Method and device for deacidifying a gaseous effluent, the device comprising a separator positioned above the regeneration sections

Abstract

The present invention relates to a device and a method for deacidifying a gaseous effluent (EF), the device comprising: - an absorption column (C101); - a line for transporting the rich absorbent solution (SA) and a line for conveying an absorbent solution to be recycled (SAR); - at least one first heat exchanger (E101A) for exchanging heat between the fluids circulating in the transport line and in the conveying line; - the transport line comprising a separator (V101) for separating the absorbent solution containing acidic compounds (SA) into a gas phase (FG) and two liquid phases (SV1 and SV2); - the regeneration column (C102) with at least one regeneration section (R20). In addition, the separator (V101) is positioned above the at least one regeneration section (R20).

Description

[0001] Process and device for the acidification of a gaseous effluent comprising a separator positioned above the regeneration sections. Technical field

[0002] The present invention relates to the field of deacidification of a gas by means of an absorbent solution, for example the decarbonation of combustion fumes or the deacidification of natural or industrial gas.

[0003] The areas targeted are essentially low-pressure decarbonization processes (biogas from waste methanization, post-combustion CO2 capture: industrial fumes from waste incinerators, coal or natural gas power plants, blast furnaces, cement plants, glassworks, aluminium production, lime production, or even FCC type refinery gases for "Fluid Catalytic Cracking" meaning catalytic cracking of fluid,

[0004]

[0005] The invention may also be relevant to high-pressure deacidification processes of natural gas and syngas.

[0006] Previous technique

[0007] Gas deacidification processes commonly employ aqueous amine solutions to remove acidic compounds from gases, including carbon dioxide (CO2), hydrogen sulfide (H2S), carbon oxysulfide (COS), carbon disulfide (CS2), sulfur dioxide (SO2), and RSH mercaptans such as methyl mercaptan (CH3SH), ethyl mercaptan (CH3CH2SH), and propyl mercaptan (CH3CH2CH2SH). The gas is deacidified by contacting it with the absorbent solution, which is then thermally regenerated.

[0008] In the energy sector, for example, the combustion of fossil fuels, which leads to the release of CO2 into the atmosphere, is a major problem, as the increase in atmospheric CO2 is recognized as a contributor to global warming. To reduce this type of emission, one solution is to capture and then store the CO2 emitted by combustion, particularly in coal-fired power plants. A CO2 capture process separates the CO2 from the other components of the flue gases produced by burning fossil fuels, thus allowing the CO2 to be transported in concentrated form to an underground storage facility. In this way, the CO2 is sequestered in the underground reservoir or used for other purposes instead of being released into the atmosphere.

[0009] A current standard method for capturing CO2 involves scrubbing combustion gases with a basic absorbent solution, such as an aqueous solution of monoethanolamine. The basic solution flows between two columns. One operates at a low temperature and scrubs the gas by absorbing acidic species, such as CO2, but also H2S, SO2, COS, etc. The other operates at a high temperature and regenerates the absorbent solution by releasing the acidic species it contains. The temperature increase in the second column is achieved by heating the absorbent solution at the bottom of the regenerator using a heating element, typically steam.

[0010] One drawback of this type of deacidification process lies in its high energy consumption. In a power plant, for example, the installation of a CO2 capture system reduces the plant's energy efficiency: part of the energy produced by the combustion of fossil fuels is consumed by the capture unit and is no longer used for electricity production.

[0011] It is therefore essential to minimize the energy consumption of such processes, particularly the energy consumption related to the regeneration of the absorbent solution. Recently, it has been proposed to use absorbent solutions that have the property of forming two liquid phases that can be immiscible depending on the temperature or CO2 concentration. This phenomenon of the solution splitting into two immiscible phases is also called demixing. Patents FR-2,898,284 and EP-1,656,983, for example, describe processes using this type of absorbent solution. In these processes, fractional regeneration is performed, consisting of regenerating only a portion of the absorbent solution from a step that separates the solution into two liquid phases upstream of the regeneration column.Thus, such fractional regeneration makes it possible to reduce the energy expenditure related to regeneration and to limit the size of the regeneration section.

[0012] The gas exiting the regeneration column consists primarily of acid gas (carbon dioxide (CO2), hydrogen sulfide (H2S), carbon oxysulfide (COS), carbon disulfide (CS2), sulfur dioxide (SO2), and RSH mercaptans such as methyl mercaptan (CH3SH), ethyl mercaptan (CH3CH2SH), and propyl mercaptan (CH3CH2CH2SH), for example) captured from the gaseous effluent in the absorption column, and water vapor. To separate the water vapor from the acid gases, a condenser is generally used to condense the water vapor from the gas exiting the regeneration column into liquid form, and to discharge it. However, the condenser generates dissipated heat, which represents an energy loss. The separation method for separating the two liquid phases of the absorbent solution loaded with acidic compounds is also a source of energy consumption because it is necessary to use circulation pumps.

[0013] The technical problem that the present invention seeks to solve is to reduce the energy consumption of the means for separating the two liquid phases of the absorbent solution containing acidic compounds. It may also involve reducing the footprint of the industrial installation, simplifying operations, limiting the number of pieces of equipment required (pumps and associated equipment), and facilitating transitional phases (start-ups and shutdowns).

[0014] Summary of the invention

[0015] The invention relates to a device for deacidifying a gaseous effluent containing acidic compounds, such as hydrogen sulfide or carbon dioxide, comprising: - an absorption column for bringing the gaseous effluent into contact with an absorbent solution in order to produce a gas depleted in acidic compounds and an absorbent solution loaded with acidic compounds, the absorbent solution being chosen for its property of forming separable phases when it has absorbed a quantity of acidic compounds and / or when it is heated;

[0016] - a transport line for the absorbing solution loaded with acidic compounds ensuring the fluidic connection between the absorption column and at least one regeneration section of a regeneration column;

[0017] - a conveying line for an absorbent solution to be recycled ensuring the fluidic connection between at least one regeneration section of the regeneration column and the absorption column;

[0018] - at least one first heat exchanger to exchange heat between the fluids flowing in the transport line and in the delivery line;

[0019] - the transport line including a separator to separate the absorbent solution loaded with acid compounds into a gaseous fraction, a first liquid fraction of absorbent solution depleted in acid compounds and a second liquid fraction of absorbent solution enriched in acid compounds;

[0020] - the regeneration column comprising at least one regeneration section to release the acidic compounds contained at least in said second liquid fraction and to produce a regenerated absorbent solution forming part of the absorbent solution to be recycled.

[0021] In addition, the separator, preferably a decanter, is positioned above said at least one regeneration section of the regeneration column in the operating position.

[0022] Preferably, the separator is a vertical decanter or a horizontal decanter.

[0023] Advantageously, the device includes a second heat exchanger positioned between the first heat exchanger and at least one regeneration section of the regeneration column on the conveying line, to exchange heat between the fluids flowing in the conveying line and in the conveying line, the separator preferably being positioned between the first heat exchanger and the second heat exchanger or positioned after the second heat exchanger.

[0024] According to one configuration of the invention, the device includes at least one heat recovery section positioned either in the separator, or above the separator, or above at least one regeneration section.

[0025] Preferably, the device includes at least one first bypass line in fluidic connection between the transport line upstream of the first heat exchanger and at least one regeneration section and / or at least one second bypass line in fluidic connection between the transport line downstream of the first heat exchanger and at least one regeneration section of the regeneration column.

[0026] Advantageously, the regeneration column includes a reflux section (R10) located above at least one regeneration section, and the device preferably includes a connecting circuit to send the gaseous fraction exiting the separator below the reflux section.

[0027] According to one variant of the invention, the device includes a conduit for sending the gaseous fraction directly to a cooling means positioned downstream of the regeneration column.

[0028] According to one embodiment of the invention, the separator is positioned above the regeneration column in the operating position.

[0029] Preferably, the separator is connected to the regeneration column by a support structure.

[0030] Advantageously, the separator and the regeneration column are cylindrical and the diameter of the separator is greater, preferably strictly greater, than the diameter of the regeneration column.

[0031] According to another embodiment of the invention, the separator is integrated into the regeneration column and positioned above at least one regeneration section in the operating position and preferably the diameter of the regeneration column at the separator is greater, preferably strictly greater, than the diameter of the regeneration column in the regeneration sections.

[0032] Preferably, the separator includes a passage for the gas flow exiting at least one regeneration section.

[0033] Advantageously, the separator includes a discharge and distribution system configured to allow the second liquid fraction to reach at least one regeneration section.

[0034] According to one configuration of the invention, the separator includes a means for regulating the pressure.

[0035] According to one aspect of the invention, the transport line includes a first heater between the first heat exchanger and the separator.

[0036] According to one variant of the invention, the transport line includes a second heater between the second heat exchanger and the regeneration column.

[0037] The invention also relates to a process for deacidifying a gaseous effluent containing acidic compounds, such as hydrogen sulfide or carbon dioxide, in which at least the following steps are carried out using a device according to one of the variants or combinations of variants described above:

[0038] a) the gaseous effluent is brought into contact with an absorbent solution in the absorption column, so as to obtain a gaseous effluent depleted in acidic compounds and an absorbent solution loaded with acidic compounds, the absorbent solution being capable of forming separable phases when it has absorbed a predetermined quantity of acidic compounds and / or when it is heated,

[0039] b) the absorbent solution loaded with acidic compounds is heated in said at least a first heat exchanger, the first heat exchanger exchanging heat with an absorbent solution to be recycled,

[0040] (c) In said separator, the heated absorbent solution loaded with acidic compounds is separated into a gaseous fraction, a first liquid fraction depleted in acidic compounds, and a second liquid fraction enriched in acidic compounds.

[0041] d) the second liquid fraction is regenerated in at least one regeneration section of the regeneration column so as to release the acidic compounds into an outgoing gas stream, thus forming a regenerated, acid-poor absorbing solution exiting the regeneration column,

[0042] e) the absorbent solution to be recycled is recycled as an absorbent solution in step a), the absorbent solution to be recycled comprising at least the absorbent solution low in acid compounds regenerated in step d) and preferably the first liquid fraction obtained in step c).

[0043] Preferably, the absorbent solution loaded with acidic compounds or the second liquid fraction is heated in at least one second heat exchanger, the second heat exchanger exchanging heat with an absorbent solution to be recycled or with the regenerated absorbent solution.

[0044] According to an advantageous embodiment of the invention, at least a first portion of the absorbing solution loaded with acid compounds is diverted into a first bypass line upstream of the first heat exchanger and this first portion is sent into at least one regeneration section of the regeneration column, and / or at least a second portion of the absorbing solution loaded with acid compounds or of the second liquid fraction is diverted into a second bypass line downstream of the first heat exchanger, and this second portion is sent into at least one regeneration section of the regeneration column.

[0045] Advantageously, the first liquid fraction is drawn from the separator by gravity, under level control, to be sent back to the absorption column.

