WO2014009536A1 - Cellule électrolytique dépourvue de séparateur et son utilisation - Google Patents

Cellule électrolytique dépourvue de séparateur et son utilisation Download PDF

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Publication number
WO2014009536A1
WO2014009536A1 PCT/EP2013/064809 EP2013064809W WO2014009536A1 WO 2014009536 A1 WO2014009536 A1 WO 2014009536A1 EP 2013064809 W EP2013064809 W EP 2013064809W WO 2014009536 A1 WO2014009536 A1 WO 2014009536A1
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WIPO (PCT)
Prior art keywords
anode
electrolyte
electrolysis
cathode
electrolytic cell
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PCT/EP2013/064809
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German (de)
English (en)
Inventor
Michael Müller
Patrick Keller
Markus Schiermeier
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United Initiators Gmbh & Co. Kg
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Priority claimed from PCT/EP2012/063783 external-priority patent/WO2013007816A2/fr
Application filed by United Initiators Gmbh & Co. Kg filed Critical United Initiators Gmbh & Co. Kg
Priority to PL13735335T priority Critical patent/PL2872673T3/pl
Priority to KR1020157000758A priority patent/KR20150034171A/ko
Priority to US14/407,205 priority patent/US9540740B2/en
Priority to ES13735335T priority patent/ES2822623T3/es
Priority to CN201380031764.0A priority patent/CN104487615B/zh
Priority to EP13735335.5A priority patent/EP2872673B1/fr
Publication of WO2014009536A1 publication Critical patent/WO2014009536A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
    • C25B9/17—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/01—Products
    • C25B1/28—Per-compounds
    • C25B1/29—Persulfates
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/01—Products
    • C25B1/28—Per-compounds
    • C25B1/30—Peroxides

