Air contactor

Abstract

In one aspect, the air contactor comprises an air inlet, an air outlet, a fan assembly for generating an air flow, a heat exchanger operable to transfer heat between a process fluid and the air flow, and an air pollutant recovery system configured to selectively remove air pollutants from the air flow. The controller has a fluid cooling and air pollutant recovery mode in which the controller controls the fan assembly to facilitate the heat exchanger transferring heat between the process fluid and the air flow and the air pollutant recovery system removing air pollutants from the air flow. The controller has a fluid cooling recovery mode in which the controller controls the fan assembly to facilitate the heat exchanger transferring heat between the process fluid and the air flow and the air pollutant recovery system removing fewer air pollutants from the air.

Description

Technical Field

[0001] (Cross - Reference to Related Applications)

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 392,018, filed on July 25, 2022, which is hereby incorporated by reference in its entirety.

[0002]

[0002] The present disclosure relates to an air contactor, and more specifically, to an air contactor having a contaminant recovery medium for removing one or more contaminants from air.

Background Art

[0003]

[0003] Some carbon recovery systems utilize an air contactor to remove air pollutants such as CO2 from the air. Some of these air contactors have a packing material and a carbon recovery solution recirculation system that sprays a carbon recovery solution onto the packing material. The air contactor has a fan assembly that generates an air flow across the packing material. The air contacts the carbon recovery solution and chemically reacts with the carbon recovery solution, as a result, carbon in the air moves into the carbon recovery solution as CO2 and forms different molecules such as K2CO3.

[0004]

[0004] The fan assemblies of these known air contactors are downstream of the contaminant recovery medium. In some applications, the spraying of the carbon recovery solution onto the packing material creates droplets of the carbon recovery solution, and those droplets can accumulate on the fan assembly. The carbon recovery solution may contain caustic chemicals, which can potentially degrade the operation of the fan assembly over time.

Summary of the Invention

[0005]

[0005] In one aspect, an air contactor is provided that includes an air inlet, an air outlet, a fan assembly for generating an air flow from the air inlet to the air outlet, and a heat exchanger operable to transfer heat between a process fluid and the air flow. The air contactor has an air pollutant recovery system configured to selectively remove air pollutants from the air flow, and the air pollutant recovery system has an air pollutant recovery medium with an affinity for air pollutants to remove the air pollutants from the air flow. In one embodiment, the air pollutant recovery medium is configured to remove gaseous air pollutants from the air flow. For example, the air pollutant recovery medium can be a liquid solution or a solid material configured to chemically react with one or more air pollutants such as CO2 in the air. In other embodiments, the air pollutant recovery medium utilizes physical absorption or physical adsorption to remove one or more air pollutants from the air.

[0006]

[0006] The air contactor further includes a controller operably connected to a fan assembly, a heat exchanger, and an air pollutant recovery system. The controller has a process fluid cooling and air pollutant recovery mode, and a process fluid cooling mode. In the process fluid cooling and air pollutant recovery mode, the controller is configured to control the fan assembly to facilitate heat transfer between the heat exchanger and the process fluid and the air stream, and to control the air pollutant recovery system to remove air pollutants from the air stream. In the fluid cooling mode, the controller is configured to control the fan assembly to facilitate heat transfer between the heat exchanger and the process fluid and the air stream, and to control the air pollutant recovery system to remove fewer air pollutants from the air than when the controller is in the process fluid cooling and air pollutant recovery mode. In this way, the air contactor can perform both removing air pollutants from the air stream and transferring heat between the air stream and the process fluid as the air stream moves between the air inlet and the air outlet. Also, the controller may operate in the process fluid cooling mode when air pollutant recovery is not required, which saves one or more resources (such as water, electrical energy, gas used in a solid absorbent-based system, etc.) used to remove air pollutants from the air stream.

[0007]

[0007] The present disclosure also provides an air contactor having a fan assembly operable to generate an air stream, an indirect heat exchanger configured to exchange heat between the air stream and a process fluid, and a liquid absorbent material configured to allow the air stream to move therethrough. The air contactor includes a liquid distribution system including an air pollutant recovery solution supply. The liquid distribution system is configured to provide an air pollutant recovery solution from the air pollutant recovery solution supply to the liquid absorbent material.

[0008]

[0008] The air contactor further includes a controller operably connected to a fan assembly and a liquid distribution assembly. The controller is configured to control the liquid distribution system to provide the air pollution recovery solution to the liquid absorption material. The controller is further configured to control the fan assembly to cause air to flow through the liquid absorption material having the air pollution recovery solution such that the air pollution recovery solution removes air pollutants from the air stream and a portion of the water in the air pollution recovery solution evaporates. The air contactor thereby utilizes the evaporation of water during the interaction between the air stream and the air pollution recovery solution to adiabatically cool the air stream or increase the humidity of the air stream as desired for a particular embodiment.

[0009]

[0009] The present disclosure also provides an air contactor having an air stream generator operable to generate an air stream. The air contactor has an air pollution recovery system including an air pollution recovery device for transferring air pollutants from the air stream to a fluid, a fluid regeneration device configured to remove air pollutants from the fluid using heat from a heat source, and a thermal energy storage unit operable to receive heat from the fluid or provide heat to the fluid regeneration device. The heat source may be an intermittent heat source such as a heat source powered by sunlight or wind power. The fluid may be an air pollution recovery fluid such as a liquid carbon recovery solution sprayed onto the packing material of the air pollution recovery device. In another embodiment, the air contactor includes a solid absorbent and the fluid is a carrier gas (e.g., nitrogen or steam) used to remove air pollutants from the solid absorbent.

[0010]

[0010] The air pollutant recovery system has a regeneration and charging mode, in which the fluid regeneration device receives heat from a heat source, the fluid regeneration device removes air pollutants from the fluid, and the thermal energy storage unit receives heat from the fluid. The air pollutant recovery system also has a regeneration and dissipation mode, in which the fluid regeneration device receives heat from the thermal energy storage unit and the fluid regeneration device removes air pollutants from the fluid. The air contactor further includes a controller operably connected to the air pollutant recovery system, and the controller is configured to operate the air pollutant recovery system in the regeneration and dissipation mode in response to a determination that the air pollutant recovery system in the regeneration and dissipation mode meets the operating criteria. In this way, the air contactor can utilize the thermal energy storage unit to provide heat to the fluid regeneration device when the heat source cannot provide sufficient heat, such as at night when the heat source uses solar photovoltaic power.

[0011]

[0011] In another aspect of the present disclosure, an air contactor is provided that includes a fan assembly for generating an air flow and an air pollutant recovery system. The air pollutant recovery system includes an air pollutant recovery device for transferring air pollutants from the air flow to the fluid and a fluid regeneration device configured to remove air pollutants from the fluid. The air contactor further includes a mechanical heat generator comprising at least one of a chiller and a heat pump, and the mechanical heat generator is configured to receive a process fluid at a first temperature from an industrial process (such as manufacturing, HVAC, energy production, data center) and a heat transfer fluid from the air pollutant recovery system. The mechanical heat generator is operable to raise the temperature of the heat transfer fluid to a second temperature higher than the first temperature to return the heat transfer fluid to the fluid regeneration device at the second temperature in order to facilitate the fluid regeneration device removing air pollutants from the fluid. Since the mechanical heat generator provides the heat transfer fluid at a higher second temperature, the air contactor can regenerate the fluid even though the process fluid has a first temperature that may be insufficient to drive the regeneration process itself.

Brief Description of the Drawings

[0012]

Figure 1

[0012] A perspective view of an air contactor train having multiple rows of air contactors for removing contaminants from air.

Figure 2

[0013] A schematic diagram of a carbon recovery system including the air contactor train of FIG. 1.

Figure 3

[0014] A cross-sectional view of an air contactor.

Figure 4

[0015] An end elevation view of the air contactor of FIG. 3.

Figure 5

[0016] A cross-sectional view of the stack of the air contactor of FIG. 3.

Figure 6

[0017] A plan view of a carbon recovery facility having air contactor trains oriented to prevent the exhaust of one air contactor train from entering another air contactor train.

Figure 7

[0018] A flow diagram of a method of liquid solvent-based carbon recovery.

Figures 8 - 9

[0019] A schematic diagram of a solid absorbent-based air contactor.

Figures 10 - 11

[0020] A schematic diagram of an electrochemical carbon recovery system.

Figure 12

[0021] A perspective view of a portion of an electrochemical cell of the electrochemical carbon recovery system of FIGS. 10 and 11.

Figure 13

[0022] A schematic diagram of an air contactor having a carbon recovery medium upstream of an indirect heat exchanger.

Figure 14

[0023] A schematic diagram of an air contactor having a water make-up supply for replenishing water evaporated from a carbon recovery solution.

Figure 15

[0024] A schematic diagram of an air contactor having a louver, a carbon recovery medium, a drift eliminator, and an indirect heat exchanger.

Figure 16

[0025] Schematic diagram of an air contactor having a carbon recovery medium and a three-way valve that enables the air contactor to utilize either a carbon recovery solution or water on the carbon recovery medium.

Figure 17A

[0026] Schematic diagram of an air contactor having a tubular membrane mass exchanger that receives a carbon recovery solution from a sealed sample.

Figure 17B

[0027] An enlarged view of one of the tubular membranes shown by a dashed circle in FIG. 17A.

Figure 18

[0028] Schematic diagram of an air contactor having a dehumidifier upstream of the carbon recovery medium and an indirect heat exchanger.

Figure 19

[0029] Schematic diagram of an air contactor having an indirect heat exchanger upstream of the carbon recovery medium.

Figure 20

[0030] Schematic diagram of an air contactor having an adiabatic cooling pad, an indirect heat exchanger, and a carbon recovery medium.

Figure 21

[0031] Schematic diagram of an air contactor having a dehumidifier, an adiabatic cooling pad, an indirect heat exchanger, and a carbon recovery pad.

Figure 22

[0032] Schematic diagram of an air contactor having an adiabatic cooling pad, a plate heat exchanger, and a carbon recovery solution distribution system operable to distribute a carbon recovery solution onto the plate heat exchanger.

Figure 23

[0033] Schematic diagram of an air contactor having a solid absorbent-based carbon recovery medium upstream of an indirect heat exchanger.

Figure 24

[0034] Schematic diagram of an air contactor having an adiabatic pad and an indirect heat exchanger upstream of a fan assembly and a carbon recovery system downstream of the fan assembly.

Figure 25

[0035] Schematic diagram of an air contactor having an indirect evaporative heat exchanger above the carbon recovery system of the air contactor.

Figure 26

[0036] Schematic diagram of an air contactor having an indirect heat exchanger with a serpentine coil above a carbon recovery system of the air contactor.

Figure 27

[0037] Schematic diagram of an air contactor having a controller that operates the air contactor based at least in part on data from an air sensor, a carbon recovery solution sensor, and a heat exchanger sensor.

Figure 28

[0038] Schematic diagram of an air contactor having a controller that communicates with a sample level sensor, and the controller operates a makeup water valve in response to data from the sample level sensor.

Figure 29

[0039] Schematic diagram of an air contactor having a controller that uses sensors to monitor parameters of the air contactor and control a water and carbon recovery solution distribution system of the air contactor.

Figure 30

[0040] Schematic diagram of an air contactor having a controller that operates a water makeup valve of a carbon recovery solution distribution system in response to the level of the carbon recovery solution in the sump of the air contactor dropping below a threshold due to evaporation of water from the carbon recovery solution.

Figure 31

[0041] Schematic diagram of an air contactor having a carbon recovery medium in a solid state and a controller that operates a valve to release CO2 collected by the carbon recovery medium in the solid state.

Figure 32

[0042] Schematic diagram of an air contactor having a heat pump low temperature component upstream of a CO2 recovery device of the air contactor.

Figure 33

[0043] Schematic diagram of an air contactor having an evaporator having a temperature lower than the dew point temperature of an inlet sweep gas, and a makeup control system that collects condensed water from the evaporator and guides the collected water to an air pollutant recovery solution regenerator of the air contactor.

Figure 34

[0044] Schematic diagram of an air contactor having an air pollutant recovery solution regenerator that receives process heat instead of or in addition to heat from a condenser of the air contactor.

Figure 35

[0045] It is a schematic diagram of an air contactor having an evaporator upstream of a CO2 recovery device and a heat exchanger downstream of the CO2 recovery device.

Figure 36

[0046] It is a schematic diagram of an air contactor having an evaporator at a temperature lower than the dew point temperature of the inlet sweep gas, and the air contactor has a replenishment control system for guiding the condensed water from the evaporator to an air pollutant recovery solution regenerator.

Figure 37

[0047] It is a schematic diagram of an air contactor having a controller operable to selectively release a recovery solution regeneration material from a storage tank to a heat absorption regeneration process to provide heat to the process.

Figure 38

[0048] It is a schematic diagram of a hyperbolic cooling tower having a CO2 recovery device and a waste heat source that generates an air flow across the CO2 recovery device due to the temperature buoyancy effect.

Figure 39

[0049] It is a schematic diagram of an air contactor system having a thermal energy storage system for selectively providing heat to a heat absorption regeneration process. FIG. 39 shows the system in a full mode, where the heat absorption process is powered by a heat source and the thermal energy storage system is full.

Figure 40

[0050] It is a diagram similar to FIG. 39, showing a system in a mode where one of the thermal energy storage systems is dissipating heat to the heat absorption regeneration process and the other thermal energy storage system is completely full.

Figure 41

[0051] It is a diagram similar to FIG. 39, showing a system in a mode where the thermal energy storage system that was dissipating heat in FIG. 40 is now being filled and the other thermal energy storage system is dissipating heat to the heat absorption regeneration process.

Figure 42

[0052] It is a diagram similar to FIG. 39 except that the other thermal energy storage system is currently being filled, and shows a system in a mode where the thermal energy storage system that was dissipating heat to the heat absorption regeneration process in FIG. 40 is dissipating heat again.

Figure 43

[0053] A diagram similar to FIG. 39, showing a system in a mode where both heat energy storage systems are dissipating heat during the endothermic regeneration process.

Figure 44

[0054] A schematic diagram of an air contactor system having an intermittent renewable heat source for providing heat to the endothermic regeneration process and a heat energy storage unit for storing heat energy for periods when the renewable heat source is not available.

Figure 45

[0055] A schematic diagram of a building having a natural gas boiler and a cooling tower.

Figure 46

[0056] A schematic diagram of a building having an air contactor for removing CO2 from ambient air, a natural gas boiler, and a carbon recovery system for removing CO2 from the flue gas of the natural gas boiler and the CO2-rich exhaust gas of the air contactor.

Figure 47

[0057] A schematic diagram of an air contactor having a heat exchanger for the carbon recovery regeneration process outside the air path of the air contactor.

Figure 48

[0058] A schematic diagram of an air contactor having a heat pump for transferring heat from a process fluid to the carbon recovery regeneration process.

Figure 49

[0059] A schematic diagram of an air contactor having a chiller for transferring heat from a process fluid to the carbon recovery regeneration process.

Figure 50

[0060] A schematic diagram of an air contactor having an air-cooled heat exchanger downstream of the carbon recovery medium and a heat pump for transferring heat from a process fluid to the carbon recovery regeneration process.

Figure 51

[0061] A schematic diagram of an air contactor having an air-cooled heat exchanger downstream of the carbon recovery medium and a chiller for transferring heat from a process fluid to the regeneration process.

Figure 52

[0062] Schematic diagram of an air contactor having an air-cooled heat exchanger and an evaporator downstream of a carbon recovery medium, the evaporator being connected to a heat pump for providing heat to a carbon recovery regeneration process.

Figure 53

[0063] Schematic diagram of an air contactor having an air-cooled heat exchanger and an evaporator downstream of a carbon recovery medium, the evaporator being connected to a chiller for providing heat to a carbon recovery regeneration process.

Figure 54

[0064] Schematic diagram of an air contactor having an open main louver and closed first and second intermediate louvers such that air flows through a dehumidifier, an air pollution recovery medium, and a heat exchanger of the air contactor.

Figure 55

[0065] Schematic diagram similar to FIG. 54, showing where the main louver and the second intermediate louver are closed and the first intermediate louver is open such that air bypasses the dehumidifier.

Figure 56

[0066] Schematic diagram similar to FIG. 54, showing where the main louver and the first intermediate louver are closed and the second intermediate louver is open such that air bypasses the dehumidifier and the recovery medium.

Figure 57

[0067] Schematic diagram similar to FIG. 54, showing where the main louver and the second intermediate louver are open and the first intermediate louver is closed such that ambient air can be directly drawn into the heat exchanger.

Figure 58

[0068] Schematic diagram of an asymmetric air contactor having one side of the air contactor configured to provide air pollution recovery and the other side of the air contactor configured to provide heat exchange.

Figure 59

[0069] Schematic diagram of an asymmetric air contactor having louvers for selectively controlling the air flow through a dehumidification component, an air pollution recovery component, a heat exchange component, and a pre-cooling component of the air contactor.

DETAILED DESCRIPTION OF THE INVENTION

[0013]

[0070] Referring to FIG. 1, an air contactor train 10 is provided having an array of air contactors 12 that draw air into the air contactors 12 in direction 16. The air contactors 12 are configured to remove one or more air pollutants from the air, such as CO2, methane, volatile organic compounds (VOCs), and / or volatile halogenated organic carbons (VOXs).

[0014]

[0071] With respect to FIG. 2, an air pollutant recovery system 20 is provided that includes an air contactor train 10 for removing one or more pollutants from air 22. In one example, the air pollutant recovery system 20 is configured to remove CO2 from air 22. The air contactor train 10 receives a carbon recovery solution 24 having a lower CO2 content and emits a carbonate solution 28 having a higher CO2 content by mixing CO2 into the carbonate solution 28. The carbon recovery solution 24 may include, for example, KOH or NaOH. The carbonate solution 28 may include, for example, K2CO3.

