System and method for dehumidifying and purifying air by coal-based electrothermal swing adsorption

Abstract

The electric thermal swing adsorption system includes an electric thermal swing adsorption device that includes a first chamber including at least one carbon monolith and a second chamber including at least one carbon monolith, and that receives a supply of air, desorbs at least one of moisture and air contaminants from the supply of air, discharges a dehumidified stream, and discharges a dehumidified exhaust stream.

Description

[Technical Field]

[0001] cross reference This patent application is a non-provisional adaptation of U.S. Provisional Patent Application No. 63 / 483,223, filed February 3, 2023, entitled "Systems and Methods for Dehumidifying and Purifying Air Through Coal-Based Electrothermal Swing Adsorption," the entire disclosure of which is incorporated herein by reference.

[0002] FIELD OF THE INVENTION Embodiments described herein relate generally to dehumidification with a coal-based electrothermal swing adsorption system for dehumidifying air and reducing air contaminants. More specifically, embodiments of the present invention relate to systems, apparatus, and methods for dehumidifying and purifying air from a building's heating, ventilation, and air conditioning (HVAC) system. [Background technology]

[0003] Many buildings are equipped with heating, ventilation, and air conditioning (HVAC) systems. Many of these HVAC systems include dehumidification systems to remove moisture from the air within the HVAC system and air purification systems to remove air contaminants from the air within the HVAC system. Liquid desiccant air conditioning (LDAC) systems are beginning to be implemented in commercial and residential applications. However, both of these systems suffer from increased costs and reduced effectiveness due to inefficiencies and recurring maintenance issues. Summary of the Invention [Means for solving the problem]

[0004] In at least one example, an electrothermal swing adsorption system includes an electrothermal swing adsorption device having a first chamber containing at least one carbon monolith and a second chamber containing at least one carbon monolith, the electrothermal swing adsorption device receiving a supply of air, desorbing at least one of moisture and air contaminants from the supply of air, outputting a dehumidified stream, and outputting a moisture- and / or air contaminant-removed exhaust stream.

[0005] In one example, at least one carbon monolith in the first chamber adsorbs at least one of moisture and air contaminants, and at least one carbon monolith in the second chamber desorbs at least one of moisture and air contaminants simultaneously with the at least one carbon monolith in the first chamber adsorbing at least one of moisture and air contaminants. In one example, at least one carbon monolith in the second chamber adsorbs at least one of moisture and air contaminants, and at least one carbon monolith in the first chamber desorbs at least one of moisture and air contaminants simultaneously with the at least one carbon monolith in the second chamber adsorbing at least one of moisture and air contaminants. In one example, the first chamber and the second chamber are cyclically operated to continuously adsorb and desorb at least one of moisture and air contaminants, with adsorption occurring in one of the first chamber and the second chamber while desorption occurs in the other of the first chamber and the second chamber. In one example, each carbon monolith comprises coal-based activated carbon fiber. In one example, each carbon monolith is optimized to adsorb moisture or a specific air contaminant. In one example, the electric thermal swing adsorption device includes a reservoir for storing moisture desorbed from at least one carbon monolith in the second chamber. In one example, the electric thermal swing adsorption system includes multiple electric thermal swing adsorption devices arranged in series, each adsorbing at least one or more of moisture and air contaminants from the supplied air. In one example, each electric thermal swing adsorption device outputs a removal exhaust stream of at least one of moisture and air contaminants. In one example, each electric thermal swing adsorption device includes a reservoir for storing the removal exhaust of at least one of moisture and air contaminants. In one example, the electric thermal swing adsorption system achieves a moisture removal efficiency of at least 396 mg / g at a relative humidity of 98% and a temperature of 298 K.

[0006] In at least one example, a method for dehumidifying and purifying air from a building's HVAC system using an electric thermal swing adsorption system includes supplying air from the building's HVAC system to a first chamber of an electric thermal swing adsorption device; adsorbing at least one of moisture and air contaminants with a first carbon monolith in the first chamber; and discharging an exhaust stream of dehumidified and purified air from the first chamber of the electric thermal swing adsorption device.

[0007] For example, the method may further include supplying a purge gas to a second chamber of the electrothermal swing adsorption device, separate from the first chamber, and desorbing at least one of moisture and air contaminants from a second carbon monolith with the purge gas in the second chamber, where the second carbon monolith has previously adsorbed at least one of moisture and air contaminants. For example, the method may further include discharging a removal stream of at least one of moisture and air contaminants from the second chamber of the electrothermal swing adsorption device. For example, the method may further include applying an electric current to the second carbon monolith in the second chamber to increase the temperature of the second carbon monolith, thereby desorbing at least one of moisture and air contaminants from the second carbon monolith. For example, the method may further include switching the supply of air from the building's HVAC system from the first chamber to the second chamber and switching the supply of purge gas from the second chamber to the first chamber when the first carbon monolith has adsorbed a predetermined amount of at least one of moisture and air contaminants.

