ADSORBER STRUCTURE FOR GAS SEPARATION PROCESSES

Abstract

A device for the separation of a carbon dioxide of a gas stream by using a bed of particulate adsorber particles contained in a sorbent particle volume, comprising at least two inlet channels and at least two outlet channels in said sorbent particle volume, the inlet channels and outlet channels mutually intertwining at least partly to form a nested structure and being arranged parallel to each other. The inlet channels and outlet channels are alternatingly arranged in both lateral dimensions so that the sorbent particle volume is confined by the interspace defined by adjacent side walls of inlet and outlet channels. Further, the sorbent particle volume surrounds the channels circumferentially.

Claims

1. A device for the separation of at least one gaseous component of a gas stream containing said at least one component as well as further different gaseous components, by using a bed of loose particulate adsorber particles contained in at least one sorbent particle volume, said gas stream entering the device at an upstream end thereof and exiting the device as a gas outflow at a downstream end thereof, said device comprising: at least two inlet channels as well as at least two outlet channels being in said sorbent particle volume, wherein the inlet channels and outlet channels being mutually intertwined at least partly to form a nested structure in said sorbent particle volume and being arranged with their principal axes all essentially parallel to each other, wherein said inlet channels have at the upstream end at least one inlet opening through which said gas stream enters the device, and being closed to airflow at the downstream end, wherein said upstream end and downstream end of the inlet channels are connected by one or a plurality of side walls circumferentially enclosing and forming said inlet channel in said sorbent particle volume; wherein said outlet channels are closed at the upstream end and have at the downstream end at least one outlet opening through which the gas outflow is exiting the device, wherein said upstream and downstream end of the outlet channels being connected by one or a plurality of side walls circumferentially enclosing and forming said outlet channel in said sorbent particle volume; wherein said side walls are permeable to the gas stream but impermeable for said loose particulate adsorber particles, and wherein, viewed along their axes, inlet channels and outlet channels are alternatingly arranged in both lateral dimensions so that said sorbent particle volume is confined by the interspace defined by adjacent side walls of inlet channels and neighbouring outlet channels and said sorbent particle volume surrounding the channels essentially circumferentially around their principal axes.

2. The device according to claim 1, wherein it comprises one single contiguous sorbent particle volume.

3. The device according to claim 1, wherein the cross-sectional shape of at least one of the inlet channels and of the outlet channels is circular, oval, polygonal, or a combination thereof.

4. The device according to claim 1, wherein the cross-sectional shape of at least one of the inlet channels and of the outlet channels is essentially the same in the sense of geometrical similarity or exactly the same, along the axial length thereof between the upstream end and the downstream end.

5. The device according to claim 1, wherein the cross-sectional shape of the inlet channels and of the outlet channels is triangular, square or a regular hexagon.

6. The device according to claim 1, wherein the inlet channels are closed at their downstream end by a laterally arranged end plate, and wherein the outlet channels are closed at their upstream end by a laterally arranged end plate.

7. The device according to claim 1, wherein the side walls are provided by a mesh or grid structure, the mesh width of which is smaller than the smallest particle size of said particulate adsorber particles.

8. The device according to claim 1, wherein the inlet channels are formed by inlet strainers or the outlet channels are formed by outlet strainers.

9. The device according to claim 1, wherein the inlet channels as well as the outlet channels are enclosed by a circumferential enclosing wall as well as an upstream and downstream axial wall.

10. The device according to claim 1, wherein it contains at least one, or two apertured plates arranged perpendicular to the axes of the channels.

11. The device according to claim 1, wherein the interspace between all the side walls of the channels of the device forms one single contiguous interspace, suitable and adapted to be filled with and or emptied from the particulate adsorber particles.

12. The device according to claim 1, wherein the particulate adsorber particles are amine functionality carrying polymer-based or inorganic particles suitable and adapted for carbon dioxide capture or are at least partly inorganic, organic or active carbon based particles.

13. A method for assembling a device according to claim 1, wherein inlet strainers and outlet strainers forming the inlet and outlet channels, respectively, are produced individually in a first step, and wherein the strainers are subsequently mounted in a carrier structure to form the device, and wherein subsequently the contiguous interspace between the strainers is filled with the particulate adsorber particles to form the sorbent particle volume, with or without mechanical agitation once the particulate adsorber particles are within the interspace.

