Aerosol removal in carbon capture

Abstract

The present invention provides an apparatus, system and method for removing carbon dioxide from a gas stream by absorption.

Description

[Technical Field]

[0001] This invention relates to an absorber tower for CO2 capture, comprising: (a) an absorber column having a first end and a second end; a first inlet for a CO2-containing gas to be treated; a second inlet for a CO2 solvent; a first outlet for a CO2-lean gas, the first outlet being disposed at the second end of the column; and a second outlet for a CO2-rich solvent liquid; (b) a plate containing a plurality of perforations, wherein the plate is disposed in the absorber column via the second end; and (c) a gas filter assembly comprising two or more gas filters and a common exhaust pipe, each of the two or more gas filters comprising a separator, the separator comprising a hollow cylindrical microporous membrane disposed between an upper end cap and a lower end cap and having a conduit having a first conduit end and a second conduit end, wherein the first conduit end is in fluid communication with the lower end cap and the second conduit end is in fluid communication with the common exhaust pipe, wherein each of the two or more gas filters is inserted into a specific perforation in the plate; and also relates to an absorber tower for CO2 capture. A method for removing aerosols from lean CO2 gas in an absorber column, the method comprising: (a) generating lean CO2 gas in an absorber column; (b) conveying the lean CO2 gas through a gas filter assembly comprising two or more gas filters and a common exhaust pipe, each of the two or more gas filters comprising a separator comprising a hollow cylindrical microporous membrane disposed between an upper end cap and a lower end cap and having a conduit having a first conduit end and a second conduit end, wherein the first conduit end is in fluid communication with the lower end cap and the second conduit end is in fluid communication with the common exhaust pipe, wherein each of the two or more gas filters is inserted into a separate perforation in a plate, wherein the gas filter assembly is disposed in an absorber column, wherein conveying the lean CO2 gas through the gas filters removes aerosols from the lean CO2 gas to obtain lean CO2 gas with reduced aerosols; and (c) conveying the lean CO2 gas with reduced aerosols from the absorber column through a gas outlet into an environment outside the absorber column. [Previous Technology]

[0002] Absorption can be used to remove carbon dioxide (CO2) from a gas stream, wherein the gas stream is in contact with a solvent and CO2 is selectively absorbed by the solvent to form a CO2-poor gas and a CO2-rich solvent liquid.

[0003] There is a need for improved apparatus, systems, and methods for removing carbon dioxide by absorbing it from a gas stream. The present invention provides improvements over at least some of the disadvantages of prior art. These and other advantages of the present invention will become apparent from the description set forth below. [Summary of the Invention]

[0004] One aspect of the present invention provides an absorber tower for CO2 capture, comprising (a) an absorber tower column having a first end and a second end; a first inlet for a CO2-containing gas to be treated; a second inlet for a CO2 solvent; a first outlet for a CO2-poor gas, the first outlet being disposed at the second end of the tower column; and a second outlet for a CO2-rich solvent liquid; (b) a plate containing a plurality of perforations, wherein the plate is disposed in the absorber tower column via the second end; and (c) at least one gas filter comprising a separator comprising a hollow cylindrical microporous medium, wherein at least one gas filter is inserted into one of the plurality of perforations in the plate.

[0005] In another embodiment, the system for CO2 capture includes an absorber column and a desorber column in fluid communication with the absorber column, the desorber column having a first end and a second end; a first inlet for a CO2-rich solvent liquid; a first outlet for a CO2 solvent; and a second outlet for CO2 gas.

[0006] In another embodiment, a method for removing aerosols from lean CO2 gas in an absorber column is provided, the method comprising: (a) generating lean CO2 gas in the absorber column; (b) conveying the lean CO2 gas through a gas filter comprising a separator comprising a hollow cylindrical microporous medium, wherein the gas filter is arranged in the absorber column, wherein conveying the lean CO2 gas through the gas filter removes aerosols from the lean CO2 gas to obtain lean CO2 gas with reduced aerosols; and (c) conveying the lean CO2 gas with reduced aerosols from the absorber column through a gas outlet into an environment outside the absorber column.

[0007] In a preferred embodiment, the method involves removing at least 99.97% of aerosols of 0.3 micrometer size under a differential pressure in the range of 1 to 20 mbar.

