Carbon Dioxide Generation from a Carbonate Fuel Cell

Abstract

The fuel cell system includes a fuel cell stack having a plurality of fuel cells, each of which includes a plurality of fuel electrodes and air electrodes. The system includes a fuel receiving unit connected to the fuel cell stack, the fuel receiving unit receiving a hydrocarbon fuel from a fuel supply. The system includes a fuel exhaust treatment unit fluidly coupled to the fuel cell stack by a slipstream, the fuel exhaust treatment unit treating the fuel exhaust from the fuel cell stack, the slipstream being fluidly connected to an exhaust stream flowing from the fuel cell stack. The fuel treatment unit removes a first portion of carbon dioxide (CO2) from the fuel exhaust in the slipstream and outputs the first portion of the CO2 in the first stream and outputs a second portion of the CO2 remaining from the fuel exhaust in the slipstream into a second stream containing hydrogen.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit and priority of U.S. Patent Application No. 63 / 079,284, filed on September 16, 2020, the entire disclosure of which is incorporated herein by reference.

Background Art

[0002] The present disclosure generally relates to the field of extraction of carbon dioxide (CO2) from carbonate fuel cells, and more specifically, to the extraction of CO2 from the internal processing streams of carbonate fuel cells.

[0003] Generally, molten carbonate fuel cells produce an internal processing stream of gas having a high CO2 concentration, which is reduced by downstream processes through CO2 consumption and dilution. Such fuel cells include a fuel - receiving anode, an air - receiving cathode, and a carbonate electrolyte. During operation of the fuel cell, a hydrocarbon - based fuel (e.g., methane) is supplied through the anode - side inlet, reforming occurs within the fuel cell, and H2 and CO2 can be produced. The generated H2 can then react with carbonate ions from the containing electrolyte to produce additional CO2. The resulting CO2 - containing gas leaving the fuel electrode can be mixed with the air supply and sent through the cathode - side inlet where the CO2 is consumed by the air - electrode reaction. During such use of a hydrocarbon (e.g., methane) - based fuel (e.g., natural gas or biogas), for each molecule of hydrocarbon, one molecule of CO2 is discharged from the fuel cell, but as described above, additional CO2 (e.g., an additional 4 molecules of CO2) can be produced by the anode (i.e., the fuel electrode) and then consumed by the cathode (i.e., the air electrode).

[0004] The exhaust stream, particularly the fuel exhaust stream (i.e., the exhaust from the anode), may contain an excess of CO2. Therefore, the excess may not be consumable or suitable for consumption in the fuel cell system and may thus ultimately be completely discharged from the fuel cell system. Thus, the excess CO2 can be released from the fuel cell system, which not only wastes potentially usable CO2 but also contributes to excessive emissions.

[0005] Therefore, in order to reduce waste and emissions, it would be advantageous to provide a fuel cell system incorporating an internal mechanism for extracting CO2 from fuel emissions rich in CO2 for recycling, treatment, or other reuse. SUMMARY OF THE INVENTION

[0006] One aspect of the present disclosure relates to a fuel cell system. The system includes a fuel cell stack having a plurality of fuel cells, the plurality of fuel cells including a plurality of fuel electrodes and a plurality of air electrodes. The system further includes a fuel receiving unit fluidly coupled to the fuel cell stack, the fuel receiving unit being configured to receive hydrocarbon fuel from a fuel supply. The system also includes a fuel exhaust treatment unit fluidly coupled to the fuel cell stack by a slip stream, the fuel exhaust treatment unit being configured to treat the fuel exhaust from the fuel cell stack, the slip stream being fluidly connected to the exhaust stream flowing from the fuel cell stack. The fuel treatment unit is configured to remove a first portion of carbon dioxide (CO2) from the fuel exhaust in the slip stream and output the first portion of CO2 in a first stream, and a second portion of the remaining CO2 in the fuel exhaust in the slip stream is output into a second stream, the second stream containing hydrogen.

[0007] In various embodiments, the amount of CO2 in the first portion is controlled by a controller in communication with the fuel cell system. In some embodiments, the amount of CO2 in the first portion is predetermined based on the operating state of the fuel cell system. In other embodiments, the amount of CO2 in the first portion is adjusted in real time in response to CO2 demand. In still other embodiments, the first fluid path is connected to the exhaust stream, the first fluid path flows to an air mixing unit, and the fuel exhaust from the first fluid path is mixed with ambient air within the air mixing unit. In various embodiments, the mixture of fuel exhaust mixed within the air mixing unit is supplied to a plurality of air electrodes via a second fluid path. In some embodiments where the air mixing unit includes a heater, the heater is configured to react hydrogen within the mixture. In other embodiments, the carbon processing unit includes an exhaust cooling component and a CO2 separation component, and the exhaust cooling component is configured to cool the fuel exhaust from the slip stream and extract water from the fuel exhaust.

