Aerosol removal in carbon capture

Abstract

Devices, systems, and methods for removing carbon dioxide from gas streams by absorption are provided.

Description

AEROSOL REMOVAL IN CARBON CAPTURECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims the benefit of U.S. Provisional Patent Application No. 63 / 569,837, filed March 26, 2024, which is incorporated by reference.BACKGROUND OF THE INVENTION

[0002] Absorption can be used in removing carbon dioxide (CO2) from gas streams, wherein the gas stream is contacted with a solvent and CO2 is selectively absorbed by the solvent, forming a CO2-lean gas. and a CO2-rich solvent liquid.

[0003] There is a need for improved devices, systems, and methods for removing carbon dioxide from gas streams by absorption. The present invention provides for ameliorating at least some of the disadvantages of the prior art. These and other advantages of the present invention will be apparent from the description as set forth below.BRIEF SUMMARY OF THE INVENTION

[0004] An aspect of the invention provides an absorber tower for use in 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 CO2-lean gas, the first outlet arranged 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 arranged in the absorber column by the second end; and, (c) at least one gas filter comprising a separator comprising a hollow cylindrical microporous medium, wherein the at least one gas filter is inserted in one of the plurality of perforations in the plate.

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

[0006] In another aspect, a method for removing aerosols from CCh-lean gas in an absorber column is provided, the method comprising: (a) producing CCh-lean gas in the absorber column; (b) passing the CCh-lean 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 passing the CCh-lean gas through the gas filter removes aerosols from the CCh-lean gas, providing an aerosol-reduced CCh-lean gas; and (c) passing the aerosol -reduced CCh-lean gas from the absorber column through a gas outlet into an environment external to the absorber column.

[0007] In a preferred aspect, the method comprises at least 99.97% aerosol removal for 0.3 micron-sized aerosols at a differential pressure in the range of 1 to 20 mbar.

[0008] In another aspect, a gas filter assembly is provided, the gas filter assembly comprising two or more gas filters and a common drain, each of the two or more gas filters comprising a separator comprising a hollow cylindrical microporous membrane arranged between an open upper end cap and an open low er 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 open lower end cap, and the second conduit end is in fluid communication with the common drain.

[0009] In another aspect, an absorber tower for use in CCh capture comprises (a) an absorber column having a first end and a second end; a first inlet for CCh-containing gas to be treated; a second inlet for CCh solvent; a first outlet for CCh-lean gas, the first outlet arranged at the second end of the column; and a second outlet for CCh-rich solvent liquid; (b) a plate containing a plurality of perforations, wherein the plate is arranged in the absorber column by the second end; and, (c) a gas filter assembly comprising two or more gas filters and a common drain, each of the two or more gas filters comprising a separator comprising a hollow cylindrical microporous membrane arranged betw een an open upper end cap and an open 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 open lower end cap, and the second conduit end is in fluid communication with the common drain, wherein each of the two or more gas filters is inserted in separate perforations in the plate.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

[0010] Figure 1 is a drawing showing, diagrammatically, an illustrative system for removing CO2 from gas streams by absorption according to an aspect of the invention, wherein the system includes an absorber tower including gas filters, a desorber tower and a solvent loop.

[0011] Figure 2 is a drawing showing the upper (second) end of an absorber tower in the system shown in Figure 1, also showing a perforated plate receiving a plurality of gas filters comprising separators for filtering CCh-lean gas (having less CO2 (and less solvent) compared to CCh-rich solvent liquid) to remove aerosols from the CO2 lean gas.

[0012] Figure 3 is a drawing showing an illustrative perforated plate for receiving a plurality of gas filters for filtering CCh-lean gas.

[0013] Figures 4A-4C are drawings showing a gas filter for filtering CCh-lean gas according to an aspect of the invention, Figure 4A shows a profile view; Figure 4B shows an isometric view, and Figure 4C shows a cross-sectional view of Figure 4B, also showing the hollow center.

