The various embodiments relate generally to carbon capture technology and, more specifically, to a low-power direct air carbon capture system.
According to many scientific studies, global warming is becoming a serious problem for both current and future generations. Many argue that a primary contributor to global warming is the human expansion of the “greenhouse effect,” in which the Earth’s atmosphere traps heat that would otherwise radiate from the Earth into space. The different gases contributing to the greenhouse effect (referred to herein as “greenhouse gases”) include water vapor, methane, nitrous oxide, and carbon dioxide. Many scientists believe that the most serious effects of global warming can be prevented by reducing human-based emissions of greenhouse gases and lowering the concentration of greenhouse gases currently in the Earth’s atmosphere. To that end, one technology being developed to address global warming is direct air carbon capture, where carbon dioxide is captured and removed from the Earth’s atmosphere.
Direct air carbon capture typically involves attempts to remove large quantities of carbon dioxide from the Earth’s atmosphere by an adsorption/desorption process. In many direct air carbon capture implementations, ambient air is exposed to a suitable sorbent, such as an amine-based material, which adsorbs the carbon dioxide present in the ambient air. The adsorbed carbon dioxide is then released from the sorbent via a desorption process for subsequent storage.
For direct air carbon capture or any other process to be a viable approach for reducing the greenhouse effect, the process of removing carbon dioxide from the Earth’s atmosphere needs to result in negative greenhouse gas emissions. That is, the amount of greenhouse gas produced when generating the energy necessary to affect the direct air carbon capture process has to be less than the amount of greenhouse gas the direct air carbon process removes from the Earth’s atmosphere.
One drawback to conventional direct air carbon capture processes is that those processes typically require significant energy, including the thermal energy needed for freeing carbon dioxide in the desorption process and, oftentimes, the fan energy needed for directing ambient air onto the sorbent material. Accordingly, in order to achieve a negative greenhouse gas emission process, direct air carbon capture facilities are typically located at or near large sources of renewable energy, such as the site of a geothermal reservoir, a solar power plant, or a wind farm. Such location constraints prevent conventional direct air carbon capture processes from being broadly implemented, which limits the effectiveness of direct air carbon capture in combating global warming. In addition, direct air carbon capture facilities are normally quite large, having the footprint on the order of a commercial building, which limits where these facilities can be built as well as the number of these facilities that can be built.
As the foregoing illustrates, what is needed in the art are more effective techniques for direct air carbon capture.
According to various embodiments, a direct air carbon capture system includes a wind turbine that includes one or more blades and generates electrical energy when first air flows across the one or more blades; a carbon dioxide (CO2) adsorption chamber that includes one or more amine-containing CO2 adsorbers and receives second air when the first air flows across the one or more blades; and a water reservoir that generates steam using a portion of the electrical energy generated by the wind turbine, wherein the water reservoir is fluidly coupled to and isolated from the CO2 adsorption chamber via one or more valves.
At least one technical advantage of the disclosed design relative to the prior art is that the disclosed design enables direct air carbon capture without needing a large, centralized source of renewable energy. In addition, the disclosed design is versatile and can be scaled down to a size suitable for residential applications or up to a size suitable for industrial-level applications. Thus, the disclosed design greatly expands where direct air carbon capture processes can be implemented relative to conventional approaches. Another technical advantage of the disclosed design is that fan energy is not required for direct air carbon capture, which enables the direct air carbon capture process effected by the disclosed design to be greenhouse gas net-negative. These technical advantages provide one or more technological advancements over prior art approaches.
So that the manner in which the above recited features of the various embodiments can be understood in detail, a more particular description of the inventive concepts, briefly summarized above, may be had by reference to various embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of the inventive concepts and are therefore not to be considered limiting of scope in any way, and that there are other equally effective embodiments.
For clarity, identical reference numbers have been used, where applicable, to designate identical elements that are common between figures. It is contemplated that features of one embodiment may be incorporated in other embodiments without further recitation.
In the following description, numerous specific details are set forth to provide a more thorough understanding of the various embodiments. However, it will be apparent to one of skilled in the art that the inventive concepts may be practiced without one or more of these specific details.
