Carbon dioxide capture and treatment system in a gaseous effluent

Abstract

The present invention relates to a system (10) and a method for capturing and treating carbon dioxide in a gaseous effluent, preferably at the source of emission of said effluent, regardless of the emission rate of the effluent and the concentration of CO2 in the gaseous effluent. Figure to be published with the abstract: Fig 1

Description

Title of the invention: System for capturing and treating carbon dioxide in a gaseous effluent Technical field

[0001] The invention relates to the technical field of carbon dioxide capture and treatment. In particular, the invention relates to a system and a method for capturing and treating carbon dioxide in a gaseous effluent.

[0002] State of the art

[0003] Reducing carbon dioxide (CO2) emissions has become an undeniable priority for everyone.

[0004] Although some significant progress has been made in reducing CO2 emissions, there remain critical gaps in the management of gaseous effluents, particularly in the agricultural, wine-growing, brewing and waste treatment sectors, in which fermentation is the source of significant CO2 emissions.

[0005] Fermentation is a natural biological process, fundamental in the production of alcoholic beverages such as wine, beer, spirits as well as for the production of biogas, in which certain microorganisms consume the sugars present in a set of organic materials, in order to produce alcohol in particular. This process generates the emission of gaseous effluents whose composition can vary depending on several factors, such as the type of microorganisms used, the fermentation conditions, the substrate and the duration of fermentation. However, the most commonly produced gas during fermentation is CO2.The amount of CO2 emitted and present in the gaseous effluents from fermentation can also vary depending on several parameters, such as the amount of sugar in the substrate, the mass of microorganisms used, the fermentation temperature, the size of the tank, the atmospheric pressure and the duration of fermentation.

[0006] However, conventional CO2 capture solutions are not adapted to these variations in flow rate and concentration and cannot be deployed efficiently and appropriately in installations in the agricultural, wine-growing, brewing or waste treatment sectors. In particular, they often prove to be poorly suited to low flow rate conditions, due to their high cost, technical complexity, bulk or high water consumption. The lack of a technical solution systematically leads to the release of CO2 into the atmosphere, due to the lack of a suitable device.

[0007] This issue is a significant challenge, because the accumulation of CO2 emissions, even if individually small, contributes significantly to the overall balance sheet. global greenhouse gas emissions.

[0008] Furthermore, beyond environmental issues, CO2 is also considered an essential raw material for the implementation of certain processes. Indeed, CO2 can be useful for many applications such as protection against oxidation of wine, carbonation of soft drinks, cryogenics or even its use as a solvent.

[0009] There is therefore a need for an alternative CO2 capture and treatment system for capturing CO2 from a gaseous effluent, particularly when the gaseous effluent has a low emission rate with a variable CO2 concentration, in an efficient, economical and ecologically responsible manner. Summary of the invention

[0010] To meet this need, the invention proposes a new system for capturing and treating CO2 in a gaseous effluent, capable in particular of capturing CO2 at the source, in the emissions of installations emitting CO2, such as agricultural, wine-growing, brewing and waste treatment installations.

[0011] The inventors have thus implemented a system for capturing and treating CO2 capable of capturing CO2 from a gaseous effluent with a low emission rate. The CO2 captured according to the invention is intended in particular to be stored and recovered.

[0012] Such a system is particularly useful in the context of the invention and overcomes the drawbacks of the prior art by making it possible to capture CO2 from a gaseous effluent, at the source, whatever its flow rate, in particular to capture CO2 in a gaseous effluent emitted at a low, or even very low, flow rate, namely at a flow rate of less than 500 m3 / hour, and whatever the CO2 concentration in the gaseous effluent.

[0013] Thus, the invention relates to a system for capturing and treating CO2 in a gaseous effluent, comprising at least: *a means of capturing a gaseous effluent, *a condenser comprising an inlet configured to receive the gaseous effluent captured by the capture means, the condenser being arranged to condense said captured gaseous effluent and to generate a liquid condensate and a gaseous effluent comprising CO2; *at least one filter comprising an inlet configured to receive the gaseous effluent comprising CO2 generated by the condenser, the filter being arranged to remove substantially all bacteria and yeasts from said gaseous effluent in order to generate purified CO2; *at least one compressor comprising an inlet configured to receive purified CO2 from the filter, the compressor being arranged to compress the purified CO2; * a reinjection loop of at least part of the CO2 compressed by the com presser to the condenser, the system comprising a device for regulating the pressure of said part of the CO2 reinjected to the condenser.

[0014] Preferably, the capture means comprises an inlet configured to be connected to the source of the effluent emission, such as a fermentation tank, in particular an alcoholic fermentation tank or a methanization tank and capable of emitting or producing a gaseous effluent comprising CO2. These are in particular agricultural, wine-growing, brewing or waste treatment installations. Advantageously, the system according to the invention makes it possible to capture and treat CO2 to purify it and use it in different applications, even when the emission flow rate is very low, namely even when it is less than 500m3 / hour.