[0008] In yet another embodiment, the fuel exhaust treatment unit further includes a carbon processing unit, and the carbon processing unit is configured to remove a first portion of the CO2 in liquid form. In some embodiments, the first portion of the CO2 is sent out from the fuel cell system via a plurality of outlet paths, and each of the plurality of outlet paths is fluidly connected to the carbon processing unit. In various embodiments, each of the plurality of outlet paths corresponds to a predetermined use associated with the first portion of the CO2. In some embodiments, the flow of fuel exhaust in the slip stream is controlled by at least one of a fan or a blower. In other embodiments, the flow is controlled based on at least one of the operating mode of the fuel cell system or the demand for CO2.

[0009] Another aspect of the present disclosure relates to a method for extracting carbon dioxide. The method includes receiving a portion of the fuel exhaust by a fuel exhaust treatment unit, the portion of the fuel exhaust flowing from a slip stream connected to an exhaust stream flowing from a fuel cell stack. The method also includes controlling the flow of the fuel exhaust in the slip stream by at least one of a fan or a blower. The method further includes removing a first portion of carbon dioxide (CO2) from the fuel exhaust in the slip stream by the fuel exhaust treatment unit. The method also includes outputting a first portion of CO2 in a first stream and a second portion of CO2 in a second stream by the fuel exhaust treatment unit, the second portion including the CO2 remaining after the first portion has been removed. The fuel cell stack includes a plurality of fuel cells, the plurality of fuel cells including a plurality of fuel electrodes and a plurality of air electrodes.

[0010] In various embodiments, the method further includes sending out the first portion of CO2 by the fuel exhaust treatment unit.

[0011] The foregoing summary is illustrative only and is not intended to be limiting in any way. In addition to the above-exemplified aspects, embodiments, and features, further aspects, embodiments, and features will become apparent by reference to the following drawings and detailed description.

Brief Description of the Drawings

[0012] The advantages and features that constitute the present disclosure, as well as the construction and operation of the typical mechanisms provided by the present disclosure, are more readily apparent by reference to the exemplary, and thus non-limiting, embodiments illustrated in the drawings that accompany and form a part of this specification, where like reference numerals designate the same elements in several of the figures:

Figure 1

Figure 2

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Figure 4

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Figure 7

Figure 8

[0013] The foregoing features and other features of the present disclosure will become apparent from the following description and the appended claims in conjunction with the accompanying drawings. It is to be understood that these drawings depict only some embodiments in accordance with the present disclosure and are not to be considered as limiting the scope thereof. The present disclosure will be described with further specificity and detail by using the accompanying drawings.

Best Mode for Carrying Out the Invention

[0014] In the following detailed description, reference is made to the accompanying drawings which form a part hereof. In the drawings, like symbols typically identify like components, unless the context dictates otherwise. The exemplary embodiments described in the detailed description, the drawings, and the claims are not intended to be limiting. Other embodiments may be utilized and other changes may be made without departing from the spirit or scope of the subject matter presented herein. It is readily understood that the aspects of the present disclosure generally described herein and illustrated in the figures can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and made a part of the present disclosure.

[0015] One embodiment of the present disclosure relates to a fuel cell system having a molten carbonate fuel cell fluidly coupled to a fuel supply section, an air supply section, and a variable load. The fuel cell may be configured to receive fuel at a fuel electrode (e.g., anode) from the fuel supply section and air at an air electrode (e.g., cathode) from the air supply section. The fuel cell system may further include an exhaust treatment portion fluidly coupled to a carbon treatment unit. The carbon treatment unit may be configured to receive at least a portion of the fuel exhaust from an outlet from the fuel electrode, and the carbon treatment unit may extract carbon and / or carbon dioxide (CO2) from the received fuel exhaust for later reuse, recycling, collection, or removal from the fuel cell system.

