CA2156359A1 - Electrolytic cell having sacrificial anodes - Google Patents
Electrolytic cell having sacrificial anodesInfo
- Publication number
- CA2156359A1 CA2156359A1 CA002156359A CA2156359A CA2156359A1 CA 2156359 A1 CA2156359 A1 CA 2156359A1 CA 002156359 A CA002156359 A CA 002156359A CA 2156359 A CA2156359 A CA 2156359A CA 2156359 A1 CA2156359 A1 CA 2156359A1
- Authority
- CA
- Canada
- Prior art keywords
- electrodes
- electrolyte
- stacked
- electrolytic cell
- duct
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/02—Electrodes; Manufacture thereof not otherwise provided for characterised by shape or form
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
- C25B9/30—Cells comprising movable electrodes, e.g. rotary electrodes; Assemblies of constructional parts thereof
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Prevention Of Electric Corrosion (AREA)
Abstract
The electrolytic cell having sacrificial anodes, which is provided with a feed line and a discharge line for electrolyte, comprises, stacked in a container (1), electrodes (4, 5) which are separated from one another by spacers (6) which form an electrode gap (7). The stack is provided with a guiding device (8) in which the indivi-dual electrodes (4, 5) are arranged slidingly. The individual electrodes (4, 5) have openings which in the case of stacked electrodes (4, 5) form a duct (9) for supplying the electrolyte into the electrode gaps (7), one end of the duct (9) being connected to the feed line (2) for electrolyte and its other end being closed.
Description
21~6359 HOECHST A~TIENGESELLSCHAFT HOE 94/F 239 DPh.HS/rh Description Electrolytic cell having sacrificial anodes The invention relates to an electrolytic cell having sacrificial anodes, which is provided with a feed line and a discharge line for electrolyte.
In the case of certain electrochemical processes, for example to prepare aromatic aldehydes by reductive carbonylation of aryl or benzyl halides or to prepare aromatic carboxylic acids by reductive carboxylation of aryl or benzyl halides and also for the preparation of aromatic ~-hydroxycarboxylic acidR by reductive carbox-ylation of aryl alkyl ketones it is known to employ 80-called sacrificial anodes (consumable anodes). Further, electrochemical processes for the preparation of sulfinic acids, silanes or tertiary phosphines are known which likewise involve the use of sacrificial anodes.
This means that for the said processes the anode process, constituting a part of the electrochemical overall process, consists in the controlled dissolution of the metallic anode. This measure, on the one hand, serves to generate the cations required for compensating for the anionic electrolysis products produced. On the other hand, employing the ~acrificial anode avoids the anodic generation of protons which, in the abovementioned cases, would interfere with the desired cathodic synthesis process .
According to European Patent No. 0 283 796, a flow electrolytic cell of the filter pre~s type i8 known which comprises continuously renewable sacrificial anodes made of metal particles in a packed bed active on both sides as the anode. In the case of electrolytic cells having a plurality of such anode elements the only sensible way of 2~3~
, .
connecting the eiectrodes is in a monopolar manner, half of the electrodes otherwise having the wrong polarity in each case and not being a~ailable for the desired objec-tive of the synthesis. A disadvantage of a monopolar connection i8 that the current feed has to be effected by means of separate current connections and current dis-tributions for each individual anode compartment, which is technically complicated in the case of packed-bed electrodes.
The European Patent 0 219 367 discloses a flow electro-lytic cell or the preparation of organic or organo-metallic compounds compriRing a pair of electrodes. One of the two electrodes is a sacrificial anode which consists of a solid cylindrical metal block having a conically pointed end. To the extent that the metal is consumed, said block slideR, under the influence of its own weight, in a hollow cone which is connected as the cathode and has geometrical ~ nRions identical to those of the anode cone. Said hollow cone in this arrangement at the same time constitutes part of the outer cell wall.
A drawback of this construction is that it iR not po~-sible to enlarge the electrode area indefinitely without at the ~ame time increaRing the reactor volume more than proportionally. To provide a larger electrode area it is therefore nece~sary to inRtall a greater number of cells.
The object of the invention i8 therefore to provide an electrolytic cell which is suitable for employing sacri-ficial anodes and has as high a ratio as possible of electrode area to electrolysis compartment volume.
This object iR achieved by an electrolytic cell of the type mentioned at the outset, wherein in a container electrodes are stacked, being separated from one another by spacers which form an electrode gap, the stack is provided with a guiding device in which the individual electrodes are arranged slidingly, the individual elec-trodes have openings which in the case of R tacked 2 1 ~ 9 . ~ .