[0046] According to one variant of the invention, the first liquid fraction exiting the separator is mixed with the regenerated absorbent solution to form the absorbent solution to be recycled.

[0047] List of figures

[0048] Other features and advantages of the device and / or method according to the invention will become apparent from the following description of non-limiting examples of embodiments, with reference to the figures attached and described below.

[0049] Figure 1 represents a first embodiment of the device and method according to the invention.

[0050] Figure 2 represents a second embodiment of the device and method according to the invention.

[0051] Figure 3 represents a third embodiment of the device and method according to the invention.

[0052] Figure 4 shows a fourth embodiment of the device and method according to the invention. Figure 5 shows a fifth embodiment of the device and method according to the invention.

[0053] Figure 6 represents a sixth embodiment of the device and method according to the invention.

[0054] Figure 7 represents a seventh embodiment of the device and method according to the invention.

[0055] Figure 8 represents a horizontal decanter which can be used as a separator in the device and process according to the invention.

[0056] Description of the implementation methods

[0057] For the purposes of the present invention:

[0058] - The term "separator" or "separation device" refers to a device that allows for the separation of at least three fluids from one another, each fluid comprising at least one gas and two liquid phases. This separator can be of any type, including gravity-based or electrostatic technology.

[0059] - A "decanter" is a separator in which the separation of different phases is achieved primarily by decantation (by gravity). The decanter allows the separation of at least three phases separately from each other, the three phases comprising one gaseous phase and two liquid phases.

[0060] - A "vertical decanter" is defined as a decanter in which the separation between the different phases occurs solely vertically, by difference in phase densities, when the decanter is in the operating position.

[0061] - A "horizontal decanter" is defined as a decanter whose different phases are separated by decantation into different compartments separated from each other and positioned horizontally next to each other in the operating position.

[0062] - The term "operating position" refers to the position of the device in which it can be used to capture acidic compounds from the gaseous effluent and to regenerate the absorbent solution.

[0063] The terms "upstream" and "downstream" are understood in the direction of the flow of the fluid at the location in question, the fluid being the gaseous effluent to be deacidified, the gas exiting the regeneration column, the absorbent solution loaded with acidic compounds, the gaseous fraction, the first liquid fraction, the second liquid fraction, the absorbent solution low in acidic compounds (i.e. the regenerated absorbent solution), the absorbent solution to be recycled for example.

[0064] The term "demixing" refers to the phenomenon of separation into two liquid phases of a single-phase liquid absorbent solution. An absorbent solution is one capable of absorbing acidic compounds from a gaseous effluent, such as CO2, H2S, COS, CS2, SO2, and mercaptans, under appropriate operating conditions (temperature, pressure, and physical elements of gas / liquid contact). The adjectives "demixing" are used in reference to the demixing phenomenon. A demixing absorbent solution is thus one capable of forming two separable liquid phases when it contains a predetermined quantity of acidic compounds.

[0065] - The terms "depleted" and "enriched" are understood in relation to each other: in other words, the first liquid fraction is less rich in acidic compounds than the second liquid fraction.

[0066] The invention relates to a device for acidifying a gaseous effluent containing acidic compounds, such as hydrogen sulfide (H2S) or carbon dioxide (CO2). The gaseous effluent acidifying device comprises:

[0067] - an absorption column to bring the gaseous effluent into contact with an absorbent solution in order to produce a gas depleted in acidic compounds and an absorbent solution charged (or "enriched") in acidic compounds; for example, when the acidic compounds are composed of carbon dioxide, the gas depleted in acidic compounds contains little or no carbon dioxide and the absorbent solution exits the absorption column charged with carbon dioxide,

[0068] - a transport line for the absorbing solution loaded with acidic compounds going (in the direction of flow of the absorbing solution in this transport line) from the absorption column to the regeneration column (preferably to at least one regeneration section of this regeneration column);

[0069] - a conveying line for an absorbent solution to be recycled going (in the direction of flow of the absorbent solution to be recycled in this conveying line) from the regeneration column (preferably from at least one regeneration section of this regeneration column) to the absorption column;

[0070] - at least one first heat exchanger to exchange heat between the fluids flowing in the transport line and in the delivery line;

[0071] - the transport line comprising a separator (or separation means) to separate the absorbing solution loaded with acid compounds into a gaseous fraction, into a first liquid fraction of absorbing solution depleted in acid compounds and into a second liquid fraction of absorbing solution enriched in acid compounds; thus, in the separator, a demixing phenomenon of two liquid fractions is generated and a gaseous fraction is generated from the vaporization of water and from the desorption of some of the absorbed acid compounds: a demixing phenomenon of two liquid fractions is therefore generated which is also separated from a gaseous fraction.- the regeneration column comprising at least one regeneration section to release the acidic compounds contained in at least said second liquid fraction and to produce a regenerated absorbent solution forming part of the absorbent solution to be recycled, said regeneration column preferably being equipped with at least one reboiler to generate steam by vaporizing a portion of the regenerated absorbent solution taken from the regeneration column. In the regeneration column, the liquid phases, in particular the absorbent solution loaded with acidic compounds and / or the second liquid fraction, move vertically downwards in the regeneration column while the gas moves vertically upwards in this regeneration column (at the top of the regeneration column).The liquid phases exit together through an outlet located at the bottom of the regeneration column, while the gas exits at the top of the regeneration column.

[0072] The absorbing solution is chosen for its ability to form separable phases when it has absorbed a quantity of acidic compounds and is heated. The absorbing solution therefore has acid absorption and separation properties related to both the acidic compounds and the temperature. The quantity of acidic compounds and / or the temperature required for the formation of separable phases can be predetermined and may depend on the absorbing solution itself, the acidic compounds to be absorbed, and the pressure and temperature conditions, among others. Thus, this quantity and / or temperature can be predetermined through experimentation.

[0073] Acidic compounds can include acidic gases, such as carbon dioxide (CO2) or hydrogen sulfide (H2S). The absorbing solution can be chosen based on factors such as the type of acidic compounds to be absorbed and the temperature.

[0074] The invention also relates to an absorbent solution as defined in this description, according to any of the variants or combinations of variants described herein, for the deacidification of a gaseous effluent containing acidic compounds, for example, for the decarbonation of combustion fumes or the deacidification of natural or industrial gas. The absorbent solution may comprise one or more reactive compounds or compounds exhibiting a physicochemical affinity with the acidic compounds and optionally one or more solvation compounds. Preferably, an absorbent solution is chosen that includes compounds reactive with the acidic compounds. The compound(s) used for the solvation of the reactive compound(s) may possess functional groups reactive with the acidic compounds to be treated.

[0075] The absorbing solution may comprise a primary reactive compound and at least one secondary reactive compound.

[0076] The term "main reactive compound" refers to the reactive compound in the absorbing solution that has the highest concentration in the absorbing solution, when the absorbing solution includes several reactive compounds: it is therefore the major reactive compound (by weight) present in the absorbing solution.

[0077] The term "secondary reactive compound" refers to a reactive compound in the absorbing solution that is different from the main reactive compound: it is therefore a reactive compound that is not the major reactive compound in the absorbing solution.

[0078] According to one configuration of the invention, the reactive compound(s) (in particular the main reactive compound and / or at least one secondary reactive compound) may be selected from the group consisting of amines, alkanolamines, amino acids, alkali salts of amino acids, amides, ureas, phosphates, carbonates and borates of alkali metals.

[0079] Reactive compounds (including main and / or secondary) may include, for example and without limitation, amines (primary, secondary, tertiary, cyclic or non-cyclic, aromatic or non-aromatic, saturated or non-saturated), alkanolamines, polyamines, amino acids, alkali salts of amino acids, amides, ureas, phosphates, carbonates or borates of alkali metals.

[0080] Reactive compounds containing an amine function preferably have the following structure:

[0081] R 1

[0082]

[0083] X represents an amine function (NR 6 ) or an oxygen atom (O) or a sulfur atom (S) or a disulfide (SS) or a carbonyl group (C=O) or a carboxyl group (O=CO) or an amide group (O=CNR 6 ) or an aromatic ring with 6 carbon atoms. n and m are integers, n can take all values ​​from 0 to 8, preferably from 0 to 6, and m all values ​​from 1 to 7, preferably from 1 to 5.

[0084] R 5 represents either a hydrogen atom or a hydrocarbon chain, branched or unbranched, saturated or unsaturated, comprising from 1 to 10 carbon atoms, preferably from 1 to 8 carbon atoms.

[0085] R 1 , R 2 , R 3 , R 4 and R 6represent either a hydrogen atom, or a hydrocarbon chain, branched or unbranched, saturated or unsaturated, comprising from 1 to 10 carbon atoms, preferably from 1 to 8 carbon atoms, or have the following structure:

[0086] — C(CR 7 R 8 ) -ÏXR 9

[0087]

[0088] lq Jp

[0089] q and p are integers, q can take all values ​​from 0 to 6, preferably from 0 to 4, and p all values ​​from 0 to 7, preferably from 0 to 5.

[0090] Y represents an amine function (NR 10 ) or an oxygen atom (O) or a sulfur atom (S) or a disulfide (SS) or a carbonyl group (C=O) or a carboxyl group (O=CO) or an amide group (O=CNR 10 ) or an aromatic ring with 6 carbon atoms. R 7 , R 8 , R 9 and R 10represent either a hydrogen atom, or a hydrocarbon chain, branched or unbranched, saturated or unsaturated, comprising from 1 to 10 carbon atoms, preferably from 1 to 8 carbon atoms.

[0091] R 1 , R 2 , R 3 , R 4 , R 5 and R 6 , and possibly R 7 , R 8 , R 9 and R 10 can be defined in such a way as to possibly constitute cycles or heterocycles, saturated or not, aromatic or not, by associating them two by two.

[0092] When X is an aromatic ring with 6 carbon atoms, X and at least one of the R groups 1 , R 2 , R 3 , R 4 , R 5 , R 6 and possibly R 7 , R 8 , R 9 and R 10 can be defined in such a way as to possibly constitute cycles or heterocycles, saturated or not, aromatic or not, by associating them two by two.

[0093] When Y is an aromatic ring with 6 carbon atoms, Y and at least one of the R groups 1 , R 2 , R 3 , R 4 , R 5 , R 6 and possibly R 7 , R 8 , R 9 and R 10 can be defined in such a way as to possibly constitute cycles or heterocycles, saturated or not, aromatic or not, by associating them two by two.

