Hydrogen generation via high fluid velocity electrolysis and gas separation

Abstract

A system and method for generating hydrogen from a liquid source comprising water is disclosed. The system comprises: a high fluid velocity electrolysis cell comprising an inlet and an outlet, the inlet of the high fluid velocity electrolysis cell being fluidly connected to a liquid source; and a gas fractionation system fluidly connected to the outlet of the high fluid velocity electrolysis cell.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Provisional Application No. 63 / 471,063, filed June 5, 2023, entitled “Hydrogen Generation Via HighFluid Velocity Electrolysis and Gas Separation,” the contents of which are incorporated herein by reference in their entirety. background

[0002] 1. Field of Invention The aspects and implementation methods disclosed herein generally involve the generation of hydrogen through the electrolysis of water.

[0003] 2. Discussion of related technologies Energy demand continues to grow worldwide. The combustion of fossil fuels currently provides approximately 80% of the world's energy, producing large amounts of carbon dioxide as a combustion byproduct. Meanwhile, there is a widespread desire to reduce carbon dioxide emissions in an effort to mitigate the impact of atmospheric carbon dioxide accumulation on global warming. Therefore, there is a growing expectation for the development and deployment of energy production systems and technologies that do not rely on the combustion of fossil fuels.

[0004] Hydrogen is an alternative fuel to fossil fuels such as oil, coal, and natural gas. The combustion of hydrogen produces water vapor and no carbon dioxide, and is therefore considered a "clean" or "green" fuel. Hydrogen can be produced through the electrolysis of water, in which water molecules are broken down into hydrogen and oxygen by applying an electric current.

[0005] Hydrogen production via water electrolysis is typically carried out using high-purity water and somewhat complex equipment, including ion-selective membranes separating the anode and cathode compartments of the electrolyzer. However, the vast majority of water on Earth is in the form of seawater, which has high levels of dissolved solids such as chlorides, sodium, sulfates, magnesium, calcium, and potassium. It would be desirable to develop and implement a simple and reliable system and process for generating hydrogen from seawater. Overview

[0006] According to an aspect of the invention, a system for generating hydrogen from a liquid source containing water is provided. The system includes: a high fluid rate electrolyzer having an inlet and an outlet, the inlet of the high fluid rate electrolyzer being fluidly connected to the liquid source; and a gas fractionation system fluidly connected to the outlet of the high fluid rate electrolyzer. Brief description of the attached diagram

[0007] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures is represented by similar numbers. For clarity, not every component may be labeled in every drawing. In the drawings: Figure 1 This is a diagram of an example of a system for generating hydrogen from seawater via electrolysis, which includes more than one pretreatment step prior to the electrolysis step; Figure 2 The figure illustrates an example of a concentric tube electrode electrolyzer that can be used according to the various aspects and implementation schemes disclosed herein; Figure 3 This is a table illustrating the amount of hydrogen generated in different electrolyzers in a series arrangement of 20 concentric tube electrode electrolyzers; Figure 4 The figure illustrates the steps in a process for gas fractionation via cryogenic gas separation; Figure 5 This is a schematic diagram of a system used to generate hydrogen from seawater; Figure 6 It is possible Figure 5 A schematic diagram of the control system used in the system; and Figure 7 It is used for Figure 6 A schematic diagram of the memory structure of the control system. Detailed Explanation

[0008] The aspects and embodiments disclosed herein are not limited to the details of the construction and arrangement of the components set forth in the following description or illustrated in the accompanying drawings. The aspects and embodiments disclosed herein can be practiced or implemented in a variety of ways. Furthermore, the wording and terminology used herein are for descriptive purposes only and should not be considered limiting. The use of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof herein is intended to cover the items listed below and their equivalents, as well as other items.

[0009] Electrolysis is a promising option for carbon-free hydrogen production from renewable and nuclear resources. Electrolysis is the process of splitting water into hydrogen and oxygen using electricity. This reaction occurs in a unit called an electrolyzer. Electrolyzers can range in size from small electrical units well-suited for small-scale distributed hydrogen production to large-scale central production facilities that can be directly connected to renewable or other non-greenhouse gas-emitting forms of electricity.

[0010] Electrolysis is a leading hydrogen production pathway to achieving the goal of reducing the cost of clean hydrogen by 80% to $1 per kilogram within 10 years ("1+11"). Hydrogen produced via electrolysis can result in zero greenhouse gas emissions, depending on the source of electricity used. When assessing the benefits and economic feasibility of hydrogen production via electrolysis, the source of electricity, including its cost and efficiency, as well as emissions from electricity generation, should be considered. In many parts of the United States, today's power grids are not ideal for powering electrolysis due to the inefficiencies in the electricity generation process, the greenhouse gas emissions released, and the amount of fuel used. Hydrogen production via electrolysis is being used in renewable energy sources (wind, solar, hydro, geothermal) and nuclear energy options. These hydrogen production pathways result in near-zero greenhouse gas and standard pollutant emissions; however, production costs should be significantly reduced to compete with more established carbon-based pathways such as natural gas reforming.

[0011] As of 2020, the global green hydrogen market was estimated at $1.14 billion and is projected to grow to $15.1 billion by 2026 (Grand View Research, 2020; Research and Markets, 2021).

[0012] Existing technologies for hydrogen electrolysis involve the use of membrane separation electrolyzers. While such devices are effective for hydrogen generation, they are highly sensitive to the quality of the influent water and require high levels of removal of total dissolved solids (TDS), total suspended solids (TSS), and organic matter for long-term operation. In terms of efficiency, membrane separation hydrogen electrolyzers separate the generated gaseous oxygen and hydrogen, simplifying downstream gas treatment.