[0008] In another embodiment, a gas filter assembly is provided, the gas filter assembly comprising two or more gas filters and a common discharge pipe, each of the two or more gas filters comprising a separator comprising a hollow cylindrical microporous membrane disposed between an upper end cap and a lower end cap and having a conduit having a first conduit end and a second conduit end, wherein the first conduit end is in fluid communication with the lower end cap and the second conduit end is in fluid communication with the common discharge pipe.

[0009] In another embodiment, the absorber tower for CO2 capture comprises (a) an absorber column having a first end and a second end; a first inlet for CO2-containing gas to be treated; a second inlet for CO2 solvent; a first outlet for lean CO2 gas, the first outlet being disposed at the second end of the column; and a second outlet for CO2-rich solvent liquid; (b) a plate containing a plurality of perforations, wherein the plate is disposed in the absorber column via the second end; and (c) a gas filter assembly comprising two or more gas filters and a common exhaust pipe, each of the two or more gas filters comprising a separator comprising a hollow cylindrical microporous membrane disposed between an upper end cap and a lower end cap and having a conduit having a first conduit end and a second conduit end, wherein the first conduit end is in fluid communication with the lower end cap and the second conduit end is in fluid communication with the common exhaust pipe, wherein each of the two or more gas filters is inserted into a specific perforation in the plate.

[0010] In another embodiment, the system for CO2 capture includes an absorber tower comprising a gas filter assembly, and a desorber tower in fluid communication with the absorber tower, the desorber tower having a first end and a second end; a first inlet for a CO2-rich solvent liquid; a first outlet for a CO2 solvent; and a second outlet for CO2 gas.

[0011] In another embodiment, a method for removing aerosols from lean CO2 gas in an absorber column is provided, the method comprising: (a) generating lean CO2 gas in an absorber column; (b) conveying the lean CO2 gas through a gas filter assembly comprising two or more gas filters and a common exhaust pipe, each of the two or more gas filters comprising a separator, the separator comprising a hollow cylindrical microporous membrane disposed between an upper end cap and a lower end cap and having a conduit having a first conduit end and a second end cap. The conduit end, wherein the first conduit end is in fluid communication with the lower end cap of the opening and the second conduit end is in fluid communication with the common discharge pipe, wherein each of two or more gas filters is inserted into a separate perforation in the plate, wherein the gas filter assembly is arranged in the absorber column, wherein lean CO2 gas is passed through the gas filters to remove aerosols from the lean CO2 gas, resulting in lean CO2 gas with reduced aerosols; and (c) the lean CO2 gas with reduced aerosols from the absorber column is passed through the gas outlet into the environment outside the absorber column.

Implementation Method

[0013] According to one aspect of the present invention, an absorber tower for CO2 capture comprises (a) an absorber column having a first end and a second end; a first inlet for a CO2-containing gas to be treated; a second inlet for a CO2 solvent; a first outlet for a CO2-poor gas, the first outlet being disposed at the second end of the column; and a second outlet for a CO2-rich solvent liquid; (b) a plate containing a plurality of perforations, wherein the plate is disposed in the absorber column via the second end; and (c) at least one gas filter comprising a separator comprising a hollow cylindrical microporous medium, wherein at least one gas filter is inserted into one of the plurality of perforations in the plate.

[0014] In some configurations of an absorber column, at least one gas filter including a separator comprises a hollow cylindrical pleated microporous membrane, the at least one gas filter having a first end cap and a second end cap, wherein the first end cap is an open end cap facing a first outlet for lean CO2 gas at a second end of the absorber column.

[0015] In a preferred embodiment, the absorber tower includes a plurality of gas filters, each of which is inserted into one of a plurality of perforations in a plate.

[0016] In another embodiment, the system for CO2 capture includes an absorber column and a desorber column in fluid communication with the absorber column, the desorber column having a first end and a second end; a first inlet for a CO2-rich solvent liquid; a first outlet for a CO2 solvent; and a second outlet for CO2 gas.

[0017] In another embodiment, a method for removing aerosols from lean CO2 gas in an absorber column is provided, the method comprising: (a) generating lean CO2 gas in the absorber column; (b) conveying the lean CO2 gas through a gas filter comprising a separator comprising a hollow cylindrical microporous medium, wherein the gas filter is arranged in the absorber column, wherein conveying the lean CO2 gas through the gas filter removes aerosols from the lean CO2 gas to obtain lean CO2 gas with reduced aerosols; and (c) conveying the lean CO2 gas with reduced aerosols from the absorber column through a gas outlet into an environment outside the absorber column.