[0010] In one example, the method further includes adsorbing at least one of moisture and air contaminants with a second carbon monolith in the second chamber, and desorbing at least one of moisture and air contaminants from the first carbon monolith in the first chamber with a purge gas. In one example, the first carbon monolith and the second carbon monolith comprise coal-based activated carbon fiber. In one example, the coal-based activated carbon fiber is optimized to adsorb moisture or a specific air contaminant. In one example, the electric thermal swing adsorption system comprises multiple electric thermal swing adsorption devices arranged in series, with a building's HVAC air supply being fed to each electric thermal swing adsorption device in series, and each electric thermal swing adsorption device adsorbing moisture or a specific air contaminant. [Brief explanation of the drawings]

[0008] The drawings illustrate several embodiments of the present disclosure, and the same reference numerals in different views or embodiments shown in the drawings refer to the same or similar elements or features.

[0009] [Figure 1] FIG. 1 shows a schematic diagram of an electric thermal swing adsorption system having multiple electric thermal swing adsorption devices according to one embodiment of the present disclosure.

[0010] [Figure 2] FIG. 1 shows a schematic diagram of an electrothermal swing adsorption device in a first configuration, according to one embodiment of the present disclosure.

[0011] [Figure 3] 3 shows a schematic diagram of the electrothermal swing adsorption device of FIG. 2 in a second configuration.

[0012] [Figure 4] 1 shows a flowchart of a method for dehumidifying and purifying air from a building's heating, ventilation, and air conditioning (HVAC) system using a first electric thermal swing adsorption device, according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] The descriptions in this specification are for illustrative purposes only and are not intended to limit the scope, applicability, or configuration of the present disclosure. Accordingly, changes may be made in the function and arrangement of the elements described, and embodiments may omit, substitute, or add other procedures or components, as appropriate, without departing from the spirit and scope of the present disclosure. For example, methods described may be performed in an order different from that described, and steps may be added, omitted, or combined. Additionally, features described with respect to some embodiments may be combined in other embodiments.

[0014] Dehumidification systems utilizing activated carbon fiber cloth have been demonstrated to be effective and renewable by being heated and regenerated by solar energy. This disclosure relates to dehumidification systems for building heating, ventilation, and air conditioning (HVAC) systems that utilize electric thermal swing adsorption systems. While this disclosure describes the use of electric thermal swing adsorption systems in building HVAC systems, electric thermal swing adsorption systems can be used in many different contexts and to dehumidify air in a variety of contexts outside of HVAC systems. For example, they can be used in solvent recovery in chemical refineries or other industrial processes, such as the manufacture of composite materials and building materials, including oriented strand board (OSB).

[0015] Electrothermal desorption can be achieved in an electric thermal swing adsorption system by passing an electric current through the activated carbon fibers in the activated carbon fiber monolith to induce Joule heating. This method has been shown to be highly efficient compared to other heating methods, such as gas burners and external resistive elements. By utilizing an electric thermal swing adsorption system containing alternating adsorption and desorption chambers, an all-electric dehumidification system can simultaneously dehumidify the air in a building's HVAC system and reduce carbon dioxide and other air pollutants. In other words, the dehumidification system can simultaneously dehumidify and purify the air in the building's HVAC system. Furthermore, the dehumidification and purification system of the present disclosure has the added benefit of reducing the amount of outside air that needs to be exchanged with the air inside a building to maintain air quality during indoor air conditioning.

[0016] FIG. 1 illustrates an electric thermal swing adsorption system 100 according to one embodiment of the present disclosure. The electric thermal swing adsorption system 100 is configured to dehumidify air and reduce carbon dioxide and other contaminants from the air. In other words, moisture is removed from the air. The electric thermal swing adsorption system 100 can be used in a building to dehumidify the air in the building's HVAC system. The electric thermal swing adsorption system 100 includes an intake stream 102 of air from the building's HVAC system and an exhaust stream 104 of dehumidified and / or purified air. "Dehumidification" refers to the percentage of moisture in the air being 30% to 50% (reduced from 50% to 100%), and does not refer to complete removal of moisture from the air. "Purification" does not refer to complete removal of all air contaminants, but rather refers to the presence of an acceptable concentration (in ppm) of air contaminants in the exhaust stream 104. For example, reducing the concentration of toxic air pollutants or hazardous air pollutants (HAPs) in urban areas from greater than 800 ppm to less than 300 ppm.

