A method for calculating carbon sequestration of solid waste-based recycled building materials

Abstract

This invention discloses a method for calculating the carbon sequestration of solid waste-based recycled building materials, belonging to the field of building material carbon sequestration calculation technology. The specific steps of the method are as follows: First, determine the raw material formula and proportion, mainly using recycled aggregate from waste concrete; second, calculate the carbon emission data of raw material production and transportation; next, statistically analyze production energy consumption and calculate carbon emission data; then, use carbon dioxide curing process to calculate carbon capture; finally, weight the carbon emission data according to the raw material proportion, add the carbon emission of production energy and deduct the carbon capture to obtain the carbon emission factor of solid waste-based recycled building materials, accurately quantifying the carbon emissions at each stage of product formation. This invention constructs a closed-loop method covering the carbon emission links at each stage of solid waste-based recycled building materials product formation, specifically incorporating the characteristics of calcium oxide active ingredients and carbon capture calculation, solving the problems of insufficient adaptability and result distortion of traditional methods, and ensuring the accuracy and comparability of data.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of carbon sink calculation of building materials, and particularly relates to a carbon sink calculation method for solid waste-based regenerated building materials. BACKGROUND

[0002] The low-carbon transformation of the building industry, as a key field of energy consumption and carbon emission, is a key link to achieve the goal of carbon peak and carbon neutrality. In 2022, the total carbon emission of the building industry in China was 51.3 billion tons of carbon dioxide, accounting for 48.3% of the total energy-related carbon emission in China. Among them, the carbon emission of the whole process of housing construction was 41.5 billion tons of carbon dioxide, accounting for 39.1%. The production and transportation of building materials are the core emission sources of the construction link, accounting for 42.9% of the whole process of housing construction. Under this background, solid waste-based regenerated building materials, with the characteristics of replacing natural raw materials with solid waste raw materials, low production energy consumption and carbon capture, have become an important path to reduce carbon emission of the building industry, and accurate calculation of the carbon sink level is the basic prerequisite for the promotion and application of the building materials and the quantification of the value.

[0003] Traditional building material carbon emission calculation methods are mostly designed for traditional raw materials such as natural sand and stone materials, and cannot well adapt to the unique properties of solid waste-based regenerated building materials. Such methods neither fully consider the significant advantage of regenerated aggregates in production and processing energy consumption compared with natural sand and stone materials, nor take into account the shortening of the transportation distance brought by the local sourcing of regenerated aggregates. More importantly, the carbon capture amount generated by the reaction of calcium oxide and carbon dioxide in the carbon dioxide curing process is not included in the accounting scope, so that the accounting result cannot truly reflect the actual low-carbon level of solid waste-based regenerated building materials. In addition, the traditional method lacks exclusive accounting logic for key factors such as the raw material proportion of solid waste-based regenerated building materials, energy consumption types, reaction process parameters, and there is no clear and unified parameter value range standard, so that the carbon sink accounting data of different production enterprises and different formulations lack comparability, and it is difficult to meet the actual needs of the industry for low-carbon value evaluation, carbon trading docking and related policy making of such building materials. SUMMARY

[0004] The present application aims to make up for the shortcomings of the prior art, and provides a solid waste-based recycled building material carbon sink calculation method, which builds a complete carbon sink accounting process from raw material formula to carbon emission factor calculation, specially fits the special characteristics of solid waste-based recycled building materials. Taking waste concrete recycled aggregate as the core raw material, fully considering the characteristics of calcium oxide active ingredients in recycled aggregate that can replace part of the cement function and capture carbon in carbon dioxide curing, the solid carbon content is included in the key link of accounting, solving the problem that the traditional method does not pay attention to; at the same time, the accounting logic of key factors such as raw material proportion, transportation mode and energy type is clear, which not only makes the data calculation more accurate, but also enables the accounting results under different production scenarios to be compared with each other. The whole method is standard in operation and has strong practicality, which not only can scientifically quantify the low-carbon value of solid waste-based recycled building materials, but also can promote the recycling of solid waste resources.

