Voltage swing method for carbon capture using porous carbon

Abstract

A method and system for carbon capture by voltage swing is provided. The method may include capturing carbon dioxide from the gas mixture by increasing the selectivity and adsorption of the adsorbent by physical adsorption, i.e. By applying a positive charge to the adsorbent, and releasing carbon dioxide from the adsorbent by removing the positive charge from the adsorbent and applying a desorption process to the adsorbent.

Description

Background Art

[0001] The present invention relates generally to the field of global warming mitigation and more particularly to carbon capture.

[0002] As the Earth warms, advances in technology are becoming increasingly critical to mitigating the accumulation of carbon dioxide in the Earth's atmosphere. One promising area of ​​technology that has the potential to make a significant impact is that of carbon capture. Carbon capture is the process of capturing carbon dioxide before it enters the atmosphere or filtering it out of the atmosphere. Carbon dioxide can be captured and separated from mixed gases by a variety of different means, such as absorption, adsorption, chemical looping, membrane gas separation, and gas hydration. However, many challenges must be overcome in this area before carbon capture can have a significant impact on atmospheric carbon dioxide levels. Summary of the invention

[0003] According to at least one embodiment, a method and system for carbon capture by a voltage-swing method is provided. The invention may include capturing carbon dioxide from a gas mixture by physical adsorption (applying an electric charge to an adsorbent to increase the selectivity and adsorption of the adsorbent) and releasing carbon dioxide from the adsorbent by removing the charge from the adsorbent and applying a desorption method to the adsorbent. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] These and other objects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments of the present invention, which is to be read in conjunction with the accompanying drawings. The various features of the drawings are not to scale, as the illustrations are intended to clearly facilitate understanding of the present invention by those skilled in the art in conjunction with the detailed description. In the drawings:

[0005] Figure 1 illustrates an exemplary voltage swing carbon capture system according to at least one embodiment;

[0006] Figure 2 is a flow chart illustrating the operation of a voltage swing carbon capture process according to at least one embodiment;

[0007] Figure 3A illustrates an exemplary voltage swing carbon capture system according to at least one embodiment;

[0008] Figure 3B illustrates an exemplary voltage swing carbon capture system according to at least one embodiment; and

[0009] Figure 4 is a flow chart illustrating the operation of a voltage swing carbon capture process according to at least one embodiment. DETAILED DESCRIPTION

[0010] Detailed embodiments of the claimed structures and methods are disclosed herein; however, it is understood that the disclosed embodiments are merely illustrative of the claimed structures and methods that may be embodied in various forms. However, the present invention may be implemented in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. In the description, details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the presented embodiments.

[0011] As mentioned previously, advances in technology are becoming increasingly critical to mitigating the buildup of carbon dioxide in the Earth's atmosphere. One promising area of ​​technology that has the potential to make a significant impact is that of carbon capture. Carbon capture is the process of capturing carbon dioxide before it enters the atmosphere (e.g., in flue gases from power plants) or filtering it out of the atmosphere. Carbon dioxide can be captured and separated from mixed gases by a variety of different means, such as absorption, adsorption, chemical looping, membrane gas separation, and gas hydration. However, many challenges must be overcome in this area before carbon capture can have a significant impact on atmospheric carbon dioxide levels.

[0012] Adsorption is an important carbon capture technology used in the art, which is the attachment of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface made of an adsorbent material called an adsorbent. Adsorbents can be attached to atoms, ions or molecules through non-bonded electrostatic interactions (as well as van der Waals interactions) called physical adsorption or through chemical bonds called chemical adsorption. In order to make an effective adsorbent, the material must have a quality called selectivity, which is the ability of the adsorbent to preferentially adsorb one gas rather than another; materials with low selectivity are largely unable to separate carbon dioxide and therefore cannot effectively perform carbon capture. In addition, once the adsorbent is collected, the adsorbent requires a regeneration step to remove carbon dioxide from it so that the adsorbent can be reused. An exemplary adsorbent is a metal organic framework (MOF), which uses physical adsorption or chemical adsorption based on the porous atomic structure of the MOF to capture carbon dioxide. Then, in the regeneration step, temperature swing adsorption or pressure swing adsorption is used to remove carbon dioxide from the MOF. However, MOFs can be very expensive, costing up to five hundred dollars a pound at the time of writing this article. Another exemplary adsorbent is activated carbon or amorphous carbon; activated carbon is highly porous, so that one gram of activated carbon can have a surface area greater than three thousand square meters, resulting in a very high ability to capture carbon dioxide. In addition, it is inexpensive, costing only a few dollars a pound at the time of this writing. Activated carbon is also easily chemically modified: N- or B-doping, oxidation, hydrogenation, metal doping, polymer functionalization, etc. However, the selectivity of unmodified activated carbon is not very high, which reduces its suitability for carbon capture applications.

