Method and system for pre-treating gaseous emissions for post-combustion CO2 capture

Abstract

To provide a process and a system for reducing the breakdown of an absorbent solution used for absorbing acidic compounds contained in a gaseous effluent.SOLUTION: The present invention concerns the field of capturing CO2 from a gaseous effluent. The incoming gaseous effluent (100) is burned with a fuel (300) so as to obtain a hot gaseous effluent (110) rich in acidic compounds, and the hot gaseous effluent (110) rich in acidic compounds is cooled to supply a cold effluent (120) rich in acidic compounds, which is subsequently used in the step of contact with an absorbent solution (500) rich in acidic compounds.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to the field of CO2 capture from gaseous emissions. CO2 capture methods form part of CCS (Carbon Capture and Storage) methods, which involve capturing CO2 molecules before, during and after industrial combustion processes in order to avoid CO2 being released into the atmosphere and thus to control greenhouse gas emissions. Three classes of capture methods are therefore envisaged: Pre-combustion: relates to collection before industrial combustion. Post-combustion: This refers to collection after conventional industrial combustion (with air), with little or no modification of the combustion method. Oxy-fuel combustion: involves post-combustion capture using pure oxygen. The present invention relates to post-combustion capture. [Background technology]

[0002] Among solutions for reducing CO2 emissions, carbon capture and storage (CCS) technologies are being developed for use by industrial emitters. These CCS technologies are essential for achieving the goals set at the Paris Climate Conference (COP21) in December 2015. These technologies are required to contribute 12% to CO2 emission reductions by 2050 if global warming is to be limited to 2°C between now and 2100. Various effective technologies are under development to meet the demand for post-combustion CO2 capture. Currently, the most promising technology for CO2 capture from flue gases and industrial gases is absorption technology using solvents. Most of the solvents used can be decomposed in the presence of oxygen. For optimal use of this method, the concentration of oxygen in the flue gas or industrial gas must be minimized.

[0003] As far as the future is concerned regarding CO2, benefits are evident from applications in cement plants, metallurgical sites and similar industrial sites, such as lime production, especially with regard to the following issues: -The manufacturing process in cement plants generates significant amounts of CO2. The energy required to capture CO2 is so great that it is comparable to the energy used to run manufacturing processes. - Combustion flue gases are rich in CO2. - Flue gas is rich in oxygen O2.

[0004] This last point is important because when using CO2 capture processes involving solvent absorption, the amount of solvent needs to be replaced more frequently, which can affect the decomposition of the solvent and therefore the operating costs of the process. The reason is that gaseous emissions such as natural gas and flue gases are generally deacidified, for example, by washing with absorbent solutions. The absorbent solutions make it possible to absorb acidic compounds present in the gaseous emissions (H2S, mercaptans, CO2, COS, SO2, CS2).

[0005] However, those skilled in the art are well aware that amines used as solvents have the drawback of decomposing under the conditions of use. In particular, amines are decomposed by oxygen, and the consumed amine and decomposition products accumulate in the unit or, if many of them are volatile, are entrained in the gaseous emissions of the process. Therefore, in processes using aqueous solutions of monoethanolamine (MEA), especially in the post-combustion treatment of flue gases, considerable amounts of ammonia are formed. The ammonia thus formed is carried into the atmosphere together with the treated flue gas, causing environmental problems.

[0006] Another potential problem outlined in relation to CO2 capture processes, and particularly in relation to post-combustion capture absorption processes, is the need to generate low- or medium-pressure steam during the solvent regeneration step. The cost of captured CO2 is highly dependent on the amount of steam required and the cost of this steam. In locations where residual steam from industrial processes cannot be captured or is insufficient to meet process needs, the cost of CO2 increases significantly.

