Chemical reaction devices involving acids and / or bases, and related systems and methods

Abstract

Chemical reaction devices involving acids and / or bases, and related systems and methods, are generally described.

Description

[0001] This application is a divisional application of a Chinese patent application with an application date of March 13, 2020, application number 202080028904.9, and invention name “Chemical reaction device involving acid and / or base, and related systems and methods”.

[0002] Related Applications

[0003] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 62 / 818,604, filed on March 14, 2019; U.S. Provisional Patent Application No. 62 / 887,143, filed on August 15, 2019; and U.S. Provisional Patent Application No. 62 / 962,061, filed on January 16, 2020; all of which are hereby incorporated by reference in their entirety for all purposes. Technical Field

[0004] Chemical reaction apparatus involving acids and / or bases, and related systems and methods are generally described. Background Art

[0005] The background art of the present invention relates to the field of chemical reaction devices and related systems and methods. Summary of the invention

[0006] Chemical reaction devices involving acids and / or bases, and related systems and methods are generally described. In some embodiments, the method includes producing a base near a first electrode (e.g., a cathode) and producing an acid near a second electrode (e.g., an anode) electrochemically coupled to the first electrode. In certain embodiments, the method includes collecting an acid and / or base. In some cases, the method includes storing an acid and / or base. In some embodiments, the method includes reacting an acid and / or base in a chemical dissolution (e.g., reacting an acid with a metal carbonate such as CaCO3 to produce a metal ion such as calcium ion, and / or carbonate ion). In certain embodiments, the method includes reacting an acid and / or base in a precipitation reaction (e.g., reacting an alkali with a metal ion such as calcium ion to produce a metal hydroxide such as Ca(OH)2). In some embodiments, the metal hydroxide can be used in a cement manufacturing process.

[0007] In some cases, the generation of acid near the second electrode and / or the generation of base near the first electrode results in the generation of gas (e.g., CO2, H2, and / or O2). In some cases, one or more gases can be collected, sold, used in downstream processes, and / or fed back into the system. In some cases, the generation of acid near the second electrode and / or the generation of base near the first electrode produces a reduced amount of gas, no gas, and / or no net amount of gas, because any gas generated is used by the system (e.g., to increase the pH gradient between the electrodes). In certain embodiments, for example, during a period of low electricity cost, the acid generated near the second electrode and / or the base generated near the first electrode can be used to generate hydrogen and / or oxygen, for example, during a period of high electricity cost.

[0008] Also described are systems and methods of the present invention for forming precipitates in spatially varying chemical composition gradients (e.g., spatially varying pH gradients). Forming precipitates in spatially varying chemical composition gradients (e.g., spatially varying pH gradients) can be achieved, for example, by: dissolving a compound (e.g., a metal salt) in a first region (e.g., an acidic region) of a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient), and collecting precipitates containing one or more elements (e.g., metals) from the compound (e.g., a metal salt) in a second region (e.g., an alkaline region) of a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). In certain embodiments, the spatially varying chemical composition gradient (e.g., spatially varying pH gradient) is established and / or maintained in an electrochemical cell and by electrolysis (e.g., electrolysis of water). According to some embodiments, after collecting the precipitate, the precipitate is heated in a kiln to manufacture cement such as Portland cement. In some cases, the subject matter of the present invention involves related products, alternative solutions to a particular problem, and / or a variety of different uses of one or more systems and / or articles.

[0009] Certain aspects relate to methods. In some embodiments, the method comprises operating a reactor in a first mode; wherein the first mode comprises: generating a base by a first electrode; generating an acid by a second electrode electrochemically coupled to the first electrode in the reactor; and collecting the acid and / or the base.

[0010] In certain embodiments, the method includes operating the reactor in a first mode; wherein the first mode includes: generating a base by a first electrode; generating an acid by a second electrode electrochemically coupled to the first electrode in the reactor; collecting the acid and / or base; and reacting the collected acid and / or base in a chemical dissolution and / or in a precipitation reaction.

[0011] In some embodiments, the method includes operating the reactor in a first mode; wherein the first mode includes: generating a base and hydrogen by a first electrode; generating an acid and oxygen by a second electrode electrochemically coupled to the first electrode in the reactor; and allowing oxygen to diffuse and / or be transported to the first electrode and / or allowing hydrogen to diffuse and / or be transported to the second electrode; and allowing oxygen to be reduced through the first electrode and / or allowing hydrogen to be oxidized through the second electrode.

[0012] In some embodiments, the method includes generating a base and a dihalide in a first reactor; generating an acid in a second reactor; collecting the acid; collecting the base; performing a chemical dissolution with the acid and / or the base; and performing a precipitation reaction with the acid and / or the base.

[0013] Certain aspects relate to systems. In certain embodiments, the system includes a first electrode; a second electrode electrochemically coupled to the first electrode; and a device configured to collect acidic products near the second electrode and / or alkaline products near the first electrode.

[0014] In some embodiments, the system includes a first electrode; a second electrode electrochemically coupled to the first electrode; a first device configured to collect acidic products near the second electrode and / or alkaline products near the first electrode; and a second device configured to react the collected acidic products and / or the collected alkaline products.

[0015] In certain embodiments, the system includes a first electrode configured to produce a base and hydrogen; and a second electrode electrochemically coupled to the first electrode and configured to produce an acid and oxygen; wherein the system is configured to allow oxygen to diffuse and / or be delivered to the first electrode and / or allow hydrogen to diffuse and / or be delivered to the second electrode; and wherein the system is configured to allow oxygen to be reduced through the first electrode and / or allow hydrogen to be oxidized through the second electrode.

[0016] In some embodiments, the system includes a first reactor configured to produce a base, a dihalide, and hydrogen; a second reactor configured to produce an acid; a first device configured to collect the acid near the second reactor and perform a chemical dissolution and / or precipitation reaction with the acid; and a second device configured to collect the base near the first reactor and perform a chemical dissolution and / or precipitation reaction with the base.

[0017] Other advantages and novel features of the present invention will become apparent from the following detailed description of multiple non-limiting embodiments of the present invention when considered in conjunction with the accompanying drawings.In the event that this specification and documents incorporated by reference include conflicting and / or inconsistent disclosures, this specification shall prevail. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying drawings, which are schematic and are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown is generally represented by a single numeral. For purposes of clarity, not every component is labeled in every drawing, nor is every component of every embodiment of the present invention shown, where specific description is not necessary to enable one of ordinary skill in the art to understand the present invention. In the drawings:

[0019] Figure 1A is a schematic diagram of a system including a first electrode, a second electrode, and a device according to certain embodiments.

[0020] Figure 1B is a schematic diagram of a system including a first electrode, a second electrode, and two devices according to certain embodiments.

[0021] Figure 1C is a schematic diagram of a system including a first electrode, a second electrode, a device, and a separator according to certain embodiments.

[0022] Figure 1D is a schematic diagram of a system including a first electrode, a second electrode, and three devices according to certain embodiments.

[0023] Figure 1E is a schematic diagram of a system including a first electrode, a second electrode, and six devices according to certain embodiments.

[0024] Figure 1F is a schematic diagram of a system including a first electrode, a second electrode, an apparatus, and a kiln according to certain embodiments.

[0025] Figure 2A is a cross-sectional schematic diagram of a system including a first electrode and a second electrode and producing hydrogen and oxygen according to certain embodiments.

[0026] Figure 2B is a cross-sectional schematic diagram of a system including a first electrode, a second electrode, and a separator and producing hydrogen and oxygen according to certain embodiments.

[0027] Figure 2C is a cross-sectional schematic diagram of a system including a first electrode, a second electrode, a separator, and two devices and producing hydrogen and oxygen according to certain embodiments.

[0028] Figure 2D is a schematic diagram of a system that includes a first electrode, a second electrode, a separator, two devices, and a kiln and produces hydrogen and oxygen, according to certain embodiments.

[0029] Figure 3A is a schematic diagram of a system including two reactors according to certain embodiments.

[0030] Figure 3B is a schematic diagram of a system including two reactors, wherein a first reactor includes a first electrode and a second electrode, according to certain embodiments.

[0031] Figure 4A is a schematic diagram of a system including two chambers, according to certain embodiments.

[0032] Figure 4B is a schematic diagram of a system including two chambers, wherein CaCO 3 is dissolved in one chamber and Ca(OH) 2 is precipitated in another chamber, according to certain embodiments.

[0033] Figure 5A is a schematic diagram of operating a reactor in a high voltage mode, according to certain embodiments.

[0034] Figure 5B is a Pourbaix diagram showing a high voltage mode.

[0035] Fig. 6A is a schematic diagram of operating a reactor in a low voltage mode, according to certain embodiments.

[0036] Figure 6B is a Pourbaix diagram showing a low voltage mode.

[0037] Figure 7 is a graph of electricity cost versus time for a 1 kW alkaline electrolyzer operating at 1.2 V (solid line) and for an electrolyzer consuming the same amount of current operating at 2 V when electricity cost > $0.05 / kWh and at 0.4 V when electricity cost < $0.05 / kWh (dashed line).

[0038] Fig. 8A is a schematic diagram of operating a reactor in low voltage mode A according to certain embodiments.

[0039] Figure 8B 3 is a Pourbaix diagram showing the low voltage mode A.

[0040] Fig. 9A is a schematic diagram of operating a reactor in low voltage mode B according to certain embodiments.

[0041] Fig. 9B 3 is a Pourbaix diagram showing the low voltage mode B.

[0042] Fig. 10A is a schematic diagram of operating a reactor in fuel cell mode, according to certain embodiments.

[0043] Fig. 10Bis a Pourbaix diagram showing a fuel cell mode.

[0044] Fig.11 is a flow chart showing the electrolysis of neutral pH water to produce acid / base for producing precipitated hydroxide according to some embodiments.

[0045] Fig.12 is a flow chart showing the electrolysis of an alkali halide electrolyte to produce an acid / base for producing a precipitated hydroxide according to certain embodiments.

[0046] FIG. 13A to FIG. 13B According to some embodiments, OH - The charge balance is performed by cations in the electrolyte passing through the separator or membrane. Fig.13A is a diagram showing that at the first electrode (eg, cathode) of reactor 1, water is reduced to produce OH - (alkaline solution) and H 2(g) . Fig. 13B At the first electrode (eg, cathode) of the reactor 1, O2 is reduced to produce OH - (alkaline solution) diagram.

[0047] FIG. 14A to FIG. 14B Chemical dissolution and precipitation reactions according to certain embodiments are shown. Fig.14A is a schematic diagram showing reacting a dihalide with hydrogen to produce the desired acid, according to certain embodiments. Fig. 14B is a schematic diagram showing the reaction of a dihalide with water to produce the desired acid and oxygen as a byproduct, according to certain embodiments. DETAILED DESCRIPTION

[0048] Chemical reaction devices related to acids and / or bases, and related systems and methods are generally described. In some embodiments, the method includes producing a base near a first electrode (e.g., a cathode) and producing an acid near a second electrode (e.g., an anode) electrochemically coupled to the first electrode. In certain embodiments, the method includes collecting an acid and / or base. In some cases, the method includes storing an acid and / or base. In some embodiments, the method includes reacting an acid and / or base in a chemical dissolution (e.g., reacting an acid with a metal carbonate such as CaCO3 to produce a metal ion such as calcium ion, and / or carbonate ion). In certain embodiments, the method includes reacting an acid and / or base in a precipitation reaction (e.g., reacting an alkali with a metal ion such as calcium ion to produce a metal hydroxide such as Ca(OH)2). In some embodiments, the metal hydroxide can be used in a cement manufacturing process.

[0049] In some cases, the generation of acid near the second electrode and / or the generation of base near the first electrode results in the generation of gas (e.g., CO2, H2, and / or O2). In some cases, one or more gases can be collected, sold, used in downstream processes, and / or fed back into the system. In some cases, the generation of acid near the second electrode and / or the generation of base near the first electrode produces a reduced amount of gas, no gas, and / or no net amount of gas, because any gas generated is used by the system (e.g., to increase the pH gradient between the electrodes). In certain embodiments, for example, during a period of low electricity cost, the acid generated near the second electrode and / or the base generated near the first electrode can be used to generate hydrogen and / or oxygen, for example, during a period of high electricity cost.

[0050] Reactors including spatially varying chemical composition gradients (e.g., spatially varying pH gradients), and related systems and methods are also described. In some embodiments, electrochemical reactors include spatially varying chemical composition gradients (e.g., spatially varying pH gradients). In certain embodiments, a spatially varying chemical composition gradient (e.g., spatially varying pH gradient) is used to form a precipitate. In some embodiments, a compound (e.g., a metal salt) is dissolved in a first region (e.g., an acidic region) of a spatially varying chemical composition gradient (e.g., spatially varying pH gradient), and a precipitate containing one or more elements (e.g., metal) from the compound (e.g., a metal salt) is formed in a second region (e.g., an alkaline region) of a spatially varying chemical composition gradient (e.g., spatially varying pH gradient).

[0051] Some embodiments relate to compositions, methods and reactor designs in which electrolysis reactions are used to generate chemical composition gradients between the positive and negative electrodes of electrochemical cells. In some embodiments, the composition gradients generated by the electrolysis are then used to perform the desired chemical reactions by feeding reactants to a chemical environment near one electrode and utilizing the chemical gradients generated by the electrolysis to generate products from the reactants when the reactants or their components diffuse toward the other electrode. In some embodiments, the desired chemical reactions are performed by collecting solutions or suspensions of different compositions generated by the electrolysis and using the solutions or suspensions to generate products from the reactants in a portion of the reactor or in a separate device. In one embodiment, such a reactor is intended to produce decomposed minerals or metal salts by electrochemical means and chemical means. In one embodiment, the use of fossil fuels for generating thermal energy and the generation of related greenhouse gases or gases as atmospheric pollutants are reduced or avoided by using such a reactor instead of conventional thermal calcinations including heating minerals or metal salts to decompose them. In some embodiments, the minerals or metal salts include metal carbonates, and the greenhouse gases generated are at least partially carbon dioxide. In another embodiment, the electrolysis driven chemical reactor is powered by electricity from a renewable energy source such as solar photovoltaic or wind power, thereby reducing the use of energy that produces greenhouse gases when performing the calcination or decomposition reaction.

[0052] Some embodiments relate to methods for producing cement, such as Portland cement. Concrete is the most widely used man-made material in the world today. Cement manufacturing is also the second largest industrial emitter of CO2 in the world, accounting for about 8% of global CO2 emissions. Conventional methods for the industrial production of cement include calcining of CaCO3 by thermal means. In the current manufacture of cement, about 60% of CO2 emissions are caused by the calcination of CaCO3, and about 40% of CO2 emissions are caused by the combustion of fossil fuels used to carry out the calcination process and the sintering process. Therefore, there is a great demand for cement manufacturing processes that emit less CO2. Some embodiments relate to cement manufacturing processes, wherein thermal calcination is replaced by the electrochemical process described herein, which produces less CO2 per produced amount of cement compared to current manufacturing.

[0053] Cement production systems and related methods including electrochemical reactors are also described. Certain embodiments relate to systems of the present invention for producing cement including an electrochemical reactor and a kiln. In certain embodiments, the electrochemical reactor is configured to receive CaCO3. In some embodiments, the electrochemical reactor includes a first outlet configured to discharge Ca(OH)2 and / or lime (CaO). In some cases, the electrochemical reactor includes a second outlet configured to discharge CO2, O2 and / or H2 gas. According to certain embodiments, the kiln is configured to heat Ca(OH)2 and / or lime (and / or its reaction products) as part of a cement manufacturing process.

[0054] In some embodiments, the system is at least partially (e.g., at least 10%, at least 25%, at least 50%, at least 75%, at least 90%, or 100%) powered by renewable electricity (e.g., solar and / or wind power). In some cases, the system has lower net carbon emissions (e.g., at least 10%, at least 25%, at least 50%, at least 75%, at least 90%, or at least 90%) than a substantially similar system using conventional thermal calcination rather than an electrochemical reactor. In some cases, the system has net zero carbon emissions.

[0055] Certain embodiments relate to methods of the present invention in which Ca(OH)2 and / or lime (CaO) are produced in an electrochemical reactor. In some embodiments, the Ca(OH)2 and / or lime from the electrochemical reactor are then transported to a kiln, which heats the Ca(OH)2 and / or lime (and / or its reaction products) as part of a cement manufacturing process. In some embodiments, the electrochemical reactor also produces CO2, O2 and / or H2 gas. According to certain embodiments, CO2 is sealed and used for liquid fuels, for oxygenated fuels, for enhanced oil recovery, for the production of dry ice and / or as an ingredient in beverages. In some cases, O2 can be sealed and used for oxygenated fuels, for CCS applications and / or for enhanced oil recovery. In some cases, H2 can be sealed and / or used as a fuel (e.g., in a fuel cell and / or for heating the system). In some embodiments, at least a portion (e.g., at least 10%, at least 25%, at least 50%, at least 75%, at least 90%, or all) of the CO2, O2, and / or H2 exhausted from the system is fed to the kiln.

[0056] As described above, certain aspects relate to systems. A non-limiting example of such a system is shown in Figures 1A to 3B middle.

[0057] In some embodiments, the system includes a first electrode. In some embodiments, the first electrode includes a cathode. For example, referring to Figure 1A, in some embodiments, the system 100 includes a first electrode 104 (eg, a cathode). Similarly, referring to Figure 2A In some embodiments, the system 200 includes a first electrode 104 (eg, a cathode). In certain embodiments, the first electrode is selected to be an electron conductor that is stable under relatively basic conditions (eg, in the basic region and / or in a base as described herein).

[0058] In certain embodiments, the first electrode comprises a metal electrode (e.g., platinum, gold, nickel, iridium, copper, iron, steel, stainless steel, manganese and / or zinc), carbon (e.g., graphite or disordered carbon), or a metal carbide (e.g., silicon carbide, titanium carbide and / or tungsten carbide). In certain embodiments, the first electrode comprises a metal alloy (e.g., nickel-chromium-iron alloy, nickel-molybdenum-cadmium alloy), a metal oxide (e.g., iridium oxide, nickel-iron-cobalt oxide, nickel-cobalt oxide, lithium cobalt oxide, lanthanum strontium cobalt oxide, barium strontium iron oxide, manganese molybdenum oxide, ruthenium dioxide, iridium ruthenium tantalum oxide), a metal organic framework, or a metal sulfide (e.g., molybdenum sulfide). In certain embodiments, an electrocatalyst or electrode material is dispersed or coated on a conductive support.

[0059] In some embodiments, the system includes a second electrode. In some embodiments, the second electrode includes an anode. For example, referring to Figure 1A In some embodiments, the system 100 includes a second electrode 105 (eg, an anode). Figure 2A In some embodiments, the system 200 includes a second electrode 105 (e.g., an anode). In some embodiments, the second electrode is electrochemically coupled to the first electrode. That is, the electrodes can be configured so that they can participate in an electrochemical process. The electrochemical coupling can be achieved, for example, by exposing the first electrode and the second electrode to an electrolyte that promotes ion transport between the two electrodes. Figure 1A In some embodiments, the first electrode 104 is electrochemically coupled to the second electrode 105. Similarly, referring to Figure 2A In some embodiments, the first electrode 104 is electrochemically coupled to the second electrode 105 .

[0060] In certain embodiments, the second electrode is selected to be an electronic conductor that is stable under relatively acidic conditions (e.g., in the acidic regions and / or acids described herein). In certain embodiments, the second electrode comprises a metal electrode (e.g., platinum, palladium, lead and / or tin) or a metal oxide (e.g., a transition metal oxide).

[0061] In certain embodiments, the first electrode and / or the second electrode include a catalyst. In some embodiments, the cathode catalyst is selected to be stable under alkaline conditions. In some embodiments, the cathode catalyst may include nickel, iron, transition metal sulfide (e.g., molybdenum sulfide), and / or transition metal oxide (e.g., MnO2, Mn2O3, Mn3O4, nickel oxide, nickel hydroxide, iron oxide, iron hydroxide, cobalt oxide), mixed transition metal spinel oxide (e.g., MnCo2O4, CoMn2O4, MnFe2O4, ZnCoMnO4), etc. In some embodiments, the anode catalyst is selected to be stable under acidic conditions. In some embodiments, the anode catalyst includes platinum, iridium, or its oxide.

[0062] In some embodiments, the system includes a reactor (e.g., an electrochemical reactor). Figure 1A , in some embodiments, the system 100 includes a reactor. Similarly, referring to Figure 2A In some cases, the system 200 includes a reactor. In some embodiments, the reactor includes a first electrode and a second electrode. For example, in some embodiments, the first electrode is electrochemically coupled to the second electrode in the reactor. For example, referring to Figure 1A In some embodiments, the first electrode 104 is electrochemically coupled to the second electrode 105 in the reactor. Figure 2A In some cases, the first electrode 104 is electrochemically coupled to the second electrode 105 in the reactor.

[0063] Some aspects involve methods, about Figures 1A to 3B It can be understood that the method. In some embodiments, the method includes running a reactor (e.g., any reactor described herein). In some cases, running the reactor includes applying an electric current to an electrode of the reactor. In some embodiments, running the reactor causes at least one chemical reaction to occur in the reactor.

[0064] In some embodiments, the method includes operating the reactor in a first mode. In some embodiments, the first mode includes generating a base near the first electrode (e.g., the base is generated by an electrochemical reaction in the first electrode). For example, referring to Figure 1A , in some embodiments, the first mode includes generating a base near the first electrode 104. Similarly, referring to Figure 2A In some cases, the first mode includes generating a base near the first electrode 104.

[0065] In some embodiments, the first electrode (e.g., in a first mode) is configured to produce an alkaline product (e.g., any of the bases described herein). In some embodiments, the alkaline product is produced by an electrochemical reaction in the first electrode. For example, referring to Figure 1A In some embodiments, the first electrode 104 is configured to generate a base. Figure 2A In some cases, first electrode 104 is configured to generate a base.

[0066] Base can have any one of multiple suitable concentrations. In some embodiments, the concentration of base is greater than or equal to 0.000001M, greater than or equal to 0.00001M, greater than or equal to 0.0001M, greater than or equal to 0.001M, greater than or equal to 0.01M, greater than or equal to 0.1M, greater than or equal to 0.5M, greater than or equal to 1M, greater than or equal to 3M, greater than or equal to 5M, greater than or equal to 7M, greater than or equal to 10M, greater than or equal to 15M, or greater than or equal to 20M. In certain embodiments, the concentration of base is less than or equal to 25M, less than or equal to 20M, less than or equal to 15M, less than or equal to 10M, less than or equal to 7M, less than or equal to 5M, or less than or equal to 3M. Combinations of these ranges are also possible (e.g., greater than or equal to 0.1M and less than or equal to 25M or greater than or equal to 0.1M and less than or equal to 10M).

[0067] According to some embodiments, the generation of base by the first electrode generates an alkaline region (e.g., any alkaline region described herein) near the first electrode (e.g., within the half of the reactor chamber closest to the first electrode). For example, in some cases, the fluid adjacent to the first electrode (e.g., the alkaline region) has a higher pH than the fluid further away from the first electrode. As an example, referring to Figure 2A , in some cases, the system includes an alkaline region 106 near the first electrode 104. Similarly, referring to Figure 1A In some cases, the system includes an alkaline region near the first electrode 104.

