EP4143130A1 - Solutions aqueuses de dioxyde de chlore et méthode de préparation associée - Google Patents

Solutions aqueuses de dioxyde de chlore et méthode de préparation associée

Info

Publication number
EP4143130A1
EP4143130A1 EP21722186.0A EP21722186A EP4143130A1 EP 4143130 A1 EP4143130 A1 EP 4143130A1 EP 21722186 A EP21722186 A EP 21722186A EP 4143130 A1 EP4143130 A1 EP 4143130A1
Authority
EP
European Patent Office
Prior art keywords
chlorine dioxide
solution
aqueous
chlorine
sodium
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.)
Withdrawn
Application number
EP21722186.0A
Other languages
German (de)
English (en)
Inventor
Sebastian Oberwalder
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alethia Life Sciences Ag
Original Assignee
Alethia Life Sciences Ag
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.)
Filing date
Publication date
Priority claimed from DE102020111417.6A external-priority patent/DE102020111417A1/de
Application filed by Alethia Life Sciences Ag filed Critical Alethia Life Sciences Ag
Publication of EP4143130A1 publication Critical patent/EP4143130A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B11/00—Oxides or oxyacids of halogens; Salts thereof
    • C01B11/02—Oxides of chlorine
    • C01B11/022—Chlorine dioxide (ClO2)
    • C01B11/028—Separation; Purification
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B11/00—Oxides or oxyacids of halogens; Salts thereof
    • C01B11/02—Oxides of chlorine
    • C01B11/022—Chlorine dioxide (ClO2)
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B11/00—Oxides or oxyacids of halogens; Salts thereof
    • C01B11/02—Oxides of chlorine
    • C01B11/022—Chlorine dioxide (ClO2)
    • C01B11/023—Preparation from chlorites or chlorates
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B11/00—Oxides or oxyacids of halogens; Salts thereof
    • C01B11/02—Oxides of chlorine
    • C01B11/022—Chlorine dioxide (ClO2)
    • C01B11/023—Preparation from chlorites or chlorates
    • C01B11/024—Preparation from chlorites or chlorates from chlorites
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B11/00—Oxides or oxyacids of halogens; Salts thereof
    • C01B11/02—Oxides of chlorine
    • C01B11/022—Chlorine dioxide (ClO2)
    • C01B11/023—Preparation from chlorites or chlorates
    • C01B11/026—Preparation from chlorites or chlorates from chlorate ions in the presence of a peroxidic compound, e.g. hydrogen peroxide, ozone, peroxysulfates
    • 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
    • C02F1/50—Treatment of water, waste water, or sewage by addition or application of a germicide or by oligodynamic treatment
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2210/00—Purification or separation of specific gases
    • C01B2210/0001—Separation or purification processing
    • C01B2210/0003—Chemical processing
    • 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
    • C02F1/72—Treatment of water, waste water, or sewage by oxidation
    • C02F1/76—Treatment of water, waste water, or sewage by oxidation with halogens or compounds of halogens
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2303/00—Specific treatment goals
    • C02F2303/04—Disinfection

