Unit design and method for direct capture of carbon dioxide from air

Abstract

Particular implementations of the disclosed subject matter provide a process for capturing carbon dioxide from a gaseous feed stream. The method may include a direct air capture (DAC) unit including a first inlet face and a second inlet face located on opposite sides of the DAC unit. A sorbent material may be located inside the DAC cell and at or behind each of the inlet faces. An outlet may be located at the top of the DAC unit and may provide an exhaust gaseous outlet stream. The exhaust gaseous outlet stream may have a stream generated by at least one fan. The method may include receiving a gaseous feed stream at the inlet face. For any wind direction and any wind speed, the gaseous feed stream may have an average CO2 concentration greater than 95% of the CO2 concentration of ambient air by minimizing reuptake of the exhaust gaseous outlet stream.

Description

Technical Field

[0001] The present invention relates to a direct air capture (DAC) unit design and method for capturing carbon dioxide (CO2) from a gaseous feed stream. More specifically, the present invention relates to a module design and method for capturing carbon dioxide (CO2) from a gaseous feed stream, wherein the gaseous feed stream has an average CO2 concentration greater than 95% of the CO2 concentration of ambient air, and wherein the ambient air has any wind direction and any wind speed. Background Art

[0002] Direct air capture (DAC) of carbon dioxide from the air has been proposed as a solution to human-induced climate change. The current estimated global atmospheric carbon dioxide content is about 420 parts per million. It is expected that by the end of the 21st century, this ratio will rise to about 900 parts per million. Therefore, DAC represents one of a range of technologies that can be used to reduce the impact of greenhouse gases (such as carbon dioxide) on the environment and help the world transition to a low-carbon economy.

[0003] A typical DAC system uses a large amount of air (or gaseous atmosphere under other conditions) as a feed stream that is pumped through a unit containing an adsorbent material that removes carbon dioxide from the feed stream. Over time, the adsorbent is filled with captured carbon dioxide. Next, the carbon dioxide captured in the adsorbent is extracted from the adsorbent in a regeneration step. Regeneration may involve a thermal process or a chemical process, depending on the type of adsorbent material selected for the DAC method. During regeneration, the captured carbon dioxide is released from the adsorbent and can be used to make sustainable fuels, chemicals, for food and beverage production, or for carbon capture and storage (CCS) to create a net negative carbon process. The energy input to the DAC system may include thermal energy in the form of steam, as well as electrical energy for the absorption (passing air through the DAC unit) and regeneration (regenerating CO2 from the adsorbent) steps.

[0004] Generally speaking, DAC is a capital intensive process due to the large amount of air that needs to be processed. Therefore, the production capacity of the DAC unit is highly important in the total cost of the captured CO2. If the production capacity of the DAC unit is reduced, the cost of the captured CO2 will increase. Therefore, it is necessary to maintain the optimal (high) production capacity of the DAC unit to minimize the cost. Summary of the invention

[0005] According to an embodiment of the disclosed subject matter, a method may include a direct air capture (DAC) unit, the DAC unit comprising: a first inlet face and a second inlet face located on opposite sides of the DAC unit. An adsorbent material may be located inside the DAC unit and located at or behind each of the first inlet face and the second inlet face. An outlet may be located at a top of the DAC unit, and the outlet may provide an exhaust gaseous outlet stream. The exhaust gaseous outlet stream may have a flow generated by at least one fan. The method may include receiving a gaseous feed stream at the inlet face, and the gaseous feed stream may have an average CO2 concentration greater than 95% of the CO2 concentration of ambient air, which may have any wind direction and any wind speed.

[0006] A specific implementation of the disclosed subject matter provides a method for capturing carbon dioxide (CO2) from a gaseous feed stream using a DAC unit, wherein the gaseous feed stream has an average CO2 concentration greater than 95% of the CO2 concentration of ambient air, and wherein the ambient air has any wind direction and any wind speed. The disclosed subject matter allows for improved efficiency and reduced costs throughout the DAC process. Additional features, advantages, and embodiments of the disclosed subject matter may be listed or apparent by considering the following detailed description, drawings, and claims. In addition, it should be understood that the foregoing summary of the invention and the following detailed description are examples and are intended to provide further explanation without limiting the scope of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The accompanying drawings, which are included to provide a further understanding of the disclosed subject matter, are incorporated into and constitute a part of this specification. The accompanying drawings also illustrate embodiments of the disclosed subject matter and, together with the detailed description, serve to explain the principles of the embodiments of the disclosed subject matter. No attempt is made to show more detailed structural details than are necessary for a basic understanding of the disclosed subject matter and the various ways in which it can be implemented.

