PROCESS FOR PURIFYING GAS OR LIQUID EFFLUENTS BY CHEMICAL MODIFICATION FOLLOWED BY TOTAL DESTRUCTION OF POLLUTANTS.

Abstract

The invention relates to a process for the chemical modification of molecules of a gaseous or liquid composition followed by their total destruction either by natural aerobic biodegradation or by an advanced oxidation process (AOP). The invention relates to a process for the purification of a gaseous or liquid composition and then its total destruction by an advanced oxidation process consisting of: a volatile inorganic compound selected from carbon dioxide, nitric oxide, nitrogen dioxide, hydrohalic acids, carboxylic acids, thionyl chloride, sulfuryl chloride, ammonia, halogens, hydrogen sulfide, carbon oxysulfide, carbon monoxide, nitrogen oxide and sulfur dioxide, and / or a functional volatile organic compound: amine, amide, nitrile, aldehyde, ketone, ester, carboxylic acid, alcohol, thiol, disulfide, thioester, halogenated organic compounds, phosgene, Hydrogen cyanide and cyanides.less one volatile inorganic compound selected from carbon dioxide, nitrogen monoxide, nitrogen dioxide, hydrohalic acids, thionyl chloride, sulfuryl chloride, ammonia, halogens, hydrogen sulfide, carbon oxysulfide and sulfur dioxide.

Description

Title of the invention: PROCESS FOR PURIFYING GASEOUS OR LIQUID EFFLUENTS BY CHEMICAL MODIFICATION THEN TOTAL DESTRUCTION OF THE POLLUTANTS.

[0001] The invention relates to a process for the chemical modification of molecules of a gaseous or liquid composition and then their total destruction either by the natural route of aerobic biodegradation or by an advanced oxidation process (AOP)

[0002] The emission of atmospheric pollutants is regulated by law, due to their negative impact, in particular on human health, biological resources, ecosystems and the climate.

[0003] These pollutants can be Volatile Organic Compounds (VOCs).

[0004] Global VOC emissions come, for 90% of them, from natural sources (biological fermentations, natural gas leaks) and for 10% from anthropogenic sources (resulting from human activities). Naturally occurring emissions are distributed evenly across the Earth's surface. On the other hand, anthropogenic emissions come mainly from industrialized countries.

[0005] Some VOCs can cause eye and throat irritation, allergies, headaches, asthma attacks, nausea, etc.

[0006] Certain VOCs also play an important role in the troposphere, leading to an increase in the amount of ozone in the air. Ozone is produced, among other things, from nitrogen dioxide under the effect of solar radiation. The ozone formed then reacts with nitric oxide to produce nitrogen dioxide. However, in the presence of VOCs, the previous cycle is modified by carbon radicals (powerful oxidants) which replace ozone during the reaction to form nitrogen dioxide, which leads to an increase in the amount of ozone. The increase in the amount of ozone, with its consequences for the environment and health, is therefore partly linked to VOC emissions.

[0007] Furthermore, greenhouse gas concentrations in the Earth's atmosphere have been increasing since the 19th century for essentially anthropogenic reasons. The increase in the main greenhouse gases is mainly due to certain human activities, including the massive use of fossil fuels (coal, oil).

[0008] In this context, the treatment of gaseous effluents, wastewater and sludge, as well as the recovery of domestic, industrial and agricultural organic residues, are of definite interest from a political, economic and environmental point of view.

[0009] With regard to the treatment of gaseous effluents, conventional processes use oxidants, such as bleach. However, these oxidative washing methods have the major disadvantage of generating oxidation by-products in the discharges which are themselves polluting and sometimes very smelly. In addition, these oxidants are unstable and their handling is dangerous. In addition, the water treated with these oxidants must be sent for destruction to approved centers at a significant cost.

[0010] Regarding the recovery of domestic, industrial and agricultural organic waste, the integration of biogas into the French energy landscape allows in particular a significant reduction in greenhouse gases released. Said biogas is a combustible gas obtained by fermentation, also called methanization, of organic waste of animal or vegetable origin in the absence of oxygen, which mainly comprises methane as well as carbon dioxide.

[0011] Indeed, the impact of methane on the greenhouse effect being 20 to 25 times greater than that of carbon dioxide, it is preferable to use biogas as a renewable energy source, rather than releasing it into the atmosphere.