Definitions

  • the present invention relates to a process for the preparation of an ammonium or alkali metal peroxodisulfate.
  • Rossberger (US 3915816 (A)) describes a process for the direct production of sodium persulfate. As electrolysis cells undivided cells are described with platinum-coated titanium-based anodes. The illustrated current yields are based on the addition of a potential-increasing promoter.
  • Sodium peroxodisulfate is produced with a current efficiency of 70 to 80% in an electrolytic cell with a diaphragm-protected cathode and a platinum anode by a neutral aqueous Anolytiösung with an initial content of 5 to 9 wt .-% sodium ions, 12 to 30% by weight of sulfate ions, 1 to 4% by weight of ammonium ions, 6 to 30% by weight of peroxodisulfate ions and a potential-increasing promoter, in particular thiocyanate, using a sulfuric acid solution as the catholyte at a current density of at least 0.5 to 2 A / cnr electrolyzed. After crystallization and separation of peroxodisulfate from the anolyte, the mother liquor is mixed with the cathode product, neutralized and fed back to the anode.
  • EP-B 0 428 171 discloses a filter press-type electrolytic cell for producing peroxo compounds, including ammonium peroxodisulfate, sodium peroxodisulfate and potassium peroxodisulfate.
  • peroxo compounds including ammonium peroxodisulfate, sodium peroxodisulfate and potassium peroxodisulfate.
  • anodes here hot isostatically applied to a valve metal platinum foils are used.
  • the anolyte used is a solution of the corresponding sulfate containing a promoter and sulfuric acid. This method also has the aforementioned problems.
  • peroxodisulfates are prepared by anodic oxidation of an aqueous solution containing neutral ammonium sulfate.
  • the solution obtained from anodic oxidation containing ammonium peroxodisulfate is reacted with caustic soda or potassium hydroxide solution.
  • the mother liquor is recycled in admixture with the catholyte produced during the electrolysis.
  • the electrolysis is carried out in the presence of a promoter on a platinum electrode as the anode.
  • the present application accordingly provides a process for the preparation of an ammonium or alkali metal peroxodisulfate, comprising
  • the electrolytic cell comprises an undivided electrolysis space between the anode and the cathode and the aqueous electrolyte does not contain a promoter for increasing the decomposition voltage of water to oxygen.
  • the ammonium sulfate, alkali metal sulfate and / or the corresponding bisulfate salt used for anodizing may be any of the alkali metal sulfate or corresponding bisulfate. In the context of the present application, however, the use of sodium and / or potassium sulfate and / or the corresponding hydrogen sulfate is particularly preferred.
  • promoter or else “polarizer” is any means known to those skilled in the art as an additive in carrying out an electrolysis to increase the decomposition voltage of water to oxygen or to improve the current efficiency
  • Thiocyanate such as, for example, sodium or ammonium thiocyanate is not used according to the invention, in other words the electrolyte has a promoter concentration of 0 g / l in the process according to the invention
  • the method eliminates, for example, cleaning requirements regarding the formation of typical electrolysis gases.
  • an anode which comprises a diamond layer arranged on a conductive support and doped with a 3- or 5-valent element.
  • the anode used can be of any shape.
  • the support material is selected from the group consisting of silicon, germanium, titanium, zirconium, niobium, tantalum, molybdenum, tungsten, carbides of these elements and / or aluminum or combinations of the elements.
  • the doped with a 3- or 5-valent element diamond layer is applied on this substrate.
  • the doped diamond layer is thus an n-conductor or a p-type conductor. It is preferred that a boron-doped and / or phosphorus-doped diamond layer is used.
  • the amount of doping is adjusted so that the desired, usually just the sufficient, conductivity is achieved.
  • the crystal structure may contain up to 10000 ppm of boron.
  • the diamond layer may be applied over the entire surface or in sections, for example, exclusively on the front side or exclusively on the backside of the carrier material.
  • Methods for applying the diamond layer are known in the art.
  • the production of the diamond electrodes can be carried out in particular in two special CVD methods (chemical vapor deposition technique). These are microwave plasma CVD and hot wire CVD.
  • microwave plasma CVD chemical vapor deposition technique
  • hot wire CVD hot wire CVD
  • the gas phase which is activated by microwave irradiation or thermally activated by hot wires to the plasma, from methane, hydrogen and optionally further additives, in particular a gaseous compound of the dopant.
  • a p-type semiconductor By using a boron compound such as trimethylboron, a p-type semiconductor can be provided. By using a gaseous phosphorus compound as a dopant, an n-type semiconductor is obtained. By deposition of the doped diamond layer on crystal inem a silicon a particularly dense and non-porous layer is obtained - a film thickness of 1 pm is usually sufficient.
  • the diamond layer is preferably in a film thickness of about 0.5 pm to 5 pm, preferably about 0.8 pm to about 2.0 pm and more preferably about 1, 0 pm on the applied Anodenarrimateriai used according to the invention.
  • the deposition can also take place on a self-passivating metal, such as titanium, tantalum, tungsten or niobium.
  • a self-passivating metal such as titanium, tantalum, tungsten or niobium.
  • anode comprising a niobium or titanium support with a boron-doped diamond layer, in particular a diamond layer boron-doped in the crystal structure up to 10000 ppm, is particularly preferred.
  • the cathode used in the process according to the invention is preferably formed from lead, carbon, tin, platinum, nickel, alloys of these elements, zirconium and / or acid-resistant stainless steels, as known to the person skilled in the art. Spatially, the cathode can be configured arbitrarily.
  • the electrolyte space between anode and cathode is undivided, i. there is no separator between anode and cathode.
