DE3006120A1 - ELECTROLYSIS PROCESS AND CHLORINE CALICELL WITH SOLID POLYMERIC ELECTROLYTE - Google Patents

Description

3Q0612Q

Electrolysis process and chlor-alkali cell with solid polymer electrolyte n

Srfinduna is never directed towards an electrolytic cell Electrolyzing of alkali chloride brines with a solid polymeric electrolyte that has a permionic membrane which has an anodic electrocatalyst embedded in or on its anodic surface and a cationic hydroxyl-developing catalyst, also called cationic flexocatalyst, embedded in or on the cathodic surface.

The invention also includes a method of making the permionic membrane as part of the solid polymer Electrolytes, as well as a method for electrolyzing alkali chloride brines with the appropriate electrolysis cells a.

Methods and devices for electrolyzing calcium chloride sols have long been known and will be operated in great Hmfana in technical proportion.

however, never-before-known devices and methods have although constantly improved, they still have a number of disadvantages.

The object of the present invention is to provide an improved To show electrolysis equipment and a method for operating these equipment.

This object is achieved by what is described in the claims Electrolytic cells, processes for their manufacture and processes for electrolyzing chloralkali salts.

The electrolytic cell according to the invention for electrolyzing of alkali chloride sols has as part of a solid polymeric electrolyte, which is a cation-selective permio-

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niche membrane contains. The free space of the permionic membrane facing the catholyte is called the cathodic surface of the membrane and the side of the permionic membrane facing the anolyte is called the anionic surface of the membrane. Both surfaces have cationic or anionic electrocatalysts embedded in or arranged on them. In a further embodiment of the invention, the cathodic surface of the permionic membrane contains a cathodic depolarizer, also known as an H0 ₂ ~ disproportionation catalyst. This H02 ~ disproportionation catalyst is used to depolarize the cathode and avoid the formation of gaseous hydrogen.

The bipolar chlor-alkali electrolysis devices according to the invention with a solid polymer electrolyte have the particular advantage that they have a particularly high Production output per unit volume of electrolysis cell enable a very high current yield to result, a allow high current density and in special embodiments avoid the occurrence of gaseous products and the aids otherwise required for this are superfluous are.

lei the chlor-alkali electrolysis with a solid polymer Aqueous alkali chloride, for example sodium chloride or potassium chloride, is in contact with the electrolyte anodic surface of the solid polymer electrolyte. An electrical voltage is applied to the cell and chlorine develops on the anodic surface of the solid polymer electrolyte.

The alkali ion, which is usually a potassium or a Sodium ion is transported through the permionic membrane of the solid polymer electrolyte to the cathodic hydroxy1-evolving catalyst on the opposite side of the permionic membrane. That Alkali ion, i.e. the sodium or potassium ion migrates to one another with its water of hydration, without any

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together with its hydration water without any substantial transport of the total amount of electrolyte takes place.

The hydroxyl ion is converted to the catalytic hydroxyl ion-developing catalyst ir ^TJ 3 =! Sergto ^p f. If, in an alternative embodiment of the invention, a cathodic depolarization catalyst, for example an HO- disproportionation catalyst, is present in the vicinity of the cathodic surface of the dermionic membrane and an oxidizing agent is supplied to the catholyte space, the development of a gaseous cathode product is avoided.

The subject of the invention becomes for a better understanding described in more detail using the illustrations.

Figure 1 is an exploded view the electrolysis device.

Fig. 2 shows a perspective view of part of the electrolysis device from Fig. 1.

Fig. 3 shows the part shown in Fig. 2 in section.

FIG. 4 is an enlarged fragmentary view of the solid polymeric electrolyte sheet as shown in FIGS. 2 and 3 is reproduced.

Fig. 5 shows a perspective view of another part of the electrolysis device shown in Fig. 1 and shows a distributor for supplying and removing the electrolyte.

Fig. 6 shows the distributor shown in Fig. 5 in section.

FIG. 7 is a perspective view of an embodiment of the bipolar element shown in FIG.

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Fig. 8 shows the bipolar element from Fig. 7 in section.

Fig. 9 shows a perspective view of an alternative embodiment of a bipolar element with devices for heat exchange.

Fig. 10 shows the part shown in Fig. 9 in section.

Fig. 11 shows another alternative in perspective Embodiment of a bipolar element in the the distributor is combined with the bipolar element.

Fig. 12 shows a section through the bipolar element of Fig. 11.

Fig. 13 shows schematically a side section of the Electrolytic cell with solid polymer electrolyte.

Fig. 14 gives the schematic for chlor-alkali electrolysis Reaction taking place again with solid polymer electrolyte.

The chlor-alkali cell, shown schematically in Fig. 14 shows the solid polymeric electrolyte (31) with the permionic membrane arranged therein. the permionic membrane (33) has an anodic surface (35) with the chlorine catalyst (37) and a cathodic surface (41) with the cathodic hydroxy1-developing catalyst (43) arranged thereon. In the The figure also shows an external power source connected to the anodic catalyst (37) through the manifold (57) and connected to the cathodic catalyst (43) through the manifold (55). Sole becomes the anodic Side of the solid polymer electrolyte (31) supplied and comes into contact with the anodic chlorine evolution catalyst (37) on the anodic surface (35) of the permionic membrane (31). That in the solution in form

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Any chlorine present in the presence of a chloride ion forms chlorine according to the following equation:

2 Cl "> Cl ₉ + 2e ~

The alkali ion, which is a sodium or potassium ion, is in Fig. 14 as sodium ion and that by Water formed hydration pass through the permionic membrane 33 to the cathodic side (41) of the permionic Membrane (33). The catholyte space is supplied with water from the outside and also the water of hydration that flows through the permionic membrane (31) enters the catholyte space. The stoichiometric reaction of the cathodic egg hydroxyl developing catalyst runs as follows:

H ₂ O + e ~ 40 H ~ + H

In an alternative embodiment, a cathodic Depolarization catalyst and an oxidizing agent are present, so that the development of aasiform hydrogen to avoid.

never »nordnupn · and the structure for this reaction is in general in V-> b. 13 reproduced, it is an electrolvtisahear> lle (11), the walls of which are denoted by 21 and the permionic membrane (33) arranged between the walls. The permionic membrane (33) has an anodic surface with the anodic catalyst (37) located thereon and a cathodic surface with the cathodic catalyst (4 3). In the alternative embodiment, a cathodic depolarization catalyst, that is, a HO ₀ disproportionation catalyst (not shown) is in the ^? Arranged near the cathodic surface (41) of the membrane (33) in order to avoid the development of gaseous hydrogen.

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Means for conducting electrical current from the walls (21) to the solid polymeric electrolyte (31) are present in the form of the distributor (57) in the anolyte space (39) to flow from the wall (21) to the anodic chlorine development ^ - to conduct catalyst (37). In the cathode area, the distributor (55) in the catholyte space conducts the current from the wall (21) to the cathodic hydroxyl developing catalyst (43).

In a preferred embodiment, the manifolds are (55) and (57) designed to cause turbulence and mixing of the electrolyte. This causes concentration polarization, gas bubble effects, clogging and dead space avoided.

To operate the cell, brine is passed through the anolyte space (39) the brine inlet (K1a) is supplied and exhausted brine is drawn off from the anolyte space (39) through the brine outlet (81b). The solvent can be drawn off as containing chlorine gas

Foam or together as dissolved chlorine and liquid brine, or as liquid chlorine and brine.

The catholyte space (45) is supplied with water through the supply device (101a) in order to keep the alkali hydroxide in solution and to avoid the deposition of solid alkali hydroxide on the membrane (33). In addition, an oxidizing agent can be supplied to the catholyte compartment (45), such as when a H02 ~ -Disproportionierungskatalysator is present and thus the formation of "t- ^T asserstof FGAS is avoided and it is else possible in this ^TLT, a completely liquid product from the catholyte compartment to be withdrawn via the outlet (101b).

A particularly desirable cell design is a bipolar electrolytic cell using a solid polymer Electrolytes. Fig. 1 shows in an exploded arrangement such a bipolar electrolysis cell with a solid polymer Electrolytes.

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The figure shows an electrolysis device with two cells (11) and (13) with solid polymer electrolytes. One However, the electrolysis device (1) can have many more such cells. The number of electrolytic cells (11, 13) within an electrolysis device (1) is limited by rectifiers and convertibility as well as through the possibility of power loss. With the prior art known today due to the rectifier and Conversion techniques have electrolysis units with 150 up to 2OO or more cells.

The individual electrolysis cell (11) has an element (31) with the solid polymeric electrolyte, as shown as part of the electrolysis device in Fig. 1 and shown individually in Fig. 2 and in section in Fig. 3. Fig. 4 is a large enlargement of a part with the catalyst particles (37) and (43) arranged on it. The figures 13 and 14 show schematically the part (31) r-'it r ⁵ » ⁷ * ¹ solid poly ^ erpn niektrolyten.

Toil (31) closes with the solid polymer electrolyte the permionic membrane (33) with the anodic chlorine decomposition catalyst (37) on the anodic surface (35) and the cathodic hydroxyl development catalyst (43) on the cathodic surface (41).

The cell boundaries may be arranged in between Cells within an electrolysis device (1) are formed by a pair of bipolar elements (21), which also are referred to as binolar back plates. In the case of the one shown in Fig. 1 reproduced electrolysis device with the first and last cells, for example cells (11) and (13), represents' the bipolar unit (21) constitutes a boundary of the electrolytic single cell and the edge plate (71) the opposite one The end plate (71) has inlet devices for supplying brine (81a) and brine outlet devices (81b), water supply devices (101a)

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and a hydroxide solution vent (101b). In the event that the cathode is to be depolarized, an additional, Inlet, not shown here, is provided for the oxidizing agent. The end plate (71) also has the Power supply lines (79).

In the case of a monopolar cell, the end members are defined by a pair of the end plates (71) as described above are formed.

The end plate (71) and the bipolar units (21) result ^ ie gas tightness and electrolyte tightness of the respective Single cells. In addition, the end plate (71) and the bipolar units (21) provide electrical contact and enable in various embodiments, the electrolyte supply and the gas vent.

The bipolar unit shown in Figures 7 and 8 (21) has an anolyte-resistant surface (23) which it ι opposite the anodic surface (35) with the anodic Catalyst (37) is located in the electrolytic cell (12). The anolyte-resistant surface (35) is in contact with the anolyte liquid and forms the boundary of the anolyte space (39) of the cell. The bipolar unit (21) also has a cathode-resistant surface (25), which is within the cell opposite the cathodic Surface (41) with the cathode catalyst (43) of the solid polymer electrolyte (31) of the next adjacent ropes (13) of the electrolysis device (1) is located.

The anolyte-resistant surface (23) is made of a rectifier metal made, which is a metal that forms an acid-resistant oxide film when in contact with aqueous acidic solutions. Suitable rectifier metals are titanium, tantalum, tungsten, columbium, hafnium, Zircon, as well as alloys of titanium, for example

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Titanyttrium alloys, titanium palladium alloys, Titanium-molybdenum alloys, titanium-nickel alloys. Alternatively, the anolyte resistance of the surface but can also be brought about by silicones or silicides.

The binolar unit (21) can consist of two foil plates or Laminates (23, 25) are produced. The surface (23) that comes into contact with the anolyte can consist of a Rectifier metal prepared as described above. In a preferred embodiment, the with the surface (23) of the bipolar unit (21) in contact with the anolyte made of a rectifier metal alloy, which is characterized by its particular resistance to hydride formation and crack corrosion.

A particularly preferred group of such alloys are ³ alloys of ¹⁷¹ Itanite rare earths. The special ones erred in the rare earths are scandium, yttrium and the lnthr'.nides. The lanthanides include lanthanum cerium, praseodymium, "eodyn, '" romethiur, samarium, europium, gadolinium, terbium, dysnrosium, holmium, erbium, thulium, ytterbium and lutetium. ^r 7enn the term rare earth is used herein, this term includes scandium, yttrium, and the lanthanides.

The rare earth leagues can be one or more contain rare earth metals. For example a combination of scandium with yttrium or cerium, or lanthanum with yttrium or with lanthanum with cerium. Yttrium is particularly preferred for alloys with rare earths.

The rare earth content in the alloy should be be at least a threshold proportion which is sufficient to reduce the occurrence of hydrogen by titanium or even avoid it. This generally requires a content of at least 0.01% by weight, but also lower proportions already have a positive effect.

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The maximum rare earth content in the alloys should be low enough to be used in the. essential education to avoid a two-phase system. Generally this is less than about 2 wt% rare earth metal for Yttrium, lanthanum, cerium, gadolinium, and erbium, although amounts up to about 4 or even 5 weight percent of these metals are tolerable are without adverse effects. Shares of up to 7% by weight are possible in the level for scandium and europium, although in this case proportions of up to 10% by weight are possible without adverse effects. In general, amounts to the proportion of rare earths from about 0.01% by weight to about 1% by weight, preferably from about 0.015% by weight to about 0.05 Weight%.

However, the titanium alloy can also contain various other impurities without this being disadvantageous Has an effect. These impurities are iron in amounts normally above about 0.01% or even 0.1%, and often up to 1%, and around vanadium and tantalum in amounts up to about 0.1% or even 1% Oxygen in amounts up to about 0.1% by weight and carbon in amounts up to about 0.1% by weight.

Alternatively, the anolyte-resistant surface (23) of the bipolar unit (21) also made of an isomorphic beta phase of a titanium-molybdenum alloy or an isomorphic alloy consist of titanium with other transition metals such as palladium, nickel and iron. In this case the Iron content lower than 0.05 GeX "/.% Iron. Isomorphs Titanium alloys and the aforementioned transition metals also have greatly improved resistance against crack corrosion and mass absorption. Of the Proportion of transition metals, e.g. iron, nickel, Palladium or molybdenum should be high enough to be resistant to crack corrosion and hydrogen to increase, but be low enough to avoid the formation of a second phase.

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never katholytbeständige surface (25) can be made from any material that rregen ^f iber concentrated alkaline solutions containing either Sauerntoff or hydrogen or both, is stable. Such materials are iron, steel, stainless steel and the like.

The sv / ei parts (23) and (25) of the bipolar unit (25) can be titanium and iron foils, foils from others above specified materials and in addition, between the anodic surface (23) and the cathodic Surface (25) a hydrogen barrier can be arranged to thus the passage of hydrogen from the cathodic surface (25) to the anodic surface (23) of the bipolar To prevent unity.

The hydrogen barrier arranged between the anodic surface (23) and the cathodic surface (25) of the bipolar unit (21) consists of a material that prevents the flow of hydrogen, for example a material with low hydrogen solubility or permeability. The hydrogen barrier can be a non-conductive material, such as silicates, glass, organic resins and paints. But it can be provided etallen also Wasserstoffscerren out for suitable ^M. Useful results are obtained with vanadium, chromium, manganese, cobalt, nickel, copper, zinc, niobium, molybdenum, silver, cadmium, rhodium, tantalum, tungsten, iridium, and gold. The best results are obtained when the hydrogen barrier has a coating of molybdenum, rhodium, iridium, silver, gold, manganese, zinc, cadmium, lead, copper or tungsten. Copper is very particularly preferred.

