Fluid connections to bipolar electrode compartments in an electrochemical acidification device

Abstract

Aspects and embodiments disclosed herein include an electrochemical system comprising a plurality of electrochemical units arranged in parallel within a closing mechanism, each of the plurality electrochemical units including an anodic compartment, a cathodic compartment, and a center compartment defined between the anodic compartment and the cathodic compartment, a solid bipolar electrode disposed between adjacent anodic and cathodic compartments. The electrochemical system further includes at least one center block housing the solid bipolar electrode and housing one of the anodic compartments and one of the cathodic compartments of electrochemical units of the plurality of electrochemical units disposed adjacent the solid bipolar electrode, spacers disposed within the at least one center block, and inlet and outlet flow passages to the anodic compartments, cathodic compartments, and center compartments of the plurality of electrochemical units defined in the spacers.

Description

[0001] FLUID CONNECTIONS TO BIPOLAR ELECTRODE COMPARTMENTS IN AN

[0002] ELECTROCHEMICAL ACIDIFICATION DEVICE

[0003] CROSS-REFERENCE TO RELATED APPLICATIONS

[0004] This application claims priority to U.S. Provisional / Application Serial No. 63 / 707,303, titled “FLUID CONNECTIONS TO BIPOLAR ELECTRODE COMPARTMENTS IN AN ELECTROCHEMICAL ACIDIFICATION DEVICE,” filed on October 15, 2024, the subject matter of same being incorporated herein by reference in its entirety for all purposes.

[0005] GOVERNMENT LICENSE RIGHTS

[0006] This invention was made with LT.S. government support under Contract No. N00014- 21-C-1019 awarded by the Department of the Navy. The U.S. government has certain rights in the invention.

[0007] FIELD OF TECHNOLOGY

[0008] The present disclosure pertains to methods of providing fluid connections to bipolar electrode compartments in an electrochemical device. The device may be used, for example, to capture inorganic carbon from seawater. Further aspects and features disclosed herein pertain to electrolytic - cation exchange modules (E-CEM ).

[0009] SUMMARY

[0010] In accordance with one aspect, there is provided an electrochemical system. The system comprises a plurality of electrochemical units arranged in parallel within a closing mechanism, each of the plurality electrochemical units including an anodic compartment, a cathodic compartment, and a center compartment defined between the anodic compartment and the cathodic compartment. A first ion permeable fluidic separator is disposed between the center compartment and the anodic compartment. A second ion permeable fluidic separator is disposed between the center compartment and the cathodic compartment. A solid bipolar electrode is disposed between adjacent anodic and cathodic compartments. The system further includes at least one center block housing the solid bipolar electrode and housing one of the anodic compartments and one of the cathodic compartments of electrochemical units of the plurality' of electrochemical units disposed adjacent the solid bipolar electrode, spacers disposed within the at least one center block, and inlet and outlet flow passages to the anodic compartments, cathodic compartments, and center compartments of the plurality of electrochemical units defined in the spacers.

[0011] In some embodiments, the closing mechanism includes first and second end blocks disposed on opposite sides of the plurality of electrochemical units, the first of the end blocks housing an anode, the second of the end blocks housing a cathode, the anode and cathode coupled to a power supply and configured to flow current across the plurality of electrochemical units.

[0012] In some embodiments, the first and second end blocks are in contact with the at least one center block.

[0013] In some embodiments, the spacers are enclosed within recesses defined in the first and second end blocks and the at least one center block.

[0014] In some embodiments, the spacers are enclosed within recesses defined in the at least one center block.

[0015] In some embodiments, the plurality of electrochemical units includes three electrochemical units and the at least one center block includes two center blocks adjacent to and in contact with one another, the spacers being fully enclosed within recesses defined in the two center blocks.

[0016] In some embodiments, the inlet and outlet flow passages to the anodic compartments include an anolyte manifold passing through the closing mechanism and the spacers.