Definitions

  • the present invention relates to aqueous chlorine dioxide-containing solutions, in particular high-purity aqueous chlorine dioxide solutions which can be used, for example, in the field of human and veterinary medicine for disinfecting surfaces, devices and instruments, as well as a method for producing such aqueous chlorine dioxide solutions.
  • the present invention provides a method for preparing an aqueous chlorine dioxide solution, in which a previously prepared aqueous chlorine dioxide solution is treated so that a high-purity aqueous chlorine dioxide solution is obtained.
  • the method according to the invention can be applied to all previously prepared aqueous chlorine dioxide solutions, regardless of the method with which the previously prepared aqueous chlorine dioxide solution has been prepared.
  • aqueous chlorine dioxide solutions can be produced far more simply and cost-effectively from previously produced aqueous chlorine dioxide solutions. It has surprisingly been found that the aqueous chlorine dioxide solutions obtainable with the process according to the invention have a high purity and a surprisingly high stability.
  • Chlorine dioxide and aqueous chlorine dioxide solutions have long been known as very effective bleaching and disinfecting agents and are used on a large scale, for example, as bleaching agents for pulp bleaching (e.g. in paper production) and as disinfectants for disinfecting drinking water. Due to known problems in the production and storage of chlorine dioxide and aqueous solutions containing it (risk of explosion!), The technical production of chlorine dioxide usually takes place immediately before use from chlorate (CIO3) or chlorite (CIO 2 ), or the corresponding salts thereof, such as the corresponding alkali salts (e.g. sodium chlorate and sodium chlorite).
  • chlorate CIO3
  • chlorite CIO 2
  • the corresponding salts thereof such as the corresponding alkali salts (e.g. sodium chlorate and sodium chlorite).
  • Chlorates especially sodium chlorate, are used as an inexpensive starting material for the production of bleaches on an industrial scale, for example sulfur dioxide (Mathieson process) or hydrochloric acid or methanol (Solvay process) being used for chlorate reduction.
  • chlorine dioxide is produced from more expensive chlorite, such as sodium chlorite, whereby for chlorite oxidation, for example, chlorine (chlorine- Chlorite process), a suitable acid (acid-chlorite process), such as hydrochloric acid (hydrochloric acid-chlorite process) or a suitable oxidizing agent, such as peroxodisulfate (peroxodisulfate-chlorite process) or electric current (chlorite electrolysis process ) be used.
  • chlorite oxidation for example, chlorine (chlorine- Chlorite process), a suitable acid (acid-chlorite process), such as hydrochloric acid (hydrochloric acid-chlorite process) or a suitable oxidizing agent, such as peroxodisulfate (peroxodisulfate-chlorite process) or electric current (chlorite electrolysis process ) be used.
  • aqueous chlorine dioxide solutions are also used in human and veterinary medicine as well as general hygiene, such as for the disinfection of surfaces, devices, instruments and the like in doctor's offices, hospitals, laboratories, vehicles, etc. Especially for such applications in the field of medicine, it is necessary that the aqueous chlorine dioxide solutions used are as free as possible of impurities and have sufficient storage stability, which enable appropriate storage and logistics. Due to the distribution channels via wholesalers and retailers as well as intermediate storage or stock keeping at the end consumer, storage stability of 18 to 24 months is a basic economic prerequisite.
  • a product that can be realized from an economic point of view particularly requires long-term and stable storage in commercially available packaging without any special additional effort, such as the need for a continuous cold chain or the like.
  • a high degree of purity of the chlorine dioxide solutions is required in order to avoid undesirable reactions with surfaces to be treated (e.g. corrosion, etc.) or with organic materials present on them (e.g. formation of toxic chlorinated organic compounds, etc.) .ä.), as well as to avoid the possible formation of harmful residues.
  • the aim is to reduce potentially harmful impurities.
  • toxic and environmentally harmful impurities should be avoided as completely as possible.
  • the permissible limit value and thus also the permissible manufacturing method are significantly influenced by the (expected) residue of chlorates.
  • the methods permitted for drinking water disinfection and the substances to be used in them are specified in detail.
  • the environmental compatibility of chlorine dioxide products depends to a considerable extent on the chlorine they contain, since chlorine, for example, can also react with organic compounds to form toxic or otherwise environmentally harmful chlorinated organic compounds.
  • GB 760,303 A describes a process for producing aqueous chlorine dioxide solutions, in which gaseous chlorine dioxide produced in a reaction zone is enriched in an inert gas flow and the gas flow is then passed into water in order to produce an aqueous chlorine dioxide solution.
  • the disadvantage of this process is that undesired gases which are used or are created in the production of the gaseous chlorine dioxide, such as chlorine and / or sulfur dioxide, are also introduced into the chlorine dioxide solution produced and are enriched there.
  • a chlorine dioxide solution produced by this process therefore contains undesired gases, in particular chlorine.
  • US 2010/0209528 A1 describes a method for producing aqueous chlorine dioxide solutions in which dilute chlorine gas is passed through a bed of essentially solid sodium chlorite and then introduced into water in order to produce chlorine dioxide solutions which contain little sodium chloride.
  • sodium chloride has a negative effect on the stability of aqueous chlorine dioxide solutions.
  • the chlorites required for the process are relatively expensive and the chlorine dioxide solutions produced contain chlorine gas, which not only accelerates the decomposition of chlorine dioxide, but can also react with organic compounds to form toxic chlorinated organic compounds.
  • the use of chlorine gas necessitates considerable safety precautions, which in (large-scale) practice necessitates expensive equipment.
  • WO 2019/180049 A1 describes a method for producing aqueous chlorine dioxide solutions in which chlorine dioxide is produced from chlorites using a method known from drinking water disinfection and is introduced into water via an inert gas stream in order to produce an aqueous chlorine dioxide solution.
  • suitable chlorine-free oxidizing agents such as, for example, peroxodisulfate
  • this process can be used to produce aqueous chlorine dioxide solutions that contain little chlorine and salts.
  • this requires relatively expensive chlorite as the starting product, as well as larger quantities of process chemicals and extremely complex equipment.
  • the inventor of the present invention has found that storable aqueous chlorine dioxide solutions can be produced inexpensively on a large scale if existing chlorine dioxide solutions - regardless of their original production method - are treated in such a way that a highly pure aqueous chlorine dioxide solution is obtained.
  • an aqueous chlorine dioxide solution is particularly stable and therefore storable if particularly impurities in the form of salts and reactive gases are reduced as far as possible in the process, so that the solution has a high degree of purity. It is believed that such impurities accelerate the decomposition of the dissolved chlorine dioxide.
