Carbonation carbon dioxide capture device
Patent Information
- Application Number
- FR2023008525
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-08-07
- Publication Date
- 2026-01-30
- Estimated Expiration
- 2043-08-07
Abstract
Description
Title of the invention: Device for trapping carbon dioxide by carbonation TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a device for trapping carbon dioxide (CO2) by carbonation of materials. It applies in particular to carbon dioxide originating from methanization units carrying out a separation of biogas. STATE OF THE ART
[0002] It is specified that the names of gases are interchangeable with their chemical name (for example carbon dioxide and CO2).
[0003] Carbonation of concrete occurs naturally in contact with the concrete and the atmosphere (with an atmospheric CO2 content of around 400 ppm). This phenomenon is explained, for example, in the scientific article “The sponge effect and carbon emission mitigation potentials of the global cernent cycle” from 2020, Nature, by Z.Cao et al. For concrete, the main reaction involved can be represented by: Ca(OH)2 + CO2 + H2O > CaCO3 + 2 H2O (Equation 1)
[0004] In this equation, calcium hydroxide reacts with CO2 to produce calcium carbonate and water. This is an exothermic reaction. The CO2 useful for the reaction can come from a gas stream containing other gases, such as methane, nitrogen or oxygen. In a configuration where the gas stream contains mainly but not only CO2, it is observed that the CO2 concentration will tend to decrease, to the benefit of the other species present in the gas stream. This drop in concentration can reduce the carbonation performance, namely the reaction kinetics but also the quantity of CO2 finally trapped. For a fixed quantity of carbonatable material, the formation of CaCO3 according to Equation 1 follows an increasing profile with time, reaching an asymptote.
[0005] Furthermore, the state of the scientific art presents a temperature range for optimal operation, generally between 20 and 50°C.
[0006] Several important definitions regarding carbonation are recalled. On the one hand, the carbon yield (in %) indicates the quantity of CO2 actually trapped compared to the quantity of CO2 made available. On the other hand, the trapping rate (or uptake, in kg of CO2 per kg of material) designates the quantity of CO2 trapped per quantity of material introduced. Ideally, we seek the highest carbon yield, with the highest trapping rate and the shortest reaction time.
[0007] Carbonation of concrete waste consists of reacting certain species chemicals present on concrete waste with CO2 to obtain new physicochemical properties of the materials and trap the injected CO2. Concrete waste refers to different concrete products that are recovered and then crushed, and where appropriate, separated into different granulometric fractions. These concrete products can be the origin of concrete production unit tank bottoms, waste from deconstruction sites, waste from recycling platforms, waste from precast concrete plants, etc. We then speak of recycled concrete 'aggregates' for fractions with a high granulometry, typically a granulometry greater than 4 mm, and recycled concrete 'sands' for fractions with a granulometry less than 4 mm, with particular attention to fines, a fraction that can correspond to a granulometry less than 1 mm.There is a fairly dense and old body of scientific work on the study of the carbonation phenomenon for concrete (including concrete waste), such as for example the scientific article "Carbonation of concrete and its prediction", Cernent and Concrète Research Volume 17, Issue 3, May 1987, Pages 489-504, by Ho et al.
[0008] It is mentioned that in patent application FR2214596, the present applicant has carried out a review of the state of the art for the invention Reactor, Device and Carbonation Method, reproduced in part below and supplemented with regard to the particularities of the present invention. Other inventions present in the state of the art dealing with the carbonation of materials are thus mentioned.
[0009] Carbonation can be carried out batch by batch (i.e. by batch), or continuously, either for the materials, or for the gas, or for both. The advantage of batch carbonation lies in the ability to control the residence time well, as well as the quantity of CO2 injected and to limit losses. However, this type of carbonation can be limited for quantities to be treated which would be high.
[0010] The presence of water (H2O) is necessary for the reaction. Carbonation can be carried out in the aqueous phase or in the gas phase. In the gas phase, an optimal quantity of water (between a minimum and a maximum) is necessary. This quantity of water is typically in the order of 3 to 20% of the mass of water relative to the mass of materials. In the aqueous phase, water is the predominant species in the reactor where the reaction takes place.
