Integrated hydrocarbon decomposition and power generation systems

Abstract

A power generation system includes a reactor configured to decompose a hydrocarbon feedstock to yield a product stream comprising hydrogen and solid carbon, a power generator coupled to the reactor and configured to generate power from the hydrogen, and a heat exchanger configured to accept an exhaust stream from the power generator and transfer heat from the exhaust stream to preheat the hydrocarbon feedstock. Generating power from a hydrocarbon feedstock includes thermocatalytically decomposing the hydrocarbon feedstock to yield a product stream comprising hydrogen and solid carbon, providing the hydrogen as a fuel source to a power generator to generate power, and preheating the hydrocarbon feedstock with heat from an exhaust stream from the power generator.

Description

Attorney Docket No.: 44807-0497WO1 / JHU 18370INTEGRATED HYDROCARBON DECOMPOSITION AND POWER GENERATION SYSTEMSCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority under 35 U.S.C. § 119(a) to U.S. Provisional Application No. 63 / 692,309, filed on September 9, 2024, entitled “INTEGRATED HYDROCARBON DECOMPOSITION AND POWER GENERATION SYSTEMS,” which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] This invention relates to systems and methods that integrate hydrocarbon decomposition and heat or power generation to realize overall process efficiency increases.BACKGROUND

[0003] Hydrogen is typically produced from hydrogen-containing molecules such as water or methane. The energy required for these processes is determined by thermodynamic and chemical principles. A number of methods to produce hydrogen via the decomposition of hydrocarbons to hydrogen and solid carbon have been developed. For instance, hydrocarbons can be decomposed using catalysts or in a plasma.SUMMARY

[0004] This disclosure describes systems and methods that integrate hydrocarbon decomposition and combined cycle generation to create efficiency gains in the generation of power, heat, or both from hydrogen. When using hydrogen produced from hydrocarbon decomposition systems, energy (e.g., heat) is supplied to heat the undecomposed reactants and drive the decomposition reaction, and then extracted from the system to cool down the products (e g., hydrogen and carbon). Certain process efficiencies can be realized by capturing some of the cool-down heat and using it to heat the undecomposed reactants. When used in powergeneration systems such as combined cycle systems, hydrogen is “delivered” to the power generation unit. Combined cycle systems can include a high temperature power unit with a fuel (e g., hydrogen)-driven turbine and a steam turbine driven by the lower temperature exhaust heat of the turbine, usually boosted with extra fuel.Attorney Docket No.: 44807-0497WO1 / JHU 18370

[0005] Although the disclosed inventive concepts include those defined in the attached claims, it should be understood that the inventive concepts can also be defined in accordance with the following embodiments.

[0006] Embodiment l is a power generation system comprising: a reactor configured to decompose a hydrocarbon feedstock to yield a product stream comprising hydrogen and solid carbon; a power generator coupled to the reactor and configured to generate power from the hydrogen; and a heat exchanger configured to accept an exhaust stream from the power generator and transfer heat from the exhaust stream to preheat the hydrocarbon feedstock.

[0007] Embodiment 2 is the power generation system of embodiment 1, wherein the power generator comprises a combustion chamber configured to combust the hydrogen.

[0008] Embodiment 3 is the power generation system of embodiment 2, further comprising a compressor configured to compress the hydrogen upstream of the combustion chamber.

[0009] Embodiment 4 is the power generation system of embodiment 2 or 3, wherein the power generator comprises a compressor, a turbine, and a shaft configured to couple the compressor and the turbine.

[0010] Embodiment 5 is the power generation system of any one of embodiments 1-4, further comprising an additional power generator coupled to the reactor.

[0011] Embodiment 6 is the power generation system of embodiment 5, further comprising an additional heat exchanger configured to accept the product stream from the reactor and transfer heat from the product stream to the additional power generator.

[0012] Embodiment 7 is the power generation system of embodiment 6, wherein the additional power generator is configured to generate power from steam.

[0013] Embodiment 8 is the power generation system of embodiment 7, wherein the additional power generator comprises a steam boiler or a steam turbine.

[0014] Embodiment 9 is the power generation system of embodiment 8, wherein the heat exchanger, the additional heat exchanger, or both are configured to transfer heat to the steam boiler.

[0015] Embodiment 10 is the power generation system of any one of embodiments 1-9, further comprising a separator configured to separate the hydrogen from the product stream.Attorney Docket No.: 44807-0497WO1 / JHU 18370

[0016] Embodiment 1 1 is the power generation system of any one of embodiments 1-10, wherein the reactor is configured to be at least partially powered by an external source of electricity.

