System and method for rapidly evaluating carbon sequestration capability of recycled concrete micropowder

Abstract

The invention relates to the field of material evaluation, and discloses a system and method for rapidly evaluating the carbon sequestration capability of recycled concrete micropowder, and the method comprises the following steps: S1, creating and naming a new project: opening thermodynamic simulation calculation software developed based on a Gibbs energy minimization principle during chemical reaction equilibrium, and establishing a new project; selecting and creating a new reaction item at the lower left corner of the guide interface, and naming the new item and writing related remarks on a defined page of the new item; s2, selecting matter states appearing in the cement hydration process: on the basis of entering the software in the step S1 and creating a new project, setting a cement simulation reaction environment; by means of GEMS thermodynamic simulation software, hydration product data under different CO input amounts are rapidly obtained in batches, the CO absorption amount is quantified according to the calcite generation amount, rapid and accurate evaluation of the recycled concrete micro-powder carbon sequestration capacity is achieved, and the problems that a traditional experiment method is long in time consumption and large in resource waste are solved.

Description

Technical Field

[0001] This invention relates to the field of materials evaluation technology, specifically to a system and method for rapidly evaluating the carbon sequestration capacity of recycled concrete micropowder. Background Technology

[0002] With the rapid development of the building materials industry, the amount of waste concrete generated is increasing year by year. Simultaneously, carbon dioxide emissions are exacerbating global warming. Recycled concrete powder (RCP) mainly originates from the old hardened mortar powder with a particle size of less than 0.16mm, which is detached from the surface of recycled aggregates during the recycling process of waste concrete. Through carbonation treatment, RCP can not only improve its activity and replace part of the cement to achieve resource utilization, but also reduce carbon dioxide emissions, contributing to the goal of carbon neutrality.

[0003] However, existing methods for assessing the carbon sequestration capacity of RCPs mainly rely on extensive experimental investigations, which have the following shortcomings: Long experimental time: Traditional experimental methods require multiple repeated experiments, which is time-consuming and difficult to meet the needs of rapid assessment. Significant resource waste: The experiments consume a large amount of materials, energy, and manpower, increasing assessment costs. High uncertainty of results: Due to limitations in experimental conditions, the experimental results often have significant uncertainty, making it difficult to accurately reflect the actual carbon sequestration capacity of RCPs. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a system and method for rapidly evaluating the carbon sequestration capacity of recycled concrete micropowder, solving the problems of existing RCP carbon sequestration capacity evaluation methods, which rely on a large number of repeated experiments, resulting in long time consumption, significant resource waste, and high uncertainty of results.

[0005] To achieve the above objectives, this invention provides the following technical solution: a thermodynamic simulation software (GEMS). GEMS (Gibbs Energy Minimization Software) is a thermodynamic simulation software developed based on the Gibbs energy minimization principle at chemical reaction equilibrium. In the field of cement chemistry, the software can simulate the phase composition of RCP under different hydration environments, thereby further calculating the carbon sequestration capacity of RCP.

[0006] The steps for operating GEMS include: Installation and Startup: Install the GEMS software and load the third-party database CEMDATA18, which contains key phase data in the field of cement chemistry.

[0007] Database adjustment: Select the cement data (cemdate) section in the database, remove phases that are not relevant to the current simulation (such as the amm section), and retain phases that are related to the carbonation process (such as cshq) to improve simulation accuracy.

[0008] The steps for single-system simulation analysis of RCP carbonization process with a fixed formulation are as follows: Creating a project: In the GEMS boot interface, select "New Project", name the project and set the simulation temperature (default 20°C).

[0009] Phase and Element Selection: In "Phasetype filters", select the phases involved in cement hydration, including Aqueous Selector Lyte (aqueous solution), Crystallines Solids (crystalline solids), and Gas Mixture (gas mixture). Select the chemical elements required for the simulation, including H, Ca, Al, Si, C, O, S, etc.

[0010] Algorithm settings: Select the "IAwithextendedDebye-Hückelequation" algorithm mode and set the parameters (e.g., convergence tolerance is 1e-004, minimum number of stable phases is 1e-023). Select KOH as the alkaline environment conditioner to simulate the alkaline conditions of cement hydration.