[0013] Another carbon capture technology is absorption, which is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a liquid solution made of an absorbent material, called a solvent. One absorption method is amine gas treatment, which refers to a group of processes that utilize aqueous solutions of various alkylamines to remove carbon dioxide from gases. However, amine gas treatment absorbs carbon dioxide by forming a chemical bond (chemisorption) between the solvent and carbon dioxide; therefore, chemisorption requires a large amount of energy to break the chemical bond and desorb carbon dioxide from the adsorbent or solvent, resulting in high energy costs to regenerate the adsorbent or solvent.

[0014] Carbon can also be captured using membrane gas filters, which use many permeable membranes to block molecules of a certain gas while allowing other gases to pass through. However, membrane gas filters are limited in performance by the fact that selectivity must be sacrificed to gain permeability, and vice versa; this makes membrane gas filters unsuitable for separating carbon dioxide from flue gas streams because, in order to achieve a level of selectivity sufficient to preferentially separate carbon dioxide from other gases, the membrane gas filter would have to sacrifice permeability to such an extent that achieving useful levels of carbon capture would require an impractically large number of gas filters, with the result that the mass transfer of the filters would become the limiting factor, and regenerating used filters would become prohibitively expensive.

[0015] It may therefore be advantageous, among other things, to implement a system for electrostatically capturing carbon dioxide by physical adsorption, resulting in energy costs for regenerating the adsorbent that are significantly lower than those of electrochemical techniques utilizing chemical adsorption. It may be further advantageous to implement a system that utilizes a voltage swing method on activated carbon to increase the selectivity of the activated carbon to a level that allows direct air capture and significantly improves adsorption, thereby overcoming the major disadvantages of activated carbon and allowing the system to benefit from the inherent low cost and high storage capacity of activated carbon. It may be further advantageous to utilize a voltage swing method in the regeneration step to reduce the selectivity of the activated carbon, thereby reducing the energy requirements for releasing the captured carbon dioxide in the regeneration step.

[0016] According to at least one embodiment, the present invention is a method of capturing carbon dioxide from a gas mixture by applying a voltage to an adsorbent to increase the selectivity and adsorption of the adsorbent, and once the adsorbent is saturated under the applied external conditions (e.g., pressure and temperature), reducing the voltage to reduce the selectivity and adsorption of the adsorbent to promote low energy release of captured carbon dioxide molecules during a regeneration step. Although activated carbon is considered in the embodiments of the present invention, those skilled in the art will understand that any conductive adsorbent has the same adsorption and selectivity benefits as activated carbon. However, activated carbon can further provide benefits in terms of cost and low environmental impact.

[0017] In some embodiments of the invention, the gas mixture may be any combination of two or more gases, one of which includes carbon dioxide. The gas mixture may, for example, include flue gas, which may primarily include a combination of nitrogen and carbon dioxide. The gas mixture may also be atmospheric air, which may be a combination of nitrogen, oxygen, carbon dioxide, etc. In some embodiments of the invention, the system may be used at industrial sites, cement manufacturing sites, and / or chemical sites where carbon dioxide is released and should be separated from the air and captured.

[0018] In some embodiments of the present invention, the voltage swing method is a method of changing the properties of activated carbon by applying an electric charge to the activated carbon. When the charge of each carbon atom in the porous carbon increases above zero, the adsorption load of carbon dioxide increases sharply with voltage, from a load of about 5 mol / kg at a charge of 0.0 electrons per atom to a load of more than 20 mol / kg at a charge of 0.1 electrons per atom. And because the adsorption load is so low at or below zero charge density, it may not be necessary to actively remove the adsorbed gas from the porous carbon at such a charge density. In addition, as the charge density increases, the selectivity also increases; the selectivity of unmodified activated carbon is less than 20, but as the charge density increases to 0.1 electrons per atom, the selectivity jumps to about 1000 (based on our computer modeling), an increase of fifty times. Due to the high selectivity of charged activated carbon for adsorbing molecules with large charge quadrupole moments (due to favorable charge-quadrupole interactions), carbon dioxide adsorption is greater than nitrogen adsorption. The selectivity of carbon dioxide over nitrogen can be further increased by releasing the first adsorbed gas into a second chamber with charged amorphous carbon, followed by a second adsorption and release; the second adsorbed gas will have an even higher purity. In charged activated carbon, the charges may be located at the tips of the peaks or at defects; this heterogeneous charge distribution produces stronger local electric fields than homogeneous charges, and these stronger electric fields can promote higher carbon dioxide selectivity and adsorption.

