Patent Application
20250215578
Climate change is one of the most pressing challenges facing the world today. It is caused by the release of greenhouse gases into the atmosphere, which trap heat and warm the planet. Process industries, such as chemicals, cement, metallurgy, and refining, are among the largest emitters of greenhouse gases. For example, cement production alone is responsible for about 8% of global CO2 emissions.
Decarbonizing the cement sector requires creating transformative pathways to reduce carbon emissions associated with cement and concrete manufacturing. In this context, the sustainable sourcing of calcium- and magnesium-based minerals represents a paramount priority due to their dominant use in more sustainable cements and presence as aggregates in concrete, respectively, but also as source of raw material for the cement manufacturing or additions to be used in cements as part of the overall binder. In response to this challenge, the current study demonstrates an innovative electrochemical mineral precipitation approach that offers a carbon-negative solution for the selective and tailorable growth of calcium- and magnesium-based minerals from ocean and sea waters via electrodeposition.
It is known that CO2 contained or added to sea water can lead to the precipitation of minerals using electrochemical methods. In fact, the methods available in the literature have as a primary objective the precipitation of minerals, without caring for the type, typology, and overall characteristics of the precipitated minerals.
For example, U.S. Pat. No. 11,413,578 [1] provides a method to remove CO2 from an aqueous stream, wherein an aqueous solution comprising CO2 and ions capable of forming an insoluble carbonate salt contacts an electroactive mesh, forcing the precipitation of carbonate solid(s) from the solution. With the focus on carbon sequestration, the method does not detail a process to produce materials specific to the construction industry, with customizable sizes and densities. Furthermore, the method does not teach how to control the different process parameters, such as pH, applied voltage, or temperature, to produce said customized materials, like the present invention does.
Another example would be WO 2022/178125 [2], disclosing a system, comprising: a fluid container; an electrode pair configured to convert the contained fluid to a solid; and a nanotextured surface configured to facilitate nucleation of the solid within the container. Like U.S. Pat. No. 11,413,578 [1], a surface is needed for the electrodeposition of the solids; furthermore, no details regarding the control of the process to produce specific particles are mentioned.
Other similar examples, also purely focusing on carbon sequestration, would be WO 2007/140544, US20100084283, EP 1 830 945 or U.S. Pat. No. 11,465,925 [3-6], whereby the formation of carbonate products is done in multiple steps, and/or using a different method than the one hereby disclosed, and never targeting the production of customizable construction materials, with specific sizes or densities.
Another application of CO2 mineralization is sea life and coral restoration. Examples of such applications include Zhang et al. (Direct Electrochemical Seawater Splitting for Green Hydrogen and Artificial Reefs, ACS Applied Energy Materials. 6 (14): 7636-7642, 2023) [7], or Carré et al. (Electrochemical calcareous deposition in seawater. A review, Environmental Chemistry Letters, 18:1193-1208, 2020) [8]. Despite similar electrochemical methods are used, the application, and consequently the desired properties of the final obtained materials, are significantly different.
Nonetheless, to use said minerals in cement production, it is beneficial to be able to predict and even control their characteristics, to ensure that the precipitated material can be used as fine aggregate, and the final product still complies with the existing norms and standards.
The prior art does not describe any detailed method for the purpose of precipitation specifically targeted minerals from the sea water to be used in the cement industry as raw material or additions to cements, or as aggregates in concrete mix designs.
Problem to solve: About 13 billion tons of sand are used annually just for construction, as the second most-used resource on Earth, and this demand is growing by about half a ton per year, expected to reach 20 billion tons annually by 2030. Due to the monumental demand for sand from the construction industry, the world is inching towards a crisis of sand depletion. Highly desirable sand from rivers and lakes is not an endless resource and already the construction industry suffers from a lack of it.
The current invention proposes a method/process and an equipment/device to mitigate the scarcity of sand (to be used in the cement and concrete industry) by using a combination of available CO2 and sea water (that contains high amounts of dissolved ions) and electrodeposition technology. Conditions are defined to favor the precipitation of selective minerals to meet the requirements of the construction industry.
This invention relates to a novel concept of electrodeposition in seawater that underpins the growth of construction materials for use in the cement and concrete industries and has the extra benefit of absorbing CO2 from the atmosphere. The overarching principle behind such a carbon-negative manufacturing approach specifically lies in injecting CO2 gas while applying an electric current in ocean and sea waters, as solely done to trigger the classical electrodeposition process. The injection of CO2 in sea and ocean waters boosts the electrodeposition of minerals at cathodic interfaces, making such an approach adequate to serve the cement and concrete industries. The invention according to the patent is that electrodeposits form in ocean and sea waters by the reaction between hydroxide ions resulting from oxygen reduction reaction and/or water electrolysis, abundant divalent ions (e.g., magnesium and calcium) in ocean and sea waters, and bicarbonate ions naturally dissolved therein. The injection of CO2 gas increases the concentration of bicarbonate ions, accelerating the growth rate of deposited minerals on the cathode surface by establishing a synergistic balance between injected CO2 and applied electrochemical potential.
The invention thus relates to a method/process and an equipment/device to produce calcium rich-based aggregates by electrodeposition in salty aqueous CO2 enriched solutions, that can be used in the construction industry.
An objective of the present invention is therefore a method to produce calcium rich-based aggregates, said method comprising the following steps:
According to a particular embodiment of the method of the present invention, the aqueous salty solution AS2 is brought in step b) at a temperature from 20° C. to 25° C. and at a pH from 8.0 to 8.4, in CR1.
According to a particular embodiment of the method of the present invention, the continuous reactor CR2 of step c) comprises at least two compartments each comprising at least one cathode or at least one anode.
According to a particular embodiment of the method of the present invention, the C-gas of step d) is re-circulated to be re-injected into CR2.
According to a particular embodiment of the method of the present invention, the volume % of CO2 injected in the continuous reactor CR2 in step d) is 0.05-10 volume % per hour.
According to a particular embodiment of the method of the present invention, the DC current ranges from 5 A/m2 to 1000 A/m2 or the voltage ranges from 0.8 V to 10.0 V volts.
According to a particular embodiment of the method of the present invention, the calcium rich-based aggregates are produced with a CaCO3 content from 20% to 90%.
According to a particular embodiment of the method of the present invention, the calcium rich-based aggregates are generally produced with an average size from 0.1 mm to 15 mm, but can exceed 50 mm. For instance, the calcium rich-based aggregates are produced with an average size from 0.1 mm to 70 mm, preferably from 0.1 mm to 50 mm, more preferably from 0.1 mm to 15 mm.