[0011] Input the formula: Enter the amounts of RCP, H2O, and CO2 according to the simulated water-cement ratio. (For example, set the water-cement ratio to 0.5). Click the "Check" button to verify the input data and eliminate system alarms by adjusting the smoothing parameter (e.g., 0.01).

[0012] Run the simulation: Click the “Simulation Calculation” button, and the software will automatically generate a report on the phase composition of the hydration products, focusing on the amount of calcite produced.

[0013] Process simulation was used to analyze the impact of CO2 gradient changes on the carbon sequestration capacity of RCP. The steps are as follows: Parent selection: Use the simulation results of a single system as the parent item to enter the "Process" module.

[0014] Variable configuration: Set the CO2 injection rate as the independent variable, and define the initial and final values. Select the hydration products to be analyzed, including CSHQ, Portlandite, Calcite, etc.

[0015] Code writing: Write the independent variable code in the "Control" and "sampling" modules to define the relevant concepts of CO2 injection rate and its logical relationship with phase formation.

[0016] Operation and Results Output: Clicking the "Calculate" button will automatically generate multiple sets of simulation data, displaying the formation of various hydration products under different CO2 input rates. Clicking the "Graph" button will generate a curve showing the change in calcite formation as a function of CO2 input.

[0017] Data Comparison: The simulation results are compared with actual experimental data to verify the accuracy of the GEMS simulation. For example, if the error between the simulated calcite production and the experimental value is less than 5%, the model is considered reliable.

[0018] Process optimization: Based on the simulation results, the RCP formulation with the best carbon fixation capacity is selected to guide the adjustment of actual carbonization process parameters, thereby reducing the number of experiments and resource consumption.

[0019] For RCP recipes not included in the CEMDATA18 database, the following steps must be taken: Cloning and Modification: In the "Compos" module, clone existing cement data (pc item) and modify its chemical composition (such as CaO and SiO2 content).

[0020] Resimulate: Import the custom recipe into the project, repeat the single system and process simulation steps, and generate a carbon sequestration capacity report for the new recipe.

[0021] This invention provides a system and method for rapidly evaluating the carbon sequestration capacity of recycled concrete powder. It offers the following advantages: 1. This invention utilizes the GEMS thermodynamic simulation software, based on the Gibbs principle of energy minimization, to complete steps such as project creation, reaction environment setup, element and algorithm selection, formula input, and simulation calculation within the software. Through single-system simulation verification, custom RCP4 composition, process simulation calculation, and configuration, it rapidly and in batches acquires hydration product data under different CO2 input levels. The CO2 absorption is quantified by the amount of calcite generated, enabling rapid and accurate evaluation of the carbon sequestration capacity of recycled concrete micropowder. This solves the problems of long time consumption, high resource waste, and high uncertainty of results associated with traditional experimental methods. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the interface for creating a new project in the GEMS software of this invention; Figure 2 This is a schematic diagram of the configuration interface for the third-party database (CEMDATA18) in the GEMS software of this invention; Figure 3 This is a schematic diagram of the chemical element selection interface during the simulation process of the present invention; Figure 4 This is a schematic diagram of the input interface for the RCP hydration formula of the present invention; Figure 5This is a schematic diagram of the report generation interface for a single system simulation of the present invention; Figure 6 This is a schematic diagram of the database modification interface for the custom RCP recipe of the present invention; Figure 7 This is a schematic diagram of the operation naming and model selection interface for the process simulation of the present invention. Figure 8 This is a schematic diagram of the CO2 input variable configuration and code writing interface of the present invention; Figure 9 This is a schematic diagram of the code editing interface for the sampling and logical relationship of hydration products in this invention; Figure 10 This is a schematic diagram of the dynamic image generation interface for the process simulation results of the present invention. Figure 11 This is a flowchart of the method of the present invention; Figure 12 This is a flowchart of step S5 of the present invention. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see the appendix Figure 1 -Appendix Figure 12 This invention provides a system for rapidly evaluating the carbon sequestration capacity of recycled concrete powder, including thermodynamic simulation software developed based on the Gibbs energy minimization principle at chemical reaction equilibrium. The thermodynamic simulation software developed based on the Gibbs energy minimization principle at chemical reaction equilibrium includes two parts: single system simulation and process simulation. The single system simulation is used for simulation of a fixed formula, and the process simulation is used for ensemble simulation of a series of formulas.