[0018] In some embodiments of the method, generating lean CO2 gas in the absorber column includes contacting the gas stream with a solvent to form a CO2-rich solvent liquid and lean CO2 gas, and treating the lean CO2 gas by one or more water washing and / or acid washing stages before conveying it through a gas filter.

[0019] In another embodiment, a gas filter assembly is provided, the gas filter assembly comprising two or more gas filters and a common discharge pipe, each of the two or more gas filters comprising a separator comprising a hollow cylindrical microporous membrane disposed between an upper end cap and a lower end cap of an opening and having a conduit having a first conduit end and a second conduit end, wherein the first conduit end is in fluid communication with the lower end cap of the opening and the second conduit end is in fluid communication with the common discharge pipe.

[0020] In another embodiment, the absorber tower for CO2 capture comprises (a) an absorber column having a first end and a second end; a first inlet for the CO2-containing gas to be treated; a second inlet for the CO2 solvent; a first outlet for the CO2-lean gas, the first outlet being disposed at the second end of the column; and a second outlet for the CO2-rich solvent liquid; (b) a plate containing a plurality of perforations, wherein the plate is disposed in the absorber column via the second end; and (c) a gas filter assembly comprising two or more gas filters and a common exhaust pipe, each of the two or more gas filters comprising a separator comprising a hollow cylindrical microporous membrane disposed between an upper end cap and a lower end cap and having a conduit having a first conduit end and a second conduit end, wherein the first conduit end is in fluid communication with the lower end cap and the second conduit end is in fluid communication with the common exhaust pipe, wherein each of the two or more gas filters is inserted into a specific perforation in the plate.

[0021] In another embodiment, the system for CO2 capture includes an absorber tower comprising a gas filter assembly, and a desorber tower in fluid communication with the absorber tower, the desorber tower having a first end and a second end; a first inlet for a CO2-rich solvent liquid; a first outlet for a CO2 solvent; and a second outlet for CO2 gas.

[0022] In some configurations, the system further includes a heat exchanger in fluid communication with the absorber tower and the desorber tower.

[0023] In another embodiment, a method for removing aerosols from lean CO2 gas in an absorber column is provided, the method comprising: (a) generating lean CO2 gas in an absorber column; (b) conveying the lean CO2 gas through a gas filter assembly comprising two or more gas filters and a common exhaust pipe, each of the two or more gas filters comprising a separator, the separator comprising a hollow cylindrical microporous membrane disposed between an upper end cap and a lower end cap and having a conduit having a first conduit end and a second end cap. The conduit end, wherein the first conduit end is in fluid communication with the lower end cap of the opening and the second conduit end is in fluid communication with the common discharge pipe, wherein each of two or more gas filters is inserted into a separate perforation in the plate, wherein the gas filter assembly is arranged in the absorber column, wherein lean CO2 gas is passed through the gas filters to remove aerosols from the lean CO2 gas, resulting in lean CO2 gas with reduced aerosols; and (c) the lean CO2 gas with reduced aerosols from the absorber column is passed through the gas outlet into the environment outside the absorber column.

[0024] In a preferred embodiment, the method involves removing at least 99.97% of aerosols of 0.3 micrometer size under a differential pressure in the range of 1 to 20 mbar.

[0025] In some cases, the methods include depleting the solvent from CO2-poor gas.

[0026] In some embodiments of these methods, generating lean CO2 gas in an absorber column includes contacting the gas stream with a solvent to form a CO2-rich solvent liquid and lean CO2 gas, and treating the lean CO2 gas by one or more water washing and / or acid washing stages before conveying it through a gas filter.

[0027] Advantageously, the present invention provides highly efficient aerosol removal (at least 99.97% aerosol removal of 0.3 micrometer-sized aerosols) to meet stringent requirements for limiting atmospheric emissions. For example, the present invention can produce solvent emissions of 1 ppmv or less.

[0028] Additional advantages include reduced frequency of water and acid washing (where water washing can saturate lean CO2 gas with water and / or fine liquid aerosols), thereby limiting liquid loss (especially solvent loss) into the environment when operating through the gas filter at reduced pressure drops (1 to 20 mbar, for example 5 to 12 mbar, preferably 1 to 10 mbar, even more preferably 1 to 5 mbar). By operating at reduced pressure drops, energy consumption can be reduced without the need for additional equipment (e.g., compressors) to provide increased pressure. Since the gas filter is arranged within the absorber tower, the footprint is not increased. These advantages avoid increased carbon capture costs associated with existing systems and procedures.

