Carbon neutral cement from gangue minerals

Abstract

The present disclosure relates to a system and method of carbon-neutral cement production, which can be achieved by incorporating an electro-synthesizer system, an acid leaching system, and an alkalinization / precipitation system into the cement manufacturing process. The system and method enables the robust processing of various serpentine-containing materials, while mitigating emissions associated with cement production. The Mg cement produced can be incorporated into building materials.

Description

CARBON NEUTRAL CEMENT FROM GANGUE MINERALSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 673,885, filed July 22, 2024, the contents of which are incorporated herein by reference in its entirety.FEDERALLY SPONSORED RESEARCH DEVELOPMENT

[0002] This invention was made with government support under grant number DE- AR0001711 awarded by the U.S. Department of Energy. The government has certain rights in the invention.FIELD

[0003] The present disclosure relates to the use of an electrochemical system, and method of using same, for the efficient and more environmentally friendly production of carbon-neutral cement from ultramafic rocks.BACKGROUND

[0004] Cement and concrete are materials critical to society and modern life but are also energy- and emissions-intensive. The U.S. produced approximately 95 million metric tons of cement in 2022, accounting for 2% of U.S. greenhouse gas emissions and 1% of U.S. energy consumption. Conventional Portland cement production involves the high-temperature calcination of limestone using fossil fuels, causing emissions of ~0.9 tons of carbon dioxide per ton of cement produced (-60% from calcium carbonate (CaCOa) decomposition).

[0005] Current efforts of emission mitigation in the cement industry focus on the capture of CO2 from exhaust gas using amine scrubbers or calcium-looping, but such strategies suffer from the high costs associated with compression, storage and transportation (e.g., to sites for sequestration or conversion) of CO2 gas [4] .

[0006] Accordingly, there remains a need in the art for carbon-neutral cement / concrete and a method of producing same.SUMMARY

[0007] In one aspect, a system for manufacturing magnesium-containing cement is described, said system comprising: one or more flow electro-synthesizer systems configured to produce an acid solution and a hydroxide base solution; one or more acid leaching systems that are in fluid communication with the acid solution from the flow electro- synthesizer system(s), wherein the acid leaching system(s) are configured to receive a serpentine-containing material comprising magnesium and separate silica from an acid leachate comprising at least Mg2+; one or more alkalinization / precipitation systems that are in fluid communication with the one or more acid leaching systems and the hydroxide base solution from the flow electro-synthesizer system(s), wherein the alkalinization / precipitation system(s) are configured to precipitate the Mg2+in the acid leachate as Mg(OH)2(s), and optionally dehydrating the Mg(OH)2(s) to MgO(s); and one or more cement formulation systems that are capable of receiving supplementary cementitious materials (SCM) to produce the Mg-containing cement, wherein the SCMs include at least one of silica from the acid leaching system(s), Mg(OH)2 from the alkalinization / precipitation system(s), and / or MgO from the alkalinization / precipitation system(s).

[0008] In another aspect, a method of producing magnesium-containing cement from a serpentine-containing material is described, said method comprising providing one or more of the systems for manufacturing magnesium-containing cement as described herein; electrochemically generating a hydrogen gas and a hydroxide base on the cathode in the first compartment; and flowing a stream comprising a generated hydrogen gas, a hydrogen gas provided by an external source, or a combination thereof, into the second compartment such that electrochemically generated hydrogen ions are formed on the anode to produce an acid solution; directing at least a portion of a second electrolyte comprising acid solution to one or more acid leaching systems, wherein the one or more acid leaching systems comprisethe serpentine-containing material, and the acid leaching system(s) separate silica from an acid leachate comprising at least Mg2+; directing at least a portion of a first electrolyte comprising the hydroxide base and the acid leachate to one or more alkalinization / precipitation systems configured to precipitate the Mg2+from the acid leachate as M (0H)2; and introducing at least one of the SCMs to the one or more cement formulation systems to produce Mg-containing cement, wherein the SCMs include at least one of silica from the acid leaching system(s), Mg(0H)2 from the alkalinization / precipitation system(s), and / or MgO from the alkalinization / precipitation system(s).

[0009] Other aspects, features and embodiments of the invention will be more fully apparent from the ensuing disclosure and appended claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIGURE 1A. Representative composition of serpentine ultramafic collected from Penn-Maryland Quarry.

[0011] FIGURE IB. Map of domestic ultramafic rock bodies (in red).

[0012] FIGURE 2. A schematic of the carbon-neutral production of MgO / Mg(OH)2 binder from ultramafic rocks.

[0013] FIGURE 3. A schematic of an exemplary electro-synthesizer system in one embodiment.

[0014] FIGURE 4 depicts methods of using an exemplary electro- synthesizer unit in one embodiment.

[0015] FIGURE 5 depicts methods of using an exemplary electro- synthesizer unit in a different embodiment.DETAILED DESCRIPTION

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Preferred methods and materials are described below, although methods and materials similar or equivalent to those described herein can be used in practice or testing of the present disclosure. All publications, patent applications,patents, and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.

[0017] For purposes of this disclosure, the chemical elements are identified in accordance with the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75thEd., inside cover, and specific functional groups are generally defined as described therein. Additionally, general principles of organic chemistry, as well as specific functional moieties and reactivity, are described in Sorrell, Organic Chemistry, 2ndedition, University Science Books, Sausalito, 2006; Smith, March's Advanced Organic Chemistry: Reactions, Mechanism, and Structure, 7thEdition, John Wiley & Sons, Inc., New York, 2013; Larock, Comprehensive Organic Transformations, 3rdEdition, John Wiley & Sons, Inc., New York, 2018; and Carruthers, Some Modern Methods of Organic Synthesis, 3rdEdition, Cambridge University Press, Cambridge, 1987; the entire contents of each of which are incorporated herein by reference.

[0018] "Substantially devoid" is defined herein to mean that none of the indicated substance is intentionally added or present. For example, less than about 1 wt%, preferably less than about 0.1 wt%, and even more preferably less than about 0.01 wt% of the indicated substance is present.

[0019] “ About” and “approximately” are used to provide flexibility to a numerical range endpoint by providing that a given value may be “slightly above” or “slightly below” the endpoint without affecting the desired result, for example, + / - 5%.

[0020] The phrase “in one embodiment” or “in some embodiments” as used herein does not necessarily refer to the same embodiment, though it may. Furthermore, the phrase “in another embodiment” as used herein does not necessarily refer to a different embodiment, although it may. Thus, as described below, various embodiments of the invention may be readily combined, without departing from the scope or spirit of the invention.

[0021] The terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that do not preclude the possibility of additional acts or structures. The singular forms “a,” “and” and “the” include plural references unless the context clearly dictates otherwise. The present disclosure also contemplates other embodiments “comprising,” “consisting of’ and“consisting essentially of,” the embodiments or elements presented herein, whether explicitly set forth or not.

[0022] It will be understood that when an element is referred to as being "connected" or "coupled" or “being in fluid and / or electrical communication” to another element, it can be directly connected, coupled, or be on fluid and / or electrical communication to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected," "directly coupled," or “in direct fluid and / or electrical communication” to another element, there are no intervening elements present. Other words used to describe the relationship between elements or layers should be interpreted in a like fashion (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," "on" versus "directly on").

[0023] As used herein, a “system” refers to a plurality of real and / or abstract elements operating together for a common purpose. In some embodiments, a “system” is an integrated assemblage of hardware and / or software elements. In some embodiments, each component of the system interacts with one or more other elements and / or is related to one or more other elements. In some embodiments, a system refers to a combination of components and software for controlling and directing methods.

