Systems and methods for processing exhaust from fuel cell and combustion sources

Abstract

Systems and methods for processing fuel cell exhaust, combustion exhaust, and / or combinations of fuel cell exhaust and combustion exhaust are provided. The systems can include exhaust processing assemblies.

Description

[0001] Systems and Methods for Processing Exhaust from Fuel Cell and Combustion Sources

[0002] CROSS REFERENCE TO RELATED APPLICATION

[0003] This application claims priority to and the benefit of U.S. Provisional Patent Application Serial No. 63 / 567,811 filed March 20, 2024, entitled “Systems and Methods for Processing Exhaust from Fuel Cell and Combustion Sources”, the entirety of which is incorporated by reference herein.

[0004] TECHNICAL FIELD

[0005] The field of the invention is systems and methods for processing exhaust from fuel cell and combustion sources.

[0006] BACKGROUND

[0007] Currently it is imperative that for modern energy production, any and / or all CO2 produced during energy production is sequestered. This sequestration can be in the form of a return for additional processing, separation, and / or liquefaction. Some energy production can produce combustion products such as combustion exhaust or flue gas, such as CO2, H2O, and N2. The CO2 can be separated from the H2O, the N2, then liquefied. Other energy production such as electrochemical processes can produce tail gases such as anode tail gases from a fuel cell anode tail gas source. These tail gases can include H2O, CO2, N2 and SYNGAS (CO and H2). The present disclosure provides systems and methods that can include fuel cell anode tail gas processing assemblies for the sequestration and / or liquefaction of CO2 from this exhaust. The present disclosure also provides for the processing of tail gas streams from fuel cells that can separate and / or utilize SYNGAS, and / or separate and liquefy CO2.

[0008] SUMMARY

[0009] Systems for processing fuel cell exhaust are provided, the systems can include: a fuel cell anode tail gas source, the fuel cell anode tail gas source producing one or more of H2O, Syngas, N2, and / or CO2; a fuel cell anode tail gas processing assembly, the assembly comprising: an H2O separation assembly operably arranged to receive fuel cell anode tail gas and to remove H2O and produce an intermediate mixture of CO2, N2, and syngas; a CO2 separation assembly operably arranged to receive the intermediate mixture and to remove CO2 and produce a mixture of syngas and N2; and a CO2 liquefaction assembly operably arranged to receive the CO2 and produce liquified CO2.

[0010] Methods for processing fuel cell exhaust are provided, the methods can include: separating H2O from a fuel cell anode tail gas to produce an intermediate mixture of CO2, N2, and syngas; separating CO2 from the intermediate mixture to produce a mixture of syngas and N2; and liquefying the CO2 to produce liquefied CO2.

[0011] Systems for processing combustion exhaust are provided, the systems can include: an H2O separation assembly operably coupled to receive combustion exhaust and to provide an intermediate mixture comprising N2, O2, and CO2; a compressor assembly operably coupled with the H2O separation assembly and configured to receive the intermediate mixture; a CO2 separation assembly configured to receive the pressurized intermediate mixture from the compressor assembly and provide CO2 and a mixture comprising N2 and O2; and a CO2 liquefaction assembly configured to receive the CO2 from the CO2 separation assembly.

[0012] Methods for processing combustion exhaust are provided, the methods can include: separating H2O from a combustion exhaust to produce an intermediate mixture of CO2, N2, and O2; separating CO2 from the intermediate mixture to produce a mixture of O2 and N2; and liquefying the CO2 to produce liquefied CO2.

[0013] Systems for processing both combustion exhaust and fuel cell exhaust are provided, the systems can include: a combustion source operatively engaged with the cathode of a fuel cell; a fuel source operatively engaged with an anode of the fuel cell; a conduit assembly configured to receive anode tail gas from the anode and portion the exhaust; a first subsystem configured to receive one portion of the anode tail gas, the first subsystem comprising: a combustion assembly configured to receive the one portion and produce a combustion exhaust; and a first separation assembly configured to separate and liquify CO2 from the combustion exhaust; a second subsystem configured to receive another portion of the anode tail gas, the second subsystem comprising: a CO reduction assembly configured to receive the second portion and produce an intermediate mixture comprising CO2, H2O, H2, and O2; and a second separation assembly configured to separate and liquify CO2 from the intermediate mixture.