[0005] The present application provides the following technical solutions to solve the above technical problems: a solid waste-based recycled building material carbon sink calculation method, the specific steps of which are: S1, raw material formula and proportion determination: determine the raw material composition and proportion of solid waste-based recycled building materials, the raw material includes recycled aggregate obtained by crushing waste concrete solid waste, and the recycled aggregate contains unreacted calcium oxide active ingredients; S2, raw material carbon emission data accounting: obtain or calculate the production and processing carbon emission data and transportation carbon emission data of each raw material, the production and processing carbon emission data is determined based on relevant standards or actual production energy consumption of the building materials industry, and the transportation carbon emission data is calculated according to the transportation mode and transportation distance; S3, production energy carbon emission data determination: statistics of all kinds of energy consumption in the whole production process, combined with the relevant energy carbon emission standards of the industry, determine the corresponding carbon emission data of each type of energy; S4, carbon capture amount accounting: using carbon dioxide curing process, carbon dioxide reacts with calcium oxide in recycled aggregate to generate calcium carbonate, and the amount of carbon dioxide absorbed by the reaction is accounted for; S5, carbon emission factor comprehensive calculation: according to the proportion of each raw material, the total carbon emission data of the raw material is weighted and summed, the production energy consumption carbon emission data is superimposed, and then the carbon capture amount is deducted to obtain the carbon emission factor of solid waste-based recycled building materials; Wherein, the recycled aggregate replaces part of the cementitious function of cement through calcium oxide active ingredients, reducing the amount of cement used.

[0006] Furthermore, the raw materials consist of recycled aggregate from construction waste, river sand, cement, admixtures, additives, and water; wherein, the recycled aggregate accounts for 45%-52% of the formula, the river sand accounts for 5%-8%, the cement accounts for 20%-25%, the admixtures account for 10%-12%, the additives account for 1%-2%, and the water accounts for 8%-10%; the admixtures are industrial solid waste admixtures of fly ash, slag powder, and steel slag powder, and the river sand preferably uses locally mined or recycled river sand with a transportation distance not exceeding 100km; the cement content is reduced by 10%-20% compared to traditional building materials.

[0007] Furthermore, the energy consumption for the production and processing of the recycled aggregate is 30%-50% of that for natural sand and gravel, and the recycled aggregate is transported using local sourcing methods, with a transportation distance not exceeding 100km.

[0008] Furthermore, the formula for calculating transportation carbon emission data in step S2 is as follows: ,in, The carbon emission factors for the transportation of each raw material. This represents the carbon emission coefficient per unit energy consumption for the corresponding mode of transportation. The transportation distance is defined by the mode of transportation, which includes one or more of the following: road transport, rail transport, and water transport.

[0009] Furthermore, when calculating the carbon emission data of raw material production and processing in step S2 using actual production energy consumption, it is obtained by summarizing various energy consumption data in the raw material production process and combining them with the carbon emission coefficients of the corresponding energy consumption types.

[0010] Furthermore, the energy source in step S3 includes one or more of the following: electricity, coal, natural gas, diesel, and gasoline. The carbon emission data corresponding to each type of energy source is determined according to the regional average energy consumption level or the emission coefficient corresponding to the energy source's own calorific value.

[0011] Furthermore, the conditions for the carbon dioxide curing process in step S4 are: curing temperature 20-30℃, carbon dioxide concentration 80%-95%, and curing time 12-24h.

[0012] Furthermore, the carbon capture amount in step S4 is calculated using one of the following two methods: (1) Composition method: through formula Accounting, among which, Carbon capture amount, For the purpose of calculating product quality, This represents the mass fraction of calcium oxide in the recycled aggregate. The reaction conversion rate of calcium oxide and carbon dioxide is given. Here is the molar mass of carbon dioxide. is the molar mass of calcium oxide; (2) Concentration method: Detect the initial and final concentrations of carbon dioxide in the curing space, and calculate the mass of carbon dioxide consumed according to the gas state equation, taking into account the volume, temperature and pressure of the curing space.

[0013] Furthermore, the mass fraction ω of calcium oxide in the recycled aggregate is 4%-8%, and the reaction conversion rate η of calcium oxide and carbon dioxide is 80%-85%.

[0014] Furthermore, the formula for calculating the carbon emission factor in step S5 is as follows: ,in, Carbon emission factors for solid waste-based recycled building materials This represents the percentage of each raw material. Carbon emission factors in the production and processing of various raw materials. The carbon emission factors for the transportation of each raw material. This refers to the consumption of various types of energy throughout the entire production and processing process. Carbon emission factors corresponding to various energy sources Carbon capture amount; The calculation method is to calculate the carbon emission factor of each raw material transportation. Carbon emission factors in production and processing The sum multiplied by the percentage of that raw material Then, sum them up.