[0013] One or more aspects disclosed herein relate to systems and methods for generating hydrogen through the electrolysis of water. According to some embodiments, the water may be brackish water or seawater. Gases such as oxygen or chlorine, which are co-generated with hydrogen during the electrolysis of water, can be separated from the hydrogen to provide a substantially pure hydrogen product. The gas separation process may include utilizing a cryogenic gas separation system.

[0014] An example of a system for generating hydrogen from seawater. Figure 1As shown in the diagram, seawater with a TDS level of 35,000 ppm or higher, a TSS level of 10 NTU or higher, and an organic compound concentration of 5 ppm or higher can be used as a hydrogen source. The seawater undergoes several pretreatment steps before electrolysis. The first pretreatment step is a solids removal step 10, in which a screen, sand filter, or other coarse filter is used to remove most of the suspended solids from the incoming seawater. The second pretreatment step is an organic matter removal step 20, which removes most of the organic pollutants. Organic matter removal can be carried out, for example, by biological treatment according to various systems and methods known in the art. Next are a series of TDS removal steps 30A, 30B, 30N, in which the partially pretreated seawater can be further filtered using membrane filtration equipment such as nanofiltration, ultrafiltration, and / or reverse osmosis equipment to reduce the TDS level of the partially pretreated seawater. The pretreated seawater with significantly reduced TDS, TSS, and organic matter levels then undergoes electrolysis to produce hydrogen and byproducts such as oxygen. Hydrogen and oxygen can be generated in separate compartments of the electrolyzer, and the gases can be extracted individually from these compartments.

[0015] Such as Figure 1 The equipment and methods shown in the figure may be undesirably expensive in terms of both capital and operating costs, and may be more complex than expected due to multiple pretreatment operations.

[0016] In the electrolysis of water, hydrogen gas is generated at the cathode of the electrolyzer based on an electrochemical reaction: .

[0017] Oxygen is generated at the anode of the electrolytic cell based on an electrochemical reaction: .

[0018] If chloride is present in the water undergoing electrolysis, the oxygen formation reaction can compete with the chlorine formation reaction: .

[0019] Hydrogen generation can also be accompanied by the production of NaOCl in an electrolyzer supplied with an aqueous solution containing NaCl, according to the following reaction: The reaction at the anode:

[0020] The reaction at the cathode:

[0021] In solution:

[0022] Overall reaction: .

[0023] In these reactions, the listed potentials are under 1 M concentration (active) conditions for reactants and products, as well as standard conditions (25 °C and 1 atm).

[0024] The voltage across the anode and cathode can be measured to determine when hydrogen begins to be generated in the electrolyzer. Parameters such as the temperature, pH, and composition of the feed entering the electrolyzer can affect the voltage at which hydrogen generation begins. Pressure, flow rate, and turbulence can also affect the voltage at which hydrogen generation begins. In some embodiments, the power supply can be controlled to provide a voltage across the anode and cathode of the electrolyzer sufficient to induce hydrogen generation. This voltage can be, for example, higher than about 1.0 V, 1.1 V, 1.2 V, 1.3 V, 1.4 V, 1.5 V, 2.0 V, 3.0 V, or 4.0 V, although, as mentioned above, factors such as the pH, composition, and / or pressure of the feed solution can alter the voltage at which hydrogen generation begins in the electrolyzer.

[0025] The composition of the solution within an electrolyzer can be altered by changing the feed flow rate or velocity. Generally, increasing the flow rate or velocity increases turbulence and mixing within the system. Since the reaction typically occurs locally at the anode or cathode of the electrolyzer, increased turbulence can affect the normalization of the solution composition and pH within the electrolyzer.

[0026] Feedback or feedforward control of flow rate or velocity can be achieved. In some implementations, the feed flow rate or velocity is measured using a flow meter. One or more parameters of a system comprising one or more electrolyzers can be adjusted in response to the flow rate or velocity measurement results. For example, flow rate or velocity, pH, or temperature can be adjusted in response to the measurement results. The measurement results can be transmitted to a circulation pump to control the flow rate or velocity as needed. The flow rate can be controlled in the range of approximately 0.1–10 m³ / s. 3 Between / hour. The flow rate can be controlled to 0.1 m³. 3 / hour, 0.5 m 3 / hour, 1.0 m 3 / hour, 2.0 m 3 / hour, 3.0 m 3 / hour, 4.0 m 3 / hour, 5.0 m 3 / hour, 6.0 m 3 / hour, 7.0 m 3 / hour, 8.0 m 3 / hour, 9.0 m 3 / hour, 9.5m 3 / hour or 10 m 3 / Hour.

[0027] The flow velocity can be controlled between approximately 1.0 m / s and 4.0 m / s. The flow velocity can be controlled at approximately 1.0 m / s, 2.0 m / s, 3.0 m / s, or 4.0 m / s. In some embodiments, the flow velocity can be controlled between approximately 2.0 m / s and 2.5 m / s. The flow velocity can be controlled between approximately 2.5 m / s and 3.0 m / s. The flow velocity can be controlled between approximately 3.0 m / s and 3.5 m / s. In some implementations, the flow rate can be controlled to approximately 2.0 m / s, 2.1 m / s, 2.2 m / s, 2.3 m / s, 2.4 m / s, 2.5 m / s, 2.6 m / s, 2.7 m / s, 2.8 m / s, 2.9 m / s, 3.0 m / s, 3.1 m / s, 3.2 m / s, 3.3 m / s, 3.4 m / s, or 3.5 m / s. The flow rate or velocity can be increased or decreased as needed to increase or decrease turbulence and mixing. For example, concentric tube electrode electrolyzers can be used in marine and offshore applications using seawater as feed. The liquid velocity through this cell can be approximately 2.1 m / s, resulting in highly turbulent flow, which can reduce the likelihood of fouling and scaling on the electrode surfaces.