14. The method according to claim 13, wherein there is provided at least one, or at least two, an upstream and downstream, apertured plate, wherein the inlet strainers and the outlet strainers are shifted into corresponding apertures of respective apertured plates and fixed in this position.

15. A method of capturing at least one of carbon dioxide and water vapor from a gas stream using a device according to claim 1.

16. The device according to claim 1, wherein it is for the separation of at least one of carbon dioxide and water vapour from an air stream

17. The device according to claim 1, wherein it comprises one single contiguous sorbent particle volume, and wherein the minimum thickness thereof, defined as the distance between adjacent side walls of neighbouring inlet and outlet channels, is at least 5 mm, or at least 7 mm, or at least 10 mm, or at least 15 mm or the thickness thereof is in the range of 5-50 mm, 5-25 mm or 10-30 mm or 7-18 mm.

18. The device according to claim 17, wherein the thickness is given over at least 70% of the side walls, or over at least 80%, or 90% of the side walls, or over all of the side walls in the device.

19. The device according to claim 17, wherein said sorbent particle volume is surrounding the channels circumferentially around their principal axes over at least 70% or at least 90% or over essentially the whole of their axial length.

20. The device according to claim 1, wherein the cross-sectional shape of at least one the inlet channels and of the outlet channels is triangular, rectangular or hexagonal.

21. The device according to claim 1, wherein the cross-sectional shape of at least one the inlet channels and of the outlet channels forming a regular triangle, square or a regular hexagon.

22. The device according to claim 1, wherein the flow area factor of the device, defined as the ratio of the cumulative flow through area of the channels to the incident cross section of the adsorber structure is greater than 5:1 or greater than 15:1, or greater than 20:1 or 25:1.

23. The device according to claim 1, wherein the cross-sectional shape of at least one the inlet channels and of the outlet channels is essentially the same in the sense of geometrical similarity or exactly the same, along the axial length thereof between the upstream end and the downstream end, wherein the size of this cross-sectional shape is decreasing from the upstream end to the downstream end in case of the inlet channels and the size of the cross-sectional shape is increasing from the upstream end to the downstream end in case of the outlet channels.

24. The device according to claim 23, wherein from the upstream end to the downstream end the cross-sectional shape reduces in area in the range of 5-50% for the inlet channels and from the downstream end to the upstream end in area in the range of 5-50% for the outlet channels, or wherein the opening angle (a) of the inlet and/or outlet channels, defined as the average angle between opposite sidewalls thereof, is in the range of 0-60°, or in the range of 0.2-30° or 2-15°, or in the range of 0.2-2° or 3-7°.

25. The device according to claim 1, wherein the size of the cross-sectional shape of the inlet channels and of the outlet channels at any given longitudinal position of the device is essentially the same for all channels.

26. The device according to claim 1, wherein the size of the cross-sectional shape is essentially the same at any longitudinal positions just for the inlet channels and respectively essentially the same at any longitudinal positions just for the outlet channels.

27. The device according to claim 26, wherein the size of the geometrically similar cross-sectional shapes is, continuously, increasing in a downstream direction for the outlet channels and is, continuously, increasing in a upstream direction for the inlet channels.

28. The device according to claim 1, wherein adjacent side walls of neighbouring channels are arranged parallel to each other, forming a regular tessellation with interspaces in the lateral directions, with either essentially the same lateral distance at any given longitudinal position between distanced adjacent inlet and outlet channels, or with adjacent inlet and outlet side walls forming sorbent particle layers of a lateral thickness which is varying over the longitudinal direction by at most 50%, or at most 30%.

29. The device according to claim 1, wherein the inlet channels are closed at their downstream end by a laterally arranged end plate and wherein the outlet channels are closed at their upstream end by a laterally arranged end plate, wherein these end plates are provided with means for mounting strainers forming the channels in a carrier structure.

30. The device according to claim 1, wherein the side walls are provided by a mesh or grid structure, the mesh width of which is smaller than the smallest particle size of said particulate adsorber particles, wherein the mesh is a wire grid, including a metal or polymer wire grids.

31. The device according to claim 30, wherein the side walls are provided by a mesh or grid structure with an aluminium or stainless steel metal wire grid.

32. The device according to claim 7, wherein there are provided two layers of grid, one first layer or cage with a grid mesh width which is substantially larger than the smallest particle size of said particulate adsorber particles, acting as a carrier grid or cage, and mounted thereon, on the side facing the particulate adsorber particles, a second layer with a grid wire, including metal wire or polymer fibres having mesh width smaller than the smallest particle size of said particulate adsorber particles, acting as retaining grid.