[0029] The components of the present invention will now be described in more detail below, wherein similar components have similar element symbols.

[0030] Figure 1 is a schematic diagram illustrating one aspect of a system 1000 for CO2 capture, which includes an absorber tower 100 for CO2 capture, comprising an absorber tower column 100A having a first end 101 and a second end 102; a first inlet 111 for CO2-containing gas to be treated; a second inlet 112 for CO2 solvent; a first outlet 121 for lean CO2 gas, the first outlet being arranged at the second end of the column; a second outlet 122 for CO2-rich solvent liquid; a plate 150 containing a plurality of perforations 151, wherein the plate is arranged in the absorber tower column by means of the second end; and at least one gas filter 160 including a separator, the at least one gas filter being inserted into one of the perforations in the plate. The illustrated schematic of the system further includes a desorber column 200, which includes a desorber column 200A in fluid communication with the absorber column, the desorber column having a first end 201 and a second end 202; a first inlet 211 for a CO2-rich solvent liquid; a first outlet 221 for a CO2 solvent; and a second outlet 222 for a CO2 gas. As will be discussed in more detail below, in some schematics, for example including a gas filter assembly 160' (see Figures 5A and 5C), the system includes an exhaust line 192.

[0031] The schematic diagram of system 1000 also includes solvent circuit 500 and cross-flow heat exchanger 600, which may be selected as appropriate. The solvent circuit is used to convey CO2-rich solvent liquid from the absorber column through a second outlet 122 for CO2-rich solvent gas along conduit 502A via conduit 502B and a first inlet 211 for CO2-rich solvent liquid to the desorber column (wherein the desorber column, the CO2-rich solvent liquid may be treated, for example, heated, subjected to reduced pressure, or treated with an inert gas to form lean CO2 gas and CO2 gas), or after conveying through a cross-flow heat exchanger 600, to convey the CO2-rich solvent liquid along conduit 502C through a second inlet 112 for CO2 solvent back to the absorber column, and to convey lean CO2 gas from the desorber column along conduit 501A through a first outlet 221 for CO2 solvent, and after conveying through the heat exchanger 600, to convey the CO2-rich solvent liquid along conduit 501B (also conduit 502C) through a second inlet 112 back to the absorber column.

[0032] Downstream of absorber column 100, at the second outlet 122, the CO2-rich solvent conveyed along conduit 500A is pumped through cross-flow heat exchanger 600, where it is preheated by regenerated lean CO2 gas to minimize energy input. In desorber column 200, CO2 is removed from heated vapor solvent supplied at a temperature of, for example, about 120°C in a reboiler (outside system 1000). The solvent evaporates in the reboiler, and the vapor enters desorber column 200 and is pumped through cross-flow heat exchanger 600, heating the CO2-rich solvent liquid entering desorber column 200 at the top. The CO2-rich solvent liquid from the reboiler is fed back to the top of absorber column 100 at a flow rate of 4 to 16 kg / kg CO2 in some samples to achieve CO2 removal of more than 90%.

[0033] The absorber column 100 is also illustrated with a processing assembly 130 including an absorber section, wherein CO2 in the gas stream is contacted with a solvent to form a CO2-rich (and solvent-rich) solvent liquid and a CO2-lean (and solvent-lean) gas. Various processing assemblies and solvents used in CO2 capture are known in this art. A typical processing assembly comprises a packed column filled with a porous packing material (e.g., Mellapak™, such as Mellapak Plus™ 252Y (Sulzer; Winterthur, Switzerland)), wherein the packed column has a suitable height (e.g., in the range of 2 to 8 m) to provide the required absorption of CO2 to the solvent. Typical solvents include amines (e.g., monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA)), piperazine with Advanced Stripper™ (PZAS™), or aqueous solutions of alkylamines or carbonates. Ideally, the solvent enters the top section of the processing assembly (column) and flows downwards to absorb CO2.

[0034] Ideally, lean CO2 gas is treated by one or more water washing and / or acid washing stages at a washing assembly 140, which typically includes at least one pump 141 and a cooler 142. Various washing assemblies are known in this art. Typically, the washing assembly includes a packed bed of water surrounded by a pump to condense and dissolve volatile solvents.