[0015] Compared with existing technologies, this method for calculating carbon sequestration in solid waste-based recycled building materials has the following advantages: I. This invention constructs a closed-loop method covering the entire lifecycle of carbon emissions in solid waste-based recycled building materials, from raw materials to finished products. This method systematically covers all carbon emission-related stages, including raw material formulation determination, raw material carbon emission accounting, production energy carbon emission determination, carbon capture calculation, and comprehensive calculation of carbon emission factors. Specifically, this method incorporates the active calcium oxide component characteristics of recycled aggregates and uses carbon capture during carbon dioxide curing as a key accounting item, thus compensating for the neglect of carbon sequestration effects from chemical reactions in traditional calculation methods. Furthermore, by weighting carbon emission data according to raw material proportions and statistically analyzing energy consumption carbon emissions by type, the data from each stage accurately corresponds to the final result. It is also adaptable to the accounting needs of multi-component raw materials such as river sand and industrial solid waste admixtures, solving the problem of distorted calculation results caused by insufficient adaptability in traditional methods.

[0016] Second, this invention uses recycled aggregate processed from waste concrete as the core raw material, combined with industrial solid waste admixtures and low-carbon-limited river sand, to form a composite raw material system of dual solid waste and low-carbon natural raw materials. Coupled with suitable carbon emission data accounting logic and standardized process parameters, it fully leverages the resource utilization advantages of recycled aggregate and industrial solid waste admixtures, as well as the low-carbon characteristics of recycled aggregate and local or recycled river sand, which are sourced locally and have low processing energy consumption. Furthermore, the calcium oxide in the recycled aggregate can replace part of the cement's function, and combined with the synergistic cementitious effect of the industrial solid waste admixture, it further reduces the amount of high-carbon-emission cement used, enhancing the low-carbon effect. In addition, it clarifies the specific accounting paths for the transportation carbon emissions and carbon capture of various raw materials, including admixtures and river sand, while ensuring reasonable ranges for relevant parameters. This facilitates operation and use in actual production and makes the accounting results comparable across different scenarios, solving the previous problems of inconsistent carbon sequestration accounting standards and incomparable data for solid waste-based recycled building materials.

[0017] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0019] Figure 1 A flowchart illustrating the overall process for calculating carbon sequestration in solid waste-based recycled building materials; Figure 2 Flowchart for carbon capture accounting; Figure 3 This is a flowchart for the comprehensive calculation of carbon emission factors. Detailed Implementation

[0020] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0021] Example 1 This embodiment uses recycled aggregate concrete blocks produced by a building materials company as the accounting object. This product uses recycled concrete aggregate from urban building demolition as its core raw material, combined with cement, high-efficiency water-reducing agent, locally recycled river sand, fly ash, and water to form a formula system. Using the carbon sequestration calculation method described in this patent, the following steps are completed sequentially: determining the raw material formula, calculating raw material carbon emissions, determining production energy carbon emissions, calculating carbon capture capacity, and comprehensively calculating carbon emission factors. This comprehensively quantifies the carbon emissions and carbon sequestration level throughout the product's entire life cycle, verifying the accuracy and operability of the method in conventional production scenarios.

[0022] The specific implementation process is as follows: S1, Determination of raw material formula and proportion First, the core raw material composition of the product was clearly defined, and waste concrete from a building demolition project in a certain city was selected as the source of recycled aggregate. This waste concrete underwent crushing, multi-stage screening, impurity removal, and particle size optimization to form recycled aggregate with a particle size of 5 to 20 mm. X-ray diffraction testing confirmed that the recycled aggregate contained unreacted calcium oxide active components, meeting the requirements for partially replacing the cementitious function. Based on the product's strength grade and low-carbon design goals, the raw material formula was determined to be: 48% recycled aggregate, 22% ordinary Portland cement, 1.5% high-efficiency water-reducing agent, 6% locally recycled river sand, 12% fly ash, and 10.5% water. The design concept for this mix proportion is as follows: the proportion of recycled aggregate is controlled at 48%, which fully leverages its low-carbon advantages while ensuring block strength through the synergistic effect of calcium oxide active ingredients and cement; the cement content is reduced by 18% compared to traditional concrete blocks, reducing the use of high-carbon emission materials; locally recycled river sand is prioritized from urban river dredging, resulting in shorter transportation distances and low-carbon environmental friendliness; fly ash, as an industrial solid waste admixture, can replace part of the cement to achieve the cementing function, further enhancing the advantages of solid waste resource utilization; the ratio of high-efficiency water-reducing agent to water can reduce the amount of mixing water, optimizing the low-carbon nature of the production process. The overall process is as follows: Figure 1 As shown.

