Method for accounting for carbon emissions in a composite production area

Abstract

The present application relates to a kind of carbon emission accounting method of composite production area, comprising: determining the system boundary of composite production area, respectively establishing the carbon input list and carbon output list of each process, according to material balance and polymerization reaction principle, determine the carbon conversion path in each process, form the carbon flow evolution model describing the carbon element flow, conversion and loss path of each process in production process;According to carbon flow evolution model, identify key carbon flow node, deploy monitoring instrument for each key carbon flow node, obtain solid carbon-containing material information, gas carbon-containing emission information, process parameters and real-time monitoring data of energy consumption information;Establish the carbon balance equation of each process and the overall production area, calculate the direct CO2 emission of each process by carbon difference subtraction method, obtain the direct carbon emission of production area;Calculate the total amount of indirect carbon emission of production area.The present application improves the process level accounting accuracy, meets the fine carbon emission management needs of composite production area.

Description

Technical Field

[0001] This invention relates to the field of carbon emission accounting technology, and in particular to a method for carbon emission accounting in a composite material production area. Background Technology

[0002] Composite materials, such as glass fiber reinforced resin matrix composites, are widely used in products such as pipes, autoclaves, and molded parts. The hot pressing and molding processes in their production are energy-intensive, and carbon emissions mainly come from the thermal decomposition of organic raw materials such as resins, the power consumption or fuel combustion of hot pressing / molding equipment, and direct greenhouse gas emissions during the curing process. Composite material production areas typically include mixing, preforming, hot pressing / molding, curing, cooling and demolding, and post-processing. The hot pressing / molding process is a complex physicochemical process involving multiple phases (solid-gas-liquid), unsteady state, and intermittent production. During the resin cross-linking and curing process, carbon elements are partially fixed in the product and partially released as volatile organic compounds or pyrolysis gases. The various processes are closely coupled through intermediate materials (mixing materials, prepregs, prepregs), energy-carrying media (heat transfer oil, steam, electric heating), and waste gas collection systems. Carbon elements undergo complex migration and transformation among raw materials, energy, intermediate products, and waste gases, making real-time monitoring and decoupling analysis extremely technically challenging.

[0003] In existing technologies, carbon emission accounting methods for composite material molding processes are mainly based on material mass balance and process energy consumption data, using the emission factor method to calculate total carbon emissions. These methods have the following main drawbacks: The accounting model performs macroscopic accounting for the entire compression molding process, but fails to deeply analyze the specific occurrence forms (such as organic carbon, carbonate carbon, volatile organic carbon, CO2, CO, CH4, etc.) and refined transformation paths of carbon elements in each process within the composite material production area (such as the resin and filler ratio in mixing, the volatile matter desorption during hot pressing, carbon fixation and release in curing and crosslinking reactions, and residual volatilization during cooling demolding and post-processing). This results in the inability to locate specific carbon loss nodes within the process.

[0004] In terms of calculation methods, the reliance on theoretical calculations, laboratory test data, or equipment rated power estimation has failed to propose a high-precision online monitoring scheme that can cover key carbon sources (such as resin raw materials, auxiliary materials, and fuels), carbon sinks (carbon sequestration in products and carbon recovery from waste), and carbon loss points (autoclave exhaust, molding fumes, curing oven exhaust, etc.) in composite material production areas and is adapted to complex industrial environments with high temperature, high dust, and volatile organic compounds. This has resulted in serious deficiencies in the real-time performance and accuracy of the model input.

[0005] Due to the lack of refined carbon flow models and supporting monitoring data, existing methods are unable to accurately distinguish the interconnected changes in carbon emissions at each process caused by resin formulation adjustments (such as high filler and low resin formulations), changes in process parameters (such as hot pressing temperature curves, holding time, and curing temperature rise rate), and changes in energy structure (such as green electricity substitution and biomass fuel substitution). This makes it impossible to provide accurate quantitative assessments of the effectiveness of specific carbon reduction technologies such as resin reduction technology, rapid curing process, and waste heat recovery, resulting in insufficient accuracy in process-level carbon emission accounting.

[0006] Therefore, there is still a lack of mature and engineerable carbon monitoring and accounting technologies for composite material production areas. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a carbon emission accounting method for composite material production areas. The aim is to solve the technical problems in existing carbon emission accounting methods, such as unclear carbon flow evolution paths, lack of systematic online monitoring schemes, and insufficient process-level accounting accuracy, which fail to meet the needs of refined carbon emission management in composite material production areas.

[0008] The technical solution adopted in this invention is as follows: This invention provides a method for carbon emission accounting in composite material production areas, comprising: The system boundary of the composite material production area is determined, and carbon input and carbon output lists for each process are established. Based on the principles of material balance and polymerization reaction, the carbon conversion path in each process is determined, and a carbon flow evolution model describing the carbon element flow, conversion and loss path in each process is formed. Based on the carbon flow evolution model, key carbon flow nodes are identified, and monitoring instruments are deployed for each key carbon flow node to obtain real-time monitoring data on solid carbon-containing materials, gaseous carbon emissions, process parameters, and energy consumption. Based on the carbon flow evolution model and real-time monitoring data, a carbon balance equation for each process and the overall production area is established. The direct CO2 emissions of each process are calculated by carbon difference subtraction to obtain the direct carbon emissions of the production area. Calculate the total indirect carbon emissions in the production area based on the purchased electricity and corresponding emission factors, and the fuel consumption and corresponding emission factors for each process. The total carbon emissions are the sum of the total direct emissions from the production area and the total indirect carbon emissions from the production area.