[0035] A typical configuration of the washing assembly according to one embodiment of the present invention has two sections: a lower water washing section and a supplemental upper acid washing section. The lower section is used to treat gases containing solvent vapors (e.g., amine vapors) and other environmentally harmful components. These are removed by contact with recycled water, while fresh water is supplied from the top of the water washing section. A portion of the recycled water is returned to the process for amine recovery, while another portion is delivered to a wastewater facility.

[0036] If the treated gas contains amines and / or harmful aerosols exceeding the prescribed limits, an additional upper acid washing section can be used for further treatment. Typically, if necessary, a higher packed bed height and a lower recirculation water temperature in the washing section can reduce the amount of amine emissions.

[0037] According to an embodiment of the invention, operating the system includes removing aerosols from a CO2-poor gas by allowing gas to flow from the outside in (flowing from the outer surface of the hollow cylindrical microporous medium through the inner surface) through one or more gas filters, wherein the filtered gas is then conveyed from the hollow interior of the cylindrical microporous medium through a second outlet 121 and exits the absorber (e.g., into the atmosphere), and the aerosols (e.g., including water and CO2-rich solvents) are discharged from the outer surface of the hollow cylindrical microporous medium. Therefore, the illustrated embodiment of the system 1000 includes a porous plate 150 (see, for example, Figures 2 and 3) containing a plurality of perforations 151, wherein the plate is arranged in the absorber column 100A via a second end 102; and a gas filter 160 containing a separator is inserted into the individual perforations in the plate.

[0038] The present invention may include any number of gas filters and any arrangement of gas filters. Although at least one gas filter is used, typically two or more gas filters are utilized. In one example, a system with a flow rate of 125,000 m3 / h would have 78 gas filters, and in some embodiments, the gas filters are connected in parallel (see, for example, Figure 2).

[0039] Because the gas filter is located near the second outlet 121 within the absorber tower, where the aerosol is smaller and the gas is at near atmospheric pressure, the gas filter can operate with a reduced pressure drop (compared to the pressure loss associated with external filtration devices, such as Brownian diffusion devices and / or external filtration devices in the housing outside the absorber tower). Additionally, this allows for a reduction in the number of water washing and acid washing stages, while still meeting stringent requirements for limiting atmospheric emissions.

[0040] The CO2 gas delivered via the second outlet 222 of the desorber column 200 (generated in the desorber, wherein the CO2-rich solvent liquid may be treated (e.g., by one or more of the following: heating, undergoing depressurization, flash desorption, treatment with an inert gas) to form a CO2-lean gas and CO2 gas) may subsequently be processed (e.g., by one or more of the following in various applications (e.g., increasing oil recovery or generating desired chemicals)) without being directly delivered to the environment.

[0041] Figures 4A to 4C and 5A to 5E illustrate an illustrative gas filter 160 according to one embodiment of the present invention, comprising a separator containing a hollow cylindrical microporous medium 161. Typically, the separator comprises a hollow cylindrical microporous membrane, such as a microporous fluoropolymer (e.g., PTFE) membrane, preferably a pleated hollow cylindrical microporous PTFE membrane. Ideally, the separator medium, such as the microporous membrane, has a critical wetting surface tension (CWST, as defined, for example, in U.S. Patent No. 4,925,572) that is lower than the surface tension of the solvent (which absorbs CO2). Typically, the microporous PTFE membrane used in the gas filter has a CWST in the range of 25 to 30 dynes / cm (25 to 30 × 10⁻⁵ N / cm).

[0042] The microporous membrane may have any suitable pore structure, such as pore size (e.g., as demonstrated by bubble point or by KL as described in, for example, U.S. Patent 4,340,479, or by capillary condensation flow porometry), mean flow pore (MFP) size (e.g., when characterized using a porosimeter, such as the Porvair Porometer (Porvair plc, Norfolk, UK), or a porosimeter available under the trademark POROLUX (Porometer.com; Belgium), pore grade, pore diameter (e.g., when characterized using the modified OSU F2 test as described in U.S. Patent 4,925,572), or removal of rating media. Typically, the membrane pore size is in the range of 0.2 micrometers to 0.6 micrometers, preferably in the range of 0.5 micrometers to 0.6 micrometers.

[0043] In the configuration shown in Figures 4A to 4C (also see Figures 2, 5A to 5E), the gas filter 160 includes a microporous medium 161 (shown as a hollow cylindrical pleated medium) disposed between an upper (facing the second gas outlet 121) end cap 164 and a lower (facing the processing assembly 130) end cap 167, typically wherein the upper end cap 164 is open. Typically, as shown, the outer diameter of the upper end cap 164 is larger than the inner diameter of the perforation 151 and / or the upper end cap has a protrusion on its outer diameter for supporting the filter in a suitable position within the porous plate.