[0024] As used herein, the term “recirculated-in-a-loop” defines a system where all streams of the system arc recirculating within the loop. It is understood that substantially all streams disclosed herein are recirculated. However, in some examples, if needed, external streams are provided. Numerous general purpose or special purpose computing devices environments or configurations can be used with the systems and methods disclosed herein. Examples of well- known computing devices, environments, and / or configurations that can be suitable for use include but are not limited to, personal computers, server computers, handheld or laptop devices, smartphones, multiprocessor systems, microprocessor-based systems, network personal computers (PCs), minicomputers, mainframe computers, embedded systems, distributed computing environments that include any of the above systems or devices, and the like.

[0025] As used herein, “serpentine” is a magnesium iron phyllosilicate mineral and can comprise other elements including chromium, manganese, cobalt, nickel, and zinc. There are three polymorphs of serpentine, including antigorite, lizardite, and chrysotile.

[0026] As used herein, the term "substantially" means that the subsequently described event or circumstance completely occurs or that the subsequently described event or circumstancegenerally, typically, or approximately occurs. The term “substantially” can, in some embodiments, refer to at least about 80 %, at least about 85 %, at least about 90 %, at least about 91 %, at least about 92 %, at least about 93 %, at least about 94 %, at least about 95 %, at least about 96 %, at least about 97 %, at least about 98 %, at least about 99 %, or about 100 % of the stated property, component, composition, or other condition for which substantially is used to characterize or otherwise quantify an amount.

[0027] Broadly, a method of manufacturing carbon-neutral cement using ultramafic rocks as feedstock is described. In some embodiments, the carbon-neutral cement is a magnesium- containing cement.

[0028] Ultramafic rocks are igneous and meta-igneous minerals rich in magnesia (typically >30%) and low in silica content (<45%) (Figure 1A). Ultramafic rocks are the primary component of the upper earth mantle with a total reservoir of approximately 10,000 gigaton (Gt) according to the U.S. Geological Survey (USGS). The Baltimore-Liberty complexes, geologic formations that stretch from southwest Pennsylvania to northern Virginia, consist of the largest ultramafic rock exposures in the Eastern U.S. (Figure IB). These areas, featuring extensively serpentinized dunite, span belts ranging from 10-30 km in length in the north, tapering to isolated pockets in Virginia. Today, ultramafic rocks such as serpentine are quarried, crushed, and sold as aggregates for construction (c.g., asphalt pavement). The global aggregates market is at a scale of approximately 50 Gt / year, indicating great potential for scalable production. As used hereinafter, the ultramafic rocks will be referred to as a “serpentine-containing material.” In some embodiments, the serpentine-containing material is present in gangue minerals and mining tailings.

[0029] The system and method of manufacturing carbon-neutral cement will start with the extraction of magnesia (MgO) from serpentine-containing material (Figure 2). In some embodiments, the extraction of magnesia (MgO) from serpentine-containing material is performed using electrochemical technology for energy-efficient synthesis of acid and base from brine (see, e.g., the electro- synthesizer (a) in Figure 2) according to:NaCl + H2O NaOH + HC1 ( 1 ) at 30-40% reduced energy intensity (1.39 MWh / ton-NaOH) in comparison to a conventional method of the prior art based on chlor-alkali electrolysis. The electro-synthesized acid will thenbe used to leach MgCl2from the serpentine-containing material (see, e.g., (b) in Figure 2) according to:Mg Si2O5(OH)4+ 6HC1 3MgCh + 5H2O + 2SiO (2)The derived MgCl2will then be recombined with the electro-synthesized base (see, e.g., (c) in Figure 2) according to:MgCl2+ 2NaOH Mg(OH)2| + 2NaCl (3) wherein after dehydration of the Mg(OH)2will yield MgO. At least one of the derived MgO, Mg(OH)2, and silica will be used as feedstocks to formulate Mg-based cement (see, e.g., (d) in Figure 2). The remaining NaCl will be recirculated back to the electro-synthesizer in (a) to close the mass balance. The whole process is electrified and compatible with renewable energy sources such as solar and wind electricity.

[0030] Referring to Figure 2, the carbon-neutral cement system comprises:(i) one or more acid acid-base electro- synthesizer systems, wherein a salt solution (e.g.,NaCl) from the alkalinization / precipitation system system (c) is split into an acid solution (e.g., HC1) and a hydroxide base (e.g., NaOH), with the former being recirculated for leaching in acid leaching system (b) and the latter being used for alkalinization / precipitation in (c);(ii) one or more acid leaching systems, wherein acid solution(s) (e.g., HC1) remove silica and other precipitates from a serpentine-containing material to produce a leachate comprising at least Mg2+;(iii) one or more alkalinization / precipitation systems, wherein the leachate comprising at least Mg2+is subjected to treatment in the presence of the hydroxide base from (a) to precipitate Mg(OH)2(s) in a salt solution (e.g., NaCl(aq)). In some embodiments, the Mg(OH)2(s) is dehydrated to MgO(s). The salt solution is recycled back to the electro-synthesizer (a); and(iv) one or more cement / concrete formulation systems, wherein at least one of the silica from the acid leaching system (b), the Mg(OH)2(s) from the alkalinization / precipitation systems of (c), and / or the MgO(s) from the alkalinization / precipitation systems of (c), are combined with other materials known in the art to make concrete.

[0031] The manufacturing process of Mg cement, as described herein, involves the integration of (electro)chemical engineering, materials science and civil engineering to yield alternative, carbon neutral supplementary cementitious materials (SCMs). The process avoids the use of carbonate based feedstocks such as limestone and thus substantially reduces the carbon emissions of cement manufacturing processes (by at least about 80%). Advantageously, the Mg cement is a viable replacement for conventional Ca cement with comparable mechanical, structural and durability performances, while possessing advantages of fire resistance and emission reduction.

[0032] It is understood that disclosed herein in Figure 2, the lines are only exemplary and only shown to demonstrate communication between different system elements. It is understood that different types and numbers of lines can be used in each system as desired.An Embodiment of an Electro-synthesizer (a)

[0033] In an exemplary and unlimiting aspect, the electro -synthesizer system comprises the system described in co-pending U.S. Patent Application No. 18 / 360,326, filed on July 27, 2023, in the name of Chao Wang et al. and entitled “Electrolyzers,” and in co-pending International Patent Application PCT / US2023 / 071105, filed on July 27, 2023, in the name of Chao Wang et al. and entitled “Electrolyzers and Use of the Same for Carbon Dioxide Capture and Mining,” which are hereby incorporated by reference herein in their entirety.

[0034] Disclosed herein are embodiments directed to an electro-synthesizer system introduced in Figure 2 but shown in more detail in Figure 3. In certain embodiments, the electro-synthesizer system is a flow unit. In further embodiments, the electro-synthesizer system comprises a number of compartments. Figure 3 shows an exemplary electro- synthesizer system 100 comprising a first compartment 102, a second compartment 104, and a third compartment 106.

[0035] The first compartment 102 can comprise a cathode 108 and a first inlet (not shown) configured to receive a first flow of a first electrolyte solution. The first compartment further comprises the first electrolyte solution 116, which is in electrical and fluid communication with the cathode 108. In such exemplary and unlimiting embodiments, a pH of the first electrolyte solution 116 can be about 6<pH<15.5, including exemplary values of about 6, about 6.5, about 7, about 7.5, about 8, about 8.5, about 9, about 9.5, about 10, about 10.5, about 11, about 11.5, about 12, about 12.5, about 13, about 13.5, about 14, about 14.5, about 15, and about 15.5. It isunderstood that at any point, the first compartment can comprise the first electrolyte having a pH value that falls within any two foregoing values. In yet still further embodiments, the pH of the first electrolyte can change during the system operation. While in yet still further embodiments, the pH of the first electrolyte is kept substantially the same during the system operation, depending on the desired outcome. In still further embodiments, the cathode is configured to generate a hydrogen gas and a hydroxide. The first compartment further comprises one or more outlets (not shown) configured to remove the generated hydrogen gas and / or a hydroxide base generated in the first compartment.