[0014] Figure 5A is a draw ing showing a perspective view of a gas filter assembly comprising a plurality of gas filters for filtering CCh-lean gas according to another aspect of the invention, the gas filter assembly further comprising separate conduits, drain cups, a common drain, and a drain outlet leading to a drain line, each separate conduit in fluid communication with a separate gas filter at one conduit end (connected to a drain cup) and in fluid communication with the common drain at the other conduit end. Figure 5A shows shows an optional frame. Figure 5B is a drawing showing an exploded view of a gas filter in the gas filter assembly shown in Figure 5A; Figure 5C is a drawing showing a side view of the gas filter assembly shown in Figure 5A; Figure 5D is a drawing showing an exploded partial view of the bottom of a gas filter in the gas filter assembly shown in Figure 5A. showing the lower end cap with a gasket for sealing a connection to a drain cup; and Figure 5E is drawing showing another perspective view of the gas filter assembly, showing the drain and the drain outlet (full drain line and frame not shown).DETAILED DESCRIPTION OF THE INVENTION

[0015] In accordance with an aspect of the invention, an absorber tower for use in CO2 capture comprises (a) an absorber column having a first end and a second end; a first inlet for C02-containing gas to be treated; a second inlet for CO2 solvent; a first outlet for CO2-lean gas, the first outlet arranged 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 arranged in the absorber column by the second end; and, (c) at least one gas filter comprising a separator comprising a hollow cylindrical microporous medium, wherein the at least one gas filter is inserted in one of the plurality of perforations in the plate.

[0016] In some aspects of the absorber tower, the at least one gas filter comprising 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 the first outlet for CCh-lean gas at the second end of the absorber column.

[0017] In a preferred aspect, the absorber tower includes a plurality of gas filters, each of the plurality of gas filters inserted in a separate one of the plurality of perforations in the plate.

[0018] In another aspect, a system for CO2 capture comprises an aspect of the absorber tower, and. a desorber tower in fluid communication with the absorber tower, the desorber column having a first end and a second end; a first inlet for CCh-rich solvent liquid; a first outlet for CO2 solvent, and a second outlet for CO2 gas.

[0019] In some aspects, the system further comprises a heat exchanger in fluid communication with the absorber tower and the desorber tower.

[0020] In another aspect, a method for removing aerosols from CCh-lean gas in an absorber column is provided, the method comprising: (a) producing CCh-lean gas in the absorber column; (b) passing the CCh-lean 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 passing the CCh-lean gas through the gas filter removes aerosols from the CCh-lean gas, providing an aerosol-reduced CCh-lean gas; and (c) passingthe aerosol-reduced CCh-lean gas from the absorber column through a gas outlet into an environment external to the absorber column.

[0021] In a preferred aspect, the method comprises at least 99.97% aerosol removal for 0.3 micron-sized aerosols at a differential pressure in the range of 1 to 20 mbar.

[0022] In some aspects, the method includes depleting solvent from the CCh-lean gas.

[0023] In some aspects of the method, producing CCh-lean gas in the absorber column includes contacting a gas stream with solvent to form CCh-rich solvent liquid and CCh-lean gas and treating the CCh-lean gas with one or more stages of water and / or acid washes, before passing the CCh-lean gas through the gas filter.

[0024] In another aspect, a gas filter assembly is provided, the gas filter assembly comprising two or more gas filters and a common drain, each of the two or more gas filters comprising a separator comprising a hollow cylindrical microporous membrane arranged between an open upper end cap and an open low er 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 open lower end cap, and the second conduit end is in fluid communication with the common drain.

[0025] In another aspect, an absorber tower for use in CCh capture comprises (a) an absorber column having a first end and a second end; a first inlet for CCh-containing gas to be treated; a second inlet for CCh solvent; a first outlet for CCh-lean gas, the first outlet arranged at the second end of the column; and a second outlet for CCh-rich solvent liquid; (b) a plate containing a plurality of perforations, wherein the plate is arranged in the absorber column by the second end; and, (c) a gas filter assembly comprising two or more gas filters and a common drain, each of the two or more gas filters comprising a separator comprising a hollow cylindrical microporous membrane arranged between an open upper end cap and an open 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 open lower end cap, and the second conduit end is in fluid communication w ith the common drain, wherein each of the tw o or more gas filters is inserted in separate perforations in the plate.