[0044] The lower end cap 167 may be open or closed; preferably open. Typically, the lower end cap 167 is connected to an element providing a discharge pipe to allow liquids from the environment (e.g., rain) to be guided away from the interior of the element column. In the illustrated sample of the gas filter (see Figures 2 and 5B), a gasket 166A is arranged between the bottom of the upper end cap 164 and the top of the perforated plate 150 for sealing the end cap to the perforated plate 150, and the upper end cap 164 also includes at least one handle 164A (two handles 164A are illustrated) for facilitating the installation of the gas filter into the perforated plate and / or for removing the gas filter from the perforated plate.

[0045] Ideally, as shown in FIG5B, the gas filter 160 includes an internally hollow cylindrical porous core 162 (illustrated as a screen) that allows flow, wherein an outer housing 163 (e.g. for handling and / or protection) is selected as appropriate, and the core or screen is inserted into the hollow interior of the microporous medium 161, which may be surrounded by the outer housing (if present). In some embodiments, the gas filter includes a support layer and / or a discharge layer (e.g., each layer containing a mesh) on either side of the microporous medium, for example, between the core and the microporous medium and / or between the microporous medium and a cage (if present).

[0046] As shown in Figures 2 and 4A, the opening in the lower end cap can be connected to a one-way valve 170 (such as a check valve, duckbill valve, float valve, or water seal device). In this type of discharge, liquid from the environment is discharged into the absorber tower (the one-way valve can be opened at the desired target pressure, such as 2 mbar) and the liquid is mixed with the separated aerosol, wherein the water combined with the aerosol can be treated with a solvent if necessary.

[0047] Figure 5A (see also Figures 5C to 5E) is a perspective view illustrating another aspect of the invention, of a gas filter assembly 160' comprising a plurality of gas filters 160 for filtering lean CO2 gas, the gas filter assembly having a common discharge pipe 190 and further comprising separate conduits 168 (each conduit having a first end 168A and a second end 168B), each separate conduit 168 being in fluid communication with an individual gas filter 160. According to the aspects shown in Figures 5B and 5D, a protrusion including an opening in each lower end cap is surrounded by a gasket 166B, which seals a discharge cup 197 in fluid communication with the common discharge pipe 190 within the absorber column. The common discharge pipe of the gas filter assembly has a plurality of connectors, conduits, and discharge cups, wherein each gas filter element in the assembly has a separate conduit and a discharge cup. The purpose of the shared discharge pipe is to collect ambient liquids and discharge them from the absorber tower 100 through discharge outlet 191 (see, for example, Figure 5E) and along discharge line 192 (see Figures 1 and 5A), so that these liquids do not mix with the solvent in the absorber tower.

[0048] As needed, as shown in Figures 5A, 5C and 5D, the gas filter assembly 160' may include a frame 195 containing several arms 196 in various configurations (e.g., radial and / or star-shaped), which are connected to the discharge cups 197 below each gas filter 160 to provide support for the gas filters.

[0049] Various gas streams (e.g., waste gas streams) can be processed according to the present invention to capture CO2. In some cases, the gas stream (e.g., waste gas stream) is cooled (e.g., in a cooling tower) before being conveyed to the absorber column.

[0050] The following embodiments further illustrate the present invention, but should not be construed as limiting the scope of the invention in any way. Embodiments

[0051] This embodiment demonstrates that aerosols can be efficiently removed by a gas filter according to one embodiment of the present invention. In a gas filter comprising a hollow cylindrical pleated microporous PTFE membrane with an average pore size of about 0.6 micrometers, a CWST of about 29 dynes / cm (about 29 × 10⁻⁵ N / cm), a diameter of 16 m, and a height of 25 m (typically corresponding to the configuration shown in Figures 4A to 4C), exhaust gas enters the gas filter from the outside to the inside at a flow rate of about 1.5 M Nm³ / h, wherein the CO₂ loading is about 12%. The pressure drop is in the range of 7 to 10 mbar. After undergoing only one water washing stage to remove gaseous aerosols, the CO₂-removed exhaust gas can be directly discharged from the gas filter into the atmosphere. 1 g / Nm³ of aerosol is present just before entering the gas filter, with an average droplet diameter of 0.5 μm. Immediately downstream of the gas filter, <1 mg / Nm³ of liquid is present in the discharged gas.

