WO2022136455A1 - Electrolyser for electrochlorination processes and a self-cleaning electrochlorination system - Google Patents
Electrolyser for electrochlorination processes and a self-cleaning electrochlorination system Download PDFInfo
- Publication number
- WO2022136455A1 WO2022136455A1 PCT/EP2021/087127 EP2021087127W WO2022136455A1 WO 2022136455 A1 WO2022136455 A1 WO 2022136455A1 EP 2021087127 W EP2021087127 W EP 2021087127W WO 2022136455 A1 WO2022136455 A1 WO 2022136455A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- chlorination
- electrolyser
- pair
- ruthenium
- electrolyser according
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 20
- 238000004140 cleaning Methods 0.000 title claims abstract description 9
- 230000008569 process Effects 0.000 title description 5
- 239000011248 coating agent Substances 0.000 claims abstract description 48
- 238000000576 coating method Methods 0.000 claims abstract description 48
- 238000005660 chlorination reaction Methods 0.000 claims abstract description 33
- 239000000758 substrate Substances 0.000 claims abstract description 28
- WQYVRQLZKVEZGA-UHFFFAOYSA-N hypochlorite Chemical compound Cl[O-] WQYVRQLZKVEZGA-UHFFFAOYSA-N 0.000 claims abstract description 26
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 claims abstract description 22
- 229910052707 ruthenium Inorganic materials 0.000 claims abstract description 22
- 239000000203 mixture Substances 0.000 claims abstract description 21
- 239000010936 titanium Substances 0.000 claims abstract description 19
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims abstract description 18
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 18
- 230000003197 catalytic effect Effects 0.000 claims abstract description 15
- 238000004519 manufacturing process Methods 0.000 claims abstract description 13
- 229910052751 metal Inorganic materials 0.000 claims abstract description 13
- 239000002184 metal Substances 0.000 claims abstract description 13
- 239000012267 brine Substances 0.000 claims abstract description 12
- 239000010955 niobium Substances 0.000 claims abstract description 12
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 claims abstract description 12
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 11
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims abstract description 11
- 238000004659 sterilization and disinfection Methods 0.000 claims abstract description 11
- 229910052715 tantalum Inorganic materials 0.000 claims abstract description 11
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 claims abstract description 11
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052718 tin Inorganic materials 0.000 claims abstract description 10
- 230000001404 mediated effect Effects 0.000 claims abstract description 9
- 239000000243 solution Substances 0.000 claims description 21
- 239000003792 electrolyte Substances 0.000 claims description 10
- 239000002243 precursor Substances 0.000 claims description 8
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 5
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 4
- -1 ethoxides Chemical class 0.000 claims description 4
- 150000002739 metals Chemical class 0.000 claims description 3
- 229910001887 tin oxide Inorganic materials 0.000 claims description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 2
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 2
- 150000001242 acetic acid derivatives Chemical class 0.000 claims description 2
- 239000004411 aluminium Substances 0.000 claims description 2
- 229910052782 aluminium Inorganic materials 0.000 claims description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 2
- 229910052797 bismuth Inorganic materials 0.000 claims description 2
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 claims description 2
- 150000003842 bromide salts Chemical class 0.000 claims description 2
- 150000001805 chlorine compounds Chemical class 0.000 claims description 2
- 150000001875 compounds Chemical class 0.000 claims description 2
- 229910052802 copper Inorganic materials 0.000 claims description 2
- 239000010949 copper Substances 0.000 claims description 2
- 229910052735 hafnium Inorganic materials 0.000 claims description 2
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052738 indium Inorganic materials 0.000 claims description 2
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 claims description 2
- 150000004694 iodide salts Chemical class 0.000 claims description 2
- 150000004704 methoxides Chemical class 0.000 claims description 2
- 150000002823 nitrates Chemical class 0.000 claims description 2
- 229910052763 palladium Inorganic materials 0.000 claims description 2
- 229910052697 platinum Inorganic materials 0.000 claims description 2
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical class CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 claims description 2
- 229910052703 rhodium Inorganic materials 0.000 claims description 2