The hydrogen barrier can be a foil or a plate. However, it can also be applied as a film or coating. According to another further embodiment, the hydrogen barrier also serve as an explosion protection film for one or both parts of the bipolar unit (21).

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In the embodiment shown in Figures 9 and 10 the binolar unit (21) is traversed by lines (121) which allow heat to be exchanged in enable the medium carried out. The heat exchange lines (121) serve to pass cold liquids through or cold gases to dissipate heat from the electrolytic cell, for example developed by current flow (I ~ R) Heat as well as the heat generated by reaction. This allows a lower pressure in The electrolytic cell will maintain when the electrolysis is carried out under pressure to produce chlorine in liquid form to win, or oxygen is supplied under pressure, or in both cases.

Another embodiment of the bipolar electrolysis cell with solid polymer electrolyte is shown in FIGS. 11 and 12. The electrolyte is supplied and distributed by the bipolar unit (21) itself. This is done in addition to or instead of the distributor (51), the line (133) leading from the supply line (115a) into the interior of the bipolar unit (21) and then to an oorous or open part (131) that distributes the electrolyte. In an analogous ^{v <T} else the opposite Elektrolvt is supplied through the pipe (143) of oorösen or open surface (141) on the opposite side of the bipolar unit.

r »he individual electrolytic cells (11) and (13) of the bipolar electrolv device (1) also include distribution devices (51) placed between the ends of the cell, for example between the bipolar one Unit (21) and the end plate (71) and the solid polymer electrolyte (31). The distribution facilities are shown in Fig. and reproduced in detail in Figures 5 and 6. The catholyte liquid lines (105a) and (ir> 5b) and the catholyte supply opening (111a) and the catholyte

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The exhaust opening (111b) characterizes this version. The outer edge (53) of the distributor (51) is designed as a circular ring. This makes electrolyte impermeability and gas-tightness of the electrolysis device (1) is achieved as well as the cells (11) and (13).

The seal, which is an alkali-resistant seal (55) or a packing (57) that is resistant to acidic chlorine-containing brines and chlorine-resistant, are preferably elastic, conductive and essentially non-catalytic. This applies to the seal (55) of the catholyte unit in the catholyte space (45), which has a higher hydrogen evolution or hydroxyl ion evolution overvoltage than that cathodic catalyst in order to avoid the electrolytic deposition of cathode products on this surface. In the same way, the seal (57) in the anolyte space (39) has a higher and higher chlorine evolution overvoltage Oxygen evolution overvoltage as the anodic catalyst, to avoid the development of chlorine or oxygen on this surface.

The seals (55) and (57) are used to conduct electrical current from the end of the cell, for example the bipolar one Unit (21) or the end plate (71), to the solid polymer electrolyte (31). It also has good electrical conductivity needed. The conduction takes place while the product is deposited on it, as described above, is avoided. The material must have a minimal contact resistance to the solid polymer electrolyte (31) and to the ends of the individual cells (11), for example the end wall (71) or a bipolar unit (21).

In addition, the distributor seal (55), (57) serves to distribute the electrolyte in the anolyte compartment (39) or in the Catholyte space (45) to thereby polarize concentration, the formation of clogging gas and liquid pockets and the deposition of solid substances such as potassium hydroxide or Avoid sodium hydroxide.

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The packings (55, 57) can be made of carbon, for example in the form of graphite, carbon felt, carbon fibers, porous graphite, activated carbon or the like. Alternatively, the seal can also consist of a metal felt, metal fibers, metal black, "letallgitter, graphitegitter, Metal screen, graphite screen or ribbons or springs or the like. Exist, with ribbons or springs extending up to solid polymeric electrolyte and extend to the bipolar unit (21) and to the end plate (71).

In another embodiment of the invention, the current collecting and distributing devices (51) serve to produce electrical contact between the cell walls (21, 71) and the solid polymeric electrolyte (31). The devices (51) can be a film of fine-meshed sieve or grid, acting on the catalyst (37, 43) and the electrically and mechanically series-connected end walls (21, 71) of the cell (11). As electrical and mechanical connections can be first and second pn-Federmetalleinrichtun' be provided ^T -'obei the first spring means act on the metal catalyst (37, 43) and r'ijo ^ wide Fedemetalleinricbtuncen act IUF the "nriw ^ n.-io ( 21 _f 71) r \ p. _R cell. The two springs ^ .etalleinrichtimn-pp are designed and attached to be removable again. Therefore, they can act on one another and one another by pressure or they can be clamped together. Alternatively, the seals (51, 57) can be . be sealing rings, spheres, Evlinder or the like, which are tightly packed in order to achieve high ^r .pitf "hirrkeit and low electrical resistance.

Another embodiment is the brine feed line and the brine discharge line (87b) as well as the water and oxidant feed line (111a) and the catholyte fluid discharge line (111b) combined with the distributor (51>.

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With such a design, the supply lines extend (87a) and (111a) extend into the seal (55) and (57) and the discharge lines (87b) and (111b) from the poetry (55, 57).

In a further embodiment, the reagent supply devices and the product extraction devices are formed by a microporous distributor, for example a micro-porous hydrophilic or microporous hydrophobic film acting on the solid polymeric electrolyte (31) under the pressure through the distribution devices (55) and (57) In an embodiment in which the feed line is a microporous Film on the solid polymer electrolyte (31), the catalyst particles (37) and (43) in the microporous Film or be arranged on the surface of the solid polymer electrolyte (35, 41).

^{r <7ie} described above, a single electrolytic cell (11, 13) a solid polymer electrolyte (31) having a permionischen membrane (33) on which an anodic catalyst (37) anodic on its surface and a cathode catalyst (43 ) contains on its cathodic surface (41). The ends of the cell are formed by the bipolar unit (21) or an end plate (71), with an electrically conductive connection between the cell ends and the solid polymeric electrolyte (31). through the distribution devices (51). Material feeds (87a) and (111a) and product take-offs (87b) and (111b) are also provided. In addition, facilities must be available to create and maintain electrolyte and gas tight seals, such as sealing rings (61). Although the sealing ring (61) is only shown between the walls (71) and the bipolar unit (21) and the manifolds (51), it is understood that in addition or instead of sealing rings (61) between the manifolds (51) and the fixed polymer electrolytes (31) can be arranged.

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The sealing rings that make contact with the anolyte space (39) can be made of any material that resists acidic chlorine-containing brines, as well as chlorine. Such Materials are silicone rubber and various elastic fluorocarbons.

The sealing rings (61) that come into contact with the catholyte space (45) can consist of any material that is opposite resistant to concentrated alkalis.

A particularly satisfactory flow system is shown in general form in Fig. 1. The brine is fed to the electrolyzer O) through the brine inlets (81a) in the end plate (71), for example by the hydrostatic pressure of a column of liquid. The brine then passes through the opening (83a) into the O-ring or sealing ring (51) and through the opening (85) into the distributor (51) on the cathodic side (45) of the cell (11) and from there to and through the opening (89a) into the fixed pole unit (31) of the electrolytic cell (11). ^Άτη distributor ( ^ς 1) is a Tf ^ rr.iqe M-opening and an outlet r * it only.T (^ 1a) through ^{r1 a} distributor (51) and the vas inlet (37n) for the supply of electrolyte to the anolyte chamber. ^r ) r> r Stron then continues through the ^? 5 ^ fnuna (91a) into the distributor (51) to the opening (93a) and the next O-ring or seal through the connection (95a) in the bipolar Unit (21) and on to the next cell (13), where the flow course essentially corresponds to that already described above. The brine is distributed through the seals (57) in the distributor (51) within the anolyte space (39) Brine removes chlorine from the anodic surface (35) and the anodic catalyst (37) and avoids the build-up of chlorine.

Dilute brine is drawn off through the outlet (37b) of the distributor (51) and the line (91b) through reduced Pressure or partial vacuum supplied.

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The reflux is then through the return port (89b) in solid polymer electrolyte element (31), through the opening (85b) in the cathodic distributor (51), the through opening (83b) in the O-ring or in the sealing ring (61) to the outlet (81b) where the exhausted brine passes the electrolyser (1) leaves.

The brine supply was with an inlet and outlet system in which the recovery of the exhausted brine and chlorine takes place through the same outlets. It goes without saying that exhausted brine and chlorine can also be drawn off separately. It goes without saying that depending on the internal pressure in the anolyte (39) and the temperature of the anolyte liquid within the anolyte space, the chlorine in liquid or in gaseous form can.

Water and oxidizing agent are supplied to the electrolyzer (1) through the inlet opening (101a) in the end plate (71). Water and oxidizing agent then pass through the passage (103a) into the O-ring or sealing ring (61) to the slack (105a) and the T-shaped line in the cathodic distributor (51) on the cathodic side (45) of the cell (11) . The T-shaped outlet includes the opening (105a) and the outlet (111a). Water and oxidizing agent are conveyed through the opening (111a) in the ring (53) of the distributor (51) of the catholyte-resistant seal (55) in the catholyte space (45) of the cell (11). The cell liquor which is an aqueous alkali metal hydroxide, for example \ ^r atriumhydroxyd or potassium hydroxide, is from the cathodic surface (41) of permionischen membrane (33) of the solid polymeric electrolyte dissipated by water, which is introduced into the cell (11). If oxidizing agents are present, the liquid is recovered through the opening (111b), if no oxidizing agent is present, the gas and liquid can be drawn off and recovered _{through the opening (111b) or in another embodiment through separate gas extraction pipes r which are not shown} .

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The electrolysis apparatus is described and shown with conventional feeders for oxidizing agent and water and customary M) zugseinrichtungen for gas and liquid, wherein 3 cables can be present, (111a, 111b) and a third, not shown line to the V ^T asserzuführung, oxidant supply and liquid recovery . Alternatively, there may be 3 lines (111a, 111b) and a third line, not shown, for the water supply and the recovery of drainage liquid and the gas removal.

Tn of the electrolysis device (1) is a total flow present in such a way that the liquid reaches the passage (105a) and continues to the opening (107a) of the solid polymers Electrolyte device (31) to the passage (109a) of the anodic distributor (51) and further through the opening (113a) the O-ring or sealing ring (61), from there to the passage (115a) of the binolar unit (21) and on the same '-'eg further through the single cell (13), as in Cell (11). The same flow scheme continues in others Cells away.

It is shown how the product to be withdrawn from the distributor (51) through the discharge opening (111b) to the passage (105b) from there to the opening (103b) in the O-ring or sealing ring (61) further to the outlet (101b) in the end plate (71) got. The flow of liquid is described in the manner to and through the manifold (51), but the flow can as well Follow bovine T-'acren. For example, inlet or outlet or both can be present in the bipolar unit (21) if the bipolar cell has a porous fiIn or an outlet conduit having. Likewise, the inlet and the outlet or both can be part of the solid polymer electrolyte element (31) be. Although the flow is described as parallel to each individual cell (11) and (13), it can also be a series flow be formed one behind the other. If the brine flow circuit is used, the T-pieces that

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the outlet opening (87) and the line (91) an L instead be a T. In the embodiment with a series flow guide the brine in each cell is less emaciated, with partially emaciated brine of one cell is supplied as an inflow to the next cell and further emaciation. In the same way, with series flow guidance of the catholyte liquid, the T-piece, the outlet opening (105), (111) have an L-shape.

^T * 7enn a series circuit for the flow is applied is the current may be simultaneously connected to a high sodium or potassium ion concentration gradient through the permionische membrane (33) or a counter-current with low sodium or potassium ion concentration gradient through the single fixed rolymerelektrolyteinheit (31).

The bipolar electrolysis unit can be arranged either horizontally or vertically, so that the bipolar electrolysis cell (1) with the solid polymer electrolyte unit (31) either a horizontal membrane (33) or a vertical one Has membrane (33). An arrangement is preferred in which the membrane (33) is arranged horizontally in such a way that that the anodic surface (35) lies on top of the permionic membrane (33) and the cathodic surface (41) on the lower side of the permionic membrane (33) facing the bottom. A horizontal version has a number of advantages. When operated under low pressure, chlorine bubbles rise through the anolyte space. With a horizontal arrangement, the build-up of concentrated alkali hydroxide at the bottom of the surface (41) of the permionic membrane (33) prevents, although the podenoherfl'Tche (41) of the nemionic membrane (33) in contact with alkali hydroxide and is thereby moistened. If an oxidizing agent is additionally present, for example a gaseous oxidizer, the horizontal arrangement allows the oxidizer in contact

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-5O-.

with the cathodic surface (41) of the pernionic (33) arrives.

The solid polymer electrolyte element (31) has a permionic Membrane (33). The pemionic membrane (33) should be chemical-resistant, cathion-selective on the anodic surface (35) an anodic chlorine evolution catalyst (37) and on the cathodic surface (41) a cathodic hydroxyl-developing catalyst (43) have.

An oermional membrane (33) made of a fluorinated hydrocarbon resin can be used as the solid polymer electrolyte (31). The characteristic is the presence of cation-selective ion exchange groups, the ion exchange capacity of the Menbran, the concentration of the lonenaustauschenden groups in the membrane on the basis of embran in the adsorbed ^{M ri?} Ssers and Glasumwandluncrstemneratur the membrane material. The fluorinated hydrocarbon resin suitable for these purposes has the following groups:

- (CF ₂ -CXX ¹ ) - and - (CF ₉ -CX) -

where: X is -F, -Cl, -H, or -CF ₃ ; X ¹ = -F, -Cl, -H, -CF ₃ or CF ₃ (CP ₂ ) _m -; .

m is an integer between 1 and 5 and Y is -Λ, -R, -A, -PA, or -0- (CF ₀ ) (P, Q, R) -A.

£ * Tl

In the unit (P, Q, R), P means - (CF ₉ ) (CXX ¹ ), (CF ₉ ),

'- CL D £ G

O (-CF ₂ -O-CXX ¹ ) _d , R (-CXX'-0-CF ₂ ) _e , and (P, O, R) contains one or more P, Q, R.

0 represents a phenylene group; η is 0 or 1; a, b, c, d and e are integers from 0 to 6.

030036/0690

BATH ORIGINAL

A typical group Y has a structure with an acidic group A linked to a C atom that carries a fluorine atom. This includes - (CF,) -A, and side chains with ether bonds such as: -0- (CF ₀ ) -A, - (0-CF ₀ -CF) -A,

Z - (0-CF ₂ -CF) _x - (O-CF ₂ -CF ₂ ) -A, and -0-CF ₂ - (CF ₂ -O-CF) _x - (CF ₂ ) -

Z Z

(CF ^ -O-CF) "A, where x, y and ζ are essentially 1 to 10 be-2 , ζ

and Z and R are -F or a C ₁ ^ ₁ perfluorinated alkyl group and A is an acid group as indicated below.

In the event that copolymers olefinic and olefinic acid groups comprise, as mentioned above, the proportion is preferably 1-40 mole percent, and most preferably 3-20 ^M olprozent of olefin-acid group units to the produced therefrom membrane has an ion exchange capacity to the extent desired admit.

The suitable acid groups are: -SO ₃ H, -COOH, -PO ₃ H ₃ and -PO ₃ H or a group which can be converted to one of the groups mentioned above by hydrolysis or neutralization.