[0017] Electric thermal swing adsorption system 100 may include multiple electric thermal swing adsorption devices 110, 120, 130 arranged in series. The illustrated embodiment shows a first electric thermal swing adsorption device 110, a second electric thermal swing adsorption device 120, and a third electric thermal swing adsorption device 130. In other words, air in intake air stream 102 is dehumidified and purified by first electric thermal swing adsorption device 110, then dehumidified and purified by second electric thermal swing adsorption device 120, and further dehumidified and purified by third electric thermal swing adsorption device 130. However, the disclosure is not limited in this respect, and electric thermal swing adsorption system 100 may include more or less than three electric thermal swing adsorption devices to dehumidify and purify intake air stream 102 from a building's HVAC system.

[0018] In some embodiments, electric thermal swing adsorption devices 110, 120, 130 of electric thermal swing adsorption system 100 may be arranged in parallel. In other words, electric thermal swing adsorption devices 110, 120, 130 may simultaneously dehumidify and purify air from intake air stream 102, increasing the rate at which the air in intake air stream 102 is dehumidified and purified.

[0019] Additionally, each of the electric thermal swing adsorption devices 110, 120, 130 of the electric thermal swing adsorption system 100 includes a removal exhaust stream 111, 121, 131 of moisture and other adsorbates exiting the respective electric thermal swing adsorption device 110, 120, 130. Each of the electric thermal swing adsorption devices 110, 120, 130 may be optimized for adsorption of moisture, carbon dioxide, or other air contaminants. For example, the first electric thermal swing adsorption device 110 may be optimized to remove moisture from the inlet air stream 102 to dehumidify the inlet air stream. The second electric thermal swing adsorption device 120 may be optimized to remove carbon dioxide from the inlet air stream 102 after the first electric thermal swing adsorption device 110 has removed moisture from the inlet air stream 102. The third electric thermal swing adsorption device 130 may be optimized to remove carbon monoxide from the inlet air stream 102 after the first and second electric thermal swing adsorption devices 110 and 120 have removed moisture and carbon dioxide from the air in the inlet air stream 102. As a result, the exhaust stream 104 is dehumidified and purified of air contaminants. The electric thermal swing adsorption system 100 may include additional electric thermal swing adsorption devices to remove other specific air contaminants from the inlet air stream 102, including, but not limited to, lead, nitrogen oxides, ozone, particulate matter, sulfur dioxide, and the like.

[0020] The first removed discharge stream 111 may transfer or discharge water or other adsorbates to a first reservoir for storage. The second removed discharge stream 121 may transfer or discharge water or other adsorbates to a second reservoir for storage. The third removed discharge stream 131 may transfer or discharge water or other adsorbates to a third reservoir for storage. In some embodiments, the first, second, and third reservoirs may be different reservoirs, each storing water or a specific adsorbate. In some embodiments, the first, second, and third reservoirs may be the same reservoir that stores water and all the different adsorbates adsorbed by the electrothermal swing adsorption devices 110, 120, and 130.

[0021] 2 shows a schematic diagram of electric thermal swing adsorption apparatus 110 in a first configuration according to one embodiment of the present disclosure. While FIG. 2 shows only the schematic diagram of electric thermal swing adsorption apparatus 110 in the first configuration, electric thermal swing adsorption apparatuses 120 and 130 in their first configurations are similar to the schematic diagram of first electric thermal swing adsorption apparatus 110 in the first configuration.

[0022] The first electrothermal swing adsorption device 110 includes a first chamber 112 and a second chamber 113. The first chamber 112 and the second chamber 113 each contain at least one carbon monolith. In some embodiments, the first chamber 112 and the second chamber 113 may each contain only a single carbon monolith. In some embodiments, the first chamber 112 and the second chamber 113 may each contain multiple carbon monoliths.

[0023] In the illustrated embodiment, the first chamber 112 contains an activated carbon monolith for adsorbing moisture and / or air contaminants, and the second chamber 113 contains a regenerated carbon monolith for desorbing moisture and / or air contaminants. The regenerated carbon monolith in the second chamber 113 has previously adsorbed moisture and / or air contaminants. In some embodiments, the carbon monolith in the second chamber 113 may not yet have adsorbed moisture and / or air contaminants when initially placed in the second chamber 113. The first chamber 112 and the second chamber 113 are cyclically operated to continuously adsorb and desorb moisture and / or air contaminants.

[0024] The carbon monoliths in the first chamber 112 and the second chamber 113 each contain coal-based activated carbon fibers. The coal-based activated carbon fibers are derived from coal feedstock, making them 50% to 75% more cost-effective than existing commercially available fibers made from polyacrylonitrile (PAN), rayon, and petroleum pitch precursors. The carbon fibers are produced by melt-blowing isotropic pitch obtained from subbituminous coal ore via a direct coal liquefaction process. Using subbituminous coal ore as a precursor allows for the production of carbon monoliths at a much lower cost than using other types of activated carbon fiber or granular activated carbon. Therefore, the subbituminous coal ore makes the system economical to manufacture. This novel carbon fiber monolith is characterized by the fact that it does not require a binder and eliminates a single carbonization step.