[0015] According to another aspect, the invention relates to a method for capturing and treating CO2 in a gaseous effluent comprising the implementation of the following steps: (a) Capture of a gaseous effluent comprising CO2; (b) Condensing the gaseous effluent comprising CO2 by means of a condenser to condense said captured gaseous effluent and to generate a liquid condensate and a gaseous effluent comprising CO2, (c) Filtration of the gaseous effluent comprising CO2 obtained in step (b) by means of a filter to obtain purified CO2, (d) Compressing the purified CO2 obtained in step (c) using a compressor to obtain compressed CO2, (e) Possibly storage of compressed CO2, (f) Reinjection of the compressed CO2 from step d) or e) into step c), said reinjection comprising a step of regulating the pressure of the CO2 reinjected in step c).

[0016] According to one embodiment, the gaseous effluent from step (a) has a flow rate of between 1 and 500 m3 / hour, preferably between 1 and 100 m3 / hour, in particular between 1 and 50 m3 / hour, in particular between 1 and 10 m3 / hour.

[0017] According to another embodiment, the gaseous effluent from step (a) has a flow rate greater than 500m3 / hour.

[0018] Advantageously, the method according to the invention is versatile in that it can be used in a wide variety of applications, from small to large-scale installations. Furthermore, the method according to the invention is adapted to the fluctuation of gaseous effluent production and to variations in CO2 concentrations in the effluent. Such a method capable of managing these variations effectively guarantees efficient CO2 capture and treatment.

[0019] Of course, the various features, variants and embodiments of the invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive.

[0020] In addition, various other features of the invention emerge from the description attached made with reference to the figures which illustrate non-limiting forms of embodiment of the invention. Brief description of the figures

[0021] [Fig.l] schematically represents a system 10 for capturing and treating CO2 according to one embodiment of the invention.

[0022] It should be noted that in this figure the structural and / or functional elements common to the different variants may have the same references.

[0023] Of course, various other modifications may be made to the invention within the scope of the appended claims. Detailed description of the invention

[0024] Definitions

[0025] For the purposes of the invention, the term “purified CO2” means the CO2 obtained in gaseous form after condensation of the gaseous effluent. The purified CO2 has a concentration preferably: - at least 70% if the purified CO2 is intended to be used as technical CO2, for example to produce bicarbonate (technical CO2 means non-food CO2 that can be used in different applications), - at least 99% if the purified CO2 is intended to be used as food CO2, - at least 99.5%, preferably at least 99.9%, if the purified CO2 is intended to be used as food CO2 compatible with oenological uses, the percentages for the concentration being given in volume (v / v).

[0026] By “compressed” is meant a gas after compression in a compressor.

[0027] For the purposes of the invention, the term “condensate” means the liquid mixture obtained after condensation of the gaseous effluent, said condensate comprises water, alcohol and aromas.

[0028] For the purposes of the invention, the term “gaseous effluent” means a mixture of gases comprising at least CO2.

[0029] CO2 capture and treatment system

[0030] With reference to [Fig.l], the present invention therefore has as its first object a system 10 for capturing and treating CO2 in a gaseous effluent, comprising at least: *a means of capturing 12 a gaseous effluent, *a condenser 14 comprising an inlet configured to receive the gaseous effluent captured by the capture means 12, the condenser being arranged to condense said captured gaseous effluent and to generate a liquid condensate and a gaseous effluent comprising CO2; *at least one filter 16 comprising an inlet configured to receive the gaseous effluent comprising CO2 generated by the condenser 14, the filter being arranged to eliminate substantially all bacteria and yeasts from said gaseous effluent in order to generate purified CO2; *at least one compressor 18 comprising an inlet configured to receive purified CO2 from the filter 16, the compressor 18 being arranged to compress the purified CO2; * a reinjection loop 20 of at least a portion of the CO2 compressed by the compressor 18 towards the condenser 14, the system comprising a device for regulating the pressure of said portion of the CO2 reinjected towards the condenser 14.

[0031] Advantageously, the reinjection loop makes it possible to regulate the pressure by recycling the compressed CO2 which makes it possible to ensure in particular a constant flow rate compatible with the purification and compression system.

[0032] In the context of the present invention, the system 10 according to the invention makes it possible to capture and treat CO2 originating from a gaseous effluent which may have a low emission rate or a high emission rate, with variations in flow rate and variations in CO2 concentrations, preferably directly at the source of the emission of the gaseous effluent.