[0009] As a preferred technical solution: The calculation of direct carbon emissions from the production area includes: Calculate the total carbon input for each process:

[0010] in, Processi The total amount of carbon input. These are the total carbon input from solid carbon-containing materials, the total carbon input from fuel, and the total carbon input from recycled waste, respectively. Calculate the total carbon content output from each process:

[0011] In the formula, For process i The total carbon output. These are the carbon sequestration content of the product, the carbon content of non-CO2 carbon components in the exhaust gas, and the carbon content of the waste material; According to the law of conservation of carbon mass, the process i China's carbon emissions in the form of CO2:

[0012] according to Obtaining process i Direct CO2 emissions.

[0013] The calculation of the total carbon content of the solid carbon-containing material includes:

[0014] In the formula, M s This represents the number of types of solid materials. For the first j The mass flow rate of a solid material For the first j The mass fraction of total organic carbon in a solid material; The calculation of the total carbon content of the fuel input includes:

[0015] In the formula, M f For the number of fuel types, For the first k Volumetric flow rate of the fuel For the first k Standard density of the fuel For the first k The carbon mass fraction of a fuel.

[0016] The calculation of the total carbon content input from the recycled waste includes:

[0017] In the formula, , For process i Mass flow rate of recycled waste and carbon mass fraction of recycled waste.

[0018] The calculation of the carbon sequestration content of the product includes:

[0019] In the formula, For process i Product quality flow rate produced The carbon mass fraction of the product; The calculation of the carbon content of non-CO2 carbon components in the exhaust gas includes:

[0020] In the formula, M g This represents the number of non-CO2 carbon-containing gaseous components. This refers to the total volumetric flow rate of the exhaust gas. For the first g The volume concentration of the components, Here are the correction factors for temperature T and pressure P, where T is the pressure P. o =273.15K, P0=101.325kPa, For the first g The number of carbon atoms in a component molecule.

[0021] The calculation of the carbon content of the waste includes:

[0022] In the formula, For process i Mass flow rate of produced scrap materials This represents the carbon mass fraction of the waste.

[0023] The method also includes verifying the reliability of the monitoring data through carbon balance closure verification; The carbon balance closure check includes:

[0024] In the formula, For process i The relative deviation of the balance closure degree; when If the data is less than the set threshold, it indicates that the monitoring data is reliable; otherwise, it is unreliable, and the monitoring plan should be adjusted.

[0025] The real-time monitoring data obtained, including information on solid carbonaceous materials, gaseous carbonaceous emissions, process parameters, and energy consumption, includes: At the raw material feeding port or conveyor belt, deploy a high-precision electronic belt scale or loss-in-weight feed scale and equip it with a near-infrared spectrometer or rapid carbon analyzer to continuously measure the mass flow rate of solid material feed and periodically detect the total organic carbon mass fraction. At the inlet and outlet nodes of exhaust pipes and waste gas treatment facilities in each process, high-temperature infrared gas analyzers are deployed to measure the concentrations of CO, CO2, and CH4; flame ionization detectors are deployed to measure the concentration of total volatile organic carbon (TVOC); and thermal or Pitot tube mass flow meters and temperature and pressure integrated instruments are deployed to measure the volumetric flow rate of waste gas, the concentration of each carbon component in the exhaust gas, as well as the temperature and pressure, in real time, and calculate the actual density and mass flow rate of each component accordingly. The consumption of natural gas, biomass gas, and fuel oil in each process is measured by a mass flow meter, while the hot pressing temperature, curing time, and holding pressure are collected in real time by the equipment control system.

[0026] The carbon input list includes carbon from resins, carbon carbonates in fillers, carbon from auxiliary materials, and carbon from fuels; the carbon output list includes carbon from CO2 emissions, carbon from CO emissions, carbon from CH4 and other VOCs, carbon from product solidification, carbon from waste recovery, and carbon carried over by waste heat.

[0027] The method further includes: Based on the total carbon emissions, the carbon emission intensity per unit product and the carbon emission intensity per unit output value are calculated, and a carbon flow Sankey diagram, a process carbon emission ratio diagram, and a carbon emission trend diagram are generated for visualization output.

