CA2103216A1 - Cell - Google Patents
CellInfo
- Publication number
- CA2103216A1 CA2103216A1 CA002103216A CA2103216A CA2103216A1 CA 2103216 A1 CA2103216 A1 CA 2103216A1 CA 002103216 A CA002103216 A CA 002103216A CA 2103216 A CA2103216 A CA 2103216A CA 2103216 A1 CA2103216 A1 CA 2103216A1
- Authority
- CA
- Canada
- Prior art keywords
- cell
- gas
- partition
- electrode
- channel
- 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.)
- Abandoned
Links
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
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/02—Electrodes; Manufacture thereof not otherwise provided for characterised by shape or form
-
- 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
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Hybrid Cells (AREA)
Abstract
ABSTRACT
The invention relates to a cell for electrolysis where gas is generated, which cell comprises separate anode and cathode compartments separated by at least one ion selective membrane (12, 12a, 12b). At least one of the anode and cathode compartments of the cell is designed for electrolysis where gas is generated and comprises at least one substantially vertical electrode (1, 1a, 1b), the front side of which is facing a membrane (12, 12a, 12b), and at least one partition (3a, 3b), so as to form at least two substantially vertical channels (4, 4a, 4b, 5, 5a, 5b) and a space (8) of larger cross-sectional area located above the partition, of which a first channel (4, 4a, 4b) for upward transport of gas-rich electrolyte is defined by the partition and the electrode while a second channel (5, 5a, 5b) for downward transport of gas-deficient electrolyte, as seen from the electrolyte (1, 1a, 1b), is located behind said first channel (4a, 4b), the partition (3a, 3b) being arranged such that gas-rich electro-lyte which is transported upwards in the first channel (4a, 4b) is subjected to a venturi effect so that the main part of the gas is separated off in an area adjacent the upper edge of the electrode and the main part of the electrolyte is recycled downwards through the second channel (5, 5a, 5b). The inven-tion also relates to the making of such a cell and to the use thereof in electrolysis.
The invention relates to a cell for electrolysis where gas is generated, which cell comprises separate anode and cathode compartments separated by at least one ion selective membrane (12, 12a, 12b). At least one of the anode and cathode compartments of the cell is designed for electrolysis where gas is generated and comprises at least one substantially vertical electrode (1, 1a, 1b), the front side of which is facing a membrane (12, 12a, 12b), and at least one partition (3a, 3b), so as to form at least two substantially vertical channels (4, 4a, 4b, 5, 5a, 5b) and a space (8) of larger cross-sectional area located above the partition, of which a first channel (4, 4a, 4b) for upward transport of gas-rich electrolyte is defined by the partition and the electrode while a second channel (5, 5a, 5b) for downward transport of gas-deficient electrolyte, as seen from the electrolyte (1, 1a, 1b), is located behind said first channel (4a, 4b), the partition (3a, 3b) being arranged such that gas-rich electro-lyte which is transported upwards in the first channel (4a, 4b) is subjected to a venturi effect so that the main part of the gas is separated off in an area adjacent the upper edge of the electrode and the main part of the electrolyte is recycled downwards through the second channel (5, 5a, 5b). The inven-tion also relates to the making of such a cell and to the use thereof in electrolysis.
Description
,~ 21~321~ ~
.. ,~ 1 :;.. :
CEhL
The present invention relates to a cell for electrolysis where gas is generated, which cell comprises separate anode and cathode compartments separated by an ion-selective 5 membrane. The invention also relates to a method for making a -~
cell according to the invention, and to the use of the cell in electrolysis. ;-Many electrolytic processes, e.g. the production of chlorine and alkali, are often carried out in cells having separate anode and cathode compartments separated by one or more ion-selective membranes. The life time of the membrane is drastically shortened owing to mechanical stress and too high a current density, which may appear locally depending on large concentration gradients in the electrolyte. For the membrane to function satisfactory, it must also be in permarlent contact with liquid, which may be difficult to achieve in electrolytic -processes with gas generation, especially with the very short electrode spacings which are aimed at to minimise the consump-tion of electric current.
Chlorine-alkali electrolysis is often performed in two-chamber cells with vertical electrodes, in which the membrane is pressed against the anode by a positive pressure in the cathode compartment. Normally, the electrode extends in each chamber as far up as the upper boundary surface of the cell, and the gas-rich liquid produced during the electrolysis leaves the cell through an outlet, whereupon the gas is separated off. Gas bubbles may get stuck between one of the electrodes, especially the anode, and the membrane, this increasing the electrical resistance of the cell and, hence, decreasing current efficiency. Another problem is the migra-tion of hydroxide ions through the membrane into the anode compartment, which give rise to undesired side reactions, unless being quickly rinsed off.
To increase the electrolyte flow between the electrode and the membrane and to promote-the removal of gas bubbles, electrodes have been designed which are provided with differ-ent types of channels on the surface, as described in EP-A 415 896 and EP-A 533 237 The patent literature also discloses electrolytic cells ~ ~ ~321~
with internal circulation, which are described e.g. in US
Patent 3,647,672, DE-A1 33 23 803 and EP-A2 383 243. None of these publications is however concerned with the problem of extending the life time of ion-selective membranes or enhanc-5 ing the efficiency of cells where an ion-selective membrane is pressed against one of the electrodes.
Electrolytic cells with internal circulation are also disclosed in EP-A 99 693, EP-A 311 575, and in US patent 5,130,008.
The invention aims at solving the problem of providing an efficient membrane cell for electrolysis where gas is generated, while considering the life time of the cell membrane. The invention also solves the problem of enhancing the efficiency of an existing membrane cell by a simple 15 modification.
According to the invention, it has been found that both the efficiency of the cell and the life time of the membrane increases if the electrolyte is flowed at a high velocity at the electrode surface. It has also been found possible to 20 prevent the membrane from being directly contacted with gas if this is separated in a region adjacent the upper edge of the electrode.
The invention relates to a cell for electrolysis where gas is generated, which cell comprises separate anode and 25 cathode compartments separat~d by at least one preferably substantially vertical ion-selective membrane. At least one of the anode and cathode compartments of the cell is designed for electrolysis where gas is generated and comprises at least one substantially vertical electrode, the front side of which is 30 facing a membrane, and at least one partition, so as to form at least two substantially vertical channels and a space of larger cross-sectional area located above the partition, of which a first channel for upward transport of gas-rich electrolyte is defined by said partition and the electrode 35 while a second channel for downward transport of gas-deficient electrolyte, as seen from the electrode, is located behind said first channel, said partition being arranged such that gas-rich electrolyte which is transported upwards in said first channel i9 subjected to a venturi effect so that the 2~321~
main part of the gas is separated off in an area adjacent the upper edge of the electrode and the main part of the electro-lyte is recycled downwards through said second channel.