[0007] Conventional technology The relevant prior art consists of post-combustion CO2 absorption processes for CO2 capture. Of particular importance is the Hicapt TM , Hicapt+ TM , and DMX TM (IFP Energies Nouvelles in France) three methods: HiCapt+ TM The process includes an additive to mitigate the decomposition of the solvent by oxygen. French Patent Application No. 2948578 discloses a Hicapt+ absorbent solution containing a decomposition inhibitor derived from triazoles or tetrazoles. TM A process for absorbing acidic compounds contained in gaseous effluents is disclosed. EP 2228119 A1 discloses a Hicapt+ process which employs gas deoxidation using an absorbent solution and is characterized by an optimized water wash section. TM The process is disclosed. EP 1 656 983 A1 proposes a DMX process for deoxidizing gases using an absorbent solution, characterized by fractional regeneration. TM A method is disclosed. Additionally, residual oxygen levels in industrial flue gases adversely affect the operating costs of the process by promoting solvent decomposition, thereby shortening the lifespan and requiring more frequent solvent replacement. Summary of the Invention [Problem to be solved by the invention]

[0008] Summary of the Invention The present invention proposes a method and system for reducing the decomposition of an absorbent solution used to absorb acidic compounds contained in gaseous effluents, the absorbent solution comprising an amine in an aqueous solution. To do this, the present invention aims to reduce the level of oxygen contained in the treated flue gas. [Means for solving the problem]

[0009] The present invention relates to a method for deoxygenating flue gases or industrial gases prior to CO capture with the production of steam, which allows a) reducing the O concentration in the flue gas and, optionally, b) producing steam for use in the solvent regeneration step, limiting the energy supplied to the solvent regeneration step.

[0010] The present invention proposes to remove oxygen from flue gas by burning a fuel with oxygen-rich flue gas as an oxidant. The amount of oxygen available in the flue gas, and hence the amount of oxidant, is sufficient to provide the required regeneration energy (from one-third to all, depending on the O2 content of the flue gas), thus demonstrating the benefits of utilizing this advantageous synergy.

[0011] The present invention provides a method for separating at least one acid gas contained in an incoming gaseous effluent, the method comprising at least the following steps: contacting the cold gaseous effluent enriched in acid compounds with an absorbent solution lean in an acid compound separation unit to obtain a gaseous effluent lean in acid compounds and an absorbent solution enriched in acid compounds; regenerating at least a portion of the acid-rich absorbent solution in a regeneration column to obtain an acid-lean absorbent solution and an acid-rich effluent, the acid-lean absorbent solution being used in the step of contacting with the cold acid-rich effluent; Including, The separation method further comprises the following steps of deoxygenation of the incoming gaseous effluent: combusting the incoming gaseous effluent with a fuel in a combustion device to obtain a hot gaseous effluent enriched in acidic compounds; cooling said hot gaseous effluent rich in acid compounds in a heat exchanger to provide a cold effluent rich in acid compounds for use in said step of contacting with an absorbent solution lean in acid compounds; Includes:

[0012] In one embodiment, the quality of the hot acidic compound-rich effluent can be controlled by the addition of at least one auxiliary oxidizer to the combustion device.

[0013] In one embodiment, a fluid in high pressure liquid form may be introduced into the heat exchanger to cool the hot gaseous effluent rich in acid compounds, and a fluid in high pressure vapor form is removed from the heat exchanger. If preferred, the fluid in high pressure vapor form may be used as an energy source to run the regeneration column.

[0014] In one embodiment, the operating quality of the regeneration column can be controlled by the addition of a supplemental fluid to the auxiliary high pressure vapor form of the fluid.

[0015] In one embodiment, a step of reheating the incoming gaseous effluent in the form of hot incoming gaseous effluent may be implemented prior to introducing the incoming gaseous effluent into the combustion device.

[0016] In one embodiment, the incoming gaseous effluent is reheated by introducing the incoming gaseous effluent into a heat exchanger from which it may be removed in the form of a hot incoming gaseous effluent.

[0017] In one embodiment, the hot gaseous effluent rich in acid compounds exiting the combustor can be used to reheat the incoming gaseous effluent.

[0018] In one embodiment, the incoming gaseous effluent may be flue gas from a previous combustion, particularly obtained from an industrial process.

[0019] In one embodiment, the effluent rich in acidic compounds can be stored underground, particularly in depleted or depleted oil or gas fields, or deep saline aquifers, or can be used to produce useful molecules, e.g., platform molecules for chemistry.

[0020] In one embodiment, the fuel may be waste from waste wood or waste from biomass.

[0021] In one embodiment, the at least one auxiliary oxidant may be dioxygen O2.