  • Aqueous chlorine dioxide solutions produced according to the present invention have a good shelf life of 18 to 24 months even without cooling.
  • the present invention thus provides a fundamental solution to the problem of producing high-purity chlorine dioxide solutions by providing a general process for the purification of (already present) chlorine dioxide solutions which, regardless of the original production method, is an even further improved, purer one Final product supplies.
  • the present invention takes the path of first removing the interfering gases by reaction (e.g. by reducing them to ionic compounds) or preventing their formation through intermittent decomposition of the chlorine dioxide or other impurities, regardless of the starting product, and then desalinating the intermediate product obtained.
  • reaction e.g. by reducing them to ionic compounds
  • this above offers considerable economic advantages.
  • the present invention provides a method of making a purified aqueous solution of chlorine dioxide.
  • the method according to the invention comprises the following steps:
  • HCIO hypochlorous acid
  • HCIO3 chloric acid
  • SO2 sulfur dioxide
  • the method according to the invention can be used according to the invention for treating (cleaning) aqueous chlorine dioxide solutions of any origin - regardless of the original production method of the first aqueous chlorine dioxide solution provided in step (1).
  • chlorite-based processes or indirect processes
  • Chlorite process via electrolysis can be used, but also the much cheaper chlorate-based processes.
  • the large-scale plants already available in the paper industry can be used to produce the first aqueous chlorine dioxide solution provided in step (1).
  • the first chlorine dioxide solution can be obtained by reacting a chlorate salt with sulfur dioxide (Mathieson method), by reacting a chlorate salt with hydrochloric acid or methanol (Solvay method), by reacting a chlorite Salt with an acid (acid-chlorite process or acid-hypochlorite-chlorite process), for example hydrochloric acid (hydrochloric acid-chlorite process), by reaction of a chlorite salt with chlorine (chlorine-chlorite process), by reaction from a chlorite salt with sodium peroxodisulfate (peroxodisulfate-chlorite process) or by electrochemical processes (e.g. chlorite electrolysis process or chlorite electrolysis process).
  • the first chlorine dioxide solution is preferably produced from a chlorate salt, particularly preferably sodium chlorate.
  • the first aqueous chlorine dioxide solution can be provided in step (1) either with a certain volume or continuously.
  • the first chlorine dioxide solution provided in step (1) can be connected via a suitable siphon to a primary production device for chlorine dioxide, so that continuously post-produced chlorine dioxide solution is available as a source for the process according to the invention, which can then be carried out continuously.
  • an aqueous chlorine dioxide solution (sometimes also referred to as an aqueous solution of chlorine dioxide) is a composition which is based on water as a solvent and which comprises chlorine dioxide in dissolved form.
  • this first chlorine dioxide solution comprises not only chlorine dioxide but also unreacted starting materials, further reaction products (by-products) and / or decomposition products, such as dissolved ones Chlorite ions, hypochlorite ions, chlorate ions, chloride ions, peroxodisulfate ions, chlorine gas, sulfur dioxide, etc.
  • the first aqueous chlorine dioxide solution which is provided in step (1) preferably comprises chlorine dioxide in a concentration of 2000 to 6500 ppm (unless stated further, the specification ppm refers to parts by weight), more preferably from 4000 to 5500 ppm, and particularly preferably from about 5000 ppm.
  • step (2) of the method according to the invention proportions of undesired reactive gases from the chlorine dioxide solution are reduced, undesired gases are preferably removed from the chlorine dioxide solution, in particular the reactive gases chlorine (CL) and / or hypochlorous acid (HCIO) and / or Chloric acid (HCIO3) and / or sulfur dioxide (SO2), particularly preferably chlorine and / or sulfur dioxide, which were used in the production of the first chlorine dioxide solution provided in step (1) or can arise therein.
  • a suitable chlorine dioxide-stable reactant is added to the first chlorine dioxide solution provided in step (1), with which such reactive gases can be reduced, preferably removed, from the solution.
  • the expression "removal of undesired gases” is used to denote a chemical reaction by which a gas dissolved in the aqueous solution is chemically bound in such a way that it can no longer escape from the solution in gaseous form.
  • a dissolved gas is chemically bound by reacting with the reagent to form corresponding dissolved ionic compounds.
  • a gas can be oxidized or reduced, or converted into a larger (ionic) molecule through an addition reaction.
  • adding the reagent to reduce the proportion of undesired gases, preferably to remove undesired gases, and the subsequent reaction with the dissolved gas, it is prevented that a gas can escape from the solution.
  • the inventive reduction, preferably removal or chemical conversion of the interfering gases by reaction with the reagent in the aqueous solution has the advantage over other methods based, for example, on reactions in the gas phase, that a rapid reduction, preferably rapid and complete removal of the unwanted gases from the aqueous solution takes place under controlled reaction conditions.
  • Hydrogen peroxide and carbonates, bicarbonates, chlorites and hydroxides are suitable as a reagent for reducing the proportion of undesired gases, preferably for removing undesired gases.
  • sodium carbonate is very particularly preferably used as the reagent for removing undesired salts, preferably in the form of buffered sodium carbonate.
  • the reagent added in step (2) for removing undesired gases can also contain two or more suitable reagents, preferably two or more of the reagents listed above.
  • mixtures comprising sodium carbonate and sodium bicarbonate for example, mixtures comprising sodium carbonate and sodium chlorite, or mixtures comprising sodium carbonate and hydrogen peroxide are preferred.
  • a mixture can be added in step (2) which comprises sodium carbonate and sodium bicarbonate in a suitable ratio.
  • the reagent used in step (2) to reduce the proportion of unwanted gases, preferably to remove unwanted gases, is preferably added in a suitable (aqueous) solution, but can also be added in solid form (e.g. in salt form).
  • aqueous solution the dosage is both easier and the reaction faster or less or no additional mixing is required.
  • an aqueous solution can preferably be added which comprises one, two or more of the reagents listed above.
  • Preferred examples are an aqueous solution comprising sodium carbonate, or an aqueous solution comprising a mixture of sodium carbonate and sodium chlorite, a mixture of sodium carbonate and hydrogen peroxide, or a mixture of sodium carbonate and sodium bicarbonate.
  • the reagent is preferably added to reduce, preferably remove, undesired gases in amounts which are sufficient to reduce, preferably remove, all of the gases present in the first chlorine dioxide solution.
  • the reagent is added in excess, preferably in a molar ratio of reagent to chlorine of 1.1: 1 to 5: 1, preferably 1.5: 1 to 2: 1.
  • the reagent is added in a molar ratio of reagent to chlorine dioxide of 0.1: 1 to 2: 1, preferably in a molar ratio of 0.5: 1 to 1.5: 1, depending on the manufacturing process.