[0026] Advantageously, aspects of the invention can provide for high efficiency aerosol removal (at least 99.97% aerosol removal for 0.3 micron-sized aerosols) to meet stringent requirements to limit atmospheric emissions. For example, aspects of the invention can result in solvent emissions of 1 ppmv or less.

[0027] Additional advantages include reducing the number of water washes and acid washes (wherein water washes can saturate CCh-lean gas with water and / or fine liquid aerosols) thus limiting liquid losses (especially solvent losses) to the environment while operating with reduced pressure drop (1 to 20 mbar. for example, 5-12 mbar, preferably 1-10 mbar, more preferably 1-5 mbar) across the gas filter. By operating at a reduced pressure loss, energy consumption can be reduced, without the use of additional equipment (e.g., compressors) to provide increased pressure. Since the gas filter is arranged within the absorber tower, the footprint is not enlarged. These advantages can avoid the increase in carbon capture costs associated with existing systems and procedures.

[0028] Each of the components of the invention will now be described in more detail below, wherein like components have like reference numbers.

[0029] Figure 1 is a drawing showing, diagrammatically, an aspect of a system for CO2 capture 1000 comprising an absorber tower 100 for use in CO2 capture comprising an absorber column 100A having a first end 101 and a second end 102; a first inlet 111 for C02-containing gas to be treated; a second inlet 112 for CO2 solvent; a first outlet 121 for CCh-lean gas, the first outlet arranged at the second end of the column; a second outlet 122 for CCh-rich solvent liquid; a plate 150 containing a plurality of perforations 151, wherein the plate is arranged in the absorber column by the second end; and, at least one gas filter 160 comprising a separator inserted in one of the perforations in the plate. The illustrated aspect of the system further comprises a desorber tower 200 comprising a desorber column 200A in fluid communication with the absorber tower, the desorber column having a first end 201 and a second end 202; a first inlet for CCh-rich solvent liquid 211; a first outlet for CO2 solvent 221, and a second outlet for CO2 gas 222. As will be discussed in more detail below, in some aspects, e.g., including a gas filter assembly 160’ (see, Figs. 5 A and 5C). the system includes a drain line 192

[0030] The illustrated aspect of the system 1000 also includes a solvent loop 500 and an optional cross flow heat exchanger 600. The solvent loop provides for passing CCh-rich solvent liquid from the absorber tower through second outlet for CCh-rich solvent gas 122 along conduit 502A to either the desorber tower via conduit 502B and first inlet for CCh-rich solvent liquid 211 (wherein, in the desorber tower, the CCh-rich solvent liquid can be treated, e.g., heated, subjected to decreased pressure, treated with inert gas(es) to form CCh-lean gas and CCh gas), or, after passing through the cross flow heat exchanger 600, CCh-rich solvent liquid passes back to the absorber tower along conduit 502C through second inlet for CCh solvent 112, and passing CCh-lean gas from the desorber tower through first outlet for CCh solvent 221 along conduit 501 A. and after passing through the heat exchanger 600. CCh-rich solvent liquid passes back to the absorber tower along conduit 50 IB through second inlet 112, that is also conduit 502C.

[0031] At the downstream of the absorber tower 100 at second outlet 122, the CCh-rich solvent passing along conduit 500A is pumped through a crossflow heat exchanger 600 where it is preheated by regenerated CCh-lean gas to minimize energy input. In the desorber tower 200, the CCh is removed from the heated steam solvent, e.g., at a temperature of about 120°C, supplied in a reboiler (external to the system 1000). The solvent is evaporated in the reboiler and the vapor enters the desorber tower 200 and is pumped through the cross flow heat exchanger 600 and heats up the CCh-rich solvent liquid that enters the desorber tower 200 at the top. The CCh-rich solvent liquid from the reboiler is fed back to the top of absorber tower 100, in some aspects with flow rate from 4 to 16kg / kgCCh to achieve more than 90% CCh removal.