[0011] Patent application WO2023012424A1 presents an 'accelerated carbonation process and its implementation in a process for the recovery of concrete waste and industrial gaseous discharges'. This is typically a process with carbonation carried out continuously (from the point of view of gas flows). One of the disadvantages of this process lies in its low carbon yield. The gas flow (containing CO2) used to carbonate the materials is not recycled and does not work in batch mode: if the reaction can be significant from the point of view of the materials (Ca(OH)2 is mainly transformed into calcium carbonate CaCO3), however little CO2 in the gas stream made available at the reactor inlet was used. Therefore, the carbon yield is particularly low, making this innovation not very relevant on streams concentrated in CO2, because a significant part of the CO2 present is not recovered.
[0012] This concept can be improved from the point of view of carbon efficiency. Patent EP3744700B1 deals with an 'improved method and device for carbonating concrete waste and / or sequestering CO2'. In this configuration, the carbon efficiency is improved by recirculating the streams of carbonatable materials. However, it is not intended to maintain a high concentration of CO2 in the gaseous atmosphere of the reactor, but rather to purify a gas containing CO2 before discharge. The carbonation performance (kinetics or carbonation rate) may therefore be lower than that of a reactor maintaining a high CO2 level. The patent does not mention batch operation, but rather refers to continuous operation of the reactor, with circulation of carbonatable materials and gases.For potential operation in batch mode, the patent does not indicate how (after introduction of the materials and / or before reopening the reactor to recover the materials) the gas would be emptied from the reactor. By not specifying this point, we can expect a loss of CO2 during the shutdown phases and a low CO2 concentration in the start-up phases. We note the recirculation of carbonatable materials to control the carbon yield, which can involve issues of cost, maintainability and energy performance to set in motion large quantities of solid materials. In this patent EP3744700B1, we note the interest of controlling the temperature in the reactor to a value lower than 60 ... 80°C, by exchangers. We note that the invention does not provide the interest of selectively cooling upstream of the compressors to improve their energy performance.
[0013] Patent application EP4116274A1 presents an innovation for the 'large-scale carbonation of concrete waste'. The process comprises several stages, with different temperature and humidity conditions depending on the stages. The CO2 level used is preferably at a content between 70 and 100% (by volume), but it does not specify: on the one hand how to maximize the CO2 level, particularly in the filling phases, on the other hand how to limit CO2 losses during the material emptying phases, and finally the procedure to follow in the case where the 0 to 30% of gases other than CO2 are non-inert gases (such as methane for example).
[0014] Patent application WO2023 / 049359A1 presents a system for capturing carbon dioxide. This invention considers liquid phase carbonation, with the presence of a water source. If the invention considers the possibility of using a gas streams with CO2 of biological origin, the issue of treatment of residual methane and / or accumulation of air gases is not mentioned.
[0015] It is recalled that there are devices in the state of the art for separating CO2 from other species in a gas mixture. These gas separation devices can be cryogenic, membrane or other in nature, such as the use of absorbent. In particular, there are solutions for preferentially separating CO2 from a mixture of nitrogen (N2) and oxygen (O2) air gases. This type of device thus contains one inlet and two outlets, each for the enriched flow. It should be remembered that the flows obtained may not be pure and still contain traces of other species. Typically, a membrane separation device intended to treat a flow of CO2 and air will be able to separate the initial flow into two flows: a flow rich in CO2, with a CO2 content greater than 80 or even 95% vol and a flow poor in CO2, but nevertheless containing a significant quantity of CO2.These devices exist for the separation of CO2 from air gases, in particular for the capture of CO2 in combustion gases.
[0016] Finally, it is recalled that biogas is a mixture of gases produced by fermentation of organic matter of biological origin and containing mainly methane (CH 4) and carbon dioxide (CO2), but also dihydrogen sulfide, or even dioxygen (O2) and dinitrogen (N2) in very small quantities because they do not come from the fermentation process. The purification of biogas into biomethane essentially produces two gas streams: a methane-rich stream called biomethane and a carbon dioxide-rich stream, called bio CO2. Depending on the devices used for the purification of biogas, the bio CO2 stream may still contain between 1 and 7% methane. Methane is a flammable gas and can form explosive atmospheres in certain concentrations. Bio CO2 may also contain a little dinitrogen (N2) and dioxygen (O2), the latter coming from the treatment of dihydrogen sulfide present in the biogas or from air entering the process.A process that would aim to selectively remove CO2 from a bioCO2 stream, without addressing the removal or destruction of CH4 and O2 would therefore run the risk of forming an explosive atmosphere.