[0094] By way of example and without limitation, reactive compounds containing an amine group may be chosen from the following list: monoethanolamine, diethanolamine, triethanolamine, 2-(2-aminoethoxy)ethanol, N,N-dimethylaminoethoxyethanol, N,N,N'-trimethyl-N'-hydroxyethyl-bisaminoethyl ether, N,N-bis-(3-dimethylaminopropyl)-N-isopropanolamine, N-(3-dimethylaminopropyl)-N,N-diisopropanolamine, N,N-dimethylethanolamine, N-(2-aminoethyl)ethanolamine, 3-amino-1-propanol, 3-ethoxypropylamine, N-methylethanolamine, N-methyldiethanolamine, diisopropanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, N,N-dimethyl-1 3-propanediamine, N,N,N-tris(3-dimethylaminopropyl)amine, N,N,N',N",N'-pentamethyldipropylenetriamine, N,N,N',N'-tetramethyliminobispropylamine, N-(3-aminopropyl)morpholine, N-(2-dimethylaminoethyl)morpholine, 3-methoxypropylamine, N-(2-aminoethyl)piperazine, 2,2-Dimorpholinodiethyl ether, N,N'-dimethylpiperazine, N,N,N',N',N”-pentamethyldiethylenetriamine, N-(3-aminopropyl)piperazine, ethyl 1-piperazine carboxylate, dipropylenetriamine, N,N-Bis(2,2-diethoxyethyl)methylamine, 3-butyl-2-(1-ethylpentyl)oxazolidine, 3-ethyl-2-methyl-2-(3-methylbutyl)oxazolidine, 1,2,2,6,6-pentamethyl-4-piperidone, 1-(2-methylpropyl)-4-piperidone, N,N,N',N'-tetraethylethylenediamine, N,N,N',N'-tetraethyliminobisethylamine, N-ethylethanolamine, N-propylethanolamine, N-butylethanolamine, 1,1 ,4,7,10,10-hexamethyltriethylenetetramine, 1-phenylpiperazine, 1-formylpiperazine, ethyl 1-piperazine carboxylate, N,N'-di-tert-butylethylenediamine, 4-ethyl-2-methyl-2-(3-methylbutyl)oxazolidine, tetraethylenepentamine, triethylenetetramine, N,N-diethyldiethylenetriamine, N1-isopropyldiethylenetriamine, piperazine, N,N-dimethyldipropylenetriamine, diethylenetriamine, N-(2-aminoethyl)-1 ,3-propanediamine, 2,2'-(ethylenedioxy)diethylamine, 4-hydroxy-N-methylpiperidine, N-(2-aminoethyl)morpholine, 4-amino-2,2,6,6-tetramethylpiperidine, 1,2-diaminocyclohexane, 2-piperidinoethylamine, 2-(2-aminoethyl)-1-methylpyrrolidine, ethylenediamine, N,N-diethylethylenediamine, N-phenylethylenediamine, N-(3-aminopropyl)piperidine, furfurylamine, 2-(aminomethyl)thiophene, 4,9-dioxa-1,12-dodecanediamine, 4,7,10-trioxa-1,13-tridecanediamine, 1,2,4-trimethylpiperazine, 2-amino-2-methylpropanol, N,N'-diethyl-N,N'-dimethylethylenediamine, N,N-diethyl-N',N'-dimethylethylenediamine, 1,4,7-trimethyl-1,4,7-triazacyclononane, 1,4-dimethyl-1,4-diazacycloheptane, N-(2-dimethylaminoethyl)-N'-methylpiperazine, N,N,N',N'-tetraethylpropylenediamine, 1-[2-(1-piperidinyl)ethyl)]piperidine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, hexamethylenediamine, 1,2-propanediamine, 2-methyl-1,2-propanediamine, 2-methylpiperazine, N-2,N-2-dimethyl-1,2-propanediamine, N-1,N-1-dimethyl-1,2-propanediamine, 4,4'-ethylenedimorpholine, N,N,N',N'-tetraethyl-N”-methyldipropylenetriamine, 4-(dimethylamino)-1,2,2,6,6-pentamethylpiperidine, N,N,N',N'-tetramethyl-1,6-hexanediamine, 1,5,9-trimethyl-1,5,9-triazacyclododecane, 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane, N,N'-difurfurylethylenediamine, 1 2-Bis(2-aminoethyl)thioethane, Bis(2-aminoethyl)disulfide, Bis(2-dimethylaminoethyl)sulfide, 2,6-dimethylpiperazine, 1-ethyl-3-piperidinamine, decahydroquinoxaline, 2,3,5,6-tetramethylpiperazine, N,N-dimethyl(2-piperidinyl)methanamine, 1-(2-piperidinylmethyl)piperidine, 1-acetyl-2-diethylaminoethane, 1-amino-2-benzylaminoethane, 1-acetyl-3-dimethylaminopropane, 1-dimethylamino-3,3-diphenylpropane, N,N-dimethylbenzylamine, 2-(dimethylaminomethyl)thiophene, N,N,5-trimethylfurfurylamine,N,N-Bis(tetrahydro-2-furanylmethyl)amine, tetrahydroisoquinoline, 2-(ethylsulfanyl)ethanamine, thiomorpholine, 2-[(2-aminoethyl)sulfanyl]ethanol, 2,2-dimethyl-1,3-propanediamine, N1,N3,2-trimethyl-1,3-propanediamine, 2-(aminomethyl)-2-methyl-1,3-propanediamine, N1,N1,2,2-tetramethyl-1,3-propanediamine, 1-methoxy-2-propanamine, 3-thiomorpholinylmethanol, 2-(butylamino)ethanethiol, Bis(2-diethylaminoethyl)ether, 1-dimethylamino-2-ethylmethylaminoethoxyethane, 1,2,3-triaminopropane and N-1-(2-aminopropyl)-1,2-propanediamine, tetrahydro-2-furanylmethylamine, 2,6-dimethylmorpholine, N-methyl(tetrahydro-2-furanyl)methanamine, N,N,N',N'-tetramethyl-1,4-butanediamine, bis(2-(N,N-dimethylamino)propyl)ether, bis(2-(N,N-dimethylamino)ethyl)ether, 1,3-bis(dimethylamino)-2-propanol, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetraethyldiethylenetriamine, 1,2-bis(dimethylaminoethyl)ethane,1-(2-piperidinylmethyl)piperidine, 1,2,3-triaminopropane, 1,2-propanediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1-ethyl-3-piperidinamine, 1-methoxy-2-propanamine, 2-(2-aminoethoxy)ethanol, 2-(aminomethyl)-2-methyl-1,3-propanediamine, 2-(aminomethyl)thiophene, 2,2-dimethyl-1,3-propanediamine, 2,3,5,6-tetramethylpiperazine, 2,6-dimethylmorpholine, 2,6-dimethylpiperazine, 2-methyl-1,2-propanediamine, 2-methylpiperazine, 3-amino-1 -propanol, 3-ethoxypropylamine, bis(aminoethyl)sulfur, decahydroquinoxaline, dipropylenetriamine, furfurylamine, hexamethylenediamine, N-(2-aminoethyl)ethanolamine, N-(2-aminoethyl)piperidine, N-(3-aminopropyl)piperazine, N-(3-aminopropyl)piperidine, N,N-dimethyl(2-piperidinyl)methanamine, N-1-(2-aminopropyl)-1,2-propanediamine, N-1,N-1,2-tetramethyl-1,3-propanediamine, N-1,N-1-dimethyl-1,2-propanediamine, N-1,N-3,2-Trimethyl-1,3-propanediamine, N-2,N-2-dimethyl-1,2-propanediamine, N-butylethanolamine, N-cyclohexyl-1,3-propanediamine, N-ethylethanolamine, N-methyl(tetrahydro-2-furanyl)methanamine, N-propylethanolamine, tetrahydro-2-furanylmethylamine.

[0095] The reactive compounds can represent from 10 to 100% by weight of the absorbing solution, preferably from 20 to 70% by weight of the absorbing solution.

[0096] When the absorbing solution comprises a primary reactive compound and at least one secondary reactive compound:

[0097] the main reactive compound can represent between 5 and 60% by weight of the absorbing solution;

[0098] and / or each of the secondary reactive compounds can represent between 0.5 and 30% by weight of the absorbing solution, preferably between 0.5 and 15% by weight of the absorbing solution and even more preferably between 1 and 10% by weight of the absorbing solution.

[0099] Solvation compounds can be any compounds that dissolve in sufficient quantity the reactive compounds or that are miscible with the reactive compounds described above and that cause the formation of two phases, for example liquid-liquid or liquid-solid, when associated with at least one of the reactive compounds having reacted with one or more acidic compounds, for example H2S, or CO2, or SO2, or mercaptans, or COS or CS2.

[0100] In addition, the absorbent solution may include a solvation compound selected from the group consisting of water, glycols, polyethylene glycols, polypropylene glycols, ethylene glycol-propylene glycol copolymers, glycol ethers, alcohols, ureas, lactams, N-alkylated pyrrolidones, N-alkylated piperidones, cyclotetramethylenesulfones, N-alkylformamides, N-alkylacetamides, ether-ketones, alkyl phosphates and their derivatives.

[0101] By way of example and without limitation, it may be water, tetraethyleneglycoldimethyl ether, sulfolane, N-methylpyrrolidone, propylene carbonate, dimethylpropyleneurea, N-methylcaprolactam, dimethylformamide, dimethylacetamide, formamide, acetamide, 2-methoxy-2-methyl-3-butanone, 2-methoxy-2-methyl-4-pentanone, or tributylphosphate.Preferably, an absorbent solution comprising water as the solvation compound and containing one or more of the following reactive compounds may be used: N,N,N',N',N”-pentamethyldiethylenetriamine, N,N,N',N”,N'-pentamethyldipropylenetriamine, N,N-bis(2,2-diethoxyethyl)methylamine, piperazine, 2-amino-2-methylpropanol, N,N-dimethyldipropylenetriamine, N,N,N',N'-tetramethyl-1,6-hexanediamine, 4-hydroxy-N-methylpiperidine, tetrahydroisoquinoline, N-methyldiethanolamine, N,N,N',N'-tetramethyl-1,4-butanediamine, bis(2-(N,N-dimethylamino)propyl)ether, bis(2-(N,N-dimethylamino)ethyl)ether, 1,3-bis(dimethylamino)-2-propanol, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetraethyldiethylenetriamine, 1,2-bis(dimethylaminoethyl)ethane.

[0102] The absorbing solution may also contain one or more salts to lower the partial pressure of acid gases at which a second phase forms through the reaction of the acid gases with the reactive compound(s). These salts may be, for example, but not limited to, salts of alkali metals, alkaline earths, metals, or amines. The associated anion may be, for example, but not limited to, a halide, phosphate, sulfate, nitrate, nitrite, phosphite, or the conjugate base of a carboxylic acid. The amine(s) used to make these salts may be one or more of the amines present in the absorbing solution as reactants with the acidic compounds, or as activators, and which are partially neutralized by one or more acids stronger than those present in the treated gaseous effluent.The acids used may include, but are not limited to, phosphoric acid, phosphorous acid, nitrous acid, oxalic acid, acetic acid, formic acid, propanoic acid, butanoic acid, nitric acid, sulfuric acid, or hydrochloric acid. Other types of amines that are completely neutralized by such acids may also be added to the absorbing solution. These salts may also result from the partial degradation of the absorbing solution, for example, following the reaction of reactive compounds with an impurity in the treated gas. Salts may also be obtained by introducing sodium hydroxide or potassium hydroxide to neutralize acids formed in the process unit. Furthermore, the addition of salts may be avoided in cases where the activators, reactive compounds, or any other additives are salts in nature.The salt concentration can be adapted according to the partial pressure and the nature of the acidic compound(s) present in the gaseous charge to be treated, as well as the implementation conditions.