In a particularly preferred embodiment of the invention, A is either a -COOH group or a functional group that can be converted into a -COOH group by hydrolysis or neutralization, such as -CN, -COF, -COCl ^ -COOR, - COOM, -CONR ₀ R ₃ ; where R ^ is a C _1-10 alkyl group and R- and R- are either hydrogen or C ._.- alkyl groups with perfluoroalkyl groups or both. M is hydrogen or alkali; when M is alkali, sodium or potassium is especially preferred.

030036/0690

In an embodiment of the invention in which Λ -CONR ₂ RJ, and where R ₃ and R are hydrogen, or a C ₁ to C _{1 (} _Alky! Group, with a perfluoroalkyl group, the cathodic surface (41) of the perinionic Membrane (33) have ion-exchanging groups in the carboxylic acid form, while the anodic surface (35) of the perir.ionic membrane has the ion exchange groups in the amide or N-substituted amide form. The formation of amide groups or N-substituted amide groups on the anodic surface ( 35) of the permionic membrane (33) makes the anodic surface (35) hydrophobic, which prevents chlorine build-up on the membrane (33).

The membrane (33) can be converted into amides or N-substituted amide groups during the synthesis or after C ¹ PiT catalyst (37) has been applied or embedded therein, for example by reaction with ammonia or

In another embodiment, A can be either a -SO, H or a functional group which can be converted into a -SO ~ H group by hydrolysis or neutralization, or a group which can be formed from a -SO ^ K group such as -SO-M ', (SO _{2 -NH) M ", -SO 3} NH-R ₁ -MH 2, or -SO ₃ NR ₄ R ₅ NR ₄ R ₆ ; where M ^{1 is} alkali, M" H , _{Is NH 4} or alkali or alkaline earth; R ₄ is H.Na or K; Rc is a C ₃ to Cg alkyl group (R ₁ J ₃ NRg, or RiNRg (R ₃ ) "IR ₆ ; Rg is H, Na, K or -SO ₃ ; and R ₁ is a C ₃ -C ₆ alkyl group.

The membrane material that is suitable for this has an ion exchange capacity of about 0.5 to about 2.0 milligrams Equivalents per gram of dry polymer, preferably from about 0.9 to about 1.8 milligram equivalents per gram dry polymer, and most preferably from about 1.1 to about 1.7 milligram equivalents per gram of dry Polymer on.

030036/0690

BAD ORiGINAL

When the ion exchange capacity is less than 0.5 milligrams Equivalents per gram of dry polymer, is the power output * Booty low at the high alkali hydroxide concentration that comes into consideration here. When the ion exchange capacity is greater than about 2.0 milligram equivalents per gram of dry polymer, the current efficiency of the membrane is much too low.

The proportion of ion exchange groups per gram of water absorbed is about 8 milligram equivalents per gram of water absorbed to about 30 milligram equivalents per gram of water absorbed, and preferably from about 10 milligram equivalents to about 28 milligram equivalents per gram of water absorbed. Most preferred is an ion exchange group content of about 14 milligram equivalents per gram of water absorbed to about 26 milligram equivalents per gram of water absorbed. ^TJ hen the content of the ion-exchange groups per Gewichtöeinheit absorbed barrels is less than about 8 milligrams per gram of absorbed water KcTuivalente or greater than about 30 milligram equivalents per gram of absorbed water, the current efficiency is far too low.

The glass transition temperature is preferably at least about 20 ° C. below the temperature of the electrolyte. If the electrolyte temperature between about 95 ° C and 11O ° C, the Glasumvandlungstenperatur the fluorinated hydrocarbon resin for the permionische membrane is less than about 90 ⁰ C and preferably below about 70 ° C. The glass transition temperature should, however, be above about minus BO ⁰ C in order to achieve a satisfactory tear strength of the membrane material. Preferably, the glass transition temperature is from about minus RO ⁰ C to about 70 ⁰ C and at a very preferred embodiment, from about minus 80 ⁰ C to about 50 ⁰ C.

030038/0600

^r "? f the glass transition temperature of the membrane within the range of from about 2O ° C to the electrolyte temperature, or is higher than the temperature of the electrolyte, the membrane resistance increases and the permanent selectivity (perm selectivity) of the diaphragm drops. Under glass transition temperature is the temperature understood below dc-r polymer segments do not have enough energy to move toward each other or move by Brownian Teilchenbewe <tion. that is, below the Glasumwandlungstenneratur is the only reversible behavior of the polymer to stress in deformation, while above the glass transition temperature, the Polymers cancels the externally applied load through internal segmental displacements.

The fluorinated hydrocarbon resins used for the permionic membrane have a water permeability of less than about 100 milliliters per hour per m at 6O ⁰ C in 4 η sodium chloride solution at pH 10. The water permeability is preferably less than 10 milliliters per hour per m "at 6O ⁰ C in 4 η sodium chloride solution at dH 10. If the water permeability of the permionic membrane under the given conditions is more than 100 milliliters per hour
Alkali hydroxide is formed.

than 100 milliliters per hour and meter can be a contaminated

The electrical resistance of the dry membrane should be from about 0.5 to about 10 ohms per square centimeter, preferably from about 0.5 to about 7 ohms oro cm.

Preferably, the fluorinated resin for the permionic membrane has a molecular weight, i.e., such a degree of Polymerization that is sufficient to

• 3

flow rate of about 100 mm per second at temperatures from about 150 to about 300 ° C to allow.

030036/0690

The thickness of the permionic membrane (33) should be such / that the membrane (33) is strong enough to withstand pressure differences and withstand the manufacturing process, for example applying the catalyst particles, but thin enough to avoid too high an electrical resistance. Preferably the membrane is from about 10 to about 1000 Micron thick and in a most preferred embodiment the thickness is from about 50 to about 200 microns. In addition, internal reinforcements or increasing thickness or Networking used, or so <rar lamination to to get to more stable membranes.

In a preferred embodiment of the permionic Membrane devices are provided to hold anolyte liquid to get into the interior of the permionic membrane. This avoids crystallization of alkali chloride salts inside the permionic membrane (33). Such Devices can be wick devices that extend, for example, up to or through the anodic catalyst (37) extend. In another embodiment exist the devices for introducing anolvtiquid into the interior of the pernionic "Fe ^ brane made of hydrophilic or Damp-absorbing fibers that extend up to the or through the anodic catalyst (37), or straight capillaries extending up to or through the anodic Extend catalyst (37).

The devices for introducing anolyte liquid into the interior of the nermionic membrane draw "water or Anolyte liquid in the interior of the membrane next to the water of hydration of the electrolytically promoted alkali ions. This causes the crystallization of alkali chlorides, such as ■■ Jatric chloride or potassium chloride within the prevented.

030036/0690

BATH ORIGINAL

^In a preferred embodiment, the electrocatalysts (37) and (43) form the membrane (33) as one unit. In this case, the electrocatalyst (37, 43) can be arranged on the distributor seal (55, 57), in which the distributor (55) and (57) are kept in a tension ratio P ¹ It of the membrane (33). In this case, the flexocatalyst (37, 43) is applied as a fi n on the permionic membrane (33). The film (33, 43) is generally from about 10 to about 200 microns thick, preferably it is from about 25 to 125 microns thick. The ideal thickness is between about 50 and about 150 microns.

The electrocatalytic permionic membrane unit (31) should be dimensionally stable, resistant to chemical and thermal degradation, electrocatalytic activity and preferably the catalyst particles should be finely distributed and porous and at least one surface of about 10 am per gram of catalyst particles.

The adhesion of the catalysts (37 and 43) on the permionic membrane (33) is produced by the Particles (37, 43) in the molten, semi-molten, liquid, plastic or thermoplastic permionic Membrane material (33) presses in at an elevated temperature. This is red when the membrane is up above it Glass transition temperature is heated, preferably to Temperatures above the temperature at which the membrane (33) can be deformed solely by pressure. With another Embodiment, the particles (37) and (43) in the partially polymerized permionic membrane or partially crosslinked permionic membrane (33) are pressed in and where the polymerization or crosslinking is then continued, for example by increasing or decreasing the temperature, Adding accelerators, adding additional monomers or using ionizing radiation or the like.

03003-6 / 0690

Do another embodiment of the process according to the invention in which a further polymerization is carried out the particles (37, 43) could be embedded into the partially polymerized permionic membrane (33). A monomer of a hydrophobic polymer can then be used be applied to the surface with, for example, an accelerator and a co-polymerization in situ with The partially polymerizing permionic membrane is carried out in order to have a hydrophobic surface in this way of the particles (37, 43). In this way the catalyst particles (37, 43) have a hydrophobic surface provided, for example to protect the anodic surface (35) from chlorine, or the cathodic surface (41) to protect against crystallization or dissolution by alkali hydroxide, or to improve the depolarization more strongly as if a cathodic HO-'- disproportionation catalyst on the cathodic surface (41) of the permionic Membrane is present.

According to a further embodiment of the invention, the green pemionic merranas can be crosslinked, for example after the catalyst particles have been brought up, in order to increase the hydrophobic character of the membrane surface partially polymerized permionic membrane are applied. Common crosslinking agents are divinybenzene, for example perfluorinated divinylbenzene. Other useful crosslinking agents are fluorinated dienes such as hexafluorobutadiene, octafluoropentadiene with 1,3 and 1,4 dienes and decafluorohexadiene with 1,3 and 1,4 and 1,5 dienes. The appropriate best crosslinking agent is divinylbenzene or nerfluorierte C ₄ to C ^. Serves, especially hexafluorobutadiene.

^In another embodiment, the anodic slectronic catalytic converter (37) is treated with silicone. This type of conversion takes place when the anodic fleece catalyst (37) is present in particulate form, namely as coated

030036/0690

ßAD ORIGINAL

counterparticles, for example silicone particles, coated with a useful chlorine evolution catalyst. In addition, silicone particles, for example coated Silicone particles, silicone particles containing silicide, and silicone particles having a silicone surface the anodic surface (35) of the permionic membrane (33) applied v / ground, both to the conductivity between To generate anode particles and between the anodic catalyst.

In this embodiment of the invention, anode particles are provided with a low overvoltage, which also includes an electrolyte-resistant, electrically conductive surface, for example made of metallic platium or ruthenium oxide on an electrically conductive carrier material, consisting partly or completely and preferably predominantly of elemental silicon, in contrast of ^q iliciden, which are understood as components of silicone or other metals. The elemental silicon contains impurities, dopants or additives, for example T ^ or, phosphorus, etc. or silicides of various metals co-nerated within the silicon in order to improve the conductivity and / or the strength of the silicon. Elemental silicon generally forms a continuous phase in which other substances can be dissolved or dispersed.

The silicon particles should be electrically conductive and have at least the electrical conductivity of graohite. The elemental silicon should have an electrical conductivity (bulk electrical conductivity) of more than 1O ² (ohm-centimeter) and preferably 10 (ohm-centimeter) or more. Substantially pure silicon, for example silicon with a purity of more than 99.99 5 atomic percent, is usually a poor conductor and is characterized as a non-conductor with a resistance of only about 1 ohm-centimeter. It is known that by introducing small trace amounts of boron,

030036/0690

• ORIGINAL BATHROOM

Phosphorus or other substances form a silicon compound that is electrically conductive. In the context of the invention it was found that with good precaution a silicon * · carrier material can be obtained in a form that is constantly against anodic attack and that such carrier materials are particularly suitable for receiving conductive surfaces.

It has been found that elemental silicon, which contains up to 2 % or up to 5% boron or up to 2% phosphorus and negligible proportions of other impurities, has the desired resistance to anodic attack by aqueous sodium chloride.

The silicon can contain iron, for example up to 40% by weight if phosphorus or boron are present, for example phosphorus and boron have a corrosion-inhibiting effect.

The silicon particles may also silicides enthalten4 particularly preferred silicides have a catalytic Kffekt or vprst ^s r ^v s conductivity. For this purpose, silicides of the "fotalls ^ er Brunnen IV, V and ν χ periodic system, for example TiSi ^, TrSi ^, • ^T bni ₉ ," aSi ^ and "Si ^ and Tchvernetallsilicide, for example CrSi, Cr ₅ Si ₃ , CrSi , CrSi ₃ and MoSi ₃ , as well as cobalt silicide as CoSi ₃ .

According to another embodiment of the invention vessel In the process, the catalyst (37, 43) is chemically precipitated, for example by hypophosphite or borohydride reduction or electrically deposited on the permionic membrane (33). In addition, the catalyst can be activated are created by co-deposition of a leachable substance, together with a less leachable material, and connect activation by leaching the more leachable substance.

030036/0690

J / BAD ORIGINAL

According to a further embodiment, the catalyst can (37, 43) on the surface of the permionic membrane Electrophoretically deposited, laser deposited, photodeposition or sputtering be applied.

Mach a further embodiment of the invention Method, the catalytic coating (37, 43) can be applied to the permionic membrane (33) using of metal chelates that react with the acidic groups of the permionic membrane (33).

A typical catalyst (43, 37) for the surface of the permionic membrane (33) is a noble metal containing Catalyst, for example of the platinum metal group or an alloy of the platinum metal group or an intermetallic Compound with a platinum group metal or an oxide, carbide, nitride, boride, silicide or sulphide of a platinum group metal. Such noble metal-containing catalysts are characterized by a "Large surface area and by the ability to be bondable either with hydrophobic particles or in hydrophobic films to be embeddable. In addition, the noble metal containing catalyst can be a partially reduced oxide or carbon black be like platinum black or palladium black, or be deposited electrically or chemically.

The catalysts (37, 43) can also be an intermetallic compound with other metals, including Precious or base metals. Such intermetallic Compounds are pyrochlore, delafossite, spinels, perovskites, bronzes, tungsten bronzes, silicides, nitrides, Carbides and borides.

Among the particularly suitable and desirable cathodic catalysts based on the solid polymer electrolytic permionic membrane (33) may be present include

030036/0690

BATH ORIGINAL

Steel, stainless steel, cobalt, nickel, nickel or iron alloys, compositions with nickel, in particular porous nickel with molybdenum, tantalum, tungsten, titanium, columbium or the like and borides, electrical conductive, electrically active borides, nitrides, silicides and carbides, such as silicides, nitrides, carbides, borides and Titanium diborides of the platinum metal group.

Other cathodic catalysts (43) suitable for the cathodic surface (41) are the metals of the platinum group, by no means platinum, palladium, ruthenium, osmium, Iridium and Rhodium, either as smooth coatings or as Deposits with large surfaces, for example as soot with surfaces greater than 10 m per gram.

It is possible to treat the permionic membrane (33) or one of its surfaces, for example the anodic surface (3S) or the catholic surface (41), with a ^{reducing agent, a complexing agent, a buffer and a 1} niprVrVrzu ^ chI ^ rrenrien metal compound or compounds of the like Bringing metals into contact. Suitable reducing agents are borohydrides or hypophosphites. The borohydride solution should contain 1 to 5 grams per liter of borohydride, for example sodium or potassium borohydride, preferably 1.5 to 2.5 grams per liter of borohydride.