[0068] In some embodiments, the pH near the first electrode (e.g., close to the first electrode) is greater than or equal to 8, greater than or equal to 9, greater than or equal to 10, greater than or equal to 11, greater than or equal to 12, or greater than or equal to 13. According to some embodiments, the pH near the first electrode is less than or equal to 14, less than or equal to 13, less than or equal to 12, less than or equal to 11, or less than or equal to 10. Combinations of these ranges are also possible (e.g., greater than or equal to 8 and less than or equal to 14).

[0069] In some embodiments, the second electrode is configured to produce an acidic product (e.g., any of the acids described herein). In certain embodiments, the acidic product is produced by an electrochemical reaction in the second electrode. For example, referring to Figure 1A In some embodiments, the second electrode 105 is configured to generate an acid. Figure 2A In some cases, the second electrode 105 is configured to generate an acid. In some embodiments, the first mode of the reactor includes generating an acid near the second electrode (e.g., generating the acid by an electrochemical reaction in the second electrode). For example, referring to Figure 1A , in some embodiments, the first mode includes generating acid near the second electrode 105. Similarly, referring to Figure 2A In some embodiments, the first mode includes generating acid near the second electrode 105.

[0070] Acid can have any one of multiple suitable concentrations. In some embodiments, the concentration of acid is greater than or equal to 0.000001M, greater than or equal to 0.00001M, greater than or equal to 0.0001M, greater than or equal to 0.001M, greater than or equal to 0.01M, greater than or equal to 0.1M, greater than or equal to 0.5M, greater than or equal to 1M, greater than or equal to 3M, greater than or equal to 5M, greater than or equal to 7M, or greater than or equal to 10M. In certain embodiments, the concentration of acid is less than or equal to 12M, less than or equal to 10M, less than or equal to 7M, less than or equal to 5M, less than or equal to 3M, or less than or equal to 1M. Combinations of these ranges are also possible (e.g., greater than or equal to 0.000001M and less than or equal to 12M or greater than or equal to 0.1M and less than or equal to 10M).

[0071] According to some embodiments, the generation of acid by the second electrode generates an acidic region (e.g., any of the acidic regions described herein) near the second electrode (e.g., within the half of the reactor chamber closest to the second electrode). For example, in some cases, the fluid adjacent to the second electrode (e.g., the acidic region) has a lower pH than the fluid further away from the second electrode. As an example, referring to Figure 2A , in some cases, the system includes an acidic region 107 near the second electrode 105. Similarly, referring to Figure 1A In some cases, the system includes an acidic region 107 near the second electrode 105 .

[0072] According to certain embodiments, the pH near the second electrode (e.g., proximal to the second electrode) has a pH less than or equal to 6, less than or equal to 5, less than or equal to 4, less than or equal to 3, less than or equal to 2, or less than or equal to 1. In some embodiments, the pH near the second electrode has a pH greater than or equal to 0, greater than or equal to 1, greater than or equal to 2, greater than or equal to 3, greater than or equal to 4, or greater than or equal to 5. Combinations of these ranges are also possible (e.g., greater than or equal to 0 and less than or equal to 6).

[0073] In some embodiments, the first electrode (e.g., cathode) is configured to generate hydrogen gas, such that hydrogen gas can be generated near the first electrode (e.g., hydrogen gas is generated by an electrochemical reaction in the first electrode). Figure 2A In some embodiments, the first electrode 104 is configured to generate hydrogen 108. Similarly, referring to Figure 1A In some cases, the first electrode 104 is configured to produce hydrogen. In some cases, operating the reactor in the first mode includes producing hydrogen (e.g., hydrogen and base) near the first electrode (e.g., producing hydrogen by an electrochemical reaction in the first electrode). In some cases, the hydrogen and / or base are produced near the first electrode by reduction of water near the first electrode.

[0074] In some embodiments, the second electrode (e.g., the anode) is configured to generate oxygen, such that oxygen can be generated near the second electrode (e.g., by an electrochemical reaction in the second electrode). Figure 2A In some embodiments, the second electrode 105 is configured to generate oxygen 109. Similarly, referring to Figure 1A In some embodiments, the second electrode 105 is configured to generate oxygen. In some cases, operating the reactor in the first mode includes generating oxygen (e.g., oxygen and acid) near the second electrode (e.g., generating oxygen by an electrochemical reaction in the second electrode). In some cases, oxygen and / or acid are generated near the second electrode by oxidation of water near the second electrode.

[0075] In some embodiments, the system is configured to allow oxygen to diffuse and / or be transported to a location near the first electrode (e.g., from a location near the second electrode). For example, in some cases, the system is configured to allow oxygen to diffuse and / or be transported from a fluid near the second electrode to a fluid near the first electrode after oxygen is generated by an electrochemical reaction in the second electrode, so that the oxygen can participate in the electrochemical reaction in the first electrode. For example, referring to Figure 2A In some embodiments, the system 200 is configured to allow oxygen 109 to diffuse from the second electrode 105 and / or be transported to the first electrode 104. Similarly, referring to Figure 1AIn certain embodiments, the system 100 is configured to allow oxygen to diffuse from the second electrode 105 and / or be transported to the first electrode 104 .

[0076] According to some embodiments, the system is configured to allow oxygen to be reduced near the first electrode (e.g., oxygen is reduced by an electrochemical reaction in the first electrode). Figure 2A In some embodiments, the system 200 is configured to allow oxygen 109 to be reduced near the first electrode 104. Figure 1A In some cases, the system 100 is configured to allow oxygen to be reduced near the first electrode 104. In some embodiments, reducing oxygen near the first electrode includes the generation of a base. In certain embodiments, the generation of a base is advantageous because it increases the total amount of base generated at the first electrode.

[0077] In some embodiments, the system is configured to allow hydrogen gas to diffuse and / or be transported to a location near the second electrode (e.g., from a location near the first electrode). For example, in some cases, the system is configured to allow hydrogen gas to diffuse and / or be transported from a fluid near the first electrode to a fluid near the second electrode after hydrogen gas is produced by an electrochemical reaction in the first electrode, so that the hydrogen gas can participate in the electrochemical reaction in the second electrode. For example, referring to Figure 2A In some cases, the system 200 is configured to allow the hydrogen 108 to diffuse from the first electrode 104 and / or be transported to the second electrode 105. Similarly, referring to Figure 1A In some cases, system 100 is configured to allow hydrogen to diffuse from first electrode 104 and / or be transported to second electrode 105 .

[0078] According to certain embodiments, the system is configured to allow hydrogen to be oxidized near the second electrode (e.g., by an electrochemical reaction in the second electrode). Figure 2A In some embodiments, the system 200 is configured to allow the hydrogen 108 to be oxidized near the second electrode 105. Similarly, referring to Figure 1A In some embodiments, the system 100 is configured to allow the hydrogen to be oxidized near the second electrode. In some embodiments, oxidizing the hydrogen near the second electrode includes the generation of an acid. In some embodiments, the generation of an acid is advantageous because it increases the total amount of acid generated at the second electrode.

[0079] In some embodiments, the system includes a separator. For example, referring to Figure 1C In some embodiments, the system 100 includes a separator 124. Similarly, referring to Figure 2BIn some embodiments, the system 200 includes a separator 124. In some embodiments, the separator is configured to allow oxygen generated at the second electrode to diffuse to the first electrode and / or allow hydrogen generated at the first electrode to diffuse to the second electrode. For example, in some embodiments, the separator is permeable to oxygen and / or hydrogen. For example, referring to Figure 1C In some embodiments, separator 124 is configured to allow oxygen generated at the second electrode to diffuse to the first electrode and / or allow hydrogen generated at the first electrode to diffuse to the second electrode. Figure 2B In certain embodiments, separator 124 is configured to allow oxygen generated at the second electrode to diffuse to the first electrode and / or to allow hydrogen generated at the first electrode to diffuse to the second electrode.

[0080] There may be many suitable methods for delivering hydrogen and / or oxygen from one electrode to another electrode. For example, in some embodiments, hydrogen and / or oxygen can be delivered with a syringe (for example, if the reactor has an inlet for a syringe near one electrode and an outlet for a syringe near another electrode, the gas can be delivered from one electrode to another electrode with a syringe). In certain embodiments, hydrogen and / or oxygen can be delivered by a conduit (for example, a pipe, a channel, a needle or a tube). In some cases, hydrogen and / or oxygen can be delivered directly from one electrode to another electrode, or hydrogen and / or oxygen can be stored after being removed from the reactor until it is added back to the reactor. In some embodiments, hydrogen and / or oxygen are delivered continuously or in batches. In certain embodiments, hydrogen and / or oxygen are delivered automatically or manually.

[0081] In some embodiments, the hydrogen produced by hydrolysis can be electrochemically oxidized by a hydrogen oxidation reaction (HOR) in which one of the dihydrogen molecules reacts to form two protons and two electrons. In other embodiments, the oxygen produced by hydrolysis can be electrochemically reduced by an oxygen reduction reaction (ORR) in which one of the dihydrogen molecules reacts with two water molecules and four electrons to form four hydroxide ions. In some embodiments, the HOR reaction is used to reduce the pH or increase the proton concentration of the acidic solution produced by the reactor. In some embodiments, the ORR reaction is used to increase the pH or increase the hydroxide concentration of the alkaline solution produced by the reactor. In some cases, the HOR reaction and the ORR reaction as described herein can be carried out using an electrode separated from the electrode for the electrolytic reaction of the reactor. In certain embodiments, these electrodes can be positioned in an electrolytic reactor, for example, as a combustion electrode in which the hydrogen and oxygen combustion reaction produces water retained in the reactor. In some cases, the electrodes for combustion, or for HOR or ORR can also be positioned in a separate container or reactor to which hydrogen and oxygen are each transferred. In some embodiments, the hydrogen produced at the cathode of the electrolysis reactor is transferred to the HOR electrode connected to the anode side of the reactor, wherein HOR is performed and the protons thus produced increase the acid concentration of the acidic solution produced by the reactor (reducing pH). In certain embodiments, the oxygen produced at the anode of the electrolysis reactor is transferred to the ORR electrode connected to the cathode side of the reactor, wherein ORR is performed and the hydroxide ions thus produced increase the hydroxide concentration of the alkaline solution produced by the reactor (increasing pH). In some cases, the HOR reaction is performed in preference to the ORR reaction, thereby reducing the release of hydrogen to the external environment compared to less active oxygen. In some cases, the electrode for hydrogen-oxygen combustion or HOR or ORR may include a compound used as an electrocatalyst. Hydrogen-oxygen combustion catalysts are described, for example, in M ​​Haruta and H Sano's "Catalytic Combustion of Hydrogen-Its Role in Hydrogen Utilization," International Journal of Hydrogen Energy, Vol. 6, No. 6, pp. 601 to 608, 1981, which is incorporated herein by reference. Examples of electrocatalysts for HOR and ORR include: platinum group metals such as Pt, Pd, Ru, Rh, Os and Ir, non-platinum group metals such as Mo, Fe, Ti, W, Cr, Co, Cu, Ag, Au and Re, used alone or as alloys or mixtures; high surface area nickel-aluminum alloys called Raney nickel, optionally coated or doped with other catalysts.Examples of electrocatalysts selective for ORR include metallic iron, iron oxides, iron sulfides, and iron hydroxides, silver alloys, oxides, and nitrates, and various forms of carbon including carbon paper, carbon felt, graphite, carbon black, and nanoscale carbon.

[0082] In certain embodiments described herein, the gaseous byproducts (e.g., CO2, H2, and / or O2) produced by electrolysis may have value and may be sold for other applications and processes, including combustion in fuel cells or gas turbines or internal combustion engines for the purpose of generating energy and power (including electrical energy). However, in some cases, it may be desirable to reduce or eliminate the generation of such gases. Therefore, in some embodiments, one or more of the gases produced by the reactor are recombined. As used herein, recombining refers to a chemical reaction or electrochemical reaction that consumes one or more of the gases produced.

[0083] In some embodiments, the hydrogen and oxygen produced by hydrolysis are recombined using hydrogen-oxygen combustion to form water. Figure 2A In some embodiments, the hydrogen 108 generated by the first electrode 104 can recombine with the oxygen 109 to form water, such as Fig. 6A Similarly, refer to Figure 1A In some embodiments, the hydrogen produced by the first electrode 104 can recombine with oxygen to form water. According to some embodiments, hydrogen-oxygen recombination can occur inside or outside the reactor, and in some cases electrode materials and designs well known to those skilled in the art and optionally catalysts can be used. In some embodiments, the method does not produce net hydrogen (or the net amount of hydrogen produced is less than 5% (e.g., less than 2% or less than 1%) of the current supplied to the reactor). For example, in some embodiments, the method does not release any hydrogen into the atmosphere (or the amount of hydrogen released is less than 5% (e.g., less than 2% or less than 1%) of the current supplied to the reactor) because the hydrogen produced recombine with oxygen to form water. Similarly, in some cases, the method does not produce net oxygen (or the net amount of oxygen produced is less than 5% (e.g., less than 2% or less than 1%) of the current supplied to the reactor). For example, in some cases, the process does not release any oxygen into the atmosphere (or the net amount of oxygen released is less than 5% (e.g., less than 2% or less than 1%) of the current supplied to the reactor) because the generated oxygen recombine with hydrogen to form water.

[0084] In some embodiments, the hydrolysis is performed without releasing hydrogen or oxygen (or the amount of hydrogen or oxygen released is less than 5% (e.g., less than 2% or less than 1%) of the current supplied to the reactor) under conditions that produce an alkaline pH near the first electrode (e.g., cathode) and an acidic pH near the second electrode (e.g., anode), respectively. For example, in some embodiments, O2 can diffuse from the second electrode (e.g., anode) where the acid and O2 are produced (e.g., by Figure 2A The electrolyte 235 and / or the air above the electrolyte) to the first electrode (e.g., the cathode), a base is generated in the first electrode and O2 will be reduced in the first electrode to form OH-(1 / 2O2+H2O+2e - →2OH - ). In certain embodiments, the reaction will occur at a pH>7 and an electrode potential less than 0.8 V relative to a standard hydrogen electrode. Similarly, in some cases, H2 can diffuse from a first electrode (e.g., cathode) where a base is produced to a second electrode (e.g., anode) where an acid is produced and where H2 will be oxidized to form H + (H2→2H + +2e - ). In some cases, this will occur at pH <7 and when the electrode potential is greater than -0.41 V relative to the standard hydrogen electrode. In other electrolyzers, such as alkaline electrolyzers, this reaction is hindered by a separator that prevents gas crossover between the two electrodes. However, in some embodiments disclosed herein, the reactor includes a separator that allows and / or promotes the crossover of H2 and / or O2 so that they can be consumed and increase the pH gradient.

[0085] In some embodiments, an acidic solution (less than pH 7) is produced from a neutral pH electrolyte at an electrode potential greater than 0.8 V relative to a standard hydrogen electrode. For example, in certain embodiments, to produce an acidic solution of pH 0, the minimum electrode potential relative to a standard hydrogen electrode will be 1.23 V. In some cases, an alkaline solution (greater than pH 7) is produced from a neutral pH electrolyte at an electrode potential less than -0.4 V relative to a standard hydrogen electrode. For example, to produce an alkaline solution of pH 14, the maximum electrode potential relative to a standard hydrogen electrode will be -0.83 V.

[0086] The Nernst potential at the second electrode (e.g., the Nernst potential in the fluid closest to the second electrode) can be any of a plurality of suitable values. In some embodiments, the Nernst potential at the second electrode (e.g., the anode) is greater than or equal to -0.4V, greater than or equal to -0.2V, greater than or equal to 0V, greater than or equal to 0.5V, greater than or equal to 0.8V, greater than or equal to 0.9V, greater than or equal to 1V, greater than or equal to 1.1V, greater than or equal to 1.2V, greater than or equal to 1.4V, or greater than or equal to 1.6V relative to a standard hydrogen electrode. In certain embodiments, the Nernst potential at the second electrode is less than or equal to 2 V, less than or equal to 1.7 V, less than or equal to 1.5 V, less than or equal to 1.4 V, less than or equal to 1.3 V, less than or equal to 1.2 V, less than or equal to 1.1 V, less than or equal to 1 V, less than or equal to 0.9 V, less than or equal to 0.8 V, less than or equal to 0.5 V, less than or equal to 0 V, or less than or equal to -0.2 V. Combinations of these ranges are also possible (e.g., greater than or equal to 0.8 V and less than or equal to 2 V, greater than or equal to 1.2 V and less than or equal to 2 V, greater than or equal to -0.4 V and less than or equal to 0.5 V, or greater than or equal to 0 V and less than or equal to 0.5 V).

[0087] In certain embodiments, the suitable Nernst potential at the second electrode depends on the reaction type at the electrode. For example, in some cases, the Nernst potential at the second electrode is greater than or equal to -0.4V (e.g., greater than or equal to -0.4V and less than or equal to 0.5V, or greater than or equal to 0V and less than or equal to 0.5V) relative to the standard hydrogen electrode when hydrogen is oxidized to acid. As another example, in some cases, the Nernst potential at the second electrode is greater than or equal to 0.8V (e.g., greater than or equal to 0.8V and less than or equal to 2V, or greater than or equal to 1.2V and less than or equal to 2V) relative to the standard hydrogen electrode when water is oxidized to acid and oxygen.

[0088] The Nernst potential at the first electrode (e.g., the Nernst potential in the fluid closest to the first electrode) can be any one of a plurality of suitable values. In certain embodiments, the Nernst potential at the first electrode (e.g., cathode) is less than or equal to 0.8V, less than or equal to 0.6V, less than or equal to 0.4V, less than or equal to 0V, less than or equal to -0.4V, less than or equal to -0.5V, less than or equal to -0.6V, less than or equal to -0.7V, less than or equal to -0.8V, less than or equal to -0.9V, less than or equal to -1V, less than or equal to -1.2V, or less than or equal to -1.4V relative to a standard hydrogen electrode. In some embodiments, the Nernst potential at the first electrode is greater than or equal to -2 V, greater than or equal to -1.7 V, greater than or equal to -1.5 V, greater than or equal to -1.2 V, greater than or equal to -1 V, greater than or equal to -0.9 V, greater than or equal to -0.8 V, greater than or equal to -0.7 V, greater than or equal to -0.6 V, greater than or equal to -0.5 V, greater than or equal to -0.4 V, greater than or equal to 0 V, greater than or equal to 0.4 V, or greater than or equal to 0.6 V relative to a standard hydrogen electrode. Combinations of these ranges are also possible (e.g., greater than or equal to -1.5 V and less than or equal to -0.4 V, greater than or equal to -1.5 V and less than or equal to -0.8 V, greater than or equal to -0.4 V and less than or equal to 0.8 V, or greater than or equal to -0.4 V and less than or equal to 0.4 V).

[0089] In certain embodiments, the suitable Nernst potential at the first electrode depends on the type of reaction at the electrode. For example, in some cases, the Nernst potential at the first electrode is less than or equal to 0.8V (e.g., less than or equal to 0.8V and greater than or equal to -0.4V, or less than or equal to 0.4V and greater than or equal to -0.4V) relative to a standard hydrogen electrode when oxygen is reduced to an alkali. As another example, in some cases, the Nernst potential at the first electrode is less than or equal to -0.4V (e.g., less than or equal to -0.4V and greater than or equal to -1.5V, or less than or equal to -0.8V and greater than or equal to -1.5V) relative to a standard hydrogen electrode when water is reduced to an alkali and hydrogen.

[0090] In certain embodiments, the cell voltage (e.g., the voltage applied to the cell during production of acid and / or base, for example) is greater than or equal to 0 V, greater than or equal to 0.5 V, greater than or equal to 1 V, greater than or equal to 1.23 V, greater than or equal to 1.5 V, greater than or equal to 2 V, greater than or equal to 2.06 V, or greater than or equal to 2.5 V relative to a standard hydrogen electrode. In some embodiments, the cell voltage is less than or equal to 5 V, less than or equal to 4 V, less than or equal to 3 V, less than or equal to 2.5 V, less than or equal to 2.25 V, less than or equal to 2 V, less than or equal to 1.5 V, less than or equal to 1 V, or less than or equal to 0.5 V relative to a standard hydrogen electrode. Combinations of these ranges are also possible (e.g., 0 V to 5 V or 0 V to 2.5 V).

[0091] In some embodiments, the system includes a reactor system for producing concentrated acid and concentrated base. According to some embodiments, the system includes a first reactor (e.g., any reactor described herein). For example, referring to Figure 3A In some embodiments, the system 300 includes a first reactor 320. According to some embodiments, the system includes a second reactor (e.g., any reactor described herein). Figure 3A In some embodiments, the system 300 includes a second reactor 301. In some cases, the first reactor and the second reactor are fluidically connected. Figure 3A According to some embodiments, the first reactor 320 is fluidly connected to the second reactor 301 via a conduit 330. For example, in some cases, the fluid (e.g., liquid or gas) produced in the first reactor can be diffused and / or transported to the second reactor. As a non-limiting example, in certain embodiments, the method includes diffusing and / or transporting hydrogen and / or dihalide from the first reactor to the second reactor.

[0092] In some embodiments, the first reactor comprises an electrochemical reactor. In some cases, the first reactor comprises a first electrode (e.g., any first electrode described herein). For example, referring to Figure 3B In some cases, the first reactor 320 includes the first electrode 104. In some cases, the first reactor includes a second electrode (e.g., any second electrode described herein). For example, referring to Figure 3B In some cases, the first reactor 320 includes a second electrode 105. In some embodiments, the second electrode is electrochemically coupled to the first electrode (e.g., the electrodes are configured so that current can flow from one electrode to the other electrode). That is, the electrodes can be configured so that they can participate in an electrochemical process. The electrochemical coupling can be achieved, for example, by exposing the first electrode and the second electrode to an electrolyte that promotes ion transport between the two electrodes. For example, referring to Figure 3A In some embodiments, the first electrode 104 is electrochemically coupled to the second electrode 105 .

[0093] In some cases, the second reactor comprises a fuel cell (e.g., a H2 / Cl2 fuel cell). In some embodiments, the method comprises generating an acid in the second reactor. For example, in some cases, Figure 3A The second reactor 301 in is configured to produce an acid (eg, any acid described herein).

[0094] In certain embodiments, the method includes generating a base (e.g., any base described herein), a dihalide, and / or hydrogen in a first reactor. Figure 3A In some cases, the first reactor 320 is configured to produce a base, a dihalide, and / or hydrogen. In some cases, the dihalide is produced near the second electrode of the first reactor (e.g., the dihalide is produced by an electrochemical reaction in the second electrode of the first reactor). For example, referring to Figure 3B In some cases, the dihalide is produced near the second electrode 105 of the first reactor 320. In some embodiments, the base and / or hydrogen are produced near the first electrode (e.g., the base and / or hydrogen are produced by an electrochemical reaction in the first electrode). For example, referring to Figure 3B , in some cases, a base is generated near the first electrode 104.