[0052] All references cited herein, including publications, patent applications and patents, are hereby incorporated by way of reference as if each reference were individually and specifically instructed to be incorporated by way of reference and fully described in this document.

[0053] Unless otherwise indicated herein or obviously contradicted by the context, in the context of describing the invention (particularly in the context of the following claims), the terms "a," "an," "the," "at least one," and similar indicators should be understood to cover both the singular and the plural. Unless otherwise indicated herein or obviously contradicted by the context, the term "at least one" following a list of one or more items (e.g., "at least one of A and B") should be understood to mean one of the listed items (A or B) or any combination of two or more of the listed items (A and B). Unless otherwise indicated, the terms "comprising," "having," "including," and "containing" should be understood as open-ended terms (i.e., meaning "including but not limited to"). Unless otherwise indicated herein, the description of value ranges herein is intended only as a shorthand for individually referring to each individual value falling within that range, and each individual value is incorporated into this specification as if it were individually described herein. Unless otherwise indicated herein or otherwise obviously contradictory to the context, all methods described herein may be performed in any suitable order. Unless otherwise asserted, the use of any and all exemplary or illustrative language (e.g., "such as") provided herein is intended only to better illustrate the invention and not to limit the scope of the invention. The language in this specification should not be construed as indicating any unclaimed element essential to the practice of the invention.

[0054] Preferred embodiments of the invention are described herein, including the best mode known to the inventors for practicing the invention. Variations of these preferred embodiments will become apparent to those skilled in the art after reading the foregoing description. The inventors expect those skilled in the art to adopt these variations where appropriate, and the inventors intend to practice the invention in ways other than those specifically described herein. Therefore, the invention includes all modifications and equivalents of the subject matter described in the appended claims, where permitted by applicable law. Furthermore, unless otherwise indicated herein or otherwise clearly contradicted by the context, the invention covers any combination of the elements described above in all possible variations. Symbol Description 1000 System for CO2 Capture 100 Absorber Tower for CO2 Capture 100A Absorber Tower Column 101 First End 102 Second End 111 First Inlet for CO2-Containing Gas to be Treated 112 Second Inlet for CO2 Solvent 121 First Outlet for CO2-Lean Gas 122 Second Outlet for CO2-Rich Solvent Liquid 150 Perforated Plate 151 Multiple Perforations 130 Processing Assembly 140 Washing Assembly 141 Pump 142 Cooler 160 Gas Filter 160' Gas Filter Assembly 161 Microporous Media 162 Perforated Core 163 Housing 164 Top Cover 164A Handle 16 6A gasket; 166B gasket; 167 lower end cap; 168 conduit; 168A first end; 168B second end; 170 one-way flow valve; 190 common discharge pipe; 191 discharge outlet; 192 discharge line; 195 frame; 196 arm; 197 discharge cup; 200 desorber tower; 200A desorber tower column; 201 first end; 202 second end; 211 first inlet for CO2-rich solvent liquid; 221 first outlet for CO2 solvent; 222 second outlet for CO2 gas; 500 solvent circuit; 600 cross-flow heat exchanger; 500A conduit; 501A conduit; 501B conduit; 502A conduit; 502B conduit; 502C conduit [Simplified Explanation of the Diagram]

[0012] [Figure 1] is a diagram illustrating an embodiment of the present invention for removing CO2 from a gas stream by absorption, wherein the system includes an absorber tower comprising a gas filter, a desorber tower, and a solvent circuit. [Figure 2] is a diagram showing the upper end (second end) of the absorber tower in the system shown in Figure 1, which also shows a porous plate housing a plurality of gas filters, the plurality of gas filters including a separator for filtering lean CO2 gas (having less CO2 (and less solvent) compared to a CO2-rich solvent liquid) to remove aerosols from the lean CO2 gas. [Figure 3] is a diagram showing a porous plate for housing a plurality of gas filters for filtering lean CO2 gas. [Figures 4A] to [Figure 4C] are diagrams illustrating a gas filter for filtering lean CO2 gas according to an embodiment of the present invention, Figure 4A showing a cross-sectional view; Figure 4B showing an isometric view, and Figure 4C showing a cross-sectional view of Figure 4B, also showing the hollow center. [Figure 5A] is a perspective view of a gas filter assembly comprising a plurality of gas filters for filtering lean CO2 gas, according to another embodiment of the invention. The gas filter assembly further includes a separation conduit, a discharge cup, a common discharge pipe, and a discharge outlet leading to the discharge line. Each separation conduit is in fluid communication with an individual gas filter at one end (connected to the discharge cup) and with the common discharge pipe at the other end. Figure 5A shows a frame, depending on the application. [Figure 5B] is an exploded view of the gas filters in the gas filter assembly shown in Figure 5A; [Figure 5C] is a side view of the gas filter assembly shown in Figure 5A; [Figure 5D] is an exploded partial view of the bottom of the gas filters in the gas filter assembly shown in Figure 5A, showing a lower end cap with a gasket for sealing the connection to the discharge cup; and [Figure 5E] is another perspective view of the gas filter assembly, showing the discharge pipe and discharge outlet (all discharge lines and frame not shown in the figure).