- 239000010948 rhodium Substances 0.000 claims description 2
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims description 2
- 229910052706 scandium Inorganic materials 0.000 claims description 2
- SIXSYDAISGFNSX-UHFFFAOYSA-N scandium atom Chemical compound [Sc] SIXSYDAISGFNSX-UHFFFAOYSA-N 0.000 claims description 2
- 229910052712 strontium Inorganic materials 0.000 claims description 2
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 claims description 2
- 150000003467 sulfuric acid derivatives Chemical class 0.000 claims description 2
- 238000007669 thermal treatment Methods 0.000 claims description 2
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 claims description 2
- 229910052726 zirconium Inorganic materials 0.000 claims description 2
- 239000010410 layer Substances 0.000 description 15
- 238000002360 preparation method Methods 0.000 description 6
- 239000000460 chlorine Substances 0.000 description 4
- 239000008199 coating composition Substances 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 3
- 239000005708 Sodium hypochlorite Substances 0.000 description 3
- 229910052801 chlorine Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 3
- 238000012956 testing procedure Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000032798 delamination Effects 0.000 description 2
- 239000002019 doping agent Substances 0.000 description 2
- 150000002500 ions Chemical group 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000013535 sea water Substances 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 229910001936 tantalum oxide Inorganic materials 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910052723 transition metal Inorganic materials 0.000 description 2
- 150000003624 transition metals Chemical class 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- 241000894006 Bacteria Species 0.000 description 1
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 1
- 241000233866 Fungi Species 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 101100425947 Mus musculus Tnfrsf13b gene Proteins 0.000 description 1
- 239000007832 Na2SO4 Substances 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 241000700605 Viruses Species 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000010866 blackwater Substances 0.000 description 1
- 238000005422 blasting Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000003841 chloride salts Chemical class 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000009849 deactivation Effects 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000003651 drinking water Substances 0.000 description 1
- 235000020188 drinking water Nutrition 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000010797 grey water Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 230000002906 microbiologic effect Effects 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 230000000877 morphologic effect Effects 0.000 description 1
- 229910000484 niobium oxide Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- BPUBBGLMJRNUCC-UHFFFAOYSA-N oxygen(2-);tantalum(5+) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ta+5].[Ta+5] BPUBBGLMJRNUCC-UHFFFAOYSA-N 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 229910001925 ruthenium oxide Inorganic materials 0.000 description 1
- WOCIAKWEIIZHES-UHFFFAOYSA-N ruthenium(iv) oxide Chemical compound O=[Ru]=O WOCIAKWEIIZHES-UHFFFAOYSA-N 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 230000009182 swimming Effects 0.000 description 1
- QHGNHLZPVBIIPX-UHFFFAOYSA-N tin(ii) oxide Chemical class [Sn]=O QHGNHLZPVBIIPX-UHFFFAOYSA-N 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/467—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction
- C02F1/4672—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction by electrooxydation
- C02F1/4674—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction by electrooxydation with halogen or compound of halogens, e.g. chlorine, bromine
-
- 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
- C25B1/24—Halogens or compounds thereof
- C25B1/26—Chlorine; Compounds 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
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
- C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
- C25B11/052—Electrodes comprising one or more electrocatalytic coatings on a substrate
- C25B11/053—Electrodes comprising one or more electrocatalytic coatings on a substrate characterised by multilayer electrocatalytic coatings
-
- 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
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
- C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
- C25B11/055—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the substrate or carrier material
- C25B11/057—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the substrate or carrier material consisting of a single element or compound
- C25B11/061—Metal or alloy
- C25B11/063—Valve metal, e.g. titanium
-
- 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