[0014] DRAWI NGS

[0015] Embodiments of the disclosure are described below with reference to the following accompanying drawings.

[0016] Fig. 1 A is a system according to an embodiment of the disclosure.

[0017] Fig. 1 B is another system according to an embodiment of the disclosure.

[0018] Fig. 2 is a system according to an embodiment of the disclosure.

[0019] Fig. 3 is a system according to an embodiment of the disclosure.

[0020] Fig. 4A is a system according to an embodiment of the disclosure.

[0021] Fig. 4B is a system according to an embodiment of the disclosure.

[0022] Fig. 40 is a system according to an embodiment of the disclosure. Fig. 4D is a system according to an embodiment of the disclosure.

[0023] Fig. 5 is a system according to an embodiment of the disclosure.

[0024] Fig. 6 is a system according to an embodiment of the disclosure.

[0025] Fig. 7 is another system according to an embodiment of the disclosure.

[0026] Fig. 8 is a system according to an embodiment of the disclosure.

[0027] Fig. 9 is a system according to an embodiment of the disclosure.

[0028] DESCRIPTION

[0029] The present disclosure will be described with reference to Figs. 1 A-9. Referring first to Fig. 1 A, system 10 is provided that depicts an anode of a fuel cell. This anode can provide an anode tail gas or exhaust as shown, and this anode tail gas can be provided to an anode tail gas processing assembly that can include a CO2 separation / liquefaction system and / or assembly that can be compiled of multiple components to generate a CO2 liquid. The anode 12 of the fuel cell will be described in more detail in the following description. The CO2 separation and / or liquefaction 14 can be a series of separation and / or liquefaction components as compiled in U.S. Patent Application Publication Numbers US 2020 / 0340665; US 2023 / 0175686; and US 2024 / 0053002, the entirety of each of which is incorporated by reference herein. In accordance with example implementations, a fuel for the fuel cell can be natural gas, for example, and electrochemical processing can generate an anode tail gas that includes CO2 , H2O, CO, H2 and / or N2. It is accepted that CO and H2 together can be considered a syngas, and it is understood that the N2 contained in this anode tail gas can be slight but also introduced with the fuel supply.

[0030] Referring next to Fig. 1 B, an additional embodiment of the disclosure is shown as system 16 that includes anode 12 generating anode tail gas which is provided to CO2 separation liquefaction components 14. As an example, these components can include a H2O separation assembly 18, a CO2 separation assembly 20 such as a pressure swing adsorption component, and CO2 liquefaction assembly 22 such as a liquefaction component. The pressure swing adsorption component 20 can be a vacuum pressure or VPSA vacuum pressure swing adsorption unit as well which is described in detail in the abovereferenced materials. In accordance with example implementations, the CO2 provided from the PSA can be provided to liquefaction 22, which then can provide liquid CO2. In accordance with example implementations, the PSA can also provide syngas and N2 which can be returned and sent to the fuel cell, of which anode 12 is a part.

[0031] Referring next to Fig. 2, system 24 is provided that includes a more detailed description of a fuel cell which includes anode 12 and cathode 26. In accordance with example implementations, fuels such as natural gas, which may include a small amount of pipeline N2, for example, can be provided to anode 12 which is in configuration to form a fuel cell with cathode 26. As an example, an electrolyte can facilitate the ion exchange of O2-between the anode 12 and cathode 26. In accordance with example implementations, air can be provided to cathode 26, and N2 can be provided from the cathode as a waste gas. As shown, the anode tail gas can include CO2, H2O, and CO and H2, of which the CO and H2 can be a syngas, and the anode tail gas can also include a portion of N2.