[0103] The absorbent solution may also contain anti-corrosion and / or anti-foaming additives. Their nature and concentration are chosen according to the type of absorbent solvent used, the load to be treated, and the application conditions. Their concentration in the absorbent solution typically varies between 0.01% and 5% by weight. These agents may be vanadium oxides (e.g., V₂O₃) or chromates (e.g., K₂Cr₂O₇).

[0104] The composition of the absorbent solution is determined in particular according to the nature of the gaseous effluent to be treated and the conditions of implementation of the deacidification process.

[0105] Of course, the absorbing solution entering the absorption column does not contain acidic compounds or has a very low concentration of acidic compounds (meaning that it arrives with a much lower concentration of acidic compounds than it leaves). At the outlet of the absorption column, the absorbing solution, which is charged with acidic compounds, is therefore enriched in acidic compounds (compared to when it entered the absorption column).

[0106] The first liquid fraction is usually an organic phase, while the second liquid fraction is an aqueous phase.

[0107] By using the transport line and the conveying line, the absorbing solution moves in a closed loop circuit between the absorption and regeneration columns (preferably at least one regeneration section of the regeneration column).

[0108] According to the invention, the separator is positioned above at least one regeneration section of the regeneration column in its operating position. This means that the separator's altitude is greater than that of the regeneration sections; that is, the lowest point of the separator is at a higher altitude than the highest point of the regeneration sections. Preferably, the separator can be positioned above or directly above the regeneration sections, but it could also be offset laterally from being directly above them. Various separator technologies can be used: for example, a decanter (gravity-fed technology) or an electrostatic separator, among others.

[0109] The use of a separator helps to reduce the degradation of the absorbent solution because this degradation is mainly of thermal origin and the use of the separator helps to limit the amount of absorbent solution sent to the regeneration column (and therefore subjected to a temperature rise), which also helps to limit energy consumption.

[0110] Furthermore, the regeneration column and the separator can be cylindrical, with a substantially vertical axis, and advantageously coaxial. Preferably, the separator can be a decanter, allowing the fluids to separate by gravity. This reduces energy consumption for separation compared to other separation technologies.

[0111] Furthermore, positioning a separator above the regeneration section(s) eliminates the need for circulation pumps and other associated equipment for the first and second liquid fractions. By removing such pumps, the system's energy consumption can be further reduced.

[0112] In addition, this also allows the second liquid fraction to be enriched in salts (the salts having more affinity with the aqueous phase of the second liquid fraction than with the organic phase of the first liquid fraction), which optimizes the reclaiming operations of the absorbing solution (the "reclaiming" is an English term to designate the elimination of dissolved salts that accumulate over time in the absorbing solution).

[0113] The separator can advantageously be positioned downstream of the first heat exchanger on the transport line. In this configuration, the first heat exchanger can warm the absorbent solution laden with acidic compounds, thus facilitating demixing.

[0114] Subsequently, the portion of the solution between the absorption column and the separator is referred to as the "acid-laden solution." Downstream of the separator, it is referred to as the "gaseous fraction," the "first liquid fraction," or the "second liquid fraction," all of which are fractions of the acid-laden solution.

[0115] According to one aspect of the invention, the separator can be a vertical decanter or a horizontal decanter.

[0116] The horizontal decanter allows the overall height to be reduced.

[0117] The vertical clarifier reduces the footprint due to its small size. This technology reduces the separator's liquid volume, simplifying the management of transient phases (start-ups and shutdowns). Furthermore, when positioned above regeneration sections, this technology eliminates the need for circulation pumps and simplifies the clarifier design. Since it does not use circulation pumps, energy consumption is also significantly reduced.Furthermore, the use of a vertical clarifier is particularly advantageous in the device of the invention, notably for reducing energy consumption (no electrical consumption of circulation pumps when the clarifier is positioned above the regeneration sections) and the footprint, despite the fact that in this device and process, the volumetric liquid flow rate is significantly higher than the volumetric gas flow rate. Indeed, vertical clarifiers are typically used when the gas flow rate exceeds the liquid flow rate because they allow for better separation under such conditions. In other words, given that the liquid flow rate is higher than the gas flow rate in the device of the invention, a person skilled in the art would be inclined to use a different separator technology and forgo a vertical clarifier for this application.

[0118] Advantageously, the device may include a second heat exchanger positioned between the first heat exchanger and the regeneration column (preferably at least one regeneration section of the regeneration column) on the transport line, to exchange heat between the fluids flowing in the transport line and the conveying line. The second heat exchanger is thus downstream of the first heat exchanger in the direction of flow of the acid-enriched absorbent solution from the absorption column to at least one regeneration section (in the transport line). Given the reverse flow direction of the regenerated absorbent solution from at least one regeneration section to the absorption column, the second heat exchanger is upstream of the first heat exchanger in this direction of flow (in the conveying line).

[0119] The use of at least two heat exchangers improves the thermal performance of the process. These exchangers promote the demixing phenomenon on the one hand, and facilitate the release of acidic compounds in the regeneration column on the other.

[0120] Preferably, the separator (preferably the decanter) can be positioned between the first and second heat exchangers, or after the second heat exchanger. When positioned between the first and second heat exchangers, the first heat exchanger heats the absorbent solution containing acidic compounds, and the second heat exchanger heats the second liquid fraction. When positioned between the second heat exchanger and at least one regeneration section, both the first and second heat exchangers heat the absorbent solution containing acidic compounds. This configuration further reduces the flow rate of the second liquid fraction to the regeneration column.Preferably, the device may include at least one heat recovery section positioned either above the separator (in particular, a decanter), within the separator, or above at least one regeneration section. The heat recovery section may therefore be either integrated into the separator, separate and independent of the regeneration column, or integrated into the regeneration column (which may or may not include the separator), or independent of both the regeneration column and the separator.

[0121] For the purposes of the invention, a heat recovery section can be a direct contact or indirect contact heat exchange section.

[0122] According to one embodiment of the invention, the device may include at least one first bypass line in fluidic connection between the transport line upstream of the first heat exchanger and at least one regeneration section. Hereafter, said "first portion" refers to the portion of fluid from the transport line passing through the first bypass line. The first portion is therefore a portion of the absorbing solution loaded with acidic compounds.

[0123] This first bypass line, leading into the regeneration column, allows the fluid from the absorbent solution containing acidic compounds to be used to cool the gas stream before it exits the regeneration column. Simultaneously, it heats the fluid arriving from this first bypass line—that is, the first portion—to facilitate the release of acidic compounds in at least one section of the regeneration process. Since the absorbent solution in the first bypass line is liquid, it flows vertically downwards in the regeneration column (while the gas flows vertically upwards in this same column).By cooling the gas stream preparing to exit the regeneration column (the gas stream exiting at the top of the regeneration column) by the first portion (exiting the regeneration column in the lower part of it), we can limit the power required for the condenser and therefore limit energy consumption.

[0124] The first bypass line is made possible in particular by the fact that the absorbing solution loaded with acidic compounds heats up less quickly than the regenerated absorbing solution (discharged of acidic compounds) cools down.

[0125] Additionally or alternatively, the device may include at least one second bypass line in fluidic connection between the transport line downstream of the first heat exchanger and at least one regeneration section. Downstream of the first heat exchanger (in the direction of flow of the absorbing solution in the transport line from the absorption column to the regeneration column), at least one second portion, either of the absorbing solution loaded with acidic compounds or of the second liquid fraction, may then be diverted into a second bypass line. This second bypass line originates downstream of the first heat exchanger (in the direction of flow in the transport line) and terminates at the regeneration column (preferably at least one regeneration section).

[0126] In other words, the device may include either the first branch line, or the second branch line, or both the first and second branch lines.

[0127] Subsequently, the term "second portion" refers to the portion of fluid from the transport line that passes into the second bypass line. The second portion is therefore either a portion of the absorbing solution laden with acidic compounds or a portion of the second liquid fraction, depending on the location of the second bypass line's origin on the transport line.

[0128] The use of a demixing absorbent solution can lead to a greater quantity of vaporized fluid in the second heat exchanger, at the same temperature, compared to a non-demixing absorbent solution. This greater vaporization then allows for a higher flow rate in the second bypass line than with a non-demixing absorbent solution such as those used in US patent 9956505 B2 or US patent application 2010 / 0242731 A1. This higher flow rate improves the cooling of the gas stream in the generation column and thus enhances the energy efficiency of the process.

[0129] This second bypass line leading into the regeneration column (preferably at least one regeneration section) allows the fluid from the absorbing solution loaded with acidic compounds to be used to cool the gas stream before it exits the regeneration column, and, in parallel, to heat the fluid arriving from this second bypass line, i.e. the said second portion, in order to facilitate the release of the acidic compounds in at least one regeneration section.

[0130] The second bypass line, like the first bypass line, is made possible by the fact that the absorbent solution loaded with acid compounds heats up more slowly than the regenerated absorbent solution (free of acid compounds) cools down. However, this second bypass line is positioned after the first heat exchanger. Consequently, the fluid temperature in this second bypass line is higher than that in the first bypass line (and than that in the transport line from the absorption column to the regeneration column, upstream of the bypass lines). Preferably, the temperature between the two heat exchangers corresponds to the bubble temperature of the absorbent solution loaded with acid compounds, the temperature at which the absorbent solution vaporizes at the operating pressure in the second heat exchanger.This vaporization, which is much more pronounced with a demixing absorbent solution according to the invention, allows a flow rate of the second bypass line much higher than that of the first bypass line, and higher than that of the prior art mentioned previously which does not use a demixing absorbent solution.

[0131] Furthermore, it is worth noting that this improvement in the thermal performance of the process with one or two bypass lines and a demixing absorbent solution is counterintuitive and occurs in a surprising manner. Indeed, as indicated in patent application EP1656983 A1 in particular, demixing absorbent solutions are used to limit the amount of solution sent to the regeneration column, and therefore limit the amount of solution to be regenerated. Thus, the aim is to send only the liquid phase, known as the "second liquid fraction," rich in acidic compounds, to the regeneration column. It is therefore counterintuitive, given this knowledge, to send a portion of the solution loaded with acidic compounds, before demixing, directly to the regeneration column (in the first and / or second lines) to improve thermal performance.Furthermore, this absorbent solution, laden with acidic compounds, is relatively "cold" since it is diverted before passing through the first or second heat exchanger, and it needs to be reheated in the regeneration column to remove the acidic compounds. Indeed, sending an additional quantity of this charged, unmixed, and relatively cold absorbent solution into the regeneration column could lead to a degradation in overall thermal performance, due to the increased volume of solution requiring regeneration.