Suitably, the partition is arranged such that from about 50%
to about 98~, preferably from about 70% to about 95~, o~ the electrolyte supplied to the cell chamber is recycled.
Generally, the partition should be placed such that the separation of gas from the electrolyte takes place as high up as possible. The upward transport of the gas-rich electrolyte takes place by the gas which is generated during the electro-lysis producing an upwardly directed pumping force Phy~aul which depends on the height of the channel and on the density difference between gas and liquid, this difference partly depending on the flow velocity. This pumping force must exceed the flow resistance PCha~e~ in the channel which depends on the hydraulic diameter thereof, the friction factor of the material, and the flow velocity. The level of separation is determined by the static pressure difference according to the formula:
P9tat = Phyd~aul Pcha:lnel The static pressure difference is directly proportional to the height to which the pumping force is able to transport the liquid and where the separation starts as foaming. Preferably, the foaminy area extends substantially as far up as the upper edge of the electrode, which in most cells means the upper boundary surface of the cell. As appears from the above, the optimal location of the partition depends on several para-meters, and so the proper position must be tried out in the particular cases by varying the location of the partition both vertically and laterally, and hence the height and cross-section of the channel, so that separation takes place as high up as possible and the desired recirculation is achieved.
The electrode suitably comprises through openings so as to be permeable to electrolyte. All known electrodes intended to be arranged vertically can be used. Examples of known electrodes are perforated plate electrodes, electrodes of expanded metal or fine-meshed netting, electrodes comprising ~ 21 ~321~
-~ 4 longitudinal or transverse rods or slats, and as well as electrodes comprising curved or straight lamellae, which may be vertically or horizontally extended, punched from a common metal sheet, for example louver electrodes. The electrode surface may, but need not, comprise channels for promoting the electrolyte flow on the side facing the membrane. These electrode types are well known and described e.g. in the above-mentioned EP-A 415 896 and EP-A 533 237, as well as in GB Patent Specification 1,324,427.
According to the invention, the anode and cathode compartments may also comprise one or more auxiliary elec-trodes, for example in the form of expanded metal or fine-meshed netting, fixed in and electrically connected to the partition, optionally via spacer means so as to be disposed adjacent the main electrode. This is especially advantageous if the main electrode has a comparatively open structure, for example is a double-sided louver electrode punched from a metal sheet.
. -: . . ,-The electrode may be manufactured from metals such as Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Ag, Pt, Ta, Pb, Al or alloys thereof. Ti or Ti alloys are preferred as anode material, while Fe, Ni or alloys thereof are preferred as cathode material. The electrode is suitably activated by a surface coating of a suitable catalytic material, depending on what reactions should be catalysed. Suitable catalytic materials are metals, metal oxides or mixtures thereof from group 8B in the Periodic table, i.e. Fe, Co, ~i, Ru, Rh, Pd, Os, Ir or Pt, of which Ir and Ru are particularly preferred.
An optional auxiliary electrode preferably consists of the same or similar materials as the electrode and is, like the electrode, provided with a suitable catalytic surface coating.
The partition is preferably arranged substantially parallel to the electrode and has preferably substantially the same lateral extension. Further, the partition is suitably made of an electrically conductive material and is galvanically connected to the electrode, e.g. by being connected to the same current source, this promoting the current distribution in the cell~ An optional auxiliary electrode may have its main current lead-in through the ' ~' .~
~ ', 2 l ~
partition. All materials that can be used for the electrode are also suitable for the partition. Preferably, use is made of the same material for the partition as for the electrode, for example titanium. Normally, the partition need not be activated, although it is of course possible.
The invention can be applied to electrolytic cells where the anode and the cathode are arranged in separate cell chambers for anolyte and catholyte, respectively. These cell chambers may be arranged beside each other and then be separated only by an ion-selective membrane. A cell may also comprise one or more chambers located between the anode and cathode compartments and separated from these and from each other by ion-selective membranes. Both the anode compartment and the cathode compartment suitably comprise an inlet for electrolyte provided in the bottom, and one or more outlets for gas and non-recycled electrolyte provided in the top. The cells are suitably arranged as separate units, for example in an electrolyser of the filter press type. A cell chamber may comprise one or more channels for ascending gas-rich electro-lyte and one or more channels for descending gas-deficient electrolyte.
According to the simplest embodiment, the cell chamber accommodates an electrode and an partition such that the rear channel is defined by the partition and the rear vessel wall of the cell. A cell chamber may also comprise a double-sided electrode, the two sides of which are facing a respective membrane. In this case, two partitions are required which together form a centrally located channel for descending gas-deficient electrolyte and which define, together with a respective electrode side, a respective channel for ascending gas-rich electrolyte. Such a cell chamber is normally of substantially symmetrical design.
A cell according to the invention may also comprise means for conducting part of the recycled electrolyte in the horizontal direction, for the purpose of further reducing the concentration gradients. This can be achieved by means of guide vanes disposed in the upper part of the cell or by varying the level of the upper edge of the partition in the cell.
According to another embodiment, the partition may comprise means for localised admixture of gas-deficient electrolyte to the channel located closest to the electrode for ascending gas-rich electrolyte, which is advantageous for large electrode surfaces, for example exceeding about 0.5 m2, since the concentration gradients in the electrolyte whic~ are detrimental to the membrane can then be reduced. In this embodiment, the channel closest to the electrode may be divided into sections at different levels, which are not in contact with each other but open in a common channel located behind for ascending gas-rich electrolyte. The partition may also quite simply have a number of openings admitting gas-deficient electrolyte to the channel closest to the electrode.
The upper edge of the partition, i.e. where gas separa-tion takes place, may be straight or have recesses in the formof different geometric figures. The upper part of the parti-tion may also comprise openings of different types.
The invention also relates to a method for making an electrolytic cell as described above. The method comprises the step of modifying an existing membrane cell having separate anode and cathode compartments separated by at least one preferably substantially vertical ion-selective membrane, at least one of the anode and cathode compartments comprising at least one substantially vertical electrode, the front side of which is facing the membrane. This modification is performed by providing at least one of the anode and cathode compart~
ments with at least one partition so as to form at least two substantially vertical channels and a space of larger cross-sectional area located above the partition, of which a first channel for upward transport of gas-rich electrolyte is defined by the partition and the electrode while a second channel for downward transport of gas-deficient electrolyte, as seen from the electrode, is located behind the first channel, the partition being arranged such that gas-rich electrolyte which is transported upwards in the first channel is subjected to a venturi effect so that the main part of the gas is separatecl off in an area adjacent the upper edge of the electrode and the main part of the electrolyte is recycled downwards through the second channel. If the electrode in the 2~2-~S
, existing cell chamber i9 comparatively open, for example like certain louver electrodes, it is advantageously made more close by providing its rear side with an auxiliary electrode of e.g. expanded metal or fine-meshed netting. All newly-added parts, such as partitions, auxiliary electrodes and the like, may first be assembled into a unit which is then mounted in the anode and cathode compartments, respectively. In other respects, reference is made to the description of the cell according to the invention.
