Method for treating materials containing organic compounds using a high density pressurized aqueous medium or an aqueous medium in the form of steam

Abstract

1. A method for treating a material comprising at least one organic compound capable of releasing undesirable anions during thermal and / or chemical and / or physical treatment, comprising at least one step in which the material is contacted with a dense pressurized aqueous medium (particularly subcritical or supercritical) or a pressurized aqueous medium in the form of steam in the presence of a material reactive to the undesirable anions and capable of fixing the undesirable anions in its structure, whereby the organic compounds are destroyed and at least partially mineralized; and at the same time, the undesirable anions are released and immediately captured by a solid material reactive to the undesirable anions and then fixed, producing an aqueous solution free of undesirable anions.

Description

[Technical Field]

[0001] The present invention relates to a method for treating materials containing organic compounds with a dense pressurized aqueous medium or an aqueous medium in the form of steam.

[0002] More precisely, the invention relates to a method for treating a material (so-called substrate material) containing organic compounds prone to release undesired anions during thermal and / or chemical and / or physical treatment, by contacting said material with a dense pressurized aqueous medium or an aqueous medium in the form of steam, in particular saturated steam.

[0003] The technical field of the present invention can be defined as that relating to the treatment of potentially hazardous or toxic organic compounds for their destruction by hydrothermal oxidation (HTO), wet oxidation (WO) or oxidation with water vapor.

[0004] The process according to the invention is particularly, but not exclusively, applicable to the treatment of halogenated organic compounds, especially fluorinated organic compounds. [Background technology]

[0005] Environmental concerns particularly call for the development of environmentally friendly industrial processes that do not use toxic organic solvents and do not produce toxic wastes that require costly and lengthy treatment.

[0006] The ever-increasing production of many manufactured products used every day (whether for mass use or for domestic use), such as mobile phones, computers, TV sets, solar panels, and even packaging and coatings for fluids such as fluorinated oils and refrigerants, generates waste when these products reach the end of their useful life, and this waste poses many problems during their disposal.

[0007] These problems are further accentuated when these wastes contain compounds that are toxic, corrosive or harmful, or that are prone to release toxic, corrosive or harmful compounds, such as halogenated polymers.

[0008] The processing of some products produced for industry or domestic consumption, particularly for their destruction or recycling, can prove to be complex.

[0009] This is especially true for organic compounds that contain anions that are corrosive, toxic or harmful to humans and the environment, or more particularly those that are prone to release toxic, harmful or corrosive anions when subjected to thermal, physical or chemical treatment.

[0010] Halogenated oils, including fluorinated oils used in the mechanical engineering industry, brominated flame-retardant resins used in computer boards, many types of halogenated and phosphorus solvents, halogenated polymers present in photovoltaic modules and electrical and electronic devices, organosulfates, etc. are all examples of organic compounds containing toxic anions, such as halide anions, or more precisely, compounds that are prone to release toxic anions when subjected to thermal, physical or chemical treatment.

[0011] This proves particularly difficult due to the release of toxic anions during the treatment of these organic compounds commonly present in waste.

[0012] In the specific case of fluorine, many industrial processes, such as iron and aluminum production, fertilizer and semiconductor production, generate large amounts of gaseous or liquid effluents contaminated with fluorine. Indeed, these effluents contaminated with fluoride anion form fluoride represent a risk to human health due to the production of HF, and a real environmental problem, since they can be highly corrosive and toxic to ecosystems in general and to humans in particular. Hydrofluoric acid is also a problem for the integrity of components for various liquid and gas phase treatment processes. Most alloys and glasses cannot tolerate it.

[0013] In general, processes such as hydrometallurgical processes are not very efficient and have significant drawbacks from an environmental standpoint.

[0014] Figure 1 is a diagram illustrating current processes (such as hydrometallurgical processes) for treating organic wastes that produce hazardous, toxic, harmful, or corrosive anions. These organic wastes can be solid or liquid and therefore can produce hazardous and toxic anions, such as fluoride, chloride, bromide, or phosphate anions.

[0015] Generally, these processes comprise at least two steps, as shown in Figure 1. In the first step, the organic waste is thermally or chemically treated to destroy the organic matter. In the second step, post-treatment of the gaseous effluent from the first step is necessary to remove the anions released during the first step. At the end of the process, a final effluent is obtained from which the anions have been removed. The anions can be separated from the effluent of the first step, in particular by treatment with activated carbon, by adsorption, by precipitation, or by treatment with membranes.

[0016] Between the first and second stages, a material capable of fixing toxic anions in its structure can be added to allow the recovery of purified recoverable species contained in the waste.

[0017] More specifically, the process depicted in Figure 1 generally involves two operations: Unit Operation I (11) and Unit Operation II (12). Unit Operation I (11) is fed with organic waste (13) that generates hazardous anions. These hazardous anions are F - , Cl - , Br - , PO4 3-... These organic wastes can be solid or liquid. They then proceed with the treatment of the organic phase (14). This treatment (14) can be thermal or chemical. In unit operation II (12), a treatment (15) of the anions resulting from the treatment of the organic phase (14) carried out during unit operation I (11) is carried out. This treatment (15) of the anions can be a treatment with activated carbon, a treatment by adsorption, a treatment by precipitation, or a treatment using a membrane. After this treatment (15) of the anions, an effluent (16) is obtained that no longer contains anions. Between unit operations I (11) and II (12), or more precisely between the treatment of the organic phase (14) and the treatment of the anions (15), certain materials (17) can be added to recover recoverable species, such as metals, during a recovery step (18).

[0018] In particular, organic compounds containing toxic anions can be treated by processes that carry out hydrothermal oxidation (HTO), wet oxidation (WO) or oxidation with steam using pressurized water at high temperatures (which are part of the process of chemical and / or thermal treatment of the organic phase referred to in FIG. 1).

[0019] For example, fluorinated and chlorinated oils are compounds that can be used as lubricants for industrial machinery. However, the destruction of these compounds by hydrothermal oxidation (HTO) or wet oxidation (WO) results in chloride (Cl). - ) and fluoride (F - ) anions, which in turn generate the corresponding acids (i.e., hydrochloric acid (HCl) and hydrofluoric acid (HF)). These acids are generated at concentrations that depend on the concentration of the treating compound initially introduced into the subcritical water (WO), supercritical water (HTO), or steam medium.

[0020] In particular, organosulfates are used as detergents in industry. The destruction of these compounds under the same temperature and pressure conditions results in the formation of sulfate anions (SO4 2- ), which then leads to the formation of sulfuric acid (H2SO4).

[0021] In particular, the nitrate group (NO3- Organic compounds having the formula (III) are used in the pharmaceutical industry. Destruction of these compounds under the same temperature and pressure conditions leads to the production of nitrate anions and the subsequent formation of nitric acid (HNO).

[0022] In the nuclear industry, tributyl phosphate (TBP) is used in nuclear fuel reprocessing processes to extract uranium and plutonium. Treatment of contaminated TBP under the same temperature and pressure conditions results in the release of phosphate anions (PO4 3- ), which then forms phosphoric acid (H3PO4).

[0023] The formation of all these anionic compounds and all these acids represents a risk for installations exposed to restrictive pressure and temperature conditions, in particular due to the fact that they induce corrosion phenomena under stress and deposition (i.e. corrosion induced by salt deposition on internal walls). Problems also arise during the treatment of these anionic compounds and these acids, once the action of sub- or supercritical water or steam is complete. In particular, problems are linked to the fact that the high toxicity of these compounds makes them difficult and even dangerous for humans to handle, and that they constitute a threat to aquatic and terrestrial ecosystems.