[0132] The temperature of the second section is higher than that of the first section because the fluid has at least passed through the first heat exchanger where it was heated. This higher temperature can lead to gradual vaporization of the fluid. Consequently, the flow rate in the second bypass line may be higher than the flow rate in the first bypass line.

[0133] Preferably, flow in the first and / or second bypass line can be controlled by manual or automatic flow control means, preferably flow regulating valves, so as to allow or prevent flow in these lines, depending on the operating situation and process characteristics. To this end, the device may therefore include manual or automatic flow control means, such as flow regulating valves, on the first and / or second bypass line.

[0134] According to one configuration of the invention, the regeneration column may include a reflux section located above at least one regeneration section. This means that the altitude of the reflux section is higher than that of the regeneration sections; that is, the lowest point of the reflux section is at a higher altitude than the highest point of the regeneration sections. Preferably, the reflux section may be positioned above or directly below the regeneration sections, but it could be offset laterally from being directly below the regeneration sections. Furthermore, the device preferably includes a connection circuit for directing the gaseous fraction exiting the separator (in particular, a decanter) below the reflux section (through a lateral or vertical inlet at an altitude lower than the lowest point of the reflux section).The reflux section is used to wash the gas before it exits the regeneration column, thus limiting the entrainment of the absorbing solution (which contains at least one reactive component, such as amines) with the gas. This reflux section also cools the gas exiting the regeneration column by washing the gas. This reflux section can advantageously be positioned at the top of the regeneration column and preferably at least above the regeneration sections. Therefore, it is preferable to direct the gas fraction exiting the separator below the reflux section to be washed and cooled with the gas exiting the regeneration sections. This configuration is advantageous because it minimizes operability and / or purity issues with the produced acid gas.

[0135] Alternatively, the device may include a conduit for sending the gaseous fraction directly to a cooling means positioned downstream of the regeneration column, said cooling means serving to cool the gas exiting the regeneration column. The cooling means can thus serve to condense the water vapor carried along with the acidic gas produced in the regeneration column.

[0136] According to one embodiment of the invention, the separator (in particular, the decanter) can be positioned above the regeneration column in its operating position. In this case, it is therefore independent of the regeneration column. Preferably, the separator (in particular, the decanter) can be connected to the regeneration column by a support structure (commonly called a "skirt"). Alternatively, it can be supported above the regeneration column by a frame (also called a "structure") not connected to the regeneration column (and therefore independent of it, for example, fixed directly to the ground).

[0137] For this implementation, the separator and the regeneration column can be cylindrical, and the diameter of the separator (particularly the settling tank), being cylindrical, can be larger, preferably strictly larger, than the diameter of the regeneration column. This diameter reduces the fluid flow velocity within the separator, thus facilitating separation. In particular, this allows for easier settling by gravity in a settling tank.

[0138] According to another embodiment of the invention, the separator (in particular, the decanter) can be integrated into the regeneration column (in other words, the regeneration column includes the separator) and positioned above at least one regeneration section in the operating position. This embodiment is particularly advantageous because the integrated design is more compact, more integrated, and avoids additional equipment such as piping, fittings, valves, and so on.

[0139] For this implementation, preferably the separator and the regeneration column can be cylindrical, and the diameter of the regeneration column at the separator (particularly in the settling tank) can be larger, preferably strictly larger, than the diameter of the regeneration column in the regeneration sections and preferably larger than that of the reflux section. In other words, the diameter of the regeneration column is largest at the separator (relative to the other sections of the regeneration column). This diameter reduces the fluid flow velocity in the separator, thus facilitating separation. In particular, this allows for easier settling by gravity in a settling tank.

[0140] The diameter of the regeneration column at the separator (especially the decanter) can be equal to the diameter of the regeneration column in the regeneration sections and preferably to that of the reflux section.

[0141] Preferably, when the separator (especially a decanter) is integrated into the regeneration column, the separator can be positioned between at least one regeneration section (located below the separator) and the reflux section (located above the separator). Alternatively, the separator can also be positioned within the regeneration column above the reflux section, which is itself above at least one regeneration section.

[0142] Furthermore, when the separator (particularly a settling tank) is integrated into the regeneration column, it may advantageously include a passage, such as one or more stacks, for the gas flow exiting at least one regeneration section. This passage may consist of a tubular opening that runs vertically (in the operating position) through the entire separator to avoid disrupting phase separation. Advantageously, the separator may include a discharge and distribution system, such as a wall, configured to allow the second liquid fraction to reach at least one regeneration section. The second liquid fraction can therefore pass over the discharge system (particularly the wall) at a level (or altitude) that exceeds the top of the wall.

[0143] According to one configuration of the invention, the separator may include a pressure regulation means (preferably when the separator is independent of the regeneration column), such as a pressure regulating valve. This ensures that the separator pressure is preferably higher than the pressure of the regeneration column (or at least one regeneration section when integrated into the regeneration column) to guarantee flow from the separator to the regeneration column (or to at least one regeneration section).

[0144] Alternatively, the separator can be in pressure equilibrium with the regeneration column (or at least one regeneration section, particularly when integrated into the regeneration column). In this case, the separator pressure is regulated by a pressure control system for the regeneration column. This ensures that the separator pressure is preferably higher than the pressure of at least one regeneration section to guarantee flow from the separator to that section.

[0145] If the separator is integrated into the regeneration column, the flow can also occur solely by gravity, without requiring a pressure difference.

[0146] Advantageously, the transport line may include a first heater between the first heat exchanger and the separator.

[0147] Additionally or alternatively, the transport line includes a second heater between the second heat exchanger and the regeneration column.

[0148] In other words, the transport line can include either the first heater, the second heater, or both the first and second heaters. The invention also relates to a method for deacidifying a gaseous effluent containing acidic compounds, such as hydrogen sulfide or carbon dioxide, in which at least the following steps are carried out from a device according to one of the variants or combinations of variants described above:

[0149] a) the gaseous effluent is brought into contact with an absorbent solution in the absorption column, so as to obtain a gaseous effluent depleted in acidic compounds and an absorbent solution loaded with acidic compounds, the absorbent solution being capable of forming separable phases when it has absorbed a predetermined quantity of acidic compounds and / or when it is heated,

[0150] b) the absorbent solution loaded with acidic compounds is heated in said at least a first heat exchanger, the first heat exchanger exchanging heat with an absorbent solution to be recycled,

[0151] (c) In said separator (preferably a decanter), the heated absorbent solution loaded with acidic compounds is separated into a gaseous fraction, a first liquid fraction depleted in acidic compounds, and a second liquid fraction enriched in acidic compounds.

[0152] d) the second liquid fraction is regenerated in at least one regeneration section of the regeneration column so as to release the acidic compounds into an outgoing gas stream, thus forming a regenerated, acid-poor absorbing solution exiting the regeneration column,

[0153] e) the absorbent solution to be recycled is recycled as an absorbent solution in step a), the absorbent solution to be recycled comprising at least the absorbent solution low in acid compounds regenerated in step d) and preferably the first liquid fraction obtained in step c).

[0154] Preferably, the absorbent solution loaded with acid compounds or the second liquid fraction can be heated in at least the second heat exchanger, the second heat exchanger exchanging heat with an absorbent solution to be recycled. Advantageously, at least a first portion of the absorbent solution loaded with acid compounds can be diverted in a first bypass line upstream of the first heat exchanger and sent to the regeneration column (preferably to at least one regeneration section).

[0155] Additionally or alternatively, at least a second portion of the absorbing solution loaded with acid compounds or of the second liquid fraction can be diverted into a second bypass line, downstream of the first heat exchanger, and this second portion can be sent into the regeneration column (preferably into at least one regeneration section).

[0156] In other words, at least a first portion of the absorbing solution loaded with acidic compounds can be derived in the first derivation line and / or at least a second portion of the absorbing solution loaded with acidic compounds or of the second liquid fraction in the second derivation line.

[0157] According to one aspect of the invention, the first liquid fraction can be withdrawn from the separator (preferably a decanter) by gravity, for example under level control, to be sent back to the absorption column.

[0158] The term "under level control" means that the level is kept constant, for example by using a control valve which can be controlled by the level in question, or by controlling the speed of the pump (which can also be controlled by the level in question).

[0159] Preferably, the first liquid fraction exiting the separator (especially the decanter) can be mixed with the regenerated absorbent solution to form the absorbent solution to be recycled, preferably downstream of the second heat exchanger when such an exchanger is used on the conveying line.

[0160] Figure 1 illustrates, schematically and without limitation, a first embodiment of the device and method according to the invention.

[0161] The device comprises an absorption column C101 and a regeneration column C102. In absorption column C101, a gaseous effluent EF, laden with acidic compounds (e.g., CO2), is brought into contact with an absorbent solution (which may include amines). The absorbent solution then absorbs the acidic compounds from the gaseous effluent EF and exits the absorption column as an absorbent solution laden with acidic compounds SA. The gaseous effluent exits absorption column C101 as a gaseous effluent depleted of acidic compounds EFS.

[0162] The absorbent solution is chosen according to the acidic compounds to be removed from the gaseous effluent so that it absorbs them and it has demixing properties.

[0163] One or more intercooler lines (IC) may be installed. Alternatively, the device may not include such a line, which therefore remains optional. This intercooler line (IC) recovers some or all of the absorbent solution from the absorption column (C101). The recovered absorbent solution is cooled by a cooling device (E104) and then reintroduced into the absorber, preferably at a lower level than where it was recovered. This cools the absorbent solution to improve absorption performance. This line (IC) is advantageously equipped with a circulation pump (P103) to aid in the circulation of the absorbent solution.

[0164] In the regeneration column C102, the absorbent solution loaded with acid compounds is regenerated, meaning it is separated from the released acid compounds in at least one regeneration section R20. It therefore exits the regeneration column as a regenerated absorbent solution SR at the bottom of the column, as the liquid phases move vertically downwards in this column, and the acid compounds exit, in gaseous form, at the top of the column (since the gases move vertically upwards in this column). The released acid compounds then pass into a cooling medium E102 where the water vapor is condensed. The gaseous acid compounds and the condensed water are then separated in a condenser V102.The condensed water, commonly referred to as reflux, can then be carried by a pump P104 to be reintroduced into the regeneration column C102, preferably above the reflux section R10.

[0165] The acidic compounds, released from the water vapor, exit the condenser V102 in the form of an outlet gas GS.