Finally, the invention relates to a method in electroly-sis where gas is generated, using a cell according to the invention.
Thanks to the invention, it has become possible to considerably increase the flow velocity of the electrolyte through a membrane cell at the same time as the generated gas can be separated from the liquid within the cell but in an area where the e~fect on the sensitive membrane is at a minimum. The life time of the membrane is extended by reducing the pH-gradient and the concentration gradient in the electro-lyte and by raising the liquid level in the electrode gap. Bydisplacing the gas separation zone and shielding it from the electrode gap, the formation of bubbles in the membrane induced by uneven current distribution can be reduced, this solving one of the most serious problems inherent in prior-art membrane cells. A special advantage is that existing cells can be easily modified so as to considerably increase their efficiency and the life time of the membrane.
The invention can be applied to all electrolytic processes which involve gas generation, usually one or more of oxygen, hydrogen gas and chlorine gas, and which can be carried out in membrane cells ha~ing separate anode and cathode compartments. Conceivable processes are the electroly-sis of sodium chloride in aqueous solution to chlorine, hydrogen and alkali, or the electrolysis of sodium sulphate in aqueous solution to oxygen, hydrogen, sulphuric acid and alkali. In the last-mentioned case, use is generally made of a cell where at least one cell chamber without electrodes i9 disposed between the anode and cathode compartments.
The invention is illustrated in the accompanying . ~ , : ~;
~ ? 21~ -.
schematic drawings. It is not restricted there~o, but many other embodiments are conceivable within the scope of the appended claims.
Fig. 1 is a lateral section of a cell with a double-sided electrode, while Fig. 2 is a front section along A-A, and Fig. 3 is a top section along B-B. Fig. 4 is a lateral section of a cell with a single-sided electrode. Figs 5-7 are front sections of three other cell designs. Figs 8a-8f show different designs of a partition. Fig. 9 is a top section showing a detail of a cell according to another embodiment, while Figs 10 and 11 show details in a lateral section along B-B and A-A.
Referring now to Figs 1-3, there is illustrated a cell chamber in the form of an anode compartment or a cathode compartment with an inlet lo for electrolyte disposed in the lower part of one short side, and an outlet 11 for gas and non-recycled liquid disposed in the upper part of the other short side. Further, the cell chamber is of substantially symmetrical design and comprises two main electrodes la, lb of the same polarity, which are preferably interconnected so as to form together a double-sided electrode having a common current lead-in. The electrodes la, lb have openings (not shown) along the surface so as to be permeable to electrolyte.
The cell chamber is defined by two ion-selective membranes 12a, 12b arranged on the front side of and optionally in contact with the respective electrode la, lb. The membranes 12a, 12b constitute boundaries to cell chambers (not shown) with electrodes of opposite polarity, or to cell chambers disposed between the anode and cathode compartments. Two partitions 3a, 3b with the same lateral extension as the e,lectrodes la, lb are arranged in the cell chamber so as to define two outer channels 4a, 4b for ascending gas-rich electrolyte, as well as an inner channel 5 for descending gas-deficient electrolyte. All the channels 4a, 4b, 5 join in a space 8 above the partitions 3a, 3b, and in a space 9 below these, the spaces 8, 9 comprising substantially the entire cross-sectional area of the cell chamber. Spacer members 7 of substantially circular cross-section are arranged in the channel 5 between the two partitions 3a, 3b and are preferably `` .':, ~'~
2 -l ~ 3 ;~
. ~ g connected to the same current source as the main electrodes la, lb. Auxiliary electrodes 2a, 2b, for example in the form of a fine-meshed netting, are arranged adjacent the main electrodes la, lb electrically connected to the spacer members 7 via the partitions 3a, 3b and permeable spacer members 6 which may consist e.g. of expanded metal. Preferably, the main electrodes la, lb as well as the auxiliary electrodes 2a, 2b are activated by a suitable catalytic surface layer. For greater clarity, the width of the channels is greatly exagger-ated in Figs 1 and 3.
Many existing electrolytic cells can be modified byassembling partitions 3a, 3b, spacer members 6, 7 and auxili-ary electrodes into a unit which is then mounted in an anode compartment or a cathode compartment to obtain a cell accord-ing to the illustrated embodiment. All joints or connectionscan normally be achieved by any welding technique suitable for the material, for example spot-welding.
When using the cell, for example in the electrolysis of sodium chloride in aqueous solution to chlorine and alkali, the illustrated cell chamber may advantageously function as anode compartment, the two membranes 12a, 12b constituting boundaries to cathode compartments which are located beside the illustrated anode compartment and designed for internal circulation according to the invention, or are of conventional design. The anode compartment is supplied with sodium chloride solution through the inlet 10, the main part of the electro-lyte being transported upwards in the outer channels 4a, 4b while a minor part passes between the anodes la, lb and the membranes 12a, 12b. In the electrolysis, bubbles of chlorine gas are formed whose density is lower than that of the liquid, this giving rise to a pumping force causing the liquid to rise in the channels 4a, 4b. When the gas-rich electrolyte reaches the space 8, the cross-sectional area increases considerably and a foaming area is formed. The chlorine gas is no longer capable of lifting the liquid but is separated off and leaves through the outlet 11. The major part of the liquid flows back through the inner channel 5 to the space 9 where it is mixed with freshly-supplied electrolyte and is again raised through the outer channels 4a, 4b. The cell functions correspondingly -`` 21~32:~$ ~-in other electrolytic processes.
It has been found that a membrane cell for chlorine-alkali electrolysis where the anode compartment is designed according to the embodiment shown in Figs 1-3, operates excellently if the anodes la, lb have a width of about 1000 mm and a height of about 300 mm, the height of the areas 8, 9 above and below, respectively, the partitions 3a, 3b being about 25 mm, the distance between the two partitions 3a, 3b being about 3 mm and the distance between the partitions 3a, 3b and the respective anode la, lb being about 2 mm.
Fig. 4 shows a cell chamber with only one electrode 1 which is defined by a membrane 12 and a vessel wall 13. A
partition 3 is arranged so as to define a channel 4 for ascending gas-rich electrolyte closest to the electrode 1 and another channel 5 for descending gas-deficient electrolyte at the vessel wall 13. Otherwise, it operates in the same way as the cell chamber in Figs 1-3.