Wind turbine 110 includes one or more blades, such as airfoil blades, and generates electrical energy 111 from a flow of ambient air (not shown in
CO2 adsorption chamber 120 is configured to remove CO2 from ambient air via an adsorption process and to release the adsorbed CO2 via a desorption process. To that end, CO2 adsorption chamber 120 includes one or more amine-containing CO2 adsorbers 121. In operation, CO2 adsorption chamber 120 receives a flow of ambient air, and CO2 present in the ambient air is adsorbed by amine-containing CO2 adsorbers 121. The adsorbed CO2 is then released from amine-containing CO2 adsorbers 121 during a desorption process, in which amine-containing CO2 adsorbers 121 are heated with steam generated in water reservoir 130. In some embodiments, the released CO2 is dissolved into the condensed steam (liquid water) that forms on surfaces of amine-containing CO2 adsorbers 121, and the CO2-containing liquid water is returned to water reservoir 130. Alternatively or additionally, in some embodiments, released gas-phase CO2 is flushed into water reservoir 130 by the steam generated in water reservoir 130 and introduced into CO2 adsorption chamber 120. In either case, during the desorption process, CO2 disposed within amine-containing CO2 adsorbers 121 is transported to water reservoir 130 for subsequent separation and/or storage.
Water reservoir 130 is configured to generate steam via electrical energy 111 that is generated by wind turbine 110. Thus, water reservoir 130 is configured to contain liquid water and includes a heater 131 for generating steam from the liquid water. Further, water reservoir 130 is fluidly coupled to and isolated from CO2 adsorption chamber 120 via one or more valves and conduits (not shown in
Direct air carbon capture system 100 enables the collection of CO2 from ambient air 201 using locally generated wind power. Thus, any location that has at least some wind power potential can be a suitable location for the construction of direct air carbon capture system 100. Further, the herein described adsorption/desorption process does not rely on large supply fan systems for exposing amine-containing CO2 adsorbers 121 to ambient air 201. As a result, direct air carbon capture system 100 does not require a large-scale renewable energy source to operate effectively, and therefore can be implemented in residential- or industrial-scale projects.
Amine-containing CO2 adsorbers 321 include a sorbent that is capable of removing CO2 from ambient air via adsorption, such as an amine-containing material. Any technically feasible amine-containing material can be employed in amine-containing CO2 adsorbers 321 that can collect CO2 from ambient air and can release the collected CO2 via thermal desorption. Thermal desorption is the process by which an adsorbate, such as CO2 molecules, is heated and thereby desorbed from surfaces of the sorbent. Generally, desorption occurs when a molecule gains sufficient energy to overcome the activation barrier or the bounding energy that keeps the molecule adsorbed to a surface. In some embodiments, amine-containing CO2 adsorbers 321 are configured as high-surface area components, such as tubes, fins, and the like. In the embodiment illustrated in
Inlet bell 322 is disposed at an inlet opening 326 of CO2 adsorption chamber 120 and facilitates the capture of ambient air 201 during an adsorption process. Inlet valve 323 is actuated to an open position (as shown) during an adsorption process, and is actuated to a closed position (dashed lines) to seal inlet opening 326 during a desorption process. Exhaust system 340 includes one or more exhaust fans 341 that are fluidly coupled to the inside of CO2 adsorption chamber 120 via one or more ducts 342 and a plurality of exhaust openings 343. Thus, exhaust system 340 removes processed (low- CO2) air 202 from CO2 adsorption chamber 120 during an adsorption process, thereby enabling ambient air 201 to continue to flow into CO2 adsorption chamber 120 during the adsorption process. In some embodiments, exhaust fan(s) 341 are powered by electrical energy 111 generated by wind turbine 110.
In the embodiment illustrated in
During the thermal desorption process, CO2 released from amine-containing CO2 adsorbers 321 is transported to water reservoir 130. In some embodiments, the CO2 released from amine-containing CO2 adsorbers 321 can be dissolved into the liquid water that is formed as steam 203 condenses during the desorption process. In such embodiments, the CO2-containing liquid water can be returned via gravity to water reservoir 130 via return conduit 333. Alternatively or additionally, in some embodiments, the CO2 released from amine-containing CO2 adsorbers 321 can be transported to water reservoir 130 via return conduit 333 as gas-phase CO2. In such embodiments, gas-phase CO2 that is released from amine-containing CO2 adsorbers 321 is displaced by the steam 203 being urged into CO2 adsorption chamber 120 by fan 334 during the thermal desorption process.
Controller 350 is configured to control operation of direct air carbon capture system 100, and may be any technically feasible hardware unit capable of processing data and/or executing instructions associated with the operation of direct air carbon capture system 100. In operation, controller 350 controls operation of inlet valve 323, exhaust fan(s) 341, fan 334, valve 335, valve 336, and heater 331. Specifically, during the adsorption process controller opens inlet valve 323, closes valve 335 and valve 336, and causes exhaust fan(s) 341 to run. During the thermal desorption process, controller 350 closes inlet valve 323, opens valve 335 and valve 336, causes exhaust fan(s) 341 to stop and fan 334 to run. In some embodiments, controller 350 receives inputs from one or more sensors, such as a processed air sensor 391 or other sensor that monitors adsorption and/or desorption processes.