[0012] Recent fluctuations in the costs associated with the importation of fossil fuels, in a context of increasing scarcity of these fossil fuels, have also had a positive impact on the renewed economic interest in the production of energy from biogas.

[0013] Biogas is used in different ways. After light treatment, it can be used close to the production site to provide heat, electricity or a mixture of the two (the high carbon dioxide content reduces the calorific value of the biogas, increases compression and transport costs and consequently limits the economic interest of using biogas far from the production site).

[0014] Biogas can also be purified to allow for wider use. In particular, biogas can be subjected to purification which consists of removing undesirable substances and traces of pollutants (ammonia, sulfur compounds, VOCs) from the raw biogas and increasing its methane content (in particular by removing CO2) to produce a gas comparable to natural gas. The biogas thus purified and enriched is called biomethane, and has a calorific value equivalent to that of natural gas. Purified biogas is also the precursor of biohydrogen obtained by steam cracking.

[0015] Indeed, research on the subject over the last ten years has highlighted the disadvantages of VOCs and in certain cases of siloxanes, present in biogas, on the operation of energy exploitation installations.

[0016] Whatever the recovery process chosen, the presence of these compounds at concentrations of the order of ppm constitutes a risk of premature degradation of the installations, as well as a depreciation of the energy recovery yields of the biogas.

[0017] For example, in the case of using biogas as engine fuel, it is necessary to eliminate siloxane compounds because, when oxidized at high temperatures, siloxanes form silica deposits which can seriously damage equipment.

[0018] Biogas purification is generally carried out according to the following processes:

[0019] - pressure swing adsorption (PSA, or in English, Pressure Swing Adsorption, PSA): the process uses an adsorbent (molecular filters or zeolites). This process is however very complex (particularly due to the need to work under pressure) and has the disadvantage of releasing CO2 into the atmosphere at the end of the treatment cycle and generating a loss of biomethane in the form of vents (or "offgas");

[0020] - water washing: this water washing process involves a water washing tower under pressure, a degassing tower and a desorption tower;

[0021] - physical absorption with an organic solvent: this process is similar to that of washing with water, the solvent in this case being an organic fluid, in particular glycols, amino alcohols or amines. However, this process requires the regeneration of the solvent;

[0022] - membrane separation: membrane separation works like a filter. This process is however complex due to the need to work under pressure, and has the disadvantage of releasing CO2 into the atmosphere at the end of the treatment cycle.

[0023] A process has now been developed for the chemical modification of the molecules of a gaseous or liquid composition and then their total destruction, comprising a controlled and mastered alkalization step at 9 <pH<l 1 avec de la soude diluée lors d'une mise en contact avec un composé de formule (I) tel que défini ci-après, permettant avantageusement de remédier aux inconvénients précités.

[0024] This method also offers several advantages.

[0025] Firstly, the method according to the invention allows the treatment of any pollutant, alone or in a multi-pollutant mixture, chosen from volatile inorganic compounds (carbon dioxide, nitrogen monoxide, nitrogen dioxide, hydrohalic acids, thionyl chloride, sulfuryl chloride, ammonia, halogens, hydrogen sulfide, carbon oxysulfide, thiols and sulfur dioxide), and functional volatile organic compounds, and this, in particular on a single washing tower.

[0026] Furthermore, the method according to the invention is simple to implement, and is easily integrated into existing systems, for example without it being necessary to modify existing washing towers.

[0027] Furthermore, the process according to the invention is competitive from an economic point of view, in particular for the production of biomethane.

[0028] Thus, according to a first aspect, the invention relates to a process for chemically modifying the molecules of a gaseous or liquid composition and then for their total destruction consisting of:

[0029] - One or more volatile inorganic compounds chosen from carbon dioxide, nitric oxide, nitrogen dioxide, hydrohalic acids, carboxylic acids, thionyl chloride, sulfuryl chloride, ammonia, halogens, hydrogen sulfide, carbon oxysulfide, carbon monoxide, nitrogen oxide and sulfur dioxide, and / or - One or more functional volatile organic compounds from among: amine, amide, nitrile, aldehyde, ketone, ester, carboxylic acid, alcohol, thiol, disulfide, thioester, halogenated organic compounds, phosgene, hydrocyanic acid and cyanides. According to a particular embodiment where the only compounds present alone or in a mixture are sulfur derivatives such as hydrogen sulfide, thiols, carbon oxysulfide, sulfur dioxide, phosgene or thionyl chloride, said composition said method comprising the following steps:

[0030] (i) alkalization in a washing system of said composition at 9 <pH<l 1 par a solution of soda or potash, to avoid excessive consumption due to the possible presence of carbon dioxide (CO2), or simply sodium carbonate.