Fig. 5 shows a cell having an inlet 10, two outlets 11, a partition 3, means 7 for supporting the partition 3, and a space 8 above and a space 9 below the partition 3. The upper edge of the partition 3 is highest in the middle, i.e.
straight above the inlet 10 of the cell, and lowers stepwise towards the two outlets. As a result, the horizontal mixing in the cell is promoted. For example, from about 5% to about 10%
of the electrolyte flow is conducted in the horizontal direction from the inlet 10 towards the outlets 11. In a special embodiment, the distance between the upper and lower edges of the partition 3 may be the same throughout the entire cell while the position of the wall 3 is varied such that the height of the space 9 below the partition 3 is small where the . ~ , height of the space ~ above the partition 3 is large. If the electrode of the cell (not shown) is double-sided, an addi- ;
tional partition should be provided before the illustrated partition 3, the means 7 serving as spacers between two -partitions 3.
Fig. 6 shows a cell which differs from that of Fig. 5 only by the location of the inlet 10 and the outlet 11 and, as ~`~
a result thereof, in that the upper edge of the partition 3 is highest at one end and lowest at the other end of the cell.
~"''',' ~
2:~G321~`
- :-. 11 Other features, like the operation, are identical with those of the cell in Fig. 5, to the description of which reference is thus made.
Fig. 7 shows a c~ll similar to that in Fig. 6, except that the partition 3 has the same height along the entire cell, but instead is provided with guide vanes 20 serving to conduct part of the circulating electrolyte in the horizontal direction towards the outlet 11.
Figs 8a-8f illustrate different designs of the upper part of a partition 3. In Figs 8a-8c, the upper edge of the partition 3 is formed with recesses of different shapes, while the partitions 3 shown in Figs 8d-8f are provided with holes of different shapes.
Figs 9-11 show an embodiment which i6 advantageous for very large electrode surfaces. None of the Figures shows the whole cell chamber, but only details thereof. The cell chamber comprises an electrode 1 which is located just behind a membrane (not shown), which together with a rear vessel wall 13 constitutes the boundary surfaces of the chamber. Adjacent the electrode 1, along the entire front side of the cell chamber, extends a channel 4a for ascending gas-rich electro-lyte. The channel 4a is divided into sections at different levels, which are not in direct contact with each other but which in their upper parts 15 open into common collecting channels 4c located behind for ascending gas-rich electrolyte.
The number of sections depends on the height of the electrode and may, for example, be from about 5 to about 10 per metre.
Between the collecting channels 4c are provided channels 5 for descending gas-deficient electrolyte. The channels 5 comprise means 14 for supplying part of the electrolyte flow therein to each section of the channel 4a closest to the electrode. The boundaries between the channels 4a, 4c, 5 consist of parti-tions 3a, 3b. The relative positions of the channels 4a, 4c, 5 appear most clearly from Fig. 9 showing a detail of the cell chamber from above. The number of channels 4b, 4c, 5a, 5b located behind the channel 4a closest to the electrode depends on the width thereof and may, for example, be from about 10 to about 30. The top and the bottom of the cell chamber comprises corresponding spaces ~not shown) having a larger cross-'~.'"' 12 ~1 a3 ~
sectional area as in the embodiments shown in Figs 1-4.
When using the cell chamber according to Figs 9~
recycled gas-deficient electrolyte will flow downwards through the channels 5. Every time the bottom of a section in channel 4a closest to the electrode is passed, part of the gas-deficient electrolyte will be supplied into said section. When the gas-rich electrolyte in a section of said channel 4a reaches the top thereof, the entire flow is fed out into one of the common collecting channels 4c. When the collecting flow : ~:
reaches the top of the cell chamber, the generated gas is separated and the main part of the liquid is recycled through the inner channel 5. ~:
~' ,. :, ~, .: ' :: ' ' ::
.. ,~ 1 :;.. :
CEhL
The present invention relates to a cell for electrolysis where gas is generated, which cell comprises separate anode and cathode compartments separated by an ion-selective 5 membrane. The invention also relates to a method for making a -~
cell according to the invention, and to the use of the cell in electrolysis. ;-Many electrolytic processes, e.g. the production of chlorine and alkali, are often carried out in cells having separate anode and cathode compartments separated by one or more ion-selective membranes. The life time of the membrane is drastically shortened owing to mechanical stress and too high a current density, which may appear locally depending on large concentration gradients in the electrolyte. For the membrane to function satisfactory, it must also be in permarlent contact with liquid, which may be difficult to achieve in electrolytic -processes with gas generation, especially with the very short electrode spacings which are aimed at to minimise the consump-tion of electric current.
Chlorine-alkali electrolysis is often performed in two-chamber cells with vertical electrodes, in which the membrane is pressed against the anode by a positive pressure in the cathode compartment. Normally, the electrode extends in each chamber as far up as the upper boundary surface of the cell, and the gas-rich liquid produced during the electrolysis leaves the cell through an outlet, whereupon the gas is separated off. Gas bubbles may get stuck between one of the electrodes, especially the anode, and the membrane, this increasing the electrical resistance of the cell and, hence, decreasing current efficiency. Another problem is the migra-tion of hydroxide ions through the membrane into the anode compartment, which give rise to undesired side reactions, unless being quickly rinsed off.
To increase the electrolyte flow between the electrode and the membrane and to promote-the removal of gas bubbles, electrodes have been designed which are provided with differ-ent types of channels on the surface, as described in EP-A 415 896 and EP-A 533 237 The patent literature also discloses electrolytic cells ~ ~ ~321~
with internal circulation, which are described e.g. in US
Patent 3,647,672, DE-A1 33 23 803 and EP-A2 383 243. None of these publications is however concerned with the problem of extending the life time of ion-selective membranes or enhanc-5 ing the efficiency of cells where an ion-selective membrane is pressed against one of the electrodes.
Electrolytic cells with internal circulation are also disclosed in EP-A 99 693, EP-A 311 575, and in US patent 5,130,008.
The invention aims at solving the problem of providing an efficient membrane cell for electrolysis where gas is generated, while considering the life time of the cell membrane. The invention also solves the problem of enhancing the efficiency of an existing membrane cell by a simple 15 modification.
According to the invention, it has been found that both the efficiency of the cell and the life time of the membrane increases if the electrolyte is flowed at a high velocity at the electrode surface. It has also been found possible to 20 prevent the membrane from being directly contacted with gas if this is separated in a region adjacent the upper edge of the electrode.