Another objective of the present invention is a device or equipment for carrying out the method according to the present invention. Preferably the device or equipment used is as detailed below and illustrated on
The electrodeposition process of solid minerals in seawater results from a complex interplay of electrochemical redox reactions and precipitation reactions, which lead to the nucleation and growth of minerals around cathodic interfaces. A crucial factor driving electrodeposition is the generation of hydroxide ions (OH−) at the cathode, which can occur either through the oxygen reduction reaction (ORR) or through the water reduction reaction (WRR) in seawater, each necessitating different reaction potentials to proceed. The total rate of OH-production is proportional to the resultant current density. However, the reaction selectivity will vary with the applied potential. The generation of OH ions (at the cathode) in the ORR regime is linked to multiple plausible reaction mechanism pathways, with one of these pathways involving the production of H2O2 in alkaline media and requiring a thermodynamic voltage of Eocell=−0.841 V. Conversely, in the WRR regime, a different mechanism is at play, necessitating a thermodynamic voltage of Eocell=−1.2287 V for water-splitting. However, an overpotential will always be required to overcome junction potential, series resistance, and slow reaction kinetics.
At potentials of −0.8 V (vs Ag/AgCl, where Ag/AgCl is a reference electrode when using a potentiostat as power source) and −1.0 V (vs Ag/AgCl), the production of OH− at cathode is achieved from ORR (oxygen here is the dissolved oxygen in seawater which is a limiting reactant in the considered closed batch system), as per Equation (1):
O2+2H2O+2eH2O2+20H− (1)
At potentials lower than or equal to −1.2 V (vs Ag/AgCl) (i.e., more negative potentials), selectivity shifts toward OH-production from WRR, evolving hydrogen gas at the cathode, as per Equation (2):
2H2O+2eH2(⬆)+2OH− (2)
In this regime, hydrogen gas bubbles form at the cathode surface, becoming more noticeable as the magnitude of the applied voltage is increased. If the solution achieves acidic conditions, hydrogen evolution can also proceed following Equation (3):
2H++2eH2(⬆) (3)
With either ORR or WRR, the generation of OH-ions lead to an increase in pH near the cathode surface, with two major effects. On the one hand, nucleation and growth of insoluble Mg(OH)2 takes place, as per Equation (4):
Mg2++2OH→Mg(OH)2(⬇) (4)
On the other hand, the carbonate equilibrium expressed in Equation (5) shifts toward a higher concentration of carbonate ions CO32−, as per Equation (6):
CO2+H2O↔H2CO3↔H++HCO3+H++CO32− (5)
OH−+HCO3→H2O+CO32− (6)
Therefore, insoluble calcium carbonate CaCO3 can also precipitate following the two typical pathways expressed in Equations (7) or (8):
Ca2++CO32−→CaCO3(⬇) (7)
Ca2++HCO3−+OH−↔H2O+CaCO3(⬇) (8)
CaCO3 is thermodynamically more stable (ΔG°F.,calcite=−1129.1 KJ mol−1, ΔG°F., aragonite=−1128.2 KJ mol−1, ΔG°F., brucite=−833.7 KJ mol−1). However, the kinetics of Mg(OH)2 formation overrides thermodynamics due to the higher concentration of Mg2+ compared to Ca2+ in seawater (typically exhibiting the ratio of about 5:1 for standard salinity conditions and insufficient availability of dissolved carbonates, leading to faster and preferential precipitation of Mg(OH)2). Specifically, irrespective of the applied potential, Mg(OH)2 generally precipitates before CaCO3. As a result of the electrodeposition of Mg(OH)2, which typically occurs in the form of brucite, the interfacial pH previously raised by the OH production locally decreases, involving two possible consequences. At limited values of potential associated with the ORR regime, the generation of OH− is contingent upon the diffusion of dissolved O2 and its reduction at the cathode (here for less negative potentials than −1.2 V (vs Ag/AgCl)). Therefore, CaCO3 minerals can precipitate in the form of aragonite or calcite after the initial precipitation of Mg(OH)2 because the local pH is sufficient for CaCO3 precipitations but not for continued Mg(OH)2 precipitations. In contrast, at significant values of potential associated with the WRR regime, OH− production rate is substantial enough to sustain a pH underpinning Mg(OH)2 precipitation (here for potentials more negative or equal to −1.2 V (vs Ag/AgCl). Therefore, a continued and preferential deposition of Mg(OH)2 is observed over CaCO3 in this regime.
While reduction reactions take place at the cathode, oxidation reactions take place at the anode, playing an equally important role in the electrodeposition of minerals in seawater. These reactions do not directly contribute to the growth of mineral depositions at the cathode. However, in systems such as the membrane-free batch reactor, they exert an influence that becomes more noticeable for increasingly negative potentials.
The complementary oxidation reactions that proceed at the anode balance the reduction reactions of oxygen and water at the cathode (Equations (1-3)) and consist of oxygen evolution reactions (OER). In the ORR regime, oxygen evolution follows Equation (9), which corresponds to cathodic half-reaction Equation (1):
H2O2O2(⬆)+2H++2e− (9)
In the WRR regime, oxygen evolution follows Equation (10) in alkaline conditions whereas Equation (11) in acidic conditions, which correspond to the cathodic half reactions expressed in Equations (2) and (3), respectively:
4OH−O2(⬆)+2H2O+4e− (10)
2H2OO2(⬆)+4H++4e− (11)
A higher magnitude of applied voltage leads to a higher production rate of H2 and OH− at the cathode and O2 and H+ at the anode, increasing the driving force for H+ and OH− ions to diffuse further away from the electrodes at which they are produced. At −1.6 V (vs Ag/AgCl) and more negative potentials, this phenomenon can result in a crosstalk of ions between the electrodes and neutralization of the OH− intended to participate, as per Equation (12):
H++OH−→H2O (12)
Besides the dissolved oxygen (O2) that is naturally present in seawater and water (H2O) itself, various other chemical species present in seawater can undergo multiple redox reactions based on their standard reduction potential and the applied potential.