[0019] In some embodiments of the present invention, the voltage swing method is a method of changing the properties of the adsorbent by applying an electric charge to the adsorbent; any conductive adsorbent can show the same adsorption and selectivity benefits as activated carbon.

[0020] In some embodiments of the present invention, the adsorbent may be any solid material that adsorbs carbon dioxide by physical adsorption and has increased carbon dioxide adsorption when the material is charged. In other words, any adsorbent material to which carbon dioxide binds due to electrical and / or van der Waals forces rather than by chemical adsorption (which uses electrochemical means to form a molecular bond between the adsorbent and carbon dioxide). The adsorbent may be activated carbon, certain metal organic frameworks (MOFs), or any other suitable adsorbent.

[0021] The amount of activated carbon required to remove carbon dioxide from a gas mixture can be expressed as follows: The number of moles of carbon dioxide adsorbed can be expressed as MCO 2 = C (mol / kg of activated carbon) * m (mass of activated carbon in kg). Setting this equal to the number of moles of carbon dioxide in the feed chamber yields the following equation: MCO 2 = V (the volume of the cavity, in m 3 =CO in the input gas 2 fraction) / 0.0224 (m under SPT 3 / mole), therefore, the volume of air required to fill activated carbon with carbon dioxide is: V=0.0224Cm / f.

[0022] In the exemplary embodiment of the system capturing carbon dioxide from flue gas, f = 0.1, then according to our calculations, for C = 20 mol / kg, the volume of air required per kilogram of activated carbon is V = 4.48 m 3 Since most of the carbon dioxide will be on the activated carbon, the residue will be nearly pure nitrogen that can be vented to the air. The activated carbon will be contaminated with nitrogen. For selectivity S, CO on the activated carbon 2 / N 2 The ratio of CO on activated carbon will be Sf. In the case of S ~ 1000 (see above) and f = 0.1, 2 / N 2 The ratio will be 100, so CO 2 The purity is 99%.

[0023] In some embodiments of the present invention, the system may, after adsorbing carbon dioxide into the adsorbent by any of the carbon capture methods mentioned herein or any other method, release the residual gas from the first adsorption into a second chamber having a charged amorphous carbon, and then perform a second adsorption and release to further increase the selectivity of the adsorbent for carbon dioxide relative to nitrogen; the second adsorbed gas will have an even higher purity. For example, in the case of a system capturing carbon from the atmosphere by direct air capture, f = 0.0004, the volume of air required to contain enough carbon dioxide to fill 1 kg of activated carbon is 1120 m 3 , and CO on activated carbon 2 / N 2 The ratio will be 4. For reference, 1 kg of activated carbon spread over 1 square meter of bed will be 0.4 mm thick at its typical density of 2.5 gm / cc. Such a high volume of air will require a fan to blow the air over the activated carbon so that each kg is exposed to 1120 m2 of air for the time the activated carbon spends adsorbing carbon dioxide. 3In this case, the activated carbon may still be highly contaminated with nitrogen, in which case the system can send the captured carbon dioxide and nitrogen mixture to another filtration unit where the carbon dioxide fraction on the second activated carbon will be S times the carbon dioxide fraction on the first activated carbon, or S 2 f=400. Then, CO in the second filter unit 2 The purity will be 99.75%.

[0024] The exemplary embodiments described below provide a system, method, and program product to capture carbon dioxide in a mixed gas by increasing the selectivity of an adsorbent by applying an electric charge, adhering carbon dioxide to the adsorbent by physical adsorption, and then removing the captured carbon dioxide by reducing the charge on the adsorbent.

[0025] refer to Figure 1 , depicts an exemplary voltage swing carbon capture system 100 according to at least one embodiment. Here, the voltage swing carbon capture system 100 includes four chambers; the first chamber 102 includes an inlet 104 for receiving a high pressure gas mixture, an outlet 106 for exhausting nitrogen, and a valve 110 connecting the first chamber 102 to the second chamber 108. The second chamber 108 includes an outlet 112 for exhausting carbon dioxide and a first capacitor plate 114. The first capacitor plate 114 may include an adsorbent, which may be charged, for example, by a battery. The first capacitor plate 114 may include any conductive adsorbent, including activated carbon, metal organic frameworks (MOFs), zeolites, etc. Mirroring the first chamber 102 is a third chamber 116, which includes an inlet 118 for receiving a high pressure gas mixture, an outlet 120 for exhausting nitrogen, and a valve 124 connecting the third chamber 116 to a fourth chamber 122. The fourth chamber 122 includes an outlet 126 for exhausting carbon dioxide and a second capacitor plate 128. The second capacitor plate 128 may include an adsorbent to which a charge may be applied, for example, by a battery. The first capacitor plate 128 may include any conductive adsorbent. The voltage swing carbon capture system 100 may also include a voltage regulator 130 electrically connected to both capacitor plates 114, 128 and regulating the charge to both capacitor plates 114, 128; the capacitor plates 114, 128 may be part of a single capacitor and / or connected so that when one carries a negative charge, the other carries a positive charge, and vice versa. The voltage regulator 130 may be connected to a power source such as a battery or an outlet. In some embodiments of the present invention, for example where the voltage swing carbon capture system 100 captures carbon from atmospheric air, the outlet 106 may be used to discharge a gas residue, wherein the gas residue may include a gas mixture from which all or most of the carbon dioxide has been removed by the voltage swing carbon capture process.