[0036] In some embodiments, the first electrolyte comprises the hydroxide base. In some embodiments, the first electrolyte is the hydroxide base. Any known in the art bases can be used including, but not limited to, sodium hydroxide, lithium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, ammonium hydroxide, amine-based bases, sodium acetate, or any combination thereof. In still further embodiments, the bases can comprise amine- based bases, such as primary, secondary, tertiary amines, or any combination thereof. It is understood that other organic bases can be utilized. In some embodiments, the first electrolyte comprises sodium hydroxide. In still further embodiments, the base can be strong or weak, depending on the desired pH, as commonly defined in chemical arts. In yet still further embodiments, the bases can also comprise Lewis bases. It is understood that the base can be present in any concentration to provide the desired pH. The concentration can be measured in M, or it can be measured in wt%, depending on the desired application. In still further embodiments, the base can be present in any concentration from 0 M to about 20 M, including exemplary values about 0.001 M, about 0.005 M, about 0.01 M, about 0.05 M, about 0.1 M, about 0.5 M, about 1 M, about 2 M, about 3 M, about 4 M, about 5 M, about 6 M, about 7 M, about 8 M, about 9 M, about 10 M, about 11 M, about 12 M, about 13 M, about 14 M, about 15 M, about 16 M, about 17 M, about 18 M, and about 19 M. It is understood that these values are only exemplary, and the base can be present in a concentration having any values between any two foregoing values.

[0037] In still further embodiments, the first electrolyte comprises one or more inorganic salts. In some exemplary and unlimiting embodiments, the first electrolyte can comprise a salt without the presence of the base. Yet, in other embodiments, the first electrolyte can comprise only a hydroxide base. In yet still further embodiments, the first electrolyte can comprise the salt andthe hydroxide base in any desired concentration. It is understood that the salt is present in the first electrolyte can be at any concentration before its saturation. In certain embodiments, the salt and the hydroxide base present in the electrolyte can have the same cation or a different cation.In yet other embodiments, the combination of various salts (having the same cations but different anions or the same anions but different cations) can be present. Yet, in still further embodiments, the combination of the various bases can also be present in the first electrolyte. In still further embodiments, the one or more inorganic salt can comprise chlorides, sulfates, nitrates, phosphates, citrates, formates, lactates, tartrates, malates, fumarates, oxalates, succinates, gluconates, ascorbates, acetates of alkaline metals and / or alkaline-earth metals, or mixtures thereof.

[0038] The second compartment 104 comprises an anode 110. The anode 110 has a first surface 109 and a second surface 111. In still further embodiments, the second compartment 104 comprises a second inlet (not shown) configured to receive a second flow of a second electrolyte solution 118 and a third inlet (not shown) configured to receive a stream 120 comprising a hydrogen gas. In still further embodiments, the second inlet of the second compartment extends into a first channel, and the third inlet extends into a second channel. In such embodiments, the first channel is positioned between an anion exchange membrane (AEM) 114 and the first surface 109 of the anode 110 and hosts the second electrolyte 118. While in other embodiments, the second channel is positioned abut the second surface 111 of the anode 110 and is configured to receive the hydrogen gas stream 120.

[0039] In certain embodiments, the hydrogen gas stream 120 can comprise the hydrogen gas generated in the first compartment 102. In such embodiments, the generated hydrogen gas is directly fed from the first compartment to the second compartment, forming the looping of the hydrogen gas between the first and the second compailment of the system. However, also disclosed herein are embodiments wherein the hydrogen gas stream 120 comprises a hydrogen gas supplied from any external source, such as a hydrogen tank, externally generated hydrogen, and the like. In yet still further embodiments, the hydrogen gas stream 120 can comprise both the hydrogen generated in the first compartment and the hydrogen gas received from the external source. In still further embodiments, disclosed are implementations where an operator can switch the supply of the hydrogen gas stream 120 as desired.

[0040] In still further embodiments, the second electrolyte comprises an acid solution. In some embodiments, the second electrolyte is the acid solution. Any known in the art acids can be used. For example, the acid solution can comprise one or more of hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfurous acid, sulfuric acid, nitric acid, phosphorous acid, phosphoric acid, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, formic acid, acetic acid, carbonic acid, or any combination thereof. In still further embodiments, the acids can comprise organic acids. In some embodiments, the second electrolyte comprises hydrochloric acid. In some embodiments, the second electrolyte comprises sulfuric acid. In still further embodiments, the acid can be strong or weak, depending on the desired pH, as commonly defined in chemical arts. In yet still further embodiments, the acid can also comprise Lewis acids. It is understood that the acid can be present in any concentration to provide for the desired pH. The concentration can be measured in M, or it can be measured in wt%, depending on the desired application. In still further embodiments, the acid can be present in any concentration from 0 M to about 10 M, including exemplary values about 0.001 M, about 0.005 M, about 0.01 M, about 0.05 M, about 0.1 M, about 0.5 M, about 1 M, about 2 M, about 3 M, about 4 M, about 5 M, about 6 M, about 7 M, about 8 M, and about 9 M. It is understood that these values are only exemplary, and the acid can be present in the acid solution at a concentration having any values between any two foregoing values.

[0041] In still further embodiments, the second electrolyte comprises one or more inorganic salts. In some exemplary and unlimiting embodiments, the second electrolyte can comprise a salt without the presence of the acid. Yet, in other embodiments, the second electrolyte can comprise only an acid. In yet still further embodiments, the second electrolyte can comprise the salt and the acid solution in any desired concentration. It is understood that the salt present in the second electrolyte can be at any concentration before its saturation. In certain embodiments, the salt and the acid present in the electrolyte can have the same cation or a different cation. In yet other embodiments, the combination of various salts (having the same cations but different anions or the same anions but different cations) can be present. Yet in still further embodiments, the combination of the various acids can also be present in the second electrolyte. In still further embodiments, the one or more inorganic salt can comprise chlorides, sulfates, nitrates, phosphates, citrates, formates, lactates, tartrates, malates, fumarates, oxalates, succinates,gluconates, ascorbates, acetates of alkaline metals and / or alkaline-earth metals, or mixtures thereof.

[0042] It is understood that using hydrogen to generate hydrogen ions (either by looping the hydrogen from the first compartment to the second compartment or using both streams of hydrogen) improves the overall efficiency of the process. The hydrogen-depolarized reaction reduces both the energy cost and the electrode polarization in this electrolysis process. For example, in embodiments where the pH gradient between the compartments is extreme (for example, pH =14 in the first compartment and pH=0 in the second compartment), the hydrogen- induced loop will only cost 0.83 V for the pH gradient, which is 60% more efficient than the typical salt splitting process. The half-reactions and their standard potential of anode (5) and cathode (4) are,At pH = 14, 2 H2O + 2 e" -> H2+ 2 OH" cp = -0.83 V vs. SHE (4)At pH = 0, H2- 2 c ^ 2 H+cp = 0 V vs. SHE (5)

[0043] In one embodiment, the second electrolyte solution 118 is in electrical and fluid communication with the anode. For example, the second electrolyte solution 118 is in electrical and fluid communication with the first surface 109 of the anode 110. In still further embodiments, a pH of the second electrolyte solution is about -1.5<pH<8, including exemplary values of about -1.5, about -1, about -0.5, 0, about 0.5, about 1, about 1.5, about 2, about 2.5, about 3, about 3.5, about 4, about 4.5, about 5, about 5.5, about 6, about 6.5, about 7, about 7.5, and about 8. It is understood that at any point of, the second compartment can comprise the second electrolyte having a pH value that falls within any two foregoing values. In yet still further embodiments, the pH of the second electrolyte can change during the system operation. While in yet still further embodiments, the pH of the second electrolyte is kept substantially the same during the system operation, depending on the desired outcome. In still further embodiments, the anode is configured to oxidate the hydrogen gas to generate hydrogen ions. In yet still further embodiments, the second compartment comprises an outlet (not shown) configured to remove an acid solution comprising the generated hydrogen ions from the second compartment.