[0017] In some embodiments, the inlet and outlet flow passages to the anodic compartments further include anolyte channels fluidically coupling the anolyte manifold to the anodic compartment of each of the plurality of electrochemical units.

[0018] In some embodiments, the anolyte channels are serpentine.

[0019] In some embodiments, the inlet and outlet flow passages to the cathodic compartments include a catholyte manifold passing through the closing mechanism and the spacers.

[0020] In some embodiments, the inlet and outlet flow passages to the cathodic compartments further include catholyte channels fluidically coupling the catholyte manifold to the cathodic compartment of each of the plurality of electrochemical units.

[0021] In some embodiments, the catholyte channels are serpentine.

[0022] In some embodiments, the inlet and outlet flow passages to the center compartments include a center compartment manifold passing through the closing mechanism and the spacers. In some embodiments, the inlet and outlet flow passages to the center compartments further include center compartment channels fluidically coupling the center compartment manifold to the center compartment of each of the plurality of electrochemical units.

[0023] In some embodiments, the center compartment channels extend linearly between the center compartment manifold and the center compartment of each of the plurality of electrochemical units.

[0024] In some embodiments, the first and second cation permeable fluidic separators of the plurality of electrochemical units are mounted on the spacers of each of the plurality of electrochemical units.

[0025] In some embodiments, the plurality of electrochemical units are electrolytic-cation exchange module electrochemical units.

[0026] In some embodiments, the first and second ion permeable fluidic separators are cation permeable fluidic separators.

[0027] In some embodiments, one or both of the anodic compartment or cathodic compartment of each of the plurality of electrochemical units has a width of less than 4 mm.

[0028] In some embodiments, the center compartment of each of the plurality electrochemical units has a width of less than 10 mm.

[0029] BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are not drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in the various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:

[0031] FIG. 1 is a schematic drawing of a device and process for electrochemically reducing the pH of a fluid stream;

[0032] FIG. 2 is a schematic drawing of a device and process for electrochemically increasing the pH of a fluid stream;

[0033] FIG. 3 is a schematic drawing of an Electrolytic - Cation Exchange Module (E-CEM) and process;

[0034] FIG. 4 is a diagram illustrating the equilibrium for inorganic carbonic species in seawater at 10 °C;

[0035] FIG. 5 schematically illustrates multiple E-CEM modules operating in parallel;

[0036] FIG. 6 schematically illustrates an E-CEM device and process including multiple sets of electrode compartments, membranes, and center compartments; FIG. 7 A schematically illustrates a manifold system for multiple seawater compartments in an E-CEM device operating in series;

[0037] FIG. 7B schematically illustrates a manifold system for multiple seawater compartments in an E-CEM device operating in parallel;

[0038] FIG. 8 schematically illustrates a manifold system for multiple seawater compartments in an E-CEM device operating in series and parallel;

[0039] FIG 9 A schematically shows the fluid flow in an example of an electrochemical device with two bipolar electrodes and three seawater compartments;

[0040] FIG. 9B schematically shows the fluid flow in another example of an electrochemical device with two bipolar electrodes and three seawater compartments;

[0041] FIG 10A shows an exploded view of an electrochemical device with two seawater compartments;

[0042] FIG. 10B show an assembled view of an electrochemical device with two seawater compartments;

[0043] FIG. 11 A illustrates a center block with two seawater spacers;

[0044] FIG 11B is a sectional diagram through line 1 of FIG. 11 A;

[0045] FIG. 11C is a sectional diagram through line 2 of FIG. 11 A;

[0046] FIG. 1 1D is a sectional diagram through line 3 of FIG. 11 A;

[0047] FIG. 12 shows the flow of catholyte in the region of Detail 1-1 in FIG. 1 IB;

[0048] FIG 13 shows the flow of anolyte in the region of Detail 1-2 in FIG. 11 B;

[0049] FIG. 14 shows the flow of saline water or seawater in the region of Detail 2-1 in FIG.