[0028] Additionally, one or more parameters of the aqueous solution entering, leaving, or within the system can be measured to determine desired adjustments to the flow rate or velocity. For example, the flow rate or velocity can be increased or decreased based on measurements of the local pH within the system or the composition of the aqueous solution entering, leaving, or within the system. The flow rate or velocity can be increased in cases where there is a wide variation in the local pH within the system to neutralize the pH, or where measurements of the properties of the aqueous solution leaving the system (“product stream”) indicate potential electrode fouling.

[0029] In some implementations, the redox potential (ORP) of the feed, aqueous solution within the system, or product stream can be measured using sensors. One or more parameters of the system can be adjusted in response to the ORP measurement results. For example, flow rate, pH, temperature, or feed composition can be adjusted in response to the ORP measurement results.

[0030] Variations in the TDS of the feed stream can affect its conductivity. Electrolytic cell voltage and conductivity are inversely related. Therefore, in some embodiments, the total power consumption of the electrolytic cell can be controlled by controlling the TDS concentration in the feed stream. The feed stream TDS concentration can be controlled by selectively introducing seawater, brackish water, brine, fresh water, or combinations thereof into or as the feed stream. The conductivity of the feed stream or product stream can be measured using sensors. One or more parameters of the system can be adjusted in response to conductivity measurements. In some embodiments, the flow rate, feed composition, or pH can be adjusted in response to conductivity measurements.

[0031] According to the aspects and embodiments disclosed herein, an electrolyzer that can be used for the electrolysis of water to produce hydrogen gas may include a plate-and-frame electrolyzer or a concentric tube electrode (CTE) electrolyzer, examples of which are described in […]. Figure 2 Various views are illustrated in the figure, and embodiments of the concentric tube electrode (CTE) electrolyzer are described in PCT application PCT / US2016 / 018210 (published as WO 2016 / 133983), which is incorporated herein by reference in its entirety for all purposes. Examples of suitable CTE electrolyzers are available from Electrocatalytic Ltd.

[0032] As used herein, the term "tube" includes cylindrical conduits; however, it does not exclude conduits having other cross-sectional geometries, such as those having square, rectangular, elliptical, or oblong geometries, or those shaped into any regular or irregular polygonal cross-sectional geometry.

[0033] As used herein, the term "concentric tube" includes tubes that share a common central axis, but does not exclude tubes that are about the common axis, which is not necessarily centered for each of the concentric tubes in a set of concentric tubes or for tubes with axes that are offset from each other.

[0034] The aspects and embodiments disclosed herein are not limited to the number of electrodes, the space between electrodes, the electrode material, the material of any partition between electrodes, the number of channels in the electrolytic cell, or the electrode coating material.

[0035] Typically, it is desirable to limit or prevent hydrogen generation in CTE electrolyzers. Electrodes in CTE electrolyzers are often formed of materials such as titanium, and hydrogen diffusion into these materials can lead to electrode embrittlement and increase the likelihood of mechanical failure. Additionally, hydrogen bubbles can partially blind the electrodes, leaving less electrode area for the desired electrochemical reactions to occur within the electrolyzer. Therefore, several methods have been developed to reduce or eliminate hydrogen generation in CTE electrolyzers. For example, PCT application publication WO 2017 / 049052, which is incorporated herein by reference, describes adding oxygen or another oxidant to the feed stream of a CTE electrolyzer to react with any hydrogen generated during operation and form water, hydroxides, or other substances superior to hydrogen.

[0036] At a flow rate of 2 m / s–3 m / s, assuming the feed stream has Na+ concentrations between approximately 10,000 ppm and 16,000 ppm. + Concentrations of Cl between approximately 18,000 ppm and 23,000 ppm -Concentrations of Mg between approximately 750 ppm and 1,800 ppm 2+ Concentrations of Ca between approximately 200 ppm and 500 ppm 2+ Concentration, such as the CTE electrolyzer disclosed in PCT / US2016 / 018210, is capable of self-cleaning operation.

[0037] The simulated hydrogen production rate of the CTE electrolyzer example is in Figure 3 The simulation results are shown in the presentation. Figure 3 The table assumes 20 CTE electrolyzer units with a capacity of 24 m 3 The seawater flowing through the system is connected in series, with a flow rate of / hour. Each electrolyzer produces 0.495m³ of water. 3 / hour of hydrogen, of which Figure 3 The second column of the table indicates the cumulative amount of hydrogen produced. The pressure at the inlet of the first electrolyzer is simulated as 20 bar, decreasing for each subsequent electrolyzer. The fourth column of the table, "Dissolved Hydrogen m³", indicates the cumulative amount of hydrogen produced. 3 " / hour" indicates the total volume of hydrogen soluble in seawater at the pressure of each electrolyzer, and the fifth column, "hydrogen in the cell (m³)", indicates the total volume of hydrogen soluble in seawater at the pressure of each electrolyzer. 3 " / hour" indicates the total amount of dissolved hydrogen (negative) or whether the seawater is saturated with hydrogen (positive). The seawater becomes saturated with hydrogen after the 10th electrolyzer. The third column, "Hydrogen volume in m³ at line pressure," indicates the total amount of dissolved hydrogen. 3 " / hour" indicates the amount of hydrogen in gaseous form in each electrolyzer and is the sum of the values ​​in the fourth and fifth columns of each electrolyzer.

[0038] As used in this article, "electrolyte" can refer to a single electrolyte unit, such as... Figure 2 The electrolytic cell unit shown in the figure may refer to multiple electrolytic cell units connected in series and / or in parallel.