[0166] These absorption columns C101 and regeneration columns C102 are connected by a transport line of an absorbing solution loaded with acidic compounds SA which carries this solution from the absorption column C101 to at least one regeneration section R20 of the regeneration column C102, and by a conveying line (which could also be called a "return line") which carries the regenerated absorbing solution SR in at least one regeneration section R20 of the regeneration column C102 back to the absorption column C101.

[0167] The transport line and the conveying line include a heat exchanger E101 A which allows heat to be exchanged between a hot SAR recycling solution (which includes at least the regenerated absorbance solution SR) and the acid-compound-loaded absorbent solution SA (to reheat it).

[0168] To facilitate fluid circulation in each transport and delivery line, each of these lines may include (not required) a circulation pump: for example, the transport line may include a P102 circulation pump and the delivery line may include a P101 circulation pump.

[0169] The transport line may optionally include a heater E106A downstream of the heat exchanger E101 A (in the direction of fluid flow in this transport line).

[0170] The conveying line may optionally include a cooler E103 downstream of the heat exchanger E101 A (in the direction of fluid flow in this conveying line). The absorbent solution loaded with acid compounds SA passes, downstream of the heat exchanger E101 A on the conveying line, and preferably after the heater E106A when it is used, into a separator V101, which may be a settling tank, in particular a vertical or horizontal settling tank. In this separator V101, the absorbent solution is separated into two liquid phases: a first liquid fraction depleted in acid compounds SV1 (also called the "organic phase" or "light phase") and a second liquid fraction enriched in acid compounds SV2 (also called the "aqueous phase" or "heavy phase"). In addition, in the separator, some of the acid compounds are released as a gaseous fraction FG.

[0171] The first liquid fraction SV1 exiting separator V101 is sent to absorption column C101, bypassing the regeneration section R20 of regeneration column C102, where it is mixed with the regenerated absorbent solution SR. Consequently, the regenerated absorbent solution SR and the first liquid fraction SV1 together form the absorbent solution to be recycled, SAR. This mixing of the regenerated absorbent solution SR and the first liquid fraction SV1 is preferably carried out upstream of heat exchanger E101 A on the conveying line (in the direction of fluid flow on this line).

[0172] The second liquid fraction SV2 is sent to the regeneration section R20 of the regeneration column C102 so that the acidic compounds are released and the regenerated absorbing solution SR can be recovered for sending back to the absorption column C101.

[0173] The C102 regeneration column includes at least one regeneration section R20 where the absorbent solution is regenerated and the acidic compounds are released (it may include several regeneration sections) and preferably a reflux section R10, positioned above the regeneration section(s) R20. This reflux section R10 allows the released gas (consisting mainly of acidic compounds and water vapor) to be washed away to reduce the amount of absorbent solution carried along with the gas.

[0174] The device also advantageously includes a reboiler E105 which heats the absorbent solution to provide the heat required by the regeneration column C102 for the regeneration operation.

[0175] According to the invention, the separator V101 is positioned above the regeneration section R20 (or regeneration sections if there are several in the regeneration column) of the regeneration column C102. In this case, the separator V101 is supported above the regeneration column C102 by means of a support structure JP. Alternatively, it could be positioned above the regeneration column C102, independently of it. Furthermore, the regeneration column C102 and the separator V101 can be cylindrical, with a substantially vertical axis, and are advantageously coaxial with each other. As shown, the diameter of the separator V101 is preferably strictly larger than the diameter of the regeneration column C102, and the support structure JP can be a substantially conical structure as illustrated.

[0176] The second liquid fraction SV2 exiting the separator V101 is sent just above the regeneration section(s) R20, and preferably below the reflux section R10 when used.

[0177] The gaseous fraction FG exiting the separator V101 is advantageously sent to the regeneration column C102 below the reflux section R10 and preferably above the regeneration section(s) R20.

[0178] Figures 2 to 7 depict other embodiments of the device and method according to the invention. In these figures, the same reference numerals as in Figure 1 correspond to the same elements and will not necessarily be detailed again. The following description of these figures concerns the differences compared to Figure 1.

[0179] Figure 2 illustrates, schematically and without limitation, a second embodiment of the device and method according to the invention.

[0180] In this figure, the transport and conveying lines include two series crossed heat exchangers, a first heat exchanger E101 A and a second heat exchanger E101 B which exchange heat between the absorbent solution to be recycled SAR and respectively the absorbent solution loaded with acid compounds SA (for the first heat exchanger E101 A) and the second liquid fraction SV2 (for the second heat exchanger E101 B).

[0181] The first and second heat exchangers E101 A and E101 B preferably operate in counterflow.

[0182] The optional heater E106A can be positioned on the transport line between the first heat exchanger E101 A and the separator V101, itself upstream of the second heat exchanger E101 B.

[0183] The optional second heater E106B can be positioned on the transport line between the second heat exchanger E101 B and the regeneration column C102. On the conveying line, the cooler E103 can be positioned downstream of the two heat exchangers (successively in the direction of flow on this line, the second heat exchanger E101B then the first heat exchanger E101A).

[0184] As in Figure 1, the separator V101 is independent of the regeneration column C102 and is positioned above it. And as in Figure 1, it can be connected to the upper part of the regeneration column C102 by a support structure JP. Alternatively, it could be independent of this regeneration column and simply positioned above it by a separate structure.

[0185] The V101 separator is positioned on the transport line between the first heat exchanger E101 A and the second heat exchanger E101 B.

[0186] Furthermore, the C102 regeneration column here includes two heat recovery sections R30A and R30B positioned between the reflux section R10 and the regeneration section(s) R20. The first heat recovery section R30A is positioned above the second heat recovery section R30B.

[0187] The gaseous fraction FG exiting separator V101 is sent to the regeneration column C102 at a level located between the regeneration section(s) R20 and the second heat recovery section R30B. Alternatively, it could be sent to the first heat recovery section R30A, to the reflux section R10, or directly to the cooling medium E102.

[0188] The second liquid fraction SV2 exiting the separator V101 is sent into the regeneration column C102 at a level located between the regeneration section(s) R20 and the second heat recovery section R30B.

[0189] The device also includes a first bypass line D1 in fluidic connection between the transport line, upstream of the first heat exchanger E101 A, and the regeneration column C102 (the regeneration section R20).

[0190] This first bypass line leads into the C102 regeneration column at a level located above the R30A and R30B heat recovery sections and below the R10 reflux section. The liquid from the first bypass line can then reach at least one R20 regeneration section by gravity.

[0191] Furthermore, the system includes a second bypass line D2 with a fluidic connection between the transport line, downstream of the first heat exchanger E101 A, and the regeneration column C102 (regeneration section R20). This second bypass line D2 originates between the separator V101 and the second heat exchanger E101 B and terminates at a level in the regeneration column located between the two heat recovery sections R30A and R30B. The fluid from the second bypass line can then reach at least one regeneration section R20 by gravity.

[0192] Figure 3 illustrates, schematically and without limitation, a third embodiment of the device and method according to the invention.

[0193] In this figure, the transport and conveying lines include two heat exchangers crossed in series: a first heat exchanger E101 A and a second heat exchanger E101 B. The first heat exchanger E101 A exchanges heat between the absorbent solution to be recycled SAR and the acid-laden absorbent solution SA. The second heat exchanger E101 B exchanges heat between the regenerated absorbent solution SR (before it is mixed with the first liquid fraction SV1 to form the absorbent solution to be recycled SAR) and the acid-laden absorbent solution SA, which has already passed through the first heat exchanger E101 A and before it passes through the separator V101.

[0194] The optional heater E106A can be positioned on the transport line downstream of the first and second heat exchangers E101 A and E101 B and upstream of the separator V101.

[0195] On the conveying line, the E103 cooler can be positioned downstream of the two heat exchangers (successively in the direction of flow on this line, the second heat exchanger E101B then the first heat exchanger E101A).

[0196] As in Figure 1, the separator V101 is independent of the regeneration column C102 and is positioned above it. And as in Figure 1, it can be connected to the upper part of the regeneration column C102 by a support structure JP. Alternatively, it could be independent of this regeneration column and simply positioned above it by a separate structure.

[0197] The V101 separator is positioned on the transport line downstream of the first and second heat exchangers E101A and E101B and downstream of the heater E106A (when in use).

[0198] Furthermore, the C102 regeneration column here includes two heat recovery sections R30A and R30B positioned between the reflux section R10 and the regeneration section(s) R20. The first heat recovery section R30A is positioned above the second heat recovery section R30B.

[0199] The gaseous fraction FG exiting separator V101 is sent to the regeneration column C102 at a level located between the regeneration section(s) R20 and the second heat recovery section R30B. Alternatively, it could be sent to the first heat recovery section R30A, to the reflux section R10, or directly to the cooling medium E102.

[0200] The second liquid fraction SV2 exiting the separator V101 is sent into the regeneration column C102 at a level located between the regeneration section(s) R20 and the second heat recovery section R30B.

[0201] The device also includes a first bypass line D1 in fluidic connection between the transport line, upstream of the first heat exchanger E101 A, and the regeneration column C102 (the regeneration section R20).

[0202] This first bypass line leads into the C102 regeneration column at a level located above the R30A and R30B heat recovery sections and below the R10 reflux section. The liquid from the first bypass line can then reach at least one R20 regeneration section by gravity.

[0203] Furthermore, the system includes a second bypass line D2 with a fluidic connection between the transport line, downstream of the first heat exchanger E101 A, and the regeneration column C102 (regeneration section R20). This second bypass line D2 originates between the first heat exchanger E101 A and the second heat exchanger E101 B and terminates at a level in the regeneration column located between the two heat recovery sections R30A and R30B. The fluid from the second bypass line can then reach at least one regeneration section R20 by gravity.

[0204] Figure 4 illustrates, schematically and without limitation, a fourth embodiment of the device and method according to the invention.

[0205] In this figure, the transport and conveying lines include two crossed heat exchangers, a first heat exchanger E101 A and a second heat exchanger E101 B. The first heat exchanger E101 A exchanges heat between the absorbent solution to be recycled SAR and the acid-laden absorbent solution SA. The second heat exchanger E101 B exchanges heat between the regenerated absorbent solution SR (before it is mixed with the first liquid fraction SV1 to form the absorbent solution to be recycled SAR) and the acid-laden absorbent solution SA, which has already passed through the first heat exchanger E101 A and before it passes through the separator V101.

[0206] The optional heater E106A can be positioned on the transport line downstream of the first and second heat exchangers E101 A and E101 B and upstream of the separator V101. On the conveying line, the cooler E103 can be positioned downstream of the two heat exchangers (successively in the direction of flow on this line, the second heat exchanger E101B then the first heat exchanger E101A).

[0207] As in Figure 1, the separator V101 is independent of the regeneration column C102 and is positioned above it. And as in Figure 1, it can be connected to the upper part of the regeneration column C102 by a support structure JP. Alternatively, it could be independent of this regeneration column and simply positioned above it by a separate structure.