[0044] The system 100 further comprises a third compartment 106 positioned between and in fluid communication with the first compartment 102 and the second compartment 104, wherein the third compartment 106 is separated from the first compartment 102 with one or more cationexchange membranes (CEM) 112 and is separated from the second compartment 104 with one or more anion exchange membranes (AEM) 114.

[0045] In still further embodiments, the third compartment 106 comprises a fourth inlet (not shown) configured to receive a third flow of a third electrolyte solution 122, which can comprise some, or all, of the salt solution from the alkalinization / precipitation system (e.g., (c) in Figure 2). In such embodiments, the third electrolyte solution 122, can have a pH of about 4<pH<10, including exemplary values of about 4, about 4.5, about 5, about 5.5, about 6, about 6.5, about 7, about 7.5, about 8, about 8.5, about 9, about 9.5, and about 10. It is understood that at any point of, the third compartment can comprise the third electrolyte having a pH value that falls within any two foregoing values. In yet still further embodiments, the pH of the third electrolyte can change during the system operation. While in yet still further embodiments, the pH of the third electrolyte is kept substantially the same during the system operation, depending on the desired outcome. In still further embodiments, the third compailment also can comprise an outlet configured (not shown) to remove the third electrolyte from the third compartment. In still further embodiments, the third electrolyte solution can comprise one or more inorganic salts. In still further embodiments, the one or more inorganic salt comprises chlorides, sulfates, nitrates, phosphates, citrates, formates, lactates, tartrates, malates, fumarates, oxalates, succinates, gluconates, ascorbates, acetates of alkaline metals and / or alkaline-earth metals, or mixtures thereof. In yet still further embodiments, the one or more inorganic salts in the third electrolyte can be referred to as brine. In some embodiments, the third electrolyte comprises salt solution (e.g., sodium chloride) from the alkalinization / precipitation system (e.g., (c) in Figure 2). In some embodiments, the third electrolyte comprises salt solution (e.g., sodium sulfate) from the alkalinization / precipitation system (e.g., (c) in Figure 2).

[0046] In still further embodiments, while the disclosed above inlets and outlets are not shown in Figure 3, the skilled practitioner can understand that inlet and outlet can be positioned anywhere within the compartment to allow inflow and outflow of respective streams as described. For example, each of the compartments can have one or more inlets and / or one or more outlets. In some embodiments, the generated in the first compartment hydrogen gas and the base solution comprising the generated hydroxide base can be removed from the same outlet. Yet in other embodiments, the first compartment can comprise two or more outlets. In such exemplary and unlimiting embodiments, the generated hydrogen gas stream and the base solution comprisingthe generated hydroxide base can be removed from separate outlets. In some embodiments, the acid solution from the second compartment can be delivered to the acid leaching system (e.g., (b) in Figure 2) for use therein. In other embodiments, the acid solution from the second compartment can be sold as a commodity chemical. In some embodiments, the base hydroxide from the first compailment can be delivered to the alkalinization / precipitation system (e.g., (c) in Figure 2) for use therein. In other embodiments, the hydroxide base from the first compartment can be sold as a commodity chemical.

[0047] In still further embodiments, the electro-synthesizer system can be constructed by any known in the art methods. For example, and without limitations, each compartment can be any vessel configured to receive and retain disclosed above streams. In yet other embodiments, the electro- synthesizer system can comprise a plurality of plates positioned such that the disclosed above compartments are formed. For example and without limitations, each of the first, second and third compartments is defined by two or more plates. It is understood that all materials that are used to form the electro- synthesizer system are chemically and physically compatible with the electrolytes used in the system as well as output streams formed in the system compartments.

[0048] In still further embodiments, each of the compailments can have any width that can accommodate the desired flow rate of the described above streams. In some embodiments, the first compartment can have a width of about 0.01 mm to about 500 mm. For example, and without limitations, the width of the first compartment can be about 0.01 mm to about 50 mm, about 1 mm to about 10 mm, or about 5 mm to about 100 mm, and so on.

[0049] In embodiments where the second compartment has the first and second channels, each channel can have any desired width that suits the streams' preferred flow rates. For example and without limitations, the first channel present in the second compartment has a width of about 0.01 to about 500 mm. For example, and without limitations, the width of the first channel can be about 0.01 mm to about 50 mm, or about 1 mm to about 10 mm, or about 5 mm to about 100 mm, and so on. In further embodiments, the second channel present in the second compartment has a width of about 0.01 to about 500 mm. For example, and without limitations, the width of the second channel can be about 0.01 mm to about 50 mm, or about 1 mm to about 10 mm, or about 5 mm to about 100 mm, and so on. In still further embodiments, the third compartment can have a width of about 0.01 to about 500 mm. For example, and without limitations, the width of the third compartment can be about 0.01 mm to about 50 mm, or about 1 mm to about 10 mm, orabout 5 mm to about 100 mm, and so on. In still further embodiments, all compartments can have the same width, while in other embodiments, some of the compartments can have the same width, and some of them can have a different width. It is understood that the desired flow rate and coulombic efficiency of the cell can determine the width of the compartment. In yet still further embodiments, the width of the compartment can be changed in the cell by introducing (or removing) additional plates, gaskets, membranes, and the like.

[0050] In still further embodiments, each of the cathode and anode are electrically connected to a power source. In still further embodiments, the power source can provide a desired current to achieve the electrochemical reaction to produce the hydroxide ions and hydrogen gas in the first compartment and the hydrogen ions in the second compartment at desired efficiencies. In certain embodiments, the current can have a current density from about 50 mAh / cm2to about 500 mAh / cm2, including exemplary values of about 75 mAh / cm2, about 100 mAh / cm2, about 125 mAh / cm-, about 150 mAh / cm , about 175 mAh / cm , about 200 mAh / cm-, about 225 mAh / cm-, about 250 mAh / cm2, about 275 mAh / cm2, about 300 mAh / cm2, about 325 mAh / cm2, about 350 mAh / cm2, about 375 mAh / cm2, about 400 mAh / cm2, about 425 mAh / cm2, about 450 mAh / cm2, and about 475 mAh / cm2. In yet still further embodiments, the current density can have any value between any two foregoing values. In still further embodiments, the power source is configured to provide a desired voltage between the cathode and anode material. In such embodiments, the provided voltage can be from about 0.5 V to about 10 V, including exemplary values of about 1 V, about 1.5 V, about 2 V, about 2.5 V, about 3 V, about 3.5 V, about 4 V, about 4.5 V, about 5 V, about 5.5 V, about 6 V, about 6.5 V, about 7 V, about 7.5 V, about 8 V, about 8.5 V, about 9 V, and about 9.5 V. It is understood that any voltage having a value between any two foregoing values can be used to achieve the desired outcome.