[0039] The high-speed fluid flow in a CTE electrolyzer can mitigate cathodic scaling in a matrix with a high concentration of divalent cations. This phenomenon is primarily due to localized pH reduction, enhanced mass transfer, and mechanical electrode scouring. While CTE electrolyzers are effective for the generation of both oxygen and hydrogen, they typically do not separate these two gases because they lack discrete compartments, limiting their effectiveness for downstream hydrogen extraction. Therefore, downstream gas separation is desirable for hydrogen generation using a non-separated high fluid velocity electrolyzer (HFVE).

[0040] Cryogenic gas separation is an example of a process that can be used for the fractionation of multiple gases. In some implementations, such a process involves compression, cooling, and purification to separate the constituent gases, refining them into discrete streams. A high-level illustrative example of an implementation of a cryogenic gas fractionation process is provided in... Figure 4As shown in the figure. Cryogenic gas fractionation systems capable of separating hydrogen from other gases (e.g., oxygen and chlorine) produced by the electrolysis of water (including brackish water or seawater) are commercially available from companies such as CleanPower Hydrogen Group Limited (Doncaster, UK) (e.g., model MFE220 membraneless electrolyzer) or AirProducts and Chemicals, Inc. (Allentown, PA) (various models).

[0041] The current limitation of such electrolyzers can be overcome by combining a high-fluid-rate, non-separated hydrogen electrolyzer (e.g., a CTE electrolyzer) with a downstream gas fractionation system. Non-limiting exemplary embodiments of a system including a high-fluid-rate, non-separated hydrogen electrolyzer and a downstream gas fractionation system are described below. Figure 5 As shown in the diagram. Such an implementation represents a membrane separation electrolyzer system relative to the current level of technology, such as... Figure 1 The diagram shows a significant improvement in the membrane separation electrolyzer system.

[0042] like Figure 5 As shown herein, the electrolytic hydrogen production system 100 may include at least a high fluid velocity electrolyzer, such as a CTE electrolyzer, for generating hydrogen and a downstream gas fractionation system for separating hydrogen and oxygen (and / or other gases).

[0043] Multiple pumps (e.g., pumps P1 and P2, and other pumps not shown) may be included in one or more sections of system 100 to induce flow of the various aqueous solutions involved. Multiple sensors S may also be present, capable of measuring various operating parameters within one or more sections of the system and the various aqueous solutions involved. One or more sensors S may monitor one or more parameters of the fluid flowing through the system, such as the aqueous solution to be introduced into the electrolyzer, the fluid inside the electrolyzer, or one or more parameters of the product solution generated by or produced in the electrolyzer. These parameters may include, for example, flow rate, ion concentration, chlorine concentration, oxygen concentration, hydrogen concentration, pH, electrical parameters, temperature, redox potential (ORP), or any other parameter of interest. Additional sensors may monitor parameters of the electrolyzer itself, such as the current and / or voltage across the anode-cathode pair in the electrolyzer, or the temperature of the electrolyzer or the temperature inside the electrolyzer.

[0044] Pumps and sensors can be communicated with a control system or controller 150, which communicates with the sensors and pumps and controls the operation of the pumps and other components of the system to achieve desired operating parameters. Multiple operating parameters of the electrolyzer disclosed herein can be controlled or adjusted by the control system or controller based on multiple parameters measured by multiple sensors located in different parts of the electrochemical system. The controller can also be configured to adjust the concentration of product compounds generated in the electrolyzer based at least on the redox potential of the liquid at the point of use, which is fluidly connected to or connected to the outlet of the electrolyzer's housing.

[0045] The controller can be programmed or configured to regulate the introduction of the aqueous solution into the electrolyzer based on at least one or more of the following: the temperature in the electrolyzer, the pH of the aqueous solution, the pH of the product solution generated in the electrolyzer, the flow rate of the aqueous solution or product solution, the ORP of the aqueous solution or product solution, or the current or voltage applied across the anode and cathode.

[0046] The controller can be programmed or configured to regulate the current across the anode-cathode pair of the electrolyzer based on the flow rate of the aqueous solution.

[0047] The controller can be configured to change, modify, or regulate the current applied by the electrodes. The controller can regulate the voltage applied across the anode and cathode. The controller can be programmed or configured to regulate the applied current or voltage in response to the flow rate of the aqueous solution entering the electrolyzer, the voltage measured across the anode and cathode, or the hydrogen concentration in the aqueous solution near the cathode. The controller can be programmed or configured to regulate the applied current, applied voltage, or electrode polarity in response to the flow rate of at least one process solution, pH measurement, temperature measurement, or redox potential. The controller can be programmed or configured to regulate the applied current, applied voltage, electrode polarity, or pulse waveform in response to the dissolved oxygen concentration or dissolved hydrogen concentration of at least one process solution.

[0048] The controller can be programmed or configured to adjust the applied current, applied voltage, or electrode polarity sufficiently to promote hydrogen generation within the electrochemical cell. The applied current, applied voltage, or electrode polarity can depend on, for example, flow conditions or turbulence within the electrolyzer, the diffusion rate of oxygen or hydrogen within the electrolyzer, the operating current, the cathode area, etc.

[0049] In some implementations, the controller can be programmed or configured to adjust one or more conditions of the aqueous solution to sufficiently enhance the amount of hydrogen generated within the electrolyzer. The controller can be programmed or configured to adjust the flow rate or composition of the aqueous solution. The adjustment of the flow rate or composition of the aqueous solution can depend on, for example, flow conditions or turbulence within the electrolyzer, the diffusion rate of oxygen or hydrogen within the electrolyzer, the operating current, the cathode area, etc. The composition of the aqueous solution can be adjusted by quantitatively adding one or more compounds, such as pH adjusters or balancing agents.