The invention relates to a cell for electrolysis where gas is generated, which cell comprises separate anode and 25 cathode compartments separat~d by at least one preferably substantially vertical ion-selective membrane. At least one of the anode and cathode compartments of the cell is designed for electrolysis where gas is generated and comprises at least one substantially vertical electrode, the front side of which is 30 facing a membrane, and at least one partition, so as to form at least two substantially vertical channels and a space of larger cross-sectional area located above the partition, of which a first channel for upward transport of gas-rich electrolyte is defined by said partition and the electrode 35 while a second channel for downward transport of gas-deficient electrolyte, as seen from the electrode, is located behind said first channel, said partition being arranged such that gas-rich electrolyte which is transported upwards in said first channel i9 subjected to a venturi effect so that the 2~321~
main part of the gas is separated off in an area adjacent the upper edge of the electrode and the main part of the electro-lyte is recycled downwards through said second channel.
Suitably, the partition is arranged such that from about 50%
to about 98~, preferably from about 70% to about 95~, o~ the electrolyte supplied to the cell chamber is recycled.
Generally, the partition should be placed such that the separation of gas from the electrolyte takes place as high up as possible. The upward transport of the gas-rich electrolyte takes place by the gas which is generated during the electro-lysis producing an upwardly directed pumping force Phy~aul which depends on the height of the channel and on the density difference between gas and liquid, this difference partly depending on the flow velocity. This pumping force must exceed the flow resistance PCha~e~ in the channel which depends on the hydraulic diameter thereof, the friction factor of the material, and the flow velocity. The level of separation is determined by the static pressure difference according to the formula:
P9tat = Phyd~aul Pcha:lnel The static pressure difference is directly proportional to the height to which the pumping force is able to transport the liquid and where the separation starts as foaming. Preferably, the foaminy area extends substantially as far up as the upper edge of the electrode, which in most cells means the upper boundary surface of the cell. As appears from the above, the optimal location of the partition depends on several para-meters, and so the proper position must be tried out in the particular cases by varying the location of the partition both vertically and laterally, and hence the height and cross-section of the channel, so that separation takes place as high up as possible and the desired recirculation is achieved.
The electrode suitably comprises through openings so as to be permeable to electrolyte. All known electrodes intended to be arranged vertically can be used. Examples of known electrodes are perforated plate electrodes, electrodes of expanded metal or fine-meshed netting, electrodes comprising ~ 21 ~321~
-~ 4 longitudinal or transverse rods or slats, and as well as electrodes comprising curved or straight lamellae, which may be vertically or horizontally extended, punched from a common metal sheet, for example louver electrodes. The electrode surface may, but need not, comprise channels for promoting the electrolyte flow on the side facing the membrane. These electrode types are well known and described e.g. in the above-mentioned EP-A 415 896 and EP-A 533 237, as well as in GB Patent Specification 1,324,427.
According to the invention, the anode and cathode compartments may also comprise one or more auxiliary elec-trodes, for example in the form of expanded metal or fine-meshed netting, fixed in and electrically connected to the partition, optionally via spacer means so as to be disposed adjacent the main electrode. This is especially advantageous if the main electrode has a comparatively open structure, for example is a double-sided louver electrode punched from a metal sheet.
. -: . . ,-The electrode may be manufactured from metals such as Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Ag, Pt, Ta, Pb, Al or alloys thereof. Ti or Ti alloys are preferred as anode material, while Fe, Ni or alloys thereof are preferred as cathode material. The electrode is suitably activated by a surface coating of a suitable catalytic material, depending on what reactions should be catalysed. Suitable catalytic materials are metals, metal oxides or mixtures thereof from group 8B in the Periodic table, i.e. Fe, Co, ~i, Ru, Rh, Pd, Os, Ir or Pt, of which Ir and Ru are particularly preferred.
An optional auxiliary electrode preferably consists of the same or similar materials as the electrode and is, like the electrode, provided with a suitable catalytic surface coating.
The partition is preferably arranged substantially parallel to the electrode and has preferably substantially the same lateral extension. Further, the partition is suitably made of an electrically conductive material and is galvanically connected to the electrode, e.g. by being connected to the same current source, this promoting the current distribution in the cell~ An optional auxiliary electrode may have its main current lead-in through the ' ~' .~
~ ', 2 l ~
partition. All materials that can be used for the electrode are also suitable for the partition. Preferably, use is made of the same material for the partition as for the electrode, for example titanium. Normally, the partition need not be activated, although it is of course possible.
The invention can be applied to electrolytic cells where the anode and the cathode are arranged in separate cell chambers for anolyte and catholyte, respectively. These cell chambers may be arranged beside each other and then be separated only by an ion-selective membrane. A cell may also comprise one or more chambers located between the anode and cathode compartments and separated from these and from each other by ion-selective membranes. Both the anode compartment and the cathode compartment suitably comprise an inlet for electrolyte provided in the bottom, and one or more outlets for gas and non-recycled electrolyte provided in the top. The cells are suitably arranged as separate units, for example in an electrolyser of the filter press type. A cell chamber may comprise one or more channels for ascending gas-rich electro-lyte and one or more channels for descending gas-deficient electrolyte.
According to the simplest embodiment, the cell chamber accommodates an electrode and an partition such that the rear channel is defined by the partition and the rear vessel wall of the cell. A cell chamber may also comprise a double-sided electrode, the two sides of which are facing a respective membrane. In this case, two partitions are required which together form a centrally located channel for descending gas-deficient electrolyte and which define, together with a respective electrode side, a respective channel for ascending gas-rich electrolyte. Such a cell chamber is normally of substantially symmetrical design.
A cell according to the invention may also comprise means for conducting part of the recycled electrolyte in the horizontal direction, for the purpose of further reducing the concentration gradients. This can be achieved by means of guide vanes disposed in the upper part of the cell or by varying the level of the upper edge of the partition in the cell.
According to another embodiment, the partition may comprise means for localised admixture of gas-deficient electrolyte to the channel located closest to the electrode for ascending gas-rich electrolyte, which is advantageous for large electrode surfaces, for example exceeding about 0.5 m2, since the concentration gradients in the electrolyte whic~ are detrimental to the membrane can then be reduced. In this embodiment, the channel closest to the electrode may be divided into sections at different levels, which are not in contact with each other but open in a common channel located behind for ascending gas-rich electrolyte. The partition may also quite simply have a number of openings admitting gas-deficient electrolyte to the channel closest to the electrode.
The upper edge of the partition, i.e. where gas separa-tion takes place, may be straight or have recesses in the formof different geometric figures. The upper part of the parti-tion may also comprise openings of different types.
