Classifications

• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F11/00—Treatment of sludge; Devices therefor
  • C02F11/06—Treatment of sludge; Devices therefor by oxidation
  • C02F11/08—Wet air oxidation
  • C02F11/086—Wet air oxidation in the supercritical state
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
  • B01J3/006—Processes utilising sub-atmospheric pressure; Apparatus therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
  • B01J3/008—Processes carried out under supercritical conditions
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/72—Treatment of water, waste water, or sewage by oxidation
  • C02F1/727—Treatment of water, waste water, or sewage by oxidation using pure oxygen or oxygen rich gas
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/72—Treatment of water, waste water, or sewage by oxidation
  • C02F1/74—Treatment of water, waste water, or sewage by oxidation with air
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K23/00—Use of substances as emulsifying, wetting, dispersing, or foam-producing agents
  • C09K23/017—Mixtures of compounds
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2101/00—Nature of the contaminant
  • C02F2101/30—Organic compounds
  • C02F2101/32—Hydrocarbons, e.g. oil
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/001—Upstream control, i.e. monitoring for predictive control
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/08—Chemical Oxygen Demand [COD]; Biological Oxygen Demand [BOD]
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/20—Total organic carbon [TOC]
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/22—O2
  • C02F2209/225—O2 in the gas phase
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2305/00—Use of specific compounds during water treatment
  • C02F2305/04—Surfactants, used as part of a formulation or alone
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K23/00—Use of substances as emulsifying, wetting, dispersing, or foam-producing agents
  • C09K23/42—Ethers, e.g. polyglycol ethers of alcohols or phenols

Definitions

• the present invention relates to the field of the treatment of organic waste by hydrothermal oxidation.
• the treatment typically leads to oxidation in the form of simple compounds such as CO 2 and H 2 O.
• the salts of metals other than alkali and alkaline earth metals are typically converted into (hydr) metal oxides.
• WO 89/08614 describes such a hydrothermal oxidation treatment method.
• the oxidation of the organic compounds contained in the effluent is carried out progressively during its flow and the heat energy produced during the oxidation reaction at each injection is used to progressively pass the reaction mixture through a subcritical state in the liquid phase to a supercritical state.
• the oxidation reaction produces a large amount of thermal energy in the areas where the oxidant concentration is highest, that is, in the oxidant injection zones.
• the appearance of these hot zones is likely to damage the walls of the reactor. It is therefore desirable to control this release of thermal energy.
• the effluents are generally characterized by their calorific value (PC).
• the calorific value of a fuel is the combustion reaction enthalpy per unit mass under normal temperature and pressure conditions.
• the PC represents the energy released in the form of heat by the combustion reaction with oxygen.
• the PC is usually expressed in kilojoules per kilogram (denoted kJ / kg or kJ-kg-1).
• COD Chemical Oxygen Demand
• the COD analysis measures the amount of oxidizable material present in the effluent, but for identical compounds, the more the oxidizable material is concentrated, the higher the heating value is high.
• the effluents are characterized by their DTO (Total Oxygen Demand), whose value is very close to COD experimentally, and has faster measurement times.
• the optimal area of use of the hydrothermal oxidation is DTO effluent to be treated understood by for example between 20 and 400 g / l, preferably between 100 and 250 g / l, more preferably between 150 and 220 g / l.
• the waste to be treated comprising at least one organic phase is either composed of a single organic phase (monophasic waste) or an at least two-phase waste comprising insoluble aggregates of average or apparent diameter greater than 1 mm or 5 mm
• the waste is particularly difficult to treat since the DTO is not homogeneous within it. Areas of very high DTO (organic phase) are observed, and possibly zones of weak DTO (aqueous phase). Direct treatment by hydrothermal oxidation gives rise to technical difficulties since "hot spots" are formed which can provoke a runaway of the reaction.
• Oneto et al involves the injection of the waste into the aqueous phase under supercritical conditions, which requires the use of expensive installations, and especially adapted for this purpose.