[0051] In still further embodiments, any known in the art cathode and anode materials can be used in the disclosed system. For example, the cathode can comprise a Pt group metal or their alloys based electrode, a Ni-and its alloys-based electrode, a NiFe-based electrode, a NiTi-based electrode, a steel-based electrode, transition metal sulfates-based electrode, such as for example, and without limitations, molybdenum sulfide, tungsten sulfide, transition metal phosphide-based electrode, for example, and without limitations cobalt phosphide, Fe-based catalysts, carbonbased materials, or any combination thereof. In still further embodiments, any cathode materials capable of inducing an electrochemical generation of hydrogen can be used.

[0052] In still further embodiments, any anodes known in the art and suitable for the desired operation can be utilized. In certain embodiments, the anode can comprise a gas diffusion layer. Yet in further embodiments, the anode further comprises a hydrogen oxidation catalyst layer. It is understood that the gas diffusion layer assists with maintaining a stable gas-liquid interface. It is further understood that other configurations capable of maintaining a stable gas-liquid interface other than the disclosed herein gas diffusion layer can be used. For example, the stable gas-liquid interface can be formed by continuous bubbling of the gas through the second channel of the second compartment.

[0053] In certain embodiments, the gas diffusion layer comprises a carbon-based gas diffusion layer, a fluorocarbon-based gas diffusion layer, a hydrophobic material comprising a plurality of pores, or any combination thereof. It is understood that any hydrophobic material can be utilized. In certain embodiments, the layer can be made from the materials that are not inherently hydrophobic but can comprise a hydrophobic coating that provides the desired utility. In certain embodiments, the gas diffusion layer comprises a carbon-based paper, a carbon-based textile, a modified carbon-based paper, a modified carbon-based textile, micro-porous PTFE membrane, mesoporous PTFE membrane, macro-porous PTFE membrane, or a combination thereof. It is understood that the term “modified” as used herein refers to the disposed desired coatings on the surfaces or any other modification of the surfaces to introduce the desired surface properties. For example, the surface can be chemically, electrochemically, physically, and / or plasma modified to increase roughness, introduce the desired chemical moieties, and the like.

[0054] In still further embodiments, the hydrogen oxidation catalyst layer comprises one or more Pt group metal (PGM) or alloys thereof-based catalysts, PGM-free catalysts, and any combination thereof. In still further exemplary and unlimiting embodiments, the hydrogen oxidation catalyst layer comprises one or more of Pt / C, Pd and its alloys, Au and its alloys, Ru and its alloys, transition metal oxides and their alloys, transition metal carbides and nitrides, metal-organic frameworks, carbon- supported metal atoms, hydrogenase, hydrogenase mimic compounds, hydrogenase, or any combinations thereof.

[0055] In still further embodiments, to collect the current through both electrodes, current collectors are used for both anode and cathode. In some embodiments, the current collector can be presented as a bipolar plate, or a wire, or a plate, or any combination thereof. For exampleand without limitations, the current collector / bipolar plates can be made of graphite (plain or porous), titanium, gold or gold-coated metal plates, etc.

[0056] It is also understood that any known in the art cation exchange membranes and anion exchange membranes can be used. In such embodiments, any known and commercially available cation exchange membranes and anion exchange membranes can be used.

[0057] In certain embodiments, the polymeric cation-exchange membranes comprise -SO3‘, - COO’, -PO32’, -PO3H- , or -C6H4O- cation exchange functional groups. The polymers for the preparation of cation-exchange membranes can be perfluorinated ionomers such as NAFION (a perfluorosulfonic -based membrane), FLEMION, and NEOSEPT A-F, partially fluorinated polymers, non-fluorinated hydrocarbon polymers, non-fluorinated polymers with aromatic backbone, or acid-base blends. It will be appreciated that in some embodiments, depending on the need to restrict or allow migration of a specific cation or an anion species between the electrolytes, a cation exchange membrane that is more restrictive and thus allows migration of one species of cations while restricting the migration of another species of cations may be used as, e.g., a cation exchange membrane that allows migration of potassium ions into the cathode electrolyte while restricting migration of other cations into the cathode electrolyte, may be used. Such restrictive cation exchange membranes are commercially available and can be selected by one ordinarily skilled in the art. Some exemplary and commercially available membranes, such as Nation ®N117, CMI-7000, CMH-PP Ralex, EMION PF1-HLF8-15-X, CEM-Type I and CEM-Type II, etc., can be used.

[0058] Anion exchange membranes (AEM) are conventionally known in the art. In some embodiments, the polymeric anion-exchange membranes comprise -NH3+, -NRH2+, -NR2H+, - NR3+, or -SRi' anion exchange functional groups. The polymers for the preparation of anion- exchange membranes can be perfluorinated ionomers such as NAFION (a perfluorosulfonic- based membrane), FLEMION, and NEOSEPTA-F, partially fluorinated polymers, non- fluorinated hydrocarbon polymers, non-fluorinated polymers with aromatic backbone, or acidbase blends. It will be appreciated that in some embodiments, depending on the need to restrict or allow migration of a specific cation or an anion species between the electrolytes, an anion exchange membrane that is more restrictive and thus allows migration of one species of anions while restricting the migration of another species of anions may be used as, e.g., an anion exchange membrane that allows migration of chloride ions into the anode electrolyte whilerestricting migration of other anions into the anode electrolyte, may be used. Such restrictive anion exchange membranes are commercially available and can be selected by one ordinarily skilled in the art. In still further embodiments, any known and commercially available anion exchange membranes can be used. For example, and without limitations, Sustainion® 37-50, Nafion® 115, PiperlON TP-85, Fumasep FAPQ-375, PBI, Neosepta ACN, etc. In certain embodiments, the system can comprise one or more of cation exchange membranes and / or anion exchange membranes. In still further embodiments, the cation and anion exchange membranes can be unsupported. While in other embodiments, the cation and anion exchange membranes can be supported or reinforced. For example, the cation and / or anion exchange membranes can be polymer reinforced. In such embodiments, the polymers that are used for reinforcement are inert to the first, second, and / or third electrolyte solutions present in the disclosed systems. In still further embodiments, the cation and / or anion exchange membranes can be PTFE-reinforced, PEEK reinforced, or any combination thereof.

[0059] In still further embodiments, the cation and anion exchange membranes can have any desired thickness. In some embodiments, the thickness of the membranes can be about 15 pm to about 450 pm, including exemplary values of about 20 pm, about 30 pm, about 40 pm, about 50 pm, about 60 pm, about 70 pm, about 80 pm, about 90 pm, about 100 pm, about 150 pm, about 200 pm, about 250 pm, about 300 pm, about 350 pm, and about 400 pm.

[0060] In still further embodiments, the flow of the first electrolyte, the second electrolyte, and / or the third electrolyte can be the same or different and can be determined based on the specific application. In certain embodiments, the first electrolyte, the second electrolyte, and / or the third electrolyte can have a flow rate from about 1 to about 5,000,000 mL / h, including exemplary values of about 50 mL / h, about 100 mL / h, about 200 mL / h, about 300 mL / h, about 400 mL / h, about 500 mL / h, about 600 mL / h, about 700 mL / h, about 800 mL / h, about 900 mL / h, about 1,000 mL / h, about 5,000 mL / h, about 10,000 mL / h, about 50,000 mL / h, about 100,000 mL / h, about 250,000 mL / h, about 500,000 mL / h, about 750,000 mL / h, about 1,000,000 mL / h, about 2,000,000 mL / h, about 3,000,000 mL / h, and about 4,000,000 mL / h. It is also understood that the flow rate can have any value between any two foregoing values.