[0023] S2, Raw material carbon emission data accounting (1) Carbon emission accounting of production and processing Carbon emission data for the production and processing of recycled aggregates are determined using actual production energy consumption statistics. This involves statistically analyzing the electricity consumption of crushing and screening equipment, as well as the diesel consumption of loaders and transport vehicles during the recycled aggregate production process. These figures are then combined with the corresponding carbon emission coefficients for each type of energy consumption to summarize the carbon emission data for the recycled aggregate production and processing stages. Carbon emission data for the production and processing of fly ash is derived by statistically analyzing the electricity consumption during its power plant waste heat utilization process, combined with the carbon emission coefficients for the corresponding energy consumption types. Carbon emission data for the production and processing of cement and high-efficiency water-reducing agents are determined with reference to the default values ​​in the carbon emission accounting standards published by the building materials industry. Carbon emission data for the production and processing of locally recycled river sand is calculated by statistically analyzing the electricity consumption during dredging, screening, and dewatering processes, combined with the regional recycled sand and gravel production energy consumption carbon emission coefficients.

[0024] (2) Carbon emission accounting for transportation The recycled aggregate is sourced locally, transported from urban solid waste treatment plants to the production plant over a distance of 45 kilometers via road transport using 15-ton new energy trucks. The calculation logic for transportation carbon emissions is as follows: based on the energy consumption per unit mileage of this type of new energy truck, combined with the corresponding carbon emission coefficient for road transport, the transportation carbon emissions per unit mass of recycled aggregate are calculated. The formula for calculating transportation carbon emissions is: ,in, The carbon emission factors for the transportation of each raw material. This represents the carbon emission coefficient per unit energy consumption for the corresponding mode of transportation. The transportation distance is considered. Cement is transported from a cement plant in another location to the plant, a distance of 220 kilometers, by rail. The carbon emission data for transportation is calculated based on the carbon emission coefficient per unit mileage of rail transportation and the transportation distance. High-efficiency water-reducing agent is purchased from a local chemical company, a distance of 30 kilometers, by road transportation, and the carbon emission data for transportation is calculated using the same logic.

[0025] S3, Carbon emission data for energy production determined. This study statistically analyzes the energy consumption throughout the entire production and processing of recycled aggregate concrete blocks, covering all stages from raw material mixing and block molding to the operation of curing equipment. Energy types include electricity and natural gas. Electricity consumption is recorded through independent meters within the plant, with the statistical period being the complete cycle of producing 100 tons of blocks to determine the total electricity consumption. Natural gas consumption is used for auxiliary heating of the curing equipment, and the total consumption is recorded through natural gas flow meters. Carbon emission data for each energy source is determined as follows: electricity carbon emission data is taken from the average carbon emission level of the regional power grid, which is published by the local energy management department and reflects the overall carbon emission intensity of regional power production; natural gas carbon emission data is determined based on its emission coefficient corresponding to its calorific value, referring to relevant provisions in the industry's energy carbon emission accounting guidelines to ensure the standardization of data accounting.

[0026] S4, Carbon Capture Calculation Carbon dioxide curing was used to cure the molded blocks in a closed carbon dioxide curing chamber. The operating parameters for the curing process were set as follows: curing temperature 25℃, carbon dioxide concentration 92%, and curing time 18 hours. The principle behind these parameters is that 25℃ is the optimal temperature for the reaction between calcium oxide and carbon dioxide, ensuring a sufficient reaction rate while avoiding increased energy consumption due to high temperatures; the 92% carbon dioxide concentration provides ample reactants to promote a complete reaction; and the 18-hour curing time ensures that the calcium oxide in the recycled aggregate reacts fully with the carbon dioxide to form structurally stable calcium carbonate. Figure 2 As shown.