Because the deposit is on a synthetic perraionic Membrane (33) and not on a metal substrate, the following connection is particularly desirable. First will brought the membrane into contact with the reducing agent and then with the metal compounds to be deposited. This The method according to the invention results in particular advantages transition metals. Particularly beneficial results are achieved with the transition metals of the seventh group of the periodic table. This practice is Particularly well suited for the joint deposit of 2 metals of group VIII, which have different levels of resistance compared to chemical leaching when the less leaching-resistant metal is subsequently leached out.

030036/0690

BADORlGtNAL

When using borohydride, alkali borohydrides, such as Potassium or sodium borohydride is particularly preferred. That Transition metal is present in the second solution as a soluble salt, for example as citrate, oxalate, glycolate, Sulfate or chloride. The acid and its alkali salt, for example sodium citrate, can serve as a buffer and complexing agent and citric acid, sodium oxalate and oxalic acid and the like. Inorganic acids can also be used, for example Phosphoric acid and sodium phosphite.

The complexing agent and the buffering are used to keep the metal ions of group VIII in solution, for example at pH values from 6 to 8.

In a very particularly preferred embodiment contains the cathodic electrocatalyst (43) porous nickel with an effectively effective proportion, for example one, the overvoltage reducing or overvoltage stabilizing proportion of transition metals of groups IV, V, VI or VII. These transition metals include titanium, zircon, hafnium, vanadium, columbium, tantalum, chromium, molybdenum Tungsten, manganese, technetium and rhenium. Preferred substances are titanium, zircon, hafnium, vanadium, colunbium, tantalum, Molybdenum and tungsten. Titanium, tantalum, zirconium and molybdenum are very particularly preferred.

The nickel content is generally above about 50% and less than about 95% and generally between about 65 to about 90% nickel, calculated as metallic nickel, based on the total weight of the porous active surface.

The second transition metal is present in the porous catalytic surface (43) in such an amount that the hydrogen overvoltage is lowered. This is a proportion of more than about 2.5%, preferably more than about 5%, but less than about 50 % and in general the proportion is between about 10 and about 35% by weight, calculated as metal, based on the total amount Nickel metal and second transition metal on the surface.

030036/0690

In general, the proportion of the second transition metal is high enough in surface to "" hold the hydrogen overvoltage effective to degrade, but low enough to degrade the high Avoid overvoltages that occur on porous surfaces, which mainly consist of the second transition metal, for example titanium, tantalum, zircon or molybdenum,

The mechanism on which the hydrogen overvoltage-lowering effect of the second transition metal is based cannot be fully explained. It is known that porous films made, for example, of molybdenum alone have a high hydrogen overvoltage, but a low hydrogen overvoltage is also achieved over long electrolysis times when a second transition metal, as described above, for example molybdenum is used in conjunction with porous nickel. In the case of molybdenum, it is assumed that molybdenum has a depolarizing or catalyzing effect on a step in the hydrogen evolution process. A.us this reason, the upper limit of the content of the second transition metal is below the concentration at which the surface never ^TT asserstoffüberspannungseigenschaften of the second transition metal comprising. This proportion is below about 50% and generally below about 35%.

The second transition metal itself can be present as elemental metal, as elemental molybdenum, titanium, tantalum, zircon or tungsten with the formal valence O, as an alloy together with nickel or as an alkali-resistant compound, for example as carbide, nitride, boride, sulfide, Phosphide, oxide, or any other compound that is insoluble in concentrated alkali hydroxide. The second transition metal is preferably present in the surface (43) together with nickel as an elemental metal or as an alloy with nickel, or as a carbide. A particularly excellent cathode (43), according to the present invention is a olvbd3n having a porous surface (43) of nickel and ^M, which is about 82 wt.% Nickel and about 18 wt.%

030036/0690

BATH ORIGINAL

Molybdenum, based on the total amount of nickel and molybdenum, has a porosity of about 0.7 and a thickness from about 75 to about 500 micrometers.

According to another embodiment of the method according to the invention, the cathode to be used is produced by Deposition of a film of nickel, the second transition metal and a leachable material on the permionic Membrane (33) and subsequent removal of the leachable material.

Any metal or compound can be used as the leachable material, which together with nickel and the second transition metal or applied together with nickel compounds and compounds of the second transition metals can be and can be dissolved out with strong acid or strong alkali without essential Shares of the nickel or the second transition metal triggered or destruction or poisoning of the nickel or the second transition metal takes place.

The "PiIm can be applied to the nemionic membrane (33) by electrical deposition of nickel, the second superordinate metal and the leachable substance. It is also possible to deposit the solid particles together. Chemical deposition, for example by hyponhosphite deposition or by Borohydride deposition on nickel compounds, compounds c "the second" transition metal and the leachable material. ^^ It is also possible to carry out the aHlacrerunCT by thermal decomposition of organic compounds of nickel, the second transition metal and the leachable material, for example, deposition and thermal Decomposition of alcoholates or resinates.

"laughing a particularly desirable embodiment of he ^c inrungs <7em ^ Pen method of manufacturing the erfindungsfpf ^ en electrode fine particles, for example those in the Irößenordnung from about o, 5 to 7O microns

030036/0690

Diameter of nickel, the second transition metal or a compound thereof and a leachable material / embedded in the partially polymerized permionic Membrane (33) and the polymerization then brought to an end, the leachable material being dissolved out either can take place before or after the polymerization. According to an alternative method, it is also possible to use the particles embedded in a hot thermoplastic permionic membrane (33).

The leachable material can be present in the particles with nickel or as separate particles. Typical leachable components are copper, zinc, gallium, Aluminum, tin, silicon or the like. Particularly preferred are nickel particles which contain about 3 to 70% winding and the remainder contain aluminum in the form of Raney Leqierunrren.

After the polymerization has been completed, the partial polymerized membrane (33) or the cooling of the hot thermor> latischen membrane (33) can the particles are extracted, for example alkaline by π, S η Sodium hydroxide or 1 η sodium hydroxide to make the leachable To remove substances such as aluminum. It is then washed with water. It is possible that some of the leachable material is in the porous electrode surface (43) is not included, but this does not result in any adverse effects. T ^ enn for example a Raney nickel aluminum alloy and molybdenum into the If the membrane (33) is embedded, the surface may contain nickel, molybdenum and aluminum, even after it has been detached. The resulting surface can contain, for example: amorphous nickel, crystalline molybdenum-nickel-aluminum alloys and traces of aluminum.

030036/0690

According to a further embodiment of the invention, the Surface (43) contain boron or phosphorus. These substances are applied by deposition of borohydride or Hypophosphite and stabilize the voltage behavior of the cathodic electrocatalyst (43). The one described here cathodic electrocatalyst (43) is generally suitable for use with perfluorinated ion exchange membranes (33), however, it is particularly advantageous if it is an ion exchange membrane (33) with carboxyic acid groups acts.

The proportion of nickel is generally above about 50% and less than about 95%, usually between about 6 5 to about 90% nickel, calculated as nickel metal, based on the total weight of the porous active surface,

The second transition metal present in the porous catalytic surface (43) is present in such an amount that that the hydrogen excess voltage is lowered. This share is above 2.5%, preferably above 5%, but below 50% and generally between about 10 and about 35 ow.%, calculated as metal, based on the total amount! .ekel and second transition metal in the surface (calculated as metal). In general, the proportion of the second long-term ^ ar.CTRnetalles in Her surface * high enough to be a sufficient. corresponding effect in terms of lowering the hydrogen overvoltage to have, but low enough to avoid the high overvoltage, <Ke with porous surfaces that consist mainly of a second transition metal, to ^ pJ i-len, such high overvoltages have porous surfaces made of titanium, tantalum, zircon or molybdenum.

In the electrolysis of alkali chloride sols, for example potassium chloride and sodium chloride sols, in an electrolysis cell with solid polymeric electrolytes, especially those that have a permionic membrane (33) with carboxy-acid groups is the purity of the brine,

030036/0890

BATH ORIGINAL

outgoing influence. The proportion of ^? The base metals in the brine should be less than 40 parts per million and preferably less than 20 parts per million to avoid fouling and poisoning the permionic membrane (33). The pH of the brine should be low enough to avoid the precipitation of magnesium ions. The calcium content should be less than 50 parts per trillion and preferably less than 20 parts per trillion. The brine should be essentially free of organic carbon compounds, especially if chlorine is to be obtained directly from the cell as a liquid and fed directly to further processes, for example organic Synthesis processes, such as the production of vinyl chloride, without further treatment. The treatment and purification of the brine can be carried out using various methods in order to achieve the required purity. For example, phosphatellings can be carried out in order to remove the calcium, for example as calcium apatite or as calcium fluoroapatite. In addition, an ion exchange resin can also be used to purify the brine. An ion exchange resin, of the chelating type, is preferably used for this. This multifunctionality removes contaminants from polyvalent metals, for example alkaline earth ions or ions of transition metals.

The water supplied to the catholyte (45) should essentially be be free of carbon dioxide and carbonates to prevent the formation and deposition of carbonates on the permionic Avoid membrane (33). The supply of deionized water is very particularly preferred.

The recovery or regeneration of the chelating agent Ion exchange resin is critical. By regeneration with a non-oxidizing acid, the entire polyvalent Cations are removed. This can be achieved by, for example, 10 to 2 times the bed volume of a

030036/0690

0.5 to 5 η HCl and preferably 10 to 20 or more times of the bed volume of 2 to 3 η -HCl as the regeneration liquid used.

Dilute mineral acids, for example from about 0.1 to 10 η and preferably from about 0.5 to 5 η, are used as regeneration liquids suitable. Cloth oxidizing acids are preferred to avoid damaging the resin. Common Acids are the halo-barrel acids, in particular HCl.

The strength of the acid should be high enough to remove the cations from the resin, that is, more than about 0.1 η and preferably more than about 0.5 n, but low enough to avoid dehydration of the membrane, ie . below about 10 n In this way, one can obtain a brine containing less than 20 parts per million transition metal and * - 'enig ° -r 20 ^r Peile contains oro trillion alkaline earths.

Operation cl "* r allows a short cell of the brine in the ^A nolytraum (3 ^q) nit exhaustion of about 10 to 15%, the Vervendung the brine as the coolant, and also ver envy Konzentrat.ionspolymerisation. F.3 , however, higher degrees of pole exhaustion are also possible, for example ■} r> 3 ·, 40% or even 50, 60, or 70 % when driving

Cells reachable.

The temperature of the cell may be above 9 ° C, particularly when the OIE ¹ ^ having a low pIT-- ^{T 'T} ert to reduce characterized i "Kp ^ ^ ilcun of hydrochloride. Alternatively, however, the ^m emperature, the cell also be kept below 9 ° C during operation in order to promote the formation of chlorohydrate, so that it is possible to see and win a dispersion of brine and chlorohydrate from the cell.

030036/0690

BATH ORIGINAL

The cell temperature should be low enough to stay in Case of obtaining chlorine in liquid state, the pressure necessary for cell operation to be maintained to keep the chlorine in the liquid state low in order to get by with normal construction methods when building ropes and to avoid the use of high pressure technology, there is never any pressure-temperature dependence of liquid chlorine shown in Table I.

⁰ F pressure χ 68.9467 (mbar) - 22 (psi, gage) Table I. - 13 3.1 - 4th 7.2 Vapor pressure of liquid chlorine + 5 13.4 temperature 14th 17.2 ⁰ C 23 23.5 32 30.6 - 30 41 38.8 - 25th ^ n 47.8 - 20th 59 CO O
' * ^ ■ ■ £ - 15 68 68.9 - in 77 81.9 - 5th 86 95.4 O 95 111.7 + 5 104 129.9 10 113 149.0 15th 122 170.8 20th 131 193.1 25th 140 218.1 30th 149 243.8 35 158 271.0 4O 167 302.4 45 176 335.7 5.0 185 37O.9 55 194 409.1 60 203 448.8 65 212 492.2 7O 221 536 75 230 586 80 239 638 85 248 694 90 257 756 95 266 822 1O0 275 888 105 284 960 11O 1035 115 120 125 130 135 14O

030036/0690

BATH ORIGINAL

If the electrolyzer is operated to produce chlorine in liquid Fprn, the pressure should be high enough to keep the chlorine in a liquid state. This allows liquid chlorine and depleted Brine can be withdrawn together. The liquid chlorine is separated from the brine and the brine is then cooled to still to convert the chlorine present in it into chlorohydrate, which is then separated from the brine. The exhausted one Brine is then enriched with salt again, purified and fed back into the circulation in the cells, while the The separated hydrochloride is heated to form chlorine again.

The pressure in the electrolysis device should be high enough to allow the withdrawal of gaseous nitrogen and oxygen from the cells and auxiliary devices without evaporating substantial amounts of liquid chlorine when the cell is operated in such a way that liquid chlorine is obtained sol " ¹ , it is necessary to keep the temperature of the cell below about 100 ° C in order to keep the pressure within the electrolyzer below about 41 bar (600 psi gage). Preferably, the cell temperature should be below about 50 ° C, to keep the pressure in the cells below about 16.65 bar (200 psi) In any event, the desired temperature and pressure in the cells will depend on the further use of the liquid chlorine and the associated vapor pressures and temperatures. For practical reasons, the pressure inside the cell depends strong on the pressure in the auxiliary equipment and the ^T 7eiterver ^r "rendung of liquid chlorine from the structural design of the actual cell components.

High pressure is particularly advantageous on the catholic side (45) of the single cell (11), whereby the k ^ thodic reaction is denolarized because of high pressure

030036/0690

BAD ORIGtNAL

prints the depolarizing agent into the catalyst and so ^ as FOt -disproprotioniert.

the Elektrolyseeir.richturig (1) at sufficiently high Pressure is operated to keep the mapped chlorine within the Änolytraun (37) in liquid form, chlorine can and the exhausted brine can be obtained from the cell fluids. Liquid chlorine is relatively difficult to mix with Sole for the prints in question here. For this Basically, the liquid chlorine can easily be separated from the brine, for example by centrifugation, filtration, or on the viscosity, surface tension or density-dependent Facilities.

After the liquid chlorine is separated, it can be stored or used in liquid form without that liquefaction is necessary. The proportion of liquid Chlorine in the anolyte compartment is only 2 to 5 mole percent of the anolyte liquid. Although the vast majority of the Chlorine is recovered and separated as an essentially pure liquid, as some chlorine dissolves in the brine. The chlorine dissolved in the brine can be obtained by Cooling the brine to 9 ° C, for example by evaporating liquid chlorine in a cooler, so that the converts the chlorine dissolved in the brine into chlorine hydrate. Hydrochloric acid are yellow crystals formed by the depleted brine can be separated and then converted back into chlorine by heating.

The cell can be operated by ultrasound treatment the permionic membrane (33) or by using a pulsating current congestion of chlorine bubbles from the anodic surface are removed, solid crystallized or highly concentrated liquid alkali hydroxide removed from the cathodic surface (41).

030036/0690

If a pulsating current is used, pulsing current can be used directly, or more rectified Alternating current or rectified alternating current of half wavelength. Preferably a direct pulsating current with a frequency of about 10 to about 40 cycles per second, preferably about 20 to about 30 Cycles per second used.