[0050] Typically, a controller can be programmed to make any changes to initiate or maintain hydrogen generation. In an IV curve, changes in voltage indicate hydrogen generation. Therefore, the controller can be configured to maintain the voltage indicating hydrogen generation (or a predetermined threshold voltage) above a limit that indicates hydrogen generation. Because hydrogen generation is generally dependent on conditions such as temperature, pH, ORP, dissolved oxygen concentration, and dissolved hydrogen concentration, any one or more of these parameters can be controlled to remain within a predetermined range that indicates hydrogen generation within the system.

[0051] A controller for monitoring and controlling the operation of various components of a system may include a computer control system. Output devices configured to act in response to instructions from the controller may include valves, pumps, or switches that can be used to introduce an aqueous solution (e.g., brine, brackish water, or seawater) from a source into the electrolyzer system and / or to control the pump speed. One or more sensors may also provide input to the controller. These sensors may include, for example, sensors such as pressure sensors, chemical concentration sensors, temperature sensors, or sensors for any other parameter of interest to the system. These sensors may be located in any part of the system where they will be useful, such as upstream of a point of use in fluid communication with the product solution, in fluid communication with the solution within the electrolyzer or near the anode or cathode, and / or upstream of the electrolyzer inlet in fluid communication with an aqueous source. Additionally, the controller may include one or more interfaces (not shown) that connect the controller to a communication network other than or as an alternative to the disclosed interconnects.

[0052] Figure 5 The system may include a pH adjustment system and a heat exchanger (for clarity, from...). Figure 5(omitted), the pH adjustment system includes a pH adjusting agent source, such as an inorganic acid or a caustic base such as NaOH. The pH adjustment system can adjust the pH of the aqueous solution to a pH favorable for the reaction to generate the desired type of product in the electrolyzer, for example, adjusting it to a sufficiently low pH to enhance hydrogen formation in the electrolyzer. The pH adjustment system can adjust the pH of the aqueous solution to, for example, between about 2 and about 14, or between about 7 and about 10. A heat exchanger can be used to adjust the temperature of the aqueous solution to a temperature that results in the desired reaction kinetics in the electrochemical cell and / or to adjust the solubility of oxygen or hydrogen in the aqueous solution.

[0053] Dissolved oxygen sensors can be used to measure the dissolved oxygen level in aqueous solutions. Dissolved hydrogen sensors can be used to measure the dissolved hydrogen level in aqueous solutions. Dissolved oxygen or dissolved hydrogen sensors can measure oxygen or hydrogen at the system's electrodes or in the product solution.

[0054] A flow sensor can provide a controller with product solution flow rate data, which the controller can use to control the operation of pumps supplying the aqueous solution and / or the current or voltage applied across the anode-cathode pair of the electrolyzer. In some embodiments, the flow sensor can provide the controller with aqueous solution flow rate data.

[0055] An electrometer, such as a potentiostat, can be used to measure electrical parameters and / or the current-voltage profile of the generated aqueous or product solution. This current-voltage profile can be used to obtain information about whether the electrolyzer is operating within a desired range. In some embodiments, the desired range is the range in which hydrogen is generated within the electrolyzer. Data from the electrometer can be used by a controller to control the operation of one or more pumps (i.e., the rate at which the aqueous solution is introduced into the electrolyzer) and / or the current or voltage applied across the anode-cathode pair of the electrolyzer.

[0056] A redox potential (ORP) meter can be set to obtain an ORP reading of the liquid at the point of use. This reading can be used by the controller to determine when and how much product solution is metered into the point of use. In some embodiments, an ORP meter can be set to obtain an ORP reading of the product solution, which can be used by the controller to adjust the rate at which the aqueous solution is introduced into the electrolyzer.

[0057] The system may also include a gas separation tower, which can be used to remove dissolved hydrogen, oxygen, or other gases from the product solution and supply these gases to a gas fractionation unit. The gas separation tower may be included in, for example... Figure 5 In the high-speed H2 generator 130 or gas fractionation system 140 of system 100.

[0058] The various components of the system can be repeated in a straight line in series. For example, the system can have multiple repeating subsystems, which include heat exchangers, pH adjustment systems, electrolyzers, and possibly pumps P arranged in a straight line in series with each other.

[0059] The feed stream of the electrolytic hydrogen production system disclosed herein may include seawater, brine, brackish water, groundwater, fresh water, or drinking water, wherein the seawater has the same characteristics as... Figure 1 and Figure 5 The TDS, TSS, and organic pollutant concentrations shown are similar to those in the table.

[0060] Seawater typically has a salinity between about 3.0% and 4.0%, for example, it can have a salinity of about 3.5%, 3.6%, or 3.7%. Seawater contains dissolved ions, including sodium, chloride, magnesium, sulfate, and calcium. Seawater may also contain one or more of sulfur, potassium, bromide, carbon, and vanadium. Seawater can have a total dissolved solids (TDS) content of about 35,000 mg / L. Brine typically has a salinity greater than about 3.5%. For example, brine can have a salinity of about 4.0%, 4.5%, 5.0%, 7.5%, or about 10%. Brine can have a TDS content greater than about 35,000 mg / L. Saturated brine can have a salinity of up to about 25.0%. Brackish water typically has a salinity less than 3.5%. Brackish water can have a salinity of about 3.0%, 2.5%, 2.0%, or 1.0%. Brackish water can have a TDS content of less than about 35,000 mg / l. For example, brackish water can have a TDS content between about 1,000 mg / l and about 10,000 mg / l. Drinking water can have a TDS content of 500 ppm or less.