[0033] Thus, according to one embodiment, the system 10 also comprises a fermentation tank 32 connected to the capture means 12, containing a product capable of emitting a gaseous effluent comprising CO2. Preferably, the fermentation tank 32 is an alcoholic fermentation tank or a methanization tank. The tank 32 comprises an outlet configured to be connected to the capture means 12. The tank comprises at least one product, such as organic matter, organic waste, grape must, etc. capable of emitting or producing a gaseous effluent comprising CO2.

[0034] The gaseous effluent emitted during fermentation in the tank 32 is captured by the capture means 12 at the outlet of said tank 32. The outlet of the tank 32 is preferably located at its upper part.

[0035] According to one embodiment, the fermentation tank 32 comprises a regulating means, such as a valve, configured to recover all or part of the gaseous effluent and / or eliminate all or part of the gaseous effluent, if the gaseous effluent is emitted, for example in too large quantities.

[0036] According to one embodiment, the regulating means is configured so that the pressure of the tank is compatible with its calculation pressure, preferably between -20 mbars and +30 mbars. This pressure may be in particular between -5 mbars and +10 mbars.

[0037] According to a variant, the capture means 12 is connected to a group of tanks 32 in which fermentation takes place in each of them and consequently an emission of gaseous effluents comprising CO2. The tanks 32 are then preferably connected to each other by means of a connector upstream of the capture means 12.

[0038] According to one embodiment, the capture means 12 comprises at least one means 44 for measuring an O2 and / or CO2 concentration of the gaseous effluent captured by the capture means 12. The capture means 12 may also comprise means for measuring other parameters, such as the flow rate and / or pressure of the gaseous effluent in the capture means 12, or the pollutant content in the gaseous effluent such as means for measuring VOCs and / or H2S in the case of emissions from methanization, or VOCs also for emissions from alcoholic fermentation. According to a variant, the capture means 12 also comprises at least one flow rate control device 46 such as a valve for example, in particular a solenoid valve.Preferably, the capture means 12 also comprise a control unit 48 receiving the O2 and / or CO2 concentration measurements of the gaseous effluent captured by the capture means, and controlling the flow control device 46 from said measurements to regulate the output of CO2 at the outlet of the capture means 12. Thus, depending on the measurements transmitted to the control unit 48 by the measurement means 44 and / or by the other measurement means, the control unit 48 connected to the control device 46 sends at least one determined action to be carried out by the control device 46 from said measurement values. These actions may in particular be the closing or opening of the valve if the control device 46 is a valve or the sending of the captured gaseous effluent to a storage area or another treatment system. Advantageously, this makes it possible to control the quality of the captured gaseous effluent according to different parameters.In particular depending on the intended use of the CO2 (technical, food, etc.), the control device 46 can be adjusted so as to vary the O2 and / or CO2 content. Indeed, the requirements for quality and / or CO2 concentration vary depending on the intended use. Thus, the system according to the invention advantageously makes it possible to control the quality of the gaseous effluent before capturing and treating the CO2.

[0039] According to an embodiment not shown in [Fig.l], the system 10 comprises at least one means 44 for measuring an O2 and / or CO2 concentration outside the capture means 12. The system 10 may also comprise one or more other measuring means such as means for measuring pollutants, pressure and / or flow rate for example, outside the capture means 12.

[0040] The capture means 12 is connected to a condenser 14. Preferably, the condenser 14 is chosen from a cooler or a heat exchanger. More precisely preferably, the condenser 14 is a plate or tubular exchanger. The condenser 14 is arranged to condense the gaseous effluent captured by the capture means 12 and to generate a liquid condensate and a gaseous effluent comprising CO2. Advantageously, the condenser makes it possible to condense certain constituents of the gaseous effluent in the form of a liquid condensate, with the exception in particular of CO2 which remains in the gaseous state.

[0041] According to one embodiment, the condenser 14 comprises a gas / liquid separator 28 arranged to separate the liquid condensate towards a first outlet and the gaseous extract comprising CO2 towards a second outlet, the inlet of the filter 16 being connected to the second outlet of the gas / liquid separator 28.

[0042] Preferably, the gas / liquid separator is chosen from a cylindrical, cyclonic and mist eliminator gas / liquid separator. More preferably, the gas / liquid separator is a mist eliminator.

[0043] The system 10 also preferably comprises a means 30 for storing the liquid condensate connected to the first outlet of the gas / liquid separator 28. Preferably, the means 30 for storing the condensate is a storage tank.

[0044] The filter 16 comprises an inlet configured to receive the gaseous effluent comprising CO2 generated by the condenser 14, the filter being arranged to remove substantially all bacteria and yeasts from said gaseous effluent in order to generate purified CO2. Preferably, the filter 16 is arranged to remove at least 99.9% of the bacteria and yeasts present in the gaseous effluent comprising CO2. Preferably, the purified CO2 at the outlet of the filter 16 comprises less than 0.1% of bacteria and yeasts (volume percentage), even more preferably the purified CO2 at the outlet of the filter 16 does not comprise bacteria and yeasts.