33. The device according to claim 32, wherein the wire thickness of the carrier grid is larger than the wire thickness of the retaining grid with or without further supporting grids integrated into the air channels.

34. The device according to claim 8, wherein the inlet channels are formed by of inlet strainers and the outlet channels are formed by outlet strainers, as separate structural elements, and wherein the device contains at least four, or at least eight, or at least 16 or at least 100 inlet strainers and at least four, or at least eight, or at least 16 or at least 100 outlet strainers.

35. The device according to claim 8, wherein there is an equal number of inlet strainers and outlet strainers, and wherein the device is surrounded by a circumferential enclosing wall and offering a gas seal against a containing structure housing the device.

36. The device according to claim 1, wherein the inlet channels as well as the outlet channels are enclosed by a circumferential enclosing wall as well as an upstream and downstream axial wall, said walls having a circumferential flange abutting against another flange of a containing structure housing the device, and wherein the device can be opened on the upper side, or is provided with at least one media connection, by way of which the interspace forming the sorbent particle volume can be filled with said particulate adsorber particles and at least one further lower media connection or re-sealable opening, on the lower side, through which the particulate adsorber particles can be emptied.

37. The device according to claim 1, wherein it contains at least one, or two apertured plates arranged perpendicular to the axes of the channels, formed by strainers, with apertures into which the strainers can be shifted, wherein there is provided an upstream apertured plate with suitably adapted apertures into which the inlet strainers can be shifted and held by fixing means and/or force closure and/or positive engagement, in that at the inlet opening of the inlet strainers there is provided a lateral flange for abutment and fixing on the apertured plate and between these apertures the upstream ends of the outlet strainers are mounted, and there is provided a downstream apertured plate with suitably adapted apertures into which the outlet strainers can be shifted, and held by fixing means and/or force closure and/or positive engagement, in that at the outlet opening of the outlet strainers there is provided a lateral flange for abutment and fixing on the apertured plate and between these apertures the downstream ends of the inlet strainers are mounted.

38. The device according to claim 1, wherein the interspace between all the side walls of the channels of the device forms one single contiguous interspace, suitable and adapted to be filled with and emptied from the particulate adsorber particles in a state in which all the channels in the form of strainers, are mounted in the device.

39. The device according to claim 1, wherein there is provided at least one heat exchanger structure in or at the device running at or through the sorbent particle volume, in the form of plates, tubing, for circulation of a heat exchange gas and/or liquid, fins, or a combination thereof.

40. The device according to claim 1, wherein the particulate adsorber particles are amine functionality carrying polymer-based or inorganic particles suitable and adapted for carbon dioxide capture or are at least partly inorganic, organic or active carbon based particles, functionalised with alkali carbonate or with amine functionality suitable and adapted for carbon dioxide capture or metal organic frameworks.

41. The device according to claim 1, wherein the particulate adsorber particles have a particle sizes in the range of 0.01-5 mm or in the range of 1-20 mm and have the property of flowing without substantial mechanical attrition and the carrier structure of which is selected from the group of polymers, ceramics, organic solids, zeolites, metals, clays, capsules or hybrids thereof.

42. The method according to claim 15, wherein the gas stream is a flue gas stream, a greenhouse gas, or atmospheric air gas stream.

43. The method according to claim 15, wherein it is captured in a pressure and/or temperature and/or humidity swing process.

44. The device according to claim 2, wherein the cross-sectional shape of at least one of the inlet channels and of the outlet channels is circular, oval, polygonal, or a combination thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Preferred embodiments of the invention are described in the following with reference to the drawings, which are for the purpose of illustrating the present preferred embodiments of the invention and not for the purpose of limiting the same. In the drawings,

[0080] FIG. 1 shows in a) a front section view of a variant of this invention with inlet and outlet channels and a sorbent volume occupying the space between them, the front section view is a cut about at the longitudinal center of the device where the shapes of the inlet and the outlet channels have essentially the same size, in b) an arrangement of strainers (just inlet-section and outlet section) to have sorbent material fill the cavities between strainers and have air pass through as it enters from one side, in c) an exemplary arrangement of a plurality of strainers (just inlet-section and outlet section) in a casing to be placed within a contactor chamber and aerated in longitudinal direction;

[0081] FIG. 2 shows a side section view of a possible variant of this invention with inlet and outlet channels and a sorbent volume occupying the space between them;