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
- C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
- C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
- C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
- C25B11/093—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds at least one noble metal or noble metal oxide and at least one non-noble metal oxide
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B15/00—Operating or servicing cells
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/46104—Devices therefor; Their operating or servicing
- C02F1/46109—Electrodes
- C02F2001/46119—Cleaning the electrodes
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/46104—Devices therefor; Their operating or servicing
- C02F1/46109—Electrodes
- C02F2001/46128—Bipolar electrodes
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/46104—Devices therefor; Their operating or servicing
- C02F1/46109—Electrodes
- C02F2001/46133—Electrodes characterised by the material
- C02F2001/46138—Electrodes comprising a substrate and a coating
- C02F2001/46142—Catalytic coating
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/42—Nature of the water, waste water, sewage or sludge to be treated from bathing facilities, e.g. swimming pools
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2201/00—Apparatus for treatment of water, waste water or sewage
- C02F2201/46—Apparatus for electrochemical processes
- C02F2201/461—Electrolysis apparatus
- C02F2201/46105—Details relating to the electrolytic devices
- C02F2201/4612—Controlling or monitoring
- C02F2201/46125—Electrical variables
- C02F2201/4613—Inversing polarity
Definitions
- the invention concerns a chlorination electrolyser operating under polarity reversal conditions, a method for producing the same and a self-cleaning electrochlorination system.
- Electrochlorination processes consist in the production of hypochlorite in salt water via an electrolytic reaction.
- the resulting sodium hypochlorite may be exploited in a variety of applications concerning water disinfection and oxidation, such as water treatment for drinking water, swimming pools or microbiological control in cooling towers.
- electrochlorination processes the active chemical is produced on site, thus avoiding transportation, environmental and/or storage issues.
- the process is carried out by applying a suitable current to an electrolytic cell comprising at least two electrodes and an electrolyte containing brine, i.e. a mixture of salt and water at varying concentrations depending on the application.
- brine i.e. a mixture of salt and water at varying concentrations depending on the application.
- the result of the electrochemical reaction is the production of sodium hypochlorite and hydrogen gas.
- each electrode works alternately as a cathode and as an anode, some elements occasionally used in the active coating composition become unstable and dissolve in the electrolyte after few inversion cycles, thereby leading to inadequate electrode lifetimes.
- polarity reversal is a detrimental operation for the active coating of the electrode, quickly causing its deactivation by delamination.
- bipolar electrodes used under polarity reversal conditions with much higher coating load than when each electrode is working only as an anode or cathode.
- electrode durability depends on polarity reversal frequency and on coating load.
- the present invention relates to a chlorination electrolyser comprising a housing provided with an inlet and an outlet suitable for the circulation of brine and at least one pair of bipolar electrodes facing each other and positioned within said housing.
- Each bipolar electrode comprises: (i) a valve metal substrate; (ii) an active coating comprising at least one layer of a catalytic composition comprising ruthenium and titanium disposed over said substrate; (iii) a top coating comprising at least one layer of a composition comprising oxides of tantalum, niobium, tin, or combinations thereof, and positioned over said active coating.
- the present invention relates to a self-cleaning electrochlorination system comprising: (i) the chlorination electrolyser described above; (ii) an electrolyte comprising a 1 -30 g/l NaCI brine solution circulating within said electrolyser; (iii) an electronic system for periodically reversing the polarity of the pair of bipolar electrodes electrically connected to the same and positioned outside the housing of the electrolyser.
- the present invention relates to a method for manufacturing the chlorination electrolyser according to the invention.
- the present invention relates to the use of the chlorination electrolyser described above in normal and low salinity pools for hypochlorite mediated water disinfection.
- the present invention relates to a method for hypochlorite- mediated water disinfection using the chlorination electrolyzer described above under polarity reversal conditions.