[0008] Figure 1 Exemplary methods and side views are shown in accordance with implementations of the disclosed subject matter.

[0009] Figure 2 An exemplary method and front view are shown according to an implementation of the disclosed subject matter.

[0010] Figure 3 An exemplary method and top view are shown according to an embodiment of the disclosed subject matter.

[0011] Figure 4 An exemplary method and top view are shown according to an embodiment of the disclosed subject matter.

[0012] Figure 5Exemplary methods and side views are shown in accordance with implementations of the disclosed subject matter.

[0013] Figure 6 Exemplary methods and side views are shown in accordance with implementations of the disclosed subject matter.

[0014] Figure 7 Exemplary methods and side views are shown in accordance with implementations of the disclosed subject matter.

[0015] Figure 8 Exemplary methods and side views are shown in accordance with implementations of the disclosed subject matter.

[0016] Fig. 9 An exemplary contour plot of CO2 concentration is shown according to an implementation of the disclosed subject matter. DETAILED DESCRIPTION

[0017] Generally, a problem or disadvantage of DAC units known in the art is the reduction in CO2 production capacity of the module or DAC unit due to the ingestion of CO2 depleted air under different wind conditions. The present invention solves this problem by increasing the CO2 production capacity, thereby resulting in lower CO2 capture costs.

[0018] The present invention is directed to a modular design of a DAC unit for capturing CO2 from air using solid or liquid adsorbents. During the adsorption / absorption process, air flows through the DAC unit via a fan and the air comes into contact with the adsorbent, which then captures CO2 from the air. The CO2-depleted air is discharged to the atmosphere at the outlet. Since DAC is a process that can be utilized on a large scale and is subject to fluctuations in wind speed and direction at a particular location, it is important to prevent the module from re-ingesting the CO2-depleted air that is exhausted at the outlet of the module. This is because the re-ingestion of CO2-depleted air reduces the CO2 production capacity - a problem that the present invention solves.

[0019] According to one embodiment, the present invention minimizes the uptake of CO2-depleted air by the DAC unit for all wind conditions and wind speeds by optimizing several design parameters. The DAC unit according to the present invention is designed in such a way that the average concentration of CO2 at all inlet faces is greater than 95% of the CO2 concentration of the ambient air by minimizing the re-uptake of the exhaust gaseous outlet stream for any and all wind directions and wind speeds, regardless of where the DAC unit may be operating geographically.

[0020] According to one embodiment of the present invention, a method for capturing carbon dioxide from a gaseous feed stream may include a direct air capture (DAC) unit. The DAC unit may include 2 or more inlet faces. For example, the DAC unit may include a first inlet face and a second inlet face, and the first inlet face and the second inlet face may be on opposite sides of the DAC unit. In a specific embodiment, the second inlet face may be a shadow inlet face. When the wind direction is not parallel to the shadow inlet face, the shadow inlet face may be a downwind face. The DAC unit may have at least two faces, at least four faces, and may have more than 4 faces.

[0021] The DAC unit may also include an adsorbent material located at or behind each of the inlet faces, and the adsorbent material may be located inside the DAC unit. The adsorbent material may be a liquid adsorbent material or a solid adsorbent material. Typical liquid adsorbent materials are aqueous solutions of alkali metal hydroxides, amino acids or amines. Typical solid adsorbent materials are alkali metal carbonates or amine components on a support material such as alumina, silica, titania or carbon.

[0022] According to one embodiment, the DAC unit may have a height equal to the distance between the highest point of the DAC unit excluding any protrusions and / or chimneys and the lowest point of the DAC unit excluding void spaces (as further described below). In addition, the DAC unit may have a length equal to the length of the longest of the first and second inlet faces. For example, if the first inlet face has a length of 3m and the second inlet face has a length of 2m, the length of the DAC unit will be 3m, which is equal to the longer length of the first inlet face of 3m. For example, if the first inlet face has a height of 15m and the second inlet face has a height of 13m, the height of the DAC unit will be 15m, which is equal to the distance between the highest point of the DAC unit (excluding any protrusions or chimneys) and the lowest point on the DAC unit (excluding any void spaces). In one embodiment, the DAC unit may have a height / length ratio greater than 0.5, greater than 0.7, and greater than 1.

[0023] When in operation, the DAC unit may receive a gaseous feed stream at each of the first inlet face and the second inlet face. According to the present invention, by minimizing the re-intake of the exhaust gaseous outlet stream, the gaseous feed stream may have an average CO2 concentration greater than 95% of the CO2 concentration of ambient air, and the ambient air may have any wind direction and any wind speed. For example, with respect to wind direction and wind speed, the DAC unit may be operated at any geographical location and may therefore be exposed to any wind direction and any wind speed in the surrounding environment.