[0025] Please see the appendix Figure 1 -Appendix Figure 12 A systematic method for rapidly assessing the carbon sequestration capacity of recycled concrete powder includes the following steps: S1. Create a new project and name it: First, install the thermodynamic simulation software based on the Gibbs energy minimization principle of chemical reaction equilibrium. Open the thermodynamic simulation software based on the Gibbs energy minimization principle of chemical reaction equilibrium (GEMS for short). In the lower left corner of the guide interface, select "Create a new reaction project." On the new project definition page, name the new project and write relevant remarks, as shown in the attached document. Figure 1As shown; Its GEMS software's core functions include simulating phase composition, ion concentration changes, and pH changes; S2. Selecting the physical states that occur during cement hydration: Based on entering the software and creating a new project in step S1, first set the reaction environment for cement simulation, specifically as follows: The first step in defining the basic elements of a new project requires staff to manually select the physical states that occur during cement hydration from the default phase type filter on the left, as shown in the attached image. Figure 2 As shown; The physical states that occur during the cement hydration process include: aqueous electrolytes, gas mixtures, non-ideal fluids, crystalline solids, dispersed solids, liquids, and other physical states that occur during the cement hydration process. Next, select the third-party database "CEMDATA18" in the database on the right, select the cement data section of the third-party database, remove the ammonium salt related components, open the CSH gel section in the silicate cement section, remove the first three items, and keep the last item; The first three items include: csh2o, csh3t, and cshkn; The last item includes: cshq; S3. Select all elements that may appear during the simulation: After selecting the reaction environment for the cement simulation in step S2, prepare the reaction elements required for the current cement simulation scheme, specifically: After selecting the cement hydration products, click Next to proceed to the second item, "Element Selection in the Simulation Process." On this page, select all elements that may appear during the simulation. Note that when simulating cement in an acidic environment such as NaCl, you need to additionally select the Cl element, as shown in the attached image. Figure 3 As shown; All the elements mentioned include: H, Na, K, Mg, Ca, Al, Si, C, O, S, Fe, etc. S4. Select Algorithm Mode and Set Parameters: After selecting the simulation elements for cement in step S3, it is necessary to set the cement simulation driving algorithm, specifically as follows: Staff need to first enter the algorithm mode definition page, select the second item on the left (IAwithextendedDebye-Heckelequation,commomb_gamma,anda0,H), and then select the last item on the right, i.e., commomb is KOH. After clicking check, the phaserecordkey changes to "aqEDH_H", and then click OK to enter the single system naming interface. in: KOH causes cement hydration to occur in a slightly alkaline environment, which is beneficial to the hydration process. The second algorithm (IAwithextendedDebye-Heckelequation,commomb_gamma,anda0,H) was chosen because it is a computational algorithm specifically designed for cement systems in an extended discipline. S5. Input the formula and perform simulation calculation: After configuring the algorithm for simulating cement in step S4, the ratio of simulated cement to water needs to be determined before performing cement simulation. After determining the ratio of cement to water, the formula is input into the algorithm for simulation calculation. The requirement to determine the ratio of simulated cement to water before conducting the cement simulation specifically involves: Naming a single system project in the single system naming interface: RCP4-CO2 and the change in simulated temperature: 20℃; Enter the input formula page of the single simulation system; select the reactants required for the cement hydration process: Aqua, CO2, O2, PC, and input 100g Aqua, 50g PC, 0.1g CO2, and 0.1g O2 according to the simulated water-cement ratio of 0.5, as shown in the attached diagram. Figure 4 As shown; S501. Selecting a single system data as the parent item for process calculation: After confirming the completion of the simulated cement algorithm configuration in step S4 and the confirmation of the cement ratio to be simulated in step S5, a trial run is conducted to troubleshoot algorithm faults or problems. Specifically: After entering the recipe, click "OK" to start the simulation of a single system. Before the simulation starts, click the check button (icon with a green checkmark) in the upper right corner of the interface. The system will automatically perform data verification to ensure that the input is correct and the previous selections are correct. If the software issues an alert, adjust the parameters in the settings menu at the bottom left of the page. There are generally three methods: 1. Smoothing parameter: Use a low positive value, such as 0.01. 