[0027] Carbon capture capacity is calculated using the composition method, and the formula is as follows: Accounting, among which, Carbon capture amount, For the purpose of calculating product quality, This represents the mass fraction of calcium oxide in the recycled aggregate. The reaction conversion rate of calcium oxide and carbon dioxide is given. Here is the molar mass of carbon dioxide. This represents the molar mass of calcium oxide. Before curing, three groups of samples were randomly selected from the recycled aggregate. The mass fraction of calcium oxide in each group was determined by chemical titration, and the average value was taken as the initial calcium oxide content. After curing, three corresponding groups of samples were selected from the molded blocks, and the mass fraction of the remaining calcium oxide was determined by chemical titration. The total amount of calcium oxide involved in the reaction was calculated. Based on the stoichiometric relationship between calcium oxide and carbon dioxide, i.e., a certain mass of calcium oxide can absorb a corresponding proportion of carbon dioxide, and combined with the total mass of 100 tons of blocks produced, the amount of carbon dioxide absorbed during the entire curing process, i.e., the carbon capture amount, was finally calculated.

[0028] S5, Comprehensive Calculation of Carbon Emission Factors First, the total carbon emission data of raw materials is summarized. The carbon emission data from the production and processing of each raw material—recycled aggregate, cement, high-efficiency water-reducing agent, locally recycled river sand, fly ash, and water—are added together with the carbon emission data from transportation to obtain the comprehensive carbon emission data for each raw material. Then, each raw material is multiplied by its proportion in the formula. Finally, the weighted carbon emission data of all raw materials are summed to obtain the total carbon emission data for the raw material stage. Next, the carbon emission data for electricity and natural gas during the production process are added together to obtain the total carbon emission data for energy consumption in production. Finally, the total carbon emission data of raw materials is summed with the total carbon emission data of energy consumption in production, and the carbon capture amount is subtracted to obtain the comprehensive carbon emission factor for 100 tons of recycled aggregate concrete blocks. The formula for calculating the carbon emission factor is: ,in, Carbon emission factors for solid waste-based recycled building materials This represents the percentage of each raw material. Carbon emission factors in the production and processing of various raw materials. The carbon emission factors for the transportation of each raw material. This refers to the consumption of various types of energy throughout the entire production and processing process. Carbon emission factors corresponding to various energy sources Carbon capture amount; The calculation method is to calculate the carbon emission factor of each raw material transportation. Carbon emission factors in production and processing The sum multiplied by the percentage of that raw material Then, the results are summed. Throughout the entire calculation process, original statistical records are retained for each step to ensure the calculation process is traceable and verifiable. For example... Figure 3 As shown.

[0029] This embodiment fully demonstrates the entire operational logic of the method of the present invention by calculating the carbon sequestration of recycled aggregate concrete blocks. From raw material formulation design to carbon emission data accounting at each stage, and then to the precise quantification of carbon capture, each step is combined with the characteristics of the actual production scenario, clarifying the data source and accounting logic, and ensuring the authenticity and reliability of the carbon emission factor calculation results. This embodiment verifies the applicability of the method of the present invention in the production of conventional solid waste-based recycled building materials. The accounting results can accurately reflect the low-carbon value of the product, providing a scientific basis for enterprises' low-carbon promotion and market marketing.

[0030] Example 2 This embodiment uses a recycled aggregate permeable brick produced by an environmental technology company as the accounting object. This product uses recycled aggregate from waste concrete generated during urban road renovation as its core raw material, combined with low-heat silicate cement, air-entraining agent, recycled river sand, slag powder, and water to form its formula. Using the carbon sequestration calculation method of this patented invention, and considering the characteristics of the permeable brick production process, the calculation logic for each stage is refined to complete the full life-cycle carbon sequestration calculation. The method's versatility and accuracy under different types of solid waste-based recycled building materials and special production processes are verified.