[0026] Reference now Figure 2 , depicts an operational flow chart illustrating a voltage swing carbon capture process 200 according to at least one embodiment. The voltage swing carbon capture process 200 utilizes the voltage swing carbon capture system 100 to alternately charge between the two sides 114 and 128 of a capacitor plate. At 202, the voltage swing carbon capture system 100 positively charges a first capacitor plate disposed within the second chamber and negatively charges a second capacitor plate disposed within the fourth chamber. Here, the voltage swing carbon capture system 100 may positively charge the first capacitor plate 114 disposed within the second chamber 108 to increase the selectivity and carbon capture rate of the first capacitor plate 114, and may simultaneously negatively charge or discharge the second capacitor plate 128 disposed within the fourth chamber 122 to release captured carbon dioxide from the second capacitor plate 128. The capacitor plates 114, 128 may be adsorbents, which may be any conductive solid material that adsorbs carbon dioxide by physical adsorption. In other words, the carbon dioxide binds to the adsorbent due to electrical and / or van der Waals rather than chemical adsorption using electrochemical means to form a molecular bond between the adsorbent and the carbon dioxide. The adsorbent may be activated carbon, a conductive metal organic framework (MOF), or any other suitable adsorbent. By making the capacitor plate 114 positively charged, the voltage swing carbon capture system 100 increases the selectivity and adsorption of the capacitor plate 114, thereby allowing the capacitor plate 114 to adsorb a high proportion and amount of carbon dioxide from the gas mixture in the second chamber 108. By making the second capacitor plate 128 negatively charged or grounded, the voltage swing carbon capture system 100 reduces the selectivity and adsorption load of the second capacitor plate 128, making it easier to strip carbon dioxide molecules from the second capacitor plate 128, thereby regenerating the second capacitor plate 128.

[0027] The voltage swing carbon capture system 100 may employ any number or type of desorption methods combined with a voltage swing, such as temperature swing adsorption or pressure swing adsorption. Temperature swing adsorption may include heating the adsorbent to add enough thermal energy to cause the captured molecules to escape the surface of the adsorbent, while pressure swing adsorption may include lowering the pressure surrounding the adsorbent to induce desorption from the adsorbent. For example, a high pressure gas mixture may be configured to create a pressure swing system while the output gas (carbon dioxide, nitrogen, gas residue) is maintained at atmospheric pressure or lower, wherein the voltage swing carbon capture system 100 will include high pressure adsorption and low pressure desorption.

[0028] At 204, the voltage swing carbon capture system 100 allows high pressure gas containing nitrogen and carbon dioxide to enter the first chamber 102 and the second chamber 108. Here, the voltage swing carbon capture system 100 may close the outlet 106 and open the input 104 and the valve 110 to allow the gas mixture to flow into the first chamber 102 and the second chamber 108 and capture carbon dioxide from the gas mixture in the first chamber 102 and the second chamber 108. The outlets 106 and 112 may remain closed at this time. The voltage swing carbon capture system 100 allows the gas mixture to flow from the first chamber 102 to the second chamber 108 through the valve 110, so that the gas mixture is exposed to the positively charged first capacitor plate 114; therefore, when molecular diffusion causes the component molecules of the gas mixture to move evenly around the two chambers 102 and 108, the positively charged first capacitor plate 114 may begin to adsorb carbon dioxide from the gas mixture in the first chamber 102 and the second chamber 108. The gas mixture may be flue gas, which may be a combination of nitrogen and carbon dioxide. The gas mixture may also be atmospheric air, which may be a combination of nitrogen, oxygen, carbon dioxide, etc. The gas mixture may be pressurized to facilitate its movement into the voltage swing carbon capture system 100, and the voltage swing carbon capture system 100 may reduce the pressure within the first chamber 102 and / or the second chamber 108 to further facilitate the movement of the gas mixture. The voltage swing carbon capture system 100 may maintain a positive charge on the first capacitor plate 114 while allowing the high pressure gas mixture to enter so as to adsorb as much carbon dioxide as possible from the gas mixture. In some embodiments of the present invention, once the first capacitor plate 114 has reached a threshold saturation of carbon dioxide, the voltage swing carbon capture system 100 may close the valve 110, isolating the first chamber 102 and the second chamber 108 from each other, trapping nitrogen in the first chamber 102 and ensuring that when carbon dioxide is desorbed from the first capacitor plate 114, the carbon dioxide will remain trapped and isolated within the second chamber 108; the voltage swing carbon capture system 100 may further close the inlet 104 to stop further input of the gas mixture.