In the WRR regime, additional potential reaction pathways involve chlorine oxidation at the anode, as per Equations (13-22). Equations (13-15) are feasible in alkaline conditions, whereas Equations (16-22) are feasible in acidic conditions, especially at-1.6 V (vs Ag/AgCl):
Cl−+6OHClO3−+3H2O+6e− (13)
Cl−+4OHClO2−+2H2O+4e− (14)
Cl−+2OHClO−+H2O+2e− (15)
ClO2+H2OClO3−+2H++e− (16)
ClO3−+H2OClO4−+2H++2e− (17)
2Cl−Cl2(⬆)+2e− (18)
Cl−+4H2OClO4−+8H++8e− (19)
Cl−+3H2OClO3−+6H++6e− (20)
Cl−+H2OHCIO+H++2e− (21)
Cl−+2H2OHClO2+3H++4e− (22)
The wide array of such secondary reactions stems from the versatility of Cl− ions to adopt various oxidation states, ranging from +1 in NaCl to +7 in ClO4− and their dependency upon the pH and the applied potential, which is observed from the Pourbaix diagram of Cl− in seawater.
These reactions at anode do not appear to influence the composition of electrodeposits, but they can affect the total yield of the electrodeposits by consuming OH− which participates in electrodeposition if used in a membrane free one pot reactor. Ion selective membranes can prevent the passage of OH− from cathodic to anodic chamber and allows only Equation 9 and Equation 11 and Equation 16-22 on anode. The role of OH ions is to enhance the formation of carbonates, leading to CaCO3 precipitation, balancing the decrease in pH caused by CO2 injection, routing towards neutralization reaction, as well as participating in precipitation reaction that produces Mg(OH)2. To achieve these goals, stoichiometrically, it is required to generate 4 moles of hydroxide (OH−) at the cathode to transform 1 mole of injected CO2 into 1 mole of CaCO3 or MgCO3, while simultaneously producing 1 mole of Mg(OH)2 or Ca(OH)2 without affecting pH of effluent seawater. The precipitation of specific types of mineral hydroxide Mg(OH)2 or Ca(OH)2 or mineral carbonate CaCO3 or MgCO3 and their specific percentage weight is governed by their saturation indices in seawater as well as several other factors including the chemistry of seawater, concentration of OH, CO32−, Ca2+, and Mg2+, electrode material features, electrochemical cell design, and magnitude of applied electrochemical potential/current.
According to a first embodiment of the invention summarized in
AS1 is pumped using for instance—but not limited to—a pumping system P0, into the conditioning reactor CR1 after passing through a filter system F1 located uphill from the reactor CR1, to remove organic debris or other pollutants and produce an aqueous salty solution AS2. The filter F1, for instance, consists of metallic grids (mesh-mesh), organic or inorganic fibers or any conventional water filtration material. AS2 is brought in CR1, where the pH and the temperature of AS2 entering CR1 are measured and regulated, to meet the operating conditions of the electrodeposition, to produce an aqueous salty solution AS3.
CR1 is equipped with heating and cooling devices respectively HD and CD, that can be located inside or outside the reactor vessel CR1V. HD is preferably heated using electrical or gas fired heating elements. The heating/cooling devices HD/CD can be an integrated heat exchanger or heat pumps or any other heating device. When located inside the reactor vessel CR1V, the heating and cooling devices HD and CD should be made of anti-corrosive materials, due to the natural corrosive properties of salty water. Heating devices HD that can be used are for example jacketed vessels, immersion heater, coils, or heat exchanger. Cooling devices CD that can be used are for example heat exchangers, jacketed vessels, or cooling coils. The temperature regulation is done using conventional thermos-elements to measure the temperature and commercially available temperature regulators acting on the heating and cooling devices. The temperature is from 18° C. to 29° C., preferably from 20° C. to 25° C.
The pH is regulated inside CR1 using industrially available pH meters, electronic regulators connected to acid (such as 0.01 to 100 volume % of H2CO3, HCl or base (such as 0.01 to 100 volume % of NaOH, Na2CO3) dispensers equipped with dosing devices. The pH is from 7.1 to 9, preferably from 8.0 to 8.4.
The aqueous solution in CR1V (ASCR1) is agitated using propellers or pumps located inside or outside the vessel V1 of CR1. Preferably, the agitation pumps can be the pumps (not showed) used to circulate ASCR1 through the HD and CD located outside CR1V.
Alternatively, additional industrial brines or salt solution can be added to AS1 prior to the filter F1 or directly to ASCR1.
The conditioning reactor CR1 typically comprises a vessel V1 in rectangular or tube form or any other form suitable for the purpose. The volume of CR1 (CR1vol) is defined by a relation between the volume of the second reactor CR2 (CR2vol) and the flow of AS3 in CR2.
According to
According to
The continuous reactor CR2 is in the form of a closed container, in the form of a parallelepiped or a cylinder or any 3-dimensional shape with one dimension larger than the other 2. CR2 is equipped with a pumping system P1 to pump AS3 from CR1 into CR2 through at least one inlet CR21 and at least one outlet CR20. The characteristics of the pump system P1 are selected so the flow rate FRAS3 of aqueous solution AS3 into the reactor CR2 is determined by the cross section of the reactor CR2 to obtain a velocity or displacement speed VAS3, located between 0.01 m/s and 5 m/s. The continuous reactor CR2 is equipped with an electroactive substrate comprising at least one cathode electrode and one anode electrode of any shape (cylindrical, concentric, flat plate, curved plate, grid, porous plate, or rod) that are in contact with the AS3 and are connected to an electrical DC supply/DC electrical power source to apply a controlled voltage or current between the cathode(s) or the anode(s). The CR2 can be also equipped with at least one online pH measuring device and one online temperature measuring device. The continuous reactor CR2 is equipped with at least one C-Gas injection device CGI located near the cathode in the lower part of the reactor, and at least a C-Gas collection device (CGC located in the upper part of the CR2 reactor).
Cathodes contemplated in this invention comprise materials selected from the group consisting of stainless steel (SS), aluminum (Al), nickel (Ni), and mixed metal oxides (MMO). Stainless steel offers good corrosion resistance and durability, while aluminum and nickel may require additional treatments for enhanced corrosion resistance. MMO-coated stainless-steel cathodes improve electrocatalytic activity and corrosion resistance. This innovation includes flat plate cathodes, mesh cathodes, and tubular cathodes among other cathode shapes. These forms can be modified to fit various CR2 reactor arrangements. Cathode sizes can be modified to fit the configurations and capacities of CR2 reactors. They could be made of tiny plates, bigger panels, mesh or porous plates or tubular structures. The active surface of the cathodes in contact with AS3 is typically selected to be located between 0.01 to 0.5 m2 per m3 of AS3, preferably between 0.1 to 0.15 m2 per m3 of AS3.