- the present invention relates to a chlorination electrolyser comprising: a housing provided with an inlet and an outlet suitable for the circulation of brine, and at least one pair of bipolar electrodes facing each other and positioned within said housing, where each bipolar electrode of said one pair comprises: (i) a valve metal substrate; (ii) an active coating comprising at least one layer of a catalytic composition comprising ruthenium and titanium disposed over said substrate; (iii) a top coating comprising at least one layer of a composition comprising oxides of tantalum, niobium, tin, or combinations thereof disposed over said active coating.
- the at least one layer of a catalytic composition comprising ruthenium and titanium is an essentially homogeneous layer in terms of its electrical properties.
- the at least one layer of a catalytic composition is also homogeneous in terms of its morphological properties and constitutes essentially a solid solution comprising ruthenium and titanium, preferably a homogeneous solid solution where the metals are predominantly oxides, i.e. ruthenium oxide and titanium oxide.
- the chlorination electrolyser according to the invention can be used for hypochlorite mediated water disinfection in a variety of applications, such as pools, waste water disinfection (such as municipal water treatment, black and gray water treatment, seawater chlorination, ... ).
- Each electrode of the pair may be coated on one or both sides.
- the two opposite electrodes should be arranged so as to have the coated sides facing each other.
- the chlorination electrolyser may comprise a plurality of bipolar electrode pairs, resulting in a stack of coated electrodes arranged substantially parallel to each other.
- the housing shall be designed so as to allow to electrically connect the bipolar electrode pair(s) to an external power generator.
- the power generator may be advantageously equipped with a system for reversing electrode polarity at a preset frequency, usually in the range of 30 min - 10 hours, depending on the application and the operative conditions, such as water contaminants and water hardness, as well known in the field.
- the valve metal substrate may be of any geometry generally used in the field, such as, but not limited to: a slab, punched sheet, mesh, louver.
- the substrate is made of titanium for its durability, cost and easy surface preparation.
- the substrate should, preferably, be cleaned, sandblasted and etched to ensure proper adhesion.
- the active coating may be disposed directly over the valve metal substrate, using roller coater, brushing, and spraying techniques.
- the claimed invention allows an intermediate coating to be interposed between the substrate and the active coating, for example to improve adhesion of the active coating. In this case, the latter shall still be considered disposed over the substrate, albeit indirectly.
- the catalytic composition of the chlorination electrolyser according to the invention comprises 25%-45% ruthenium and 55%-75% titanium expressed in weight percentage with respect to the elements.
- the catalytic composition may optionally comprise 2%-5% of doping elements selected from the group consisting of scandium, strontium, hafnium, bismuth, zirconium, aluminium, copper, rhodium, indium, platinum, palladium and their mutual combinations. These dopants may advantageously contribute to improved lifetime and free available chlorine efficiency of the chlorination electrolyser.
- an insulating top coating of tantalum, niobium or tin oxides (combined or separately) on the active coating according to any of the embodiments above allows, for a given lifetime target of the electrode, to reduce the load of Ru up to 38%, without affecting the efficiency.
- the reduction of the load of Ru provides a significant advantage because of its scarcity and thr consequent procurement and cost issues, especially in comparison with the metal oxides used in the top coating composition of the present invention.
- a top coating of tin oxide works particularly well in the execution of the invention, since Sn appears to form an oxide that allows a better diffusion of Cl’ ion to the active layer than Ta or Nb.
- the Sn top coating also forms a less cracked surface, due to its lower tendency to form dislocations, that cause the typical cracks that can be observed for example on a tantalum oxide surface.
- a less cracked surface prevents the electrolyte from dissolving the unstable portion of the active layer.
- the top coating is preferably sufficiently thin, between 0,5-7 microns, as it may contribute to preserve the free available chlorine (FAC) efficiency of the active layer.
- the active coating may have a load of ruthenium of 1 -30 g/m 2 , which may work both for applications with a salinity above 6 g/l (but preferably below 30 g/l), such as applications for seawater chlorinators, and for applications with salinity below 6 g/l, such as 0,5-4 g/l found in pools.