[0024] Furthermore, waste that is organic waste, especially originating from used manufactured products, is in fact most often a "multi-compound" formed by various solid or liquid organic substances together with metals and / or minerals.

[0025] This more or less complex combination of materials makes the sorting, subsequent processing and / or recycling operations difficult.

[0026] For example, electronic circuit boards for computers are epoxy resin plates lined with a thin layer of copper covered with varnish, onto which electronic devices and connectors are integrated. Traditionally, electronic circuit boards are made of approximately 40% metal, 30% fiberglass and ceramic, and 30% organic materials. The presence of toxic epoxy resins and brominated flame retardants makes it impossible to consider a simple and effective recycling cycle. Also, incineration of these electronic components is inappropriate because it produces toxic emissions of heavy metal vapors and brominated dioxins. Chemical treatment may be considered, but it may produce toxic effluents containing hydrobromic acid (HBr). In this type of treatment, bromide anions (Br - ) can be released in large quantities, and post-treatment must be considered.

[0027] Additionally, photovoltaic (PV) panel modules are difficult to process due to the presence of a fluorinated polymer, such as poly(vinyl fluoride) ("PVF"), as a component of the film, i.e., a protective (backside) layer called the "backsheet." This "backsheet" generally consists of several polymer layers. Most often, it consists of two layers of fluorinated polymer (PVF, PVDF, or other) surrounding a PET layer. There are also "backsheets" without fluorinated polymers, for example, composed of two PET layers.

[0028] Total or partial destruction of this polymer by hydrothermal oxidation (HTO), wet oxidation (WO), or oxidation with water vapor under these temperature and pressure conditions produces hydrofluoric acid (HF), a highly aggressive compound that is incompatible with stainless steel equipment or even most alloys.

[0029] Given the above, oxidation by hydrothermal oxidation (HTO), wet oxidation (WO) or steam processes for the treatment of materials containing organic compounds appears to have many advantages, especially in terms of environmental considerations, since they use only water and ultimately produce only carbon dioxide and water.

[0030] For example, the primary interest of HTO or WO or water vapor processes for electronics recycling is their ability to process liquid or solid organometallic materials with high percentage destruction of the organic matter and recovery of the desired metals.

[0031] Furthermore, the NO produced by these processes x and SO x Emissions are very limited in this process type.

[0032] It should be noted that, as clearly stated above, when these processes are used to treat compounds that release undesirable anions in a first step, i.e., anions that are dangerous, toxic, harmful or corrosive under the conditions of these processes, it is then necessary to remove the released anions contained in the effluent of the first step in a separate second step. The processes intended to remove these anions are complex, time- and energy-consuming, and their efficiency is often not optimal. Summary of the Invention [Problem to be solved by the invention]

[0033] In light of the above, therefore, there is a need for a method for treating materials containing organic compounds that are prone to releasing undesirable anions during thermal and / or chemical and / or physical processing that allows for a single step or unit operation that simultaneously decomposes the organic compounds and captures and immobilizes the undesirable anions to avoid the production of dangerous, harmful, toxic or corrosive substances, such as acids, from these anions.

[0034] There remains a need for a method that is simple, reliable, does not use often toxic solvents or other materials, does not produce toxic, harmful, hazardous, corrosive, or difficult-to-treat effluents, and is environmentally friendly.

[0035] The present invention aims to provide such a process that addresses, among other things, these needs and these demands.

[0036] In particular, the present invention aims to provide such a treatment method that does not have the drawbacks, deficiencies and disadvantages of prior art treatment processes, especially in oxidation involving hydrothermal oxidation (HTO), wet oxidation (WO) or steam processes.

[0037] The present invention also aims to provide such a process which overcomes the problems encountered in prior art processes, particularly oxidation processes involving hydrothermal oxidation (HTO), wet oxidation (WO) or steam processes. [Means for solving the problem]

[0038] This and other objects are achieved according to the invention by a method for treating a material containing at least one organic compound prone to release undesirable anions during a thermal and / or chemical and / or physical treatment, comprising at least one step during which said material is brought into contact with a dense pressurized aqueous medium (in particular under subcritical or supercritical pressure) or a pressurized aqueous medium in the form of steam, in the presence of a material reactive towards said undesirable anions and capable of fixing said undesirable anions in its structure, whereby said organic compound is destroyed and at least partially inorganic and simultaneously, the undesired anions are released and immediately captured by the material reactive to the undesired anions, and then immobilized, producing an undesired anion-free aqueous solution.

[0039] In particular, the heat treatment may be a hydrothermal treatment.

[0040] The material reactive towards undesired anions is also sometimes referred to as a material capable of reacting with undesired anions, and may in particular be chosen from among glasses and ion exchangers.

[0041] In particular, the material reactive with the undesired anions may be a solid or a liquid.

[0042] Treatment materials that include at least one organic compound susceptible to releasing unwanted anions during thermal and / or chemical and / or physical treatment may also be referred to as substrate materials.

[0043] inorganic It should be understood that by polymerization, partial destruction, the molecules of the organic compound are broken down into molecules having smaller size and lower molecular weight, but still containing carbon-carbon bonds.

[0044] Overall or Ultimate inorganic It must be understood that by oxidation, the molecules of the organic compound are decomposed, inter alia, into CO2, N2 and H2O.

[0045] for example, inorganic In the case of polymerization or partial destruction, the long chains of molecules of organic polymers can be broken down into smaller molecules or monomers, inorganic In the case of total and ultimate decomposition, they can be decomposed into, among other things, CO2, N2 and H2O.

[0046] The method according to the invention differs fundamentally from prior art methods for treating materials containing organic compounds prone to releasing undesirable anions in that, in the same step, the material to be treated is contacted with a dense pressurized aqueous medium or a pressurized aqueous medium in the form of steam, and the undesirable anions are immobilized by the presence of a material that is reactive towards and prone to capture the undesirable anions.

[0047] In the method according to the invention, in one and the same unit step, the organic compounds are destroyed and at least partially inorganic At the same time, the undesired anions are released and immediately after their release from the organic compound, are captured by a material reactive with the undesired anions and then fixed, so that it is not necessary to resort to a separate subsequent process of separating, capturing and fixing the already captured undesired anions.

[0048] The method according to the present invention does not have the drawbacks, deficiencies and disadvantages of prior art processing methods, particularly oxidation, including hydrothermal oxidation (HTO), wet oxidation (WO) or steam processes.

[0049] The method according to the present invention overcomes the problems presented by the prior art oxidation processes, particularly those involving hydrothermal oxidation (HTO), wet oxidation (WO) or steam processes.

[0050] In particular, undesirable anions may be dangerous and / or toxic and / or harmful and / or corrosive anions and / or anions prone to forming dangerous and / or toxic and / or harmful and / or corrosive compounds.

[0051] The undesirable anions may be selected from among anions of elements in groups V, VI and VII of the periodic table of the elements, and anions containing elements in groups V, VI and VII of the periodic table of the elements.

[0052] Undesirable anions include, in particular, halide anions such as chloride, iodide, bromide and fluoride anions (Group VII of the Periodic Table of the Elements); sulfate anions (Group VI); nitrate anions; phosphate anions; arsenate anions (AsO4 8- ) (Group V); and anions containing metals such as oxo- and polyoxometalates of Groups V, VI, and VII of the Periodic Table of the Elements.

[0053] In fact, in the process according to the invention, the organic compounds are degraded during the treatment with a dense pressurized aqueous medium or a pressurized aqueous medium in the form of steam, without the formation of undesirable anions, in particular corrosive anions, with respect to the materials of construction of the equipment used, for example, during the hydrothermal oxidation treatment, and possibly inorganic It will be transformed.