[0031] The specific implementation process is as follows: S1, Determination of raw material formula and proportion The core raw material, recycled aggregate, originates from waste concrete demolished during urban road renovation projects. After crushing, shaping, screening, and washing, recycled aggregate with a particle size of 3 to 10 mm is obtained. This particle size range is suitable for the permeable pore structure design of permeable bricks. X-ray diffraction testing confirmed that the calcium oxide active component content in the recycled aggregate meets the requirements and can replace part of the cementitious function. Based on the permeability coefficient and strength requirements of permeable bricks, the raw material formula is determined to be 50% recycled aggregate, 20% low-heat silicate cement, 1% air-entraining agent, 7% recycled river sand, 11% slag powder, and 11% water. The core idea behind this mix design is to control the proportion of recycled aggregate at 50% to maximize the low-carbon advantages of solid waste resource utilization. Its active calcium oxide component can work synergistically with cement and slag powder to compensate for the strength loss caused by the reduction in cement usage. Low-heat silicate cement is selected, which reduces carbon emissions during its production process by 18% compared to ordinary cement, further enhancing the low-carbon effect. The recycled river sand uses waste sand and gravel recycled from urban road reconstruction and expansion, meeting the requirements for low-carbon raw materials. Slag powder, as an industrial solid waste admixture, can improve the pore structure stability and cementitious strength of permeable bricks. The air-entraining agent can form micro-bubbles inside the concrete, improving permeability and workability. The water ratio is adapted to the mixing and molding requirements of permeable bricks.

[0032] S2, Raw material carbon emission data accounting (1) Carbon emission accounting of production and processing Carbon emission data for the production and processing of recycled aggregates are calculated based on actual production energy consumption. The electricity consumption of each process—crushing, shaping, screening, and sand washing—as well as diesel consumption during raw material transportation, are statistically analyzed and combined with the corresponding carbon emission coefficients to obtain the carbon emission data per unit mass of recycled aggregate. Carbon emission data for the production and processing of slag powder is derived by referring to the carbon emission accounting standards for industrial solid waste processing in the steel industry, statistically analyzing the electricity consumption of its crushing and grinding processes, and combining this with the corresponding carbon emission coefficients. Carbon emission data for the production and processing of recycled river sand is derived by statistically analyzing the electricity and diesel consumption of its waste sand and gravel crushing, screening, and impurity removal processes, combined with regional recycled sand and gravel production energy consumption standards. Carbon emission data for the production and processing of low-heat silicate cement is derived by referring to the specific carbon emission accounting standards issued by the cement industry. These standards have developed a dedicated carbon emission accounting method for the production process of low-heat cement, ensuring the data's relevance. Carbon emission data for the production and processing of air-entraining agents is derived by referencing the corresponding category benchmark values ​​in the carbon emission accounting standards of the chemical industry.

[0033] (2) Carbon emission accounting for transportation The transportation of recycled aggregates utilizes a combination of road and rail transport. The solid waste treatment plant uses small trucks to transfer waste concrete to the nearest railway freight station, then transports it by rail to a freight station near the production plant, and finally transfers it to the plant via small trucks, with a total transportation distance of 55 kilometers. Recycled river sand is transported from the locally upgraded solid waste treatment plant to the plant, a distance of 42 kilometers, using road transport and new energy trucks. Slag powder is transported from the local steel plant to the plant, a distance of 78 kilometers, also by road. The carbon emission calculation logic for transportation is as follows: the distances for both road and rail transport are calculated separately, and the carbon emission coefficients per unit mileage for each transport method are combined to calculate the carbon emission data for each segment of transportation, summing up the total carbon emission data for recycled aggregate transportation. Cement is transported over a distance of 300 kilometers by rail, calculated based on the carbon emission coefficient and distance of rail transport; air-entraining agent is transported over a distance of 80 kilometers by road, with data calculated according to the road transport carbon emission calculation logic.

[0034] S3, Carbon emission data for energy production determined. Energy consumption in the production process includes electricity, coal, and natural gas. Electricity consumption covers all electrical equipment such as mixing equipment, molding equipment, screening equipment, and ventilation equipment. The total electricity consumption is calculated by summing the data from individual electricity meters for each stage. Coal is used for workshop insulation during winter production, and the total consumption is recorded by weighing the coal. Natural gas is used for auxiliary heating during curing, and the total consumption is recorded by flow meters. Carbon emission data for each energy source is determined as follows: electricity carbon emission data is based on the average level of the regional power grid; coal carbon emission data is determined based on the emission coefficient corresponding to its lower heating value, obtained by testing the lower heating value of coal and combining it with conversion rules in industry standards; natural gas carbon emission data is taken with reference to the regulations in the energy industry carbon emission accounting guidelines to ensure the accuracy of data accounting.