[0045] The compressor 18 compresses the purified CO2 to store it and / or reinject it into the reinjection loop 20. The compressor 18 preferably comprises drying cartridges capable of reducing the quantity of residual water possibly present in the purified CO2 at the outlet of the filter 16. The compressor 18 may in particular be a high-pressure compressor. According to a variant, the compressor 18 comprises at the outlet a pressure control means associated with a pressure measuring means arranged to adjust the compression ratio.

[0046] According to one embodiment, the system 10 comprises at least one storage means 22 for compressed CO2, comprising an inlet configured to receive CO2 compressed by the compressor. The storage means 22 preferably also comprises an outlet configured to reinject the compressed CO2 stored in the reinjection loop 20. Preferably, the storage means 22 comprises CO2 compressed to at least 25 bars, preferably to at least 30 bars.

[0047] Preferably, the reinjection loop 20 of the system 10 comprises at least one expander 24 comprising an inlet configured to receive CO2 compressed by the compressor 18 and arranged to expand said compressed CO2 and at least one heat exchanger 26 comprising an inlet configured to receive CO2 expanded by the expander 24 and an outlet configured to be connected to said inlet of the condenser 14, in order to reinject the reheated CO2 into the condenser 14.

[0048] Preferably, the regulator 24 is characterized by a pressure of between 1 and 15 bars, in particular between 4 and 8 bars.

[0049] Preferably, the heat exchanger 26 is chosen from plate or tube and shell or spiral or even electric exchangers. According to a variant, the heat exchanger 26 heats the CO2 between 0 and 15°C.

[0050] According to the embodiment shown in [Fig.l], the system 10 comprises at least one first pressure measuring means 34 of a first pressure which is located at the outlet of the capture means 12, at least one second pressure measuring means 36 of a second pressure which is located in the system 10, preferably at the outlet of the reinjection loop, a flow rate control device 40 of CO2 reinjected towards the condenser, and a control unit 38 receiving the measurements of the first and second pressures, and controlling the flow rate control device 40 from said measurements to regulate the pressure of the CO2 reinjected towards the condenser 14. The flow rate control device 40 may be a valve, preferably a solenoid valve. According to a variant, the system 10 also comprises at least one flow rate measuring device 42 of the gaseous effluent captured by the capture means 12.Preferably, the control unit 38 also receives the flow rate measurements from the measuring device 42, in addition to the first and second pressure measurements, and controls the flow rate control device 40 from said measurements to regulate the pressure of the CO2 reinjected into the condenser 14. Preferably, the control unit 38 recovers the pressure data at the outlet of the capture means 12 and within the system, preferably at the outlet of the reinjection loop 20, compares the two pressure values, and possibly takes into account the flow rate value at the outlet of the capture means 12, and adjusts the flow rate as well as the pressure using said at least one flow rate control device 40 so that the pressure at the outlet of the capture means 12 is equal to the pressure reinjected into the condenser 14 at the outlet of the reinjection loop 20.

[0051] Advantageously, the pressure within the system according to the invention can thus be regulated and remain constant despite fluctuations in flow rate and / or pressure of the captured gaseous effluent.

[0052] According to one embodiment, the system 10 may comprise at least one valve 40 intended to regulate the pressure comprising an inlet configured to be connected to the outlet of the heat exchanger 26 and an outlet configured to be connected upstream of the condenser 14, preferably between the outlet of the capture means 12 and the inlet of the condenser 14. Said valve 40 intended to regulate the pressure is preferably connected to the pressure measuring means 34, 36 and is controlled by a control unit 38 receiving the data from the pressure measuring means 34, 36, which generates a determined action on the valve 40 from the measured pressure value. When the pressure at the outlet of the capture means 12 is too low compared to the pressure in the rest of the system 10, in particular when the flow rate of the captured gaseous effluent is low, the control unit 38 of the valve 40 causes the valve 40 to open, causing the injection of CO2 at the outlet of the reinjection loop 20 towards the condenser 14.

[0053] According to one embodiment, the system 10 comprises a pressure measuring means 50 of a pressure which is at the inlet of the injection loop 20, preferably of the expander 24, a device for controlling the flow rate 52 of the compressed CO2 at the outlet of the storage means 22 and / or at the outlet of the compressor 18, and a control unit 54 receiving the pressure measurements from the pressure measuring means 50, and controlling the flow rate control device 52 from said measurements to regulate the pressure of the CO2 reinjected towards the expander 14.