[0032] Referring next to Fig. 3, system 30 can include a system that includes H2O separation assembly 18 operationally configured to provide substantially dry anode tail gas to a VPSA 36, which can separate the CO2 and provide same to CO2 liquefaction assembly 22. The VPSA can also be configured to return syngas to the fuel cell.

[0033] Referring next to Figs. 4A and 4B, at least a pair of configurations of more detailed separation and / or liquefaction systems are provided. Referring first to Fig. 4A, a general separation system 40 is shown that includes a combustion exhaust stream that includes N2, O2, H2O, and CO2. This stream is provided to water removal heat exchanger 42. After water removal heat exchange, a composition that may comprise N2, O2, and CO2 is provided to compressor 44, and upon compression, N2, O2, and CO2 at approximately 85 PSIG is provided to a pressure swing adsorption system 46 which may also be a vacuum pressure swing adsorption system, for example. This vacuum pressure swing adsorption system is configured to separate the CO2 from the N2 and O2, then provide the CO2 to liquefaction component 48 to provide liquid CO2. The N2 and O2 from pressure swing adsorption system 46 can be provided to an energy recovery expander / compressor assembly 50 at 75 PSIG, to provide N2 and O2 at 10 PSIG, or -75° F, and this cooled low pressure N2 and O2 can be provided to a liquefaction heat exchange assembly 52 which can be part of liquefaction unit 48. Upon being provided to liquefaction heat exchanger, this N2 and O2 can be provided to water removal heat exchange assembly 42, to further assist in providing cooling temperatures to the water removal heat exchanger. In accordance with example implementations, the water removal heat exchanger can provide water which can be provided to water treatment and disposal component 54. While demonstrated in Fig. 4A as a system for processing a combustion exhaust stream, the system can be configured to process anode tail gas. Example anode tail gas can be free of oxygen.

[0034] Referring next to Fig. 4B, a more detailed view of combustion exhaust handling system 60 is shown that includes a stream of N2, O2, H2O and CO2 being provided to water removal heat exchanger component 42. As described in Fig. 4A, the system can include compressor component 44, and pressure swing adsorption system 46. However, system 60 provides more detail in relation to liquefaction 48. As shown, liquefaction components 48 can include a vacuum pump 62 which is operatively aligned with a compressor 64 which is operatively aligned with an energy recovery heat exchanger 66, as well as a liquefaction heat exchanger 68, which is operatively aligned with a vapor separator 70, as well as a cryogenic tank 72 and a supplemental refrigeration unit 74 which is operatively engaged between cryogenic tank 72 and liquefaction heat exchanger 68. Cryogenic tank 72 can be operatively aligned with liquid CO2 pump and offtake panel 76, which all form part of liquefaction components 48, for example. In accordance with example implementations and as shown, the N2 and O2 received from pressure swing adsorption system 46 can be provided to energy recovery expander / compressor assembly 50, and from there, N2 and O2 at approximately 10 PSIG and -75° F can be provided to the liquefaction heat exchanger 68 of the liquefaction components 48.

[0035] Referring next to Fig. 4G, system 80 is configured to receive and process anode tail gas, which can include H2O, CO2, CO, N2, H2, and / or CH4. In accordance with example implementations, water removal heat exchanger 42 can provide CO2, CO, N2, H2, and CH4 to a compressor 44 which can then provide CO2, CO, N2, H2, and CH4 at 85 PSIG, for example, to pressure swing adsorption system 46, which can provide 98% CO2 vapor at -12 PSIG to liquefaction components 48. Pressure swing adsorption system 46 can also provide CO, N2, H2, and CH4 at 75 PSIG to energy recovery expander / compressor assembly 50 which can provide CO, N2, H2, and CH4 at 10 PSIG and -75° F to liquefaction heat exchanger component 68. As shown, the CO, N2, and H2 can be provided as a cold source to water removal heat exchanger 42, and after provided therein, return to fuel cell.