[0035] S4, Carbon Capture Calculation The process employs carbon dioxide curing, using a continuous carbon dioxide curing tunnel. The curing parameters are set as follows: curing temperature 28℃, carbon dioxide concentration 88%, and curing time 22 hours. These parameters are designed based on the fact that permeable bricks have a highly porous structure; the 28℃ curing temperature promotes carbon dioxide diffusion within the pores, improving reaction uniformity; the 88% carbon dioxide concentration ensures sufficient reaction while minimizing carbon dioxide waste; and the 22-hour curing time ensures that the calcium oxide within the recycled aggregate also reacts fully with the carbon dioxide.

[0036] Carbon capture was calculated using a concentration method. The maintenance tunnel was a sealed structure, with carbon dioxide concentration detectors installed at both the tunnel entrance and exit to record the initial and final carbon dioxide concentrations in real time during the maintenance process. Simultaneously, temperature and pressure sensors recorded the real-time temperature and pressure within the maintenance tunnel, measuring its effective volume. Based on the core principles of the gas law, and combining the difference between the initial and final concentrations, tunnel volume, and temperature and pressure data, the total mass of carbon dioxide consumed during the maintenance process—the carbon capture amount—was calculated. During the calculation, concentration, temperature, and pressure data were recorded hourly, and the average value was used for calculation to improve data accuracy.

[0037] S5, Comprehensive Calculation of Carbon Emission Factors The first step is to summarize the total carbon emission data of raw materials. First, calculate the sum of carbon emissions from the production and processing of each raw material (recycled aggregate, cement, air-entraining agent, recycled river sand, slag powder, and water) and their transportation. Then, weight the comprehensive carbon emission data of each raw material according to its proportion in the formula. Finally, sum the weighted data of all raw materials to obtain the total carbon emission data for the raw material stage. The second step is to calculate the total carbon emission data for production energy consumption. Add the carbon emission data corresponding to the consumption of electricity, coal, and natural gas separately to obtain the total carbon emission data for the production stage. The third step is to calculate the comprehensive carbon emission factor. Add the total carbon emission data of raw materials to the total carbon emission data of production energy consumption, and then subtract the carbon capture amount to obtain the comprehensive carbon emission factor for 100 tons of recycled aggregate permeable bricks. During the calculation process, the data for each stage is verified multiple times to ensure that there are no statistical errors.

[0038] This embodiment, taking into account the product characteristics and special production process of recycled aggregate permeable bricks, refines the carbon sequestration accounting logic for each stage, particularly differing from Embodiment 1 in terms of transportation methods, energy types, and carbon capture calculation methods. This fully verifies the versatility and adaptability of the method of this invention. During implementation, the working principle of each module is deeply integrated with actual production scenarios, with clear data sources and rigorous accounting logic, ensuring the accuracy of carbon emission factor calculation results. This embodiment demonstrates that the method of this invention can be adapted to different types of solid waste-based recycled building material production scenarios, providing the industry with a unified and standardized carbon sequestration accounting solution, and facilitating the large-scale promotion of solid waste-based recycled building materials and the low-carbon transformation of the construction industry.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for calculating carbon sequestration in solid waste-based recycled building materials, characterized in that, The specific steps of this method are as follows: S1, Determination of raw material formula and proportion: Clarify the raw material composition and proportion of each raw material of the solid waste-based recycled building material. The raw materials include recycled aggregates made from crushed and processed waste concrete solid waste, and the recycled aggregates contain unreacted calcium oxide active ingredients. S2, Raw material carbon emission data accounting: Obtain or calculate carbon emission data for the production and processing of each raw material and carbon emission data for transportation. The carbon emission data for production and processing is determined based on relevant standards in the building materials industry or actual production energy consumption, and the carbon emission data for transportation is calculated based on the mode of transportation and transportation distance. S3, Determining Carbon Emission Data for Production Energy: Statistically analyze the consumption of various types of energy throughout the entire production and processing process, and combine this with relevant industry carbon emission standards to determine the corresponding carbon emission data for each type of energy. S4, Carbon Capture Calculation: Using carbon dioxide curing process, carbon dioxide reacts with calcium oxide in recycled aggregate to produce calcium carbonate, and the amount of carbon dioxide absorbed by this reaction is calculated. S5, Comprehensive calculation of carbon emission factor: The total carbon emission data of raw materials is weighted and summarized according to the proportion of each raw material, the carbon emission data of production energy consumption is superimposed, and the carbon capture amount is deducted to obtain the carbon emission factor of solid waste-based recycled building materials.