  • the use of an undivided cell allows electrolyte solutions with very high solids concentrations, which in turn significantly reduces the energy required for salt recovery, essentially crystallization and water evaporation, directly proportional to the solids increase, but at least 25% of that of a divided cell.
  • the method according to the invention is carried out in preferred embodiments in a two-dimensional or three-dimensional cell.
  • the cell is preferably designed as a flat or tubular cell.
  • a tube geometry ie a tube cell, consisting of an inner tube as the anode, preferably made of diamond-coated niobium, and an outer tube as the cathode, preferably made of acid-resistant stainless steel, represents, with low material costs, an advantageous construction.
  • the use of an annular gap as the common electrolyte space is preferred and leads to a uniform and thus low-flow throughflow and thus to a high utilization of the available electrolysis areas, which in turn means a high current efficiency.
  • the manufacturing costs of such a cell are low in relation to a so-called flat cell.
  • the electrolyte used in the process according to the invention preferably has an acidic, preferably sulfur-acidic, or neutral pH.
  • the electrolyte is circulated through the electrolytic cell during the process. This prevents a, the decomposition of the persulfate accelerating and thus undesirable high electrolyte temperature in the cell.
  • the method comprises a discharge of electrolyte solution from the electrolyte circuit. This can be done in particular for the production of peroxodisulfate produced.
  • a further preferred embodiment therefore relates to the recovery of peroxodisulfates produced by crystallization and separation of the crystals from the electrolyte solution to form an electrolyte solution, wherein the electrolyte solution has been preferably previously discharged from the electrolyte circuit.
  • a further preferred embodiment comprises a recirculation of the electrolyte mother liquor, in particular if previously produced peroxodisulfates were separated, increasing the content of acid, sulfate and / or hydrogen sulfate in the electrolysis cell.
  • the anodization is preferably carried out according to the invention at an anodic current density of 50-1 500 mA / cm 2 and more preferably about 50-1 200 mA / cm 2 .
  • a particularly preferred current density is in the range of 60-975 mA / cm 2 .
  • the electrolyte used in the process according to the invention preferably has a total solids content of about 0.5 to 650 g / l.
  • the (working) electrolyte preferably contains from about 100 to about 500 g / L of persulfate, more preferably about 150 to about 450 g / L of persulfate, and most preferably 250-400 g / L of persulfate.
  • the inventive method thus enables in particular high solids concentrations in the electrolyte solution, without the addition of a potential-enhancing agent or promoter and the resulting requirements for exhaust gas and wastewater treatment at the same time high current yields in Peroxodisul father ein.
  • the electrolytic solution preferably contains about 0.1 to about 3.5 moles of sulfuric acid per liter of (I) electrolytic solution, more preferably 1-3 moles of sulfuric acid per liter of electrolyte solution, and most preferably 2.2 to 2.8 moles of sulfuric acid per liter of electrolyte solution.
  • an electrolyte having the following composition: per liter of electrolyte 1, 50 to 500 g of persulfate and 0.1 to 3.5 mol of sulfuric acid per mole of electrolyte solution.
  • the total solids content is preferably 0.5 g / L to 650 g / L, more preferably 100-500 g / L, and most preferably 250-400 g / L, with the sulfate content being variable.
  • the promoter content is 0 g / l.
  • the invention further relates to a constructed of individual components, undivided electrolysis cell, an electrolysis device constructed from a plurality of such electrolysis cells, and their use for the oxidation of an electrolyte.
  • electrolysis is meant a chemical change caused by the passage of electricity through an electrolyte, which is expressed in a direct conversion of electrical energy into chemical energy through the mechanism of the electrode reactions and ion migration Saline solution, in which sodium hydroxide solution and chlorine gas are produced, and the production of inorganic peroxides is nowadays carried out industrially in electrolysis cells.
  • anode and cathode materials must meet the mechanical requirements at high solids concentrations and therefore be extremely resistant to wear.
  • the electrolysis cells In order to make the electrolysis as economical as possible, the electrolysis cells must be designed so that the electrolysis can be carried out at possibly high current densities. This is only possible if anode and cathode have good electrical conductivity and are chemically inert to the electrolyte.
  • the anode material used is graphite or platinum. However, these materials have the disadvantage that they do not have sufficient abrasion resistance at high solids concentrations.
  • electrodes are coated with an electrically conductive diamond layer, wherein the diamond layer is applied by a chemical vapor deposition method (CVD).
  • CVD chemical vapor deposition method
  • the object of the present invention is to provide an electrolysis cell which enables a continuous and optimized electrolysis process at high solids concentrations (up to about 650 g / l) and at high current density ranges (up to about 1500 mA / cm 2 ).
  • the electrolysis cell should be adapted to the electrochemical reactions to be performed and individual components can be easily replaced without the actual cell body is destroyed.
  • an electrolysis cell comprising the components:
  • anode and cathode are arranged concentrically to each other, so that preferably the electrolyte space forms as an annular gap between the inside anode and the outside cathode.
  • the diameter of the cathode is larger than that of the anode.
  • the electrolyte space contains no membrane or no diaphragm.
  • it is an electrolytic cell with a common electrolyte space, i. the electrolysis cell is undivided.