[0022] In one embodiment, the at least one acid gas can include at least one compound including carbon dioxide CO2.

[0023] In one embodiment, the acidic compound-rich absorbent solution and the acidic compound-lean absorbent solution can be two states of the same solvent containing an amine solution with reactive compounds in aqueous solution, the two solutions containing more or less acidic compounds.

[0024] The present invention relates to a system for separating at least one acid gas contained in an incoming gaseous effluent, suitable for carrying out the method of the present invention.

[0025] Other characteristics and advantages of the method according to the invention will become apparent from reading the following description of non-limiting exemplary embodiments, with reference to the accompanying drawings, which are described below. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 shows a combustion configuration according to the prior art. [Figure 2] FIG. 1 illustrates a combustion configuration according to a first embodiment of the present invention. [Figure 3] FIG. 4 illustrates a combustion configuration according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] FIG. 1 illustrates a prior art method for separating at least one acid gas from a gaseous effluent. Consider a gaseous effluent (e.g., flue gas, industrial gas, etc.) (100) from industrial combustion containing oxygen in the form of dioxygen (O). O2 is present in the flue gas or industrial gas because O2 is in excess during industrial combustion to ensure both completion and temperature control. Oxygen can also come from ambient air leaking into the flue gas line, insofar as combustion equipment is typically operated at reduced pressure for environmental safety reasons. This combustion effluent can result from the combustion of fossil, synthetic, or natural carbonaceous materials (whether converted or not). Therefore, this combustion effluent typically contains significant amounts of acidic compounds (e.g., H2S, mercaptans, CO2, COS, SO2, CS2, among others), such as carbon dioxide (CO2) from combustion. While the following description focuses only on the example of carbon dioxide, the process is applicable to all types of acidic compounds (e.g., H2S, mercaptans, CO2, COS, SO2, CS2). The CO2 is absorbed in a separation unit (1001), also referred to as an absorber. The acidic compound (200)-lean output from the separation unit (1001) is a flue gas with a substantially reduced CO2 content. The separation unit (1001) provides CO2 separation by adsorption or absorption. In the case of CO2 separation using an amine solvent, the absorber is a gas / liquid contactor that contacts the incoming gaseous effluent (100) for treatment with a liquid absorbent solution (501) that is lean in acidic compounds, also referred to as an amine solution. The amine solution is charged with CO2 within the separation unit (1001). The resulting solution, an acidic compound-rich and CO2-rich absorbent solution (500), is sent to a regeneration column (1002), also referred to as a regenerator. The function of the regenerator is to extract the CO2 contained in the acid-rich effluent (500) to form an effluent gas (700) containing the extracted CO2. This regeneration is achieved by thermal effects and by reducing the partial pressure of CO2 in the gas phase, which is in equilibrium with the amine solution in the regenerator.The LP (low pressure) or MP (medium pressure) hot utility (400) is used to perform regeneration, for example, by a reboiler (not shown). The regenerated amine solution (501) is called lean amine. It is sent to an absorber (1001) to capture CO2.

[0028] The present invention provides a method for separating at least one acid gas contained in an incoming effluent (100), comprising at least the following steps: contacting the cold gaseous effluent (120) enriched in acid compounds with an absorbent solution (501) lean in acid compounds in a separation unit (1001) to obtain a gaseous effluent (200) lean in acid compounds and an absorbent solution (500) enriched in acid compounds; regenerating at least a portion of the acid-rich absorbent solution (500) in a regeneration column (1002) to obtain an acid-lean absorbent solution (501) and an acid-rich effluent (700), the acid-lean absorbent solution (501) being used in the step of contacting the acid-rich cold effluent (120); combusting the incoming effluent (100) with fuel (300) in a combustion device (2000) to obtain a hot gaseous effluent (110) enriched in acidic compounds; cooling the hot gaseous effluent (110) rich in acid compounds in a heat exchanger (3000) to provide the cold effluent (120) rich in acid compounds for use in the step of contacting with the absorbent solution (501) lean in acid compounds.

[0029] The contacting and regeneration steps in the separation unit (1001) may follow conventional methods, particularly as described in connection with Figure 1. The steps of burning the hot gaseous effluent and cooling the hot gaseous effluent are steps that deoxygenate the incoming gaseous effluent (100).