[0017] Embodiment 12 is the power generation system of any one of embodiments 1-11, wherein the hydrocarbon feedstock comprises methane, ethane, propane, natural gas, higher alkanes, any isomer thereof.

[0018] Embodiment 13 is the power generation system of any one of embodiments 1-12, wherein the reactor comprises a catalyst configured to increase a rate of decomposition of the hydrocarbon feedstock.

[0019] Embodiment 14 is the power generation system of any one of embodiments 1-13, wherein the reactor is configured to generate a plasma medium to decompose the hydrocarbon feedstock.

[0020] Embodiment 15 is the power generation system of any one of embodiments 1-14, wherein the heat from the exhaust stream and the heat from the product stream are combined upstream of the reactor or in the reactor.

[0021] Embodiment 16 is a method of generating power from a hydrocarbon feedstock, the method comprising: thermocatalytically decomposing the hydrocarbon feedstock to yield a product stream comprising hydrogen and solid carbon; providing the hydrogen as a fuel source to a power generator to generate power; and preheating the hydrocarbon feedstock with heat from an exhaust stream from the power generator.

[0022] Embodiment 17 is the method of embodiment 16, further comprising compressing the hydrogen before providing the hydrogen to the power generator.

[0023] Embodiment 18 is the method of embodiment 16 or 17, further comprising separating the hydrogen from the product stream before providing the hydrogen to the power generator.

[0024] Embodiment 19 is the method of any one of embodiments 16-18, wherein the power generator comprises a compressor, a turbine, and a shaft configured to couple the compressor and the turbine.Attorney Docket No.: 44807-0497WO1 / JHU 18370

[0025] Embodiment 20 is the method of any one of embodiments 16-19, further comprising, after preheating the hydrocarbon feedstock with heat from the exhaust stream, providing heat from the exhaust stream to an additional power generator.

[0026] Embodiment 21 is the method of embodiment 20, further comprising providing heat from the product stream to the additional power generator.

[0027] Embodiment 22 is the method of embodiment 21, wherein the additional power generator comprises a steam turbine or a steam boiler.

[0028] Embodiment 23 is the method of embodiment 22, further comprising heating water in the additional power generator with the heat from the exhaust stream, the heat from the product stream, or both.

[0029] Embodiment 24 is the method of any one of embodiments 21-23, further comprising combining the heat from the exhaust stream and the heat from the product stream upstream of the additional power generator.

[0030] Embodiment 25 is the method of any one of embodiments 16-24, further comprising providing heat from an additional source to the additional power generator.

[0031] Embodiment 26 is the method of any one of embodiments 16-25, wherein the product stream comprises at least 70 vol%, at least 80 vol%, at least 90 vol%, at least 95 vol%, or at least 99 vol% hydrogen.

[0032] Embodiment 27 is the method of any one of embodiments 16-26, wherein the product stream comprises less than 20 vol%, less than 10 vol%, less than 5 vol%, or less than 1 vol% carbon dioxide.

[0033] Embodiment 28 is the method of any one of embodiments 16-27, wherein the hydrocarbon feedstock comprises up to 20 vol% carbon dioxide.

[0034] Embodiment 29 is the method of any one of embodiments 16-28, wherein the hydrocarbon feedstock comprises up to 1 vol% air.

[0035] Embodiment 30 is the method of any one of embodiments 16-29, wherein the hydrocarbon feedstock comprises up to 1 vol% oxygen.

[0036] Embodiment 31 is the method of any one of embodiments 16-30, wherein the hydrocarbon feedstock comprises up to 1 vol% water.

[0037] The details of one or more embodiments of the subject matter of this disclosure are set forth in the accompanying drawings and the description. Other features, aspects, andAttorney Docket No.: 44807-0497WO1 / JHU 18370 advantages of the subject matter will become apparent from the description, the drawings, and the claims.BRIEF DESCRIPTION OF DRAWINGS

[0038] FIG. 1 shows a schematic representation of a hydrocarbon decomposition unit integrated with a hydrogen-fueled power turbine unit and a steam generator-powered turbine.

[0039] FIGS. 2A and 2B (Table 1) show the detailed mass and heat flows in an example integrated methane decomposition unit employing a thermocatalytic hydrogen decomposition method, a power turbine, and a steam turbine producing approximately 30 MW of power from an input of approximately 3.5 kg of methane / sec. In this example, the mass flow of the catalyst is small relative to all other mass flows.DETAILED DESCRIPTION

[0040] This disclosure describes systems and methods to integrate hydrocarbon decomposition and power generation in ways that synergistically increase the efficiencies of these processes into an integrated power generation system. FIG. 1 shows a block diagram of an integrated power generation system including a hydrocarbon decomposition unit 1 (e.g., a hydrocarbon decomposition reactor), a power turbine unit 2 (e.g., a power generator), and a steam turbine unit 3. The hydrocarbon decomposition reactor decomposes a hydrocarbon feedstock to yield a product stream including hydrogen and solid carbon. The hydrocarbon decomposition unit operates temperatures above 850 °C, and thus the product stream 4 (which includes hydrogen, carbon, and catalyst used in the decomposition) exits at a high temperature. The power generator is coupled to the hydrocarbon decomposition reactor and generates power from the hydrogen. Heat is extracted from the product stream 4 by a heat exchanger 6 to yield a cooled product stream and heat stream 5. The heat exchanger 6 accepts an exhaust stream from the power generator power turbine unit 2 and transfers heat from the exhaust stream to preheat the hydrocarbon feedstock. The heat in exhaust stream 5 is used as a source of energy to generate steam for the steam turbine unit 3. Hydrogen is separated from the cooled product stream by a separation unit 7. Separation unit 7 may achieve separation of solid components inAttorney Docket No.: 44807-0497WO1 / JHU 18370 the cooled product stream by mechanisms such as filtration, cyclone separation, magnetic separation (if the catalyst is magnetic), another suitable method, or any combination thereof.

[0041] Heat in exhaust stream 9 from the power turbine unit 2 is used to pre-heat the hydrocarbon fuel 10 in heat exchanger 11 before the hydrocarbon fuel is provided to the hydrocarbon decomposition unit 1. Exhaust stream 8 from heat exchanger 11 is provided to steam turbine unit 3, separately or together with exhaust stream 5. Exhaust streams 8 and 5 are each at a temperature above that required to generate steam. An optional combustor 12 can be incorporated into the steam turbine unit 3 to boost heat going to the boiler.

[0042] Integration of the hydrocarbon decomposition unit, the power turbine unit, and the steam turbine unit yields overall process efficiencies in the decomposition of hydrocarbons to hydrogen fuel and subsequent use of the fuel to drive a power turbine. By combining the exhaust streams from the hydrocarbon decomposition reactor and the power turbine unit into a single stream 13, overall system process efficiency is improved by using the combined quantity of heat produced to boil water in the boiler and drive the steam turbine unit. By using the turbine exhaust heat to raise the temperature of the hydrocarbon fuel going into the hydrocarbon decomposition reactor, the power needed for the hydrocarbon decomposition unit is reduced. In addition, the power 14 generated by the steam turbine may be sufficient to supply power to the hydrocarbon decomposition reactor, for instance, as electrical heating power 15. In this way, except for air and water driving the turbines, the system can be thought of as self-contained: hydrocarbon fuel (e.g., natural gas) enters, while power and solid carbon exit. In some embodiments, catalyst will also enter and exit the system.

[0043] In some cases, hydrogen 16 produced by the hydrocarbon decomposition unit may not be at a sufficient pressure to inject into the power turbine unit 2. In this case, a compressor 17 can be employed (e.g., positioned upstream of the fuel inlet stream of the power turbine). Compressor 17 can be mechanically coupled to the shaft of the power turbine 18.

[0044] In certain cases, the power generation system includes a reactor, a power generator, and a heat exchanger, and synergistically increases the efficiencies of these processes into an integrated power generation system. The reactor decomposes a hydrocarbon feedstock to yield a product stream that includes hydrogen and solid carbon. The power generator is coupled to the reactor and generates power from the hydrogen. The heat exchanger accepts an exhaust streamAttorney Docket No.: 44807-0497WO1 / JHU 18370 from the power generator and transfers heat from the exhaust stream to preheat the hydrocarbon feedstock.

[0045] The power generator can include a combustion chamber to combust the hydrogen, a compressor, a turbine, and a shaft that couples the compressor and the turbine.

[0046] The power generation system can include a compressor that compresses the hydrogen upstream of the combustion chamber and can also include an additional power generator coupled to the reactor. An additional heat exchanger that accepts the product stream from the reactor and transfers heat from the product stream to the additional power generator can also be included in the power generation system.

[0047] The additional power generator is configured to generate power from steam, and can include a steam boiler or a steam turbine. The heat exchanger, the additional heat exchanger, or both can transfer heat to the steam boiler.

[0048] The reactor can be at least partially powered by an external source of electricity, for example an electrical grid or a battery. The reactor can include a catalyst that increases a rate of decomposition of the hydrocarbon feedstock. The catalyst can be any catalyst that increases a rate of decomposition of the hydrocarbon feedstock, and can be for example nickel, iron, or cobalt containing catalysts, or mixtures thereof. The reactor can generate a plasma medium to decompose the hydrocarbon feedstock. The hydrocarbon feedstock can include one or more of methane, ethane, propane, natural gas, higher alkanes, or any isomer thereof. In some examples, the hydrocarbon feedstock can include up to 20 vol% carbon dioxide, up to 1 vol% air, up to 1 vol% oxygen, up to 1 vol% water, or combinations thereof.

[0049] The power generation system can further include a separator to separate the hydrogen from the product stream. The heat from the exhaust stream and the heat from the product stream can be combined upstream of the reactor, or in the reactor.

[0050] Generating power from a hydrocarbon feedstock can include thermocatalytically decomposing the hydrocarbon feedstock to yield a product stream that includes hydrogen and solid carbon. The hydrogen is provided as a fuel source to a power generator to generate power, and the hydrocarbon feedstock is preheated with heat from an exhaust stream from the power generator.Attorney Docket No.: 44807-0497WO1 / JHU 18370

[0051] The hydrogen can be separated from the product stream and compressed before providing the hydrogen to the power generator. The power generator can include a compressor, a turbine and a shaft configured to couple the compressor and the turbine.After preheating the hydrocarbon feedstock with heat from the exhaust stream, heat from the exhaust stream can be provided to an additional power generator. Further, heat from the product stream can be provided to the additional power generator. The additional power generator includes a steam turbine or a steam boiler, and the method can include heating water in the additional power generator with heat from the exhaust stream or the product stream. The heat from the exhaust stream and heat from the product stream can be combined upstream of the additional power generator. Further, heat from an additional source can be provided to the additional power generator.EXAMPLE

[0052] An example of a power generation system including integrated hydrocarbon decomposition and power generation is shown in FIG. 2A, illustrating the flow diagram, mass flows, units, and stream temperatures and pressures, which are listed in Table 1 shown in FIG. 2B. This example is not meant to provide an optimized system but is meant to illustrate components of an integrated hydrocarbon decomposition and power generation system. In this example, a power turbine 100 employs 125.19 kg / sec of air 102 compressed to 25 bar 103 mixed with 0.91 kg / sec of hydrogen compressed to 25 bar 104. The hydrogen originates at the exit of the hydrocarbon decomposition unit 105 at 120 °C and 3 bar of pressure, and is compressed to 25 bar using 5.1 MW of power in a hydrogen compressor 106. As depicted, the hydrogen compressor is mechanically coupled to the spindle of the air compressor and turbine. In other examples, the hydrogen compressor is not mechanically coupled to the spindle of the air compressor and turbine. After compression, the temperatures of the gases are each approximately 500 °C and are brought to 1200 °C in a combustion chamber 107. Upon depressurization in the power turbine 100, a net turbine power of 30 MW is produced, as well as an exhaust stream 108 at 516 °C including air and steam produced by combustion of hydrogen. Little to no carbon dioxide is generated in the integrated hydrocarbon decomposition and power generation system depending on the purity of the input hydrocarbon stream.

[0053] The hydrocarbon decomposition reactor 109 is fed hot methane and catalyst, which are heated in heat exchangers 110 and 111 and enter the reactor at approximately 1050 °C. OtherAttorney Docket No.: 44807-0497WO1 / JHU 18370 suitable hydrocarbons for use in a hydrocarbon decomposition include ethane, propane, natural gas, higher alkanes, and any mixture thereof. Fractions of carbon dioxide (e.g., up to 20 vol%), air (e.g., up to 1 vol%), oxygen (e.g., up to 1 vol%), or water (e.g., up to 1 vol%) can be added to the hydrocarbon stream. In some cases (e.g., if a plasma decomposition process is used in the hydrocarbon decomposition reactor), a catalyst is not needed in the hydrocarbon stream. In some cases, heat is supplied to the hydrocarbon decomposition reactor by electric heating elements, through the hot walls of a firebox, or by generation of a high temperature plasma. These details will change the specific power requirements of the hydrocarbon decomposition reactor and the outlet temperature of the hydrogen gas produced. In the example depicted in FIG. 2, 21 MW of electrical power is used to decompose an inlet stream 112 of approximately 3.5 kg / sec of methane into 0.91 kg / sec of hydrogen and 2.6 kg / sec of solid carbon entrained in the exit gas along with catalyst input into the system. The mass flow rate of the input catalyst 113 in this example is small relative to the mass flow rate of methane and does not significantly impact any mass flow rates.

[0054] Upon exit from the hydrocarbon decomposition reactor, the hot hydrogen, solid carbon, and catalyst is used for recuperative heat exchange with the inlet reactants in heat exchanger 111, heating the inlet stream from approximately 373 °C to approximately 1050 °C and cooling this exit stream to approximately 566 °C. This stream is then further cooled through heat exchange with a steam boiler 114, reaching a temperature of approximately 120 °C. Once this temperature is achieved, the solid carbon and catalyst is separated from hydrogen. This may be accomplished via a separation unit 115, which may include a filter, a cyclone separator, a magnetic separator (if the catalyst is magnetic), or other suitable apparatus for separating solids and gasses.

[0055] The exhaust 108 from the turbine is a stream of air (depleted of some oxygen via combustion with hydrogen fuel) and steam (from reaction of hydrogen fuel with oxygen in air) at approximately 523 °C at a mass flow rate of approximately 126 kg / sec. This is a significantly higher mass flow rate than then input methane and catalyst going into the hydrocarbon decomposition reactor, and thus can be used for heat exchange in heat exchanger 110, raising the input methane and catalyst stream to approximately 373 °C while cooling the exhaust stream to 500 °C.Attorney Docket No.: 44807-0497WO1 / JHU 18370

[0056] By integrating heat exchange between exhaust from the power turbine and the inlet stream to the hydrocarbon decomposition reactor, the heat required to be independently delivered to the hot zone of the decomposition reactor is reduced. In addition, the heat from heat exchangers 110 and 111 can be combined to provide approximately 61 MW to the steam boiler 114 fed by water at 70 bar, 105 °C 116. This steam is used to generate approximately 23.5 MW of power from a steam turbine.

[0057] In this example, the output power from the steam turbine can be used to provide the 21.3 MW of power required for operation of the heating system in the hydrocarbon decomposition unit. Discounting the small excess power from the steam generator, this system provides an integrated unit in which methane enters, is internally decomposed to solid carbon and hydrogen, and then power is generated from combustion of the hydrogen. The net energy generated in this example system is 29.5 MW. Importantly, little to no carbon dioxide emissions (e g., less than 20 vol%, less than 10 vol%, less than 5 vol%, or less than 1 vol%) are generated if the input hydrocarbon stream is free of oxygen-containing species and the hydrocarbon decomposition reactor conversion efficiency is high. Furthermore, by limiting the temperature of the combustion chamber in the power turbine to 1200 °C, nitrous oxide formation is minimized. From the standpoint of the energy content (lower heating value) of natural gas, the overall efficiency of this system is approximately 20%. If the power required to run the hydrocarbon decomposition reactor 109 is externally supplied, for instance from renewable electricity sources, then the power output of the steam generator can be combined with the power output from the turbine generator for a net power output of 53 MW, and an overall efficiency of 56% from the standpoint of the energy content of natural gas.

[0058] Without the efficiency improvements disclosed herein, the overall efficiency of the system is calculated from the power content of natural gas fed to an independent hydrocarbon decomposition reactor, the power required to run the hydrocarbon decomposition reactor, and the power generated by an independent CC unit powered by hydrogen. For this example, the overall efficiency would be approximately 15%, so the improvements disclosed herein raise the efficiency approximately 33%.

[0059] Although this disclosure contains many specific embodiment details, these should not be construed as limitations on the scope of the subject matter or on the scope of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments.Attorney Docket No.: 44807-0497WO1 / JHU 18370Certain features that are described in this disclosure in the context of separate embodiments can also be implemented, in combination, in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments, separately, or in any suitable sub-combination. Moreover, although previously described features may be described as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can, in some cases, be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

[0060] Particular embodiments of the subject matter have been described. Other embodiments, alterations, and permutations of the described embodiments are within the scope of the following claims as will be apparent to those skilled in the art. While operations are depicted in the drawings or claims in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed (some operations may be considered optional), to achieve desirable results.