[0061] The concentration of different dissolved solids in seawater can vary depending on location; however, an example of seawater can include the following components: Table 1: Typical seawater components and concentrations

[0062] The different ionic components of seawater from different locations are indicated in Table 2 below: Table 2: Major Ionic Composition of Seawater (mg / L)

[0063] Typically, the conductivity of the feed stream can range from about 0 S / cm to 25 S / cm, depending on the salinity. Slightly brackish water with a salinity between about 0.5% and 2.0% can have a conductivity between about 0.5 S / cm and about 4.0 S / cm, for example, about 0.8 S / cm or about 3.0 S / cm. Seawater with a salinity of about 3.5% can have a conductivity between about 4.5 S / cm and 5.5 S / cm, for example, about 5.0 S / cm or about 4.8 S / cm. Brine with a salinity between about 5.0% and 10% can have a conductivity between about 7 S / cm and 13.0 S / cm, for example, about 12.6 S / cm. Saturated brine with a salinity of about 25% can have a conductivity between about 20.0 S / cm and about 23.0 S / cm, for example, about 22.2 S / cm. Typically, salinity and conductivity can follow a linear relationship: y = 0.9132x + 1.6332, where y is conductivity (S / cm) and x is salinity percentage (%NaCl).

[0064] The electrolyzers and apparatus disclosed herein can be included as part of a larger system. In some embodiments, the system is a marine-based system, such as a vessel or oil drilling rig, and in other embodiments, it is a land-based structure, such as a power plant, oil drilling facility or system, or other industrial facility. In other embodiments, the system is or may include a swimming pool or a treatment system for drinking water, wastewater, or industrial water treatment processes that use one or more products, such as disinfectants, in the electrolyzer within the system to treat or disinfect water.

[0065] Such a system can draw process liquids or electrolytes (which in some embodiments are seawater, brackish water, or brine) from external and / or internal sources. For example, if the system is ocean-based, the external source could be the ocean, and the internal source could be, for example, ballast tanks in a ship. In a land-based system, the external source could be the ocean, and the internal source could be brackish wastewater from an industrial process carried out in the system.

[0066] One or more electrolyzers can produce product solutions, such as chlorinated water and / or solutions containing sodium hypochlorite, from aqueous solutions and distribute them to points of use. Points of use can be sources of cooling water for systems, sources of disinfectants for ballast tanks in ships, the bottom of wells in oil drilling systems, or any other system where chlorine-based disinfectant solutions can be useful.

[0067] Return to reference Figure 5 The hydrogen generation system 100 receives an aqueous feed solution, such as seawater, brackish water, fresh water, or drinking water or a combination thereof, at inlet 110. Figure 5The parameters of the influent aqueous solution are consistent with those of seawater, but system 100 is not limited to using seawater as the hydrogen source. The influent aqueous solution can be pretreated in a solids removal device 120, such as a coarse screen, hydrocyclone, settling tank, or other form of solids removal device, to remove suspended solids, such as suspended solids having characteristic dimensions (e.g., length or width) greater than 1 μm, greater than 5 μm, greater than 25 μm, or any other size required for a particular embodiment. The pretreated aqueous solution, having a reduced TSS concentration compared to the influent aqueous solution, is introduced into a high-speed hydrogen generator 130, which is also referred to herein as a high fluid velocity electrolyzer. The high-speed hydrogen generator 130 can be or may include one or more electrolyzer units, such as a CTE electrolyzer as described above. One or more electrolyzer units can be fluidly connected in series or parallel and can be considered “high-speed” because the aqueous solution is pumped through one or more electrolyzer units by a fluid pump P1 at a speed sufficient to self-clean one or more electrolyzer units, for example, at a speed sufficient to prevent scaling on the electrodes of one or more electrolyzer units. This velocity can be, for example, 2 m / s or greater. Hydrogen and other gases, such as oxygen or chlorine, are removed from the outlet of the high-speed hydrogen generator 130 via a gas pump P2, and the hydrogen and other gases, such as oxygen or chlorine, are introduced into a gas fractionation system 140. The gas fractionation system 140 can be a cryogenic gas fractionation system. The gas fractionation system 140 separates the gas from the high-speed hydrogen generator 130 into a primary hydrogen product that is captured for energy generation and other gaseous products, such as oxygen, that can be captured or released into the environment. The aqueous solution leaving the high-speed hydrogen generator 130 may include useful products, such as hypochlorite, which may optionally be sent to the point of use after further processing to remove any undesirable components.

[0068] It should be noted that, Figure 5 In system 100, with Figure 1 Compared to other systems, there is no need to remove or reduce organic pollutants or dissolve solids between the solids removal operation (solids removal device 110) and the electrolysis operation (high-speed hydrogen generator 130). Therefore, system 100 can be configured without a membrane filtration device between the aqueous liquid source and the inlet of the high-fluid-rate electrolyzer and / or without a bioreactor between the aqueous liquid source and the inlet of the high-fluid-rate electrolyzer.

[0069] One or more sensors S may be located at multiple sites within system 100 and may be configured to measure one or more parameters of any aqueous solution and / or gas generated by the high-speed hydrogen generator 130 in different parts of system 100, such as temperature, flow rate, contaminant concentration, pH, oxidation-reduction potential (ORP), total organic carbon (TOC), dissolved oxygen concentration and / or dissolved hydrogen concentration, hydrogen peroxide concentration, purity, etc., and / or operating parameters of any unit operation of the system, such as operating parameters of the high-speed hydrogen generator 130. The controller 150 of the system, further described below, may receive readings from one or more sensors S and adjust one or more operating parameters of the system to obtain a desired level of one or more parameters read by one or more sensors S. For clarity, Figure 5 The signal and control circuits are not shown in the diagram. System operating parameters may include, for example, the power (current or voltage or both) applied to the high-speed hydrogen generator 130, the flow rate of the aqueous solution, or any other operating parameters of the system.

[0070] Multiple additional pumps or valves may be included in the system described above to control the flow of the various aqueous solutions involved, but they are not illustrated for clarity.