[0036] Referring next to Fig. 4D, in accordance with an alternative embodiment, system 90 is provided. System 90 includes an H2 separation assembly 92, such as a pressure swing adsorption system that is configured to receive CO, N2, H2, and / or CH4 at about 75 PSIG from pressure swing adsorption system 46 to separate H2 from this mixture and provide H2 for H2 management and CO, N2, and CH4 at 65 PSIG to energy recovery expander / compressor assembly 50. Accordingly, this low pressure, low temperature mixture from energy recovery expander / compressor assembly 50 can be provided to a component of liquefaction 48 such as liquefaction heat exchanger 68. Upon providing same, this mixture can be provided back to water removal 42 and then provided for CO, N2, and CH4 gas management, for example.

[0037] The following Tables are exemplary data for systems 80 or 90.

[0038] Table 1 is the Anode Tail Gas composition.

[0039] Table 2 is an exemplary feed rate to water removal heat exchanger 42 of systems 80 or 90. Table 3 is the production rate of liquid CO2 as part of Separation / Liquefaction 14. Table 4 is exemplary waste gas separated during separation.

[0040] Table 5 is exemplary Hydrogen Separation in accordance with system 90 using assembly 92. Referring next to Fig. 5, in accordance with an additional embodiment, system 100 is provided that can include the processing of anode tail gas utilizing a water gas shift (WGS) assembly 102 which is operatively coupled to CO2 separation and liquefaction components 14 which have H2O separation assembly 18 components, which can include cooling component 32, a compressor assembly 34, and an additional drying component 104. The system can also be coupled to a vacuum pressure swing adsorption component 36 and a CO2 liquefaction assembly 22 to provide liquid CO2.

[0041] In accordance with example implementations, the anode tail gas of Fig. 5 can be provided from a fuel cell such as a solid oxide fuel cell. Accordingly, anode tail gas can be provided to a WGS component 102. WGS component 102 can be configured to receive mixed gas from the anode electrode of a fuel cell and to account for fuel utilization. Not all fuel is consumed at the electrode and some fuel gas leaves with the anode tail gas stream. In a high temperature fuel cell such as the Solid Oxide Fuel Cell, this unutilized fuel gas is generally in the form of syngas, which is a combination of carbon monoxide (CO) and hydrogen (H2). Therefore, the total anode tail gas can be comprised primarily of: CO, H2, CO2, H2O (steam), with small secondary amounts of N2 and CH4 (from delivered pipeline fuel).

[0042] Referring next to Fig. 6, a fuel cell exhaust processing system and / or method is depicted. The amount of CO in the exhaust gas is reduced in a water gas shift assembly and this reduced CO fuel cell exhaust gas is then provided to an adsorption chiller before being provided to a heat exchanger assembly where water is reduced / removed before the treated exhaust fuel is compressed. After compression, the intermediate mixture is provided to a pressure swing adsorption assembly where CO2 is separated from at least N2. While the separated CO2 is provided to a liquefaction system, the N2 can be used for energy recovery in an expander / compressor, then an additional heat exchange in the liquefaction system before being provided to the heat exchange assembly to assist with water removal. In the liquefaction system, the CO2 can also be provided to another energy recovery heat exchanger system.

[0043] In accordance with another embodiment, Fig. 7 depicts system 110 that utilizes a molten carbonate fuel cell. System 110 can include a catalytic combustion component that is operatively aligned with separation / liquefaction component 14 or WGS component 102 operatively aligned with separation / liquefaction component 14.

[0044] In order to capture (separate and / or liquify) CO2, the water can be removed, and then CO2 from remaining practically dry tail gas. After both the H2O and CO2 are removed, the remaining tail gas contains the syngas which preferably is sent back to the fuel cell as additional fuel. Note that CO, H2, and CH4 are valid fuels for the Solid Oxide Fuel Cell. Feedback of these fuel gases reduces the amount of pipeline Natural Gas required by the fuel cell.