The anode components may be made of mixed metal oxides (MMO), titanium (Ti), graphite, and platinum (Pt). In seawater, titanium offers great resistance to corrosion, whereas platinum and MMO have a high electrocatalytic activity. The corrosion resistance of titanium and the electrocatalytic qualities of metal oxides, such as ruthenium oxide or iridium oxide or tantalum oxide, are combined in MMO-coated anodes. Anodes can have coatings applied to improve their performance. Options for coatings include Platinum, Platinum-Palladium, IrO2, RuO2, IrO2—Ta2O5, IrO2—RuO2, mixed metal oxides (MMO) coatings on Titanium base (grade1 or grade 2) to improve electrocatalytic characteristics, and platinum-iridium coatings to improve durability and performance. Anodes can encompass a variety of shapes, such as flat plate anodes, mesh anodes, and tubular anodes. These shapes can be modified to fit the CR2 system's unique specifications and needs. The CR2 reactor's size and capacity have an impact on the anode's size. Anode sizes can range from small discs to large panels, depending on the reactor's specs and production needs.
Electrodes (both cathode and anode) may also be coated with conductive and non-corrosive material such as Platinum-coated Titanium, Iridium-coated titanium, IrO2 coating, Mixed metal oxide (MMO) coating, polymer coating (e.g. perfluorosulfonic acid (PFSA)) etc.
The surface area ratio (SAR) between the cathode and anode surfaces should fall within the range of 1 or 3, preferably between 1 to 1.5. A SAR less than 1, indicating a smaller cathode and a larger anode, results in increased production yield but a higher Mg(OH)2 content in aggregates. Conversely, a SAR exceeding 1.5, indicating a larger cathode and a smaller anode, compromises aggregate yield. SAR significantly influences various factors, including reaction rates, mass transport, current density, electrodeposition uniformity, and energy efficiency in electrochemical processes. Optimal solid product output is achieved by selecting a SAR between 1 and 1.5. Ratios above this range demand enhanced energy efficiency, while ratios below this range may accelerate electrode degradation and raise anode costs.
The electrochemical reactor (CR2) is designed to operate on DC power supply. The DC supply in the system typically utilizes a rectification circuit to convert alternating current (AC) power from the electrical grid into direct current (DC) power. This DC supply is intended to supply the electrochemical reactor with a consistent and controlled voltage and current. A standard auto range DC supply operating in the range 0-100V and 0-50 A, available market options such as 6V & 5A or 20 V & 2 A or 30 V & 5 A or 35 V & 1A or 60 V & 40 A or a custom designed DC supply in the specified operating range can be used. The voltage and current levels within the reactor can be adjusted as needed to optimize the electrochemical processes, ensuring effective aggregates production while maintaining system safety and control. For instance, a constant DC current ranging from 1 A/m2 to 5000 A/m2, preferably from 5 A/m2 to 1000 A/m2, the m2 representing the deployed surface of the electrodes in contact with AS3, or a voltage ranging from 0.5 V to 20.0 V, preferably from 0.8 V to 10.0 V volts, is applied, to the electrodes.
When working with low current and voltage, solid deposits can accumulate on the surface of the electrodes over time. Once these deposits reach the required size or thickness, one alternative to remove the precipitated material is to apply a high voltage to crack or dislodge the solid deposits from the electrode surface. The cracked solids then fall to the bottom of the container or system for later collection.
According to
The distance between the cathodes and anodes in the electrochemical reactor can significantly impact the efficiency and effectiveness of the electrochemical processes. The optimal distance between them depends on several factors, including the electrical conductivity of cathodes and anodes, their sizes, the desired reaction rates, and the hydrodynamics of the electrolyte which can be in the range of 5-100 cm or maximum available as per size of the reactor vessel and electrodes.
The C-Gas (preferably containing from 10% to 100% CO2, more preferably from 20 to 100 volume % of CO2) is injected below the electrodes specifically cathodes, using one or many entry points (CGI) to the vessel CR2V, and may include a C-Gas piping system inside the vessel CR2V to distribute the C-Gas evenly in the vessel CR2V in contact with the aqueous salty solution AS3. The C-Gas bubble towards the surface of AS3 and is collected in the upper part of the CR2 reactor. The C-Gas collected can then be re-circulated using a circulating device GL (for example, at least one pipe and one gas circulating pump, a fan or blower connecting the upper part of CR2 to CGI), to be re-injected into the vessel CR2V. The C-Gas recirculating system can be connected to a source of CO2-Rich gas (containing up to 100% CO2) to maintain the CO2 content in the C-Gas above 20% volume %, preferably between 30 and 50 volume %, and compensate for the CO2 depletion of the C-Gas by the carbonation reaction in the CR2 vessel. The CO2-rich source can be pure CO2 or any gas or industrial flue gas having a CO2 content significantly higher than the minimum CO2 content required in the C-Gas. The C-gas is injected into AS3 using a C-gas mass flow controller and can be selected by flowrate of gas injection or volume of CO2 required to be injected or concentration of CO2 needed to be injected in AS3 for enhanced growth rate. The flow rate of CO2 injection from C-gas stream can be adjusted in the range of 0 to 1000 sccm (standard cubic centimeters per minute) per cubic meter of AS3 preferably in the range of 100-300 scc per minute per cubic meter of AS3. The C-gas flow rate in reactor CR2 is selected so that the volume % of CO2 injected in AS3 should be 25-30 total volume % of AS3, or so that the volume % of CO2 injected in CR2 is 0.05-10 volume % per hour, preferably 0.05-5 volume % per hour, more preferably from 0.4-5 volume % per hour. C-gas flow rate can be calculated using the relation (in volume units per hour)=(Volume % of CO2 desired*100)*(Volume of the reactor (CR2))/time.
The process and parameters (temperature and pH of AS3, flow rate of AS3) are maintained constant for some hours to some days (e.g. 24-168 hours, 7 days, or 30 days), until the electrodeposited aggregates are removed from the bottom of CR2 and/or the surface of the electrodes, and post-processed (washing, drying, remove salt traces, grinding, etc.) to be used typically in the material construction industry (cement, mortar, asphalt, concrete, or limestone-based industry).