[0061] In still further embodiments, the electro-synthesizer system is a recirculated-in-a-loop system. In still further embodiments, the electro- synthesizer system can be connected to one or more pumps. It is understood that in some embodiments, the desired flow of the electrolytes andother streams can be provided by any means known in the art. In some embodiments, one or more pumps are used to deliver the desired stream. While in other embodiments, pumps are not used. It is understood that any known in the art pumps can be utilized.

[0001] Exemplary recirculated- in- a-loop systems of operation are shown in Figures. 4 and 5. For example, Figure 4 shows that system 300 is a recirculated-in-a-loop system designed to produce high-concentration acid and base solutions using the described herein electro- synthesizer unit 100. The base solution formed in the first compartment 102 is directed from the outlet by line 320 to reservoir 302, configured to collect the formed base solution. At least a portion of the collected base solution is removed by line 314. If needed, the remaining portion of the collected base solution in reservoir 302 can be diluted with water in line 312. The diluted remaining base solution is recirculated into the first compartment by lines 322 and 323 using a pumping device 304.

[0002] A hydrogen gas produced in the first compartment can also be removed from the first compartment using line 320. In some embodiments, the hydrogen gas can be removed by a separate line (not shown). In certain embodiments, the generated hydrogen gas can be moved to reservoir 302, separated from the base solution, and delivered to hydrogen reservoir 310. In certain embodiments, the generated hydrogen can be moved out of the first compartment by a separate line and directly communicated to the hydrogen reservoir (not shown). Hydrogen from the hydrogen reservoir can be delivered by line 328 to the second channel 120 of the second compartment and recirculated back by line 326 to hydrogen reservoir 310. In still further embodiments, the acid solution formed in the second compartment is delivered with line 330 to an acid reservoir 306.

[0003] At least a portion of the generated acid solution can be removed by line 318. The remaining portion of the acid solution can be diluted with water by line 316. The diluted acid solution can then be recirculated into the first channel 118 of the second compartment with lines 322 and 334 using an optional pump 308. It is understood that since the electro-synthesizer unit is a flow unit, the third electrolyte in the third compartment continuously flows through the system (not shown).

[0004] Figure 5 shows a similar setup with only a difference where the hydrogen gas formed in the first compartment is not recirculated back to the hydrogen reservoir 410. The hydrogen reservoir 410 is configured to receive a hydrogen gas from an external source 411 by line 427.Similarly to Figure 4, the hydrogen gas stream 120 delivered to the second channel is recirculated back to the hydrogen reservoir 410 by lines 428 and 426. Line 430 collects the generated acid solution and delivers it to acid reservoir 406, where at least a portion of the acid solution is removed by line 418, and the remaining portion is diluted with water by line 416. The diluted acid solution is then recirculated back to the first channel 118 of the second compartment with lines 432 and 434 using optional pump 408.

[0005] The generated base solution is removed from the first compartment by line 420 and delivered to a base reservoir 402. A generated hydrogen gas is removed from the reservoir by line 415, and at least a portion of the generated base is removed by line 414. The remaining portion of the generated base is diluted by line 412 and delivered back to the first compartment as the first electrolyte by lines 422 and 423 using an optional pump 404.

[0062] In still further embodiments, if desired the disclosed herein one or more electrosynthesizer systems can be driven by different cathodic and anodic reactions including but not limited to hydrogen oxidation reaction (HOR), hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR).

[0063] In still further embodiments, the disclosed herein electro-synthesizer system can be in communication with a controller. The controller can comprise a processor that allows control of the desired process. In some embodiments, the controller is a feedback loop base controller designed to adjust processing conditions based on an output. In still further embodiments, the power source used to operate the disclosed herein electro- synthesizer system can be a conventional grid power source, a renewable power source or any combination thereof. In still further embodiments, the electro-synthesizer system can be designed to work during the off-peak time to allow energy savings.

[0064] In still further embodiments, the electro-synthesizer system disclosed herein has a coulombic efficiency of greater than about 80%, about 85%, about 90%, about 95%, and 100%. In still other embodiments, the electro-synthesizer system disclosed herein exhibits a coulombic efficiency of substantially 100%.

[0065] Also disclosed herein are carbon-neutral cement systems comprising one or more of the electro- synthesizer systems disclosed herein. In some embodiments, the carbon-neutral cement systems can comprise from 1 to about 1000, including exemplary values of 2, 3, 5, 10, 15, 20, 30, 50, 100, 250, 500, and 750 of electro-synthesizer systems. It is understood that there isactually no limit to the number of electro-synthesizer systems present in the carbon-neutral cement systems.

[0066] In still further embodiments, it is understood that the one or more electro- synthesizer systems (a) generate the acid solution and the hydroxide base solution in a batch or a continuous operation. In yet still further embodiments, the one or more electro-synthesizer systems generate the acid solution and the hydroxide base solution utilizing an energy source configured to operate continuously or on demand. For example, in some embodiments, the electro-synthesizer systems can utilize off-peak periods when the energy is cheap. In such exemplary and unlimiting embodiments, the flow electro-synthesizer systems can be stopped when energy is expensive and operate only when energy is cheap. In certain embodiments, the generated acids / bases can be utilized immediately. While in other embodiments, the generated acids / bases can be collected for further desired applications. In yet still further embodiments, other parts of the system operate continuously without interruptions.Leaching System (b)

[0067] Acid leaching systems are known in the art. In some embodiments, the at least one acid leaching system comprises at least one container comprising a single or multiple concentrations of acid solution. Scrpcntinc-containing materials arc introduced to the at least one container wherein the acid solution, for example from the electro-synthesizer system (e.g., (a) in Figure 2) removes magnesia (MgO) and other precipitates to produce a silica waste product and leachates comprising at least Mg2+. It is understood that all materials that are used to form the acid leaching system are chemically and physically compatible with the acid solution used in the system as well as output streams formed in the system. In some embodiments, if desired, the one or more acid leaching systems can comprise mixing means. In some embodiments, the leaching system comprises one container with a single concentration of acid solution. In some embodiments, the leaching system comprises more than one container, wherein each container has substantially the same concentration of acid solution (e.g., the leaching occurs in parallel). In some other embodiments, the leaching system comprises more than one container, wherein each container has a different concentration of acid solution (e.g., a multi-step leaching system, wherein the leaching process is in series).

[0068] In some embodiments, the serpentine-containing materials can be size-reduced and have an average size of about 5 mm to about 100 pm, including exemplary values of about 4 mm, about 3 mm, about 2 mm, about 1 mm, about 900 pm, about 800 pm, about 700 pm, about 600 pm, about 500 pm, about 400 pm, about 300 pm, about 200, and about 150 pm.

[0069] As shown in Figure 1, the acid leaching system (b) is connected to the alkalinization / precipitation system (c), the cement / concrete formulation system (d), and (optionally) the acid-base electro-synthesis system (a).

[0070] In some embodiments, to obtain a concentrated leachate, a multi-step leaching process with different concentrations of acid can be applied. When there are more than two containers in the multi-step leaching process, in some embodiments Cn>Cn-i>...>C2>Ci, while in some other embodiments Cn=Cn-i=...=C2>Ci, while in some other embodiments Cn=Cn-i=...=C3>C2>Ci, wherein C is the concentration of the acid in each respective container.

[0071] As shown in Figure 2, in some embodiments, a source for the acid solution can be the acid-base electro-synthesizer system (a). That said, it should be appreciated by the person skilled in the art that a source of all, or a portion, of the acid solution can be from an external source instead. Further, as shown in Figure 2, in some embodiments, the silica is sent to a cement / concrete formulation system (d) for incorporation into cement / concrete.