[0095] The Nernst potential at the second electrode of the first reactor (e.g., the Nernst potential in the fluid closest to the second electrode) can be any one of a plurality of suitable values. In some embodiments, the Nernst potential at the second electrode (e.g., anode) of the first reactor is greater than or equal to 1.3V, greater than or equal to 1.5V, greater than or equal to 1.7V, greater than or equal to 1.9V, greater than or equal to 2.1V, or greater than or equal to 2.3V relative to a standard hydrogen electrode. In certain embodiments, the Nernst potential at the second electrode of the first reactor is less than or equal to 2.5V, less than or equal to 2.3V, less than or equal to 2.1V, less than or equal to 1.9V, less than or equal to 1.7V, or less than or equal to 1.5V relative to a standard hydrogen electrode. Combinations of these ranges are also possible (e.g., greater than or equal to 1.3V and less than or equal to 2.5V).

[0096] In certain embodiments, the suitable Nernst potential at the second electrode of the first reactor depends on the type of reaction at the electrode. For example, in some cases, when a dihalide is produced (e.g., chloride ions are oxidized to form Cl2), the Nernst potential at the second electrode is greater than or equal to 1.3V (e.g., greater than or equal to 1.3V and less than or equal to 2.5V) relative to a standard hydrogen electrode.

[0097] In some embodiments, Cl2 is produced from Cl- at a Nernst potential greater than 1.36 V relative to a standard hydrogen electrode (e.g., greater than or equal to 1.4 V, greater than or equal to 1.5 V, greater than or equal to 1.7 V, or greater than or equal to 2 V; less than or equal to 5 V, less than or equal to 3 V, less than or equal to 2 V, or less than or equal to 1.5 V; combinations are also possible).

[0098] In certain embodiments, Br2 is produced from Br- at a Nernst potential greater than 1.06 V relative to a standard hydrogen electrode (e.g., greater than or equal to 1.1 V, greater than or equal to 1.2 V, greater than or equal to 1.3 V, greater than or equal to 1.5 V, or greater than or equal to 1.8 V; less than or equal to 4 V, less than or equal to 3 V, less than or equal to 2 V, or less than or equal to 1.5 V; combinations are also possible).

[0099] In some cases, I2 is produced from I- at a Nernst potential greater than 0.54 V relative to a standard hydrogen electrode (e.g., greater than or equal to 0.6 V, greater than or equal to 0.7 V, greater than or equal to 0.8 V, greater than or equal to 0.9 V, greater than or equal to 1 V, or greater than or equal to 1.2 V; less than or equal to 3 V, less than or equal to 2 V, less than or equal to 1.5 V, less than or equal to 1.3 V, or less than or equal to 1 V; combinations are also possible).

[0100] The Nernst potential at the first electrode of the first reactor (e.g., the Nernst potential in the fluid closest to the first electrode) can be any one of a plurality of suitable values. In some embodiments, the Nernst potential at the first electrode (e.g., cathode) of the first reactor is greater than or equal to -2V, greater than or equal to -1.8V, greater than or equal to -1.6V, greater than or equal to -1.4V, greater than or equal to -1.2V, greater than or equal to -1.0V, greater than or equal to -0.8V, greater than or equal to -0.6V, greater than or equal to -0.4V, greater than or equal to -0.2V, greater than or equal to 0V, greater than or equal to 0.2V, greater than or equal to 0.4V, or greater than or equal to 0.6V relative to a standard hydrogen electrode. In certain embodiments, the Nernst potential at the first electrode of the first reactor is less than or equal to 0.8 V, less than or equal to 0.6 V, less than or equal to 0.4 V, less than or equal to 0.2 V, less than or equal to 0 V, less than or equal to -0.2 V, less than or equal to -0.4 V, less than or equal to -0.6 V, less than or equal to -0.8 V, less than or equal to -1.0 V, less than or equal to -1.2 V, less than or equal to -1.4 V, or less than or equal to -1.6 V relative to standard hydrogen electrode. Combinations of these ranges are also possible (e.g., greater than or equal to -2 V and less than or equal to 0.8 V, greater than or equal to -1.4 V and less than or equal to 0.4 V, greater than or equal to -2 V and less than or equal to -0.4 V, or greater than or equal to -2 V and less than or equal to -0.8 V).

[0101] In certain embodiments, the suitable Nernst potential at the first electrode of the first reactor depends on the reaction type at the electrode. For example, in some cases, when oxygen is reduced to form a base, the Nernst potential at the first electrode is less than or equal to 0.8V relative to a standard hydrogen electrode (e.g., greater than or equal to -2V and less than or equal to 0.8V or greater than or equal to -1.4V and less than or equal to 0.4V). As another example, in some cases, when water is reduced to hydrogen and a base, the Nernst potential at the first electrode is less than or equal to -0.4V relative to a standard hydrogen electrode (e.g., greater than or equal to -2V and less than or equal to -0.4V or greater than or equal to -2V and less than or equal to -0.8V).

[0102] In certain embodiments, the first reactor produces an alkali / alkaline solution, a dihalide, and hydrogen from an electrolyte comprising a halide salt. According to certain embodiments, Fig.11A reactor based on a neutral water electrolyzer as disclosed herein is shown, whereby electrolysis or hydrolysis produces an acidic solution and an alkaline solution, the acidic solution is then used to decarbonize a starting metal carbonate, and the alkaline solution is then used to precipitate a metal hydroxide from the dissolved metal ions of the starting metal carbonate. In some embodiments, the volume concentration of reactants operating on such a reactor is determined by the pH value produced by the electrolyzer.

[0103] According to certain embodiments, an alternative reactor concept is shown in Fig.12 According to some embodiments, the reactor is capable of producing Fig.11 In some embodiments, the system includes a first reactor that electrolytically oxidizes a nearly neutral solution of a dissolved metal salt to produce an alkaline solution, hydrogen, and a compound rich in cations of the metal salt. In some embodiments, the metal salt is an alkali metal halide salt or an alkaline earth metal halide salt and the compound produced is a dihalide. According to certain embodiments, the second reactor produces an acidic solution by reacting the compound and hydrogen with water. In some embodiments, the acidic solution produced by the second reactor and the alkaline solution produced by the first reactor are then used to dissolve the metal carbonate that releases CO2 and precipitate the metal hydroxide, respectively. With respect to systems where achieving absolute H+ and OH- concentrations greater than about 1 molar may be difficult Fig.11 In certain embodiments, Fig.12 The reactor can reach 3 molar, 5 molar, or even higher concentrations.

[0104] In certain embodiments, the first reactor comprises a second electrode (e.g., an anode), a first electrode (e.g., a cathode), a semipermeable membrane between the two electrodes, an inlet for an electrolyte, and an outlet for electrolysis products (H2, dihalides, and alkaline solution). In some embodiments, an additional inlet near the first electrode introduces O2. In some cases, the electrolyte is a near-neutral aqueous solution in which a metal salt is dissolved. In some cases, the aqueous solution comprises a halide anion (e.g., F - , Cl - Br - ,I - ) and the corresponding cations (e.g., Li + 、Na + , K + NH4 + Mg 2+ , Ca 2+). In certain embodiments, the concentration of the halide salt in the electrolyte may be anywhere from 0.01 wt % to 50 wt %. In some embodiments, the electrolyte is introduced into the second electrode (e.g., anode) through an inlet. In some cases, the active material on the surface of the second electrode may include platinum, graphite, platinized titanium, mixed metal oxides, mixed metal oxide-coated titanium, platinized metal oxides (e.g., platinized lead oxide, manganese dioxide), platinized ferrosilicon, platinum-iridium alloys, ruthenium oxides, titanium oxides, ruthenium and / or titanium mixed metal oxides.

[0105] In some cases, the halide anions are oxidized to produce dihalides (e.g., Cl2, Br2, I2) at the second electrode of the reactor 1. For example, in some cases, the oxidation of dissolved Cl- produces Cl2 gas.

[0106] 2Cl - (aq) →Cl 2(g) +2e -

[0107] In certain embodiments, at room temperature, oxidation of Br- produces Br2 (smoky liquid), and oxidation of I- produces I2 (solid). In some cases, the dihalide is collected from the electrolyzer via the outlet and used to prepare the acid in the subsequent steps described below. In some cases, the cation (e.g., Li + 、Na + , K + NH4 + ) is moved toward the first electrode (e.g., cathode) through a semipermeable membrane (diaphragm or ion exchange membrane). In some cases, the diaphragm or membrane prevents the alkaline solution generated at the first electrode from increasing the pH at the second electrode. In certain embodiments, the surface of the first electrode may include an electrocatalytic compound. Examples of electrocatalytic compounds include platinum, platinized titanium, mixed metal oxide-coated titanium, platinized metal oxides (e.g., platinized lead oxide, manganese dioxide), platinized ferrosilicon, platinum-iridium alloys, stainless steel, graphite, non-alloyed titanium, stainless steel, nickel, nickel oxide. In certain embodiments, the second electrode includes a metal electrode such as platinum, gold, nickel, iridium, copper, iron, steel, stainless steel, manganese and zinc, or carbon such as graphite or disordered carbon, or a metal carbide such as silicon carbide, titanium carbide or tungsten carbide. In certain embodiments, the second electrode comprises a metal alloy (e.g., nickel-chromium-iron alloy, nickel-molybdenum-cadmium alloy), a metal oxide (e.g., iridium oxide, nickel-iron-cobalt oxide, nickel-cobalt oxide, lithium-cobalt oxide, lanthanum-strontium-cobalt oxide, barium-strontium-iron oxide, manganese-molybdenum oxide, ruthenium dioxide, iridium-ruthenium-tantalum oxide), a metal-organic framework, or a metal sulfide (e.g., molybdenum sulfide). In certain embodiments, the electrocatalyst or electrode material is dispersed or coated on a conductive support. In some embodiments, such as Fig.13A As shown, at the first electrode (e.g., cathode) of the reactor 1, water is reduced to produce OH- (alkaline solution) and H 2(g) :

[0108] H2O+2e - →H2+2OH -

[0109] In another embodiment, at the first electrode (e.g., cathode) of reactor 1, O2 is reduced to produce OH- (alkaline solution); see Fig.13A .

[0110] 1 / 2O2+H2O+2e - →2OH -

[0111] In some embodiments, OH- is charge balanced by cations passing through a diaphragm or membrane in electrolysis, e.g. Fig.13A and 13B As shown. In some cases, an alkali metal hydroxide solution (e.g., NaOH, KOH) having a pH greater than 7 and a base concentration of 0.01 mol / L or greater is collected from the reactor from the outlet. In some cases, H2 is collected from the reactor from a different outlet. In some cases, the reactor 1 produces an alkaline solution at one electrode and produces hydrogen and a dihalide (in the case where the metal salt is a metal halide) at another electrode.

[0112] According to some embodiments, Fig.12 In the reactor 2, the acid is produced by reacting the hydrogen produced at the anode of the reactor 1 with a dihalide, or by reacting the dihalide with water. Without being limited by the following examples, two embodiments of the reactor are shown in FIG. 14A to FIG. 14B According to certain embodiments, Fig.14A In, the reactor includes a first chamber, an inlet through which H2 is introduced into the first chamber, a second inlet through which dihalide is introduced into the first chamber, and an outlet through which hydrogen halide (e.g., HCl, HBr, HI) is removed from the first chamber, an inlet through which hydrogen halide is introduced into the second chamber, an inlet through which water is introduced into the second chamber, and an outlet through which an acidic aqueous solution of hydrogen halide is removed from the second chamber. In some embodiments, dihalide reacts with H2 in the first chamber to form hydrogen halide. In certain embodiments, the reaction between H2 and dihalide can be assisted by heating or by radiation of electromagnetic waves. For example, in some embodiments, if dihalide is Cl2, the following reaction occurs in reactor 2:

[0113] Cl2+H2→2HCl

[0114] In some cases, in the second chamber, a hydrogen halide is dissolved in water to produce an acidic solution. For example, HCl can be dissolved in water to produce protons.

[0115] According to certain embodiments, Fig. 14B In some cases, the reactor includes a first chamber, an inlet through which H2O is introduced into the first chamber, and a second inlet through which the dihalide is introduced into the first chamber. In some cases, the reactor also includes an outlet through which hydrogen halide (e.g., HCl, HBr, HI) is removed from the first chamber and an outlet through which O2 is removed from the first chamber. In some cases, the reaction between chlorine and water as an exemplary dihalide is:

[0116] Cl2+H2O→2HCl+1 / 2O2

[0117] In some embodiments, the relative amounts of dihalide and water will determine whether pure hydrogen halide is produced, or a blend of hydrogen halide and water, including, for example, a solution of hydrogen halide in water. Optionally, in certain embodiments, the reactor may include a second chamber having an inlet through which hydrogen halide is introduced, wherein hydrogen halide is dissolved in water to prepare an acidic solution, an inlet through which water is introduced into the second chamber, and an outlet through which the acidic aqueous solution of hydrogen halide is removed from the reactor, such as Fig. 14B shown.

[0118] In some embodiments, the system includes a device. For example, referring to Figure 1A In some embodiments, the system includes a first device 118. Similarly, referring to Figure 2C , in some cases, the system includes a first device 118. Similarly, referring to Figure 3A In some cases, the system includes a first device 118. In some cases, the device is a container (e.g., a container that is not open to the atmosphere). According to certain embodiments, the device is configured to collect one or more products or byproducts of the reactor (e.g., acid, base, hydrogen, oxygen and / or carbon dioxide gas, etc.), store one or more of the one or more products or byproducts, and / or react one or more of the one or more products or byproducts (e.g., in a chemical dissolution and / or precipitation reaction).

[0119] In certain embodiments, the system includes a plurality of devices. In some embodiments, the system includes greater than or equal to 1, greater than or equal to 2, greater than or equal to 3, greater than or equal to 4, or greater than or equal to 5 devices. In some cases, the system includes less than or equal to 6, less than or equal to 5, less than or equal to 4, less than or equal to 3, or less than or equal to 2 devices. Combinations of these ranges are also possible (e.g., 1 to 6 devices). In some embodiments, the system includes a first device and a second device. For example, in Figure 1B In some embodiments, the system includes a first device 118 and a second device 119. Similarly, referring to Figure 2C In some embodiments, the system includes a first device 118 and a second device 119. Similarly, referring to Figure 3A In some cases, the system includes a first device 118 and a second device 119. Each device can independently have one or more functions. Any device or configuration of a device disclosed herein can be used with any system disclosed herein.

[0120] In certain embodiments, the device is fluidically connected to the reactor. For example, in some cases, the device is connected to the reactor by a conduit (e.g., a pipe, channel, needle, or tube) through which the fluid can flow. For example, referring to Figure 1A , in some embodiments, the device 118 is fluidically connected to the reactor via a conduit. Figure 2C , in certain embodiments, the device 118 is fluidically connected to the reactor via a conduit. Figure 3A In some cases, device 118 is fluidly connected to the reactor via a conduit.

[0121] In some cases, a device is fluidically connected to one or more additional devices (e.g., via a conduit, such as a tube, channel, needle, or tube). Figure 1D , the first device 118 is fluidically connected to the third device 120 via a conduit. Similarly, referring to Figure 2C In some embodiments, the first device 118 can be fluidly connected to the third device (e.g., via a catheter). Similarly, referring to Figure 3A In some cases, the first device 118 can be fluidly connected to a third device (e.g., via a catheter). As another example, refer to Figure 1E In some embodiments, the first device 118 is fluidly connected to the third device 120 (e.g., via a catheter), and the third device 120 is fluidly connected to the fifth device 122 (e.g., via a catheter), while the second device 119 is fluidly connected to the fourth device 121 (e.g., via a catheter), and the fourth device 121 is fluidly connected to the sixth device 123 (e.g., via a catheter).

[0122] According to some embodiments, described method comprises collecting acid and / or alkali.For example, in some embodiments, described method comprises removing acid and / or alkali from the container (for example, reactor) producing acid and / or alkali.A non-limiting example of a suitable method for collecting acid and / or alkali comprises moving acid and / or alkali to a separate container by a conduit (for example, pipeline, channel, needle or tube).Other suitable examples of collecting acid and / or alkali comprise directly moving acid and / or alkali to a separate container (for example, being connected to the container of the reactor by a panel that can be moved to block or allow fluid diffusion).In some embodiments, acid and / or alkali are collected continuously or in batches.In certain embodiments, acid and / or alkali are collected automatically or manually.

[0123] In some embodiments, the device is configured to collect acid near the second electrode (and / or the second reactor) and / or base near the first electrode (and / or the first reactor) (e.g., collect acid from an acidic region and / or collect base from an alkaline region). Figure 1A In some embodiments, the system includes a first device 118 configured to collect base near the first electrode 104. Similarly, referring to Figure 2C In some embodiments, the system includes a first device 118 configured to collect base near the first electrode 104. Similarly, referring to Figure 3A , the system 300 includes a first device 118 configured to collect base near the first reactor 320 (e.g., near the first electrode 104 of the first reactor 320). In some embodiments, the first device 118 can be configured to collect acid near the second electrode (and / or the second reactor) in addition to collecting base near the first electrode (and / or the first reactor), or to collect acid near the second electrode (and / or the second reactor) instead of collecting base near the first electrode (and / or the first reactor).

[0124] In some embodiments, the second device is configured to collect acid near the second electrode (and / or the second reactor) and / or base near the first electrode (and / or the first reactor). In some embodiments where the first device is configured to collect base near the first electrode, the second device is configured to collect acid near the second electrode. For example, referring to Figure 1B In some embodiments, the system includes a first device 118 and a second device 119, and in some cases, the first device 118 is configured to collect base near the first electrode 104 and the second device 119 is configured to collect acid near the second electrode 105. Similarly, referring to Figure 2CIn some embodiments, the system includes a first device 118 and a second device 119, and in some cases, the first device 118 is configured to collect base near the first electrode 104 and the second device 119 is configured to collect acid near the second electrode 105. Similarly, referring to Figure 3A In some cases, the system 300 includes a first device 118 and a second device 119, and in some cases, the first device 118 is configured to collect base near the first reactor 320 (e.g., the first electrode 104) and the device 119 is configured to collect acid near the second reactor 301. Alternatively, in embodiments in which the first device is configured to collect acid near the second electrode (and / or the second reactor), the second device can be configured to collect base near the first electrode (and / or the first reactor).

[0125] In certain embodiments, collecting acid comprises collecting acid produced by the electrode from a vicinity close enough to the electrode that the acid has not been significantly diluted and / or reacted (e.g., the pH of the collected acid is within one pH unit of the acid with the lowest pH in the reactor). Similarly, in some embodiments, collecting base comprises collecting base produced by the electrode from a vicinity close enough to the electrode that the base has not been significantly diluted and / or reacted (e.g., the pH of the collected base is within one pH unit of the base with the highest pH in the reactor).

[0126] According to some embodiments, the method includes storing acid and / or alkali. For example, in certain embodiments, after acid and / or alkali are collected in a separate container, the method includes keeping the acid and / or alkali in a separate container for at least a period of time. In some embodiments, the method includes storing the acid and / or alkali for greater than or equal to 5 minutes, greater than or equal to 15 minutes, greater than or equal to 30 minutes, greater than or equal to 1 hour, greater than or equal to 5 hours, greater than or equal to 12 hours, greater than or equal to 1 day, greater than or equal to 2 days, greater than or equal to 3 days, greater than or equal to 1 week, greater than or equal to 2 weeks, or greater than or equal to 1 month. In certain embodiments, the method includes storing the acid and / or alkali for less than or equal to 1 year, less than or equal to 6 months, less than or equal to 3 months, less than or equal to 2 months, less than or equal to 1 month, less than or equal to 2 weeks, less than or equal to 1 week, less than or equal to 3 days, less than or equal to 2 days, less than or equal to 1 day, or less than or equal to 12 hours. Combinations of these ranges are also possible (eg, greater than or equal to 5 minutes and less than or equal to 1 year, greater than or equal to 5 hours and less than or equal to 1 day, or greater than or equal to 1 week and less than or equal to 1 year).

[0127] In certain embodiments, the device (e.g., the first device and / or the second device) is configured to store an acid and / or a base. Figure 1AIn some embodiments, the first device 118 is configured to store a base. Figure 2C In some embodiments, the first device 118 is configured to store a base. Figure 3A In some cases, the first device 118 is configured to store a base.

[0128] As another example, refer to Figure 1B In some embodiments, the second device 119 is configured to store acid. Figure 2C In some cases, the second device 119 is configured to store acid. Figure 3A In some cases, the second device 119 is configured to store acid.

[0129] In some embodiments where the first device is configured to store a base, the second device is configured to store an acid. Figure 1B In some embodiments, the system includes a first device 118 and a second device 119, and in some cases, the first device 118 is configured to store a base, and the second device 119 is configured to store an acid. Figure 2C , in some cases, the system includes a first device 118 and a second device 119, and in some cases, the first device 118 is configured to store a base, and the second device 119 is configured to store an acid. Similarly, referring to Figure 3A According to some embodiments, the system includes a first device 118 and a second device 119, and in some cases, the first device 118 is configured to store a base, and the second device 119 is configured to store an acid. Alternatively, in embodiments where the first device is configured to store an acid, the second device may be configured to store a base.

[0130] According to some embodiments, the method includes reacting acid and / or alkali in chemical dissolution and / or in precipitation reaction. In certain embodiments, chemical dissolution is before precipitation reaction (for example, the product of chemical dissolution is used for precipitation reaction). In some cases, precipitation reaction is before chemical dissolution (for example, the product of precipitation reaction is used for chemical dissolution). In some cases, chemical dissolution and precipitation reaction are simultaneous and / or unrelated (for example, the product of one is not used for the other, and vice versa).

[0131] In some embodiments, the device (e.g., the first device and / or the second device) is configured to react the acid in a chemical dissolution and / or in a precipitation reaction. Figure 1B In some embodiments, the second device 119 is configured to react the acid (eg, in a chemical dissolution and / or in a precipitation reaction). Figure 2CIn some embodiments, the second device 119 is configured to react an acid (e.g., in a chemical dissolution and / or in a precipitation reaction). Figure 3A According to some embodiments, the second device 119 is configured to react the acid (eg, in a chemical dissolution and / or in a precipitation reaction).

[0132] In certain embodiments, the device (e.g., the first device and / or the second device) is configured to react a base in a chemical dissolution and / or in a precipitation reaction. As another example, referring to Figure 1A In some embodiments, the first device 118 is configured to react a base (e.g., in a chemical dissolution and / or in a precipitation reaction). Similarly, referring to Figure 2C In some embodiments, the first device 118 is configured to react a base (eg, in a chemical dissolution and / or in a precipitation reaction). Similarly, referring to Figure 3A According to some embodiments, the first device 118 is configured to react a base (eg, in a chemical dissolution and / or in a precipitation reaction).

[0133] In some embodiments where the first device is configured to react a base (e.g., in a chemical dissolution and / or in a precipitation reaction), the second device is configured to react an acid (e.g., in a chemical dissolution and / or in a precipitation reaction). Figure 1B In some embodiments, the system includes a first device 118 and a second device 119, and in some cases, the first device 118 is configured to react a base (e.g., in a chemical dissolution and / or in a precipitation reaction), and the second device 119 is configured to react an acid (e.g., in a chemical dissolution and / or in a precipitation reaction). Similarly, with reference to Figure 2C In some embodiments, the system includes a first device 118 and a second device 119, and in some cases, the first device 118 is configured to react a base (e.g., in a chemical dissolution and / or in a precipitation reaction), and the second device 119 is configured to react an acid (e.g., in a chemical dissolution and / or in a precipitation reaction). Similarly, with reference to Figure 3A According to some embodiments, the system includes a first device 118 and a second device 119, and in some cases, the first device 118 is configured to react a base (e.g., in a chemical dissolution and / or in a precipitation reaction), and the second device 119 is configured to react an acid (e.g., in a chemical dissolution and / or in a precipitation reaction). Alternatively, in embodiments where the first device is configured to react an acid, the second device may be configured to react a base.