The invention also relates to a method for making an electrolytic cell as described above. The method comprises the step of modifying an existing membrane cell having separate anode and cathode compartments separated by at least one preferably substantially vertical ion-selective membrane, at least one of the anode and cathode compartments comprising at least one substantially vertical electrode, the front side of which is facing the membrane. This modification is performed by providing at least one of the anode and cathode compart~
ments with at least one partition so as to form at least two substantially vertical channels and a space of larger cross-sectional area located above the partition, of which a first channel for upward transport of gas-rich electrolyte is defined by the partition and the electrode while a second channel for downward transport of gas-deficient electrolyte, as seen from the electrode, is located behind the first channel, the partition being arranged such that gas-rich electrolyte which is transported upwards in the first channel is subjected to a venturi effect so that the main part of the gas is separatecl off in an area adjacent the upper edge of the electrode and the main part of the electrolyte is recycled downwards through the second channel. If the electrode in the 2~2-~S
, existing cell chamber i9 comparatively open, for example like certain louver electrodes, it is advantageously made more close by providing its rear side with an auxiliary electrode of e.g. expanded metal or fine-meshed netting. All newly-added parts, such as partitions, auxiliary electrodes and the like, may first be assembled into a unit which is then mounted in the anode and cathode compartments, respectively. In other respects, reference is made to the description of the cell according to the invention.
Finally, the invention relates to a method in electroly-sis where gas is generated, using a cell according to the invention.
Thanks to the invention, it has become possible to considerably increase the flow velocity of the electrolyte through a membrane cell at the same time as the generated gas can be separated from the liquid within the cell but in an area where the e~fect on the sensitive membrane is at a minimum. The life time of the membrane is extended by reducing the pH-gradient and the concentration gradient in the electro-lyte and by raising the liquid level in the electrode gap. Bydisplacing the gas separation zone and shielding it from the electrode gap, the formation of bubbles in the membrane induced by uneven current distribution can be reduced, this solving one of the most serious problems inherent in prior-art membrane cells. A special advantage is that existing cells can be easily modified so as to considerably increase their efficiency and the life time of the membrane.
The invention can be applied to all electrolytic processes which involve gas generation, usually one or more of oxygen, hydrogen gas and chlorine gas, and which can be carried out in membrane cells ha~ing separate anode and cathode compartments. Conceivable processes are the electroly-sis of sodium chloride in aqueous solution to chlorine, hydrogen and alkali, or the electrolysis of sodium sulphate in aqueous solution to oxygen, hydrogen, sulphuric acid and alkali. In the last-mentioned case, use is generally made of a cell where at least one cell chamber without electrodes i9 disposed between the anode and cathode compartments.
The invention is illustrated in the accompanying . ~ , : ~;
~ ? 21~ -.
schematic drawings. It is not restricted there~o, but many other embodiments are conceivable within the scope of the appended claims.
Fig. 1 is a lateral section of a cell with a double-sided electrode, while Fig. 2 is a front section along A-A, and Fig. 3 is a top section along B-B. Fig. 4 is a lateral section of a cell with a single-sided electrode. Figs 5-7 are front sections of three other cell designs. Figs 8a-8f show different designs of a partition. Fig. 9 is a top section showing a detail of a cell according to another embodiment, while Figs 10 and 11 show details in a lateral section along B-B and A-A.
Referring now to Figs 1-3, there is illustrated a cell chamber in the form of an anode compartment or a cathode compartment with an inlet lo for electrolyte disposed in the lower part of one short side, and an outlet 11 for gas and non-recycled liquid disposed in the upper part of the other short side. Further, the cell chamber is of substantially symmetrical design and comprises two main electrodes la, lb of the same polarity, which are preferably interconnected so as to form together a double-sided electrode having a common current lead-in. The electrodes la, lb have openings (not shown) along the surface so as to be permeable to electrolyte.
The cell chamber is defined by two ion-selective membranes 12a, 12b arranged on the front side of and optionally in contact with the respective electrode la, lb. The membranes 12a, 12b constitute boundaries to cell chambers (not shown) with electrodes of opposite polarity, or to cell chambers disposed between the anode and cathode compartments. Two partitions 3a, 3b with the same lateral extension as the e,lectrodes la, lb are arranged in the cell chamber so as to define two outer channels 4a, 4b for ascending gas-rich electrolyte, as well as an inner channel 5 for descending gas-deficient electrolyte. All the channels 4a, 4b, 5 join in a space 8 above the partitions 3a, 3b, and in a space 9 below these, the spaces 8, 9 comprising substantially the entire cross-sectional area of the cell chamber. Spacer members 7 of substantially circular cross-section are arranged in the channel 5 between the two partitions 3a, 3b and are preferably `` .':, ~'~
2 -l ~ 3 ;~
. ~ g connected to the same current source as the main electrodes la, lb. Auxiliary electrodes 2a, 2b, for example in the form of a fine-meshed netting, are arranged adjacent the main electrodes la, lb electrically connected to the spacer members 7 via the partitions 3a, 3b and permeable spacer members 6 which may consist e.g. of expanded metal. Preferably, the main electrodes la, lb as well as the auxiliary electrodes 2a, 2b are activated by a suitable catalytic surface layer. For greater clarity, the width of the channels is greatly exagger-ated in Figs 1 and 3.
Many existing electrolytic cells can be modified byassembling partitions 3a, 3b, spacer members 6, 7 and auxili-ary electrodes into a unit which is then mounted in an anode compartment or a cathode compartment to obtain a cell accord-ing to the illustrated embodiment. All joints or connectionscan normally be achieved by any welding technique suitable for the material, for example spot-welding.
When using the cell, for example in the electrolysis of sodium chloride in aqueous solution to chlorine and alkali, the illustrated cell chamber may advantageously function as anode compartment, the two membranes 12a, 12b constituting boundaries to cathode compartments which are located beside the illustrated anode compartment and designed for internal circulation according to the invention, or are of conventional design. The anode compartment is supplied with sodium chloride solution through the inlet 10, the main part of the electro-lyte being transported upwards in the outer channels 4a, 4b while a minor part passes between the anodes la, lb and the membranes 12a, 12b. In the electrolysis, bubbles of chlorine gas are formed whose density is lower than that of the liquid, this giving rise to a pumping force causing the liquid to rise in the channels 4a, 4b. When the gas-rich electrolyte reaches the space 8, the cross-sectional area increases considerably and a foaming area is formed. The chlorine gas is no longer capable of lifting the liquid but is separated off and leaves through the outlet 11. The major part of the liquid flows back through the inner channel 5 to the space 9 where it is mixed with freshly-supplied electrolyte and is again raised through the outer channels 4a, 4b. The cell functions correspondingly -`` 21~32:~$ ~-in other electrolytic processes.
It has been found that a membrane cell for chlorine-alkali electrolysis where the anode compartment is designed according to the embodiment shown in Figs 1-3, operates excellently if the anodes la, lb have a width of about 1000 mm and a height of about 300 mm, the height of the areas 8, 9 above and below, respectively, the partitions 3a, 3b being about 25 mm, the distance between the two partitions 3a, 3b being about 3 mm and the distance between the partitions 3a, 3b and the respective anode la, lb being about 2 mm.