[0016] In various embodiments, the exhaust treatment portion may include one or more fluid paths (e.g., slip streams) connected to the fuel exhaust, through which the fuel exhaust rich in CO2 may flow for downstream reuse, recycling, collection, or removal. In various embodiments, the exhaust treatment portion may include a circulation device (e.g., a fan, a blower, etc.) to facilitate the flow of one or more portions of the fuel exhaust through corresponding one or more fluid paths (e.g., slip streams). In various embodiments, the amount of fuel exhaust (and thus the amount of CO2) directed into the one or more fluid paths may be controlled by a circulation device (e.g., a fan, a blower, etc.). In various embodiments, some of the fluid paths may be controlled by one or more controllable vents and / or valves. In various embodiments, the amount of fuel exhaust directed into the one or more fluid paths and / or some of the one or more fluid paths may be predetermined based on the operating mode of the fuel cell system (e.g., high efficiency, low emissions, power maximization, etc.). In various embodiments, the amount of fuel exhaust directed into the one or more fluid paths and / or some of the one or more fluid paths may be predetermined based on the needs of a given application (e.g., extraction for use in food, extraction for future chemical reagent use, etc.).

[0017] In various embodiments, the carbon processing unit may be configured to controllably remove a certain amount of CO2 from the received fuel exhaust. In various embodiments, the carbon processing unit may be configured to remove a certain amount of CO2 based on the requirements of a given application (e.g., extraction for food use, extraction for future chemical reagent use, etc.). In various embodiments, the carbon processing unit may include one or more filters, cooling and / or condensation devices, membranes, etc. to facilitate the separation of CO2 from one or more portions of the received fuel exhaust.

[0018] In various embodiments, the fuel cell system may be operably coupled to a controller that can control the operation of the fuel cell and fluidly coupled components. In various embodiments, the controller may control the operation of the fuel exhaust treatment portion, the carbon processing unit, and / or the circulation device. In various embodiments, the controller may be configured to operate the fuel cell system in one or more predetermined modes, and the amount of fuel exhaust and / or the amount of CO2 or carbon extracted is based on one or more predetermined modes. In various embodiments, the one or more predetermined modes may include, but are not limited to, a maximum efficiency mode, a maximum power mode, and a minimum emissions mode.

[0019] Referring generally to the figures, a CO2 generating fuel cell system having a carbonate fuel cell may be fluidly coupled to a fuel supply, an air supply, and a variable load according to various exemplary embodiments. The carbonate fuel cell may be configured to receive fuel at a fuel electrode (e.g., anode) from the fuel supply and air at an air electrode (e.g., cathode) from the air supply. In various embodiments, the fuel cell system may further include an exhaust treatment portion fluidly coupled to the carbon processing unit. The carbon processing unit may be configured to receive at least a portion of the fuel exhaust from an outlet from the fuel electrode via the exhaust treatment portion, and the carbon processing unit may extract carbon and / or carbon dioxide (CO2) from the received fuel exhaust for later reuse, recycling, collection, or removal from the fuel cell system (hereinafter "processing").

[0020] In various embodiments, the exhaust treatment portion may include one or more fluid paths (e.g., slip streams) connected to the fuel exhaust, through which the fuel exhaust rich in CO2 may flow for downstream processing. In various embodiments, the exhaust treatment portion may include a circulation device (e.g., a fan, a blower, etc.) to facilitate the flow of one or more portions of the fuel exhaust through the corresponding one or more fluid paths (e.g., slip streams). In various embodiments, the circulation device may be configured to control the amount of fuel exhaust (and thus the amount of CO2) introduced into the one or more fluid paths. In various embodiments, the fuel exhaust treatment portion may include one or more vents and / or valves that may control the amount of fuel exhaust introduced into the one or more fluid paths. In various embodiments, the one or more vents and / or valves may determine some of the fluid paths present within the exhaust treatment portion.

[0021] In various embodiments, the one or more fluid paths within the exhaust treatment portion and / or the amount of fuel exhaust introduced into some of the one or more fluid paths may be predetermined based on the operating mode of the fuel cell system (e.g., high efficiency, low emissions, power maximization, etc.). In various embodiments, the one or more fluid paths within the exhaust treatment portion and / or the amount of fuel exhaust introduced into some of the one or more fluid paths may be predetermined based on the requirements of a given application (e.g., extraction for use in food, extraction for future chemical reagent use, etc.). In various embodiments, the operating mode of the fuel cell system may be based on the requirements of a given application.

[0022] In various embodiments, the carbon processing unit can be configured to controllably remove a certain amount of CO2 from the received fuel exhaust. In various embodiments, the carbon processing unit can be configured to remove a certain amount of CO2 based on the needs of a given application (e.g., extraction for food use, extraction for future chemical reagent use, etc.). In various embodiments, the carbon processing unit can include one or more filters, cooling and / or condensation devices, membranes, etc. to facilitate the separation of CO2 from one or more portions of the received fuel exhaust. In various embodiments, the amount of CO2 removed can be based on the type of fuel supplied to the fuel cell system. In various embodiments, the amount of CO2 removed can be based on the amount of fuel supplied to the fuel cell system.