According to
The choice of membrane type and its details are essential for the proper functioning of the electrochemical system. The specific membrane chosen depends on the electrochemical processes taking place in the compartments, the ions involved, and the desired selectivity. Membranes are critical for maintaining the integrity of the separate compartments, preventing unwanted reactions, and controlling ion transport between the anodes and cathodes. Here are some common types of membranes used in such setups and how they work:
on-Selective Membranes: Ion-selective membranes are designed to allow specific ions to pass while blocking others. They work based on the principle of selective ion transport. For example, cation-selective membranes (CSM) permit the passage of positively charged ions (cations) while blocking negatively charged ions (anions). Anion-selective membranes (ASM) perform the opposite function. Cation selective ion provides the option to permit the possible cations such as Ca2+, Mg2+, Na+, Sr2+, K+, H+ not limited to and other possible cations in AS3 and anion selective membranes permits anions such as OH−, Cl−, HCO3, CO32− not limited to from one compartment to another. Examples of such membranes but not limited to include sulfonated tetrafluoroethylene-based fluoropolymer-copolymer, a fluorinated ion-exchange membrane, perfluorosulfonic acid based, organic polymer materials such as polystyrene polymer-based, conducting polymer-based membranes.
Permeable Membranes (PM): These membranes are designed to allow the passage of specific molecules or ions based on size and charge. They provide a controlled barrier between compartments, regulating the exchange of species while preventing mixing. Examples of such separators include, but are not limited to, polytetrafluoroethylene, polyvinylidene Fluoride, cellulose acetate, polyethersulfone and mixed cellulose ester membranes.
Separator Membranes (SM): Separator membranes are designed to physically separate the compartments to prevent direct contact between anodes and cathodes. They are typically made of materials that are chemically stable and resist corrosion in the harsh electrochemical environment. Examples of such separators include but are not limited to, glass fiber separator, polypropylene separator, ceramic separator, and nonwoven separator membranes.
Additionally, the invention allows for flexibility in the design, which means that additional compartments with appropriate membranes can be incorporated based on the specific needs and goals of the electrochemical system, further enhancing its versatility and adaptability.
This layout presents various advantages:
For the series arrangement (
For the parallel arrangement (
In both cases, respectively in
Preferably, a design using multiple compartments will have chambers arranged in series, with an equal number of cathodes-containing compartments and anodes-containing compartments.
Aggregates. Inert granular material that comprises as much as 60% to 80% of a typical concrete mix. It is composed of geological materials such as gravel, sand and crushed rock. The size of the particles determines whether it is a coarse aggregate (8-32 mm) or a fine aggregate (4-8 mm). Lower than 4 mm aggregates are defined as “Sand”. Concrete aggregate can be used in its natural state or crushed, depending on the use and application of the concrete.
Anode. The anode is the positively charged electrode, attracting electrons or anions.
Asphalt. A mixture of dark bituminous pitch with sand or gravel, used for surfacing roads, flooring, roofing, etc.
Batch reactor. It is a non-continuous type of reactor where the reactants are fed into the reactor all at once initially. The vessel contains an agitator and an internal heating or cooling system.
Binder. Material with cementing properties that sets and hardens due to hydration even under water. Hydraulic binders produce calcium silicate hydrates also known as CSH.
Brine. Water strongly impregnated with salt.
Carbonation. Carbonation is the reaction between carbon dioxide gas and a solid (for example, minerals) or liquid (for example, water).
Cathode. The cathode is the negatively charged electrode. Attracting cations or positive charges.
Cement. It is a binder that sets and hardens and brings materials together. The most common cement is the ordinary Portland cement (OPC) and a series of Portland cements blended with other cementitious materials.
Concrete. A building material made from a mixture of broken stone or gravel, sand, cement, and water, which can be spread or poured into moulds and forms a mass resembling stone on hardening.
Continuous reactor. Reactors that carry material as a flowing stream. Reactants are continuously fed into the reactor and emerge as a continuous stream of product.
Crystal. A solid whose atoms are arranged in a “highly ordered” repeating pattern.
DC Power supply. A type of power supply that gives direct current (DC) voltage to power a device. Direct current (DC) is a type of electrical current that flows in only one direction. Batteries and solar cells supply DC electricity.
Electric potential. The amount of work energy needed per unit of electric charge to move this charge from a reference point to the specific point in an electric field.
Electroactive substrate. In voltammetry and related techniques, a substance that undergoes a change of oxidation state, or the breaking or formation of chemical bonds, in a charge-transfer step.
Electrode. A conductor through which electricity enters or leaves an object, substance, or region.
Electrodeposition. Deposition of a substance on an electrode by the action of electricity. It is a process that uses electric current to reduce dissolved cations so that they form a coating or a deposit on an electrode.
Greenhouse gas. A gas that contributes to the greenhouse effect by absorbing infrared radiation. Carbon dioxide and chlorofluorocarbons are examples of greenhouse gases.
Hydration. It is the mechanism through which OPC or other inorganic materials react with water to develop strength. Calcium silicate hydrates are formed and other species like ettringite, monosulfate, Portlandite, etc.
Hydraulic binder. It is a material with cementing properties that sets and hardens due to hydration even under water. Hydraulic binders produce calcium silicate hydrates also known as CSH.
Limestone. A hard sedimentary rock, composed mainly of calcium carbonate or dolomite, used as building material and in the making of cement.
Mineralization. Carbon mineralization is the process that chemically transforms carbon into solid mineral (carbonate). It occurs in nature when certain rocks are exposed to carbon dioxide. Mineralization may be accelerated and used to capture CO2 in various minerals and materials using different conditions like temperature, pressure, or humidity. The advantage of this process is that CO2 becomes permanently bound and cannot escape back to the atmosphere.
Minerals. A naturally occurring inorganic solid that has a definite chemical composition, and an ordered internal structure.
Mortar. Mortar is made from cement, sand, and sometimes lime or admixtures, and is used for bonding bricks, stones, and other materials.
Ordinary Portland cement (OPC). Hydraulic cement is made from grinding clinkers with gypsum. Portland cement contains calcium silicate, calcium aluminate and calcium ferro-aluminate phases. These mineral phases react with water to produce strength.
Overpotential. The potential difference (voltage) between a half-reaction's thermodynamically determined reduction potential and the potential at which the redox event is experimentally observed.
Polymorphs. A condition when a solid chemical substance exhibits more than one crystalline form.
Potentiostat. A potentiostat is an electronic device that measures and controls the potential difference (voltage) and current between two electrodes by using three electrodes (working electrode as cathode, counter electrode as anode and reference electrode) electrochemical cell. It is commonly used to study electrochemistry involving electrochemical reactions such as battery, electrodeposition, corrosion etc.