[0015]

[0072] The air pollutant recovery system 20 includes a pellet reactor 26 that receives the carbonate solution 28 and contains a chemical that reacts with the carbonate solution 28 to precipitate carbon in the carbonate solution 28 as a solid 29, such as a pellet. For example, the pellet reactor 26 may contain CaOH2. The CaOH2 in the pellet reactor 26 reacts with K2CO3 in the carbonate solution 28 to form liquid KOH and precipitate CaCO3 as a solid 29, such as a pellet. The solid 29 that precipitates in the pellet reactor 26 is collected and provided to a calciner 30. The calciner 31 burns natural gas and oxygen 32. In one embodiment, the calciner 31 emits CO2 and forms CaO. The CO2 is emitted as an output 34, for example, in the form of a gas.

[0016]

[0073] CaO is sent to slaker 40 and mixed with water to form CaOH. System 20 may also include a steam turbine 36 that uses waste heat from calciner 31 to generate electricity, and a cryogenic air separation unit 38. The cryogenic air separation unit 38 produces high-concentration oxygen under pressure, such as 99% or more pure O2 at 10 MPa, and supplies it to the calciner 31. In this way, system 20 generates pure CO2 34 from the air passing through the air contactor train 10.

[0017]

[0074] Referring to FIG. 3, the air contactor 12 has a housing 50, an air inlet 54, and an air outlet 80. The air contactor 12 has an air flow generator such as a fan assembly 56, which draws CO2-rich ambient air into the air inlet 54 in direction 58. The fan assembly 56 generally has a fan 60 and a motor 62 upstream of the CO₂ recovery system 64 of the air contactor 12. The CO₂ recovery system has a CO₂ recovery medium such as a liquid carbon recovery solution 27 distributed on a support such as a packing 67. As another example, the support may be a liquid absorption material such as a pad.

[0018]

[0075] The CO₂ recovery system 64 includes a carbon recovery solution distribution system 66 for distributing the liquid carbon recovery solution 27 onto the packing 67. The packing 67 is suspended or otherwise supported within the housing 50 between the air inlet 54 and the air outlet 80. The carbon recovery solution distribution system 66 has one or more nozzles 70 for distributing the carbon recovery solution 24 onto the packing 67.

[0019]

[0076] The fan assembly 56 directs an air flow in a direction 72 across the packing material 67 within the housing 50. The carbon capture solution 24 on the surface of the packing material 67 chemically reacts with CO2 in the air to incorporate the CO2 in the air into the carbon capture solution 24, which is then collected (see the description of FIG. 7 below). The air flows across the packing material 67 and exits the housing 50 in a direction 82 via an outlet 80. The air exiting the housing 50 via the outlet 80 is CO2 poor or CO2 depleted compared to the CO2 rich ambient air entering the air inlet 54. The air contactor 12 may include a drift eliminator 84 for collecting droplets of the carbon capture solution in the air downstream of the packing material 67. Since the carbon capture distribution system 66 is downstream of the fan assembly 56, there is little risk of droplets of the carbon capture solution 24 contacting the fan assembly 56. Accordingly, the operating life of the fan assembly 56 is extended by preventing the carbon capture solution 24 from contacting the fan assembly 56, which improves the durability of the air contactor 12. In one embodiment, the fan 60 has a diameter 90 of 11 feet, the housing 50 has a length 92 of 25 feet 4 inches, the housing 50 has a height 94 of 13 feet, and the packing material 67 includes a rectangular packing sheet having a height 98 of 9 feet 4 inches and a length 100 of 13 feet 4 inches.

[0020]

[0077] With respect to FIG. 4, the fan 60 has four blades, although other blade configurations may be used. The air contactors 12 of the air contactor train 10 may each have a separate motor 62 that drives the fan 60 of the air contactor 12, or may have a single motor that drives a plurality of fans 60. The air contactor 12 may have a width 102 that can be, for example, 14 feet.

[0021]

[0078] With reference to FIG. 5, the air contactor train 10 includes a plurality of air contactor stacks 110 having a plurality of air contactors 12 assembled overlapping one another. For example, air contactors 12A, 12B, 12C, 12C are shown stacked on one another. In the embodiment of FIG. 5, the air contactor stack 110 includes a carbon recovery solution supply section 111 that provides the carbon recovery solution 24 to the carbon recovery solution distribution system 66 of the air contactors 12A, 12B, 12C, 12D. The air contactors 12A, 12B, 12C, 12D have a floor 68 with one or more openings that allow the carbon recovery solution 24 to fall from the packing 67 of each air contactor 12 into the interior 52 of the lower air contactor 12. The carbon recovery solution supply section 111 has a primary distribution head in the air contactor 12A and intervening distribution heads in the air contactors 12B, 12C, 12D that provide a lower flow rate than the primary distribution head. The intervening distribution heads operate to provide a make-up carbon recovery solution to compensate for leakage or drift losses or to provide fresh carbon recovery solution along the flow of the carbon recovery solution through the stack 110. In another embodiment, the carbon recovery solution supply section 111 provides the carbon recovery solution only to the air contactor 12A and the carbon recovery solution flows down little by little from air contactor to air contactor.

[0022]

[0079] The air contactor stack 111 has a sump 116 that collects the carbon recovery solution 24 after the carbon recovery solution 24 has moved through the air contactors 12A - 12D in the direction 118. The air contactor stack 110 has a carbon recovery solution return section 119 that provides the CO2-rich carbonate solution 28 to the pellet reactor 26. In one embodiment, the air contactor stack 111 has a plurality of sumps 116 and a plurality of carbon recovery solution return sections 119, such as sumps 116 and carbon recovery solution return sections 119 for each of the air contactors 12A - 12D.

[0023]

[0080] Referring to FIG. 6, a plan view of an exemplary air contactor facility 150 is provided. The air contactor facility 150 has air contactor trains 152, 154, 156, 158 similar to the air contactor train 10 described above. The air contactor trains 152, 154, 156, 158 each have an air inlet 160 and an air outlet 162, which are oriented to limit one of the air inlets of the air contactor trains 152, 154, 156, 158 from receiving air from the air outlet 162 of the nearest air contactor train 152, 154, 156, 158. For this purpose, the air contactor facility 150 has an intermediate spacing 166 between the air inlets 160 of the nearest air contactor trains 152, 154, 156, 158. Air can move downward (into the plane of FIG. 6) and move substantially horizontally into the air inlet 160 along the ground 159. The spacing 166 can be, for example, 160 feet. The air contactor facility 150 has a central spacing 170 between the air outlets 162 of the air contactor trains 154, 156. The central spacing 170 is between the air outlets 162 and can be, for example, 640 feet, which is larger than the intermediate spacing 166. The larger central spacing 170 keeps the air outlets 162 away from the air inlets 160 of the air contactor trains 154, 156. Keeping the air from the air outlets 162 away from the air inlets 160 ensures that CO2-rich air is not drawn into the air inlets 160 and improves the efficiency of the carbon capture process.

[0024]

[0081] Referring to FIG. 7, a liquid solution-based carbon recovery method 200 is provided that includes air 202 containing CO2 entering an air contactor 204 such as the air contactor 12 described above. The air contactor 204 emits air 206 with a reduced CO2 content compared to air 202. In the air contactor 204, CO2 208 in the air contacts a carbon recovery solution 210 such as KOH that is distributed on a support such as a packing material or a liquid absorption pad. The CO2 in the air reacts with the carbon recovery solution 210 to form water 212 and a carbonate solution 214, and the carbonate solution is then removed from the air contactor 204. A portion of the water 212 and the water in the carbonate solution 214 can be lost by evaporation. In one approach, the carbonate solution 214 is a molar solution. That is, the carbonate solution 214 is made by dissolving 1 gram of K2CO3 in water to make 1 liter of the carbonate solution 214. The carbonate solution 214 is provided to a pellet reactor 216 such as the pellet reactor 26 described above.

[0025]

[0082] In the pellet reactor 30, the carbonate solution 214 reacts with Ca(OH)2 216 provided to the pellet reactor 216 as pellets. The chemical reaction within the pellet reactor 216 produces a carbon recovery solution 210 and CaCO3 220. CaCO3 receives heat 226, for example, from a geothermal heat source or by burning a fuel such as natural gas, or is provided to a calciner 224. The calciner 226 produces CO2 as the recovered gas 228 and quicklime or CaO 230 as a solid. The CO2 gas recovered in operation 228 is directed to a compressor to compress the CO2 and liquefy the CO2 for storage and transportation.

[0026]

[0083] CaO230 is supplied to the slaker 232, which combines the CaO230 with water to form slaked lime CA(OH)2 as a solid. The chemical reaction in the slaker 232 is exothermic and releases heat 234, which can be recovered. The recovered heat 234 may be used to reduce the heat required in operation 226 or for another industrial process. The method 200 described uses a KOH carbon recovery solution, but other solutions may be used as appropriate depending on the particular application.

[0027]

[0084] Referring to FIGS. 8 to 9, in another embodiment, one or more of the air contactors 12 utilize a solid absorbent-based CO2 recovery method 250. For example, the air contactor 252 has a first mode 254 and a second mode 256. In the first mode 254, ambient air 258 is drawn into the air inlet 260 by a fan or the like of the air contactor 252 and moves through a carbon recovery medium such as a mass exchanger. The mass exchanger operates to remove contaminants such as CO2 from the air using adsorption or absorption. In one embodiment, the mass exchanger includes a filter 262. The air passes through the filter 262 and moves out of the air contactor 252 via the air outlet 264.

[0028]

[0085] CO2 in the ambient air adheres to the filter 262, and as a result, the air 266 that is dissipated has a reduced CO2 content. When the filter 262 becomes saturated, the air contactor 252 is reconfigured to a second mode 256 in which the air contactor 252 heats the filter 262 to a temperature of, for example, 100°C. The air contactor 252 has a CO2 recovery system 268 for removing the recovered CO2 from the filter 262. For example, the CO2 recovery system 268 may include a vacuum and a container 270 for collecting the CO2 released from the filter 262.

[0029]

[0086] Referring to FIGS. 10 to 12, in another embodiment, one or more of the air contactors 12 utilize the electrochemical CO2 recovery method 300 of FIGS. 10 and 11. The method 300 includes utilizing a carbon recovery system 302 that includes a carbon recovery medium such as an electrochemical cell assembly 304, and a control system 306 having a power source 308. The electrochemical cell assembly 304 includes an inner electrode 309 and an outer electrode 307. The outer electrode 307 is coated with a poly-1,4-anthraquinone complex and is operable to recover CO2 via carboxylation of quinone. The inner electrode 304 contains polyvinylferrocene and operates as an electron source or electron sink for quinone reduction and quinone oxidation. The inner electrode 304 is a driving force for the outer electrode 307 to recover CO2 from an air stream or release CO2 into the air stream.

[0030]

[0087] Depending on the polarity of the power source 308 applied to the electrochemical cell assembly 304, air moving through the air flow channel 310 in direction 312 will either have CO2 removed by the outer electrode 307 or obtain CO2 from the electrode 307.

[0031]

[0088] For example, referring to FIG. 10, the control system 306 has a carbon recovery configuration in which a negative polarity 320 is applied to the outer electrode 307 and a positive polarity 322 is applied to the inner electrode 308. Conversely, in FIG. 11, the control system 306 is shown in a CO2 dissipation configuration in which the power source 308 applies a negative polarity 326 to the inner electrode 309 and a positive polarity 328 to the outer electrode 307. The control system 306 reconfigures from the carbon recovery configuration of FIG. 10 to the carbon dissipation configuration of FIG. 11 when the electrochemical cell assembly 304 becomes saturated with CO2. The carbon recovery system 302 may be used in a batch process approach, in which air is provided to a sealed chamber containing the electrochemical cell assembly 304, the control system 306 operates in the carbon recovery configuration to recover CO2, air free of CO2 is released, the control system 306 is switched to the CO2 dissipation configuration, and a carrier gas is injected into the sealed chamber to flush the CO2 out of the chamber.

[0032]

[0089] In another approach, the carbon capture system 302 may be used in a flow process, in which air flows over the electrochemical cell assembly 304 until the outer electrode 307 is filled with CO2. The air flow over the outer electrode 307 is stopped, and then a carrier gas is introduced over the outer electrode 307 while the control system 306 assumes a carbon dissipation configuration to remove CO2 from the outer electrode 307.

[0033]

[0090] With reference to FIG. 13, an air contactor system 350 is provided that includes an air contactor 352 that is similar in many respects to the air contactor 12 described above. The air contactor system 350 includes a controller 354 that is integrated with or operably connected to the air contactor 352. The controller includes a memory 356 for storing non-transitory instructions for operating the air contactor 352, such as logic and programs. The controller 354 includes a processor 358 that is operably connected to the memory 356 and a communication circuit 360. The processor 358 may include, by way of example, a microprocessor, a gate array, a system-on-chip, and / or an application-specific integrated circuit. The communication circuit 360 is configured to communicate via a network 362 with one or more remote devices. The one or more remote devices may include, for example, one or more portable electronic devices such as an HVAC system controller 366, a server computer 364, and / or a smartphone 368. The communication circuit 360 may receive a carbon capture request from a remote device of the air contactor system 350 and operate the CO2 capture system 380 of the air contactor 352.

[0034]

[0091] The air contactor 352 is described as being configured to remove CO2 from air, but the air contactor 352 may be configured to remove additional or alternative contaminants from air using a suitable recovery medium. The recovery medium may include, for example, a carbon recovery solution distributed over a packing sheet, a block of packing material, and / or a pad. Alternative recovery media may be used, such as a liquid solvent-based air pollutant recovery system that utilizes a spray of fine droplets of the recovery solution through which air is directed to pass. Other recovery media may be utilized, such as a solid absorbent-based or an electrochemical-based air pollutant recovery system.

[0035]

[0092] Referring to FIG. 13, the air contactor 352 has an outer structure or housing 370, an air inlet 372, and an air outlet 374. CO2-rich air enters the air inlet 372 in direction 375, and CO2-depleted air exits the air outlet 374 in direction 377. The air contactor 352 has a fan assembly 355 for generating an air flow between the air inlet 372 and the air outlet 374. The fan assembly 355 includes a motor having a drive shaft and fan blades attached to the drive shaft.

[0036]

[0093] To remove CO2 from air, the air contactor 352 has a CO2 recovery system 380, which includes a carbon recovery solution distribution system 382 having one or more outlets such as a spray nozzle 384 for distributing the carbon recovery solution 391 over the recovery medium 390. In one embodiment, the recovery medium 390 is a packing sheet such as a rubber sheet or a plastic sheet.

[0037]

[0094] The CO2-rich air moves from the air inlet 372 in direction 375 and contacts the carbon recovery solution on the surface of the recovery medium 390. The carbon recovery solution chemically reacts with the CO2 in the CO2-rich air and incorporates the CO2 into the carbon recovery solution that generally moves downward along the recovery medium 390 under the influence of gravity.

[0038]

[0095] The CO2 recovery system 380 includes a trough 392 for collecting the carbon recovery solution 391 from the recovery medium 390, a sump 394, and a pump 396 for recirculating the carbon recovery solution 391 back to the spray nozzle 384. The sump 394 may be open or sealed. In one embodiment, the CO2 recovery system 380 typically operates as a closed loop within the air contactor 352, and the carbon recovery solution 391 moves from the sump 394 to the recovery medium 390 and back to the sump 394. The concentration of CO2 in the carbon recovery solution 391 increases over time as the carbon recovery solution 391 continues to incorporate CO2 from the air. In another embodiment, the CO2 recovery system 380 discharges the CO2-rich carbon recovery solution 391 from the air contactor 352 for treatment.

[0039]

[0096] In one embodiment, the air contactor 352 has a sensor 398 for detecting variables such as pH indicating the concentration of carbon in the carbon recovery solution 391. When the parameters satisfy concentration conditions such as exceeding a threshold concentration parameter, the controller 354 can open the valve 400 to direct the CO2-rich carbon recovery solution 391 or carbonate from the sump 394 to the drain section 402. The drain section 402 directs the CO2-rich carbon recovery solution 391 to a tank such as the pellet reactor 26 described above. In another approach, the controller 354 can operate the valve 400 after a predetermined period such as several hours, several days, or a period based on the duration of operation of the air contactor 352. When the sump 394 is partially or fully drained, the controller 354 can operate the valve 404 to open the carbon recovery solution supply section 406 to provide fresh carbon recovery solution 391 to the sump 394.

[0040]

[0097] The air contactor 352 also includes a heat exchanger such as an indirect heat exchanger 410. The indirect heat exchanger 410 has an inlet 412 for receiving a fluid such as a process fluid or refrigerant and an outlet 414. The flow of air across the outer surface of the dry heat exchanger 410 indirectly cools the fluid within the indirect heat exchanger 410.

[0041]

[0098] In one embodiment, the recovery medium 390 provides adiabatic cooling to the air moving across the recovery medium 390 by evaporation of water in the carbon recovery solution 391. The recovery medium 390 may include the carbon recovery solution 391 that penetrates a liquid absorbent material, while the liquid absorbent material allows air to move through the material. For example, the recovery medium 390 may include an adiabatic cooling pad. The adiabatic cooling provided by the carbon recovery solution 391 on the recovery medium 390 reduces the dry bulb temperature of the air before the air reaches the indirect heat exchanger 410, which improves the efficiency of the heat exchange between the air and the indirect heat exchanger 410.

[0042]

[0099] The air contactors 12, 352 and other air contactors described herein are similar in many respects. The following description of the embodiments focuses on the differences between the various embodiments, but the structural and operational similarities between the embodiments will be apparent to the reader.