2. Minimum number of stable phases: Use a low value, such as 1×10⁻²³. 3. Convergence tolerance parameter: Use a high value, such as 1×10⁻ 4 The maximum value appears to be 5 × 10⁻³. Re-verify until no alarms appear; Click the "Simulation Calculation" button (icon with a yellow downward arrow) to begin the simulation. During the calculation, the system displays a progress bar in real time, ensuring you understand the simulation's progress. Once a single system simulation is complete, the system automatically generates a simulation report with detailed output results, including the fitted data for each cement hydration product. For specific output results, click the "Report" button to view the detailed volume and mass data of the cement hydration products, as shown in the attached image. Figure 5As shown; S502. Configure the process simulator and select variable materials: To ensure the realism of the simulation, during the simulation process, staff can adjust the composition of cement in the database according to the current situation, specifically as follows: Third-party cement databases use a fixed chemical composition for cement. To simulate RCP hydration with a different chemical composition than that in the database, you need to customize the RCP information. Click the "Database" button in the upper left corner to access the software's main menu. Click "Composition" at the bottom left, select the Silicate Cement item in the left-hand project bar to clone it, define the required RCP4 chemical composition for the simulation based on the existing cement information, and save it, as shown in the attached image. Figure 6 As shown; Click the "Start" button in the upper left corner and select the new project created above. Clicking "Open Project" will bring up a prompt asking "New material composition has appeared. Do you want to add it to this project?" Accept the conditions and return to the system's input formula page. Remove the original silicate cement (PC), add the newly added RCP, and reset all input quantities. Repeat steps S5 to S6 to obtain the single-system output result of the newly added RCP4, and save the data; S503. Write the relevant code for the independent variable, CO2: Use the batch mode function to perform queued simulation and prediction for multiple sets of experiments, specifically: Perform process simulation calculations based on a single system. Click the second "process" button in the left menu to enter the process simulation calculation, select the RCP4 single system data established above as the parent item for process calculation, and click "OK" to enter the process calculation naming interface; The process simulation calculation avoids the complex calculation of a single system, and calculates a single system with different input changes in a module to obtain a set of output results of specific CO2 input gradients; After entering the name of the procedure operation (RCP4-CO2) and relevant remarks in the procedure operation naming interface, enter "S" in the last field, as shown in the attached document. Figure 7 As shown; S504. Perform calculations and generate specific data on hydration products: Finally, conduct a cement simulation experiment and display the experimental conclusions, including: The first step in process simulation configuration is to configure the process simulator and re-determine the computational model for process simulation as "S". The "S" term corresponds to a direct sequential change between the overall composition and the constraints of change, i.e., the influence of the simulated change on the physical composition of cement hydration products. The software's process simulator has three types: 1. "Sequential": only the input GEM (geochemical model) parameters are modified (modes P, S, L); 2. "Interactive": the next step depends on the GEM output of the previous step (e.g., phase composition) (mode R); 3. "Reverse": the GEM input is adjusted to obtain a specified GEM output value (e.g., pH; mode G). The second step in process simulation configuration: process simulator control. Select CO2 as the variable substance to be simulated in RCP4 hydration. Enter the initial input amount of CO2: -0.35g (each 100g of RCP already contains 0.35g of CO2), the termination value: 60g, and the gradient: 1g. Write the CO2-related code, defining the independent variable substance, such as... Figure 8 As shown; The third step in process simulation configuration: selection of the sampling items. First, select PHm (PHvol) in the "property" item column on the left, and then select the hydration products that may appear during the RCP4 hydration process on the right: CSHQ, Portlandite, C3(AF)S0.84H (SO4_OH_AFm+OH_SO4_AFm), ettringite (SO4_CO3_AFt+CO3_SO4_AFt), straetlingite, Calcite, Gypsum, Gibbsite, and OH-hydrotalcite. Write the code for the logical relationship between each hydration product and the CO2 input, such as... Figure 9 As shown; Step 4 of the process simulation configuration: Important data object dimensions. Input the number of steps to be executed in the simulation: 61 (determined by the number of operation steps in step one); number of columns in the array: 2 (i.e., the number of variables); number of columns in the "yp" table: 15; number of columns in the "xp" table: 0; Skip steps five and six of the process simulation configuration (these two steps are related to subsequent data management and will not be modified), and proceed to the code writing area for process simulation. In "control", check or modify the relevant code for the CO2 input quantity, and in "sampling", check or modify the relevant code for the items to be sampled. Click the "Calculation" button (a calculator-style icon), and the software will perform calculations on the written code. Relevant data will gradually appear in the two sets of data in "control," while specific data for each hydration product will appear in "results." Click the "Graphing" button, and the software will automatically generate a graph showing how cement hydration products change with variations in the variable substances, as shown in the attached image. Figure 10As shown; from Figure 10 As can be seen, with the addition of CO2, Ca(OH)2 (Portland stone) in cement first reacts with CO2 dissolved in water to form CaCO3 (calcite). Therefore, the amount of CO2 absorbed is quantified by the amount of calcite formed.