In the case of certain electrochemical processes, for example to prepare aromatic aldehydes by reductive carbonylation of aryl or benzyl halides or to prepare aromatic carboxylic acids by reductive carboxylation of aryl or benzyl halides and also for the preparation of aromatic ~-hydroxycarboxylic acidR by reductive carbox-ylation of aryl alkyl ketones it is known to employ 80-called sacrificial anodes (consumable anodes). Further, electrochemical processes for the preparation of sulfinic acids, silanes or tertiary phosphines are known which likewise involve the use of sacrificial anodes.
This means that for the said processes the anode process, constituting a part of the electrochemical overall process, consists in the controlled dissolution of the metallic anode. This measure, on the one hand, serves to generate the cations required for compensating for the anionic electrolysis products produced. On the other hand, employing the ~acrificial anode avoids the anodic generation of protons which, in the abovementioned cases, would interfere with the desired cathodic synthesis process .
According to European Patent No. 0 283 796, a flow electrolytic cell of the filter pre~s type i8 known which comprises continuously renewable sacrificial anodes made of metal particles in a packed bed active on both sides as the anode. In the case of electrolytic cells having a plurality of such anode elements the only sensible way of 2~3~
, .
connecting the eiectrodes is in a monopolar manner, half of the electrodes otherwise having the wrong polarity in each case and not being a~ailable for the desired objec-tive of the synthesis. A disadvantage of a monopolar connection i8 that the current feed has to be effected by means of separate current connections and current dis-tributions for each individual anode compartment, which is technically complicated in the case of packed-bed electrodes.
The European Patent 0 219 367 discloses a flow electro-lytic cell or the preparation of organic or organo-metallic compounds compriRing a pair of electrodes. One of the two electrodes is a sacrificial anode which consists of a solid cylindrical metal block having a conically pointed end. To the extent that the metal is consumed, said block slideR, under the influence of its own weight, in a hollow cone which is connected as the cathode and has geometrical ~ nRions identical to those of the anode cone. Said hollow cone in this arrangement at the same time constitutes part of the outer cell wall.
A drawback of this construction is that it iR not po~-sible to enlarge the electrode area indefinitely without at the ~ame time increaRing the reactor volume more than proportionally. To provide a larger electrode area it is therefore nece~sary to inRtall a greater number of cells.
The object of the invention i8 therefore to provide an electrolytic cell which is suitable for employing sacri-ficial anodes and has as high a ratio as possible of electrode area to electrolysis compartment volume.
This object iR achieved by an electrolytic cell of the type mentioned at the outset, wherein in a container electrodes are stacked, being separated from one another by spacers which form an electrode gap, the stack is provided with a guiding device in which the individual electrodes are arranged slidingly, the individual elec-trodes have openings which in the case of R tacked 2 1 ~ 9 . ~ .
electrodes form a duct for supplying the electrolyte into the electrode gap~, one end of the duct being connected to the feed line for electrolyte and it~ other end being closed.
S The electrodes may comprise compound electrodes in which cathode and Racrificial anode are in each case connected to each other electroconductively. The compound elec-trodes are stacked and are separated from one another by spacers.
The guiding device may encompa~s the electrode stack. The individual electrodes may in each case have a central opening and the opening~, in the case of stacked elec-trodes, may form a central duct. The duct may have arranged therein, as the guiding device, a pipe provided with orifices via which the electrolyte is supplied to the electrode gaps. The cathodes can be made o steel, alloy steel, nickel, lead, zinc, iron, gold, platinum, copper, tin, cadmium, graphite, vitreous carbon or a composite of metal or graphite and plastic. The sacri-ficial anodes can be made of a reducing metal, in parti-cular of magnesium, aluminum or zinc.
The essential advantage of the invention should be seen in the ratio of electrode area to reactor volume being maintained in spite of the anodes being consumed.
Further~ore, the cell can be adapted without difficulty to operational requirements.
The invention is explained below in more detail with reference to an example and to the figures, in which Figure 1 shows a ~ectional view of the electrolytic cell with electrodés connected in a bipolar manner and a centrally disposed guide arrangement, and Figure 2 shows a ~ectional view of the electrolytic cell wi~h electrodes connected in a monopolar manner and a guide arrangement disposed on the electrode perimeter.
~15~9 ,~. . .
e - 4 -In the electrolytic cell cont~;ner 1, which i8 provided with a feed line 2 and a discharge line 3 for electro-lyte, cathodes 4 and sacrificial anodes 5 are arranged alternately. Cathodes 4 and anode~ S are separated from one another by a spacer 6 which forms the electrode gap 7 between the electrodes 4, 5. The electrode stack is provided with a guiding device 8, in which the indivi-dual, circular, square or rectangular electrodes 4, 5 are arranged slidingly. Individual electrodes 4, 5 have openings which in the ca~e of stacked electrodes form a duct 9 for supplying the electrolyte into the electrode gaps 7, one end of the duct 9 being connected to the feed line 2 for electrolyte and its other end being closed.