[0043]

[0100] Referring to FIG. 14, the air contactor 450 includes a CO2 recovery system 452 that includes a recovery medium 454, a carbon recovery solution distribution system 456, a sump 458, and a pump 459. The air contactor 450 has a drain valve 460 for draining the carbon recovery solution having a concentration above a predetermined threshold from the sump 458. The air contactor 450 further includes a carbon recovery supply valve 462 for providing fresh carbon recovery solution to the sump 458 and a water make-up valve 464 for providing make-up water 466 to the sump 458. The water make-up valve 464 can be opened to provide make-up water 466 to the sump 458 to compensate for the evaporation of water from the carbon recovery solution 453. Water can evaporate from the carbon recovery solution 453, for example, when the CO2-rich air moving into the air contactor 450 in the direction 467 contacts the carbon recovery solution 453 sprayed onto the recovery medium 454. In one embodiment, the carbon recovery solution may be purged and replaced with water so that the air contactor 450 can operate in a water-only mode. The recovery medium 454 may include an adiabatic cooling pad, and the air contactor 450 can operate as an adiabatic cooler or condenser in the water-only mode. The air contactor 450 can operate in the water-only mode in certain situations such as when the required cooling capacity is increasing, the capacity of the associated CO2 treatment system is insufficient to regenerate the carbon recovery solution, and / or the associated CO2 utilization process (e.g., generating fuel from the recovered CO2) does not currently require CO2.

[0044]

[0101] With reference to FIG. 15, an air contactor 500 is provided having a CO2 recovery system 500 that distributes a carbon recovery solution 502 onto a carbon recovery medium 504 of a CO2 recovery system 501. The carbon recovery solution 502 can be corrosive to metals. The air contactor 500 has an upstream louver 506 at an inlet 508 of the air contactor 500 and a drift eliminator 510 downstream of the recovery medium 504. The drift eliminator 510 prevents droplets of the carbon recovery solution from carrying over from the recovery medium 504 of the air contactor 500 to the heat exchanger 512 and splashing. In one embodiment, the drift eliminator 510 is operably connected to a trough 514 of the CO2 recovery system 501 to direct the collected carbon recovery solution to the trough 514, whereby the solution can be directed to a sump 516 of the CO2 recovery system 500. In another embodiment, the louver can be utilized to direct the CO2 recovery solution into the sump, such as a filled sheet having louvers.

[0045]

[0102] Referring to FIG. 16, an air contactor 550 is provided that is operable as a carbon recovery device or as a fluid cooler having a pre-cooling option such as a condenser. More specifically, the air contactor 550 has a liquid distribution system 552 that is operable to distribute a liquid 554 onto a recovery medium 556. The liquid 554 can be an air pollutant recovery solution or water depending on the operating mode of the air contactor 550.

[0046]

[0103] In one embodiment, the recovery medium 556 comprises a liquid absorption material. The liquid 554 sprayed onto the recovery medium 556 saturates the recovery medium 556, and excess liquid collects in a trough 558 and moves to a sump 562 via a return pipe 560. The sump 562 is shown in FIG. 16 with an open top, but in other embodiments, the sump 562 may be sealed.

[0047]

[0104] In one embodiment, the recovery medium 556 allows saturated recovery medium 556 to move through air in order to cool the air. For example, the recovery medium 556 may include a pad such as an adiabatic cooling pad. The pad may include, for example, cellulose fibers and / or aspen fibers coated for biocontrol and fire resistance. Alternatively or additionally, the pad may include a polymer (e.g., PVC), ceramic, and / or a coated metal.

[0048]

[0105] The air contactor 550 has a pump 564 that recirculates liquid back from the sump 562 to the recovery medium 556. The air contactor 550 has a heat exchanger such as an indirect heat exchanger 566, which may be a dry heat exchanger. In another embodiment, the liquid distribution system 552 may be configured to distribute liquid onto the indirect heat exchanger 566 when the air contactor 550 operates in a wet mode.

[0049]

[0106] The air contactor 550 has one or more valves operable to direct either an air pollutant recovery solution (e.g., a carbon recovery solution) or water into the liquid distribution system 552. For example, the air contactor 550 may include a supply three-way valve 567 and a drain three-way valve 568. The supply three-way valve 567 is operable to connect a supply line 569 for the sump 562 to either a water supply section 570 or a carbon recovery solution supply section 572. The drain three-way valve 568 is operable to connect a drain section 574 from the sump 562 to either a drainage section 576 or a CO2-rich carbon recovery solution drain section 578.

[0050]

[0107] Supply three-way valve 567 can be opened to carbon recovery solution supply section 572 to fill sump 562 in response to air contactor 550 being in carbon recovery mode. When the carbon recovery mode ends or during refill operation, drain three-way valve 568 can direct the CO2-rich carbon recovery solution from sump 562 to CO2-rich carbon recovery solution drain section 578. When carbon recovery solution is being drained from liquid distribution system 552 to refill the system with fresh carbon recovery solution, supply three-way valve 567 operates to direct carbon recovery solution from carbon recovery solution supply section 572 to sump 562. In another embodiment, air contactor 550 operates in a "through-flow" approach where carbon recovery solution is directed into air contactor 550 for CO2 removal from the carbon recovery solution, distributed over recovery medium 556, collected, and directed out of air contactor 550. When air contactor 550 is reconfigured from carbon recovery mode to wet heat exchange mode, air contactor 550 operates supply three-way valve 567 to direct water from water supply section 570 into sump 574 after the carbon recovery solution in sump 574 has emptied. Liquid distribution system 552 then distributes water over recovery medium 556. Water moving across recovery medium 556 can directly cool the air upstream of indirect heat exchanger 566, which improves the efficiency of heat exchange between the air and indirect heat exchanger 566. In one embodiment, three-way valve 567 can operate to provide water to replenish water evaporated from the carbon recovery solution. In another embodiment, three-way valve 567 and pump 564 can operate to provide water for cleaning recovery medium 556.

[0051]

[0108] Air contactor 550 can have a dry heat exchanger mode in which pump 564 does not operate to distribute liquid over recovery medium 556. In the dry mode, air contactor 550 utilizes the air flow over indirect heat exchanger 566 to remove heat from the fluid in indirect heat exchanger 566.

[0052]

[0109] With respect to FIGS. 17A and 17B, an air contactor 600 having a confined carbon recovery solution is provided, which in some embodiments eliminates the risk of splashing and droplet carryover from the carbon recovery medium and reduces water loss. More specifically, the air contactor 600 has a liquid distribution system 602, which pumps an air pollutant recovery solution, such as a carbon recovery solution, from a sealed sump 604 through a pump 606 to a membrane assembly, such as a tubular membrane assembly 608. The tubular membrane thermal assembly 608 includes an inlet header 610, an outlet header 612, and a tubular membrane 614 having a cannula or interior 616 for guiding the carbon recovery solution from the inlet header 610 to the outlet header 612. In other embodiments, different membranes, such as flat sheets, may be used.

[0053]

[0110] Referring to FIG. 17B, each of the tubular membranes 614 includes an interior 616 and a sidewall 618 extending around it. The sidewall 618 is made of one or more materials configured to be highly selective for the air pollutants to be recovered. In one embodiment, the air pollutant to be recovered is CO2, and the tubular membrane 614 has a high permeability to CO2 for a given surface area and concentration gradient.

[0054]

[0111] The air contactor 600 has a fan assembly 615 operable to generate an air flow from the air inlet 617 of the air contactor 600, through the tubular membrane assembly 608, through an indirect heat exchanger 630, and to the air outlet 619 of the air contactor 600. As air flows through the tubular membrane assembly 608, it flows across the outer surface 622 of the tubular membrane 610. CO2 in the air permeates through the sidewall 618 from the outer surface 622 to the inner surface 624 of the tubular membrane 610. When the CO2 reaches the interior 616 of the tubular membrane 610, it is absorbed by the carbon recovery solution flowing through the interior 616. The CO2 in the air is thereby recovered by the solution in the interior 616 of the tubular membrane 614.

[0055]

[0112] The air contactor 600 has a heat exchanger 630, which can be, for example, an indirect heat exchanger. The air contactor 600 includes a carbon recovery solution supply valve 632 and a CO2-rich carbon recovery solution drain valve 634.

[0056]

[0113] In one embodiment, the air contactor 600 has a wet pre-cooling mode in which water is provided to the tubular membrane 614 instead of the carbon recovery solution. The material of the tubular membrane 614 may be selected to be permeable to CO2 and water vapor, such that water can be used within the tubular membrane 608 to pre-cool the air reaching the heat exchanger 630 instead of the tubular membrane assembly 608 recovering CO2 from the air. The water vapor discharged from the tubular membrane 614 cools the air upstream of the indirect heat exchanger 630, approving the efficiency of the heat exchange between the air and the heat exchanger 630.

[0057]

[0114] In another embodiment, the air contactor 600 has a vacuum inside 616 instead of the carbon recovery solution. The pump 606 can be a vacuum pump that collects the CO2 that penetrates through the side wall 618 of the tubular membrane 610. The sump 604 may be replaced with a storage unit for storing the recovered CO2 until the CO2 is removed from the storage unit.

[0058]

[0115] In yet another embodiment, the air contactor 600 may include a solid absorbent and a membrane (e.g., a sheet) associated with the solid absorbent to selectively limit which components of the air can contact the solid absorbent. For example, the air contactor 600 may have a water-impermeable and CO2-permeable membrane to prevent water vapor in the air from contacting the solid absorbent while allowing CO2 in the air to be absorbed or adsorbed by the solid absorbent. By doing so, the efficiency of the solid absorbent can be improved using the membrane.

[0059]

[0116] Referring to FIG. 18, an air contactor 700 having a dehumidifier 702 is provided upstream of an air pollutant recovery system 704. The air pollutant recovery system 704 includes a liquid distribution system 706 that distributes a liquid, such as a carbon recovery solution 708, onto a recovery medium 710. The air contactor 700 further includes a heat exchanger 711 downstream of the recovery medium 710. The dehumidifier 702 collects water 712 that can be used as a water make-up to supplement water evaporated from the carbon recovery solution 708 during operation of the air contactor 700. Use of the collected water 712 can reduce the amount of fresh water required to regenerate the carbon recovery solution.

[0060]

[0117] The dehumidifier 702 can include, for example, a vacuum-driven membrane heat exchanger and / or a mass exchanger. Other examples of the dehumidifier 702 include a liquid desiccant-driven membrane heat exchanger and a mass exchanger. Further examples include a fin-tube heat exchanger coated with a desiccant material, a desiccant wheel, and / or a sub-dew point cooling heat exchanger. Dehumidification of the air upstream of the recovery medium 710 improves the efficiency of the recovery system 704 for some embodiments. For example, removing moisture can enhance the efficiency of a solid absorbent such as zeolite. Dehumidifying the air reduces the water recovered by the zeolite medium from the air, which increases the ability of the zeolite medium to store CO2. The dehumidifier also provides water that can be used in situ in the air contactor 700 as make-up water or as a new water source for another process. In another embodiment, the pollutant recovery medium may benefit from having a higher humidity, and as a result, the dehumidifier 702 may be omitted.

[0061]

[0118] The air contactor 700 can have a wet pre-cooler mode in which the air pollution recovery system 704 recirculates water instead of the carbon recovery solution. The air pollution recovery system 704 sprays water onto the recovery medium 710, which cools the air before it reaches the heat exchanger 711, improving the efficiency of the heat exchanger 711. The dehumidifier 702 removes moisture from the air, which reduces the wet bulb temperature of the air. The reduction in the wet bulb temperature increases the amount of adiabatic pre-cooling achievable by the recovery medium 710 (which can be one or more pads) wetted with water. The recovery medium 710 wetted with water can then reduce the dry bulb temperature of the air flowing across the recovery medium 710. In another embodiment, dry cooling or sensible heat cooling can be used instead of the adiabatic cooling provided by the recovery medium 710. Sensible heat cooling can be provided using a refrigerant such as chilled water or glycol from a chiller. Sensible heat cooling may also be provided by the evaporator of a refrigeration system.

[0062]

[0119] When the recovery medium 710 includes an adiabatic pad and the air contactor 700 is operating in a water-only or wet pre-cooler mode, dehumidification of the air upstream of the recovery medium 710 improves the efficiency of the adiabatic heat exchange in the adiabatic pad. Also, when the air contactor 700 is operating in a water-only mode and the adiabatic pad of the recovery medium 710 is reducing the dry bulb temperature, the efficiency of the heat exchanger 711 is enhanced by dehumidification of the air upstream of the recovery medium 710.

[0063]

[0120] Referring to FIG. 19, an air contactor 750 is provided that is similar in many respects to the air contactor 750. The air contactor 750 has a carbon recovery solution distribution system 752 with a support such as a pad 754 downstream of the heat exchanger 756. The heat exchanger 756 can include a dry heat exchanger and / or a wet indirect heat exchanger.

[0064]

[0121] The heat exchanger 756 receives air from the inlet 758 of the air contactor 750, heats the air, and dissipates heat 760 to the carbon recovery medium 754. The carbon recovery solution distribution system 752 distributes the carbon recovery solution 762 onto the pad 754 downstream of the heat exchanger 756, thus reducing the risk of drift of the carbon recovery solution from the carbon recovery medium 754 onto the heat exchanger 756. Also, the heat exchanger 756 heats the air before the air reaches the pad 754, which can improve the efficiency of some types of carbon recovery solutions 762. For example, some adsorbents are known to be more effective at higher temperatures. The preheating of the air by the heat exchanger 756 reduces the relative humidity of the air, which can be beneficial for some types of carbon recovery solutions 762.

[0065]

[0122] In another embodiment, the heat exchanger 756 includes a direct heat exchanger such as a system that distributes a process fluid onto a packing sheet. The direct heat exchanger can increase the humidity of the air upstream of the pad 754, which can improve the efficiency of some types of carbon recovery solutions 762. Humidifying the air upstream of the pad 754 using the evaporating water in the process fluid of the direct heat exchanger can promote a water-neutral carbon recovery process.

[0066]

[0123] Referring to FIG. 20, an air contactor 800 is provided that can simultaneously use water to pre-cool the air entering the air inlet 802 and a carbon recovery solution to remove CO2 from the air within the air contactor 800 before the air exits through the air outlet 804. More specifically, the air contactor 800 includes a carbon recovery system 810 having a carbon recovery solution distribution system 812, a carbon recovery medium 814, a carbon recovery solution sump 816, and a pump 818. The air contactor 800 has valves 820, 822 to selectively enable the carbon recovery solution to enter the sump 816 from the carbon recovery solution source 824 or to exit the sump 816 to the CO2-rich carbon recovery solution drain 826.

[0067]

[0124] The air contactor 800 has an indirect heat exchanger 830 upstream of the carbon recovery medium 814 and a pre-cooler 832 upstream of the dry heat exchanger 830. The pre-cooler 832 includes a water distribution system 834 that distributes water over the liquid absorption material 836. The liquid absorption material 836 is configured to be saturated with water while allowing air to flow through the liquid absorption material 836. The air moving through the liquid absorption material 836 becomes cooler and more humid before reaching the indirect heat exchanger 830, which improves the efficiency of the operation of the indirect heat exchanger 830. In another embodiment, the pre-cooler 832 is a membrane heat exchanger, a dry heat exchanger having an internal fluid cooler than air, and / or a liquid desiccant dehumidifier.

[0068]

[0125] The water distribution system 834 further includes a trough 838 for collecting water from the liquid absorption material 836 and guiding the water to a water sump 840. Also, a pump 842 is operable to recirculate water from the sump 840 to an outlet such as a spray nozzle 844 of the water distribution system 834. The air contactor 800 further includes valves 850, 852 that are selectively operable to remove water from the sump 842 to a drain 854 and to provide water from a water source 856 to the sump 840.

[0069]

[0126] Referring to FIG. 21, an air contactor 900 is provided having a CO2 recovery system 902 that includes a carbon recovery medium 904, an indirect heat exchanger 906, a precooler system 908, and a dehumidifier 910. The precooler 908 includes a water distribution system 912 having a pump 914 that circulates water from a water sump 916 to a liquid absorbent material 918 of the precooler system 908. The water distribution system 912 includes outlets such as nozzles 920 that spray water onto the liquid absorbent material 918. The CO2 recovery system 904 has a carbon recovery solution distribution system 930 that includes one or more nozzles 932 for spraying a carbon recovery solution onto the carbon recovery medium 904 and a trough 934 for collecting the carbon recovery solution from the carbon recovery medium 904. The CO2 recovery system 904 includes a carbon recovery solution sump 936 and a pump 938 for recirculating the carbon recovery solution. The air contactor 900 includes a drain valve 940, a water supply valve 942, a carbon recovery solution drain valve 944, and a carbon recovery solution supply section 946.

[0070]

[0127] The air contactor 900 has a fan assembly 958 that moves air from an air inlet 950, through the dehumidifier 910, through the precooler system 908, through the indirect heat exchanger 906, through the carbon recovery medium 904, and out an air outlet 960 of the air contactor 900. The dehumidifier 910 provides dehumidified air 952 upstream of the precooler 908, the precooler 908 provides cooler and slightly moist air 954 upstream of the indirect heat exchanger 906, and the indirect heat exchanger 906 reduces humidity and provides heated air 956 upstream of the carbon recovery medium 904. The dehumidification and cooling of the air upstream of the indirect heat exchanger 906 improves the efficiency of the indirect heat exchanger 906. Another advantage of the air contactor 900 is that the air contactor 900 provides flexibility in the provision of optimally conditioned air to the indirect heat exchanger 906 and / or the CO2 recovery process. The air contactor 900 also provides flexibility in the optimization of waste heat and / or water and energy use for the CO2 recovery process.

[0071]

[0128] With respect to FIG. 22, an air contactor 1000 having a CO2 recovery system 1002 and a pre-cooler 1004 is provided. The CO2 recovery system 1002 includes a carbon recovery solution distribution system 1006 having one or more outlets such as a nozzle 1008 for distributing the carbon recovery solution onto the indirect heat exchanger 1010. The nozzle 1008 is configured to cover the outer surface of the indirect heat exchanger 1010 with the carbon recovery solution. The flow rate of the carbon recovery solution can be adjusted to optimize the recovery efficiency and minimize energy use, such as pump capacity and air-side pressure drop.

[0072]

[0129] The indirect heat exchanger 1010 may be a pillow-type indirect heat exchanger including an inlet 1014 for receiving a fluid and an outlet 1016 for the fluid. The indirect heat exchanger 1010 may be made of a material selected to withstand the carbon recovery solution, such as galvanized steel, aluminum, stainless steel, platinum, polymer material, and / or ceramic, suitable for a particular embodiment.