[0024] The DAC unit may also include an outlet at the top of the DAC unit. The outlet may provide an exhaust gaseous outlet stream that is discharged back into the ambient air or atmosphere. The exhaust gaseous outlet stream may have a flow generated by at least one fan. Flow as used herein may refer to the movement of a stream, such as a gaseous feed stream and / or the movement of an exhaust gaseous outlet stream. The exhaust gaseous outlet stream is a gaseous stream depleted of CO2. As described above, according to one embodiment, the DAC unit may provide an exhaust gaseous outlet stream. The exhaust gaseous outlet stream may have a discharge rate of less than 15m / s and greater than 2m / s, and less than 10m / s and greater than 5m / s.

[0025] According to one embodiment, the method for capturing carbon dioxide from a gaseous feed stream as described herein may also include a direct air capture (DAC) unit, which may include 1) an inlet air section, 2) an adsorbent section, and 3) an outlet air section. The DAC unit may receive a gaseous feed stream at the inlet air section. At least a portion of the gaseous feed stream may contact an adsorbent material located in the adsorbent section. An exhaust gaseous outlet stream may be provided from the outlet air section. The total pressure loss across the inlet air section and the outlet air section may be maintained at less than 200 Pa. The gaseous feed stream may have a volume flow rate in the adsorbent section, and the volume flow rate may have a maximum flow rate and a minimum flow rate. The minimum flow rate may be maintained in the range of 0% to 20% lower than the maximum flow rate over the entire adsorbent section.

[0026] In one embodiment, the outlet at the top of the DAC unit may also include a plurality of exhaust channels. The exhaust rate of the exhaust gaseous outlet stream may be based on the area of ​​each exhaust channel in the plurality of exhaust channels. In addition, each exhaust channel in the plurality of exhaust channels may include a fan. The outlet of the DAC unit may also include a chimney.

[0027] According to one embodiment, the DAC unit may also include two shutters at the top of the DAC unit. The shutter may extend near the first inlet face and the second inlet face and extend at an angle relative to the first inlet face and the second inlet face. The DAC unit may also include more than two shutters at the top of the DAC unit. In another embodiment, the DAC unit may also include two shutters at the bottom of the DAC unit. The shutter may extend near the first inlet face and the second inlet face and extend at an angle relative to the first inlet face and the second inlet face. The DAC unit may also include more than two shutters at the bottom of the DAC unit. According to another embodiment, the DAC unit may also include four shutters, two of which are located at the top of the DAC unit, and two of which are located at the bottom of the DAC unit. All four shutters may extend near the inlet face, and each shutter may extend at an angle relative to the two inlet faces.

[0028] According to one embodiment, the method may also include a void space below the DAC unit. The void space may have a void height equal to the distance from the solid support plane below the DAC unit to the bottom of the DAC unit. The void height may be greater than 0.5 m, greater than 1 m, and greater than 2 m. The solid support plane may be any surface below the DAC unit, such as the ground, a structure, a ship / vessel, or any other solid support plane that may provide support below the DAC unit.

[0029] In order to promote an understanding of the principles of the invention, reference will now be made to the embodiments shown in the accompanying drawings, which will be described in more detail below. The embodiments disclosed herein are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. The present invention includes any changes and further modifications to the illustrated apparatus and described methods and further applications of the principles of the invention set forth in the claims.

[0030] Figure 1 Exemplary methods according to specific implementations of the disclosed subject matter are shown. In particular, Figure 1 1 shows a side view of a DAC unit according to an embodiment of the present invention. Figure 1 As shown, a method for capturing carbon dioxide from a gaseous feed stream 5 may include a direct air capture (DAC) unit 10. The DAC unit 10 may include two or more inlet faces 20, 30. For example, as shown, the DAC unit 10 may include a first inlet face 20 and a second inlet face 30. The first inlet face 20 and the second inlet face 30 may be on opposite sides of the DAC unit 10, such as Figure 1 As shown. Figure 1 Not shown, but DAC cell 10 may have at least two faces, at least four faces, and may have more than four faces.

[0031] like Figure 1 As shown, the DAC unit 10 may also include an adsorbent material 40 located at or behind each of the inlet faces 20, 30, and the adsorbent material 40 may be located inside the DAC unit 10. The adsorbent material may be a liquid adsorbent material or a solid adsorbent material.

[0032] Likewise Figure 1 As shown, the DAC unit 10 may also include an outlet 50 located at the top of the DAC unit 10. The outlet 50 may provide an exhaust gaseous outlet stream 60, and the exhaust gaseous outlet stream 60 may have a flow generated by at least one fan 70.