[0028] The technical solution of the present invention can achieve at least some of the following beneficial effects: This invention addresses the green and low-carbon development needs of the composite materials industry. Through the synergy of a carbon flow evolution module, an engineerably deployable online monitoring module, and a module for calculating carbon emission intensity during the production processes of intermediate composite materials (prepregs, prepregs) and final products (pipes, autoclaves, molded parts), it can be widely applied to carbon management and carbon market compliance for glass fiber reinforced resin-based composite material (such as pipes, autoclaves, molded parts) manufacturers. It also has the potential to be extended to the production processes of other high-performance composite materials such as carbon fiber composites and bio-based composites. After implementing this invention, companies can accurately identify carbon emission hotspots in key processes such as hot pressing and molding, quantify the actual emission reduction effects of carbon reduction technologies such as process optimization, waste recycling, and energy substitution, and significantly reduce carbon compliance costs. Specific advantages are reflected in the following aspects: The carbon flow evolution model constructed in this invention not only covers all major processes in the composite material production area, but also delves into the specific transformation paths of carbon elements between different phases (solid products, gaseous volatiles, liquid resin intermediates, and solid waste). It can clearly depict the entire process of carbon from raw material input such as resin powder to product carbon fixation, waste gas carbon emissions, and waste carbon loss via a Sankey diagram, achieving precise location of carbon loss nodes and improving decision-making transparency. Taking the production of composite material pipelines in autoclaves as an example, the carbon flow model of this invention can identify that the excessively rapid heating rate in the curing process leads to intensified resin thermal decomposition, causing VOCs carbon loss to account for 12%~18% of the total input carbon. However, by adopting a gradient heating process, this loss can be reduced to 6%~9%, a level of precision that traditional stage segmentation methods cannot achieve.

[0029] This invention can accurately calculate the carbon emission intensity of the production process for intermediate composite materials (prepregs, prepregs) and final products (pipes, autoclaves, molded parts). After applying this method, the true carbon footprint of a unit product can be distinguished under different formulation systems (unsaturated polyester resin, epoxy resin, phenolic resin, etc.) and different process routes (autoclave process vs. molding process), avoiding the "one-size-fits-all" error caused by the traditional method's use of industry average emission factors. Taking glass fiber reinforced epoxy resin pipes exported to the EU as an example, the carbon footprint data calculated using this method is accurate to 1.82 kg CO2 equivalent per kilogram of product (of which raw material carbon contribution is 1.21 kg, process energy consumption carbon contribution is 0.53 kg, and waste carbon loss is 0.08 kg), a deviation of 15.3% compared to the industry default factor method (2.15 kg CO2 equivalent / kg). This level of precision provides composite material companies with compliant, accurate, and traceable data support for participating in carbon market compliance, responding to the EU Carbon Border Adjustment Mechanism (CBAM), and conducting Product Environmental Declaration (EPD) certification, significantly enhancing the international green competitiveness of their products.

[0030] This invention overcomes the shortcomings of existing technologies that "emphasize accounting but neglect monitoring," and for the first time proposes an engineering-deployable online monitoring scheme covering three types of carbon flows: carbon in solid materials, carbon-containing components in waste gas, and process energy consumption. It clarifies the specific locations of key measuring points (resin powder feed inlet, hot press exhaust outlet, curing oven exhaust pipe, waste gas treatment facility inlet and outlet, etc.), the monitored physical quantities (material mass flow rate, total organic carbon content, CO / CO2 / CH4 / TVOC concentration and flow rate in waste gas, power consumption, fuel consumption, etc.), recommended instruments (loss-in-weight feed scale, near-infrared spectrometer, infrared gas analyzer, flame ionization detector, thermal mass flow meter, etc.), and monitoring methods (sampling frequency of no less than once per minute, real-time data aggregation and time alignment). After actual deployment and verification in a production area with an annual output of 30,000 tons of composite molded parts, this monitoring scheme improves the time resolution of carbon accounting input data from the traditional annual / monthly average to the minute level, shortens the accounting cycle from 15 days of manual statistics to real-time automatic accounting, and significantly enhances data traceability.

[0031] The calculation results of this invention can be directly applied to carbon quota compliance in composite material production areas, evaluation of the effects of low-carbon formulation and process optimization (such as high filler and low resin formulations, low-temperature rapid curing processes, green electricity substitution, etc.), carbon reduction calculation of waste recycling technology, and carbon footprint certification of exported products (to address the EU's Carbon Border Adjustment Mechanism CBAM), providing a scientific basis for the refined carbon management of composite material enterprises. Attached Figure Description

[0032] Figure 1 This is a flowchart illustrating the method of an embodiment of the present invention. Detailed Implementation

[0033] The specific embodiments of the present invention are described below with reference to the accompanying drawings.

[0034] See Figure 1 This embodiment provides a method for carbon emission accounting in a composite material production area, including: S1. Determine the system boundary of the composite material production area, establish carbon input and carbon output lists for each process, determine the carbon conversion path in each process based on material balance and polymerization reaction principles, and form a carbon flow evolution model that describes the carbon element flow, conversion and loss path in each process during production.

[0035] Specifically, the process includes a mixing process, a molding process (hot pressing and / or molding), a curing process, a cooling and demolding process, and a post-processing process.