- the top coating has a preferred total load of 2-6 g/m 2 .
- the top coating according to the present invention forms a net rather than a barrier: it reduces the mechanical wear of the surface of the active coating due to the friction of the bubbles and retains the material partially dissolved when polarity reversal occurs, thereby preventing delamination of the coating and dissolution of ruthenium and other optional dopants in the electrolyte.
- the porosity and thinness of the top coating allow the electrolyte to reach the catalytic centers of the active coating.
- the invention relates to a self-cleaning electrochlorination system comprising: (i) the chlorinator electrolyser above described; (ii) an electrolyte comprising a 1 -30 g/l NaCI brine solution circulating within said electrolyser; (iii) an electronic system for periodically reversing the polarity of the bipolar electrodes of the electrolyser, the electronic system being preferably positioned outside the housing of the electrolyser and electrically connected to the bipolar electrodes.
- the electronic system for periodically reversing the polarity of the bipolar electrodes is equipped with an internal clock which allows to reverse the polarity of the bipolar electrodes at preset time intervals, in the range of 30 min - 10 hours.
- the inventors observed that the self-cleaning electrochlorination system according to the invention performs particularly well when the electronic system inverts the polarity of the bipolar electrode pairs at a preset interval of 1 -4 hours.
- a stack comprising 5-15 bipolar electrode pairs connected in parallel has been found to be beneficial in the execution of the invention.
- the electronic system according to the invention may advantageously operate at a current density of roughly 200-600 A/m 2 , preferably 200-400 A/m 2
- the invention relates to a method for the production of the chlorination electrolyser described hereinbefore, comprising the step of manufacturing each electrode of the at least one pair of bipolar electrodes in accordance with the following sequential passages: a) apply an active coating solution comprising precursors of ruthenium and titanium to a valve metal substrate thus obtaining a coated substrate; b) bake the coated substrate for 2-10 minutes at a temperature of 450-550°C; c) repeat steps a) and b) until achieving the desired load of ruthenium; d) apply a top coating solution comprising precursors of tantalum, niobium, tin, or combinations thereof to the coated substrate; e) bake the coated substrate for 2-10 minutes at a temperature of 450-550°C; f) repeat steps d) and e) until achieving the desired load of tantalum, niobium, tin or their combination; g) perform a final thermal treatment at a temperature in the range of 450-550°
- the precursors of ruthenium and titanium, and the precursors of tantalum, niobium or tin are compounds selected from the group consisting of methoxides, ethoxides, propoxides, butoxides, chlorides, nitrates, iodides, bromides, sulfates or acetates of the metals and mixtures thereof.
- the coated substrate may be air-dried for 2-10 minutes at a temperature of 20-80°C.
- the chlorination electrolyser according to the invention in particular in regard to the bipolar electrodes architecture, can be successfully employed in all applications for hypochlorite production that undergo polarity reversal, to reduce the noble metal load of the active coating or exhibit extended lifetimes if the same load is applied, without compromising the FAC efficiency.
- the inventors have found the chlorination electrolyser to work particularly well in pool applications, operating at a salinity of 0,5-4 g/l.
- the present invention is directed to the use of the chlorination electrolyser according to the invention in normal and low salinity pools for hypochlorite mediated water disinfection, i.e. for use in pools operating at salt levels equal or below 6 g/l (typically 0,5-2, 5 g/l NaCI in low salinity and 2,5-4 g/l NaCI in normal salinity applications).
- the present invention also concerns a method for hypochlorite-mediated water disinfection comprising the steps of a) circulating an electrolyte comprising 1-30 g/l NaCI brine solution within at least one chlorination electrolyser as defined above, said chlorination electrolyser comprising one or more bipolar electrode pairs; b) applying an electrical current onto said bipolar electrode pairs to produce hypochlorite in said NaCI brine solution; c) periodically reversing the polarity of the at least one pair of bipolar electrodes during application of said electrical current.