• this method does not allow implementation in the context of a hydrothermal oxidation under subcritical starting conditions.
• the applicant has solved this technical problem by implementing a step of preparation of an oil-in-water emulsion with a DTO controlled from a waste comprising at least one organic phase, prior to the implementation. of the hydrothermal oxidation step.
• An object of the present invention thus relates to a waste treatment process comprising at least one organic phase, said process comprising the following successive steps: a) preparation of an oil-in-water emulsion, with a DTO controlled from a waste to be treated comprising at least one organic phase, by mixing in a mixer, preferably at high shear, said waste with an aqueous phase; b) optionally adjusting the DTO of the emulsion obtained in step a);
• - consists of a single organic phase (monophasic waste), or a multiphasic waste (at least biphasic) comprising at least one organic phase, in the form of a decanted or emulsion comprising aggregates or drops of average or apparent diameter greater than 1 mm, preferably greater than 5 mm.
• Another object of the present invention also relates to an installation adapted for implementing the method according to the invention, comprising:
• a mixer (1) preferably high shear, adapted to receive an aqueous phase and the waste to be treated to prepare the emulsion;
• a hydrothermal oxidation reactor (6) preferably tubular and comprising several points of injection of the oxidant, for carrying out the hydrothermal oxidation of the emulsion under subcritical or supercritical starting conditions.
• Figure 1 is a schematic representation of an installation adapted for implementing an advantageous embodiment of the method according to the invention.
• oil-in-water emulsion means an at least two-phase composition comprising a continuous phase and at least one discontinuous phase, the continuous phase being of aqueous nature, and the discontinuous phase being essentially of a nature organic.
• the emulsion is biphasic.
• the term "waste to be treated comprising at least one organic phase” means a waste which consists either of a single organic phase (monophasic waste) or an at least two-phase waste comprising at least one organic phase.
• a multiphasic waste comprising at least one organic phase is presented by example in decanted form or emulsion comprising aggregates or macroscopic drops, that is to say whose average or apparent diameter is greater than 1 mm, preferably greater than 5 mm.
• the term "organic phase” is intended to mean a water-immiscible phase which is, for example, in the form of a decanted form or of aggregates or macroscopic drops, that is to say of which the average diameter or apparent is greater than 1 mm, preferably greater than 5 mm.
• the organic phase preferably comprises essentially organic constituents (optionally mixed with inorganic material), and is present at a concentration which exceeds its saturation concentration in water.
• the organic phase is therefore distinct from the aqueous phase, which itself consists essentially of water, optionally mixed with inorganic material (preferably soluble).
• the organic phase thus constitutes the discontinuous phase of the oil-emulsion. in water ..
• Total oxygen demand means the mass of ⁇ 2 (oxygen) necessary to effect the complete oxidation of one liter of organic waste, and / or inorganic waste, ie the total decomposition of the waste into CO 2 and H 2 O, etc. under thermal oxidation conditions.
• DTO is expressed in g / L.
• the measurement of the DTO can in particular be carried out according to the following procedure. A sample volume of the effluent to be analyzed is introduced into an oven at 1200 ° C., for example, in which circulates a controlled flow of ⁇ 2 gas. This flow of oxygen is measured at the furnace outlet, for example using a zirconium detector.
• the thermal oxidation of the effluent in the furnace is assumed to be total at this temperature, and causes a decrease in the measured oxygen flow at the outlet. Measuring the oxygen flow consumed by the reaction is used to express the DTO in g ⁇ 2 per liter of waste.
• COD or "chemical oxygen demand” is also mentioned, which for the purposes of the present invention is defined as the mass of O 2 necessary to effect the complete oxidation of one liter of organic waste, and or inorganic, that is to say the total decomposition of the waste CO 2 and H 2 O, etc. under chemical oxidation conditions.
• the measurement of COD can in particular be carried out using a customary COD meter, for example as described in the standards NFT90-101 and ISO15705.