[0031] (ii) in-situ contact with a compound of general formula (I) in the presence of a phase transfer agent of alkaline quaternary ammonium type, bactericidal or virucidal:

[0032] X-CH2-CO-R (I)

[0033] in which:

[0034] X represents: • a halogen,

[0035] R represents: • an OH group or an ONa group,

[0036] to obtain a new chemically modified composition, as well as a new product resulting from the reaction of the pollutant with said alkaline solution and / or said compound of formula (I);

[0037] A process for the chemical modification of a malodorous sulfur compound with the compound of general formula (I) is carried out in the presence of an alkaline, bactericidal or virucidal quaternary ammonium phase transfer agent to obtain a new odorless compound.

[0038] Chemical modification process in which said composition is a product derived from nature (Algae).

[0039] Chemical modification process in which said composition is a product resulting from the treatment of wastewater.

[0040] According to a particular embodiment, for any other composition not containing a sulfur derivative as mentioned above:

[0041] (iii) bringing said gaseous or liquid composition into contact by washing in an exchanger or by simple bubbling with sodium percarbonate (PCS) CAS No. 15630-89-4 also called "solid hydrogen peroxide" in the presence of a source of intense UV radiation in an advanced oxidation process (AOP).

[0042] UV rays transform hydrogen peroxide (H2O2) in sodium percarbonate into hydroxyl radicals which attack and break down pollutants.

[0043] The total degradation products are: • CO — > carbon dioxide • NOx—> sodium nitrate • SOx— > sodium sulfate • Any volatile organic compounds (VOCs) are transformed into CO2 + H2O

[0044] The claimed method is based on an advanced oxidation process (AOP) in the sodium percarbonate / UV radiation couple according to an aqueous phase oxidation method which consists of using highly reactive derivatives for the destruction of the target pollutants. In water, the POA process generates the hydroxyl radical, a secondary oxidant more powerful than hydrogen peroxide alone. This secondary oxidant can oxidize the majority of organic compounds until they are completely mineralized in the form of carbon dioxide and water. The oxidation potential of the hydroxyl radical is much higher than that of hydrogen peroxide alone and its reaction rate is increased. As a result, contact time and footprint can be reduced.

[0045] Advanced oxidation processes (abbreviated POA), in the broad sense, are a set of physicochemical treatment procedures designed to destroy organic and sometimes inorganic matter suspended or dissolved in domestic, urban or industrial effluent water, by oxidation via reactions with hydroxyl radicals (HO*).

[0046] In the field of wastewater treatment chemistry, this expression more specifically designates a subset of these chemical processes based on ozone (03), hydrogen peroxide (H2O2) or UV light; in all these cases, we also speak of “in situ chemical oxidation”.

[0047] Organic or semi-organic contaminants are converted to a large extent into stable inorganic compounds (mainly water and carbon dioxide, and metal or metalloid salts). This is therefore an accelerated mineralization process. The POA makes it possible to reduce organic pollution and the toxicity of the effluent to the point where it can be safely reintroduced into the receiving environment or, at worst, into conventional wastewater treatment. The POA alone cannot eliminate mineral and metallic toxins that require additional treatment. It destroys pollutants that otherwise resist treatment plants, such as pesticide residues, antibiotic and other drug residues, and many endocrine disruptors.

[0048] Thus, only the inert gaseous compounds (methane, butane, propane, nitrogen, oxygen) are not captured. The method according to the present invention therefore makes it possible to purify gaseous streams comprising mainly said inert gaseous compounds, alone or in mixtures.

[0049] According to a particular embodiment, said composition is a biogas.

[0050] Said biogas comes in particular from the methanization of industrial or agricultural waste, household waste, sewage sludge or products of natural hydraulic fracturing.