[0054] The undesirable anions released during the decomposition of organic compounds interact with materials already present that are reactive toward the undesirable anions. As soon as they are generated, these undesirable anions are immediately captured and fixed by the materials reactive toward the undesirable anions, and do not have the potential to have harmful, toxic, or corrosive effects. These anions do not have the potential to form dangerous, harmful, toxic, or corrosive compounds, such as acids.

[0055] Surprisingly, the method according to the invention allows, by incorporating into a material reactive towards undesired anions, such as a glassy matrix, in a single unit operation, the treatment of organic compounds, such as halogenated organic wastes, which may be toxic and corrosive with respect to the equipment, in particular by hydrothermal oxidation (HTO), by wet oxidation (WO) or by oxidation with water vapor, using a dense pressurized aqueous medium or a pressurized aqueous medium in the form of steam.

[0056] The method according to the invention does not use chemical reagents which are often toxic and dangerous to humans and the environment.

[0057] The process according to the invention is carried out by partially or completely reacting organic compounds in one and the same step, i.e. in a single step. inorganic This not only neutralizes, but also at the same time makes it possible to neutralize, capture and fix undesirable anions released during the decomposition of organic compounds.

[0058] In other words, the method according to the invention ensures the treatment of organic compounds, such as halogenated organic waste, in a single unit operation in which the organic compounds are destroyed and decomposed and no undesirable anions, in particular toxic halide anions, are produced. The method according to the invention therefore does not include a subsequent step of removing the anions following said step.

[0059] In other words, the process according to the invention does not involve a post-treatment to remove undesired anions following treatment with a dense pressurized aqueous medium or a pressurized aqueous medium in the form of steam.

[0060] The process according to the invention produces an aqueous solution as an effluent that is free of undesired anions.

[0061] In the case of partial decomposition, the solution may contain molecules having smaller sizes and lower molecular weights than the treated organic compounds, but the solution is not necessarily dangerous, harmful, toxic or corrosive.

[0062] Other effluents from the process are inorganic In the case of combustion, these are in particular CO2, N2 and water, which can be emitted without risk.

[0063] In the process according to the invention, the oxidation is carried out in an aqueous medium and the reaction of the organic compound inorganic There is a substantial synergy between materials that are reactive towards unwanted anions and materials that allow for immobilization of unwanted anions generated during polymerization.

[0064] Finally, the method according to the invention ensures the treatment of materials containing organic compounds without the generation of harmful, dangerous, toxic or corrosive compounds, such as acids, from these organic compounds by a double effect in a single step, namely the hydrolysis / oxidation of the organic compounds and the incorporation of undesired, especially toxic and / or corrosive anions into the inorganic phase (i.e. the material reactive towards the undesired anions).

[0065] The process according to the invention is environmentally friendly: in fact, it uses water in various forms rather than toxic organic solvents.

[0066] The organic compounds that can be treated by the method according to the present invention to destroy and decompose are not limited. The treatment material or material to be treated (also called substrate material) comprises at least one organic compound.

[0067] The treatment material (substrate material) and the organic compound may be solid and / or liquid.

[0068] In particular, the organic compounds of the treatment material may be chosen from among liquid or solid halogenated organic compounds, such as fluorinated and / or chlorinated and / or iodinated compounds.

[0069] Among the organic compounds in liquid form, mention may be made in particular of fluorinated lubricants, refrigerants and all halogenated liquid residues.

[0070] Advantageously, the organic compounds of the treatment material are selected from among organic polymers, in particular halogenated organic polymers, such as fluorinated and / or chlorinated organic polymers, and organic resins, in particular halogenated organic resins.

[0071] In particular, these polymers and organic resins may be selected from among poly(vinyl fluoride) ("PVF"), poly(vinylidene fluoride) ("PVDF"), poly(vinyl chloride) ("PVC"), polystyrene, especially expanded polystyrene or polystyrene foam, epoxy resins, polyamides, polyolefins, polyurethanes, polyterephthalates such as PET, polyesters, and polycarbonates.

[0072] These polymers may contain flame retardants such as bromine compounds like penta- and octa-BDE (bromodiphenyl ether).

[0073] These polymers may also be iodinated polymers such as grafted dextrans, which are used as contrast agents in imaging, or conducting polymers such as polyfluorenes, propylene, polyazulenes, polynaphthalenes, polyacetylenes, and poly(p-phenylene vinylenes).

[0074] In addition to iodine and fluorine, these polymers may be doped with atoms such as sulfur (S) or boron (B), as well as all their derivatives: oxidized or reduced forms.

[0075] The treatment material (substrate material) may be an organic material consisting of one or more organic compounds, particularly as described above; or the treatment material may be a composite material comprising at least one organic compound as well as at least one compound that is not organic but is an inorganic compound.

[0076] This inorganic compound, which may form a material reactive with unwanted anions, may be chosen in particular from among glasses, ceramics and metals.

[0077] The at least one inorganic compound, which may form a material reactive with the undesired anions, may be selected from among glasses, ceramics, and metals, and may then be recovered once contacting is complete.

[0078] The composite materials (which may include materials reactive to undesired anions) may form or be part of liquid or solid waste products, emissions or effluents.

[0079] The composite material (which may include materials reactive to undesired anions) may form or be part of any type of device, object or component, particularly end-of-life devices, objects or components that are to be processed for their total or partial recycling.

[0080] Thus, the composite material (which may include a material reactive to unwanted anions) may form or be part of a multilayer device comprising at least one organic layer, such as a photovoltaic panel; a photovoltaic module, such as a photovoltaic module using silicon, e.g., crystalline silicon technology, or any photovoltaic module comprising at least one organic layer; food packaging; pharmaceutical packaging; electronic devices, such as computer screens, mobile phones, TV sets, or devices comprising light-emitting diodes, particularly organic light-emitting diodes. In these multilayer devices, particularly in photovoltaic panels, the organic compound is in solid form and generally consists of a polymer, particularly a halogenated polymer (especially PVF or PVDF).

[0081] The composite material may be formed by the lower protective layer, also called the backside, or backing layer or sheet ("backsheet") of a photovoltaic module (PV module).

[0082] The backing layer or backsheet "backsheet" generally consists of several layers, ie, two, three or more layers.

[0083] Each of these layers generally consists of a polymer selected from among fluorinated polymers such as poly(vinyl fluoride) (“PVF”) and poly(vinylidene fluoride) (“PVDF”); and non-fluorinated polymers such as poly(ethylene terephthalate) (“PET”) and polyamide (“PA”).

[0084] Various combinations of layers and polymers can form the backing layer or backing sheet.

[0085] The following combinations are presented for illustrative purposes only, and the list is by no means exhaustive.

[0086] Thus, a three-layer backing layer or backing sheet may comprise PVDF layer / PET layer / PVDF layer or PVF layer / PET layer / PVF layer, or another fluorinated polymer (different from PVF and PVDF) layer / PET layer / another fluorinated polymer layer.

[0087] The two-layer backing layer or backing sheet may comprise a layer of another fluorinated polymer (different from PVF and PVDF) / a layer of PET, or may otherwise be constituted by, for example, two layers of PET.

[0088] Generally, so-called undercoat adhesion layers or surface activation treatments are applied to the "inner" layers, ie those that will be inside the module after lamination.

[0089] The composite material may also form or be part of an object, device or part used in the automotive, aerospace or space industries, particularly an end-of-life object, device or part that is treated for full or partial recycling.