[0082] FIG. 3 shows cuts perpendicular to the longitudinal direction through a device viewed from the inlet side, wherein in a) a cut at a longitudinal position closer to the inlet side is given, where the cross section of the inlet channels is larger than of the outlet channels, in b) a cut at a longitudinal position about half way, where the cross section of the inlet channels is the same as of the outlet channels, and in c) a cut at a longitudinal position closer to the outlet side, where the cross section of the outlet channels is larger than of the inlet channels;

[0083] FIG. 4 shows a comparison of the normal gas flow velocity v for variants with a) tapered and b) parallel wall inlet channels in a diagram c);

[0084] FIG. 5 shows a front view of an adsorption structure mechanically integrated into a containing structure;

[0085] FIG. 6 shows breakthrough curves of CO.sub.2 when passed through an adsorber structure according to this invention with a) being the inlet CO.sub.2 concentration and b) the outlet concentration;

[0086] FIG. 7 shows a cross sectional view of a) looping and b) single pass heat exchanger conduits integrated into the contiguous sorbent volume superimposed on the strainer wall including distributor plenums;

[0087] FIG. 8 shows a front view of the adsorber structure with heat exchanger conduits integrated into the contiguous sorbent volume between the air inlet and outlet channels partially shown with two forms of fins spanning at least one heat transfer conduit and including the special case of heat transfer conduits placed in inactive zones; and

[0088] FIG. 9 shows a cross sectional view of a movable heat exchanger integrated into air channels contacting the walls of the strainers.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0089] FIG. 1 in a) shows a cross section view through one possible adsorber structure 1 based on this invention in a direction parallel to the air flow and viewed from the direction of inlet gas flow 2 showing five inlet 3 and four outlet gas 4 channels separated each by a layer of sorbent material 5 occupying the space between the gas channels and the circumferential wall 6 and forming the contiguous sorbent particle volume. Gas flow 2 enters the gas inlet channels 3 and as these are impermeable to gas flow at their distal extremity but permeable laterally to the gas flow through the sorbent material layer 5, the gas flow is radially distributed through the sorbent material volume 5 and penetrates it. In this example, the gas channels are seen to be square in cross section and arranged such that flat faces of adjacent gas channels are parallel forming thusly a circumferential sorbent layer of essentially homogenous thickness. The sorbent material is in this example injected into and in a further step can be removed from the adsorber structure by the connections 7 located at the top and bottom of the adsorber structure 1 respectively which offer a media connection into the space 5a between the gas channels 3, 4 and the circumferential wall 6. To support the filling and removal of sorbent material, the gas channels 3, 4 in this example are arranged such that no faces are strictly perpendicular to the global direction of filling or emptying of sorbent; thereby assuring that sorbent material for example filled from the top of the adsorber structure 1 will fill progressively all available spaces in the adsorber structure 1 without forming empty pockets.

[0090] FIG. 1 b) schematically shows a sectioned view in a perspective of an arrangement of five grid/strainer structures (for example four inlet 15a and one outlet 15b) or strainers forming the interspace 5a for the granulate adsorbent volume 5 and to have loose particular sorbent material fill the interspace 5a between the strainers 15 further having mesh sidewalls 17 impermeable to the sorbent material but permeable for gas flow. Impermeable end caps 9 are shown as well as the inlet flange 26 of the inlet opening 16 of the inlet strainer; both elements being used for fixing the strainers in the relevant aperture plate (not shown). For clarity, in this figure, the surrounding circumferential wall 6 which would contain the adsorbent volume 5, and seal against the containing structure 14, is not shown. Further the channels shown in the split sections are aligned along the longitudinal axis 21.

[0091] FIG. 1 c) shows a split view of an exemplary arrangement of a plurality of inlet 15a and outlet 15b strainers affixed in two aperture plates 18 having holes 19 for fixing the strainers and enclosed in a circumferential wall 6 (only top plate of circumferential wall shown) to be placed within a contactor chamber and aerated in longitudinal direction. The interspace volume 5a is clearly seen between inlet 15a and outlet 15b strainers, the channels of which have a have differing cross sections at the longitudinal position of the split due to the applied taper.