[0073]

[0130] The air contactor 1000 includes a drift eliminator 1039 intermediate the indirect heat exchanger 1010 and the fan assembly 1041. The drift eliminator 1039 is configured to prevent carbon recovery solution drift from reaching the fan assembly 1041.

[0074]

[0131] The carbon recovery solution distribution system 1002 includes a trough 1012 for collecting the carbon recovery solution 1009 after the carbon recovery solution 1009 has moved along the outer surface of the indirect heat exchanger 1010. The air flow across the outer surface of the indirect heat exchanger 1010 having the carbon recovery solution 1009 thereon indirectly cools the fluid inside the indirect heat exchanger 1010. Also, some of the water in the carbon recovery solution 1009 may evaporate as the carbon recovery solution 1009 moves along the outer surface of the indirect heat exchanger 1010. The evaporating water removes additional heat from the indirect heat exchanger 1010.

[0075]

[0132] The carbon recovery solution 1009 on the outer surface of the indirect heat exchanger 1010 is positioned to allow CO2 to mix into the carbon recovery solution 1009 as air moves through the indirect heat exchanger 1010. The CO2 recovery system 1002 includes a carbon recovery solution sample 1020, a pump 1022, and valves 1024, 1026 for providing a CO2-rich carbon recovery solution to the drain section 1028 or receiving a new carbon recovery solution from the supply section 1030.

[0076]

[0133] The precooler 1004 includes a water distribution system 1040 having one or more outlets such as a nozzle 1042 for distributing water 1044 onto the liquid absorption material 1046. The water distribution system 1040 further includes a trough 1048 for collecting water from the liquid absorption material 1046, a water sample 1050, a water pump 1052, and valves 1054, 1056 for receiving water from the water supply section 1058 or directing water from the water sample 1050 to the drain section 1060.

[0077]

[0134] The air contactor 1000 is operable in different operating modes. For example, the air contactor 1000 has a dry cooling mode in which air flows over the indirect heat exchanger 1010 and pumps 1024, 1052 are turned off. The air contactor 1000 has a pure CO2 recovery mode in which pump 1024 operates to distribute the carbon recovery solution onto the indirect heat exchanger 1010 but there is no fluid moving through the interior of the indirect heat exchanger 1010. The air contactor 1000 has an adiabatic cooling mode in which pump 1024 is off, pump 1052 is on to pump water to the liquid absorption material 1046, and there is a fluid moving through the interior of the indirect heat exchanger 1010. The air contactor 1000 has a CO2 recovery and fluid cooling mode in which pump 1024 is on and the indirect heat exchanger 1010 has a fluid moving through its interior. The air contactor 1000 has a CO2 recovery, fluid cooling, and adiabatic precooling mode in which pumps 1024, 1052 are on and the indirect heat exchanger 1010 has a fluid moving through its interior.

[0078]

[0135] In some embodiments, the precooler 1004 and the indirect heat exchanger 1010 may include, for example, serpentine tubes, membrane heat exchangers, and / or sprays on a dry heat exchanger. In some embodiments, the air contactor 1000 may include a three-way valve that enables switching between a CO2 recovery system 1002 that utilizes a carbon recovery solution and one that utilizes water. In one embodiment, the component of reference numeral 1004 may be an air pollutant recovery device, and the component of 1002 may be a direct heat exchanger such as a wet indirect heat exchanger and / or a packing material.

[0079]

[0136] Referring to FIG. 23, an air contactor 1100 is provided that includes an air inlet 1102, an air outlet 1104, and a fan assembly 1106 for generating an air flow therebetween. The air contactor 1100 has a solid absorbent-based carbon recovery media system 1110. The solid absorbent-based carbon recovery media system 1110 may include, for example, amines, zeolites, and / or metal organic frameworks. In one embodiment, the carbon recovery media system 1110 includes a carbon recovery media having a filter 1112 that recovers CO2 from the air moving through the air contactor 1100. The solid absorbent-based carbon recovery media system 1110 includes a heat source 1114 that heats the filter 1112 when the filter 1112 becomes saturated in order to release CO2 from the filter 1112. The solid absorbent-based carbon recovery media system 1110 further includes a CO2 exhaust 1116 for removing CO2 from the filter 1112. For example, the CO2 exhaust 1116 may include a vacuum. In one embodiment, the air inlet 1102 and the air outlet 1104 may have features such as louvers or movable panels for closing the air inlet and air outlet 1102, 1104 during the removal of CO2 from the filter 1112. Other embodiments may utilize only a vacuum approach for removing CO2 from the filter. Further, some embodiments may use heating and vacuum operations to release most of the CO2 and then use heat and a carrier gas to flush the adsorbent material.

[0080]

[0137] The air contactor 1100 includes a heat exchanger 1120 downstream of the filter 1112. Examples of solid absorbent materials include alkaline earth oxides, amines, zeolites, and / or metal organic frameworks. In one embodiment, the air contactor 1100 may include an electrochemical CO2 recovery medium (see FIGS. 10 - 12 and related description) instead of or in addition to the solid absorbent-based carbon recovery media system 1110.

[0081]

[0138] Referring to FIG. 24, an air contactor 1150 is provided that is similar in many respects to the air contactor described above. The air contactor 1150 has a pre-cooler 1152, a heat exchanger 1154, and a carbon recovery system 1156. The carbon recovery system 1156 is intermediate the fan assembly 1158 and the air outlet 1160 of the air contactor 1150. The carbon recovery system 1156 may include, for example, a solid absorbent, a liquid solvent, and / or an approach based on an electrochemical adsorbent to remove CO2 from the air flowing through the air contactor 1150. The heat exchanger 1154 may include an indirect evaporative heat exchanger. The pre-cooler 1152 includes a water distribution system 1162, a liquid absorbent material 1164, a sump 1166, a pump 1168, and valves 1170, 1172. The valves 1170, 1172 control the flow of water from the water supply 1174 and the flow of water to the drain 1176. The carbon recovery system 1156 is downstream of the fan assembly 1158, which may be desirable for some embodiments as a technique to protect the fan assembly 1158 while making the carbon recovery system 1156 easily maintainable. Positioning the carbon recovery system 1156 downstream of the fan assembly 1158 may, in some cases, reduce the risk of ambient air contamination by plumes and microorganisms. In one embodiment, the carbon recovery system 1156 is configured to be retrofitted to an existing cooling tower, which enables the cooling tower to provide CO2 recovery capabilities without increasing the installation area of the cooling tower. The air contactor utilizing the carbon recovery system 1156 may have a forced ventilation configuration with a larger dissipation area and a lower pressure drop across the air contactor. The lower pressure drop and larger dissipation area may, in some embodiments, enable a more efficient carbon recovery operation.

[0082]

[0139] Referring to FIG. 25, an air contactor 1200 is provided having an evaporative indirect heat exchanger system 1202 and a CO2 recovery system 1204 that can operate independently of each other. Also, the indirect evaporative heat exchanger system 1202 can operate in a dry mode or a wet mode regardless of whether the carbon recovery system 1204 is operating. More specifically, the indirect evaporative heat exchanger system 1202 includes an indirect heat exchanger 1206 having an inlet header 1208 with an inlet 1210 for receiving a fluid, a coil such as one or more serpentine tubes 1212, and an outlet header 1214 with a fluid outlet 1216.

[0083]

[0140] The indirect evaporative indirect heat exchanger 1202 includes a liquid distribution system 1220 having nozzles 1226 for distributing an evaporative liquid onto the serpentine tubes 1212, a sump 1222 for collecting the evaporative liquid, and a pump 1224 for circulating the evaporative liquid back to the nozzles 1226 of the liquid distribution system 1220. The air contactor 1200 has a fan assembly 1250 that generates an air flow from an air inlet 1230, through the indirect heat exchanger 1206, through a drift eliminator 1232, and out of the air outlet 1234 of the air contactor 1200.

[0084]

[0141] The air contactor 1200 includes another air inlet 1240 having louvers 1242, which can be opened to allow air to enter the interior of the housing 1244 of the air contactor 1200 and move across the carbon recovery medium 1246 of the CO2 recovery system 1204. The carbon recovery medium 1246 can include, for example, a carbon recovery solution distributed on a packing sheet. The louvers 1242 may be closed when the CO2 recovery system is not operating. With the louvers 1242 open, the fan assembly 1250 can generate an air flow from the air inlet 1240, through the carbon recovery medium 1246, and to the air outlet 1234.

[0085]

[0142] The CO2 recovery system 1204 includes a carbon recovery solution distribution system 1260 having one or more outlets such as a nozzle 1262 for guiding the carbon recovery solution onto the carbon recovery medium 1246. The CO2 recovery system 1204 further includes a sump 1264 for collecting the carbon recovery solution from the carbon recovery medium 1246, and a pump 1266 for recirculating the carbon recovery solution back to the nozzle 1262.

[0086]

[0143] The air contactor 1200 includes a supply valve 1270 and a drain valve 1272 for controlling the flow of water from the water supply section 1274 to the sump 1222 and for controlling the flow of water from the sump 1222 to the drain section 1276. Similarly, the air contactor 1200 includes valves 1280, 1282 for controlling the flow of fresh carbon recovery solution from the supply section 1284 to the sump 1264 and for controlling the flow of the CO2-rich carbon recovery solution to the drain section 1286. In one embodiment, the air contactor 1200 is configured to flow either the carbon recovery solution or water over both the indirect evaporative heat exchanger 1202 and the carbon recovery medium 1264, depending on the operating mode of the air contactor 1200. In another embodiment, the air contactor 1200 may include a carbon recovery system (e.g., a system for distributing the carbon recovery solution onto an insulating pad) upstream and / or downstream of the indirect evaporative heat exchanger 1202 and the carbon recovery medium 1264.

[0087]

[0144] Referring to FIG. 26, an air contactor 1300 is provided that is similar to the air contactor 1200 in many respects. The air contactor 1300 has air inlets 1302, 1304 and an air outlet 1306. The air contactor 1300 has a heat exchanger system 1310 that includes a dry heat exchanger system 1312 at the air outlet 1306 and an evaporative heat exchanger system 1314 at the air inlet 1302. The dry heat exchanger system 1312 includes an indirect heat exchanger 1313 such as a tube and fin heat exchanger, a fluid inlet 1316 for receiving a fluid such as a high temperature process fluid, and a fluid outlet 1318 that directs the process fluid to the evaporative heat exchange system 1314 after the fluid is cooled by indirect contact between the fluid in the indirect heat exchanger 1313 and an air flow that moves across the indirect heat exchanger generated by the fan assembly 1320 of the air contactor 1300. The fluid flows from the fluid outlet 1318 of the dry heat exchanger 1311 to the indirect heat exchanger 1315 of the evaporative heat exchanger system 1314.

[0088]

[0145] The indirect heat exchanger 1315 may include, for example, a coil such as one or more serpentine tubes and / or a plate heat exchanger. In one embodiment, the indirect heat exchanger 1315 includes an inlet header 1324 having an inlet 1322 for receiving fluid from the fluid outlet 1318 of the dry heat exchanger 1311. The indirect heat exchanger 1315 further includes an outlet header 1326 and a serpentine tube 1328 connecting the inlet header 1324 and the outlet header 1326.

[0089]

[0146] The evaporative heat exchanger system 1314 has a liquid distribution system 1330 that includes one or more outlets such as nozzles 1332 for distributing an evaporative liquid onto the serpentine tube 1328, a sump 1347 for collecting the evaporative liquid from the serpentine tube 1328, and a pump 1342 for circulating the evaporative fluid. The evaporative heat exchanger system 1314 further includes a water make-up valve 1344 and a drain valve 1346 for controlling the flow of liquid entering and leaving the sump 1347.

[0090]

[0147] The air contactor 1300 further includes a CO2 recovery system 1350 having a carbon recovery solution distribution system 1352 operable to distribute a carbon recovery medium, such as a carbon recovery solution, onto a support 1354, such as a packing sheet. The carbon recovery solution distribution system 1352 includes a sump 1356 for collecting the carbon recovery solution as it moves away from the packing 1354 and a pump 1358 for circulating the carbon recovery solution. The CO2 recovery system 1350 further includes a carbon recovery solution supply valve 1360 and a carbon recovery solution drain valve 1362. The evaporative heat exchanger system 1314 can operate in a dry mode to enable cooling of the process fluid through indirect heat exchange between the air moving through the air contactor 1300 and the fluid in the heat exchangers 1313, 1315 when the pump 1342 is turned off. The dry heat exchanger system 1312 provides additional cooling capacity to the air contactor 1300 by removing heat from the fluid before the fluid reaches the indirect heat exchanger 1315. Also, the dry heat exchanger system 1312 can reduce the plume in some embodiments by raising the temperature of the air exiting the air contactor 1300.

[0091]

[0148] In another embodiment, the air contactor 1300 has a full CO2 recovery mode in which the air contactor 1300 distributes the carbon recovery solution onto both the support 1354 and the serpentine tube 1328. This allows both the serpentine tube 1328 and the recovery medium 1354 to be used as media for exchanging CO2 into the carbon recovery solution. In one embodiment, a solid absorbent-based electrochemical carbon recovery medium can be used in the air contactor 1300. In one embodiment, the air contactor 1300 has a carbon recovery system (e.g., a system for distributing a carbon recovery solution onto an adiabatic pad) upstream and / or downstream of the indirect evaporative heat exchanger 1314 and the CO2 recovery system 1350. In yet another embodiment, the air contactor 1300 has a solid absorbent-based recovery medium instead of or in addition to the dry heat exchanger system 1312.

[0092]

[0149] Referring to FIG. 27, an air contactor 1400 is provided that is similar in many respects to the air contactor 352 described above. The air contactor 1400 includes an air pollution recovery system such as a CO2 recovery system 1402 having a support such as a liquid absorption material 1404, a carbon recovery solution sample 1406, a pump 1408, and one or more outlets such as a nozzle for dispensing the carbon recovery solution 1410 onto the liquid absorption material 1404. The recovery solution can be suitable for recovering, for example, CO2, methane, or VOCs. The air contactor 1400 has an air inlet 1420, an air outlet 1422, a heat exchanger 1424, and a controller 1426. To monitor and control the operation of the air contactor 1400, the controller 1426 is operably connected to air sensors 1430, 1432, one or more fluid sensors 1436, and one or more carbon recovery solution sensors 1438. The air sensors 1430, 1432 can measure, for example, one or more of temperature, relative humidity, carbon dioxide concentration, carbon monoxide concentration, volatile organic compound (VOX) concentration, ozone concentration, sulfur dioxide concentration, nitrogen dioxide concentration, and / or the concentration of a particular substance (e.g., 2.5 and / or 10 micrometer diameter). The one or more fluid sensors 1436 can measure, for example, the inlet temperature, outlet temperature, flow rate, and / or pressure of the fluid in the heat exchanger 1424. The one or more liquid sensors 1438 can measure temperature, conductivity, pH, solids content, carbon dioxide concentration, carbon monoxide concentration, volatile organic compound concentration, ozone concentration, sulfur dioxide concentration, and / or nitrogen dioxide concentration.

[0093]

[0150] The controller 1426 can operate the fan motor 1450 of the air contactor 1400 to ensure the process fluid temperature set point and / or pressure set point by monitoring the fluid temperature and / or fluid pressure via the sensor 1436 and controlling the speed of the fan 1452 accordingly. The controller 1426 can ensure the optimal operation of the CO2 recovery process by measuring the air-side recovery performance, for example, the difference between the inlet CO2 concentration and the outlet CO2 concentration over time, and / or by measuring specific parameters of the carbon recovery solution to verify that the recovery solution does not exceed a preset CO2 saturation threshold. When the CO2 saturation threshold is reached, the controller 1426 operates the drain valve 1456 to drain the saturated carbon recovery solution. Next, the controller 1426 closes the drain valve 1456 and opens the make-up carbon recovery solution valve 1458 to provide a new carbon recovery solution to the sump 1406. The controller 1426 can switch the operation of the heat exchanger 1424 and / or the CO2 recovery process on / off as needed.

[0094]

[0151] The controller 1426 can perform other operations for maintaining the air contactor 1400. For example, if the liquid absorption material 1404 contains a liquid absorption material, the controller 1426 can turn off the pump 1408 and operate the fan 1452 in the reverse direction to clean the liquid absorption material 1404. The controller 1426 can reduce the fan speed and / or reduce the distribution of the fluid onto the liquid absorption material 1404 in response to an increase in drift and / or the occurrence of a plume. The air contactor 1400 may open the carbon recovery solution valve 1458 to add carbon recovery solution to compensate for drift losses, leakage losses, and / or splashing.

[0095]

[0152] In one embodiment, the controller 1426 may operate the motor 1450 to optimize the contaminant recovery process. In one approach, the control system may optimize both the contaminant recovery process and the fluid cooling process. The controller 1426 may utilize logic that takes into account other parameters such as, by way of example, ambient air temperature, relative humidity, time, total amount of contaminant recovery over a relevant period, and / or energy cost.

[0096]

[0153] The controller of the air contactor disclosed herein may optimize (e.g., minimize) one or more operating parameters such as energy consumption, water consumption, carbon footprint (relating to the CO2 recovery process), and operating cost. The optimization enables optimal control of the fan speed and / or liquid supply to the carbon recovery system (either directly or by setting different outlet water temperature setpoints and / or outlet air CO2 concentration setpoints) to minimize one or more of the operating parameters. The optimization may be limited, for example, by way of example, to some minimum and maximum values of the outlet water temperature, process fluid temperature / pressure, and / or outlet air CO2 concentration. Thus, the optimization may be based on the cooling performance and / or efficiency of the CO2 recovery process.

[0097]

[0154] The controller of the air contactor operates the air contactor based on the intermittent nature of the CO2 recovery process, particularly in the case of solid state recovery materials. For example, the controller of the air contactor may periodically change the operator of the air contactor to enable isolation of the carbon recovery system and desorption of the recovered CO2. The controller may optimize the timing of the isolation / desorption operation, for example, based on cooling requirements, time, and energy price. The controller may optimize the rate at which CO2 is absorbed to ensure that the desorption process occurs during downtime of the cooling process, such as at night and / or on weekends.