[0023] In various embodiments, the fuel cell system can be operably coupled to a controller that can control the operation of the fuel cell and fluidly coupled components. In various embodiments, the controller can control the operation of the fuel cell system, including but not limited to, the fuel exhaust treatment portion, the carbon processing unit, and / or the circulation device. In various embodiments, the controller can be configured to operate the fuel cell system in one or more predetermined modes, and the amount of fuel exhaust and / or the amount of CO2 or carbon extracted is based on one or more predetermined modes. In various embodiments, the one or more predetermined modes can include, but are not limited to, a maximum efficiency mode, a maximum power mode, and a minimum emissions mode. In various embodiments, the controller can control the amount of fuel supplied to the fuel cell system, thereby controlling the amount of CO2 extracted from the fuel exhaust.

[0024] Turning now to the drawings, and in particular to FIG. 1, there is shown a schematic view of a carbonate fuel cell 10 of a CO2 generating fuel cell system 100 according to an exemplary embodiment. As shown, the fuel cell 10 includes an anode side fuel passage 15 adjacent to the anode 27 and a cathode side air passage 20 adjacent to the cathode 25, and the anode 27 and the cathode 25 are separated by an electrolyte 30 having carbonate ions. A hydrocarbon fuel 35, such as methane, can be supplied to the anode side fuel passage 15, and the fuel 35 undergoes reforming to produce H2 and CO2. The produced H2 can then react with carbonate ions at the surface of the anode 15 to produce water and additional CO2. As shown, the fuel exhaust 40 from the anode side fuel passage 15, which contains the produced CO2, can be directed to an inlet on the cathode side air passage 20. The fuel exhaust 40 can be mixed with ambient air 45 supplied to the cathode side air passage 20 at the inlet. Within the cathode side air passage 20, the CO2 and O2 from the fuel exhaust and the ambient air can react at the surface of the cathode 25, respectively, to form carbonate ions. Excess CO2 at the cathode 25 is then led out of the fuel cell 10 via the exhaust stream 47, and the exhaust stream 47 can be directed to further processing or released.

[0025] FIG. 2 shows a perspective view of a fuel cell 10 according to an exemplary embodiment. As shown, hydrocarbon fuel 35 can be supplied to anode 27 (e.g., via anode-side fuel passage 15), and ambient air 45 can be supplied to cathode 25 (e.g., via cathode-side air passage 20). As illustrated, electrolyte 30 can be dispersed within fuel cell 10 to enable ion movement and exchange. In use, a plurality of fuel cells 10 can be assembled to form a fuel cell stack. Thus, fuel cell 10 can also include a bipolar plate 50 that prevents mixing of fuel 35 and ambient air 45 within fuel cell 10 and conducts current between each of the fuel cells 10 within the stack. Thus, as illustrated in FIG. 3, electrons generated by fuel cell 10 during the electrochemical reaction at anode 27 can be provided as a current to variable load 60, which can be coupled to fuel cell 10 or a stack including a plurality of fuel cells 10.

[0026] FIG. 4 shows a schematic diagram of a CO2-producing fuel cell system 100 according to an exemplary embodiment. As shown, fuel cell system 100 can be configured to provide power 107 to one or more variable loads (e.g., similar or equivalent to variable load 60). Fuel cell system 100 includes a fuel cell stack 105 that includes a plurality of fuel electrodes 110 (e.g., anodes) and air electrodes 115 (e.g., cathodes) included within a plurality of fuel cells (e.g., each similar or equivalent to fuel cell 10). Fuel cell stack 105 can be fluidly coupled to a fuel receiving unit 120, a fuel exhaust treatment unit 125, and an air mixing unit 130.

[0027] The fuel receiving unit 120 may be configured to receive hydrocarbon fuel via the fuel supply unit 135 and provide it to the fuel cell stack 105. In various embodiments, the fuel from the fuel supply unit 135 may be natural gas or other hydrocarbon fuels such as biogas. The received fuel may be humidified by water from the water supply unit 140 and guided to the fuel electrode 110 via the fuel path 145. The fuel provided via the fuel path 145 may undergo an electrochemical reaction on the surface of the fuel electrode 110 to form CO2, water, and energy (in the form of electrons). The generated energy may then be supplied over time as electric power 107 to a coupled variable load (e.g., similar or equivalent to the variable load 60).