Reactant. A substance that takes part in and undergoes change during a reaction.
Sand. Manufactured, natural or recycled minerals with a particle size lower than 4 mm.
Selectivity. Ratio of the desired product to the undesired product formed.
Silicate. Silicates are responsible for mechanical properties of cement.
Stoichiometric. It is the relation between the quantities of substances that take part in a reaction or form a compound.
Strength development—setting/hardening. The setting time starts when the construction material changes from plastic to rigid. In the rigid stage the material cannot be poured or moved anymore. After this phase the strength development corresponds to the hardening of the material.
Surface area. The total area covered by all the faces of a 3D object.
Voltage. The difference in electric potential energy per unit charge between two points. A voltage which is a measure of electric potential difference, is the cause of electrical current to flow in a closed circuit.
Yield. A measure of the quantity of moles of a product formed in relation to the reactant consumed, obtained in a chemical reaction, usually expressed as a percentage.
Abbreviations used to describe the system
Artificial saltwater was synthesized using sea salt (ASTM D1141-98) from Lake Products Company LLC and Type 1 ultrapure water (18.2 Mwcm of resistivity at 25° C.) from Millipore Sigma. As a result, 41.953 g of sea salt was completely dissolved in 1 liter of water to meet the ASTM D1141-98 requirement. Instant mixed seawater was found to have a pH that ranged from 8.3 to 8.4 at ambient temperatures.
A mass flow controller of range 0.01-300 sccm (standard cubic centimeter per minute) from Alicat Scientific Inc. was used for CO2 injection.
CO2 injected from a gaseous stream of 0.01% to 100% CO2 at a flowrate so that the concentration of CO2 in cathodic chamber injected in the range 30-100 mM in seawater. For a reactor vessel of 2-liter, the flowrate between 0.15-0.45 sccm (standard cubic centimeter per minute) from a 99.9% concentrated CO2 stream can maintain the required concentration.
All the experiments have been performed on a batch scale on a 2-liter artificial seawater in a controlled laboratory setting. Initially, the system is allowed to equilibrate for 1 hour as the open circuit potential is measured. Electrodeposits are created by applying a constant current or voltage for a time 24 or 72 or 120 or 168 h (i.e., 1 day-7 days) using a DC power source. The working current range is 1-5000 A/m2 including 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 3000, 4000, 5000 A/m2. The working potential range is 0.1-10 V including voltages of −0.8, −1.0, −1.2, −1.4, −1.6, −1.8, −2, −3, −4, −5, −6, −7, −8-, −9, −10 V (vs Ag/AgCl i.e. silver-silver chloride) corresponding to −0.803, −1.003, 1.203, and −1.403, −1.603, −1.803, −2.803, −3.803, −4.803, −5.803, −6.803, −7.803, −8.803, −8.803, −9.803 V (vs SHE i.e. standard hydrogen electrode).
High-Pressure water Jet Cleaning: High-pressure water jet cleaning utilizes pressurized water to dislodge and remove deposits. This method is effective for removing tough, adherent deposits. It's important to adjust the water pressure to a level that can remove deposits without damaging the stainless steel and titanium. Abrasive Cleaning: Abrasive methods involve using abrasive materials, such as sandpaper, wire brushes, or abrasive compounds, to physically scrub away deposits.
Sanding and Polishing: In some cases, light sanding and polishing may be used to remove deposits and restore the smooth surface of the cathode and reactor components. This can be particularly effective if deposits have caused surface irregularities.
Automated Cleaning Systems: For larger industrial setups, automated cleaning systems that involve cleaning with rotating brushes or mechanical arms can be employed for more efficient and consistent cleaning. These systems can be programmed to clean on a regular schedule or in response to deposit buildup.
Electrodeposits are collected for upcoming physicochemical characterizations after each test is finished. The deposits are removed from the reactor and dried in a desiccator for 48 hours at room temperature. Scanning electron microscopy (SEM) is used to photograph the electrodeposits' surface and morphological characteristics. X-Ray diffraction (XRD) spectra are obtained at room temperature to determine the crystalline phases of the electrodeposits. The thermal stability of the electrodeposits and corresponding carbon content is investigated using thermogravimetric analysis (TGA).
Working example 1: In a method for electrodeposition in seawater for the purpose of obtaining aggregates in the form of electrodeposits, an electric current with a density of −840 A/m2 is applied to the cathode, where the cathode and anode have a surface area ratio of 1.5. The cathode and anode are positioned at a separation distance equal to the length of the anode. Simultaneously, CO2 gas is introduced at a rate of 0.15 sccm (standard cubic centimeter per minute) at the bottom of a batch reactor with a volume of 2 liters, the reactor employing artificial seawater with an initial pH in the range of 8.3-8.5. The cathode's surface area is nearly 1.5 cm2 per unit volume of the reactor. The electrodeposition process is sustained for a duration of 72 hours. The resulting electrodeposit has a mass of 355.67 mg/cm2 and comprises aragonite (93.05%), calcite (6.81%), and brucite (0.11%), yielding a composite with 45.43% CaCO3 and 54.57% Mg(OH)2. The electrodeposit exhibits a density of 2.91 g/cc, and its aggregate size ranges from 0.01 to 5 mm. (
Working example 2: In a method for electrodeposition in seawater for the purpose of obtaining aggregates in the form of electrodeposits, an electric current with a density of −840 A/m2 is applied to the cathode, where the cathode and anode have a surface area ratio of 1.5. The cathode and anode are positioned at a separation distance equal to the length of the anode. Simultaneously, CO2 gas is introduced at a rate of 0.30 sccm (standard cubic centimeter per minute) at the bottom of a batch reactor with a volume of 2 liters, the reactor employing artificial seawater with an initial pH in the range of 8.3-8.5. The cathode's surface area is nearly 1.5 cm2 per unit volume of the reactor. The electrodeposition process is sustained for a duration of 72 hours. The resulting electrodeposit has a mass of 685.78 mg/cm2 and comprises aragonite (65.89%), calcite (9.31%), and brucite (24.79%), yielding a composite with 52.01% CaCO3 and 47.99% Mg(OH)2. The electrodeposit exhibits a density of 2.75 g/cc, and its aggregate size ranges from 0.01 to 5 mm. (