[0098]

[0155] Referring to FIG. 28, an air contactor 1500 is provided that is similar in many respects to the air contactor 1400 described above. The air contactor 1500 has a carbon recovery solution system 1502 that includes a carbon recovery solution sample 1504 and a water makeup valve 1506 that controls the flow of makeup water to the carbon recovery solution sample 1504. The air contactor 1500 has one or more sensors 1508 that are similar to the sensors described above with respect to the air contactor 1400, and a level sensor 1510 that detects the level of the carbon recovery solution within the recovery solution sample 1504. The air contactor 1500 includes a controller 1516 that can open the valve 1506 to replenish water lost from the carbon recovery solution via evaporation. Since the volume of the carbon recovery solution within the sample 1504 will decrease as water evaporates from the carbon recovery solution, the controller 1516 can use the level sensor 1510 of the recovery solution sample 1504 to monitor the evaporative water loss. When the lower threshold value of the carbon recovery solution within the recovery solution sample 1504 is reached, the controller 1516 opens the valve 1506. When the upper threshold value of the recovery solution within the recovery solution sample 1504 is reached by the addition of makeup water to the sample 1504, the controller 1516 closes the valve 1506.

[0099]

[0156] Water loss due to evaporation of the recovery solution can also be determined indirectly. For example, the controller 1516 can determine the evaporative loss via the difference in humidity between the air entering the air inlet 1520 of the air contactor 1500 and the air exiting the air outlet 1522 of the air contactor 1500. As another example, the controller 1516 may detect a change in the concentration of one or more parameters of the carbon recovery solution, such as pH, conductivity, and / or CO2 concentration.

[0100]

[0157] With reference to FIG. 29, an air contactor 1550 similar to the air contactor 900 described above is provided. The air contactor 1550 includes an air inlet 1552, a dehumidifier 1554, a pre-cooler system 1556, a heat exchanger 1558, an air pollutant recovery system such as a CO2 recovery system 1560, a fan assembly 1562, and a controller 1564. The controller 1564 operates pumps 1570, 1572 of the pre-cooler system 1556 and the CO2 recovery system 1560, the dehumidifier 1554, the fan assembly 1562, drain valves and water supply valves 1576, 1578, and carbon recovery solution supply valves and drain valves 1580, 1582.

[0101]

[0158] The controller 1564 incorporates logic for controlling various components of the air contactor 1550 based at least in part on data from an air sensor 1584, a fluid sensor 1586, a liquid sensor 1588, and a level sensor 1590. The controller 1564 utilizes logic similar to the operation of the air contactor 900 described above. Also, the controller 1564 can enhance the heat transfer capacity by turning on the pump 1570 to enable pre-cooling of the air upstream of the heat exchanger 1558. The controller 1564 can monitor the level of water and other parameters of the water in the sump 1571 to drain and / or replenish water as needed. In one approach, the controller 1564 can utilize the relative humidity and / or temperature information detected by the air sensor 1584 to determine whether pre-cooling is worthwhile.

[0102]

[0159] The controller 1564 can also determine whether to operate the dehumidifier 1554 to enhance the cooling capacity and / or to generate water. Operating the dehumidifier 1554 can include, for example, controlling a vacuum pump, a motor, a valve, or other mechanical components of the dehumidifier 1554. The controller 1564 can utilize the relative humidity and / or temperature of the air detected by the air sensor 1584 to determine whether it is useful to operate the dehumidifier 1554.

[0103]

[0160] Controller 1564 may be configured to optimize the operation of the air pollutant recovery process by, for example, measuring the air-side recovery performance over time, such as the difference between the CO2 concentration at the air inlet 1552 and the CO2 concentration in the air exiting at the air outlet 1553. Alternatively or additionally, the optimization of the operation of the air pollutant recovery process may include a set of measurements of the parameters of the recovery solution, such as by using data from the liquid sensor 1558 to verify that the recovery solution does not exceed a pre-set saturation level. When the saturation level is reached, the controller 1564 may operate the recovery solution drain valve 1580 to drain the saturated solution and then operate the recovery solution supply valve 1580 to replace the recovery solution with a new recovery solution.

[0104]

[0161] Controller 1564 may be used to switch the fluid cooling and / or air pollutant recovery process on or off. Controller 1564 may also operate the fan assembly 1562 to primarily optimize the air pollutant recovery process or co-optimize the air pollutant recovery process and the cooling process. Controller 1564 may consider parameters such as air temperature, relative humidity, time, total amount of air pollutant recovery over a period of time, and / or energy cost as some of the variables monitored to control the operation of the air contactor 1550.

[0105]

[0162] Controller 1564 may switch between a wet cooling mode or a dry cooling mode based on the required cooling capacity. For example, controller 1564 may operate the pre-cooling system 1554 when the required cooling capacity is higher and may not operate the pre-cooling system 1554 when the required cooling capacity is lower. Also, for embodiments where the air contactor 1550 may utilize water or a carbon recovery solution within the pre-cooler system 1556, controller 1564 may utilize water within the pre-cooler system 1556 when a higher cooling capacity is required than that of the carbon recovery solution.

[0106]

[0163] The controller 1564 can also determine whether to operate the CO2 recovery system 1560 based on signals from the CO2 utilization process. For example, if the CO2 storage tank is full and / or the value is insufficient for CO2 recovery, the controller 1564 may not operate the CO2 recovery system 1560.

[0107]

[0164] The air contactor 1550 may recirculate the carbon recovery solution within the CO2 recovery system 1560 or utilize a cross - flow approach. The air contactor 1550 may have a time - based bleed or drainage of the recirculated water, or drainage based on the conductivity of the water, to avoid excessive scaling and / or corrosion of the unit.

[0108]

[0165] Referring to FIG. 30, an air contactor 1600 is provided that is similar to the above - described air contactor 1550 in many respects. The air contactor 1600 includes an air pollutant recovery system such as a CO2 recovery system 1602 having a sump 1604 with a level sensor 1606. The air contactor 1600 has a controller 1608 operably connected to the level sensor 1606 and a water supply valve 1610, whereby the controller 1608 can selectively provide makeup water to the sump 1604 to compensate for the evaporation of water from the carbon recovery solution. The level sensor 1606 enables the controller 1608 to directly measure the water loss due to evaporation and control the valve 1610 in response to the level of the recovery solution dropping to a predetermined threshold. Alternatively or additionally, the controller 1608 can indirectly determine the water loss using other sensors of the air contactor 1600 in a manner similar to the approach described above. For example, the water loss can be estimated through the difference in humidity between the air entering and exiting the air contactor 1600, or through changes in concentration parameters of the carbon recovery solution such as pH, conductivity, and / or pollutant concentration.

[0109]

[0166] With respect to FIG. 31, an air contactor 1650 is provided that is similar in many respects to the air contactor 1100 described above. The air contactor 1650 has an air inlet 1652, a CO2 recovery system 1651, a heat exchanger 1654, a fan assembly 1656, an air outlet 1658, and a controller 1660. The CO2 recovery system 1651 has a CO2 recovery medium 1653 that can include, for example, a solid absorbent and / or an electrochemical absorption / desorption process device. The air contactor 1650 includes an air sensor 1662, a fluid 1664, and a CO2 recovery medium sensor 1668 of the CO2 recovery medium 1653.

[0110]

[0167] The controller 1660 can control the operation of the CO2 recovery system 1651, such as by controlling a resistance heater of the CO2 recovery medium 1653, the fan assembly 1656, and a CO2 exhaust valve 1680. When the CO2 recovery system 1651 is in an operating mode and thereby the CO2 recovery medium 1653 collects CO2, the controller 1660 can close the CO2 exhaust valve 1680. The controller 1660 can shift to a CO2 removal mode in which the controller 1660 stops the operation of the fan assembly 1656, closes the air inlet 1652 and the air outlet 1658, opens the CO2 exhaust valve 1680, and operates the vacuum of the CO2 recovery system 1651 to draw CO2 from the CO2 recovery medium 1653 through the CO2 exhaust valve 1680 into a CO2 storage container.

[0111]

[0168] The air sensor 1662 can measure parameters similar to those described above with respect to the air sensors of the other air contactors described above. Similarly, the fluid sensor 1664 can measure at least one of the temperature and pressure of the fluid in the heat exchanger 1654. The CO2 recovery medium sensor 1668 can detect at least one of temperature, potential / resistivity, carbon dioxide concentration, carbon monoxide concentration, volatile organic compound (VOC) concentration, ozone concentration, sulfur dioxide concentration, and nitrogen dioxide concentration.

[0112]

[0169] The controller 1660 can operate the air contactor 1650 using logic similar to the above-described logic, such as operating the fan assembly 1656 to adjust the fan speed to provide the required process fluid temperature setpoint and / or process fluid pressure setpoint.

[0113]

[0170] The controller 1660 can measure the air-side recovery performance over time, such as the difference between the CO2 concentration entering at the air inlet 1652 and the CO2 concentration exiting at the air outlet 1658 via data from the air sensor 1662, to ensure the optimal operation of the CO2 recovery process. Alternatively or additionally, the controller 1660 can optimize the air pollutant recovery process by verifying that the air pollutant recovery medium 1650 does not exceed a pre-set saturation level using one or more parameters of the CO2 recovery medium 1653. When the saturation level is reached, the controller 1660 can change from the CO2 recovery stage to the CO2 removal stage. For example, the controller 1660 can operate the CO2 recovery medium 1650 to apply different voltage potentials to the CO2 recovery medium 1653, increase or decrease the temperature of the CO2 recovery medium 1653, and / or wash the CO2 recovered from the recovery medium 1653 in the liquid distribution system. Another embodiment removes the CO2 recovered from the recovery medium 1653 using a gas.

[0114]

[0171] Referring to FIG. 32, an air contactor such as a chiller or heat pump 1700 is provided. The heat pump 1700 has a CO2 recovery device 1702 configured to recover CO2 using either absorption or adsorption. In another embodiment, the recovery device 1702 can be configured to remove another air pollutant such as methane or a combination of air pollutants. In one embodiment, the CO2 recovery device 1702 uses a liquid recovery solution that is directed to a regenerator 1704 to regenerate the recovery fluid by removing CO2 from the liquid recovery solution. The regenerator 1704 outputs pollutants 1705 such as gaseous CO2 for collection.

[0115]

[0172] The heat pump 1700 further includes a heat pump 1706 having a high-temperature component 1708 that can include, for example, a condenser. The heat pump 1706 has a low-temperature component 1710 that can include, for example, an evaporator. In another embodiment, the heat pump low-temperature component 1710 can include an intermediate cooler between two CO2 recovery devices. The heat pump low-temperature component 1710 operates as an air conditioner that removes heat from a sweep gas such as air 1712 that moves through the heat pump 1700. The heat pump 1700 has a fan assembly 1714 for generating the movement of air 1712 within the outer structure 1716 of the heat pump 1700.

[0116]

[0173] In one embodiment, the temperature of the heat pump low-temperature component 1710 is higher than the dew point of the air 1712. This reduces the dry bulb temperature of the air 1712 and increases the relative humidity of the air 1712 downstream of the heat pump low-temperature component 1710. Depending on the air pollutant recovery medium utilized, the CO2 recovery device 1702 can benefit from the higher relative humidity as part of the air pollutant (e.g., CO2) removal process.

[0117]

[0174] Referring to FIG. 33, a heat pump 1750 is provided having a CO2 recovery device 1752, a regenerator 1754, an evaporator 1756, and a condenser 1758. The temperature of the evaporator 1756 can be below the dew point of the sweep gas 1760 entering the heat pump 1710. The lower temperature of the evaporator 1756 reduces the humidity of the air and operates as a dehumidifier. Reducing the humidity of the air downstream of the evaporator 1756 is beneficial for the CO2 recovery device 1752 that utilizes low humidity air as part of the air pollutant removal process. The heat pump 1750 has a make-up control system 1764 that collects water 1762 from the evaporator 1756 and guides the collected water 1762 to the regenerator 1754. For example, the CO2 recovery device 1752 can utilize a liquid carbon recovery fluid, and the make-up water 1766 is used to replenish the water evaporated from the carbon recovery solution. As another example, the water 1762 collected from the evaporator 1756 may be used in another process such as an industrial process that utilizes drinking water.

[0118]

[0175] With respect to FIG. 34, a heat pump 1800 is provided that is similar in many respects to the heat pump described above. The heat pump 1800 includes a CO2 recovery device 1802, a regenerator 1804, an evaporator 1806, and a condenser 1808. The heat required by the regenerator 1804 to regenerate the air pollutant recovery solution significantly exceeds the temperature of the condenser 1808. To provide the required heat, heat from a heat source 1810 is used as heat to the regenerator 1804. The heat source 1810 can include, for example, a resistance heating element, direct fire, nuclear power, sunlight, nuclear fission, a heat exchanger between plasma nuclear fusion, geothermal energy, and / or magma beneath the earth's crust.

[0119]

[0176] The heat from the condenser 1808 may be combined with the heat from the heat source 1810 or may be used for different purposes such as providing heat for district heating or industrial processes. The presence of the evaporator 1806 in the path of the sweep gas flow 1812 through the heat pump 1800 improves the efficiency of the CO2 recovery device 1802 in some embodiments by removing heat from the sweep gas flow 1812 upstream of the CO2 recovery device 1802.

[0120]

[0177] With reference to FIG. 35, a heat pump 1850 similar to the heat pump 1800 described above is provided. The heat pump 1850 includes a CO2 recovery device 1852, a regenerator 1854, an evaporator 1856, a condenser 1858, and a heat source 1860. The heat pump 1850 further includes a heat exchanger 1862 downstream of the CO2 recovery device 1852. The heat exchanger 1862 can be wet or dry and can be a direct heat exchanger or an indirect heat exchanger. Examples of the heat exchanger 1862 include a liquid spray / fill material system, a fin-tube heat exchanger, and a serpentine coil. The heat exchanger 1862 exhausts waste heat into the sweep gas 1864. The evaporator 1856 reduces the wet-bulb temperature of the sweep gas 1864 below the wet-bulb temperature of the ambient air, and the CO2 recovery device 1852 reduces the dry-bulb temperature of the sweep gas (e.g., air) below the dry-bulb temperature of the ambient air. The heat exchanger 1862 exhausts waste heat into the sweep gas 1864 and has a higher heat exchange capacity because the heat exchanger 1862 exhausts waste heat into air having a lower dry-bulb temperature and wet-bulb temperature than the ambient air. In another embodiment, the evaporator 1856 is downstream of the heat exchanger 1862, so that water can be condensed from the sweep gas 1864 providing the water source and the risk of plume can be reduced. In certain applications, positioning the evaporator 1856 downstream of the heat exchanger 1862 can provide a higher condenser temperature.

[0121]

[0178] Referring to FIG. 36, a heat pump 1900 is provided having an evaporator 1902 having a temperature lower than the dew point temperature. The heat pump 1900 further includes a makeup control system 1904 that directs the water 1906 collected from the evaporator 1902 to the regenerator 1910 as makeup water 1908. The heat pump 1900 further includes a CO2 recovery device 1912, a condenser 1914, and a heat exchanger 1916 intermediate the evaporator 1902 and the CO2 recovery device 1912. In this embodiment, the CO2 recovery device 1912 functions better with dry air. The temperature of the evaporator 1916 is below the dry bulb temperature but upstream of the CO2 recovery device 1912. The evaporator 1916 reduces the relative humidity of the sweep gas 1920 (e.g., air) by raising the dry bulb temperature of the air after the evaporator 1902 removes water from the sweep gas 1920. Positioning the heat exchanger 1916 upstream of the CO2 recovery device 1912 provides several advantages for some embodiments. First, the operation of the CO2 recovery device 1912 may raise the dry bulb temperature and / or wet bulb temperature of the sweep gas 1920, which can adversely affect the efficiency of the heat exchanger downstream of the CO2 recovery device 1912. Second, the operation of the CO2 recovery device 1912 may benefit from warmer air, and the heat exchanger 1916 can supplement the cooling provided by the evaporator 1902. Third, the risk that the solvent of the CO2 recovery device 1912 is carried onto the heat exchanger 1916 is reduced.

[0122]

[0179] Referring to FIG. 37, an air contactor system 1950 is provided that includes a CO2 recovery device 1952, a fan assembly 1954, an endothermic regeneration process 1956, an exothermic regeneration process 1958, and storage tanks 1960, 1962. The air contactor system 1950 includes a controller 1964 that operates the storage tank 1960 to selectively release one or more chemicals into the exothermic regeneration process 1958 and selectively provide heat to a process 1970 that utilizes heat. For example, the controller 1964 may execute the exothermic regeneration process 1958 at night to supply heat to a process 1970 that uses an air source heat pump during the day. As an example, the process 1970 may include district heating. The controller 1964 may receive data from a data source 1972, such as weather, electricity costs, process demands, or other information utilized by the controller 1964, to determine when to operate the exothermic regeneration process 1958.

[0123]

[0180] For example, the carbon recovery solution utilized by the CO2 recovery device 1952 may be a caustic alkali solution (NaOH), which incorporates carbon from the air and reacts with the air to form potassium carbonate. The output 1974 of the CO2 recovery device 1952 includes a solution of potassium carbonate flakes and the solution. The endothermic regeneration process 1956 bakes the flakes at, for example, 900°C. The baked carbonate flakes are stored in the storage tank 1960 until the controller 1964 instructs the storage tank 1960 to release the baked flakes into the exothermic regeneration process 1958. The exothermic regeneration process 1958 may involve, for example, adding water to the carbonate flakes. Water (H2O) donates hydrogen atoms to the carbonate to provide a carbon recovery solution at the output 1976 of the exothermic regeneration process 1958. Also, the combination of water and the carbonate flakes generates heat, which is transferred to the process 1970. The carbon recovery solution from the exothermic regeneration process is stored in the storage tank 1962 until required by the CO2 recovery device 1952. The controller 1964 may operate the storage tank 1962 to direct the carbon recovery solution to the CO2 recovery device 1952 and refill the CO2 recovery device 1952 with fresh carbon recovery solution.