[0025] Carbon monoliths and coal-based activated carbon fibers may be optimized for moisture or specific air pollutant adsorption. Activated carbon fibers can be functionalized to specifically target moisture and indoor air pollutants, as evaluated for oxygen-containing functional groups and demonstrated in activated carbon fibers doped with silica nanoparticles. Tailoring the properties of activated carbon fibers can improve moisture adsorption and system performance. Activated carbon fiber properties include pore size, pore size distribution, BET specific surface area, thermal conductivity, bulk density, air permeability, and electrical resistivity. The carbon monoliths in the first chamber 112 and the second chamber 113 may be similar so that each monolith targets moisture or the same specific air pollutant.

[0026] For example, the bulk density of a carbon monolith is approximately 0.05 g / cm 3 In some cases, the bulk density of the carbon monolith is about 0.05 g / cm 3 to approximately 0.7 g / cm 3 In some cases, the bulk density range may be about 0.7 g / cm 3 In other examples, the bulk density may be less than 0.6 g / cm 3 Less than 0.5g / cm 3 Less than or equal to 0.1g / cm 3 In some examples, the bulk density of the carbon monolith may be less than about 0.05 g / cm 3 to approximately 0.2 g / cm 3 Another range may be about 0.2 g / cm 3 to approximately 0.4 g / cm 3 , approximately 0.4 g / cm 3 to about 0.5 g / cm 3 , about 0.5g / cm 3 to approximately 0.6 g / cm 3 , or about 0.6 g / cm 3 to approximately 0.7 g / cm 3In some cases, the bulk density can be adjusted by adjusting the rate of temperature increase during the formation of the carbon fiber monolith, but can also be adjusted by adjusting the air flow or oxygen concentration during the formation of the carbon fiber monolith.

[0027] In some cases, the air permeability of a carbon monolith may vary primarily based on bulk density. In some cases, the air permeability may also be affected by the fiber spacing and the degree of fusion at the nodes when forming the carbon fiber monolith. In some cases, the air permeability of a carbon monolith may be approximately 1×10 -10 m 2 to approximately 8.5 x 10 -11 m 2 In some cases, the air permeability may range from about 9.8×10 -11 m 2 In other examples, the air permeability may be less than 9.5×10 -11 m 2 Less than 9.0 x 10 -11 m 2 Less than or 8.8 x 10 -11 m 2 In some cases, the air permeability of the carbon monolith may be less than about 1×10 -10 m 2 to approximately 9.8 x 10 -11 m 2 Another range may be about 9.8×10 -11 m 2 to approximately 9.5 x 10 -11 m 2 , about 9.5×10 -11 m 2 to approximately 9.3 x 10 -11 m 2 , about 9.3×10 -11 m 2 to approximately 9.0 × 10 -11 m 2 , about 9.0×10 -11 m 2 to approximately 8.8 x 10 -11 m 2 , or approximately 8.8 × 10 -11 m 2 to approximately 8.5 x 10 -11 m 2The intrinsic permeability of a porous medium, such as a carbon monolith, measures its ability to pass a fluid under the influence of a pressure gradient. For practical applications, it is very important to predict the permeability of a given medium based on its porous structure.

[0028] Additionally, the properties of the activated carbon fiber can be tailored to reduce the temperature and energy required to desorb moisture and / or air contaminants from the carbon monolith. As described below, applying an electric current to the carbon monolith can aid in the desorption process by increasing the temperature of the carbon fibers in the carbon monolith through Joule heating due to the electrical resistance of the carbon fibers, thereby removing moisture and air contaminants from the regenerated carbon monolith. As an example, the electrothermal swing adsorption device 110 can desorb air contaminants (e.g., methyl ethyl ketone) in moist air at rates ranging from about 9.9 kJ / g to about 28 kJ / g.

[0029] First electrothermal swing adsorption device 110 includes a feed stream 114, which is intake air from a building's HVAC system. Feed stream 114 may be the same as intake air stream 102. Feed stream 114 may include airborne moisture and other airborne contaminants.