[0092] FIG. 2 shows a further longitudinal section view of one possible adsorber structure 1 according to this invention in a direction parallel to the air flow and demonstrates the wall flow principle of this invention. An inlet gas flow 2 enters the two inlet gas channels 3 and the due to the lateral/radial permeability of the gas inlet channel 3 formed of a gas permeable circumferential wall 8 of (aluminum or stainless steel) wire mesh and due to the impermeable plug 9 is forced to pass through the sorbent material layer 5 into the neighboring gas outlet channel(s) 4 before exiting the adsorber structure 1 as exiting air stream 22. The inlet channels 3 are in this example tapered with a tapering angle α in a contracting fashion in the global flow direction in such a manner that the axial/lateral velocity of gas does not exceed a specific limiting flow speed and correspondingly the pressure drop—most importantly at the entrance of the inlet channels 3, does not exceed a certain allowable value. The same logic holds for the expanding taper of the outlet channel 4. The inlet and outlet gas channels 3 and 4 at their open ends are held with impermeable rings 10 in their respective axial walls and the space between the channels and the circumferential wall 6 is occupied by sorbent material volume 5 filled through and optionally emptied through the media connections 7.

[0093] FIG. 3 shows exemplary section views of a portion of one possible adsorber structure at three longitudinal positions along a longitudinal axis 21 through a possible adsorber structure containing inlet channels 3 and outlet 4 channels formed for example of strainers and forming thereby an interspace volume 5a. It is to be understood that these sections are portions of a larger adsorber structure having a plurality of such repeated forms. FIG. 3 a) demonstrates the cross section of the inlet 3 and outlet 4 channels at the of close to the upstream end of the adsorber structure where the highest flows in the inlet channels 3 and lowest flows in the outlet channels 4 (both along the longitudinal axis) are expected and correspondingly the inlet channel 3 cross section is larger than that of the outlet channel 4. FIG. 3b) demonstrates the cross section of the inlet channels 3 and outlet channels in the middle of the adsorber structure where the volume flows in the inlet 3 and outlet 4 channels along the longitudinal axis are essentially equal implying the same cross section of the individual channels. Finally, FIG. 3c) shows the outlet end of or close to outlet of the adsorber structure where the flow in the outlet channel 4 is larger than the flow in the inlet channels 3 along the longitudinal axis and correspondingly the former has a larger cross section than the latter. It is seen that the walls of neighboring inlet and outlet channels are parallel and are separated in all three sections by the same distance resulting in a sorbent layer thickness which is constant between inlet and outlet channels over the longitudinal axis of the adsorber structure. Conversely, the distance between the corners of the channels of the same type (e.g. just inlet) is not constant due to the tapered form. Thusly at any longitudinal position, a regular tessellation of channels and sorbent interspace is formed which in the case of tapered channels is unique at each longitudinal position. Were the channels non-tapered, the tessellation would by identical at each longitudinal position.

[0094] FIG. 4 shows the impact of tapered inlet channels against channels of continuous cross section. One possible adsorber structure is shown having inlet channels 3 with a length of 0.9 m, being subjected to a inlet gas flow 2 wherein the inlet channel is impermeable sealed at its distal extremity by the impermeable plug 9 and surrounded in a radial fashion (NB: a section view of the adsorber structure is shown) by a sorbent material volume 5. The gas flow normal velocity v through the permeable wall 8 and correspondingly through the sorbent material is shown in FIG. 4c along the longitudinal length L of the inlet channel 3 for tapered in line a) and parallel (i.e. non tapered) in line b) in FIG. 4c) configurations. It was found that the inhomogeneity of the velocity v can be in a parallel channel variant as given in FIG. 4b) very pronounced when compared against that of the tapered variant as given in FIG. 4a). The result of this inhomogeneity can be inhomogeneous sorbent loading with the desired adsorbate yielding a poor utilization of the sorbent and high specific work costs for moving the gas flow. The tapered variant with yields a more homogenous normal velocity v distribution which firstly reduces the effective pressure drops of the sorbent layer as well as improves the sorbent loading. Further improvements can be foreseen to the variant a) such as a sorbent layer thickness with a variability a along the length L of the inlet channel which would further reduce the increasing tail of the curve a) in FIG. 4c) at the extremity of the channel.

[0095] FIG. 5 shows the one option of mechanical coupling of the adsorber structure 1 with the containing structure 14 for example a vacuum chamber containing an element for propelling air such as fan. Specifically, in this example an adsorber structure 1 comprising a plurality of inlet 3 and outlet channels 4 with square cross section is mechanically affixed at its axial wall 11 by fasteners 12 to a circumferential flange 13 of the containing structure 14. In this manner tilting or displacement of the containing structure 14 under vacuum or transport loads or its own weight can be carried by the axial wall 11 in the manner of a membrane, preventing potentially damaging displacements. This method of construction is particularly useful for polydirectional load in a plane. Further this effective method of fixing the adsorber structure can be well utilized to seal the adsorber structure 1 against the containing structure 14 thereby preventing bypassing.