[0033] The DAC unit 10 may also include a void space 80 beneath the DAC unit, and the DAC unit 10 may operate on a solid support plane 90 .

[0034] Figure 2 Exemplary methods according to specific implementations of the disclosed subject matter are shown. In particular, Figure 2 1 shows a front view of a DAC unit 10 according to an embodiment of the present invention. Figure 2 As shown, a direct air capture (DAC) unit 10 may include an inlet face 20 and an adsorbent material 40 located at or behind the inlet face 20. The DAC unit 10 may have a height 100 equal to the distance between the highest point of the DAC unit (excluding any extensions and / or chimneys) and the lowest point of the DAC unit (excluding any void spaces, such as void spaces 80), as shown. In addition, the DAC unit 10 may have a length 110 equal to the length of the longest inlet face. In one embodiment, the DAC unit 10 may have a height / length ratio greater than 0.5, greater than 0.7, and greater than 1. The outlet at the top of the DAC unit 10 may also include a chimney 120.

[0035] Likewise Figure 2 As shown, the void space 80 may have a void height 140 equal to the distance from the solid support plane 90 below the DAC unit to the bottom of the DAC unit 10. The void height 140 may be greater than 0.5 m, greater than 1 m, and greater than 2 m. The solid support plane 90 may be any surface below the DAC unit 10, such as the ground, a structure, a ship / vessel, or any other solid support plane that may provide support below the DAC unit 10.

[0036] Figure 3 Exemplary methods according to specific implementations of the disclosed subject matter are shown. In particular, Figure 3 1 shows a plurality of top views of a DAC cell 10 according to an embodiment of the present invention. Figure 3 (a) to Figure 3 As shown in (c), the DAC unit 10 may include a first inlet surface 20 and a second inlet surface 30. The wind direction of the ambient air 500 may be orthogonal to the second inlet surface 30 (see Figure 3 (a)), parallel to the second inlet surface 30 (see Figure 3 (b)), or at an angle to the second inlet face 30 (see Figure 3 (c)). Figure 3 (a) and Figure 3 In the specific embodiment shown in (c), the second inlet surface 30 may be a shadow inlet surface. When the wind direction is not parallel to the shadow inlet surface, the shadow inlet surface may be a downwind surface.

[0037] Figure 4 Exemplary methods according to specific implementations of the disclosed subject matter are shown. In particular, Figure 41 shows a plurality of top views of a DAC unit 10 according to an embodiment of the present invention. As shown, the DAC unit 10 may include an outlet 50 located at the top of the DAC unit 10. Figure 4 (a) and Figure 4 (b) as shown, the outlet 50 can provide a discharge gaseous outlet stream ( Figure 4 ), and the exhaust gaseous outlet stream may have a flow generated by at least one fan 70. Figure 4 (a) and Figure 4 As shown in (b), the outlet 50 at the top of the DAC unit 10 may also include a plurality of exhaust channels 150. The exhaust rate of the exhaust gaseous outlet stream may be based on the area of ​​each exhaust channel 150. In addition, each exhaust channel 150 may include a fan 70. Figure 4 (a) shows an exemplary outlet 50 including a plurality of discharge channels 150, wherein Figure 4 Each of the discharge channels 150 in (a) has a Figure 4 (b) The area of ​​each of the exhaust channels 150 shown in FIG. 1 is relatively large compared to the area of ​​the exhaust channel 150. Therefore, according to the present invention, the flow rate and the exhaust rate of the exhaust gaseous outlet stream can be controlled to a desired size based on the area of ​​each of the exhaust channels, the number of exhaust channels, the number of fans, etc. Further reference is made to Figure 4 , the exhaust passage 150 may further include a chimney (not shown).

[0038] Figure 5 Exemplary methods according to specific implementations of the disclosed subject matter are shown. In particular, Figure 5 1 shows a side view of a DAC unit according to an embodiment of the present invention. Figure 5 As shown, a method for capturing carbon dioxide from a gaseous feed stream 5 may include a direct air capture (DAC) unit 10. The DAC unit 10 may include two or more inlet faces 20, 30. For example, as shown, the DAC unit 10 may include a first inlet face 20 and a second inlet face 30. The first inlet face 20 and the second inlet face 30 may be on opposite sides of the DAC unit 10, such as Figure 5 As shown. Figure 5 As shown, the DAC unit 10 may also include an adsorbent material 40 located at or behind each of the inlet faces 20 , 30 , and the adsorbent material 40 may be located within the DAC unit 10 .