- the polarity of said at least one pair of bipolar electrodes is reversed at time intervals selected from a range of one minute to 20 hours, preferably from a range of 30 min to 10 hours and particularly preferred from a range of 1 to 4 hours.
- the electrical current is applied onto said at least one pair of bipolar electrodes at a current density selected from a range of 200 to 600 A/m 2 , preferably from a range of 200 to 400 A/m 2
- valve metal substrate of a pair of bipolar electrodes was manufactured starting from a titanium grade 1 plate of 100 mm x 100 mm x 1 mm size, degreased with acetone in an ultrasonic bath, and subsequently subject to blasting and full boiling HCI etching at 22% concentration.
- the catalytic solution used for the preparation of electrode samples E1 , E2a, E2b, and samples C1 -C3 was obtained by dissolving chloride salts of ruthenium and titanium in aqueous HCI at 10%, in a ratio of Ru:Ti equal to 28:72 in weight percentage referred to the elements, with a final concentration of ruthenium in each catalytic solution equal to 45 g/l.
- Sample E1 resulting from the EXPERIMENT PREPARATION was further coated with a top coating solution obtained from a Sn acetate solution diluted with acetic acid until reaching a final concentration of 40 g/l.
- the top coating solution was applied in 4 layers by brush, with a total Sn load of 4,5 g/m 2 After each layer, the sample was subsequently baked at a temperature of 500-550°C for 10 minutes.
- the sample After the last layer, the sample underwent a post-bake treatment for 3 hours at a temperature of 500-550°C.
- Sample electrode E1 was tested according to the following accelerated testing procedure: A pair of same electrode samples was placed in a housing provided with an inlet and outlet and featured an interelectrodic gap of 3 mm and containing 1 I of an aqueous solution of 4 g/l NaCI and 70 g/l Na 2 SO 4 at 25°C.
- the electrode pair was operated at a current density of 1000 A/m 2 and was subject to polarity inversion every 1 minute during the test duration. The electrode pair was kept in testing conditions until cell voltage exceeded 8,5 volt (the “Accelerated Lifetime”, measured in hours for each g/m 2 of ruthenium in the catalytic composition).
- Samples E2, i.e. E2a and E2b, resulting from the EXPERIMENT PREPARATION were both further coated with a top coating solution obtained by dissolving 80 g of TaCIs in 1 I of HCI at a 20% concentration and stirring the solution at room temperature for 30 minutes.
- the top coating solution was applied in 1 layer by brush, with a total a Ta load of 1 g/m 2
- the sample was baked first at a temperature of 300-350°C for 10 minutes and then at a temperature of 500-550°C for 10 minutes.
- Samples C i.e. C1 -C3, resulting from the EXPERIMENT PREPARATION underwent a postbake treatment for 3 hours at a temperature of 500-550°C and were tested according to the testing procedure described in EXAMPLE 1 .