  • Aqueous chlorine dioxide solutions that have been produced according to more recent processes or processes known as “cleaner” in the state of the art require a smaller amount of reagent than those from older processes or processes known as less “clean”.
  • the pH of the first solution provided in step (1) is adjusted to a slightly acidic to neutral pH of 4.0 to 7.5 adjusted, particularly preferably to a neutral pH, preferably in the range from 6.5 to 7.5.
  • the neutral pH value is more preferably a pH value in the range from 6.8 to 7.2 and the neutral pH value is particularly preferably approximately 7.0.
  • the neutral pH is preferably stabilized by adding a buffer system. Suitable buffer systems and methods for establishing a neutral pH are known in the art. That is preferred Buffer system selected from a carbonate buffer system, a phosphate buffer system and a peroxodisulfate buffer system. When hydrogen peroxide and chlorites are added, the pH of the first solution is preferably not adjusted to a neutral value.
  • step (1) By setting a neutral pH value for the first aqueous chlorine dioxide solution provided in step (1), the new formation of undesired gases, in particular chlorine gas, through any acid or base-mediated reactions (such as the decomposition of chlorine dioxide) is effectively prevented .
  • the pH of the first solution provided in step (1) can be adjusted by adding the reagent to the Removal of unwanted gases in step 2) can be set to a neutral value.
  • This special embodiment of the method according to the invention can be used in particular when the first chlorine dioxide solution provided in step (1) is an acidic solution (pH ⁇ 6.5). Since all known manufacturing processes for chlorine dioxide take place in the acidic range, an acidic solution will usually be present.
  • step (3) of the process according to the invention the chlorine dioxide is then separated off from the chlorine dioxide solution which has been purified from undesired gases in step (2).
  • the chlorine dioxide can be separated off from the chlorine dioxide solution which has been purified from undesired gases in step (2) using any method known in the art.
  • the chlorine dioxide is preferably separated from the aqueous solution in step 3) in the gaseous state, for example by contacting a carrier gas stream (so-called "stripping" process) or by distilling under reduced pressure (so-called "sub-boiling” distillation) .
  • the chlorine dioxide solution which has been purified from undesired gases in step (2) is mixed with a suitable one Carrier gas brought into contact.
  • the carrier gas can, for example, be passed over the surface of the chlorine dioxide solution or blown through the chlorine dioxide solution using suitable nozzles in order to enrich the chlorine dioxide more quickly in the carrier gas.
  • the carrier gas enriched with chlorine dioxide is then separated from the remaining aqueous solution using suitable lines, pumps, etc.
  • the carrier gas used is preferably a carrier gas that is inert to chlorine dioxide, such as, for example, air, nitrogen, carbon dioxide, oxygen, a noble gas such as, for example, argon, and mixtures thereof.
  • the carrier gas is preferably selected from nitrogen, carbon dioxide and argon.
  • the preferred flow rate of carrier gas is related to the amount of chlorine dioxide solution.
  • the carrier gas is preferably blown at a flow rate of 0.01 to 1% of the volume of the chlorine dioxide solution per minute over the surface of the chlorine dioxide solution cleaned of undesired gases in step (2) or at a flow rate of 0.1% to 10% of the volume of the chlorine dioxide solution per minute blown through the chlorine dioxide solution cleaned of undesired gases in step (2).
  • the flow rate of an air stream is 1 to 100 liters per minute, preferably 5 to 10 liters per minute.
  • the chlorine dioxide is separated from the chlorine dioxide solution which has been purified from undesired gases in step (2) by distillation under reduced pressure (so-called "sub-boiling" distillation).
  • the process according to the invention enables sensible distillation by first removing all interfering gases from the chlorine dioxide-containing solution in step (2).
  • the inventor of the present invention has found that a distillation of chlorine dioxide from an aqueous solution can be carried out safely if the distillation temperature is reduced to well below 45 ° C. by lowering the pressure. Under correspondingly reduced pressure conditions, chlorine dioxide can thus be separated from the chlorine dioxide solution, which has been purified from undesired gases in step (2), by distillation under reduced pressure, without product decomposition or explosion.
  • the pressure is preferably reduced to such an extent that the distillation takes place at a temperature of 35.degree or less, more preferably at room temperature (for example a temperature of 20 to 25 ° C.) or a temperature of 20 ° C. or 25 ° C. (standard room temperature).
  • room temperature for example a temperature of 20 to 25 ° C.
  • 20 ° C. or 25 ° C. standard room temperature.
  • a temperature-pressure combination is selected at which the water does not yet boil, for example more than 30 mbar at 20 ° C or more than 40 mbar at 25 ° C.
  • a temperature-pressure combination is selected to increase process reliability at which the water also boils, for example 23 mbar at 20 ° C or 32 mbar at 25 ° C. More preferably, the boiling point of the water has not yet been reached, so that there is no significant bubble formation with even higher impurities caused by this, for example 24 mbar at 20 ° C. or 33 mbar at 25 ° C. Due to the (almost) boiling of the water, certain impurities are accepted, on the other hand, the water-chlorine dioxide mixture ensures that the chlorine dioxide concentration does not exceed 10% at any time and therefore that there is no theoretical risk of explosion at any time. Since in this embodiment a significantly larger amount of distillate arrives in the collecting container due to the distilled water, a greater temperature difference between the output container and the collecting container and / or cooling of the collecting container is desirable in this embodiment.
  • distillation steps can take place one after the other, the distillation can be carried out via a cascade of several water containers or the distillation can be repeated one or more times.
  • a distillation is carried out under reduced pressure in combination with a stream of carrier gas being blown through the chlorine dioxide solution which has been purified from undesired gases in step (2).
  • additional (chemical) filters can preferably be used to increase the purity in the distillation stream between the containers, such as, in particular, solid NaCl0 2 as a chemical chlorine filter or chlorine dioxide-resistant particle filter as Salt filters, for example HEPA / ULPA filters made of PTFE.
  • the chlorine dioxide separated off in step (3) is redissolved in water in step (4) to produce a purified second aqueous chlorine dioxide solution.
  • the water in which the chlorine dioxide separated off in step (3) is dissolved is preferably pure water, for example distilled water or water completely desalinated by osmosis (deionized water).
  • the pH of the water can be adjusted to a neutral value (preferably a pH of 6.5 to 7.5, more preferably from 6.8 to 7.2, and particularly preferably about 7.0) with a suitable buffer system (preferably a carbonate, phosphate or peroxodisulfate buffer system).
  • a suitable buffer system preferably a carbonate, phosphate or peroxodisulfate buffer system.
  • the second aqueous chlorine dioxide solution produced contains not only water and chlorine dioxide but also the respective buffer system.