[0134] According to certain embodiments, the device (e.g., the first device and / or the second device) can be configured to (i) collect the acid near the second electrode and / or the base near the first electrode; (ii) store the acid and / or the base; and / or (iii) react the acid and / or the base (e.g., in a chemical dissolution and / or in a precipitation reaction). For example, referring to Figure 1A In some embodiments, the first device 118 is configured to (i) collect the base near the first electrode; (ii) store the base; and (iii) react the base (e.g., in a chemical dissolution and / or in a precipitation reaction). Figure 2C , in some embodiments, the first device 118 is configured to (i) collect the base near the first electrode; (ii) store the base; and (iii) react the base (e.g., in a chemical dissolution and / or in a precipitation reaction). Similarly, referring to Figure 3A In some cases, the first device 118 is configured to (i) collect the base near the first electrode; (ii) store the base; and (iii) react the base (eg, in a chemical dissolution and / or in a precipitation reaction).

[0135] As another example, see Figure 1B In some embodiments, the second device 119 is configured to (i) collect the acid near the second electrode; (ii) store the acid; and (iii) react the acid (e.g., in a chemical dissolution and / or in a precipitation reaction). Figure 2C In some embodiments, the second device 119 is configured to (i) collect the acid near the second electrode; (ii) store the acid; and (iii) react the acid (e.g., in a chemical dissolution and / or in a precipitation reaction). Figure 3A , the second device 119 is configured to (i) collect the acid near the second electrode; (ii) store the acid; and (iii) react the acid (eg, in a chemical dissolution and / or in a precipitation reaction).

[0136] According to some embodiments, each device may have only one function. For example, in some embodiments, a first device is configured to collect a base near a first electrode, a second device is configured to collect an acid near a second electrode, and a third device is configured to react the base and / or the acid (e.g., in a chemical dissolution and / or in a precipitation reaction). For example, in Figure 1DIn some embodiments, the first device 118 is configured to collect bases near the first electrode 104, the second device 119 is configured to collect acids near the second electrode 105, and the third device 120 is configured to react the bases (e.g., in chemical dissolution and / or in a precipitation reaction). As another non-limiting example, in some embodiments, the first device is configured to collect bases near the first electrode and store the bases; the second device is configured to collect acids near the second electrode, store the acids, and react the acids (e.g., in chemical dissolution and / or in a precipitation reaction); and the third device is configured to react the bases (e.g., in chemical dissolution and / or in a precipitation reaction). For example, in Figure 1D In some embodiments, the first device 118 is configured to collect base near the first electrode 104 and store the base; the second device 119 is configured to collect acid near the second electrode 105, store the acid, and react the acid (e.g., in chemical dissolution and / or in a precipitation reaction); and the third device 120 is configured to react the base (e.g., in chemical dissolution and / or in a precipitation reaction).

[0137] In yet another example, in some embodiments, the first device is configured to collect base near the first electrode, the second device is configured to collect acid near the second electrode, the third device is configured to store base, the fourth device is configured to store acid, the fifth device is configured to react the base (e.g., in a chemical dissolution and / or in a precipitation reaction), and the sixth device is configured to react the acid (e.g., in a chemical dissolution and / or in a precipitation reaction). Figure 1E In some cases, the first device 118 is configured to collect bases near the first electrode 104, the second device 119 is configured to collect acids near the second electrode 105, the third device 120 is configured to store bases, the fourth device 121 is configured to store acids, the fifth device 122 is configured to react the bases (e.g., in chemical dissolution and / or in a precipitation reaction), and the sixth device 123 is configured to react the acids (e.g., in chemical dissolution and / or in a precipitation reaction).

[0138] In some embodiments, acid and / or alkali described herein are reacted in chemical dissolution and / or precipitation reaction. In some cases, acid and / or alkali are reacted in chemical dissolution. In some embodiments, chemical dissolution includes dissolving solid to form two dissolved ions. In some embodiments, solid includes metal, metal alloy, metalloid, metal salt, metal oxide, metal hydroxide, and / or silicate. In certain embodiments, solid is crystalline, amorphous, nanocrystalline, and / or its mixture. In some embodiments, solid includes Ag, Al, As, Au, Ba, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Ti, Tl, V, W and / or Zn (for example, in elemental form or as salt).

[0139] In some embodiments, the metal and / or metal alloy includes iron, iron-based alloys, stainless steel, nonferrous metals, nonferrous alloys, aluminum, brass, bronze, copper, zinc, tin, and / or coin alloys.

[0140] Examples of metal salts, metal oxides, and metal hydroxides include salts, oxides, and hydroxides of calcium, magnesium, barium, strontium, manganese, iron, cobalt, zinc, cadmium, lead, and / or nickel. For example, in some embodiments, the metal salt includes a metal carbonate. Examples of suitable metal carbonates include calcium carbonate, magnesium carbonate, barium carbonate, strontium carbonate, manganese carbonate, iron carbonate, cobalt carbonate, zinc carbonate, cadmium carbonate, lead carbonate, and / or nickel carbonate.

[0141] Examples of suitable metal oxides include calcium oxide, magnesium oxide, strontium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, zinc oxide, cadmium oxide, lead oxide, silicon dioxide, and / or aluminum oxide.

[0142] Examples of suitable metal hydroxides include calcium hydroxide, magnesium hydroxide, strontium hydroxide, manganese hydroxide, iron oxides, cobalt hydroxide, nickel hydroxide, zinc hydroxide, cadmium hydroxide, lead hydroxide, silicon hydroxide, and / or aluminum hydroxide.

[0143] In some embodiments, the acid reacts in the chemical dissolution of a metal, metal alloy, metalloid, metal salt, metal oxide, and / or metal hydroxide. In certain embodiments, the base reacts in the chemical dissolution of a metal oxide (e.g., silicon dioxide and / or aluminum oxide) and / or metal hydroxide (e.g., silicon hydroxide and / or aluminum hydroxide).

[0144] In some cases, acid and / or base react in the precipitation reaction. In certain embodiments, the precipitation reaction comprises the combination of two dissolved ions to form a solid precipitate. In some embodiments, the solid precipitate comprises a metal hydroxide. Examples of suitable metal hydroxides include calcium hydroxide, magnesium hydroxide, barium hydroxide, strontium hydroxide, manganese hydroxide, iron hydroxide, cobalt hydroxide, zinc hydroxide, cadmium hydroxide, lead hydroxide, and / or nickel hydroxide.

[0145] According to some embodiments, the base reacts in the precipitation reaction to form a metal hydroxide. In certain embodiments, the acid reacts in the precipitation reaction to form a metal hydroxide.

[0146] In certain embodiments, when in the first mode (for example, as described above) the reactor is intermittently operated. In some cases, the reactor is continuously operated with the first mode. In some cases, the reactor is intermittently operated with the first mode, and the reaction (for example, chemical dissolution and / or precipitation reaction) with the acid and / or alkali collected is continuously carried out. For example, in some embodiments, when operating with the first mode, the reactor produces enough acid and / or alkali so that it only needs to be intermittently operated to produce enough acid and / or alkali to react (for example, chemical dissolution and / or precipitation reaction) continuously.

[0147] In some embodiments, the desired chemical reaction is performed by collecting solutions or suspensions of different compositions produced by electrolysis and using the solution or suspensions to produce products from the reactants in a portion of the reactor or in a separate device. For example, according to some embodiments, FIG. 4A to FIG. 4B Reactors are shown in which the electrolyzer produces low pH and high pH solutions that flow to separate areas of the reactor or to separate reactors. According to some embodiments, an acidic solution is used to dissolve CaCO3 in the first chamber, thereby releasing CO2 gas in the process (see Figure 4B In the second chamber, in some embodiments, the dissolved solution reacts with an alkaline solution produced by an electrolytic cell to produce Ca(OH)2 (see Figure 4B ). In some embodiments, the two chambers are storage tanks for acidic solutions and for alkaline solutions. In certain embodiments, the acid storage tank comprises a polymer material or a glass lining. In some embodiments, the alkaline storage tank comprises a polymer material or a metal. In some embodiments, the metal tank comprises iron or steel.

[0148] In some cases, the by-product of the precipitation reaction is fed back into the system (e.g., the first reactor). In some cases, the system is configured to feed the by-product from the precipitation reaction into the system (e.g., the first reactor). In some embodiments, the by-product has a neutral pH. For example, in some cases, the pH of the by-product is greater than 6, greater than or equal to 6.25, greater than or equal to 6.5, greater than or equal to 6.75, or greater than or equal to 6.9. In some cases, the pH of the by-product is less than 8, less than or equal to 7.75, less than or equal to 7.5, less than or equal to 7.25, or less than or equal to 7.1. The combination of these ranges is also possible (e.g., greater than 6 and less than 8, or greater than or equal to 6.9 and less than or equal to 7.1). In some embodiments, the pH of the by-product is 7.

[0149] In some cases, the byproduct comprises an alkali halide (e.g., a byproduct in the precipitation of an alkali hydroxide) (e.g., NaCl). In some cases, the byproduct comprises an alkali metal salt (e.g., NaClO4, NaNO3, sodium trifluoromethanesulfonate and / or sodium acetate).

[0150] In some embodiments, the method includes operating the reactor in a second mode. In some cases, the polarity of the reactor in the second mode is opposite to the polarity of the reactor in the first mode. According to some embodiments, operating the reactor in the first mode uses more electricity than operating the reactor in the second mode. For example, in certain embodiments, operating the reactor in the first mode uses at least 10%, at least 20%, at least 30%, or at least 40% more electricity than operating the reactor in the second mode. In some cases, operating the reactor in the first mode uses less than or equal to 50%, less than or equal to 40%, less than or equal to 30%, or less than or equal to 20% electricity than operating the reactor in the second mode. Combinations of these ranges are also possible (e.g., at least 10% and less than or equal to 50%). Any embodiment associated with the second mode can be applied to any one of the systems described herein.

[0151] In some embodiments, operating the reactor in the second mode includes adding a base to the reactor near the second electrode. For example, in some embodiments, operating the reactor in the second mode includes adding a base to the reactor in a manner such that the base is available for electrochemical reaction at the second electrode. For example, referring to Figure 1A , in some embodiments, operating the reactor in the second mode includes adding a base near the second electrode 105. Similarly, referring to Figure 2AIn some embodiments, operating the reactor in the second mode includes adding a base near the second electrode 105. According to some embodiments, when the reactor is operated in the first mode, the base added to the reactor is collected from near the first electrode and stored until the reactor is operated in the second mode. In some embodiments, operating the reactor in the second mode includes oxidizing the added base (e.g., the base that has been stored) near the second electrode to produce oxygen. For example, in some cases, operating the reactor in the second mode includes oxidizing the added base to oxygen through the second electrode.

[0152] In some embodiments, operating the reactor in the second mode includes adding an acid to the reactor near the first electrode. For example, in some embodiments, operating the reactor in the second mode includes adding an acid to the reactor in a manner such that the acid is available for electrochemical reaction at the first electrode. For example, referring to Figure 1A , in some embodiments, operating the reactor in the second mode includes adding an acid near the first electrode 104. Similarly, referring to Figure 2A In some embodiments, operating the reactor in the second mode includes adding an acid near the first electrode 104. According to some embodiments, the acid added to the reactor is collected from near the second electrode when the reactor is operated in the first mode and stored until the reactor is operated in the second mode. In some embodiments, operating the reactor in the second mode includes reducing the added acid (e.g., the acid that has been stored) near the first electrode to produce hydrogen. For example, in some cases, operating the reactor in the second mode includes reducing the added acid to hydrogen through the first electrode.

[0153] In comparison, in some embodiments, operating the reactor in the first mode includes adding a near-neutral input solution to the reactor. In some cases, the pH of the near-neutral input solution is greater than 6, greater than or equal to 6.25, greater than or equal to 6.5, greater than or equal to 6.75, or greater than or equal to 6.9. In some cases, the pH of the near-neutral input solution is less than 8, less than or equal to 7.75, less than or equal to 7.5, less than or equal to 7.25, or less than or equal to 7.1. Combinations of these ranges are also possible (e.g., greater than 6 and less than 8, or greater than or equal to 6.9 and less than or equal to 7.1). In some embodiments, the pH of the near-neutral input solution is 7. In certain embodiments, the near-neutral input solution comprises a salt. Examples of suitable salts include alkali metal sulfates, alkali metal chlorates, alkali metal halides, alkali metal nitrates, alkali metal perchlorates, alkali metal acetates, alkali metal nitrites, and / or alkali metal triflates.

[0154] In some embodiments, it may be advantageous to operate the reactor in a second mode rather than in a first mode when the cost of electricity is high and / or when electricity is lacking. For example, in certain embodiments, if electricity is purchased from a power supplier, the cost of electricity from the power supplier and / or the availability of electricity may fluctuate, and it may be advantageous to operate the reactor in a first mode when the cost of electricity is low and / or the availability of electricity is high and then to operate the reactor in a second mode when the cost of electricity is high and / or the availability of electricity is low. As another example, in certain embodiments, if electricity comes from a renewable energy source, such as solar or wind energy, there may be fluctuations in the availability of electricity, such that it may be advantageous to operate the reactor in a first mode when the availability of electricity is high (e.g., during daytime and / or during summer for solar energy or during windy periods for wind energy) and then to operate the reactor in a second mode when the availability of electricity is low (e.g., during nighttime and / or during winter for solar energy or during periods without significant wind). In some cases, the reactor is operated in a first mode when the cost of electricity is a first cost and the availability of electricity is a first availability, and the reactor is operated in a second mode when the cost of electricity is a second cost and the availability of electricity is a second availability, wherein the second cost is greater than the first cost (e.g., at least 10%, 25%, 50%, or 100% greater) and / or the first availability is greater than the second availability (e.g., at least 10%, 25%, 50%, or 100% greater).

[0155] In some embodiments, the acidic solution and / or alkaline solution produced by the electrolytic reactor is at least partially collected and / or stored during periods of high electricity availability and / or low electricity costs, thereby allowing chemical dissolution reactions in the acid and chemical precipitation reactions in the base to be carried out to produce CO2 during periods of reduced or low electrolyzer operation or electricity availability and / or high electricity costs. In some embodiments, the storage of acidic and alkaline solutions acts as chemical storage, allowing the output of chemical reaction products, which can usually be solid, liquid or gas, to vary less or be stable compared to the output rate of the electrolyzer. In some embodiments, the size or volume of the stored acidic or alkaline solution allows the chemical reaction product to be produced at a rate that does not completely deplete the stored acidic or alkaline solution during periods of reduced or low electrolyzer operation or electricity availability and / or high electricity costs. In some embodiments, the system includes a source of variable electricity, the electrolyzer, and the chemical storage tank and chemical reactor. In some embodiments, methods include operating such a system to produce a less variable, or a constant or relatively constant flow of chemical reaction products from a more variable or intermittent power source.

[0156] In some embodiments, the method includes producing an acid and a base in a low voltage mode (e.g., at a lower voltage than the high voltage mode described herein). Any embodiments associated with the low voltage mode can be used with any system disclosed herein. In some embodiments, the method does not produce oxygen and / or hydrogen. For example, in some embodiments, the electrolysis reaction occurring in the low voltage mode can be to oxidize hydrogen (H2→2H + +2e - ) and reducing water at the first electrode (2H2O+2e - →H2+2OH - ), so no oxygen is produced. In another example, in certain embodiments, the electrolysis reaction occurring in the low voltage mode can be oxidation of water at the first electrode (2H2O→O2+4H + +4e - ) and oxygen reduction at the second electrode (O2+2H2O+4e - →4OH-), so no hydrogen is produced.

[0157] For purposes of illustration, some exemplary systems are described below.

[0158] System 1: Exemplary system for producing low-cost H2 at a constant rate using intermittent renewable energy

[0159] According to some embodiments, the system may include a reactor comprising a region comprising a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). In some embodiments, the reactor may include a first electrode and a second electrode, one or more inlets for supplying a liquid and / or a gas undergoing one or more electrolysis reactions, and a portion of the reactor in which the solution is stored after undergoing the electrolysis reaction or a separate device in which the solution is stored after undergoing the electrolysis reaction.

[0160] In certain embodiments, the method comprises: FIG. 5A to FIG. 5B The reactor is operated in a first mode including: generating a base near a first electrode; generating an acid near a second electrode electrochemically coupled to the first electrode in the reactor; collecting the acid and / or base; and reacting the collected acid and / or base in a chemical dissolution and / or in a precipitation reaction.

[0161] In certain embodiments, the electrolysis reaction can produce H2, O2, an acidic solution, and an alkaline solution. This is an example of a high voltage mode, which requires a higher voltage than a low voltage mode. A non-limiting example of an electrolysis reaction occurring in the high voltage mode is oxidation of water at the second electrode (2H2O→O2+4H + +4e -) and reducing water at the first electrode (2H2O+2e - →H2+2OH - ); this reaction requires a minimum voltage of 2 V when the pH at the second electrode is 0 and the pH at the first electrode is 14 (see FIG. 5A to FIG. 5B ). In certain embodiments, the acidic solution and the alkaline solution generated at the electrodes can be collected and stored separately.

[0162] In certain embodiments, the method comprises conducting the experiment in a second mode (e.g., a low voltage mode, such as FIG. 6A to FIG. 6B In some embodiments, the second mode includes adding a base collected and / or stored to the reactor near the second electrode. In certain embodiments, the second mode includes oxidizing the added base near the second electrode to produce oxygen. In some embodiments, the second mode includes adding an acid collected and / or stored to the reactor near the first electrode. In certain embodiments, the second mode includes reducing the added acid near the first electrode to produce hydrogen.

[0163] In some embodiments, the electrolysis reaction can neutralize the acidic solution and the alkaline solution while producing H2 and O2. This is an example of a low voltage mode, which requires a lower voltage than the aforementioned high voltage mode. A non-limiting example of an electrolysis reaction occurring in the low voltage mode is oxidation of hydroxide ions (4OH-→O2+2H2O+4e2O) at the second electrode (e.g., the anode). - ) and reducing protons (2H + +2e - →H2); this reaction requires a minimum voltage of 0.4 V when the pH at the second electrode is 14 and the pH at the first electrode is 0 (see FIG. 6A to FIG. 6B ). In certain embodiments, the inlet of the reactor can supply a solution having a pH greater than 8 to the second electrode and a solution having a pH less than 6 to the first electrode.

[0164] In certain embodiments, different reactors can be operated with high voltage mode and low voltage mode. In another embodiment, a single reactor can be configured so that it can be operated with high voltage mode or with low voltage mode. In some embodiments, by changing the pH of the liquid flowing to the electrode, the reactor can be converted to low voltage mode from high voltage mode. For example, in order to convert low voltage mode from high voltage mode, an alkaline solution can be introduced into the second electrode, while an acidic solution can be introduced into the first electrode.

[0165] In some embodiments, the decision to switch between a high voltage mode (e.g., producing H2 / O2 while producing acid / base) and a low voltage mode (e.g., producing H2 / O2 while neutralizing acid / base) can be based on the cost or availability of electricity, which may fluctuate throughout the day, month, or year. In certain embodiments, when the cost of electricity is below a certain value, the reactor can operate in a high voltage mode (e.g., consuming more power while producing H2, O2, acid, and base); when the cost of electricity is above a certain value, the reactor can operate in a low voltage mode (e.g., consuming less power while using an acidic solution and an alkaline solution to produce H2 and O2). In some embodiments, the system can effectively mediate the cost of electricity to produce H2: when electricity is cheap, the system uses more electricity by operating in a high voltage mode, where some of the cheap electrical energy is converted into chemical energy that can be physically stored (e.g., in the form of acidic and alkaline solutions); when electricity is expensive, the system can use less electricity by operating in a low voltage mode, where the stored chemical energy (e.g., acidic and alkaline solutions) can be used to reduce the energy required to produce H2 and O2. In some embodiments, the system can be used to reduce the cost of electricity to produce H2 and O2. In some embodiments, the system can be used to produce hydrogen and oxygen at a constant rate using electricity that fluctuates in price or availability.

[0166] Figure 7 A non-limiting example is shown in which a system uses intermittent renewable electricity to reduce the energy cost of producing H2 by 20%. In this example, the cost of renewable energy fluctuates between $0.02 / kWh and $0.07 / kWh (based on the energy production rate of a typical wind turbine on a typical day). The electricity cost of running a 1kW alkaline or PEM electrolyzer at a fixed voltage (1.2V, 32kWh / kg H2) is shown relative to time. Figure 7 According to some embodiments, Figure 7Also shown is the energy cost of a variable voltage electrolyzer operating in high voltage mode (2V, 54kWh / kgH2) when the cost of electricity is below average ($0.05 / kWh) and in low voltage mode (0.4V, 10kWh / kg H2) when the cost of electricity is above average. In this example, the two electrolyzers produce H2 at the same rate and use the same amount of energy on average (32kWh / kg H2), however, the energy cost of running the two cells is different. In this example, the variable voltage electrolyzer uses less expensive electricity (by operating in low voltage mode) and more cheap electricity (by operating in high voltage mode). In this example, the average energy cost of the fixed voltage electrolyzer is $0.05 / kWh, and the average energy cost of the variable voltage electrolyzer is $0.04 / kWh (20% less). Note that, according to some embodiments, the amount of cost savings possible in a variable voltage electrolyzer is proportional to the magnitude of the cost fluctuation: the greater the change in electricity cost, the greater the cost savings.

[0167] System 2: Exemplary system for co-production of low-cost hydrogen and acidic / alkaline solutions using intermittent renewable electricity

[0168] According to some embodiments, the system may include a reactor including a region including a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). In some embodiments, the reactor may include a first electrode and a second electrode, one or more inlets for supplying liquids and / or gases undergoing one or more electrolytic reactions, and a portion of the reactor in which a solution is stored after undergoing an electrolytic reaction or a separate device in which a solution is stored after undergoing an electrolytic reaction. In some embodiments, the electrolytic reaction may produce a pH of less than about 6 near the second electrode and a pH of greater than about 8 near the first electrode; high pH solutions and low pH solutions may be collected and stored separately. In some embodiments, the electrode may be configured to perform one or more electrolytic reactions to produce a high pH solution or a low pH solution.

[0169] In some embodiments, the electrolysis reaction can produce H2, O2, an acidic solution, and an alkaline solution. This is an example of a high voltage mode, which requires a higher voltage than a low voltage mode. A non-limiting example of an electrolysis reaction occurring in a high voltage mode is oxidation of water (2H2O→O2+4H + +4e - ) and reducing water (2H2O+2e - →H2+2OH - ); this reaction requires a minimum voltage of 2 V when the pH at the second electrode is 0 and the pH at the first electrode is 14 (see FIG. 5A to FIG. 5B). In certain embodiments, the acidic solution and the alkaline solution generated at the electrodes can be collected and stored separately.

[0170] In certain embodiments, the reactor may sometimes produce acidic and alkaline solutions in a low voltage mode requiring a lower voltage than the high voltage mode. Non-limiting examples of electrolytic reactions that produce acidic and alkaline solutions in a low voltage mode include the following.