[0090] The composite material may also form or be part of a wind turbine blade, particularly an end-of-life wind turbine blade that is treated as a total or partial reclamation thereof.

[0091] The aforementioned composite materials are generally materials that are prone to generating toxic halogenated or other toxic compounds during thermal, chemical or physical processing.

[0092] The aqueous medium may be selected from water and aqueous solutions.

[0093] Materials reactive to undesired anions (materials capable of reacting with undesired anions) and capable of immobilizing undesired anions in their structure may be selected from among materials containing alkali and / or alkaline earth elements.

[0094] The material reactive towards undesired anions may be selected from silica-based glassy materials containing alkali and / or alkaline earth elements, such as soda-lime-silica, boron-lime-silica and silica-lime-alumina glassy materials, in particular soda-lime-silica, boron-lime-silica and silica-lime-alumina glassy materials.

[0095] Materials that are reactive towards undesired anions and capable of fixing undesired anions in their structure, in particular materials containing alkali and / or alkaline earth elements, may be selected from natural materials, in particular of animal or vegetable or mineral origin, for example materials forming the shells or carapaces of animals such as mollusks and crustaceans, or materials of vegetable origin, for example with a high silica and silica-lime content; artificial materials; and synthetic materials.

[0096] Materials that are reactive towards undesired anions and capable of fixing undesired anions in their structure, in particular materials containing alkali and / or alkaline earth elements, such as the silica-based vitreous materials containing alkali and / or alkaline earth elements used in the method according to the invention, have the advantage of being stable, available and low-cost materials.

[0097] The material, which is reactive towards undesired anions and capable of fixing undesired anions in its structure, in particular the material containing alkali and / or alkaline earth elements, such as the silica-based vitreous material containing alkali and / or alkaline earth elements, such as soda-lime silica or boron-lime silica or silica-lime-alumina glass, used in the method according to the invention, may not already be present in the material to be treated, but is subsequently (voluntarily) added to the dense pressurized aqueous medium or pressurized aqueous medium in steam form and / or to the (treatment) material to be treated, generally in the reactor in which the method is carried out.

[0098] A material that is reactive to undesired anions and capable of fixing undesired anions in its structure, in particular a material containing alkali and / or alkaline earth elements, for example a silica-based vitreous material containing alkali and / or alkaline earth elements, may be added depending on the applied pressure and temperature conditions while controlling its shape, its specific surface area, its composition, and / or its ratio to the amount of organic compound to be treated.

[0099] If a material reactive towards undesired anions, in particular a material containing alkali and / or alkaline earth elements, such as a silica-based vitreous material containing alkali and / or alkaline earth elements used in the method according to the invention, such as soda-lime silica or boron-lime silica or silica-lime alumina glass, is not already present in the treated material, this material may be, for example, a glass made from silica (SiO2) mixed with fluxes and additives according to different glass-making methods.

[0100] The materials reactive towards undesired anions, in particular materials containing alkali and / or alkaline earth elements, such as soda-lime-silica or boron-lime-silica or silica-lime-alumina glasses, used in the method according to the invention, may originate from glass recycling, for example from recycled bottles or from vitreous waste originating from insulation materials used in buildings.

[0101] Materials that are reactive towards undesired anions and capable of fixing undesired anions in their structure, in particular materials containing alkali and / or alkaline earth elements, for example silica-based vitreous materials containing alkali and / or alkaline earth elements, such as soda-lime silica glass or boron-lime silica glass or silica-lime alumina glass, may already be present by design in the treatment material before the method according to the invention is carried out.

[0102] This is especially true when the treatment material (substrate material) is a composite material, such as a photovoltaic solar panel, an electronic device screen or any other material that contains several compounds (multi-compound materials), such as polymers, glass and metals.

[0103] The "post-consumer" glass already present in the treatment material prior to the method according to the invention may be glass produced by conventional methods or recycled glass.

[0104] Materials that are reactive to undesired anions and capable of fixing undesired anions in their structure, particularly materials containing alkali and / or alkaline earth elements, for example, silica-based vitreous materials containing alkali and / or alkaline earth elements, such as soda-lime silica glass or boron-lime silica glass or silica-lime alumina glass, may be in a wide variety of shapes and sizes, especially if they are not already present in the treatment material and are added.

[0105] Advantageously, the material that is reactive towards undesired anions and capable of fixing undesired anions in its structure, in particular the material containing alkali and / or alkaline earth elements, for example the silica-based vitreous material containing alkali and / or alkaline earth elements, such as soda-lime silica glass or boron-lime silica glass or silica-lime alumina glass, is in the form of (discrete) particles, for example grains, granules or beads, also particles with a random shape, which form increases its specific surface area available for adsorption of undesired anions.

[0106] Preferably, these particles have a size defined by their largest dimension, such as a diameter of 10 nm to 5 cm in the case of beads, more preferably 100 nm to 1 cm, better still 0.1 mm to 2 mm, even better still 0.5 mm to 2 mm. Particles with such a size, which can be described as "small" particles, have an increased specific surface area available for reaction with and immobilization of undesired anions.

[0107] It will be appreciated that the material reactive to undesired anions and capable of fixing undesired anions in its structure, in particular the material containing alkali and / or alkaline earth elements, for example, silica-based vitreous materials containing alkali and / or alkaline earth metals, such as soda-lime silica glass, boron-lime silica glass, or silica-lime alumina glass, may already be present in the material to be treated before the method according to the invention is carried out, or, even if it is not yet present in the material to be treated, may be in a form other than particulate form, for example, in the form of a sheet, layer, part, or object, in particular a large object generally having a size greater than 5 mm. For example, if the material reactive to undesired anions is not yet present in the material to be treated, this material reactive to undesired anions may be in the form of a sheet, layer, part, or object, in particular a large object forming the filling or interior of the reactor in which the method is carried out.

[0108] Advantageously, materials that are reactive to undesired anions and capable of immobilizing undesired anions in their structure, such as glassy materials, are porous materials, also herein increasing their specific surface area available for capturing and immobilizing undesired anions.

[0109] Preferably, the material, e.g., glassy material, which is reactive towards undesired anions and capable of immobilizing undesired anions in its structure, is in the form of small porous particles which allow maximizing the specific surface area available for immobilization of undesired anions.

[0110] Advantageously, materials that are reactive to undesired anions and capable of fixing undesired anions in their structure, in particular materials containing alkali and / or alkaline earth elements, for example silica-based vitreous materials containing alkali and / or alkaline earth elements, such as soda-lime silica glass or boron-lime silica glass or silica-lime alumina glass, are used in a range of 0.1 to 1,000 m 2 / g, preferably 1 to 200m 2 / g, more preferably 10 to 200m 2 / g specific surface area.

[0111] When a material that is reactive to undesirable anions and capable of fixing undesirable anions in its structure, in particular a material containing alkali and / or alkaline earth elements, for example, a silica-based vitreous material containing alkali and / or alkaline earth elements, such as soda-lime silica glass or boron-lime silica glass or silica-lime alumina glass, has such a specific surface area, the yield of capturing, capturing and fixing undesirable anions, in particular fluoride anions, is significantly increased.

[0112] Advantageously, the ratio of the mass of organic compounds (which is only the mass of organic compounds contained in the treatment material (substrate material), i.e., if the treatment material is a composite material, the mass of organic compounds contained in the composite material, or if the organic compounds are exclusively organic, such as fluorinated oils, the mass of organic compounds forming the entire treatment material) to the mass of material reactive towards undesired anions and capable of fixing undesired anions in its structure, for example the mass of soda-lime-silica glass, is between 0.01 and 0.5, preferably between 0.025 and 0.25, for example between 0.05 and 0.1.