[0029] At 206, the voltage swing carbon capture system 100 discharges the released carbon dioxide from the fourth chamber 122 and discharges nitrogen from the third chamber 116. Here, the previously captured carbon dioxide has been desorbed from the second capacitor plate 128 by making it negatively charged or grounded for an additional desorption method. In this way, the fourth chamber 122 can be filled with almost pure carbon dioxide. This carbon dioxide can be released from the system, for example, by opening the outlet 126. Once released into some kind of storage, the carbon dioxide can be stored, such as for sequestration or industrial use. The voltage swing carbon capture system 100 can maintain a negative or neutral charge on the second capacitor plate 128 during the duration of the carbon dioxide discharge in order to re-adsorb as little desorbed carbon dioxide as possible. The voltage swing carbon capture system 100 can release nitrogen from the third chamber 116 by opening the outlet 120. The nitrogen in the third chamber 116 can be a gas mixture from which all or most of the carbon dioxide has been removed by the positively charged second capacitor plate 128. Nitrogen may alternatively be referred to herein as a nitrogen-rich residual gas residue remaining after carbon dioxide has been removed from the gas mixture, which may be released into the atmosphere or captured and stored. Once carbon dioxide has been exhausted from the fourth chamber 122 and nitrogen has been exhausted from the third chamber 116, as determined, for example, by sensor data or inferred after a predetermined period of time, the voltage swing carbon capture system 100 may close outlets 126 and 120.

[0030] At 208, the voltage swing carbon capture system 100 charges the first capacitor plate 114 negatively and charges the second capacitor plate 128 positively. Here, the voltage swing carbon capture system 100 may switch the polarity of the voltage regulator 130 to charge the first capacitor plate 114 negatively or grounded to release the captured carbon dioxide, and charge the second capacitor plate 128 disposed within the fourth chamber 122 positively to capture carbon dioxide. Here, by charging the first capacitor plate 114 negatively or grounded, the voltage swing carbon capture system 100 reduces the selectivity and adsorption of the first capacitor plate 114, reducing the energy required to strip carbon dioxide molecules from the first capacitor plate 114, thereby reducing the energy required to regenerate the first capacitor plate 114. By charging the second capacitor plate 128 positively, the voltage swing carbon capture system 100 increases the selectivity and adsorption of the second capacitor plate 128, thereby allowing the second capacitor plate 128 to adsorb a high proportion and amount of carbon dioxide when exposed to the gas mixture.

[0031] The voltage swing carbon capture system 100 may employ any number or type of desorption methods (e.g., temperature swing or pressure swing) in combination with negative charging or grounding. Temperature swing adsorption may include heating the adsorbent to add enough thermal energy to cause the captured molecules to escape the surface of the adsorbent, while pressure swing adsorption may include reducing the pressure surrounding the adsorbent to induce desorption from the adsorbent.

[0032] At 210, the voltage swing carbon capture system 100 exhausts the released carbon dioxide from the second chamber 108 and exhausts nitrogen from the first chamber 102. Here, the previously captured carbon dioxide has been desorbed from the first capacitor plate 114 due to the negative or zero charge employed and any additional desorption methods. Therefore, the second chamber 108 can be filled with almost pure carbon dioxide. The voltage swing carbon capture system 100 can release this carbon dioxide from the third chamber 116 by opening the outlet 112, which can then be stored, such as for sequestration or industrial use. At the same time, with most of the carbon dioxide adsorbed, the voltage swing carbon capture system 100 can open the outlet 106 to release nitrogen from the first chamber 102, which is the nitrogen remaining after the carbon dioxide is adsorbed into the first transistor plate 114. Once the carbon dioxide has been exhausted from the second chamber 108 and the nitrogen has been exhausted from the first chamber 102, as determined, for example, by sensor data or inferred after a predetermined period of time, the voltage swing carbon capture system 100 can close the outlets 106 and 112.