[0036] In one specific embodiment, a production area for glass fiber reinforced resin matrix composite products (mainly including composite pipes, autoclave shells, and molded parts) with an annual output of approximately 50,000 tons is configured as follows: a mixing workshop (equipped with 2 high-speed mixers and a loss-in-weight feeding system), a hot pressing workshop (equipped with 5 hot presses, with nominal pressures of 1000t×2 and 500t×3 respectively, and electric heating), an autoclave workshop (equipped with 3 autoclaves, with a diameter of 2.5m×length of 8m, a maximum working pressure of 1.2MPa, a maximum working temperature of 200℃, and electric heating), and a curing oven workshop (equipped with...). The facility includes 4 hot air circulating curing ovens with a working temperature of 80℃~220℃ (heated by natural gas), a cooling and demolding area (equipped with forced air cooling and natural cooling stations), and a post-processing workshop (equipped with trimming machines, grinding machines, drilling equipment, and a central dust removal system). The system boundary of the composite material production area is defined as follows: with a monthly (30-day) accounting cycle, the system boundary of the production area is defined from the time when raw and auxiliary materials such as glass fiber, resin powder, fillers, and additives enter the mixing process until the finished composite material products (pipes, autoclave shells, molded parts) are produced and volatile organic compounds (VOCs), CO2, CO, CH4, waste materials, and residual heat are discharged.

[0037] Specifically, the carbon input list includes resin carbon, carbonate carbon in fillers, auxiliary material carbon, and fuel carbon; the carbon output list includes CO2 emission carbon, CO emission carbon, CH4 and other VOCs carbon, product solid carbon, waste recovery carbon, and waste heat carried carbon.

[0038] In one specific implementation, the input and output list for each process is as follows: Mixing process: Inputs: glass fiber (carbon mass fraction approximately 0%, as it is an inorganic material), unsaturated polyester resin powder (carbon mass fraction approximately 58%), calcium carbonate filler (carbon mass fraction approximately 12%, existing in the form of carbonate), curing agent (methyl ethyl ketone peroxide, carbon mass fraction approximately 35%), release agent (zinc stearate, carbon mass fraction approximately 68%), etc. Output: Mixture (physical mixture, carbon has not undergone chemical transformation) and feed dust (containing a small amount of organic carbon); Hot pressing / molding process: Inputs: Energy consumption for mixture and electric heating; Output: semi-cured blank, VOCs (including styrene, toluene, etc.) volatilized at the moment of mold opening, and a small amount of CO; Curing process: Input: Semi-cured preform and heat energy (electric heating or natural gas combustion heating); Output: Cured finished product, curing oven exhaust gas (mainly containing CO2, CO, CH4, benzene compounds, aldehydes, and other VOCs). Curing temperature range: 130℃~220℃, holding time range: 1min~60min; Cooling and demolding process: Input: High-temperature cured product; Output: Cooled product and residual volatiles; Post-processing steps: Input: Demolded product and electrical energy (trimming, grinding, and drilling equipment); Output: Finished products, scrap materials (containing glass fiber and cured resin, with a carbon mass fraction of approximately 30%~40%), and grinding dust (containing organic carbon).

[0039] Specifically, based on material balance and polymerization reaction principles, the typical parameter ranges of carbon in each process's carbon conversion pathway are determined, thereby clarifying the specific conversion mechanisms within each process and laying a model foundation for subsequent monitoring and accounting, including: In the hot pressing / molding process, under the conditions of temperature 120℃~200℃ and pressure 0.5MPa~10MPa, the resin softens and flows when heated, some low molecular weight organic components volatilize to form VOCs (including CH4, benzene series, etc.), and carbon elements begin to migrate to the gas phase. During the curing process, under the conditions of temperature 130℃~220℃ and holding time 1min~60min, the resin undergoes a cross-linking polymerization reaction. Part of the carbon element is fixed in the three-dimensional network structure to form fixed carbon in the product, while the other part releases CO2, CO and small molecule hydrocarbons due to thermal decomposition. During the cooling and demolding process, the product is cooled to below 60°C, and the residual volatiles continue to dissipate; during the post-processing process (trimming, grinding, drilling), some of the organic carbon in the scrap is released in the form of dust, and some enters the solid waste. This completes the carbon evolution path map of the composite material production area.

[0040] S2. Identify key carbon flow nodes based on the carbon flow evolution model, deploy monitoring instruments for each key carbon flow node, and obtain real-time monitoring data on solid carbon-containing materials, gaseous carbon emissions, process parameters, and energy consumption.

[0041] Preferably, the real-time monitoring of the solid carbon-containing material information includes: High-precision electronic belt scales or loss-in-weight feed scales are installed at the feeding ports or conveyor belts of raw materials such as resin powder, glass fiber, and fillers, and equipped with near-infrared spectrometers or rapid carbon analyzers to continuously measure the mass flow rate of solid material feed and periodically detect the mass fraction of total organic carbon (TOC).