[0051] According to a particular embodiment, said composition is a natural gas, obtained in particular by hydraulic fracturing. Hydraulic fracturing is in particular a technique which makes it possible to release the gas trapped in underground rocks. This is then referred to as hydrofracturing or "fracking". It can also be natural hydraulic fracturing (or cryoclasty), which can be terrestrial or marine, for example green algae or sargassum algae.

[0052] According to a particular embodiment, said composition is a pyrolysis gas or Syngas composed of: • Chemically neutral fuels such as light non-condensable hydrocarbons • Functional substances such as hydrochloric, hydrocyanic, hydrofluoric acids, ammonia, nitrogen oxides, sulfur dioxide, hydrogen sulfide.

[0053] According to a particular embodiment, said composition is a combustion gas composed of:

[0054] Carbon dioxide, nitrogen, oxygen, carbon monoxide, water, nitrogen oxides (NOx) and sulfur oxides (SOx).

[0055] According to a particular embodiment, said composition is a refined petroleum product such as diesel, jet fuel, kerosene and other fuels such as fuel oils.

[0056] In refineries, gas-liquid or liquid-liquid extraction is widely used in the improvement phase, and it is also very useful for removing undesirable sulfur compounds from petroleum hydrocarbons. This treatment, called "sweetening," rids these products of sulfur pollutants.

[0057] In all these cases, the method according to the invention finds application, for example, in the following sectors: • petrochemicals, • refining, • steel industry, foundries, • waste and hydrocarbon treatment industries, • mineral chemistry industries: for example production of sulfuric acid and titanium oxide, • chemical industries (organic chemistry, fine chemistry), • the paper industries, • the agri-food industries. • bioenergies (biogas, biomethane and biohydrogen), • agriculture.

[0058] The method according to the invention is easily integrated into existing systems, in particular without it being necessary to modify the existing washing towers.

[0059] For example, step (i) can be carried out in a single washing tower. This is then a discontinuous process, known as a “batch”. The tower can then be drained, and the liquid effluent discharged to a basin for receiving industrial water. The tower can then be recharged for another operation.

[0060] Alternatively, the composition to be treated can be sent to a treatment unit generally comprising two to three washing towers. For example, each tower is equipped with at least one recycling pump. The base of each tower serves as a retention volume and suction tank for the bath recirculation pump. In each tower, air is introduced from bottom to top and the washing solutions are sprayed counter-currently, from top to bottom. This type of 2 or 3-stage installation is suitable for continuous treatment. Once the first tower has reached saturation controlled by pH-metry (in particular pH < 9), the flow can be switched to the second tower, and so on.

[0061] The most widely used technologies are packed columns, spray and atomization towers, and horizontal washing towers, all well known in the art.

[0062] Plastic, vitrified or stainless steel materials are most often recommended to avoid or limit corrosion problems.

[0063] According to a particular embodiment, OR is an OH group.

[0064] According to a particular embodiment X represents chlorine, the compound of formula (I) then represents monochloroacetic acid (CAS No. 79-11-8).

[0065] When X represents chlorine and R represents an ONa group, the compound of formula (I) then represents sodium monochloroacetate (CAS No. 3926-62-3).

[0066] According to a particular embodiment, the functional volatile organic compound is chosen from volatile organic compounds carrying an amine, amide, nitrile, aldehyde, ketone, ester, carboxylic acid, alcohol, thiol, disulfide, thioester group, halogenated volatile organic compounds, phosgene and hydrocyanic acid.

[0067] Volatile aldehydes, particularly in gaseous form, are for example formaldehyde.

[0068] Volatile aldehydes, especially in the form of aerosols, are for example acetaldehyde, butanal, pentanal, hexanal and heptanal.

[0069] Volatile ketones, in particular in the form of aerosols, are for example acetone, methyl ethyl ketone, methyl isobuthyl ketone.

[0070] Volatile carboxylic acids, especially in the form of aerosols, are for example formic acid, acetic acid, acrylic acid.

[0071] Halogenated volatile organic compounds are, for example, methyl chloride, dichloromethane, chloroform, carbon tetrachloride, their C2 or C3 analogues, chlorofluorocarbons, vinyl chloride, dichloroethylene, trichloroethylene, tetrachloroethylene, dichloroacetylene and allyl chloride.