Fig. 4 shows a cell chamber with only one electrode 1 which is defined by a membrane 12 and a vessel wall 13. A
partition 3 is arranged so as to define a channel 4 for ascending gas-rich electrolyte closest to the electrode 1 and another channel 5 for descending gas-deficient electrolyte at the vessel wall 13. Otherwise, it operates in the same way as the cell chamber in Figs 1-3.
Fig. 5 shows a cell having an inlet 10, two outlets 11, a partition 3, means 7 for supporting the partition 3, and a space 8 above and a space 9 below the partition 3. The upper edge of the partition 3 is highest in the middle, i.e.
straight above the inlet 10 of the cell, and lowers stepwise towards the two outlets. As a result, the horizontal mixing in the cell is promoted. For example, from about 5% to about 10%
of the electrolyte flow is conducted in the horizontal direction from the inlet 10 towards the outlets 11. In a special embodiment, the distance between the upper and lower edges of the partition 3 may be the same throughout the entire cell while the position of the wall 3 is varied such that the height of the space 9 below the partition 3 is small where the . ~ , height of the space ~ above the partition 3 is large. If the electrode of the cell (not shown) is double-sided, an addi- ;
tional partition should be provided before the illustrated partition 3, the means 7 serving as spacers between two -partitions 3.
Fig. 6 shows a cell which differs from that of Fig. 5 only by the location of the inlet 10 and the outlet 11 and, as ~`~
a result thereof, in that the upper edge of the partition 3 is highest at one end and lowest at the other end of the cell.
~"''',' ~
2:~G321~`
- :-. 11 Other features, like the operation, are identical with those of the cell in Fig. 5, to the description of which reference is thus made.
Fig. 7 shows a c~ll similar to that in Fig. 6, except that the partition 3 has the same height along the entire cell, but instead is provided with guide vanes 20 serving to conduct part of the circulating electrolyte in the horizontal direction towards the outlet 11.
Figs 8a-8f illustrate different designs of the upper part of a partition 3. In Figs 8a-8c, the upper edge of the partition 3 is formed with recesses of different shapes, while the partitions 3 shown in Figs 8d-8f are provided with holes of different shapes.
Figs 9-11 show an embodiment which i6 advantageous for very large electrode surfaces. None of the Figures shows the whole cell chamber, but only details thereof. The cell chamber comprises an electrode 1 which is located just behind a membrane (not shown), which together with a rear vessel wall 13 constitutes the boundary surfaces of the chamber. Adjacent the electrode 1, along the entire front side of the cell chamber, extends a channel 4a for ascending gas-rich electro-lyte. The channel 4a is divided into sections at different levels, which are not in direct contact with each other but which in their upper parts 15 open into common collecting channels 4c located behind for ascending gas-rich electrolyte.
The number of sections depends on the height of the electrode and may, for example, be from about 5 to about 10 per metre.
Between the collecting channels 4c are provided channels 5 for descending gas-deficient electrolyte. The channels 5 comprise means 14 for supplying part of the electrolyte flow therein to each section of the channel 4a closest to the electrode. The boundaries between the channels 4a, 4c, 5 consist of parti-tions 3a, 3b. The relative positions of the channels 4a, 4c, 5 appear most clearly from Fig. 9 showing a detail of the cell chamber from above. The number of channels 4b, 4c, 5a, 5b located behind the channel 4a closest to the electrode depends on the width thereof and may, for example, be from about 10 to about 30. The top and the bottom of the cell chamber comprises corresponding spaces ~not shown) having a larger cross-'~.'"' 12 ~1 a3 ~
sectional area as in the embodiments shown in Figs 1-4.
When using the cell chamber according to Figs 9~
recycled gas-deficient electrolyte will flow downwards through the channels 5. Every time the bottom of a section in channel 4a closest to the electrode is passed, part of the gas-deficient electrolyte will be supplied into said section. When the gas-rich electrolyte in a section of said channel 4a reaches the top thereof, the entire flow is fed out into one of the common collecting channels 4c. When the collecting flow : ~:
reaches the top of the cell chamber, the generated gas is separated and the main part of the liquid is recycled through the inner channel 5. ~:
~' ,. :, ~, .: ' :: ' ' ::
Claims (10)
1. A cell for electrolysis where gas is generated, which cell comprises separate anode and cathode compartments separated by at least one ion-selective membrane (12, 12a, 12b), c h a r a c t e r i s e d in that at least one of the anode and cathode compartments of the cell is designed for electrolysis where gas is generated and comprises at least one substantially vertical electrode (1, 1a, 1b) whose front side is facing a membrane (12, 12a, 12b), and at least one parti-tion (3a, 3b), so as to form at least two substantially vertical channels (4, 4a, 4b, 5, 5a, 5b) and a space (8) of larger cross-sectional area located above the partition, of which a first channel (4, 4a, 4b) for upward transport of gas-rich electrolyte is defined by said partition and the elec-trode while a second channel (5, 5a, 5b) for downward trans-port of gas-deficient electrolyte, as seen from the electrode (1, 1a, 1b), is located behind said first channel (4a, 4b), said partition (3a, 3b) being arranged such that gas-rich electrolyte which is transported upwards in said first channel (4a, 4b) is subjected to a venturi effect so that the main part of the gas is separated off in an area adjacent the upper edge of the electrode and the main part of the electrolyte is recycled downwards through said second channel (5, 5a, 5b).
2. A cell as claimed in claim 1, c h a r a c t e r i s -e d in that the partition (3a, 3b) is made of an electrically conductive material and is connected to the same current source as the electrode (1, 1a, 1b).
3. A cell as claimed in any one of claims 1-2, c h a r -a c t e r i s e d in that the electrode (1, 1a, 1b) has through openings.
4. A cell as claimed in any one of claims 2-3, c h a r -a c t e r i s e d in that at least one of the anode and cathode compartments comprises one or more auxiliary elec-trodes (2a, 2b) fixed to and in electrical contact with the partition (3a, 3b).
5. A cell as claimed in any one of claims 1-4, c h a r -a c t e r i s e d in that the partition (3a, 3b) is arranged substantially parallel to the electrode (1, 1a, 1b) and has substantially the same lateral extension as the electrode (1, 1a, 1b).
6. A cell as claimed in any one of claims 1-5, c h a r -a c t e r i s e d in that the partition comprises means for localised admixture of gas-deficient electrolyte to the channel (4a) with gas-rich electrolyte.
7. A cell as claimed in any one of claims 1-6, c h a r -a c t e r i s e d in that the partition is arranged such that from about 50% to about 98% of the electrolyte supplied to the cell chamber is recycled.
