
US4342629A (en) * 1979-11-08 1982-08-03 Ppg Industries, Inc. Solid polymer electrolyte chlor-alkali process
US4315805A (en) * 1979-11-08 1982-02-16 Ppg Industries, Inc. Solid polymer electrolyte chlor-alkali process
US4276145A (en) * 1980-01-31 1981-06-30 Skala Stephen F Electrolytic anolyte dehydration of castner cells
US4265719A (en) * 1980-03-26 1981-05-05 The Dow Chemical Company Electrolysis of aqueous solutions of alkali-metal halides employing a flexible polymeric hydraulically-impermeable membrane disposed against a roughened surface cathode
US4345986A (en) * 1980-06-02 1982-08-24 Ppg Industries, Inc. Cathode element for solid polymer electrolyte
US4409074A (en) * 1980-07-28 1983-10-11 Kanegafuchi Kagaku Kogyo Kabushiki Kaisha Process for electrolysis of an aqueous alkali metal chloride solution
US4477321A (en) * 1981-01-16 1984-10-16 E. I. Du Pont De Nemours And Company Sacrificial reinforcements in cation exchange membrane
US4402809A (en) * 1981-09-03 1983-09-06 Ppg Industries, Inc. Bipolar electrolyzer
US4749452A (en) * 1981-12-30 1988-06-07 Oronzio De Nora Impianti Elettrochimici S.P.A. Multi-layer electrode membrane-assembly and electrolysis process using same
US4560443A (en) * 1983-05-31 1985-12-24 Chevron Research Company Gas diffusion anode
US4755272A (en) * 1986-05-02 1988-07-05 The Dow Chemical Company Bipolar electrochemical cell having novel means for electrically connecting anode and cathode of adjacent cell units
EP1201609A1 (en) * 1999-05-06 2002-05-02 Japan Science and Technology Corporation Apparatus for oxidatively destructing trace injurious substance
EP1201609A4 (en) * 1999-05-06 2006-12-13 Japan Science & Tech Agency Apparatus for oxidatively destructing trace injurious substance
US20100140092A1 (en) * 2008-12-04 2010-06-10 Palo Alto Research Center Incorporated Flow de-ionization using independently controlled voltages
US8404093B2 (en) * 2008-12-04 2013-03-26 Palo Alto Research Center Incorporated Flow de-ionization using independently controlled voltages
US8652314B2 (en) 2008-12-04 2014-02-18 Palo Alto Research Center Incorporated Flow de-ionization using independently controlled voltages
US20110053052A1 (en) * 2009-08-28 2011-03-03 Enerfuel, Inc. Fuel cell composite flow field element and method of forming the same
WO2015200147A1 (en) 2014-06-24 2015-12-30 Chemetics Inc. Narrow gap, undivided electrolysis cell

Also Published As

Publication number Publication date
DE1252643B (en) 1967-10-26
NL128257C (en)
ES268960A1 (en) 1961-12-16
CH433210A (en) 1967-04-15
FI42952B (en) 1970-09-02
GB905141A (en) 1962-09-05
NL266652A (en)

Similar Documents

Publication Publication Date Title
US3242059A (en) Electrolytic process for production of chlorine and caustic
US4013525A (en) Electrolytic cells
US4927509A (en) Bipolar electrolyzer
US4142950A (en) Apparatus and process for electrolysis using a cation-permselective membrane and turbulence inducing means
US3222270A (en) Multi-electrolytic cells
US3855104A (en) PROCESS AND APPARATUS FOR THE ELECTROLYSIS OF HCl CONTAINING SOLUTIONS WITH GRAPHITE ELECTRODES WHICH KEEP THE CHLORINE AND HYDROGEN GASES SEPARATE
US3849281A (en) Bipolar hypochlorite cell
US3809630A (en) Electrolysis cell with permeable valve metal anode and diaphragms on both the anode and cathode
SU1291029A3 (en) Bipolar electrode
US4204939A (en) Diaphragm cell
RU2062307C1 (en) Electrolytic cell to produce chlorine and alkali
US3755105A (en) Vacuum electrical contacts for use in electrolytic cells
US3910827A (en) Diaphragm cell
EP0383243A2 (en) Electrolyser for chlor-alkali electrolysis, and anode
US3928166A (en) Dimensionally adjustable anode-dimensionally stable diaphragm combination for electrolytic cells
US3948750A (en) Hollow bipolar electrode
US3898149A (en) Electrolytic diaphragm cell
US4121990A (en) Electrolytic cell
CA1106312A (en) Electrolytic cell with membrane
US3390072A (en) Diaphragm electrolytic alkali halogen cell
US4233147A (en) Membrane cell with an electrode for the production of a gas
US3945907A (en) Electrolytic cell having rhenium coated cathodes
US3796648A (en) Electrolytic cell having self-aligning anodes
US2749301A (en) Mercury type, caustic, chlorine cell
US3932261A (en) Electrode assembly for an electrolytic cell