[0039] According to one embodiment, Figure 5As shown, the DAC unit 10 may also include two shields 200 located at the top of the DAC unit 10. The shields 200 may extend at an angle near the first inlet face 20 and the second inlet face 30. The DAC unit may also include more than two shields located at the top of the DAC unit.

[0040] Likewise Figure 5 As shown, the DAC unit 10 may further include an outlet 50 located at the top of the DAC unit 10. The outlet 50 may provide an exhaust gaseous outlet stream 60, and the exhaust gaseous outlet stream 60 may have a flow generated by at least one fan 70. The DAC unit 10 may further include a void space 80 located below the DAC unit 10, and the DAC unit 10 may be supported by a solid support plane 90.

[0041] Figure 6 Exemplary methods according to specific implementations of the disclosed subject matter are shown. In particular, Figure 6 1 shows a side view of a DAC unit according to an embodiment of the present invention. Figure 6 As shown, a method for capturing carbon dioxide from a gaseous feed stream 5 may include a DAC unit 10. The DAC unit 10 may include two or more inlet faces 20, 30. For example, as shown, the DAC unit 10 may include a first inlet face 20 and a second inlet face 30. The first inlet face 20 and the second inlet face 30 may be on opposite sides of the DAC unit 10, such as Figure 6 As shown. Figure 6 As shown, the DAC unit 10 may also include an adsorbent material 40 located at or behind each of the inlet faces 20 , 30 , and the adsorbent material 40 may be located within the DAC unit 10 .

[0042] According to one embodiment, Figure 6 As shown, the DAC unit 10 may also include two shields 200 located at the top of the DAC unit 10. The shields 200 may extend at an angle near the first inlet face 20 and the second inlet face 30. The DAC unit may also include more than two shields located at the top of the DAC unit.

[0043] In addition, Figure 6As shown, the DAC unit may also include two shields 210 located at the bottom of the DAC unit. As shown, the bottom shield 210 may be close to the first inlet face and the second inlet face and extend at an angle relative to the first inlet face and the second inlet face. Although not shown, the DAC unit may also include more than two shields located at the bottom of the DAC unit. According to another embodiment, the DAC unit may also include four shields, wherein two shields 200 are located at the top of the DAC unit, and two shields 210 are located at the bottom of the DAC unit. All four shields 200, 210 may extend close to the inlet face, and each shield may extend at an angle relative to the two inlet faces.

[0044] Likewise Figure 6 As shown, the DAC unit 10 may further include an outlet 50 located at the top of the DAC unit 10. The outlet 50 may provide an exhaust gaseous outlet stream 60, and the exhaust gaseous outlet stream 60 may have a flow generated by at least one fan 70. The DAC unit 10 may further include a void space 80 located below the DAC unit 10, and the DAC unit 10 may be supported by a solid support plane 90.

[0045] Figure 7 Exemplary methods according to specific implementations of the disclosed subject matter are shown. In particular, Figure 7 A side view of a DAC cell according to an embodiment of the present invention is shown. Figure 7 It is shown that all the above-mentioned features can be combined according to the specific implementation of the disclosed subject matter. Figure 7 As shown, a method for capturing carbon dioxide from a gaseous feed stream 5 may include a direct air capture (DAC) unit 10. The DAC unit 10 may include two or more inlet faces 20, 30. For example, as shown, the DAC unit 10 may include a first inlet face 20 and a second inlet face 30. The first inlet face 20 and the second inlet face 30 may be on opposite sides of the DAC unit 10, such as Figure 7 As shown. Figure 7 As shown, the DAC unit 10 may also include an adsorbent material 40 located at or behind each of the inlet faces 20 , 30 , and the adsorbent material 40 may be located within the DAC unit 10 .

[0046] According to one embodiment, Figure 7 As shown, the DAC unit 10 may also include two shields 200 located at the top of the DAC unit 10. The shields 200 may extend at an angle near the first inlet face 20 and the second inlet face 30. The DAC unit may also include more than two shields located at the top of the DAC unit.

[0047] In addition, Figure 7As shown, the DAC unit may also include two shields 210 located at the bottom of the DAC unit. As shown, the bottom shield 210 may be close to the first inlet face and the second inlet face and extend at an angle relative to the first inlet face and the second inlet face. Although not shown, the DAC unit may also include more than two shields located at the bottom of the DAC unit. According to another embodiment, the DAC unit may also include four shields, wherein two shields 200 are located at the top of the DAC unit, and two shields 210 are located at the bottom of the DAC unit. All four shields 200, 210 may extend close to the inlet face, and each shield may extend at an angle relative to the two inlet faces.