[0017] Patent EP3909735A1 'Process and installation for preparing concrete granules by CO2 treatment' proposes using bioCO2 according to certain methods of use. This patent mentions the possibility of using a gas containing other components (including dioxygen), but does not mention a means for treating the residual methane, nor a means for maintaining the CO2 level high as it is consumed (the inerts accumulating in the reactor). Furthermore, if the invention presents in claim 8, the possibility of draining the excess CO2 to another reactor, it does not provide for the draining of the air present in the reactor at start-up after loading the carbonatable materials, or in continuous operation.
[0018] The direct use of bioCO2 with residual methane comes up against the problem of the concentration of this methane. Indeed, the carbonation reaction leading to the consumption of CO2, a reactor which would be supplied with bioCO2 with residual methane would have the following major drawbacks: on the one hand, the CH4 present which would be evacuated to the atmosphere (because not trapped) would represent a leak of methane, that is to say a significant greenhouse gas emission which would drastically reduce the interest of the proposed solution. On the other hand, the concentration of CH4 in the reactor would increase, possibly to the point of forming an explosive atmosphere.
[0019] The liquefaction of bioCO2 makes it possible to increase its purity (typically greater than 99% vol in CO2) by separating the residual methane (which can, if necessary, be revalued into biomethane). The disadvantages of this solution lie on the one hand in the high energy expenditure for liquefaction (of the order of 200kWh electric / tCO2), on the other hand in the costs associated with the process, which significantly increase the costs of trapping CO2.
[0020] The state of the art includes several solutions for the destruction of residual methane in bioCO2. Patent EP2891513A2 presents a gas cleaning installation having a high inert gas content and a low methane gas content. This device is partly envisaged to eliminate residual methane in the bioCO2 flow. It will be noted that such a device can use part of the combustion energy to work in an adequate temperature range but call upon an external system for heating when the methane level is too low. It will also be noted that it requires the introduction of air to carry out the combustion, and therefore oxygen and nitrogen which will end up in the reactor. Therefore, there are solutions to reduce the methane content, but at the expense of a reduction in the CO2 concentration.Since the air is not consumed by the carbonation reaction, it will accumulate in the reactor, thus reducing the carbonation performance. Evacuating the air present (by opening a valve leading to a vent) will lead to an uncontrolled loss of CO2, reducing the carbon yield and reducing the control of the quantities of CO2 actually trapped in the materials.
[0021] Thus, there are state-of-the-art solutions for carrying out the carbonation of concrete waste (or other carbonatable materials) from bioCO2 from gas-phase methanization, but these have the following disadvantages: a. The absence of treatment of the residual methane induces, through the accumulation effect, a risk of explosion and / or a methane leak (therefore significant greenhouse gas emissions). b. Treating methane by simply venting the gas reduces the carbon yield (by venting CO2) and does not solve the emissions problem greenhouse gases; c. Purification of bioCO2 by liquefaction significantly increases the costs of bioCO2 and the energy consumption of the process; d. The treatment of methane contained in bioCO2 by catalytic combustion induces on the one hand an introduction of air, the emptying of this excess air inducing a loss of bioCO2, and therefore a reduction in carbon yield, and on the other hand an increase in the temperature in the reactor, which can harm carbonation performance. Furthermore, if the methane level is too low, an external device is necessary to produce heat and achieve the minimum temperature conditions. It induces additional energy consumption and / or the introduction of more air gas than necessary; e. Generally speaking, for batch-type reactors, the means to be implemented to drain the air-rich gas mixture after introduction of the materials, and above all to avoid CO2 losses, are not specified;
[0022] Furthermore, the simple juxtaposition of inventions presented in the state of the art (invention of carbonation and invention of destruction of residual methane) would not make it possible to respond to the difficulties and limits presented above. OBJECT OF THE INVENTION
[0023] The present invention aims to remedy all or part of these drawbacks. To this end, according to a first aspect, the present invention aims at a device for trapping carbon dioxide by carbonation of materials (10), comprising: a. A gas inlet (101) b. A booster (102) c. A gas tank (103) d. A main circuit (110) connecting the gas tank (103) and the reactor (120) and comprising: i. an actuable register (111) ii. a device for oxidizing residual methane (114), this device itself comprising an inlet for combustion gas (115) e. A carbonation reactor (120); f. A gas recirculation circuit (130) between the reactor and the oxidant inlet (115) of the residual methane oxidation device (114) comprising: i. an actuable register (131); ii. a gas separation device (132), comprising an inlet (133), an outlet for the CO2-concentrated gas (134) and an outlet for the CO2-depleted gas (135); g. A vent circuit (140) positioned on the gas recirculation circuit (130) downstream of the gas separation device (132) and comprising: i. an actionable register (141); ii. an exhaust vent (142) to the atmosphere; h. An oxidant supply circuit (150), connected to the oxidant supply (115) of the residual methane oxidation device (114) and comprising: i. an actionable register (151); ii. an oxidant inlet (152); i. A CO2-rich gas reintroduction circuit (160) connecting the CO2-concentrated gas outlet (134) of the gas separation device (132) and the gas reservoir (103).