The guiding device 8 may comprise electrically non-conductive guide sections, e.g. round bars, L, T or Urails, which are arranged parallel to the stack axis and are per~-n~ntly attached to the container. These guide ~ections may penetrate the stack or encompass it.
In the embodiment according to Figure 1, the individual electrodes 4, 5 each have a central opening which, in the case of stacked electrodes, forms a central duct 9 in which a pipe 10 is arranged as a guiding device 8 and at the same time as a feed line 2. The pipe 10 is provided with orifices 11, e.g. with slots 11 rl~nn;ng parallel to the axis, via which slots the electrolyte is supplied to the electrode gap~ 7.
The spacer 6, which is made of plastic, expediently has a net-like structure, in order for the electrolyte to be distributed evenly in the electrode gaps 7. In the case of the embodiment according to Figure 1, the electrode stack 4, 5 may be provided with a ~ealing sleeve 12 ~urrolln~;ng the pipe 10 and with a weight 13. The purpose of the sealing sleeve 12 is to prevent the direct outflow of the electrolyte into the container 1, that of the weight 13 being to assist in the feed-forward of the electrode~ 4, 5. If the electrodes are connected in a monopolar manner, the electrodes 4, 5 may be provided 21~359 with flexible connection line~ 14, 15.
S The electrodes may comprise compound electrodes in which cathode and Racrificial anode are in each case connected to each other electroconductively. The compound elec-trodes are stacked and are separated from one another by spacers.
The guiding device may encompa~s the electrode stack. The individual electrodes may in each case have a central opening and the opening~, in the case of stacked elec-trodes, may form a central duct. The duct may have arranged therein, as the guiding device, a pipe provided with orifices via which the electrolyte is supplied to the electrode gaps. The cathodes can be made o steel, alloy steel, nickel, lead, zinc, iron, gold, platinum, copper, tin, cadmium, graphite, vitreous carbon or a composite of metal or graphite and plastic. The sacri-ficial anodes can be made of a reducing metal, in parti-cular of magnesium, aluminum or zinc.
The essential advantage of the invention should be seen in the ratio of electrode area to reactor volume being maintained in spite of the anodes being consumed.
Further~ore, the cell can be adapted without difficulty to operational requirements.
The invention is explained below in more detail with reference to an example and to the figures, in which Figure 1 shows a ~ectional view of the electrolytic cell with electrodés connected in a bipolar manner and a centrally disposed guide arrangement, and Figure 2 shows a ~ectional view of the electrolytic cell wi~h electrodes connected in a monopolar manner and a guide arrangement disposed on the electrode perimeter.
~15~9 ,~. . .
e - 4 -In the electrolytic cell cont~;ner 1, which i8 provided with a feed line 2 and a discharge line 3 for electro-lyte, cathodes 4 and sacrificial anodes 5 are arranged alternately. Cathodes 4 and anode~ S are separated from one another by a spacer 6 which forms the electrode gap 7 between the electrodes 4, 5. The electrode stack is provided with a guiding device 8, in which the indivi-dual, circular, square or rectangular electrodes 4, 5 are arranged slidingly. Individual electrodes 4, 5 have openings which in the ca~e of stacked electrodes form a duct 9 for supplying the electrolyte into the electrode gaps 7, one end of the duct 9 being connected to the feed line 2 for electrolyte and its other end being closed.
The guiding device 8 may comprise electrically non-conductive guide sections, e.g. round bars, L, T or Urails, which are arranged parallel to the stack axis and are per~-n~ntly attached to the container. These guide ~ections may penetrate the stack or encompass it.
In the embodiment according to Figure 1, the individual electrodes 4, 5 each have a central opening which, in the case of stacked electrodes, forms a central duct 9 in which a pipe 10 is arranged as a guiding device 8 and at the same time as a feed line 2. The pipe 10 is provided with orifices 11, e.g. with slots 11 rl~nn;ng parallel to the axis, via which slots the electrolyte is supplied to the electrode gap~ 7.
The spacer 6, which is made of plastic, expediently has a net-like structure, in order for the electrolyte to be distributed evenly in the electrode gaps 7. In the case of the embodiment according to Figure 1, the electrode stack 4, 5 may be provided with a ~ealing sleeve 12 ~urrolln~;ng the pipe 10 and with a weight 13. The purpose of the sealing sleeve 12 is to prevent the direct outflow of the electrolyte into the container 1, that of the weight 13 being to assist in the feed-forward of the electrode~ 4, 5. If the electrodes are connected in a monopolar manner, the electrodes 4, 5 may be provided 21~359 with flexible connection line~ 14, 15.