[0054] Thus, the system 10 may comprise at least one flow control device 52, such as a valve, in particular a solenoid valve, intended to regulate the pressure comprising an inlet configured to be connected to the outlet of the compressor 18 and / or the storage means 22 and an outlet configured to be connected to the inlet of the reinjection loop 20, preferably between the outlet of the compressor 18 and / or the storage means 22 and the inlet of the pressure reducer 44. The control device 52 intended to regulate the pressure is preferably connected to the pressure measuring means 34, 50 and possibly 36, and is controlled by a control unit 54 receiving the data from the pressure measuring means 34, 50 and possibly 36, which generates a determined action on the flow control device 52 from the value of the measured pressure.When the pressure at the outlet of the capture means 12 is too low compared to the pressure in the rest of the system 10, in particular when the flow rate of the captured gaseous effluent is low, the control unit 54 of the flow rate control device 52 causes the flow rate control device 52 to open, causing CO2 to be injected at the outlet of the compressor and / or the storage means 22 towards the reinjection loop.

[0055] According to a particular embodiment, the system 10 comprises a measuring means connected to the output of the compressor 18 capable of measuring at least one parameter chosen from temperature, the quantity of O2, the quantity of CO2, the pressure and the humidity. This may for example be the measuring means 50.

[0056] According to a variant, the control unit 38, the control unit 54 is the same unit of control and can control both the flow control device 40 and the flow control device 52.

[0057] According to another variant, the control unit 38, the control unit 48 is the same control unit and can control both the flow control device 40 and the control device 46.

[0058] According to another variant, the control unit 54, the control unit 48 is the same control unit and can control both the flow control device 54 and the control device 46.

[0059] According to another variant, the control unit 38, the control unit 54 and the control unit 48 is the same control unit and can control at the same time the flow control device 40, the flow control device 54 and the control device 46.

[0060] Advantageously, the control unit(s) by acting on the control devices makes it possible to guarantee the maintenance of a constant pressure and flow rate within the system according to the invention, thus avoiding problems of overpressure or depression.

[0061] Method for capturing and treating CO2

[0062] According to another object, the invention relates to a method for capturing and treating CO2 in a gaseous effluent. This method can be implemented by any means, in particular with the CO2 capture and treatment system 10 according to the invention as described above.

[0063] The process for capturing and treating CO2 in a gaseous effluent comprises the implementation of the following steps: (a) Capture of a gaseous effluent comprising CO2; (b) Condensing the gaseous effluent comprising CO2 by means of a condenser to condense said captured gaseous effluent and to generate a liquid condensate and a gaseous effluent comprising CO2, (c) Filtration of the gaseous effluent comprising CO2 obtained in step (b) by means of a filter to obtain purified CO2, (d) Compressing the purified CO2 obtained in step (c) using a compressor to obtain compressed CO2, (e) Possibly storage of compressed CO2, (f) Reinjection of the compressed CO2 from step d) or e) into step c), said reinjection comprising a step of regulating the pressure of the CO2 reinjected in step c).

[0064] Preferably, the method according to the invention comprises a fermentation step (a') upstream of step (a). This fermentation can be carried out for example in a fermentation tank. The fermentation can be in particular an alcoholic fermentation or a methanization. The fermentation tank can be in particular an alcoholic fermentation tank or a methanization tank.

[0065] Preferably, the alcoholic fermentation of step (a') is carried out from grape must, organic waste, a brew, apples, or any other alcoholic fermentation from fruit or plants or organic matter.

[0066] Thus, according to a particularly suitable embodiment, the method according to the invention comprises a fermentation step, before step a), and the gaseous effluent comprising CO2 is a gaseous effluent emitted during this fermentation step.

[0067] According to one embodiment, the flow rate of the gaseous effluent from step (a') and captured in step (a) is between 1 and 500m3 / hour, in particular between 1 and 100m3 / hour, in particular between 1 and 50m3 / hour.

[0068] Advantageously, the method according to the invention makes it possible to extract CO2 from a gaseous effluent, even when the gaseous effluent has a low flow rate, namely a flow rate of less than 500 m3 / hour.

[0069] According to another embodiment, the flow rate of the gaseous effluent from step (a') and captured in step (a) is greater than 500m3 / hour.

[0070] According to one embodiment, the method according to the invention comprises at least one step of measuring the O2 and / or CO2 concentration of the gaseous effluent. Preferably, this step is carried out at least during step (a) of capturing the gaseous effluent, and very preferably upstream of step (b) of condensation.

[0071] This step makes it possible to qualitatively analyze the gaseous effluent before treatment of the CO2. When the O2 and / or CO2 concentration is not satisfactory, the gaseous effluent is preferably eliminated or sent to another system and is not treated according to the invention.