T) XR obtained from the cell catholyte usually contains more than 20 wt.% Alkali hydroxide. If, in a preferred embodiment of the invention, the permionic membrane (3 3) is a membrane which contains caroxylic acid groups, as described above, the xatholyte liquid can contain more than 30 to 35%, for example 40 or even 45 or more% by weight of alkali hydroxide .

can in ^ lektrolse ^ ell ^ n (11) F> it "psten Electrolytes higher than with conventional ones

nermionic membranes or in niaphragm cells. At-

9 more than 200 inner per ^Q ? 9, O3 ct ¹ and preferential

r ^Q hr as 4OO Annerepro ^q 2 ^q , ^r > 3 cm "". ^p ei a cr-

TimtRn niektrolysevorfahren, ger ^ '^ ß present Frfindun'', K-Tin «-" if »electrolysis ¹ ^ eI" tromdleiten von Soo odpr 1.2 ¹ ^ o ^ nppppro ^ 29 cm' carried out v / earth. The current density is defined as the total current passage through the inch divided by the surface area on one side of the permionic membrane (33).

a particularly preferred embodiment of the invention In the process, the cathode is depolarized, in order in this way to cause the formation of a gaseous cathode product to avoid. An oxidizing agent is used to maintain this depolarization of the cathode during operation the cathodic surface (41) of the solid polymer electrolyte (31) fed, while the usual catalyst

030036/0690

BATH

(43) in contact with the cathodic surface (41) of the solid polymer electrolyte (31) is and thereby the formation of gaseous hydrogen is avoided. If the Electrolysis device (1) and the electrolytic cell (11) are kept under increased pressure, as it was already has been described, the development of a gaseous product can be avoided, so that the associated Problems do not arise.

In a process for the production of alkali hydroxide and chlorine by electrolysis of alkali chloride sols, for example an aqueous solution of sodium chloride or potassium chloride is used to add the alkali chloride solution to the cell, a voltage is applied to the cell, so that chlorine develops at the anode and alkali hydroxide in the electrolyte occurs when it comes into contact with the cathode. Hydrogen can develop at the cathode.

The overall anode reaction is the following:

2 Cl "* ^C1 2 ^{+ 2e} ~ ⁽¹⁾

the overall reaction at the cathode can be expressed as follows Express the equation:

2 H ₂ O + 2e ~ * H ₂ + 20H ~ (2)

ⁿ räziser the cathode reaction is represented by: H ₂ O + e "" H _ad8 + OH "(3)

whereby monatomic hydrogen is adsorbed on the surface of the cathode. In an alkaline medium, the adsorbed Alternatively, hydrogen can be converted after 2 reactions when desorbing:

2 «, * H _n or (4)

ad.s 2.

^H ads ^{+ H} 2 ° ^{+ e} "* ^H 2 ^{+ H0} ~ ⁽⁵⁾

030036/0690

BAP ORIGINAL

The hydrogen desorption step, i.e. reaction (4) or reaction (5) is that of hydrogen overvoltage determining step. It is the speed-controlling step and its activation energy is direct Relationship to cathodic hydrogen overvoltage. The cathode voltage for the development of hydrogen after reaction (2) is of the order of magnitude 1.5 to about 1.6 volts, against a saturated calomel electrode on iron in a basic medium, with the hydrogen overvoltage component is about 0.4 to 0.5 volts.

One method of reducing the cathode voltage is to provide substitute reactions for the evolution of gaseous hydrogen, that is, to enable a reaction in which a liquid product is formed instead of gaseous hydrogen. For example, water can be formed by an oxidizing agent fed to the cathode. The oxidizing agent can be a crash-shaped oxidizing agent, such as air, oxygen or the like. ^ s can he be used in liquid form and oxidizing agents such as ^rT asserstof fperoxyd, Hydroperoxvde, peroxyacids or like a ^.

^TT hen as the oxidant is oxygen, for example, used in air or gaseous substance Gauer, run the following reaction at the cathode: ■

O ₂ + 2 H ₀ O + 4e ~> 4 0H ~ (6)

Tj ^ r ₃ O τ = oSiVt-ion can also be formulated as an electron superordinate reaction:

0 _? + H ₂ O + 2e ~ d HO ₇ "" + oh "(7)

where a surface reaction then follows: 2 HO ₂ "* O ₂ + 2 OH" (8)

030036/0690

BAD ORIGINAL

It is believed that the predominant response to the hydrophobic surface is the reaction (7) and the reaction (8) runs off the surface of the catalyst particles (43). These catalyst particles are dispersed in and through the cathodic surface (41) of the solid polymeric electrolyte (31). Close the catalyst particles the particles of the electro-catalyst described below. This is how the high hydrogen overvoltage occurs avoided in the desorption step.

If the oxidizing agent is a peroxy compound, will anaenorimen that the following reaction takes place at the cathode:

RCOO "+ 2H ₂ O + 2e ~ bRCOH + 3 OH ~ (9).

This reaction is called electron transfer reaction subsequent surface reaction viewed.

Organic oxidizing agents and organic compounds containing a reduced peroxy group (COO-). Suitable oxidizing agents are organic eroxides, organic hydroperoxides, organic peracids, also called peroxyacids. A preferred group of organic oxidizing agents are organic hydroperoxides. Very particularly preferred organic oxidizing agents are organic hydroperoxides of alcohols, which are soluble in water in all concentrations. also preferred and suitable hydroperoxides of alcohols having limited solubility in water or even those with low water solubility. For example, highly suitable sin ^ ¹ hydroperoxides such as methyl hydroperoxide of methyl alcohol, ethyl hydroperoxide of ethyl alcohol, h-propyl-HydroOeroxyd of n-propyl alcohol , i-propyl hydroxide of i-propyl alcohol and t-butyl hydroperoxide of t-butyl alcohol, but hydroperoxides of alcohols with limited solubility in water, such as η-butyl hydroperoxide, are also useful for the process according to the invention of η-butyl alcohol, sec-butyl hydroperoxide of sec-butyl-A alcohol, i- ^ utyl-hydroperoxide of i-butyl-alcohol

030036/0690

BATH ORIGINAL

hols and t-pentyl hydroperoxide of t-pentyl alcohol. Alternatively, however, hydroperoxides can also be used for the cathodic reaction, which are made from sparingly soluble Alcohols are made, such as n-pentyl hydroperoxide by means of n-pentyl alcohol, i-pentyl hydroperoxide des i-Pentyl alcohol, s-pentyl hydroperoxide of s-pentyl Alcohol, neopentyl hydroperoxide of neopentyl alcohol. Cuiren hydroperoxide of cumyl alcohol can also be used and methyl-phenyl-carbinol ethylbenzene hydroperoxide

Another group of hydroperoxides which can be used as oxidizing agents in the process of the invention are dihydroperoxides. Dihydroperoxides of glycols are fed to the catholyte space of the electrolytic cell, as has already been explained. Preferred Dihydroperoxyde are those which are fully miscible with water, or those which are at least partially soluble in water, never PREFERRED Dihydroperoxyde are the Dihydroperoxyde of C, to Cj ₀ alkyl groups having Dihydroneroxvden, Mlryl '-'. Ptten of C _r 'nig <"* -., _ f ^ .nz especially b

Dlh ^ droperoxvcie are Hexan- ^ ihvdroneroxvd,

Octane Dihyöroneroxyd, Nonan-riihydroperoxyd, and npcan dihydroperoxide.

Been erv / ähnt here Venn alcohols, ketones, aldehydes and glycols is to assume that they arise only as intermediates, and then react further by dehydrogenation un olefins and form ^K ther su or with other additives, e organic .Tiuren to ^ the-art or \ l \ oholate ^ it Ml-a- zn ^ ildon. '^; enn there «? "Mixed product oin '13 · 'ohoI is, i'er Mi'ohol' -reiter react to pin" vther. The alcohol may from? Lellflüssigkeit be separated, un to be implemented ^v ther to, for example, a .Alkylierungsmittel as alkyl sulfate. So if the organic oxidizing agent is tertiary butyl hydroperoxide, tertiary rutyl alcohol is withdrawn as an intermediate product from the catholyte space.

030038/0890

BAD ORlRJWAJ

The tertiary butyl alcohol can be withdrawn from the cell, is then separated from the cell fluid, for example by distillation and then reacted with methyl sulfate to form methyl tertiary butyl ether. Methyl tertiary butyl ether can be used as a lubricating oil additive.

Particularly desirable hydroperoxides are those which give alcohols in all proportions in water are soluble and can be used for a wide variety of purposes. forms t-butyl hydroperoxide t-butyl alcohol as a cathodic reduction product. t-Butyl alcohol can be used as an anti-knock agent for automotive fuels.

Dialkyl peroxides have the formula R..OOR_, where R- and R »can be the following groups: - CH-, -CH _g , - C ₃ H ₇ , -C ₄ Hg, -CH ₉ CH = CH ₂ . However, all other dialkyl peroxides which are soluble in water or organic solvents can also be used for the process according to the invention. In addition to dialkyl peroxides, polyoxides of the general formula RO R ₃ can also be used when n is 3 or 4. Cycloperoxides of the formula R ₁ JOOR _{2 can also be used} for the process according to the invention.

Peroxy acids, known as peracids, have the formula R (CO-H), where R can have the following meanings: -H, -CH ₃ , -CH ₂ Cl, -C ₂ H ₅ , -Cn-C ₃ H ₇ ), - (1-C ₄ H ₉ ), -Cn-C ₅ H ₁₁ ). However, all other peracids which are soluble in water or in organic solvents can also be used for the purposes of the invention. Likewise, acyl, peroxyls or precursors of other peroxy acids can be used for the process according to the invention. This also applies to aryl diperoxy acid.

030036/0690

BATH

The process according to the invention is described with respect to the organic oxidizing agents, for example, by organic peroxides, organic hydroperoxides (with the general formula ROO-H) and inorganic peroxy acids (with the general formula RCO ₃ H), but it goes without saying that the most varied of organic oxidizing agents It is also possible to use, for example salts of organic oxidizing agents, that is, salts of organic hydroperoxides with the formula ROOM) and salts of organic peroxy acids of the formula RCO 'T, where M is a cation. As a rule, M is an alkali or an alkaline earth cation or an ammonium radical. But it can also be lithium, sodium, potassium, rubidium or cesium, the most commonly used. Cations are sodium or potassium. Among the alkaline earths beryllium, magnesium, calcium, strontite and barium, magnesium or calcium are most preferred. If the catholyte liquid has an aqueous potassium hydroxide (MOH), the organic oxidizing agent is either in the acidic form, for example ROOR, RCO ₃ H or as the alkali salt ROOM, RCO ₃ M, where M is the same alkali metal T'ydroxyd and in the organic oxidizing agent.

the method of the invention using organic Peroxide becomes the cathode reaction product of the oxidizing agent from the catholyte space (45) along with withdrawn from the cell fluid. The cathodic reduction products of the oxidizing agent can be partially or completely be gaseous, or vapors such as methyl alcohol, ethyl alcohol, n-propyl alcohol, i-pronyl alcohol, or t-butyl alcohol. However, the resulting products can also be zocren as a liquid, together with the cell fluid will. Such liquids are methyl alcohol, n-propyl alcohol, i-propyl alcohol, t-butyl alcohol, sec-butyl alcohol, i-butyl alcohol, n-butyl alcohol, or t-pentyl alcohol, n-pentyl alcohol, i-pentyl alcohol or amyl alcohol.

030036/0890

BAD ORIGlMAJ

The cathodic product can also be obtained as an emulsion or suspension with excess proportions of poorly soluble alcohols, for example with sec-butyl alcohol, i-butyl alcohol, n-butyl alcohol, t-pentyl alcohol, n-pentyl alcohol, i-pentyl alcohol or amyl alcohol. When the cathodic reaction product of the oxidizing agent is withdrawn either as a gas or as a gas and liquid, the product is separated from the water vapor and recovered from the gas phase. The cathodic reaction product obtained from the cell can also be obtained in purely liquid form either as a solution with water or as a suspension or as an emulsion with water. This form occurs when it is methyl alcohol, ethyl alcohol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, i-butyl alcohol, sec-butyl alcohol, t-butyl alcohol, t-pentyl alcohol, n-pentyl alcohol , i-pentyl alcohol, neopentyl alcohol or s-pentyl alcohol. In these cases, the cathodic reaction product is separated from the cell fluid by known techniques, such as fractional distillation, extraction, absorption, stripping or other phase separation techniques or the like. In one embodiment of the invention, t-butyl alcohol is obtained during the electrolysis of sodium chloride brine. In this embodiment of the invention, sodium chloride brine is introduced into the anolyte space (39) of the electrolytic cell and t-butyl hydroperoxide is fed to the catholyte space (45) of the cell and an electric current from the anode (37) of the cell (11) to the cathode (43) the cell (11) routed to chlorine thereby evolved at the anode, and t-butyl alcohol and ^A ceton in the catholyte form. An aqueous ethyl acetate liquid containing sodium hydroxide, t-butyl alcohol, acetone and excess t-butyl hydroperoxides is drawn off from the catholyte space (45) of the cell. The supplied solution of tertiary butyl hydroperoxide and t-butyl alcohol form an aceotrope so that it can be recovered from the cell fluid by distillation. The aceotrope contains 11.76% barrel and 38.24% t-butyl alcohol.

030036/0690

BATH

In the execution?; Form of the invention in which. with one Excess of tertiary butyl hydroperoxide flow in the When work is carried out, the t-butyl alcohol is used as an aceotrope obtained, the sodium hydroperoxide as salt can crystallize out from the concentrated aqueous solution of NaOH if the solution contains more than 40% by weight of "atriumhydroxyc". The sodium salt of the t- ^ utyl hydroperoxide can then be im Circulation to the "atholy space (45) of the cells (11 and 13) be fed back. For a further embodiment According to the invention, the cell fluid can be further Cell (13) are supplied, for example dom catholyte (45) to thereby reduce the catholyte liquid in the alkali hydroxide content to increase and to reduce the content of organic oxidizing agent. The remaining oxidizer can then continue to be used in the subsequent cell or cells with the cell fluids, to be able to obtain more by-products from electrolysis, for example more ketones, aldehydes, acids, Alcohols or glycols and alkali hydroxide solutions with higher concentration. In this embodiment there is a series flow the catholyte liquid through the bipolar electrolysis device (1) used.

^In a further embodiment of the method according to the invention, the oxidizing agent can also be a redox system in which the oxidizing agent is reduced inside the cell and then reoxidation takes place outside the cell in order to be able to circulate the oxidizing agent. A common redox system is a FuDferverbindungen that is supplied to the cell as a Cu-II compound and accumulates as a reduced Cu-I compound at the cathode (43) and is withdrawn from the cathode chamber in this state. The Cuprο connection can then be oxidized again to the Cupri connection outside the electrolysis device (1) and fed back into the circuit. Common copper compounds for this purpose are chelate compounds such as phthalocyanines.

030036/0690

'BAD ORIGINAL

However, a quinone-hydroquinone redox system is also used as a redox system useful for the purposes of the invention. With this procedure, Ouinon becomes electrolytic Hydroquinone is reduced at the cathode (43) and hydroquinone is obtained from the catholyte liquid (45), and outside oxidized to quinone in the cell.