Controller 350 can be implemented as any suitable processor or computing device, such as a central processing unit (CPU), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of processing unit, or a combination of different processing units, such as a CPU configured to operate in conjunction with a GPU or digital signal processor (DSP). In some embodiments, controller 350 is implemented as a one or more integrated circuits or chips included in direct air carbon capture system 100. Alternatively, in some embodiments, controller 350 is implemented as a computing device, such as a desktop computer, laptop computer, mobile phone, electronic tablet, and/or the like.
In the embodiment illustrated in
In the embodiment illustrated in
In the above-described embodiments, a continuous flow of ambient air into CO2 adsorption chamber 120 is maintained during an adsorption process via exhaust system 340. In other embodiments, a continuous flow of ambient air into CO2 adsorption chamber 120 is maintained during an adsorption process without the expenditure of fan energy. One such embodiment is described below in conjunction with
It is noted that the same flow of ambient air 201 that enables wind turbine 110 to generate electrical energy 111 facilitates a continuous flow of ambient air 201 into CO2 adsorption chamber 520 during the adsorption process. As a result, no fan energy is required during the adsorption process, increasing the total negative greenhouse gas emissions associated with the operation of direct air carbon capture system 500.
In the embodiment illustrated in
As shown, a method 600 begins at step 601, where controller 350 configures direct air carbon capture system 100 for an adsorption process. Specifically, controller 350 causes inlet valve 323 to open and enable ambient air 201 to enter CO2 adsorption chamber 120. In some embodiments, controller 350 also causes one or more exhaust fans 341 to begin running, thereby removing processed air 202 from CO2 adsorption chamber 120. In other embodiments, controller 350 causes outlet valve 524 to open, so that processed air 202 can passively flow out of CO2 adsorption chamber 120.
In step 602, an adsorption process begins as ambient air 201 flows into CO2 adsorption chamber 120 and CO2 is collected by amine-containing CO2 adsorbers 121. During the adsorption process, processed air 202 is removed from and/or flows from CO2 adsorption chamber 120 as ambient air 201 flows into CO2 adsorption chamber 120.
In step 603, controller 350 determines that the adsorption process is complete. In some embodiments, controller 350 makes such a determination based on a sensor input. In such embodiments, controller 350 may receive an input from processed air sensor 391 indicating that a CO2 concentration of processed air 202 has exceeded a threshold value. Additionally or alternatively, in some embodiments, controller 350 makes such a determination based on a duration of the adsorption process. Additionally or alternatively, in some embodiments, controller 350 makes such a determination based on an estimated quantity of ambient air that has been processed.
In step 604, controller 350 configures direct air carbon capture system 100 for a desorption process. Specifically, controller 350 causes inlet valve 323 to close and fluidly isolating CO2 adsorption chamber 120 from ambient air 201. In addition, controller 350 causes CO2 adsorption chamber 120 to be fluidly coupled to water reservoir 130, for example by opening valve 335 and valve 336, and by causing fan 334 to begin running. Alternatively, in some embodiments, controller 350 causes a single valve to fluidly couple CO2 adsorption chamber 120 to water reservoir 130, for example outlet valve 524.
In step 605, a desorption process begins as steam 203 flows into CO2 adsorption chamber 120, and CO2 that is adsorbed by amine-containing CO2 adsorbers 121 is released. Steam 203 heats amine-containing CO2 adsorbers 121 to a temperature sufficient for desorption of adsorbed CO2 therefrom. For example, in some embodiments, in the desorption process, amine-containing CO2 adsorbers 121 are heated to a temperature of about 100 C, a temperature at which CO2 molecules gain sufficient energy to overcome the activation barrier or the bounding energy that keeps the CO2 molecules adsorbed to surfaces of amine-containing CO2 adsorbers 121. During the desorption process, CO2205 is transported from CO2 adsorption chamber 120 to water reservoir 130 for subsequent storage.
In step 606, controller 350 determines that the desorption process is complete. In some embodiments, controller 350 makes such a determination based on a sensor input. Additionally or alternatively, in some embodiments, controller 350 makes such a determination based on a duration of the desorption process.
In sum, the various embodiments shown and provided herein set forth techniques for a low-energy direct air carbon capture process that is powered using electrical energy generated by a wind turbine. Specifically, a flow of ambient air enables the wind turbine to generate electrical power while amine-containing CO2 adsorbers collect CO2 from the ambient air via an adsorption process. The electrical power generates steam that is then employed to heat the amine-containing CO2 adsorbers in a thermal desorption process that releases adsorbed CO2 from the amine-containing CO2 adsorbers.