[0026] CO2 + H2O = 2H+ + CO32- (1) Ca(OH)2=Ca++2OH-(2) Ca++CO32-=CaCO3(3) Ca(OH)2+CO2=CaCO3↓+H2O (4) Equation (4) shows that 1 mol of CO2 reacts to produce 1 mol of CaCO3.

[0027] Furthermore, the molar mass of CO2 is 44.01 g / mol, and the molar mass of CaCO3 is 100.09 g / mol. Simulation calculations show that when the Ca(OH)2 (Portlandite) in 100 g of RCP4 cement reacts completely with CO2, the amount of CaCO3 (calcite) produced is 34.20374 g. Therefore, based on the conservation of molar mass, the calculated CO2 absorption is X = 34.20374 × 44.01 ÷ 100.09 = 15.039 g, which differs from the simulated CO2 absorption of 15.95 g by an error of 0.911 g. This error is too small and is within the allowable error range. Therefore, the simulated CO2 absorption of 100 g RCP4, calculated as 15.95 g, is relatively reliable and can be used as evaluation data. S6. Generate a simulation report and view the generation data of hydration products: After obtaining the results of the cement simulation calculation in step S5, a corresponding simulation report is generated based on the experimental simulation results, so that staff can view the generation data of hydration products.

[0028] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for using a system for rapidly evaluating the carbon sequestration capacity of recycled concrete powder, characterized in that, Includes the following steps: S1. Create a new project and name it: Open the thermodynamic simulation software based on the Gibbs energy minimization principle at chemical reaction equilibrium. In the lower left corner of the guide interface, select to create a new reaction project. On the new project definition page, name the new project and write relevant notes. S2. Select the physical state that appears during cement hydration: Based on entering the software and creating a new project in step S1, first set the reaction environment for cement simulation; S3. Select all elements that may appear during the simulation: After selecting the reaction environment for the cement simulation in step S2, prepare the reaction elements required for the current cement simulation scheme. S4. Select Algorithm Mode and Set Parameters: After selecting the simulation elements for cement in step S3, it is necessary to set the cement simulation driving algorithm, specifically as follows: S5. Input the formula and perform simulation calculation: After configuring the algorithm for simulating cement in step S4, the ratio of simulated cement to water needs to be determined before performing cement simulation. After determining the ratio of cement to water, the formula is input into the algorithm for simulation calculation. S6. Generate a simulation report and view the generation data of hydration products: After obtaining the results of the cement simulation calculation in step S5, generate a corresponding simulation report based on the experimental simulation results.

2. The method of using the system for rapidly evaluating the carbon sequestration capacity of recycled concrete powder according to claim 1, characterized in that, Step S5 includes: S501. Selecting a single system data as the parent item for process calculation: After confirming the completion of the simulated cement algorithm configuration in step S4 and the confirmation of the cement ratio to be simulated in step S5, a trial run is conducted to troubleshoot algorithm faults or problems. S502. Configure the process simulator and select variable materials: To ensure the realism of the simulation, during the simulation process, the staff adjusts the composition of cement in the database according to the current actual situation. S503. Write the relevant code for the independent variable substance CO2: Use the batch mode function to perform queue simulation and prediction for multiple sets of experiments; S504. Perform calculations and generate specific data on hydration products: Finally, conduct a cement simulation experiment and display the experimental results.

3. A system for rapidly evaluating the carbon sequestration capacity of recycled concrete powder according to any one of claims 1-2, comprising thermodynamic simulation software developed based on the Gibbs energy minimization principle at chemical reaction equilibrium, wherein the thermodynamic simulation software developed based on the Gibbs energy minimization principle at chemical reaction equilibrium comprises two parts: single system simulation and process simulation, wherein the single system simulation is used for simulation of a fixed formulation, and the process simulation is used for ensemble simulation of a series of formulations.

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