[0045] In the embodiment of Figs. 5, 7, and 9, a process called Water Gas Shift (WGS) is introduced which is expected to be at a temperature >250° F. In accordance with example implementations, WGS can be utilized to reduce CO. The Water Gas Shift reaction is as follows: CO + H2O >> CO2 + H2. This reaction is slightly exothermic and is not equilibrium shifted by pressure.

[0046] Since the anode tail gas contains both CO and H2O (steam), WGS may be utilized to nearly eliminate carbon monoxide (CO), in order to increase CO2 and H2 which are thus much easier to separate downstream. Following WGS the remaining water can be dropped out (by cooling) resulting in a DRY stream of remaining tail gas. Because of WGS, CO is reduced to <0.2% of the original DRY fraction.

[0047] There are two types of WGS components which can operate at either Medium Temperature WGS, and Low Temperature WGS.

[0048] The Medium Temperature WGS reactor (MTWGS) receives syngas in the range of 280° F to 625° F which then passes through a bed of copper promoted iron-chromium or copper zinc alumina catalyst. The CO content is dropped to approximately 0.5% of the DRY basis gas.

[0049] A Low Temperature WGS reactor (LTWGS) is utilized immediately following the MTWGS and typically utilizes a Zn-Cu catalyst to further reduce CO content to <0.2% of the DRY basis gas while maximizing both carbon dioxide and hydrogen content.

[0050] With CO greatly reduced, the downstream carbon capture process (VPSA) can separate out CO2 and provide fuel gas back to the fuel cell.

[0051] System 100 of Fig. 5 also provides a drying component. This component can be configured as described in the referenced publications to provide less than 10 ppm H2O mix to VPSA 36.

[0052] Referring to Figs. 7 and 8, systems 110 and 120 for processing both combustion exhaust and fuel cell exhaust are provided. System 110 can include a combustion source operatively engaged with the cathode of a fuel cell, in this example a carbonate fuel cell. A fuel source operatively engaged with an anode of the fuel cell. As shown a portion of the anode tail gas can be provided to the cathode. A conduit assembly is shown to receive anode tail gas from the anode and portion the exhaust.

[0053] One subsystem can be configured to receive one portion of the anode tail gas. The one subsystem can include: a combustion assembly configured to receive the one portion and produce a combustion exhaust then provide same to a combustion processing assembly 14. Another subsystem is configured to receive another portion of the anode tail gas. The other subsystem can include: a CO reduction assembly 102 configured to receive the second portion and produce an intermediate mixture comprising CO2, H2O, H2, and O2; and an exhaust gas processing assembly 14 configured to separate and liquify CO2 from the intermediate mixture. In accordance with another embodiment, system 120 of Fig. 8 can include a microturbine component 122 that is configured to receive external air and anode tail gas from a solid oxide fuel cell anode. Microturbine component 122 can be configured to operatively drive generator 124 to provide electrical power while also providing a CO2 mixture for separation / liquefaction component 14. Turbine assembly 122, such as combustion turbine, can be configured to combust the tail gas with external air. The combustion products can proceed to separation / liquefaction component 14.

[0054] In an additional embodiment in accordance with system 130 of Fig. 9, steam methane reforming assembly 134 can be provided to receive methane and steam generated by a combustion boiler 132. A mixture of CO2, CO, and H2 can be received from assembly 134 and provided to WGS assembly 102 to provide CO2 and H2 which is provided to CO2 separation assembly 20 and CO2 liquefaction assembly 22. From CO2 separation assembly 20 can be provided ppm level CO and primarily H2 which can be methanated (CO + 3H2 -> CH4 + H2O) to form CH4 and H2 which can be provided to a hydrogen fuel cell. Additionally, system 130 can be configured to perform CO2 Separation / Liquefaction 14.

Claims

CLAI MS1 . A system for processing fuel cell exhaust, the system comprising: a fuel cell anode tail gas source, the fuel cell anode tail gas source producing one or more of H2O, Syngas, N2, and / or CO2; a fuel cell anode tail gas processing assembly, the assembly comprising: an H2O separation assembly operably arranged to receive fuel cell anode tail gas and to remove H2O and produce an intermediate mixture of CO2, N2, and syngas; a CO2 separation assembly operably arranged to receive the intermediate mixture and to remove CO2 and produce a mixture of syngas and N2; and a CO2 liquefaction assembly operably arranged to receive the CO2 and produce liquified CO2.