[0042] Preferably, the real-time monitoring of the gaseous carbon emissions information includes: At key points such as the exhaust port of the hot press, the exhaust pipe of the hot autoclave, the exhaust pipe of the curing oven, the mold opening flue gas collection port, and the inlet and outlet of the waste gas treatment facility, high-temperature resistant infrared gas analyzers are deployed to measure the concentrations of CO, CO2, and CH4; flame ionization detectors are deployed to measure the concentration of total volatile organic carbon (TVOC); and thermal or Pitot tube mass flow meters and temperature-pressure integrated instruments are deployed to measure the volumetric flow rate of waste gas, the concentration of each carbon-containing component, and the temperature and pressure in real time, and to calculate the actual density and mass flow rate of each component accordingly.

[0043] Preferably, real-time monitoring of process parameters and energy consumption information includes: Multifunctional high-precision meters are deployed at the power distribution end of the electric heating system of the hot press / autoclave / curing oven. Gas turbine flow meters or liquid mass flow meters are deployed at the fuel inlet of the heat transfer oil or steam heating system to measure the consumption of natural gas, biomass gas, fuel oil, etc. At the same time, process parameters such as hot pressing temperature, curing time, and holding pressure are collected in real time through the equipment control system.

[0044] Specifically, all monitoring data is aggregated, time-aligned, and stored in real time through a central data acquisition platform, with a sampling frequency of no less than once per minute, providing high-precision and traceable input data for subsequent carbon emission accounting.

[0045] In one specific implementation, key monitoring nodes are identified based on a carbon flow model, monitoring instruments are deployed in the composite material production area, and various information is monitored in real time, including: (1) Monitoring of solid carbon-containing materials: A loss-in-weight feeder (accuracy ±0.2%) was installed at the resin powder feeding silo outlet pipe, and equipped with a near-infrared spectrometer (NIR, model Bruker MATRIX-F, sampling interval 5 minutes) to continuously measure the resin powder mass flow rate and total organic carbon (TOC) mass fraction. The total resin powder feeding volume for the month was measured as Qsz = 11250 tons, with an average TOC mass fraction of wsz = 58.2%. An electronic belt scale (accuracy ±0.5%) was installed at the calcium carbonate filler feeding port, and samples were taken periodically (once per shift) to determine the total carbon mass fraction using a high-temperature combustion-infrared absorption carbon-sulfur analyzer (model LECO CS230). The total filler feeding volume for the month was measured as QCaCO3 = 18750 tons, with an average total carbon mass fraction of wCaCO3 = 11.8%. An electronic belt scale (accuracy ±0.5%) was installed at the glass fiber feeding port; the glass fiber carbon mass fraction was approximately 0%, and only the mass flow rate was measured. The total glass fiber feeding volume for the month was Qbx = 15000 tons. Electronic belt scales were deployed on the waste recycling line in the post-processing workshop, and samples were taken to measure the carbon mass fraction of the waste (average value wrecycle=34.13%) for the calculation of carbon content in the waste recycling.

[0046] (2) Monitoring of carbon emissions from gases: An infrared gas analyzer (measuring CO and CO2), a flame ionization detector (measuring TVOC), a thermal mass flow meter (model FCI ST100), and a temperature and pressure integrated instrument are deployed at the exhaust port (flue gas collection hood duct at the moment of mold opening) of each hot press. The flow rate and component concentration of the exhaust gas are monitored in real time at the moment of mold opening during the hot pressing process (lasting approximately 10-30 seconds).

[0047] An infrared multi-component gas analyzer (measuring CO, CO2, and CH4), a flame ionization detector (measuring TVOC), a Pitot tube flow meter (Rosemount 3051S), and a temperature and pressure integrated instrument are deployed on the main exhaust pipe of the curing oven (0.5m before the inlet of the waste gas treatment facility). The curing waste gas is continuously monitored in real time, with a sampling frequency of once per minute, and the data is taken as an hourly average.

[0048] Infrared gas analyzers and thermal mass flow meters are deployed in the exhaust stack of the dust removal system in the post-processing workshop to monitor the release of organic carbon oxidation carried by grinding dust.

[0049] (3) Monitoring of process parameters and energy consumption: Multifunctional high-precision meters (accuracy class 0.5S, model DTSD341) are deployed at the power distribution terminals of the electric heating systems of the hot press and autoclave to measure the power consumption of each piece of equipment. All monitoring data are aggregated in real time, time-aligned (using NTP synchronization, sampling period of 1 minute, and hourly average value for calculation) and stored through a central data acquisition platform (based on OPC UA protocol and industrial Ethernet), with a data retention period of no less than 3 years.

[0050] S3. Based on the carbon flow evolution model and real-time monitoring data, establish the carbon balance equation for each process and the overall production area. Calculate the direct CO2 emissions of each process using the carbon difference subtraction method to obtain the direct carbon emissions of the production area. Calculate the total indirect carbon emissions of the production area based on the purchased electricity and corresponding emission factors, and the fuel consumption and corresponding emission factors of each process.