[0124]

[0181] Referring to FIG. 38, an air contactor system 2000 is provided having an air flow generator such as a heat source 2002, a CO2 recovery device 2004, and a hyperbolic outer structure 2006. The heat source 2002 may be, for example, waste heat from an industrial process or a geothermal heat source. Heating of the sweep gas 2008 by the heat source 2002 causes the air to move upward due to the temperature buoyancy effect of the air and pass through the hyperbolic outer structure 2006. In this way, the heat source 2002 operates as an air flow generator that causes the movement of the sweep gas across the sorber 2004. In this manner, the air contactor 2000 provides an air flow across the CO2 recovery device 2004 without the need to power a fan, although a fan may be used in some applications.

[0125]

[0182] Referring to FIGS. 39 to 43, an air pollutant recovery system 2500 is provided that is similar in many respects to the above-described embodiments. Some carbon recovery systems include a regeneration process driven by heat. The heat is then dispersed into the atmosphere using a heat exchanger. The air pollutant recovery system 2500 uses a thermal energy storage unit to recover at least a portion of the heat utilized for regeneration and significantly reduce the amount of external heat provided within the system.

[0126]

[0183] More specifically, referring to FIG. 39, the air pollutant recovery system 2500 includes an air contactor 2502 having a CO2 recovery device 2504 that utilizes a recovery solution. The recovery solution incorporates air pollutants such as CO2 through contact with the air. The recovery solution may be circulated within the air contactor 2502 until the recovery solution has a concentration of air pollutants that exceeds a predetermined threshold. The air pollutant recovery system 2500 may include a pump 2503 for pumping the recovery solution between components of the air pollutant recovery system 2500.

[0127]

[0184] When the recovered solution reaches saturation with air pollutants, the recovered solution is regenerated, and the recovered air pollutants are removed from the recovered solution using an endothermic regeneration process 2506 and an optional exothermic regeneration process 2508. More specifically, some carbon recovery media (solid or liquid) require an increase in temperature conditions to be regenerated. The output of the CO2 recovery device 2504 can be, for example, a carbon recovery solution if the CO2 recovery device 2504 utilizes a liquid recovery solvent. Alternatively, the output of the CO2 recovery device 2504 can be a heat transfer fluid such as N2 gas if the CO2 recovery device 2504 utilizes a solid absorbent.

[0128]

[0185] The exothermic regeneration process 2508 can, in one form, simply be a cooling step of the liquid recovery solvent. The air pollutant recovery system 2500 can include intermediate operations between the endothermic regeneration process 2506 and the exothermic regeneration process 2508, such as the operations described above with respect to FIG. 7.

[0129]

[0186] The endothermic regeneration process 2506 receives heat from a heat source 2510 and outputs a regenerated material 2512 that is directed to one or more process controls such as three-way valves 2514, 2516. An example of the endothermic regeneration process 2506 includes the regeneration of KOH, specifically, the regeneration of pellets in a calcination furnace. In the case of a solid absorbent, zeolite and amine (and other substances) require a higher temperature to expel molecules and the like absorbed by the solid absorbent.

[0130]

[0187] The regenerated material 2512 can be a liquid or slurry for a recovery system that utilizes a liquid solvent. In the case of a solid absorbent, the regenerated material 2512 can be a carrier fluid (e.g., gas) used to remove CO2 from the solid absorbent.

[0131]

[0188] The three-way valves 2514, 2516 have inlets 2520, 2522 and outlets 2524, 2526, 2528, 2530, which are selectively communicated with each other so as to control the flow of the regeneration material 2512 to the exothermic regeneration process 2508 and the thermal energy storage units 2532, 2534. The thermal energy storage units 2532, 2534 may include, for example, storage tanks. For example, the thermal energy storage units 2532, 2534 may include storage tanks (e.g., made of metal and / or plastic), and may house one or more heat exchangers made of metal, plastic, and / or ceramic materials. The heat exchanger may include, for example, a serpentine coil, a pillow plate heat exchanger, a plate heat exchanger, a finned tube heat exchanger, etc. The storage tanks of the thermal energy storage units 2532, 2534 may be filled with water or another liquid for single-phase storage. In one embodiment, the liquid may be under pressure so as not to exceed the boiling point. Alternatively or additionally, the storage tanks of the thermal energy storage units 2532, 2534 may be filled with a solid having a high heat capacity (e.g., concrete or metal), or a phase change material having a melting temperature selected to closely match the process temperature. Examples of phase change materials include molten metals, hydrated salts, paraffins, or bio-based phase change materials (PCMs).

[0132]

[0189] The air pollutant recovery system 2500 further includes a controller 2540 that communicates with the components of the system 2500, and this controller operates various components of the system 2500 based on the data from the sensors 2542. The sensors 2542 include temperature sensors 2550, 2552, 2554, 2556, 2558, 2560, 2562 for detecting the temperature of the regeneration material 2512. The sensors 2542 may measure, for example, flow rate, pH (in the case of a KOH solvent or a NaOH solvent, etc.), CO2 concentration (in the case of using a gaseous carrier fluid, for example), pressure (positive pressure or vacuum), water content (in the case of using an aqueous solution, for example), and / or relative humidity (in the case of a gas flow, for example).

[0133]

[0190] Sensor 2542 further includes storage sensors 2570, 2572 for generating data indicating the full state of the thermal energy storage units 2532, 2534. The storage sensors 2570, 2572 can detect, for example, temperature, level (e.g., volume within a tank), and density. Since a phase change material (PCM) can have a significant variation in density between the solid state and the liquid state, detecting the density of the PCM within the thermal energy storage units 2532, 2534 can be used to determine the energy stored within the thermal energy storage units 2532, 2534.

[0134]

[0191] As an example using PCM, the controller 2540 can determine the level of PCM within the storage tank when the PCM is liquid or fully melted (0% full) and when the PCM is solid or fully fused (100% full). The controller 2540 can then interpolate between the levels of the PCM in real time to obtain an indication of the instantaneous level of fullness of the PCM.

[0135]

[0192] Alternatively or additionally, the controller 2540 can determine the fullness of the PCM using the temperature of the PCM. For example, if the melting temperature is 80°F, the controller 2540 can estimate the fullness level of the PCM using data from one or more of the sensors 2542. If the sensor 2542 detects a temperature of the PCM of approximately 80°F and then the sensor 2542 begins to detect an increase in temperature, the controller 2540 can determine that the PCM has melted at the location of the sensor 2542. Conversely, if the temperature gradually drops from 90°F to around 80°F and then remains constant (and in some cases begins to cool very slowly below 80°F), the controller 2540 can determine that the PCM has melted at the location of the sensor 2542.

[0136]

[0193] Regarding single-phase storage, the controller 2540 can determine the full level using temperature data from one or more sensors 2542. The controller 2540 correlates the level of fullness based on the temperature difference between the storage medium and the fluid being heated / cooled. As the difference between the temperatures decreases (e.g., 2°F), it can become increasingly difficult to fill and dissipate the thermal storage unit to a completely full point or a completely dissipated point. Thus, the controller 2540 can operate the system to maintain a predetermined temperature difference between the storage medium and the fluid being heated or cooled.

[0137]

[0194] The air pollutant recovery system 2500 further includes a thermal energy storage heat energy transfer circuit 2580 having conduits 2582, 2584 and dissipation pumps 2586, 2588 for transferring heat between the thermal energy storage units 2532, 2534 and the endothermic regeneration process 2506. In one embodiment, the heat transfer fluid is water, such as water below 212°F. In another embodiment, the heat transfer fluid is steam, and the dissipation pumps 2586, 2588 include, by way of some examples, blowers and / or compressors.

[0138]

[0195] Different high-temperature carrier fluids may be used to transfer heat between the thermal energy storage units 2532, 2534 and the endothermic regeneration process 2506. In another embodiment, the endothermic regeneration process 2506 can be performed within the tanks of the thermal energy storage units 2532, 2534. An external heat source may be used to provide heat to the endothermic regeneration process 2506 within the tanks.

[0139]

[0196] The air pollutant recovery system 2500 has a regeneration and filling mode as shown in FIG. 39. Regeneration is performed in parallel with the filling of the thermal energy storage units 2532 and 2534. More specifically, the outlets 2526 and 2530 of the three-way valves 2514, 2516 are closed, whereby the regeneration material 2512 from the endothermic regeneration process 2506 is guided to the thermal energy storage units 2532, 2534. The regeneration material 2512 transfers heat from the regenerative material 2512 to the thermal energy storage units 2532, 2534. The regenerative material 2512 is then guided from the thermal energy storage units 2532, 2534 to the exothermic regeneration process 2508. After the regenerative material 2512 undergoes an exothermic chemical reaction in the exothermic regeneration process 2508, it is guided to the CO2 recovery device 2504.

[0140]

[0197] With respect to FIG. 40, the air pollutant recovery system 2500 is shown in a regeneration, dissipation, and storage mode. More specifically, the heat source 2510 provides auxiliary heat if necessary, but does not have to be the main heat source for the endothermic reaction of the endothermic regeneration process 2506. Instead, the dissipation pump 2586 operates to transfer heat from the thermal energy storage unit 2532 to the endothermic regeneration process 2506. Also, the outlet 2524 of the three-way valve 2514 is closed, whereby the regenerative material 2512 from the endothermic regeneration process 2506 is not directed into the thermal energy storage unit 2532 but is guided to the exothermic regeneration process 2508.

[0141]

[0198] In FIG. 40, the thermal energy storage unit 2534 is fully filled and stores thermal energy. More specifically, the dissipation pump 2588 is off, and as a result, the stored thermal energy in the thermal energy storage unit 2534 is not supplied to the endothermic regeneration process 2506. Also, the outlet 2528 of the three-way valve 2516 is closed, whereby the regenerative material 2512 from the endothermic regeneration process 2506 is not guided to the thermal energy storage unit 2534 but instead moves to the exothermic regeneration process 2508.

[0142]

[0199] With respect to FIG. 41, the air pollutant recovery system 2500 has regeneration, filling, and dissipation modes. The heat source 2510 provides auxiliary heat to the endothermic regeneration process 2506 if necessary. The thermal energy storage unit 2534 is fully filled, and the dissipation pump 2588 pumps the stored thermal energy from the full thermal energy storage unit 2534 to the endothermic regeneration process 2506. The thermal energy storage unit 2532 is depleted and the dissipation pump 2586 is turned off.

[0143]

[0200] In FIG. 41, to guide the regenerative material 2512 into the storage unit 2532 to fill the storage unit 2532, the outlet 2526 of the valve 2514 is closed and the outlet 2524 is open. The regenerative material 2512 moves from the storage unit 2532 to the exothermic regeneration process 2508. The inlet 2522 and outlets 2528, 2530 of the valve 2516 are closed to prevent the regenerative material 2512 from moving to the storage unit 2534.

[0144]

[0201] Referring to FIG. 42, the air pollutant recovery system 2500 has regeneration, dissipation, and filling modes. The storage unit 2532 is fully filled, and the pump 2586 guides the stored thermal energy to the endothermic regeneration process 2506. The valve 2514 is closed to prevent the regenerative material 2512 from flowing into or out of the thermal storage unit 2532.

[0145]

[0202] In FIG. 42, the thermal energy storage unit 2534 is being refilled. Specifically, the pump 2588 is off. The inlet 2522 and outlet 2528 of the three-way valve 2516 are open to guide the regenerative material 2512 towards the thermal energy storage unit 2534. The thermal energy storage unit 2534 absorbs heat from the regenerative material 2512, and then the regenerative material 2512 is guided to the exothermic regeneration process 2508.

[0146]

[0203] With reference to FIG. 43, the air pollutant recovery system 2500 has a regeneration and dual dissipation mode. In this mode, both the thermal energy storage units 2532, 2534 are in dissipation to provide heat to the endothermic regeneration process 2506. More specifically, the outlets 2526, 2530 of the three-way valves 2514, 2516 are closed, while the inlets 2520, 2522 and the outlets 2524, 2528 are open to allow the regenerative material to flow from the endothermic regeneration process 2506 to the thermal energy storage units 2532, 2534. Also, the dissipation pumps 2586, 2588 are operating to transfer the stored thermal energy from the thermal energy storage units 2532, 2534 to the endothermic regeneration process 2506.

[0147]

[0204] The controller 2540 can switch between various operating modes of the air pollutant recovery system 2500 based on data from various sensors 2542. For example, the controller 2542 may fill one thermal energy storage unit 2532 while dissipating the other thermal energy storage unit 2534 such that at least one of the thermal energy storage units 2532, 2534 that provides stored thermal energy to the endothermic regeneration process 2506 is present to reduce external heat from the heat source 2510.

[0148]

[0205] Referring to FIG. 44, an air pollutant recovery system 2600 is provided that is similar in many respects to the above-described air pollutant recovery system 2500. The air pollutant recovery system 2600 includes an air contactor 2602 having a CO2 recovery device 2604, a pump 2603, an endothermic regeneration process 2606, and an optional exothermic regeneration process 2608. The exothermic regeneration process 2608 may not be used in some air pollutant recovery technologies.

[0149]

[0206] The air pollutant recovery system 2600 includes, as some examples, an intermittent renewable heat source 2608 such as concentrated solar power or wind power. The air pollutant recovery system 2600 includes a dissipation pump 2610 for circulating a heat exchange fluid 2612, such as water, to a valve 2614 that controls the flow of the heat exchange fluid 2612 to either an endothermic regeneration process 2602 or a thermal energy storage unit 2630. The heat exchange fluid 2612 can be, for example, water, steam, oil, molten salt, liquid metal, nanoparticles, and / or a slurry.

[0150]

[0207] The valve 2614 has an inlet 2616, an outlet 2618 for guiding the fluid to an exothermic regeneration process 2606, and an outlet 2620 for guiding the fluid to the thermal energy storage unit 2630. The thermal energy storage unit 2630 is configured to store the thermal energy used by the endothermic regeneration process 2606 when a removable heat source 2608 is not available, such as at night in the case of an example of concentrated solar power.

[0151]

[0208] The air pollutant recovery system 2600 includes a dissipation pump 2632 for pumping a heat exchange fluid from the thermal energy storage unit 2630 to the endothermic regeneration process 2602 in response to a request from a controller 2634 of the air pollutant recovery system 2600. The controller 2634 can be operably connected to a sensor 2636 of the thermal energy storage unit 2630 to determine the capacity of the thermal energy storage unit 2630. The controller 2634 is also operably connected to the dissipation pumps 2610, 2632 and the valve 2614.

[0152]

[0209] When a removable heat source 2608 is providing heat, the thermal energy storage unit 2630 can be filled, for example, by the controller 2634 operating the valve 2614 to close the outlet 2618, open the inlet 2616 and the outlet 2620, and operating the pump 2610 to direct the heat transfer fluid to the thermal energy storage unit 2630.

[0153]

[0210] In another example, the renewable heat source 2608 can provide heat to both the thermal energy storage unit 2630 and the endothermic regeneration process 2606. More specifically, the controller 2634 operates the valve 2614 to open the inlet 2616, the outlet 2618, and the outlet 2620, and operates the pump 2610 to direct the heat transfer fluid from the renewable heat source 2608 to both the endothermic regeneration process 2606 and the thermal energy storage unit 2630.

[0154]

[0211] When the thermal energy storage unit 2630 is completely filled, the controller 2634 can operate the valve 2614 to close the outlet 2620 while leaving the inlet 2612 and the outlet 2618 open. The pump 2610 continues to direct the heat transfer fluid to the endothermic regeneration process 2606.

[0155]

[0212] The air pollutant recovery system 2600 also includes valves 2640, 2642 and thermal energy storage units 2644, 2646, and dissipation pumps 2648, 2650 that enable storage and dissipation of thermal energy to the endothermic regeneration process 2606 as desired.

[0156]

[0213] In one embodiment, the CO2 recovery device 2604 includes a solid absorbent, and the pump 2603 directs a carrier gas (e.g., N2 or steam) to the endothermic regeneration process 2606. The solid absorbent can be heated by the carrier gas or another heat source within the CO2 recovery device 2604. Alternatively or additionally, a vacuum can be utilized to remove air pollutants from the solid absorbent of the CO2 recovery device 2604. In yet another embodiment, instead of using a pump to direct N2 gas, N2 gas is provided to the CO2 recovery device 2604 from a pressurized container.

[0157]

[0214] Referring to FIG. 45, a building 2700 having a cooling tower 2702 and a natural gas boiler 2704 is shown. The natural gas boiler 2704 has a flue 2706 that discharges flue gas 2708 having a CO2 concentration within approximately 10%. The cooling tower 2702 draws in ambient air 2710 and dissipates humidified ambient air 2712. As shown in FIG. 45, the flue gas has a CO2 concentration significantly higher than the humidified air going out of the cooling tower 2702.

[0158]

[0215] With respect to FIG. 46, a point source recovery and direct air recovery system 2800 is provided for a building 2801. The system 2800 includes an air contactor 2802 equipped with a heat exchanger such as a wet heat exchanger for transferring heat between ambient air 2804 and a process fluid. The air contactor 2802 also includes a CO2 recovery system 2806 for recovering CO2 from the ambient air. For example, the CO2 recovery system 2806 may utilize one of the solvent-based or other CO2 recovery approaches described herein. The air contactor 2802 dissipates a CO2-rich gas stream 2815 having a CO2 concentration higher than that of the ambient air.

[0159]

[0216] The system 2800 includes a CO2 scrubber such as a boiler flue gas carbon recovery system 2810 configured to remove CO2 from the flue gas 2819 exiting the boiler 2814. For example, the flue gas 2819 exiting the boiler 2814 has a CO2 content of approximately 10%, while the flue gas 2812 exiting the building 2801 has a CO2 content of approximately 1%. The boiler 2814 can be a natural gas or coal-fired ignition process such as those used in various commercial, residential, and / or industrial buildings.