[0028] The generated CO2 and water can be directed away from the fuel electrode 110 from the fuel exhaust stream 150 through the slip stream 200 to the fuel exhaust treatment unit 125. In various embodiments, the fuel exhaust treatment unit 125 can include one or more components for treating the received fuel exhaust to facilitate the cooling, condensation, drying, and / or removal of CO2. In various embodiments, the removed CO2 can be sent through the stream 210. In various embodiments, the amount of CO2 extracted can be controlled based on one or more uses (e.g., by a controller in communication with the fuel cell system 100). In various embodiments, the amount can be adjusted in real time to correspond to the CO2 demand. In other embodiments, the amount can be predetermined based on the mode or set operating state of the fuel cell system 100. The residual gas from the extracted slip stream 200, consisting mainly of hydrogen and any unremoved CO2, can be sent through the stream 246 for later use, including, but not limited to, beneficial uses of hydrogen such as sale as an industrial gas, use as fuel for a cryogenic fuel cell-powered transport vehicle or other device, and / or recycling to the fuel exhaust stream 150. The fuel exhaust not extracted in the stream 200 can then be directed through the fluid path 155 (fluidly connected to the exhaust stream 150) to the air mixing unit 130, the treated fuel exhaust can be mixed with ambient air from the air supply unit 160, and supplied to the air electrode 115 via the fluid path 165. Oxygen and CO2 from the treated exhaust and air can then undergo an electrochemical reaction on the surface of the air electrode 115 to form carbonate ions. The remaining CO2 from the air electrode 115 is discharged through the air exhaust 167, directed to the fuel receiving unit 120, and can provide heat for fuel humidification, the CO2 from the air exhaust 167 can be recycled through the fluid path 145, and / or removed from the fuel cell system 100 via the system exhaust 169.

[0029] FIG. 5 shows a schematic diagram of a fuel cell system 100 not configured for CO2 delivery, according to another embodiment. As shown, fuel can be provided from a fuel supply section 135 to a fuel electrode 110 via a fluid path and a fuel receiving unit 120. In various embodiments, the fuel receiving unit 120 can include one or more heaters 180 to facilitate heating and / or humidifying of the fuel received from the fuel supply section 135 and / or the air exhaust 167 (e.g., using water received from a water supply section 140). Thus, the fuel supplied to the fuel electrode 110 can generate energy that can undergo an electrochemical reaction and be provided over time to a variable load through a power output 107. As shown, the generated energy can be additionally supplied via a secondary power output 170 to one or more power conversion and / or internal system loads, such as, but not limited to, a bidirectional power inverter, a combined energy storage system, etc.

[0030] A fuel exhaust stream 150 containing CO2 can flow directly from the fuel electrode 110 to an air mixing unit 130. Finally, as shown in FIG. 5, the air mixing unit 130 can include a heater 175 configured to react the heated, reacted fuel exhaust with air received from an ambient air supply section 160 so that the mixture can be circulated to an air electrode 115 via a fluid path 165, reacting the residual hydrogen in the fuel exhaust from the fluid path 155 to generate heat.

[0031] Figure 6 shows a schematic diagram of a CO2 - generating fuel cell system 100 according to yet another embodiment. As shown, the fuel exhaust stream 150 can be split within the fuel exhaust treatment unit 125 such that a slip stream 200 can carry a portion of the fuel exhaust stream 150 to a carbon treatment unit 205 (i.e., included in the fuel exhaust treatment unit 125). The slip stream 200, which contains a high CO2 concentration due to CO2 generation during the electrochemical reaction at the fuel electrode 110, can pass through the carbon treatment unit 205, and the CO2 can be extracted in gaseous or liquid form and led away from the fuel cell system through the CO2 outlet 210 for subsequent processing. In various embodiments, the flow through the slip stream 200 can be measured by a slip stream management system 215, which can include one or more circulation devices including, but not limited to, blowers and fans. The slip stream management system 215 can be controlled by one or more controllers in communication with the fuel cell system 100. In some embodiments, the flow of fuel exhaust through the slip stream 200 is based on one or more end - use applications. In various embodiments, the flow can be adjusted in real - time to match the CO2 demand. In other embodiments, the flow can be pre - determined based on the mode or set operating state of the fuel cell system 100. In various embodiments, the carbon treatment unit 205 can include one or more filters, membranes, cooling devices, and / or condensation devices configured to extract CO2 from the fuel exhaust slip stream 200. Typical techniques for extracting CO2 (e.g., from the slip stream 200) can include, but are not limited to, compression and cooling of the gas in the slip stream 200 for extraction of CO2 through liquid, solid, and / or liquid materials that can absorb CO2 and be regenerated by heating. Alternatively or in addition, a membrane that allows CO2 to selectively pass through (while other components do not) can be implemented (e.g., within the slip stream 200 and / or the carbon treatment unit 205). In various embodiments, the amount of CO2 extracted can be controlled based on one or more end - use applications.After the extraction of CO2, the residual gas from the slip stream 200 can contain, in addition to mostly hydrogen, any unextracted CO2. The gas in stream 246 can be sent out for beneficial use of hydrogen, such as for sale as an industrial gas, for use as fuel for a fuel cell powered transport vehicle or other device, and / or for recycling to the treatment in stream 155. Finally, as shown in FIG. 6, the air mixing unit 130 can include a heater 175 configured to react the air received from the ambient air supply unit 160 with the residual hydrogen in the fuel exhaust from the fluid path 155 to generate heat so that the heated, reacted fuel exhaust and air mixture can be circulated to the air electrode 115 via the fluid path 165.