[0051] Specifically, the calculation of direct carbon emissions from the production area includes: calculating the total carbon input of each process, which is the sum of the products of the mass flow rate of all solid inputs (resin powder, glass fiber, fillers, additives, etc.) and their corresponding total organic carbon content, the sum of the products of the mass or volume flow rate of all fuel inputs (natural gas, biomass fuel, etc.) and their carbon content, and the carbon content in recycled waste; calculating the total output carbon, which is the sum of the carbon content in the product (product demolding mass multiplied by product carbon mass fraction, where product carbon mass fraction is determined by elemental analysis through random sampling) and the carbon content in the exhaust gas (the sum of the volume flow rate of each carbon-containing component in the exhaust gas × component concentration × component density) and the carbon content in the waste (mass of scrap waste × waste carbon mass fraction); and calculating CO2 emissions through carbon difference subtraction.

[0052] As a preferred method, step S3 specifically includes the following steps: S31. Calculation of direct carbon emissions from the production area, including: S311. Calculate the total carbon input for each process:

[0053] in, Process i The total amount of carbon input. These are the total carbon input from solid carbon-containing materials, the total carbon input from fuel, and the total carbon input from recycled waste, respectively. The calculation of the total carbon content of solid carbon-containing materials includes:

[0054] In the formula, M s This refers to the number of solid material types (including resin powder, glass fiber, filler, curing agent, release agent, etc.). For the first j Mass flow rate (kg / h or t / month) of a solid material. For the first j Total organic carbon (TOC) mass fraction (%) of a solid material; The calculation of the total carbon content of fuel input includes:

[0055] In the formula, M f This refers to the number of fuel types (natural gas, biomass fuel, etc.). For the first k Volumetric flow rate of the fuel (m³) 3 / h), For the first k Standard density of the fuel (kg / m³) 3 ), For the first k The carbon mass fraction (%) of each fuel.

[0056] The calculation of the total carbon content input from recycled waste includes:

[0057] In the formula, , For process i Mass flow rate of recycled waste (kg / h), carbon mass fraction of recycled waste (%).

[0058] S312. Calculate the total carbon content output from each process step:

[0059] In the formula, For process i The total carbon output. These are the carbon sequestration content of the product, the carbon content of non-CO2 carbon components (CO, CH4, VOCs, etc.) in the exhaust gas, and the carbon content of the waste material; The calculation of the carbon sequestration content of the product includes:

[0060] In the formula, For process i Product mass flow rate (kg / h). Carbon mass fraction of the product (%) The calculation of the carbon content of non-CO2 carbon components in the exhaust gas includes:

[0061] In the formula, M g This represents the number of non-CO2 carbon-containing gaseous components (CO, CH4, VOCs, etc.). Total volumetric flow rate of exhaust gas (measured value, m³) 3 / h), For the first g Volume concentration (ppm or %) of each component. Here are the correction factors for temperature T and pressure P, where T is the pressure P. o =273.15K, P0=101.325kPa, For the first g The number of carbon atoms in a component molecule.

[0062] The calculation of the carbon content in the waste includes:

[0063] In the formula, For processi Mass flow rate of produced scrap material (kg / h). The carbon mass fraction (%) of the waste.

[0064] S313. According to the law of conservation of carbon mass, the process... i China's carbon emissions in the form of CO2:

[0065] according to Obtaining process i Direct CO2 emissions; due to It does not contain CO2 carbon, therefore This refers to the carbon content of CO2 in the exhaust gas, which is used to calculate the process steps. i Direct CO2 emissions:

[0066] The total direct carbon emissions to the production area are obtained by adding up the direct CO2 emissions calculated from each step S31, including mixing, molding, curing, cooling and demolding, and post-processing.

[0067] S32. Then, based on the product of the purchased electricity and the regional power grid carbon emission factor for each process, and the product of the fuel consumption and the corresponding fuel carbon emission factor for each process, calculate the total indirect carbon emissions (where the direct emissions from fuel combustion have been included in step (3), and only the "well-to-gate" emissions upstream of the fuel are counted here; if a simplified accounting method is used, only the indirect emissions corresponding to the purchased electricity are counted).

[0068] As a preferred method, the reliability of the monitoring data is verified through carbon balance closure verification; The carbon balance closure check includes:

[0069] In the formula, For process i The relative deviation of the balance closure degree; when If the data is less than the set threshold, it indicates that the monitoring data is reliable; otherwise, it is unreliable and the monitoring plan needs to be adjusted.

[0070] S4. The total carbon emissions are obtained by adding the total direct emissions from the production area to the total indirect carbon emissions from the production area.