Example 1. Structure to Sorbent Ratio

[0096] Another possible adsorber structure according to this invention has been analyzed for the ratio of structure to sorbent material and compared to a typical DAC adsorber structure of the prior art with the results shown in the table below:

TABLE-US-00001 Sorbent Structure Mass (kg) Mass (kg) This invention 705 484 Prior Art* 384 533 *e.g. WO2018083109

[0097] The ratio of masses of sorbent to structure for the adsorber structure of this invention structure material is higher than that of the prior art. The higher sorbent mass which can be brought into the adsorber structure of this invention leads to a higher produced CO.sub.2 amount per desorption while the lower structure mass reduces the thermal energy demand for a temperature swing desorption process in.

Example 2. Sorbent Replacement Duration

[0098] The filling and emptying duration for a device as proposed was compared with a prior art adsorber structure having the same substantial envelope dimensions. The adsorber structure of this invention in this example consisted to seven inlet and outlet channels of square cross section and a globally square cross sectional adsorber structure with characteristic dimension according to the hydraulic diameter of 0.65 m and a length of 0.9 m. The adsorber structure was filled with 80 kg of sorbent material suitable for DAC application in 10 min. The structure could also be emptied in 10 minutes. As a comparison, an adsorber structure of the prior art consisting of 14 frame elements built into a stack required a filling time of 140-280 minutes for 65 kg of sorbent (despite the envelope dimensions being equal) and an emptying time of ca. 200 minutes. As such the single sorbent volume feature of this invention leads to enormous time and cost savings for sorbent replacement operations.

Example 3. Proof of Concept of Adsorber Structure

[0099] The invention herein disclosed has been tested for adsorption performance with a common amine functionalized DAC sorbent material. Said adsorber structure was realized with 100 inlet and 100 outlet channels realized with a tapering square cross section and forming a spacing of 28 mm between porous walls of the air channels substantially along the complete 1.1 m length of the channels. The ratio of the through flow area of the channels to the incident flow area of the adsorber was in this case 19.3 producing a corresponding reduction in the gas flow velocity through the sorbent material by this factor. The structure was filled with a common sorbent material suitable for DAC based on the prior art (WO2019092127) having pellets of mean particle size of 0.8-1.4 mm utilizing an alkali carbonate functionalization and having a BET surface area less than 500 m2/g and a mean pore diameter in the range of 2-50 nm and exposed to an airflow of 20 000 Nm3/h. A typical breakthrough curve under adsorption was recorded and is shown in FIG. 6 for the uptake of CO2 from atmospheric air with a) showing the inlet CO2 concentration to the adsorber structure and b) the outlet concentration from the adsorber structure. A pressure drop over the complete adsorber structure of 345 Pa was recorded and an attractive CO2 uptake over the duration of a possible CO2 adsorption stage of 4 hours was demonstrated proving the suitability of the adsorber structure for DAC applications. As an aside, because the adsorber structure of this invention has significantly fewer sealing points against prior art structures, it is foreseeable, that its performance will remain constant whereas that of prior art structures could over time deteriorate due to the growth of bypassing zones leading to an overall decrease in CO.sub.2 capture efficiency.

[0100] In a further investigation, the adsorber structure of this example was filled with a second common sorbent material suitable for DAC based on spherical polymer granules of mean particle size of 0.5-0.8 mm utilizing a primary amine functionalization having an amine concentration of greater than 2 eq/L, but having a different pore architecture characterized by 30-50 m2/g specific BET surface area and a more nano-porous pore size in the range of 20-50 nm. To adapt to the presumed higher uptake kinetics of this sorbent, a higher gas flow rate of 28,000 Nm3/h was applied to the adsorber structure while a reduced sorbent material layer of 21 mm was used to retain the pressure drop at a manageable level. Surprisingly the breakthrough curve of this modified structure and sorbent combination was largely the same as that of FIG. 6 while the pressure drop increased to 380 Pa. This example shows further the superb capabilities of the disclosed invention to be very easily adapted to different operating points and sorbent characteristics.