2. The method for calculating carbon sequestration of solid waste-based recycled building materials according to claim 1, characterized in that, The raw materials consist of recycled aggregate from construction waste, river sand, cement, admixtures, additives, and water. The recycled aggregate accounts for 45%-52% of the formula, river sand 5%-8%, cement 20%-25%, admixtures 10%-12%, additives 1%-2%, and water 8%-10%. The admixtures are industrial solid waste admixtures of fly ash, slag powder, and steel slag powder. River sand is preferably locally mined or recycled and transported no more than 100km away. The cement content is reduced by 10%-20% compared to traditional building materials.

3. The method for calculating carbon sequestration of solid waste-based recycled building materials according to claim 1, characterized in that, The energy consumption for the production and processing of the recycled aggregate is 30%-50% of that for natural sand and gravel. The recycled aggregate is transported using local sourcing methods, with a transportation distance not exceeding 100km.

4. The method for calculating carbon sequestration of solid waste-based recycled building materials according to claim 1, characterized in that, The formula for calculating transportation carbon emission data in step S2 is as follows: ,in, The carbon emission factors for the transportation of each raw material. This represents the carbon emission coefficient per unit energy consumption for the corresponding mode of transportation. The transportation distance is defined by the mode of transportation, which includes one or more of the following: road transport, rail transport, and water transport.

5. The method for calculating carbon sequestration of solid waste-based recycled building materials according to claim 1, characterized in that, When calculating the carbon emission data of raw material production and processing in step S2 using actual production energy consumption, it is obtained by summarizing various energy consumption data in the raw material production process and combining them with the carbon emission coefficients of the corresponding energy consumption types.

6. The method for calculating carbon sequestration of solid waste-based recycled building materials according to claim 1, characterized in that, The energy sources in step S3 include one or more of the following: electricity, coal, natural gas, diesel, and gasoline. The carbon emission data for each type of energy source are determined based on the regional average energy consumption level or the emission coefficient corresponding to the energy's own calorific value.

7. The method for calculating carbon sequestration of solid waste-based recycled building materials according to claim 1, characterized in that, The conditions for the carbon dioxide curing process in step S4 are: curing temperature 20-30℃, carbon dioxide concentration 80%-95%, and curing time 12-24h.

8. The method for calculating carbon sequestration of solid waste-based recycled building materials according to claim 1, characterized in that, The carbon capture amount in step S4 is calculated using one of the following two methods: (1) Composition method: through formula Accounting, among which, Carbon capture amount, For the purpose of calculating product quality, This represents the mass fraction of calcium oxide in the recycled aggregate. The reaction conversion rate of calcium oxide and carbon dioxide is given. Here is the molar mass of carbon dioxide. is the molar mass of calcium oxide; (2) Concentration method: Detect the initial and final concentrations of carbon dioxide in the curing space, and calculate the mass of carbon dioxide consumed according to the gas state equation, taking into account the volume, temperature and pressure of the curing space.

9. The method for calculating carbon sequestration of solid waste-based recycled building materials according to claim 8, characterized in that, The mass fraction ω of calcium oxide in the recycled aggregate is 4%-8%, and the reaction conversion rate η of calcium oxide and carbon dioxide is 80%-85%.

10. The method for calculating carbon sequestration of solid waste-based recycled building materials according to claim 1, characterized in that, The formula for calculating the carbon emission factor in step S5 is as follows: ,in, Carbon emission factors for solid waste-based recycled building materials This represents the percentage of each raw material. Carbon emission factors in the production and processing of various raw materials. The carbon emission factors for the transportation of each raw material. This refers to the consumption of various types of energy throughout the entire production and processing process. Carbon emission factors corresponding to various energy sources Carbon capture amount; The calculation method is to calculate the carbon emission factor of each raw material transportation. Carbon emission factors in production and processing The sum multiplied by the percentage of that raw material Then, sum them up.

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