[0032] FIG. 7 shows a schematic diagram of a CO2 - generating fuel cell system according to an exemplary embodiment. As shown, the carbon processing unit 205 may include a fuel exhaust cooling component 220 and a CO2 separation component 223. In various embodiments, the exhaust cooling component 220 may be configured to cool the fuel exhaust from the slip stream 200 to collect and remove water, and the extracted water may be directed to leave the slip stream 200 via the water path 227. In various embodiments, the water in the water path 227 may be recycled and reused within the fuel cell system 100 (e.g., via the water supply section 140). In various embodiments, the water in the water path 227 may be directed away from the fuel cell system 100 and removed to provide water as a useful product stream, such as for use in nearby facilities to reduce water consumption. The exhaust from the slip stream 200 that has passed through the fuel exhaust cooling component 220 may flow through the fluid path 225 to the CO2 separation component 223 (which may include one or more condensers), and CO2 may be controllably extracted from the exhaust via the CO2 outlet 210 and sent out from the fuel cell system 100 as a useful product stream, such as for use in nearby facilities to reduce water consumption. In various embodiments, the amount of CO2 extracted may be controlled based on one or more uses. After the extraction of CO2, the residual gas from the slip stream 200 may contain mostly hydrogen in addition to any unextracted CO2. The gas in the stream 246 may be sent out for beneficial use of hydrogen, including, but not limited to, sale as an industrial gas, use as fuel for cryogenic fuel cell - powered transport vehicles or other devices, and / or recycling to the process in the stream 155.

[0033] FIG. 8 shows a schematic diagram of a fuel exhaust treatment unit 125 according to an exemplary embodiment. As shown, a carbon treatment unit 205 within the fuel exhaust treatment unit 125 may receive fuel exhaust through a slipstream 200. After the fuel exhaust is processed within the carbon treatment unit 205, the extracted CO2 may be sent out from the fuel cell system 100 via a plurality of CO2 outlets 210 that are fluidly connected to the carbon treatment unit 205. As shown, the CO2 outlets 210 may include a plurality of paths 235, 240, and 245, and each path may be directed according to a specific or predetermined use associated with the extracted CO2. In various embodiments, the uses associated with the extracted CO2 may include, but are not limited to, food-related uses, medical-related uses, fire protection uses, and chemical reagent uses. In various embodiments, the delivery of CO2 through the paths 235, 240, and / or 245 may be controlled or determined by one or more vents and / or valves disposed within the carbon treatment unit.

[0034] In various embodiments, the fuel extraction unit 125 and the carbon treatment unit 205 may be operably coupled to a controller 250 that may be configured to control the treatment of the fuel exhaust within the slipstream 200. In various embodiments, the controller 250 may control the amount of fuel exhaust within the slipstream 200. In various embodiments, the amount of fuel exhaust within the slipstream 200 may range from about 0% to about 40% of the fuel exhaust within the fuel exhaust stream 150. In various embodiments, the amount of CO2 extracted from the slipstream 200 may be controlled by the controller 250. In various embodiments, the amount of CO2 extracted from the slipstream 200 may range from about 0% to about 95% of the CO2 within the slipstream 200. In various embodiments, some of the CO2 outlets 210 may be determined and controlled by the controller 250.

[0035] In various embodiments, the fuel cell system 100 can be configured to operate in a plurality of predefined modes, which can be determined by the controller 250. In various embodiments, the predefined modes can include, but are not limited to, a high-efficiency mode, a high-power mode, a low-emission mode, and a usage mode. In various embodiments, the predefined modes can be determined and / or selected by a user or operator of the controller 250. In various embodiments, the amount of fuel exhaust in the slipstream 200 can be determined based on the predefined mode. In various embodiments, the amount of CO2 extracted for delivery from the slipstream 200 can be based on the predefined mode. In various embodiments, the delivery of CO2 via the paths 235, 240, and 245 can be based on the predefined mode.