According to a further embodiment 'of the invention Process can also use solid oxygen carriers to the catholyte TP. (45) are supplied, and partially free oxygen to be recovered. Such compounds include manganese (II) complexes, transition metal pthalocyanine tetrasulfonate complexes and binuclear copper (II) complexes - "it T-phenyl-1,3,5-hexane trietate.

The cathodic catalyst which can be used for these embodiments of the process according to the invention has the properties of a H0 ₂ disproportionation catalyst.

This is a catalyst that is able to catalyze the following surface reaction:

2 HO ₂ 9 O ₂ +? .OH ~ (10)

The catalyst can also catalyze the electron transfer reaction:

~~ ^{+ 0H} ~ ⁱ¹¹ >

The catalyst should, however, be chemically resistant be the catholyte.

Satisfactory H0 ₂ ~ -Disproportionierunqskatalysator are carbon, the ^f? Transition metals of Group VIII such as iron, cobalt, nickel, palladium, ruthenium, rhodium, platinum, osmium, iridium and compounds of these Elenente.

030036/0690

BATH ORIGINAL

Catalysts are also suitable, copper, ^ xyde of lead. The transition metals can be present in metallic form, as alloys and as intermetallic compounds. If, for example, Tickel is used, it can be mixed with ^M .o, Ta or Ti. This mixture allows a low cathode voltage to be maintained over long electrolysis times.

Any group III, IV, V, VI, VII, I, II or IHb metal, including their alloys and mixtures, can can be used when the metal or alloys are resistant to the catholyte liquid as coating substrates for the cathode (43) or as a catalyst on the surface of the permionic membrane (33).

Furthermore, solid metalloids such as phthalocyanines of the metals of group VIII, perovskites, ^{T <t} olf rambronzen, spinels, delafossite and pyrochlores and others can be used as catalysts for the catalytic surface (43) on the membrane (33) . Particularly preferred catalysts are those of the platinum metals and compounds of the platinum metals, such as oxides, carbides, silicides, phosphides and nitrides and intermetallic compounds and oxides thereof, for example in the rutile form RuO-TiO ₀ which has semiconducting properties.

"A further embodiment of the invention is the cathodic electrocatalyst an electron transfer catalyst for the following reaction:

HO + e ~ ^ OH "+ H

The borides of the transition metals are particularly suitable for this. The borides of the transition metals have the required chemical resistance to concentrated aqueous alkali hydroxides have surface catalysts Activity for the aforementioned reaction if there is

03QQ36 / Q & 90

BATH ORIGINAL

are diborides of transition metals of group IV, V and VI of the periodic table. These metals include titanium, zircon, hafnium, vanadium, niobium, (columbium), Tantalum, chromium, molybdenum and tungsten, the transition metals of groups IV, V and VI are preferred because of their Borides have higher chemical resistance. These include in particular titanium, vanadium, niobium, columbium, Tantalum, chrome and tungsten. Titanium diboride, TiB, is very particularly preferred for the purposes of the invention.

According to a preferred embodiment of the invention For example, an intermediate compound of carbon and fluorine can be used as the cathodic catalyst (43).

An intermediate compound of carbon and fluorine is understood to mean a carbonized material that is in the Graphite layer lattice crystallizes. While in graphite the lattice layers from each other about 1.41 ^ naström Spaced, the layer spacing is greater in the present case, at least about 3.35 angstroms, with fluorine atoms between layers. The resulting bond between carbon and fluorine can be called carbon monofluoride are designated by the empirical formula (CF), in which x has values between 0.68 and 0.995.

"In an alternative embodiment, the layers in the intermediate connection can also be essentially flat, so that a designation as tetra-carbon monofluoride is possible, according to an empirical formula (CF,) where x- ^{r <} 7ths between 0.25 and 0, 30. Fs are thus various intermediate stages and non-stoichiometric compounds.

These intermediate compounds of carbon and fluorine are also known as fluorinated graphite or graphite fluoride. They can be characterized by their infrared spectrum, which has an absorption band at 1,220 cm.

030C36 / 0S90

BATH ORIGINAL

The carbon-fluorine interconnect catalyst (43) can also use the HO disproprotionation catalyst contain.

gaseous oxidizing agents such as air or oxygen the part of the catalytic converter that allows the electron transfer to be hydrophilic, while the part of the catalyst responsible for surface freezing is decisive, should be either hydrophilic or hydrophobic, but preferably hydrophobic. The surface reaction catalyst is therefore hydrophobic or embedded in or arranged on a hydrophobic film. The hydrophobic film can be a porous hydrophobic material such as graphite or a film of a fluorocarbon polymer on the catalyst. The surface reaction catalyst and the electron transfer catalyst should be arranged in close proximity to each other. That can can be achieved by mixing them or by having different surfaces on the same substrate form. For example, a particularly useful desired catalyst can be in a microporous film on top of the permionic membrane surface (41) consist of the catalyst (43) in the form of a hydrophobic microporous FiInes carries.

In a further embodiment of the invention, a depolarization cathode will be used in which the electrodes are weeping electrodes, ie electrodes which allow the oxidizing agent to escape. ^T / ^T hen drip such electrodes are used, the oxidizing agent is applied through the manifold (51) to the catalyst (43) and distributed, wherein contact with the catholyte in KathoLyträum is avoided (45). In another embodiment, however, the oxidizing agent can also be introduced and distributed through second distribution devices on the cathodic surface (41) of the permionic membrane or on the catalyst particles (43).

OAfS

- 85 -.: ■ "· - - '■■ -" ■

The oxidizing agent can be supplied in gaseous form, with an excess of air or oxygen. If an excess of air or oxygen is used, this excess serves as a heat exchange medium to keep the temperature low enough that the vapor pressure of the liquid chlorine is correspondingly low. However, several oxidizing agents can also be used at the same time, for example a combination of air and oxygen, or air and peroxy compounds, or oxygen and peroxy compounds, or air or oxygen and a redox system. ^T 7enn air or oxygen is used as an oxidizing agent, they should be essentially free of carbon dioxide to carbonate formation to avoid the cathode.

The use of a horizontal cell gives particular advantages when using a cathode with depolarization will. Particularly satisfactory results are achieved with an arrangement in which the anodic surface

(35) of the permionic membrane (33) and the anodic catalyst (37) are arranged on the upper side of the permionic membrane (31) and the cathodic surface (41) and the cathodic catalyst (43) are on the lower side of the permionic membrane (33), thereby flooding the oxidation catalyst, ie the FIO- disproportionation catalyst " ¹ It -kali hydroxide, while the provision of a thin film of alkali hydroxide on the membrane surface (A 1) below the cathode surface makes contact" atalvsator «? ( ^Λ 3)" HLt c ^1flTT1 O

030036/0890

BATH ORIGINAL

^τ 'η 7.n? S count list

1 electrolysis device, 11, 13, electrolysis cell

21 walls of the electrolytic cell, bipolar unit,

bipolar back plates

23 Anolyte-resistant surface of the unit

25 Catholyte-resistant surface of a unit

31 solid polymeric pick

33 pernionic membrane

35 anodic «* surface of the permionic membrane

37 chlorine-evolving fleVtrocatalyst, more anodic ^ electrocatalyst

3 π Ptiolvtraun

41 Catholic surface of the Perrionic Merb

4 3 cathodic electrocatalyst, cathodic

Hydroxy! -Developing catalyst

4 5 I'.atho Iy dream

51 Distributor, spring metal device

5 3 ⁷ VuR enr and

55, 57 distributors, seals,

61 sealing rings

71 Find disk

R1a brine supply line, inlet R1b ? - ο Ie discharge, outlet 83a, 85a connection openings R3 ^>, 85b discharge openings 87a brine supply line 87h brine supply line P9a, 91a, ° 3a, 95a brine connection openings, F.inqsöffnurgei

^ 1b, "Ob, ^ 3b, 9 5b Vents, Abziigsleituncren 1oia inlet port io3a, 105a, 107a, 109a, 113a passage openings 1 ° 5a / b catholyte fluid line 111a catholyte supply opening 111b catholyte withdrawal opening 1oia water inlet, inlet OK1b catholyte discharge, outlet 115n / b lines for electrolyte

1030036/0690 BATH ORIGINAL

Reference Lists - continued

121 wire exchange facility

133 Conductor for electrolyte

131 open or porous surface

141 open o ^ rr porous surface

143 Line for electrolyte

030036/0690

BATH

Claims (1)