[0072] Volatile alcohols, especially in the form of aerosols, are for example methanol, ethanol, propanol, butanol and ethylene glycol.

[0073] Volatile thiols are for example methanethiol, ethanethiol, 1-propanethiol, 2-propanethiol, tert-butanethiol.

[0074] Volatile thioesters are for example methylthioacetate, methylthiobutanoate, methylthiopentanoate.

[0075] According to a particular embodiment, in which steps (i) and (ii) are followed by a step (iii) of total destruction of said capture product, in particular in the form of liquid effluents, in particular in a treatment plant, more particularly in a biological treatment plant, even more particularly by aerobic biopurification.

[0076] In particular, the liquid effluents obtained at the end of the process according to the invention are odorless and colorless.

[0077] In the case of discharge into a collective sanitation network equipped with a treatment plant, the limit values ​​for discharge of wastewater are typically as follows: • Suspended solids: 600 mg / 1; • Chemical Oxygen Demand (COD): 2,000 mg / 1; • Biochemical Oxygen Demand, for 5 days (BOD5): 800 mg / 1.

[0078] The method according to the invention is compatible with such regulations, in the sense that said capture product makes it possible to fully comply with these limit values.

[0079] In fact, the process according to the invention makes it possible to obtain an absolutely odorless and colorless liquid treated product which can be directly discharged into a self-neutralization basin of a purification station; furthermore, the acidification does not regenerate mercaptans or hydrogen sulfide.

[0080] The chemical treatment of total destruction by advanced oxidation (POA) generates only minerals, water and CO2.

[0081] Biological treatment in a treatment plant also does not create any new nuisances, either at the level of the sanitation network or at the level of the plant itself.

[0082] In fact, BOD (Biological Oxygen Demand) and COD (Chemical Oxygen Demand) measurements are improved compared to conventional oxidative destruction processes.

[0083] The embodiments presented above with regard to the method according to the invention also concern the use according to the invention. Definitions

[0084] By “gaseous or liquid composition” is meant in particular a fluid (gas or liquid), for example air, nitrogen, oxygen, methane, butane, propane or their mixture, containing at least one pollutant.

[0085] By “purified composition” is meant in particular a composition obtained at the end of step (ii),

[0086] By "volatile organic compound" is meant any chemical compound having carbon and hydrogen, which can be replaced by other atoms such as halogens, oxygen, phosphorus, sulfur, silicon or nitrogen, and having a saturated vapor pressure greater than 10 Pa under normal conditions of temperature and pressure, with the exception of carbon oxides and inorganic carbonates and bicarbonates.

[0087] By "functional volatile organic compound" is meant any VOC carrying at least one functional group. In particular, the functional volatile organic compound is chosen from volatile organic compounds carrying an amine, amide, nitrile, aldehyde, ketone, ester, carboxylic acid, alcohol, thiol, disulfide, thioester group, halogenated volatile organic compounds, phosgene and hydrocyanic acid.

[0088] By "capture product" is meant the reaction product of at least one pollutant with said base and / or said compound of formula (I). These are in particular liquid effluents.

[0089] By "biogas" is meant a gas produced by the fermentation of organic matter in the absence of oxygen.

[0090] By "siloxane" is meant a saturated silicon-oxygen hydride with unbranched or branched chains alternating silicon and oxygen (each silicon atom is separated from its nearest neighboring silicon atoms by single oxygen atoms).

[0091] By "hydrohalic acid" is meant hydrofluoric acid, hydrochloric acid, hydrobromic acid or hydroiodic acid. EXAMPLES

[0092] Treatment of a gas stream from a petrochemical process gas unit.

[0093] Example 1: Chemical modification of the components to be treated Composition of the gaseous effluent to be treated:

[0094] Air flow with a flow rate of 1000 m3 / h. containing: • Hydrogen sulfide 5.7 mg / m3 (4.1 ppm) • Ethyl mercaptan 130 mg / m3 (51.2 ppm) Material

[0095] Existing absorption column on site, height: 3 m, base area: 0.28 m2 (diameter 60 cm), tray packing, air outlet in a 40 m high chimney.

[0096] Fluid circulation pump adjustable from 0 to 25 m3 / h.