[0032] Absorber tower 100 is also illustrated with a treatment assembly 130 including an absorber stage wherein CCh in the gas stream is contacted with a solvent to form CCh-rich (and solvent rich) solvent liquid and CCh-lean (and solvent lean) gas. A variety of treatment assemblies and solvents for use in CCh capture, are known in the art. Typical treatment assemblies comprise packed columns filled with porous packing material (for example, Mellapak™, e.g., Mellapak Plus™ 252Y (Sulzer; Winterthur, Switzerland)), wherein the packed column has a suitable height (e.g., in the range of 2-8 m, to provide a desired absorption of CCh to solvent). Typical solvents include amines (e.g., monoethanolamine (MEA), diethanolamine (DEA), methyl diethanolamine (MDEA)), Piperazine with the Advanced Stripper™ (PZAS™) or an aqueous solution of alky animes, or carbonates.Desirably, the solvent enters the top section of the treatment assembly (column) and flows downwardly, absorbing CO2.

[0033] Desirably, the CCh-lean gas is treated with one or more stages of water and / or acid washes at washing assembly 140. that typically includes at least one pump 141 and a cooler 142. A variety of washing assemblies are known in the art. Typically, washing assemblies include a packed bed with a pump around the water to condense and solubilize volatile solvent.

[0034] A typical configuration of the washing assembly in accordance with an aspect of the invention has two sections: a lower water wash section, and a supplementary upper acid wash section. The lower section is for treating the gas comprising solvent vapor (e.g., amine vapor) and other environmentally hazardous components. Those are removed by contacting recycled water while makeup fresh water is supplied from the top of the water wash section. A part of the recycled water is returned to the process for amine recovery7, while the other part is delivered to a wastewater facility.

[0035] If the treated gas contains beyond regulation limits of amines and / or hazardous aerosols, the supplementary upper acid water wash section can be used for additional treatment. Typically, if needed, a higher packed bed height and a lower recycled water temperature in the water wash section can decrease the amount of amine emissions.

[0036] In accordance with aspects of the invention, operating the system includes removing aerosols from the CCh-lean gas by passing the gas via outside-in flow (flow from the exterior surface of the hollow cylindrical microporous medium through the interior surface) through one or a plurality of gas filters, wherein the filtered gas is subsequently passed from the hollow interior of the cylindrical microporous medium through the second outlet 121 and out of the absorber (e.g., passed to the atmosphere), and aerosols (e.g., including water and CCh-rich solvent) drain off the exterior surface of the hollow cylindrical microporous medium. Thus, the illustrated aspect of the system 1000 includes a perforated plate 150 containing a plurality of perforations 151 (see, for example. Figs. 2 and 3), wherein the plate is arranged in the absorber column 100 A by the second end 102; and gas filters 160 comprising separators are inserted in separate perforations in the plate.

[0037] Aspects of the invention can include any number of gas filters and any arrangement of gas filters. While at least one gas filter is used, typically, 2 or more gas filters are utilized. In one example, a system with a flow rate of 125,000 m3 / hr will have 78 gas filters, in some aspects, with the gas filters in parallel (see, e.g., Fig. 2).

[0038] Since the gas filter(s) are within the absorber tower near the second outlet 121, where the aerosols are small and the gas is at near-atmospheric pressure, the gas filters can operate at a reduced pressure drop (in contrast with pressure losses associated with, for example, Brownian diffusion devices and / or external filter devices in housings external to the absorber tower). Additionally, this can allow a reduction in the number of water and acid wash stages while meeting stringent requirements to limit atmospheric emissions.

[0039] CO2 gas (produced in the desorber wherein the CCh-rich solvent liquid can be treated (e.g., treated according to one or more of any of the following: heated, subjected to decreased pressure, flash desorption, treated with inert gas(es)) to form CCh-lean gas and CO2 gas) passed via second outlet 222 of the desorber column 200 can be subsequently processed (e.g., transported and one of more of compressed, stored and / or utilized in various applications, for example, enhanced oil recovery or production of desired chemicals), without passing directly to the environment.