At least one technical advantage of the disclosed design relative to the prior art is that the disclosed design enables direct air carbon capture without the need of a large, centralized source of renewable energy. In addition, the disclosed design can be scaled down to a size suitable for residential applications or up to a size suitable for industrial-level applications. Thus, the disclosed design greatly expands where direct air carbon capture facilities can be operated. A further advantage of the disclosed design is that the expenditure of fan energy is not required for a direct air carbon capture process, thereby increasing the total negative greenhouse gas emissions of the process. These technical advantages provide one or more technological advancements over prior art approaches.
1. In some embodiments, a direct air carbon capture system includes: a wind turbine that includes one or more blades and generates electrical energy when first air flows across the one or more blades; a carbon dioxide (CO2) adsorption chamber that includes one or more amine-containing CO2 adsorbers and receives second air when the first air flows across the one or more blades; and a water reservoir that generates steam using a portion of the electrical energy generated by the wind turbine, wherein the water reservoir is fluidly coupled to and isolated from the CO2 adsorption chamber via one or more valves.
2. The direct air carbon capture system of clause 1, further comprising a return conduit that fluidly couples the water reservoir to the CO2 adsorption chamber.
3. The direct air carbon capture system of clauses 1 or 2, further comprising a controller that causes a first valve that is included in the one or more valves and is disposed within the return conduit to close during an adsorption phase.
4. The direct air carbon capture system of any of clauses 1-3, further comprising a supply conduit that fluidly couples the water reservoir to the CO2 adsorption chamber.
5. The direct air carbon capture system of any of clauses 1-4, further comprising a controller that causes a first valve that is included in the one or more valves and is disposed within the supply conduit to close during an adsorption phase.
6. The direct air carbon capture system of any of clauses 1-5, wherein a first valve included in the one or more valves selectively closes the supply conduit and opens an outlet of the CO2 adsorption chamber.
7. The direct air carbon capture system of any of clauses 1-6, further comprising a fan that is disposed within the supply conduit and blows steam from the water reservoir to the CO2 adsorption chamber.
8. The direct air carbon capture system of any of clauses 1-7, wherein the fan is powered by another portion of the electrical energy generated by wind turbine.
9. The direct air carbon capture system of any of clauses 1-8, further comprising a controller that causes a valve disposed proximate to an inlet of the CO2 adsorption chamber to open during an adsorption process and close during a desorption process.
10. The direct air carbon capture system of any of clauses 1-9, wherein the one or more amine-containing CO2 adsorbers comprise an array of amine-containing tubes.
11. The direct air carbon capture system of any of clauses 1-10, wherein the amine-containing tubes are oriented substantially parallel to a longitudinal axis of the CO2 adsorption chamber.
12. The direct air carbon capture system of any of clauses 1-11, wherein the CO2 adsorption chamber includes exhaust openings that are fluidly coupled to an exhaust fan system.
13. The direct air carbon capture system of any of clauses 1-12, wherein the exhaust fan system is powered by another portion of the electrical energy generated by the wind turbine.
14. In some embodiments, a method includes: adsorbing carbon dioxide (CO2) from a first portion of a flow of ambient air via a CO2 adsorption chamber that includes one or more amine-containing CO2 adsorbers; while adsorbing the CO2, generating electrical energy from a second portion of the flow of ambient air via a wind turbine; generating steam in a water reservoir using a portion of the electrical energy; and heating the one or more amine-containing CO2 adsorbers with the steam.
15. The method of clause 14, wherein heating the one or more amine-containing CO2 adsorbers with the steam comprises fluidly coupling the CO2 adsorption chamber to the water reservoir.
16. The method of clauses 14 or 15, further comprising blowing the steam into the CO2 adsorption chamber with a fan.
17. The method of any of clauses 14-16, wherein the steam enters the CO2 adsorption chamber via fee convection.
18. The method of any of clauses 14-17, further comprising, prior to adsorbing the CO2 from the first portion of the flow of ambient air, fluidly decoupling the CO2 adsorption chamber from the water reservoir.
19. The method of any of clauses 14-18, further comprising, prior to adsorbing the CO2 from the first portion of the flow of ambient air, fluidly coupling the CO2 adsorption chamber to an exhaust fan system.
20. The method of any of clauses 14-19, further comprising, prior to heating the one or more amine-containing CO2 adsorbers with the steam, fluidly decoupling the CO2 adsorption chamber from the flow of ambient air.
Any and all combinations of any of the claim elements recited in any of the claims and/or any elements described in this application, in any fashion, fall within the contemplated scope of the present invention and protection.
The descriptions of the various embodiments have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.
While the preceding is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
This application claims priority benefit of the United States Provisional Patent Application titled, “TECHNIQUES FOR LOW-POWER, LARGE SCALE DIRECT AIR CAPTURE” filed on Dec. 3, 2021 and having Serial No. 63/285,977. The subject matter of this related application is hereby incorporated herein by reference.
Number | Date | Country | |
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63285977 | Dec 2021 | US |