Working example 3: In a method for electrodeposition in seawater for the purpose of obtaining aggregates in the form of electrodeposits, an electric current with a density of −840 A/m2 is applied to the cathode, where the cathode and anode have a surface area ratio of 1.5. The cathode and anode are positioned at a separation distance equal to the length of the anode. Simultaneously, CO2 gas is introduced at a rate of 0.45 sccm (standard cubic centimeter per minute) at the bottom of a batch reactor with a volume of 2 liters, the reactor employing artificial seawater with an initial pH in the range of 8.3-8.5. The cathode's surface area is nearly 1.5 cm2 per unit volume of the reactor. The electrodeposition process is sustained for a duration of 72 hours. The resulting electrodeposit has a mass of 430.70 mg/cm2 and comprises aragonite (64.4%), calcite (26.41%), and brucite (9.18%), yielding a composite with 62.91% CaCO3 and 37.09% Mg(OH)2. The electrodeposit exhibits a density of 2.81 g/cc, and its aggregate size ranges from 0.01 to 5 mm. (
Working Example 4: In a method for electrodeposition in seawater for the purpose of obtaining aggregates in the form of electrodeposits, an electric potential vs Ag/AgCl reference electrode of −2 V is applied to the cathode, where the cathode and anode have a surface area ratio of 1.5. The cathode and anode are positioned at a separation distance equal to the length of the anode. Simultaneously, CO2 gas is introduced at a rate of 0.15 sccm (standard cubic centimeter per minute) at the bottom of a batch reactor with a volume of 2 liters, the reactor employing artificial seawater with an initial pH in the range of 8.3-8.5. The cathode's surface area is nearly 1.5 cm2 per unit volume of the reactor. The electrodeposition process is sustained for a duration of 72 hours. The resulting electrodeposit has a mass of 637.43 mg/cm2 and comprises aragonite (69.01%), calcite (3.93%), and brucite (27.06%), yielding a composite with 69.28% CaCO3 and 30.71% Mg(OH)2. The electrodeposit exhibits a density of 2.75 g/cc, and its aggregate size ranges from 0.01 to 5 mm. (
Working Example 5: In a method for electrodeposition in seawater for the purpose of obtaining aggregates in the form of electrodeposits, an electric potential vs Ag/AgCl reference electrode of −2 V is applied to the cathode, where the cathode and anode have a surface area ratio of 1.5. The cathode and anode are positioned at a separation distance equal to the length of the anode. Simultaneously, CO2 gas is introduced at a rate of 0.30 sccm (standard cubic centimeter per minute) at the bottom of a batch reactor with a volume of 2 liters, the reactor employing artificial seawater with an initial pH in the range of 8.3-8.5. The cathode's surface area is nearly 1.5 cm2 per unit volume of the reactor. The electrodeposition process is sustained for a duration of 72 hours. The resulting electrodeposit has a mass of 654.68 mg/cm2 and comprises aragonite (62.25%), calcite (20.93%), and brucite (16.81%), yielding a composite with 67.58% CaCO3 and 32.41% Mg(OH)2. The electrodeposit exhibits a density of 2.78 g/cc, and its aggregate size ranges from 0.01 to 5 mm. (
Working Example 6: In a method for electrodeposition in seawater for the purpose of obtaining aggregates in the form of electrodeposits, an electric potential vs Ag/AgCl reference electrode of −2 V is applied to the cathode, where the cathode and anode have a surface area ratio of 1.5. The cathode and anode are positioned at a separation distance equal to the length of the anode. Simultaneously, CO2 gas is introduced at a rate of 0.15 sccm (standard cubic centimeter per minute) at the bottom of a batch reactor with a volume of 2 liters, the reactor employing artificial seawater with an initial pH in the range of 8.3-8.5. The cathode's surface area is nearly 1.5 cm2 per unit volume of the reactor. The electrodeposition process is sustained for a duration of 72 hours. The resulting electrodeposit has a mass of 589.30 mg/cm2 and comprises aragonite (41.95%), calcite (7.64%), and brucite (50.41%), yielding a composite with 43.92% CaCO3 and 56.08% Mg(OH)2. The electrodeposit exhibits a density of 2.61 g/cc, and its aggregate size ranges from 0.01 to 5 mm. (
Applying a current density of −840 mA/cm2 without injecting any external CO2 produces lesser yield (170.84 mg/cm2) with higher energy consumption (311.63 kJ) as compared to the product yield achieved with CO2 injection (>350 mg/cm2) with similar experimental parameters and conditions and lower energy (127.79 kJ). The magnitude of current density described leads to an elevated production rate of OH-ions, resulting in a high interfacial pH near the cathode. However, due to the limited availability of carbonate and bicarbonate ions in seawater (in case of absence of external CO2 injection) compared to calcium and magnesium, coupled with the concurrent generation of H+ at the anode, both OH and H+ ions can engage in neutralization reactions independently of OH-participation in precipitation reactions results in lower production yield. This underscores the significance of carbonate ion concentrations in achieving the solubility precipitation index of CaCO3 and increase the yield as well as CO2 sequestration in CaCO3. (
Applying a voltage of −2 V vs Ag/AgCl reference electrode without injecting any external CO2 produces lesser yield (217.47 mg/cm2) with equal energy consumption (139.63 kJ) as compared to the product yield achieved with CO2 injection (>550 mg/cm2) with similar experimental parameters and conditions and energy consumption (˜100 kJ). This is again due to the reason of sufficient production of OH ions but limited availability of carbonate ions. Moreover, as the electrochemical reactions that produce OH-ions are voltage dependent, a lower electrochemical voltage can provide a higher yield with less energy consumption when there is no CO2 injection. Applying a voltage of −2 V (vs Ag/AgCl reference electrode) without introducing external CO2 results in a lower yield (217.47 mg/cm2) with equivalent energy consumption (139.63 kJ) compared to the product yield achieved through CO2 injection (>550 mg/cm2) under similar experimental parameters and conditions, with energy consumption approximately around 100 kJ. This disparity arises from the ample production of OH-ions at this voltage but limited availability of carbonate ions in the absence of CO2 injection. Furthermore, given that the electrochemical reactions generating OH-ions are voltage-dependent, a lower electrochemical voltage (e.g., −1.4 V) can yield higher outputs with reduced energy consumption as compared to −2 V when external CO2 is not introduced. (
Applying a current density of −1680 A/m2 and injecting a CO2 concentration of 0.30 scm CO2 results in a lower product yield (332.9 mg/cm2) compared to −840 mA/cm2 (685.58 mg/cm2) while consuming significantly more energy. This outcome underscores the insight that merely augmenting the rate of OH-generation at the cathode, coupled with the availability of calcium and carbonates, does not necessarily enhance the precipitation rate. The observed limitation arises from the dynamics of a membrane-free, one-pot batch reactor, where increasing current density leads to heightened mass transfer of ions, cross talk of ions, and side reactions, thereby impeding precipitation. This observation suggests the utilization of membranes in the reactor design.