[0040] Figures 4A-4C. 5A-5E show an illustrative gas filter 160 comprising a separator comprising a hollow cylindrical microporous medium 161 in accordance with an aspect of the invention. 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. Desirably, the separator medium, e.g., a microporous membrane, has a critical wetting surface tension (CWST. as defined in, for example, U.S. Patent 4,925,572) lower than the surface tension of the solvent (that absorbs the CO2). Typically, a microporous PTFE membrane used in the gas filter has a CWST in the range of 25-30 dynes / cm (25-30 x 10'5N / cm).

[0041] The microporous membrane can have any suitable pore structure, e.g., a pore size (for example, as evidenced by bubble point, or by KL as described in, for example, U.S.Patent 4,340,479, or evidenced by capillary condensation flow porometry), a mean flow pore (MFP) size (e.g., when characterized using a porometer, for example. a Porvair Porometer (Porvair pic, Norfolk, UK), or a porometer available under the trademark POROLUX(Porometer.com; Belgium)), a pore rating, a pore diameter (e.g., when characterized using the modified OSU F2 test as described in, for example, U.S. Patent 4,925,572), or removal rating media. Typically, the membrane has a pore size in the range of 0.2 micrometers to 0.6 micrometers, preferably 0.5 micrometers to 0.6 micrometers.

[0042] In the aspects shown in Figures 4A-4C (see also. Figs. 2, 5A-5E), the gas filter 160 comprises the microporous medium 161 (shown as a hollow cylindrical pleated medium) arranged between an upper (facing the second gas outlet 121) end cap 164 and a lower (facing the treatment assembly 130) end cap 167, typically, wherein the upper end cap 164 is open. Typically, as shown in the Figures, the upper end cap 164 has an outer diameter greater than the inner diameter of the perforations 151 and / or the upper end cap has tabs on the outer diameter for supporting the filters in position in the perforated plate.

[0043] The lower end cap 167 can be open or closed; preferably, open. Typically, the lower end cap 167 is connected to an element providing a drain to allow liquids from the environment (e.g., rain) to be directed away from the interior of the element column. In the illustrated aspect of the gas filter (see, Figs. 2, and 5B), a gasket 166A is arranged betw een 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 ease of installing the gas filter into and / or for removing the gas filter from, the perforated plate.

[0044] Desirably, as shown in Figure 5B, aspects of the gas filter 160 include an inner hollow^ cylindrical perforated core 162 (illustrated as a screen) allowing through flow wherein an outer cage 163 (e.g., for handling and / or protection) is optional, and the core or screen is inserted in the hollow interior of the microporous medium 161, and the medium can be surrounded by the outer cage, if present. In some aspects, the gas filter includes support and / or drainage layers (e.g., each layer comprising a mesh) on either side of the microporous medium, e.g., between the core and the microporous medium and / or between the microporous medium and the cage (if present).

[0045] In accordance with the aspect shown in Figures 2 and 4A, the opening in the lower endcap can be connected to a one-way flow7valve 170 (such as, for example, a check valve, a duck-bill valve, float valve, or water lock device). In this type of drain, liquids from the environment are drained into the absorber tower (the one-way flow valve can open at adesired target pressure, e.g., 2 mbar) and the liquids mixed with the separated aerosols, wherein, if desired, the water combined with aerosols can be processed with the solvent.

[0046] Figure 5 A (see also, Figs. 5C-5E) is a drawing showing a perspective of a gas filter assembly 160' comprising a plurality of gas filters 160 for filtering CCh-lean gas according to another aspect of the invention, the gas filter assembly having a common drain 190 and further comprising separate conduits 168 (each conduit having a first end 168A and a second end 168B), each separate conduit 168 in fluid communication with a separate gas filter 160. In accordance with the aspect shown in Figures 5B and 5D, the projection including an opening in each lower endcap is surrounded by a gasket 166B that seals against drain cup 197 that is in fluid communication with common drain 190 within the absorber column. The common drain of the gas filter assembly has a plurality of connections, conduits and drain cups, with a separate conduit and drain cup for each gas filter element in the assembly. The purpose of the common drain is to collect environmental liquids and drain them through drain outlet 191 (see, for example, Figure 5E) and from the absorber tow er 100 along drain line 192 (see, Figs. 1 and 5 A), so these liquids don’t mix with the solvents in the absorber tower.