[0030] The feed stream 114 flows along a feed flow path 115, including a first feed flow path 115A. The feed flow path 115 is introduced or received into a first chamber 112 via the first feed flow path 115A. Moisture and / or air contaminants are adsorbed by the activated carbon monolith in the first chamber 112, thereby dehumidifying and / or purifying the feed stream 114. The first chamber 112 is connected to an exhaust stream 104, and the purified feed stream 114 is discharged from the first chamber 112 via a first exhaust stream 104A. The exhaust streams 104, 104A are dehumidified and free of the air contaminants that were desorbed by the activated carbon monolith in the first chamber 112. In some embodiments, the exhaust streams 104, 104A are dehumidified and / or do not contain the specific air contaminants for which the carbon monolith in the first chamber 112 is optimized, but may contain additional air contaminants that are removed by subsequent electric thermal swing adsorption devices (e.g., 120, 130). As described above, the exhaust streams 104, 104A may then be introduced into the second electric thermal swing adsorption device 120 and then into the third electric thermal swing adsorption device 130. As described above, after the feed stream 114 has been discharged from all electric thermal swing adsorption devices 110, 120, 130 as the exhaust stream 104, the electric thermal swing adsorption system 100 can achieve a high water removal efficiency of at least 396 mg / g at 98% relative humidity and 298 K. Furthermore, after chemical modification treatment, significantly higher adsorption of 0.5-0.6 mL of water per gram of fiber and 100% desorption after heating to 100°C have been observed.

[0031] The first electrothermal swing adsorption device 110 further includes a purge 116. The purge 116 is a reservoir of purge gas used to desorb moisture and / or air contaminants from the carbon monolith in the second chamber 113. The purge 116 flows along purge flow paths 117, including a first purge flow path 117A. The purge 116 is introduced or received into the second chamber 113 via the first purge flow path 117A. By way of example, the purge gas may include nitrogen or a noble gas. The purge gas may contain various concentrations of oxygen, although oxygen impurities in the purge gas can reduce regeneration efficiency and shorten the life of the adsorbent. The moisture and / or air contaminants are desorbed from the regenerated carbon monolith in the second chamber 113. The regenerated carbon monolith in the second chamber 113 is regenerated by applying an electric current to the regenerated carbon monolith, which induces Joule heating due to the electrical resistance of the carbon fibers within the carbon monolith, raising the temperature of the carbon monolith to 100°C-150°C and desorbing other adsorbed substances, such as moisture and indoor air pollutants. The desorption temperature may depend on the characteristics of the carbon monolith in the second chamber 113, the trapped moisture or air pollutants to be desorbed from the carbon monolith, and the chemical modification of the carbon monolith. The moisture and air pollutants are desorbed from the carbon monolith and enter the purge 116. The purge gas containing the moisture and / or concentrated air pollutants may be exhausted from the second chamber 113 via the first removal exhaust stream 111A and then through the removal exhaust stream 111.

[0032] The removed exhaust stream 111 may be connected to a reservoir 118 that collects and stores moisture and / or air contaminants from the first electrothermal swing adsorption device 110, particularly the first chamber 112. As described above, the reservoir 118 may collect and store moisture and / or certain air contaminants adsorbed by the carbon monolith in the first electrothermal swing adsorption device 110. In some embodiments, the reservoir 118 may include a flow path 119 that is in fluid communication with the feed flow path 115 via a first flow path 119A and with the purge flow path 117 via a second flow path 119B. As an example, this design of the reactor system may minimize the temperature exposure of the first electrothermal swing adsorption device 110 due to partial cooling of the containment vessel walls by the incoming purge flow path 117 and / or second flow path 119B.

[0033] The first electrothermal swing adsorption device 110 operates continuously and cyclically. In other words, a feed stream 114 (e.g., the inlet air stream 102) is continuously introduced into the first chamber 112 to adsorb moisture and / or air contaminants from the feed stream 114, and a purge 116 is continuously introduced into the second chamber 113 to desorb moisture and / or air contaminants from the carbon monolith in the second chamber 113. When the activated carbon monolith in the first chamber 112 begins to reach a predetermined adsorption capacity (e.g., when the carbon monolith cannot adsorb any more moisture and / or air contaminants), the first electrothermal swing adsorption device 110 is switched over. In other words, the carbon monolith in the first chamber 112 can be regenerated by desorbing moisture and / or air contaminants from the carbon monolith using the purge 116, and the carbon monolith in the second chamber 113 can be activated by adsorbing moisture and / or air contaminants from the feed stream 114. Thus, first electrothermal swing adsorption device 110 uses carbon monoliths in first chamber 112 and second chamber 113 to continuously adsorb and desorb moisture and / or air contaminants.

[0034] 3 shows a schematic diagram of first electrothermal swing adsorption apparatus 110 in a second configuration. The second configuration of first electrothermal swing adsorption apparatus 110 is the reverse of the first configuration. While FIG. 3 shows a schematic diagram of first electrothermal swing adsorption apparatus 110 in the second configuration, electric thermal swing adsorption apparatuses 120 and 130 in the second configuration are similar to the schematic diagram of first electrothermal swing adsorption apparatus 110 in the second configuration.