[0171] In certain embodiments, the electrolysis reaction occurring in the low voltage mode may be oxidation of hydrogen (H2→2H + +2e - ) and reducing water (2H2O+2e - →H2+2OH - ) (e.g., HRR / HER reaction); this reaction requires a minimum voltage of 0.8 V when the pH at the second electrode is 0 and the pH at the first electrode is 14 (see FIG. 8A to FIG. 8B ).

[0172] In certain embodiments, the electrolysis reaction occurring in the low voltage mode can be oxidation of water (2H2O→O2+4H + +4e - ) and reducing oxygen (O2+2H2O+4e - →4OH - ) (e.g., OER / ORR reaction); this reaction requires a minimum voltage of 0.8 V when the pH at the second electrode is 0 and the pH at the first electrode is 14 (see FIG. 9A to FIG. 9B ).

[0173] In some embodiments, the decision to switch between high voltage mode (e.g., producing acid / base and co-producing H2 / O2) or low voltage mode (e.g., producing acid / base without producing a net amount of gas) can be based on the cost or availability of electricity, which may fluctuate throughout the day, month, or year. In certain embodiments, when the cost of electricity is below a certain value, the reactor can operate in high voltage mode (e.g., consuming more power while producing H2, O2, acid, and base). In certain embodiments, when the cost of electricity is above a certain value, the reactor can operate in low voltage mode (e.g., consuming less power, only producing acid and base).

[0174] In some embodiments, the system can take advantage of low electricity prices by co-producing H2 and O2 and acidic and alkaline solutions: when electricity is cheap, the system can use more electricity by operating in a high voltage mode, which produces acid, base, H2, and O2; when electricity is expensive, the system can use less electricity by operating in a low voltage mode, which produces acid and base, but no net amount of H2 or O2. In some embodiments, the system is used to reduce the cost of electricity to produce H2 and O2.

[0175] System 3: Exemplary system for producing low-cost acid / base at a constant rate using intermittent renewable energy

[0176] According to some embodiments, the system may include a reactor including a region including a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). In some embodiments, the reactor may include a first electrode and a second electrode, one or more inlets for supplying liquids and / or gases undergoing one or more electrolytic reactions, and a portion of the reactor in which a solution is stored after undergoing an electrolytic reaction or a separate device in which a solution is stored after undergoing an electrolytic reaction. In some embodiments, the electrolytic reaction may produce a pH of less than about 6 near the second electrode and a pH of greater than about 8 near the first electrode; high pH solutions and low pH solutions may be collected and stored separately. In some embodiments, the electrode may be configured to perform one or more electrolytic reactions to produce a high pH solution or a low pH solution.

[0177] In some embodiments, the electrolysis reaction can produce H2, O2, an acidic solution, and an alkaline solution. This is an example of an electrolysis mode because it requires a higher voltage than the fuel cell mode described later. A non-limiting example of an electrolysis reaction occurring in the electrolysis mode is oxidation of water (2H2O→O2+4H + +4e - ) and reducing water (2H2O+2e - →H2+2OH-); when the pH at the second electrode is 0 and the pH at the first electrode is 14, this reaction requires a minimum voltage of 2 V (see FIG. 5A to FIG. 5B ). In certain embodiments, the acidic solution and the alkaline solution generated at the electrodes can be collected and stored separately.

[0178] In certain embodiments, the reaction occurring in the fuel cell mode may be the oxidation of hydrogen (H2→2H + +2e - ) and reducing oxygen (O2+2H2O+4e -→4OH-) (e.g., HRR / ORR reactions); this leads to spontaneous reactions that produce energy (see FIG. 10A to FIG. 10B ).

[0179] In some embodiments, the system can effectively mediate the cost of electricity to produce acidic and alkaline solutions: when electricity is cheap, the system can use more electricity by operating in an electrolysis mode, where some of the cheap electrical energy is converted into chemical energy that can be physically stored (in the form of H2 and O2 gases); when electricity is expensive, the system can use less electricity by operating in a fuel cell mode, where the stored chemical energy (H2 and O2 gases) can be used to produce acid, base, and electricity. In some embodiments, the system is used to reduce the cost of electricity to produce acidic and alkaline solutions. In some embodiments, the system is used to produce acidic and alkaline solutions at a constant rate using electricity that fluctuates in price or availability.

[0180] In some embodiments, the chemical dissolution and / or precipitation reactions occur inside the reactor.

[0181] According to certain embodiments, the reactor comprises a spatially varying chemical composition gradient between the first electrode and the second electrode. In some embodiments, the spatially varying chemical composition gradient comprises a spatially varying pH gradient. For example, referring to Figure 2B , in some cases, the system 200 includes an alkaline region 106 near the first electrode 104 and an acidic region 107 near the second electrode 105; thus, the system 200 includes a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient) between the first electrode and the second electrode. In some embodiments, the first region includes an acidic region. In certain embodiments, the second region includes an alkaline region. In other embodiments, the first region includes an alkaline region and the second region includes an acidic region.

[0182] In some embodiments, the reactor is configured such that a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient) is established and / or maintained at least in part by electrolysis. Figure 2BIn some cases, the system 200 includes a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient), which includes an alkaline region 106 and an acidic region 107. In some such embodiments, the spatially varying chemical composition gradient (e.g., a spatially varying pH gradient) is established and / or maintained by electrolysis. According to some embodiments, the electrolysis of a neutral electrolyte can produce a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient) between electrodes (e.g., a first electrode 104 and a second electrode 105). In some embodiments, an electrolysis reaction is used to produce a chemical composition gradient between a positive electrode and a negative electrode of an electrochemical cell.

[0183] According to certain embodiments, an electrolytically generated chemical composition gradient may be employed to conduct a desired chemical reaction by feeding reactants to a chemical environment near one electrode and utilizing the electrolytically generated chemical composition gradient to produce products from the reactants as the reactants or components thereof diffuse toward another electrode.

[0184] In some embodiments, electrolysis includes hydrolysis. As used herein, hydrolysis refers to the electrolysis of water. For example, in some embodiments, the reaction occurring in the cathode converts 2 H2O molecules and 2 electrons into H2 and 2OH-, while the reaction occurring in the anode converts 2 H2O molecules into 4 electrons, O2 and 4 protons. In some embodiments, hydroxide ions are generated near the first electrode 104 to establish and / or maintain an alkaline pH near the first electrode 104, establish and / or maintain an alkaline region 106, while protons are generated near the second electrode 105 to establish an acidic pH near the second electrode 105, establish and / or maintain an acidic region 107. Therefore, in certain embodiments, the reactor is configured so that a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient) is established and / or maintained at least in part by hydrolysis.

[0185] According to certain embodiments, the reactor comprises an inlet connected to a first region (e.g., an acidic region) of a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). In certain embodiments, the electrochemical reactor and / or outlet are configured to receive a solid (e.g., CaCO3).

[0186] In some embodiments, the reactor includes a reactor outlet. In some embodiments, the reactor outlet is configured to discharge Ca (OH) 2 (for example, solid calcium hydroxide) and / or lime (CaO). In some embodiments, the reactor includes an outlet connected to a second region (for example, alkaline region) of a chemical composition gradient (for example, pH gradient) that varies spatially. In certain embodiments, the outlet is configured so that solids can be discharged from the reactor. In some embodiments, the reactor includes a solid treatment device, which is associated with the outlet and is configured to remove solids from the reactor. For example, in some embodiments, the solid treatment device is configured to remove solids (for example, solid metal hydroxides such as solid nickel hydroxide, solid calcium hydroxide or solid magnesium hydroxide) from the reactor. The example of a solid treatment device includes but is not limited to a conveyor belt, a drill, a pump, a groove or any other device that can transport solids from the reactor. In some embodiments, the solid treatment device utilizes one or a combination of fluid flow, filtration, sedimentation, centrifugal force, electrophoresis, dielectrophoresis or magnetic separation to separate solids from liquid.

[0187] In some embodiments, the reactor includes more than one reactor outlet (e.g., at least 1, at least 2, at least 3, at least 4, less than or equal to 5, less than or equal to 4, less than or equal to 3, or less than or equal to 2; combinations of these ranges are also possible). In certain embodiments, the reactor includes a second outlet.

[0188] In certain embodiments, the second outlet is configured to exhaust gas (e.g., CO2, O2, and / or H2). In some cases, CO2 is sequestered and used for liquid fuels, for oxygenated fuels, for enhanced oil recovery, for the production of dry ice, and / or as an ingredient in beverages. In some embodiments, O2 is sequestered and used as oxygenated fuels, for CCS applications, and / or for enhanced oil recovery. In some cases, H2 is sequestered and / or used as a fuel (e.g., for use in fuel cells and / or for heating systems). In some embodiments, at least a portion (e.g., at least 10%, at least 25%, at least 50%, at least 75%, at least 90%, or all) of the CO2, O2, and / or H2 exhausted by the system is fed to the kiln.

[0189] In some embodiments, the reactor includes a third outlet and / or a fourth outlet. In some cases, the second outlet, the third outlet and / or the fourth outlet are configured to discharge CO2, O2 and / or H2. For example, in some cases, the second outlet is configured to discharge CO2 and O2, and the third outlet is configured to discharge H2. In some cases, the second outlet is configured to discharge CO2, the third outlet is configured to discharge O2, and the fourth outlet is configured to discharge H2.

[0190] According to some embodiments, the reactor also includes one or more membranes that are selectively permeable to ions between the first electrode and the second electrode. In certain embodiments, the one or more membranes that are selectively permeable to ions include two membranes that are selectively permeable to ions. In certain embodiments, the two membranes that are selectively permeable to ions are different from each other.

[0191] In some embodiments, the one or more membranes that are selectively permeable to ions are configured to prevent solids from precipitating on the first electrode, to prevent solids from passivating the first electrode, and / or to prevent two different solids from contaminating each other. According to certain embodiments, the membrane that is selectively permeable to ions allows ions to pass while limiting (or excluding) the passage of solids. For example, in some embodiments, metal ions (e.g., Ca 2+ ) can pass through, while solid metal salts (e.g., solid metal carbonates, such as solid CaCO3) or precipitates (e.g., solid metal hydroxides, such as solid Ca(OH)2) are restricted (or cannot pass at all).

[0192] In some embodiments, the membrane that is selectively permeable to ions allows ions to pass through but limits (or excludes) non-ionic compounds to pass through. In certain embodiments, the membrane that is selectively permeable to ions allows ions to pass through at a first rate and allows non-ionic compounds to pass through at a second rate that is slower than the first rate. In some embodiments, the membrane that is selectively permeable to ions allows certain ions to pass through but limits (or excludes) other ions to pass through. In certain embodiments, the membrane that is selectively permeable to ions allows certain ions to pass through at a first rate and allows other ions to pass through at a second rate that is slower than the first rate. In some embodiments, the membrane that is selectively permeable to ions can allow certain metal ions to pass through but limits (or excludes) other ions to pass through (or allows certain metal ions to pass through faster than other ions), can allow H + Pass but limit (or exclude) OH - By (or allow H + OH - Faster passage), which allows OH - Pass but limit (or exclude) H + By (or allow OH - H + faster), allowing metal ions to pass but limiting (or excluding) H + and / or OH - By (or allowing metal ions to be larger than H + and / or OH - faster), and / or may allow H + and / or OH - ions but restrict (or exclude) the passage of metal ions (or allow H+ and / or OH - ions pass through faster than metal ions).

[0193] For example, in some embodiments, the selectively ion-permeable membrane is permeable to OH - ions but relatively less permeable to Ca 2+ ions, while the membrane selectively permeable to ions can pass Ca 2+ ions but relatively less permeable to OH- ions. In this example, Ca from the first region (e.g., the acidic region) 2+ The OH- ions from the second region (e.g., the alkaline region) may diffuse into the separation chamber through the membrane that is selectively permeable to ions, but may not diffuse into the second region (e.g., the alkaline region) through the membrane that is selectively permeable to ions. In addition, in this example, the OH- ions from the second region (e.g., the alkaline region) may diffuse into the separation chamber through the membrane that is selectively permeable to ions, but may not diffuse through the membrane that is selectively permeable to ions. Therefore, in this example, Ca 2+ and OH- will only be able to react in separate chambers to form solid Ca(OH)2, thereby preventing solid Ca(OH)2 from forming on the cathode or anode. Therefore, in some embodiments, one or more membranes that are selectively permeable to ions can prevent solids (e.g., solid metal hydroxides, such as solid Ca(OH)2) from precipitating on the first electrode (e.g., cathode), prevent solids (e.g., solid metal hydroxides, such as solid Ca(OH)2) from passivating the first electrode (e.g., cathode); and / or prevent two different solids - compounds (e.g., metal salts, such as solid metal carbonates, such as solid calcium carbonate) and precipitates (e.g., solid hydroxides, such as solid metal hydroxides, such as solid Ca(OH)2) from contaminating each other.

[0194] In certain embodiments, the reactor is intended to produce calcined or decomposed minerals or metal salts (e.g., metal carbonates) by electrochemical and chemical means. In some embodiments, the use of fossil fuels for generating thermal energy, and the generation of associated greenhouse gases (e.g., CO2) or gases as atmospheric pollutants, is reduced or avoided by using such a reactor instead of conventional thermal calcination involving heating a mineral or metal salt to decompose it.

[0195] Certain aspects relate to systems for producing cement. In some embodiments, the system includes a reactor. In certain embodiments, the reactor includes any one or a combination of the reactor embodiments disclosed above or disclosed elsewhere herein.

[0196] In certain embodiments, a system (e.g., any system described herein) includes a kiln. Figure 1F, in some embodiments, the system includes an electrochemical reactor and a kiln 150. Similarly, referring to Figure 2D In some embodiments, the system includes an electrochemical reactor and a kiln 150. In some embodiments, the kiln includes a kiln inlet. According to some embodiments, the kiln is directly attached to the reactor and / or device (e.g., a device configured to react an acid and / or a base in a precipitation reaction). The kiln (e.g., any kiln described herein) can be used in any system described herein.

[0197] According to some embodiments, the kiln is downstream of the reactor, reactor outlet and / or one or more devices. According to certain embodiments, the system also includes a heater between the reactor, reactor outlet and / or one or more devices and the kiln inlet. Examples of heaters include devices for heating or dehydrating materials placed inside them. In some embodiments, the reactor outlet is directly attached to the kiln inlet.

[0198] As used herein, there is direct attachment between a first unit and a second unit (and the two units are considered to be "directly attached" to each other) when the first unit and the second unit are connected to each other and the composition of the material transferred between the units does not substantially change when the material is transferred from the first unit to the second unit (i.e., no component changes in relative abundance by more than 5%). As an illustrative example, a conduit connecting the first unit and the second unit and wherein the pressure and temperature of the contents of the conduit are adjusted but the composition of the contents is not changed is considered to directly attach the first unit and the second unit. On the other hand, if a separation step is performed and / or a chemical reaction is performed so that the composition of the contents of the conduit is significantly changed during passage from the first unit to the second unit, the conduit will not be considered to directly connect the first unit and the second unit. In some embodiments, the two units that are directly attached to each other are configured so that there is no phase change of the material when the material is transferred from the first unit to the second unit.

[0199] In certain embodiments, the kiln entrance is configured to receive at least a portion of solid calcium hydroxide and / or solid calcium oxide derived from at least a portion of solid calcium hydroxide. For example, in some embodiments, calcium hydroxide is collected from a reactor, a reactor outlet, and / or more devices, and the reactor, the reactor outlet, and / or more devices are directly attached to the kiln entrance so that the kiln entrance is configured to receive at least a portion of solid calcium hydroxide. In certain embodiments, calcium hydroxide is collected from a reactor, a reactor outlet, and / or more devices, and is transported to a heater. In some embodiments, calcium hydroxide is converted into calcium oxide in whole or in part by a heater. In some embodiments, the kiln entrance is configured to receive at least a portion of solid calcium hydroxide and / or solid calcium oxide derived from at least a portion of solid calcium hydroxide from a heater.

[0200] According to some embodiments, the kiln is configured to heat Ca(OH)2 (e.g., solid calcium hydroxide) and / or lime (e.g., solid calcium oxide) and / or reaction products thereof as part of a cement manufacturing process. In some embodiments, heating Ca(OH)2 and / or lime as part of a cement manufacturing process includes heating the Ca(OH)2 and / or lime with other compounds in the kiln. For example, the Ca(OH)2 and / or lime may be heated in the kiln with SiO2 or other minerals.

[0201] In some cases, the system has lower net carbon emissions (e.g., at least 10% lower, at least 25% lower, at least 50% lower, at least 75% lower, or at least 90% lower) than a substantially similar system using conventional thermal calcination rather than an electrochemical reactor. In some cases, the system has net zero carbon emissions.

[0202] Certain aspects and methods of forming a precipitate in a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). According to some embodiments, the method is performed in a reactor and / or system as described in conjunction with any embodiment disclosed above or elsewhere herein, or a combination thereof.

[0203] According to some embodiments, the method includes delivering a compound (e.g., a metal salt) to a first region (e.g., an acidic region) of a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). In certain embodiments, the metal salt comprises a metal carbonate. According to some embodiments, the metal carbonate comprises calcium carbonate, magnesium carbonate, and / or nickel carbonate. For example, according to some embodiments, the method includes delivering calcium carbonate to a first region (e.g., an acidic region) of a spatially varying pH gradient.

[0204] According to certain embodiments, a compound (e.g., a metal salt) is dissolved and / or reacted in a liquid in a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). Non-limiting examples of liquids include non-aqueous solutions or aqueous solutions. Examples of non-aqueous solutions include solutions comprising non-aqueous solvents and electrolyte salts and / or solutions comprising ionic liquids. Examples of aqueous solutions include solutions comprising water and electrolyte salts. Examples of electrolyte salts include NaSO4 and NaClO4. In some embodiments, a compound (e.g., a metal salt) is dissolved and reacted in a liquid in a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). For example, in some embodiments, calcium carbonate is dissolved and / or reacted in a liquid in a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). In some embodiments, calcium carbonate is dissolved and reacted in a liquid in a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). For example, a compound (e.g., a metal salt) (e.g., calcium carbonate) is added to the first region (e.g., the acidic region), and the compound (e.g., the metal salt) (e.g., calcium carbonate) reacts with the protons in the first region (e.g., the acidic region), so that the compound (e.g., the metal salt) (e.g., calcium carbonate) dissolves to form one or more elements such as metals (e.g., forming Ca 2+ and HCO 3- or Ca 2+ In some embodiments, one or more elements (e.g., metals such as Ca 2+ ) moves to a second region (e.g., an alkaline region), where one or more elements react with hydroxide ions in the second region (e.g., an alkaline region) to form a precipitate (e.g., a metal precipitate, such as Ca(OH)2).

[0205] In some embodiments, the first region comprises an acidic region. In certain embodiments, the second region comprises an alkaline region. According to some embodiments, the compound (e.g., a metal salt) is dissolved in the acidic region and one or more elements (e.g., a metal, such as Ca 2+ ) in an alkaline region. In other embodiments, the first region comprises an alkaline region. In some embodiments, the second region comprises an acidic region. According to certain embodiments, the compound (e.g., a metal salt) is dissolved in an alkaline region and one or more elements (e.g., a metal, such as Ca 2+ ) reacts in an acidic region.

[0206] According to some embodiments, the method includes collecting a precipitate from a second region (e.g., an alkaline region) of a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). In certain embodiments, the precipitate includes a metal precipitate, such as a metal hydroxide. Non-limiting examples of metal hydroxides include nickel hydroxide, calcium hydroxide, and magnesium hydroxide. For example, in the examples given above, one or more elements (e.g., metals such as Ca 2+ ) moves to a second region (e.g., an alkaline region) where one or more elements react with hydroxide ions in the second region (e.g., an alkaline region) to form a precipitate (e.g., a metal precipitate, such as Ca(OH)2). Thus, in some embodiments, the method includes collecting solid calcium hydroxide from an alkaline region of a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). Non-limiting examples of ways in which one or more elements (e.g., metals) can be moved to a second region (e.g., an alkaline region) include diffusion, transport by convection, and / or transport by flow.

[0207] According to certain embodiments, the precipitate comprises one or more elements (e.g., metal) of a compound (e.g., a metal salt) dissolved and / or reacted in a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient). In some embodiments, one or more elements include metallic elements. As used herein, metal refers to a metal-containing metal (metallic metal) or a metal ion. In some embodiments, the precipitate comprises a metal cation from a metal salt dissolved and / or reacted in a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient), and the metal cation is ionically bonded to an anion in the precipitate. For example, in certain embodiments, solid calcium hydroxide comprises calcium from calcium carbonate dissolved and / or reacted in a spatially varying chemical composition gradient (e.g., a spatially varying pH gradient).

[0208] According to certain embodiments, the method is a method of making cement.

[0209] According to certain embodiments, the method includes heating Ca(OH)2 (e.g., solid calcium hydroxide) and / or lime (e.g., solid calcium oxide) and / or its reactant products in a kiln to make cement. In some embodiments, this includes taking calcium hydroxide out of a reactor and placing it directly in a kiln. Alternatively, in certain embodiments, there is a step between collecting calcium hydroxide and heating in a kiln (heater). In some embodiments, the heater converts calcium hydroxide into its calcium oxide, and then the calcium hydroxide and / or oxide calcium oxide is heated in a kiln. In some embodiments, the heater converts 100% (by weight) of calcium hydroxide into its calcium oxide and only heats the calcium oxide in a kiln. In other embodiments, the heater converts 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, up to 90%, up to 95%, or up to 99% (by weight) of calcium hydroxide into calcium oxide. Combinations of these ranges are also possible (e.g., 10% to 100% (by weight) (including end values)). In some embodiments, both calcium hydroxide and calcium oxide are heated in a kiln. Examples of heaters include devices that heat or dehydrate a substance placed therein.

[0210] In some embodiments, heating Ca(OH)2 (e.g., solid calcium hydroxide) and / or lime (e.g., solid calcium oxide) and / or its reactant products in a kiln to make cement includes heating Ca(OH)2 (e.g., solid calcium hydroxide) and / or lime (e.g., solid calcium oxide) and / or its reactant products with other compounds in a kiln. For example, Ca(OH)2 (e.g., solid calcium hydroxide) and / or lime (e.g., solid calcium oxide) and / or its reactant products can be heated with SiO2 or other minerals in a kiln.

[0211] In certain embodiments, there are subsequent steps after heating Ca(OH)2 (e.g., solid calcium hydroxide) and / or lime (e.g., solid calcium oxide) and / or its reactant products in a kiln before making cement. For example, in certain embodiments, there is a cooling step after the kiln.

[0212] According to some embodiments, the method is part of a batch process. In certain embodiments, a precipitate (e.g., a metal hydroxide, such as Ca (OH) 2) is collected regularly from a reactor. According to certain embodiments, the method is carried out continuously. In some embodiments, a compound (e.g., a metal salt, such as a metal carbonate such as CaCO 3) is added continuously or regularly at an anode and / or the first region (e.g., an acidic region). In certain embodiments, a precipitate (e.g., a metal hydroxide, such as Ca (OH) 2) is collected continuously or regularly. Non-limiting examples of collecting a precipitate (e.g., a metal hydroxide such as Ca (OH) 2) include collecting a precipitate with a flowing stream and / or allowing the precipitate to be deposited on a surface, and collecting a precipitate continuously or regularly from the surface.