[0072] Because serpentine-containing materials can further comprise iron, chromium, manganese, cobalt, nickel, and zinc, in some embodiments, the acid leachate further comprises at least one of Fe2+, Fe3+, Cr3+, Mn2+, Co2+, Co3+, Ni2+, and Zn2+. Accordingly, the acid leachate can be further processed, prior to introduction to the alkalinization / precipitation system (c) to remove any or all of these metal ions for use elsewhere, e.g., after conversion to a useful product, bringing additional value to the system.The Alkalinization / Precipitation System (c)

[0073] In some embodiments, a source for the hydroxide base for the alkalinization / precipitation system solution can be the acid-base electro- synthesizer system (a), via a fluidic connection such as that shown in Figure 2. It should be appreciated by the person skilled in the art that a source of all, or a portion, of the hydroxide base for the alkalinization / precipitation system can be from an external source instead.

[0074] In still further embodiments, as shown in Figure 2, the alkalinization / precipitation system is in fluid communication with the one or more acid leaching systems (b). In still further embodiments, at least the third compailment of the one or more electro- synthesizer systems is in fluid communication with the alkalinization / precipitation system.

[0075] In some embodiments, at least a portion of the concentrated leachate (e.g., comprising Mg2+) from the acid leaching system and at least a portion of the hydroxide base from the electrosynthesizer (a) is introduced to the alkalinization / precipitation system for reaction therein. Within the alkalinization / precipitation system, magnesium in the concentrated leachate is sequestrated as solid (Mg(OH)2) and a salt solution (e.g., NaCl) is generated and fed back to the third compartment of the acid-base electro-synthesizer system (a) to close the mass balance. In still further embodiments, it is understood that at least a portion of the third electrolyte solution comprises the salt solution formed in the one or more alkalinization / precipitation systems, and wherein the salt solution is the same or different from one or more inorganic salts present in the third electrolyte. The flow rate of each stream can have any value of the disclosed above flow rates.

[0076] In some embodiments, the solid Mg(OH)2 is separated from the salt solution and at least a portion, or all, is dehydrated to MgO(s). In some embodiments, the Mg(OH)2(s) is sent to the ccmcnt / concrctc formulation system (e.g., (d) in Figure 2) for incorporation into the cement / concrete. In some embodiments, the MgO(s) is sent to the cement / concrete formulation system (e.g., (d) in Figure 2) for incorporation into the cement / concrete. In some embodiments, some Mg(OH)2(s) and some MgO(s) is sent to the cement / concrete formulation system (e.g., (d) in Figure 2) for incorporation into the cement / concrete.

[0077] It is understood that all materials that are used to form the alkalinization / precipitation system are chemically and physically compatible with the concentrated leachate (from the acid leaching system) and the hydroxide base solution (from the electro- synthesizer) used in the system as well as output streams formed in the system. In still further embodiments, if desired, the one or more alkalinization / precipitation devices can comprise mixing means.The Cement / Concrete System

[0078] Using the materials generated herein, including at least one SCM, i.e., at least one of the silica from the acid leaching system (b), the Mg(OH)2(s) from the alkalinization / precipitationsystems of (c), and / or the MgO(s) from the alkalinization / precipitation systems of (c), are combined with other materials known in the ail, e.g., aggregates, to make cement / concrete.

[0079] Accordingly, in a first aspect, a system for manufacturing magnesium-containing cement is described, said system comprising: one or more flow electro-synthesizer systems configured to produce an acid solution and a hydroxide base solution; one or more acid leaching systems that are in fluid communication with the acid solution from the flow electro- synthesizer system(s), wherein the acid leaching system(s) are configured to receive a serpentine-containing material comprising magnesium and separate silica from an acid leachate comprising at least Mg2+; one or more alkalinization / precipitation systems that are in fluid communication with the one or more acid leaching systems and the hydroxide base solution from the flow electro-synthesizer system(s), wherein the alkalinization / precipitation system(s) are configured to precipitate the Mg2+in the acid leachate as Mg(OH)2(s), and optionally dehydrating the Mg(OH)2(s) to MgO(s); and one or more cement formulation systems that arc capable of receiving supplementary cementitious materials (SCM) to produce the Mg-containing cement, wherein the SCMs include at least one of silica from the acid leaching systcm(s), Mg(OH)2 from the alkalinization / precipitation system(s), and / or MgO from the alkalinization / precipitation system(s).

[0080] In a second aspect, a method of producing magnesium-containing cement from a serpentine-containing material is described, said method comprising: obtaining a source of an acid solution a source of a hydroxide base; directing the acid solution to one or more acid leaching systems, wherein the one or more acid leaching systems comprise the serpentine-containing material, and the acid leaching system(s) separate silica from an acid leachate comprising at least Mg2+; directing the hydroxide base and the acid leachate to one or more alkalinization / precipitation systems configured to precipitate the Mg2+from the acid leachate as Mg(OH)2; and introducing at least one of the SCMs to the one or more cement formulation systems to produce Mg-containing cement, wherein the SCMs include at least one of silica from the acid leachingsystem(s), Mg(0H)2 from the alkalinization / precipitation system(s), and / or MgO from the alkalinization / precipitation sy s tem( s ) .In some embodiments, the acid solution and the hydroxide base are electrochemically generated. In some embodiments, the acid solution and the hydroxide base are electrochemically generated in the same flow electro- synthesizer system. In some embodiments, the flow electro- synthesizer system is described herein.

[0081] In some embodiments of the second aspect, the method of producing magnesium- containing cement from a serpentine-containing material comprises: providing one or more of the systems described herein; electrochemically generating a hydrogen gas and a hydroxide base on the cathode in the first compartment; and flowing a stream comprising a generated hydrogen gas, a hydrogen gas provided by an external source, or a combination thereof, into the second compartment such that electrochemically generated hydrogen ions are formed on the anode to produce an acid solution; directing at least a portion of a second electrolyte comprising acid solution to one or more acid leaching systems, wherein the one or more acid leaching systems comprise the serpentine-containing material, and the acid leaching systcm(s) separate silica from an acid leachate comprising at least Mg2+; directing at least a portion of a first electrolyte comprising the hydroxide base and the acid leachate to one or more alkalinization / precipitation systems configured to precipitate the Mg2+from the acid leachate as Mg(OH)2; and introducing at least one of the SCMs to the one or more cement formulation systems to produce Mg-containing cement, wherein the SCMs include at least one of silica from the acid leaching system(s), Mg(OH)2 from the alkalinization / precipitation system(s), and / or MgO from the alkalinization / precipitation system(s).

[0082] In some embodiments, no carbonate-based feedstocks such as limestone are added to the concrete / cement. In some other embodiments, no more than about 10 wt% of the concrete / cement feedstock is carbonate -based. In some other embodiments, no more than about 20 wt% of the concrete / cement feedstock is carbonate-based. In some other embodiments, no more than about 30 wt% of the concrete / cement feedstock is carbonate-based. In some otherembodiments, no more than about 40 wt% of the concrete / cement feedstock is carbonate -based. In some other embodiments, no more than about 50 wt% of the concrete / cement feedstock is carbonate-based. In some embodiments, only the aggregate added to the concrete comprise carbonate. In some embodiments, the final cement / concrete product is a substantially Mg- containing cement with comparable mechanical, structural and durability performances, while possessing advantages of fire resistance and emission reduction. In some embodiments, the final cement / concrete product is a substantially Mg-containing cement that is substantially carbon- neutral.