[0033] At 212, the voltage swing carbon capture system 100 allows the high pressure gas including nitrogen and carbon dioxide to enter the third chamber 116. Here, both the second chamber 108 and the fourth chamber 122 have been emptied of carbon dioxide, the former by ventilation and the latter by adsorption. The voltage swing carbon capture system 100 opens the inlet 118 and the valve 124 to allow the gas mixture to flow into the third chamber 116 and then into the fourth chamber 122 through the valve 124, so that the gas mixture is exposed to the second capacitor plate 128. The gas mixture may be pressurized to facilitate its movement into the voltage swing carbon capture system 100, and the voltage swing carbon capture system 100 may reduce the pressure within the third chamber 116 and / or the fourth chamber 122 to further facilitate the movement of the gas mixture. The voltage swing carbon capture system 100 may maintain a positive charge on the second capacitor plate 128 while allowing the high pressure gas mixture to enter in order to adsorb as much carbon dioxide as possible from the gas mixture. In some embodiments of the present invention, once the second capacitor plate 128 has reached a threshold saturation of carbon dioxide, the voltage swing carbon capture system 100 can close the valve 124 to isolate the fourth chamber 122 and the third chamber 116 from each other, trapping the nitrogen in the third chamber 116 and ensuring that when the carbon dioxide is desorbed from the second capacitor plate 128, the carbon dioxide is trapped and isolated within the fourth chamber 122; the voltage swing carbon capture system 100 can further close the inlet 118 to stop further input of the gas mixture.

[0034] At 214, the voltage swing carbon capture system 100 determines whether the carbon capture cycle has terminated. In some embodiments of the present invention, the voltage swing carbon capture system 100 may cycle for as long as the carbon dioxide gas mixture is produced, which may be as long as the power plant burns fuel or the industrial site produces the gas mixture. Therefore, the voltage swing carbon capture system 100 may continue to operate until it receives a termination command. The voltage swing carbon capture system 100 may receive a termination command from an authorized user, where the authorized user may be a user who has been authenticated in one or more combinations of ways. The termination command may be a digital transmission received by the voltage swing carbon capture system 100 over a network, and / or may be a specific input typed on a user interface device integrated into the voltage swing carbon capture system 100. According to one embodiment, if the voltage swing carbon capture system 100 determines that the carbon capture cycle has not received a termination command and therefore has not terminated (step 214, "no" branch), the voltage swing carbon capture system 100 may continue to step 202 to positively charge the first capacitor plate 114 disposed in the second chamber 108 and negatively charge the second capacitor plate 128 disposed in the fourth chamber 122. If the voltage swing carbon capture system 100 determines that the voltage swing carbon capture system 100 has received a termination command from an authorized user, and therefore the carbon capture cycle has terminated (step 214 , “yes” branch), the voltage swing carbon capture system 100 may terminate the voltage swing carbon capture process 200 .

[0035] Reference now Figure 3A , depicts an exemplary voltage swing carbon capture system 300 according to at least one embodiment. Here, the voltage swing carbon capture system 300 includes two chambers, a first chamber 302 including an inlet 304 for a gas mixture (which may be atmospheric air or flue gas) and an outlet 306 for exhausting residual gas, and a second chamber 308 including an outlet 310 for regeneration gas. Disposed within the first chamber is a porous carbon adsorbent 312, which may be an adsorbent composed of activated carbon, and the porous carbon adsorbent 312 may in turn be disposed within a conductive container 314, which may be slidable between the first chamber 302 and the second chamber 308. The voltage swing carbon capture system 300 may be electrically connected to a voltage source 316 and a ground 318.

[0036] Reference now Figure 3B , depicts an exemplary voltage swing carbon capture system 300 according to at least one embodiment. Figure 3B The voltage swing carbon capture system 300 is shown at a state during a voltage swing carbon capture process, wherein the porous carbon adsorbent 312 has been transferred from the first chamber 302 to the second chamber 308 .

[0037] Reference now Figure 4 , depicts an operational flow chart illustrating a voltage swing carbon capture process 400 according to at least one embodiment. The voltage swing carbon capture process 400 moves a porous carbon adsorbent 312 between two chambers 302, 308, thereby moving carbon dioxide from the first chamber 302 to the second chamber 308. At 402, the voltage swing carbon capture system 300 applies an electric charge to the porous carbon adsorbent 312 disposed within the first chamber 302. Here, the voltage swing carbon capture system 300 may apply a uniform positive charge to the porous carbon adsorbent 312 via a voltage source 316; the voltage swing carbon capture system 300 may apply a charge to the porous carbon adsorbent 312 to, for example, 0.1 electron charge per atom, thereby increasing adsorption to about 20 mol / kg (according to our computer modeling). Since 20 mol / kg is close to the saturation value, increasing the charge more may not necessarily capture more carbon dioxide. However, for different activated carbon structures, the charge at saturation may be different, so deviations from this value are contemplated without departing from the scope of the present invention.