• the measurement of the COD may in particular be carried out according to the following procedure. A sample volume of the effluent to be analyzed is introduced into a commercial tube comprising potassium dichromate, and the tube is then introduced into an oven at 148 ° C. for two hours. The tube is then taken out of the oven, and a colorimetric measurement at the 605 nm wavelength is performed.
• the DCO meter which is calibrated, directly gives a COD value by correlation with the measured absorbance value.
• the effluents are characterized by their DTO (Total Oxygen Demand), the value of which is very close to COD experimentally. In general, there is a difference of at most 5% between the measured values of DTO and COD.
• DTO Total Oxygen Demand
• the term "hydrothermal oxidation (OHT) under supercritical starting conditions” is intended to mean that the hydrothermal oxidation is conducted at the inlet of the reactor under conditions of pressure and temperature such as water, which is the solvent of the reaction and therefore the major constituent of the reaction mixture, is in the form of supercritical fluid.
• the supercritical point of water corresponds to the temperature of about 374 ° C at a pressure of about 221 bar.
• the initial temperature of the effluent at the inlet of the reactor in which the hydrothermal oxidation takes place is preferably between 374 ° C. and 600 ° C., and at a pressure of between 221 and 300 bar.
• the term "hydrothermal oxidation (OHT) under subcritical starting conditions” means that the hydrothermal oxidation is carried out according to a process in which the effluent (comprising the waste to be treated) is treated within of a reactor by introducing the oxidizing agent into at least one injection point, thereby increasing the temperature of the effluent from a subcritical initial temperature to a higher subcritical temperature or supercritical.
• the initial subcritical temperature of the effluent at the inlet of the reactor in which the hydrothermal oxidation takes place is preferably between 20 ° C.
• the hydrothermal oxidation stage under subcritical starting conditions according to the invention is preferably carried out according to a continuous process.
• the reactor used is a tubular reactor as described in WO 02/20414. DETAILED DESCRIPTION OF THE INVENTION
• the present invention relates firstly to a waste treatment process comprising at least one organic phase, said process comprising the following successive steps: a) preparation of an oil-in-water emulsion with a DTO controlled from a waste to be treated comprising at least one organic phase, by mixing in a mixer, preferably at high shear, said waste with an aqueous phase; b) optionally adjusting the DTO of the emulsion obtained in step a);
• high shear mixer is meant in the sense of the present invention a mixer capable of mixing two immiscible liquids of possibly different viscosities with a shear rate sufficient for the formation of an emulsion, as opposed to a low shear mixer which does not allow such a mixture.
• high-shear mixers of the SILVERSON® brand mention may be made in particular of high-shear mixers of the SILVERSON® brand.
• the waste to be treated comprising at least one organic phase is: - consists of a single organic phase (monophasic waste), or a multiphasic waste (at least biphasic) comprising at least one organic phase, in the form of a decanted or emulsion comprising aggregates or drops of average or apparent diameter greater than 1 mm, preferably greater than 5 mm.
• the waste to be treated is monophasic, and therefore comprises a single organic phase, optionally mixed with inorganic material, such as inorganic salts (inorganic or metallic).
• the waste comprising at least one organic phase is preferably selected from petroleum residues or residues from the chemical industry. They include, in particular, bitumens, tars, effluents of the draining oil type, and organic solvents. Said waste may have a very high viscosity.
• the DTO of the oil-in-water emulsion obtained at the end of step b), and used for the implementation of step c), is for example between 20 and 400 g / L, preferably between 100 and 250 g / l, more preferably between 150 and 220 g / l. DTO values of less than 400 g / L prevent excessive temperature rise within the reactor during OHT, which could lead to damage to the reactor. Step c) is then conducted under conditions to ensure the total safety of the process, and to increase the service life of the equipment used for the implementation of step c).
• DTO values above 100 g / L generally make the autothermal hydrothermal oxidation process possible, the oxidation reaction producing sufficient heat for self-maintenance, and the residual heat being advantageously recycled to other steps in the process or another industrial process, or reused to produce electricity.