[0030] FIG. 2 provides a non-limiting description of a method according to a first embodiment of the present invention, including several embodiment options, which can be considered independently of one another. The diagram shows an incoming gaseous effluent (100), also called flue gas, which in this case is treated in a combustor (2000). The combustor (2000) has two functions. The first function of the combustor (2000) is to reduce the O content of the flue gas (100) to a value compatible with the operation of the amine selected to operate the separation unit (1001) and the regeneration column (1002). The second function of the combustor (2000) is to increase the energy content of the flue gas (100) by substantially increasing its temperature. These two functions are ensured by the combustion of a fuel or fuel mixture (300). This carbonaceous feed may be the same or a different feed whose industrial combustion results in the formation of the incoming gaseous effluent (100).

[0031] In one embodiment of the present invention, the fuel (300) may be waste from wood or biomass. Therefore, in the context of reducing the environmental impact, this feedstock may be, for example, but not limited to, industrial waste or waste from biomass value recovery centers, such as wood waste, forestry residues, agricultural by-products, or energy crops. In this latter instance of biomass, downstream capture of CO2 results in negative emissions being considered, which is particularly advantageous from the standpoint of greenhouse gas emissions balance. Another oxidant with a positive effect on emissions is hydrogen. This is because hydrogen is an oxidant with high energy value and can be easily separated from flue gases by direct use of its combustion product, water. Furthermore, this is an advantageous route to process hybridization between fuel and electricity, since the latter can easily be used to supply hydrogen by devices such as electrolyzers. The advantage offered by this hybridization is its flexibility to accommodate the amount of decarbonized electricity available in the network, whether in excess or not.

[0032] The result of this combustion is a hot effluent (110) rich in acidic compounds, with an oxygen content that can be below the threshold recommended by the supplier of the amine solvent, i.e., generally less than 10% on a dry basis, and preferably less than 6% on a dry basis.

[0033] For example, in the case of a lack of oxidant, meaning that the energy supply required for regeneration cannot be achieved by combustion, in one embodiment, auxiliary air (600) can be used, if necessary. Indeed, in one embodiment, the quality of the hot effluent (110) enriched in acidic compounds is controlled by adding at least one auxiliary oxidant (600) to the combustion device (2000). In one embodiment of the present invention, said at least one auxiliary oxidant (600) is dioxygen O2.

[0034] This acid-rich effluent (110) is cooled in a heat exchanger (3000) to produce a high-pressure steam stream (410), also called high-temperature utility, of sufficient temperature and quantity to regenerate the amines, including the captured CO, from the acid-rich absorbent solution (500), starting from the high-pressure liquid form fluid (800). This is because, in one embodiment of the present invention, the process may also include a step of introducing the high-pressure liquid form fluid (800) into a heat exchanger (3000) from which a high-pressure vapor form fluid (410), also called a pressurized vapor form fluid, is withdrawn. In other words, in the heat exchanger (3000), the high-pressure liquid form fluid (800) recovers thermal energy from the high-temperature acid-rich effluent (110) to form a high-temperature utility (410) and an acid-rich effluent (120), which exit the heat exchanger (3000) in cooled form.

[0035] In one embodiment of the present invention, the fluid (410) in the form of high pressure steam can be used as an energy source to operate the regeneration column (1002). The use of the fluid (410) in the form of high pressure steam as an energy source to operate the regeneration column (1002) is particularly useful in that condensing this steam in a reboiler is an effective way of transferring heat to the process. As a non-limiting example, the fluid (410) in the form of high pressure steam is saturated steam with a predetermined condensation point on the order of 10°C to 20°C above the operating temperature of the reboiler intended to regenerate the amine solution. That is, for a 30 wt% MEA solution in water, operation is typically performed at 120°C, which corresponds to a supply of steam with a condensation point of 140°C. The air supplement (600) is used (particularly when an existing plant is adapted to add a CO capture device, within the limits allowed by the unit's capacity in terms of flow rate and temperature) to increase the amount of fuel that can be combusted to produce a hot effluent (110) rich in acid compounds, thereby increasing the energy content of the high-pressure steam fluid (410).