Dr. Michael Hann (1293) HST / Pe Patent attorney
Ludwigstrasse 67
63 casting 1 Electrolysis process and chlor-alkali cell with solid polymer electrolyte Applicant: PPG Industries, Inc., One Gateway Center ,, Pittsburq, PA; United States Priority: USA, February 23, 1979, Serial Nos .: 14,465; 14,466; 14,467; 14,468; 14,469; 15,521; 15,525; 15,526; 15,527; 15,528; 15,529 Claims 1. Electrolytic cell with solid polymer electrolyte with a permionic membrane having a coating on the cathodic surface, thereby characterized in that the cathode is a boride of a superior metal contains. 2. Electrolytic cell according to Claim 1, characterized in that that the boride is a boride or a mixture of borides of titanium, vanadium, niobium, tantalum, chromium or Wolfram acts. 3. electrolytic cell according to claim 1, characterized in that that as titanium boride TiB. is used. 030036/0690 ■ ORIGINAL BATHROOM 4. Method of electrolysis in an electrolytic cell with a solid polymeric electrolyte which is a permionic Has membrane, which has a Peschichtuna with a cathodic electrocatalyst on one surface having, wherein the cell ^ alkali chloride is supplied and an electrical potential is applied to the cell will, characterized in that a cathode is used which is a boride of a contains transition metal. 5. The method according to claim 4,
characterized in that it is a boride or a mixture of borides of titanium, vanadium, niobium, tantalum, chromium or tungsten. 6. Procedure after Anbruch 5,
characterized in that ^R one uses titanium boride in the form of Ti ^ _0. 7. Electrolytic cell with a solid polymeric electrolyte, with cell walls on at least one surface a layer of an electrocatalyst is present, with ^ Electronic connection devices on top of the electrocfitalyser and opposing cell walls, characterized in that the power connection devices are first spring metal devices <ren (51) stored on the electrocatalyst (37, 43) and second spring metal devices (51) stored on enclose the cell outer walls (21) and wherein the first and second FidernGtalleinrichtunrren (51) are removable are attached. 8. ^1; Electric cell with a solid polymer electrical with a permionic Me ^ hran -it nine "anodic on the nnnriiqchpri first - ^ side dor Ü3OÖ36 / Q69Ö ORIGINAL permiodic membrane and a cathodic flexcatalyst on the r, the cathodic 7 ^T - / pit-pn ^c eite dor rsprnion thereby α <=>. ke η η % e tch η et that the permionishe ^M i> r ^l iran (33) ^ ine fluorinated cation exchange m ^ brane with carboxylic acid exs>r> s as ion-exchanging groups, which has a ion exchange capacity. about 0.5 to 2.0 milli-equivalents per grain. drier polymer and a glass enveloping temperature above et ^ ra 'iinus 80 ° C and below about 90 ° C. 9. bipolar electrolysis cell p.it electrolysis cells connected mechanically and electrically in series, which have a solid polymeric electrolyte in an oermionic membrane, with an anodic electrocatalyst on the anodic first side of the permionic membrane and with a cathodic electrocatalyst on the surface opposite to the first surface second side of the Permionian ^M embran, characterized in that the permionic membrane (33) is a fluorinated ion exchange bar with carboxylic acid tubes as the ion-exchanging orupt><? n, which has an ion exchange capacity of about 0.5 to 2.0 "uniäauivalent nro grams drier ¹ polymer and a glass transition temperature fiber about minus 80 ⁰ C and below about 90 ° C. 10. A method for electrolyzing an alkali chloride solo in an electrolytic cell comprising an isolated by a ^f most polymeric electrolyte from the catholyte anolyte compartment, said dor solid polymeric electrolyte, a permionische membrane contains with an anodic electrocatalyst on the anodic surface and cathodic P'lektrokatalysator on the cathodic surface of the membrane, by supplying brine to the cell, passing electric current through the solid polymeric electrolyte and 030036/0690 - BAD ORIGINAL Removal of chlorine from the anolyte compartment and alkali hydroxide from the catholic dream, characterized in that nan uses a permionic membrane, the one fluorinated cation exchange membrane with xarboxylic acid sources than ion-exchanging green is. 11. The method according to claim 10, characterized in that that a cation exchanger is used which has an exchange capacity of 0.5 to 2.0 milliequivalents per gram of dry polymer and a Glasunwandlungstemoeratur above about minus 80 C and about 20 ° C below Has electrolyte temperature. 12. ^ experience according to claim 11, characterized in that that a polymer is used as the permionic membrane which contains> 'ether compounds in carboxylic acid groups Has side chains. 13. Method according to Ansoruch 10, thereby crekennzeicb.net, that a catholyte liquid containing alkali hydroxide removes with at least 30 wt.% alkali hydroxide. 14. The method according to claim 10, characterized by maintaining a hydrostatic pressure lying above de ^ vapor pressure of the developed chlorine in the anolyte and withdrawing the chlorine in liquid form from the anolyte. 15. A method for electrolyzing an alkali chloride brine in an electrolytic cell, the one by a solid polymer Has electrolyte separated from the catholyte anolyte, wherein the solid polymeric electrolyte is a permionic membrane contains with an anodic electrocatalyst on the ano- 030038/0690 -BAD ORIGINAL The first surface and the cathodic one Electrocatalyst on the second cathodic surface, by supplying brine to the cell, passing it through electric current through the solid polymer electrolyte and removal of chlorine from the anolyte space and alkali hydroxide from the catholyte, characterized in that a catholyte liquid with at least 30 wt.% Alkali hydroxide withdraws from the KathoIytraun. 16. A method for electrolyzing an alkali chloride brine in an electrolysis cell which has an anolyte chamber separated from the catholyte room by a solid polymeric electrolyte wherein the solid polymeric electrolyte contains a permionic membrane with an anodic T-electrocatalyst on the anodic first surface and with a cathodic electrocatalyst on the second cathodic surface by supplying brine to the cell electric current through the solid polymeric electrolyte and removal of chlorine from the anolving chamber and alkali hydroxide from the catholyte dream, marked by Maintaining one above the back pressure of the developed Chlorine lying hydrostatic pressure in the anolyte and withdrawing the chlorine in liquid form from the anolyte compartment. 17. Process for the electrolysis of an »alkali chloride brine in an electrolytic cell, which has an anolyte space separated from the catholyte by a solid polymer electrolyte having, wherein the solid polymer electrolyte contains a pernionic membrane, with an anodic electrocatalyst on the anodic surface and with a cathodic catalytic converter on the cathodic surface, by supplying brine to the cell, passing electrical through it stromo.s through the solid polvmer ^ n TMektrolvten and 030036/0690 BAD'ORIGINAL Removal of chlorine from the anolyte and alkali hydroxide from the catholic dream, characterized in that the solid polymeric Flektrolvt i ^{1 "1} vresentlichen so disposed horizontally that he anodipche ^f1 ^ lektrokatalvsator on the upper side and the Catholic ^T: iektrokatalysator efinrio.n on the lower side of death ^ that the chlorine nan ¹ Removed for small polymeric electrolytes and forming a thin film of metal hydroxide on the ice. 18. Method Sun Elcktrolysieren an alkali chloride brine in an electrolysis cell, which has an anolyte, separated by a solid electrolyte from the catholyte, wherein the solid polymer electrolyte contains an oermionic membrane, with an anodic electrical catalyst on the inorganic surface and with one , cathodic electrocatalyst on the cathodic surface, - ^! urch supplying brine to cell Rirdurchleiten electrical Strones, through the solid electrolyte and polvmeren removal of chlorine from de ™ ⁿ nolytraum and Alkalihvdroxvd from the * Katholvtraum thereby cre characterizes that the solid polymer electrolyte is a fluorinated npolymero. ^p arboxyls ^ nre-peririionische membrane and is substantially anqeordnet such horizontal, that the anodic Flektrokatalvsator on the upper Feite and the cathodically ^T is 'lektrokatalys => tor are on the lower, Roden side, ^T' emove the chlorine from solid nolvneren elektrolvten and forming a thin film of alkali hydroxide on the solid polymeric flectrolyte. 10. riektrolytische cell with a solid polymer electrolyte with an anodic on the anodic F.lektrokatalysator first f! Eite and a cathodic electrocatalyst on dom solid polymeric electrolyte, ^v inrichtunken -un supplying an oxidizing agent and 030036/0690 am of an oxygenation catalyst in contact with the cathodic second surface of the solid polymer electrolyte characterized in that the solid olefin electrolyte (31) is substantially is arranged horizontally so that the anodic Chlorine-evolving catalyst (37) is located on the upper surface, so that the evolved chlorine is in front of "solid" polymer electrolyte (31) removed and that the cathodic hydroxyl-developing catalyst (43) is located on the bottom side to form a film of alkali hydroxide on the solid polymeric electrolyte (31). 20. A method for electrolyzing an alkali chloride brine in an electrolytic cell, which is one by a solid polymer electrolytes. Catholyte chamber has separate anolyte, the solid polymeric electrolyte being an anodic Elektrokatalvsator on the ^ nite to .Anolytraun and a Vathodic electrocatalyst and a hydrogen oxidation catalyst has on the side to the catholyte space, Supplying an aqueous alkali toride brine to the cell, ■ supply of an oxidizing agent into the catholic space, Applying an electrical potential to the solid polymer electrolyte, Removal of chlorine from the anolyte and alkali hydroxide from the catholic dream, thereby Te ken η is characterized in that the solid polymeric electrolyte is arranged essentially horizontally in such a way that the anodic adhesive catalyst is on its surface and the cathodic adhesive catalyst is located on its outer side and that on the bottom side of the solid polymeric electrolyte a layer of aqueous alkali hydroxide is maintained and that on the <^ her £ l '^ chn ^ ps solid nolv ^ ron ^r Jlo> trolvton nin OxidritirinT "! ttel vnrh- ^ ndon is to ^Tr or'i'!«! sorun'r * "$ 030036/0690 . BATH ORIGINAL 21. Method of electrolyzing using a bipolar electrolysis cell with solid polymer electrolyte, with bipolar units between each electrolytic cell ^ by introducing alkali chloride brine into the anolyte space of the single cells, Introducing ^{T <r} ater electrical in the catholyte compartment of the single cells, and passing current through the cell, characterized in that at least one inflow means through within the bipolar unit of the bipolar electrolysis cell between a pair of individual cells arranged heat exchanger devices conducts and thus removes heat from the individual cells. 22. Bipolar electrolysis device with a large number of individual cells mechanically and electrically connected in series with a solid polymer electrolyte, each of the cells being one with a solid polymer electrolyte has separated from the catholyte anolyte, wherein the solid polymer electrolyte is a permionic Membrane contains an anodic electrocatalyst on the anodic first surface-and with a cathodic Electrocatalyst "on the cathodic second surface and with each pair of cells through one in between arranged bipolar unit is separated, which has a first surface and resistant to acidic brines has a second surface resistant to aqueous alkali hydroxide, characterized in that the bipolar unit (21) is one between the first and having a hydrogen barrier arranged on the second surface. 23. Bipolar electrolvse device according to claim 22, characterized in that that the hydrogen barrier is made of one of the metals vanadium, 030036/0690 BATH ORIGINAL Chromium, manganese, cobalt, nickel, copper, zinc, columbium Molybdenum, silver, cadmium, rhodium, tantalum, tungsten, iridium or gold. 24. Bipolar electrolysis device according to claim 23, characterized thereby gekennzeic h η et, that the hydrogen barrier is made of copper. 25, bipolar electrolyzer with a variety of single cells mechanically and electrically connected in series with a solid polymer electrolyte, whereby each of the cells has an anolyte compartment separated from the catholyte compartment by a solid polymeric electrolyte, wherein the solid polymer electrolyte contains a permionic membrane with an anodic electrocatalyst the anodic first side and with a cathodic electrocatalyst on the cathodic second side and in which each pair of cells is separated by a bipolar unit arranged between the individual cells, characterized in that the bipolar unit (21) has external electrolyte lines (115) and facilities (133, 143) for transport of the electrolyte from the external line (115) in and through the bipolar unit (21) onto the surface of the bipolar unit, parallel to the solid polymer electrolyte, has and that on the surface (23, 25) devices (131, 141) for distributing the electrolyte are present. 26. Bipolar electrolysis device according to claim 25, characterized in that that the bipolar unit (21) has devices for withdrawing the products. 27. A method of electrolyzing using a bipolar electrolyzer unit from a plurality of mechanically and electrically connected in series bipolar 030036/0690 BATH - ίο - Electrolytic cells with a solid polymer electrolyte, wherein each of the individual cells has a permionic membrane with an anodic electrocatalyst the anodic first surface and a cathodic electrocatalyst on the second cathodic surface and each of the cells is separated from one another by an interposed binolar unit, by feeding brine into the analyte space from the outside Lines from an external reservoir, supplying water to the catholyte space from one outer stock, Applying an electrical voltage to the electrolysis device, Withdrawal of anolyte fluid from the anolyte space and Removal of catholyte fluid from the catholyte space, characterized in that that the individual cells are brine and barrel from the outside Supplies into and through the bipolar unit, on the surface of which is parallel to the solid polymer electrolyte, through porous means in the bipolar unit. 28. The method according to claim 27,
characterized in that product is withdrawn through the bipolar unit. 29. Electrolytic cell with a solid polymer electrolyte that has an anodic electrocatalyst its anodic first surface and a cathodic electrocatalyst on its second cathodic Has surface, having means for supplying an oxidizing agent to the cathodic second surface of the solid polymer Electrolytes, characterized in that one is in contact with the cathodic second surface (41) of the solid polymer electrolyte (31) standing HOj -dispronortioning catalyst on an electrically 030036/0690 BATH ORIGINAL conductive substrate with a porous hydrophobic surface is present. 30. Electrolysis cell according to claim 29, characterized in that that the HO2 disproportionation catalyst is a porous carbon support with a porous fluorocarbon surface (fluorocarbon surface). 31. Electrolysis cell according to claim 30, characterized in that that the HO., - Disproportionation catalyst with the cathodic electrocatalyst (43) is mixed. 32. Electrolytic cell with a solid polymer electrolyte which has an electrocatalyst on its anodic first surface and a cathodic electrocatalyst has an opposite second cathodic surface, with facilities for supplying an oxidizing agent to the cathodic second surface of the solid polymer electrolyte, _{characterized in that a H0 2} ~ -Oisproportionation catalyst in contact with the cathodic second surface (41) of the solid polymeric electrolyte (31) is present on a porous electrically conductive carbon substrate with a porous hydrophobic fluorocarbon surface. 33 .., electrolytic cell according to claim 32, characterized in that the H0 ₂ ~ -Disproportionxerungskatalysator is mixed with the cathodic electrocatalyst (43). 030036/0690 34. Electrolytic cell with a solid polymer electrolyte, the an anodic electrocatalyst on its first anodic surface and a cathodic electrocatalyst on its second cathodic surface with features on the cathodic surface for supplying an oxidizing agent to the second surface of the solid polymeric electrolyte, characterized in that one is in contact with the cathodic second surface (41) of the solid polymer electrolyte (31) standing HO- -DisproDortionierunaskatalyst on a porous electrically conductive substrate with a porous hydrophobic surface is present and the disproportionation catalyst is mixed with the cathodic electrocatalyst (43). 35. Electrolysis cell according to claim 34, characterized in that the TiO ₀ -Dispronortionierunapkatalvsator has a porous carbon fiber Mcrer with a fluorocarbon surface. 3fi. ElektrolyseζelIe with a solid polymeric electrolyte which has a permionic membrane with an anodic electrocatalyst on the first anodic surface and a cathodic electrocatalyst on the opposite second cathodic surface of the membrane, characterized in that the permionic membrane (33) is a fluorinated cation exchange membrane, which is a Ion exchange capacity of about 0.5 to 2.0 milligram equivalents per dry polymer, a carboxylic acid group content of about 8 to 30 milli equivalents per gram of absorbed water and a glass transition temperature above about minus 80 ° C and below about .70 ⁰ C and at which the anodic surface (35) the permionic membrane (33) cross-linking 030036/0690 BATH ORIGINAL Has groups to make the surface hydrophobic. 37. electrolytic cell according to claim 36, characterized in that that the crosslinking groups perfluorinated dienes and / or Are divinyl benzene. 38. Electrolysis cell with a solid polymer electrolyte, which is a perfluorinated carbon permionic membrane contains an anodic electrocatalyst on its anodic first surface and a cathodic Has electrocatalyst on its cathodic second surface, characterized in that the solid polymeric electrolyte (31) on its anodic surface having crosslinking groups to make the anodic surface hydrophobic. 39. Electrolytic cell according to claim 38, characterized in that the crosslinking grums are perfluorinated dienes and / or are Diviny! benzene. Ao. A method for electrolysing alkali chloride brines using an electrolysis cell which has an anolyte chamber separated from the catholyte chamber by a solid polymer electrolyte, the permionic membrane of which has an anodic electrocatalyst on its anodic side and a cathodic electrocatalyst on its cathodic side, by supplying alkali chloride brine into the cell , Applying an electrical voltage to the solid polymer electrolyte, Removal of chlorine from the anolyte compartment and removal of alkali hydroxide from the catholyte compartment, characterized, that the ionic membrane is a perfluorinated 030036/0690 Carbon-carboxylic acid permionic membrane with cross-linking Groups used on the anodic surface. 41. The method according to claim 40,
characterized in that the crosslinking groups of the membranes used are perfluorinated dienes and / or divinylbenzene. 42. A method for electrolyzing alkali chloride brine using an electrolytic cell that has a through a having solid polymer electrolyte separated from the catholyte anolyte, the permionic membrane of which on their anodic first surface an anodic electrocatalyst and on its cathodic second surface has a cathodic Elektrokatalvsator, by supplying alkali chloride brine in the cell, Applying an electrical voltage to the solid polymer i'lektrolvten, peeling off rhlor au? fTe ^ ^ nolytraum and Extractor of alkali hydroxide from the "catholyte room, thus n-characteristic, -faß nan a nermionic membrane vpr- 'enriflt,' '^ ren anodic ·? TherFl ^ c ^ e "" ■ ernetzendp; Has groups to to make the * anodic surface hydrophobic. 43. ^ "experienced according to claim 42,
characterized in that the crosslinking groups of the permionic membrane are perfluorinated dienes and / or divinylbenzene. 44. Process for the electrolyzing of alkali chloride brines under Use of an electrolytic cell that separated one from the catholyte space by a solid polymeric electrolyte Has anolyte, by supplying alkali chloride brine into the cell, withdrawing chlorine from the anolyte and Removal of alkali hydroxide from the catholyte space, characterized in that that the brine has less than 20 parts per trillion calcium 030036/0690 BATH ORIGINAL and has less than 20 parts per million iron. 45. The method according to claim 44,