  • the distance between the anode outer surface and the cathode inner surface is between 1 -20 mm, more preferably between 1 -1 5 mm, even more preferably between 2-1 0 mm, and most preferably between 2-6 mm.
  • the inner diameter of the cathode is preferably between 1 0-400 mm, more preferably between 20-300 mm, even more preferably between 25-250 mm.
  • the anode and cathode are each independently between 20-120 cm, more preferably between 25-75 cm long.
  • the length of the electrolyte space is preferably at least 20 cm, more preferably at least 25 cm, and most preferably 1 20 cm, more preferably 75 cm.
  • the cathode used in accordance with the invention is preferably made of lead, carbon, tin, platinum, nickel, alloys of these elements, zirconium and / or iron alloys, in particular of stainless steel, in particular of acid-resistant stainless steel. In a preferred embodiment, the cathode is made of acid-resistant stainless steel.
  • the base material of the rod-shaped or tubular, preferably tubular, anode is preferably silicon, germanium, titanium, zirconium, niobium, tantalum, molybdenum, tungsten, carbides of these elements, and / or aluminum, or combinations of the elements.
  • the anode support material may be identical to or different from the anode base material.
  • the anode base material functions as a conductive carrier.
  • the conductive support any conductive material known in the art can be used. Particularly preferred support materials are sil icium, germanium, titanium, zirconium, niobium, tantalum, molybdenum, tungsten, carbides of these elements, and / or aluminum, or combinations of the elements. Silicon, titanium, niobium, tantalum, tungsten or carbides of these elements, more preferably niobium or titanium, even more preferably niobium, is particularly preferably used as the conductive support.
  • a conductive diamond layer is applied on this substrate.
  • the diamond layer may be doped with at least one 3- or at least one 5-valent main or subgroup element.
  • the doped diamond layer is thus an n-conductor or a p-type conductor. It is preferred that a boron-doped and / or phosphorus-doped diamond layer is used.
  • the amount of doping is adjusted so that the desired, usually just the sufficient, conductivity is achieved.
  • the crystal structure may contain up to 10,000 ppm, preferably from 10 ppm to 2,000 ppm, of boron and / or phosphorus.
  • the diamond layer may be applied over the entire surface or in sections, preferably on the entire outer surface of the rod-shaped or tubular anode.
  • the conductive diamond layer is preferably non-porous.
  • the preparation of the diamond electrodes can be carried out in particular in two special CVD processes (Chemical Vapor Deposition). These are the microwave plasma CVD and the hot wire CVD method. In both cases, the gas phase, which is activated by microwave irradiation or thermally activated by hot wires to the plasma, from methane, hydrogen and optionally further additives, in particular a gaseous compound of the dopant.
  • CVD Chemical Vapor Deposition
  • a p-type semiconductor By using the boron compound such as trimethylboron, a p-type semiconductor can be provided. By using a gaseous phosphorus compound as a dopant, an n-type semiconductor is obtained. By deposition of the doped diamond layer on crystal inem a silicon a particularly dense and non-porous layer is obtained.
  • the diamond layer is preferably applied to the conductive support used according to the invention in a film thickness of about 0.5-5 ⁇ m, preferably about 0.8-2.0 ⁇ m and particularly preferably about 1 ⁇ m. In another embodiment, the diamond layer is preferably applied in a film thickness of 0.5-35 ⁇ m, preferably 5-25 ⁇ m, most preferably 10-20 ⁇ m, to the conductive support used according to the invention.
  • the deposition can also be carried out on a self-passivating metal, such as titanium, tantalum, tungsten, or niobium.
  • a self-passivating metal such as titanium, tantalum, tungsten, or niobium.
  • PA Michaud Electrochemical and Solid State Letters, 3 (2) 77-79 (2000).
  • the use of an anode comprising a nitrile or titanium support with a boron-doped diamond layer, in particular with a diamond layer doped with up to 10000 ppm of boron is particularly preferred.
  • the diamond-coated electrodes are characterized by a very high mechanical strength and abrasion resistance.
  • the anode and / or the cathode more preferably the anode and the cathode, even more preferably the anode is connected to the power source via the distributor means.
  • the distributor device is electrically insulated in accordance with electrically. In any case, ensure good electrical contact between anode and / or cathode and distribution device.
  • the distribution device further ensures a homogeneous feed of the electrolyte from the inlet pipe into the electrolyte space. After the electrolyte has passed the electrolyte space, the reacted electrolyte (electrolysis product) is effectively collected by means of at least one upstream distribution device and discharged via a drain pipe.
  • the distributor devices according to the invention preferably consist independently of one another of silicon, germanium, titanium, zirconium, niobium, tantalum, molybdenum, tungsten, carbides of these elements and / or aluminum or combinations of the elements, particularly preferably of titanium.
  • the distribution devices preferably have at least one connection point for at least one discharge or supply pipe and a connection point for the anode.
  • the connection point for the anode forms an optionally closed Hohlzyl inder, which is flush with the anode tube or completed.
  • the hollow cylinder in the distributor devices can close off the anode tube so that no electrolyte can get into the interior of the anode.
  • the connection point of the distributor device to the anode can have a relief bore into the anode tube. This prevents electrolyte from flowing into the anode tube if the pressure on the distributor element is too high.
  • the optionally closed hollow cylinder of the distributor device can be mounted on the support material of the anode or directly on the diamond-coated carrier. In the latter case, therefore, the carrier and the distributor device are separated from one another by the conductive diamond layer.