[0101] FIG. 7 shows two possible realizations of a heat exchanger integrated into the proposed adsorber structure wherein in a), a looping realization of the conduit 27 is applied and shown superimposed on an inlet air channel 3 which borders a sorbent particle volume 5 by a permeable wall of a strainer 8. The heat transfer fluids inlet 29a and outlet 29b are contained in the same distributor plenum 28 in this case from the same side of the adsorber structure. In b) the single pass heat transfer fluid conduits are fed from the distributor plenum 28 through the inlet 29a and collected in the distributor at the outlet 29b with both distributor plenums being at both extremities of the adsorber structure. In this example, the main axial direction of the conduits follows the main axis of the air channels 21, but could equally well be placed unaligned with this axis.

[0102] FIG. 8 shows the front view of the adsorber structure at a particular cross section with the heat exchanger conduits 27 distributed in the interspace 5a for the sorbent particle volume 5 around the inlet 3 and outlet 4 channels. In this example, the conduits are not in contact with the strainer walls of the inlet or outlet channels and are substantially centered in the interspace 5. For illustrative purposes, certain conduits have fins 30, which in this example are shown to enclose single conduits as well as three conduits. The special conduits in the inactive zone of the adsorber structure 31 are also shown, where there is no air flow expected in the adsorption and correspondingly inactive sorbent.

Example 4. Dimensioning of a Heat Exchanger for an Adsorber Structure

[0103] In this example, one possible variant of the adsorber structure with a heat exchanger is presented wherein the conduits pass a heat transfer fluid and are affixed to the strainer walls—these being realized with a wire mesh—on both the inlet and outlet air channels of the strainers. In this example, the adsorber structure has dimensions of 0.6×0.6×0.6 m (width, height, depth) and a sorbent capacity of 70 kg. The thermal conductivity of the granular sorbent material is assumed to be around 0.08 W/mK. The strainers in this example use a constant square cross section of 45 mm at the inlet opening 16 and outlet opening 20 respectively and are separated by a sorbent material layer of 30 mm giving 8 strainers per transverse direction or a total 128 (as seen from one end of the adsorber structure) inlet and outlet strainers respectively. For this geometry, conduits of 4 mm outer diameter are placed on the strainer walls with a spacing of 11 mm leading to 3 conduits per inlet or outlet strainer wall or 12 conduits per inlet or outlet strainer which are in this example thermally connected with the wire mesh leading to a specific heat transfer surface area of 0.27 m.sup.2/kg sorbent. In this adsorber structure 5.4 kg (i.e. less than 1%) of sorbent material are displaced by the herein described heat exchanger. If the conduits for the heat transfer fluid are realized in the looping embodiment, a distributor plenum will have 128 heat transfer fluid connections for example at the air inlet extremity of the adsorber structure and built into the apertured plate. FIG. 9 shows one possible variant for a movable heat exchanger integrated into the air channels in the desorption. The air channel heat exchanger elements 32 can be inserted into the inlet 3 and outlet 4 air channels such that their outer surface 33b is contacted with permeable walls of the strainers 8. Further an inlet flow of heat transfer fluid 29a—in this example steam—is injected into the heat exchanger such that it contacts the inner surface 33a, thereby delivering heat from the heat transfer fluid through the walls of the heat exchanger, the walls of the strainer and into the sorbent.

TABLE-US-00002 LIST OF REFERENCE SIGNS  1 adsorber structure  2 gas inflow  3 inlet channel  4 outlet channel  5 sorbent particle volume  5a interspace for 5  6 circumferential wall of the whole structure  7 media connections  8 permeable wall of strainer  9 impermeable plug/end cap 10 impermeable ring 11 axial wall 12 fasteners 13 circumferential flange 14 containing structure 15 strainer 15a inlet strainer 15b outlet strainer 16 inlet opening of 15a 17 mesh sidewall of 15 18 apertured plate 19 hole in 18 for 15a 20 outlet opening of 15b 21 axis of strainer, longitudinal direction 22 gas outflow 23 upstream end 24 downstream end 25 lateral directions 26 lateral flange 27 heat exchanger conduits 28 distributor plenum 29a heat transfer fluid inlet 29b heat transfer fluid outlet 30 heat exchanger fins 31 inactive zone conduits 32 heat exchange channel 33a inner surface of heat exchange channel 33b outer surface of heat exchange channel v normal velocity α opening angle σ variability of sorbent layer thickness L length t lateral thickness