[0036] Figures 6-8 show a fuel cell system 100 having a single slipstream 200, although various embodiments of the fuel cell system 100 can include any number of slipstreams 200. In various embodiments, the fuel exhaust treatment unit 125 can be configured to process additional compounds from within the slipstream 200 (e.g., H2, H2O, etc.).

[0037] Notwithstanding the embodiments described above with reference to FIGS. 1-8, various modifications and incorporations to these embodiments are contemplated and considered within the scope of the present disclosure.

[0038] It should also be understood that the construction and arrangement of the elements of the systems and methods as shown in the representative embodiments are merely illustrative. Although only some embodiments of the present disclosure have been described in detail, those skilled in the art reviewing the disclosure will readily appreciate that many modifications (e.g., changes in the size, dimensions, structure, shape, and ratio of various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) are possible without substantially departing from the novel teachings and advantages of the disclosed subject matter.

[0039] Accordingly, all such modifications are intended to be included within the scope of the present disclosure. Any means-plus-function clauses are intended to cover not only the structures described herein as performing the recited functions and structural equivalents thereof, but also equivalent structures. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the preferred and other exemplary embodiments without departing from the scope of the present disclosure or the scope of the appended claims.

[0040] Furthermore, the above functions and procedures may be performed by a special purpose device designed to perform the specific functions and procedures. The functions may also be performed by a general purpose device that executes commands related to the functions and procedures, or each function and procedure may be performed by different devices using one device that functions as a control or using separate control devices.

[0041] The subject matter described in this specification may illustrate different components that are included within or connected to different other components. It should be understood that such depicted architectures are merely exemplary, and in practice, many other architectures can be implemented that achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" so that the desired functionality is achieved. Thus, any two components combined herein to achieve a particular functionality can be considered to be "associated" with each other such that the desired functionality is achieved, regardless of the architecture or intermediate components. Similarly, any two components so associated can also be viewed as being "operably connected" or "operably coupled" to each other to achieve the desired functionality, and any two components that can be so associated can also be viewed as being "operably couplable" to each other to achieve the desired functionality. Specific examples of operably couplable include, but are not limited to, components that are physically couplable and / or physically interact, and / or components that wirelessly interact and / or wirelessly interact, and / or components that logically interact and / or logically interactable.

[0042] Regarding the use of substantially any plural and / or singular terms herein, one of ordinary skill in the art can interpret from plural to singular and / or from singular to plural as appropriate for the context and / or application. Various singular / plural substitutions may be explicitly shown herein for clarity.

[0043] Generally, the terms used herein, and especially in the appended claims (e.g., the body of the appended claims), are generally intended to be open terms (e.g., the term “comprising” should be interpreted as “comprising, but not limited to,” the term “having” should be interpreted as “having at least,” and the term “including” should be interpreted as “including, but not limited to”). It will be understood by those skilled in the art that if a specific number of introduced claim recitations is intended, such intent will be explicitly recited in the claims, and if there is no such recitation, such intent does not exist. For example, by way of illustration, the following appended claims may include the use of introductory phrases “at least one” and “one or more” to introduce claim recitations. However, even if the same claim includes introductory phrases such as “one or more” or “at least one” and indefinite articles such as “a” or “an,” the use of such phrases should not be interpreted such that the introduction of a claim recitation by the indefinite article “a” or “an” limits any particular claim that includes such introduced claim recitation to an invention that includes only one such recitation (e.g., “a” and / or “an” should typically be interpreted as meaning “at least one” or “one or more”), and the same is true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of introduced claim recitations is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted as meaning at least the recited number (e.g., a mere recitation of “two recitations” without other modifying phrases typically means at least two recitations, or two or more recitations). Similarly, unless otherwise specified, the phrase “based on” should not be interpreted in a limiting way and should thus be understood as “based at least in part on.”Furthermore, when conventions similar to "at least one of A, B, and C, etc." are used, generally, such syntax is intended in the sense that those skilled in the art will understand the convention (for example, "a system having at least one of A, B, and C" includes, but is not limited to, a system having A alone, B alone, C alone, both A and B, both A and C, both B and C, and / or all of A, B, and C, etc.). When conventions similar to "at least one of A, B, or C, etc." are used, generally, such syntax is intended in the sense that those skilled in the art will understand the convention (for example, "a system having at least one of A, B, or C" includes, but is not limited to, a system having A alone, B alone, C alone, both A and B, both A and C, both B and C, and / or all of A, B, and C, etc.). Regardless of the specification, the claims, or the drawings, it will be further understood by those skilled in the art that substantially any discrete words and / or phrases presenting two or more alternative terms should be understood to contemplate the possibility of including one of the terms, any of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B". Further, unless otherwise specified, the use of words such as "approximate", "about", "around", "substantially", etc. means plus or minus 10%.