[0035] The first electrothermal swing adsorption device 110 in the second configuration includes a first chamber 112 and a second chamber 113. In the illustrated second configuration of the first electrothermal swing adsorption device 110, the first chamber 112 includes a regenerated carbon monolith for desorbing moisture and / or air contaminants, and the second chamber 113 includes an activated carbon monolith for adsorbing moisture and / or air contaminants. Previously, the regenerated carbon monolith in the first chamber 112 was the activated carbon monolith in the first configuration, and the activated carbon monolith in the second chamber 113 was the regenerated carbon monolith in the second chamber 113 in the first configuration. In this manner, the first chamber 112 and the second chamber 113 are cyclically operated to continuously adsorb and desorb moisture and / or air contaminants.

[0036] First electrothermal swing adsorption device 110 includes a feed stream 114, which is intake air from a building's HVAC system. Feed stream 114 may be the same as intake air stream 102. Feed stream 114 may include airborne moisture and other airborne contaminants.

[0037] The feed stream 114 flows along the feed flow path 115, which includes the second feed flow path 115B. The feed flow path 115 is introduced or received into the second chamber 113 via the second feed flow path 115B. Moisture and / or air contaminants are adsorbed by the activated carbon monolith in the second chamber 113, thereby dehumidifying and / or purifying the feed stream 114. The activated carbon monolith in the second chamber 113 is the regenerated carbon monolith of the second chamber 113 in the first configuration. The second chamber 113 is connected to the exhaust stream 104, and the purified feed stream 114 is exhausted from the second chamber 113. The exhaust stream 104 is dehumidified and free of air contaminants due to the desorption of the moisture and air contaminants by the activated carbon monolith in the second chamber 113. In some embodiments, the exhaust streams 104, 104A do not contain the specific air contaminants for which the carbon monolith in the first chamber 112 was optimized, but may contain additional air contaminants that are removed by subsequent electric thermal swing adsorption devices (e.g., 120, 130) located in series downstream of the inlet air stream 102 of the electric thermal swing adsorption system 100. As described above, the exhaust stream 104 may be introduced into the second electric thermal swing adsorption device 120 and then into the third electric thermal swing adsorption device 130. As described above, after the feed stream 114 has been discharged from all electric thermal swing adsorption devices 110, 120, 130 as the exhaust stream 104, the electric thermal swing adsorption system 100 can achieve a high water removal efficiency of at least 396 mg / g at 98% relative humidity and 298 K. Furthermore, after chemical modification treatment, significantly higher adsorption rates of 0.5–0.6 ml / g and 100% desorption after heating to 100°C have been observed.

[0038] The first electrothermal swing adsorption device 110 further includes a purge 116. The purge 116 is a reservoir of purge gas used to desorb moisture and / or air contaminants from the carbon monolith in the first chamber 112 in the second configuration. In some examples, the purge gas may include nitrogen or a noble gas. In some examples, the purge gas may include various concentrations of oxygen and may be comprised of room air or ambient air. The purge 116 flows along a purge flow path 117, which includes a second purge flow path 117B that is different from the first purge flow path 117A. The purge 116 is introduced or received into the first chamber 112 via the second purge flow path 117B. Moisture and / or air contaminants are desorbed in the first chamber 112 from the regenerated carbon monolith used as the activated carbon monolith in the first configuration. The regenerated carbon monolith in the first chamber 112 is regenerated by applying an electric current to the regenerated carbon monolith, which induces Joule heating due to the electrical resistance of the carbon fibers within the carbon monolith, raising the temperature of the carbon monolith to 100°C to 150°C, thereby desorbing moisture and other adsorbed substances, such as indoor air pollutants. The desorption temperature may depend on the characteristics of the carbon monolith in the first chamber 112, the moisture or air pollutants to be desorbed from the carbon monolith, and the chemical modification of the carbon monolith. The moisture and / or air pollutants are desorbed from the carbon monolith and enter the purge 116. The moisture or concentrated air pollutants in the purge 116 may be discharged from the first chamber 112 through the removal exhaust stream 111 via the second removal exhaust stream 111B.

[0039] 4 shows a flowchart of a method 200 for dehumidifying and purifying air from a building's HVAC system using a first electric thermal swing adsorption device 110. However, the method is also applicable to a second electric thermal swing adsorption device 120 and a third electric thermal swing adsorption device 130.