[0047] Optionally, as shown in Figures 5 A, 5C, and 5D, the gas filter assembly 160’ can include a frame 195 comprising a number of arms 196 in a variety of configurations (e.g., radial and / or star-shaped) attached to drain cups 197 below each gas filter 160 to provide support for the gas filters.

[0048] A variety of gas streams, e.g., flue gas streams, can be processed to capture CO2 according to aspects of the invention. In some aspects, the gas stream, e.g., a flue gas stream, is cooled (for example, in a cooling tower) before passing it into the absorber column.

[0049] The following example further illustrates the invention but, of course, should not be construed as in any way limiting its scope.EXAMPLE

[0050] This example demonstrates efficient aerosol removal by a gas filter according to an aspect of the invention. In a gas filter (generally corresponding to the configuration shown in Figs. 4A-4C) comprising a hollow cylindrical pleated microporous PTFE membranehaving a mean pore size of about 0.6 micrometers having a CWST of about 29 dynes / cm (about 29 x 1 O’5N / cm) with a diameter of 1 m and a height of 25m, flue gas enters the gas filter via outside-in flow at an approximate flowrate of 1.5M Nnf’ / h, with approximately 12% CO2 loading. The pressure drop is in the range of 7-10 mbar. The flue gas, with CO2 removed, exits the gas filter by direct venting to the air after only 1 water wash stage to remove vapor-phase aerosols. Directly before entering the gas filter, there are 1 g / Nm3aerosols, with an average droplet diameter of 0.5um. Directly downstream after the gas filter, there is <1 mg / Nm3of liquid present in the vented gas.

[0051] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0052] The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be constmed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B”) is to be constmed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0053] Preferred aspects of this invention are described herein, including the best mode know n to the inventors for carrying out the invention. Variations of those preferred aspects may become apparent to those of ordinary' skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law-. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted bv context.

Claims

CLAIM(S):1 . An absorber tower for use in CO2 capture comprising:(a) an absorber column having a first end and a second end; a first inlet for CCh-containing gas to be treated; a second inlet for CO2 solvent; a first outlet for CO2-lean gas. the first outlet arranged at the second end of the column; and a second outlet for CCh-rich solvent liquid;(b) a plate containing a plurality of perforations, wherein the plate is arranged in the absorber column by the second end; and,(c) at least one gas filter comprising a separator comprising a hollow cylindrical microporous medium, wherein the at least one gas filter is inserted in one of the plurality of perforations in the plate.

2. The absorber tower of claim 1, wherein the at least one filter comprising a separator comprises a hollow cylindrical pleated microporous membrane, the filter 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 CCh-lean gas at the second end of the absorber column.

3. The absorber tower of claim 1 or 2, including a plurality of gas filters, each of the plurality of gas filters inserted in a separate one of the plurality of perforations in the plate.

4. A system for CO2 capture comprising: the absorber tower of any one claims 1-3, and a desorber tower in fluid communication with the absorber tower, the desorber column having a first end and a second end; a first inlet for CCh-rich solvent liquid; a first outlet for CO2 solvent, and a second outlet for CO2 gas.

5. The system of claim 4, further comprising a heat exchanger in fluid communication with the absorber tower and the desorber tower.

6. A method for removing aerosols from CCh-lean gas in an absorber column, the method comprising:(a) producing CCh-lean gas in the absorber column;(b) passing the CCh-lean 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 passing the CCh-lean gas through the gas filter removes aerosols from the CCh-lean gas, providing an aerosol-reduced CCh-lean gas; and(c) passing the aerosol-reduced CCh-lean gas from the absorber column through a gas outlet into an environment external to the absorber column.

7. The method of claim 6, comprising at least 99.97% aerosol removal for 0.3 micron-sized aerosols at a differential pressure in the range of 1 to 20 mbar.

8. The method of claim 6 or 7 including removing solvent from the CCh-lean gas.

9. The method of any one of claims 6-8 wherein producing CCh-lean gas in the absorber column includes contacting a gas stream with solvent to form CCh-rich solvent liquid and CCh-lean gas and treating the CCh-lean gas with one or more stages of water and / or acid washes, before passing the CCh-lean gas through the gas filter.

Images