[0071] In any of the embodiments that may be associated with one or more aspects, the systems and techniques disclosed herein may utilize one or more subsystems that adjust or regulate, or at least facilitate the adjustment or regulation of, at least one operating parameter, state, or condition of at least one unit operation or component of the system, or one or more characteristics or physical properties of the process flow. To facilitate such adjustment and regulation features, one or more embodiments may utilize controllers and indicating devices that provide the condition, state, or condition of one or more components or processes. For example, at least one sensor may be used to provide an indication of, for example, the intensity or extent of an inflow of an aqueous solution into the system. Thus, according to particularly advantageous embodiments, the systems and techniques may involve one or more sensors or other indicating devices, such as constituent analyzers or conductivity cells, that provide an indication of, for example, the state, condition, characteristics, or quality of an aqueous solution entering or leaving the system.

[0072] The various operating parameters of the electrochlorination system disclosed herein can be controlled or adjusted by an associated control system or controller based on a variety of parameters measured by multiple sensors located in different parts of the system. The controller can be programmed or configured to adjust one or more of the current across the anode-cathode pair of the electrolyzer used to generate H2 or the voltage applied across the anode-cathode pair of the electrolyzer used to generate H2 based on the flow rate or composition of the aqueous solution.

[0073] A controller used for monitoring and controlling the operation of various components of the system disclosed herein may include a computer control system. Multiple aspects of the controller may be incorporated into a general-purpose computer system 200, such as... Figure 6 The computer system 200 shown is implemented using dedicated software. The computer system 200 may include a processor 202 connected to one or more memory devices 204, such as disk drives, solid-state storage, or other devices for storing data. The memory 204 is typically used to store programs and data during operation of the computer system 200. Components of the computer system 200 may be interconnected via an interconnection mechanism 206, which may include one or more buses (e.g., between components integrated within the same machine) and / or networks (e.g., between components residing on separate, independent machines). The interconnection mechanism 206 enables the exchange of communications (e.g., data, instructions) between system components of the system 200. The computer system 200 also includes one or more input devices 208, such as a keyboard, mouse, trackball, microphone, touchscreen, sensors, and one or more output devices 210, such as a printer, display screen, and / or speakers, one of pumps P1 or P2, or a power supply 160 for a high-speed hydrogen generator 130.

[0074] Output device 210 may also include valves, pumps, or switches that can be used to control the speed of a pump or the state (open or closed) of a valve in a system disclosed herein. One or more sensors 214 may also provide input to computer system 200. These sensors may include, for example, sensors S, which may be, for example, pressure sensors, chemical concentration sensors, temperature sensors, or sensors for any other parameters of interest in the system disclosed herein. These sensors may be located in any part of the system where they will be useful. In addition, computer system 200 may include one or more interfaces (not shown) that additionally connect computer system 200 to a communication network or, alternatively, to interconnect mechanism 206.

[0075] exist Figure 7The storage system 212, shown in more detail below, typically includes a computer-readable and writable non-volatile recording medium 302, in which signals defining a program to be executed by the processor 202 or information to be processed by the program are stored. This medium may include, for example, disk storage or flash memory. Typically, in operation, the processor causes data to be read from the non-volatile recording medium 302 to another memory 304, which allows information to be accessed by the processor more rapidly than the medium 302. This memory 304 is typically a volatile random access memory, such as dynamic random access memory (DRAM) or static random access memory (SRAM). It may reside in the storage system 212, as shown, or in the memory system 204. The processor 202 typically manipulates data in the integrated circuit memory 304 and then copies the data back to the medium 302 after processing is complete. Various mechanisms are known for managing data movement between the medium 302 and the integrated circuit memory element 304, and the aspects and embodiments disclosed herein are not limited thereto. The aspects and embodiments disclosed herein are not limited to the specific memory system 204 or storage system 212.

[0076] Computer systems may include specially programmed, dedicated hardware, such as application-specific integrated circuits (ASICs). The aspects and embodiments disclosed herein may be implemented in software, hardware, or firmware, or any combination thereof. Furthermore, such methods, actions, systems, system elements, and components may be implemented as part of the computer system described above or as independent components.

[0077] Although computer system 200 is shown by way of example as a type of computer system on which the various aspects and embodiments disclosed herein can be practiced, it should be understood that the aspects and embodiments disclosed herein are not limited to being implemented on the computer system shown in Figure 20. The various aspects and embodiments disclosed herein can be implemented on systems with... Figure 6 The different constructions and components shown are implemented on one or more computers.

[0078] Computer system 200 may be a general-purpose computer system programmable using a high-level computer programming language. Computer system 200 may also be implemented using specialized hardware that is specifically programmed. In computer system 200, processor 202 is typically a commercially available processor, such as the well-known Core processor available from Intel Corporation. TMProcessors of this type are also available. Many other processors are also available, including programmable logic controllers. Such processors typically run an operating system, which may be, for example, Windows 10 or Windows 11 from Microsoft Corporation, macOS from Apple Computer, Solaris from Sun Microsystems, or UNIX from various sources. Many other operating systems can be used.

[0079] The processor and operating system together define the computer platform on which applications are written in high-level programming languages. It should be understood that this invention is not limited to a specific computer system platform, processor, operating system, or network. Furthermore, it will be apparent to those skilled in the art that the aspects and embodiments disclosed herein are not limited to a specific programming language or computer system. Additionally, it should be understood that other suitable programming languages ​​and other suitable computer systems can also be used.

[0080] One or more parts of a computer system may be distributed across one or more computer systems (not shown) connected to a communication network. These computer systems may also be general-purpose computer systems. For example, multiple aspects of the present invention may be distributed across one or more computer systems configured to provide services (e.g., servers) to one or more client computers, or to perform general tasks as part of a distributed system. For example, multiple aspects and embodiments disclosed herein may be implemented on a client-server system comprising components distributed across one or more server systems performing various functions according to multiple aspects and embodiments disclosed herein. These components may be executable code, intermediate code (e.g., IL), or interpreted code (e.g., Java) communicating over a communication network (e.g., the Internet) using a communication protocol (e.g., TCP / IP). In some embodiments, one or more components of computer system 200 may communicate with one or more other components over a wireless network, including, for example, a cellular telephone network.