[0024] In embodiments, the gas mixture from the gas inlet is a gas comprising CO2.
[0025] In embodiments, the gas mixture comprising CO2 comes from a biogas purification unit into biomethane and is referred to as bioCO2.
[0026] In embodiments, the treated gas mixture comes from the scrubber of a methanization unit and contains more than 93% by volume of CO2, at least 0.7% by volume of methane, less than 1% by volume of nitrogen and less than 1% by volume of oxygen.
[0027] In embodiments, the gas mixture contains greater than 98% carbon dioxide (CO2) and about 0.7% to 1% methane.
[0028] In embodiments, the gas mixture contains more than 5% CO2;
[0029] In embodiments, the booster is optional, as the gas mixture is sufficiently pressurized.
[0030] In embodiments, the gas reservoir (103) is a gasometer capable of containing between 3 and 30 times the nominal flow rate of gas arriving through the gas inlet.
[0031] In embodiments, the materials to be carbonated in the reactor are concrete waste.
[0032] In embodiments, the materials to be carbonated in the reactor are materials comprising a carbonatable base, i.e. an alkaline type base such as magnesium Mg2+, calcium Ca2+, sodium Na+, lithium Li+, potassium K+.
[0033] In embodiments, the bioCO2 from the gas inlet (101) is slightly pressurized in the booster (202) for storage in the gas tank (203). Gas storage is relevant because the reactor (120) operates in batch mode, but gas production can be continuous. The gas storage (103) also makes it possible to recover the remaining CO2 contained in the reactor (120), before opening it to extract the carbonated materials. When the register (111) is opened, the bioCO2 still containing residual methane is conveyed to the residual methane oxidation device (114), which will proceed to the destruction of the methane via a combustion reaction, in the presence of air, the latter being introduced via the circuit (150) within the oxidant inlet (115). The bioCO2 freed from its residual methane, but comprising nitrogen and potentially oxygen, is conveyed to the reactor (120) for the carbonation reaction. The reactor (120) can be drained continuously or before opening or after opening, via the gas recovery circuit (130). In this embodiment, the only driving force for the gases is the booster (102). The objective is to maintain a high CO2 level (parameter favorable to carbonation), while minimizing CO2 losses during the evacuation of the gases contained in the reactor (among which may be nitrogen or oxygen). The gas mixture extracted from the reactor possibly contains CO2, nitrogen and oxygen.The recovery circuit (130) and its CO2 separation device (132) make it possible to recover CO2 before releasing the gases into the atmosphere, thus increasing the carbon efficiency.