[0036] In one embodiment, this energy supply is also provided by an external supply of energy in the form of a supplemental high pressure steam fluid (401). In one embodiment of the present invention, the quality of operation of the regeneration column (1002) is actually controlled by adding a supplemental fluid in the form of supplemental high pressure steam (401).

[0037] The reason is that the oxygen content of the incoming gaseous effluent (100) is not always sufficient to provide combustion of a sufficient amount of fuel to regenerate a solvent in an amount corresponding to the total CO2 desired to be captured. For example, this is the case for MEA solvents in flue gases, which typically contain more than 20% CO2 and less than 5% O2 on a dry basis. This supplement in the form of a supplementary high-pressure steam fluid (401) can prevail without losing the benefit of the utility's energy contribution in the form of high-pressure steam fluid (410). Efforts are made to tune the system for producing high-temperature utilities to the greatest possible extent, generally in the form of steam fluid (401), and to optimize the overall system energy balance. This means, for example, partial reheating of the fluid used to produce the high-pressure steam fluid (401) on the flue gas path between the incoming gaseous effluent (100) and the acid-poor effluent (200), particularly in a heat exchanger (3000) (not shown). The primary function of the heat exchanger (3000) is to produce a high temperature utility in the form of a high pressure vapor fluid (410) by heat exchange with a reheat stream in the form of a hot acid compound-rich effluent (110). The heat exchanger (3000) also includes an auxiliary heat exchanger for producing a stream in the form of a cold acid compound-rich effluent (120), which has a temperature compatible with the optimum operation of the selected amine, typically below 50°C for a 30 wt% MEA solution in water.

[0038] In one embodiment of the present invention, the process may include reheating the incoming gaseous effluent (100) in the form of a hot incoming effluent (101) prior to introducing the incoming gaseous effluent (100) into the combustion device (2000).

[0039] The incoming gaseous effluent (100) is preferably reheated by introduction into a heat exchanger (3000) and removed in the form of hot incoming effluent (101).

[0040] FIG. 3 illustrates a second embodiment of the present invention, which, compared to the embodiment of FIG. 2, includes the additional step of reheating the incoming gaseous effluent (100), which is a CO2-rich effluent, in a heat exchanger (3000) to produce a stream in the form of a hot incoming gaseous effluent (101). The temperature is selected to facilitate ignition of the fuel (300) upon contact with the oxygen contained in the hot incoming gaseous effluent (101). Typically, for a known oxygen partial pressure and a known concentration of a specific fuel, it is possible to define an autoignition point, which is a factor that can enable the definition of the minimum temperature of the hot incoming gaseous effluent (101) stream that must be reached to achieve complete combustion of the fuel (300). This minimum temperature can also be reduced by using devices such as catalytic burners. Preheating the incoming gaseous effluent (100) to produce a hot incoming gaseous effluent (101) can be performed by heat exchange with a dedicated hot utility (not shown), by heat integration with a device that generates a secondary hot utility in the form of a secondary high pressure steam fluid (401) in a suitable location (not shown), or by integration into the exhaust charge around the combustion device (2000), such as a dedicated heat exchange section of a heat exchange device (3000) as shown in Figure 3. In this latter variant, in the heat exchanger (3000), the high pressure liquid form fluid (800) and also the incoming gaseous effluent recovers heat energy from the hot acid compound-rich effluent (110) to form a hot utility (410), a hot incoming gaseous effluent (101), and a cold acid compound-rich effluent (120). In other words, the hot acid compound gaseous effluent (110) exiting the combustor is used to reheat the incoming gaseous effluent (100).

[0041] In one embodiment of the present invention, the incoming gaseous effluent (100) may be flue gas from a previous combustion, particularly obtained from an industrial process.

[0042] In one embodiment of the present invention, the acidic compound-rich effluent (700) may be stored underground, particularly in an oil field.

[0043] In one embodiment, the at least one acid gas may include at least one of compounds including carbon dioxide CO2.

[0044] In one embodiment of the present invention, the acid-rich absorbent solution (500) and the acid-poor absorbent solution (501) are two versions of the same solvent, comprising an amine solution with reactive compounds in aqueous solution, said two solutions containing more or less acid compounds.