[0113] Advantageously, the contacting is carried out at a temperature between 100° C. and 600° C., preferably between 100° C. and 550° C., and at a pressure between 0.2 MPa (2 bar) and 40 MPa (400 bar), for a time preferably between 1 and 600 minutes.

[0114] According to a first embodiment of the method according to the invention, the material to be treated (substrate material) is contacted with pressurized water in the form of steam.

[0115] Generally, the contacting is carried out at a pressure of 0.2 to 2 MPa (2 to 20 bar) and at a temperature of 100 to 150° C., preferably for a time of 30 to 600 minutes, better still 240 to 600 minutes.

[0116] According to a second embodiment of the method according to the invention, the substrate material is contacted with pressurized water in subcritical conditions.

[0117] Generally, the contacting is carried out at a pressure ranging from above 2 MPa (20 bar), for example 2.1 MPa (21 bar), to less than 22.1 MPa (221 bar), for example up to 22 MPa (220 bar), and at a temperature ranging from above 150°C, for example 151°C, to less than 374°C, for example 373°C, especially at a temperature of 250°C, for a time preferably of from 10 to 600 minutes, more preferably 30 to 600 minutes, better still 120 to 600 minutes.

[0118] It should be noted that the critical temperature and pressure of water are 374°C and 221 bar (22.1 MPa). We discuss subcritical water (a well-known term) in the region where superheated water approaches the critical point with decreasing density at constant pressures below 221 bar (22.1 MPa).

[0119] This treatment is carried out at temperatures and pressures below the critical temperature and pressure of water, ie at a temperature T<374° C. and a pressure P<22.1 MPa.

[0120] Under the above-mentioned conditions of temperature and pressure, water, under pressure and at a temperature below its critical temperature (<374°C), has the advantage of being not only a good solvent but also a reactive medium capable of hydrolyzing, and therefore degrading, organic compounds much more efficiently.

[0121] According to a third embodiment of the method according to the invention, the substrate material is contacted with pressurized water in the supercritical state.

[0122] Generally, the contacting is carried out at a pressure of 22.1 MPa or more, preferably 22.1 to 40 MPa (221 to 400 bar), and at a temperature of 374°C or more, preferably 374°C to 600°C, more preferably 400 to 600°C, for example 400°C, for a time period of preferably 1 to 180 minutes, even more preferably 10 to 180 minutes, and better still 20 to 120 minutes.

[0123] Water in the supercritical state (Pc > 22.1 MPa and Tc > 374°C) has very specific properties: due to the considerable reduction in the dielectric constant in this region (which is 80 under standard conditions of pressure and temperature and less than 5 above the critical point), so-called supercritical water is slightly polar, capable of forming a single homogeneous phase with organic compounds and oxygen, and has solvation properties close to those of organic solvents.

[0124] On the other hand, mineral salts have very low solubility in supercritical water.

[0125] Organic compounds solubilized in any proportion in supercritical water are hydrolyzed and then rapidly decomposed.

[0126] Thus, large chains of organic polymer molecules (based on CHON) originating from the matrix material are decomposed into smaller molecules or monomers, or in the event of ultimate destruction into CO2 and HO. Under these conditions, the presence of materials that are reactive towards undesired anions and capable of fixing undesired anions in their structure, such as glassy materials, allows the fixing and neutralization of the released undesired anions by their interaction with the constituent elements of the material, such as glassy materials, that are reactive towards undesired anions.

[0127] The hydrolysis / oxidation reaction may be carried out in the presence or absence of an oxidizing agent (O, O / N, H0). The presence of an oxidizing agent, generally introduced in stoichiometric excess, makes it possible to shorten the duration of the treatment and consequently reduce energy costs.

[0128] Advantageously, the treatment material (substrate material), which may be partially or completely organic, may be contacted with a dense pressurized aqueous medium or a pressurized aqueous medium in the form of steam, in the presence of a further oxidizing agent.

[0129] In particular, an oxidizing agent may be present in the above-mentioned first, second and third embodiments of the process according to the invention.

[0130] Preferably, the oxidizing agent may be selected from among pure oxygen, air and hydrogen peroxide H2O2.

[0131] The presence of a stoichiometric excess of oxidizing agent, which is preferred but not essential, allows for a significant reduction in the duration of the treatment and therefore in energy and operating costs.

[0132] The duration of the treatment in the presence of an oxidizing agent may be from 1 to 60 minutes in all embodiments of the method according to the invention, whether the pressurized water is in steam form, subcritical or supercritical.

[0133] Furthermore, the presence of an oxidizing agent can increase the overall inorganic This ensures that the resulting data is accurate.

[0134] The process according to the invention, in particular the contacting step, may be carried out in one and the same reactor, into which the material to be treated or substrate material and a material reactive with undesired anions and capable of fixing undesired anions in its structure, such as a soda-lime-silica vitreous material, are introduced and brought into contact with a dense pressurized aqueous medium or a pressurized aqueous medium in the form of steam.

[0135] The process according to the invention, in particular the contacting step, may be carried out continuously, semi-continuously or discontinuously "batchwise", preferably in one and the same reactor.

[0136] Discontinuous "batch" operation, with or without stirring, preferably in one and the same reactor, is preferred for materials such as solid organic waste.

[0137] Semi-continuous operation, with or without agitation, preferably in one and the same reactor, is preferred for materials such as semi-liquids (e.g., consisting of a heterogeneous mixture containing a liquid dispersed phase and a solid dispersed phase, in other words, suspended solids in a liquid), or for both solid and liquid organic wastes.

[0138] Continuous operation, preferably in one and the same reactor, with or without agitation, is preferred for materials such as liquid organic waste.

[0139] The invention will be better understood on reading the description of particular embodiments, in particular in the form of examples, presented below for illustrative and non-limiting purposes.

[0140] This presentation is made with reference to the accompanying drawings. [Brief explanation of the drawings]