[0034] According to a second aspect, the present invention relates to a device for trapping carbon dioxide by carbonation of materials (20), comprising: a. A gas inlet (201) b. A booster (202) c. A gas tank (203) d. A main circuit (210) connecting the gas tank (203) and the reactor carbonation (220) on which are positioned: i. an actionable register (211) ii. a heat exchanger, on the flow side to be heated (212) iii. a heat exchanger (213) iv. a residual methane oxidation device (214), comprising an oxidant inlet (215) v. a compressor (216) vi. a heat exchanger, of the cooler type (217) e. A carbonation reactor (220), comprising: i. a non-return device for the injected gas coming from the main circuit (210) ii. a device for introducing and removing carbonatable materials; iii. an instrumentation system f. A gas recirculation circuit (230) between the reactor (220) and the oxidant inlet (215) of the residual methane oxidation device (214) comprising: i. an actionable register (231); ii. the heat exchanger, flow side to be cooled (212); üi. a gas separation device (232), comprising an inlet (233), an outlet for the CO2-concentrated gas (234) and an outlet for the CO2-depleted gas (235); g. A vent circuit (240) positioned on the gas recirculation circuit (230) downstream of the gas separation device (232) and comprising: i. an actuatable damper (241) ii. an exhaust vent (242) to the atmosphere h. An oxidant supply circuit (250), connected to the gas recirculation circuit (230) downstream of the vent circuit (240) and comprising: i. an actuable register (251); ii. an oxidant inlet (252); i. A CO2-rich gas reintroduction circuit (260) connecting the CO2-concentrated gas outlet (234) of the gas separation device (232) and the gas reservoir (203), said circuit comprising: i. a vacuum pump (261), allowing the pressure at the outlet for the CO2-concentrated gas (234) to be reduced.
[0035] The aims, advantages and particular characteristics of the device which is the subject of the second aspect of the present invention being similar to those of the device which is the subject of the first aspect of the present invention, they are not recalled here. In addition to these advantages, this second aspect makes it possible to optimize carbon efficiency, operating time and energy consumption.
[0036] In embodiments, the heat exchanger (212) is a heat exchanger allowing the gas from the gas reservoir (203) to be heated by cooling the gas from the reactor (220), from the gas recirculation circuit (230). This makes it possible to improve the energy balance of the process, in particular for the low levels of methane present in the bioCO2. If the gas from the gas inlet is generally at a temperature between 10 and 30°C, the gas stored in the gasometer can be at a lower temperature.
[0037] In embodiments, the heat exchanger (212) allows the cooling of the gases coming from the reactor (220), to a temperature below 40°C upstream of the gas separation device (232) via the gas recirculation circuit (230)
[0038] In embodiments, the residual methane oxidation device (214) comprises an external heating means, of the electrical type or by gas injection. This makes it possible to guarantee the proper operation of the device even for low methane levels.
[0039] In embodiments, the heat exchanger (213) is a heat exchanger allowing the additional heating of the gas entering the device oxidation of residual methane (214), via cooling of the gas leaving the same device. This limits the use of external heating means, particularly for the low levels of methane present in the bioCO2. This also improves the performance of the compressor (216), because the compression efficiency is better on a cold gas than on a hot gas.
[0040] In embodiments, the oxidant used at the oxidant inlet (252) is air, then mixed with the gas from the outlet (235). In fact, the oxidant used at the oxidant inlet (215) of the residual methane oxidation device (214) is a mixture comprising air and CO2. This makes it possible to increase the carbon efficiency of the process.
[0041] In embodiments, the oxidant used at the oxidant inlet (215) of the residual methane oxidation device (214) is a mixture comprising air and more than 10% by volume of CO2. This makes it possible to increase the carbon efficiency of the process.
[0042] In embodiments, the oxidant used in the residual methane oxidation device (214) is a gas mixture comprising at least 90% dioxygen, the remainder being predominantly dinitrogen. It will nevertheless be noted that using concentrated dioxygen as an oxidant increases costs (compared to the use of air) and that, moreover, the problem of draining the air present in the reactor when loading the materials remains.
[0043] In embodiments, the heat exchanger (217) is of the gas cooler type, placed after the compressor. This makes it possible to control the temperature in the reactor, typically at a level below 60°C.
[0044] In embodiments, the heat exchanger (217) makes it possible to cool the gas leaving the compressor by heating the gas before entering the exchanger (213), at the level of the main circuit (210). This makes it possible to control the temperature at the inlet to the reactor while improving the heat balance at the level of the residual methane oxidation device.
[0045] In embodiments, the compressor (216) is for example of the piston compressor or screw compressor type, and makes it possible to increase the pressure in the carbonation reactor, typically by a pressure ratio between 2 and 10. The increase in pressure makes it possible on the one hand to improve the performance of the carbonation, in terms of reaction kinetics and the quantity of CO2 trapped. This also makes it possible to improve the performance of the separation device, in particular when the latter is of the membrane separation type.
[0046] In embodiments, the compressor has a gas cooler, of the air cooler type, upstream of the compression stage. This makes it possible to optimize the performance of the compressor.