• the control of the DTO of the emulsion used for the implementation of step c) makes it possible both to optimize the safety and the energy cost of the process.
• Step a) is advantageously carried out at atmospheric pressure and at room temperature. These reaction conditions make it possible to reduce the energy costs of the process.
• the aqueous phase consists essentially of water. It can nevertheless comprise between 1 and 30% of additives such as alcohols or sugars.
• the aqueous phase does not contain hydrogen peroxide.
• a surfactant is used in the aqueous phase to stabilize the emulsion.
• the aqueous phase of the emulsion in step a) comprises at least one surfactant, representing less than 10% by weight, for example from 0.1 to 10% by weight, relative to the total weight of the aqueous phase.
• a surfactant is not necessary to obtain an emulsion from the waste to be treated, which may comprise constituents acting as surfactants. Nevertheless, for the treatment of certain wastes, it seems preferable to use a surfactant. This may be of anionic, cationic or nonionic nature. Those skilled in the art will be able to adapt the choice of surfactant to the particular nature of the waste to be treated.
• the surfactant used in this embodiment is of the nonionic type.
• the polysorbates and nonylphenol ethoxylates have particularly advantageous emulsifying and heat-resisting properties for the implementation of step a).
• the surfactant according to the present invention is preferably chosen from polysorbates and nonylphenol ethoxylates.
• polysorbates is preferably meant pegylated derivatives of sorbitan, that is to say sorbitan derivatives comprising several polyoxyethylene chains and esterified with a fatty acid.
• Polysorbates are well known to those skilled in the art.
• the polysorbates comprise between 10 and 50 oxyethylene units - (CH 2 CH 2 O) -, more preferably between 15 and 30 oxyethylene units - (CH 2 CH 2 O) -, more preferably 20 oxyethylene units - (CH 2 CH 2 O) -.
• Polysorbate 20 or TWEEN® 20 Polyoxyethylene (20) sorbitan monolaurate, CAS 9005-64-5
• Polysorbate 40 or TWEEN® 40 Polyoxyethylene (20) sorbitan monopalmitate, CAS 9005-66-7
• Polysorbate 60 or TWEEN® 60 Polyoxyethylene (20) sorbitan monostearate, CAS 9005-67-8
• Polysorbate 80 or TWEEN® 80 Polyoxyethylene (20) sorbitan monooleate, CAS 9005-65-6.
• the polysorbate used is Polysorbate 80 or TWEEN® 80.
• nonylphenol ethoxylates preference is given to nonylphenol ethoxylates comprising between 10 and 50 oxyethylene units - (CH 2 CH 2 O) -, more preferably between 15 and 30 oxyethylene units - (CH 2 CH 2 O) -, preferably 20 oxyethylene units - (CH 2 CH 2 O) -.
• nonylphenol ethoxylates comprising between 10 and 50 oxyethylene units - (CH 2 CH 2 O) -, more preferably between 15 and 30 oxyethylene units - (CH 2 CH 2 O) -, preferably 20 oxyethylene units - (CH 2 CH 2 O) -.
• Tergitol NP® Tergitol 15-S®.
• the nonionic surfactant preferably represents from 0.1 to 10% by weight, preferably from 0.1 to 5% by weight, more preferably from 0.1% to 1% by weight relative to the total weight of the aqueous phase.
• the nonionic surfactant is mixed with the aqueous phase.
• the aqueous phase comprises from 0.1 to 10% by weight, relative to the total weight of the aqueous phase, of at least one nonionic surfactant.
• the waste to be treated comprising at least one organic phase is gradually incorporated into said aqueous phase comprising the nonionic surfactant in a mixer, leading to the formation of the oil-in-water emulsion.
• the mixer is a high shear mixer.
• the waste to be treated comprising at least one organic phase and the aqueous phase comprising the nonionic surfactant are mixed for a period of less than 24 hours, preferably less than 12 hours, preferably for approximately 1 hour.
• the method according to the invention comprises a step b) of adjusting the DTO.