2. The system of claim 1 wherein the CO2 separation assembly is operably coupled to the fuel cell anode tail gas source, and the mixture of the syngas and N2 produced by the CO2 separation assembly is provided to the fuel cell anode tail gas source.

3. The system of claim 1 wherein the syngas is CO and H2.

4. The system of claim 1 wherein the fuel cell exhaust source utilizes natural gas as a fuel.

5. The system of claim 1 further comprising a compressor assembly configured to compress the intermediate mixture and provide the compressed intermediate mixture to the CO2 separation assembly.

6. The system of claim 1 further comprising an energy recovery expander / compressor operatively aligned to receive the mixture of the syngas and N2 produced by the CO2 separation assembly.

7. The system of claim 1 further comprising at least one heat exchange assembly operably coupled with the CO2 liquefaction assembly.

8. The system of claim 7 wherein the CO2 separation assembly is operably coupled to the at least one heat exchange assembly, and the mixture of the syngas and N2 produced by the CO2 separation assembly is provided to the at least one heat exchange assembly.

9. The system of claim 1 further comprising at least one heat exchange assembly operably coupled with the H2O separation assembly.

10. The system of claim 9 wherein the CO2 separation assembly is operably coupled to the at least one heat exchange assembly, and the mixture of the syngas and N2 produced by the CO2 separation assembly is provided to the at least one heat exchange assembly.1 1 . The system of claim 1 further comprising: an energy recovery expander / compressor assembly operably engaged to receive the mixture from the CO2 separation assembly; a first heat exchange assembly operably coupled with the CO2 liquefaction assembly and operably engaged to receive the mixture from the energy recovery expander and compressor assembly; and a second heat exchange assembly operably coupled with the H2O separation assembly and operably engaged to receive the mixture from the first heat exchange assembly.

12. The system of claim 1 further comprising an H2 separation assembly operably coupled to receive the mixture from the CO2 separation assembly and provide H2.

13. The system of claim 1 further comprising a water-gas-shift assembly operably aligned to receive the anode tail gas and provide a lowered CO exhaust gas mixture to the H2O separation assembly.

14. The system of claim 1 further comprising a combustion turbine operably engaged to receive the anode tail gas and provide combustion products to the H2O separation assembly.

15. A method for processing fuel cell exhaust, the method comprising: separating H2O from a fuel cell anode tail gas to produce an intermediate mixture of CO2, N2, and syngas; separating CO2 from the intermediate mixture to produce a mixture of syngas and N2; and liquefying the CO2 to produce liquefied CO2.

16. The method of claim 15 wherein the separating CO2 further comprises providing the mixture of syngas and N2 produced to a fuel cell anode tail gas source.

17. The method of claim 16 wherein the fuel cell exhaust source utilizes natural gas as fuel18. The method of claim 15 wherein the syngas comprises CO and H2.

19. The method of claim 15 further comprising providing a compressed intermediate mixture to the CO2 separation assembly.

20. The method of claim 15 further comprising expanding the mixture of syngas and N2 to recover energy.

21. The method of claim 15 further comprising using the mixture of syngas and N2 to provide liquified CO2.

22. The method of claim 15 further comprising using the mixture of syngas and N2 to remove H2O from the anode tail gas.

23. The method of claim 15 further comprising: expanding the mixture of syngas and N2 to recover energy; using the mixture of syngas and N2 to provide liquified CO2; and using the mixture of syngas and N2 to remove H2O from the anode tail gas.

24. The method of claim 15 wherein the CO2 separated from the intermediate mixture comprises H2, the method further comprising producing H2 from the CO2 separated from the intermediate mixture.

25. The method of claim 15 further comprising lowering the CO content of the anode tail gas prior to separating water from the anode tail gas.