Non-working example 4: Applying a less negative potential such as-1.4 V vs Ag/AgCl and injecting a concentration of CO2 (0.15 sccm CO2) produces lesser yield of the product after CO2 injection (195.05 mg/cm2 as compared to 322.86 mg/cm2) due to decrease in pH and insufficient availability of OH ions to participate in precipitation reactions. The result directs towards a shift in potential required to produce a higher yield with CO2 injection as there needs extra moles of OH-ions to neutralize the acidity introduced by CO2. Hence, achieving an optimal equilibrium between the rate of OH-ion production at the cathode and the concentration of carbonates/CO2 is essential for achieving a higher product yield and enhanced CO2 sequestration.
Similarly,
An optimum yield at a higher volume of injected CO2 requires a balance in pH because of simultaneous generation of alkalinity (due to voltage/current) and acidity (due to CO2). It is evident that CO2 injection leads to an increase in the total electrodeposits yield, however, needs a higher overpotential to fulfill the upraised requirement of OH− raised due to drop in pH caused by CO2.
pH trend depicts that the generation or consumption of both H+ and OH-during the electrochemical conversion process of CO2 is influenced by the voltage/current, which in turn impacts the precipitation reactions taking place at the cathode. On the other hand, the applied voltage helps generate protons (H+) at the anode, where oxidation events occur. The pH of the seawater solution near the anode may decrease because of these protons' additional contribution to the acidification of the solution. Controlling the pH facilitates the subsequent mineral precipitation process and improves the electrochemical system's overall stability.
The electrodeposition process allows tailoring an electrodeposit mixture of CaCO3 and Mg(OH)2 in a range of percentage weight of 50:50, 30:70 and 10:90. The carbonates content in mixture of electrodeposits highlights the efficacy of the carbon-negative electrodeposition approach in sequestering carbon dioxide from the atmosphere.
It is possible to fine-tune variables including carbon dioxide input, applied electrochemical potential, and reactor design to regulate crucial electrodeposited mineral properties. Aspects including morphology, size, content, mineral structure, yield, and carbon sequestration capability are included in this.
The type of polymorph is a function of the Mg: Ca ratio in AS1 and temperature. The possible polymorphs of CaCO3 to precipitate are calcite, aragonite, and vaterite in order of their decreasing thermodynamic stability. We have not observed vaterite formation on a lab scale so far. It is possible to form vaterite under certain conditions (low temperature, pH>9) but even if it forms, it can transform aragonite within 60 minutes when exposed to a temperature of 60° C. or more and it can change into calcite over 24 hours when kept at room temperature. (Geochimica et Cosmochimica Acta, Vol. 67, No. 9, pp. 1659-1666, 2003, Geology; January 1997; v. 25; no. 1; p. 85-87) [9].
To ensure and maintain a high calcium content in precipitated aggregates results show that maintaining the pH within the range of 9.5 to 10 is advisable, as exceeding a pH of 10 may induce preferential precipitation of magnesium hydroxide (Mg(OH)2). Calcium hydroxide (Ca(OH)2) does not precipitate under these conditions as it remains undersaturated in the pH range below 12.
Carbon sequestration through electrodeposition: One of the primary advantages is the substantial reduction of carbon emissions in the cement and concrete industries. The proposed technique actively absorbs the dissolved carbon dioxide during the electrodeposition process, contributing to carbon sequestration. By harnessing ocean and sea waters to electrodeposit calcium and magnesium-based minerals while injecting carbon dioxide gas, the process actively absorbs carbon dioxide in the form of mineral carbonates. This dual functionality addresses both the production of construction materials and the removal of carbon dioxide from the atmosphere. This addresses a pressing global challenge of mitigating climate change by directly reducing the carbon footprint associated with construction materials.
Utilization of abundant oceanic mineral resources: By capitalizing on the substantial mineral resources found in ocean and sea waters, the invention taps into an abundant and naturally available source of calcium, magnesium, and bicarbonate ions. Electrodeposition allows the conversion of calcium present in seawater into calcium carbonates and magnesium in the form of hydroxides which can also be converted into magnesium carbonates later step by reacting with more carbon-dioxide. This approach reduces the environmental impact linked to conventional mining for cement and concrete production raw materials, offering a sustainable alternative for aggregates production that can substitute traditional mined resources in the industry.
Sustainable construction materials: The electrodeposition technique offers a sustainable alternative for manufacturing construction materials. By cultivating minerals from oceanic resources, the approach minimizes the ecological footprint of the cement and concrete industries. This aligns with the growing demand for environmentally friendly and sustainable practices in the construction sector. The technique leverages the interaction of hydroxide ions generated in the water-splitting electrode with the naturally occurring calcium and magnesium ions in ocean and sea waters and externally injected carbon-dioxide allows the availability of sufficient carbonate ions. This enhances mineral deposition rates, making the manufacturing process more efficient and potentially cost-effective.
Customization of mineral attributes: The innovation allows for the tailoring of central attributes of electrodeposited minerals, including their morphology, size, composition, mineral form, yield, and carbon sequestration potential. This level of customization provides flexibility in adapting the construction materials to specific requirements, ensuring their suitability for various applications in the cement and concrete industries.
Laboratory-validated feasibility: The experimental laboratory tests conducted in custom-designed electrochemical cells confirm the feasibility of the proposed approach. This scientific validation establishes a foundation for further development and implementation, assuring that the technique is not just theoretical but can be practically applied on a larger scale.
Scalable implementation: The findings pave the way for scalable implementation of the proposed approach, indicating that it has the potential to be adopted on a larger, industrial scale. This scalability is crucial for addressing the significant demands of the construction industry while maintaining sustainability.
Comprehensive solution to industry challenges: The proposed innovation offers a comprehensive solution to the pressing global challenges faced by the cement and concrete industries. By addressing both carbon emissions and the sustainable sourcing of construction materials, it represents a holistic approach that aligns with the broader goals of sustainable development and environmental stewardship.