  • the second aqueous chlorine dioxide solution produced can also comprise one or more suitable, chlorine dioxide-stable surfactants.
  • Suitable surfactants or surfactant combinations include, for example, quaternary ammonium compounds and / or non-ionic surfactants, preferably carboxylic acid esters and / or phosphate esters, such as, in particular, ethoxylated aliphatic phosphate esters or phosphate diesters and / or ethoxylated carboxylic acid esters, preferably aliphatic carboxylic acid esters and / or alkyl ethers Phosphates, as well as ethoxylated fatty alcohols, ethoxylated fatty amines, ethoxylated alkylphenols, and / or ethoxylated fatty acids.
  • a chlorine dioxide solution according to the invention preferably contains a surfactant or a surfactant combination in a concentration of 10% by weight or less, more preferably in a concentration of 5% by weight or less, and particularly preferably in a concentration of 1% by weight. % Or less.
  • the surfactant is contained in the aqueous collecting solution from the start, since it promotes the absorption of the chlorine dioxide gas or minimizes its renewed stripping by the gas flow from the collecting container to the vacuum pump or to the gas outlet.
  • the water in which the chlorine dioxide separated off in step (3) is dissolved is cooled to a temperature of less than 20 ° C., preferably to a temperature of less than 10 ° C. and preferably kept there
  • the carrier gas / chlorine dioxide mixture can preferably be injected into the (preferably cooled) water can be introduced and distributed in order to dissolve the chlorine dioxide more quickly in the water.
  • Devices and methods suitable for this are known, for example, from GB 760,303 A and WO 2019/180049 A1.
  • the chlorine dioxide can be passed directly into the (preferably cooled, e.g. to 10 ° C or less) water for condensation and thus dissolved therein.
  • the distillation process represents a particularly preferred embodiment of the process according to the invention, since it offers the further advantage over the likewise possible carrier gas flow process, for example, that no gas flow has to be passed through the water.
  • a flow through the manufactured product is always associated with the risk that the outflowing carrier gas flow in turn entrains chlorine dioxide from the product solution and thus leads to a reduced chlorine dioxide concentration in the product and the associated losses and costs.
  • the chlorine dioxide separated off in step (3) (for example the sub-boiling distillate or the stripping chlorine dioxide carrier gas stream) is cooled to a temperature of less than 11 ° C., preferably to less than 0 ° C., and particularly preferably to -8 to -30 ° C.
  • the temperature should preferably always be higher than the boiling or condensation temperature of chlorine (Cb) at the respective pressure (for example, at normal pressure always higher than -34.03 ° C., the boiling point of chlorine under normal pressure).
  • the cooling is preferably carried out via suitable cooled surfaces, such as, for example, suitable cooling tubes, cooling spirals, cooling coils, and the like.
  • Cooling can preferably take place, for example, with the aid of commercially available cooling devices, such as a circulating cooler or a cryostat device (such as model RC5 from IKA), which are operated as a cheap source of cold with a suitable cooling medium (e.g. ethanol in water 50% v / v) can be.
  • a suitable cooling medium e.g. ethanol in water 50% v / v
  • Such a cooling of the separated chlorine dioxide or chlorine dioxide-carrier gas mixture leads to condensation of the chlorine dioxide contained and, if applicable, of the water contained in the distillate or air stream, but not of any residual chlorine (Cb) content, which leads to further dechlorination of the product can be achieved by fractional condensation or sublimation.
  • the pure chlorine dioxide condenses, while the water content (including any salts it may contain) freezes on the surface of the cooling device unit carrying the cooling medium (e.g. cooling coil in the Graham cooler) and in this way is withdrawn from the distillate.
  • the temperature is likewise preferably above -34.03 ° C. in order to avoid temperatures being reached at which the residual chlorine possibly contained in the distillate or air stream also condenses.
  • the frozen water content can after completion of the distillation or stripping Process or through periodic cleaning intervals with an increase in the temperature in the cooling circuit and removed from the system.
  • the cooling process preferably takes place at a very low flow rate of the distillate or the stripping carrier gas stream (flow rate of 0.01 to 1% of the volume of the chlorine dioxide solution per minute) in order to achieve the most complete possible condensation of the chlorine dioxide.
  • the chlorine dioxide separated off in step (3) e.g. the sub-boiling distillate or the stripping chlorine dioxide carrier gas stream
  • the cooling unit or the cooling units preferably forms a gradient at the end of which the condensed chlorine dioxide can easily be separated off.
  • the pure chlorine dioxide separated out in this way can either be converted directly into a suitable solvent, such as preferably pure (distilled or fully demineralized) water, or it can be processed further as a pure substance.
  • a first aqueous chlorine dioxide solution is provided in a first step, which was prepared from chlorate, for example by reacting sodium chlorate with hydrochloric acid.
  • the pH of this first aqueous chlorine dioxide solution is adjusted to a neutral value in the range from 6.5 to 7.5 and sodium carbonate is added in order to remove dissolved chlorine gas from the solution or to bind it chemically.
  • the chlorine dioxide is distilled off under reduced pressure and dissolved in (pure) water to produce a purified second aqueous chlorine dioxide solution.
  • the present invention provides a method for producing a high-purity aqueous chlorine dioxide solution, in which existing large-scale plants and methods can be used to produce an inexpensive first aqueous chlorine dioxide solution in large quantities, which is then purified by the method according to the invention that it is suitable, for example, for applications in the medical field.
  • the costs can be reduced by 75 to 90% compared to other processes.
  • the method according to the invention does not require the use of hazardous chemicals, such as chlorine gas or the like, which makes it easier to carry out and reduces costs compared to other methods.
  • the inventive removal of the interfering gases by reaction in aqueous solution has the advantage over other methods based, for example, on reactions in the gas phase, that the undesired gases can be removed quickly and completely controllable reaction conditions takes place.
  • the process according to the invention thus reliably produces chlorine-free chlorine dioxide solutions which are suitable, for example, for applications in the medical field.
  • the separation of the chlorine dioxide from the aqueous solution previously purified from undesired gases, in particular chlorine and sulfur dioxide, which is particularly preferably carried out by distillation under reduced pressure, and the subsequent dissolution in (pure) water reliably leads to an aqueous chlorine dioxide solution, which does not contain unwanted salts.
  • Chlorates for example, are undesirable because limit values for the use of chlorine dioxide are often determined by the chlorate content.
  • the content of cations, such as sodium ions, and anions, such as chloride ions, is also advantageously low.