• the adjustment of the DTO can be obtained:
• step a) if the measured DTO of the emulsion resulting from step a) is too high: by dilution, for example by addition of water or of another lower DTO effluent;
• the measured DTO of the emulsion resulting from step a) is too low: by concentration, for example by adding organic and / or inorganic waste or a higher DTO effluent in the effluent to be treated, preferably said waste comprising at least one organic phase, or by addition of a soluble organic additive in the continuous phase, generally alcohols, in particular linear or branched C 1 -C 8 alcohols, or sugars such as glucose.
• linear or branched C 1 -C 8 alcohol means a linear or branched alkyl comprising at least one alcohol (OH) function.
• OH alcohol
• isopropanol will be considered.
• step b a sample is taken of the emulsion obtained at the end of step a), and a measurement of the DTO of this sample is carried out. It is noted that the location of the sampling on the mixing system is indifferent for the measurement of the DTO. Depending on the result of DTO obtained, that is:
• the effluent is sent to a storage tank, that is to say in the hydrothermal oxidation reactor by appropriate feed means including in particular a feed pump, and optionally including a heating system of the emulsion;
• step c) water or another less concentrated aqueous effluent is added, preferably water, optionally obtained at the end of step c) and recycled;
• an organic and / or inorganic waste or a more concentrated effluent in the emulsion is added, preferably it is said waste comprising at least one organic phase.
• steps a) and b) are conducted according to a batch or batch process (also called batch process).
• the emulsion obtained at the end of step a) or b) is typically sent to a storage tank, which is used to supply the reactor for the implementation of step c).
• the emulsion obtained at the end of step a) or b) comprises between 5 and 50% by weight, preferably between 15 and 45% by weight, and still more advantageously between 25 and 35% by weight. of organic phase relative to the total weight of the emulsion.
• the remainder of the emulsion consists of the aqueous phase, and optionally at least one surfactant, especially a nonionic surfactant, and / or additives.
• the emulsion obtained at the end of step a) or b) is advantageously homogeneous.
• the DTO of the emulsion is homogeneous on a macroscopic scale.
• the distribution of the drops in the emulsion is homogeneous.
• the emulsion obtained at the end of step a) or b) advantageously has an average drop size of less than 1000 ⁇ , preferably between 0.1 and 100 ⁇ , more preferably between 0.5 and 10 ⁇ , of more preferably between 0.5 and 5 ⁇ .
• average drop size is meant within the meaning of the present invention as well the mean diameter of discontinuous phase drops, as the apparent diameter of the possible aggregates.
• aggregate is meant in the sense of the present invention an assembly of several drops bonded together but not fused.
• step a) of forming the oil-in-water emulsion is essential for the treatment of the waste to be treated comprising at least one organic phase according to the present invention, since it allows both reduce the DTO of the waste to be treated, and increase the homogeneity of the DTO within it.
• the emulsion obtained at the end of step a) or b) is advantageously stable for a period of between 1 hour and 24 hours, preferably between 1 hour and 3 days, more preferably between 1 and 7 days.
• the desired minimum stability time is defined by the residence time of the emulsion between the storage tank and the inlet of the hydrothermal oxidation reactor. This stability is therefore particularly observed at temperatures between 15 ° C and 374 ° C, and at pressures between 1 and 300 bar. It should be noted that the turbulence accompanying the flow of the emulsion in the facilities contributes to the preservation of stability.
• stable is meant that the properties of homogeneity, average size of drops and waste content comprising at least one organic phase are preserved over the times and under the conditions of temperature and pressure mentioned. In particular, no aggregate formation is observed for a period of between 1 and 7 days, in particular about 3 days.
• This stability makes it possible to store the emulsion formed in step a) or b), in particular in order to conduct the possible measurements of DTO before the implementation of step c).
• the oxidant used in this step c) does not comprise hydrogen peroxide (H2O2).
• H2O2 hydrogen peroxide
• it consists solely of oxygen (O2) or air, or a mixture thereof.