26. A system for processing combustion exhaust, the system comprising: an H2O separation assembly operably coupled to receive combustion exhaust and to provide an intermediate mixture comprising N2, O2, and CO2; a compressor assembly operably coupled with the H2O separation assembly and configured to receive the intermediate mixture; a CO2 separation assembly configured to receive the pressurized intermediate mixture from the compressor assembly and provide CO2 and a mixture comprising N2 and O2; and a CO2 liquefaction assembly configured to receive the CO2 from the CO2 separation assembly.

27. The system of claim 26 further comprising an energy recovery expander / compressor assembly operatively aligned to receive the mixture of the O2 and N2 produced by the CO2 separation assembly.

28. The system of claim 26 further comprising at least one heat exchange assembly operably coupled with the CO2 liquefaction assembly.

29. The system of claim 28 wherein the CO2 separation assembly is operably coupled to the at least one heat exchange assembly, and the mixture of the O2 and N2 produced by the CO2 separation assembly is provided to the at least one heat exchange assembly.

30. The system of claim 26 further comprising at least one heat exchange assembly operably coupled with the H2O separation assembly.

31. The system of claim 30 wherein the CO2 separation assembly is operably coupled to the at least one heat exchange assembly, and the mixture of the O2 and N2 produced by the CO2 separation assembly is provided to the at least one heat exchange assembly.

32. The system of claim 26 further comprising: an energy recovery expander / compressor assembly operably engaged to receive the mixture from the CO2 separation assembly; a first heat exchange assembly operably coupled with the CO2 liquefaction assembly and operably engaged to receive the mixture from the energy recovery expander and compressor assembly; and a second heat exchange assembly operably coupled with the H2O separation assembly and operably engaged to receive the mixture from the first heat exchange assembly.

33. The system of claim 26 further comprising: a combustion boiler configured to produce the combustion exhaust and steam; a steam methane reforming assembly operably engaged to receive the steam from the combustion boiler, and methane, and provide an smr-mixture comprising CO2, H2, and CO; a WGS assembly operably engaged to receive the smr-mixture from the steam methane reforming assembly and provide low CO mixture comprising CO2 and H2; a methanation assembly configured to receive the H2 and CO and provide H2 and CH4; and a hydrogen fuel cell operatively engaged to receive the H2 and CH4.

34. A method for processing combustion exhaust, the method comprising: separating H2O from a combustion exhaust to produce an intermediate mixture of CO2, N2, and O2; separating CO2 from the intermediate mixture to produce a mixture of O2 and N2; and liquefying the CO2 to produce liquefied CO2.

35. The method of claim 34 further comprising compressing the intermediate mixture before separating the CO2 from the intermediate assembly.

36. The method of claim 34 further comprising expanding the mixture of O2 and N2 to recover energy.

37. The method of claim 34 further comprising using the mixture of O2 and N2 to provide liquified CO2.

38. The method of claim 34 further comprising using the mixture of O2 and N2 to remove H2O from the combustion exhaust.

39. The method of claim 34 further comprising: expanding the mixture of O2 and N2 to recover energy; using the mixture of O2 and N2 to provide liquified CO2; and using the mixture of O2 and N2 to remove H2O from the combustion exhaust.

40. A system for processing both combustion exhaust and fuel cell exhaust, the system comprising: a combustion source operatively engaged with the cathode of a fuel cell; a fuel source operatively engaged with an anode of the fuel cell; a conduit assembly configured to receive anode tail gas from the anode and portion the exhaust; a first subsystem configured to receive one portion of the anode tail gas, the first subsystem comprising : a combustion assembly configured to receive the one portion and produce a combustion exhaust; and a first separation assembly configured to separate and liquify CO2 from the combustion exhaust; a second subsystem configured to receive another portion of the anode tail gas, the second subsystem comprising: a CO reduction assembly configured to receive the second portion and produce an intermediate mixture comprising CO2, H2O, and H2; and a second separation assembly configured to separate and liquify CO2 from the intermediate mixture.

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