  • the total content of impurities in the aqueous chlorine dioxide solution produced by the process according to the invention is preferably less than 1000 ppm, more preferably less than 500 ppm, more preferably less than 100 ppm, more preferably less than 50 ppm, and particularly preferably less than 10 ppm .
  • an aqueous chlorine dioxide solution produced according to the invention has a chlorine dioxide concentration of at least 100 ppm.
  • a chlorine dioxide solution can be used directly without a concentrate having to be prepared and diluted beforehand.
  • the present invention also enables the manufacture of concentrates.
  • Concentrates preferably have a chlorine dioxide concentration of at least 1500 ppm, more preferably of at least 2000 ppm.
  • the total content of all impurities (gases and salts) is preferably less than 1000 ppm, more preferably less than 100 ppm, more preferably less than 10 ppm.
  • both the chlorine content and the chlorate content and the sodium content and the calcium content are each less than 100, more preferably less than 1 ppm, and particularly preferably the total chlorine content is chlorate , Calcium, magnesium and sodium less than 100, preferably less than 10 ppm.
  • the total content of chlorine, chlorate and sodium is preferably less than 100, preferably less than 5 ppm, more preferably less than 1 ppm.
  • an aqueous chlorine dioxide solution produced according to the invention has a conductance of less than 25 pS / cm (microsiemens), particularly preferably less than 10 pS / cm, more preferably less than 2 pS / cm.
  • the conductance of the aqueous chlorine dioxide solution can be measured, for example, using suitable laboratory equipment such as, for example, Seven Go Duo ph / lon / Cond meter SG 78-USP-K from Mettler Toledo.
  • a chlorine dioxide solution prepared according to the invention preferably retains more than 90% of the original concentration of chlorine dioxide for at least 18 months when stored at room temperature (15 to 25 ° C.). In particular, a chlorine dioxide solution prepared according to the invention retains more than 95% of the original concentration of chlorine dioxide when stored at room temperature (15 to 25 ° C.) for at least 24 months.
  • the inventively produced chlorine dioxide solutions are preferably packaged in suitable containers, for example in glass bottles with (poly) fluoroelastomers or PVC coated closures or caps, made of or containing (poly) fluoroelastomers, such as in particular PTFE, PEEK, Viton ®, or a PTFE-polymer mixture.
  • suitable containers for example in glass bottles with (poly) fluoroelastomers or PVC coated closures or caps, made of or containing (poly) fluoroelastomers, such as in particular PTFE, PEEK, Viton ®, or a PTFE-polymer mixture.
  • plastic bottles made from the polymers mentioned can also be used.
  • Packaging preferably offers protection against light radiation and other external influences, such as rapid temperature fluctuations, shocks or the like.
  • a packaging can be an opaque container (for example a dark glass bottle or the like).
  • the chlorine dioxide solutions produced according to the invention are packaged in shipping units of 4 or 6 glass bottles in a suitably
  • the present invention additionally also provides a disinfectant based on the chlorine dioxide solution prepared according to the invention.
  • a disinfectant based on the chlorine dioxide solution prepared according to the invention.
  • This is produced by adding at least one suitable, chlorine dioxide-stable surfactant to the chlorine dioxide solution prepared according to the invention, such as a quaternary ammonium compound and / or a non-ionic surfactant, preferably carboxylic acid esters and / or phosphate esters such as, in particular, ethoxylated aliphatic phosphate esters or Phosphate diesters and / or ethoxylated carboxylic acid esters, preferably aliphatic carboxylic acid esters and / or alkyl ether phosphates, as well as ethoxylated fatty alcohols, ethoxylated fatty amines, ethoxylated alkylphenols, and / or ethoxylated fatty acids.
  • a surfactant or a surfactant combination is preferably added to the chlorine dioxide solution according to the invention in a concentration of 10% by weight or less, more preferably in a concentration of 5% by weight or less, and particularly preferably in a concentration of 1% by weight. -% Or less.
  • the chlorine dioxide solutions produced by the process according to the invention are preferably used for surface disinfection and as medical products and in human and veterinary medicine. When used on surfaces, hardly any or only negligible residues are left behind. Finally, when used medicinally, it offers be it as a drug or as a medical product, there are significant advantages, as no impurities can influence the effect, which means that it can be defined much more clearly. This leads, among other things, to lower use quantities / concentrations or fewer side effects.
  • a chlorine dioxide solution according to the invention can preferably be used, for example, to disinfect solid surfaces or water, in particular to remove bacteria, viruses, protozoa, molds and / or spores from these surfaces or the water.
  • An application in the human or veterinary medical field can also relate to the treatment of skin, nails, hooves, claws, wounds, etc.
  • a chlorine dioxide solution according to the invention can also be used for disinfecting food.
  • pH-neutral chlorine dioxide solution according to the invention which contains one of the surfactants disclosed in a concentration of less than 500ppm, more preferably less than 150ppm, since this solution surprisingly proved to be particularly skin-friendly due to the low residues and the selected surfactant Has.
  • the pH value of an aqueous chlorine dioxide solution (1.0 liter with a chlorine dioxide concentration of 5000 ppm and a pH value of 2.0) prepared by reacting sodium chlorate with hydrochloric acid according to the industrial process for bleaching agents is determined by adding an aqueous Solution of 5.0 wt .-% sodium carbonate and 2.0 wt .-% sodium hydrogen sulfate as a buffer adjusted to 7.0 in order to bind chlorine gas present in the solution. Then the chlorine dioxide is distilled off at room temperature (about 20 ° C) and a pressure of 40 mbar and dissolved directly in 1.0 liter of distilled water (deionized water), which is cooled to 10 ° C, up to a concentration of 2000 ppm .
  • the aqueous chlorine dioxide solution produced in this way is packed in glass bottles with a stopper made of a PTFE-polymer mixture, and the bottles are again light-tight in a shock-absorbing styrofoam packaging.
  • the chlorine dioxide solution After storage at room temperature for 18 months, the chlorine dioxide solution has a concentration of 1860 ppm (93% of the initial concentration) and after 24 months a concentration of 1820 ppm (91% of the initial concentration).
  • a disinfectant solution containing chlorine dioxide chlorine dioxide is distilled off as in Example 1, but then at 10 ° C in 1.0 liter of distilled water that is mixed with a carbonate / phosphate buffer (sodium carbonate (soda) and phosphoric acid, each approx. 01 mol) is set to a pH of 7.0 and contains a surfactant (“Dehyton AB 30” from BASF) in a concentration of 2 g / l, up to a concentration of 2000 ppm in the solution.
  • the aqueous disinfectant solution containing chlorine dioxide produced in this way is packed in glass bottles which are closed with a stopper made from a PTFE polymer, and the bottles are again light-tight in shock-absorbing styrofoam packaging.
  • the disinfectant solution After storage at room temperature for 18 months, the disinfectant solution has a chlorine dioxide concentration of 1900 ppm (95% of the initial concentration) and a chlorine dioxide concentration of 1860 ppm after 24 months (93% of the initial concentration).