Claims

1. An absorber column for CO2 capture, comprising: (a) an absorber column having a first end and a second end; a first inlet for a CO2-containing gas to be treated; a second inlet for a CO2 solvent; a first outlet for a CO2-lean gas, the first outlet being disposed at the second end of the column; and a second outlet for a CO2-rich solvent liquid; (b) a plate having a plurality of perforations, wherein the plate is disposed in the absorber column via the second end; and, (c) A gas filter assembly comprising two or more gas filters and a common exhaust pipe, each of the two or more gas filters including a separator, the separator including a hollow cylindrical microporous membrane disposed between an upper end cap and a lower end cap and having a conduit having a first conduit end and a second conduit end, wherein the first conduit end is in fluid communication with the lower end cap and the second conduit end is in fluid communication with the common exhaust pipe, wherein each of the two or more gas filters is inserted into a separate perforation in the plate, and wherein the two or more gas filters are close to the second outlet.

2. The absorber column of claim 1, wherein each of the two or more filters includes a separator comprising a hollow cylindrical pleated microporous membrane, the filters having a first end cap and a second end cap, wherein the first end cap is an open end cap facing the first outlet for lean CO2 gas at the second end of the absorber column.

3. A system for CO2 capture, comprising: an absorber column as claimed in claim 1 or 2, and a desorber column in fluid communication with the absorber column, the desorber column having a first end and a second end; a first inlet for a CO2-rich solvent liquid; a first outlet for a CO2 solvent; and a second outlet for a CO2 gas.

4. The system of claim 3 further includes a heat exchanger in fluid communication with the absorber tower and the desorber tower.

5. A method for removing aerosols from lean CO2 gas in an absorber column, the method comprising: (a) generating a lean CO2 gas in the absorber column; (b) passing the lean CO2 gas through a gas filter assembly comprising two or more gas filters and a common exhaust pipe, each of the two or more gas filters comprising a separator, the separator comprising a hollow cylindrical microporous membrane disposed between an upper open end cap and a lower open end cap and having a conduit having a first conduit end and a second conduit end, wherein the first conduit end is in fluid communication with the lower open end cap and the second conduit end is in fluid communication with the common exhaust pipe, wherein each of the two or more gas filters is inserted into a respective perforation in the plate, wherein the gas filter assembly is disposed in the absorber column, wherein passing the lean CO2 gas through the gas filters removes aerosols from the lean CO2 gas to obtain a lean CO2 gas with reduced aerosols, wherein... (c) At least 99.97% aerosol removal of 0.3 micrometer-sized aerosols at a differential pressure in the range of 1 to 20 mbar; and (d) conveying the reduced CO2 gas from the absorber column through a gas outlet into the environment outside the absorber column.

6. The method of claim 5, which includes removing solvent from the lean CO2 gas.

7. The method of claim 5, wherein generating the lean CO2 gas in the absorber column includes contacting a gas stream with a solvent to form a CO2-rich solvent liquid and a lean CO2 gas, and treating the lean CO2 gas by one or more water washing and / or acid washing stages before conveying the lean CO2 gas through the gas filter.

8. A gas filter assembly comprising two or more gas filters and a common exhaust pipe, wherein the common exhaust pipe has a plurality of exhaust cups, each of the two or more gas filters includes a separator comprising a microporous membrane disposed between an upper opening cap and a lower opening cap and having a conduit having a first conduit end and a second conduit end, wherein the first conduit end is in fluid communication with the lower opening cap and the second conduit end is in fluid communication with the common exhaust pipe.

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