  • the distributor device is irreversibly connected to the anode, particularly preferably welded. This is particularly advantageous when working at high currents.
  • the anode and the manifold may be welded by diffusion bonding, electron beam welding or laser welding.
  • Radial bores are distributed over the circumference of the hollow cylinder of the distributor device.
  • the distributor device 3 more preferably 4 and even more preferably has 5 radial bores. Due to the radial bores in the distributor device, the electrolyte can be distributed homogeneously and in a streamlined manner into the electrolyte space and, after passage of the electrolyte space, the electrolysis product can be effectively removed.
  • the electrolyte is preferably supplied via the inlet pipe of the electrolytic cell and in particular the distributor device.
  • the electrolysis product is preferably removed from the electrolysis cell via the outlet pipe, in particular after the electrolysis product has been collected in the distributor device.
  • the manifold is designed to seal the tubular cathode so that no electrolyte or electrolysis product can escape from the cathode.
  • the distributor device fulfills several tasks independently of one another:
  • anode, cathode, distribution device, inlet and outlet pipe can be assembled by an appropriate, known in the art, mounting devices to an electrolytic cell.
  • the individual components may be formed in different materials and replaced or replaced individually in case of damage. It has thus been possible to easily connect the diamond anode according to the invention and the other components, which are made of cheaper materials, to one another in a very compact electrolytic cell in construction.
  • the tubular electrolysis cell is also characterized by high Strength with low material usage. Parts that wear over time, for example due to the abrasive electrolytes, can be replaced individually, so that in this respect an economical use of materials is guaranteed.
  • the Elekrolytraum is flow streamlined, thereby avoiding flow losses and the surface for the electrochemical mass transfer are optimally utilized. A continuous and homogeneous electrolysis process at high solids concentrations and current density ranges is possible due to the electrode material and electrode arrangement.
  • Another aspect of the present invention is an electrolysis device which comprises at least two electrolytic cells according to the invention, wherein the electrolyte passes through the electrolysis cells in succession and the electrolysis cells are operated electrochemically in parallel.
  • the plant services are flexible and feasible without limits.
  • the electrolytic cell according to the invention or the electrolysis device according to the invention is particularly suitable for the oxidation of an electrolyte.
  • the undivided electrolysis cell is particularly suitable for the oxidation of an electrolyte when neither electrolyte nor electrolysis product, which are produced or reacted at the anode or cathode, are changed in a disturbing way by the respective other electrode process or react with each other.
  • the electrolysis cells according to the invention can be operated with a current density between 50-1 500 mA / cm 2 , preferably 50-1 200 mA / cm 2 , more preferably 60-975 mA / cm 2 , thus enabling large-scale and economic processes.
  • the electrolysis cells / electrolysis devices according to the invention can moreover be used at very high solids contents of between 0.5-650 g / l, preferably 100-500 g / l, more preferably 1-50-450 g / l and even more preferably 250-400 g / l.
  • the electrolysis cells / devices according to the invention are particularly suitable for the anodic oxidation of sulfate to peroxodisulfate.
  • electrolysis cells / electrolysis devices according to the invention have proven particularly suitable for the production of peroxodisulfates.
  • Rossberger (US Pat. No. 391 581 6 (A)) describes a process for the direct preparation of sodium persulfate. As electrolysis cells undivided cells are described with platinum-coated titanium-based anodes. The illustrated current yields are based on the addition of a potential-increasing promoter.
  • sodium peroxodisulfate is produced with a current efficiency of 70 to 80% in an electrolytic cell with a diaphragm protected by a cathode and a platinum anode by a neutral aqueous Anolytiosung with an initial content of 5 to 9 wt .-% sodium ions, 1 2 to 30% by weight of sulfate ions, 1 to 4% by weight of ammonium ions, 6 to 30% by weight of peroxodisulfate ions and a potential-increasing promoter, in particular thiocyanate, using a Sulfuric acid solution as a catholyte at a current density of at least
  • the mother liquor is mixed with the cathode product, neutralized and fed back to the anode.
  • EP-B 0 428 1 71 discloses a filter press-type electrolytic cell for producing peroxo compounds, including ammonium peroxodisulfate, sodium peroxodisulfate and potassium peroxodisulfate.
  • the anodes used here are hot isostatic platinum foils applied to a valve metal.
  • the anolyte used is a solution of the corresponding sulfate containing a promoter and sulfuric acid. This method also has the aforementioned problems.
  • peroxodisulfates are prepared by anodic oxidation of an aqueous solution containing neutral ammonium sulfate.
  • the solution obtained from the anodic oxidation which contains ammonium peroxodisulfate, is reacted with sodium hydroxide solution or potassium hydroxide solution.
  • the mother liquor is recycled in admixture with the catholyte produced during the electrolysis.
  • the electrolysis is carried out in the presence of a promoter on a platinum electrode as the anode.
  • the used for the anodic oxidation salt from the series ammonium sulfate, Al kalimetallsulfat and / or the corresponding bisulfate may be any alkali metal sulfate or corresponding bisulfate. In the context of the present application, however, the use of sodium and / or potassium sulfate and / or the corresponding hydrogen sulfate is particularly preferred.
  • the electrolyte space between anode and cathode is undivided, ie. there is no separator between anode and cathode.