[0141] [Figure 1] 1 is a diagram of a known method for treating organic waste that generates hazardous anions. [Figure 2] 1 is a diagram of a method according to the invention; [Figure 3] 1 is a spectrogram obtained by ion chromatography of the residual aqueous phase obtained after treatment of the back layer ("backsheet") of a photovoltaic module with supercritical water in the absence of a soda-lime-silica matrix (Example 2). Conductivity (pS / cm) is plotted on the vertical axis, and time (min) is plotted on the horizontal axis. The ionic conductivity of the medium is measured, which is then compared to a calibration curve to obtain the concentration. [Figure 4] 1 is a graph showing the fluoride ion (F-) uptake capacity of glass beads with a diameter of 2 mm as a function of the mass ratio (mBA / mBI) of the mass of the treated "backsheet" (mBA) to the mass of the glass beads. The vertical axis plots the fluoride uptake capacity (mg / g), while the horizontal axis plots the mBA / mBI mass ratio. The dots (◯) represent experimentally obtained capacity values, and the solid curve is a logarithmic regression curve. [Figure 5]1 is a graph showing fluoride ion uptake after treatment of a photovoltaic module "backsheet" by a method according to the present invention (Example 4). Fluoride ion uptake (%) is plotted on the vertical axis, and the mBA / mBI mass ratio is plotted on the horizontal axis. The dots (◯) represent experimentally obtained uptake values, and the dotted curve is a logarithmic regression curve. [Figure 6A] Photographs taken with an optical microscope of glass beads before treatment of the back layer ("backsheet") of a photovoltaic module with supercritical water in the presence of a material reactive to undesired anions, such as a soda-lime-silica matrix (Examples 3 and 4). [Figure 6B] Photographs taken with an optical microscope of glass beads after treatment of the back layer ("backsheet") of a photovoltaic module with supercritical water in the presence of a material reactive to undesired anions, namely a soda-lime-silica matrix (Examples 3 and 4). [Figure 7A] 7A and 7B are photographs obtained using a scanning electron microscope (SEM) of glass beads before treatment of the back layer ("backsheet") of a photovoltaic module with supercritical water in the presence of a material reactive to undesired anions, namely a soda-lime-silica matrix (Examples 3 and 4). The scale plotted in FIG. 7A represents 500 μm. [Figure 7B] 7A and 7B are photographs obtained using a scanning electron microscope (SEM) of glass beads after treatment of the back layer ("backsheet") of a photovoltaic module with supercritical water in the presence of a material reactive to undesired anions, i.e., a soda-lime-silica matrix (Examples 3 and 4). The scale plotted in FIG. 7B represents 500 μm. [Figure 8A] 8A and 8B are photographs taken at magnification using a scanning electron microscope (SEM) of glass beads after treatment of the back layer ("backsheet") of a photovoltaic module with supercritical water in the presence of a material reactive to undesired anions, i.e., a soda-lime-silica matrix (Examples 3 and 4). The scale plotted in Figure 8A represents 500 μm. [Figure 8B] 8A and 8B are photographs taken at magnification using a scanning electron microscope (SEM) of glass beads after treatment of the back layer ("backsheet") of a photovoltaic module with supercritical water in the presence of a material reactive to undesired anions, i.e., a soda-lime-silica matrix (Examples 3 and 4). The scale plotted in FIG. 8B represents 30 μm. [Figure 8C] 8A and 8B are photographs taken at magnification using a scanning electron microscope (SEM) of glass beads after treatment of the back layer ("backsheet") of a photovoltaic module with supercritical water in the presence of a material reactive to undesired anions, i.e., a soda-lime-silica matrix (Examples 3 and 4). The scale plotted in FIG. 8C represents 100 μm. [Figure 9] 1 shows a spectrum obtained by energy dispersive X-ray spectroscopy (EDX) of treated glass beads (material reactive to unwanted anions) (Example 3). The vertical axis is plotted in cps / eV. The horizontal axis is plotted in keV. DETAILED DESCRIPTION OF THE INVENTION

[0142] Figure 1, already mentioned, is a diagram of a classical process described in the literature. An analysis of the literature shows that there are many processes capable of chemically or thermally treating organic waste, but that, without exception, the treatment of the organic phase (destruction of compounds) and the treatment of anions (trapped by a specific matrix) are carried out according to two separate unit operations.

[0143] FIG. 2 is a diagram of a method according to the invention for treating materials (21) (substrate materials), such as solid or liquid waste, containing organic compounds prone to releasing undesirable anions, i.e., dangerous, toxic, harmful, corrosive anions, or more precisely, anions prone to forming undesirable compounds, i.e., dangerous, toxic, harmful, corrosive compounds, such as halide (fluoride, chloride, bromide, iodide), phosphate, sulfate, nitrate anions, etc.

[0144] These materials are then subjected to a treatment (22) in a particularly dense pressurized aqueous medium.

[0145] These materials (21) may therefore be sent or placed in a reactor, also called a high-pressure contactor, where they are subjected to treatment (22) with a dense aqueous medium or with an aqueous medium in the form of steam.

[0146] By "fed," it should be understood that material (21) is generally introduced into the reactor during the process. This generally applies to liquid materials, but not to solid materials.

[0147] By "charged" it should be understood that the material (21) is generally placed in the reactor prior to the process. This generally applies to solid materials.

[0148] The reactor is suitable for reaction media, namely steam, subcritical water or supercritical water, and the material from which the reactor is made is a material such as Inconel that is resistant to the most aggressive medium used, namely supercritical water.

[0149] Water (23) and a material (24) that is reactive to undesired anions and capable of fixing undesired anions in its structure, for example, a glassy material such as a soda-lime-silica glassy material (e.g., soda-lime-silica glass), are introduced directly, separately, or together into the reactor and / or into the material to be treated before being introduced into the reactor.

[0150] A material, such as a glassy material, that is reactive to undesired anions and capable of fixing undesired anions in its structure may already be present in the material (21) to be treated and / or may be added spontaneously, incorporated into the material or water prior to introduction into reactor (22), or added directly to the material.

[0151] Upon completion of the unique steps of the method according to the invention, which are carried out in a reactor, a contacting device, resulting in contact (22) with the treatment material (21) (substrate material), a material (25) reactive to undesired anions, e.g., a glassy material such as a soda-lime silica material (e.g., soda-lime silica glass), is obtained, on or in which decomposition of organic compounds, inorganic Anions released by the oxidation (e.g., anions, F -、 Cl - , Br - , I - ) is fixed by the action of the pressurized aqueous medium. This material (25) reactive towards undesired anions, for example this glassy material such as soda-lime-silica or boron-lime-silica glass, remains in the reactor at the end of the process and can be recovered and emptied.

[0152] If the treatment material (substrate material) is a composite material containing inorganic compounds such as metals, ceramics, glass, etc. in addition to organic compounds, these inorganic compounds forming recoverable materials such as metals can be recovered in the reactor and then recycled.

[0153] In FIG. 2, the recovery of recoverable materials such as metals is indicated by the symbol (26).

[0154] During and upon completion of the unique contacting step of the process according to the invention, a liquid effluent (27), i.e., an aqueous solution, is also produced, which is free of undesired anions and may contain some decomposition products of the organic compounds, if decomposition is only partial. Generally, these liquid effluents leave the reactor continuously throughout the process.

[0155] During (i.e., during and at the end of) the unique contacting step of the process of the present invention, a gaseous effluent (27) is produced, which may contain gases resulting from the decomposition of the organic compounds, such as water, oxygen, nitrogen, and carbon dioxide, if the decomposition of these organic compounds is total.

[0156] Additionally, these gaseous effluents may contain oxidizing agents such as oxygen if such agents are used in stoichiometric excess.

[0157] Generally, these gaseous effluents leave the reactor continuously throughout the process.

[0158] The invention will now be described with reference to the following examples, given for illustrative, non-limiting purposes. [Example]

[0159] In the following examples illustrating the process according to the invention, fluoride anion (F - ) was chosen as the anion to be removed because the fluoride anion leads to the production of HF (hydrofluoric acid), which is one of the most aggressive and dangerous acids and poses major problems regarding the strength of the materials it comes into contact with.

[0160] In Example 1 according to the invention, the method of the invention is carried out on a model aqueous solution of sodium fluoride (NaF).

[0161] This model solution of sodium fluoride (NaF) is used as an example of a waste, effluent, or liquid (substrate material) with a high concentration of fluoride (1,200 ppm) to illustrate the phenomenon of fluoride ion incorporation into a material reactive to undesired anions, such as soda-lime-silica glass, introduced into the medium according to the method of the present invention.

[0162] In Example 2, not according to the invention, a sample of a backing layer "backsheet" such as that found in a photovoltaic module (substrate material) consisting of a multilayer assembly of polyethylene terephthalate (PET) bonded between two layers of a fluorinated polymer such as polyvinyl fluoride (PVF) was treated with supercritical water but without soda-lime silica glass (a material reactive to undesired anions).

[0163] In Example 3 according to the invention, the method of the invention is carried out on samples of backing layers "backsheets" such as those present in photovoltaic modules (substrate materials). These samples of backing layers "backsheets" such as those present in photovoltaic modules are used as examples of solid organic waste (substrate materials).