Claims (6)
1. An electrolytic cell having sacrificial anodes, which is provided with a feed line and a discharge line for electrolyte, wherein in a container (1) electrodes (4, 5) are stacked, being separated from one another by spacers (6) which form an electrode gap (7), the stack provided with a guiding device (8) in which the individual electrodes (4, 5) are arranged slidingly, the individual electrodes (4, 5) having openings which in the case of stacked elec-trodes (4, 5) form a duct (9) for supplying the electrolyte into the electrode gaps (7), one end of the duct (9) being connected to the feed line (2) for electrolyte and its other end being closed.
2. The electrolytic cell as claimed in claim 1, wherein in the container (1) the electrodes (4, 5) are stacked as compound electrodes which in each case comprise a cathode (4) and sacrificial anode (5) connected to each other electroconductively, the compound electrodes are stacked, being separated from one another by spacers (6) which form an elec-trode gap (7), the stack is provided with a guiding device (8) in which the individual electrodes (4, 5) are arranged slidingly, the individual electrodes (4, 5) having openings which in the case of stacked electrodes (4, 5) form a duct (9) for supplying the electrolyte into the electrode gaps (7), one end of the duct (9) being connected to the feed line (2) for electrolyte and its other end being closed.
3. The electrolytic cell as claimed in claim 1, wherein the guiding device (8) encompasses the electrode stack.
4. The electrolytic cell as claimed in claim 3, wherein the guiding device (8) encompasses the electrode stack and the individual electrodes (4, 5) each have a central opening and the openings of stacked elec-trodes (4, 5) form a central duct (9).
5. The electrolytic cell as claimed in claim 1, wherein individual electrodes (4, 5) each have a central opening and the openings of stacked electrodes (4, 5) form a central duct (9) wherein, as a guiding device (8), a pipe (10) is arranged which is pro-vided with orifices (11) via which the electrolyte is supplied to the electrode gaps (7).
6. The electrolytic cell as claimed in claim 1, wherein the cathodes (4) are made of steel, alloy steel, nickel, lead, zinc, iron, gold, platinum, copper, tin, cadmium, graphite, vitreous carbon or a compos-ite of metal or graphite and plastic, and the sacri-ficial anodes (5) are made of a reducing metal, in particular of magnesium, aluminum or zinc.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4429354.2 | 1994-08-18 | ||
| DE4429354A DE4429354A1 (en) | 1994-08-18 | 1994-08-18 | Electrolytic cell with consumption anodes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2156359A1 true CA2156359A1 (en) | 1996-02-19 |
Family
ID=6526032
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002156359A Abandoned CA2156359A1 (en) | 1994-08-18 | 1995-08-17 | Electrolytic cell having sacrificial anodes |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0697473A1 (en) |
| JP (1) | JPH0860389A (en) |
| CA (1) | CA2156359A1 (en) |
| DE (1) | DE4429354A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19935452A1 (en) * | 1999-07-28 | 2001-03-08 | Basf Ag | Fibrous adhesive composition |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2444500A1 (en) * | 1978-12-20 | 1980-07-18 | Ecopol | ELECTROLYSIS DEVICE |
| FR2586710B1 (en) | 1985-09-05 | 1990-03-30 | Poudres & Explosifs Ste Nale | ORGANIC ELECTROLYSIS CELL WITH CONSUMABLE ELECTRODE |
| IT1203373B (en) | 1987-03-18 | 1989-02-15 | Silvestri Silvestri | DEVICE FOR THE TRANSFORMATION OF ELECTROLYTIC CELLS OF THE FILTER TYPE PRESS IN CELLS WITH CONTINUOUS RENEWABLE SACRIFICAL ELECTRODES |
| YU74987A (en) * | 1987-04-24 | 1989-08-31 | Aleksandar Despic | Electrochemical cell with movable electrode |
| FR2617197B1 (en) * | 1987-06-25 | 1991-07-12 | Poudres & Explosifs Ste Nale | ELECTROLYSIS CELL WITH CONSUMABLE BIPOLAR ELECTRODES |
-
1994
- 1994-08-18 DE DE4429354A patent/DE4429354A1/en not_active Withdrawn
-
1995
- 1995-08-07 EP EP95112394A patent/EP0697473A1/en not_active Withdrawn
- 1995-08-17 CA CA002156359A patent/CA2156359A1/en not_active Abandoned
- 1995-08-17 JP JP7209396A patent/JPH0860389A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| EP0697473A1 (en) | 1996-02-21 |
| JPH0860389A (en) | 1996-03-05 |
| DE4429354A1 (en) | 1996-02-22 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |