Integrating salt- or ion-containing water with a carbon oxide electrolyzer

Abstract

The present disclosure is related to integrating salt- or ion-containing water with a carbon oxide electrolyzer, and associated systems and methods.

Description

INTEGRATING SALT- OR ION-CONTAINING WATER WITH A CARBON OXIDE ELECTROLYZERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] A PCT Request Form is filed concurrently with this specification as part of the present application. Each application that the present application claims benefit of or priority to as identified in the concurrently filed PCT Request Form is incorporated by reference herein in their entireties and for all purposes.TECHNICAL FIELD

[0002] This disclosure relates generally to the carbon oxide electrolyzer field, and more specifically to a new and useful system and method for integrating salt- or ion-containing water with a carbon oxide electrolyzer.BACKGROUND

[0003] Electrolyzers typically operate using water from purified water sources. However, in areas where such purified water sources are limited, e.g., drought-prone areas and / or contaminated areas, other sources of water (e.g., untreated and / or impure water sources) may need to be sought after.

[0004] Thus, there is a need in the carbon oxide electrolyzer field to create a new and useful system and method for treating and purifying (e.g., desalinating) water.SUMMARY

[0005] The present disclosure is related to integrating salt- or ion-containing water with a carbon oxide electrolyzer. This summary is provided to introduce some concepts in simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claim.

[0006] In some aspects, methods are provided. In some embodiments, the method comprises providing a carbon oxide (COX) electrolyzer comprising one or more membrane electrode assemblies, wherein at least one of the membrane electrode assemblies comprises a cathode layer comprising a carbon oxide reduction catalyst that promotes reduction of a carbon oxide, an anode layer, and a polymer electrolyte membrane layer disposed between, and in contact with, the cathode layer and the anode layer; introducing an anolyte inlet stream to the COXelectrolyzer and producing an anolyte outlet stream having a higher temperature than theanolyte inlet stream; heating a first aqueous stream via indirect heat exchange with the anolyte outlet stream to thereby produce a heated first aqueous stream; directing at least a portion of the heated first aqueous stream to a desalination system; and outputting a desalinated aqueous stream.

[0007] In some embodiments, the first aqueous stream is one or more seawater, brackish water, wastewater, and flowback water. In some embodiments, the first aqueous stream is one of lake water, pond water, river water, creek water, ground or tap water, reservoir water, and / or rainwater.

[0008] In some embodiments, at least a portion of the desalinated aqueous stream is directed to the anolyte inlet stream of the CO2 electrolyzer.

[0009] In some embodiments, at least a portion of the desalinated aqueous stream is directed to the anolyte inlet of a water electrolyzer. The water electrolyzer may be configured to produce hydrogen.

[0010] In some embodiments, the method may further include synthesizing syngas, and in some instances, syngas may be directed to a downstream reactor. In some embodiments, the downstream reactor is a Fischer-Tropsch reactor.

[0011] In some embodiments, the desalination system is a thermal desalination unit where, in some cases, additional heat may be introduced to the desalination system. In some embodiments, the thermal desalination unit is operated under vacuum. In some embodiments, thermal desalination unit is configured to desalinate the heated first aqueous stream to produce the desalinated aqueous stream. In some embodiments, the thermal desalination unit is configured to vaporize water from the heated first aqueous stream and condensing the vaporized water to produce the desalinated aqueous stream.

[0012] In some embodiments, the desalination system is an ion-exchange desalination unit. In some embodiments, ion-exchange desalination unit is configured to receive a second aqueous stream and desalinate the second aqueous stream to produce the desalinated water. In some embodiments, the second aqueous stream is one or more seawater, brackish water, wastewater, and flowback water.

[0013] In some embodiments, the method may further include adding salt to the anolyte inlet stream of the CO2 electrolyzer. The CO2 electrolyzer may be configured to produce an output stream may include a carbon monoxide and a carbon dioxide. In some embodiments, the method further may include directing the output stream to a carbon monoxide purification unit configured to separate carbon monoxide from the carbon dioxide. In some implementations,the separated carbon dioxide may be recirculated to the CO2 electrolyzer. In some embodiments, the separated carbon monoxide is combined with hydrogen to produce syngas.

[0014] In some embodiments, the method may further include separating oxygen from the anolyte outlet stream, and the anolyte outlet stream may be oxygen deficient.

[0015] In some embodiments, the heat exchanger system may include one or more heat exchanger units.

[0016] In some aspects, a system is provided. In some embodiments, the system comprises a carbon oxide (COX) electrolyzer comprising one or more membrane electrode assemblies configured to receive an anolyte inlet stream and output an anolyte outlet stream, wherein at least one of the membrane electrode assemblies comprises: a cathode layer comprising a carbon oxide reduction catalyst that promotes reduction of a carbon oxide; an anode layer; and a polymer electrolyte membrane layer disposed between, and in contact with, the cathode layer and the anode layer, wherein the anolyte outlet stream has a higher temperature than the anolyte inlet stream; a heat exchanger system comprising one or more heat exchanger units, wherein the heat exchanger system is configured to heat a first aqueous stream via indirect heat exchange with the anolyte outlet stream to thereby produce a heated first aqueous stream; and a desalination system configured to receive at least a portion of the heated first aqueous stream and to output a desalinated aqueous stream.

[0017] In some embodiments, the system also includes a recirculation loop configured to direct the desalinated aqueous stream to an anolyte inlet stream of an electrolyzer.BRIEF DESCRIPTION OF THE FIGURES

[0018] Figures 1A and IB are schematic representations of an embodiment of a carbon oxide electrolyzer and a variation of the embodiment, respectively, according to some embodiments.

[0019] Figures 1C and ID are schematic representations of a first and second example, respectively, of the embodiment of a carbon oxide electrolyzer, according to some embodiments.

[0020] Figure 2 is a schematic representation that depicts the major components of a carbon oxide electrolyzer including a single electrolyzer cell, in accordance with some embodiments.

[0021] Figure 3 depicts an example of a carbon oxide electrolyzer that incorporates heat exchanger(s) to regulate the temperatures of anolyte output and anolyte input stream, according to some embodiments.

[0022] Figure 4A depicts an example of an integrated system comprising a carbon oxide electrolyzer that uses a first aqueous stream (e.g., seawater) to regulate the temperatures ofanolyte output and anolyte input stream via a single heat exchanger loop and downstream integration with a thermal desalination unit, according to some embodiments.

[0023] Figure 4B depicts an example of an integrated system as shown in Figure 4A that is additionally integrated with a water electrolyzer and downstream process(es), according to some embodiments.

[0024] Figure 4C depicts an example of an integrated system comprising a carbon oxide electrolyzer that uses a first aqueous stream (e.g., seawater) to regulate the temperatures of anolyte output and anolyte input stream via a single heat exchanger loop and downstream integration with an ion-exchange desalination unit, according to some embodiments.

[0025] Figure 4D depicts an example of an integrated system as shown in Figure 4C that is additionally integrated with a water electrolyzer and downstream process(es), according to some embodiments.

[0026] Figure 4E depicts an example of an integrated system as shown in Figure 4A that is additionally integrated with a water electrolyzer and associated heat exchanger(s), according to some embodiments.

[0027] Figure 4F depicts an example of an integrated system as shown in Figure 4C that is additionally integrated with a water electrolyzer and associated heat exchanger(s), according to some embodiments.

[0028] Figure 5A depicts an example of a carbon oxide electrolyzer that uses a first aqueous stream (e.g., seawater) to regulate the temperatures of anolyte output and anolyte input stream via a double heat exchanger loop and downstream integration with an ion-exchange desalination unit, according to some embodiments.

[0029] Figure 5B depicts an example of a carbon oxide electrolyzer that uses a first aqueous stream (e.g., seawater) to regulate the temperatures of anolyte output and anolyte input stream via a double heat exchanger loop and downstream integration with a thermal desalination unit, according to some embodiments.

[0030] Figure 6A depicts an example of an integrated system comprising a thermal desalination unit coupled to a carbon dioxide electrolyzer unit that includes a variety of optional components, according to some embodiments.

[0031] Figure 6B depicts an example of an integrated system comprising an ion-exchange desalination unit coupled to a carbon dioxide electrolyzer unit that includes a variety of optional components, according to some embodiments.

[0032] Figure 7 depicts an integrated system employing a carbon dioxide electrolyzer and water electrolyzer that may act in concert to produce a syngas that is provided to a Fischer- Tropsch reactor to produce a fuel such as an aviation turbine fuel.DESCRIPTION

[0033] Provided herein are systems and methods for integrating salt- or ion-containing water (e.g., seawater) with a carbon oxide electrolyzer system. The embodiments may exploit waste heat produced by a carbon oxide electrolyzer and / or associated units (e.g., water electrolyzer, downstream process(es), etc.) to desalinate or deionize salt- or ion-containing water. Nonlimiting examples of salt- or ion- containing water include but are not limited to seawater, brackish water, wastewater, flowback water, or water produced during oil and / or gas extraction processes. The waste heat produced by the carbon oxide electrolyzer system can be used to pre-heat salt- or ion-containing water and facilitate the desalination of salt- or ion-containing water to provide pure or deionized water, suitable as feed water for the carbon oxide electrolyzer. In some embodiments, the pure or deionized water produced using the waste heat of the carbon oxide electrolyzer system may be used in other operations or systems, such as feed for a water electrolyzer. Embodiments disclosed herein may be beneficial for more efficient use of waste heat produced by the carbon oxide electrolyzer by recycling the heat produced by the carbon oxide electrolyzer for use in the desalination system. Another benefit of integrating salt-containing water is that the salt- or ion-containing water may be used in regions lacking freshwater (e.g., drought-prone areas and / or deserts). For example, salt- or ioncontaining water may be provided to the carbon oxide electrolyzer system as cooling liquid and / or may be used in the desalination process coupled with a carbon oxide electrolyzer to produce water input feed for downstream processes such as carbon oxide electrolyzers, water electrolyzers, and Fischer-Tropsch reactors.

[0034] Other aspects include methods and systems for utilizing salt- or ion-containing water (e.g., seawater) as a coolant in one or more heat exchanger(s) coupled with the carbon oxide electrolyzer system to reduce the temperature of the anolyte outlet stream.

[0035] The following description of the preferred embodiments is not intended to limit the disclosure to these embodiments, but rather to enable any person skilled in the art to make and use this disclosure.Carbon Oxide Electrolyzer System

[0036] The system can include a carbon oxide electrolyzer (e.g., carbon dioxide electrolyzer) that generates carbon-containing products (e.g., CO, alkanes, alcohols, etc.) and / or hydrogenfrom an input (e.g., an input stream, such as a fluid stream) that includes carbon oxide (e.g., carbon dioxide). Example carbon oxide electrolyzers 100A-100D are illustrated in Figures 1A-1D. The carbon oxide electrolyzers may be configured to accept a gas-phase carbon dioxide input and / or performs the reaction(s) using gas-phase carbon dioxide (e.g., is a gasphase reactor), but can additionally or alternatively accept liquid-phase carbon dioxide, supercritical fluid-phase carbon dioxide, solid-phase carbon dioxide, and / or any other suitable carbon dioxide input. While the discussion herein focuses on carbon dioxide electrolyzers, in many cases the discussion applies equally to other carbon oxide electrolyzers, e.g., carbon monoxide electrolyzers (e.g., electrochemical carbon monoxide reduction reactors), and carbonate and / or bicarbonate reduction electrolyzers. So, unless otherwise specified or clear from context, reference to carbon dioxide electrolyzers is understood to more generally reference carbon oxide electrolyzers. As indicated, the carbon oxide electrolyzer (e.g., electrochemical reactor) may be a gas-phase polymer-electrolyte membrane electrolyzer, but can additionally or alternatively include any other suitable electrolyzer types.

[0037] Examples of carbon oxide reactants include carbon dioxide and carbon monoxide, typically though not necessarily in gaseous form. Other examples of carbon oxide reactant include carbonate ions and compound, and bicarbonate ions and compounds.

[0038] The carbon oxide electrolyzer may include one or more: electrodes (e.g., anode, cathode), catalysts (e.g., within and / or adjacent the cathode and / or anode), gas diffusion layers (e.g., adjacent the cathode and / or anode), and / or flow fields (e.g., defined within and / or adjacent the electrodes and / or gas diffusion layers, such as one or more channels defined opposing the cathode across the gas diffusion layer). In some embodiments, the reactor includes a membrane stack or membrane electrode assembly (MEA) having one or more polymer electrolyte membranes (PEMs), providing ionic communication between the anode and cathode of the reactor. In certain embodiments, the reactor includes a membrane stack including: a cathode layer including a reduction catalyst and an ion-conducting polymer; a PEM membrane (e.g., bipolar membrane, monopolar membrane, etc.; membrane including one or more anion conductors such as anion exchange membranes (AEMs), proton and / or cation conductors such as proton exchange membranes, and / or any other suitable ion-conducting polymers; membrane including one or more buffer layers; etc.); and an anode layer including an oxidation catalyst and an ion-conducting polymer. The ion-conducting polymers of each layer can be the same or different ion-conducting polymers.

[0039] In some embodiments, one or more of the catalysts (e.g., reduction catalyst, oxidation catalyst) can include catalyst particles (e.g., defining a porous network of particles), such asnanoparticles. One or more of the catalysts can additionally or alternatively include one or more polymer electrolytes, optionally wherein the polymer electrolyte is mixed with the catalyst nanoparticles (e.g., arranged within the porous network, such as loaded into the open regions defined by the porous network). The catalyst nanoparticles can define one or more characteristic sizes (e.g., mean size, median size, minimum size, maximum size, size at a particular percentile of the particle size distribution, etc.), and / or the porous network can define a porosity (e.g., fraction of empty space within the network), density, circuitousness (e.g., characteristic path length per layer thickness, area, and / or volume, such as path through the empty spaces or path along interconnected particles, etc.), and / or any other suitable porous network metrics.

[0040] In some configurations, a bipolar MEA has the following stacked arrangement: cathode layer / cathode buffer layer (an anion conducting layer) / cation conductive layer (with may be a PEM) / anode layer. In some implementations, the bipolar MEA has a cathode layer containing an anion conductive polymer and / or an anode layer containing a cation conductive layer. In some implementations, the bipolar MEA has an anode buffer layer, which may contain a cation conductive material, between the cation conductive layer and the anode layer.

[0041] In some configurations, a bipolar MEA has the following stacked arrangement: cathode layer / cation conducting layer (with may be a PEM) / anion conductive layer / anode layer. In some applications, a bipolar MEA having this arrangement is configured in a system for reducing a carbonate and / or bicarbonate feedstock such as an aqueous solution of carbonate and / or bicarbonate.

[0042] In some configurations, an MEA has the following stacked arrangement: cathode layer / anion conducting layer / anode layer. In some implementations, this MEA has no cation conductive layers between the cathode layer and the anode layer. In some applications, an MEA containing only anion conductive material between the cathode and anode is configured in a system for reducing carbon monoxide feedstock.

[0043] In some embodiments, the carbon oxide electrolyzer includes one or more elements such as described in U.S. Patent Application serial number 15 / 586,182, filed 03-MAY-2017 and titled “Reactor with Advanced Architecture for the Electrochemical Reaction of CO2, CO and Other Chemical Compounds”, which is hereby incorporated in its entirety by this reference. However, the electrolyzer can additionally or alternatively include any other suitable elements in any suitable arrangement.

[0044] Additional information regarding optional embodiments and / or elements of the system and / or method are provided below, in US Patent Application Publication No. 2017 / 0321334,filed May 3, 2017, and in US Provisional Patent Application No. 62 / 939,960, filed November 25, 2019, which are incorporated herein by reference in their entireties.

[0045] A carbon oxide electrolyzer may comprise more than one cells or MEAs. The multiple cells or MEAs may be arranged in a stack, electrically connected to one another in series and / or parallel. Unless otherwise indicated, all references herein to a carbon oxide reduction reactor, a carbon oxide electrolyzer, and the like embody single cell electrolyzers and multicell stacks of electrolyzers.

[0046] A non-limiting example of a carbon dioxide electrolyzer in the form of a single-cell COx reduction electrolyzer is illustrated in Figure 2. Figure 2 illustrates the flow of reactants, products, ions, and electrons through a COXelectrolyzer 200 (e.g., a carbon dioxide electrolyzer). An MEA 202 incorporates a cathode 212 and an anode 220 that are separated by an ion-exchange layer 204. The ion-exchange layer 204 can include three sublayers: a cathode buffer layer 214, a polymer electrolyte membrane 216, and an optional anode buffer layer 218. The carbon dioxide electrolyzer 200 also has a cathode support structure 210 located adjacent to the cathode 212. In addition, an anode support structure 222 is adjacent to the anode 220.

[0047] The cathode support structure 210 may be formed of graphite, and / or other suitable electrically conductive material to which a voltage can be applied. Flow field channels can be cut or formed into an inside surface of a cathode polar plate 208 that is part of the cathode support structure 210. These flow field channels may be cut or formed as serpentine, parallel, interdigitated, or other channel designs, such as pin fields. A cathode gas diffusion layer 206 may be positioned adjacent to the inside surface of the cathode polar plate 208. In an alternative embodiment, there may be additional cathode gas diffusion layers (not shown) that abut the cathode gas diffusion layer 206 shown in Figure 2. The cathode gas diffusion layer(s) 206 facilitate the flow of gas (e.g., carbon dioxide) into and out of the MEA 202.

[0048] Similarly, the anode support structure 222 may have an anode polar plate 224 to which a voltage can be applied. The anode polar plate 224 may be formed of metal and / or other suitable electrically conductive material(s). The anode support structure 222 can also incorporate flow field channels, such as the serpentine and other channel designs described above, including pin fields, that are formed in the inside surface of the anode polar plate 224. Some embodiments may incorporate more than one anode gas diffusion layer (e.g., adjacent to, abutting, or offset from other anode gas diffusion layer(s)), not shown in Figure 2. The anode gas diffusion layer 226 facilitates the flow of gas into and out of the MEA 202. In some implementations, the anode gas diffusion layer 226 may be made from titanium mesh or titanium felt, but other suitable materials can be used as well. An additional embodimentprovides microporous cathode gas diffusion and / or anode gas diffusion layers 206, 226 to adjust the flow of gas into and out of the MEA 202.

[0049] Additional inlets and outlets can be provided in the cathode support structures 210 and anode support structures 222 to allow products and reactants to flow to and from the MEA 202. For example, according to some embodiments, the carbon oxide electrolyzer may include a cathode inlet, a cathode outlet, an anode inlet, and an anode outlet, e.g., as represented by the arrows indicating anode feed material and oxidation product (anode inlet & anode outlet) and COXfeed and reduction product (cathode inlet & cathode outlet) shown in Figure 2. In some cases, the cathode input comprises a cathode reactant such as carbon dioxide (e.g., gaseous carbon dioxide), and the cathode output comprises a reduction product stream including one or more reduction products formed from electrochemical reduction of carbon oxide (e.g., carbon dioxide). According to some embodiments, the anode input comprises an anode reactant or feed material, and the anode output comprises an oxidation product stream including one or more oxidation products formed from electrochemical oxidation of the anode reactant or feed material. According to some embodiments, the anode feed may include any of a variety of suitable liquid or gaseous feeds, such as water, hydrogen gas, methane, ammonia, etc.

[0050] A carbon oxide electrolyzer may obtain carbon oxides from various sources. As mentioned, examples of carbon oxide reactants include carbon dioxide, carbon monoxide, carbonate, and / or bicarbonate. In certain embodiments, a carbonate or bicarbonate is provided in the form of an aqueous solution (e.g., an aqueous solution of potassium bicarbonate) that can be delivered to the cathode of a reduction cell. Carbonates and bicarbonates may be obtained from various sources (e.g., minerals) and / or by various reactions (e.g., reacting carbon dioxide with hydroxide).

[0051] A system may optionally include an upstream source of carbon oxide input (e.g., carbon dioxide input), connected to an input of a carbon oxide electrolyzer (e.g., carbon dioxide electrolyzer) of the disclosure, including one or more of: a biogas production system; an ethanol fermentation system such as com ethanol production system, a beer production system, a wine production system; a natural gas processing system; a cement production system; a blast furnace system, for example a steel blast furnace system, capable of producing blast furnace gas; a coke gas production system; power plant systems, such as petroleum power plant systems, natural gas power plant systems, coal power plant systems; petroleum refinery systems; ethylene production systems; ammonia production systems; hydrogen production systems, such as water-gas shift systems; natural gas processing plants (e.g., Benfield processing); ethylene oxide production systems; aluminum smelting systems; liquified naturalgas (LNG) production systems; solid feedstock gasifiers (e.g., municipal solid waste, biomass, or coal feedstocks); reformers (e.g., steam methane reformers, autothermal reformers); systems performing Boudouard reactions; direct air capture (DAC) of carbon dioxide process; atmospheres of planets or moons (e.g., the Martian atmosphere), soil of moons (e.g., the soil of the earth’s moon), and / or any other system capable of producing carbon dioxide. An upstream source of carbon dioxide may be connected directly to an input of a carbon dioxide electrolyzer of the disclosure (e.g., serves as the input, such as connected to the reduction catalyst via the cathode flow field and / or gas diffusion layer, etc.) or alternatively the upstream source may be connected to a purification system; a gas compression system; or both a purification system and a gas compression system, in either order; which then connect to an input of a carbon dioxide system of the disclosure. Multiple purification and / or gas compression systems (e.g., scrubbers, etc.) may be employed.

[0052] The carbon dioxide, carbon monoxide, or carbonate provided as input to a carbon oxide electrolyzer may, depending on the construction and operating conditions of the reactor, have a range of concentrations. In certain embodiments, carbon dioxide provided to a carbon dioxide electrolyzer has a concentration of at least about 20 mole percent, or at least about 40 mole percent, or at least about 75 mole percent, or at least about 90 mole percent. In certain embodiments, carbon dioxide provided to a carbon dioxide electrolyzer has a concentration of about 40 to 60 mole percent.

[0053] An upstream source of water or anolyte for a carbon oxide electrolyzer may come from any of various source and in various forms such as purified tap water, purified sea water, a byproduct of direct air capture of water, optionally with capture of carbon dioxide, combustion processes that may also produce carbon dioxide feedstock, fuel cell byproduct, and the like.

[0054] In embodiments in which a source of purified water is not readily available (e.g., in drought-prone areas) for use in the electrolyzer, other sources of impure or non-purified water (e.g., aqueous streams such as a salt- or ion-containing water) may be used. In some such embodiments, desalination systems and methods may be employed to treat and desalinate such sources of non-purified water, as described in more detail below.

[0055] In some embodiments, purified water may be distilled, or deionized water may be produced by utilizing waste heat produced by a carbon oxide electrolyzer system to desalinate or deionize an aqueous stream such as a salt- and / or ion-containing water.

[0056] In some aspects, systems and methods related to desalinating an aqueous stream are described herein. In some embodiments, the aqueous stream is a salt and / or ion-containing water. In some embodiments, ion-containing water may refer to water or an aqueous streamthat contains one or more impurities such as dissolved ions and / or minerals. A dissolved ion is generally an ion that has been solubilized to such an extent that the ion is no longer ionically bonded to a counter-ion. Ion-containing water may include cations such as alkali metal or alkaline earth metals dissolved in water, additionally or alternatively include anions. Ioncontaining water may include any number of ion species such as phosphorus (e.g., phosphate, phosphite, etc.), nitrogen (e.g., nitrate, nitride, nitrite, etc.), sulfur (e.g., sulfate), sodium, potassium, calcium, magnesium, carbonate, silicate, halides, and combinations thereof. Ioncontaining water can additionally contain some amount of dissolved gases, for example, oxygen and carbon dioxide. In some embodiments, the ion-containing water, in addition to solubilized ion species, may also comprise a suspended and / or emulsified phase that is immiscible in water (e.g., oil and / or grease). Desalination, in some embodiments, may include any of a variety of appropriate methods by which some amount of the dissolved ions and / or minerals are at least partially separated from one or more components (e.g., water) in the aqueous stream (e.g., ion- and / or salt-containing water). Additionally or alternatively, desalination may also be employed separate other impurities (e.g., suspended and / or emulsified phase, dissolved gases) from one or more components (e.g., water) in the aqueous stream (e.g., ion- or salt-containing water).

[0057] In some embodiments, ion-containing water may comprise dissolved salt or dissociated salt ions, e.g., a salt-containing water. In some embodiments, a salt may refer to ionic compound(s) comprising a cation and an anion (e.g., sodium chloride) and salt-containing water may refer to water comprising dissociated or solubilized salt cation and anions and may have some amount of salinity. Seawater contains sodium chloride salt, which is dissolved as sodium and chloride ions, and is a prominent example of a salt-containing water. Seawater may have about 35,000 ppm or at least 35,000 ppm of dissolved salt. Freshwater may also include some salt though at much lower levels than seawater. For example, tap water may have less than 500 ppm or less than 300 ppm salt, standard freshwater (e.g., in lakes or rivers) may have less than 1000 ppm salt, slightly saline water may have about 1,000 to 3,000 ppm of salt, moderately saline water may include about 3000 ppm to 10,000 ppm of salt, and highly saline water may include about 10,000 ppm to 35,000 ppm of salt. The methods and systems described herein may use any of these as a water source.

[0058] The aqueous stream (e.g., ion- and / or salt-containing water) described herein can comprise any of a number of solubilized ion species including, but not limited to, Na+, Mg2+, Ca2+, Sr2+, Ba2+, Cl’, carbonate anions, bicarbonate anions, sulfate anions, bisulfate anions, and / or dissolved silica. In some embodiments, the ion- or salt-containing water comprises atleast one solubilized monovalent cation (i.e., a cation with a redox state of + 1 when solubilized). For example, in some embodiments, the aqueous stream (e.g., ion- or saltcontaining water) comprises Na+and / or K+. In certain embodiments, the ion- or salt-containing water comprises at least one monovalent anion (i.e., an anion having redox state of -1 when solubilized). For example, in some embodiments, the aqueous stream (e.g., the ion- or saltcontaining water) comprises Cl’ and / or Br". In some embodiments, the aqueous stream (e.g., the ion- or salt-containing water) comprises at least one monovalent cation and at least one monovalent anion. In some embodiments, the aqueous stream comprises one or more divalent cations (i.e., a cation with a redox state of +2 when solubilized) and / or one or more divalent anions (i.e., an anion with a redox state of -2 when solubilized). Cations and / or anions having other valencies may also be present in the aqueous stream, in some embodiments.

[0059] The aqueous stream (e.g., ion- and / or salt-containing water) described herein may contain some amount of dissolved ions (e.g., dissociated salt cation and / or anions), for example, having at least 100 ppm, at least 200 ppm, at least 300 ppm, at least 500 ppm, at least 1,000 ppm, at least 3,000 ppm, at least 10,000 ppm, at least 35,000 ppm, at least 50,000 ppm, at least 60,000 ppm, at least 80,000 ppm, at least 100,000 ppm and / or no more than 800,000 ppm, no more than 500,000 ppm, no more than 100,000 ppm, no more than 80,000 ppm, no more than 60,000 ppm, no more than 50,000 ppm, no more than 35,000 ppm, no more than 10,000 ppm, no more than 3,000 ppm, no more than 1,000 ppm, no more than 500 ppm, no more than 300 ppm, no more than 500 ppm of ions (e.g., salt ions). Combinations of the abovereferences ranges are also possible (e.g., between 200 ppm and 50,000 ppm, between 35,000 ppm and 100,000 ppm, between 1000 and 3000 ppm, between 3000 and 10000 ppm, between 10000 and 35000 ppm, between 35,000 ppm and 500,000 ppm, between 200 ppm and 1,000 ppm, between 500 ppm and 1,000 ppm, or between 60,000 ppm and 500,000 ppm). Other ranges are also possible.

[0060] In one set of embodiments, the aqueous stream (e.g., the ion- or salt-containing water) may have a relatively low ion concentration or salinity. For example, the ion- or salt-containing water may have an ion (e.g., salt ion) concentration or salinity of at least 100 ppm, at least 200 ppm, at least 300 ppm, at least 500 ppm, at least 1,000 ppm, and / or no more than 2,000 ppm, no more than 1,000 ppm, no more than 500 ppm, no more than 300 ppm, no more than 200 ppm. Combinations of the above-references ranges are also possible (e.g., between 100 ppm and 2,000 ppm, between 200 ppm and 1,000 ppm, between 500 ppm and 1,000 ppm, etc.). In some such embodiments, the source of the aqueous stream (e.g., ion- or salt-containing water) may be a large body of naturally occurring water or a ‘man-made’ body of water and may beexposed to the atmosphere or be subterranean. Examples of sources for such aqueous stream include, but are not limited to, freshwater sources lake water, pond water, river water, creek water, ground or tap water, reservoir water, rainwater, etc. The desalination methods and systems described herein may use any of these as a water source.

[0061] In one set of embodiments, the aqueous stream (e.g., the ion- or salt-containing water) may have a relatively high ion concentration or salinity. For example, the ion- or saltcontaining water may have an ion (e.g., salt ion) concentration or salinity of at least 1,000 ppm, at least 3,000 ppm, at least 10,000 ppm, at least 35,000 ppm, at least 50,000 ppm, at least 60,000 ppm, at least 80,000 ppm, at least 100,000 ppm and / or no more than 500,000 ppm, no more than 100,000 ppm, no more than 80,000 ppm, no more than 60,000 ppm, no more than 50,000 ppm, no more than 35,000 ppm, no more than 10,000 ppm, or no more than 3,000 ppm. Combinations of the above-references ranges are also possible (e.g., greater than 1000 ppm and no more than 3,000 ppm, between 3,000 ppm and 10,000 ppm, between 10,000 ppm and 35,000 ppm, between 35,000 ppm and 500,000 ppm, or between 60,000 ppm and 500,000 ppm). In some such embodiments, the source of the aqueous stream (e.g., ion- or saltcontaining water) may be a large body of naturally occurring water or a ‘man-made’ body of water and may be exposed to the atmosphere or be subterranean. Examples of sources for such aqueous stream (e.g., ion- or salt-containing water) include, but are not limited to, seawater or streams derived from seawater, brackish water, wastewater, flowback water, effluent of a chemical process, or water produced during oil and / or gas extraction processes. The desalination methods and systems described herein may use any of these as a water source.

[0062] In some embodiments, the waste heat produced by the carbon oxide electrolyzer and / or associated unit(s) may be used (or supplement the energy needed) to facilitate the desalination or deionization of the aqueous stream (e.g., salt- or ion-containing water) via one or more pathways. For example, in one set of embodiments, the waste heat produced by the carbon oxide electrolyzer and / or associated unit(s) may be used (or reduce the energy needed) to vaporize or boil the aqueous stream (e.g., salt- or ion-containing water), which may then be cooled and / or condensed to produce pure or deionized water in a desalination system (e.g., a thermal desalination unit). In some embodiments, the desalination system is a deionization system. In one set of embodiments, the waste heat produced by the carbon oxide electrolyzer may be used to heat and recharge a desalination system (e.g., an ion-exchange desalination unit), which would allow for repeated desalination or deionization of the aqueous stream (e.g., salt- or ion-containing water), e.g., via ion removal, to produce desalinated or deionized water. In some embodiments, the purified, desalinated or deionized salt- or ion-containing water maybe used as an upstream source of water for a carbon oxide electrolyzer. Alternatively, or additionally, this desalinated or purified salt- or ion-containing water may be used water source for a water electrolyzer. Additional details on purifying (i.e., desalinating or deionizing) the aqueous stream (e.g., salt- or ion-containing water) utilizing the waste heat from the carbon oxide electrolyzer and / or associated unit(s) are provided below. Non-limiting examples of associated component(s) include one or more unit(s) coupled (e.g., fluidically coupled) to the carbon oxide electrolyzer that is capable of producing waste heat, such as a water electrolyzer or one or more downstream reactors configured to perform an exothermic reaction (e.g., a Fischer-Tropsch reaction).

[0063] A system may include an input of a downstream system, capable of transforming chemical outputs from a carbon oxide electrolyzer (e.g., carbon dioxide electrolyzer) of the disclosure, connected to an output of a carbon oxide electrolyzer of the disclosure. As examples, a downstream system of the disclosure may include one or more of: a bioreactor system; a liquid hydrocarbon synthesis reactor (e.g., a Fischer-Tropsch system); a gas fermentation system; an anaerobic fermentation system; an aerobic fermentation system, a syngas fermentation system; a ketone and / or polyketone production system; a formate (e.g., metal formate) production system; a formate ester production system; a formamide production system; a hydroformylation system; a methanol synthesis system; an ethylene polymerization system; a phosgene production system, an isocyanate (e.g., diisocyanate) production system, a polymer (e.g., a polycarbonate, polyethylene terephthalate, or polyurethane) production system, an ethylene glycol production system, a monoethylene glycol (MEG) production system, a polyethylene glycol production system, an ethylene production system, an acetic acid production system, an oxalic acid production system, an electrical energy conversion system (e.g., a syngas combustion turbine, a fuel cell, etc.), and / or any other system capable of transforming chemical outputs from a carbon oxide electrolyzer. A carbon dioxide electrolyzer output of the disclosure may be directly connected (e.g., via the cathode flow field and / or gas diffusion layer) to a downstream system, and / or the carbon dioxide electrolyzer output may be connected to a purification system; a gas compression system; or both a purification system and a gas compression system, in either order; which then optionally connect to an input of a downstream system. Multiple purification systems and / or gas compression systems may be employed.

[0064] A downstream system may produce carbon dioxide output in addition to other product outputs. A system may further include a connection between a carbon dioxide containing output of a downstream system and an input of a carbon dioxide electrolyzer. The carbondioxide containing output of a downstream system may be directly connected to an input of a carbon dioxide electrolyzer or alternatively the downstream carbon dioxide containing output may be connected to a purification system; a gas compression system; or both a purification system and a gas compression system, in either order; which then connect to an input of a carbon dioxide electrolyzer of the disclosure. Multiple purification systems and / or gas compression systems may be employed.

[0065] A carbon dioxide electrolyzer can make a range of products (for example, methane, ethylene, carbon monoxide (CO), molecular hydrogen (H2), ethanol, formate, formic acid, acetate, acetic acid, propanol, butanol, ethane, methanol) that can be used in downstream systems and processes. Different carbon dioxide electrolyzers (e.g., including different layer stacks, catalysts and / or catalyst layers, PEMs, flow fields, gas diffusion layers, cell compression configurations, and / or any other suitable aspects, etc.) can be used to achieve different reduction products (e.g., product compositions such as HCR); however, different reduction products can additionally or alternatively be achieved by adjusting the operation parameters, and / or be otherwise achieved. Many possible downstream systems and processes release CO2 (examples include bio-utilization of methane, bio-utilization of formic acid or formate, bio-utilization of acetic acid or acetate, Fischer-Tropsch processes, and methanol synthesis). A carbon dioxide recycling system sized appropriately for the specific application can be used in many of these cases to return CO2 from the downstream system output to an input of a carbon dioxide electrolyzers of the disclosure to increase the carbon efficiency of the overall process.Carbon Oxide Electrolyzer Operation

[0066] The method may be implemented using any of the components described above including a carbon oxide electrolyzer but can additionally or alternatively be implemented using any other suitable system(s). The method optionally includes running the electrolyzer under controlled process conditions (e.g., as described below in further detail) to produce the desired outputs (e.g., CO, H2, etc.) in the desired ratios (e.g., molecular hydrogen-to-carbon- containing product (CCP) ratio (HCR) and / or CCP-to-molecular hydrogen ratio), and / or altering the process conditions to alter the outputs and / or output ratios.

[0067] Running the reactor can include: providing one or more inputs (e.g., gasses, liquids, solids, etc.), such as carbon dioxide, carbon monoxide, a carbon oxide source (e.g., waste gas), and / or water; causing all or some of the inputs to undergo reactions (e.g., by applying a voltage across the device electrodes), thereby generating products; and / or removing the products from the reactor (e.g., as an output gas stream). Such reactions can include, for example, reducingcarbon dioxide and / or water to generate products such as CO (and / or other CCPs, such as formic acid, methanol, glyoxal, methane, acetic acid, glycolaldehyde, ethylene glycol, acetaldehyde, ethanol, ethylene, hydroxyacetone, acetone, allyl alcohol, propionaldehyde, n- propanol, etc.), and / or H2. However, running the reactor can additionally or alternatively include causing any other suitable reactions to occur, and / or can additionally or alternatively include any other suitable elements performed in any suitable manner.

[0068] Under some conditions, the method may achieve carbon dioxide conversion (e.g., CO fractional yield) greater than 95% (e.g., up to 100%), such as wherein the system, run under such conditions, can achieve at least the threshold conversion metric. However, the method can additionally or alternatively include achieving carbon dioxide conversion greater than 50%, 60%, 70%, 80%, 90%; between 10%-100%, such as 10-40, 30-50, 40-60, 50-70, 60-75, 70- 85, 80-95, 90-95, 92-98, and / or 95-100%; and / or any other suitable carbon dioxide conversion.

[0069] The method optionally includes providing the reactor products (or a subset thereof) to a downstream consumer of the products (e.g., as described above, such as regarding applications of the reactor output, etc.). The method can optionally include altering the reactor products after they are produced (e.g., before feeding the altered products to a downstream consumer, etc.). Altering the reactor products can additionally or alternatively include mixing additional gasses (and / or other substances) into a reactor output stream (and / or input stream), such as to achieve a desired output metric. In one variation, if the CO:H2 ratio of the reactor output differs from a desired value, the ratio can be adjusted by mixing the reactor output with other gasses (e.g., substantially pure CO and / or H2; another mixture of CO and H2, such as previously produced and stored outputs of the reactor, the output of a second reactor, outputs and / or waste gasses of other systems, etc.). For example, the CO:H2 ratio of the output stream (and / or gasses in any other portion of the reactor) can be monitored (e.g., continuously during reactor production), and deviations from the desired value can be compensated for by mixing in other gasses (e.g., adding CO and / or a CO-rich mixture to increase the ratio, adding H2 and / or an H2-rich mixture to decrease the ratio). This example may also include altering the process conditions in order to correct the reactor outputs (e.g., as described above regarding closed-loop control). In a second variation, in which an external gas supply (e.g., the outputs and / or waste gasses of one or more other system, such as a steel mill) is fed to a downstream consumer (e.g., a gas fermenter), the reactor products are used to alter the CCP:H2 ratio (e.g., CO:H2 ratio) of the external gas supply (e.g., if the CCP:H2 ratio of the external gas supply differs from a desired value, mixing in the reactor products to achieve the desired value). Forexample, based on the deviation of the external gas supply from the desired value, the process conditions can be controlled to alter the C0:H2 ratio of the reactor products (e.g., increasing the ratio in response to a CO-poor external gas supply, decreasing the ratio in response to a CO-rich external gas supply), and / or the quantity of reactor product mixed into the external gas supply can be controlled (e.g., to achieve the desired value). However, the reactor output stream can additionally or alternatively be altered in any other suitable manner or can be used without alteration.

[0070] The process conditions can include, e.g., input carbon dioxide flow rate and / or pressure, input gas hydration, current density, voltage (e.g., maintained between about 1.5 V and 3 V, additionally or alternatively operated at less than about 1.5 V, between about 2 V-2.5 V, between about 2 V-4 V, greater than about 4 V, and / or at any other suitable voltage(s)), and / or temperature. The process conditions can additionally or alternatively include system configurations, such as gas diffusion layer aspects, catalyst aspects, flow field aspects, and / or PEM aspects.

[0071] The process conditions may include a pressure (e.g., input gas pressure, reactor pressure, etc.) greater than atmospheric pressure (e.g., within and / or greater than a threshold pressure range, such as about 1-5, about 5-10, about 10-20, about 20-50, about 50-100, about 100-300, about 300-1000, about 1-10, about 5-50, about 10-100, about 20-500, and / or greater than about 1000 atm, about 14-50, about 50-150, about 100-300, about 200-500, about 500-1000, about 750-1500, about 1000-3000, about 3000-10,000, about 10,000-20,000, and / or greater than about 20,000 psi, etc.) and / or greater than pressures typically feasible in electrolyzers other than gas-phase electrolyzers, but can additionally or alternatively include pressures substantially equal to 1 atmosphere, less than about 1 atmosphere, and / or any other suitable pressures. The process conditions may include a temperature (e.g., electrolyzer temperature) greater than typical room temperature (e.g., within and / or greater than a threshold temperature range, such as about 25-50 °C, about 40-60 °C, about 50-100 °C, about 50-75 °C, about 70-100 °C, and / or greater than about 100 °C, etc.) and / or greater than temperatures typically feasible in electrolyzers other than gas-phase electrolyzers, but can additionally or alternatively include temperatures substantially equal to room temperature (e.g., about 20-30 °C), less than room temperature, and / or any other suitable temperatures. However, the process conditions can additionally or alternatively include any other suitable process conditions.

[0072] The catalyst can additionally or alternatively include V, Cr, Mn, Fe, Co, Ni, Cu, Sn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Ir, Hg, Al, Si, In, Ga, Tl, Pb, Bi, Sb, Te, Sm, Tb, Ce, Nd, and / or combinations thereof. The catalyst can additionally or alternatively beassociated with (e.g., attached to, supported by, embedded in, adjacent, in contact with, etc.) one or more support structures (e.g., support particles, support matrix, etc.), which may be conductive support structures such as carbon, boron-doped diamond, and / or fluorine-doped tin oxide. However, the catalyst can additionally or alternatively include any other suitable materials.

[0073] In certain embodiments, a carbon oxide electrolyzer is configured to produce, and when operating actually produces, an output stream having a CO:CO2 molar ratio of at least about 1:1 or at least about 1:2 or at least about 1:3. A high CO output stream may alternatively be characterized as having a CO concentration of at least about 25 mole %, or at least about 33 mole %, or at least about 50 mole %. In certain embodiments, an electrolyzer is configured to produce, and in operation actually produces, an output stream having a (H2+CO):CO2 molar ratio of at least about 2:1 or at least about 1:2 or at least about 1:3. In certain embodiments, a carbon dioxide electrolyzer is configured to produce, and when operating actually produces, an output stream having H2:CO in a molar ratio of at least about 1:1. In certain embodiments, a carbon dioxide electrolyzer is configured to produce, and when operating actually produces, an output stream having CO:H2 in a molar ratio of at least about 2:1.Integration Schemes

[0074] Additional information regarding optional embodiments and / or elements of the system and / or method is provided below.

[0075] A product gas from a carbon oxide electrolyzer of the disclosure can be used in one or more downstream processes. For example, a carbon oxide electrolyzer (e.g., a COXelectrolyzer such as a CO2 electrolyzer) of the disclosure configured for CO production can output a stream of CO and unreacted CO2. In some embodiments, the carbon oxide electrolyzer (e.g., a carbon dioxide electrolyzer) configured for syngas production can output a stream of CO, H2, and / or CO2. The carbon oxide electrolyzer may comprise any of a variety of components described elsewhere herein, such as one or more MEAs, a cathode layer comprising a cathode catalyst capable of promoting electrochemical reduction of carbon oxide (e.g., CO2) into one or more carbon-containing species (e.g., CO), an anode layer comprising an oxidation catalyst, a polymer electrolyte membrane layer disposed between (and in contact with) the cathode layer and the anode layer, etc. The heat produced during the operation of a carbon oxide electrolyzer (and optionally a water electrolyzer) may be used in one or more upstream and / or downstream processes that require heating.

[0076] In some embodiments, one or more heat exchanger(s) may be placed downstream of the carbon oxide electrolyzer to remove the heat produced during the operation.

[0077] In some embodiments, a carbon oxide electrolyzer utilizes one or more heat exchanger(s) in an anolyte recirculation loop. Figure 3 depicts an example of a carbon oxide electrolyzer (e.g., a COXelectrolyzer 310 such as a CO2 electrolyzer) that incorporates heat exchanger(s) or heat exchange devices 330 (e.g., radiator, cooling tower, chiller, etc.) to regulate the temperatures of anolyte output 316 and anolyte input stream 318. In various embodiments, one or more heat exchangers or heat exchange devices are used in an anolyte recirculation loop. As depicted in Figure 3, a carbon oxide electrolyzer 310 receives a feed stream of COX(e.g., CO2) 312 and produces an output stream 314 that contains a carbon- containing product (e.g., CO), which may or may not contain some of the unreacted COX(e.g., CO2). The carbon-containing product is a reduction product of COX, according to some embodiments. In some embodiments, the carbon oxide electrolyzer 310 produces hydrogen (H2) as described elsewhere herein, and the output stream 314 containing the carbon-containing product and unreacted COX(e.g., CO and CO2) may contain some H2. In some embodiments, the anolyte outlet stream 316 from the CO2 electrolyzer may be recirculated and provided to the COXelectrolyzer 310 (e.g., CO2 electrolyzer) as an anolyte inlet feed stream 318. In some cases, the anolyte outlet stream 316 may be subjected to various processing units in the recirculation loop, including, but not limited to, one or more oxygen separators 320, one or more heat exchangers 330 (e.g., radiator, cooling tower, chiller), and recirculation pump(s) 340.

[0078] In the recirculation loop, a stream of anolyte outlet 316 may be provided to one or more oxygen separators 320, which are configured to separate oxygen gas 324 in the anolyte outlet stream 316 and provide a stream of oxygen-deficient anolyte outlet 322 to one or more heat exchangers 330. The one or more heat exchangers 330 may be configured to cool (using a cooling fluid) the stream of oxygen-deficient anolyte outlet 322 to produce a stream of cooled anolyte stream 336. Cooled anolyte stream 336 may form a portion of the stream of anolyte inlet 318 that is provided back to the carbon oxide electrolyzer 310. In some embodiments, upstream of the carbon oxide electrolyzer 310, salt (or salt solution) 352 may be injected (e.g., via salt addition unit 350) into the feed stream of the anolyte inlet 316, if necessary, to provide the feed stream of anolyte inlet 318 to the carbon oxide electrolyzer 310 with an appropriate electrolyte concentration or conductivity. In some embodiments, a carbon oxide electrolyzer may optionally utilize a fan and one or more pumps 340 (e.g., recirculation pumps) in the recirculation loop to pump cooled anolyte stream 336 to carbon oxide electrolyzer 310, such as via line 342.

[0079] In some embodiments, due to the heat produced during the operation of the carbon oxide electrolyzer, the stream of anolyte outlet may be at elevated temperatures. For example, as shown in Figure 3, the anolyte outlet stream 316 or 322 may be about 43°C, or between 45 °C to 80 °C. In various embodiments, one or more heat exchangers (e.g., unit 330) may be used to reduce the temperatures of the anolyte outlet stream.

[0080] In some embodiments, the heat exchanger systems may exploit cooling air and / or cooling liquid to reduce the temperature of the anolyte outlet stream to an appropriate temperature range.

[0081] In some embodiments, the heat exchanger systems may involve liquid-to-liquid and / or liquid-to-air heat exchanger units.

[0082] In various embodiments, the heat exchanger systems contain one or more heat exchanger units where each heat exchanger unit, independently, is a liquid-to-liquid heat exchanger unit or liquid-to-air heat exchanger unit.

[0083] When used, heat exchanger systems utilizing liquid-to-air heat exchanger units reduce the temperature of the anolyte outlet stream by using cooling air (e.g., such as shown in Figure 3). Cooling air refers to the air that has a temperature less than the temperature of the anolyte outlet stream. In some embodiments, cooling air may be air drawn in from the exterior of the carbon oxide electrolyzers. In some instances, heat exchanger systems based on liquid-to-air heat exchanger units may be the anolyte outlet stream exposed to cooling air. As shown in Figure 3, cooling fluid 332 such as air may be used to absorb heat from the anolyte outlet stream 322 to produce a cooling fluid 334 having an elevated temperature and the cooled anolyte stream 336. In some embodiments, a heat exchanger system based on a liquid-to-air heat exchanger unit utilizes one or more liquid-to-air heat exchanger units.

[0084] In some embodiments, a heat exchanger system may be a liquid-to-liquid heat exchanger unit interfaced with a liquid-to-air heat exchanger unit to moderate the temperature of the anolyte outlet stream. For instance, such a heat exchanger system may contain a first and second heat exchanger unit, where at least one of the heat exchanger units is a liquid-to-liquid heat exchanger unit. In some embodiments, the first heat exchanger unit is a liquid-to-air heat exchanger unit, and the second heat exchanger unit is a liquid-to-liquid heat exchanger unit. When such a configuration of heat exchanger units is used, cooling air may be supplied to the first heat exchanger unit which is used to reduce the temperature of the cooling liquid. This cooling liquid is supplied to the second heat exchanger unit. The second heat exchanger unit receives and utilizes this cooling liquid to reduce the temperature of the anolyte outlet stream.

[0085] In some embodiments, the cooling liquid may be primarily water but can contain additives such as glycol. The additives may be used to prevent freezing of the cooling liquid. For example, a cooling liquid may be a mixture of water and glycol. In some embodiments, the water / glycol mixture is used as a coolant in regions where the temperatures of the air may reach below the freezing point of water.

[0086] The advantage of the heat exchanger system utilizing the liquid-to-liquid heat exchanger unit interfaced with the liquid-to-air heat exchanger unit is that it may be used in regions subjected to below 0°C temperatures.

[0087] In one example, the first liquid-to-air heat exchanger unit may be located outside and / or on the exterior of the carbon oxide electrolyzer (e.g., carbon dioxide electrolyzer). In some embodiments, the second liquid-to-liquid heat exchanger unit is located inside and / or the interior of the carbon oxide electrolyzer.

[0088] In some embodiments, cooling liquid may be exposed to air and may include an optional (not shown) water source and water inlet providing a feed stream of water, as necessary, to maintain the volume and concentration of the cooling liquid.

[0089] In some embodiments, the heat exchanger unit may use an aqueous stream such as an ion- or salt-containing water stream, such as seawater, as a cooling liquid to reduce the temperature of the anolyte outlet stream to an appropriate temperature range. Examples of saltcontaining water include but are not limited to seawater, brackish water, wastewater, flowback water, water produced during oil and / or gas extraction processes, or any other water source described elsewhere herein. In some embodiments, the heat produced by the carbon oxide electrolyzer is transferred to the salt-containing water stream. In some embodiments, the heat produced by the carbon oxide electrolyzer (which is transferred to the aqueous stream (e.g., ion- or salt-containing water stream)) may be employed to desalinate salt-containing water stream into a pure water stream for use in one or more downstream units (e.g., carbon oxide electrolyzer, water electrolyzer, etc.).

[0090] It will be understood that the descriptions and examples herein are provided in the context of an aqueous stream such as ion- or salt-containing water. Any of a variety of appropriate aqueous stream described elsewhere herein may be used.

[0091] In addition, the descriptions and examples herein are provided in the context of desalination, it will be understood that an aqueous stream (e.g., salt- or ion-containing water) can be deionized to produce purified (deionized water). For example, an aqueous stream (e.g., salt-or ion-containing water) may be deionized to produce purified water. In many of the embodiments described, a particular process to treat water may be described as bothdesalination and deionization. For example, desalinizing an aqueous stream (e.g., ion- or saltcontaining water) may involve deionization of salt ions (e.g., sodium and chloride ions) from the aqueous stream. In various embodiments, an aqueous stream (e.g., salt- or ion-containing water) may be desalinated or deionized to produce purified water. In some cases, purified water is desalinated water resulting from distillation (by a thermal desalination process) or deionization (by ion-exchange desalination process) of an aqueous stream such as salt- or ioncontaining water.

[0092] Utilizing an aqueous stream such as an ion- or salt-containing water as the cooling liquid may be advantageous as the aqueous stream is less likely to be subjected to freezing limitations compared to using water as a cooling liquid. Hence, even when the carbon oxide electrolyzers are operated in regions subjected to below 0°C, an ion- or salt-containing waterbased heat exchanger unit may be operated in the absence of the second heat exchanger unit.

[0093] Figures 4A - 4F depict examples of a carbon oxide (COX) electrolyzer (e.g., a carbon dioxide (CO2) electrolyzer) that uses a salt-containing water stream (e.g., seawater) to regulate the temperatures of anolyte output stream and anolyte input stream. Figures 4A - 4F also illustrate downstream integration schemes utilizing a salt-containing water stream (e.g., seawater stream) and the carbon oxide electrolyzer with a desalination unit with a single heat exchanger loop. While examples in Figures 4A - 4F are described in the context of seawater, embodiments may be practiced using any other types of aqueous stream described elsewhere herein. It will be understood that references to seawater apply to any aqueous stream described herein, with references to the sea applying to any source or storage of aqueous stream. The aqueous stream may have any appropriate salinity and / or composition and may be sourced from any appropriate sources described elsewhere herein. For example, any references to seawater may be replaced by other aqueous streams such as brackish water, wastewater, flowback water, effluent of a chemical process, or water produced during oil and / or gas extraction processes, lake water, pond water, river water, creek water, ground or tap water, reservoir water, rainwater, etc. Similarly, while examples in Figures 4A - 4F are described in the context of a MEA -based carbon dioxide electrolyzer, embodiments may be practiced using any other types of carbon oxide electrolyzer. The MEA-based carbon dioxide electrolyzer may have any appropriate configuration and / or property described elsewhere herein, such as with reference to Figures 1A-2.

[0094] In some embodiments, as shown in Figures 4A-4F, an anolyte inlet stream 318 is introduced to the COXelectrolyzer 310 (e.g., CO2 electrolyzer) and an anolyte outlet stream 316 having a higher temperature than the anolyte inlet stream 318 is produced. The anolyteinlet stream 318, in some cases, may serve as a cooling liquid configured absorb waste heat produced by the COXelectrolyzer during operation. In some such embodiments, an anolyte outlet stream 316 having a higher temperature than the anolyte inlet stream 318 is produced. Additionally, in some embodiments, at least a portion (e.g., a relatively small portion) of the anolyte inlet stream 318 may undergo oxidation reaction to electrochemically produce oxidation products (e.g., oxygen) from the anolyte inlet stream. The oxidation reaction may be facilitated by anode catalyst capable of promoting oxidation of water present within the anolyte inlet stream. In some cases, one or more separation units (e.g., an oxygen separator 320) may be employed to remove oxygen (e.g., via oxygen outlet stream 324) from the anolyte outlet stream (e.g., stream 316) to produce an oxygen deficient anolyte stream (e.g., stream 322).

[0095] In some embodiments, a substantial amount of the anolyte input (e.g., stream 318 as shown in Figures 4A-4F) fed to the COXelectrolyzer may serve as a cooling liquid, e.g., such it does not undergo electrochemical reaction and may be flowed out of the anolyte outlet stream as unreacted anolyte (while only a small amount of the anolyte may undergo electrochemical reaction). For example, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 99%, at least 99.9%, and / or up to 90%, up to 95%, up to 99%, up to 99.9%, up to 99.95%, up to 99.99% or more of the anolyte input stream by mass may be flowed out in the anolyte output stream as unreacted anolyte without undergoing electrochemical reaction, in some embodiments. Combinations of the above-referenced ranges are possible (e.g., at least 50% and up to 99.9%, at least 60% and up to 90%, at least 80 and up to 90%, at least 90% and up to 99.9%, at least 95% and up to 99.95%, at least 99.9% and up to 99.99%, etc.). Other ranges are also possible.

[0096] In some embodiments, the anolyte inlet stream (e.g., stream 318 as shown in Figures 4A-4F) comprises anolyte (e.g., anode water), which is water or an aqueous solution containing a predetermined concentration and / or type of salt(s) and / or ion(s). In some cases, the anolyte inlet stream is a salt water and / or ionized water. In some embodiments, the anolyte outlet stream (e.g., stream 316 as shown in Figures 4A-4F) comprises an oxidation product of water (e.g., molecular oxygen) and any unreacted anolyte (e.g., anode water).

[0097] The anolyte inlet stream (e.g., stream 318 as shown in Figures 4A-4F) may have any of a variety of appropriate temperatures, such as at least 20 °C, at least 25 °C, at least 30 °C, at least 35 °C, at least 40 °C, at least 45 °C, at least 50 °C, at least 55 °C, at least 60 °C, at least 63 °C, at least 65 °C, and / or no more than 80 °C, no more than 70 °C, no more than 65 °C, no more than 63 °C, no more than 60 °C, no more than 55 °C, no more than 50 °C, no more than 45 °C, no more than 40 °C, no more than 35 °C, no more than 30 °C. Combinations of theabove-referenced ranges are possible (e.g., at least 25 °C and no more than 70 °C, at least 35 °C and no more than 65 °C, at least 35 °C and no more than 63 °C, at least 35 °C and no more than 50 °C, etc.). Other ranges are also possible.

[0098] The anolyte outlet stream (e.g., stream 316 as shown in Figures 4A-4F) may have any of a variety of appropriate temperatures, such as at least 20 °C, at least 25 °C, at least 30 °C, at least 35 °C, at least 40 °C, at least 45 °C, at least 50 °C, at least 55 °C, at least 60 °C, at least 63 °C, at least 65 °C, at least 70 °C, and / or no more than 85 °C, no more than 80 °C, no more than 70 °C, no more than 65 °C, no more than 63 °C, no more than 60 °C, no more than 55 °C, no more than 50 °C, no more than 45 °C, no more than 40 °C, no more than 35 °C, no more than 30 °C. Combinations of the above-referenced ranges are possible (e.g., at least 30 °C and no more than 75 °C, at least 40 °C and no more than 70 °C, at least 40 °C and no more than 65 °C, etc.). Other ranges are also possible.

[0099] In some embodiments, the anolyte outlet stream (e.g., stream 316 as shown in Figures 4A-4F) may have a temperature that is higher than the anolyte inlet stream (e.g., stream 318 as shown in Figures 4A-4F). For example, the anolyte outlet stream may have a temperature that is at least 0.1 °C, at least 0.5 °C, least 1 °C, at least 2 °C, at least 3 °C, at least 5 °C, at least 10 °C, at least 15 °C, and / or no more than 20 °C, no more than 15 °C, no more than 10 °C, no more than 5 °C, no more than 3 °C, no more than 2 °C, no more than 1 °C, or no more than 0.5 °C higher than the anolyte inlet stream. Combinations of the above-referenced ranges are possible (e.g., at least 0.1 °C and no more than 15 °C, at least 0.5 °C and no more than 10 °C, at least 1 °C and no more than 10 °C, at least 1 °C and no more than 5 °C, at least 1 °C and no more than 3 °C, etc.). Other ranges are also possible.

[0100] In some embodiments, as depicted in Figures 4A and 4B, the carbon oxide electrolyzer 310 may use a liquid-liquid heat exchanger system 410 (e.g., a seawater-based heat exchanger unit) configured to exchange heat between the anolyte outlet stream 322 and a first aqueous stream 412 (e.g., an ion- or salt-containing water stream such as a seawater stream). In some cases, via the heat exchanger unit, the first aqueous stream 412 (e.g., an ion- or salt-containing water stream such as the seawater inlet stream) is heated via indirect heat exchange with the anolyte outlet stream 322 to thereby produce a heated first aqueous stream 414 (e.g., a heated first salt- or ion-containing water stream such as a warm seawater stream). In some such cases, a corresponding amount of heat is removed from the anolyte outlet stream 322 entering into the heat exchanger 410 to produce a cooled anolyte stream 416 having a lower temperature than the anolyte outlet stream 322. The cooled anolyte stream 416 may be recycled via recycle path 426 into the anolyte inlet stream 318. The anolyte inlet 318 and outlet 322 streams mayhave any of a variety of appropriate temperatures described above. According to some embodiments, the heat exchange process depicted herein transfers waste heat produced by the carbon oxide electrolyzer 310 to the first aqueous stream 412 (e.g., an ion- or salt-containing stream such as a seawater stream); thereafter, the waste heat carried by the heated first aqueous stream 414 (e.g., warm seawater stream) may be used in various downstream processes, such as a desalination system 420 to desalinate an aqueous stream (e.g., a salt-containing water stream such as a seawater stream) and produce pure, distilled, or deionized (DI) water.

[0101] The first aqueous stream 412 (e.g., a salt-containing stream such as seawater inlet stream) introduced into the heat exchanger system may have any of a variety of appropriate temperatures, such as at least 5 °C, at least 10 °C, at least 15 °C, at least 20 °C, at least 25 °C, at least 30 °C, at least 35 °C, at least 40 °C, at least 41 °C, and / or no more than 50 °C, no more than 45 °C, no more than 41 °C, no more than 40 °C, no more than 35 °C, no more than 30 °C, no more than 25 °C, no more than 20 °C, no more than 15 °C, no more than 10 °C. Combinations of the above-referenced ranges are possible (e.g., at least 5 °C and no more than 45 °C, at least 5 °C and no more than 41 °C, etc.). Other ranges are also possible.

[0102] The heated first aqueous stream 414 (e.g., a salt-containing stream seawater outlet stream) output from the heat exchanger unit may have any of a variety of appropriate temperatures, such as at least 7 °C, at least 10 °C, at least 15 °C, at least 20 °C, at least 25 °C, at least 30 °C, at least 35 °C, at least 40 °C, at least 43 °C, and / or no more than 50 °C, no more than 45 °C, no more than 43 °C, no more than 40 °C, no more than 35 °C, no more than 30 °C, no more than 25 °C, no more than 20 °C, no more than 15 °C, no more than 10 °C. Combinations of the above-referenced ranges are possible (e.g., at least 7 °C and no more than 50 °C, at least 7 °C and no more than 43 °C, etc.). Other ranges are also possible.

[0103] In some embodiments in which the heat exchanger unit described herein (e.g., unit 410 as shown in Figures 4A-4F) is a seawater-based heat exchanger unit, seawater may be used as the cooling liquid. Such a heat exchanger unit draws in seawater to reduce the temperature of the anolyte outlet stream (e.g., stream 322) and outputs seawater (e.g., stream 414) at an elevated temperature while producing an anolyte stream (e.g., stream 416) at a reduced temperature. As shown, according to some embodiments, the stream of the anolyte outlet (e.g., stream 316) exiting from the carbon oxide electrolyzer (e.g., unit 320) may be optionally provided to one or more oxygen separators (e.g., separators 316), which separates oxygen gas (as oxygen output) in the anolyte outlet stream and provides oxygen-deficient anolyte outlet stream (e.g., stream 322) to one or more heat exchanger units.

[0104] The various streams associated with the heat exchanger system may have one or more temperatures described above. For example, in one set of embodiments, the anolyte outlet stream (e.g., stream 316 or 322) may be between 40°C and 65 °C, and the heat exchanger unit(s) receives an aqueous stream such as seawater, thereby reducing the temperature of the anolyte and outputting the anolyte stream (e.g., stream 416, 426, or 318) at between 35 °C and 63 °C. In some cases, the seawater inlet stream (e.g., stream 412) may have a temperature of between 5 °C and 41 °C, and the heat exchanger unit(s) outlets warm seawater (e.g., stream 414) at between 7 °C and 43 °C. Other temperature ranges described elsewhere herein are also possible. The heat exchange process depicted herein transfers waste heat produced by the carbon oxide electrolyzer to the seawater; thereafter, the waste heat carried by the seawater may be used in various downstream processes. For example, the waste heat may be used to desalinate seawater and produce pure, distilled, or deionized (DI) water.

[0105] In some embodiments, the system comprises a desalination system configured to receive at least a portion of the heated first aqueous stream (e.g., a heated salt-containing water stream such as warm seawater) and to output a desalinated aqueous stream (e.g., a DI water). In some embodiments, as depicted in Figures 4A and 4B, the systems 400A-400B comprise a desalination system 420 and at least a portion (e.g., at least 10% and up to 90%, at least 50% and up to 80%, or all) of the heated first aqueous stream 414 (e.g., a heated ion- or saltcontaining stream such as a warm seawater stream) is directed to the desalination system 420 (e.g., via stream 415) to produce a desalinated aqueous stream 424 (e.g., a distilled or deionized water stream).

[0106] The desalinated aqueous stream may have any of a variety of appropriate ion or salt concentration (e.g., salinity). For example, the desalinated aqueous stream may have an ion or salt concentration of no more than 500 ppm, no more than 300 ppm, no more than 200 ppm, no more than 100 ppm, no more than 50 ppm, or less (such as a near-zero level of ions), in some embodiments. In some embodiments, the desalinated aqueous stream is a distilled or deionized water stream.

[0107] In some embodiments, the desalination system comprises a thermal desalination unit. In some such embodiments, the desalination may occur via desalinating the heated first aqueous stream (e.g., a heated ion- or salt-containing stream such as warm seawater) output from the heat exchanger unit(s) to thereby produce a desalinated aqueous stream (e.g., DI water). This may be achieved by vaporizing water from the heated first aqueous stream and condensing the vaporized water to produce the desalinated aqueous stream, in some embodiments. For example, the desalination system 420 in Figures 4A-4B may comprise athermal desalination unit. For example, in one set of embodiments, the heat exchanger unit(s) 410 may utilize the waste heat produced by the carbon oxide electrolyzer 310 (via heat exchange with the anolyte outlet stream 322) to ‘preheat’ at least a portion of the first aqueous stream 412 (e.g., a cold seawater stream) into the heated first aqueous stream 414 (e.g., a warm seawater stream) and feed at least a portion of the heated first aqueous stream 415 (e.g., warm seawater) to the thermal desalination unit 420. Subsequently, the thermal desalination 420 unit, with application of heat 422, may evaporate the heated first aqueous stream (e.g., warm seawater) into water steam / vapor and condenses the steam / vapor to produce desalinated aqueous stream (e.g., DI or pure water). ‘Preheating’ the first aqueous stream (e.g., cold seawater) using waste heat from carbon oxide electrolyzers via heat exchanger systems may allow for more efficient heat usage since less heat and energy would be needed by the thermal desalination unit to vaporize and desalinate the first aqueous stream (e.g., cold seawater).

[0108] As depicted in Figures 4A-4B, in some cases, additional heat 422 may be introduced to the thermal desalination unit to evaporate the heated first aqueous stream 415 (e.g., a heated ion- or salt-containing water stream such as warm seawater) when producing the desalinated aqueous stream 424 (e.g., DI or pure water). In some embodiments, instead or in addition to introducing heat, pressure may be tuned to facilitate evaporation. For example, vacuum may be applied during the thermal desalination process to reduce the amount of heat / energy needed to evaporate the seawater. In some instances, thermal desalination process is performed at low pressures (e.g., no more than 1000 mPa, no more than 100 mPa, no more than 10 mPa, no more than 1 mPa, no more than 0.1 mPa, etc.) or in vacuum to allow the heated first aqueous stream 415 (e.g., warm seawater) to evaporate at a lower temperature. In some embodiments, pressure may be sufficiently low such that the heated first aqueous stream 415 (e.g., warm seawater) evaporates with little to essentially no additional heat introduced to the desalination system. In some embodiments, application of a vacuum on the heated first aqueous stream (e.g., warm seawater as shown in Figures 4A-4B) (without additional heat) may be sufficient for evaporation / desalination to occur.

[0109] In various embodiments, the thermal desalination unit (e.g., such as desalination system 420 in Figures 4A-4B) includes an evaporation unit (e.g., a boiler, an evaporator, etc.) configured to boil the heated first aqueous stream (e.g., a heated ion- or salt-containing water stream such as warm seawater) and a condenser unit (e.g., a condenser, a chiller, etc.) configured to condense the water vapor produced by the evaporation unit. In some cases, the boiler may be a vacuum boiler. Alternatively, the thermal desalination unit can include, for example, distillation units such as a multiple-effect distillation (MED), multistage-flashdistillation (MSF), vapor-compression distillation (VCD), membrane distillation, etc. In some embodiments, the thermal desalination unit may be a type of humidification and / or dehumidification (HDH) desalination system which include a humidification unit (e.g., humidifier) and a dehumidification unit (e.g., dehumidifier). HDH desalination system, when in use, can contact the heated first aqueous stream (e.g., a heated first ion- or salt-containing water stream such as warm seawater) with a carrier gas in a humidification unit, such that the carrier gas becomes heated and humidified. Subsequently, the heated and humidified gas may be brought into contact with cold water in a dehumidification unit, thereby producing the desalinated aqueous stream (e.g., purified water such as distilled and / or deionized water).

[0110] In some embodiments, at least a portion of the desalinated aqueous stream (e.g., desalinated seawater) may be provided to the downstream electrolyzer(s), such as a carbon oxide electrolyzer and / or water electrolyzer (when present), as a source stream of purified water (e.g., DI water) for the anolyte inlet stream fed to the downstream electrolyzer(s). As shown in Figure 4A, the desalination system 420 outputs a desalinated aqueous stream 424 (e.g., desalinated seawater) in the form of purified water (e.g., DI water), and at least a portion of the purified water output from the desalination system 420 may be introduced to the anolyte inlet stream 318 of the carbon oxide electrolyzer 310 via recirculation loop 426, together with a recycled stream of cooled anolyte 416 output from the heat exchanger(s) 410.

[0111] In some embodiments, as shown in Figures 4A, via a salt addition or dosing unit 352 upstream of the carbon oxide electrolyzer 310, salt (or a salt solution) 352 may be injected into the anolyte inlet stream 318 to provide a feed stream of anolyte inlet to the carbon oxide electrolyzer with an appropriate electrolyte concentration to maintain conductivity. In some embodiments, the system may optionally utilize a fan and one or more pumps (e.g., recirculation pumps) 340 in the recirculation loop 426.

[0112] While Figure 4A illustrates an embodiment in which the system comprises a carbon dioxide electrolyzer, it should be understood that other types of electrolyzers, such as a water electrolyzer, may also be present in the system (e.g., such as water electrolyzer 440 as shown in Figure 4B). In some embodiments in which a water electrolyzer is present, at least a portion of the desalinated water outlet stream (e.g., in the form of DI water output) from the desalination system may be directed to a water electrolyzer as a source stream of anolyte feed for the water electrolyzer. For example, as depicted in Figure 4B, at least a portion of the desalinated aqueous stream 424 (e.g., DI water output) from the desalination system 420 may be directed and recycled to both the anolyte inlet stream 318 of the carbon oxide electrolyzer 310 (e.g., via stream 424a and anolyte recirculation loop 426) and the anolyte inlet stream 432of the water electrolyzer 440 (e.g., via stream 424b). One or more pumps 430 may be present upstream of the water electrolyzer 440 (and downstream of the desalination system 420) to introduce desalinated aqueous streams 424b (e.g., DI water) produced by the desalination system to the water electrolyzer. In some embodiments, optional salt addition units (not shown) may be present upstream of the water electrolyzer 440.

[0113] The water electrolyzer 440 may be configured to outlet a stream 444 containing water and oxy gen-containing products (e.g., O2), in some embodiments. The water electrolyzer 440 may be configured to produce hydrogen 442 which can be provided to and / or integrated with downstream process(es) or reactor(s) 460. For example, as illustrated in Figures 4B and 4D, at least a portion of the hydrogen 442 produced by the water electrolyzer 440 and at least a portion of the COXreduction product 452 (e.g., carbon monoxide) produced by the carbon oxide electrolyzer 310 (e.g., CO2 electrolyzer) may be combined to form a combined stream 446 (e.g., a syngas stream) that is then provided to downstream process(es) or reactor(s). Any of a variety of appropriate downstream process(es) described elsewhere herein may be employed.

[0114] In some embodiments, the downstream process(es) includes one or more downstream process(es) or reactors such as described in U.S. Patent Application serial number 18 / 052,845, filed November 04, 2021 and titled “System and method for carbon dioxide reactor control”, which is hereby incorporated in its entirety by this reference. However, the downstream process(es) can additionally or alternatively include any other suitable elements in any suitable arrangement.

[0115] In some implementations, downstream processes and reactors may include but are not limited to, Fischer-Tropsch reactors, formate production unit, gas fermentation reactors, acetic acid production units, polycarbonate production units, oxalic acid production units, polyethylene terephthalate production units, polyurethane production units, isocyanate production units, phosgene production units, ethylene glycol production units, methanol production units, polycarbonate production units, MEG production units, etc.

[0116] In some embodiments, as depicted in Figures 4A-4B, the product stream 314 of a carbon oxide electrolyzer 310 contains COXreduction product (e.g., carbon monoxide (CO)) and unreacted carbon oxide (e.g., carbon dioxide). As described elsewhere herein, this product stream may be supplied to an optional purification unit 450 (e.g., CO purification unit) configured to receive a stream of COXreduction product and unreacted COX(e.g., CO / CO2), and separate the COXreduction product (e.g., CO) from COX(e.g., CO2). In some embodiments, the separated COX(e.g., CO2) stream 454 is recycled back to the carbon oxide electrolyzer 310via recycle path 454, and the separated COXreduction product 452 (e.g., CO) is directed to downstream processes / reactors 460 described above (e.g., a Fischer-Tropsch process).

[0117] While Figures 4A-4B illustrate an embodiment in which the desalination system comprises a thermal desalination unit, it should be understood that the disclosure is not limited and that in certain embodiments, other types of desalination unit may be employed in the desalination system. In some embodiments, the desalination system may include a deionization or ion-exchange unit configured to selectively remove or exchange ions using a membrane and / or absorbent based system. For example, in some embodiments, the desalination system may include an ion-exchange desalination unit (e.g., a recharged ion-exchange desalination unit). The ion-exchange unit may contain resins that contain synthetic polymeric beads or granules with charged sites that can attract, from a solution, ions of the opposite charge, to desalinate by removing or concentrating impurities. During the operation, these ion-exchange resins are used and may become “spent” (i.e., they no longer contain charged sites). In some cases, recharging or regenerating the ‘spent’ ion-exchange resins may be achieved by heating up the ‘spent’ resin, and the recharged / regenerated ion-exchange resin may be used in desalinizing (i.e., remove ions from) a stream of an aqueous stream such as an ion- or saltcontaining water (e.g., seawater) into a desalinated aqueous stream (e.g., DI water). Other types of deionization or ion-exchanged units are described elsewhere herein.

[0118] Figures 4C-4D illustrate downstream integration schemes of utilizing a carbon oxide electrolyzer 310 (e.g., CO2 electrolyzer) with a desalination system 500 that includes one or more ion-exchange desalination units. As shown in systems 400C-400D, an anolyte inlet stream 318 (e.g., anode water) is introduced to the COXelectrolyzer 310 and an anolyte outlet stream 316 having a higher temperature than the anolyte inlet stream 318 is produced, similar to as described with respective to Figures 4A-4B. Similar to as described above, the anolyte outlet stream 316 may be introduced to an oxygen separator 320 such that oxygen 324 is removed from the anolyte outlet stream 316. The anolyte outlet stream 316 may be then directed into a heat exchanger system 410 to exchange heat with a first aqueous stream 412 (e.g., a first ion- or salt-containing water stream such as a seawater inlet stream), such that a heated first aqueous stream 502 (e.g., a heated first ion- or salt-containing water stream such as a warm seawater stream) and a cooled anolyte stream 416 having a temperature that is lower than the anolyte outlet stream 322 are produced via the indirect heat exchange. According to some embodiments, at least a portion of the heated first aqueous stream 502 (e.g., warm seawater stream) is directed to an ion-exchange desalination unit in the desalination system 500, thereby providing heat to the ion-exchange desalination unit. As shown in Figures 4C-4D, the ion-exchange desalination unit (as desalination system 500) may utilize the heat carried by the heated first aqueous stream 502 (e.g., heated first ion- or salt-containing water stream such as warm seawater stream) to heat up and recharge the ‘spent’ resin (not shown) within the ion-exchange desalination unit. As shown, after the recharge, the heated first aqueous stream 502 becomes a cooled first aqueous stream 508 and is removed from the desalination system 500.

[0119] In some embodiments, upon recharging, the ion-exchange desalination unit may be employed to desalinate (e.g., de-ionize) a second aqueous stream (e.g., a second ion- or saltcontaining water stream) flowing through the ion-exchange desalination unit. For example, as shown in Figures 4C-4D, after recharging the ion-exchange desalination unit in desalination system 500, a second aqueous stream 504 (e.g., a second ion- or salt-containing water stream such as a cold seawater stream) may be introduced into the recharged ion-exchange desalination unit in desalination system 500, which can be then desalinated by the recharged ion-exchange resins to produce a desalinated aqueous stream 506 (e.g., DI water). In some embodiments, the first aqueous stream 412 (e.g., first ion- or salt-containing water stream) fed to the heat exchanger 410 and the second aqueous stream 504 (e.g., second ion- or saltcontaining water stream) fed to the desalination system 500 may be the same or different and may be selected from a variety of water types described elsewhere herein. The second aqueous stream may have any appropriate ion (e.g., salt ion) concentration or salinity and / or may originate from any appropriate sources as described with respect to the first aqueous stream. In some embodiments, the second aqueous stream is the same as the first aqueous stream (e.g., having the same salinity and / or originate from the same source). Alternatively, the second aqueous stream differs from the first aqueous stream (e.g., having different salinity and / or originate from a different source).

[0120] In various implementations, as shown in Figures 4C-4D, the heated first aqueous stream 502 (e.g., the first heated ion- or salt-containing water such as warm seawater stream), after providing heat to the ion-exchange desalination unit in desalination system 500, is output from the ion-exchange desalination unit as a cooled first aqueous stream 508 (e.g., a cooled first salt-containing water stream such as a cold seawater stream). The cooled first aqueous stream 508 may be returned to a source of the aqueous stream (e.g., source of ion-or saltcontaining water such as the sea). Alternatively or additionally, the cooled first aqueous stream 508 (e.g., the cooled first salt-containing water stream such as cold seawater) may be recycled back to the desalination unit via a recirculation loop (not shown) to form at least a portion of the second aqueous stream 504 (e.g., the second ion- or salt-containing water stream such asthe seawater input stream) and undergo further desalination to produce the desalinated aqueous stream 506 (e.g., DI water). Alternatively or additionally, the cooled first aqueous stream 508 (e.g., the cooled first salt-containing water stream such as cold seawater) may be recycled back to the heat exchanger 410 via a recirculation loop (not shown) to form at least a portion of the first aqueous stream 412 (e.g., the first ion- or salt-containing stream such as cold seawater) and undergo further heat exchange with the anolyte outlet stream 322, in some embodiments.

[0121] In some embodiments, as depicted in Figures 4C-4D, the desalination process may be operated continuously, where the ‘spent’ ion-exchange resin can be repeatedly recharged or regenerated by the heated first aqueous stream 502 (e.g., the heated first ion- or salt-containing water stream such as warm seawater) to allow for desalination of the second aqueous stream 504 (e.g., the second ion- or salt-containing water stream such as the seawater input stream) to produce the desalinated water stream 506 (e.g., DI water).

[0122] In some embodiments, the desalinated aqueous stream (e.g., desalinated seawater in the form of DI water) may be provided to the downstream electrolyzer(s), such as a carbon oxide electrolyzer or water electrolyzer, as a source stream of DI water. As shown in Figure 4C, at least a portion of the desalinated aqueous stream 506 (e.g., DI water) output from the desalination system 500 may be introduced to the anolyte inlet of the carbon oxide electrolyzer 310 via recirculation loop 426 and anolyte inlet stream 318. In some embodiments, as shown in Figure 4C, via a salt dosing or addition unit 350 upstream of the carbon oxide electrolyzer 310, salt (or salt solution) may be injected into the anolyte inlet stream 318, if necessary, to provide a feed stream of anolyte inlet to the carbon oxide electrolyzer 310 with an appropriate electrolyte concentration maintaining conductivity. In some embodiments, a carbon oxide electrolyzer may optionally utilize a fan and one or more pumps (e.g., recirculation pumps) in the recirculation loop.

[0123] In some embodiments in which a water electrolyzer is present (as depicted by Figure 4D), at least a portion of the desalinated aqueous stream 506 (e.g., DI water) output from the desalination system 500 may be directed to a water electrolyzer 440 as a source stream of anolyte feed (e.g., DI water). In some embodiments, a portion of the desalinated aqueous stream 506 (e.g., DI water) output from the desalination system 500 is directed and recycled to both the carbon oxide electrolyzer 310 (via stream 506a and anolyte recirculation loop 426) and the water electrolyzer 440 (via stream 506b), as illustrated in Figure 4D. Additionally, one or more pumps may be present upstream of the water electrolyzer 430 (and downstream of the desalination unit) to introduce the desalinated aqueous stream 432 (e.g., DI water) produced by the desalination unit to the water electrolyzer. In some embodiments, an optional salt additionunit (not shown) may be present upstream of the water electrolyzer. System 400D in Figure 4D may include identical components (e.g., downstream process(es) 460, purification unit 450, COXrecycle path 454, etc.) and fluidic connectivity described elsewhere herein, such as with respect to Figure 4B.

[0124] In some embodiments, the integration scheme further comprises using waste heat produced by a water electrolyzer, in addition to using waste heat from the carbon oxide electrolyzer as described with respect to Figures 4A-4D, to facilitate desalination of an ion- and / or salt-containing water (e.g., seawater). Examples of one such embodiment are depicted in Figures 4E-4F. Specifically, Figure 4E is identical to Figure 4B and Figure 4F is identical to Figure 4D, with the exception of one or more additional heat exchanger unit(s) 470 downstream the water electrolyzer 440 and optionally, an additional oxygen separator 480 downstream the additional heat exchange unit(s) 470. As shown in Figures 4E-4F, according to some embodiments, the water electrolyzer 440 may produce a heated product stream 473 comprising unreacted water and oxygen that is directed into the additional heat exchanger unit(s) 470 downstream the water electrolyzer. The heat may be transferred to another aqueous stream 472 (e.g., another ion- or salt- containing water stream such as a seawater inlet stream) fed to the additional heat exchanger unit(s) 470 to produce an additional heated aqueous stream 474 (e.g., an additional heated ion- or salt-containing outlet stream such as warm seawater stream). The additional heated aqueous stream 474 (e.g., warm seawater stream) produced by the additional heat exchanger unit(s) 470 downstream the water electrolyzer 440 may be combined with the first heated aqueous stream 414 or 502 (e.g., the heated first ion- or saltcontaining water stream such as a warm seawater stream) produced by the heat exchanger unit(s) 410 downstream the carbon oxide electrolyzer 310 to produce a combined heated aqueous stream 415 or 503. The combined heated aqueous stream 415 or 503 may be introduced to the desalination system 420 or 500 to facilitate desalination of an aqueous stream (e.g., combined heated aqueous stream 415 or a second aqueous stream 504) into a desalinated aqueous stream 424 or 506 (e.g., DI water), as shown in Figures 4E-4F. Specifics of the desalination systems 420 and 500 are described in more detail elsewhere herein, such as with respect to Figures 4A-4D.

[0125] In some embodiments, as shown in Figures 4E-4F, the heated product stream 476 comprising unreacted water and oxygen may be directed to an oxygen separator 480 to separate oxygen 482 from water 484. The separated water 484, in some embodiments, may be recycled back to the water electrolyzer anolyte input stream 432 via a recirculation loop (not shown).

[0126] Alternatively, or additionally, the above-described integration schemes (e.g., desalination systems 420 and 500 as shown in Figures 4A-4F) may use other types of suitable desalination unit(s) or system(s). Examples of other types of desalination units / sy stems include, but are not limited to, membrane-based desalination or deionization units (e.g., electrodialysis, electrodialysis reversal, and reverse osmosis, etc.).

[0127] While Figures 4A-4F illustrate embodiments in which the integrated systems comprise a single heat exchanger (e.g., a single liquid-liquid heat exchanger), it should be understood that the disclosure is not so limited and that in certain embodiments, multiple heat exchangers (e.g., multiple liquid-liquid heat exchangers) may be employed. In some embodiments, two or more heat exchangers (i.e., two cooling loops) may be used, where one or more heat exchangers may utilize an aqueous stream such as an ion- or salt-containing water stream (e.g., seawater) as a cooling liquid. Figure 5A depicts an illustrative example of an integrated system 600A comprising a carbon oxide electrolyzer 610 coupled with two heat exchangers 630 and 640 (i.e., double heat exchanger loop) incorporating an aqueous stream 642 (e.g., seawater) as the cooling liquid, which is further coupled with a desalination system 680.

[0128] As depicted in Figure 5A, a carbon oxide electrolyzer 610 receives a feed stream of carbon oxide COX612 (e.g., CO2) and produces an output stream 614 of COXreduction product (e.g., CO), which may or may not contain some of the unreacted COX(e.g., CO2). The stream of anolyte outlet 618 may be provided to one or more oxygen separators 620, which separates oxygen gas 624 in the anolyte outlet stream 618 and provides an oxygen deficient anolyte outlet stream 622 to a first heat exchanger 630.

[0129] Due to the heat produced during the operation of the carbon oxide electrolyzer, the stream of anolyte outlet 618 or 622 may be at elevated temperatures (e.g., about 43°C, between 35 °C and 80 °C, between 40 °C and 80 °C, between 45 °C and 80 °C, or between 45 °C to 70 °C). In some cases, the first cooling loop includes the first heat exchanger 630, which may be a liquid-to-liquid heat exchanger. In some embodiments, the first cooling liquid 652 may be a mixture of water and glycol. The first cooling liquid 652 may be fed into the first heat exchanger 630 at a temperature of, e.g., between about 31 °C to 72 °C, or between about 33 °C and 72 °C, and may be used to reduce the temperature of the anolyte stream 622 to produce a cooled anolyte stream 632 having a temperature of, e.g., between about 30 °C to 75 °C, 35 °C to 75 °C, or 40 °C to 75 °C, and consequently elevating the temperature of the first cooling liquid 652 to produce a heated cooling liquid (e.g., glycol / water) stream 634 having elevated temperatures (e.g., between about 33 °C to 70 °C, or between about 35 °C to 70 °C). The cooledanolyte feed stream 632 may be recirculated to the anolyte inlet stream 616 of the carbon oxide electrolyzer 610 via a recirculation loop 638.

[0130] In some embodiments, upstream of the carbon oxide electrolyzer 610, salt or salt solution 672 may be injected into the feed stream 616 of the anolyte inlet, if necessary, to provide the feed stream of the anolyte inlet to the carbon oxide electrolyzer with an appropriate electrolyte concentration and maintain conductivity. The carbon oxide electrolyzer may optionally utilize a fan and one or more pumps 660 (e.g., recirculation pumps) in the anolyte recirculation loop 638.

[0131] In some embodiments, as shown in Figure 5A, a second cooling loop is used in conjunction to remove heat from the first cooling liquid 634 (e.g., a glycol and water mixture). The second cooling loop may include a second heat exchanger 640. In some cases, the second heat exchanger is a liquid-to-liquid heat exchanger. When in use, the second heat exchanger 640 can be used to reduce the temperature of the first cooling liquid 634 (e.g., a mixture of water and glycol at elevated temperature) output from the first heat exchanger 630. The second heat exchanger 640 may reduce the temperature of the first cooling liquid 634 to produce a first cooling liquid outlet stream 646 having a temperature of, e.g., between about 31 °C and 72 °C, or between about 33 °C and 72 °C, etc. In some embodiments, this first cooling liquid outlet stream 646 output from the second heat exchanger 640 may be directed and recirculated to the first heat exchanger 630 via recirculation pump 650 and stream 652.

[0132] In various embodiments, as depicted in Figure 5A, the second heat exchanger 640 may use a first aqueous stream 642 such as an ion- or salt-containing water stream (e.g., seawater inlet stream) as the second cooling liquid to remove heat from the first cooling liquid stream 634 (e.g., mixture of glycol and water) output from the first heat exchanger 630. During operation, the second heat exchanger 640 may receive the first aqueous stream 642 (e.g., the first ion- or salt-containing water stream such as a cold seawater inlet stream) and reduce the temperature of first cooling liquid stream 634 (e.g., the mixture of glycol and water), which would elevate the temperature of the first aqueous stream 642 (e.g., cold seawater). For example, the second heat exchanger 640 may receive the first aqueous stream 642 (e.g., cold seawater) at a temperature of, e.g., between about -2 °C and 30 °C, or between about 0 °C and 30 °C, depending on the temperature of the source of the first aqueous stream (e.g., seawater). Using the first aqueous stream (e.g., cold seawater) as the second cooling liquid, the second heat exchanger 640 may reduce the temperature of the first cooling liquid stream 634 (e.g., glycol and water mixture), which would elevate the temperature of the first aqueous stream 642 (e.g., cold seawater) and produce a heated first aqueous stream 644 (e.g., warm seawater)having a temperature, e.g., of between about 32 °C and 71 °C, between about 30 °C and 75 °C, between about 25 °C and 70 °C, etc. In some embodiments, where a vacuum is applied during the heat exchange process in the second cooling loop, the heated first aqueous stream 644 (e.g., warm seawater) may be output from the second heat exchanger 640 at a temperature that is close to or at its boiling point.

[0133] As shown in Figure 5A, at least a portion of the heated first aqueous stream 644 (e.g., warm seawater) may be directed to a desalination system 680 to produce a desalinated aqueous stream 684 (e.g., DI water). The type and operation of desalination system 680 may be identical to that of desalination system 500 described with respect in Figures 4C-4D and 4F. For example, the desalination system 680 may include an ion-exchange desalination unit (e.g., a recharged bed desalination unit). In some cases, the heated first aqueous stream 644 may be employed to heat the desalination system 680 to recharge the spent resin bed (not shown) within the desalination system 680. Upon recharging the spent resin bed, a second aqueous stream 682 (e.g., an ion- or salt-containing stream such as seawater) may be introduced to the desalination system 680 and undergo desalination to produce a desalinated aqueous stream 684. The desalinated aqueous stream 684 may be optionally recycled via recycle path 686 to the anolyte recirculation loop 638, such that it can be recycled to the inlet of the carbon oxide electrolyzer 610 as a part of the anolyte inlet stream 616.

[0134] While the example embodiment described in Figure 5A is described in the context of a desalination unit based on recharged ion-exchange beads (i.e., ion-exchange desalination unit), it should be understood that any suitable desalination units / system may be used, e.g., thermal desalination unit or any other desalination units described elsewhere herein. For example, as shown in Figure 5B, system 600B illustrates a desalination system 690 including a thermal desalination unit. The type and operation of desalination system 680 may be identical to that of desalination system 420 described with respect to Figures 4A-4B and 4E. Streams 692, 694, 696, and 698 in Figure 5B may be identical to (and correspond) to streams 414, 415, 422, and 424 in Figures 4A-4B and 4E, respectively. For example, in embodiments in which a thermal desalination is employed, at least a portion of the heated first aqueous stream 692 may be directed to desalination system 690 (via stream 694), such that the heated first aqueous stream 692 undergoes thermal desalination (e.g., via evaporation followed by condensation) to produce a desalinated stream 698 that is subsequently recycled (via stream 686) to the anolyte inlet stream 616 of the carbon oxide electrolyzer 610.

[0135] In some embodiments, the various heat exchange units described herein (e.g., unit 630 and / or 640 as shown in Figures 5A-5B) may utilize other types of cooling liquid(s), forexample, such as other aqueous streams (e.g., ion-or salt- containing water) described elsewhere herein. Non-limiting examples include brackish water, wastewater, flowback water, effluent of a chemical process, water produced during oil and / or gas extraction processes lake water, river water, ground or tap water, pond water, rainwater, etc.

[0136] A double heat exchanger may be incorporated into any of the above-described systems including those shown in Figures 4A-4F. For example, the heat exchanger system illustrated in Figures 4A-4F may comprise one or more heat exchanger units, such as a double heat exchanger unit as shown in Figures 5A-5B. Figures 5A-5B may also include additional downstream units, such as the water electrolyzer 440 and associated heat exchanger 470, purification unit 450 (e.g., CO purification unit), downstream process(es) 460, as well as the fluidic connectivity between the various units or systems shown in Figures 4A-4F.

[0137] The carbon dioxide electrolyzer described herein, such as with respect to electrolyzer 310 / 610 as shown in Figures 3-5B, may further comprise a variety of optional support or processing units configurated to facilitate operation of the electrolyzer unit. These units may be employed to regulate and process the anode and / or cathode inputs of the carbon dioxide electrolyzer unit. Figures 6A-6B are schematic diagrams of systems 700A-700B comprising carbon dioxide electrolyzer unit 704 comprising various such optional units. As described in more detail below, Figures 6A-6B illustrate optional units that can be used to regulate the various electrolyzer input and output streams, such as anode input 785 and output 787, cathode input 781 and output 783 (corresponding respectively to anode inlet streams 318 / 616 and outlet streams 316 / 618, cathode inlet streams 312 / 612 and outlet streams 314 / 614, as shown in Figures 3-5B).

[0138] As shown in Figures 6A-6B, operating the carbon dioxide electrolyzer unit may require three main inputs: water, carbon dioxide, and controlled current. Each input may be provided through a specialized system allowing for control of variables affecting output of carbon dioxide electrolyzer unit 704. The carbon dioxide electrolyzer unit may be coupled to a water system configured to regulate anolyte input and output and a gas system configured to regulate cathode input and output. A water system may include flow control, salt addition and mixing unit(s) (e.g., units 720, 722, 726, etc.), a circulation pump (e.g., unit 738), temperature control (e.g., unit 734, 736, etc.) for startup as well as normal operating conditions, automated freshwater makeup (e.g., unit 716), conductivity and / or pH control, and drain capability from the anolyte circulation system. A gas system, using, for example, carbon dioxide, may include controls for inlet pressure control, outlet water and formic acid knockout (e.g. unit 730), gas separator (e.g., unit 740), and gas speciation measurement. The gas system may also includea combustible gas detector 714 on the O2 product stream 712. In some embodiments, the combustible gas detector may be configured to detect the presence of certain flammable gases contained within the product stream and / or determine the concentration of the gases. The power source includes a programmable power supply that provides constant current, a contactor, and a bleed-down resistor. Carbon oxide electrolyzer unit may also include monitoring, data recording, and automation systems.

[0139] Operating the carbon oxide electrolyzer plant begins with providing the three main inputs needed: power, water, and carbon dioxide. Input power is provided by power source 706. In some embodiments, power source 706 includes a programmable power supply capable of controlling current delivery.

[0140] The second main input to the carbon dioxide electrolyzer unit 704 is water, which may be provided from anolyte source via water inlet 716. The source of anolyte may be a source of impure aqueous stream such as a salt- or ion-containing water (e.g., seawater) that may need to be desalinated prior to being input into the carbon dioxide electrolyzer 704. Any of a variety of appropriate salt- or ion-containing water described elsewhere herein may be used. The inlet water can be input to water filtration module 718A / 718B, which may be a desalination system including one or more desalination unit(s) (e.g., a thermal desalination unit, an ion-exchange desalination unit, etc.) described elsewhere herein. Anolyte source may provide water to the anode water recirculation loop that delivers water to anode inlet 784 and removes (and recirculate) water from anode outlet 786 of carbon dioxide electrolyzer unit 704. The water recirculation loop includes water filtration module 718A / 718B (e.g., a desalination system) and brine mix tank 722. Water filtration module 718A / 718B provides input to brine mix tank 722 and also to anolyte tank 726. In some cases, the water fed to anode inlet 784 may be adjusted to contain a desired ion conductivity or concentration of salt. This may be accomplished via the use of a salt-dosing system configured to control the conductivity or concentration of salt ions in the anolyte feed to the electrolyzer unit. For example, brine mix tank 722 may receive desalinated water (e.g., purified water such as DI water) from water filtration module 718A / 718B and also receives an input of solid salt at salt-containing source 720. The solid salt from salt-containing source 720 may be input to brine mix tank 722 to ensure a source of concentrated salt solution is available. The inputs of water and solid salt may be used to dose the anode water with purified water and / or concentrated salt to adjust the composition of the anode water fed into carbon dioxide electrolyzer unit 704.

[0141] The third input to the carbon oxide electrolyzer plant 702 is gaseous carbon dioxide 781, which is provided via carbon dioxide gas inlet 710. Gas inlet 710 is a part of the gaseouscarbon oxide recirculation loop that provides gaseous carbon dioxide as a feed stream to cathode inlet 780 of carbon dioxide reduction electrolyzer 704. After passing through the carbon dioxide electrolyzer unit 704 and the electrolyzer process, a reduction product stream is output via cathode outlet 782 of carbon dioxide electrolyzer unit 704.

[0142] After the three inputs of power, water, and gaseous carbon oxides have been input to carbon dioxide electrolyzer unit 704, an electrolysis process (as illustrated in Figure 2 described above) can begin. Carbon dioxide electrolyzer unit 704 can include multiple membrane electrode assemblies (MEA), as described above in reference to Figure 2.

[0143] During electrolysis, carbon dioxide electrolyzer unit 704 may be supplied with carbon dioxide gas to cathode inlet 780. This carbon dioxide gas may be reduced over the carbon oxide reduction catalysts in the presence of protons and electrons. Once the electrolyzing process has been completed, a cathode output or reduction product stream 783 may be produced. Reduction product stream 783 leaving the carbon dioxide electrolyzer unit 704 may contain unreacted carbon dioxide, carbon-containing reduction product (e.g., carbon monoxide), H2, cathode water and impurities (e.g., formic acid, etc.). The carbon-containing reduction product may be present in any appropriate ratio (relative to carbon dioxide and / or H2) described below. Reduction product stream 783 from cathode outlet 783 may be fed to a liquid-gas separation unit such as water knockout system 730, where the gas product (e.g., carbon dioxide, carbon monoxide, H2) can be removed from the liquids (cathode water and other liquid impurities such as formic acid). The cathode water (and other liquid impurities) removed may be sent to cathode water tank 732. After the water knockout, gas product 729 may be sent to chiller 728. The output of chiller 728 may be sent to external gas separation module 740. The output of the external gas separation module 740 may be configured to separate unreacted carbon dioxide from gas stream 743 containing carbon-containing reduction product (e.g., CO) and H2. Unreacted carbon dioxide may be recycled via carbon dioxide recycle loop 741 to cathode inlet 780 and separated gas stream 743 may be sent for further processing to the external product processing module 742 (e.g., such as a liquid hydrocarbon synthesis reactor).

[0144] The cathode water collected in the cathode water tank 732 can be recirculated by sending it to anolyte tank 726. Optionally, if the cathode water is not used for recirculation to anolyte tank 726, it may be sent to external wastewater tank 744. In an embodiment, if the cathode water is used for recirculation to anolyte tank 726, the cathode water will need to be treated, such as with, e.g., a resin column or reverse osmosis system (not shown) to purify the cathode water, before it is introduced into anolyte tank 726.

[0145] On the anode side of electrolyzer unit 704, anolyte may be introduced to anode inlet 784 and reacted (e.g., oxidized) to produce anolyte output stream 787 via anode outlet 786. Anolyte output stream 787 may include unreacted anolyte and oxidation products such as molecular oxygen (e.g., O2). Anode output stream 787 may be introduced to anolyte separator 724 (e.g., an oxygen separator) to remove oxygen 715 from unreacted anolyte 725. Unreacted anolyte 725 may be collected in anolyte tank 726 can also be recirculated, optionally along with cathode water 733, via the anolyte recirculation system. The anolyte recirculation system also incorporates an anolyte circulation pump 738 which provides a predetermined amount of anolyte circulation through electrolyzer unit 704. The input line to anolyte tank 726 connected to anolyte separator 724 can also be connected to a line connected to brine mix tank 722. This input from brine mix tank 722 allows adjustment of the composition of the anolyte (e.g., salt concentration) in anolyte tank 726. Anolyte circulation to electrolyzer unit 784 can be facilitated by anolyte circulation pump 738. Anolyte circulation temperature may be controlled via a temperature control system, e.g., via heat exchanger 736 and heat exchanger 734. The anolyte circulation can be controlled through control programming and measurements of the anolyte concentration and temperature. As part of the anolyte circulation, some of the anolyte can be purged to external wastewater tank 744, assisted by anolyte circulation pump 738. Anolyte can also bypass the electrolyzer unit such as via bypass line 746 for maintenance and troubleshooting purposes for the anolyte loop.

[0146] In addition, system 702 may include a control and automation system configured to assist with startup of the system through startup sequencing. The control and automation system also allows changing the operating set points for the carbon dioxide electrolyzer unit 704 as needed. For example, during startup, the temperature control system may be caused to preheat the anolyte that is provided to the electrolyzer stack to a preset initial operating temperature; once the electrolysis reaction is established, the controller may cause the temperature control system to instead switch to a cooling mode (for example, if anolyte is being recirculated, latent heat in the anolyte from a prior passage of the anolyte through the electrolyzer may need to be removed prior to re-introducing the anolyte into the electrolyzer, e.g., via the anolyte recirculation system).

[0147] In some embodiments, as depicted in Figures 6A-6B, via the one or more heat exchangers 734 / 736, heat produced by the carbon dioxide electrolyzer 704 may be employed to desalinate an aqueous stream 735 and / or 716 (e.g., a salt- or ion-containing water stream such as seawater) to produce a desalinated aqueous stream 719 for use as an anolyte feed in the carbon dioxide electrolyzer 704. While Figure 6A illustrates a type of thermal desalinationunit 718A (identical to unit 500 shown in Figures 4C-4D and 4F), Figure 6B illustrates a type of ion-exchange desalination unit 718B (identical to unit 420 shown in Figures 4A-4B and 4E).

[0148] As shown in Figures 6A-6B, a first aqueous stream 735 (e.g., salt- or ion-containing water stream such as cold seawater) may be directed to heat exchanger 734 for indirect heat exchange with an anolyte outlet stream 789, to produce a cooled first anolyte stream 785 and a heated first aqueous stream 737 (e.g., warm seawater). In embodiments in which the desalination system includes a thermal desalination unit (e.g., Figure 6A), at least a portion of the heated first aqueous stream 737 may be directed to thermal desalination unit 718A, such that the heated first aqueous stream 737 undergoes thermal desalination (e.g., via evaporation followed by condensation) to produce a desalinated stream 719 that is subsequently provided to the carbon oxide electrolyzer 704 as part of the anolyte feed. In embodiments in which the desalination system includes an ion-exchange desalination unit such as a recharged bed desalination unit (e.g., Figure 6B), the heated first aqueous stream 737 (e.g., warm seawater) may be directed to the ion-exchange desalination unit 718B to recharge (i.e., reactivate) the spent resin bed (not shown) within the desalination unit 718B and produce a cooled first aqueous stream 792 (e.g., cooled seawater). Upon recharging the spent resin bed, a second aqueous stream (e.g., an ion- or salt-containing stream such as seawater) may be introduced to the ion-exchange desalination unit 718B via water inlet 716 and undergo desalination to produce a desalinated aqueous stream 719, which is subsequently provided to the carbon oxide electrolyzer 704 as part of the anolyte feed.Naphthas and Fuels

[0149] As noted above, according to some embodiments, the carbon dioxide electrolyzer unit may be fluidically connected to downstream process(es), e.g., as shown in Figures 4A-4F. The downstream system may comprise a liquid hydrocarbon synthesis reactor configured to react the carbon-containing reduction product(s) from the carbon dioxide electrolyzer unit and produce liquid hydrocarbon(s), according to some embodiments. In some cases, the liquid hydrocarbon synthesis reactor may be configured to perform a Fischer-Tropsch process or reaction. As indicated, Fischer-Tropsch (F-T) reactions may be characterized by the following general expression:(2n+l)H2+ nCO -> CnH2n + nH2O

[0150] In some cases, to perform a Fischer-Tropsch reaction, the system may be configured to react carbon monoxide produced by the carbon dioxide electrolyzer unit and molecular hydrogen to form the liquid hydrocarbon(s). As described in more detail below, the molecularhydrogen may be produced by the carbon dioxide electrolyzer unit as a part of its cathode output and / or supplied by a separate molecular hydrogen source, e.g., a water electrolyzer unit configured to produce molecular hydrogen.

[0151] While the following discussion focuses on Fischer-Tropsch reactions, those of skill in the art appreciate that a class of related reactions may be employed to produce liquid hydrocarbons and mixtures thereof (often generally referred to as naphthas) from input streams that include hydrogen and carbon monoxide. The class of reactions produce various compositions of liquid hydrocarbon mixtures dependent on the composition of the input stream and the reaction conditions. While the term Fischer-Tropsch is used herein, it should be understood to cover any of a class of reactions that produce naphtha from a mixture including carbon monoxide and hydrogen. Generally, such reactions or exothermic.

[0152] In various embodiments, the input stream to a Fischer-Tropsch reactor is about 1:2 molar ratio of CO:H2. To use CO2 as starting point for producing CO / H2 mixture (or other Fischer-Tropsch input), some conventional, non-electrolytic processes require two steps. For example, a conventional process employs a first process to produce CO2 + H2 (step 1) and then a reverse water gas shift (RWSG) reaction (step 2) to react CO2 + H2 and produce CO and water to result in a gas having a ratio close to the required 2:1 CO:H2. Thus, in a conventional process, only after obtaining the CO and hydrogen in the correct ratio can a Fischer-Tropsch reaction be employed to produce liquid hydrocarbons. Water shift (WSG) reaction and reverse water shift reaction catalysts can produce metal dust that is detrimental to downstream processes. Further, the water shift reactions require a feed of carbon monoxide and / or hydrogen.

[0153] Note that a conventional syngas process is sometimes used to directly produce CO + H2 mixture (rather than using a WSG and / or RWSG reaction or a carbon dioxide electrolyzer which may emphasize production of CO). However, syngas production often uses coal.A Fischer-Tropsch system that employs a carbon dioxide electrolyzer as a source of carbon monoxide has various advantages over the WSG or syngas routes. For example, unlike a RWSG reaction, a carbon dioxide electrolyzer does not produce metal dust. Additionally, in comparison to the RWGS reaction, a carbon dioxide electrolyzer provides a higher conversion of CO2 to CO. In some embodiments, the CO:CO2 ratio in the cathode outlet stream of a carbon dioxide electrolyzer may be at least 1:3, at least 1:2, at least 1:1, at least 2:1, at least 5:1, at least 10:1, at least 100:1, or more.

[0154] In some cases, compared to RWGS reaction, the carbon dioxide electrolyzer described herein may be advantageously operated at a relatively low temperature. The process conditionsassociated with the CO2 electrolyzer may include a temperature (e.g., reactor temperature) greater than typical room temperature (e.g., within and / or greater than a threshold temperature range, such as about 25-50 °C, about 40-60 °C, about 50-100 °C, about 50-75 °C, about 70- 100 °C, and / or no more than 100 °C, etc.) and / or greater than temperatures typically feasible in electrolyzers other than gas-phase electrolyzers, but can additionally or alternatively include temperatures substantially equal to room temperature (e.g., about 20-30 °C), less than room temperature, and / or any other suitable temperatures (e.g., between 20 °C and 100 °C, between 20 °C and 90 °C, between 25 °C and 50 °C, or between 50 °C and 80 °C, etc.). However, the process conditions can additionally or alternatively include any other suitable process conditions.

[0155] However, a carbon dioxide electrolyzer may not produce gas having the required approximately 1:2 molar ratio of CO:H2 for a Fischer-Tropsch feed. In some cases, a carbon dioxide electrolyzer may produce a CO-rich stream. For example, in some embodiments, the CO-rich stream may have a CO:H2 ratio of greater than 1:1, greater than or equal to 2: 1 , greater than or equal to 5: 1, greater than or equal to 10:1, greater than or equal to 20: 1, greater than or equal to 50:1, or greater than or equal to 100:1. In some embodiments, the CO-rich stream may have a CO:H2 ratio of no more than 1000:1, no more than 100:1, no more than 50:1, no more than 20:1, no more than 10:1, no more than 5:1, or no more than 2:1. Combinations of the above-referenced ranges are possible (e.g., greater than 1:1 and no more than 1000:1, greater than or equal to 2:1 and no more than 100:1, etc.). Therefore, in some embodiments, a Fischer-Tropsch system, or any other system that requires a carbon monoxide and hydrogen mixture, may employ a water electrolyzer or other source of hydrogen that optionally works in conjunction with carbon dioxide electrolyzer. The water electrolyzer is configured to make gaseous hydrogen to supplement the CO-rich output of the carbon dioxide electrolyzer. In some embodiments, syngas that is relatively rich in hydrogen can be produced as part of coelectrolysis of carbon dioxide and water. To achieve an approximately 1:2 CO:H2 feed concentration for a F-T reaction, the system may include sensors configured to determine the concentration of CO and H2 coming through the gas separation unit from the CO2 electrolyzer. Using the sensed information as feedback, the operating conditions of a water electrolyzer may be adjusted to deliver a hydrogen stream with the quantity of H2 needed to bring the total stream to approximately 1:2 CO:H2 concentration.

[0156] Alternatively, a single CO2 electrolyzer can be used to produce a suitable Fischer- Tropsch CO and H2 feed blend. This can be accomplished by operating the electrolyzer in a way that biases the output toward hydrogen production and / or by processing the electrolyzeroutput to adjust its composition prior to delivery to the Fischer-Tropsch reactor. In certain embodiments, a carbon dioxide electrolyzer includes an MEA that allows a relatively high proportion of H+ to reach the cathode. One way to promote a relatively high flux of H+ at the cathode is for a bipolar MEA to employ a relatively thin cathode buffer layer and / or to employ cathode and cathode buffer layers having polymers with a relatively high H+ transference number. In another approach, the carbon dioxide electrolyzer is constructed or operated in a way that starves it of carbon dioxide. In certain embodiments, the electrolyzer is operated at a relatively high current density, which tends to produce a higher ratio of hydrogen to carbon monoxide ratio. In some implementations, the electrolyzer employs both a relatively high current density and relatively low carbon dioxide feed to the electrolyzer. Operating at a relatively high current density has the advantage of producing employing a relatively inexpensive electrolyzer for the cost of the equipment.

[0157] The output of a CO2 electrolyzer contains product CO, byproduct H2, unreacted CO2, and water vapor, as illustrated respectively by output stream 314, 614, or 783 in Figures 3-6B. The system may be configured to remove the water vapor and separate the unreacted carbon dioxide. A gas separation unit may be used to separate the CO2 from the CO and H2 and / or otherwise concentrate the CO and H2. The system may include a recycle loop to recycle water to a water inlet of a CO2 or water electrolyzer. The unreacted and separated CO2 is then compressed and returned to the inlet of the CO2 electrolyzer. Examples of gas separation units are presented in Figures 6A-6B, and the associated description.

[0158] A F-T reactor may operate above about 300 psi and between about 150-300°C. If the output of a carbon dioxide electrolyzer and optional water electrolyzer is not at the required pressure, the system may employ a compressor to bring up the feed gas pressure before entering the F-T reactor. In the F-T reactor, the CO-H2 mixture is converted into raw F-T liquid and waxes. A system may include a separator following the F-T reactor to separate water, high melting point F-T liquid, medium melting point F-T liquid, and tail gas, a mixture of volatile hydrocarbons, CO2, CO, and H2. The F-T liquid may be further upgraded via hydrocracking. Distillation and separation of different fractions of the F-T liquid may result in jet fuel, diesel, and gasoline. Water from the F-T reactor can be filtered to remove impurities and fed to a water input of the CO2 and / or optional water electrolyzers.

[0159] A F-T system may be designed so that tail gas and / or volatile hydrocarbons (e.g. including methane) are recycled back to the CO2 electrolyzer. The system may be configured to separate the tail gas into CO2, which may be compressed and fed directly to the electrolyzer inlet and volatile hydrocarbons and unreacted CO and H2. The system may be designed orconfigured such that these products are fed to a combustion reactor to generate heat, energy, and CO2. The CO2 is then fed to the CO2 electrolyzer inlet. The O2 from the electrolyzer may be used as the oxygen source for combustion, resulting in a pure CO2 output stream. The combustion reactor may be run in “rich burn” mode utilizing an excess of fuel to oxygen to minimize the concentration of oxygen in the outlet stream. Water from the combustion reaction may be separated from the gas output and can be fed to the water input of the CO2 electrolyzer or water electrolyzer.

[0160] Because a Fischer-Tropsch reaction is exothermic, it produces heat that may be used for other purposes in a system. Examples of such other uses include separations (e.g., distillation of light hydrocarbons) and reactions. In conventional systems, such reactions are endothermic reactions for production of syngas such as reforming of fossil fuels, gasification of biomass, or production from carbon dioxide and hydrogen via reverse water gas shift. Hence, in conventional processing, all or a significant portion of the excess heat from a Fischer- Tropsch reaction is typically directed to the syngas production. In the present case, however, which produces syngas at a low temperature (e.g. less than about 100 °C) by processes such as carbon dioxide electrolysis optionally along with low temperature water electrolysis, there is more excess heat from the Fischer-Tropsch reaction available for other processes such as carbon dioxide capture, thereby reducing the overall external heat requirement of the system and improving carbon and energy efficiency of the carbon dioxide to fuel synthesis pathway.

[0161] In some embodiments, at least a portion the heat produced by the Fischer-Tropsch reaction may be employed to facilitate desalination of an aqueous stream described elsewhere herein, such as an ion- or salt-containing water (e.g., seawater). As a non-limiting example, as depicted in Figures 4B and 4D-4F, the downstream process(es) 460 may be a liquid hydrocarbon synthesis reactor configured to carry out a Fischer-Tropsch reaction employing the syngas 446. In some embodiments, the liquid hydrocarbon synthesis reactor 460 may be configured to produce one or more heated output streams (not shown), such as a wastewater stream. The one or more heated output streams may be directed to a heat exchanger (e.g., a heat exchanger similar to 410 or 470) that accepts a cold aqueous stream (e.g., a cold ion- or salt-containing water such as cold seawater that is similar to stream 412 or 472) and outputs a heated aqueous stream (e.g., a heated ion or salt-containing water such as warm seawater that is similar to stream 414, 474, or 502). At least a portion of the heated aqueous stream may be directed to a desalination system (e.g., desalination system 420 or 500) to produce a desalinated aqueous stream (e.g., stream 424 or 506) that is subsequently recirculated to the carbon oxide electrolyzer (e.g., electrolyzer 310) as part of an anolyte inlet stream (e.g., stream 318).Supplemental Hydrogen Sources

[0162] In certain embodiments, an integrated system employing a carbon oxide electrolyzer includes an additional source of hydrogen (beyond that generated from the electrolyzer) or are configured to receive additional hydrogen from an external source. Examples of integrated systems that may employ additional sources of hydrogen include Fischer-Tropsch systems, polycarbonate production systems, ethylene glycol production systems, polyethylene terephthalate production systems, methanol, butanol, and / or other alcohol production systems, acetic acid production systems, isocyanate production systems, polyurethane production systems, and oxalic production systems. In certain embodiments, the additional source of hydrogen is a water electrolyzer such as a proton exchange membrane water electrolyzer. In some implementations, a water electrolyzer shares electrical infrastructure with a carbon oxide reduction electrolyzer. Embodiments of water electrolyzer are described and / or illustrated in Figures 4B and 4D-4F.Syngas Preparation

[0163] Embodiments described in this section and / or illustrated in Figures 4B and 4D-4F pertain to making mixtures of carbon monoxide and hydrogen. Some of these mixtures may be referred to as syngas. The embodiments described here concern methods and systems configured to receive a mixture of carbon monoxide, carbon dioxide, and hydrogen and modify the mixture to produce a mixture of carbon monoxide and hydrogen having a particular composition. In some cases, the input is a gaseous mixture obtained from a carbon oxide electrolyzer such as one of the carbon oxide electrolyzers described herein.

[0164] A carbon monoxide and hydrogen mixture produced as described here may have various applications. It can be used to produce a naphtha or other liquid hydrocarbon composition such as may be produced by a Fischer-Tropsch process. It can also be used as an input to a gas fermentation reactor. It can also be sued to produce any of various chemicals such as alcohols and / or polyols. A mixture of carbon monoxide and hydrogen may be produced by directly removing either CO or CO2 from an input stream. In embodiments that produce the mixture by directly separating CO from the input stream, hydrogen may be added to a purified CO stream downstream from a CO purification operation. For example, purified hydrogen may be prepared by separating it from CO2 in an operation that is downstream from the CO separation operation.Heat Produced by a Carbon Oxide Electrolyzer

[0165] During normal operation, a carbon oxide electrolyzer may generate heat. In some cases, about 25 to 50% of the power supplied to a carbon oxide electrolyzer is converted to heat.Some or all the generated heat may be used in one or more downstream or upstream processes. In some embodiments, a carbon dioxide electrolyzer generates a gas and / or liquid stream containing heat energy. In some cases, the gas and / or liquid stream has a temperature of about 25-90C. In certain implementations, a carbon oxide electrolyzer generates a cathode output gas stream containing heat that may be supplied, by an integrated system, to one or more upstream or downstream units or subsystems. In some implementations, a carbon oxide electrolyzer generates an anode liquid output stream containing heat that may be supplied, by an integrated system, to one or more upstream or downstream units or subsystems. In some cases, a carbon oxide electrolyzer contains a dedicated heat transfer element such as a jacket and / or conduit(s) that, during operation, have coolant circulating. In some implementations, one or more bipolar plates of the electrolyzer are configured to have such coolant circulate through them. Heat transferred from the electrolyzer to the coolant may be supplied to other units or subsystems in an integrated system.

[0166] In some embodiments, heat generated by an electrolyzer is used to pre-heat an inlet stream to a subsystem such as a boiler. In some embodiments, heat generated by an electrolyzer is used in a heat a swing process such as a direct air process for capturing carbon dioxide, a carbon dioxide stripping process, and / or a carbon monoxide stripping process. In the integration embodiments described herein, any upstream or downstream unit operation that can utilize heat of the type produced by a carbon oxide electrolyzer in the integration embodiment may be configured to receive heat from the electrolyzer. Examples include driers, separators, and reactors, including those for making polymers or bulk chemicals such as any of those disclosed herein. Thus, during normal operation a system may deliver heat generated by a carbon oxide electrolyzer to one or more separate subsystems that make use of such heat to facilitate their operation.Shared Infrastructure for CO2 Electrolysis and H2O Electrolysis

[0167] In some embodiments, an integrated system includes a CO2 electrolyzer and an H2O electrolyzer. The CO2 electrolyzer may be configured to produce CO, which may be combined with H2 produced by the H2O electrolyzer to produce syngas. The integrated system may additionally include a liquid hydrocarbon synthesis reactor configured to receive the syngas and produce liquid hydrocarbons.

[0168] In some embodiments, an integrated system is configured to use waste heat to heat water used as input to an H2O electrolyzer. The waste heat may be generated by any of various elements in the integrated system. Examples include a carbon dioxide electrolyzer and anyreactor that carries out an exothermic reaction (e.g., production of liquid hydrocarbons by a Fischer-Tropsch reactor).

[0169] Some H2O electrolyzers such as solid oxide electrolyzers require vaporized water to operate. Waste heat from, e.g., a Fischer-Tropsch reactor may be employed to vaporize the water. Waste a liquid hydrocarbon synthesis reactor may be provided via a stream of tail gas, a steam stream used to carry heat away from the reactor, etc. In some embodiments, the steam from the liquid hydrocarbon synthesis reactor is used as an input to the H2O electrolyzer. In some embodiments, the steam is purified before entering the H2O electrolyzer. Regardless, the steam can at least be used to heat the water electrolyzer or the water supplied to the electrolyzer as a reactant.

[0170] Electrical integration of multiple electrolyzers such as separate H2O and CO2 electrolyzers may employ shared electrical power infrastructure. Both H2O and CO2 electrolyzers employ DC power. So, in some embodiments, an electrical unit is configured to receive AC power from, e.g., an electrical grid, convert that power to lower AC or fully to DC, and deliver AC power to both an H2O electrolyzer and a CO2 electrolyzer. The electrical unit may comprise DC bus that provides electrical power to multiple CO2 electrolyzer stacks. In some implementations, the electrical power infrastructure is configured to minimize the loss in an electrolyzer system that utilizes multiple stacks.

[0171] In some embodiments, a liquid hydrocarbon synthesis reactor and a water electrolyzer and / or a CO2 electrolyzer share one or more compressors. A Fischer-Tropsch reactor, for example, may employ two compressors, one for recycling tail gas and another for recompressing unreacted hydrogen from a hydrocracker. If the hydrogen outlet pressure from a water electrolyzer is less than about 520PSIG, it may need to be pressurized. In such cases, an inlet for providing hydrogen from an H2O electrolyzer and a hydrogen recycle stream can share a compressor.

[0172] In some embodiments, an integrated system is configured to capture water from air (or other impure CO2 source) via a DAC unit and supply that water as an input a CO2 electrolyzer, along with the purified CO2.Integrated System with a Hydrocarbon Synthesis Reactor, a CO2 Electrolyzer, and an H2O Electrolyzer

[0173] Figure 7 can be used to illustrate an integrated system for producing a fuel such as jet fuel (i.e., aviation turbine fuel). The system in this figure comprise one or more carbon dioxide reduction electrolyzers, one or more water electrolyzers, and one or more Fischer-Tropsch reactors. Examples of the design, components, and operation of carbon dioxide electrolyzersand water electrolyzers are described elsewhere herein. Any of the features described elsewhere herein may be applied to implement the carbon dioxide and water electrolyzers described in Figure 7.

[0174] Figure 7 depicts an integrated system 2801 comprising, inter alia, a carbon dioxide electrolyzer unit 2820, a water electrolyzer unit 2830, and a Fischer-Tropsch reactor 2850. The carbon dioxide electrolyzer unit may comprise one or more carbon dioxide electrolyzer cells and / or stacks and various optional components, as described in more detail below. Similarly, the water electrolyzer unit may comprise one or more water electrolyzer cells and / or stacks in addition to various optional components, in some embodiments. Carbon dioxide electrolyzer unit 2820 is configured to produce carbon monoxide by reducing carbon dioxide from a feed stream delivered via a conduit 2803, while water electrolyzer unit 2830 is configured to produce molecular hydrogen (H2) by reducing water from a feed stream delivered via a conduit 2805. The carbon monoxide produced by carbon dioxide electrolyzer unit 2820 is provided in an output stream via a conduit 2822, while the hydrogen produced by water electrolyzer unit 2830 is provided in an output stream via a conduit 2832.

[0175] The carbon monoxide in the output stream may contain some unreacted carbon dioxide along with molecular hydrogen. As depicted, integrated system 2801 includes a carbon monoxide purification unit 2840 configured to receive the output stream via conduit 2822 and separate its components into a first output stream comprising purified carbon monoxide and hydrogen and a second output stream comprising purified carbon dioxide. Carbon monoxide purification unit 2840 may have any conventional or custom design. For example, such purification units may employ separation technologies based on sorbent, membranes, or cryogenics. In certain embodiments, carbon monoxide purification unit 2840 is a sorbentbased unit of the type presented in Figures 4B, 4D-4F, and 6A-6B and the associated description. In one embodiment, carbon monoxide purification unit 2840 is a sorbent-based pressure swing separator comprising a solid sorbent that (a) at high pressure, absorbs carbon dioxide from the gas stream in conduit 2822 while passing carbon monoxide and hydrogen as the first output stream, and (b) at lower pressure, releases the purified carbon dioxide as the second output stream. In certain embodiments, the solid sorbent in carbon monoxide purification unit 2840 is a zeolite.

[0176] Integrated system 2801 is configured to utilize the second output stream of purified carbon dioxide by recycling it to an input of carbon dioxide electrolyzer unit 2820 via a recycle conduit 2842. Integrated system 2801 is further configured to transport the first output stream of purified carbon monoxide and hydrogen stream via a conduit 2844. At least a portion of thehydrogen in output stream 2832 from water electrolyzer unit 2830 is combined with the carbon monoxide and hydrogen in conduit 2844 to form syngas and transport the syngas to an input of Fischer-Tropsch reactor 2850 via a conduit 2846. In certain embodiments, integrated system 2801 is configured to feed carbon monoxide and hydrogen in a defined ratio to Fischer-Tropsch reactor 2850. As examples, the hydrogen to carbon monoxide ratio may be about 1.5:1 to 2.5:1, or about 1.8:1 to 2.1:1, or about 2:1 to 2.3:1, or about 2:1 to 2.1:1, or about 2.05:1 to 2.1:1.

[0177] Fischer-Tropsch reactor 2850 is configured to convert syngas provided via conduit 2846 to liquid hydrocarbons and tail gas. More specifically, Fischer-Tropsch reactor 2850 is configured to produce a mix of hydrocarbons, and it is outfitted with outlet lines to provide different fractions of these hydrocarbons. In the depicted embodiment, Fischer-Tropsch reactor 2850 has four outlines that comprise a tail gas or “vent” gas outlet conduit 2852, a light cut crude outlet conduit 2854, a heavy cut crude outlet conduit 2856, and oily wastewater outlet conduit.

[0178] Heavy and light cut crude fractions are understood to those of skill in the art to define physical and chemical properties such as density, boiling point, and chemical composition. The light cut crude is sometimes referred to as “light Fischer-Tropsch liquid” or LFTL. The heavy cut crude is sometimes referred to as heavy Fischer-Tropsch liquid (HFTL) or Fischer- Tropsch wax, which may comprise a saturated paraffin.

[0179] Vent gas outlet conduit 2852 connects to vent gas or flare system outlet 2858. A flare system may simply combust the tail gas or one or more components thereof. Optionally, as described elsewhere in this disclosure, combusted tail gas may be employed to provide carbon dioxide for recycle to a carbon dioxide electrolyzer, such as carbon dioxide electrolyzer unit 2820 and / or provide heat for one or more subsystems in the integrated system 2801.

[0180] In some implementations, Fischer-Tropsch reactor 2850 comprises a main reactor and a cooling region. In some embodiments, the main reactor of Fischer-Tropsch reactor 2850 is comprised of multiple tubes filled with catalyst inside a larger shell. The main reactor may comprise an iron-based and / or a cobalt-based metal catalyst. The exothermic Fischer-Tropsch reaction produces products substantially in the gas phase. The cooling region produces the liquid heavy cut crude and light cut crude fractions. The tail gas remains a gas phase product. In some embodiments, boiler feed water is fed to the reactor to control its temperature. In some embodiments, Fischer-Tropsch reactor 2850 includes a recycle loop with a compressor.

[0181] Light cut crude outlet conduit 2854 is configured to transport the light cut crude to a product fractionation unit 2865. Integrated system 2801 also includes a conduit 2862 for delivering cracked crude (described below) to product fractionation unit 2865. Productfractionation unit 2865 is configured to separate input hydrocarbons into a naphtha component, which may be transported in an outlet conduit 2867, a fuel component such as jet fuel, which may be transported in an outlet conduit 2869, and a heavy cut crude component, which may be transported in an outlet conduit 2871. In some configurations, integrated system 2801 may provide storage for naphtha provided via conduit 2867 and / or provide storage for fuel provided via conduit 2869.

[0182] In certain embodiments, product fractionation unit 2865 may be implemented as a distillation apparatus, whose temperature and / or pressure are controlled to output naphtha and jet fuel as separate streams. Regardless of how product fractionation unit 2865 is implemented, it may be operated in manner that produces a fuel of appropriate physical and chemical characteristics such as carbon chain size, degree of isomerization / branching, boiling point, freezing point, viscosity, vapor pressure, or any combination thereof. In certain embodiments, the fuel output has properties falling with the ranges conventionally used for aviation turbine fuel. For example, see the standards defined by ASTM D7566 Annex 1 (2022), which is incorporated herein by reference in its entirety. In some embodiments, the hydrocarbons in the jet fuel fraction have a size of about C8 to C15 and the hydrocarbons in the naphtha fraction have a size of about C5 to C9.

[0183] As illustrated, heavy cut crude transported via conduits 2856 and 2871 is provided to a hydro-processing unit 2860 configured to chemically modify the heavy cut crude. As illustrated, some hydrogen from water electrolyzer unit 2830 is provided to hydro-processing unit 2860 via conduit 2832. The hydrogen is fed to hydro-processing unit 2860 reactor both to serve as a reactant and for temperature management as unit 2860 produces exothermic reactions. In some implementations, integrated system 2801 also includes a hydrogen recycle loop with a compressor.

[0184] In certain embodiments, hydro-processing unit 2860 is configured to crack heavy cut crude to produce short chain hydrocarbons in the range of naphtha and jet fuel cuts. The cracking reaction may be a catalytic reaction between hydrogen and hydrocarbons of the heavy cut crude. In some implementations, hydro-processing unit 2860 comprises a catalytic cracking sub-unit and an isomerization sub-unit (not shown). The isomerization sub-unit isomerizes hydrocarbons such as the short chain hydrocarbons produced by cracking. In some implementations, the isomerization sub-unit increases the branching of short chain hydrocarbons. Thus, in some embodiments, hydro-processing unit 2860 contains two types of catalyst, one for cracking (breaking long chains into smaller chains) and one for isomerization.The cracked crude produced by hydro-processing unit 2860 is transported via outlet conduit 2862 to product fractionation unit 2865.

[0185] Returning to carbon dioxide electrolyzer unit 2820, it has as feedstock inlets carbon dioxide conduit 2803 and a water inlet 2807, as well as an inlet for carbon dioxide recycle conduit 2842. Carbon dioxide electrolyzer unit 2820 has three primary outlets, carbon monoxide outlet conduit 2822, an oxygen outlet conduit 2809, and an acidic wastewater outlet 2811. In alternative embodiments, acidic water produced in carbon dioxide electrolyzer unit 2820 is treated in a manner that allows it to be recycled as anode water.

[0186] As noted above, the carbon dioxide electrolyzer unit 2820 may comprise one or a plurality of carbon dioxide electrolyzers (e.g., carbon dioxide electrolyzer stacks) and optional components. For example, the carbon dioxide electrolyzer unit 2820 may be identical to unit 702 as shown in Figures 6A-6B and include identical optional units. Optional components may include one or more components (e.g., support components, downstream processing components, etc.) described elsewhere herein, such as one or more components upstream gas separation unit 740 illustrated in Figures 6A-6B. Non-limiting examples of such include water knockout 730, cathode water tank 732, chiller 728, circulation pump 2251, recycle line 733, temperature control unit (e.g., heat exchangers 734 / 736), salt-dosing system including unit 722, oxygen separator 724, mass flow meter or controller, ion exchanger, anode water recirculation loop 787, water filtration or desalination system 718A-718B, etc.

[0187] For example, in one set of embodiments, carbon dioxide electrolyzer unit 2820 may comprise carbon dioxide electrolyzer(s) (e.g., unit 704 as shown in Figures 6A-6B) configured to receive carbon dioxide from carbon dioxide conduit 2803 and recycle conduit 2842, and water from water inlet 2807. The carbon dioxide electrolyzer(s) may be configured to output a reduction product stream comprising CO, H2, unreacted CO2, water, along with a small amount (if any) of byproducts (e.g., formic acid, ions, etc.) at the cathode outlet. The carbon dioxide electrolyzer(s) may also be configured to output an oxidation product stream comprising anode water and oxygen at the anode outlet. In some embodiments, the reduction product stream comprising CO, H2, unreacted CO2, water, and byproducts may be introduced to a gas-liquid separator (e.g., a water knockout) such as water separator 730 shown in Figures 6A-6B so as to remove and / or separate liquids (e.g., water and / or byproducts such formic acid) from the gases (e.g., CO / H2 / CO2) in the reduction product stream. In some embodiments, the separated gases (e.g., CO / H2 / CO2) may be transported out of electrolyzer unit 2820 via outlet conduit 2822, and some of the separated liquids may be transported out of electrolyzer unit 2820 via acidic wastewater outlet 2811 as wastewater. In some embodiments, the oxidationproduct stream comprising anode water and oxygen may be separated from one another via a separation unit, such as separation unit 730 described with respect to Figures 6A-6B, so that some of the separated water optionally can be recycled back to the anode of the electrolyzers via an anode recirculation loop and the oxygen can be removed via oxygen outlet conduit 2809. In some embodiments, carbon dioxide electrolysis unit 2801 may further comprise a salt dosing system configured to introduce salt and / or ions into the anode water introduced from water inlet 2807 so as to control the salt and / or ion concentration in the anode water fed to the electrolysis unit.

[0188] In some embodiments, the water inlet 2807 for the carbon dioxide electrolysis unit 2820 as shown in Figure 7 may correspond to the water inlet 701 as shown in Figures 6A-6B. The water entering into the water inlet 2807 may be an unpurified water or aqueous stream described elsewhere herein, such as a salt- or ion-containing water (e.g., seawater), and may be subjected to a desalination process described elsewhere herein (such as shown and / or illustrated in Figures 4A-6B) before it can be used as an anolyte feed for the carbon dioxide electrolyzer unit. As a non-limiting example, the unpurified water (e.g., seawater) entering into water inlet 2807 may be directed to a water filtration or desalination system in a manner identical to as shown in Figures 6A-6B, e.g., where unpurified water (e.g., seawater) entering into water inlet 716 is directed to a water filtration or desalination system 718A / 718B to produce a desalinated water stream for use in the carbon dioxide electrolyzer 704. As mentioned previously, the desalination systems 718A / 718B may include a thermal desalination unit and / or a deionization unit (e.g., ion-exchange unit) and the heat from the anolyte outlet stream 789 produced by the carbon dioxide electrolyzer 704 and / or associated units (e.g., water electrolyzer, Fischer- Tropsch reactor) may be transferred via one or more heat exchanger(s) 734 to facilitate the desalination process. As another non-limiting example, the carbon oxide electrolyzer unit 2820 may include one or more carbon oxide electrolyzer(s), heat exchanger(s), oxygen separator(s), desalination system(s), and salt addition unit(s) positioned and operated in a manner as shown and described in Figures 4A-4F. The water inlet 2807, carbon dioxide inlet 2803, oxygen output 2809, and reduction product outlet 2822 as shown in Figure 7 may correspond respectively to streams 412, 312, 324, and 314 as shown in Figures 4E-4F and may be provided to the various units (e.g., carbon oxide electrolyzer 310, heat exchanger(s) 410, oxygen separator 320, and desalination system 420 / 500) with the carbon dioxide electrolysis unit 2820 in the same manner as illustrated in Figures 4A-4F.

[0189] Returning to water electrolyzer unit 2830, as mentioned, it has water inlet conduit 2805 as a source of water feedstock. Water electrolyzer unit 2830 has three primary outlets,hydrogen outlet conduit 2832, an oxygen outlet conduit 2813, and a wastewater outlet 2815. Oxygen outlet conduits 2813 and 2809 transport oxygen out of integrated system 2801 to storage, a reactor, or, as illustrated, the atmosphere. In some embodiments, the water electrolyzer unit, in addition to comprising one or more water electrolyzers (e.g., water electrolyzer stack(s)), may also comprise various optional components described elsewhere herein, such as one or more of the optional components described with respect to carbon dioxide unit 2820. Non-limiting examples include separation unit, gas separator, circulation pump, electrical grid, transformer, rectifiers, variable supply, mass flow meter or controller, ion exchanger, anode water recirculation loop, etc. For example, in some embodiments, the water electrolyzer unit may comprise separation units (e.g., gas separators, condensers, driers, etc.) configured to remove and / or separate liquids or moisture from gases (e.g., hydrogen and / or oxygen) in the water electrolyzer outlet streams. Some of these separated liquids may be transported out of electrolysis unit 2830 via wastewater outlet 2815, in some embodiments.

[0190] In some embodiments, the water inlet 2805 for the water electrolyzer unit 2830 may be configured to accept an unpurified water or aqueous stream described elsewhere herein, such as a salt- or ion-containing water (e.g., seawater), and may be subjected to a desalination process described elsewhere herein (such as shown and / or illustrated in Figures 4A-6B) before it can be used as an anolyte feed for the water electrolyzer unit. As a non-limiting example, the water electrolyzer unit 2830 may include one or more water electrolyzer(s), heat exchanger(s), oxygen separator(s), and desalination system(s) positioned and operated in a manner as shown and described in Figures 4E-4F. The water inlet 2805, oxygen output 2813, hydrogen output 2832, and acidic wastewater output as shown in Figure 7 may correspond respectively to streams 432, 482, 442, and 484 as shown in Figures 4E-4F and may be provided to the various units (e.g., water electrolyzer 440, heat exchanger(s) 470, oxygen separator 480, and desalination system 420 / 500) within water electrolyzer unit 2830 in the same manner as illustrated in Figures 4E-4F.

[0191] As illustrated, wastewater conduits 2815 and 2811 transport wastewater out of integrated system 2801 to storage. Additionally, carbon monoxide purification unit 2840 comprises an acid wastewater outlet connected to a conduit 2815 configured to transport the acidic wastewater to the wastewater storage mentioned here. Still further, Fischer-Tropsch reactor 2850, hydro-processing unit 2860, and product fractionation unit 2865 all may produce wastewater that is ultimately provided to storage outside integrated system 2801.

[0192] Each of the Fischer-Tropsch reactor 2850, the hydro-processing unit 2860, and the product fractionation unit 2865 may produce vent gas, as illustrated, and the vent gas from these different units may be combined and delivered to the vent gas flare system 2858.

[0193] Various optional ancillary or support units or systems are not depicted in Figure 7. These may include feedstock storage such as storage of carbon dioxide and water. In certain embodiments, liquid carbon dioxide is stored as a feedstock. The liquid carbon dioxide storage is accompanied by a vaporizer to supply to the carbon dioxide as a gas to the carbon dioxide electrolyzer unit 2820. Alternatively, in some embodiments, the feed carbon dioxide can be directly stored and supplied in gaseous form.

[0194] Also not shown are product storage units, such as product storage for fuel provided via conduit 2869 and naphtha provided via conduit 2867. Similarly, storage or disposal systems for wastewater such as oily wastewater and acidic wastewater are not shown. Also not shown in Figure 7 are utilities such as sources of electrical power and water. Also not shown are venting and / or flaring systems. A flaring system may be used to process waste gas streams and be available to bum the gases in emergency relief scenarios to allow safe shutdown of the plant. In some embodiments, integrated system 2801 employs an enclosed flare (so no open flame).

[0195] In some implementations, integrated system 2801 employs compressors for providing differing pressures to the components, optionally at different times. In one example, the integrated system 2801 includes a compressor to boost the carbon dioxide electrolyzer’s operating pressure and improve the performance carbon monoxide purification unit 2840, a compressor to boost the syngas up to pressure for the Fischer-Tropsch reactor, and a compressor to recycle carbon dioxide to the to the carbon dioxide electrolyzer.

[0196] Examples of utilities that may be available to integrated system 2801 include cooling water, nitrogen, instrument air, deionized water, and electrical power.Additional information regarding optional embodiments and / or elements of the system and / or method are provided below, in US Provisional Patent Application Serial No. 63 / 645,749, filed May 10, 2024, entitled “Integrating Salt- or Ion-Containing Water with a Carbon Oxide Electrolyzer” by Frank, et. al., which is incorporated herein by reference in its entirety.Controller Embodiments

[0197] In embodiments employing a controller or other logic for controlling operation of one or more reactors, pumps, separators, and / or other components of a system the controller or logic may employ program instructions such as executable instructions on computer-readable medium. The instructions may be executed by computer-executable components such as those integrated with a communication system. The computer-readable medium may be stored onany suitable computer readable media such as RAMs, ROMs, flash memory, EEPROMs, optical devices (CD or DVD), hard drives, floppy drives, or any suitable device. The computerexecutable component is optionally a processor, but the instructions may alternatively or additionally be executed by any suitable dedicated hardware device.

[0198] Although omitted for conciseness, embodiments of the system and / or method can include every combination and permutation of the various system components and the various method processes, wherein one or more instances of the method and / or processes described herein can be performed asynchronously (e.g., sequentially), concurrently (e.g., in parallel), or in any other suitable order by and / or using one or more instances of the systems, elements, and / or entities described herein.

[0199] The Figures illustrate the architecture, functionality and operation of possible implementations of systems, methods and computer program products according to disclosed embodiments, example configurations, and variations thereof. In this regard, each block in the flowchart or block diagrams may represent a module, segment, step, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block can occur out of the order noted in the FIGURES. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and / or flowchart illustration, and combinations of blocks in the block diagrams and / or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

[0200] As a person skilled in the art will recognize from the previous detailed description and from the figures and claims, modifications and changes can be made to the disclosed embodiments of the disclosure without departing from the scope of this disclosure defined in the following claims.

[0201] While several embodiments of the present invention have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and / or structures for performing the functions and / or obtaining the results and / or one or more of the advantages described herein, and each of such variations and / or modifications is deemed to be within the scope of the present invention. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and / orconfigurations will depend upon the specific application or applications for which the teachings of the present invention is / are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the invention may be practiced otherwise than as specifically described and claimed. The present invention is directed to each individual feature, system, article, material, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, and / or methods, if such features, systems, articles, materials, and / or methods are not mutually inconsistent, is included within the scope of the present invention.

[0202] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0203] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified unless clearly indicated to the contrary. Thus, as a non-limiting example, a reference to “A and / or B,” when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A without B (optionally including elements other than B); in another embodiment, to B without A (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0204] As used herein, the term “about” is understood to account for minor increases and / or decreases beyond a recited value, which changes do not significantly impact the desired function of the parameter beyond the recited value(s). In some cases, “about” encompasses + / — 10% of any recited value. As used herein, this term modifies any recited value, range of values, or endpoints of one or more ranges.

[0205] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly oneelement of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0206] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0207] Some embodiments may be embodied as a method, of which various examples have been described. The acts performed as part of the methods may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include different (e.g., more or less) acts than those that are described, and / or that may involve performing some acts simultaneously, even though the acts are shown as being performed sequentially in the embodiments specifically described above.

[0208] Use of ordinal terms such as “first,” “second,” “third,” etc., 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.

[0209] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” and thelike are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be 5 closed or semiclosed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.

Claims

CLAIMSWhat is claimed is:

1. A method comprising: providing a carbon oxide (COX) electrolyzer comprising one or more membrane electrode assemblies, wherein at least one of the membrane electrode assemblies comprises a cathode layer comprising a carbon oxide reduction catalyst that promotes reduction of a carbon oxide, an anode layer, and a polymer electrolyte membrane layer disposed between, and in contact with, the cathode layer and the anode layer; introducing an anolyte inlet stream to the COXelectrolyzer and producing an anolyte outlet stream having a higher temperature than the anolyte inlet stream; heating a first aqueous stream via indirect heat exchange with the anolyte outlet stream to thereby produce a heated first aqueous stream; directing at least a portion of the heated first aqueous stream to a desalination system; and outputting a desalinated aqueous stream.

2. The method of claim 1, further comprising directing at least a portion of the desalinated aqueous stream to an anolyte inlet stream of an electrolyzer.

3. The method of claim 2, wherein at least a portion of the desalinated aqueous stream is directed to the anolyte inlet stream of the COXelectrolyzer.

4. The method of any one of claims 2-3, wherein at least a portion of the desalinated aqueous stream is directed to an anolyte inlet stream of a water electrolyzer.

5. The method of any one of claims 1-4, wherein the desalination system comprises a thermal desalination unit.

6. The method of any one of claims 1-5, further comprising desalinating the heated first aqueous stream to thereby produce the desalinated aqueous stream.

7. The method of claim 6, wherein the desalinating comprises vaporizing water from the heated first aqueous stream and condensing the vaporized water to produce the desalinated aqueous stream.

8. The method of any of claims 1-7, further comprising introducing additional heat to the desalination system.

9. The method of any one of claims 1-8, wherein the desalination system is operated under vacuum.

10. The method of any one of claims 1-9, wherein the desalination system comprises an ion-exchange desalination unit.

11. The method of any one of claims 1-10, further comprising, via directing at least a portion of the heated first aqueous stream to the desalination system, heating the desalination system to recharge the desalination system.

12. The method of any one of claims 1-11, prior to the outputting, further comprising introducing a second aqueous stream into the desalination system and desalinating the second aqueous stream to produce the desalinated aqueous stream.

13. The method of any one of claims 1-12, further comprising introducing salt to the anolyte inlet stream of the COXelectrolyzer to establish a predetermined salt concentration.

14. The method of any one of claims 1-13, further comprising inputting a source of carbon oxide to the COXelectrolyzer to produce an output stream comprising a carbon- containing product and unreacted carbon oxide, wherein the carbon-containing product is a reduction product of carbon oxide.

15. The method of any one of claims 1-14, wherein the COXelectrolyzer is a carbon dioxide (CO2) electrolyzer configured to receive a source of carbon dioxide and to output carbon monoxide and unreacted carbon dioxide.

16. The method of claim 15, further comprising directing the output stream to a carbon monoxide purification unit configured to separate carbon monoxide from unreacted carbon dioxide.

17. The method of claim 16, wherein at least a portion of the separated carbon dioxide is recirculated to the CO2 electrolyzer.

18. The method of any one of claims 15-17, wherein at least a portion of the carbon monoxide produced by the CO2 electrolyzer is combined with molecular hydrogen to produce syngas.

19. The method of any one of claims 4-18, further comprising producing molecular hydrogen from the water electrolyzer.

20. The method of any one of claims 18-19, further comprising directing the syngas to a downstream reactor.

21. The method of claim 20, wherein the downstream reactor comprises a Fischer- Tropsch reactor.

22. The method of any one of claims 1-21, wherein the anolyte outlet stream of the COXelectrolyzer comprises an oxidation product of the anolyte and unreacted anolyte, wherein the oxidation product comprises molecular oxygen.

23. The method of any one of claims 1-22, wherein, prior to the heating, separating molecular oxygen from the anolyte outlet stream to produce an anolyte outlet stream that is oxygen deficient.

24. The method of any one of claims 1-23, wherein the first aqueous stream is an ion- or salt-containing water.

25. The method of any one of claims 1-24, wherein the first aqueous stream comprises one or more of seawater, brackish water, wastewater, flowback water, lake water, pond water, river water, creek water, ground or tap water, reservoir water, and / or rainwater.

26. The method of any one of claims 1-25, wherein the first aqueous stream has about at least 200 ppm of ions.

27. The method of any one of claims 1-26, wherein the first aqueous stream has about at least 500 ppm of ions.

28. The method of any one of claims 1-27, wherein the first aqueous stream has about at least 1,000 ppm of ions.

29. The method of any one of claims 1-28, wherein the first aqueous stream has about at least about 3,000 ppm of ions.

30. The method of any one of claims 1-29, wherein the first aqueous stream has about at least about 10,000 ppm of ions.

31. The method of any one of claims 1-30, wherein the first aqueous stream has about at least about 30,000 ppm of ions.

32. The method of any one of claims 12-31, wherein the second aqueous stream is an ion- or salt-containing water that is the same or different from the first aqueous stream.

33. The method of any one of claims 12-32, wherein the second aqueous stream comprises one or more of seawater, brackish water, wastewater, flowback water, lake water, pond water, river water, creek water, ground or tap water, reservoir water, and / or rainwater.

34. The method of any one of claims 1-33, wherein the indirect heat exchange occurs via a heat exchanger system comprising one or more heat exchanger units.

35. A system comprising: a carbon oxide (COX) electrolyzer comprising one or more membrane electrode assemblies configured to receive an anolyte inlet stream and output an anolyte outlet stream, wherein at least one of the membrane electrode assemblies comprises: a cathode layer comprising a carbon oxide reduction catalyst that promotes reduction of a carbon oxide;an anode layer; and a polymer electrolyte membrane layer disposed between, and in contact with, the cathode layer and the anode layer, wherein the anolyte outlet stream has a higher temperature than the anolyte inlet stream; a heat exchanger system comprising one or more heat exchanger units, wherein the heat exchanger system is configured to heat a first aqueous stream via indirect heat exchange with the anolyte outlet stream to thereby produce a heated first aqueous stream; and a desalination system configured to receive at least a portion of the heated first aqueous stream and to output a desalinated aqueous stream.

36. The system of claim 35, further comprising a recirculation loop configured to direct at least a portion of the desalinated aqueous stream to the anolyte inlet stream of the COXelectrolyzer.

37. The system of any one of claims 35-36, wherein the COXelectrolyzer is a carbon dioxide (CO2) electrolyzer fluidically connected to a source of carbon dioxide, wherein the CO2 electrolyzer is configured to receive an input of carbon dioxide and to output carbon monoxide and unreacted carbon dioxide.

38. The system of claim 37, wherein the system further comprises a carbon monoxide purification unit downstream the CO2 electrolyzer configured to separate carbon monoxide from unreacted carbon dioxide.

39. The system of any one of claims 35-38, further comprising a salt dosing unit upstream the COXelectrolyzer.

40. The system of any one of claims 35-39, wherein the system further comprises a water electrolyzer configured to produce molecular hydrogen.

41. The system of claim 40, further comprising a recirculation loop configured to direct at least a portion of the desalinated aqueous stream to an anolyte inlet stream of the water electrolyzer.

42. The system of any one of claims 40-41, further comprising a Fischer-Tropsch reactor downstream of the COXelectrolyzer and / or the water electrolyzer.

43. The system of any one of claims 35-42, wherein the desalination system comprises a thermal desalination unit.

44. The system of any one of claims 35-43, wherein the desalination system is configured to desalinate the heated first aqueous stream to produce the desalinated aqueous stream.

45. The system of any one of claims 35-44, wherein the desalination system comprises an ion-exchange desalination unit.

46. The system of any one of claims 35-45, wherein the desalination system is configured to receive a second aqueous stream and desalinate the second aqueous stream to produce the desalinated aqueous stream.

47. The method or system of any one of claims 1-46, wherein the desalination system comprises an evaporation unit coupled to a condenser unit.

48. The method or system of any one of claims 1-47, wherein the desalination system comprises one or more of a multiple-effect distillation (MED), multistage-flash distillation (MSF), vapor-compression distillation (VCD), membrane distillation, and / or a humidification and dehumidification (HDH) desalination system.

49. The method or system of any one of claims 1-48, wherein the desalination system comprises a recharged ion-exchange desalination unit.

Images