[0071] In one specific implementation, based on the monitoring data obtained in step S2, a carbon balance equation for each process is established and CO2 emissions are calculated, including the following steps: 1. Taking the curing process as an example, calculate the carbon balance equation and CO2 emissions for this process: (1) Input total carbon content calculation: The amount of carbon input (C) for resin powder in the mixing process sz =Q sz × w sz =11250 tons × 58.2% = 6547.5 tons; Input carbon content C of calcium carbonate filler CaCO3 = Q CaCO3 × w CaCO3 = 18750 tons × 11.8% = 2212.5 tons; Input carbon content C of curing agent (methyl ethyl ketone peroxide) C8H18O6 = Q C8H18O6 × w C8H18O6 = 375 tons × 35% = 131.25 tons; Release agent (zinc stearate) input carbon content C CHO4Zn =Q CHO4Zn × w CHO4Zn = 187.5 tons × 68% = 127.5 tons; Carbon input C for glass fiber bx ≈ 0 tons; Total carbon input for the mixing process C hl = 6547.5 + 2212.5 + 131.25 + 127.5 = 9018.75 tons; The carbon output of the mixing process is only the mixture (without chemical conversion), and the total output carbon amount is equal to the total input carbon amount (the carbon loss from the feed dust is about 0.5%, which can be ignored or calculated separately).

[0072] Total carbon input for hot pressing process = 9018.75 tons. Calculation of carbon output in the mold opening exhaust gas of the hot pressing process (cumulative for the current month): Average composition of exhaust gas from a single mold opening: CO2 2800 ppm, CO 150 ppm, TVOC 850 ppm (calculated as carbon, the average molecular weight of TVOC is equivalent to C6H6, and the carbon mass fraction is approximately 92.3%).

[0073] The exhaust gas volume for a single mold opening is 2.5 m³. 3 1200 times that month, total exhaust gas volume 3000 m³ 3 (Converted under standard conditions, temperature 25℃, 101.325 kPa); CO2 carbon content ≈ 4.5 tons; CO carbon content ≈ 0.24 tons; TVOC carbon content ≈ 1.26 tons. Total carbon output from the hot pressing process ≈ 6.0 tons. Carbon content of the semi-cured blank after hot pressing = Total input carbon - Carbon output from waste gas = 9018.75 - 6.0 = 9012.75 tons.

[0074] Besides the carbon input from natural gas combustion, the carbon input from the curing process is 9012.75 tons. (Carbon input from natural gas combustion in the curing oven) = 48500 m 3× 73.6% × (12 / 22.4) ≈ 191.2 tons. Total carbon input for the curing process. =9203.95 tons.

[0075] (2) Calculation of carbon output from the curing oven process (excluding carbon from CO2 gas): Carbon content of cured product: Based on a resin carbon retention rate of 70%, the carbon content of the product is... = 6547.5 × 70% = 4583.25 tons.

[0076] Carbon content of waste output from the curing process: The post-processing workshop generates approximately 3750 tons of waste (accounting for 7.5% of the total product mass), with a measured carbon mass fraction of 34.13%. =3750 × 34.13% = 1280 tons. VOCs (CO, CH4, TVOC) output from the curing process: calculated based on the measured waste gas volume and concentration (after deducting the natural gas combustion portion, the remainder is resin pyrolysis products). Measured CO volume: 426.24 m³ 3 The carbon content of CO is 426.24 × (12 / 22.4) = 228.3 tons; the volume of CH4 is 59.94 m³. 3 CH4 carbon content = 59.94 × (12 / 22.4) = 32.1 tons; TVOC volume 559.44 m³ 3 The TVOC carbon content, calculated based on a carbon mass fraction of 92.3%, is 559.44 × (12 / 22.4) × 0.923 = 276.5 tons.

[0077] The total VOCs (carbon dioxide) emissions are 228.3 + 32.1 + 276.5 = 536.9 tons. Natural gas consumption is 48,500 m³. 3 The natural gas contains 191.2 tons of carbon.

[0078] The CO2 carbon output from the solidification process = Input carbon - Product carbon - Waste carbon - VOCs carbon - Natural gas combustion carbon = 2612.6 tons.

[0079] Direct CO2 emissions from the curing process (from resin pyrolysis) = 2612.6 × (44 / 12) ≈ 9579.5 tons. All natural gas is converted to CO2 upon combustion, with a CO2 mass of 191.2 × (44 / 12) = 701.1 tons. This portion is included in the direct emissions from fuel combustion during the curing process.

[0080] Therefore, the total direct CO2 emissions from the curing process are 10,208.6 tons.

[0081] (3) The same calculation method is used to calculate that the mixing process emits about 2.1 tons of CO2, the hot pressing process emits about 185 tons of CO2, the cooling and demolding process emits about 45 tons of CO2, and the post-processing process directly emits about 5 tons of CO2. Among them, the relative deviation of the closure degree is 1.79%, which is less than 5%, and the data is reliable.

[0082] 2. Total carbon emissions accounting for the production area: Summary of direct CO2 emissions from each process: Total direct carbon emissions from the production area = 2.1 + 185 + 10208.6 + 45 + 5 = 10445.7 tons of CO2 / month.

[0083] 3. Calculation of indirect carbon emissions: Purchased electricity: Total purchased electricity for hot press, autoclave, mixing equipment, post-processing equipment, etc. in the current month = 580 + 320 + 210 + 185 = 1295 MWh (the curing oven is heated by natural gas and is not included in the electricity calculation).

[0084] The carbon emission factor for the regional power grid is taken as 0.610 tCO2 / MWh (average value of East China Power Grid in 2025).