[0081] It should be understood that the aspects and embodiments disclosed herein are not limited to implementation on any particular system or group of systems. Furthermore, it should be understood that the aspects and embodiments disclosed herein are not limited to any particular distributed architecture, network, or communication protocol. Many of the aspects and embodiments disclosed herein can be programmed using object-oriented programming languages ​​such as Smalltalk, Java, C++, Ada, or C# (C-Sharp). Other object-oriented programming languages ​​may also be used. Alternatively, functional, scripting, and / or logic programming languages, such as ladder logic, may be used. Many of the aspects and embodiments disclosed herein can be implemented in non-programming environments (e.g., files created in HTML, XML, or other formats to render graphical user interface (GUI) aspects or perform other functions when viewed in a browser program window). Many of the aspects and embodiments disclosed herein can be implemented as programmed elements or non-programmed elements, or any combination thereof.

[0082] The wording and terminology used herein are for descriptive purposes and should not be considered restrictive. As used herein, the term "plurality" means two or more items or components. The terms "comprising," "including," "carrying," "having," "containing," and "involving," whether in the written description, claims, or similar texts, are open-ended terms, meaning "including but not limited to." Therefore, the use of such terms implies coverage of the items listed thereafter and their equivalents, as well as additional items. Regarding claims, only the transitional phrases "consisting of" and "consisting substantially of" are closed or semi-closed transitional phrases, respectively. The use of ordinal terms such as "first," "second," "third," and similar terms modifying claim elements in claims does not, in itself, imply any priority, precedence, or order of one claim element relative to another claim element, or the chronological order in which the actions of the methods are performed, but is merely used as markers to distinguish one claim element having a certain name from another element having the same name (but using ordinal terms).

[0083] Several aspects of at least one embodiment have been described so far; it should be understood that various changes, modifications, and improvements will readily occur to those skilled in the art. Any feature described in any embodiment may be included in or substitute for any feature in any other embodiment. Such changes, modifications, and improvements are intended to be part of this disclosure and are intended to be within the scope of the invention. Therefore, the foregoing description and drawings are by way of example only.

Claims

1. A system for generating hydrogen from an aqueous source, the system comprising: A high fluid velocity electrolyzer having an inlet and an outlet, wherein the inlet of the high fluid velocity electrolyzer is fluidly connected to the aqueous solution source; as well as A gas fractionation system that is fluidly connected to the outlet of the high fluid velocity electrolyzer.

2. The system according to claim 1, wherein the high fluid velocity electrolyzer comprises a concentric tube electrode electrolyzer.

3. The system of claim 2, wherein the high fluid velocity electrolyzer comprises more than one concentric tube electrode electrolyzer connected in series in a fluid manner.

4. The system of claim 1 further includes a pump configured to cause the aqueous solution to flow through the high fluid velocity electrolyzer at a rate of at least 2 m / s.

5. The system of claim 1, wherein the high fluid velocity electrolyzer is configured to generate hydrogen and one or more other gases from an aqueous solution, and to direct the generated hydrogen and one or more other gases into the gas fractionation system.

6. The system of claim 5, wherein the gas fractionation system is a cryogenic gas fractionation system configured to separate the hydrogen from the one or more other gases.

7. The system according to claim 1, wherein the aqueous solution source is either a brackish water source or a seawater source.

8. The system of claim 7 further includes a solids removal device disposed between the aqueous solution source and the inlet of the high fluid velocity electrolyzer.

9. The system of claim 8, wherein no membrane filtration device is provided between the aqueous solution source and the inlet of the high fluid velocity electrolyzer.

10. The system of claim 8, wherein no bioreactor is disposed between the aqueous solution source and the inlet of the high fluid velocity electrolyzer.

11. A method for generating hydrogen from an aqueous liquid source, the system comprising: An aqueous solution is introduced into the inlet of a high-fluid-velocity electrolyzer with an inlet and an outlet; Hydrogen is extracted from the outlet of the high fluid velocity electrolyzer; as well as The hydrogen is purified in a gas fractionation system that is fluidly connected to the outlet of the high-fluid-rate electrolyzer.

12. The method of claim 11, wherein introducing the aqueous solution into the inlet of the high fluid velocity electrolyzer comprises introducing the aqueous solution into the inlet of the concentric tube electrode electrolyzer.

13. The method of claim 12, wherein introducing the aqueous solution into the inlet of the high fluid velocity electrolyzer comprises introducing the aqueous solution into the inlet of more than one concentric tube electrode electrolyzer connected in series in a fluid manner.

14. The method of claim 11, further comprising causing the aqueous solution to flow through the high fluid velocity electrolyzer at a speed of at least 2 m / s.

15. The method of claim 11, further comprising: Hydrogen and one or more other gases are generated from the aqueous solution in the high fluid velocity electrolyzer. as well as The generated hydrogen and one or more other gases are directed into the gas fractionation system.

16. The method of claim 15, wherein directing the generated hydrogen and one or more other gases into the gas fractionation system comprises directing the generated hydrogen and one or more other gases into a cryogenic gas fractionation system configured to separate the hydrogen from the one or more other gases.

17. The method of claim 11, wherein introducing the aqueous solution into the inlet of the high fluid velocity electrolyzer comprises introducing one of brackish water or seawater into the inlet of the high fluid velocity electrolyzer.

18. The method of claim 12, further comprising removing suspended solids from the aqueous solution upstream of the inlet of the high fluid velocity electrolyzer.

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