[0048] Likewise Figure 7 As shown, the DAC unit 10 may also include an outlet 50 at the top of the DAC unit 10. The outlet 50 may provide an exhaust gaseous outlet stream 60, and the exhaust gaseous outlet stream 60 may have a flow generated by at least one fan 70. The DAC unit 10 may also include a void space 80 below the DAC unit 10, and the DAC unit 10 may be supported by a solid support plane 90. The outlet at the top of the DAC unit 10 may also include a chimney 120.

[0049] Figure 8 Exemplary methods according to specific implementations of the disclosed subject matter are shown. In particular, Figure 8 A side view of a DAC cell according to an embodiment of the present invention is shown. Figure 8 An embodiment is shown in which the adsorbent material 40 may be contained in a stack of containers including partially or fully enclosed bottom and top panels, thereby forming compartments or sections within the adsorbent material 40 and / or inlet faces 20, 30. Such containers may be, for example, standard or modified marine containers.

[0050] In order to promote an understanding of the principles of the invention, reference will now be made to examples performed from various embodiments of the invention, which will be described in more detail below. The examples and embodiments disclosed herein are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following examples. The present invention includes any changes and further modifications to the provided examples and described methods and further applications of the principles of the invention set forth in the claims.

[0051] Example :

[0052] The commercially available multi-physics modeling software StarCCM+ was used to calculate the fluid flow pattern and carbon dioxide concentration distribution for the airflow around the DAC unit. The dimensions of a container were set to 12.19m×2.59m×2.44m. The direction of the incoming wind was set to be perpendicular to the first inlet face. Table 1 below summarizes the simulation results of different comparative embodiments according to specific implementations of the disclosed subject matter.

[0053] For each simulation in the simulation, the ambient carbon dioxide concentration was set to 400 parts per million by volume (ppmv). The wind direction was set to be perpendicular to the first inlet face of the DAC unit. Due to the simulation configuration, the carbon dioxide concentration at the first inlet face was 400 ppmv. The average carbon dioxide concentration at the second inlet face 30 was different in the various comparative designs (as shown in column 2 of Table 1). Column 3 in Table 1 compares the variation in carbon dioxide concentration across the second inlet face in the various comparative designs. In these simulations, the second inlet face is the shaded inlet face. Column 4 in Table 1 compares the average carbon dioxide concentration on the first inlet face and the second inlet face, expressed as a percentage of the carbon dioxide concentration in the ambient air.

[0054] Comparative Design 1 is a DAC unit having one container placed on the ground, with the long face of the side being the inlet face and the top face being the outlet face.

[0055] Comparative Design 2 is a DAC unit consisting of four containers stacked vertically and placed on the ground, wherein the long face of the side is the inlet face, and the top face of the topmost container is the outlet. For Comparative Design 1 and Comparative Design 2, the CO2 concentration at the inlet face given in Comparative Table 1 shows the beneficial effect of the increased height to length ratio of the DAC unit. As shown in Table 1, the CO2 concentration at the second inlet face of the DAC unit with one container (i.e., the height to length ratio is less than 0.5) is 279ppmv, while the CO2 concentration at the second inlet face of the DAC unit consisting of a stack of four containers (i.e., the height to length ratio is greater than 0.5) is 331ppmv. This demonstrates that when the height to length ratio of the DAC unit is increased, an excellent CO2 concentration is achieved at the second inlet face.

[0056] Comparative Design 3 is a DAC cell similar to Comparative Design 2, with a void space below the DAC cell. Comparing the CO2 concentrations at the inlet face given in Table 1 for Comparative Design 2 and Comparative Design 3 shows the beneficial effect of the void space below the DAC cell. As shown in Table 1, the CO2 concentration at the second inlet face of the DAC cell without the void space below is 331 ppmv, while the CO2 concentration at the second inlet face of the DAC cell with the void space below the DAC cell is 351 ppmv. This demonstrates the excellent CO2 concentration at the second inlet face achieved when there is a void space below the DAC cell.

[0057] Comparative Design 4 is a DAC unit consisting of a total of twelve containers, such that three columns each consist of four vertically stacked containers, with the left face of the left vertical stack and the right face of the right vertical stack being the inlet face. The outlet is located on the top, with an area of ​​29.7 m 2 There is also void space below the DAC unit.

[0058] Comparative Design 5 is a DAC unit similar to Comparative Design 4, with the addition of a 29.7 m 2 Chimney of area. Comparison of the CO2 concentrations at the inlet face given in Table 1 for Comparative Design 4 and Comparative Design 5 shows the beneficial effect of the chimney located on the outlet of the DAC unit. As shown in Table 1, the CO2 concentration at the second inlet face without the chimney located at the outlet of the DAC unit is 347 ppmv, while the CO2 concentration at the second inlet face with the chimney located at the outlet of the DAC unit is 356 ppmv. This demonstrates the excellent CO2 concentration at the second inlet face achieved when the chimney is located at the outlet of the DAC unit.