[0208] The V101 separator is positioned on the transport line downstream of the first and second heat exchangers E101A and E101B and downstream of the heater E106A (when in use).

[0209] In addition, the C102 regeneration column here includes a heat recovery section R30A positioned between the reflux section R10 and the regeneration section(s) R20.

[0210] In addition, the V101 separator includes two heat recovery sections R30C and R30D located in the upper part of the separator.

[0211] The gaseous fraction FG exiting separator V101 is sent to the regeneration column C102 at a level located between the regeneration section(s) R20 and the heat recovery section R30A. Alternatively, it could be sent to the level of the first heat recovery section R30A, to the reflux section R10, or directly to the cooling medium E102.

[0212] The second liquid fraction SV2 exiting the separator V101 is sent into the regeneration column C102 at a level located between the regeneration section(s) R20 and the heat recovery section R30A.

[0213] The device also includes a first bypass line D1 with a fluidic connection between the transport line, upstream of the first heat exchanger E101 A, and the regeneration column C102 (regeneration section R20). More specifically, the first bypass line passes through the heat recovery sections R30C and R30D located above the separator V101 (which is upstream of the regeneration column C102). In other words, the fluid in this first bypass line D1 flows by gravity into the heat recovery sections R30C and R30D and then into the separator V101, where the acid-laden absorbent solution from the first bypass is separated from the acid-laden absorbent solution passing through the first and second heat exchangers E101A and E101B.The system also includes a second bypass line D2 in fluidic connection between the transport line, downstream of the first heat exchanger E101 A, and the regeneration column C102 (regeneration section R20). This second bypass line D2 originates between the first heat exchanger E101 A and the second heat exchanger E101 B and passes through a level located between the two heat recovery sections R30C and R30D. The acid-laden absorbent solution from this second bypass line then flows through the recovery section R30D (the lower of the two), and then by gravity into the separator V101 where the acid-laden absorbent solution from the second bypass is separated from the acid-laden absorbent solution passing through the first and second heat exchangers E101 A and E101 B, and from that of the first bypass.

[0214] The second liquid fraction SV2 exiting the separator V101 is sent into the regeneration column C102 above at least one regeneration section R20.

[0215] Furthermore, the device includes a third bypass line D3 in fluidic connection between the transport line, downstream of the first heat exchanger E101 A, and the regeneration column C102 (regeneration section R20). This third bypass line D3 originates from the second bypass line D2, before the separator V101, and is connected at a point in the regeneration column located between the heat recovery section R30A and the reflux section R10. The absorbent solution, laden with acidic compounds, from this third bypass line flows by gravity through the heat recovery section R30A to reach the inlet of the regeneration section R20, which it then passes through to be discharged of the acidic compounds it contains.

[0216] Figure 5 illustrates, schematically and without limitation, a fifth embodiment of the device and method according to the invention.

[0217] In this figure, the transport and conveying lines include a single cross heat exchanger E101 A which exchanges heat between the absorbent solution to be recycled SAR and the absorbent solution loaded with acid compounds SA.

[0218] The optional heater E106A can be positioned on the transport line between the first heat exchanger E101 A and at least one regeneration section R20 of the regeneration column C102.

[0219] On the conveying line, the E103 cooler can be positioned downstream of the E101 A cross heat exchanger.

[0220] Unlike Figures 1 to 4, the separator V101 is integrated into the regeneration column C102; in other words, the regeneration column C102 includes the separator V101. The separator V101 is then positioned above the regeneration section(s) R20 and preferably below the reflux section R10 of the regeneration column C102. The separator V101 includes a passage C50 for the gas flow exiting the regeneration section(s) R20.

[0221] Furthermore, the regeneration column C102 and the separator V101 can be cylindrical, with a substantially vertical axis, and advantageously coaxial. The diameter of the separator V101 is preferably strictly larger than the diameter of the regeneration column C102 at the reflux section R10 and the regeneration section(s) R20 (and any heat recovery sections). In other words, the diameter of the regeneration column C102 is at its maximum at the separator V101.

[0222] The V101 separator is positioned on the transport line between the first heat exchanger E101 A (preferably downstream of the heater E106A if it is used) and at least one regeneration section R20.

[0223] Furthermore, the C102 regeneration column includes a reflux section R10 and the R20 regeneration section(s). The V101 separator is positioned here between the R20 regeneration section(s) and the R10 reflux section.

[0224] The gaseous fraction exiting the separator V101 then passes through the reflux section R10 and exits the regeneration column C102, at the top of it.

[0225] The second liquid fraction exiting the separator is sent directly, by gravity, to the R20 regeneration section(s) located just below the V101 separator.

[0226] The first liquid fraction SV1 exiting the separator comes out of the regeneration column, preferably by level control, without passing through the regeneration section(s) R20, and is mixed with the regenerated absorbent solution SR to form the absorbent solution to be recycled SAR upstream of the heat exchanger E101 A.

[0227] Figure 6 illustrates, schematically and without limitation, a sixth embodiment of the device and method according to the invention.

[0228] In this figure, the transport and conveying lines include two series crossed heat exchangers, a first heat exchanger E101 A and a second heat exchanger E101 B which exchange heat between the absorbent solution to be recycled SAR and respectively the absorbent solution loaded with acid compounds SA (for the first heat exchanger E101 A) and the second liquid fraction SV2 (for the second heat exchanger E101 B).

[0229] An optional first heater E106A can be positioned on the transport line between the first heat exchanger E101A and the second heat exchanger E101 B, and preferably upstream of the separator V101. On the conveying line, the cooler E103 can be positioned downstream of the two heat exchangers E101A and E101 B (successively in the direction of flow on this line, the second heat exchanger E101 B then the first heat exchanger E101A).

[0230] Unlike Figures 1 to 4, the separator V101 is integrated into the regeneration column C102; in other words, the regeneration column C102 includes the separator V101. The separator V101 is then positioned above the regeneration section(s) R20 and preferably below the reflux section R10 of the regeneration column C102. The separator V101 includes a passage C50 for the gas flow exiting the regeneration section(s) R20.

[0231] Furthermore, the regeneration column C102 and the separator V101 can be cylindrical, with a substantially vertical axis, and advantageously coaxial. The diameter of the separator V101 is preferably strictly larger than the diameter of the regeneration column C102 at the reflux section R10 and the regeneration section(s) R20 (and the heat recovery sections R30A and R30B). In other words, the diameter of the regeneration column C102 is at its maximum at the separator V101.

[0232] The V101 separator is positioned on the transport line between the first heat exchanger E101 A and the second heat exchanger E101 B.

[0233] Furthermore, the C102 regeneration column here includes two heat recovery sections R30A and R30B positioned between the reflux section R10 and the separator V101. The first heat recovery section R30A is positioned above the second heat recovery section R30B.

[0234] The gaseous fraction FG exiting separator V101 emerges from the upper part of separator V101 and can successively join the second heat recovery section R30B, the first heat recovery section R30A, and then the reflux section R10. The second liquid fraction SV2 exiting separator V101 is sent to the second heat exchanger E101B, possibly to a second heater E106B (which is optional) before being reinjected into the regeneration column C102 at a level located between separator V101 and the regeneration section(s) R20, so that the liquid passes through the regeneration section(s) R20 by gravity.

[0235] The device also includes a first bypass line D1 in fluidic connection between the transport line, upstream of the first heat exchanger E101 A, and at least one regeneration section R20 of the regeneration column C102. This first bypass line is connected in the regeneration column C102 at a level located above the heat recovery sections R30A and R30B and below the reflux section R10. The liquid absorbent solution it contains can then pass through the heat recovery sections R30A and R30B and then the separator V101 where the absorbent solution loaded with acidic compounds from the first bypass is separated from the absorbent solution loaded with acidic compounds passing through the first heat exchanger E101 A and the optional heater E106A.The second liquid fraction SV2 exiting the separator V101 is sent into the regeneration column C102 above at least one regeneration section R20 so that the liquid descends by gravity into this at least one regeneration section R20.

[0236] Furthermore, the device includes a second bypass line D2 with a fluidic connection between the transport line, downstream of the first heat exchanger E101A, and the regeneration section R20 of the regeneration column C102. This second bypass line D2 originates between the first heat exchanger E101A and the separator V101 and is connected at a point in the regeneration column located between the two heat recovery sections R30A and R30B. The liquid absorbent solution it contains can then pass through the heat recovery section R30B and then the separator V101, where the absorbent solution containing acidic compounds from this second bypass is separated from the absorbent solution containing acidic compounds passing through the first heat exchanger E101A and the optional heater E106A, as well as from the first bypass.The second liquid fraction SV2 exiting the separator V101 is sent into the regeneration column C102 above at least one regeneration section R20 so that the liquid descends by gravity into this at least one regeneration section R20.

[0237] The first liquid fraction SV1 exits the separator V101 to be mixed with the regenerated absorbent solution SR to form the absorbent solution to be recycled SAR, at a point on the conveying line located between the second heat exchanger E101 B and the first heat exchanger E101 A.

[0238] Figure 7 illustrates, schematically and without limitation, a seventh embodiment of the device and method according to the invention.

[0239] In this figure, the transport and conveying lines include two heat exchangers crossed in series: a first heat exchanger E101 A and a second heat exchanger E101 B. The first heat exchanger E101 A exchanges heat between the absorbent solution to be recycled SAR and the absorbent solution loaded with acid compounds SA. The second heat exchanger E101 B exchanges heat between the regenerated absorbent solution SR and the absorbent solution loaded with acid compounds SA that has already passed through the first heat exchanger E101 A (and before it enters the separator V101).

[0240] An optional heater E106A can be positioned on the transport line downstream of the first and second heat exchangers E101 A and E101 B, and preferably upstream of the separator V101.

[0241] On the conveying line, the E103 cooler can be positioned downstream of the two heat exchangers (successively in the direction of flow on this line, the second heat exchanger E101B then the first heat exchanger E101A).

[0242] Unlike Figures 1 to 4, the separator V101 is integrated into the regeneration column C102; in other words, the regeneration column C102 includes the separator V101. The separator V101 is then positioned above the regeneration section(s) R20 and preferably below the reflux section R10 of the regeneration column C102. The separator V101 includes a passage C50 for the gas flow exiting the regeneration section(s) R20.

[0243] Furthermore, the regeneration column C102 and the separator V101 can be cylindrical, with a substantially vertical axis, and advantageously coaxial. The diameter of the separator V101 is preferably strictly larger than the diameter of the regeneration column C102 at the reflux section R10 and the regeneration section(s) R20 (and the heat recovery sections R30E, R30F, and R30G). In other words, the diameter of the regeneration column C102 is at its maximum at the separator V101.

[0244] The V101 separator is positioned on the transport line downstream of the first and second heat exchangers E101A and E101 B and preferably downstream of the heater E106A when it is in use.