[0050] 11C;

[0051] FIG. 15 shows the flow of saline water or seawater in the region of Detail 2-2 in FIG.

[0052] 11C;

[0053] FIG 16 shows the flow of anolyte in the region of Detail 3-1 in FIG. 11 D; and FIG. 17 shows the flow of catholyte in the region of Detail 3-2 in FIG. 1 ID.

[0054] DETAILED DESCRIPTION

[0055] The total carbon content of the world's oceans is approximately 38,000 gigatons

[0056] (GT). Over 95% of this carbon is in the form of dissolved bicarbonate ion (HCO3---). This bicarbonate ion, along with the carbonate ion (CO32---), is responsible for buffering and maintaining the pH of the ocean which is relatively constant below the first 100 meters of ocean depth. The dissolved bicarbonate and carbonate ions present in the ocean are effectively bound CO2, and the sum of the concentrations of these species, along with dissolved gaseous CO2, represents the total carbon dioxide concentration [CO2]T, of seawater.

[0057] At a typical ocean pH of 7.8, kept relatively constant by a complex bicarbonate- carbonate buffer system, [ CO2]Tis about 2000 μmoles / kg near the surface and about 2400 μmoles / kg at depths below 300 meters. Thi s equates to approximately 100 mg / L of [CO2]T. Of the total CO2in the ocean, about 2-3% is dissolved gaseous CO2, about 1% is present as the dissolved carbonate ion, and the remainder, about 96%, is present as the dissolved bicarbonate ion. It is known that the equilibrium form and concentration of water containing CO2and its various ionic forms is dependent on the pH of the water. For example, at a seawater pH of 4.5, 99% of all carbonate species in seawater exist as carbonic acid, H2CO3. Thus, to convert HCO3---to H2CO3, the pH of seawater may be lowered. CO2dissolved in water is in equilibrium with H2CO3as shown in equation 1 : CO2+ H2O H2CO3(1)

[0058] The hydration equilibrium constant is 1 .70* IO-3. This indicates that H2CO3is not stable in water at elevated concentrations and gaseous CO2readily dissociates at pH of 4.5, allowing CO2to be easily removed by degassing or stripping once the seawater has been acidified such that the unstable H2CO3is deprotonated to the predominant carbonate species.

[0059] Electrochemical cells are used in marine, offshore, municipal, industrial, and commercial implementations. The design parameters of electrochemical cells, for example, inter-electrode spacing, thickness of electrodes and coating density, electrode areas, methods of electrical connections, etc., can be selected for different implementations. Aspects and embodiments disclosed herein are not limited to the number of electrodes, the space between electrodes, the electrode material, material of any spacers between electrodes, number of passes within the electrochemical cells, or electrode coating material.

[0060] An electrochemical device with ion exchange membranes can be designed to change the pH of a fluid stream while generating reaction products at the electrodes. FIGS. 1 and 2 show two variations of a device with three fluid streams separated by two ion exchange membranes of the same ionic selectivity. The electrode reactions depend on the composition of the electrolytes, electrode materials and operating conditions. Common reactions include:

[0061] Anode: (1)

[0062] Cathode: (2) In addition, chlorine gas evolution is possible at the anode if the anolyte contains chloride ions:

[0063] In FIG. 1, both membranes are cation exchange membranes (CEM), which preferentially pass cations. Under a DC voltage, H+ions generated at the anode in the anodic compartment 5 pass into the center compartment 10 and acidifies the fluid stream by reacting with anions such as HCO3- or SO4-2. Excess H+ions either continue into the cathodic compartment 15, where they react with OFF ions to form water or are swept out of the center compartment 10 by the fluid.

[0064] Conversely, in FIG. 2, both membranes are anion exchange membranes (AEM), which preferentially pass anions. OH’ ions generated at the cathode pass into the center compartment 10 and increases the pH of the fluid stream. Excess OH' ions either continue into the anodic compartment 5, where they react with H+ions to form water or are swept out of the center compartment 10 by the fluid.

[0065] One application of the device in FIG. 1 is the Electrolytic - Cation Exchange Module (E-CEM) process to reduce seawater pH and convert dissolved bicarbonate ions to CO2gas while simultaneously producing hydrogen gas through electrolytic dissociation of water in the cathodic compartment and oxygen gas in the anodic compartment. The CO2and H2 gas are feedstock to a modified Fischer-Tropsch to produce jet fuel, as detailed in, e.g., U.S. Patent No. 9,303,323 B2, which is incorporated herein by reference. Furthermore, the oxygen gas may be utilized for a variety of applications in the industrial, environmental, medical, and / or energy sectors.

[0066] FIG. 3 is a schematic diagram of an example E-CEM device.

[0067] The main reactions in the center (seawater) compartment 10 are: (3) (4)

[0068] The pKi and pF2values are for seawater at 10 °C. Other ions may react with the H\ such as conversion of borate to boric acid.

[0069] Seawater has a pH of ~ 8. FIG. 4 shows the equilibrium diagram for inorganic carbonic species in seawater at 10 °C. If the pH is reduced to less than ~ 4, essentially all the carbonate and bicarbonate are converted to H2CO3. CO2gas can be extracted from the center compartment effluent by vacuum or by membrane degasification.

[0070] The feeds to the anodic and cathodic compartments are conductive solutions, such as deionized water, reverse osmosis (RO) product water with conductivity < 200 μS / cm, or sodium sulfate solution with conductivity of ~ 200 - 3000 μS / cm.

[0071] The electrodes of an electrolytic device, for example, an E-CEM device may be fabricated from solid or expanded titanium plate with a coating selected for the electrode solution and reaction, current density, cost and operating lifetime. The coating may contain platinum or mixed metal oxides (MMO) such as iridium oxide, ruthenium oxide, or other metal oxides. The thickness of the electrodes is typically less than 1 mm.

[0072] The stack of electrodes, electrode compartments, membranes, and center (seawater) compartment is referred to herein as an “electrochemical unit”. In the E-CEM device shown in FIG. 3, the electrodes and electrode compartments are in non-conductive “endblocks”, while the center seawater compartment is inside a non-conductive seawater spacer, also referred to herein as a “spacer”.

[0073] The thickness of an electrode compartment 5, 15 may be less than 4 mm, for example about 3.5 mm. The inlet and outlet to each compartment 5, 15 is through flow passages inside an endblock. The thickness of a seawater compartment 10 may be in the range of 10 mm - 20 mm or less than 10 mm, for example, about 9.5 mm. The inlet and outlet to the seawater compartment 10 can be through the top and bottom walls of the spacer or, as shown in FIG. 3, through passages in the endblocks.

[0074] The endblocks are pulled together by multiple threaded rods and nuts (“tie-rods”) to compress and seal the stack of endblocks, spacer, and membranes and counter the internal fluid pressure. In alternative designs, each endblock is structurally backed up by an endplate, which may be machined from metal or molded from plastic.

[0075] The assembly of endblocks, electrodes, spacers, membranes, tie-rods, and optional endplates is referred to as the E-CEM module. To increase the throughput from an E-CEM process such as that illustrated in FIG. 3, the flow rate through the center compartment 10 can be increased (residence time reduced) or the width of the compartment 10 can be increased while maintaining the same residence time.

[0076] The set of endplates, endblocks, and tie-rods is referred to as a “closing mechanism” and is in effect an overhead requirement that does not function directly as part of the electrochemical process. It adds cost, weight, footprint, and maintenance requirement to a module.

[0077] To further increase the production rate of an E-CEM system, multiple modules 100 can be installed and operated in parallel (see, e.g., FIG. 5). Each module would utilize a set of closing mechanisms (not shown) per center compartment 10. Each module 100 may have its own DC power supply, or a single power supply may be used for multiple modules 100 with the modules 100 electrically connected in parallel.

[0078] It would be advantageous if a set of closing mechanisms can be used for multiple electrochemical units, providing for an overall reduction in cost, weight, and footprint.

[0079] FIG. 6 shows such a process. Multiple sets of electrode compartments 5, 15, membranes CEM and center compartments 10 are separated by bipolar electrodes 110. Each bipolar electrode 110 is coated on both sides, with one side functioning as an anode 120 and the other as cathode 130. Compared to the system of FIG. 5, only one set of closing mechanisms (not shown) may be utilized for the same number of center compartments 10.

[0080] The challenges in designing an E-CEM module with multiple electrolyte compartment, center compartments, and bipolar electrodes include isolation of the electrolyte streams on opposite sides of each bipolar electrode and a method of providing fluid inlets and outlets to the electrolyte streams, since the bipolar electrodes are not adjacent to endblocks as in the E-CEM device of FIG. 3. As detailed above, the width of the electrode compartments may be on the order of 3-4 mm of less so as to limit voltage drop per electrochemical unit.

[0081] For the ECEM device shown in FIG. 6 with multiple electrochemical units, an embodiment of the present disclosure proposes a method of supporting and sealing the bipolar electrodes 110 and providing inlets and outlets to the separate electrolyte compartments 5, 15 on the two sides of each bipolar electrode 1 10.

[0082] An electrochemical device with multiple units or compartments operating in series or parallel typically use a manifold system to connect the multiple inlets and outlets. FIGS. 7A and 7B show, for example, manifold systems for multiple seawater compartments in an E- CEM device. When the compartments are in parallel, there are typically manifolds with lateral channels that distribute the flow to the compartments and collect the effluents. FIG. 8 shows a manifold system for two sets of seawater compartments 10 operating in parallel that are in turn connected in series.

[0083] Manifold systems as in FIGS. 7 and 8 are difficult to design for electrode compartments 5, 15 that are typically ≤ 4 mm thick because there is insufficient solid material in between the compartments 5, 15 to accommodate the flow channels. In the E-CEM device as shown in FIG. 3, the inlet and outlet flow passages for the electrolyte compartments 5, 15 are inside the endblocks, which are much thicker than the electrolyte compartments 5, 15.

[0084] The spacers for the seawater compartments 10 are typically 3 - 6 times thicker than the electrolyte compartments 5, 15. In embodiments of the present disclosure, the bipolar electrodes 110 and the adjacent electrolyte compartments 5, 15 are housed in center blocks, while the electrolyte inlet and outlet flow passages are provided inside the seawater spacers.

[0085] FIG. 9A shows a fluid flow in a device with two bipolar electrodes 110, three seawater compartments 10, two endblocks 140, two center blocks 150, and the spacers 160. Each of the endblocks 140 includes inlet ports for a catholyte inlet manifold 170A, a seawater / center compartment inlet manifold 190 A, and an anolyte inlet manifold 180 A and outlet ports for a catholyte outlet manifold 170B, a seawater / center compartment outlet manifold 190B, and an anolyte outlet manifold 180B. The ports to the catholyte inlet manifold 170A, seawater / center compartment inlet manifold I90A, and anolyte inlet manifold 180A are plugged in endblock 140B and open in endblock 140A. The ports to the catholyte outlet manifold 170B, seawater / center compartment outlet manifold 190B, and anolyte outlet manifold 180B are plugged in endblock 140A and open in endblock 140B. Catholyte flows through the cathodic compartments 15 from catholyte inlet flow passages or channels 170C (see FIG. 12) from the catholyte inlet manifold 170A and through catholyte outlet flow passages 170D (see FIG. 17) to the catholyte outlet manifold 170B. Anolyte flows through the anodic compartments 5 from anolyte inlet flow passages 180C (see FIG. 16) from the anolyte inlet manifold 180 A and through anolyte outlet flow passages 180D (see FIG. 13) to the anolyte outlet manifold 180B. Saline water, for example, seawater flows through the center compartments 10 from saline water inlet flow passages 190C (see FIG. 14) from the seawater / center compartment inlet manifold 190 A and through outlet flow passages 190D (see FIG. 15) to the seawater / center compartment outlet manifold 190B. As also illustrated in FIGS. 9A and 9B, the bipolar electrodes 110 may be mounted to the center blocks 150 utilizing one or more seals 110S.

[0086] In general, the E-CEM devices have inlet and outlet ports on both ends (in both endblocks 140) so that the installer / user has the option of piping with inlet and outlet ports on opposite ends of the device or on the same end. The choice depends on the design of the overall system, which includes, in addition to the E-CEM devices, frame, piping, instrumentation, power supplies and control panel. For example, FIG. 9B illustrates an example of a device similar to that of FIG. 9 A, with the difference being that each of the inlet or outlet manifolds are plugged in endblock 140 A and none of the inlet or outlet manifolds are plugged in the other endblock 140B. Anolyte, catholyte, and saline water / seawater may flow into and out of the device through endblock 140B, but not endblock 140A,

[0087] Option 1 (FIG. 9 A) may result in better flow distribution within the inlet and outlet manifolds and may result in better division of flow to each flow compartment. However, the requirement for piping to both ends of a device may require more space around the device and may result in more cumbersome access to inlet and outlet controls such as valves.

[0088] Option 2 (FIG. 9B) may require less space and provide more convenient access to inlet and outlet controls. However, the flow rate to each flow compartment may not be as uniform as in Option 1, particularly as the number of seawater and electrode compartments increase. It is more possible for the flow to preferentially flow through the compartments closer to the inlet and outlet end (shorter flow path, “short circuiting”) so the compartments farthest from the inlet and outlet end may receive less flow.

[0089] FIGS. 10 A and 10B show an exploded view and assembled view, respectively, of an E-CEM device with two center / seawater compartments as an example. The monopolar electrodes 120, 130 at the two ends are housed in endblocks 140 and the bipolar electrode 110 is housed in a center block 150. The center block 150 has recesses on both sides to accommodate seawater spacers 160. The endblocks 140 also include recesses on the sides facing the inside of the device to accommodate seawater spacers 160 along with recesses in outward facing sides of center blocks 150 adjacent to the endblock 140. The depth of the recesses is such that in an assembled device the endblocks 140 and center block 150 are in contact and the seawater spacers 160 are not visible; they are “inboard” (see also FIG. 9).

[0090] FIG. 10B illustrates possible locations where inlet and outlet manifolds 170A, 170B, 180A, 180B, 190A, 190B for cathodic compartments 15, anodic compartments 5, and saline water / seawater / center compartments 10 respectively, may pass through one of the endblocks 140. In some embodiments, in use, one of the endblocks 140 would only utilize the inlet manifold s 170A, 180A, 190A and the other of the endblocks would only utilize the outlet manifolds 170B, 180B, 190B. For example, the unused inlet or outlet manifolds may be plugged, as illustrated in FIGS. 9 A. In alternate embodiments, each inlet and outlet manifold port in only one of the endblocks 140 may be utilized for providing fluid communication with each of the inlet and outlet manifold s, for example, as illustrated in FIG. 9B.

[0091] FIG. 1 1 A shows a center block 150 with two seawater spacers 160 (only one of which is visible because the other is on the other side of the center block 150 from that illustrated). For each fluid stream (anolyte, saline water / seawater, and catholyte) there are inlet and outlet manifolds 170A, 170B, 180A, 180B, 190A, 190B with lateral flow passages, also referred to herein as channels, that serve as inlets and outlets to the respective flow compartments 15, 5 10.

[0092] FIG. 1 IB is a sectional diagram through line 1 of FIG. 11 A. FIG. 11C is a sectional diagram through line 2 of FIG, 11 A. FIG. 1 I D is a sectional diagram through line 3 of FIG. 11 A.

[0093] FIG. 12 shows the flow of catholyte in the region of Detail 1-1 in FIG. 1 IB. Visible in FIG. 12 are the catholyte inlet flow passages 170C (labelled “channels” in FIG. 12) that provide for fluid flow from the from the catholyte inlet manifold 170A into the cathodic compartments 15. The catholyte inlet flow passages 170C are defined in a spacer 160 and may be serpentine as illustrated.

[0094] FIG. 13 shows the flow of anolyte in the region of Detail 1-2 in FIG, 1 IB. Visible in FIG. 13 are the anolyte outlet flow passages 180D that provide for fluid flow from the from the anodic compartments 5 into the anolyte outlet manifold 180B. The anolyte outlet flow passages 180D are defined in a spacer 160 and may be serpentine as illustrated. Furthermore, while center block 150 is shown in FIG. 13 as a singular part, it is to be understood that center block 150 may be formed of two or more parts bonded or otherwise coupled together for the purposes of, e.g., ease of manufacturing.

[0095] FIG. 14 shows the flow of saline water or seawater in the region of Detail 2-1 in FIG. 11C. Visible in FIG. 14 are the saline water / seawater inlet flow passages 190C (labelled “channels” in FIG. 14) that provide for fluid flow from the from the seawater / center compartment inlet manifold 190A into the seawater / center compartments 10. The saline water / seawater inlet flow passages 190C are defined in a spacer 160 and may be linear as illustrated.

[0096] FIG. 15 shows the flow of saline water or seawater in the region of Detail 2-2 in FIG. 11C. Visible in FIG. 14 are the saline water / seawater outlet flow passages 190D that provide for fluid flow from the from seawater / center compartments 10 into the seawater / center compartment outlet manifold 190B. The saline water / seawater outlet flow passages 190D are defined in a spacer 160 and may be linear as illustrated.

[0097] FIG. 16 shows the flow of anolyte in the region of Detail 3-1 in FIG, 1 ID. Visible in FIG. 16 are the anolyte inlet flow passages 180C (labelled “channels” in FIG. 16) that provide for fluid flow from the from the anolyte inlet manifold 180A into the anodic compartments 5. The anolyte inlet flow passages 180C are defined in a spacer 160 and may be serpentine as illustrated. FIG. 17 shows the flow of catholyte in the region of Detail 3-2 in FIG. 1 ID. Visible in FIG. 17 are the catholyte outlet flow passages 170D that provide for fluid flow from the from cathodic compartments 15 into the catholyte outlet manifold 170B. The catholyte outlet flow passages 170D are defined in a spacer 160 and may be serpentine as illustrated.

[0098] It is to be understood that aspects and embodiments disclosed herein may be applied to other electrochemical devices with bipolar electrodes.

[0099] The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. As used herein, the term “plurality” refers to two or more items or components. The terms “comprising,” “including,” “carrying,” “having,” “containing,” and “involving,” whether in the written description or the claims and the like, are open-ended terms, i.e., to mean “including but not limited to.” Thus, the use of such terms is meant to encompass the items listed thereafter, and equivalents thereof, as well as additional items. Only the transitional phrases “consisting of” and “consisting essentially of,” are closed or semi-closed transitional phrases, respectively, with respect to the claims. Use of ordinal terms such as “first,” “second,” “third,” and the like in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.

[0100] Having thus described several aspects of at least one embodiment, it is to be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. Any feature described in any embodiment may be included in or substituted for any feature of any other embodiment. Such alterations, modifications, and improvements are intended to be part of this disclosure and are intended to be within the scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.