[0083] Advantageously, the Mg cement can be incorporated into, or completely replace, building materials such as concrete (Portland cement), gypsum (calcined calcium sulfate), cementitious boards and pre-cast, post-tensioned, components.Computer program product

[0084] The present subject matter described herein may be a system, a method, and / or a computer program product. In some embodiments, the computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present subject matter.

[0085] In some embodiments, the computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a RAM, a ROM, an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic wavespropagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.

[0086] In some embodiments, computer readable program instructions described herein can be downloaded to respective computing / processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and / or a wireless network, or Near Field Communication. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and / or edge servers. A network adapter card or network interface in each computing / processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing / processing device.

[0087] In some embodiments, computer readable program instructions for carrying out operations of the present subject matter may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++, Javascript or the like, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present subject matter.

[0088] In some embodiments, the computer readable program instructions may be provided to a processor of a computer, special purpose computer, or other programmable data processingapparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks. In some embodiments, the computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and / or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function / act specified in the flowchart and / or block diagram block or blocks.

[0089] In some embodiments, the computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0090] It is understood that the foregoing detailed description and accompanying examples are merely illustrative and are not to be taken as limitations upon the scope of the disclosure, which is defined solely by the appended claims and their equivalents.

[0091] Various changes and modifications to the disclosed embodiments will be apparent to those skilled in the art. Such changes and modifications, including without limitation those relating to the chemical structures, substituents, derivatives, intermediates, syntheses, compositions, formulations, or methods of use of the disclosure, may be made without departing from the spirit and scope thereof.

Claims

CLAIMSWhat is claimed is:

1. A system for manufacturing magnesium-containing cement comprising: one or more flow electro-synthesizer systems configured to produce an acid solution and a hydroxide base solution; one or more acid leaching systems that are in fluid communication with the acid solution from the flow electro- synthesizer system(s), wherein the acid leaching system(s) are configured to receive a serpentine-containing material comprising magnesium and separate silica from an acid leachate comprising at least Mg2+; one or more alkalinization / precipitation systems that are in fluid communication with the one or more acid leaching systems and the hydroxide base solution from the flow electro-synthesizer system(s), wherein the alkalinization / precipitation system(s) are configured to precipitate the Mg2+in the acid leachate as Mg(OH)i(s), and optionally dehydrating the Mg(OH)2(s) to MgO(s); and one or more cement formulation systems that are capable of receiving supplementary cementitious materials (SCM) to produce the Mg-containing cement, wherein the SCMs include at least one of silica from the acid leaching system(s), Mg(0H)2 from the alkalinization / precipitation system(s), and / or MgO from the alkalinization / precipitation system(s).

2. The system of claim 1, wherein the one or more flow electro-synthesizer systems comprise: a first compartment comprising: a cathode; a first electrolyte solution that is in electrical and fluid communication with the cathode; wherein a pH of the first electrolyte solution is 6 <pH<15.5; wherein the cathode is configured to generate a hydrogen gas and the hydroxide base solution; a second compartment comprising: an anode; anda second electrolyte solution that is in electrical and fluid communication with the anode; wherein a pH of the second electrolyte solution is -1.5<pH<8; wherein the anode is configured to generate the acid solution; and a third compartment positioned between and in fluid communication with the first compartment and the second compartment and comprising: a third electrolyte solution, wherein a pH of the third electrolyte solution is 4<pH<10.

3. The system of claim 2, wherein the third electrolyte solution comprises one or more inorganic salts.

4. The system of any one of claims 1-3, wherein the hydroxide base comprises one or more of sodium hydroxide, lithium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, ammonium hydroxide, or any combination thereof, preferably sodium hydroxide.

5. The system of any one of claims 1-4, wherein the acid solution comprises one or more of hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfurous acid, sulfuric acid, nitric acid, phosphorous acid, phosphoric acid, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, formic acid, acetic acid, carbonic acid, or any combination thereof, preferably hydrochloric acid.

6. The system of any one of claims 3-5, wherein the one or more inorganic salts comprise sodium chloride, potassium chloride, lithium chloride, sodium bromide, potassium bromide, lithium bromide, sodium iodide, potassium iodide, lithium iodide, sodium sulfite, potassium sulfite, lithium sulfite, sodium sulfate, potassium sulfate, lithium sulfate, sodium nitrate, potassium nitrate, lithium nitrate, sodium nitrite, potassium nitrite, lithium nitrite, sodium phosphite, potassium phosphite, lithium phosphite sodium phosphate, potassium phosphate, lithium phosphate, sodium hypochlorite, potassium hypochlorite, lithium hypochlorite, sodium chlorite, potassium chlorite, lithium chlorite, sodium chlorate, potassium chlorate, lithium chlorate, sodium perchlorate, potassium perchlorate, and lithium perchlorate, or any combination thereof, preferably sodium sulfate.

7. The system of any one of claims 2-6, wherein the second compartment is configured to receive a hydrogen stream to be oxidized on the anode to produce the acid solution, wherein the hydrogen stream comprises the hydrogen gas formed in the first compartment, a hydrogen provided from an external source, or a combination thereof.

8. The system of any one of claims 2-7, wherein the third compartment is separated from the first compartment with one or more cation exchange membranes and is separated from the second compartment with one or more anion exchange membranes.

9. The system of any one of claims 2-8, wherein the one or more flow electro-synthesizer systems operate at a voltage of about 1.0 V to about 10.0 V.

10. The system of any one of claims 2-9, wherein the one or more flow electro- synthesizer systems generate the acid solution and the hydroxide base solution in a batch or in a continuous operation.

11. The system of any one of claims 1-10, wherein at least a portion of the hydroxide base solution formed in the first compartment is fed to the one or more alkalinization / precipitation systems to precipitate the Mg2+in the acid leachate as Mg(OH)2(s) and to produce a salt solution.

12. The system of any one of claims 1-11, wherein the one or more alkalinization / precipitation systems is in fluid communication with the one or more flow electro- synthesizer systems.

13. The system of claims 11 or 12, wherein the salt solution from the one or more alkalinization / precipitation systems is delivered to the third compartment of the one or more flow electro- synthesizer systems.

14. The system of any one of claims 1-13, wherein at least a portion of the acid solution formed in the second compartment of the one or more electro- synthesizer systems is fed to one or more acid leaching systems.

15. The system of any of claims 1-14, wherein at least a portion of the Mg(OH) is dehydrated to MgO.

16. The system of any of claims 1-15, wherein at least one acid leaching system comprises multiple containers, wherein the concentration of acid in the multiple containers is different from one another.

17. A method of producing magnesium-containing cement from a serpentine-containing material comprising providing one or more of the systems of any of claims 1-16; electrochemically generating a hydrogen gas and a hydroxide base on the cathode in the first compartment; and flowing a stream comprising a generated hydrogen gas, a hydrogen gas provided by an external source, or a combination thereof, into the second compartment such that electrochemically generated hydrogen ions are formed on the anode to produce an acid solution; directing at least a portion of a second electrolyte comprising acid solution to one or more acid leaching systems, wherein the one or more acid leaching systems comprise the serpentine-containing material, and the acid leaching system(s) separate silica from an acid leachate comprising at least Mg2+; directing at least a portion of a first electrolyte comprising the hydroxide base and the acid leachate to one or more alkalinization / precipitation systems configured to precipitate the Mg2+from the acid leachate as Mg(0H)2; and introducing at least one of the SCMs to the one or more cement formulation systems to produce Mg-containing cement, wherein the SCMs include at least one of silica from the acid leaching system(s), Mg(0H)2 from the alkalinization / precipitation system(s), and / or MgO from the alkalinization / precipitation system(s).

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