[0164] In this example, the backing layer being treated consists of a layer of PET between two layers of PVF.

[0165] This example aims to show that the absorption of fluoride ions by a soda-lime-silica glass matrix (a material reactive towards undesired anions) remains effective during the oxidation reaction (in this example, hydrothermal) of the polymer (the substrate material).

[0166] Ion chromatography is used to quantify fluoride in the residual liquid phase after treatment of both the NaF solution and the "backsheet."

[0167] In the case of "backsheet" treatment, the final structure of the solid phase is characterized by scanning electron microscopy (SEM).

[0168] Example 1 In this example, treatment of an aqueous effluent containing fluoride anions is carried out.

[0169] As already stated above, 1,200 ppm (initial concentration [F - ] i An aqueous solution of NaF containing a (ppm) concentration of fluoride is used as the model effluent or substrate material to be treated.

[0170] The aqueous effluent is treated in a high-pressure reactor operating in a "batch" mode without stirring.

[0171] A set point temperature of 400°C is applied at 400°C at 28.0 MPa for a 2 hour period.

[0172] Under these conditions of temperature and pressure, water is in a supercritical state.

[0173] According to the method of the present invention, treatment with supercritical water is carried out in the presence of a material reactive with undesired anions placed in a reactor.

[0174] In separate tests, two types of materials reactive to unwanted anions are used: - Soda lime silica glass beads with a diameter of 2 mm. The specific surface area of ​​these beads was measured and found to be 1 m 2 / g or less, even 0; - Poraverre® recycled glass porous granules with an average size of 0.5 mm, which have a larger contact surface than soda lime glass beads with a diameter of 2 mm. In fact, the specific surface area of ​​these beads has been measured and found to be 2 m 2 / g. - NaF(initial concentration [F - ] i A volume of 35 mL of aqueous effluent (substrate material) containing (ppm) is contacted with each 6.0 g of material reactive with the undesired anion.

[0175] At the end of each test, the remaining liquid phase was analyzed by ion chromatography to determine its fluoride concentration (final concentration [F - ] f (ppm)).

[0176] Table 1 below presents the results of treatment with materials used that are reactive towards undesired anions.

[0177] [Table 1]

[0178] In Table 1, R (%) is the removal rate of fluoride in the effluent, and Q (mg g -1) is the uptake capacity of the material reactive to unwanted anions.

[0179] The efficiency of the method according to the invention in capturing fluoride anions in a supercritical aqueous medium in the presence of glassy materials reactive towards undesired anions is achieved with a removal rate of more than 70% for the two glassy materials used.

[0180] The removal rate of fluoride anions in the effluent (R (%)) and the uptake capacity of the reactive material towards undesired anions (Q (mg g -1 )) is higher than Poraverre®.

[0181] This demonstrates the relationship between the developed surface of the material, which is reactive towards unwanted anions, and its ability to incorporate fluoride anions.

[0182] Thus, Poraverre®, which has a larger specific surface (bead diameter 0.5 mm) and macroporosity (pore size approximately 10 μm), and therefore a larger contact surface, allows for increased uptake of fluoride ions released during treatment with supercritical water.

[0183] This incorporation may be accomplished in both types of materials that are reactive towards undesired anions, for example, by reaction and subsequent immobilization of calcium fluoride in soda-lime-silica based materials that are reactive towards undesired anions. 2+ + 2F -According to →CaF2, calcium fluoride is formed in the glassy matrix, which is incorporated and fixed therein, thereby avoiding its re-dissolution in the aqueous phase, the release of fluoride anions and the possible formation of HF during depressurization and cooling of the reactor. The test is carried out in a closed "batch" manner. The temperature is increased to the desired level (here 400 °C) depending on the power introduced (in our case about 5 °C / min). A pressure is applied, which depends on the amount of water previously introduced (here 28 MPa, 280 bar). The depressurization of the reactor is rapid (less than 5 minutes) and the cooling is achieved in our reactor in 1 hour (due to inertia).

[0184] The results obtained in this example according to the present invention confirm that during the hydrothermal oxidation reaction carried out in this example in the absence of an organic polymer (substrate material), fluoride anions were captured and immobilized by the soda-lime-silica matrix of the two materials tested, which is reactive towards undesired anions.

[0185] If the material reactive to the unwanted anions, here the glass matrix, has a larger contact surface, F - It can be seen that this immobilization of ions is even more pronounced.

[0186] Example 2 In this example, supercritical water is used to treat the "backsheet" (fluorinated substrate material) in the absence of a material reactive to undesired anions, namely the soda-lime-silica matrix, without the present invention.

[0187] In this example, the backsheet (3.0 g) is oxidized using supercritical water (volume: 35 mL) in the absence of a soda-lime-silica matrix in a batch reactor at 400° C. and 28.0 MPa (280 bar) for 2 hours.

[0188] Result of the operation: The remaining liquid phase, the final aqueous solution, has the following characteristics:

[0189] The mass fraction of fluoride ions released by the backsheet (substrate material) into the remaining liquid phase, the final aqueous solution, is 5.9±0.5% fluoride ions (this is the mass % of fluoride ions in the final aqueous solution).

[0190] - The fluoride content in the remaining liquid phase, the final aqueous solution, is 493±35 mg / L. - Fluorine mass: M F* is the mass of fluoride reduced to 35 ml of water, which is 17.7 ± 1.4 mg in the remaining liquid phase, the final aqueous solution.

[0191] The remaining liquid phase, the final aqueous solution, has a pH of 2.5. mineral The pH of the condensed water is 6.

[0192] Please note that the residual liquid phase should be understood as the liquid phase after heat treatment and the initial pH should be understood as the pH of the initial liquid phase before heat treatment.

[0193] - Figure 3 shows the spectrogram obtained by ion chromatography of the residual aqueous phase obtained after treatment of the "backsheet".

[0194] Example 3 In this example according to the invention, the "backsheet" (substrate material) is treated with supercritical water under the same conditions as in Example 2, but in the presence of a material reactive to undesired anions, i.e., a soda-lime-silica matrix.

[0195] This soda-lime-silica matrix consists of the glass beads already described above, with a diameter of 2 mm.

[0196] 3 g of glass beads were used, which resulted in the mass (m BA) and the mass (m BI ) mass ratio: m BA / m BI = 0.10.

[0197] Upon completion of the test, a residual liquid phase is obtained and the final aqueous solution has a fluoride concentration in the range of 318±26 mg / L. The pH is 7.2.

[0198] Example 4 In this example according to the invention, a "backsheet" (substrate material) is treated in the presence of a material reactive to undesired anions (i.e., a soda-lime-silica matrix) using supercritical water under the same conditions as in Example 3 (i.e., again using beads having a diameter of 2 mm).

[0199] Mass of the treated backsheet (substrate material) (m BA ) and the mass (m BI ) mass ratio: m BA / m BI A series of tests are carried out varying between 0.025 and 0.25.

[0200] The graph in Figure 4 shows the relationship between the amount of glass beads used and fluorine (specifically, fluoride ions F - ) and the uptake capacity of the

[0201] Mass ratio used (m BA / m BI When these results are expressed as fluoride ion uptake or rejection (R%) as a function of mass, it is noted that 80% of the fluoride ions present are captured at a mass ratio of 2.5% of the input soda-lime silica (material reactive to undesired anions) to the backsheet (substrate material), as shown in FIG. 5.