[0213] According to some embodiments, the method produces byproducts other than the precipitate. For example, in some embodiments, the method produces byproducts other than solid calcium hydroxide and / or solid calcium oxide. In some embodiments, the byproducts include CO2, O2, and / or H2. For example, in some embodiments, the hydrolysis is performed in the reactor, and the reaction occurring in the cathode converts 2 H2O molecules and 2 electrons into H2(g) and 2 OH - , while the reaction occurring in the anode converts 2 H2O molecules into O2(g), 4 electrons and 4 protons. In certain embodiments, a compound (e.g., a metal salt) (e.g., a metal carbonate such as calcium carbonate) is added to the first region (e.g., an acidic region) and the compound (e.g., a metal salt) (e.g., a metal carbonate such as calcium carbonate) is reacted with the protons in the first region (e.g., an acidic region) so that the compound (e.g., a metal salt) (e.g., a metal carbonate such as calcium carbonate) dissolves to form one or more elements (e.g., metals). In some embodiments, the net reaction between CaCO3 and the two protons results in the formation of H2O, Ca 2+ and CO2(g).

[0214] According to certain embodiments, the method further comprises collecting byproducts. For example, in some embodiments, the byproducts include CO2, O2, and H2. In certain embodiments, collecting byproducts comprises collecting each of CO2, O2, and H2; collecting only CO2; collecting only O2; collecting only H2; collecting CO2 and O2; collecting CO2 and H2, or collecting O2 and H2. For example, in certain embodiments, the byproducts include CO2, and collecting byproducts comprises sequestering CO2.

[0215] According to some embodiments, the byproduct is used as a fuel. In some embodiments, H2 can be used as a fuel. Non-limiting examples include directly burning H2 or using it with a fuel such as natural gas. In some embodiments, O2 and CO2 are used to support the combustion of fuels such as fossil fuels. In some embodiments, the byproduct is used as a kiln fuel. For example, in some embodiments, O2 and CO2 are fed into a kiln to support the combustion of fuels such as fossil fuels. In certain embodiments, H2, O2 and CO2 are reacted in a fuel cell such as a solid oxide fuel cell. In certain embodiments, H2 and O2 are reacted in a fuel cell to produce electricity.

[0216] According to some embodiments, the reactor described herein, system and method show one or more beneficial characteristics and have one or more applications. For example, some embodiments of the reactor described herein, system and method can be used to produce cement (e.g., Portland cement). For example, in some embodiments, the reactor is used to replace the calcination in the conventional cement manufacturing process.

[0217] In addition, certain embodiments of the reactors, systems, and methods described herein can be used to produce cement with reduced production of atmospheric pollutants or greenhouse gases, such as CO2, compared to conventional cement manufacturing processes. Conventional cement manufacturing processes include calcining CaCO3 by thermal means, which accounts for about 60% of CO2 emissions, while about 40% of CO2 emissions are generated by the combustion of fossil fuels used to carry out the calcination process and the sintering process.

[0218] In some embodiments, Ca(OH)2 produced by the methods, reactors and / or systems described herein can be used to produce CaO for cement manufacturing, replacing conventional calcination of CaCO3 to CaO. The minimum energy requirement for thermal dehydration of Ca(OH)2 to CaO (71.2 kJ / mol) is 25% lower than thermal calcination of CaCO3 to CaO (97.0 kJ / mol).

[0219] According to certain embodiments, the reactor and / or system is partially or fully powered by renewable electricity (eg, solar, wind, and / or hydroelectricity).

[0220] According to certain embodiments, byproducts such as CO2, H2 and / or O2 are generated, which have many possible uses, including for oxyfuel combustion, improving kiln efficiency, reducing NO x The by-products may be discharged, and / or used as flue gas suitable for carbon capture and sequestration (CCS). Thus, in some embodiments, the by-products may be sold or used.

[0221] In one embodiment, the electrolysis driven chemical reactor comprises an electrolysis cell for electrolyzing water. In some embodiments, when electrolysis is performed, such a cell is at the cathode (wherein the hydrogen evolution reaction (HER) occurs and OH is produced). - ) produces a high pH at the anode, where the oxygen evolution reaction (OER) occurs and produces H + ) produces a low pH. Thus, according to certain embodiments, a pH gradient is produced between the cathode and the anode. In other such electrolytic cells, other types of gradients may be produced depending on the nature of the electrolysis reaction.

[0222] In one embodiment, the pH gradient is used to dissolve the metal carbonate at the low pH near the anode and to precipitate the metal hydroxide as the metal ions diffuse toward the higher pH environment at the cathode. In some such embodiments, as the metal carbonate dissolves near the anode, CO2 gas is produced and metal cations of the carbonate are produced in solution. According to some such embodiments, these metal cations then diffuse toward the high pH environment generated by the HER at the cathode or are optionally transported by convection or flow. According to some embodiments, the metal ions react with the OH produced at the cathode. - The reaction of ions leads to the precipitation of metal hydroxide. According to some embodiments, the electrochemical reaction and chemical reaction and the overall reaction occurring at each electrode. Almost any metal carbonate or mixture of metal carbonates can be converted into one or more hydroxides thereof by such a process, wherein the non-limiting examples of metal carbonates include CaCO , MgCO and NiCO . In some such embodiments, while producing metal hydroxides by the starting metal carbonate, hydrogen is released at the cathode and a mixture of oxygen and carbon dioxide gas is released at the anode.

[0223] In one or more embodiments, the reactor is operated in an intermittent manner, thereby regularly collecting the product metal hydroxide. In one or more embodiments, the reactor is operated in a continuous manner, so that other metal carbonates are continuously or regularly added at the anode, and the precipitated metal hydroxide is continuously or regularly removed from the reaction zone. For example, the precipitated metal hydroxide can be removed and collected from the reaction zone using a flowing stream, or the precipitate can be allowed to deposit on the surface, and the precipitate is continuously or regularly removed from the surface while the reactor is continuously operated.

[0224] In some embodiments, the hydrogen and / or oxygen produced by the electrochemical reactor is advantageously used or sold. In some embodiments, hydrogen and oxygen are reacted in a fuel cell to produce electricity. In some embodiments, hydrogen is burned as a fuel or as a component of a fuel in order to heat a reactor or a kiln or furnace.

[0225] In some embodiments, the electricity used to run the electrolysis-driven chemical reactor is generated from renewable energy sources including, but not limited to, solar, wind, or hydroelectric power.

[0226] In one embodiment, the electrochemically driven chemical reactor is used to decarbonize CaCO and produce Ca (OH) as a precursor for producing cement such as portland cement. It is useful to compare the total energy consumption of the two and consider the form of the energy consumed and its carbon intensity. For simplicity, it is assumed that the high temperature heat treatment that makes CaO react with aluminosilicate and other components to form portland cement is the same for these two processes. The energy consumption of making the CaO produced by thermal calcination of CaCO and thermal dehydration of Ca (OH) followed by electrochemical decarbonization reach the same starting temperature of 90°C has been considered. The energy / mole input for heating reactants or products to a given temperature has been calculated based on its heat capacity. The energy / mole for carrying out the decomposition reaction has been given as the standard free energy of reaction (that is, the gas partial pressure is 1 atmosphere).

[0227] In this example, the energy / mole for thermal calcination of CaCO3 is compared to the energy / mole for thermal dehydration of Ca(OH)2, which has a 25% lower minimum energy requirement of 72.1 kJ / mole versus 97.0 kJ / mole. In this example, the electrochemical process also includes a decarbonation reaction, where CaCO3 is converted to Ca(OH)2 with a standard free energy of 74.3 kJ / mole; this is an additional energy expense for the electrochemical process. However, this exemplary process, as well as the electrolysis reaction, can be powered by electricity from low-carbon or zero-carbon renewable energy sources at a near-zero marginal electricity cost.

[0228] In this exemplary process, the electrolysis reaction necessary to run the reactor requires 237.1 kJ / mole; however, this energy can firstly also be generated from low carbon sources and secondly, produces hydrogen and oxygen which can be used indirectly as value added products or can be used to power the cement manufacturing process, for example by using fuel cells to provide electricity or by providing reaction heat through a combustion process. The energy produced can be used to run the electrolyser or to heat a high temperature kiln.

[0229] In some embodiments, calcium hydroxide (also known as slaked lime) and / or calcium oxide (which reacts with water to produce slaked lime) produced herein (e.g., from a precipitation reaction) can be used in applications including, but not limited to, papermaking, flue gas treatment carbon capture, gypsum admixtures and masonry (including pozzolanic cement), soil stabilization, pH adjustment, water treatment, waste treatment, and sugar refining. The following are non-limiting examples of uses for calcium hydroxide (also known as slaked lime) and / or calcium oxide (also known as lime).

[0230] 1. Metallurgical use

[0231] a) Ferrous metals

[0232] In some embodiments, slaked lime and / or lime produced by the reactor, system and / or method disclosed herein are used to make iron and / or steel. For example, when making iron and / or steel, lime can be used as a flux to form a slag to prevent oxidation of iron and / or steel and to remove impurities such as silicon dioxide, phosphate, manganese and sulfur. In some cases, slaked lime (dried or as a slurry) is used when making iron and / or steel as a lubricant for drawing wires or rods through a die, as a coating on a casting mold to prevent adhesion, and / or as a coating on a steel product to prevent corrosion. In some cases, lime or slaked lime is also used to neutralize acidic waste.

[0233] b) Non-ferrous metals

[0234] In some embodiments, slaked lime and / or lime produced by the reactor disclosed herein, system and / or method are used to manufacture nonferrous metals including but not limited to: copper, mercury, silver, gold, zinc, nickel, lead, aluminum, uranium, magnesium and / or calcium. In some cases, lime can be used as a flux to remove impurities (e.g., silicon dioxide, aluminum oxide, phosphate, carbonate, sulfur, sulfate) from ore. For example, lime and slaked lime can be used for flotation or recovery of nonferrous metal ores. In some cases, lime acts as a sedimentation aid to maintain appropriate alkalinity and / or remove impurities (e.g., sulfur and / or silicon). In some cases, in the smelting and refining of copper, zinc, lead and / or other nonferrous metal ores, slaked lime is used to neutralize sulfur-containing gases and / or prevent the formation of sulfuric acid. In some cases, lime and / or slaked lime are also used as a coating on a metal to prevent reaction with sulfur-containing substances. In some cases, in the production of aluminum, lime and / or slaked lime are used to remove impurities (e.g., silica and / or carbonates) from bauxite ore, and / or for adjusting pH. In some cases, lime is used to maintain an alkaline pH to dissolve gold, silver, and / or nickel during cyanide extraction. In the production of zinc, lime is used as a reducing agent in some cases. In some cases, in the production of metallic calcium and / or magnesium, magnesium oxide and / or calcium oxide are reduced at high temperatures to form magnesium metal and / or calcium metal.

[0235] 2. Construction

[0236] a) Masonry (other than Portland cement)

[0237] In some embodiments, slaked lime and / or lime produced by reactors, systems and / or methods disclosed herein are used to make masonry mortar, mortar, plaster, whitewash, grout, brick, board and / or non-Portland cement. In these applications, in certain embodiments, lime and / or slaked lime can be mixed with other additives and exposed to carbon dioxide to produce calcium carbonate, lime and / or slaked lime can be reacted with other additives (e.g., aluminosilicate) to form a binder, and / or lime and / or slaked lime can be used as a calcium source. In the case of mortar, mortar, plaster and whitewash, in some cases, lime and / or slaked lime are mixed with additives and / or aggregate (e.g., sand) to form a paste / slurry, which hardens as water evaporates and as lime and / or slaked lime reacts with atmospheric carbon dioxide to form calcium carbonate. In the case of hydraulic pozzolanic cements, in some cases, lime and / or slaked lime is reacted with aluminates, silicates, and / or other pozzolanic materials (e.g., pulverized fuel ash, volcanic stone, blast furnace slag, and / or calcined clay) to form a water-based paste / slurry that hardens as insoluble calcium aluminosilicates are formed. In the case of other hydraulic cements, in some cases, lime and / or slaked lime is reacted with a silica source, an alumina source, and / or other additives at elevated temperatures to form cementitious compounds, including dicalcium silicate, calcium aluminate, tricalcium silicate, and / or monocalcium silicate. In some cases, sand-lime bricks are made by reacting slaked lime with a silica source (e.g., sand, crushed silica, and / or flint) and / or other additives at temperatures required to form calcium silicates and / or calcium silicate hydrates. In some cases, light concrete (e.g., aerated concrete (aircrete)) is made by reacting lime and / or slaked lime with active silica, aluminum powder, water, and / or other additives; the reaction between slaked lime and silicate / aluminate results in the formation of calcium silicate / calcium aluminate and / or calcium silicate hydrate, while the reaction between water, slaked lime and aluminum results in the formation of hydrogen bubbles in the hardened paste. White paint is a white paint made from a suspension of slaked lime, which hardens and solidifies as the slaked lime reacts with carbon dioxide from the atmosphere. In some cases, when the material (e.g., lime, slaked lime, silica and / or cement) forming calcium silicate and additives (e.g., cellulose fibers and / or flame retardants) and water are mixed together, cast or pressed to form, calcium silicate boards, concrete, and other cast calcium silicate products are formed. In some cases, high temperatures are used to react lime, slaked lime, and / or silica, and / or cement is hydrated.

[0238] b) Soil stability

[0239] In some embodiments, slaked lime and / or lime produced by reactor disclosed herein, system and / or method are used to stabilize soil, harden and / or dry.For example, lime and / or slaked lime can be applied to loose or fine-grained soil before building roads, runways and / or railway tracks, and / or are used to stabilize embankments and / or slopes.In some cases, when lime is applied to clay soil, pozzolanic reaction may occur between clay and lime to produce calcium silicate hydrate and / or calcium aluminate hydrate, which strengthens and / or hardens soil.In some cases, lime and / or slaked lime applied to soil can also react with carbon dioxide to produce solid calcium carbonate, which can also strengthen and / or harden soil.In some cases, because lime easily reacts with water to form slaked lime, lime can also be used to dry wet soil on construction site.

[0240] c) Asphalt additives and asphalt recovery

[0241] In some embodiments, slaked lime and / or lime produced by reactor, system and / or method disclosed herein are used to manufacture and / or recycle asphalt. For example, in some cases, slaked lime is added to hot asphalt mixture as mineral filler and / or antioxidant, and / or is used to increase water stripping resistance. In some cases, slaked lime can react with aluminosilicate and / or carbon dioxide to produce a solid product that improves the bonding between the binder and aggregate in asphalt. In some cases, as a mineral filler, lime can increase the viscosity of the binder, the rigidity of asphalt, the tensile strength of asphalt and / or the compressive strength of asphalt. In some cases, as a hydraulic road oil, lime can reduce moisture sensitivity and / or stripping, strengthen the binder so that it is rutting-resistant, and / or improve toughness and / or fracture resistance under low temperature. In some cases, lime and / or slaked lime added to recycle asphalt cause greater early strength and / or resistance to moisture damage.

[0242] 3. Waste treatment, water treatment, gas treatment

[0243] a) Gas treatment

[0244] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to remove acidic gases (e.g., hydrogen chloride, sulfur dioxide, sulfur trioxide, and / or hydrogen fluoride) and / or carbon dioxide from a gas mixture (e.g., flue gas, atmospheric air, air in a storage chamber, and / or air in a closed breathing environment such as a submarine). For example, in some cases, lime and / or slaked lime is exposed to flue gas, causing the lime and / or slaked lime to react with components of the flue gas (e.g., acidic gases, including hydrogen chloride, sulfur dioxide, and / or carbon dioxide), thereby resulting in the formation of non-gaseous calcium compounds (e.g., calcium chloride, calcium sulfite, and / or calcium carbonate). In certain embodiments, exposing the gas to slaked lime is accomplished by spraying a slaked lime solution and / or slurry into the gas, and / or by reacting the gas stream with dry lime and / or slaked lime. In certain embodiments, a gas stream comprising one or more acidic gases is first reacted with a solution of an alkali metal hydroxide (e.g., sodium hydroxide and / or potassium hydroxide) to form a soluble intermediate material (e.g., potassium carbonate), which is then reacted with lime and / or slaked lime to produce a solid calcium material (e.g., calcium carbonate) and to regenerate the original alkali metal hydroxide solution. In some embodiments, calcium carbonate formed by the reaction of lime and / or slaked lime with carbon dioxide or an alkali metal carbonate is returned to the reactor, system, and / or method disclosed herein so that the lime and / or slaked lime can be regenerated and / or so that the carbon dioxide can be sequestered.

[0245] b) Non-gaseous waste treatment

[0246] In some embodiments, slaked lime and / or lime produced by reactor disclosed herein, system and / or method are used to process waste material such as biological waste, industrial waste, wastewater and / or sludge. In some cases, lime and / or slaked lime can be applied to waste material to form an alkaline environment, which is used to neutralize acidic waste, suppress pathogens, stop flies or rodents, control odor, prevent leaching, and / or stabilize and / or precipitate pollutants (such as heavy metals, chromium, copper, and / or suspended / dissolved solids) and / or the dissolved ions (calcium ions and / or magnesium ions) causing scaling. In some cases, lime can be used to dehydrate oily waste. In some cases, slaked lime can be used to precipitate certain materials such as phosphate, nitrate and / or sulfur-containing compounds, and / or prevent leaching. In some cases, lime and / or slaked lime can be used to promote the decomposition of organic matter by keeping the alkaline conditions conducive to hydrolysis.

[0247] c) Water treatment

[0248] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to treat water. For example, in some cases, lime and / or slaked lime can be used to create an alkaline environment that is used for disinfection, removal of suspended / colloidal materials, reduction of hardness, pH adjustment, precipitation of ions that contribute to water hardness, precipitation of dissolved metals (e.g., iron, aluminum, manganese, barium, cadmium, chromium, lead, copper, and / or nickel), and / or precipitation of other ions (e.g., fluoride, sulfate, sulfite, phosphate, and / or nitrate).

[0249] 4. Agriculture and Food

[0250] -agriculture

[0251] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used in agriculture. For example, in some cases, lime and / or slaked lime can be used alone or as an additive in fertilizers to adjust the pH of soil and / or fertilizer mixtures to provide optimal growing conditions and / or improve crop yields.

[0252] -sugar

[0253] In some embodiments, slaked lime and / or lime produced by the reactor, system and / or method disclosed herein are used to refine sugar. For example, in some cases, lime and / or slaked lime are used to increase the pH of raw sugar juice, destroy enzymes in raw sugar juice, and / or react with inorganic and / or organic substances to form precipitates. In some cases, excess calcium can be precipitated with carbon dioxide. In some cases, the resulting precipitated calcium carbonate can be returned to the reactor, system and / or method disclosed herein to regenerate slaked lime.

[0254] -leather

[0255] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make leather and / or parchment. In the leather manufacturing process, in some cases, lime is used to remove hair and / or keratin from raw hides, split fibers, and / or remove fat.

[0256] -Glue, gelatin

[0257] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make glue and / or gelatin. In the process of making glue and / or gelatin, in some cases, animal bones and / or hides are soaked in slaked lime to hydrolyze collagen and other proteins, thereby forming a mixture of protein fragments of different molecular weights.

[0258] - Dairy products

[0259] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to manufacture dairy products. In some cases, slaked lime is used to neutralize the acidity of cream before pasteurization. In some cases, slaked lime is used to precipitate calcium caseinate from an acidic solution of casein. In some cases, slaked lime is added to fermented skim milk to produce calcium lactate.

[0260] -Fruit industry

[0261] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used in the fruit industry. For example, in some cases, slaked lime and / or lime are used to remove carbon dioxide from air during fruit storage. In some cases, slaked lime is used to neutralize waste citric acid and to increase the pH of juice.

[0262] - Insecticides / fungicides

[0263] In some embodiments, slaked lime and / or lime produced by the reactor, system and / or method disclosed herein is used as an additive in a fungicide and / or pesticide. For example, slaked lime can be mixed with copper sulfate to form tetracopper sulfate (pesticide). In some cases, lime can also be used as a carrier for other types of pesticides because lime forms a film on leaves when it is carbonated, thereby retaining the pesticide on the leaves. In some cases, slaked lime is used to control the infestation of starfish on oyster beds.

[0264] -food additives

[0265] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used as food additives. In some cases, lime and / or slaked lime can be used as an acidity regulator, as a pickling agent, to remove cellulose (e.g., from grains such as corn), and / or to precipitate certain anions (e.g., carbonate) from brine.

[0266] 5. Chemicals

[0267] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make chemicals. For example, lime and / or slaked lime can be used as a source of calcium and / or magnesium, an alkali, a drying agent, a causticizing agent, a saponifying agent, a binder, a flocculant and / or a precipitant, a flux, a glass forming product, an organic matter degrading agent, a lubricant, a filler and / or a hydrolyzing agent, etc.

[0268] a) Inorganic calcium compounds

[0269] -Precipitated calcium carbonate

[0270] In some embodiments, slaked lime and / or lime produced by reactor disclosed herein, system and / or method are used to manufacture precipitated calcium carbonate. In some cases, solution and / or slurry of slaked lime and / or solution of calcium ion are reacted with carbon dioxide and / or alkali carbonate so as to form the precipitate of calcium carbonate and / or magnesium carbonate. In some cases, precipitated alkali carbonate can be used as filler to reduce shrinkage, improve adhesion, increase density, change rheology and / or make plastics (such as PVC and latex), rubber, paper, paint, ink, cosmetics and / or other coatings whiten / brighten. In some cases, precipitated carbonate can be used as flame retardant or dusting agent. In some cases, precipitated calcium carbonate can be used as alkalizing agent, for agriculture, as preservative, flour additive, brewing additive, digestive aid and / or additive for asphalt products, abrasive (in cleaner, detergent, polishing agent and / or toothpaste), dispersant and / or desiccant in pest control agent.

[0271] -Calcium hypochlorite

[0272] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make calcium hypochlorite (bleaching agent) by reacting chlorine with the lime and / or slaked lime.

[0273] -Calcium carbide

[0274] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein is used to make calcium carbide (a precursor for acetylene) by reacting the lime with a carbonaceous material (e.g., coke) at high temperatures.

[0275] -Calcium phosphate

[0276] In some embodiments, slaked lime and / or lime produced by reactor disclosed herein, system and / or method are used to make calcium phosphate (monocalcium phosphate, dicalcium phosphate and / or tricalcium phosphate) by making phosphoric acid and slaked lime and / or aqueous calcium ion react with appropriate ratio. In some cases, monocalcium phosphate can be used as the additive in self-raising flour (food rich in minerals), as the stabilizer for dairy products and / or as feed additive. In some cases, dicalcium phosphate dihydrate is used in toothpaste, as gentle abrasive, for the mineral enrichment of food, as granulation aid and / or as thickener. In some cases, tricalcium phosphate is used in toothpaste, and / or as the anti-caking agent in food and / or fertilizer.

[0277] -Calcium Bromide

[0278] In some embodiments, slaked lime and / or lime produced by the reactor, system and / or method disclosed herein are used to make calcium bromide. In some cases, this is accomplished by reacting lime and / or slaked lime with hydrobromic acid and / or bromine and a reducing agent (e.g., formic acid and / or formaldehyde).