  • the use of an undivided cell allows electrolyte solutions with very high solids concentrations, which in turn significantly reduces the energy required for salt recovery, essentially crystallization and water evaporation, directly proportional to the solids increase, but at least 25% of that of a divided cell.
  • the use of a promoter is not necessary.
  • promoter is any suitable agent which is known to the person skilled in the art as an additive in carrying out an electrolysis for increasing the decomposition voltage of water to oxygen or for improving the current efficiency
  • Promoter is thiocyanate such as sodium or ammonium thiocyanate.
  • the electrolyte used preferably has an acidic, preferably sulfur-acidic, or neutral pH.
  • the electrolyte may be circulated through the electrolytic cell during the process. This prevents a, the decomposition of the persulfate accelerating and thus undesirable high electrolyte temperature in the cell.
  • a discharge of electrolyte solution from the electrolyte circuit takes place to obtain generated peroxodisulfate.
  • the produced peroxodisulfate can be obtained by crystallizing and separating the crystals from the electrolytic solution to form an electrolyte liquor.
  • the electrolyte used preferably has a total solids content of about 0.5 to 650 g / l at the beginning of the electrolysis.
  • the electrolyte preferably contains from about 100 to about 500 g / L of sulfate, more preferably from about 150 to about 450 g / L of sulfate, and most preferably 250-400 g / L of sulfate at the beginning of the reaction.
  • the use of the electrolysis cell / device according to the invention thus allows high concentrations of solids in the electrolyte solution, without the addition of a potential-enhancing agent or promoter and the resulting requirements for exhaust and wastewater treatment at the same time high current yields in Peroxodisul father ein.
  • the electrolytic solution preferably contains about 0.1 to about 3.5 moles of sulfuric acid per liter of (I) electrolytic solution, more preferably 1-3 moles of sulfuric acid per liter of electrolyte solution, and most preferably 2.2 to 2.8 moles of sulfuric acid per liter of electrolyte solution.
  • an electrolyte having the following composition: per liter of starting electrolyte, 150 to 500 g of sulphate and 0.1 to 3.5 mol of sulfuric acid per liter of electrolyte solution.
  • the total solids content is preferably from 0.5 g / l to 650 g / l, more preferably from 1 00 to 500 g / l, and most preferably from 250 to 400 g / l.
  • the promoter content is 0 g / l. characters
  • FIG. 1 Current yields in comparison of different cell types with and without rhodanide (promoter).
  • FIG. 2a current / voltage in Pt / HIP and diamond electrodes.
  • FIG. 2b current / yield in Pt / H IP and diamond electrodes.
  • Fig ur 3 electrolysis cell according to the invention - top view
  • FIG. 4 Cross section of an electrolysis cell according to the invention
  • FIG. 5 individual components of the electrokineal cell according to the invention
  • FIG. 6 Distribution device
  • FIG. 3 shows a possible embodiment of an electrolytic cell according to the present invention.
  • FIG. 1 A cross section of this model is shown schematically in FIG.
  • the electrolyte passes into the distributor device (2a) and is supplied from there aerodynamically to the electrolyte space (3).
  • the electrolyte space (3) is formed by the annular gap between the outer surface of the anode (4) and the inner surface of the cathode (5).
  • the electrolysis product is collected by distributor device (2b) and transferred into the discharge pipe (6). Seals (7) close the electrolyte space between inlet and outlet pipe and inner surface of the cathode.
  • the distributor device (2) can be designed such that the distributor device simultaneously undertakes the sealing of the electrolyte space.
  • FIG. 5 shows the individual components of the electrolysis cell according to the invention. The numbering is analogous to FIG. 4. Further components for sealing the electrolysis cell and for mounting are shown in FIG. 5 but not numbered. These components are known in the art and can be exchanged bel.
  • FIG. 6 is an enlarged view of the distributor device (2).
  • the distribution devices has a connection point (21) for a waste or inlet pipe and a connection point (22) for the anode (4).
  • the connection point for the anode forms a hollow cylinder which terminates flush with the anode tube or rod (4).
  • Radial bores (23) are distributed over the circumference of the hollow cylinder of the distributor device. Through the radial bores (23) in the distributor device, the electrolyte can be homogeneously fed into the electrolyte space and be effectively removed after passage of the electrolyte space.
  • the distributor device 3, more preferably 4 and even more preferably has 5 radial bores.
  • Electrolyte initial composition :
  • Cathode material acid-resistant stainless steel: 1 .4539
  • Solubility limit sodium persulfate of the system approx. 65 - 80 g / l.
  • the electrolyte was concentrated accordingly by circulating (see FIGS. 1 and 2).
  • the current efficiency of a diamond-coated niobium anode is about 1 0% higher even without the addition of a potential-increasing agent than in a cell with conventional platinum-titanium anode and adding a potential-increasing agent and about 40% higher than in a cell Cell with conventional platinum titanium anode without addition of a potential-enhancing agent.
  • the voltage drop across a diamond-coated anode is about 0.9 volts higher than for a comparable cell with a platinum-titanium anode. It was further shown that the current yield in a diamond electrode to be used according to the invention without the addition of a promoter only increases with increasing total content of sodium peroxodisulfate in the electrolyte slowly decreases - under the experimental conditions, for example, at a current efficiency of equal to or above 65% electrolyte solutions with a Natriumperoxodisulfatgehalt of about 400 - 650 g / l win.
  • the working current density can be significantly reduced compared to platinum anodes with the same amount of production, whereby less ohmic losses occur in the system and thus the cooling effort is reduced and the degree of freedom in the design of the electrolysis cells and the cathodes is increased.