[0045] The present invention also resides in a system for separating at least one acid gas contained in an incoming gaseous effluent (100), suitable for carrying out a method according to any one of the above method variants or combinations of variants. [Example]

[0046] To illustrate the proposed solution, reference is made to an amine scrubbing method for CO2 absorption. The assumed performance qualities are those of a scrubbing method using 40 wt% monoethanolamine (MEA) to capture CO2 on a typical flue gas from a coal-fired power plant. These performance qualities were observed experimentally.

[0047] For each case presented, the characteristics of the flue gas stream for treatment are as follows:

[0048] [Table 1]

[0049] For simplicity, the incoming gaseous effluent (100) is considered to be free of impurities such as SOx or NOx. Its oxygen content is approximately 5 vol% on a dry basis. The composition of the flue gas at the furnace outlet is generally provided on a dry basis. For the purposes of these examples, consider a hydrated flue gas containing 0.043 kg HO / kg dry gas (a value collected from a typical flue gas from a coal-fired power plant). Its composition is as follows:

[0050] [Table 2]

[0051] A CO2 absorber operated by washing with 40 wt% MEA in the separation unit (1001) produces an acid-poor effluent (200) containing 90 wt% less CO2, the composition of which is shown in the table below:

[0052] [Table 3]

[0053] The regeneration column (1002) is 3.02 GJ / t. 捕集されたCO2 % CO2 by weight. In Figure 1, the vapor stream from the high temperature unit (400) returns to the regeneration column (1002). This basic example, known in the prior art, does not specify how the vapor is formed, but shows the amount of steam required to capture 90% of the CO2 in the incoming gaseous effluent. The steam flow rate required for the high temperature unit (400) to reboil the solvent to capture 90% of the CO2 by weight with 40% MEA is shown in the table below:

[0054] [Table 4]

[0055] The performance characteristics of the device are compared across three cases, with an inlet gaseous effluent (100) containing 5 Vol% oxygen (same composition as the flue gas in the reference case), 10 Vol% and 15 Vol% on a dry basis. The flue gas compositions considered are as follows:

[0056] [Table 5]

[0057] The fuel (300) used in this device is methane at 7 bar and 25°C, with a pressure of 5.003 x 10 4 The exhaust gas stream leaving the combustion unit (2000) has an LHV of 100 kJ / kg. Complete combustion with excess oxygen proceeds until the oxygen content in the exhaust gas stream leaving the combustion unit (2000) reaches a value of 2% by volume. The target oxygen content is variable, but the aim is to minimize it in order to obtain a flue gas stream whose oxygen content does not cause excessive decomposition of the amine in the separation unit (1001). The lower the oxygen content selected, the greater the energy recovered for steam generation, but this also affects the amount of fuel consumed. This value can therefore be optimized.

[0058] The incoming gaseous effluent (100), initially at 150°C, is first heated to 650°C in the heat exchanger (3000) using the hot effluent (110), rich in acid compounds, at the outlet of the combustion unit (2000) as the hot fluid. A temperature of 650°C is higher than the ignition temperature of the fuel (300), in this case methane, at 540°C. This ensures the combustion of the fuel with the flue gas for processing. The temperatures observed for the various cases are shown in the table below. The higher the oxygen content of the incoming flue gas, the more combustion occurs in the unit and therefore the higher the outlet temperature.

[0059] [Table 6]

[0060] The flue gas stream exiting the combustor (2000) allows for preheating of the flue gas for processing and for generating steam by evaporating boiling feed water at 140°C and 3.6 bar (the steam conditions required for the steam required to run the regenerator with 40 wt% MEA solvent). This steam stream is then used by the regeneration column (1002) as a hot utility, high pressure steam stream (410). The amount of steam generated is 3.02 GJ / t 捕集されたCO2The amount of CO2 generated is related to the amount of energy required for the regeneration of the MEA solvent, and the amount of steam produced is itself related to the amount of CO2 that can be captured by absorption in the separation unit (1001). The performance values ​​obtained for the three cases are shown in the table below:

[0061] [Table 7]

[0062] Note: The CO2 capture rate takes into account the additional CO2 produced by combustion in the combustion unit (2000). The amount of CO2 ultimately emitted (after the combustion unit and CO2 capture unit) compared to the amount of CO2 initially emitted without the capture unit leads to the concept of the level of CO2 avoided capture. According to the present invention, the higher the oxygen content of the flue gas stream for treatment, the greater the amount of water vapor produced by heat recovery from the flue gas, and therefore the greater the CO2 capture rate achieved by the method according to the present invention.