• the effluent treated at the outlet of the oxidation reactor undergoes expansion, which generates gases on the one hand, essentially comprising CO2, and liquid water on the other hand.
• the liquid water thus obtained at the end of the hydrothermal oxidation step c) may undergo subsequent optional treatments, for example demineralization, in particular by reverse osmosis.
• the treated effluent can be recycled as a water source for the aqueous phase of step a), or the optional adjustment step b).
• the method according to the invention also comprises steps for analyzing other parameters such as the halogen content, preferably carried out between steps a) and b), so that step b) can also be used to adjust the halogen content for example.
• the present invention also relates to an installation adapted for implementing the method according to the invention, comprising: - a mixer (1), preferably high shear, adapted to receive an aqueous phase and the waste to be treated to prepare the emulsion; and
• a hydrothermal oxidation reactor (6) preferably tubular and comprising several points of injection of the oxidant, for carrying out the hydrothermal oxidation of the emulsion under subcritical or supercritical starting conditions, preferably under criticism.
• the installation further comprises a storage tank (2) for the emulsion adapted to receive and store the emulsion, the tank being located between the mixer (1) and the hydrothermal oxidation reactor (6), the storage tank being adapted to receive the emulsion to be treated in batches and for coupling the batch production of the emulsion to a continuous hydrothermal oxidation process.
• FIG. 1 represents a particular embodiment of the installation according to the invention.
• the installation comprises:
• a mixer preferably high shear receiving as input the aqueous phase comprising the surfactant and the waste comprising at least one organic phase;
• a storage tank (2) for the emulsion adapted to receive and store the emulsion at the outlet of the mixer;
• a hydrothermal oxidation reactor (6) preferably tubular and comprising a plurality of injection points (preferably three injection points) of the oxidant, the oxidant is preferably dioxygen;
• the mixer (1) advantageously comprises a manual valve or a valve (10) for taking an emulsion sample to measure in particular the DTO of said emulsion to optionally adjust to a suitable value.
• the valve or valve can be located on an in-line sampling loop.
• the aqueous phase is optionally stored in the tank (15), while the waste to be treated is stored in the tank (14).
• the tanks (14) and (15) are connected to the inputs of the mixer (1).
• the storage tank (2) makes it possible to receive the emulsion to be treated in batches (batchs), and to continuously feed the feed pump (3). In this way, the storage tank makes it possible to couple a batch process for manufacturing the emulsion which will serve as a reagent for the hydrothermal oxidation reaction, for a continuous hydrothermal oxidation process.
• the feed pump (3) injects the emulsion under pressure into the heat exchanger (4).
• the emulsion changes from atmospheric pressure to a pressure of preferably between 221 and 300 bar. At this stage, the emulsion is in the liquid state.
• the heat exchanger (4) is used to heat the emulsion at the outlet of the pump (3) by heat exchange with the effluent treated at the outlet of the reactor (6).
• the temperature of the emulsion is then between 150 and 374 ° C., preferably between 250 ° C. and 340 ° C.
• the exchanger transfers a part of the heat of the supercritical fluid obtained at the outlet of the hydrothermal oxidation reactor (6) to the emulsion used as reagent for the hydrothermal oxidation reaction.
• Such a device makes it possible to minimize the overall energy consumption of the process.
• the electric heater (5) makes it possible to heat the emulsion during the transitional start-up phase of the process when the effluent leaving the reactor has not reached a temperature sufficient to bring the emulsion to a temperature of between 150 and 374. ° C, preferably between 250 ° C and 340 ° C.
• the reactor (6) receives as input the emulsion from the exchanger (4) or the electric heater (5).
• the reactor (6) receives, on the one hand, the emulsion and, on the other hand, the oxygen under pressure necessary for the hydrothermal oxidation reaction.
• the emulsion circulates in the reactor.
• the oxygen is injected at different points of the reactor (preferably 3 points) along the flow path of the effluent.
• the effluent collected at the outlet of the reactor (6) has a DTO preferably of less than 300 mg / l, and is at a temperature of between 374 ° C. and 600 ° C., preferably between 500 ° C. and 500 ° C. ° C and 600 ° C.