8. A method for making a cell as claimed any one of claims 1-7, c h a r a c t e r i s e d by the step of modifying an existing membrane cell having separate anode and cathode compartments separated by at least one ion-selective membrane (12a, 12b), at least one the anode and cathode compartments comprising at least one substantially vertical electrode (1a, 1b), the front side of which is facing the membrane (12a, 12b), said modification being performed by providing at least one of the anode and cathode compartments with at least one partition (3, 3a, 3b), so as to form at least two substantially vertical channels (4, 4a, 4b, 5, 5a, 5b) and a space (8) of larger cross-sectional area located above the partition (3), of which a first channel (4, 4a, 4b) for upward transport of gas-rich electrolyte is defined by said partition (3, 3a, 3b) and the electrode (1, 1a, 1b) while a second channel (5, 5a, 5b) for downward transport of gas-deficient electrolyte, as seen from the electrode, is located behind said first channel (4, 4a, 4b), said partition being arranged such that gas-rich electrolyte which is transported upwards in said first channel (4, 4a, 4b) is subjected to a venturi effect so that the main part of the gas is separated off in an area adjacent the upper edge of the electrode and the main part of the electrolyte is recycled downwards through said second channel (5, 5a, 5b).
9. A method as claimed in claim 8, c h a r a c t e r i -s e d by first assembling all newly-added parts into a unit which is then mounted in the anode and cathode compartments, respectively.
10. A method in electrolysis, c h a r a c t e r i s e d by using a cell as claimed in any one of claims 1-7.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE9203514-6 | 1992-11-23 | ||
| SE9203514A SE9203514L (en) | 1992-11-23 | 1992-11-23 | Cell |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2103216A1 true CA2103216A1 (en) | 1994-05-24 |
Family
ID=20387903
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002103216A Abandoned CA2103216A1 (en) | 1992-11-23 | 1993-11-16 | Cell |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0599363A1 (en) |
| CN (1) | CN1090340A (en) |
| BR (1) | BR9304749A (en) |
| CA (1) | CA2103216A1 (en) |
| SE (1) | SE9203514L (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4444114C2 (en) * | 1994-12-12 | 1997-01-23 | Bayer Ag | Electrochemical half cell with pressure compensation |
| JP4007565B2 (en) | 1998-05-11 | 2007-11-14 | クロリンエンジニアズ株式会社 | Ion exchange membrane electrolytic cell |
| DE19850071A1 (en) | 1998-10-30 | 2000-05-04 | Bayer Ag | Membrane electrolysis cell with active gas / liquid separation |
| ITMI20012561A1 (en) * | 2001-12-05 | 2003-06-05 | Uhdenora Technologies Srl | NEW ION EXCHANGE MEMBRANE ELECTROLIZER |
| CN102983341A (en) * | 2012-12-31 | 2013-03-20 | 刘军 | Battery electrode with auxiliary electrode structure and high-power battery |
| CN117385384A (en) * | 2023-10-31 | 2024-01-12 | 苏州希倍优氢能源科技有限公司 | Electrolysis trough with inside natural circulation |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1200272A (en) * | 1967-11-13 | 1970-07-29 | Nautchno Izsledovatelski Inst | Improvements in or relating to electrodes for electrolysis |
| GB1324427A (en) * | 1969-12-06 | 1973-07-25 | Nippon Soda Co | Electrode assembly for electrolysis cells |
| US4340460A (en) * | 1980-11-24 | 1982-07-20 | Olin Corporation | Internal downcomer for electrolytic recirculation |
| IT1229874B (en) * | 1989-02-13 | 1991-09-13 | Permelec Spa Nora | PROCEDURE FOR IMPROVING THE TRANSPORT OF MATERIAL TO AN ELECTRODE IN A DIAPHRAGM CELL AND RELATED HYDRODYNAMIC MEDIA. |
| IT1247483B (en) * | 1991-03-21 | 1994-12-17 | Permelec Spa Nora | DEVICE FOR THE EXTRACTION OF TWO-PHASE FLUIDS FROM ELECTROLYSIS CELLS |
-
1992
- 1992-11-23 SE SE9203514A patent/SE9203514L/en not_active Application Discontinuation
-
1993
- 1993-10-26 EP EP93202985A patent/EP0599363A1/en not_active Withdrawn
- 1993-11-16 CA CA002103216A patent/CA2103216A1/en not_active Abandoned
- 1993-11-17 BR BR9304749A patent/BR9304749A/en unknown
- 1993-11-22 CN CN93114761A patent/CN1090340A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| SE9203514D0 (en) | 1992-11-23 |
| SE9203514L (en) | 1994-05-24 |
| CN1090340A (en) | 1994-08-03 |
| BR9304749A (en) | 1994-05-31 |
| EP0599363A1 (en) | 1994-06-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1169808A (en) | Bipolar diaphragm cell with vertical flow channels | |
| FI60038B (en) | ELEKTROLYSCELL | |
| JP2739607B2 (en) | Electrode | |
| JP3707778B2 (en) | Unit cell for alkaline metal chloride aqueous electrolytic cell | |
| US4664770A (en) | Electrolyzer | |
| JP3555197B2 (en) | Bipolar ion exchange membrane electrolytic cell | |
| US5660698A (en) | Electrode configuration for gas-forming electrolytic processes in membrane cells or diapragm cells | |
| JPH0657874B2 (en) | Membrane type electrolytic cell | |
| US5130008A (en) | Frame unit for an electrolyser of the filter-press type and monopolar electrolyser of the filter-press type | |
| CA2103216A1 (en) | Cell | |
| US5322604A (en) | Electrolytic cell and electrodes therefor | |
| KR20230039712A (en) | Combined current carrier circulation chamber and frame for use in unipolar electrochemical devices | |
| US5314591A (en) | Electrolyzer and method of production | |
| CA1312844C (en) | Electrode assembly for gas-producing electrolyzer comprising vertical plate electrodes | |
| CA1041040A (en) | Electrode assembly for an electrolytic cell | |
| US6063257A (en) | Bipolar type ion exchange membrane electrolytic cell | |
| US4048046A (en) | Electrolytic cell design | |
| CS221549B2 (en) | Electrolyser for electrolysis of liquid electrolyte | |
| US4233147A (en) | Membrane cell with an electrode for the production of a gas | |
| US4174259A (en) | Electrolytic cell structure and method of assembly | |
| US4568433A (en) | Electrolytic process of an aqueous alkali metal halide solution | |
| JPS6119789A (en) | Double polarity electrode | |
| KR910004872B1 (en) | Electrolytic cell | |
| CA1232232A (en) | Chlorine cell design for electrolyte series flow | |
| JPS5848366Y2 (en) | anode chamber |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |