ELECTROCHEMICAL CELL SYSTEM INCLUDING HIGH DENSITY COLUMN MODULE ARCHITECTURE

Abstract

An electrochemical column module includes a column support, columns of electrochemical cells arranged in a row and disposed on the column support, electrical contacts configured to electrically connect the columns to a power source, a first conduit housing, a second conduit housing, an inlet conduit that extends through the first conduit housing and is fluidly connected to the columns, and an outlet conduit that extends through the second conduit housing and is fluidly connected to the columns.

Claims

1. An electrochemical column module, comprising: a column support; columns of electrochemical cells arranged in a row and disposed on the column support; electrical contacts configured to electrically connect the columns to a power source; a first conduit housing; a second conduit housing; an inlet conduit that extends through the first conduit housing and is fluidly connected to the columns; and an outlet conduit that extends through the second conduit housing and is fluidly connected to the columns.

2. The column module of claim 1, wherein the electrical contacts comprise: first contacts that extend through the column support and are configured to electrically connect the columns to electrical terminals; and second contacts that electrically connect adjacent pairs of the columns.

3. The column module of claim 2, wherein: ends of the first contacts are exposed from the column support and configured to mate with electrical terminals; and each pair of adjacent columns is electrically connected to two of the first contacts.

4. The column module of claim 1, further comprising a thermally insulating base disposed under the column support and configured to thermally insulate the columns.

5. The column module of claim 4, further comprising a rail cart disposed under the base.

6. The column module of claim 1, wherein the inlet and outlet conduits comprises flanges configured to fluidly connect the inlet and outlet conduits to other conduits.

7. The column module of claim 1, wherein the first and second conduit housings are disposed below the columns on opposing sides of the column support.

8. The column module of claim 1, wherein: the first conduit housing is disposed below the columns; and the second conduit housing is disposed above the columns.

9. The column module of claim 1, wherein: the columns are arranged in the same direction or in alternating directions; and the electrochemical cells comprise solid oxide electrolyzer cells.

10. An electrolyzer system comprising: a furnace comprising at least one door disposed on a front side of the furnace, and electrical terminals disposed on the furnace; the column module of claim 1 removably disposed in the furnace; additional column modules removable disposed in the furnace; steam header configured to provide steam to column modules disposed in the furnace; and a product header configured to receive a hydrogen-containing product from the column modules.

11. An electrolyzer system comprising: a furnace comprising at least one door disposed on a front side of the furnace, and electrical terminals disposed on the furnace; column modules removably disposed in the furnace; steam header configured to provide steam to column modules disposed in the furnace; and a product header configured to receive a hydrogen-containing product from the column modules, wherein each of column modules comprises: columns of electrochemical cells disposed in a row; an inlet conduit that fluidly connects the steam header to the columns; an outlet conduit that fluidly connects the product heater to the columns; and electrical contacts configured to electrically connect the columns to the electrical terminals.

12. The system of claim 11, further comprising: a steam heater configured to heat the steam provided to the steam header; a steam recuperator heat exchanger configured to heat the steam by extracting heat from the hydrogen-containing product; and a recycle blower configured to recycle at least a portion of the hydrogen-containing product from the product header to the steam header.

13. The system of claim 12, further comprising: an air blower configured to provide air to the furnace; an air recuperator heat exchanger configured to heat the air provided to the furnace by extracting heat from air exhaust output from the furnace; and valves configured to control fluid flow between the steam and product headers and the column modules.

14. The system of claim 11, wherein the furnace comprises: a housing; and a base frame disposed under the housing, wherein: the inlet conduits extend under the housing to fluidly connect the cell modules to the steam header, and the outlet conduits extend under the housing to fluidly connect the cell modules to the product header.

15. The system of claim 14, wherein: the furnace comprises dividers configured to divide the housing into module chambers that are each configured to receive one of the column modules; the furnace further comprises rails disposed on the base frame; and the column modules further comprise rail carts that support the columns and are configured to roll along the rails.

16. The system of claim 11, wherein: the column modules each comprise a column support disposed under the cell columns and a base disposed under the column support; and the bases form at least a portion of a lower level of the furnace.

17. The system of claim 16, wherein the electrical contacts comprise: first electrical contacts configured to electrically connect the columns to the terminals which are disposed on the backside of the furnace; and second electrical contacts configured to electrically connect adjacent columns.

18. The system of claim 11, wherein the columns of electrochemical cells are internally manifolded for steam.

19. The system of claim 18, wherein: one or more air blowers are configured to provide air to conduits that are fluidly connected to the columns of electrochemical cells; and the columns of electrochemical cells are internally manifolded for air.

20. A method of operating an electrolyzer system, comprising: providing steam and electric power to a plurality of electrolyzer column modules located in a furnace to generate a hydrogen-containing product and oxygen by electrolysis of the steam; and shutting down a first one of the electrolyzer column modules and removing the first one of the electrolyzer column modules from the furnace while a second one of the electrolyzer column modules continues to generate the hydrogen-containing product and the oxygen by the electrolysis of the steam.

21. The method of claim 20, further comprising, prior to the step of removing the first one of the electrolyzer column modules from the furnace, performing the steps of: closing a first valve between a steam header and the first one of the electrolyzer column modules; closing a second valve between a product header and the first one of the electrolyzer column modules; decoupling a first flange of a steam header inlet conduit from a second flange of a module inlet conduit which fluidly connect the steam header to the first one of the electrolyzer column modules, while the steam continues to be provided from the steam header to the second one of the electrolyzer column modules; and decoupling a third flange of a product header outlet conduit from a fourth flange of a module outlet conduit which fluidly connect the product header to the first one of the electrolyzer column modules, while the second one of the electrolyzer column modules continues to provide the hydrogen-containing product to the product header.

22. The method of claim 20, wherein the step of removing the first one of the electrolyzer column modules from the furnace comprises opening a door of the furnace, and pulling out a first skid cart supporting the first one of the electrolyzer column modules from the furnace using rails, while the second one of the electrolyzer column modules remains on a second skid cart in the furnace.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate example embodiments of the invention, and together with the general description given above and the detailed description given below, serve to explain the features of the invention.

[0007] FIG. 1A is a perspective view of a counter-flow or co-flow electrochemical cell stack, according to various embodiments of the present disclosure, FIG. 1B is a sectional view of a portion of the stack of FIG. 1A, and FIG. 1C is a perspective view of an externally manifolded electrochemical cell column including stacks of FIG. 1A.

[0008] FIG. 2A is an exploded view of a cross flow electrochemical cell stack, according to various embodiments of the present disclosure, FIG. 2B is a top view of a fuel side of an interconnect of FIG. 2A, and FIG. 2C is a perspective view of an internally manifolded electrochemical cell column including electrochemical cell stacks of FIG. 2A.

[0009] FIG. 3 is a schematic of an electrochemical cell system, according to various embodiments of the present disclosure.

[0010] FIG. 4A is a sectional view showing components of the hotbox or furnace of the system of FIG. 3, and FIG. 4B shows an exploded portion of FIG. 4A.

[0011] FIG. 5A is a perspective view of the front side of a furnace 500a that may be utilized in the system 300 of FIG. 3 and with the modules 400a of FIG. 4A, FIG. 5B shows the loading of a module 400a into the front side of the furnace 500a, FIGS. 5C and 5D are perspective top views showing alternative configurations of the furnace 500a with a roof of the furnace 500a removed, FIG. 5E is a perspective view showing the back side of the furnace 500a, and FIG. 5F is an enlarged portion P of FIG. 5E.

[0012] FIG. 6A is a perspective view of an alternative electrolyzer module 400b, according to various embodiments of the present disclosure, and FIG. 6B is a schematic view illustrating the orientations of columns 200A included in the module 400b.

[0013] FIGS. 7A and 7B are perspective views showing the front side of a furnace 500b including the modules 400b, according to various embodiments of the present disclosure,

[0014] FIG. 7C is a perspective view showing the back side of the furnace 500b, and FIG. 7D is a perspective view wherein a roof of the furnace 500b and upper portions of the modules 400d are omitted.

[0015] FIG. 8A is a perspective view of the fuel side of a partial counterflow interconnect, according to various embodiments of the present disclosure, and FIG. 8B is a perspective view of the air side of the interconnect of FIG. 8A.

[0016] FIG. 9A is a perspective view of an alternative electrolyzer module 600b, according to various embodiments of the present disclosure, and FIG. 9B is a perspective view illustrating the arrangement of modules 600b of FIG. 9A included in another furnace embodiment of the present disclosure.

DETAILED DESCRIPTION

[0017] As set forth herein, various aspects of the disclosure are described with reference to the exemplary embodiments and/or the accompanying drawings in which exemplary embodiments of the invention are illustrated. This invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments shown in the drawings or described herein. It will be appreciated that the various disclosed embodiments may involve particular features, elements or steps that are described in connection with that particular embodiment. It will also be appreciated that a particular feature, element or step, although described in relation to one particular embodiment, may be interchanged or combined with alternate embodiments in various non-illustrated combinations or permutations.

[0018] The various embodiments will be described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. References made to particular examples and implementations are for illustrative purposes and are not intended to limit the scope of the invention or the claims.

[0019] Ranges can be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, examples include from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent about or substantially it will be understood that the particular value forms another aspect. In some embodiments, a value of about X may include values of +/1% X. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0020] Electrochemical cell systems include fuel cell and electrolyzer cell systems. In a high temperature fuel cell system, such as a solid oxide fuel cell (SOFC) system, an oxidizing flow is directed to the cathode side of the fuel cell while a fuel flow is directed to the anode side of the fuel cell. The oxidizing flow is typically air, while the fuel flow can be a hydrogen (H.sub.2) or a hydrocarbon fuel, such as methane, natural gas, pentane, ethanol, or methanol. The fuel cell, operating at a typical temperature between 750 C. and 950 C., enables the transport of negatively charged oxygen ions from the cathode flow stream to the anode flow stream, where the oxygen ions combine with either free hydrogen or hydrogen in a hydrocarbon molecule to form water vapor and/or with carbon monoxide to form carbon dioxide. The excess electrons from the negatively charged ions are routed back to the cathode side of the fuel cell through an electrical circuit completed between anode and cathode, resulting in an electrical current flow through the circuit. In an electrolyzer system, such as a solid oxide electrolyzer system, the fuel may comprise steam which is separated into hydrogen and oxygen by applying a voltage across the electrolyzer cells.

[0021] FIG. 1A is a perspective view of a counter-flow or co-flow electrochemical stack 50, FIG. 1B is a sectional view of a portion of the stack 50, according to various embodiments of the present disclosure, and FIG. 1C is a perspective view of an externally manifolded electrochemical cell column 200A including stacks 50 of FIG. 1A. In the embodiments below, the stack 50 is described as being operated as a solid oxide electrolyzer cell (SOEC) stack 50. However, it should be noted that the stack 50 may also be operated as a solid oxide fuel cell (SOFC) stack.

[0022] Referring to FIGS. 1A and 1B, the stack 50 includes electrochemical cells 30, such as fuel cells (e.g., SOFCs) or electrolyzer cells (e.g., SOECs), separated by interconnects 10. In the embodiments below, the electrochemical cells 30 are described as being electrolyzer cells. Referring to FIG. 1B, each electrochemical cell 30 comprises an air electrode (e.g., SOFC cathode or SOEC anode) 33, a solid oxide electrolyte 35, and a fuel electrode (e.g., SOFC anode or SOEC cathode) 37. In some embodiments, the electrochemical cells 30 may include a conductive layer 39, such as a nickel mesh, disposed between the fuel electrode 37 and an adjacent interconnect 10.

[0023] Various materials may be used for the air electrode 33, electrolyte 35, and fuel electrode 37. For example, the fuel electrode 37 may comprise a cermet comprising a nickel containing phase and a ceramic phase. The nickel containing phase may consist entirely of nickel in a reduced state. This phase may form nickel oxide when it is in an oxidized state. Thus, the fuel electrode 37 is preferably annealed in a reducing atmosphere prior to operation to reduce the nickel oxide to nickel. The nickel containing phase may include other metals in addition to nickel and/or nickel alloys. The ceramic phase may comprise a stabilized zirconia, such as yttria and/or scandia stabilized zirconia and/or a doped ceria, such as gadolinia, yttria and/or samaria doped ceria.

[0024] The electrolyte 35 may comprise a stabilized zirconia, such as scandia stabilized zirconia (SSZ) or yttria stabilized zirconia (YSZ). Alternatively, the electrolyte 35 may comprise another ionically conductive material, such as a doped ceria.

[0025] The air electrode 33 may comprise an electrically conductive material, such as an electrically conductive perovskite material, such as lanthanum strontium manganite (LSM). Other conductive perovskites, such as LSCo, etc., or metals, such as Pt, may also be used. The air electrode 33 may also contain a ceramic phase similar to the fuel electrode 37. The electrodes and the electrolyte may each comprise one or more sublayers of one or more of the above described materials.

[0026] Electrochemical cell stacks 50 are frequently built from a multiplicity of electrochemical cells 30 in the form of planar elements, tubes, or other geometries. Although the stack 50 in FIG. 1A is vertically oriented, the electrochemical cell stacks may be oriented horizontally or in any other direction. Fuel and air may be provided to the electrochemically active surface, which can be large. For example, fuel may be provided through fuel holes (e.g., fuel riser openings) 20 that extend through the interconnects 10 and electrochemical cells 30 to form fuel conduits that extend through the stack 50.

[0027] Each interconnect 10 electrically connects adjacent electrochemical cells 30 in the stack 50. In particular, an interconnect 10 may electrically connect the fuel electrode 37 of one electrochemical cell 30 to the air electrode 33 of an adjacent electrochemical cell 30. FIG. 1B shows that the lower electrochemical cell 30 is located between two interconnects 10. An optional Ni mesh 39 may be used to electrically connect the interconnect 10 to the fuel electrode 37 of an adjacent electrochemical cell 30.

[0028] Each interconnect 10 includes fuel ribs 12A that at least partially define fuel channels 8A, and air ribs 12B that at least partially define oxidant (e.g., air) channels 8B. The interconnect 10 may operate as a gas-fuel separator that separates a fuel, such as a hydrocarbon fuel, a hydrogen based fuel or steam, flowing to the fuel electrode 37 of one cell in the stack from oxidant, such as air, flowing to the air electrode 33 of an adjacent cell in the stack. The air and fuel may flow in opposite directions, such that the stack 50 has a counter-flow configuration, or the air and fuel may flow in the same direction, such that the stack 50 has a co-flow configuration.

[0029] Each interconnect 10 may be made of or may contain electrically conductive material, such as a metal alloy (e.g., chromium-iron alloy) which has a similar coefficient of thermal expansion to that of the solid oxide electrolyte in the cells (e.g., a difference of 0-10%). For example, the interconnects 10 may each include a metallic substrate comprising a high-temperature stable metal alloy, such as a chromium-iron alloy, such as 4-6 weight percent iron, optionally 1 or less weight percent yttrium and balance chromium alloy and may electrically connect the fuel-side of one cell 30 to the air side of an adjacent cell 30. An electrically conductive contact layer, such as a nickel layer or mesh (e.g., layer 39), may be provided between fuel electrodes 37 and a fuel side of each interconnect 10.

[0030] An electrically conductive protective layer 11 may be provided on at least an air side of each interconnect 10. The protective layer 11 may be configured to decrease the growth rate of a chromium oxide surface layer on the interconnect 10 and to suppress evaporation of chromium vapor species which can poison air electrodes 33. The protective layer 11 may be a perovskite layer such as lanthanum strontium manganite (LSM) and may be formed using a spray coating or dip coating process. Alternatively, other metal oxide coatings, such as a spinel, such as an (Mn, Co).sub.3O.sub.4 spinel (MCO), can be used instead of or in addition to LSM. Any spinel having the composition Mn.sub.2xCo.sub.1+xO.sub.4 (0x1) or written as z(Mn.sub.3O.sub.4)+(1z) (Co.sub.3O.sub.4), where (z) or written as (Mn, Co).sub.3O.sub.4 may be used. In other embodiments, a mixed layer of LSM and MCO, or a stack of LSM and MCO layers may be used as the protective layer 11.

[0031] Referring to FIG. 1C, the cell column 200A may include one or more stacks 50 and may be externally manifolded for air and internally manifolded for fuel. In particular, the cell column 200A may include a fuel conduit 232, an exhaust conduit 234 or a product (i.e., hydrogen-containing product for electrolyzer configurations) conduit 234, and fuel feed/return splitter plates 236. The cell column 200A may also include side baffles 238, a compression assembly 240, a top plate 242, a bottom plate 244, a top terminal plate 246, and a bottom terminal plate 248. The side baffles 238, components of the compression assembly 240, the top plate 242, the bottom plate 244, and may be formed of a ceramic material. The side baffles 238 may be connected to the top plate 242 and the bottom plate 248 by ceramic connectors 239. The compression assembly 240 may be configured to generate a biasing force between the top plate and the stacks 50, so as to compress the stacks 50. For example, the compression assembly 240 may include a biasing element and other support elements and/or plates. The terminal plates 246, 248 may comprise a metal alloy and may be electrically connected to the stacks 50. The cell columns 200B may be located on a support 101 (see FIG. 2C), such as a hot box base.

[0032] The fuel conduit 232 is fluidly connected to the splitter plates 236 and is configured to provide the fuel inlet stream to each splitter plate 236. The product conduit 234 is fluidly connected to the splitter plates 236 and is configured to receive a product stream (e.g., a hydrogen containing product stream in electrolyzer configurations) from each splitter plate 236. The splitter plates 236 are disposed between the stacks 50 and are configured to provide the fuel inlet stream (e.g., steam for electrolyzer configurations) to the stacks 50 and to receive the product stream from the stacks 50. For example, the splitter plates 236 may be fluidly connected to the fuel holes 20 formed in the stacks 50.

[0033] FIG. 2A is an exploded view of a cross flow electrochemical cell stack 52, according to various embodiments of the present disclosure, FIG. 2B is a top view of a fuel side of an interconnect 40 of FIG. 2A, and FIG. 2C is a perspective view of an electrochemical cell column 200B, which lacks splitter plates and includes cell stacks 52 of FIG. 2A. The components of FIGS. 2A-2C may be similar to the components of FIGS. 1A-1C. As such, only the differences therebetween will be discussed in detail.

[0034] Referring to FIGS. 2A-2C, the electrochemical cell stack 52 includes electrochemical cells 30 separated by cross flow interconnects 40 that include fuel holes 20, air channels separated by air ribs in an air flow field 48B, and fuel channels separated by fuel ribs in the fuel flow field 48A on the opposite side of the interconnect 40 from the air flow field 48B. The air channels and fuel channels may extend in perpendicular directions. As such, an air flow direction A and a fuel flow direction F across each interconnect 40 and through the cell column 200B, may be perpendicular to one another. The fuel holes 20 may be larger and/or more numerous than the fuel holes of a counter flow or co-flow interconnect 10. The fuel holes 20 may form fuel manifolds that do not pass through the electrochemical cells 30.

[0035] As shown in FIG. 2C, the cell column 200B may include multiple cell stacks 52, side baffles 238, a top plate 242, a bottom plate 244, and a compression assembly 240. Due to the enlarged fuel holes 20, the cell column 200B may omit splitter plates between the stacks 52. The side baffles 238 may connect the top plate 242 and the bottom plate 244, such that the compression assembly 240 may apply pressure to the stacks 52/column 200B. The side baffles 238 may be curved baffle plates, such that each baffle plate covers at least portions of three sides of the electrochemical cell stacks 52. Uncovered portions for the front and back sides of the stacks 52 allow the air to flow through the cell column 200B. The bottom plate 244 may be disposed below the stacks 52, may include multiple ceramic plates and may be configured to operate as a fuel plenum to provide a hydrogen-containing fuel feed (e.g., natural gas for SOFC configurations or water/steam for SOEC configurations) to the stacks 52, and may receive a fuel exhaust or hydrogen product from the stacks 52. The bottom plate 244 may be connected to fuel inlet and exhaust/product outlet conduits disposed below the cell column 200B.

[0036] One or more cell columns 200A or 200B may be thermally integrated with other components of an electrochemical system, such as an SOEC system as discussed in detail below.

[0037] Due to the high power output of SOFCs, prior power generating SOFC systems having a relatively low cell packing density can generate significant amounts of power without occupying an excessively large site footprint. However, in order to generate hydrogen at industrial scales, it is desirable for SOEC systems to have a higher cell packing density. However, current SOEC systems having high cell packing densities are generally expensive to construct and difficult to service. Accordingly, various embodiments provide electrochemical systems that are easy to install and service and have high electrochemical cell column packing densities (such as high electrolyzer cell column densities).

[0038] FIG. 3 is a schematic view of an electrochemical system, such as an electrolyzer system 300, according to various embodiments of the present disclosure. Referring to FIG. 3, the system 300 may include column modules 400 and a furnace 500 (e.g., heated enclosure). The furnace 500 may be configured to maintain the modules 400 at a desired operating temperature. In one embodiment, the furnace 500 excludes heating elements which heat the furnace 500 from the outside. In this embodiment, the furnace comprises a hotbox which is heated using heaters located inside the hotbox. In an alternative embodiment, the furnace 500 may include at least one external heating element, such as resistive or inductive heating element, which heats the walls of the furnace 500. In these embodiments, the furnace 500 comprises an electric furnace, such as a resistive or inductive furnace. Each module 400 includes a linear array of electrochemical cell columns, such as electrolyzer cell (e.g., SOEC) columns 200 or stacks, such as columns 200A and/or 200B described with respect to FIGS. 1C and 2C, respectively.

[0039] In one embodiment, the electrolyzer system 300 may also include a steam recuperator heat exchanger 108, a steam heater 110, an air recuperator heat exchanger 112, an air blower 118, a recycle blower 120, a steam header 132, and a product header 134, which may be disposed outside of the furnace 500. In an alternative embodiment, the steam recuperator 108, steam heater 110, and/or air recuperator 112 may be disposed inside of the furnace 500. Alternatively, the heat exchangers 108 and/or 112 may be located inside the furnace. The system 300 may be fluidly connected to a hydrogen source 102 and a steam source 104. The hydrogen source 102 may comprise a hydrogen storage vessel, such as a hydrogen gas tank. The steam source 104 may comprise a steam generator or a building steam source (e.g., boiler, etc.). In some embodiments, the steam may be generated from heat exhaust provided by other industrial equipment/operations occurring at the site of the electrolyzer system 300 installation. In some embodiments, the system 300 may optionally include a backup air blower 118b and/or a backup recycle blower 120b in case the primary blowers 118 and/or 120 fail or do not provide sufficient fluid throughput.

[0040] During operation, the air blower 118 may be operated to provide ambient air to the furnace 500 via an air inlet conduit 114. Oxygen rich air exhaust may be exhausted from the furnace 500 via an air exhaust conduit 116. The conduits 114, 116 may be fluidly connected to the air recuperator 112, which may be configured to heat the incoming ambient air using the air exhaust. Air flow through the furnace 500 may be configured to sweep oxygen gas generated in the columns 200 during electrolysis and prevent excessive oxygen levels in the furnace 500. As such, the air exhaust in conduit 116 output from the furnace 500 may be oxygen rich.

[0041] In some embodiments, ambient air may be provided to the furnace 500 in multiple locations and/or air may be exhausted from the furnace 500 in multiple locations, in order to normalize air flow through the furnace 500 and past the columns 200. In some embodiments, the ambient air may be filtered to remove contaminants, prior to being provided to the air recuperator 112 and/or the air blower 118.

[0042] The columns 200 may be provided with steam and electric current or voltage from an external power source. In particular, the steam may be provided to the fuel electrodes 37 of the electrolyzer cells 30 of the columns 200, in order to electrochemically split steam molecules and generate hydrogen (e.g., H.sub.2) and oxygen (e.g., O.sub.2). Air may optionally be provided to the air electrodes 33, in order to sweep the oxygen from the air electrodes 33. As such, the column 200 may output a hydrogen containing product stream (e.g., hydrogen and residual steam) and an oxygen-rich air exhaust stream.

[0043] Steam output from the steam source 104 may be provided to the steam recuperator 108. In some embodiments, the steam may include small amounts of dissolved air and/or oxygen.

[0044] In some embodiments, external hydrogen may be provided from the external hydrogen source 102 to the columns 200 during system startup and shutdown operations. The hydrogen may be either shut off or provided to the columns 200 during steady-state operations. For example, during startup, the hydrogen may be provided from the hydrogen source 102. During steady-state operation, the hydrogen may be provided from the hydrogen source 102 and/or by diverting and then recycling a portion of the hydrogen-containing product stream generated by the columns 200 to the columns 200. In particular, the recycle blower 120 may selectively recycle a portion of the generated hydrogen-containing product stream diverted by a splitter 122 into the incoming steam during steady-state operation.

[0045] The steam recuperator 108 may be a heat exchanger configured to recover heat from the hydrogen-containing product stream output from the columns 200 and to heat the steam provided to the columns 200. As such, the steam recuperator 108 increases the efficiency of the system 300.

[0046] The steam output from the steam recuperator 108 may be provided to the steam heater 110, which is located downstream from the steam recuperator 108 with respect to a steam flow direction. The steam heater 110 may include a heating element, such as a resistive or inductive heating element. The steam heater 110 may be configured to heat the steam to a temperature at or above the operating temperature of the columns 200. Accordingly, the columns 200 may be provided with steam or a steam-hydrogen mixture at a temperature that allows for efficient hydrogen generation.

[0047] In an alternative embodiment, the steam recuperator 108 may be located downstream from the steam heater 110, such that steam exiting the steam heater 110 enters the steam recuperator 108 instead of vice-versa. In some embodiments, the steam heater 110 may include multiple steam heater zones with independent power levels (divided vertically or circumferentially or both), in order to enhance thermal uniformity.

[0048] The heated steam output from the steam heater 110 may be provided to the modules 400 by the steam header 132. The hydrogen-containing product produced by the modules 400 may be provided to the steam recuperator 108 by the product header 134. The cooled hydrogen-containing product output from the steam recuperator 108 may be further processed and stored or provided to a customer. In particular, the hydrogen-containing product may be dehumidified and/or pressurized, for example, using an electrochemical hydrogen pump (not shown).

[0049] The system 300 may include various valves to control fluid flow. For example, the system 300 may include valves 140, 142, 144 and 146 such as ball valves or the like, to control fluid flow between the modules 400 and the steam header 132 and the product header 134. The system 300 may include mating flanges 136a, 136b to fluidly connect the modules 400 to the steam header 132 and the product header 134. The flanges 136a may comprise terminals of the header inlet and outlet conduits 312, 314 (see FIG. 5F) which fluidly connect the respective headers 132, 134 to the modules 400. The flanges 136b may comprise terminals of the module inlet and outlet conduits 412, 414 (see FIG. 4A). A combination of a mating pair of the header inlet conduit 312 and the module inlet conduit 412 provide the steam from the steam header 132 to the respective module 400 through one mating flange pair 136a, 136b. A combination of a mating pair of the header outlet conduit 314 and the module outlet conduit 414 provide the product stream from the respective module 400 to the product header 114 through another mating flange pair 136a, 136b.

[0050] According to various embodiments, the system 300 may include a controller 125, such as a central processing unit, that is configured to control the operation of the system 300. The controller 125 may be wired or wirelessly connected to various elements of the system 300 to control the same. For example, the controller 125 may be configured to control the speed of the air blower 118 and the recycle blower 120, the temperatures of the steam heater 110 and the furnace 500, and/or an amount of power supplied to the modules 400. In some embodiments, the controller 125 may be configured to control the operation of the valves 140, 142, 144 and/or 146 if the valves are electrically actuated. In other embodiments, the valves may be manually operated. The controller 125 may be configured to monitor the status of stacks or columns in column modules 400 and be configured to isolate fuel and air flow to individual column modules 400 to allow such column modules to be serviced independently of other column modules in the system 300.

[0051] FIG. 4A is a perspective view of a column module 400a that may be included in the system 300 of FIG. 3, according to various embodiments of the present disclosure, and FIG. 4B is an exploded perspective view of a portion of a column module 400a of FIG. 4A. Referring to FIGS. 3, 4A and 4B, the module 400a may include a skid cart 402, a first conduit housing 410a, a second conduit housing 410b, a column support 420, and cell columns 200A that are shown in FIG. 1C.

[0052] The skid cart 402 may include a cart frame 404, 408 and wheels 406. The wheels 406 may be metal or ceramic wheels configured to roll on a corresponding metal track. For example, the skid cart 402 may be a rail cart. The cart frame 404, 408 may comprise any suitable skid having an upper surface (i.e., an insulating deck, such as a ceramic base 408) which rests upon pedestals (e.g., metal rails 404) that are connected to the base 408. The base 408 may be configured to support the weight of the columns 200A, and thermally insulate the columns 200A when they are disposed in the furnace 500. For example, the base 408 may be formed of a thermally insulating ceramic material and may form part of the floor of the housing 510 of the furnace 500. In some embodiments, the base 408 may be formed of stacked refractory bricks.

[0053] The conduit housings 410a, 410b and the column support 420 may be disposed on the base 408, and the columns 200A may be linearly arranged (e.g., disposed in a row) on the column support 420. In particular, the columns 200A may be oriented in the same direction, such that the fuel conduits 232 and the product conduits 234 are disposed on the same side of the columns 200A.

[0054] The module 400a may include the module inlet conduit 412 and the module outlet conduit 414. The inlet and outlet conduits 412, 414 may extend through the base 408 and respectively into the first conduit housing 410a and the second conduit housing 410b. As shown in FIG. 4B, the fuel conduits 232 and the product conduits 234 may extend through apertures 411 formed in the conduit housings 410a, 410b and may be fluidly connected to the inlet and outlet conduits 412, 414. In particular, distal ends of the inlet and outlet conduits 412, 414 may include flanges 136b that are configured to respectively connect the inlet and outlet conduits 412, 414 to corresponding flanges 136a of the header inlet and outlet conduits 312, 314 of the respective fuel and product headers 132, 134. As such, the inlet conduit 412 may be configured to provide steam from the fuel header 132 to the columns 200A and the outlet conduit 414 may be configured to receive the hydrogen-containing product from the columns 200A and to provide it to the product header 134.

[0055] The module 400a may include electrical contacts configured to electrically connect the columns 200A to a power source and/or to one another. For example, the electrical contacts may include first contacts 430 and second contacts 432. The first contacts 430 may be embedded in the column support 420. Each first contact 430 includes a proximal end that contacts the bottom terminal plate 248 (see FIG. 1C) of a corresponding column 200A, and a distal end that is connected to a voltage source (not shown). The second contacts 432 may comprise electrically conductive jumpers which electrically connect the top terminal plates 246 of adjacent columns 200A. Accordingly, each pair of columns 200A is electrically connected to the voltage source by two of the first contacts 430 (e.g., a positive and a negative terminal contacts), and are electrically connected to each other by two of the second contacts 432.

[0056] In some embodiments, the column support 420 may include multiple stacked sublayers, such as first, second, and third sub-layers 420a, 420b, 420c. For example, the sublayers 420a, 420b, 420c may be precast ceramic material layers configured to accommodate routing of the first contacts 430 therethrough, as shown in FIG. 4B.

[0057] FIG. 5A is a perspective view of the front side of a furnace 500a that may be utilized in the system 300 of FIG. 3 and with the modules 400a of FIG. 4A, FIG. 5B shows the loading of a module 400a into the front side of the furnace 500a, FIGS. 5C and 5D are perspective top views showing alternative configurations of the furnace 500a with a roof of the furnace 500a removed, FIG. 5E is a perspective view showing the back side of the furnace 500a, and FIG. 5F is an enlarged portion P of FIG. 5E.

[0058] Referring to FIG. 3, and 5A-5C, the furnace 500a may include a housing 510 comprising doors 502, air openings 503, optional module chambers 504, and optional dividers 506. Referring to FIG. 5D, in an alternative embodiment, the separate module chambers 504 and the dividers 506 may be omitted, and all modules 400a are located in the same single furnace chamber 505. The housing 510 may be disposed on a base frame 512. The base frame 512 may include loading rails 514. The doors 502 may comprise one side of the module chambers 504 when closed and may be thermally insulated. In some embodiments, the doors 502 may be hinged to open laterally, as shown in FIG. 5B. However, in other embodiments, the doors 502 may be configured to open vertically, as shown in FIGS. 7A and 7B. The air openings 503 may be located in a back of the housing 510 and may be fluidly connected to the air blower 118.

[0059] The dividers 506 may divide the internal space of the furnace 500a to form the module chambers 504. In some embodiments, the furnace 500a may be configured to individually control the heating of each chamber 504, and the dividers 506 may thermally insulate the chambers 504 from one another. As such, the furnace 500a may be configured to control the temperature of each module 400a. Temperature control of each chamber 504 may be monitored and adjusted in response to control signals originating from the system controller 125.

[0060] For example, the temperature of a chamber 504 may be reduced, in order to reduce the temperature of a module 400a disposed therein, prior to removing the module 400a. In addition, when a door 502 is opened to access one of the module chambers 504, the dividers 506 may limit heat loss in the other chambers 504. As such, one or more of the module chambers 504 may be accessed without significant heat loss from the other module chambers 504.

[0061] However, in an alternative embodiment shown in FIG. 5D, the dividers 506 may be omitted and the furnace 500 may include a single chamber 505 configured to receive multiple modules 400a. The arrows in FIG. 5D illustrate the air circulation through the air openings 503, along the sides of the modules 400a and passing laterally through the modules 400a between adjacent columns 200A in each module 400a.

[0062] The loading rails 514 may be disposed on the base frame 512 below each of the module chambers 504 (or the furnace chamber 505 in the embodiment of FIG. 5D). Transfer rails 524 may extend perpendicular to the loading rails 514. In order to load the module 400a into the furnace 500a, the module 400a may be disposed on a transfer cart 520 configured to move along on the transfer rails 524. The transfer cart 520 may include cart loading rails 522 that correspond in gauge to the loading rails 514. A module 400a may be positioned in front of a corresponding chamber 504 (or portion of the furnace chamber 505) by moving the transfer cart 520 along the transfer rails 524 until the cart loading rails 522 are aligned with the loading rails 514.

[0063] The module 400a may be loaded into the chamber 504 or 505 by moving the cart 402 from the transfer cart 520 along the cart loading rails 522 and onto the loading rails 514. The base 408 may mate with the furnace 500a and form a portion of the bottom surface of a corresponding module chamber 504 or furnace chamber 505.

[0064] Referring to FIGS. 3, 4A, 5E and 5F, ends of the first contacts 430 may be exposed from the column support 420 and configured to mate with electrical terminals 518 disposed on the back side of the furnace 500a. The terminals 518 may be electrically connected to a voltage and/or current source (not shown). The inlet and outlet conduits 412, 414 may be exposed from the furnace 500a. The flanges 136a, 136b may be connected to fluidly connect the inlet and outlet conduits 412, 414 to the respective header inlet and outlet conduits 312, 314 of the respective steam and product headers 132, 134. The corresponding valves 140 may be opened to complete the connection process.

[0065] The above steps may be reversed in order to remove a module 400a. For example, the corresponding valves 140 may be closed, the corresponding flanges 136a, 136b may be disconnected, the corresponding door 502 may be opened, and then the module 400a may then be pulled out of the furnace 500a on the cart 402, thereby disconnecting the first contacts 430 and the corresponding terminal 518. In some embodiments, the furnace 500a may be controlled to reduce the temperature of the module 400a, before the module 400a is removed, in order to increase safety. In some embodiments, one or more modules 400a may be shutdown and removed from the furnace 500a while the remaining modules 400a in the same furnace 500a continue to operate (e.g., to generate the hydrogen-containing product stream from electrolyzing steam).

[0066] FIG. 6A is a perspective view of an alternative electrolyzer module 400b, according to various embodiments of the present disclosure, and FIG. 6B is a schematic view illustrating the orientations of columns 200A included in the module 400b. The column module 400b may be similar to the column module 400a, as such, only the differences therebetween will be discussed in detail.

[0067] Referring to FIGS. 6A and 6B, the module 400b may include columns 200A disposed between a first conduit housing 410a and a second conduit housing 410b. The conduit housings 410a, 410b are vertically separated from each other (rather than laterally separated as in module 400a), and the columns 200A are located between the conduit housings 410a, 410b along the vertical direction. The columns 200A may arranged in a row such that adjacent columns 200A are rotated by 180 relative to each other. In other words, the fuel (e.g., steam) and product conduits 232, 234 of adjacent columns 200A may be disposed on opposite sides of the module 400b (i.e., on opposite sides of the row of columns 200A). This configuration allows for the columns 200A to be disposed in very close proximity and/or even in contact with adjacent columns 200A.

[0068] An inlet conduit 412 may be disposed in the first conduit housing 410a and an outlet conduit 414 may be disposed in the second conduit housing 410b. However, in other embodiments, the outlet conduit 414 may be disposed in the first conduit housing 410a and the inlet conduit 412 may be disposed in the second conduit housing 410b. The fuel (e.g., steam) conduit 232 may be connected to the inlet conduit 412, and the product conduits 234 may be connected to the outlet conduit 414. Accordingly, the fuel may flow upwards though the fuel conduits 232 from the inlet conduit 412, and the product may flow upwards through the product conduits 234 to the outlet conduit 414 as illustrated in FIG. 6A. The present inventors discovered that this configuration may provide improved fluid flow to the columns 200A, by providing a more even fluid flow rate through all portions of the columns 200A.

[0069] Although not shown, the module 400b may also include the insulating base 408, the column support 420, the first contacts 430, and/or the second contacts 432. Furthermore, the module 400b may also optionally be disposed on the cart 402, as shown in FIG. 4A.

[0070] FIGS. 7A and 7B are perspective views showing the front side of a furnace 500b including the modules 400b, according to various embodiments of the present disclosure, FIG. 7C is a perspective view showing the back side of the furnace 500b, and FIG. 7D is a perspective view in which a roof of the furnace 500b and upper portions of the modules 400d are omitted. The furnace 500b may be similar to the furnace 500a. As such, only the differences therebetween will be described in detail.

[0071] Referring to FIGS. 6A and 7A-7C, one or more of the doors 502 may be opened to install and/or remove modules 400b from the furnace 500b. For example, as shown in FIG. 7A, multiple doors 502 may be opened, or as shown in FIG. 7B, a single door may be opened in order to gain access to the inside of the furnace 500b. As shown in FIGS. 7A and 7B, the doors 502 may be opened and closed by swinging in a vertical direction.

[0072] The modules 400b may slide along the bottom of the furnace when the modules 400b are inserted and removed from the furnace 500b. In some embodiments, a forklift or similar device may be used for inserting and removing the modules 400b, which may be configured to slide along the furnace 500b base. However, in other embodiments, a cart and/or rail system may be used to move the modules, as described above.

[0073] In some embodiments, one or more modules 400b may be shutdown and removed from the furnace 500b while the remaining modules 400b in the same furnace 500b continue to operate (e.g., to generate the hydrogen-containing product stream from electrolyzing steam).

[0074] When the modules 400b are positioned in the furnace 500b, the inlet and outlet conduits 412, 414 may extend out of the back of the housing 510. For example, the inlet conduits 412 may be disposed near the bottom of the furnace 500b and the outlet conduits 414 may be disposed near the top of the furnace 500b. Flanges 136a, 136b may be connected to connect the inlet and outlet conduits 412, 414 to the respective header inlet and outlet conduits 312, 314 of the respective steam header 132 and product header 134.

[0075] As shown in FIG. 7D, air may be provided to the furnace 500b to sweep oxygen generated during operation of the columns 200A from the columns 200A and the furnace 500b. For example, ambient air may be heated by oxygen enriched air exhausted from the furnace 500b, and the heated air may be used to sweep oxygen from the columns 200A and the furnace 500b, in order to prevent excessive oxygen accumulation. In some embodiments, the heated ambient air may be provided into either odd numbered or even numbered aisles formed between the modules 400b, and the oxygen enriched air stream may be exhausted from the furnace 500b through the other ones of odd numbered or even numbered aisles.

[0076] According to various embodiments, the modules 400 may alternatively include columns 200B that are internally manifolded for fuel as shown in FIG. 2C. Such modules 400 may have configurations as shown above. In other words, the modules 400a, 400b may include the internally manifolded columns 200B rather than the columns 200A. Since the columns 200B include internal fuel and product conduits, modules including the columns 200B may be inserted into a furnace to provide an even higher column density. In other words, aisles between such modules may be reduced in size, since no space is required for external product and fuel conduits.

[0077] In another alternative embodiment, the modules 400 may include columns 200B that are internally manifolded for fuel and air. For example, FIG. 8A is a perspective view of the fuel side of a partial counterflow interconnect, according to various embodiments of the present disclosure, and FIG. 8B is a perspective view of the air side of the interconnect of FIG. 8A.

[0078] Referring to FIG. 8A, the interconnect 800 includes one fuel inlet 810 formed adjacent to a middle of the first edge 801, and one fuel outlet 820 formed adjacent to a middle the second edge 802. The interconnect 800 also includes two air outlets 870 formed on opposing sides of the fuel inlet 810 and two air inlets 860 formed on opposing sides of the fuel outlet 820. The air inlets 860 and outlets 870 are located at respective corners of the interconnect 800. The fuel inlet 810 is separated from the air outlets 870 by raised neck regions 815, and the fuel outlet 820 is separated from the air inlets 860 by additional raised neck regions 815. The neck regions 815 comprise raised regions which prevent fuel flow from the fuel inlet 810 into the air outlets 870, and fuel exhaust flow from the fuel outlet 820 into the air inlets 860. The interconnect 800 also includes a fuel inlet manifold 814 fluidly connecting the fuel inlet 810 to the fuel field 830, and a fuel outlet manifold 816 fluidly connecting the fuel outlet 820 to the fuel field 830.

[0079] When the interconnect 800 is utilized in the columns 200B, fuel from the fuel inlet 810 enters the fuel inlet manifold 814, which distributes the fuel to the fuel field 830. Fuel flows through the fuel field 830 toward the second edge 802. Fuel flows out of the fuel field 830 and enters the fuel outlet manifold 816, which directs the fuel to the fuel outlet 820. A seal material may be located on a fuel side seal surface 850 to seal the perimeter of the interconnect 800 and to internally seal the air inlets and outlets 860, 870. For example, the fuel side seal surface 850 may include portions of the fuel side that internally surround the air inlets and outlets 860, 870.

[0080] Referring to FIG. 8B, the air side of the interconnect 800 includes an air inlet manifold 844 that fluidly connects the air inlets 860 to the air field 840, and an air outlet manifold 846 that fluidly connects the air field 840 to the air outlets 870. Air from the air inlets 860 is distributed to the air field 840 by the air inlet manifold 844, flows through the air field 840 to the air outlet manifold 846, which directs the air into the air outlets 870. A seal material may be located on an air seal surface 852 to seal the perimeter of the interconnect 800 and to internally seal the fuel inlet 810 and fuel outlet 820. For example, the air seal surface 852 may include surfaces of the air side that surround the fuel inlet 810 and fuel outlet 820.

[0081] When the interconnect 800 is utilized in the columns 200B, the columns 200B may include internal fuel riser channels that are at least partially defined by the fuel inlet 810 and fuel outlet 820, and internal air riser channels that are at least partially defined by the air inlets and outlets 860, 870. Accordingly, the columns 200B may be internally manifolded for both fuel and air.

[0082] FIG. 9A is a perspective view of an alternative electrolyzer module 600b, according to various embodiments of the present disclosure, and FIG. 9B is a perspective view illustrating the orientation of modules 600b of FIG. 9A included in a furnace 600a. The columns 200B in FIG. 9A can incorporate interconnects 800 illustrated in FIGS. 8A, 8B. As such, the columns 200B do not require external fuel and exhaust conduits or fuel/feed return splitter plates like those utilized with column 200A in FIG. 1C. Moreover, the columns 200B incorporating interconnects 800 do not require air flow channels to be located on opposite sides of the columns 200B. In contrast, columns 200B incorporating interconnects 800 can be provided with air via conduits fluidly connected to one or more air blowers (not shown). As a consequence, alternative electrolyzer modules 600b can be more densely packed in a furnace occupying a given length and width.

[0083] FIG. 9B is a perspective view illustrating the arrangement of modules 600b of FIG. 9A in a furnace 600a in another embodiment of the present disclosure. As illustrated in FIG. 9B, the spacing 603 between rows of modules 600b can be narrower because the spacing 603 does not need to incorporate fuel rails, splitter plates, or air channels for air to flow through the columns 200B since the columns 200B are internally manifolded for fuel and air. However, there needs to be a sufficient clearance between the modules 600b so that individual modules 600b can be serviced through corresponding access doors 602 and there needs to be sufficient spacing between live electrical connection points (e.g., column electrical terminals) to avoid electric arcing between laterally adjacent modules 600b. While modules 600b can utilize the interconnect structure illustrated in FIGS. 8A and 8B, other interconnect structures are also possible. For instance, the interconnect structures described in pending U.S. provisional patent application No. 63/598,678 entitled Internally Manifolded Interconnects with Plural Flow Directions and Electrochemical Cell Column Including Same, the content of which is incorporated herein by reference in its entirety, can alternatively be incorporated in the columns 200B and modules 600b.

[0084] According to various embodiments, the modular electrolyzer system architectures allow for a high density of electrolyzer cell columns to be disposed in the hot zone of a furnace, while also providing easy column serviceability. In particular, modules may be easily swapped without stopping operation of the remaining modules.

[0085] According to various embodiments, a method of operating an electrolyzer system 300 includes providing steam and electric power to a plurality of electrolyzer column modules 400 located in a furnace 500 to generate a hydrogen-containing product and oxygen by electrolysis of the steam; and shutting down a first one of the electrolyzer column modules and removing the first one of the electrolyzer column modules from the furnace while a second one of the electrolyzer column modules continues to generate the hydrogen-containing product and the oxygen by the electrolysis of the steam.

[0086] In one embodiment, prior to the step of removing the first one of the electrolyzer column modules 400 from the furnace 500, the following steps are performed: closing a first valve 140 between a steam header 132 and the first one of the electrolyzer column modules 400; closing a second valve 140 between a product header 134 and the first one of the electrolyzer column modules 400; decoupling a first flange 136a of a steam header inlet conduit 312 from a second flange 136b of a module inlet conduit 412 which fluidly connect the steam header 132 to the first one of the electrolyzer column modules 400, while the steam continues to be provided from the steam header 132 to the second one of the electrolyzer column modules 400; and decoupling a third flange 136a of a product header outlet conduit 314 from a fourth flange 136b of a module outlet conduit 414 which fluidly connect the product header 134 to the first one of the electrolyzer column modules 400, while the second one of the electrolyzer column modules 400 continues to provide the hydrogen-containing product to the product header 134.

[0087] In one embodiment, the step of removing the first one of the electrolyzer column modules 400 from the furnace 500 (e.g., 500a) comprises opening a door 502 of the furnace 500, and pulling out a first skid cart 402 supporting the first one of the electrolyzer column modules 400 (e.g., 400a) from the furnace using rails 514, while the second one of the electrolyzer column modules 400 (e.g., 400a) remains on a second skid cart 402 in the furnace 500.

[0088] Fuel cell and electrolyzer systems of the embodiments of the present disclosure are designed to reduce greenhouse gas emissions and have a positive impact on the climate.

[0089] The preceding description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the invention. Thus, the present invention is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.