[0047] In embodiments, the compressor (216) is positioned upstream of the residual methane oxidation device (214). This makes it possible to improve heat recovery, at the expense of additional costs in the main circuit (the pressure pipe being longer).
[0048] In embodiments, the reactor (220) is a gas-tight and water-tight tank, capable of operating at a pressure of between 0.5 bar absolute and 10 bar absolute. Operation at a pressure lower than atmospheric pressure is related to the consumption of gas by the carbonation reaction according to Equation 1, which causes a drop in pressure in the reactor (220). This drop in pressure can be compensated by sending gas into the reactor, via the opening of the register (211).
[0049] In embodiments, the reactor (220) may be opened for the introduction of materials to be carbonated and then closed, then reopened to be emptied of the carbonated materials. The leaktight nature of the reactor is considered only when it is closed.
[0050] In embodiments, the reactor (220) comprises a water inlet in the form of a spray. This water inlet makes it possible to control the temperature in the reactor downwards and to provide a little water to facilitate the carbonation reaction.
[0051] In embodiments, the reactor (220) comprises a water outlet, to be able to evacuate the excess water formed during the reaction and maintain an optimum water level, in particular at the end of the reaction. This outlet is positioned at the low point of the reactor.
[0052] In embodiments, the reactor (220) comprises an instrumentation system for measuring in particular the temperature, the gas flow rates at the inlet and in the recirculation circuit, the CO2 content in the reactor, at the inlet and on the recirculation circuit, the pressure, the relative humidity. On the basis of this information, the various actuators (register 211, compressor, register 231, water inlet valve, water discharge valve) can be actuated when necessary in order to optimize the carbonation reaction in terms of kinetics and uptake. This instrumentation system also makes it possible to finely measure the quantity of CO2 trapped in the material.
[0053] In embodiments, the register (231) positioned on the gas recirculation circuit (231) is of the actuable type. This makes it possible to drain the reactor under the following conditions: a. after loading the materials into the reactor, the gas present in the reactor being essentially air; b. before discharging the reactor materials to the outside; c. in operation, when the CO2 level in the reactor (220) reaches a minimum level
[0054] In embodiments, the register (231) is continuously adjustable, this makes it possible to optimize the gas flow rate to the recirculation circuit.
[0055] In embodiments, the recirculation circuit (230) conveys the gas to the exchanger (212) then to the separation device (232). This makes it possible on the one hand to heat the gas coming from the gas storage (203) and thus to improve the energy balance of the residual methane oxidation device (214) and on the other hand to protect the gas separation device (232) against an excessively high inlet temperature.
[0056] In embodiments, the gas separation device is a membrane-type device (232), with an inlet for the gas coming from the gas recirculation circuit (233), an outlet for the permeate (234) leading to the recovery circuit (260) and an outlet for the retentate (235), for the gas from the recirculation circuit purified of CO2. The membrane has a high permeability for carbon dioxide with respect to nitrogen as well as for carbon dioxide with respect to oxygen. In operation, the performance of the system depends on the ratio between the pressure at the inlet (233) and at the outlet of the permeate (234). This pressure ratio can be advantageously modulated via the operation of the compressor (216) and the vacuum pump (261);
[0057] In embodiments, the vacuum pump (261) has a direct connection with the reactor (220), via a parallel circuit. This makes it possible to empty the reactor of CO2-rich gas before opening the reactor, and thus to maximize the carbon yield.
[0058] In embodiments, several reactors (220) are positioned in parallel and can be opened, filled, emptied, closed independently of the other reactors, each reactor operating in batch mode, each reactor being connected to the main circuit and to the gas recovery circuit. This makes it possible to increase the treatment capacity of the units;
[0059] In embodiments, the methane content in the gas mixture is variable, and on the other hand, the CO2 requirements over time are variable. The opening of the registers, the operation of the compressor, the operation of the vacuum pump are dynamically regulated to be able on the one hand to maximize the carbonation performance in terms of reaction kinetics and uptake, by maintaining a high CO2 concentration in the reactor, and on the other hand to maximize the carbon yield, by rejecting the minimum of CO2 at the vent (242). This regulation, in particular via the reincorporation of a portion of the gas mixed with the oxidizing gas at the inlet (215) takes into account the residual methane level and the thermal requirements of the residual methane oxidation device (214). BRIEF DESCRIPTION OF THE FIGURES
[0060] Other advantages, aims and particular characteristics of the invention will emerge from the following non-limiting description of at least one particular embodiment of the device and method which are the subject of the present invention, with reference to the appended drawings, in which:
[0061] [Fig.l] schematically represents a first particular embodiment of the carbon dioxide device by carbonation of materials
[0062] [Fig.2] schematically represents a second particular embodiment of the carbon dioxide device by carbonation of materials
[0063] The present description is given without limitation, each characteristic of an embodiment being able to be combined with any other characteristic of any other embodiment in an advantageous manner. It should be noted from now on that the figures are not to scale.