[0040] Step 202 involves supplying air from a building's HVAC system to the first chamber 112 of the first electrothermal swing adsorption device 110. The supply stream may contain moisture and airborne contaminants. Step 204 involves adsorbing the moisture and / or airborne contaminants with a first carbon monolith in the first chamber 112. In some embodiments, the first carbon monolith may be optimized to adsorb either moisture or a specific airborne contaminant. In some embodiments, the carbon monolith may be optimized to adsorb moisture and multiple airborne contaminants. Step 206 involves discharging the dehumidified and purified exhaust stream 104 from the first chamber 112 of the first electrothermal swing adsorption device 110. In some embodiments, the dehumidified and purified exhaust stream 104 does not contain the moisture and / or specific airborne contaminants adsorbed by the first carbon monolith in the first chamber 112, but may contain additional moisture and / or airborne contaminants removed by the electrothermal swing adsorption devices 120, 130.

[0041] Step 208 involves supplying a purge gas to a second chamber 113 of the first electrothermal swing adsorption device 110, separate from the first chamber 112. Step 210 involves desorbing moisture and / or air contaminants from a second carbon monolith with the purge gas in the second chamber 113. The adsorption of moisture and / or air contaminants in the first chamber 112 occurs simultaneously with the desorption of moisture and / or air contaminants in the second chamber 113. In some embodiments, the second carbon monolith may have previously adsorbed moisture and / or air contaminants. In some situations, the second carbon monolith may not have adsorbed any moisture and / or air contaminants, for example, when the second carbon monolith is being placed in the second chamber 113 for the first time. Step 212 involves applying an electric current to the second carbon monolith in the second chamber 113 to increase the temperature of the regenerated carbon monolith and desorb the moisture and / or air contaminants from the regenerated carbon monolith. The temperature can be increased to a range of 100°C to 150°C. This temperature increase is performed to accelerate the desorption process. Therefore, the temperature increase is performed simultaneously with the desorption step 210. Step 214 involves discharging the moisture and / or air contaminant-depleted exhaust stream 111 from the second chamber 113 of the first electrothermal swing adsorption device 110.

[0042] Step 216 involves switching the supply of air from the building's HVAC system from the first chamber 112 to the second chamber 113 and switching the supply of purge gas from the second chamber 113 to the first chamber 112 when the first carbon monolith has adsorbed a predetermined amount of moisture and / or air contaminants. In other words, this occurs when the carbon monolith reaches a predetermined adsorption capacity. In some embodiments, the first chamber 112 and the second chamber 113 each include a sensor to monitor the amount of moisture and / or air contaminants adsorbed by the carbon monolith, and based on that, the first electrothermal swing adsorption device 110 can be switched to remove the moisture and / or air contaminants from the carbon monolith. Thus, the second carbon monolith in the second chamber 113 can adsorb moisture and / or air contaminants, and the carbon monolith in the first chamber 112 can desorb the moisture and / or air contaminants captured by the carbon monolith.

[0043] Carbon fiber is a good conductor of electricity and heat, and a relatively small amount of energy is required to raise its temperature through an electrothermal process.

[0044] The low cost of coal-based activated carbon fiber and the low operating costs of electric thermal swing adsorption / desorption allow coal-based electric thermal swing adsorption to be cost-competitive with other desiccant-type systems, such as liquid desiccant air conditioning and solid desiccant systems. The low cost of coal-based activated carbon fiber in activated carbon monoliths and the low operating costs of electric thermal swing adsorption allow electric thermal swing adsorption systems, including activated carbon fiber-based dehumidification systems, to be cost-competitive with other types of dehumidification systems.

[0045] As used herein, the terms "about" or "substantially" refer to a tolerance of ±10% or ±5% from the value of the term modified by "about" or "substantially." Furthermore, the terms "less than," "less than or equal to," "greater than," "more than," or "more than or equal to" include the value modified by "less than," "less than or equal to," "greater than," "more than," or "more than or equal to" as endpoints.

[0046] While various aspects and embodiments have been disclosed herein, other aspects and embodiments are also contemplated. For purposes of explanation, the description herein uses specific nomenclature to provide a thorough understanding of the disclosed embodiments. However, it will be apparent to those skilled in the art that specific details are not required to practice the disclosed embodiments. Thus, the descriptions of the specific embodiments set forth herein have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to those skilled in the art that numerous modifications and variations are possible in light of the above disclosure.

[0047] Various inventions have been described herein with reference to specific embodiments and examples. However, those skilled in the art will recognize that many variations are possible without departing from the scope and spirit of the invention disclosed herein. Thus, the invention as set forth in the appended claims is intended to encompass all variations and modifications thereof that do not depart from the spirit of the invention disclosed herein. As used in the specification and claims, the terms "including" and "having" are intended to be synonymous with the term "comprising."