[0061] Accordingly, the previously described example embodiments do not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure.

Claims

Attorney Docket No.: 44807-0497WO1 / JHU 18370WHAT IS CLAIMED IS:

1. A power generation system comprising: a reactor configured to decompose a hydrocarbon feedstock to yield a product stream comprising hydrogen and solid carbon; a power generator coupled to the reactor and configured to generate power from the hydrogen; and a heat exchanger configured to accept an exhaust stream from the power generator and transfer heat from the exhaust stream to preheat the hydrocarbon feedstock.

2. The power generation system of claim 1, wherein the power generator comprises a combustion chamber configured to combust the hydrogen.

3. The power generation system of claim 2, further comprising a compressor configured to compress the hydrogen upstream of the combustion chamber.

4. The power generation system of claim 2, wherein the power generator comprises a compressor, a turbine, and a shaft configured to couple the compressor and the turbine.

5. The power generation system of claim 1, further comprising an additional power generator coupled to the reactor.

6. The power generation system of claim 5, further comprising an additional heat exchanger configured to accept the product stream from the reactor and transfer heat from the product stream to the additional power generator.

7. The power generation system of claim 6, wherein the additional power generator is configured to generate power from steam.

8. The power generation system of claim 7, wherein the additional power generator comprises a steam boiler or a steam turbine.Attorney Docket No.: 44807-0497WO1 / JHU 183709. The power generation system of claim 8, wherein the heat exchanger, the additional heat exchanger, or both are configured to transfer heat to the steam boiler.

10. The power generation system of claim 1, further comprising a separator configured to separate the hydrogen from the product stream.

11. The power generation system of claim 1, wherein the reactor is configured to be at least partially powered by an external source of electricity.

12. The power generation system of claim 1, wherein the hydrocarbon feedstock comprises methane, ethane, propane, natural gas, higher alkanes, any isomer thereof.

13. The power generation system of claim 1, wherein the reactor comprises a catalyst configured to increase a rate of decomposition of the hydrocarbon feedstock.

14. The power generation system of claim 1, wherein the reactor is configured to generate a plasma medium to decompose the hydrocarbon feedstock.

15. The power generation system of claim 1, wherein the heat from the exhaust stream and the heat from the product stream are combined upstream of the reactor or in the reactor.

16. A method of generating power from a hydrocarbon feedstock, the method comprising: thermocatalytically decomposing the hydrocarbon feedstock to yield a product stream comprising hydrogen and solid carbon; providing the hydrogen as a fuel source to a power generator to generate power; and preheating the hydrocarbon feedstock with heat from an exhaust stream from the power generator.

17. The method of claim 16, further comprising compressing the hydrogen before providing the hydrogen to the power generator.Attorney Docket No.: 44807-0497WO1 / JHU 1837018. The method of claim 16, further comprising separating the hydrogen from the product stream before providing the hydrogen to the power generator.

19. The method of claim 16, wherein the power generator comprises a compressor, a turbine, and a shaft configured to couple the compressor and the turbine.

20. The method of claim 16, further comprising, after preheating the hydrocarbon feedstock with heat from the exhaust stream, providing heat from the exhaust stream to an additional power generator.

21. The method of claim 20, further comprising providing heat from the product stream to the additional power generator.

22. The method of claim 21, wherein the additional power generator comprises a steam turbine or a steam boiler.

23. The method of claim 22, further comprising heating water in the additional power generator with the heat from the exhaust stream, the heat from the product stream, or both.

24. The method of claim 21, further comprising combining the heat from the exhaust stream and the heat from the product stream upstream of the additional power generator.

25. The method of claim 20, further comprising providing heat from an additional source to the additional power generator.

26. The method of claim 16, wherein the product stream comprises at least 70 vol%, at least 80 vol%, at least 90 vol%, at least 95 vol%, or at least 99 vol% hydrogen.

27. The method of claim 16, wherein the product stream comprises less than 20 vol%, less than 10 vol%, less than 5 vol%, or less than 1 vol% carbon dioxide.Attorney Docket No.: 44807-0497WO1 / JHU 1837028. The method of claim 16, wherein the hydrocarbon feedstock comprises up to 20 vol% carbon dioxide.

29. The method of claim 16, wherein the hydrocarbon feedstock comprises up to 1 vol% air.

30. The method of claim 16, wherein the hydrocarbon feedstock comprises up to 1 vol% oxygen.

31. The method of claim 16, wherein the hydrocarbon feedstock comprises up to 1 vol% water.

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