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  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)

Abstract

L'invention concerne un procédé de production d'un peroxodisulfate d'ammonium ou de métal alcalin, une cellule électrolytique dépourvue de séparateur et constituée de différents éléments, et un dispositif électrolytique constitué de plusieurs cellules électrolytiques de ce type.
PCT/EP2013/064809 2012-07-13 2013-07-12 Cellule électrolytique dépourvue de séparateur et son utilisation WO2014009536A1 (fr)

Priority Applications (6)

Application Number Priority Date Filing Date Title
PL13735335T PL2872673T3 (pl) 2012-07-13 2013-07-12 Niepodzielone ogniwo elektrolityczne i jego zastosowanie
KR1020157000758A KR20150034171A (ko) 2012-07-13 2013-07-12 무격막 전해셀 및 이의 사용 방법
US14/407,205 US9540740B2 (en) 2012-07-13 2013-07-12 Undivided electrolytic cell and use thereof
ES13735335T ES2822623T3 (es) 2012-07-13 2013-07-12 Celda de electrólisis no dividida y su uso
CN201380031764.0A CN104487615B (zh) 2012-07-13 2013-07-12 不分离的电解槽及其应用
EP13735335.5A EP2872673B1 (fr) 2012-07-13 2013-07-12 Cellule électrolytique dépourvue de séparateur et son utilisation

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EPPCT/EP2012/063783 2012-07-13
PCT/EP2012/063783 WO2013007816A2 (fr) 2011-07-14 2012-07-13 Cellule électrolytique non divisée et son utilisation