characterized in that a brine is used which contains a total of less than 40 parts per billion alkaline earths and a total of less than 40 parts per million transition metals. 46. Bipolar electrolyzer with a solid polymer electrolyte, with a variety of mechanical and electrical individual electrolysis cells connected in series, between which bipolar units are arranged, characterized in that the anodic surface of the bipolar unit (21) consists of a titanium alloy with molybdenum, palladium, nickel, iron, scandium, yttrium or lanthanides as Alloy metal and that the alloy metal is present in such an amount to absorb the hydrogen of titanium, but the amount is so small that the formation of a two-phase system is essentially is avoided. 47. Bipolar electrolvse device according to claim 46, characterized in that that the alloy metal is a rare earth group metal. 48. Bipolar electrolvse device according to claim 47, characterized in that that the rare earth metal is yttrium. 49. Bipolar electrolvse device according to claim 46, characterized in that that the alloy contains from about 0.01 to about 1.0 weight percent alloy metal. 50. electrolytic cell with a solid polymer electrolyte, 030036/0690 which contains a permionic membrane that has an anodic electrocatalyst on its anodic first surface and a cathodic electrocatalyst on its opposite cathodic second surface having, characterized in that the permionic membrane (33) is a perfluorinated one Cation exchange membrane with carboxylic acid groups as ion exchange groups is having an ion exchange capacity from about 0.5 to 2.0 milliequivalents per gram of dry polymer and a glass transition temperature above about minus 80 ° and below about 70 ° C and the electrolytic cell facilities for common withdrawal of liquid chlorine and exhausted brine. 51. electrolytic cell according to claim 51, characterized in that the cell has facilities for extracting chlorine from the exhausted brine has. 52. Electrolytic cell according to claim 51, characterized in that that the means for recovering chlorine from the exhausted brine means for cooling the exhausted ones Brine to form hydrochloride and contain means for separating the hydrochloride from the exhausted brine. 53. electrolytic cell with a solid polymer electrolyte, the oine permionic '-'enbran contains, with an anodic Electrocatalyst on its anodic first surface and a cathodic electrocatalyst on its cathodic second surface, characterized that facilities are available to withdraw liquid chlorine and exhausted brine from the cell and ^ facilities are in place to separate the exhausted Poles of liquid chlorine. 030036/0690 BATH ORIGINAL 54. Electrolysis cell according to claim 53, characterized in that that there are facilities to extract chlorine from the exhausted brine. 55. Electrolysis cell according to claim 54, characterized in that that the means for obtaining chlorine from the exhausted brine means for cooling the exhausted one Brine to form chlorohydrate and contain means for separating the chlorohydrate from the exhausted brine. 56. A method for electrolyzing alkali chloride brine using an electrolytic cell that has a by a solid polymer electrolyte from the catholyte compartment separated anolyte, the solid polymer electrolyte a fluorinated cation exchange membrane with carbonic acid groups as ion exchange GrupOen contains and the membrane on its anodic surface an anodic electrocatalyst and on has a cathodic electrocatalyst on its cathodic surface, by supplying brine to the cell, applying an electrical voltage to the solid polymer electrolyte, Removal of chlorine from the anolyte space and removal of alkali hydroxide from the catholyte space, characterized in that one has chlorine in liquid form and exhausted brine withdraws from the cell and separates the liquid chlorine from the exhausted brine. 57. The method according to claim 56, characterized in that chlorine is obtained from the exhausted brine. 030036/0690 BATH ORIGINAL 58. The method according to claim 57,
characterized in that the exhausted brine is cooled, thereby forming chlorohydrate and separating the chlorohydrate from the brine. 59. The method according to claim 58,
characterized in that the exhausted brine is cooled below 9 ° C to form hydrochloride. 60. A method for electrolyzing alkali chloride brine using an electrolytic cell that has a has an anolyte compartment separated from the catholyte compartment by a solid polymeric electrolyte, the solid polymeric electrolyte containing a permionic membrane, with an anodic electrocatalyst on it anodic first surface and a cathodic electrocatalyst on its second surface, by supplying brine to the cell, applying an electrical voltage to the solid polymer electrolyte, Removal of chlorine and exhausted brine from the anolyte compartment and removal of alkali metal hydroxide from the Catholic dreams, characterized in that one liquid chlorine and exhausted sole from the Anolyte withdraws and separates liquid chlorine from the exhausted brine. 61. The method according to claim 60,
characterized in that chlorine is obtained from the exhausted brine. 62. The method according to claim 61,
characterized in that the exhausted brine is cooled, thereby forming chlorohydrate and separating the chlorohydrate from the exhausted brine. 030036/0690 63. The method according to claim 62, characterized in that that one cools the exhausted brine to 9 ° C and thereby forms hydrochloride. 64. A method for the electrolyzing of alkali chloride brine in an electrolysis cell, the one by a solid polymer electrolytes separated from the cathode space Has anolyte space, by supplying brine to the cell, applying an electrical voltage to the cell and removing it Chlorine and exhausted brine from the anolyte compartment and removal of alkali hydroxide from the catholyte compartment, Characterized by this, one ate liquid chlorine and exhausted brine from the Anolytrauia withdraws and separates liquid chlorine from the exhausted brine. 65. The method according to claim 64, characterized in that that chlorine is obtained from the exhausted brine. 66. The method according to claim 65, characterized in that that one cools the exhausted brine and thereby forms hydrochloride and the hydrochloride from the exhausted one Brine separates. 67. The method according to claim 66, characterized in that that one cools the exhausted brine below 9 ° C and thereby forms chlorohydrate. 68. Process for the preparation of a solid polymeric electrolyte characterized by forming particles that are a transition metal and a contain leachable metal, 030036/0690 Dissolving the leachable metal from the particles and forming porous particles, Depositing the porous particles on a permionic membrane to form a solid polymeric electrolyte. 69. The method according to claim 68,
characterized in that the transition metal is iron, cobalt or nickel. 70. The method according to claims 68 or 69, indicated by the fact that the leachable metal is aluminum. 71. The method according to claim 68,
characterized in that the particles are formed by flame spraying an alloy of a transition metal and a leachable metal onto a refractory surface, the sprayed particles are leached and the sprayed leached particles are deposited on a permionic membrane. 72. The method according to claim 71,
characterized in that the sprayed particles adhere to the heat-resistant surface and are removed therefrom and deposited on the permionic membrane. 73. Procedure according to claim 71,
characterized in that the .Spritzteilchen aborallen from the heat-resistant surface. 74. Process for electrolyzing alkali chloride brines in an electrolytic cell with a through a solid polymer electrolyte separated from the catholyte anolyte, with the solid polymer electrolyte on its, the side facing the anolyte has an anodic electrical G30036 / 0690 catalyst and has a cathodic electrocatalyst on its side facing the catholyte space, by supplying brine to the electrolytic cell, applying an electrical voltage to the solid polymer Electrolytes, removal of chlorine from the anolyte and removing alkali hydroxide from the catholyte space, characterized in that, that one uses a solid polymer electrolyte which has a cathodic side on its cathodic side Depolarization catalyst with an intermediate compound of fluorine and carbon, the Catholyte space supplies oxidizing agent and thereby essentially the evolution of hydrogen at the cationic Turns off hydroxy1-forming catalyst. 75. The method according to claim 74, because it is characterized by the fact that a solid polymer electrolyte is used, the one fluorinated cation exchange membrane with carboxylic acid groups as ion-exchanging groups is. 76. The method according to claim 75,
characterized in that the cation exchange membrane has an ion exchange capacity of 0.5 to 2.0 milliequivalents per gram of dry polymer and a glass transition temperature above minus 80 C but at least 20 ° C below the electrolyte temperature. 77. The method according to claim 74,
characterized in that a cathode is used which has a hydrophilic part and a hydroohobic part in connection with the oxidizing agent and wherein the hydrophobic part contains an intermediate compound of carbon and fluorine. 030036/0690 78. The method according to speeches 74 to 77, characterized in that that one uses oxygen as the oxidation agent. 7 ^Q. The method of claim 74, characterized in that the intermediate compound of carbon and fluorine has the empirical formula CF _x , where χ is between 0.25 and 1.0. 80. The method according to claim 74, characterized in that a cathode is used which has an H0 "-ion disproportionation catalyst contains. . Electrolytic cell having an ^1, solid polymer electrolyte, having on its first surface anodic an anodic electrocatalyst and on its second side gegenüberlieaenden cathodic a cathodic catalyst, characterized, that the cell means for supplying an oxidizing agent to the cathodic second surface (41) of the having solid polymeric electrolyte (31) and in connection with the second cathodic surface (41) of the solid polymeric electrolyte (31) standing cathodic catalyst (43) an intermediate one Contains compound of carbon and fluorine. 82. Electrolysis cell according to claim 81, characterized in that that the solid intermediate compound of carbon and fluorine has the empirical formula CF, Jv where χ is between 0.25 and 0.70. 83. Electrolysis cell according to claim 81, characterized in that that the one with the cathodic second surface (41) 030036/0690 the solid polymer electrolyte (31) related cathodic catalyst
Contains portioning compound. standing cathodic catalyst (43) a HO dispro 84. Process for electrolyzing alkali chloride brines in an electrolvse cell with an anolyte compartment separated from the catholyte compartment by a solid polymer electrolyte, the solid polymer electrolyte having an anodic catalyst on its side facing the anolyte compartment and has a cathodic catalyst on its side facing the catholyte space, by supplying Brine into the anolyte space, supply of an oxidizing agent into the catholyte space, application of an electrical voltage on the solid polymer electrolyte and removing chlorine from the anolyte and alkali hydroxide from the Catholyte dream, characterized in that the oxidizing agent is added to the catholyte space as a complex supplies. 85. The method according to claim 84, characterized in that the complex is a manganese, (II) complex, a transition - metal - phthalocyanine - tetrasulfonate complex, phosphinonangankoTiDlex and / or a binuclear copper (II) complex of 1-phenyl-1,3,5-hexane trionate or a mixture thereof is. Pf ·. Electrolytic cell with a solid polymer electrolyte with a permionic membrane with an anodic electrocatalytic coating on its anodic first surface and a cathodic electrocatalyst on its cathodic second surface, characterized in that the cathodic electrocatalyst (43) contains a first transition metal of group VIII of the periodic table. 030036/0690 BATH ORIGINAL 87. Electrolytic cell according to claim 86, characterized in that that the cathodic electrocatalyst (43) has an upper 2
has an area of at least 10 m per gram. 88. The electrolytic cell according to claim 86, characterized in that that the cathodic electrocatalyst (43) ausßerde ™ contains a second transition metal, the titanium, zirconium, hafnium, vanadium, columbium, tantalum, molybdenum and / or Tungsten is. 89. Electrolysis cell according to claim 88, characterized in that that the second transition metal is molybdenum. 90. Electrolysis cell according to claim 86, characterized in that that the cathodic electrocatalyst (43) also contains phosphorus and / or boron. 91. Electrolysis cell according to claim 86, characterized in that the permionic membrane (33) is a fluorinated cation exchange membrane with carboxylic acid groups as ion-exchanging groups, which has an ion exchange capacity of about 0.5 to 2.0 milliequivalents per gram of dry polymer and a concentration of carboxylic acid nuclei of about 8 having up to 30 milliequivalents nro grams of absorbed water and a Glasunwandlungstemperatur above about minus 80 ° and about 70 ⁰ C. 92. Process for electrolyzing alkali chloride brine in an electrolytic cell with a through a solid polymer electrolyte separated from the catholyte anolyte, wherein the solid polymer electrolyte a permionic membrane with an anodic electrocata- 030036/0690 BATH ORIGINAL lysator on their anodic first surface and has a cathodic electrocatalyst on its cathodic second surface, by supplying aqueous alkali chloride to the cell, applying an electrical voltage to the solid polymer electrolytes and removal of chlorine from the anolyte and alkali hydroxide from the catholyte, characterized in that an electrocatalyst is used which is a first transition metal containing VIII. 93. The method for electrolyzing according to claim 92, characterized in that that one uses a cathodic electrocatalyst with a surface area of at least 10 m per gram. 94. The method according to claim 92, characterized in that that a cathodic electrocatalyst is used which also contains a second transition metal, which is titanium, zircon, hafnium, vanadium, columbium, tantalum, molybdenum and / or a mixture. 95. The method for electrolyzing according to claim 94, characterized in that geke η η that a cathodic electrocatalyst is used, which contains molybdenum as the second transition metal. 96. The method for electrolyzing according to claim 92, characterized in that that one uses a cathodic electrocatalyst which also contains phosphorus and / or boron. 97. Process for the production of a solid polymeric electrolyte, characterized, 030036/0690 that you have a permionic membrane with a first Solution which contains hypophosphite and / or borohydride as a reducing agent, brings into contact and then the permionic membrane with a second solution containing a salt of a metal that is present on the nermionic membrane to be deposited, contains a complexing agent and a buffer. 98. The method of claim 97, characterized in that ⁱ bergangsnetall deposited as a metal on the membrane permionischen ^a?. 99. The method according to claim 93, characterized in that that the transition metal is a transition metal of group VIII of the periodic table. 100. The method according to claim 99, characterized in that the ^ Transition metal nickel or an ^M which is etal. 101. The method according to claim 98, characterized in that one more unr! a less leachable deposits ^ bergangnmetall together and then the better auslauabare ^f? berqangsmetall dissolves. 102. ^ experience according to claim 101, characterized in that that on the permionic membrane there is common iron and, as the second transition metal, a metal of Group VIII deposits and then removes the iron. 103. Electrolytic cell with a solid polymer electrolyte, with a permionic membrane with an anodic one Electrocatalyst on its anodic first surface 080036 / G690 RAD HRIfSIMAJ Electrocatalyst on its anodic first surface and a cathodic electrocatalyst on its cathodic second surface, characterized in that the anodic electrocatalyst (37) has active catalyst particles and contains silicon. 104. Electrolysis cell according to claim 103, characterized in that that the active particles have a silicon core with a cathalytic outer surface aiif. 1Ο5. Electrolysis cell according to claim 103, characterized in that that the electrocatalyst contains silicon particles. 106. Process for the electrolysis of alkali chloride brines with an electrolysis cell that has a solid having polymer electrolytes separated from the catholyte anolyte, with a permionic membrane on an anodic electrocatalyst on its anodic first surface and on its cathodic second surface having a cathodic electrocatalyst by supplying aqueous alkali chloride to the cell, applying it an electrical voltage on the solid polymer electrolyte and removal of chlorine from the anolyte space and alkali hydroxide from the catholyte compartment, characterized in that an anodic electrocatalyst is used which Contains enlarged silicon catalyst particles. 107. The method according to claim 106, characterized in that that the silicon enlarged catalyst particles one Contains filicium core with a catalytic outer surface. 000036/0690 BAt) ORIGINAL 108. Method for electrolyzing alkali chloride brines in an electrolytic cell with a through a solid polymer electrolyte separated from the catholyte anolyte, with ^ Pr solid polymeric electrolyte on its side facing the anolyte has an anodic electrocatalyst and on its side facing the catholyte Side has a cathodic electrocatalyst, by supplying aqueous alkali chloride brine to the electrolysis cell, Applying an electrical voltage to the solid polymer electrolyte and removing chlorine from it the anolyte space and alkali hydroxide from the catholyte space, characterized in that on the cathodic side of the solid polymer Electrolytes, a cathodic depolarization catalyst is present and peroxide is supplied to the catholyte space and thereby avoids the evolution of hydrogen on the cathodic surface of the solid polymeric electrolyte. The method of claim 108,
characterized in that the K-τ. tho Iy dreams supplied peroxide, hydrogen peroxide, organic peroxides, organic hydro-deroxides, organic peroxy acids and / or derivatives thereof. 11 <">. A method for electrolyzing alkali metal chloride brine in an electrolytic cell with an older by a fixed noly ^ electrolyte from the catholyte compartment separated ö.nolvtraum, wherein the solid polymeric Elektrolvt? Uf his, the ^A nolytraum facing side, an anodic Ele ^ dry ^ talvsator and has a cathodic electrocatalyzer on its side facing the catholyte space, by supplying aqueous alkali chloride brine to the electrolysis cell, applying an electrical voltage on the solid polymer electrolytes and OÖ0036 / 069Q DAM ADIOIMAL Removal of chlorine from the anolyte compartment and alkali hydroxide from the catholyte space, characterized that on the cathodic side of the solid polymeric electrolyte a cathodic polarization catalyst is present and that a redox couple is fed to the catholyte space and thereby the formation of hydrogen on the cathodic surface of the solid polymeric electrolyte. 111. The method according to claim 110, characterized in that the oxidizing agent used is a copper (II) compound used. 112. The method according to claim 110, characterized in that a copper (II) compound is added to the catholyte space supplies and wins a catholyte liquid that contains copper-I ions. 113. The method according to claim 110, characterized in that a quinone is used as the oxidizing agent. 114. The method according to claim 113, characterized in that a quinone is fed to the catholyte space and one Catholyte liquid containing hydroquinone wins. 115. electrolytic cell with a solid polymer electrolyte with an anodic electrocatalyst on its anodic first surface and a cathodic Electrocatalyst on the opposite cathodic second surface, characterized in that the electrolytic cell (11, 13) also has devices for supplying oxidizing agent containing particles to the 030036/0690 ORIGINAL cathodic second surface (43) of the solid polymeric electrolyte (31) and a cathodic depolarization catalyst in contact with the cathodic second surface. 11fi. Electrolytic cell according to claim 115, characterized in that the particles containing the oxidizing agent the contain cathodic depolarization catalyst. 117. Process for electrolyzing alkali chloride brines in an electrolytic cell with a separated by a solid polymer electrolyte from the catholyte compartment Anolyte, where the solid polymer electrolyte has an anodic on its side facing the anolyte Electrocatalyst and on his, that. Catholic dream facing side, has a cathodic electrocatalyst, by supplying aqueous calcium chloride brine to the cell, Applying an electrical voltage to the fixed door Electrolytes and removal of chlorine from the anolyte and alkali hydroxide from the catholyte, characterized, that on the cathodic side of the solid polymeric electrolyte a cathodic depolarization catalyst is provided and oxidizing agent-containing particles are fed to the catholyte space and thereby the development avoids hydrogen on the cathodic surface of the solid polymeric electrolyte. 030036/0690 BAD. ORIGINAL