[0059] Comparative Design 6 is a DAC unit similar to Comparative Design 4, except that the outlet area is reduced to 14.8m 2 Comparison of the CO2 concentrations at the inlet face given in Table 1 for Comparative Design 4 and Comparative Design 6 shows the beneficial effect of increasing the velocity of the exhaust gaseous outlet stream of the DAC unit. As shown in Table 1, the outlet area is 29.7 m 2 The CO2 concentration at the second inlet face of the DAC unit is 347 ppmv, while the outlet area is 29.7 m 2 The CO2 concentration at the second inlet face of the DAC unit is 379 ppmv. This demonstrates that when the velocity of the outlet gaseous stream of the DAC unit is increased, an excellent CO2 concentration is achieved at the second inlet face.

[0060] Comparative Design 7 is a DAC unit similar to Comparative Design 5, except that the chimney has a 22.3m 2Comparison of the CO2 concentrations at the inlet face given in Table 1 for Comparative Design 5 and Comparative Design 7 shows the beneficial effect of increasing the velocity of the exhaust gaseous outlet stream of the DAC unit. As shown in Table 1, the outlet area is 29.7 m 2 The CO2 concentration at the second inlet face of the DAC unit is 356 ppmv, while the outlet area is 22.3 m 2 The CO2 concentration at the second inlet face of the DAC unit is 388 ppmv. This demonstrates that when the velocity of the outlet gaseous stream of the DAC unit is increased, an excellent CO2 concentration is achieved at the second inlet face.

[0061] Comparative Design 8 is a DAC unit similar to Comparative Design 5, with a shield extending perpendicular to the two inlet faces on the top of the unit. Comparing the CO2 concentrations at the inlet faces given in Table 1 for Comparative Design 5 and Comparative Design 8 shows the beneficial effect of the shield located at the top of the DAC unit. As shown in Table 1, the CO2 concentration at the second inlet face of the DAC unit without the shield is 356ppmv, while the CO2 concentration at the second inlet face of the DAC unit with the shield is 385ppmv. This demonstrates the excellent CO2 concentration at the second inlet face achieved when there is a shield on the top of the DAC unit.

[0062] As demonstrated and illustrated in Column 4 of Table 1, Comparative Designs 5, 6, 7, and 8 (according to specific implementations of the disclosed subject matter) have an average carbon dioxide concentration at the inlet face that is greater than or equal to 95% of the carbon dioxide concentration in ambient air.

[0063] Table 1 below shows the CO2 concentration of the second inlet face for different designs, the variation of CO2 concentration on the second (shaded) inlet face, and the average CO2 concentration on all inlet faces according to various embodiments of the disclosed invention. The average CO2 concentration on all inlet faces is the average of the simulated CO2 concentrations at the first inlet face and the second (shaded) inlet face.

[0064]

[0065] Fig. 9 The comparison design 1 (such as Fig. 9 (a)) and comparative design 8 (as shown in Fig. 9 (b) shows the carbon dioxide concentration contour line on the second inlet face 30 of the DAC unit 10. Fig. 9 (a) and Fig. 9A solid support plane 90 is shown in (b) because the DAC cell 10 is placed on the solid support plane 90 in Comparative Design 1 and has a void space 80 below the DAC cell 10 for Comparative Design 8. As shown in the grayscale contour plot legend shown on the right, the darker the gray shade on the face, the lower the carbon dioxide concentration. Therefore, by comparing Fig. 9 (a) and Fig. 9 (b) It can be seen that the comparative design 8 shows a higher carbon dioxide concentration than the comparative design 1. In addition, the contour lines displayed on the inlet face indicate the CO2 concentration values ​​across the second inlet face 30. By comparison Fig. 9 (a) and Fig. 9 As can be seen from the count lines shown in (b), Comparative Design 1 has a higher variation in CO2 concentration (also shown in column 3 of Table 1) than Comparative Design 8. These two factors indicate that Comparative Design 8 is an excellent design because it provides a higher average carbon dioxide concentration at the second inlet face 30 and a lower variation in carbon dioxide concentration across the second inlet face 30, which indicates a higher production capacity of the DAC unit 10.

[0066] For the purpose of explanation, the foregoing description has been described with reference to specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments of the disclosed subject matter to the precise forms disclosed. In view of the above teachings, many modifications and variations are possible. The embodiments are selected and described to explain the principles of the embodiments of the disclosed subject matter and their practical applications, so that other persons skilled in the art can utilize those embodiments and various embodiments with various modifications that may be suitable for the specific purposes contemplated.