[0097] Adjustable polluting gas effluent feed valve. Reagents

[0098] The quantities of sodium hydroxide and compound of formula (I) to be used are evaluated below, as a function of: • the hourly flow rate of the composition flow to be purified in m3; • the duration of daily processing; • the concentration of compounds to be captured in mg / m3. • Water at the bottom of the column: 600 L. • 30% potash: 13.7 kg (equivalent to 30% soda: 9.8 kg) • 40% reagent: 19.8 kg

[0099] This load was designed for a continuous operating time of approximately 30 hours.

[0100] The flow rate of the gases from the industrial column is limited to 1000 m3 / h. and the flow rate of the 7.5 m3 / h washing solution circulation pump.

[0101] The quantities of reagents, as well as those linked to the methods of the prior art are calculated with the following stoichiometries: Pollutant (1 eq.) Soda or potash (eq.) Compound of formula (I) (eq.) Bleach 47° (eq.) C1O2 (eq.) Ozone (eq.) H2O2 (eq.) Hydrogen sulfide 4.2 4.2 5.2 8.5 3.2 12.0 Ethyl mercaptan 1.1 1.1 8.5 8.2 4.0 8.5 Hourly air flow in m3 1000 Material in Kg Daily flow in kg Cost evaluation Duration of discharge in hours 30 Concentration of hair in mg / m3 of air Equivalent in ppm Units mg / m3 Price of materials recorded per Kg in € (ARCA NE) Carbon dioxide Pure reagent 4.00 Hydrogen sulfide 4.10 5.7 0.17 0.13 Pure potash 3.80 Methyl mercaptan Potash at 30% 2.90 Ethyl mercaptan 51.27 130.0 3.90 3.12 Pure soda 2.40 Propanethiol 1 or 2 Sodium hydroxide at 30% 1.60 Sulphur dioxide Bleach 147° 1.30 Hydrochloric acid Base required for neutralization in Kg (Soda or Potash as desired) Cost € hourly Cost € daily 30% soda lye Pure soda 30% potash lye 13.7 1.32 31.80 Pure potash Compound of formula (I) required for the reaction Cost € hourly Cost € daily Pure dry product (in kg) 7.93 6.34 0.26 6.24 40% solution required (in kg) 19.82 15.85 0.66 15.84 Equivalences for comparative information with the prior art: Cost € hourly Cost € daily Quantities of 47° Cl bleach required in the prior art systems 44 1.46 2.50 60

[0102] Thus, treatment with bleach is approximately twice as expensive as the process according to the invention. Treatments with C1O2 or H2O2 are even more expensive, being 10 times more expensive than the process according to the invention. In addition, the costs of transporting and destroying this bleached treatment water at an approved center must be taken into account. Results

[0103] This demonstration made it possible to ensure the planned operating time of 30 hours during which regular efficiency checks verified the absence of pollutants at the outlet of the industrial installation.

[0104] Controls'. Absence of hydrogen sulfide (H2S) and methyl mercatan (C2H5-SH) validated at the column outlet.

[0105] Before biological treatment

[0106] Clear and colorless appearance

[0107] pH = 10.9

[0108] Odor: no dominant odor

[0109] COD = 691mg / L

[0110] Example 2: Total destruction of the components to be treated modified in example 1.

[0111] The treatment water, approximately 600 l, perfectly clear, is transferred into a separate tank for advanced oxidizing treatment (AOT). Material

[0112] 1000 1 double-jacketed tank equipped with central agitation

[0113] Fluid recirculation pump adjustable from 0 to 25 m3 / h.

[0114] UV system on the fluid recirculation loop Reagents

[0115] Sodium percarbonate powder: 21.5 kg Operating mode

[0116] The treatment water from example 1, once loaded into the tank, is stirred.

[0117] The tank is preheated between 30 and 40°C

[0118] The recirculation loop is started between 20 and 25 m3 / h.

[0119] The UV system is activated.

[0120] The sodium percarbonate is added manually in regular scoops over a period of approximately 2 hours.