Publications (1)

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WO2014009536A1 true WO2014009536A1 (fr) 2014-01-16

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EP (1) EP2872673B1 (fr)
KR (1) KR20150034171A (fr)
TW (1) TW201406998A (fr)
WO (1) WO2014009536A1 (fr)

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3915816A (en) 1973-09-18 1975-10-28 Peroxid Chemie Gmbh Process for the electrolytic production of sodium peroxodisulfate
US3984303A (en) * 1975-07-02 1976-10-05 Diamond Shamrock Corporation Membrane electrolytic cell with concentric electrodes
DE2757861A1 (de) 1976-12-23 1978-06-29 Fmc Corp Verfahren zur herstellung von natriumperoxydisulfat
EP0428171B1 (fr) 1989-11-16 1993-09-29 Peroxid-Chemie GmbH Cellule d'électrolyse pour la production de composés peroxo et perhalogénés
DE19913820A1 (de) 1998-03-30 1999-10-07 Mitsubishi Gas Chemical Co Verfahren zur Herstellung von Persulfaten
DE19911746A1 (de) 1999-03-16 2000-09-21 Basf Ag Diamantelektroden
EP1148155B1 (fr) 2000-04-20 2005-06-08 Degussa AG Procédé de production de bisulfate peroxyde de métal alcalin et d'ammonium
WO2005054545A1 (fr) * 2003-12-04 2005-06-16 Dirk Schulze Generateur d'ozone electrochimique
WO2005121408A2 (fr) * 2004-06-05 2005-12-22 Degussa Initiators Gmbh & Co. Kg Procede pour produire des peroxodisulfates en solution aqueuse
WO2011066632A1 (fr) * 2009-12-01 2011-06-09 Universidade Estadual De Campinas - Unicamp Cellule électrochimique cylindrique avec anode coaxiale de diamant dopé obtenue par procédé de dépôt de films de diamant sur des substrats cylindriques mécaniquement résistants en vue d'une application dans des procédés de purification de solutions aqueuses

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3915816A (en) 1973-09-18 1975-10-28 Peroxid Chemie Gmbh Process for the electrolytic production of sodium peroxodisulfate
US3984303A (en) * 1975-07-02 1976-10-05 Diamond Shamrock Corporation Membrane electrolytic cell with concentric electrodes
DE2757861A1 (de) 1976-12-23 1978-06-29 Fmc Corp Verfahren zur herstellung von natriumperoxydisulfat
EP0428171B1 (fr) 1989-11-16 1993-09-29 Peroxid-Chemie GmbH Cellule d'électrolyse pour la production de composés peroxo et perhalogénés
DE19913820A1 (de) 1998-03-30 1999-10-07 Mitsubishi Gas Chemical Co Verfahren zur Herstellung von Persulfaten
DE19911746A1 (de) 1999-03-16 2000-09-21 Basf Ag Diamantelektroden
EP1148155B1 (fr) 2000-04-20 2005-06-08 Degussa AG Procédé de production de bisulfate peroxyde de métal alcalin et d'ammonium
WO2005054545A1 (fr) * 2003-12-04 2005-06-16 Dirk Schulze Generateur d'ozone electrochimique
WO2005121408A2 (fr) * 2004-06-05 2005-12-22 Degussa Initiators Gmbh & Co. Kg Procede pour produire des peroxodisulfates en solution aqueuse
WO2011066632A1 (fr) * 2009-12-01 2011-06-09 Universidade Estadual De Campinas - Unicamp Cellule électrochimique cylindrique avec anode coaxiale de diamant dopé obtenue par procédé de dépôt de films de diamant sur des substrats cylindriques mécaniquement résistants en vue d'une application dans des procédés de purification de solutions aqueuses

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
P.A. MICHAUD ET AL., ELECTRO CHEMICAL AND SOLID-STATE LETTERS, vol. 3, no. 2, 2000, pages 77 - 79
P.A. MICHAUD, ELECTROCHEMICAL AND SOLID STATE LETTERS, vol. 3, no. 2, 2000, pages 77 - 79

Also Published As

Publication number Publication date
EP2872673B1 (fr) 2020-09-09
EP2872673A1 (fr) 2015-05-20
KR20150034171A (ko) 2015-04-02
TW201406998A (zh) 2014-02-16

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