[0279] -Calcium ferrocyanide

[0280] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make calcium ferrocyanide by reacting lime and / or slaked lime with hydrogen cyanide in an aqueous solution of ferrous chloride. The calcium ferrocyanide can then be converted to an alkali metal salt or hexacyanoferrate. These are used as pigments and anti-caking agents.

[0281] -Silicon Calcium

[0282] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make calcium silicate by reacting lime, quartz and / or carbonaceous materials at high temperatures. In some cases, calcium silicate is used as a deoxidizer, as a desulfurizer and / or for modifying non-metallic inclusions in ferrous metals.

[0283] -Calcium dichromate

[0284] In some embodiments, slaked lime and / or lime produced by the reactors, systems, and / or methods disclosed herein is used to make calcium dichromate by roasting chromate ore with lime.

[0285] -Calcium tungstate

[0286] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein is used to make calcium tungstate by reacting the lime and / or slaked lime with sodium tungstate for use in producing ferrotungsten and / or phosphors for use in items such as lasers, fluorescent lamps, and / or oscilloscopes.

[0287] b) Organic calcium compounds

[0288] -Calcium Citrate

[0289] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make calcium citrate by reacting lime and / or slaked lime with citric acid. In some cases, calcium citrate can be reacted with sulfuric acid to regenerate pure citric acid.

[0290] - Calcium soap

[0291] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make lime soaps by reacting slaked lime with fatty acids, wax acids, unsaturated carboxylic acids (e.g., oleic acid, linoleic acid, ethylhexanoate acid), cyclohexane acids, and / or resin acids. In some cases, the lime soaps are used as lubricants, stabilizers, mold release agents, waterproofing agents, additives in coatings and / or printing inks.

[0292] -Calcium lactate

[0293] In some embodiments, slaked lime and / or lime produced by the reactor, system and / or method disclosed herein are used to make calcium lactate by reacting slaked lime with lactic acid. In some cases, lactic acid can be reacted with sulfuric acid in a second step to produce pure lactic acid. In some cases, these chemicals serve as coagulants and foaming agents. In some cases, calcium lactate is used as a calcium source in medicaments and / or foods, and / or as a buffer.

[0294] -Calcium tartrate

[0295] In some embodiments, slaked lime and / or lime produced by the reactor, system and / or method disclosed herein is used to make calcium tartrate by reacting slaked lime with alkaline bitartrate. In some cases, calcium tartrate can be reacted with sulfuric acid in a second step to produce pure tartaric acid. In some cases, tartaric acid is used in food, pharmaceutical preparations, and / or as an additive in plasters and / or metal polishes.

[0296] c) Inorganic chemicals

[0297] -Alumina

[0298] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make alumina. In the preparation of alumina, lime is used to precipitate impurities (e.g., silicates, carbonates and / or phosphates) from the bauxite ore being processed.

[0299] - Alkali metal carbonates and alkali metal bicarbonates

[0300] In some embodiments, slaked lime and / or lime produced by the reactor, system and / or method disclosed herein are used to make alkali carbonate and / or alkali bicarbonate from alkali chloride in the ammonia-soda process. In the method, in some cases, after the ammonia (and / or amine) reacts with the alkali chloride, the lime and / or slaked lime is reacted with ammonium chloride (and / or ammonium chloride, such as isopropylammonium chloride) to regenerate the ammonia (and / or amine, such as isopropylamine). In some cases, the resulting calcium chloride can be reacted with an alkaline stream from the reactor, system and / or method disclosed herein to regenerate slaked lime.

[0301] - Strontium carbonate

[0302] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make strontium carbonate. In some cases, lime and / or slaked lime are used to regenerate ammonia from ammonium sulfate, which is formed after ammonia is carbonated and reacted with strontium sulfate.

[0303] -Calcium zirconate

[0304] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make calcium zirconate. In some cases, lime and / or slaked lime is reacted with zircon (ZrSiO4) to produce calcium silicate and calcium zirconate, which are further purified.

[0305] -Alkali metal hydroxide

[0306] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make alkali hydroxide from alkali carbonates in a process generally referred to as causticizing or recausticizing. In some cases, slaked lime is reacted with alkali carbonate to produce alkali hydroxide and calcium carbonate. In some cases, the process of causticizing alkali carbonates is a feature of several other processes including purification of bauxite ore, processing of phenol oils, and Kraft liquor circulation (wherein "green liquor" containing sodium carbonate is reacted with slaked lime to form "white liquor" containing sodium hydroxide).

[0307] -Magnesium hydroxide

[0308] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make magnesium hydroxide. In some cases, adding slaked lime to a solution containing magnesium ions (e.g., seawater and / or brine solution) causes magnesium hydroxide to precipitate from the solution.

[0309] d) Organic chemicals

[0310] -Olefin oxide.

[0311] In some embodiments, slaked lime and / or lime produced by reactor, system and / or method disclosed herein are used to make olefin oxide. In some cases, lime is used to saponify propyl chloroethanol and / or butyl chloroethanol or remove hydrogen chloride to produce corresponding oxide. In some cases, oxide can then be converted into glycol by acidic hydrolysis.

[0312] -Diacetone alcohol.

[0313] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make diacetone alcohol. In some cases, slaked lime is used as an alkaline catalyst to promote the self-condensation of acetone to form diacetone alcohol, which is used as a solvent for resins, and / or as an intermediate in the production of mesityl oxide, methyl isobutyl ketone, and / or hexylene glycol.

[0314] -Neopentyl glycol hydroxypivalate, pentaerythritol.

[0315] In some embodiments, slaked lime and / or lime produced by the reactors, systems, and / or methods disclosed herein is used as an alkaline catalyst to produce neopentyl glycol hydroxypivalate and / or pentaerythritol.

[0316] -Anthraquinone dyes and intermediates.

[0317] In some embodiments, slaked lime and / or lime produced by the reactors, systems, and / or methods disclosed herein is used as an alkaline agent to replace sulfonic acid groups with hydroxides in the manufacture of anthraquinone dyes and / or intermediates.

[0318] -Trichloroethylene

[0319] In some embodiments, hydrated lime and / or lime produced by the reactors, systems and / or methods disclosed herein is used to remove chlorine from tetrachloroethane to form trichloroethylene.

[0320] 6. Miscellaneous uses

[0321] -Silicon dioxide, silicon carbide and zirconium oxide refractories.

[0322] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used as a binder, adhesive and / or stabilizer in the manufacture of silica, silicon carbide and / or zirconia refractories.

[0323] -Lime glass.

[0324] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used as a source of lime in soda-lime glassmaking. In some cases, lime and / or slaked lime are heated to a high temperature along with other raw materials including silicon dioxide, sodium carbonate and / or additives such as aluminum oxide and / or magnesium oxide. In some cases, the molten mixture forms glass after cooling.

[0325] -White earthenware and enamel.

[0326] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used to make white pottery and / or enamel. In some cases, slaked lime is blended with clay to act as a flux, a glass former to help bind the material, and / or to increase the whiteness of the final product.

[0327] -Lubricants for casting and drawing.

[0328] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used as lubricants for casting and / or drawing of materials such as iron, aluminum, copper, steel and / or precious metals. In some cases, calcium-based lubricants can be used at high temperatures to prevent metal from sticking to the mold. In some cases, the lubricant can be a blend of lime and other materials including silica, alumina, carbon and / or fluxing agents such as fluorite and / or alkali metal oxides, calcium soaps. In some cases, slaked lime is used as a lubricant carrier. In some cases, slaked lime is bonded to the surface of the wire to increase surface roughness and / or improve adhesion of the drawing compound.

[0329] -Drilling mud.

[0330] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used in drilling mud formulations to maintain high alkalinity and / or to keep clay in a non-plastic state. In some cases, drilling mud can be pumped through a hollow drill pipe when drilling through rock for oil and gas. In some cases, the drilling mud carries rock fragments generated by the drill bit to the surface.

[0331] -Oil additives and greases.

[0332] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used as oil additives and / or greases. In some cases, lime is reacted with alkylphenols and / or organic sulfonates to make calcium soaps, which are blended with other additives to make oil additives and / or greases. In some cases, lime-based additives prevent sludge buildup and reduce the acidity of products from combustion, especially at high temperatures.

[0333] -Pulp and paper

[0334] In some embodiments, slaked lime and / or lime produced by the reactor, system and / or method disclosed herein are used in the pulp and / or paper industry. For example, slaked lime is used in the kraft process (Kraft) to re-causticize sodium carbonate into sodium hydroxide. In some cases, the calcium carbonate formed by the reaction can be returned to the reactor, system and / or method disclosed herein to regenerate slaked lime. In some cases, slaked lime can also be used as an alkali source in sulfite pulping to prepare liquid (liquor). In some cases, slaked lime is added to sulfurous acid solution to form acid sulfite. In some cases, a mixture of sulfurous acid and acid sulfite is used to cook pulp. In some cases, slaked lime can also be used to precipitate calcium lignin sulfonate from sulfite waste liquor.

[0335] -aquarium

[0336] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein is used as a source of calcium and / or alkalinity for marine aquariums and / or reef growth.

[0337] -Methods of storing heat

[0338] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used for thermochemical energy storage (e.g., for self-heating food containers and / or for solar thermal storage).

[0339] -Flame retardant

[0340] In some embodiments, calcium hydroxide and / or magnesium hydroxide produced by the reactors, systems, and / or methods disclosed herein are used as flame retardants, cable insulation, and / or additives for plastic insulation.

[0341] - Antimicrobial agents

[0342] In some embodiments, slaked lime and / or lime produced by the reactors, systems and / or methods disclosed herein are used as antimicrobial agents. For example, in some cases, lime and / or slaked lime are used to treat disease-contaminated areas, such as walls, floors, bedding and / or animal housing.

[0343] The following examples are intended to illustrate certain embodiments of the invention, but are not intended to illustrate the full scope of the invention.

[0344] Example 1

[0345] This example describes the system operating in a first mode, where the produced acid and base are collected.

[0346] Nearly neutral 1M Na2SO4 solution was fed to the anode (made of carbon felt) and cathode (also carbon felt) of the flow cell at a rate of 10 mL / min, and then the solution was taken out from the anode and cathode. When a voltage of 2.5 V was applied to the cell, the pH of the solution from the anode was 1.5, and the pH of the solution from the cathode was 12.5.

[0347] Example 2

[0348] This example describes a system operating in a first mode, where the generated acid and base are collected and reacted.

[0349] A hydrolysis reaction is carried out in an electrochemical cell comprising a first electrode and a second electrode, so that a base and hydrogen are produced at the first electrode (cathode) and an acid and oxygen are produced at the second electrode (anode). The base is collected from the reactor by a conduit into a first device connected to the reactor fluid, and the base is stored in the device. The acid is collected from the reactor by a conduit into a second device connected to the reactor fluid, and the acid is stored in the device.

[0350] When needed, the base is transferred to a third device fluidically connected to the first device, and the acid is transferred to a fourth device fluidically connected to the second device. The acid is then used in the fourth device to dissolve CaCO3 in a chemical solution to form CaCO3. 2+ Ions and CO3 2- ions. Then Ca 2+ The ions are transported to a third device (which is fluidly connected to a fourth device) where a base is reacted with Ca 2+ ions are used together for precipitation reaction to form Ca(OH) 2. Ca(OH) 2 can optionally be used in cement manufacturing process, for example, using kilns and / or heaters.

[0351] Example 3

[0352] This embodiment describes a system operating in a first mode, wherein generated oxygen and hydrogen are transported and reduced and oxidized, respectively.

[0353] A hydrolysis reaction is performed in an electrochemical cell comprising a first electrode and a second electrode, so that a base and hydrogen are produced at the first electrode (cathode) and an acid and oxygen are produced at the second electrode (anode). Hydrogen is transported from the cathode to the anode through a conduit, where the hydrogen is oxidized to produce an acid. The production of acid further reduces the pH at the anode. Oxygen is transported from the anode to the cathode through a conduit, where the oxygen is reduced to produce a base. The production of the base further increases the pH at the cathode.

[0354] In some such systems or methods, the acid and base are optionally collected and / or reacted as described in Example 1.

[0355] Example 4

[0356] This embodiment describes a system operating in a first mode, where the generated oxygen and hydrogen can be collected and sold or used, or recombined to form water.

[0357] The hydrolysis reaction is carried out in an electrochemical cell comprising a first electrode and a second electrode, so that a base and hydrogen are produced at the first electrode (cathode) and an acid and oxygen are produced at the second electrode (anode). The hydrogen and oxygen can be collected and sold or used, or if the production of gas is not desired, they are recombined to form water.

[0358] Example 5

[0359] This embodiment describes a system that operates alternately in a first mode and a second mode.

[0360] The system or method of Example 1 is used in periods of low electricity cost and / or high electricity availability, but some or all of the acid and base are stored rather than used in chemical dissolution and / or precipitation reactions. When electricity costs increase and / or become less available, the system is switched to a second mode in which the polarity of the electrodes is opposite to that in Example 1. The stored base from Example 1 is then added to the anode, where the base is oxidized to form oxygen. The stored acid is then added to the cathode, where the acid is reduced to produce hydrogen. Hydrogen and oxygen may optionally be collected and sold or used.

[0361] Example 6

[0362] This example describes the operation of a system comprising two reactors to produce acid and base that can be used in chemical dissolution and / or precipitation reactions.

[0363] Operation comprises the system of two reactors connected with fluid.The first reactor produces alkali, dihalide (for example, Cl2) and hydrogen.The first reactor is connected with the second reactor fluid, and the hydrogen and dihalide produced in the first reactor are transported to the second reactor.Water is also added in the second reactor, and the second reactor produces acid (for example, HCl).

[0364] The base is collected from the first reactor by the first device and the acid is collected from the second reactor by the second device. The acid is used for chemical dissolution in the second device, for example, solid CaCO3 to Ca 2+ Ions and CO3 2- The second device is fluidically connected to the first device, and the Ca from the second device is 2+The ions are transported to a first device where they react with a base in a precipitation reaction to form Ca(OH) 2. The Ca(OH) 2 can optionally be used in a cement manufacturing process, for example using a kiln and / or a heater.

[0365] Although several embodiments of the present invention have been described and illustrated herein, a person of ordinary skill in the art will readily conceive of a variety of other ways and / or structures for performing the functions described herein and / or obtaining the results and / or one or more advantages described herein, and each such variation and / or modification is considered to be within the scope of the present invention. More generally, it will be readily understood by those skilled in the art that all parameters, dimensions, materials, and configurations described herein are intended to be exemplary, and that the actual parameters, dimensions, materials, and / or configurations will depend on the specific one or more applications for which the teachings of the present invention are used. Those skilled in the art will recognize or be able to determine many equivalents of the specific embodiments of the present invention described herein using only routine experiments. Therefore, it should be understood that the foregoing embodiments are given only as examples, and within the scope of the appended claims and their equivalents, the present invention can be implemented in a manner other than specifically described and claimed. The present invention relates 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 is included within the scope of the present invention if such features, systems, articles, materials, and / or methods do not contradict each other.

[0366] Unless explicitly stated to the contrary, the indefinite articles "a" or "an" as used herein in the specification and claims should be understood to mean "at least one."

[0367] The phrase "and / or" as used herein in the specification and claims should be understood to mean "either or both" of the elements so combined, i.e., elements that are present together in some cases and separately in other cases. Unless expressly indicated to the contrary, other elements may optionally be present in addition to the elements specifically identified by the "and / or" clause, whether related or unrelated to those specifically identified. Thus, as a non-limiting example, when used in conjunction with open language such as "comprising," a reference to "A and / or B" may refer to A without B (optionally including elements other than B) in one embodiment; to B without A (optionally including elements other than A) in another embodiment; to both A and B (optionally including other elements) in yet another embodiment; and so on.

[0368] As used herein in the specification and 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" should be interpreted as inclusive, i.e., including at least one of a plurality of elements or a list of elements, but also including more than one, and optional additional unlisted items. Only explicitly indicating the opposite term, such as "only one" or "exactly one" or when used in the claims, "consisting of..." will refer to including exactly one element in a plurality of elements or a list of elements. Usually, when there is an exclusive term (such as "either", "one", "only one" or "exactly one") in front, the term "or" as used herein should only be interpreted as indicating an exclusive alternative (i.e., "one or the other, but not both"). When used in the claims, "essentially consisting of..." should have its usual meaning as used in the field of patent law.

[0369] As used herein in the specification and claims, the phrase "at least one" when referring to a list of one or more elements should be understood to mean at least one element selected from any one or more elements in the list of elements, but does not necessarily include at least one of each element specifically listed in the list of elements, nor exclude any combination of elements in the list of elements. This definition also allows that elements other than the elements specifically identified in the list of elements referred to by the phrase "at least one" may optionally be present, 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") may refer to at least one A, optionally including more than one A, without B (and optionally including elements other than B) in one embodiment; to at least one B, optionally including more than one B, without A (and optionally including elements other than A) in another embodiment; to at least one A, optionally including more than one A, and at least one B, optionally including more than one B (and optionally including other elements) in yet another embodiment; and so on.

[0370] In the claims and in the foregoing description, all transitional phrases such as "comprising," "including," "with," "having," "containing," "involving," "maintaining," and the like shall be construed as open ended, i.e., meaning including, but not limited to. Only the transitional phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed transitional phrases, respectively, as set forth in Section 2111.03 of the U.S. Patent Office Manual of Patent Examining Procedures.

[0371] 1. A method comprising:

[0372] operating the reactor in a first mode;

[0373] The first mode includes:

[0374] generating a base from a first electrode;

[0375] generating an acid from a second electrode electrochemically coupled to the first electrode in the reactor; and

[0376] The acid and / or the base are collected.

[0377] 2. The method according to item 1 also includes reacting the collected acid and / or base in a chemical dissolution and / or in a precipitation reaction.

[0378] 3. A method comprising:

[0379] operating the reactor in a first mode;

[0380] The first mode includes:

[0381] generating a base from a first electrode;

[0382] generating an acid from a second electrode electrochemically coupled to the first electrode in the reactor;

[0383] collecting the acid and / or the base; and

[0384] The collected acid and / or base is reacted in a chemical dissolution and / or in a precipitation reaction.

[0385] 4. A method according to any one of items 1 to 3, wherein the first mode comprises generating oxygen by the second electrode.

[0386] 5. A method according to any one of items 1 to 4, wherein the first mode comprises generating hydrogen gas by the first electrode.

[0387] 6. A method comprising:

[0388] operating the reactor in a first mode;

[0389] The first mode includes:

[0390] generating alkali and hydrogen gas from the first electrode;

[0391] generating acid and oxygen gas from a second electrode electrochemically coupled to the first electrode in the reactor; and

[0392] allowing the oxygen to diffuse and / or be transported to the first electrode and / or allowing the hydrogen to diffuse and / or be transported to the second electrode; and

[0393] The oxygen is allowed to be reduced through the first electrode and / or the hydrogen is allowed to be oxidized through the second electrode.

[0394] 7. The method according to item 6 also includes collecting the acid and / or the base.

[0395] 8. The method according to any one of items 6 to 7 further comprises reacting the collected acid and / or base in a chemical dissolution and / or in a precipitation reaction.

[0396] 9. The method of any one of items 4 to 8, wherein generating an acid by the second electrode and generating oxygen by the second electrode comprises oxidizing water by the second electrode to generate oxygen and an acid.

[0397] 10. The method of any one of items 5 to 9, wherein generating a base by the first electrode and generating hydrogen by the first electrode comprises reducing water by the first electrode to generate hydrogen and a base.

[0398] 11. A method according to any preceding clause, comprising collecting the acid.

[0399] 12. The method according to any of the preceding clauses, comprising collecting the base.

[0400] 13. A method according to any of the preceding clauses, comprising reacting the collected acid in a chemical dissolution.

[0401] 14. A method according to any one of the preceding items, comprising reacting the collected base in a precipitation reaction.

[0402] 15. The method according to any of the preceding clauses, further comprising storing the acid and / or the base.

[0403] 16. A method according to any preceding clause, comprising storing the acid.

[0404] 17. The method according to any of the preceding clauses, comprising storing the base.

[0405] 18. The method according to any of the preceding clauses, further comprising operating the reactor in a second mode, wherein the polarity of the reactor in the second mode is opposite compared to the polarity of the reactor in the first mode.

[0406] 19. A method according to claim 18, wherein the cost of electricity for operating the reactor in the first mode is a first cost and the availability of electricity for operating the reactor in the first mode is a first availability, wherein the cost of electricity for operating the reactor in the second mode is a second cost and the availability of electricity for operating the reactor in the second mode is a second availability, and wherein the second cost is greater than the first cost and / or the first availability is greater than the second availability.

[0407] 20. A method according to any one of items 18 to 19, wherein the second mode comprises adding stored base to the reactor in the vicinity of the second electrode.

[0408] 21. A method according to any one of items 18 to 20, wherein the second mode comprises oxidizing the stored base near the second electrode to produce oxygen.

[0409] 22. A method according to any one of items 18 to 21, wherein the second mode comprises adding stored acid to the reactor near the first electrode.

[0410] 23. A method according to any one of items 18 to 22, wherein the second mode comprises reducing the stored acid near the first electrode to produce hydrogen.

[0411] 24. A method according to any one of items 5 to 23, comprising oxidizing the hydrogen by means of the second electrode.

[0412] 25. A method according to any one of items 5 to 24, comprising oxidizing the hydrogen gas to produce an acid via the second electrode.

[0413] 26. A method according to any one of items 5 to 25, wherein the hydrogen is allowed to diffuse from the vicinity of the first electrode to the vicinity of the second electrode.

[0414] 27. A method according to any one of items 5 to 26, wherein the hydrogen is transported from the vicinity of the first electrode to the vicinity of the second electrode.

[0415] 28. A method according to any one of items 1 to 3, 5 and 9 to 27, wherein the method does not produce oxygen.

[0416] 29. A method according to any one of the preceding clauses, wherein the method does not produce net hydrogen.

[0417] 30. A method according to any one of items 4 to 27 and 29, comprising reducing the oxygen by the first electrode.

[0418] 31. A method according to any one of items 4 to 27 and 29 to 30, comprising reducing the oxygen by the first electrode to produce a base.

[0419] 32. A method according to any one of items 4 to 27 and 29 to 31, wherein the oxygen is allowed to diffuse from the vicinity of the second electrode to the vicinity of the first electrode.

[0420] 33. A method according to any one of items 4 to 27 and 29 to 32, wherein the oxygen is transported from the vicinity of the second electrode to the vicinity of the first electrode.

[0421] 34. A method according to any one of items 1 to 4 and 9 to 33, wherein the method does not produce hydrogen.

[0422] 35. A method according to any of the preceding clauses, wherein the method does not produce net oxygen.

[0423] 36. A method according to any one of items 2 to 5 and 8 to 35, wherein the chemical dissolution comprises chemical dissolution of a metal, a metal alloy, a metalloid, a metal salt, a metal oxide, and / or a silicate.

[0424] 37. A method according to claim 36, wherein the metal and / or the metal alloy comprises iron, iron-based alloys, stainless steel, non-ferrous metals, non-ferrous alloys, aluminum, brass, bronze, copper, zinc, tin, and / or coin alloys.