[0121] Maintain the temperature between 30 and 40°C as well as agitation and recirculation under UV for 1 hour. Results

[0122] The treatment solution consists of: • water initially loaded into the column and sodium chloride (NaCl) from Example 1, sodium carbonate and water from sodium percarbonate • sodium sulfate (Na2SO4), carbon dioxide (CO2) and water from the chemical degradation of the compound of formula (I) having reacted with the compounds to be treated in example 1

[0123] Analyses at the end of advanced oxidizing treatment:

[0124] Appearance: colorless

[0125] pH = 8.3

[0126] Odor: None

[0127] COD = 276 mg / L

[0128] Reminder of the limit values ​​in all cases, before discharge into the natural environment or into a collective sanitation network:

[0129] pH 5.5 - 8.5 (9.5 in the case of alkaline neutralization);

[0130] Temperature < 30 °C;

[0131] Suspended matter: 600 mg / 1;

[0132] COD: 2,000 mg / l;

[0133] DBO5: 800 mg / 1.

Claims

Claims

1. Process for the chemical modification of a gaseous or liquid composition characterized in that it comprises the following steps: (a) Chemical modification of the molecule(s) constituting the gaseous or liquid composition of the effluent to be treated. (b) Total destruction of the new molecule(s) formed either by aerobic biodegradation in a treatment plant or by advanced oxidation known as POA. Said total destruction is carried out by bringing the product of (a) into contact for an advanced oxidation known as POA with sodium percarbonate known as PCS in the presence of UV.The gaseous or liquid effluents are: - One or more volatile inorganic compounds selected from carbon dioxide, nitrogen monoxide, nitrogen dioxide, hydrohalic acids, carboxylic acids, thionyl chloride, sulfuryl chloride, ammonia, halogens, hydrogen sulfide, carbon oxysulfide, carbon monoxide, nitrogen oxide and sulfur dioxide, and / or - One or more functional volatile organic compounds from: amine, amide, nitrile, aldehyde, ketone, ester, carboxylic acid, alcohol, thiol, disulfide, thioester, halogenated organic compounds, phosgene, hydrocyanic acid and cyanides.

2. Chemical modification process according to claim 1 characterized in that it comprises the following steps: (i) alkalization in a washing system of said composition at 9 <pH<l 1 par une solution de soude ou de potasse. (ii) la mise en contact in-situ avec un composé de formule générale: X-CH2-CO-R (I) en présence de soude ou de potasse dans laquelle : X représente : un halogène, R représente : un groupe OH ou un groupe ONa

3. Chemical modification process according to claims 1 and 2 characterized in that it comprises the chemical modification of an inorganic sulfur-containing malodorous compound such as hydrogen sulfide or organic such as thiols with a compound of general formula (I) in the presence of a phase transfer agent of alkaline quaternary ammonium type, bactericidal or virucidal.

4. Chemical modification process according to claim 3 characterized in that it comprises the reaction of the effluent with the solution of said compound of formula (I) in the presence of a sodium hydroxide or potassium hydroxide solution to obtain a new odorless organic compound.

5. Chemical modification process according to claim 1 characterized in that the gaseous or liquid effluents are any other inorganic composition chosen from carbon dioxide, nitrogen monoxide, nitrogen dioxide, hydrohalic acids, carboxylic acids, ammonia, halogens, carbon monoxide and nitrogen oxides. Said inorganic composition is brought into contact for an advanced oxidation called POA with sodium percarbonate called PCS in the presence of a source of intense UV radiation.

6. Chemical modification process according to claim 1 characterized in that the gaseous or liquid effluents are any other organic composition: amine, amide, nitrile, aldehyde, ketone, ester, carboxylic acid, alcohol, disulfide, thioester, halogenated organic compounds, phosgene, hydrocyanic acid and cyanides. Said organic composition is brought into contact for advanced oxidation called POA with sodium percarbonate called PCS in the presence of a source of intense UV radiation.

7. Chemical modification process according to any one of claims 1 to 6, characterized in that the gaseous composition of the effluent to be treated is a biogas or a pyrolysis gas or Syngas.

8. Chemical modification process according to any one of claims 1 to 6, characterized in that the gaseous or liquid composition to be treated is a petroleum product.

9. Chemical modification process according to any one of claims 1 to 6, characterized in that the gaseous composition of the effluent to be treated comes from algae.

10. Method according to any one of claims 1 to 6, characterized in that the gaseous or liquid composition of the effluent to be treated is an effluent resulting from the treatment of wastewater.

11. Chemical modification process according to any one of claims 1 to 6, characterized in that the gaseous or liquid composition of the effluent to be treated is an effluent from agriculture.