Claims
Claims
1. Device for trapping carbon dioxide by carbonation of materials (10), comprising: a. A gas inlet (101) b. A booster (102) c. A gas tank (103) d. A main circuit (110) connecting the gas tank (103) and the reactor (120) and comprising: i. an actuable register (111) ii. a device for oxidizing residual methane (114), this device itself comprising an inlet for combustion gas (115) e. A carbonation reactor (120); f. A gas recirculation circuit (130) between the reactor and the oxidant inlet (115) of the residual methane oxidation device (114) comprising: i. an actionable register (131); ii. a gas separation device (132), comprising an inlet (133), an outlet for the CO2-concentrated gas (134) and an outlet for the CO2-depleted gas (135); g. A vent circuit (140) positioned on the gas recirculation circuit (130) downstream of the gas separation device (132) and comprising: i. an actionable register (141); ii. an exhaust vent (142) to the atmosphere; h. An oxidant supply circuit (150), connected to the oxidant supply (115) of the residual methane oxidation device (114) and comprising: i. an actionable register (151); ii. an oxidant inlet (152); i. A CO2-rich gas reintroduction circuit (160) connecting the CO2-concentrated gas outlet (134) of the gas separation device (132) and the gas reservoir (103)
2. Device for trapping carbon dioxide by carbonation of materials (20), comprising: a. A gas inlet (201) b. A booster (202) c. A gas tank (203) d. A main circuit (210) connecting the gas tank (203) and the carbonation reactor (220) on which are positioned: i. an actionable register (211); ii. a heat exchanger, on the flow side to be heated (212); iii. a heat exchanger (213); iv. a residual methane oxidation device (214), comprising an oxidant inlet (215); v. a compressor (216); vi. a heat exchanger, of the cooler type (217); e. A carbonation reactor (220), comprising: i. a non-return device for the injected gas coming from the main circuit (210); ii. a device for introducing and removing carbonatable materials; iii. an instrumentation system; f. A gas recirculation circuit (230) between the reactor (220) and the oxidant inlet (215) of the residual methane oxidation device (214) comprising: i. an actuable register (231); ii. the heat exchanger, flow side to be cooled (212); iii. a gas separation device (232), comprising an inlet (233), an outlet for the CO2-concentrated gas (234) and an outlet for the CO2-depleted gas (235); g. A vent circuit (240) positioned on the gas recirculation circuit (230) downstream of the gas separation device (232) and comprising: i. an actionable register (241); ii. an exhaust vent (242) to the atmosphere; h. An oxidant supply circuit (250), connected to the gas recirculation circuit (230) downstream of the vent circuit (240) and comprising: i. an actionable register (251); ii. an oxidant inlet (252); i. A CO2-rich gas reintroduction circuit (260) connecting the CO2-concentrated gas outlet (234) of the gas separation device (232) and the gas reservoir (203), said circuit comprising: i. a vacuum pump (261), allowing the pressure at the outlet for the CO2-concentrated gas (234) to be reduced
3. A carbon dioxide trapping device according to any preceding claim, wherein the gas separation device is a membrane-type device (232), with an inlet for the gas from the gas recirculation circuit (233), an outlet for the permeate (234) leading to the recovery circuit (260) and an outlet for the retentate (235), for the gas from the recirculation circuit stripped of CO2.
4. Carbon dioxide trapping device according to any one of the preceding claims, for which several reactors (220) are positioned in parallel and can be opened, filled, emptied, closed independently of the other reactors, each reactor operating in batch mode, each reactor being connected to the main circuit and to the gas recovery circuit
5. Carbon dioxide trapping device according to one of 2 to 7, for which the vacuum pump (261) has a direct connection with the reactor (220), via a parallel circuit.