[0425] 38. A method according to any one of items 36 to 37, wherein the metal oxide comprises calcium oxide, magnesium oxide, strontium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, zinc oxide, cadmium oxide, lead oxide, silicon dioxide, and / or aluminum oxide.

[0426] 39. A method according to any one of items 36 to 38, wherein the metal salt comprises a metal carbonate.

[0427] 40. A method according to claim 39, wherein the metal carbonate comprises calcium carbonate, magnesium carbonate, barium carbonate, strontium carbonate, manganese carbonate, iron carbonate, cobalt carbonate, zinc carbonate, cadmium carbonate, lead carbonate, and / or nickel carbonate.

[0428] 41. A method according to any one of items 2 to 5 and 8 to 35, wherein the precipitation reaction comprises precipitating a metal hydroxide.

[0429] 42. A method according to claim 41, wherein the metal hydroxide comprises calcium hydroxide, magnesium hydroxide, barium hydroxide, strontium hydroxide, manganese hydroxide, iron hydroxide, cobalt hydroxide, zinc hydroxide, cadmium hydroxide, lead hydroxide, and / or nickel hydroxide.

[0430] 43. The method according to any of the preceding clauses, wherein the concentration of the acid is greater than or equal to 0.00001M.

[0431] 44. A method according to any of the preceding clauses, wherein the concentration of the acid is greater than or equal to 1M.

[0432] 45. The method according to any of the preceding clauses, wherein the concentration of the acid is less than or equal to 10M.

[0433] 46. ​​The method according to any of the preceding items, wherein the concentration of the base is greater than or equal to 0.00001M.

[0434] 47. A method according to any of the preceding items, wherein the concentration of the base is greater than or equal to 1M.

[0435] 48. The method according to any of the preceding items, wherein the concentration of the base is less than or equal to 10M.

[0436] 49. A method according to any of the preceding items, wherein the pH near the second electrode is less than or equal to 6.

[0437] 50. A method according to any of the preceding items, wherein the pH near the first electrode is greater than or equal to 8.

[0438] 51. A method according to any of the preceding items, wherein the Nernst potential at the second electrode is greater than or equal to -0.4 V relative to a standard hydrogen electrode.

[0439] 52. A method according to any of the preceding items, wherein the Nernst potential at the second electrode is greater than or equal to 0.8 V relative to a standard hydrogen electrode.

[0440] 53. A method according to any of the preceding items, wherein the Nernst potential at the first electrode is less than or equal to 0.8 V relative to a standard hydrogen electrode.

[0441] 54. A method according to any of the preceding items, wherein the Nernst potential at the first electrode is less than or equal to -0.4 V relative to a standard hydrogen electrode.

[0442] 55. A method according to any one of items 2 to 5 and 8 to 54, wherein operating the reactor in the first mode is intermittent, and reacting the collected acid and / or base in a chemical dissolution and / or in a precipitation reaction is continuous.

[0443] 56. A method according to any of the preceding clauses, comprising adding a near-neutral input solution to the reactor.

[0444] 57. A method according to claim 56, wherein the near-neutral input solution comprises salt.

[0445] 58. A method according to claim 57, wherein the salt comprises an alkali metal sulfate, an alkali metal chlorate, an alkali metal halide, an alkali metal nitrate, an alkali metal perchlorate, an alkali metal acetate, an alkali metal nitrite, and / or an alkali metal triflate.

[0446] 59. A method according to any of the preceding items, comprising reacting the collected base in a chemical dissolution.

[0447] 60. A method according to any of the preceding items, comprising reacting the collected acid in a precipitation reaction.

[0448] 61. A system comprising:

[0449] a first electrode;

[0450] a second electrode electrochemically coupled to the first electrode; and

[0451] A device is configured to collect acidic products near the second electrode and / or alkaline products near the first electrode.

[0452] 62. A system comprising:

[0453] a first electrode;

[0454] a second electrode electrochemically coupled to the first electrode;

[0455] a first device configured to collect acidic products near the second electrode and / or alkaline products near the first electrode; and

[0456] A second device is configured to react the collected acidic product and / or the collected basic product.

[0457] 63. A system according to any one of items 61 to 62, wherein the first electrode is configured to produce alkali and / or hydrogen.

[0458] 64. A system according to any one of items 61 to 63, wherein the second electrode is configured to produce acid and / or oxygen.

[0459] 65. A system according to any one of items 61 to 64, wherein the system is configured to allow oxygen to diffuse and / or be delivered to the first electrode and / or to allow hydrogen to diffuse and / or be delivered to the second electrode.

[0460] 66. A system according to any one of items 61 to 65, wherein the system is configured to allow the oxygen to be reduced through the first electrode and / or to allow the hydrogen to be oxidized through the second electrode.

[0461] 67. A system comprising:

[0462] a first electrode configured to generate an alkali and hydrogen gas; and

[0463] a second electrode electrochemically coupled to the first electrode and configured to generate acid and oxygen;

[0464] wherein the system is configured to allow oxygen to diffuse and / or be delivered to the first electrode and / or to allow hydrogen to diffuse and / or be delivered to the second electrode; and

[0465] The system is configured to allow the oxygen to be reduced through the first electrode and / or to allow the hydrogen to be oxidized through the second electrode.

[0466] 68. The system of claim 67, further comprising a device configured to collect acidic products near the second electrode and / or alkaline products near the first electrode.

[0467] 69. The system according to any one of items 61 to 68 further includes a separator configured to allow oxygen generated at the second electrode to diffuse to the first electrode and / or allow hydrogen generated at the first electrode to diffuse to the second electrode.

[0468] 70. The system according to any one of items 61, 63 to 66 and 68 to 69, further comprising a second device configured to react the collected acidic product and / or the collected alkaline product in a chemical dissolution and / or in a precipitation reaction.

[0469] 71. A system according to any one of items 62 to 66 and 70, wherein the second device is configured to react the collected acidic product and / or the collected alkaline product in a chemical dissolution.

[0470] 72. A system according to any one of items 62 to 66 and 70 to 71, wherein the second device is configured to react the collected acidic product and / or the collected alkaline product in a precipitation reaction.

[0471] 73. A system according to any one of items 61 to 66 and 69 to 72, wherein the second electrode is configured to produce an acid.

[0472] 74. A system according to any one of items 61 to 66 and 69 to 73, wherein the second electrode is configured to produce oxygen.

[0473] 75. A system according to any one of items 61 to 66 and 69 to 74, wherein the first electrode is configured to produce a base.

[0474] 76. A system according to any one of items 61 to 66 and 69 to 75, wherein the first electrode is configured to produce hydrogen.

[0475] 77. A system according to any one of items 64 to 76, wherein the system is configured to allow oxygen to diffuse to the first electrode.

[0476] 78. A system according to any one of items 63 to 77, wherein the system is configured to allow hydrogen to diffuse to the second electrode.

[0477] 79. A system according to any one of items 64 to 78, wherein the system is configured to allow the oxygen to be reduced through the first electrode.

[0478] 80. A system according to any one of items 63 to 79, wherein the system is configured to allow the hydrogen to be oxidized through the second electrode.

[0479] 81. A system according to any one of items 61 to 80, wherein the device is configured to collect the acidic output near the second electrode.

[0480] 82. A system according to any one of items 61 to 81, wherein the device is configured to collect the alkaline product near the first electrode.

[0481] 83. A system according to any one of items 61 to 82, comprising a device configured to store the acid and / or the base.

[0482] 84. A system according to any one of items 61 to 83, comprising a device configured to store the acid.

[0483] 85. A system according to any one of items 61 to 84, comprising a device configured to store the base.

[0484] 86. A system according to any one of items 61 to 85, wherein the system is configured to enable addition of a base in the vicinity of the second electrode.

[0485] 87. A system according to any one of items 61 to 86, wherein the system is configured to oxidize the base to produce oxygen through the second electrode.

[0486] 88. A system according to any one of items 61 to 87, wherein the system is configured to enable addition of acid near the first electrode.

[0487] 89. A system according to any one of items 61 to 88, wherein the system is configured to reduce the acid to produce hydrogen through the second electrode.

[0488] 90. A system according to any one of items 63 to 89, wherein the system is configured to oxidize the hydrogen gas to produce an acid via the second electrode.

[0489] 91. A system according to any one of items 63 to 90, wherein the system is configured to allow the hydrogen to be transported from near the first electrode to near the second electrode.

[0490] 92. A system according to any one of items 61 to 66, 69 to 73, 75 to 86 and 88 to 91, wherein the system is configured not to produce oxygen.

[0491] 93. A system according to any one of items 61 to 92, wherein the system is configured to produce no net hydrogen.

[0492] 94. A system according to any one of items 64 to 91 and 93, wherein the system is configured to reduce the oxygen through the first electrode to produce a base.

[0493] 95. A system according to any one of items 64 to 91 and 93 to 94, wherein the system is configured to allow the oxygen to be transported from the vicinity of the second electrode to the vicinity of the first electrode.

[0494] 96. A system according to any one of items 61 to 66, 69 to 75, 77 to 88 and 90 to 95, wherein the system is configured not to produce hydrogen.

[0495] 97. A system according to any one of items 61 to 96, wherein the system is configured to produce no net oxygen.

[0496] 98. A method comprising:

[0497] producing a base and a dihalide in a first reactor;

[0498] generating an acid in a second reactor;

[0499] collecting the acid;

[0500] collecting the base;

[0501] Chemical dissolution with the acid and / or the base; and

[0502] The precipitation reaction is carried out using the acid and / or the base.

[0503] 99. The method according to claim 98 includes producing hydrogen in the first reactor.

[0504] 100. A method according to any one of items 98 to 99, comprising feeding a neutral pH alkali metal halide by-product from the precipitation reaction into the first reactor.

[0505] 101. A method according to any one of items 98 to 100, comprising storing the acid and / or the base.

[0506] 102. A method according to any one of items 98 to 101, wherein the chemical dissolution comprises chemical dissolution of metals, metal alloys, metalloids, metal salts, metal oxides, and / or silicates.

[0507] 103. A method according to item 102, wherein the metal and / or the metal alloy comprises iron, iron-based alloys, stainless steel, non-ferrous metals, non-ferrous alloys, aluminum, brass, bronze, copper, zinc, tin, and / or coin alloys.

[0508] 104. A method according to any one of items 102 to 103, wherein the metal oxide comprises calcium oxide, magnesium oxide, strontium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, zinc oxide, cadmium oxide, lead oxide, silicon dioxide, and / or aluminum oxide.

[0509] 105. A method according to any one of items 102 to 104, wherein the metal salt comprises a metal carbonate.

[0510] 106. A method according to item 105, wherein the metal carbonate comprises calcium carbonate, magnesium carbonate, barium carbonate, strontium carbonate, manganese carbonate, iron carbonate, cobalt carbonate, zinc carbonate, cadmium carbonate, lead carbonate, and / or nickel carbonate.

[0511] 107. A method according to any one of items 98 to 106, wherein the precipitation reaction comprises precipitating a metal hydroxide.

[0512] 108. A method according to item 107, wherein the metal hydroxide comprises calcium hydroxide, magnesium hydroxide, barium hydroxide, strontium hydroxide, manganese hydroxide, iron hydroxide, cobalt hydroxide, zinc hydroxide, cadmium hydroxide, lead hydroxide, and / or nickel hydroxide.

[0513] 109. A method according to any one of items 98 to 108, wherein the concentration of the acid is greater than or equal to 0.1M.

[0514] 110. A method according to any one of items 98 to 109, wherein the concentration of the acid is greater than or equal to 1M.

[0515] 111. A method according to any one of items 98 to 110, wherein the concentration of the acid is less than or equal to 12M.

[0516] 112. A method according to any one of items 98 to 111, wherein the concentration of the base is greater than or equal to 0.1M.

[0517] 113. A method according to any one of items 98 to 112, wherein the concentration of the base is greater than or equal to 1M.

[0518] 114. A method according to any one of items 98 to 113, wherein the concentration of the base is less than or equal to 25M.

[0519] 115. A method according to any one of items 98 to 114, wherein the pH near the second reactor is less than or equal to 6.

[0520] 116. A method according to any one of items 98 to 115, wherein the pH near the first reactor is greater than or equal to 8.

[0521] 117. A method according to any one of items 98 to 116, wherein the first reactor includes a second electrode and the Nernst potential at the second electrode is greater than or equal to 1.36 V relative to a standard hydrogen electrode.

[0522] 118. A method according to any one of items 98 to 117, wherein the first reactor comprises a second electrode and the dihalide is produced by the second electrode.

[0523] 119. A method according to any one of items 98 to 118, wherein the first reactor comprises a first electrode and the Nernst potential at the first electrode is less than or equal to 0.8 V relative to a standard hydrogen electrode.

[0524] 120. A method according to any one of items 98 to 118, wherein the first reactor comprises a first electrode and the Nernst potential at the first electrode is less than or equal to 0.4 V relative to a standard hydrogen electrode.

[0525] 121. A method according to any one of items 98 to 118, wherein the first reactor comprises a first electrode and the Nernst potential at the first electrode is less than or equal to -0.41 V relative to a standard hydrogen electrode.

[0526] 122. A method according to any one of items 98 to 118, wherein the first reactor comprises a first electrode and the Nernst potential at the first electrode is less than or equal to -0.82 V relative to a standard hydrogen electrode.

[0527] 123. A method according to any one of items 98 to 122, wherein the first reactor comprises a first electrode and the base is produced by the first electrode.

[0528] 124. A method according to any one of items 98 to 123, wherein the second reactor is a chemical reactor or a fuel cell.

[0529] 125. A method according to any one of items 98 to 124, wherein the second reactor is a H2 / Cl2 fuel cell.

[0530] 126. A method according to any one of items 98 to 125, comprising performing the chemical dissolution with the acid.

[0531] 127. A method according to any one of items 98 to 126, comprising performing the chemical dissolution with the base.

[0532] 128. The method of any one of items 98 to 127, comprising carrying out the precipitation reaction with the acid.

[0533] 129. The method of any one of items 98 to 128, comprising carrying out the precipitation reaction with the base.

[0534] 130. A system comprising:

[0535] a first reactor configured to produce a base, a dihalide, and hydrogen;

[0536] a second reactor configured to produce an acid;

[0537] a first device configured to collect the acid near the second reactor and perform a chemical dissolution and / or precipitation reaction with the acid; and

[0538] A second device is configured to collect the base near the first reactor and perform a chemical dissolution and / or precipitation reaction with the base.

[0539] 131. A system according to claim 130, wherein the system is configured to feed a neutral pH alkali metal halide byproduct from the precipitation reaction into the first reactor.

[0540] 132. A system according to any one of items 130 to 131, wherein the system is configured to store the acid and / or the base.

[0541] 133. A system according to any one of items 130 to 132, wherein the chemical dissolution comprises chemical dissolution of metals, metal alloys, metalloids, metal salts, metal oxides, and / or silicates.

[0542] 134. A method according to item 133, wherein the metal and / or the metal alloy comprises iron, iron-based alloys, stainless steel, non-ferrous metals, non-ferrous alloys, aluminum, brass, bronze, copper, zinc, tin, and / or coin alloys.

[0543] 135. A method according to any one of items 133 to 134, wherein the metal oxide comprises calcium oxide, magnesium oxide, strontium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, zinc oxide, cadmium oxide, lead oxide, silicon dioxide, and / or aluminum oxide.

[0544] 136. A method according to any one of items 133 to 135, wherein the metal salt comprises a metal carbonate.

[0545] 137. A system according to item 136, wherein the metal carbonate comprises calcium carbonate, magnesium carbonate, barium carbonate, strontium carbonate, manganese carbonate, iron carbonate, cobalt carbonate, zinc carbonate, cadmium carbonate, lead carbonate, and / or nickel carbonate.

[0546] 138. A system according to any one of items 130 to 137, wherein the precipitation reaction comprises precipitating a metal hydroxide.

[0547] 139. A system according to item 138, wherein the metal hydroxide comprises calcium hydroxide, magnesium hydroxide, barium hydroxide, strontium hydroxide, manganese hydroxide, iron hydroxide, cobalt hydroxide, zinc hydroxide, cadmium hydroxide, lead hydroxide, and / or nickel hydroxide.

[0548] 140. A system according to any one of items 130 to 139, wherein the concentration of the acid is greater than or equal to 0.1M.

[0549] 141. A system according to any one of items 130 to 140, wherein the concentration of the acid is greater than or equal to 1M.

[0550] 142. A system according to any one of items 130 to 141, wherein the concentration of the acid is less than or equal to 12M.

[0551] 143. A system according to any one of items 130 to 142, wherein the concentration of the base is greater than or equal to 0.1M.

[0552] 144. A system according to any one of items 130 to 143, wherein the concentration of the base is greater than or equal to 1M.

[0553] 145. A system according to any one of items 130 to 144, wherein the concentration of the base is less than or equal to 25M.

[0554] 146. A system according to any one of items 130 to 145, wherein the first device is configured to perform the chemical dissolution with the acid.

[0555] 147. A system according to any one of items 130 to 146, wherein the first device is configured to perform the precipitation reaction with the acid.

[0556] 148. A system according to any one of items 130 to 147, wherein the second device is configured to perform the chemical dissolution with the base.

[0557] 149. A system according to any one of items 130 to 148, wherein the second device is configured to perform the precipitation reaction with the base.

Claims

1. A method comprising: Produces acids and bases by electrolysis; dissolving a material containing calcium and silicon using the acid to generate ions containing calcium in a region of pH 6 or less; precipitating calcium hydroxide from ions containing calcium in a pH region of 10 or higher using an alkali; as well as The calcium hydroxide is used to form cement.

2. The method according to claim 1, wherein the acid and / or the base are stored before being used in the dissolution and / or precipitation reaction.

3. The process according to claim 1, wherein the acid and / or the base is generated in a system of reactors, and the dissolution and / or the precipitation takes place in another reactor or system of reactors.

4. The method of claim 1, wherein dissolving the material using the acid to produce calcium ions comprises using the acid to dissolve metal from the material.

5. The method of claim 4, wherein dissolving the material using the acid comprises capturing CO2 from dissolution of carbonates in the acid.

6. The method of claim 1, wherein forming cement with the calcium hydroxide comprises mixing the calcium hydroxide with an aluminate, a silicate, and / or a pozzolanic material.

7. The method of claim 6, wherein forming the cement comprises mixing the calcium hydroxide with the silicate.

8. The method of claim 6, wherein forming the cement comprises mixing the calcium hydroxide with the pozzolanic material.

9. The method of claim 1, wherein generating the acid and base by electrolysis comprises: forming a dihalide in a first reactor; as well as The dihalide is reacted in a second reactor.

10. The method of claim 9, wherein the dihalide is Cl2.

11. The method according to claim 9, wherein: forming the dihalide in the first reactor comprises electrolyzing to form the dihalide and hydrogen; Reacting the dihalide in the second reactor includes reacting the dihalide with the hydrogen gas to form a hydrogen halide.

12. The method of claim 11, wherein the hydrogen halide comprises HCl, HBr or HI.

13. The method of claim 11, further comprising dissolving the hydrogen halide in water to form the acid.

14. The method of claim 1, wherein the material further comprises at least one of magnesium, aluminum, or iron.

15. The method of claim 14, wherein dissolving the material produces ions comprising magnesium.

16. The method of claim 15, further comprising precipitating magnesium hydroxide from the magnesium-containing ions.

17. The method of claim 1, wherein the cement comprises pozzolanic cement.

18. The method of claim 1, further comprising mixing the cement with water and additives to form concrete.

19. A method comprising: electrolyzing in a first reactor to form a dihalide and hydrogen; reacting the dihalide with the hydrogen in a second reactor to form hydrogen halide; dissolving the hydrogen halide in water to form an acid; dissolving a material containing calcium and silicon using the acid to generate ions containing calcium in a region of pH 6 or less; precipitating calcium hydroxide from ions containing calcium in a pH region of 10 or higher using an alkali; as well as The calcium hydroxide is used to form cement.

20. The method of claim 19, wherein the dihalide is Cl2 and the hydrogen halide comprises HCl.

21. A method comprising: operating the reactor in a first mode; The first mode includes: generating a base from a first electrode; generating an acid from a second electrode electrochemically coupled to the first electrode in the reactor; and The acid and / or the base are collected.

22. A method comprising: operating the reactor in a first mode; The first mode includes: generating a base from a first electrode; generating an acid from a second electrode electrochemically coupled to the first electrode in the reactor; collecting the acid and / or the base; and The collected acid and / or base is reacted in a chemical dissolution and / or in a precipitation reaction.

23. A method comprising: operating the reactor in a first mode; The first mode includes: generating alkali and hydrogen gas from the first electrode; generating acid and oxygen gas from a second electrode electrochemically coupled to the first electrode in the reactor; and allowing the oxygen to diffuse and / or be transported to the first electrode and / or allowing the hydrogen to diffuse and / or be transported to the second electrode; and The oxygen is allowed to be reduced through the first electrode and / or the hydrogen is allowed to be oxidized through the second electrode.

24. A system comprising: a first electrode; a second electrode electrochemically coupled to the first electrode; and A device is configured to collect acidic products near the second electrode and / or alkaline products near the first electrode.

25. A system comprising: a first electrode; a second electrode electrochemically coupled to the first electrode; a first device configured to collect acidic products near the second electrode and / or alkaline products near the first electrode; as well as A second device is configured to react the collected acidic product and / or the collected basic product.

26. A system comprising: a first electrode configured to produce an alkali and hydrogen gas; as well as a second electrode electrochemically coupled to the first electrode and configured to generate acid and oxygen; wherein the system is configured to allow oxygen to diffuse and / or be delivered to the first electrode and / or to allow hydrogen to diffuse and / or be delivered to the second electrode; as well as The system is configured to allow the oxygen to be reduced through the first electrode and / or to allow the hydrogen to be oxidized through the second electrode.

27. A method comprising: producing a base and a dihalide in a first reactor; generating acid in a second reactor; collecting the acid; collecting the base; Chemical dissolution using the acid and / or the base; as well as The precipitation reaction is carried out using the acid and / or the base.

28. A system comprising: a first reactor configured to produce a base, a dihalide, and hydrogen; a second reactor configured to produce an acid; a first device configured to collect the acid near the second reactor and perform a chemical dissolution and / or precipitation reaction with the acid; as well as A second device is configured to collect the base near the first reactor and perform a chemical dissolution and / or precipitation reaction with the base.

29. A method of forming a precipitate using a reactor comprising a spatially varying chemical composition gradient, comprising: dissolving a metal salt in a first region of the spatially varying chemical composition gradient of the reactor; as well as A precipitate comprising one or more elements from the metal salt is formed in the second region of the spatially varying chemical composition gradient.

30. A system configured to operate in a first mode and a second mode, Wherein, in the first mode, electrical energy is consumed to generate H2 and O2 gases; in the second mode, the H2 and O2 gases generated in the first mode are consumed to generate acid, alkali and electricity; or The system includes a flow cell, which includes an anode made of carbon felt and a cathode made of carbon felt, wherein in the first mode, a nearly neutral 1M Na2SO4 solution is fed to the anode and the cathode of the flow cell at a rate of 10 mL / min, and then an acidic solution and an alkaline solution are taken out from the anode and the cathode, respectively; in the second mode, the polarity of the electrodes is reversed, the alkaline solution is added to the anode to generate O2 gas, and the acidic solution is added to the cathode to generate H2 gas.

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