• the effluent is then injected into the heat exchanger (4) to heat the emulsion at the inlet of the reactor (6).
• the effluent at the outlet of the exchanger (4) which is then typically at a temperature of between 200 ° C. and 250 ° C., is cooled by a cooler (7) to a temperature for example of between 15 ° C. and 100 ° C, preferably 15 ° C and 30 ° C.
• the cooler advantageously makes it possible to enhance the thermal energy of the effluent by using it for example for the generation of electricity or for heating (steam network or other).
• the cooled effluent thus obtained at the outlet of the cooler (7) undergoes expansion thanks to the expansion valve (8).
• the effluent then passes under atmospheric pressure. It is in the form of a mixture of gas and liquid, the gas phase including CO2 and ⁇ 2, optionally mixed with N 2 , and the liquid consisting essentially of water containing no organic matter.
• the liquid effluent obtained at this stage of the treatment has, for example, a COD of less than 300 mg / l, preferably less than 100 mg / l, more preferably less than 50 mg / l.
• the separator (9) separates the gaseous phase from the liquid phase.
• a portion of the liquid phase is taken at the outlet of the separator to be injected at the inlet of the mixer (1) to adjust the amount of water in the emulsion.
• Said liquid phase optionally undergoes additional treatment in order to adjust the quality of the water of the liquid phase.
• valves 1 1, 12 and 13 control the flow rate of the pressurized oxygen (oxidant), possibly in supercritical phase, injected into the reactor (6) at each of the three injection points.
• the process and the installation according to the invention thus make it possible to extend the field of application of the hydrothermal oxidation process to the treatment of waste comprising at least one organic phase under subcritical starting conditions, and this to the using a method that does not require special adaptation of the process itself but only a preparation of the effluent.
• the present invention allows a very particular improvement of the safety and the control of the process in terms of management of the temperature profile in the reactor (s), in particular thanks to a control of the DTO of the reagent (emulsion) used in the hydrothermal oxidation reaction.
• the present invention also allows an economic gain vis-à-vis the method described by Sanchez-Oneto.
• the process is conducted in an installation as described in FIG.
• the waste to be treated is an oil of the type used for transport vehicles. It essentially contains compounds based on elements C, H and O (used hydrocarbon waste), and is monophasic.
• Each test is based on 50g samples.
• the surfactant is mixed with deionized water.
• the aqueous phase thus obtained comprises 1% by weight of surfactant, relative to the total weight of the aqueous phase.
• the waste to be treated is gradually incorporated into said aqueous phase comprising the surfactant in a high-shear mixer of the brand Ultra Turrax®, marketed by the company IKA.
• the mixture is sheared for 1 to 5 minutes.
• Oil-in-water emulsions are then obtained.
• the amounts of water and waste are such that the emulsions obtained consist of 50% by weight of aqueous phase and 50% of effluent to be treated.
• the aqueous phase comprises 1% by weight of surfactant.
• 24.75 g of demineralised water, 0.25 g of surfactant and 25 g of waste to be treated are added.
• TTAB tetradecyltrimethylammonium bromide
• an anionic surfactant sodium lauryl sulphate
• the aqueous phase consists of 100% demineralized water, and the final emulsion comprises 50% by weight of demineralized water and 50% by weight of waste to be treated.
• the emulsion obtained has a DTO of between 850 g / l and 950 g / l.
• a dilution step by addition of demineralized water is therefore necessary to obtain a DTO of desired value (between 100 and 250 g / l).
• Stable emulsions which do not attach to the walls of the reactors are obtained, even after dilution, with TWEEN® 80 surfactants and sodium lauryl sulphate.
• the average diameter of the drops in the emulsions obtained is approximately 1 ⁇ .
• Waste is a toxic industrial two-phase waste. Its organic phase contains mainly compounds based on elements C, H and O (used hydrocarbon waste), and is in decanted form.