[0072] After recovery of the gaseous effluent in step (a), it is condensed during step (b) by means of a condenser so as to obtain cooled CO2 and a liquid condensate. Preferably, during step (b), the gaseous effluent is condensed at a temperature between 0 and 15°C, more preferably a temperature between 4 and 8°C. A temperature below 15°C thus makes it possible to condense the water vapors, alcohol vapors and possibly the flavors and to cool the CO2.

[0073] According to one embodiment, the filtration step (c) is preceded by a step of separating the condensate in liquid form and the CO2 in gaseous form by means of a gas / liquid separator.

[0074] During step (b), CO2 is then obtained in gaseous form and a condensate in liquid form. The liquid condensate and the CO2 in gaseous form can be separated in particular by means of a gas / liquid separator. Preferably, the gas / liquid separator is chosen from a cylindrical, cyclonic and demister gas / liquid separator. More preferably, the gas / liquid separator is a demister.

[0075] At the end of step (b), a condensate separated from the CO2 is then obtained in the form gaseous. The condensate can then be removed or possibly stored, for example, in a storage tank. The recovered CO2 in gaseous form is then filtered during step (c).

[0076] Preferably, during step (c), the CO2 in gaseous form from which the liquid condensate has been removed is preferentially filtered to remove at least 99.9% of the bacteria and yeasts. According to one embodiment, the purified CO2 from step (c) comprises less than 0.1% of bacteria and yeasts, preferably it does not comprise bacteria and yeast.

[0077] After step (c) of filtering the purified CO2, it is compressed during step (d) by means of a compressor. Preferably, the purified CO2 is compressed during step (d) to a value between 10 and 300 bars, preferably between 15 and 200 bars.

[0078] Preferably, during compression step (d), the purified CO2 is also dried using drying cartridges.

[0079] The compressed CO2 from step (d) can be stored in step (e) in a storage means or injected into a reinjection loop.

[0080] When the compressed CO2 is stored by means of a storage tank, said storage tank is preferably configured so that the CO2 is maintained at a pressure lower than atmospheric pressure. Preferably, said CO2 storage tank is configured so that the CO2 is maintained at a pressure equal to the pressure at the outlet of the compressor.

[0081] At the end of steps (d) or (e), the CO2 is then obtained in compressed form. Said compressed CO2 can then be reinjected by implementing step (f).

[0082] Step (f) preferably comprises a step of expanding the compressed gas by means of an expander and a step which consists of reheating the gas after expansion, in particular with a heat exchanger. Step (f) of reinjection therefore preferably comprises at least one step of expanding and reheating the compressed CO2 before regulating the pressure and reinjection in step (b). The expansion of the compressed CO2 using an expander makes it possible to reinject it into the process in order to maintain a pressure and a flow rate of the gaseous effluent upstream of the condensation. The expansion of the compressed CO2 causes a drastic reduction in the temperature of the CO2 which is then preferably reheated by means of a heat exchanger, in particular between 0 and 15°C.

[0083] Other measurements of different parameters can be carried out at the effluent capture step (a) and / or at any other step of the process, in particular before step (b) and / or during step (f) and / or after step (f). Preferably, the measurements involve a control action on certain parameters, in particular the flow rate and / or the pressure of the effluent. This control can be carried out in particular at the time of the capture to control the entry of the captured effluent and / or after step (d) and / or after step (e) before step (f), and / or during step (f) and / or at the end of step (f).

[0084] In the method according to the invention, the regulation of the pressure in step (f) is preferably carried out as a function in particular of the pressure and / or the flow rate of the gaseous effluent comprising CO2 captured in step (a) and the pressure and / or the flow rate of the CO2 after step (d) or (e).

[0085] According to one embodiment, the method according to the invention comprises: - a step of measuring the pressure of the gaseous effluent, after the capture step (a) and before the condensation step (b), - a step of measuring the pressure of the compressed CO2, in step (f), before reinjection in step (b), into the condenser with the captured gaseous effluent.

[0086] The method according to the invention may also comprise a step of measuring the flow rate of the gaseous effluent after the capture step (a) and before the condensation step (b).

[0087] Preferably, the pressure and / or flow rate measurements are transmitted to a control unit which regulates the pressure of the CO2 reinjected in step (b).

[0088] In the method according to the invention, the regulation of the pressure before reinjection into the condenser in step (b) can be carried out by means of at least one valve, in particular a solenoid valve.

[0089] Preferably, the steps of measuring different parameters and controlling the flow rate are carried out continuously so as to guarantee constant pressure and flow rate during the process according to the invention.

[0090] Advantageously, the method according to the invention is implemented by means of a so-called dynamic system, that is to say that when the flow rate of the gaseous effluent is too low and is likely to cause a variation in flow rate and pressure in the system, the method is implemented continuously and the gaseous effluent is immediately treated and recycled by means in particular of a condenser, a gas / liquid separator, a filter, a compressor, an expansion valve and a heat exchanger. Said method is then implemented continuously.