[0160]

[0217] System 2800 further includes an ambient air source 2820 and an ambient air mixer 2817, which introduces ambient air into the CO2-rich gas stream 2815 to reduce the CO2 concentration of the CO2-rich gas stream 2815 to a concentration that matches the CO2 concentration of the flue gas 2815 exiting the boiler 2814. The ambient air mixer 2817 can include, for example, a fan, valve, louver, actuator, motor, and / or movable duct section for selectively introducing ambient air into the CO2-rich gas stream 2815.

[0161]

[0218] System 2800 operates the ambient air mixer 2817 so that the CO2-rich gas stream 2815 has a CO2 concentration similar to that of the flue gas 2819 exiting the boiler 2814, enabling the boiler flue gas carbon recovery system 2810 to remove CO2 from both the CO2-rich gas stream 2815 and the flue gas 2819. Since the CO2 concentrations in the flue gas 2819 and the CO2-rich gas stream 2815 are similar, the boiler flue gas carbon recovery system 2810 can use the same chemical process to remove CO2 from the CO2-rich gas stream 2815 and the flue gas 2819. By doing so, the air contactor 2802 can be retrofitted to a building 2801 having a boiler flue gas carbon recovery system 2810 to add ambient air carbon recovery capabilities to the building 2801.

[0162]

[0219] Matching the CO2 concentrations can facilitate highly efficient CO2 removal from both the flue gas 2819 and the CO2-rich gas stream 2815 in conjunction with a separation, purification, and liquefaction process having the expected CO2 and N2 concentrations. In one embodiment, the air contactor 2802 utilizes a solid absorbent and N2 gas dissipated from the air contactor 2802 rather than ambient air 2820 as a carrier gas for the recovered CO2.

[0163]

[0220] The boiler flue gas carbon recovery system 2810 removes CO2 from the flue gas 2819 by diverting the flue gas 2812 into the system 2810 from the flue 2831 via the conduit 2830. The system 2810 also receives the CO2-rich exhaust gas 2815 via the conduit 2833. Next, the system 2810 separates CO2, nitrogen, and oxygen. The CO2 is converted into liquid CO2 2822 and collected, such as in a tank.

[0164]

[0221] In one embodiment, the CO2-rich gas stream 2815 may already have a CO2 concentration that matches the CO2 content of the flue gas 2819, such that ambient air is not added to the CO2-rich gas stream 2815. In this embodiment, the ambient air mixer 2817 may not be provided. Alternatively, the ambient air mixer 2817 has a CO2 sensor that detects a similar CO2 concentration and prevents the addition of ambient air to the CO2-rich gas stream 2815.

[0165]

[0222] Optimization of the air contactor design

[0223] For some embodiments, there are several design parameters that can be optimized to improve the CO2 recovery performance of the air contactor and reduce the operating and equipment costs. These design parameters include the following.

[0166]

Table 1

[0167]

[0224] One approach to optimizing the design of the air contactor is to utilize a "coarse" series of guesses, that is, focus on the volume of the packing (presumed to be the most expensive part of the equipment) and the energy consumption rate per given amount of CO2 recovered.

[0168]

[0225] A more detailed approach to optimizing the design of an air contactor includes operating costs (notably pump capacity, solvent cost, and water cost) and net CO2 recovery rate. This more detailed approach can show that the air contactor equipment itself incurs a negative carbon “burden” (i.e., embodied carbon) due to its manufacture, installation, use, and end-of-life. Also, the operation of the equipment itself can result in CO2 emissions in terms of energy, water, and solvent consumption.

[0169]

[0226] Therefore, the net carbon recovery rate can be calculated as follows.

[0170]

Equation

[0171]

[0227] Where,

[0172]

Equation

[0173] is the net CO2 recovery rate in kg / s,

[0174]

Equation

[0175] is the average CO2 recovery rate in kg / s (estimated using test data, basic mass transfer models, and / or numerical simulations), m CO2,embodied is the mass of embodied CO2 of the equipment in kg, t lifetime is the expected operating life of the equipment in seconds,

[0176]

Equation

[0177] is the CO2 emission rate due to the operation of the equipment in kg / s.

[0178]

[0228] The CO2 emission rate by operation is defined as follows.

[0179]

Number

[0180]

[0229] Here, the fan power and pump power are in kW (estimated using test data, fan and pump manufacturer data, basic air and liquid flow models, and / or numerical simulations), the electricity carbon intensity is in kgCO2 / kW, the water consumption is in kg / s and is defined as the sum of the water evaporation rate in kg / s (estimated using test data, basic heat and mass transfer models, and / or numerical simulations) and the water drift rate in kg / s (defined as the overall drift rate in kg / s multiplied by the mass fraction of water in the solution in kg / kg), the water carbon intensity is in kgCO2 / kg, the solvent consumption is in kg / s and is defined as the sum of the solvent renewal rate in kg / s (i.e., it is assumed that the solvent does not persist over the entire service life of the unit and must be "refreshed") and the solvent drift rate in kg / s (defined as the overall drift rate in kg / s multiplied by the mass fraction of solvent in the solution in kg / kg). The solvent carbon intensity is in kgCO2 / kg.

[0181]

[0230] A given contactor design may include power generation (e.g., heat recovery and reuse, photovoltaic (PV)), in which case the CO2 emission rate by operation would be defined as follows.

[0182]

Number

[0183]

[0231] The power generation is in kW and is presumed to be the net generated power as the power generation device itself may consume energy. In some cases, the power generation can be greater than the power consumption, which may mean that the power can be sold and / or utilized in other areas of the carbon capture facility.

[0184]

[0232] Similarly, the contactor design may include an encapsulated water generation facility (e.g., dehumidification of the inlet and / or diffused air stream), in which case the CO2 emission rate due to operation will be defined as follows.

[0185]

Number

[0186]

[0233] The water generation power is in kW units and the water generation is in kg / s units. In some cases, the water generation can be greater than the water consumption, which can mean that the water can be sold and / or used in other areas of the carbon capture facility.

[0187]

[0234] In one approach, the air contactor design is optimized using the following optimization criteria or figure of merit (FOM). Cost of capture (CoC... in US dollars per kgCO2 unit), water intensity of capture (WIoC... in kg water per kgCO2 unit), energy intensity of capture (EIoC... in kJ per kgCO2 unit), and footprint of capture (FoC... in 1 per kgCO2 unit). Each of these optimization criteria is described in more detail below.

[0188]

[0235] Cost of capture (CoC... in US dollars per kg CO2 unit)

[0236] The cost of capture can be calculated using the following equation.

[0189]

Number

[0190]

[0237] Here, the capital cost is the total installed cost of the equipment including maintenance (and in some cases decommissioning measures) in US dollars, and the operating cost is defined as follows. Operating cost = ((fan power + pump power) × electricity cost) + (water consumption × water cost) + (solvent consumption × solvent cost) [Equation 6]

[0191]

[0238] Here, the electricity cost is in US dollars per kW, the water cost is in US dollars per kg, and the solvent cost is in US dollars per kg. A given contactor design may include power generation (e.g., heat recovery and reuse, solar PV power generation), in which case the operating cost will be defined as follows. Operating cost = ((fan power + pump power - power generation) × electricity cost) + (water consumption × water cost) + (solvent consumption × solvent cost) [Equation 7]

[0192]

[0239] Similarly, the contactor design may include an encapsulated water generation facility (e.g., dehumidification of the inlet and / or diffused air stream), in which case the operating cost will be defined as follows. Operating cost = ((fan power + pump power + water generation power) × electricity cost) + ((water consumption - water generation) × water cost) + (solvent consumption × solvent cost) [Equation 8]

[0193]

[0240] Water intensity of recovery (WIoC…kg 水 / kg CO2 unit)

[0241] The water intensity of recovery can be determined using the following equation.

[0194]

Number

[0195]

[0242] Here, water consumption is in kg / s, defined as the sum of the water evaporation rate in kg / s (which can be estimated using test data, basic heat and mass transfer models, numerical simulations, or any combination thereof) and the water drift rate in kg / s (defined as the overall drift rate in kg / s multiplied by the mass fraction of water in the solution in kg / kg). Water consumption may include on-site water generation as presented in the previous paragraph.

[0196]

[0243] Another expression of water intensity may include the water intensity of the power generation process, in which case the recovered water intensity would be defined as follows.

[0197]

Number

[0198]

[0244] Here, the power consumption is in kW and is defined as one of the methods presented in the previous paragraph, and the grid water intensity is in kg / kW.

[0199]

[0245] The recovered energy intensity (EIoC…kJ / kg CO2 unit)

[0246] The recovered energy intensity can be defined using the following equation.

[0200]

Number

[0201]

[0247] Here, the power consumption is in kg / s and is defined as the sum of the power consumption of the fans and pumps (and auxiliary equipment as defined in the previous paragraph). The power consumption may include on-site water generation, as presented in the previous paragraph.

[0202]

[0248] Another expression of energy intensity may include the power consumption of the water generation process, in which case the recovered energy intensity would be defined as follows.

[0203]

Number

[0204]

[0249] Here, the water consumption is in kg / s and is defined as one of the methods presented in the previous paragraph, and the water generation energy intensity is in kW / kg.

[0205]

[0250] Design optimization

[0251] The optimal design for a particular embodiment will satisfy one of the following equations, depending on the suitable optimization goal. Optimal design = min(CoC Design 1 , CoC Design 2 , CoC Design 3 , …, CoC Design n ) [Equation 13] Optimal design = min(WIoC Design 1 , WIoC Design 2 , WIoC Design 3 , …, WIoC Design n ) [Equation 14] Optimal design = min(EIoC Design 1 , EIoC Design 2 , EIoC Design 3 , …, EIoC Design n ) [Equation 15]

[0206]

[0252] In one approach, the optimization can be based on a given optimization parameter, but with an "upper limit" threshold for one or both of the remaining optimization parameters. For example, CoC is minimized, but it is desirable to ensure that WIoC < 2.5 kg 水 / kg CO2 and EIoC < 2e^3 kJ / kgCO2.

[0207]

[0253] The footprint of recovery (FoC…1 / kg CO2 unit)

[0254] One design optimization approach can include weighting the coefficients A, B, and C based on specific regulatory requirements, design philosophies, or other criteria of interest, and defining the overall footprint of recovery as follows. FoC = A × CoC + B × WIoC + C × EIoC [Equation 16]

[0208] [[ID= 55]]

[0255] Here, A is in units of 1 / US dollar, B is in units of 1 / kg 水 unit, and C is in units of 1 / kJ.

[0209]

[0256] Therefore, the optimal design will satisfy the following equation. Optimal design = min(FoC Design 1 , FoC Design 2 , FoC Design 3 , …, FoC Design n ) [Equation 17]

[0210]

[0257] Referring to FIG. 47, an air contactor 2900 is provided having a carbon recovery device 2902 and a regeneration process 2904 for regenerating the carbon recovery device 2902, such as by removing carbon from the carbon recovery solution. In another embodiment, the carbon recovery device 2902 may include a solid absorbent recovery device, and the regeneration process 2904 removes CO2 from a carrier gas used to remove CO2 from the solid absorbent recovery device.

[0211]

[0258] The air contactor 2900 has a fan assembly 2906 that generates a flow of air 2908 through the air contactor 2900 and through the carbon recovery device 2902. The air contactor 2900 is similar to the air contactor of FIG. 35, but the air contactor 2900 has a heat exchanger 2910 that is off the path of the air 2908 as the air 2908 moves through the air contactor 2900. In some embodiments, the heat exchanger 2910 outside the air path can reduce energy consumption by reducing the pressure drop of the air passing through the air contactor 2900. The heat exchanger 2910 receives a hot process fluid 2912 and returns a cooled process fluid 2914. The heat exchanger 2910 exchanges heat between the hot process fluid 2912 and the regeneration fluid 2916. The regeneration fluid 2916 can include, for example, a fluid (such as water) for providing heat to the regeneration process 2904 and / or a carbon recovery solution heated by the heat exchanger 2910. The heat exchanger 2910 returns the regeneration fluid 2918 to the regeneration process 2904. The regeneration process 2904 utilizes the heat from the heat exchanger 2910 to refresh the recovery fluid 2922 or remove carbon from the recovery fluid. The regeneration process 2904 directs the regenerated recovery fluid 2920 to the carbon recovery solution 2902, where the regenerated recovery fluid 2920 has a lower carbon content than the recovery fluid 292. The regeneration process 2904 stores or outputs the carbon removed from the recovery fluid 2922. As described above, the recovery solution 2922 can be continuously or intermittently directed from the carbon recovery device 2902 to the regeneration process 2904.

[0212]

[0259] Referring to FIG. 48, an air contactor 3000 is provided having a carbon recovery device 3002, a regeneration process 3004, and a heat pump 3006 for transferring heat from a high-temperature process fluid 3008 to a regeneration fluid 3010 from the regeneration process 3004. Instead of directly heating the regeneration fluid 3010 using the high-temperature process fluid 3008, the heat pump 3006 has a closed circuit of a heat pump fluid 3017 that operates as an intermediary between the high-temperature process fluid 3008 and the regeneration fluid 3010. The heat pump fluid 3017 can include, for example, hydrofluorocarbons (e.g., R410A, R134A, R407C, R32, R1234ZE), propane (e.g., R290, R744), carbon dioxide, or ammonia (e.g., R717).

[0213]

[0260] The heat pump 3006 has a compressor 3106 that raises the temperature and pressure of the heat pump fluid 3017 as the heat pump fluid 3017 moves from the evaporator 3012 to the condenser 3014, so the heat pump 3006 has a condenser 3014 that operates at a temperature higher than the high-temperature process fluid 3008. For example, the evaporator 3012 of the heat pump 3006 transfers heat from the high-temperature process fluid 3008 to the heat pump fluid 3017. In one embodiment, the heat pump fluid 3017 enters the evaporator 3012 as a liquid, the heat pump fluid 3017 boils in the evaporator 3012 by the heat from the process fluid 3008, and the heat pump fluid 3017 exits the evaporator 3012 as a gas.

[0214]

[0261] In the condenser 3014 of the heat pump 3006, the fluid of the heat pump 3006 has heat taken from the regeneration fluid 3010. A phase change occurs in the condenser 3014 (for example, the gas condenses into a liquid), but the temperature and pressure remain generally constant. The heat pump 3006 further includes a compressor 3016 and an expansion valve 3018. The expansion valve 3018 causes a rapid pressure drop of the heat pump fluid 3017 and a related rapid temperature drop of the heat pump fluid 3017. Since the coefficient of performance of the heat pump 3006 is greater than 1, the heat pump 3006 can heat the recovery fluid 3010 more efficiently than an electric heater. More specifically, the energy transferred by the heat pump 3006 to the regeneration fluid 3010 is greater than the energy consumed by the compressor 3106.

[0215]

[0262] Referring to FIG. 49, an air contactor 3100 is provided having a carbon recovery device 3102, a regeneration process 3104, and a chiller 3106. The chiller 3106 has a chiller fluid 3107 that receives heat from the process fluid 3108. The chiller 3106 has a compressor 3116 that raises the temperature of the process fluid 3108, a condenser 3114 for transferring heat to the regeneration fluid 3110, and an expansion valve 3109. The air contactor 3100 is similar to the air contactor 3000, except that the air contactor 3100 has a chiller 3106 instead of the heat pump 3006. The evaporator 3112 and condenser 3114 of the chiller 3106 have lower temperatures than the evaporator 3012 and condenser 3014 of the air contactor 3000, which can improve the efficiency of the process of receiving the cooled process fluid 3120 from the chiller 3106. More specifically, since the chiller 3106 is sized to provide a specific cooling capacity for the process fluid 3120, the chiller 3106 can operate at a colder temperature than the heat pump 3006. In contrast, since the main function of the heat pump 3006 is to heat the regeneration fluid 3110, the heat pump 3006 can be configured to raise the temperature of the regeneration fluid 3110 and operate at a higher temperature than the chiller 3106.

[0216]

[0263] With reference to FIG. 50, an air contactor 3200 is provided having a carbon recovery device 3202, an air-cooled heat exchanger 3204, a heat pump 3206, and a regeneration process 3208. The air-cooled heat exchanger 3204 may include, for example, a direct heat exchanger, a dry indirect heat exchanger, a wet indirect heat exchanger, a hybrid wet / dry heat exchanger, and / or an adiabatic heat exchanger. The heat pump 3206 has an evaporator 3210 that receives a high-temperature process fluid 3212 and absorbs heat therefrom. The evaporator 3210 directs the process fluid 3212 to the air-cooled heat exchanger 3204 where the process fluid is removed of additional heat by an air stream passing through the air contactor 3200. The air contactor 3200 directs the cooled process fluid 3214 back from the air-cooled heat exchanger 3204 to the associated process. The heat pump 3206 has a condenser 3220 that transfers heat to a regeneration fluid 3222. The regeneration process 3208 utilizes the heated regeneration fluid 3222 to replenish or generate a regenerated recovery fluid 3224 for the carbon recovery device 3202. The heat pump 3206 provides additional waste heat capacity to the air contactor 3200. In addition to or instead of the carbon recovery device 3202, the air contactor 3200 may include a system that distributes (e.g., sprays or floods) a carbon recovery solution to the indirect heat exchanger of the air-cooled heat exchanger 3204 to enhance the overall CO2 recovery capacity and provide some additional waste heat capacity via evaporation of water in the carbon recovery solution.

[0217]

[0264] Referring to FIG. 51, an air contactor 3300 is provided that is similar in many respects to the above-described air contactor 3200, except that the air contactor 3300 includes a chiller 3302 instead of a heat exchanger. Since the temperatures of the evaporator 3304 and the condenser 3306 of the chiller 3302 are lower, the controller of the air contactor 3300 may reduce the speed of the fan assembly 3308 and reduce power consumption in accordance with the need for a lower waste heat capacity.