Claims

1. A method for capturing carbon dioxide from a gaseous feed stream, the method comprising: a) a direct air capture (DAC) unit, said DAC unit comprising: 1) a first inlet face and a second inlet face, wherein the first inlet face and the second inlet face are located on opposite sides of the DAC unit; 2) an adsorbent material located at or behind each of the first inlet face and the second inlet face, and wherein the adsorbent material is located inside the DAC unit; and 3) an outlet located at a top of the DAC unit, wherein the outlet provides an exhaust gaseous outlet stream, and wherein the exhaust gaseous outlet stream has a flow generated by at least one fan; b) receiving a gaseous feed stream at each of the first inlet face and the second inlet face, wherein the gaseous feed stream has an average CO2 concentration greater than 95% of the CO2 concentration of ambient air by minimizing re-intake of the exhaust gaseous outlet stream, and wherein the ambient air has any wind direction and any wind speed.

2. The method for capturing carbon dioxide from a gaseous feed stream according to claim [0020], wherein the second inlet face is a shadow inlet face, and the shadow inlet face is a downwind face when the wind direction is not parallel to the shadow inlet face.

3. The method for capturing carbon dioxide from a gaseous feed stream according to claim [0020] or 2, wherein the DAC unit further comprises: 1) Inlet air section, 2) an adsorbent section, and 3) Outlet air section, And wherein the method further comprises: b) receiving the gaseous feed stream at the inlet air section; c) contacting at least a portion of the gaseous feed stream with the adsorbent material located within the adsorbent section; d) providing said exhaust gaseous outlet stream from said outlet air section, wherein the total pressure loss across the inlet air section and the outlet air section is maintained at less than 200 Pa; wherein the gaseous feed stream has a volume flow rate within the adsorbent section, wherein the volume flow rate has a maximum flow rate and a minimum flow rate, and The DAC unit further comprises at least one structural element for maintaining the minimum flow rate within a range of 0% to 20% below the maximum flow rate over the entire adsorbent section.

4. A method for capturing carbon dioxide from a gaseous feed stream according to any one of claims [0020], 2 or 3, wherein the DAC unit has a height equal to the distance between the top and the bottom of the DAC unit, and the DAC unit has a length equal to the length of the longest of the first inlet face and the second inlet face, and wherein the DAC unit has a height / length ratio greater than 0.

5.

5. A method for capturing carbon dioxide from a gaseous feed stream according to any one of claims [0020], 2 or 3, wherein the exhaust gaseous outlet stream has a discharge velocity of less than 15 m / s and greater than 2 m / s.

6. A method for capturing carbon dioxide from a gaseous feed stream according to claim [0022], wherein the outlet located at the top of the DAC unit also includes a plurality of exhaust channels, and wherein the exhaust rate of the exhaust gaseous outlet stream is based on the area of ​​each exhaust channel in the plurality of exhaust channels.

7. A method for capturing carbon dioxide from a gaseous feed stream according to claim [0025], wherein each of the plurality of exhaust channels comprises a fan.

8. A method for capturing carbon dioxide from a gaseous feed stream according to any one of claims [0020], 2 or 3, wherein the outlet at the top of the DAC unit further comprises a chimney.

9. A method for capturing carbon dioxide from a gaseous feed stream according to any one of claims [0020], 2 or 3, wherein the DAC unit further comprises two baffles located at the top of the DAC unit, and wherein the baffles are proximate to the first inlet face and the second inlet face and extend at an angle relative to the first inlet face and the second inlet face.

10. A method for capturing carbon dioxide from a gaseous feed stream according to any one of claims [0020], 2 or 3, wherein a void space is located below the DAC unit, and wherein the void space has a void height equal to the distance from a solid support plane below the DAC unit to the bottom of the DAC unit, and wherein the void height is greater than 0.5 m.

11. A method for capturing carbon dioxide from a gaseous feed stream according to any one of claims [0020], 2 or 3, wherein the DAC unit further comprises two baffles located at the bottom of the DAC unit, and wherein the baffles are proximate to the first inlet face and the second inlet face and extend at an angle relative to the first inlet face and the second inlet face.

12. A method for capturing carbon dioxide from a gaseous feed stream according to any one of claims [0020], 2 or 3, wherein the DAC unit further comprises four baffles, wherein two baffles are located at the top of the DAC unit and two baffles are located at the bottom of the DAC unit, and wherein the four baffles are proximate to two inlet faces and each extends at an angle relative to the two inlet faces.

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