[0245] Furthermore, the C102 regeneration column here comprises three heat recovery sections R30E, R30F, and R30G positioned between the reflux section R10 and the regeneration section(s) R20. More specifically, the first heat recovery section R30E is positioned above the regeneration section(s) R20 and below the separator V101. The second heat recovery section R30F is positioned above the separator V101 and below the third heat recovery section R30G, which is itself below the reflux section R10. The gaseous fraction exiting the separator V101 flows out at the top of the separator and can successively enter the second heat recovery section R30F, the third heat recovery section R30G, and then the reflux section R10.

[0246] The second liquid fraction exiting the V101 separator passes into the first heat recovery section R30E and then into the regeneration section(s) R20.

[0247] The device also includes a first bypass line D1 in fluidic connection between the transport line, upstream of the first heat exchanger E101 A, and at least one regeneration section R20 of the regeneration column C102.

[0248] This first bypass line is connected in the C102 regeneration column at a level located above the R30F and R30G heat recovery sections and below the R10 reflux section.

[0249] In addition, the device includes a second bypass line D2 in fluidic connection between the transport line, downstream of the first heat exchanger E101A, and at least one regeneration section R20 of the regeneration column C102. This second bypass line D2 originates here between the first heat exchanger E101 A and the second heat exchanger E101 B and is connected at a level in the regeneration column located between the second and third heat recovery sections R30F and R30G.

[0250] The device also includes a third bypass line D3 branching off from the second bypass line D2, upstream of the separator V101. This third bypass line D3 leads to the first heat recovery section R30E in the regeneration column C102.

[0251] The first liquid fraction SV1 exits the separator V101 to be mixed with the regenerated absorbent solution SR to form the absorbent solution to be recycled SAR, at a point on the conveying line located between the second heat exchanger E101 B and the first heat exchanger E101 A.

[0252] In all the preceding figures, the separator V101 can preferably be a decanter, and more advantageously a horizontal or vertical decanter.

[0253] Figures 2 to 4 and 6 and 7 present solutions with 2 or 3 derivation lines, but of course, the invention could include a single derivation line.

[0254] Figure 8 illustrates, schematically and without limitation, an example of a horizontal decanter that could be used as a separator in the device and method of the invention. The decanter here comprises a settling compartment CD, a light phase compartment CPLe and a heavy phase compartment CPLo.

[0255] The absorbing solution loaded with acidic compounds SA arrives in the settling compartment CD. By settling, it separates into a gaseous phase which comes out as a gaseous fraction FG from the top of the settling tank, and into two liquid phases, a so-called "heavy" phase which corresponds to the aqueous phase, i.e. the second liquid fraction, and a so-called "light" phase which corresponds to the organic phase, i.e. the first liquid fraction.

[0256] The light phase, having settled in the settling compartment, is located above the heavy phase. The interface between the heavy and light phases is represented by the ILL interface in the diagram.

[0257] Furthermore, a portion of the absorbent solution loaded with acidic compounds (SA) can form an emulsion positioned between an upper interface (ILLs) that separates the emulsion from the light phase and a lower interface (ILLi) that separates the emulsion from the heavy phase. The light phase flows over a separating wall of the settling compartment (CD) from the light phase compartment (CPLe) by overflow (Dev) and is stored in this compartment (CPLe).

[0258] The heavy phase is conveyed by TLo piping from the CD settling compartment to the CPLo heavy phase compartment which can, for example, and as shown, be separated from the light phase compartment by a (watertight) wall.

[0259] The light phase exits the decanter forming the first liquid fraction SV1 and the heavy phase exits the decanter forming the second liquid fraction SV2.

Claims

Demands 1. Device for the deacidification of a gaseous effluent (FE) containing acidic compounds, such as hydrogen sulfide or carbon dioxide, comprising: - an absorption column (C101) for bringing the gaseous effluent (FE) into contact with an absorbing solution in order to produce a gas depleted in acidic compounds (FE) and an absorbing solution loaded with acidic compounds (SA), the absorbing solution being chosen for its property of forming separable phases when it has absorbed a quantity of acidic compounds and / or when it is heated; - a transport line for the absorbing solution loaded with acidic compounds (SA) ensuring the fluidic connection between the absorption column (C101) and at least one regeneration section (R20) of a regeneration column (C102); - a conveying line for an absorbent solution to be recycled (SAR) ensuring the fluidic connection between at least one regeneration section (R20) of the regeneration column (C102) and the absorption column (C101); - at least one first heat exchanger (E101 A) to exchange heat between the fluids flowing in the transport line and in the conveying line; - the transport line including a separator (V101) to separate the absorbent solution loaded with acid compounds (SA) into a gaseous fraction (FG), into a first liquid fraction (SV1) of absorbent solution depleted in acid compounds and into a second liquid fraction (SV2) of absorbent solution enriched in acid compounds; - the regeneration column (C102) comprising at least one regeneration section (R20) to release the acidic compounds contained at least in said second liquid fraction (SV2) and to produce a regenerated absorbent solution (SR) forming part of the absorbent solution to be recycled (SAR), characterized in that the separator (V101), preferably a decanter, is positioned above said at least one regeneration section (R20) of the regeneration column (C102) in the operating position.

2. Device according to claim 1, wherein the separator (V101) is a vertical decanter or a horizontal decanter.

3. Device according to any one of claims 1 or 2, wherein the device comprises a second heat exchanger (E101 B) positioned between the first heat exchanger (E101A) and at least one regeneration section of the regeneration column (C102) on the conveying line, for exchanging heat between the fluids flowing in the conveying line and in the conveying line, the separator (V101) preferably being positioned between the first heat exchanger (E101A) and the second heat exchanger (E101B) or positioned after the second heat exchanger (E101 B).

4. Device according to any one of the preceding claims, wherein the device comprises at least one heat recovery section (R30A, R30B, R30C, R30D, R30E, R30F, R30G) positioned either in the separator (V101), or above the separator (V101), or above at least one regeneration section (R20).

5. Device according to any one of the preceding claims, wherein the device comprises at least one first bypass line (D1) in fluidic connection between the transport line upstream of the first heat exchanger (E101 A) and at least one regeneration section (R20) and / or at least one second bypass line (D2) in fluidic connection between the transport line downstream of the first heat exchanger (E101 A) and at least one regeneration section (R20) of the regeneration column (C102).

6. Device according to any one of the preceding claims, wherein the regeneration column (C102) comprises a reflux section (R10) located above at least one regeneration section (R20), and the device preferably comprises a connecting circuit for sending the gaseous fraction (FG) exiting the separator (V101) below the reflux section (R10).

7. Device according to any one of the preceding claims, wherein the device comprises a conduit for sending the gaseous fraction (FG) directly to a cooling means (E102) positioned downstream of the regeneration column (C102).

8. Device according to any one of the preceding claims, wherein the separator (V101) is positioned above the regeneration column (C102) in the operating position.

9. Device according to claim 8, wherein the separator (V101) is connected to the regeneration column (C102) by a support structure (JP).

10. Device according to any one of claims 8 or 9, wherein the separator and the regeneration column are cylindrical and the diameter of the separator (V101) is greater, preferably strictly greater, than the diameter of the regeneration column (C102).

11. Device according to any one of claims 1 to 7, wherein the separator (V101) is integrated into the regeneration column (C102) and positioned above at least one regeneration section (R20) in the operating position and preferably the diameter of the regeneration column (C102) at the level of the separator (V101) is greater, preferably strictly greater, than the diameter of the regeneration column (C102) in the regeneration sections (R20).

12. Device according to claim 11, wherein the separator (V101) includes a passage (C50) for the gas flow exiting from at least one regeneration section (R20).

13. Device according to any one of claims 11 or 12, wherein the separator (V101) includes a discharge and distribution system configured to allow the second liquid fraction (SV2) to join at least one regeneration section (R20).

14. Device according to any one of the preceding claims, wherein the separator (V101) includes a pressure regulation means.

15. Device according to any one of the preceding claims, wherein the transport line includes a first heater (E106A) between the first heat exchanger (E101A) and the separator (V101).

16. Device according to any one of the preceding claims, wherein the transport line comprises a second heater (E106B) between the second heat exchanger (E101 B) and the regeneration column (C102) 17. A process for deacidifying a gaseous effluent (FE) containing acidic compounds, such as hydrogen sulfide or carbon dioxide, wherein at least the following steps are carried out from a device according to any one of the preceding claims: a) the gaseous effluent (EF) is brought into contact with an absorbent solution in the absorption column (C101), so as to obtain a gaseous effluent depleted in acid compounds (EFS) and an absorbent solution loaded with acid compounds (SA), the absorbent solution being capable of forming separable phases when it has absorbed a predetermined quantity of acid compounds and / or when it is heated, b) the absorbent solution loaded with acid compounds (SA) is heated in said at least one first heat exchanger (E101 A), the first heat exchanger (E101 A) exchanging heat with an absorbent solution to be recycled (SAR), c) In said separator (V101), the heated absorbing solution loaded with acidic compounds (SA) is separated into a gaseous fraction (FG), into a first liquid fraction depleted in acidic compounds (SV1) and into a second liquid fraction enriched in acidic compounds (SV2), d) the second liquid fraction (SV2) is regenerated in at least one regeneration section (R20) of the regeneration column (C102) so as to release the acid compounds into an outgoing gas stream thus forming a regenerated acid-poor absorbing solution (SR) exiting the regeneration column (C102), e) the absorbent solution to be recycled (SAR) is recycled as an absorbent solution in step a), the absorbent solution to be recycled comprising at least the regenerated acid-poor absorbent solution (SR) in step d) and preferably the first liquid fraction (SV1) obtained in step c).

18. A process according to claim 17, wherein the acid-laden absorbent solution (SA) or the second liquid fraction (SV2) is heated in at least one second heat exchanger (E101 B), the second heat exchanger (E101 B) exchanging heat with an absorbent solution to be recycled (SAR) or with the regenerated absorbent solution (SR).

19. A method according to any one of claims 17 or 18, wherein at least a first portion of the absorbing solution loaded with acid compounds (SA) is diverted into a first bypass line (D1), upstream of the first heat exchanger (E101 A) and this first portion is sent into at least one regeneration section (R20) of the regeneration column (C102), and / or at least a second portion of the absorbing solution loaded with acid compounds (SA) or of the second liquid fraction (SV2) is diverted into a second bypass line (D2), downstream of the first heat exchanger (E101 A), and this second portion is sent into at least one regeneration section (R20) of the regeneration column (C102).

20. A method according to any one of claims 17 to 19, wherein the first liquid fraction (SV1) is withdrawn from the separator (V101) by gravity, under level control, to be returned to the absorption column (C101).

21. A process according to any one of claims 17 to 20, wherein the first liquid fraction (SV1) exiting the separator (V101) is mixed with the regenerated absorbent solution (SR) to form the absorbent solution to be recycled (SAR).

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