Abstract
Description
Claims
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2021405486A AU2021405486A1 (en) | 2020-12-22 | 2021-12-21 | Electrolyser for electrochlorination processes and a self-cleaning electrochlorination system |
EP21839231.4A EP4267521A1 (en) | 2020-12-22 | 2021-12-21 | Electrolyser for electrochlorination processes and a self-cleaning electrochlorination system |
IL303788A IL303788A (en) | 2020-12-22 | 2021-12-21 | Electrolyser for electrochlorination processes and a self-cleaning electrochlorination system |
KR1020237025057A KR20230125009A (en) | 2020-12-22 | 2021-12-21 | Electrolyzer for electrochlorination process and self-cleaning electrochlorination system |
JP2023538786A JP2024502947A (en) | 2020-12-22 | 2021-12-21 | Electrolytic cells and self-cleaning electrochlorination systems for electrochlorination methods |
CN202180080235.4A CN116601336A (en) | 2020-12-22 | 2021-12-21 | Electrolysis device for electrolytic chlorination process and self-cleaning electrolytic chlorination system |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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IT102020000031802 | 2020-12-22 | ||
IT102020000031802A IT202000031802A1 (en) | 2020-12-22 | 2020-12-22 | ELECTROLYSER FOR ELECTROCHLORINATION PROCESSES AND A SELF-CLEANING ELECTROCHLORINATION SYSTEM |
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WO2022136455A1 true WO2022136455A1 (en) | 2022-06-30 |
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PCT/EP2021/087127 WO2022136455A1 (en) | 2020-12-22 | 2021-12-21 | Electrolyser for electrochlorination processes and a self-cleaning electrochlorination system |
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EP (1) | EP4267521A1 (en) |
JP (1) | JP2024502947A (en) |
KR (1) | KR20230125009A (en) |
CN (1) | CN116601336A (en) |
AU (1) | AU2021405486A1 (en) |
IL (1) | IL303788A (en) |
IT (1) | IT202000031802A1 (en) |
TW (1) | TW202225486A (en) |
WO (1) | WO2022136455A1 (en) |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3917518A (en) * | 1973-04-19 | 1975-11-04 | Diamond Shamrock Corp | Hypochlorite production |
US4118307A (en) * | 1977-02-14 | 1978-10-03 | Diamond Shamrock Corporation | Batch sodium hypochlorite generator |
US6007693A (en) * | 1995-03-30 | 1999-12-28 | Bioquest | Spa halogen generator and method of operating |
US20060042937A1 (en) * | 2004-08-31 | 2006-03-02 | Kazuhiro Kaneda | Electrode for electrolysis and method of manufacturing electrode for electrolysis |
WO2019215944A1 (en) | 2018-05-07 | 2019-11-14 | パナソニックIpマネジメント株式会社 | Electrode for electrolysis use, and electric device and ozone generating device each provided with same |
-
2020
- 2020-12-22 IT IT102020000031802A patent/IT202000031802A1/en unknown
-
2021
- 2021-12-21 KR KR1020237025057A patent/KR20230125009A/en unknown
- 2021-12-21 CN CN202180080235.4A patent/CN116601336A/en active Pending
- 2021-12-21 AU AU2021405486A patent/AU2021405486A1/en active Pending
- 2021-12-21 WO PCT/EP2021/087127 patent/WO2022136455A1/en active Application Filing
- 2021-12-21 TW TW110147811A patent/TW202225486A/en unknown
- 2021-12-21 EP EP21839231.4A patent/EP4267521A1/en active Pending
- 2021-12-21 IL IL303788A patent/IL303788A/en unknown
- 2021-12-21 JP JP2023538786A patent/JP2024502947A/en active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3917518A (en) * | 1973-04-19 | 1975-11-04 | Diamond Shamrock Corp | Hypochlorite production |
US4118307A (en) * | 1977-02-14 | 1978-10-03 | Diamond Shamrock Corporation | Batch sodium hypochlorite generator |
US6007693A (en) * | 1995-03-30 | 1999-12-28 | Bioquest | Spa halogen generator and method of operating |
US20060042937A1 (en) * | 2004-08-31 | 2006-03-02 | Kazuhiro Kaneda | Electrode for electrolysis and method of manufacturing electrode for electrolysis |
WO2019215944A1 (en) | 2018-05-07 | 2019-11-14 | パナソニックIpマネジメント株式会社 | Electrode for electrolysis use, and electric device and ozone generating device each provided with same |
Also Published As
Publication number | Publication date |
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IL303788A (en) | 2023-08-01 |
TW202225486A (en) | 2022-07-01 |
CN116601336A (en) | 2023-08-15 |
AU2021405486A1 (en) | 2023-07-20 |
JP2024502947A (en) | 2024-01-24 |
IT202000031802A1 (en) | 2022-06-22 |
KR20230125009A (en) | 2023-08-28 |
EP4267521A1 (en) | 2023-11-01 |
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