[0218]

[0265] Referring to FIG. 52, an air contactor 3400 is provided having a carbon recovery device 3402, an air-cooled heat exchanger 3404, an evaporator 3406, a heat pump 3408, and a regeneration process 3410. The air-cooled heat exchanger 3404 receives a high-temperature process fluid 3412 and transfers heat to air 3414 that moves through the air contactor 3400 upstream of the evaporator 3406. In one embodiment, the evaporator 3406 includes a fin-tube heat exchanger. The evaporator 3406 receives the heated air 3414 downstream of the air-cooled heat exchanger 3404 and transfers heat from the heated air stream to the fluid of the heat pump 3408. The heat pump 3408 has a condenser 3420 that transfers heat to the regeneration fluid 3422 of the regeneration process 3410. Positioning the evaporator 3406 within the air stream allows the high-temperature air from the air-cooled heat exchanger 3404 to be used as a heat source for the heat pump 3408. By doing so, a high temperature can be provided in the condenser 3420 and the energy efficiency for the regeneration process 3410 is increased.

[0219]

[0266] Referring to FIG. 53, an air contactor 3500 is provided that is similar to the air contactor 3400 described above in many respects. One difference between the air contactor 3500 and the air contactor 3400 is that the air contactor 3500 includes a chiller 3502 instead of the heat pump 3408 of the air contactor 3400. The chiller 3502 provides chiller fluid to an evaporator 3504 within the air stream flowing through the air contactor 3500. The evaporator 3504 absorbs heat from the air downstream of the air-cooled heat exchanger 3506, thereby cooling the air after it has moved through the air-cooled heat exchanger 3506. The cooling provided by the evaporator 3504 can reduce the risk of plume. Also, the evaporator 3504 may include a water regeneration system 3505, and the cooling provided by the evaporator 3504 may condense water from the air and that water may be used in another process such as a makeup water source. The water regeneration system 3505 may include, for example, a trough arranged to collect condensed water falling from an indirect heat exchanger of the evaporator 3504.

[0220]

[0267] Referring to FIG. 54, an air contactor 3600 is provided having an outer structure such as a housing 3602 and including a damper 3604 for controlling an air flow moving through the air contactor 3600. The damper 3604 can be closed, opened, or partially opened respectively to control the air flow through the damper 3604. In one embodiment, the damper 3604 includes a main louver 3606 at an inlet 3608 of the air contactor 3600, a first intermediate louver 3610, and a second intermediate louver 3612. The air contactor 3600 has a fan assembly 3614 for generating an air flow exiting the air contactor 3600 from an outlet 3616 through one or more of the louvers 3606, 3610, 3612.

[0221]

[0268] The air contactor 3600 includes a dehumidifier 3620, a recovery device 3622, and a heat exchanger 3624. The dehumidifier 3620, the recovery device 3622, and the heat exchanger 3624 can be similar to the related components described above. The heat exchanger 3624 receives a process fluid via a process fluid return portion 3630 and exchanges heat with the air flowing through the air contactor 3600. The heat exchanger 3624 returns the process fluid to the process via a process fluid supply portion 3632. In one embodiment, the process fluid return portion 3630 provides a heated process fluid, and the heat exchanger 3624 removes heat from the process fluid before guiding the process fluid to the process fluid supply portion 3632.

[0222]

[0269] In FIG. 54, the air contactor 3600 is shown in a first configuration in which the main louver 3606 is open and the first and second intermediate louvers 3610, 3612 are closed. In the first configuration, what is drawn into the air contactor 3600 by the fan assembly 3614 is guided through the dehumidifier 3620, the recovery medium 3622, and the heat exchanger 3624. The air contactor 3600 can operate in the first configuration when the recovery medium 3622 removes air pollutants from the air, dehumidification is desired upstream of the recovery medium 3622, and the heat exchanger 3624 exchanges heat between the air and the process fluid.

[0223]

[0270] Referring to FIG. 55, the air contactor 3600 is shown in a second configuration where the main louver 3606 and the second intermediate louver 3612 are closed and the first intermediate louver 3610 is open. A controller associated with the air contactor 3600 can reconfigure the air contactor 3600 from the first configuration of FIG. 54 to either the second configuration of FIG. 55 or other configurations described below, such as by operating the linear actuator of the air contactor 3600 to adjust the louvers 3606, 3610, 3612.

[0224]

[0271] In the second configuration, the air flow enters the air contactor 3600 generally in direction 3650 through the first intermediate louver 3610, moves through the recovery medium 3622 and the heat exchanger 3624, and then exits through the outlet 3616. In the second configuration, the air flow bypasses the dehumidifier 3620. The air contactor 3600 can operate in the second configuration when the recovery medium 3622 and the heat exchanger 3624 are operating but dehumidification is not required. Bypassing the dehumidifier 3620 can reduce the power consumed by the fan assembly 3614 when the dehumidifier is not operating.

[0225]

[0272] Referring to FIG. 56, the air contactor 3600 is shown in a third configuration where the main louver 3606 and the first intermediate louver 3610 are closed and the second intermediate louver 3612 is open. The air flow enters the air contactor 3600 generally in direction 3652 through the second intermediate louver 3612, moves through the heat exchanger 3624, and exits the air contactor through the outlet 3616. Since the main louver 3606 and the first intermediate louver 3610 are closed, the air flow bypasses the dehumidifier 3620 and the recovery medium 3622. The air contactor 3600 can be shifted to the third configuration to reduce the power draw of the fan assembly 3614, for example, when the recovery medium 3622 is not being used.

[0226]

[0273] Referring to FIG. 57, the air contactor 3600 is shown in a fourth configuration where the main louver 3606 and the second intermediate louver 3612 are open while the first intermediate louver 3610 is closed. In this way, the air flow can enter the air contactor 3600 through the main louver 3606 and move through the dehumidifier 3620, the recovery medium 3622, and the heat exchanger 3624. The open second intermediate louver 3612 allows air to be directed through the heat exchanger 3624 in addition to the air entering the air contactor 3600 through the main louver 3606. The air entering through the second intermediate louver 3612 may have a different makeup (e.g., not in contact with the carbon recovery solution) and / or may be cooler than the air moving from the recovery medium 3622 to the heat exchanger 3624. The air drawn into the open second intermediate louver 3612 can dilute the air flow coming from the air pollution recovery process, which, in some embodiments, reduces the concentration of corrosive chemicals in the air flow. The air drawn into the open second intermediate louver 3612 can also reduce the plume in embodiments where the operation of the recovery medium 3622 increases the humidity of the air flow.

[0227]

[0274] Also, the air entering through the second intermediate louver 3612 can provide an additional volume of air, whereby the heat exchanger 3624 has a higher flow rate of air moving through it than the dehumidifier 3620 and the recovery medium 3622. The ability to provide different air flow rates through the recovery medium 3622 and through the heat exchanger 3624 allows for precise control of the air pollution recovery process and the waste heat process. In some embodiments, one or more of the louvers 3606, 3610, 3612 can be partially opened to optimize the air path distribution, flow rate, and / or air velocity. The louvers 3606, 3610, 3612 can be located on one or more vertical, horizontal, inclined, upper, bottom, and / or side walls of the air contactor 3600.

[0228]

[0275] The internal components of the air contactors of FIGS. 50 to 57 can be arranged such that air contacts the components in a desired order, generally as described above with respect to FIGS. 13 to 37. For example, the air contactors of FIGS. 50 to 57 may, in some embodiments, include a heat exchanger upstream of the recovery device. The dehumidifier and / or evaporator may similarly be positioned upstream or downstream of the recovery device. As an example in this regard, the waste heat section 3506 of the cooling tower 3500 and the evaporator 3504 may be provided upstream of the recovery device 3501. As yet another example, the evaporator 3504 may be downstream of the recovery device 3501 while the waste heat section 3506 is upstream of the recovery device 3501.

[0229]

[0276] With respect to FIG. 58, an air contactor 3700 is provided having a first air inlet 3702, a second air inlet 3704, and an air outlet 3706. The air contactor 3700 has a dehumidifier 3706 and a recovery device 3708 on one side of the air contactor 3700 and a heat exchanger 3710 and a precooler 3712 on the opposite side of the air contactor 3700. By doing so, the air contactor 3700 becomes asymmetric, whereby one side of the air contactor 3700 provides the possibility of an air pollutant recovery operation and the opposite side of the air contactor 3700 provides the possibility of a heat exchange operation. The precooler 3712 may include, for example, a heat insulation pad system. The air moving from the recovery device 3708 and the heat exchanger 3710 is combined and dissipated through the air outlet 3706 via the operation of the fan assembly 3714.

[0230]

[0277] With reference to FIG. 59, an air contactor 3800 is provided that is similar to the air contactor 3700 in many respects. The air contactor 3800 includes a dehumidifier 3802, a recovery device 3804, a heat exchanger 3806, and a precooler 3808. The air contactor 3800 has a first air inlet 3810 with a first main louver 3812, a second air inlet 3814 with a main louver 3816, and first and second intermediate louvers 3820, 3822. The louvers 3812, 3816, 3820, 3822 can be opened and closed to control the air flow to different sections of the air contactor 3800. The louvers 3812, 3816, 3820, 3822 may be partially opened and closed according to the air velocity and / or flow rate requirements of the air contactor 3800, the expected energy and / or water consumption, and / or the heat transfer load required for the air contactor 3800. The louvers of the air contactor 3800 may enable independent operation of the unit's air pollutant recovery and air evacuation capabilities. For example, the main louver 3812 and the first intermediate louver 3820 may be closed so that air bypasses the dehumidifier 3802 and the recovery device 3804 when air pollutant recovery is not required. Bypassing the dehumidifier and the recovery device 3804 can reduce the power consumption of the fan assembly 3830 of the air contactor 3800. Conversely, when heat exchanger operation is not required, the louvers 3816, 3822 may be closed while the main louver 3812 and the first intermediate louver 3820 are opened to enable air pollutant recovery operation while bypassing the heat exchanger 3806 and the precooler 3808.

[0231]

[0278] The use of singular terms such as "a", "an", etc. is intended to include both singular and plural forms unless otherwise indicated herein or clearly contradicted by the context. The terms "comprising", "having", "including", and "containing" should be construed as open-ended terms. The phrase "at least one of" as used herein is intended to be interpreted in a disjunctive sense. For example, the phrase "at least one of A and B" is intended to cover A, B, or both A and B.

[0232]

[0279] Although specific embodiments of the present invention have been illustrated and described, those skilled in the art will recognize that various modifications, changes, and combinations can be made to the above-described embodiments without departing from the scope of the present invention, and that such modifications, changes, and combinations should be considered to be within the scope of the inventive concept. For example, although various embodiments of an air contactor are described herein as being configured to remove CO2 from air, it will be apparent that the air contactor can be configured to remove other air pollutants such as methane, VOCs, and VOX, in addition to or instead of CO2, by utilizing appropriate recovery techniques. As another example, although a water replenishment system is described for some air contactors, it will be understood that the water replenishment system can be used with any air contactor for which water replenishment would be useful.

Claims

1. An airflow generator capable of operating to generate airflow, An air pollutant recovery system comprising: an air pollutant recovery device for transferring air pollutants from the airflow to a fluid; a fluid regeneration device configured to remove the air pollutants from the fluid using heat from a heat source; and a thermal energy storage unit operable to receive heat from the fluid or to provide heat to the fluid regeneration device, wherein the system has a regeneration and filling mode in which the fluid regeneration device receives heat from the heat source, the fluid regeneration device removes the air pollutants from the fluid, and the thermal energy storage unit receives heat from the fluid; and a regeneration and dissipation mode in which the fluid regeneration device receives heat from the thermal energy storage unit, and the fluid regeneration device removes the air pollutants from the fluid, A controller operably connected to the air pollutant capture system, configured to operate the air pollutant capture system in the regeneration and release mode in response to a determination that the air pollutant capture system in the regeneration and release mode satisfies the operating criteria, An air contactor equipped with the following features.

2. The air contactor according to claim 1, wherein the operating criteria include the ability of the fluid regeneration device to remove the air pollutants from the fluid even though the heat source cannot provide enough heat to operate the fluid regeneration device.

3. The air contactor according to claim 1, wherein the aforementioned operating criteria include saving energy.

4. The air contactor according to claim 1, wherein the controller is configured to operate the air pollutant recovery system in the regeneration and filling modes in response to a determination that the heat source can provide sufficient heat to the fluid regeneration process and a determination that the thermal energy storage unit is insufficiently filled.

5. The air contactor according to claim 1, wherein the air pollutant recovery system has a regeneration mode in which the fluid regeneration device receives heat from the heat source, the fluid regeneration device removes the air pollutants from the fluid, and the thermal energy storage unit receives less heat from the fluid than when the air pollutant recovery system is in the regeneration and filling mode.

6. The air pollutant recovery system includes a pump capable of operating to pressurize the heat transfer fluid between the thermal energy storage unit and the fluid regeneration device. The air contactor according to claim 1, wherein when the air pollutant recovery system is in the regeneration and release mode, the pump pressurizes the heat transfer fluid between the thermal energy storage unit and the fluid regeneration device, causing the fluid regeneration device to receive heat from the thermal energy storage unit.

7. The air pollutant recovery system includes a valve located between the fluid regeneration device and the thermal energy storage unit. When the air pollutant recovery system is in the regeneration and filling mode, the valve has a first configuration that allows the valve to guide the fluid from the fluid regeneration device to the thermal energy storage unit. The air contactor according to claim 1, wherein when the air pollutant recovery system is in the regeneration and release mode, the valve has a second configuration that allows the fluid to bypass the thermal energy storage unit.

8. The aforementioned thermal energy storage unit comprises a plurality of thermal energy storage units, The air contactor according to claim 1, wherein when the air pollutant recovery system is in the regeneration and release mode, the fluid regeneration device receives heat from the plurality of thermal energy storage units.

9. The thermal energy storage unit comprises a first thermal energy storage unit and a second thermal energy storage unit. The air contactor according to claim 1, wherein the air pollutant recovery system has regeneration, filling, and dissipation modes, wherein the fluid regeneration device receives heat from the heat source, the fluid regeneration device removes the air pollutants from the fluid, the first thermal energy storage unit receives heat from the fluid, and the fluid regeneration device receives heat from the second thermal energy storage unit.

10. The aforementioned controller, A determination that the heat source cannot provide sufficient heat to the fluid regeneration device, The determination of insufficient filling of the first thermal energy storage unit and sufficient filling of the second thermal energy storage unit, The air contactor according to claim 9, configured to operate the air pollutant recovery system in the regeneration, filling, and release modes in response to the air contactor according to claim 9.

11. The air contactor according to claim 1, further comprising a fluid regeneration device configured to receive the fluid from the air pollutant recovery device.

12. The air contactor according to claim 11, wherein the air pollution recovery fluid regeneration device further comprises an exothermic regeneration process configured to receive the fluid from the endothermic regeneration device.

13. The air pollutant recovery system includes a heat source thermal energy storage unit, The aforementioned air pollutant recovery system is The fluid regeneration device has regeneration, filling, and heat source active modes, wherein the fluid regeneration device receives heat from the heat source to remove air pollutants from the fluid, the thermal energy storage unit receives heat from the fluid, and the heat source thermal energy storage unit receives heat from the heat source. The aforementioned air pollutant recovery system is The air contactor according to claim 1, having regeneration, filling, and heat source inactive modes, wherein the fluid regeneration device receives heat from the heat source thermal energy storage unit to remove the air pollutants from the fluid, and the thermal energy storage unit receives heat from the fluid.

14. The air pollutant recovery system includes a heat source thermal energy storage unit, The aforementioned air pollutant recovery system is The fluid regeneration device has regeneration, filling, and heat source active modes, wherein the fluid regeneration device receives heat from the heat source to remove air pollutants from the fluid, the thermal energy storage unit receives heat from the fluid, and the heat source thermal energy storage unit receives heat from the heat source. The aforementioned air pollutant recovery system is The air contactor according to claim 1, wherein the fluid regeneration device has regeneration, dissipation, and heat source inactive modes, which receive heat from the heat source thermal energy storage unit and remove the air pollutants from the fluid.

15. The aforementioned air pollutant recovery medium comprises a solid absorbent, The air contactor according to claim 1, wherein the fluid comprises a gas.

16. The air contactor according to claim 1, wherein the airflow generator comprises a fan assembly operably connected to the controller.

17. The air contactor according to claim 1, wherein the fluid regeneration device comprises at least one of a heat pump and a chiller.

18. The fluid is carbon dioxide (CO2) in the airflow. ２ ) reacts chemically with the airflow and the CO ２ An air contactor according to claim 1, configured to remove [something].

19. The aforementioned air pollutants are carbon dioxide (CO2). ２ ), methane (CH ４ The air contactor according to claim 1, wherein the contactor is a volatile organic compound (VOC), a volatile halogenated organic carbon (VOX), or a combination thereof.

20. A fan assembly for generating airflow, An air pollutant recovery system comprising: an air pollutant recovery device for transferring air pollutants from the airflow to a fluid; and a fluid regeneration device configured to remove the air pollutants from the fluid; A mechanical heat generator comprising at least one of a chiller and a heat pump, configured to receive process fluid from an industrial process at a first temperature and to receive heat transfer fluid from the air pollutant recovery system, The mechanical heat generator is operable to raise the temperature of the heat transfer fluid to a second temperature higher than the first temperature, in order to facilitate the fluid regeneration device's removal of the air pollutants from the fluid, and to return the heat transfer fluid to the fluid regeneration device at the second temperature. Air contactor.

21. The air contactor according to claim 20, further comprising a heat exchanger configured to transfer heat between the process fluid and the airflow.

22. The air contactor of claim 20, wherein the heat exchanger is located downstream of the air pollutant recovery device so that the heat exchanger transfers heat between the process fluid and the air flow after the fluid has removed the air pollutants from the air flow.

23. The air contactor according to claim 20, wherein the air pollutant recovery device comprises a liquid absorbent material.

24. The air contactor according to claim 20, wherein the mechanical heat generator comprises a first heat exchanger configured to transfer heat between the process fluid and the mechanical heat generator fluid, a second heat exchanger configured to transfer heat between the mechanical heat generator fluid and the heat transfer fluid, an expansion valve, and a compressor.

25. The air contactor of claim 20, wherein the mechanical heat generator includes the chiller.

26. The air contactor of claim 20, wherein the mechanical heat generator includes the heat pump.

27. The air contactor according to claim 20, wherein the fluid is configured to chemically react with the air pollutants to remove them from the airflow.

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