• the decanted waste was separated into an aqueous phase and an organic phase.
• the waste to be treated consists of the organic phase.
• Each test is based on 50g samples.
• the surfactant is mixed directly with the aqueous phase after separation of the two phases of the waste.
• the aqueous phase thus obtained comprises 1% by weight of the surfactant, relative to the total weight of the aqueous phase.
• the organic phase of the waste to be treated is gradually incorporated into said aqueous phase comprising the surfactant in a Ultra Turrax® high shear mixer, marketed by IKA.
• the mixture is sheared for 1 to 5 minutes.
• each phase is such that the emulsions obtained consist of 50% by weight of aqueous phase and 50% of organic phase.
• the aqueous phase comprises 1% by weight of surfactant.
• 24.75 g of aqueous phase isolated from the treated waste, 0.25 g of surfactant and 25 g of organic phase isolated from the waste to be treated are added.
• an anionic surfactant sodium lauryl sulphate
• a nonionic surfactant Polysorbate 80 or TWEEN® 80. Oil-in-water emulsions are then obtained only when an anionic or nonionic surfactant is used. No emulsions are formed with a cationic surfactant.
• the emulsions obtained (sodium lauryl sulphate and TWEEN® 80) have a DTO of between 850 g / l and 1050 g / l.
• a dilution step by addition of demineralized water is therefore necessary to obtain a DTO of desired value (between 100 and 250 g / l).
• Non-recoverable hydrocarbon waste The waste to be treated is a monophasic waste from the non-recoverable oil industry. Its organic phase essentially contains compounds based on elements C, H, O and S (crude oil type waste).
• Each test is based on 50g samples.
• the surfactant is mixed with deionized water.
• the aqueous phase thus obtained comprises 0%, 1%, 2% or 5% by weight, relative to the total weight of the aqueous phase, of the surfactant.
• the waste is gradually incorporated into said aqueous phase comprising the surfactant in a high shear mixer brand Ultra Turrax®, sold by the company IKA.
• the mixture is sheared for 1 to 5 minutes.
• the amounts of water and waste are such that the emulsions obtained consist of 70% by weight of aqueous phase and 30% of effluent to be treated.
• the aqueous phase comprises 0%, 1%, 2% or 5% by weight of surfactant.
• Polysorbate 80 or TWEEN® 80 (surfactant A);
• Tergitol® NP7 a surfactant of the family Nonylphenol Ethoxylates (surfactant B);
• the emulsions obtained have a DTO of between 225 g / l and
• the emulsion obtained is not stable. Moreover, it is noted that under these conditions, only the emulsion E9 requires additional dilution to obtain a DTO of less than 250 g / l.
• Example 2 Implementation of the hydrothermal oxidation reaction on the emulsions obtained according to the invention
• the waste to be treated is a monophasic waste from the non-recoverable petroleum industry (waste similar to the third waste of Example 1). Its organic phase essentially contains compounds based on elements C, H, O and S (crude oil type waste).
• a doping phase is then carried out using a second waste containing alcohols (isopropanol and butanol) in aqueous phase and perfectly soluble.
• 450L of dopant are added to the mixture and the whole is stirred for 12h.
• the DTO of the mixture obtained is 177 g / l.
• This emulsion is then used to continuously feed the hydrothermal oxidation plant under subcritical startup conditions.
• the emulsion is preheated at the inlet of the reactor and then injected into the reactor where a multiple oxygen injection is made at three points further downstream.
• the first injection raises the medium to a temperature T1, the second to a temperature T2 and the third to a temperature T3, according to a temperature profile increasing (without temperature decrease).
• the DTO of the flow at the outlet of the reactor was measured.
• Effective conversion of the emulsion is obtained with a final DTO equal to 27 mg / l and with control of the rise in temperature.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Hydrology & Water Resources (AREA)
• Water Supply & Treatment (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Treatment Of Water By Oxidation Or Reduction (AREA)
• Processing Of Solid Wastes (AREA)
• Treatment Of Sludge (AREA)
• Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)

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