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Treatment Of Water By Oxidation Or Reduction (AREA)
  • Agricultural Chemicals And Associated Chemicals (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

La présente invention concerne des solutions aqueuses contenant du dioxyde de chlore, en particulier des solutions aqueuses de dioxyde de chlore de haute pureté, qui peuvent être utilisées par exemple dans le domaine de la médecine humaine et vétérinaire pour désinfecter des surfaces, des appareils et des instruments, et une méthode de préparation de telles solutions aqueuses de dioxyde de chlore. En particulier, la présente invention concerne une méthode de préparation d'une solution aqueuse de dioxyde de chlore, dans laquelle une solution aqueuse de dioxyde de chlore préparée précédemment est traitée de telle sorte qu'une solution aqueuse de dioxyde de chlore de haute pureté est obtenue. La méthode selon l'invention peut être appliquée à toutes les solutions aqueuses de dioxyde de chlore préparées précédemment, quelles que soient les méthodes par lesquelles la solution aqueuse de dioxyde de chlore préparée précédemment a été préparée. En appliquant la méthode selon l'invention, des solutions aqueuses de dioxyde de chlore de haute pureté, peuvent notamment être préparées à partir de solutions aqueuses de dioxyde de chlore préparées précédemment d'une manière beaucoup plus simple et plus économique. Il a été découvert de manière surprenante que les solutions aqueuses de dioxyde de chlore pouvant être obtenues au moyen de la méthode selon l'invention présentent un niveau élevé de pureté et un niveau de stabilité étonnamment élevé.
EP21722186.0A 2020-04-27 2021-04-27 Solutions aqueuses de dioxyde de chlore et méthode de préparation associée Withdrawn EP4143130A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102020111417.6A DE102020111417A1 (de) 2020-04-27 2020-04-27 Wässerige Chlordioxid-Lösungen und Verfahren zur Herstellung derselben
DE102020113390 2020-05-18
PCT/EP2021/060904 WO2021219587A1 (fr) 2020-04-27 2021-04-27 Solutions aqueuses de dioxyde de chlore et méthode de préparation associée