[0202] During the tests described in Examples 3 and 4, carried out in the presence of soda-lime-silica glass in a supercritical aqueous medium, a substantial acid-base neutralization reaction was also observed, accompanied by an increase in the pH of the residual liquid phase, i.e., the final aqueous solution (final pH close to 7), confirming that HF ​​is not preferably formed, but instead induces the consumption of fluoride ions by a material (here, the glass matrix) that is reactive towards undesired anions.

[0203] In other words, the initial pH before supercritical treatment is mineral The pH of the fluoride ions is approximately the pH of the fluoride-containing water (i.e., approximately 6). The final pH after supercritical processing is neutral (pH = 7), indicating the absence of HF in solution, thus demonstrating that the fluoride ions have been captured and immobilized by a material reactive toward undesired anions, here in a glassy matrix.

[0204] Scanning electron microscope (SEM) analyses (FIGS. 6A, 6B, 7A, 7B, 8A, 8B, and 8C) were performed on the soda-lime-silica matrix before and after treatment under the conditions of Example 3.

[0205] The material reactive towards undesired anions, here a soda-lime-silica matrix, consists of the glass beads already described above, with a diameter of 2 mm.

[0206] Mass of the treated backsheet (substrate material) (m BA ) and the mass (m BI ) mass ratio: m BA / m BI is between 0.025 and 0.25.

[0207] Glass beads have a translucent appearance in their initial form (Figure 6A).

[0208] After treatment, the beads have a milky appearance (FIG. 6B), indicating the presence of a crystalline phase in the glassy matrix, presumably attributable to fluoride-based crystals, presumably CaF2 (see reaction above).

[0209] SEM analysis confirms the modification of the treated glass beads.

[0210] The hydrothermal treatment changes the overall structure of the glass, which is characterized by small cracks (Figures 7A, 7B, 8A, 8B, and 8C).

[0211] A more detailed characterization (Figures 8A, 8B, and 8C) shows an internal modification of the beads with significant cracking, which is prone to porosity (creation of voids and thus an increase in specific surface area) and fluoride deposition (presumably CaF2). Fluorides are characterized by the presence of their crystals on the surface.

[0212] Complementary characterization by EDX (FIG. 9) of the glass beads (already described above, with a diameter of 2 mm) after treatment under the conditions of Example 3 reveals the presence of characteristic peaks of fluorine in the vicinity of other elements such as oxygen, sodium and calcium.

[0213] This presence of fluorine measured on the surface of the glass beads (as indicated by the presence of bright green spots in photographs of the beads after treatment) confirms that the fluorine released during hydrothermal oxidation reacts with the glassy structure to form stable fluoride (presumably CaF2) crystals within the glassy matrix.

[0214] Example 5 In this example according to the invention, a "backsheet" (substrate material) is treated with supercritical water under the same conditions as in Example 3 in the presence of a soda-lime-silica matrix (a material reactive to undesired anions) consisting of Poraverre® glass granules having a larger specific surface area than the glass beads used in Example 3.

[0215] 3 g of glass granules was used, which resulted in a backsheet mass (m BA ) and the mass of the glass beads (m BI ) mass ratio: m BA / m BI = 0.10.

[0216] In this example, the use of a Poraverre® soda-lime silica matrix, which has a larger specific surface area than the glass beads previously used, resulted in a lower m BA / m BI Ratio(m BA / m BI = 0.1) and under the same operating conditions, it is possible to improve the uptake or removal rate of fluoride by up to 84%.

[0217] This example clearly demonstrates that the rate of incorporation of fluoride ions during treatment by hydrothermal oxidation of fluorinated materials depends on the nature and specific surface area of ​​the material used for this incorporation that is reactive towards the undesired anions.

[0218] This example also demonstrates the incorporation yield of 0.1 to 1,000 m 2 / g. [Explanation of symbols]

[0219] 11 Unit Operations I 12 Unit Operations II 13 Organic waste 14 Treatment of the organic phase 15 Treatment of anions 16 Spills 17 Specific Materials 18 Recovery process 21 Processing materials 22 Reactor (treatment, contact) 23 water 24 Materials capable of immobilizing unwanted anions in their structure 25 Materials reactive to unwanted anions 26 Collation 27 Spillage

Claims

1. 1. A method for treating a material containing at least one organic compound prone to release undesirable anions during thermal and / or chemical and / or physical treatment, the method comprising at least one step in which the material is contacted with a sub- or supercritical aqueous medium in the presence of a material reactive to the undesirable anions and capable of fixing the undesirable anions in its structure, whereby the organic compound is destroyed and at least partially mineralized; and simultaneously, the undesirable anions are released and immediately captured by the material reactive to the undesirable anions and then fixed, producing an aqueous solution free of undesirable anions.

2. 2. The method of claim 1, wherein the undesired anions are dangerous and / or toxic and / or harmful and / or corrosive anions and / or anions prone to form dangerous and / or toxic and / or harmful and / or corrosive compounds.

3. 3. The method of claim 2, wherein the undesired anions are selected from among anions of elements in Groups V, VI, and VII of the Periodic Table of the Elements and anions comprising elements in Groups V, VI, and VII of the Periodic Table of the Elements.

4. 4. The method according to claim 1, wherein the organic compound of the treatment material is selected from organic polymers.

5. 5. The method of claim 1, wherein the treatment material consists of one or more organic compounds; or the treatment material is a composite material comprising, in addition to said one or more organic compounds, at least one inorganic compound, and said at least one inorganic compound is recovered once contacting is complete.

6. 6. The method of claim 5, wherein the composite material forms part of a multilayer device or a multilayer device comprising at least one organic layer; a photovoltaic module or any photovoltaic module comprising at least one organic layer; food packaging; pharmaceutical packaging; or an electronic device.

7. 7. The method of claim 6, wherein the composite material comprises a lower protective layer, also called the backside, or backing layer or sheet ("backsheet") of a photovoltaic module (PV module).

8. 8. The method according to any one of claims 1 to 7, wherein the aqueous medium is selected from water and aqueous solutions.

9. 9. The method according to any one of claims 1 to 8, wherein the material reactive towards the undesired anions is selected from among materials containing alkali and / or alkaline earth elements.

10. 10. The method of claim 1, wherein the material reactive to the undesired anions is selected from natural materials; artificial materials; and synthetic materials.

11. 11. The method of claim 1, wherein the material reactive with the undesired anions is in the form of particles.

12. The material reactive to the undesired anions is 0.1 to 1,000 m ２ 12. The method according to claim 1, wherein the sintered body has a specific surface area of ​​0.15 to 0.25g / g.

13. 13. The method according to any one of claims 1 to 12, wherein the ratio of the mass of the organic compound to the mass of the material reactive towards the undesired anions is between 0.01 and 0.

5.

14. 14. The method of claim 1, wherein the material reactive with the undesired anions is already present in the process material.

15. 14. The method of claim 1, wherein the material reactive with the undesired anions is not already present in the process material and is added to the subcritical or supercritical aqueous medium and / or to the process material.

16. 16. The method of any one of claims 1 to 15, wherein the treatment material is contacted with pressurized water in a subcritical state at a pressure ranging from greater than 2 MPa (20 bar) to less than 22.1 MPa (221 bar) and a temperature from greater than 150°C to less than 374°C.

17. 16. The method of any one of claims 1 to 15, wherein the treated material is contacted with pressurized water in a supercritical state at a pressure of 22.1 MPa or greater and a temperature of 374°C or greater.

18. 18. The method of any one of claims 1 to 17, wherein the treatment material is contacted with the subcritical or supercritical aqueous medium further in the presence of an oxidizing agent.

19. 19. The method of claim 18, wherein the oxidizing agent is selected from pure oxygen, air, and hydrogen peroxide.

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