[0038] At 404, the voltage swing carbon capture system 300 allows a gas mixture to enter the first chamber 302. The gas mixture may be flue gas or atmospheric air. Here, the voltage swing carbon capture system 300 opens the inlet 304 to allow the gas mixture to enter, which may be pressurized to facilitate its movement through the voltage swing carbon capture system 300. This gas mixture may then come into contact with the charged porous carbon adsorbent 312, which may adsorb carbon dioxide from the gas mixture. At this stage, the outlet 306 may be closed.

[0039] At 406, the voltage swing carbon capture system 300 moves the charged porous carbon adsorbent 312 to the second chamber 308. The charged porous carbon adsorbent 312 may be placed in a conductive container 314 that may slide between the first chamber 302 to the second chamber 308 using pneumatic, motorized, or any other means. The charged porous carbon adsorbent 312 may be moved when the charged porous carbon adsorbent 312 is saturated with carbon dioxide, which may be positively detected by a sensor or may be approximated at regular intervals per cycle based on the input rate of the input gas mixture and the adsorption rate of the charged porous carbon adsorbent 312. Thus, the voltage swing carbon capture system 300 may shuttle the captured carbon dioxide out of the first chamber 302 and leave a gas residue containing the original gas mixture but deficient in carbon dioxide.

[0040] At 408, the voltage swing carbon capture system 300 regenerates the gas in the second chamber 308 by releasing the voltage from the porous carbon adsorbent 312. Here, the porous carbon adsorbent 312 is saturated with carbon dioxide from the first chamber 302. The voltage swing carbon capture system 300 releases the charge to the porous carbon adsorbent 312, causing its charge to decrease to zero, which in turn reduces the selectivity and adsorption of the porous carbon adsorbent 312, and reduces the energy cost of releasing the captured carbon dioxide from the surface of the porous carbon adsorbent 312, and reduces the efficiency and rate at which the porous carbon adsorbent 312 can re-adsorb carbon dioxide that has been previously released therefrom. The voltage swing carbon capture system 300 can remove the captured carbon dioxide from the surface of the porous carbon adsorbent 312 by using any number of desorption techniques (e.g., pressure swing adsorption and temperature swing adsorption) or a combination of desorption techniques. Through the desorption / regeneration of the porous carbon adsorbent 312, the voltage swing carbon capture system 300 can fill the second chamber 308 with the released carbon dioxide gas.

[0041] At 410, the voltage swing carbon capture system 300 exhausts residual gas from the first chamber 302 by reducing the pressure in the first chamber 302. Here, the first chamber 302 may contain residual gas, which may be the remaining portion of the original gas mixture once the porous carbon adsorbent 312 has adsorbed and removed carbon dioxide from the gas mixture. The voltage swing carbon capture system 300 may exhaust the residual gas, for example, by opening the outlet 306. The residual gas may be directly discharged to the atmosphere or captured for sequestration or for other purposes. The voltage swing carbon capture system 300 may exhaust the residual gas by reducing the pressure outside the outlet 306 so that the gas escapes.

[0042] At 412, the voltage swing carbon capture system 300 moves the porous carbon adsorbent 312 to the first chamber 302. Here, the voltage swing carbon capture system 300 moves the discharged and newly regenerated porous carbon adsorbent 312 from the second chamber 308 to the first chamber 302 to recharge at the first chamber 302 and begin adsorbing additional carbon dioxide from the gas mixture.

[0043] At 414, the voltage swing carbon capture system 300 exhausts carbon dioxide from the second chamber 308 by reducing the pressure outside the outlet 310. Here, the voltage swing carbon capture system 300 opens the outlet 310 to release the contents of the chamber 308, which may be carbon dioxide desorbed from the porous carbon adsorbent 312 during the regeneration process. The carbon dioxide may be sequestered or used in industrial applications.

[0044] At 416, the voltage swing carbon capture system 300 determines whether the efficiency of the porous carbon adsorbent 312 has dropped below a threshold. The threshold may represent the efficiency of the porous carbon adsorbent 312 in separating carbon dioxide from the gas mixture, and may be measured by measuring the proportion of carbon dioxide remaining in the gas residue exhausted from the outlet 306. According to one embodiment, if the voltage swing carbon capture system 300 determines that the efficiency of the porous carbon adsorbent 312 has not dropped below the threshold (step 416, "no" branch), the voltage swing carbon capture system 300 may continue to step 402 to apply an electric charge to the porous carbon adsorbent 312 disposed in the first chamber. If the voltage swing carbon capture system 400 determines that the efficiency of the porous carbon adsorbent 312 has dropped below the threshold (step 416, "yes" branch), the voltage swing carbon capture system 300 may terminate the voltage swing carbon capture process 400. In some embodiments of the present invention, the voltage swing carbon capture system 300 may alternatively or additionally determine whether the carbon capture cycle has terminated by determining whether the voltage swing carbon capture system 300 has received a termination command from an authorized user.