Publications (1)

Publication Number Publication Date
EP4143130A1 true EP4143130A1 (fr) 2023-03-08

Family

ID=75728843

Family Applications (1)

Application Number Title Priority Date Filing Date
EP21722186.0A Withdrawn EP4143130A1 (fr) 2020-04-27 2021-04-27 Solutions aqueuses de dioxyde de chlore et méthode de préparation associée

Country Status (5)

Country Link
US (1) US20230183065A1 (fr)
EP (1) EP4143130A1 (fr)
CN (1) CN115461304A (fr)
CA (1) CA3173825A1 (fr)
WO (1) WO2021219587A1 (fr)

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB460376A (en) * 1935-07-26 1937-01-26 Mathieson Alkali Works Improvements in or relating to the production of chlorine dioxide
GB760303A (en) 1954-02-16 1956-10-31 Cardox Corp Improvements in or relating to apparatus for manufacture of chlorine dioxide hydrateand the like
US5433938A (en) * 1992-10-23 1995-07-18 Vulcan Chemicals Chlorine-destruct method
DE19514612A1 (de) 1995-04-25 1996-10-31 Fritz Dr Kueke Verfahren zur Herstellung einer wässrigen Chlordioxid-Lösung
AU2006332600B2 (en) 2005-11-14 2011-10-13 Cdg Environmental, Llc. Storage-stable aqueous solutions of chlorine dioxide and methods for preparing and using them
EP2307310A4 (fr) * 2008-07-25 2012-10-31 Siemens Industry Inc Systèmes et procédés de génération de dioxyde de chlore
TW201808792A (zh) * 2016-09-14 2018-03-16 優尼克生技股份有限公司 二氧化氯純化方法
DE102018107018A1 (de) 2018-03-23 2019-09-26 Fritz Küke Verfahren und Vorrichtung zum Herstellen einer Chlordioxid enthaltenden wässrigen Lösung

Also Published As

Publication number Publication date
CN115461304A (zh) 2022-12-09
US20230183065A1 (en) 2023-06-15
CA3173825A1 (fr) 2021-11-04
WO2021219587A1 (fr) 2021-11-04

Similar Documents

Publication Publication Date Title
DE3620609C2 (fr)
EP2654940B1 (fr) Procédé de fabrication d'une solution aqueuse, stable, de dioxyde de chlore
DE69002442T2 (de) Biozide verfahren für im kreislauf geführte wässrige systeme.
DE69013516T2 (de) Calciumhypochloridzusammensetzungen zum verhindern von kesselsteinbildung und methode zu deren verwendung.
EP0822920A1 (fr) Procede de preparation d'une solution desinfectante renfermant du dioxyde de chlore pour le traitement de l'eau
DE2022390A1 (de) Eine stabilisiertes Chlordioxid enthaltende waessrige Loesung
EP3527696A1 (fr) Procédé de traitement et de valorisation d'une eau de processus salée
EP2662328B1 (fr) Procédé et dispositif destinés à la production de dioxyde de chlore
EP1483204A1 (fr) Preparation d'eaux residuaires contenant du chlorure de sodium et destinees a etre utilisees dans l'electrolyse a l'alcali et au chlore
DE1492495B1 (de) Keimtötendes Mittel und seine Verwendung
US20120148477A1 (en) Aqueous solutions of chlorine dioxide with enhanced stability and methods for producing and packaging them
DE202018102846U1 (de) Desinfektionsmittel aus wirkungsverstärktem Natriumhypochlorit
EP0059978A1 (fr) Procédé pour le traitement chimique et pour la désinfection des eaux et des systèmes aqueux
DE1542249A1 (de) Verfahren zum Herstellen eines Metallsalzes aus einem Metallchlorid und einer Saeure
EP3578510A1 (fr) Procédé de fourniture de gaz diluant lors de la production de chlore et de dioxyde de chlore sans éduits et sans sous-produits
WO2021219587A1 (fr) Solutions aqueuses de dioxyde de chlore et méthode de préparation associée
DE68919707T2 (de) Verfahren zur erzeugung von unterchloriger säure.
EP1916226B1 (fr) L'utilisation d'un agent organique de réduction pour la suppression de chloramine, de chlore et autres liaisons actives de chlore d'eau d'aquarium pour des organismes aquatiques
DE102020111417A1 (de) Wässerige Chlordioxid-Lösungen und Verfahren zur Herstellung derselben
DE102010011699B4 (de) Verfahren zur Erzeugung einer Chlordioxid-Lösung
DE69125683T2 (de) Chlorigsäurelösungen
DE102018107018A1 (de) Verfahren und Vorrichtung zum Herstellen einer Chlordioxid enthaltenden wässrigen Lösung
DE102005059135A1 (de) Verfahren und Mittel zum Desinfizieren von Wasser
DE2217644C3 (de) Verfahren zur Verminderung der Konzentration wasserlöslicher carboxylischer Verunreinigungen in chloridhaltigen Salzlösungen
WO2016026646A1 (fr) Procédé et système de traitement de l'eau de piscine et piscine équipée d'un tel système

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20220928

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20231101