[0091] When the flow rate of the gaseous effluent is not likely to cause a variation in flow rate and pressure in the system, the process can be carried out batchwise. Indeed, if the gaseous effluent from step (a) does not cause a variation in pressure and flow rate, step (f) may not be carried out.

[0092] According to another aspect, the invention relates to a method for capturing and treating and recovering CO2 from a gaseous effluent comprising the implementation of the following steps: (1) Capture and treatment of CO2 from a gaseous effluent by implementing a capture and treatment method according to any one of the embodiments previously described; and (2) Use of the compressed CO2 from step (1) for at least one application chosen from transformation into bicarbonate, carbonation of water or a beverage or alcohol, snow production, dry ice production, reduction of the alcohol content in wine, preparation of alcoholic beverages such as wine or beer, production of biogas such as methane and combinations thereof.

[0093] Indeed, after compression in step (d) and / or after storage in step (e), the purified CO2 can be used to be recovered in different applications. Thus, after compression in step (d) and / or after storage in step (e), all or part of the compressed CO2 can either be reinjected into the process by implementing step (f) continuously, or used to be recovered in different applications.

[0094] Thus the CO2 treated according to the invention can be used for various applications such as gasifying beer or wine, oenological uses (extraction, reduction of alcohol content by stripping), gasifying water to reduce water consumption, the use of liquid CO2 to produce dry ice to inert wine or beer tanks, for cold production applications, or cryogenic cleaning. The CO2 treated according to the invention can also be used for example for the production of microalgae or cyanobacteria for example.

Claims

Claims

1. System for capturing and treating (10) carbon dioxide (CO2) in a gaseous effluent comprising: *a means for capturing (12) a gaseous effluent, *a condenser (14) comprising an inlet configured to receive the gaseous effluent captured by the capturing means (12), the condenser being arranged to condense said captured gaseous effluent and to generate a liquid condensate and a gaseous effluent comprising CO2; *at least one filter (16) comprising an inlet configured to receive the gaseous effluent comprising CO2 generated by the condenser (14), the filter being arranged to remove substantially all bacteria and yeasts from said gaseous effluent in order to generate purified CO2; *at least one compressor (18) comprising an inlet configured to receive purified CO2 from the filter (16), the compressor (18) being arranged to compress the purified CO2;* a reinjection loop (20) of at least part of the CO2 compressed by the compressor (18) towards the condenser (14), the system comprising a device for regulating the pressure of said part of the CO2 reinjected towards the condenser (14).;

2. System (10) according to the preceding claim, characterized in that it comprises at least one means (22) for storing compressed CO2 and comprising an inlet configured to receive CO2 compressed by the compressor.

3. System (10) according to one of the preceding claims, characterized in that said reinjection loop (20) comprises at least one expander (24) comprising an inlet configured to receive CO2 compressed by the compressor (18) and arranged to expand said compressed CO2 and at least one heat exchanger (26) comprising an inlet configured to receive CO2 expanded by the expander (24) and an outlet configured to be connected to said inlet of the condenser (14), in order to reinject the reheated CO2 into the condenser (14).

4. System (10) according to one of the preceding claims, characterized in that the condenser (14) comprises a gas / liquid separator (28) arranged to separate the liquid condensate towards a first outlet and the gaseous extract comprising CO2 towards a second outlet, the inlet of the filter (16) being connected to the second outlet of the gas / liquid separator (28).

5. System (10) according to one of the preceding claims, characterized in that it also comprises a means (30) for storing the liquid condensate connected to the first outlet of the gas / liquid separator (28).

6. System (10) according to one of the preceding claims, characterized in that it also comprises a fermentation tank (32) connected to the capture means (12), containing a product capable of emitting a gaseous effluent comprising CO2.

7. System (10) according to one of the preceding claims, characterized in that it comprises at least a first pressure measuring means (34) of a first pressure which is at the outlet of the capture means (12), at least a second pressure measuring means (36) of a second pressure which is at the outlet of the reinjection loop, a device for controlling the flow rate (40) of CO2 reinjected towards the condenser, and a control unit (38) receiving the measurements of the first and second pressures, and controlling the flow rate control device (40) from said measurements to regulate the pressure of the CO2 reinjected towards the condenser (14).

8. System (10) according to the preceding claim, characterized in that it also comprises at least one flow rate measuring device (42) of the gaseous effluent captured by the capture means (12), and in that said control unit (38) also receives the flow rate measurements, in addition to the first and second pressure measurements, and controls the flow rate control device (40) from said measurements to regulate the pressure of the CO2 reinjected towards the condenser (14).