Claims

1. 1. A method for separating at least one acid gas contained in an incoming gaseous effluent (100), comprising at least the following steps: contacting the cold gaseous effluent (120) rich in acid compounds with an absorbent solution (501) lean in acid compounds in a separation unit (1001) to obtain a gaseous effluent (200) lean in acid compounds and an absorbent solution (500) rich in acid compounds; regenerating at least a portion of the acid-rich absorbent solution (500) in a regeneration column (1002) to obtain an acid-lean absorbent solution (501) and an acid-rich effluent (700), the acid-lean absorbent solution (501) being used in the step of contacting the acid-rich cold gaseous effluent (120); Including, The separation method further comprises the steps of: Combustion of the incoming gaseous effluent (100) with fuel (300) in a combustion device (2000) to obtain a hot gaseous effluent (110) enriched in acidic compounds; cooling the hot gaseous effluent (110) rich in acid compounds in a heat exchanger (3000) to give a cold gaseous effluent (120) rich in acid compounds, which is used in the step of contacting with the absorbent solution (501) lean in acid compounds; Including, 10. A method according to claim 1, wherein the separation method also comprises a step of reheating the incoming gaseous effluent (100) before introducing it into the combustion device (2000) in the form of a hot incoming gaseous effluent (101).

2. 10. The method of claim 1, wherein the quality of the hot gaseous effluent (110) rich in acidic compounds is controlled by the addition of at least one auxiliary oxidizer (600) to the combustion device (2000).

3. 3. The method of claim 1 or 2, further comprising introducing a fluid (800) in high pressure liquid form into the heat exchanger (3000) from which a fluid (410) in high pressure vapor form is removed.

4. 4. The method of claim 3, wherein the fluid (410) in the form of high pressure steam is used as an energy source to run the regeneration column (1002).

5. 5. The method of claim 4, wherein the operability of the regeneration column (1002) is controlled by the addition of a supplemental make-up fluid (401) in the form of high pressure steam.

6. 6. The method of any one of claims 1 to 5, wherein the incoming gaseous effluent (100) is reheated by introduction into a heat exchanger (3000) and removed from said heat exchanger (3000) in the form of a hot incoming gaseous effluent (101).

7. The method of any one of claims 1 to 6, wherein the incoming gaseous effluent (100) is flue gas from a preceding combustion.

8. The method of any one of claims 1 to 7, wherein the acid compound-rich effluent (700) is stored underground.

9. The method according to any one of claims 1 to 8, wherein the fuel (300) is waste from waste wood or waste from biomass.

10. At least one auxiliary oxidant (600) is oxygen O ２ The method according to any one of claims 2 to 9, wherein

11. The at least one acid gas is carbon dioxide CO ２ The method of any one of claims 1 to 10, comprising at least one compound comprising:

12. A system for separating at least one acid gas contained in an incoming gaseous effluent (100) for carrying out the method according to any one of claims 1 to 11, comprising: a separation unit (1001) for contacting the cold gaseous effluent (120) rich in acid compounds with an absorbent solution (501) lean in acid compounds to obtain a gaseous effluent (200) lean in acid compounds and an absorbent solution (500) rich in acid compounds; a regeneration column (1002) for regenerating at least a portion of the acid-rich absorbent solution (500) to obtain an acid-lean absorbent solution (501) and an acid-rich effluent (700), the acid-lean absorbent solution (501) being used in contacting the cold acid-rich gaseous effluent (120) in the separation unit (1001); a combustion device (2000) for combusting the incoming gaseous effluent (100) with fuel (300) to obtain a hot gaseous effluent (110) enriched in acidic compounds; a heat exchanger (3000) for cooling the hot acid-rich gaseous effluent (110) to provide a cold acid-rich gaseous effluent (120) for contacting with the acid-lean absorbent solution (501) in said separation unit (1001); Including, the system.

Images