[0044] Moreover, the figures show a particular order of method operations, but the order of operations may be different from that depicted. Also, two or more operations may be performed simultaneously or partially simultaneously. Such variations will depend on the selected software system and hardware system, as well as the designer's choices. All such variations are within the scope of the present disclosure. Similarly, software implementations can be achieved using standard programming techniques with rule-based logic and other logic to accomplish various connection operations, processing operations, comparison operations, and decision operations.

Claims

1. A fuel cell system, comprising a fuel cell stack including a plurality of fuel cells, each of the plurality of fuel cells including a fuel electrode and an air electrode; a fuel cell stack, a fuel receiving unit fluidly coupled to the fuel cell stack, configured to receive a hydrocarbon fuel from a fuel supply unit and provide the hydrocarbon fuel to the fuel electrode of the fuel cell stack; a fuel receiving unit, a first fluid path configured to receive fuel exhaust from the fuel electrode of the fuel cell stack, a second fluid path configured to receive a first portion of the fuel exhaust from the first fluid path, a third fluid path configured to receive a second portion of the fuel exhaust from the first fluid path, configured to receive the first portion of the fuel exhaust from the second fluid path and remove a first portion of carbon dioxide (CO ２ 2) from the first portion of the fuel exhaust in liquid form, output the first portion of CO ２ 2 in a first stream, and output the remainder of the first portion of the fuel exhaust including a second portion of CO ２ 2 and hydrogen; a carbon processing unit, and an air mixing unit configured to receive the second portion of the fuel exhaust from the third fluid path, mix the second portion of the fuel exhaust with air, and provide a mixture of the second portion of the fuel exhaust and the air to the air electrode of the fuel cell stack. A fuel cell system.

2. The fuel cell system according to claim 1, further comprising a controller in communication with the fuel cell system for controlling the amount of the first portion of the fuel exhaust provided to the carbon processing unit.

3. The fuel cell system according to claim 2, wherein the controller is configured to control the amount of the first portion of the fuel exhaust provided to the carbon treatment unit based on an operating state of the fuel cell system.

4. The controller is configured to control, in real time in response to a demand, the amount of the first portion of the fuel exhaust provided to the carbon treatment unit. ２ The fuel cell system according to claim 2.

5. The fuel cell system according to claim 1, wherein the air mixing unit includes a heater configured to react hydrogen in the mixture.

6. The carbon treatment unit includes an exhaust cooling component and a CO ２ separation component, and the exhaust cooling component is configured to cool the first portion of the fuel exhaust and extract water from the first portion of the fuel exhaust. The fuel cell system according to claim 5.

7. The fuel cell system further includes a plurality of outlet paths for sending out the first portion of the CO ２ from the fuel cell system, and each of the plurality of outlet paths is fluidly connected to the carbon treatment unit. The fuel cell system according to claim 1.

8. Each of the plurality of outlet paths corresponds to a predetermined use associated with the first portion of the CO ２ The fuel cell system according to claim 7.

9. The fuel cell system according to claim 2, further including a fan or a blower, and the controller is configured to control the fan or the blower to control the amount of the first portion of the fuel exhaust provided to the carbon treatment unit.

10. The fuel cell system according to claim 3, further comprising a fan or a blower, wherein the controller is configured to control the fan or the blower to control the amount of the first portion of the fuel exhaust provided to the carbon treatment unit.

11. The fuel cell system according to claim 4, further comprising a fan or a blower, wherein the controller is configured to control the fan or the blower to control the amount of the first portion of the fuel exhaust provided to the carbon treatment unit.

12. A method for extracting carbon dioxide in the fuel cell system according to any one of claims 1 to 11, comprising: receiving, by the carbon treatment unit, the first portion of the fuel exhaust from the second fluid path; controlling, by a circulation device, the flow of the first portion of the fuel exhaust to the carbon treatment unit; removing, by the carbon treatment unit, the first portion of CO ２ from the first portion of the fuel exhaust; outputting, by the carbon treatment unit, the first portion of CO ２ , and the remaining portion of the first portion of the fuel exhaust including the second portion of CO ２ and hydrogen.

13. The method according to claim 12, further comprising sending, by the carbon treatment unit, the first portion of CO ２ out of the fuel cell system.

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