[0045] Understandably, Figure 1-Figure 4 Only illustrations of various embodiments are provided, and no limitations on how different embodiments may be implemented are implied. Many modifications may be made to the depicted environment based on design and implementation requirements. For example, in at least one embodiment of the present invention, only one side of the voltage swing carbon capture system 100 may be employed, having chambers 102 and 108, inlet 104, valve 110, and outlets 106 and 112. The capacitor plate 114 may alternate between a positive charge and a negative charge or zero charge, wherein adsorption of carbon dioxide occurs during the phase of positive charge and desorption of carbon dioxide occurs during the phase of negative charge or zero charge. During the positive charge phase, the inlet 104 and valve 110 may be opened, and the outlets 106 and 112 may be closed to allow high pressure gas including nitrogen and carbon dioxide to enter, while during the negative charge or zero charge phase, the inlet 104 and valve 110 may be closed, and the outlets 106 and 112 may be opened to release the separated gas.

[0046] The description of various embodiments of the present invention has been given for the purpose of illustration, but is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, practical applications, or technical improvements over technologies found in the marketplace, or to enable those of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for carbon capture, the method comprising: Capturing carbon dioxide from a gas mixture by applying a positive charge to the adsorbent to increase the selectivity and adsorption of the adsorbent; as well as The carbon dioxide is released from the adsorbent by removing the positive charge from the adsorbent and subjecting the adsorbent to a desorption process.

2. The method according to claim 1, wherein: The adsorbent includes activated carbon, conductive metal organic framework (MOF) or conductive zeolite.

3. The method according to claim 1, wherein: The adsorbent captures carbon dioxide from the gas mixture by physical adsorption.

4. The method according to claim 1, wherein: The desorption methods include pressure swing and temperature swing.

5. The method according to claim 1, wherein: The gas mixture is flue gas or atmospheric air.

6. The method according to claim 1, wherein: The capturing is responsive to determining that an efficiency of the adsorbent is not below a threshold value.

7. The method according to claim 1, wherein: The adsorbent includes activated carbon, and the positive charge includes a charge density of 0.1 electrons per atom in the adsorbent.

8. A method for carbon capture, the method comprising: charging a capacitor including two plates of opposite charge such that when a first plate of the two plates is negatively charged, a second plate of the two plates is positively charged, and when the first plate of the two plates is positively charged, the second plate of the two plates is negatively charged; capturing carbon dioxide from a gas mixture using the positively charged side of the capacitor; desorbing previously captured carbon dioxide using the negatively charged side of the capacitor and one or more desorption methods; and The two capacitor plates are charged alternately at regular intervals.

9. The method according to claim 8, wherein: The adsorbent includes activated carbon, conductive metal organic framework (MOF) or conductive zeolite.

10. The method according to claim 8, wherein: The adsorbent captures carbon dioxide from the gas mixture by physical adsorption.

11. The method according to claim 8, wherein: The desorption methods include pressure swing and temperature swing.

12. The method according to claim 8, wherein: The gas mixture is flue gas or atmospheric air.

13. The method according to claim 8, wherein: The capturing is responsive to determining that an efficiency of the adsorbent is not below a threshold value.

14. The method according to claim 8, wherein: The adsorbent includes activated carbon, and the positive charge includes a charge density of 0.1 electrons per atom of the adsorbent.

15. A method for carbon capture, the method comprising: capturing carbon dioxide from the gas mixture to produce a residual gas by applying a positive charge to the adsorbent disposed in the first chamber to increase selectivity and adsorption of the adsorbent; moving the charged adsorbent to a second chamber; Discharging the charged adsorbent; desorbing captured carbon dioxide from the discharged sorbent into a second chamber; exhausting the residual gas from the first chamber; moving the discharged sorbent to the first chamber; as well as The reabsorbed carbon dioxide is exhausted from the second chamber.

16. The method according to claim 15, wherein: The adsorbent includes activated carbon, conductive metal organic framework (MOF) or conductive zeolite.

17. The method according to claim 15, wherein: The adsorbent captures carbon dioxide from the gas mixture by physical adsorption.

18. The method according to claim 15, wherein: The desorption methods include pressure swing and temperature swing.

19. The method according to claim 15, wherein: The gas mixture is flue gas or atmospheric air.

20. The method of claim 15, wherein the capturing is responsive to determining that an efficiency of the adsorbent is not below a threshold.

Images