Claims

1. 1. An electric thermal swing adsorption system comprising an electric thermal swing adsorption device, The electrothermal swing adsorption device is a first chamber comprising at least one carbon monolith; a second chamber comprising at least one carbon monolith; Including, the electrothermal swing adsorption device is configured to receive a supply of air; the electrothermal swing adsorption system desorbs at least one of moisture and air contaminants from the supply of air; the electrothermal swing adsorption device discharges a dehumidified stream; the electrothermal swing adsorption device outputs a removal exhaust stream of at least one of moisture and air contaminants; Electrically heated swing adsorption system.

2. 2. The electrothermal swing adsorption system of claim 1, wherein the at least one carbon monolith in the first chamber adsorbs at least one of moisture and air contaminants, and the at least one carbon monolith in the second chamber desorbs at least one of moisture and air contaminants simultaneously as the at least one carbon monolith in the first chamber adsorbs at least one of moisture and air contaminants.

3. 2. The electrothermal swing adsorption system of claim 1, wherein the at least one carbon monolith in the second chamber adsorbs at least one of moisture and air contaminants, and the at least one carbon monolith in the first chamber desorbs at least one of moisture and air contaminants simultaneously as the at least one carbon monolith in the second chamber adsorbs at least one of moisture and air contaminants.

4. 2. The electrothermal swing adsorption system of claim 1, wherein the first chamber and the second chamber are cyclically operated to successively adsorb and desorb at least one of moisture and air contaminants, and adsorption is occurring in one of the first chamber and the second chamber while desorption is occurring in the other of the first chamber and the second chamber.

5. The electric thermal swing adsorption system of claim 1 , wherein each carbon monolith comprises coal-based activated carbon fiber.

6. 10. The electrothermal swing adsorption system of claim 1, wherein each carbon monolith is optimized to adsorb moisture or a specific air contaminant.

7. 3. The electric thermal swing adsorption system of claim 2, wherein the electric thermal swing adsorption device comprises a reservoir for storing moisture desorbed from the at least one carbon monolith in the second chamber.

8. 10. The electric thermal swing adsorption system of claim 1, comprising a plurality of electric thermal swing adsorption devices arranged in series such that each electric thermal swing adsorption device adsorbs at least one or more of moisture and airborne contaminants from the supply of air.

9. The electric thermal swing adsorption system of claim 8 , wherein each electric thermal swing adsorption device discharges the removal exhaust stream of at least one of moisture and air contaminants.

10. 10. The electric thermal swing adsorption system of claim 9, wherein each electric thermal swing adsorption device includes a reservoir for storing an output of at least one of moisture and air contaminants.

11. 10. The electric thermal swing adsorption system of claim 1, wherein the electric thermal swing adsorption system achieves a moisture removal efficiency of at least 396 mg / g at a relative humidity of 98% and a temperature of 298K.

12. 1. A method for dehumidifying and purifying air from a building's HVAC system utilizing an electric thermal swing adsorption system, comprising: supplying air from a building's HVAC system to a first chamber of an electrothermal swing adsorption device; adsorbing at least one of moisture and air contaminants by a first carbon monolith in the first chamber; discharging an exhaust stream of dehumidified and purified air from the first chamber of the electrothermal swing adsorption device; A method comprising:

13. providing a purge gas to a second chamber of the electrothermal swing adsorption device separate from the first chamber; desorbing at least one of moisture and air contaminants from the second carbon monolith with a purge gas in the second chamber; The method of claim 12 , wherein the second carbon monolith has previously adsorbed at least one of moisture and air contaminants.

14. 14. The method of claim 13, further comprising the step of discharging a removal stream of at least one of moisture and air contaminants from the second chamber of the electrothermal swing adsorption device.

15. 14. The method of claim 13, further comprising applying an electric current to the second carbon monolith in the second chamber to increase the temperature of the second carbon monolith and desorb at least one of moisture and air contaminants from the second carbon monolith.

16. 14. The method of claim 13, further comprising the step of switching the supply of air from a building's HVAC from the first chamber to the second chamber and switching the supply of purge gas from the second chamber to the first chamber when the first carbon monolith has adsorbed a predetermined amount of at least one of moisture and airborne contaminants.

17. adsorbing at least one of moisture and air contaminants by the second carbon monolith in the second chamber; desorbing at least one of moisture and air contaminants from the first carbon monolith in the first chamber with a purge gas; 17. The method of claim 16, further comprising:

18. 14. The method of claim 13, wherein the first carbon monolith and the second carbon monolith comprise coal-based activated carbon fibers.

19. 20. The method of claim 18, wherein the coal-based activated carbon fiber is optimized to adsorb moisture or specific air pollutants.

20. 14. The method of claim 13, wherein the electric thermal swing adsorption system comprises a plurality of electric thermal swing adsorption devices arranged in series, with a building's HVAC air supply or an industrial process air supply being fed to each electric thermal swing adsorption device in series, and each electric thermal swing adsorption device adsorbing moisture or a specific air contaminant.

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