9. System (10) according to one of the preceding claims, characterized in that it comprises at least one means (44) for measuring an O2 and / or CO2 concentration of the gaseous effluent captured by the capture means.

10. System (10) according to one of the preceding claims, characterized in that the capture means (12) comprise at least one means (44) for measuring an O2 and / or CO2 concentration of the gaseous effluent captured by the capture means.

11. System (10) according to the preceding claim, characterized in that the capture means (12) also comprise at least one flow control device (46), and a control unit (48) receiving the O2 and / or CO2 concentration measurements of the gaseous effluent captured by the capture means, and controlling the flow control device (46) from said measurements to regulate the output of CO2 at the outlet of the means of capture (12).

12. System (10) according to one of the preceding claims, characterized in that it comprises a pressure measuring means (50) of a pressure which is at the inlet of the regulator (24), a device for controlling the flow rate (52) of the compressed CO2 at the outlet of the storage means (22) and / or at the outlet of the compressor (18), and a control unit (54) receiving the pressure measurements from the pressure measuring means (50), and controlling the flow rate control device (52) from said measurements to regulate the pressure of the CO2 reinjected towards the regulator (14).

13. System (10) according to one of the preceding claims, characterized in that the compressor (18) comprises drying cartridges capable of reducing the quantity of residual water present in the purified CO2 at the outlet of the filter (16).

14. A method for capturing and treating CO2 from a gaseous effluent, comprising implementing the following steps: (a) Capturing a gaseous effluent comprising CO2; (b) Condensing the gaseous effluent comprising CO2 by means of a condenser to condense said captured gaseous effluent and to generate a liquid condensate and a gaseous effluent comprising CO2, (c) Filtrating the gaseous effluent comprising CO2 obtained in step (b) by means of a filter to obtain purified CO2, (d) Compressing the purified CO2 obtained in step (c) by means of a compressor to obtain compressed CO2, (e) Optionally storing the compressed CO2, (f) Reinjecting the compressed CO2 from step d) or e) into step c), said reinjection comprising a step of regulating the pressure of the CO2 reinjected in step c).

15. Method according to the preceding claim, characterized in that the regulation of the pressure in step f) is carried out as a function of the pressure of the gaseous effluent comprising CO2 captured in step a) and the pressure of the CO2 after step (d) or (e).

16. Method according to one of claims 14 or 15, characterized in that it also comprises: - a step of measuring the pressure of the gaseous effluent, after the capture step (a) and before the condensation step (b), - a step of measuring the pressure of the compressed CO2, in step (f), before reinjection in step (b).

17. Method according to the preceding claim, characterized in that the pressure measurements are transmitted to a control unit which regulates the pressure of the CO2 reinjected in step (b).

18. Method according to one of claims 14 to 17, characterized in that the regulation of the pressure before reinjection into the condenser is carried out by means of at least one valve.

19. Method according to one of claims 14 to 18, characterized in that the reinjection step (f) comprises at least one step of expansion and reheating of the compressed CO2 before regulation of the pressure and reinjection in step (b).

20. Method according to one of claims 14 to 19, characterized in that the filtration step c) is preceded by a step of separation of the condensate in liquid form and the CO2 in gaseous form by means of a gas / liquid separator.

21. Method according to one of claims 14 to 20, characterized in that before step a) it comprises a fermentation step and in that the gaseous effluent comprising CO2 is a gaseous effluent emitted during this fermentation step.

22. Method according to the preceding claim, characterized in that the fermentation step is an alcoholic fermentation or a methanization.

23. Method according to one of claims 14 to 22, characterized in that it also comprises a step of measuring the flow rate of the gaseous effluent after the capture step (a) and before the condensation step (b).

24. Method according to one of claims 14 to 23, characterized in that the flow rate of the gaseous effluent in step (a) is between 1 and 500m3 / hour, in particular between 1 and 100m3 / hour.

25. Method according to one of claims 14 to 24, characterized in that it comprises a step of measuring the O2 and / or CO2 concentration of the gaseous effluent upstream of step (b).

26. Method according to one of claims 14 to 25, characterized in that it comprises a step of storing the condensate from step (b).

27. ​​Method according to one of claims 14 to 26, characterized in that it is implemented with a system according to one of claims 1 to 13.

28. Method for capturing, treating and recovering CO2 from a gaseous effluent comprising the implementation of the following steps: (1) Capture and treatment of CO2 from a gaseous effluent by implementing the method according to one of claims 14 to 27 to obtain a purified CO2; (2) Use of the purified CO2 from step (1) for at least one app- plication chosen from the transformation into bicarbonate, the carbonation of water or a beverage or alcohol, the manufacture of snow, the manufacture of dry ice, the reduction of the alcohol level in wine, the preparation of an alcoholic beverage such as wine or beer, the manufacture of biogas such as methane and their combinations.

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