[0101] Those skilled in the art should appreciate that the parameters and configurations described herein are exemplary and that actual parameters and / or configurations will depend on the specific application in which the disclosed methods and materials are used. Those skilled in the art should also recognize or be able to ascertain, using no more than routine experimentation, equivalents to the specific embodiments disclosed.

[0102] What is claimed is:

Claims

CLAIMS1. An electrochemical system comprising: a plurality of electrochemical units arranged in parallel within a closing mechanism, each of the plurality electrochemical units including: an anodic compartment; a cathodic compartment; and a center compartment defined between the anodic compartment and the cathodic compartment; a first ion permeable fluidic separator disposed between the center compartment and the anodic compartment; and a second ion permeable fluidic separator disposed between the center compartment and the cathodic compartment; a solid bipolar electrode disposed between adjacent anodic and cathodic compartments; at least one center block housing the solid bipolar electrode and housing one of the anodic compartments and one of the cathodic compartments of electrochemical units of the plurality of electrochemical units disposed adjacent the solid bipolar electrode; spacers disposed within the at least one center block; and inlet and outlet flow passages to the anodic compartments, cathodic compartments, and center compartments of the plurality of electrochemical units defined in the spacers.

2. The system of claim 1, wherein the closing mechanism includes first and second end blocks disposed on opposite sides of the plurality' of electrochemical units, the first of the end blocks housing an anode, the second of the end blocks housing a cathode, the anode and cathode coupled to a power supply and configured to flow current across the plurality of electrochemical units.

3. The system of claim 2, wherein the first and second end blocks are in contact with the at least one center block.

4. The system of claim 3, wherein the spacers are enclosed within recesses defined in the first and second end blocks and the at least one center block.

5. The system of claim 3, wherein the spacers are enclosed within recesses defined in the at least one center block.

6. The system of claim 3, wherein the plurality of electrochemical units includes three electrochemical units and the at least one center block includes two center blocks adjacent to and in contact with one another, the spacers being fully enclosed within recesses defined in the two center blocks.

7. The system of claim 1, wherein the inlet and outlet flow passages to the anodic compartments include an anolyte manifold passing through the closing mechanism and the spacers.

8. The system of claim 7, wherein the inlet and outlet flow passages to the anodic compartments further include anolyte channels fluidically coupling the anolyte manifold to the anodic compartment of each of the plurality of electrochemical units.

9. The system of claim 8, wherein the anolyte channels are serpentine.

10. The system of claim 1, wherein the inlet and outlet flow passages to the cathodic compartments include a catholyte manifold passing through the closing mechanism and the spacers.

11. The system of claim 10, wherein the inlet and outlet flow passages to the cathodic compartments further include catholyte channels fluidically coupling the catholyte manifold to the cathodic compartment of each of the plurality of electrochemical units.

12. The system of claim 11, wherein the catholyte channels are serpentine.

13. The system of claim 1, wherein the inlet and outlet flow passages to the center compartments include a center compartment manifold passing through the closing mechanism and the spacers.

14. The system of claim 13, wherein the inlet and outlet flow passages to the center compartments further include center compartment channels fluidically coupling the centercompartment manifold to the center compartment of each of the plurality of electrochemical units.

15. The system of claim 14, wherein the center compartment channels extend linearly between the center compartment manifold and the center compartment of each of the plurality of electrochemical units.

16. The system of claim 1, wherein the first and second cation permeable fluidic separators of the plurality of electrochemical units are mounted on the spacers of each of the plurality of electrochemical units.

17. The system of claim 1, wherein the plurality of electrochemical units are electrolytic- cation exchange module electrochemical units.

18. The system of claim 17, wherein the first and second ion permeable fluidic separators are cation permeable fluidic separators.

19. The system of claim 1, wherein one or both of the anodic compartment or cathodic compartment of each of the plurality of electrochemical units has a width of less than 4 mm.

20. The system of claim 1, wherein the center compartment of each of the plurality electrochemical units has a width of less than 10 mm.

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