[0085] Indirect carbon emissions = 1295 × 0.610 = 790.0 tons of CO2.

[0086] 4. Total carbon emissions from the production area = Direct emissions of 10,445.7 tons + Indirect emissions (electricity) of 790.0 tons = 11,235.7 tons of CO2 / month.

[0087] As a preferred embodiment, the method further includes: S5. Based on the total carbon emissions, calculate indicators such as carbon emission intensity per unit product (kg CO2 / t product) and carbon emission intensity per unit output value (kg CO2 / 10,000 yuan of output value), and generate carbon flow Sankey diagrams, process carbon emission ratio diagrams, and carbon emission trend diagrams for visualization output.

[0088] In one specific implementation, the calculation of carbon emission intensity per unit product includes: The total monthly product output is 50,000 tons (including pipes, autoclave shells, and molded parts); the carbon emission intensity per unit product = 11,307.7 tons of CO2 ÷ 50,000 tons of product = 0.226 tons of CO2 / ton of product. A Sankey diagram of carbon flow is generated, clearly showing the flow of carbon from sources such as resin powder, fillers, and curing agents into each process, ultimately resulting in CO2 emissions (approximately 92.8%), carbon sequestration in products (approximately 4.0%), carbon in waste materials (approximately 2.1%), and VOCs carbon (approximately 0.9%).

[0089] Verification has shown that, based on the refined carbon flow monitoring and accounting method of this embodiment, a typical enterprise with an annual output of 50,000 tons of composite material products can save an average of 5 million to 15 million yuan in carbon compliance costs annually, while reducing the cost of manual monitoring and carbon data accounting by approximately 30%-50%. This demonstrates the effectiveness and practicality of the method of this invention in carbon flow monitoring, accurate carbon emission accounting, and quantitative assessment of carbon reduction technologies in composite material production areas.

[0090] With the potential expansion of the EU's Carbon Border Adjustment Mechanism (CBAM) to include composite materials and their downstream products, this invention can provide export-oriented composite material companies with compliant and traceable carbon footprint data, helping them cope with international carbon barriers and enhance the green competitiveness of their products in the international market. This invention will also strongly support my country's building materials and composite materials industry in achieving its "dual carbon" goals, promoting the industry's transformation from high energy consumption and high emissions to low-carbon processes and green manufacturing, resulting in significant economic and social benefits.

[0091] It will be understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for carbon emission accounting in a composite material production area, characterized in that, include: The system boundary of the composite material production area is determined, and carbon input and carbon output lists for each process are established. Based on the principles of material balance and polymerization reaction, the carbon conversion path in each process is determined, and a carbon flow evolution model describing the carbon element flow, conversion and loss path in each process is formed. Based on the carbon flow evolution model, key carbon flow nodes are identified, and monitoring instruments are deployed for each key carbon flow node to obtain real-time monitoring data on solid carbon-containing materials, gaseous carbon emissions, process parameters, and energy consumption. Based on the carbon flow evolution model and real-time monitoring data, a carbon balance equation for each process and the overall production area is established. The direct CO2 emissions of each process are calculated by carbon difference subtraction to obtain the direct carbon emissions of the production area. Calculate the total indirect carbon emissions in the production area based on the purchased electricity and corresponding emission factors, fuel consumption and corresponding emission factors for each process. The total carbon emissions are the sum of the total direct emissions from the production area and the total indirect carbon emissions from the production area.

2. The method according to claim 1, characterized in that, The calculation of direct carbon emissions from the production area includes: Calculate the total carbon input for each process: ， in, Process i The total amount of carbon input. These are the total carbon input from solid carbon-containing materials, the total carbon input from fuel, and the total carbon input from recycled waste, respectively. Calculate the total carbon content output from each process: ，， In the formula, For process i The total carbon output. These are the carbon sequestration content of the product, the carbon content of non-CO2 carbon components in the exhaust gas, and the carbon content of the waste material; According to the law of conservation of carbon mass, the process i China's carbon emissions in the form of CO2: ， according to Obtaining process i Direct CO2 emissions.

3. The method according to claim 2, characterized in that, The calculation of the total carbon content of the solid carbon-containing material includes: ， In the formula, M s This represents the number of types of solid materials. For the first j The mass flow rate of a solid material For the first j The mass fraction of total organic carbon in a solid material; The calculation of the total carbon content of the fuel input includes: ， In the formula, M f For the number of fuel types, For the first k Volumetric flow rate of the fuel For the first k Standard density of the fuel For the first k The carbon mass fraction of a fuel.

4. The method according to claim 2, characterized in that, The calculation of the total carbon content input from the recycled waste includes: ， In the formula, , For process i Mass flow rate of recycled waste and carbon mass fraction of recycled waste.

5. The method according to claim 3, characterized in that, The calculation of the carbon sequestration content of the product includes: ， In the formula, For process i Product quality flow rate produced The carbon mass fraction of the product; The calculation of the carbon content of non-CO2 carbon components in the exhaust gas includes: ， In the formula, M g This represents the number of non-CO2 carbon-containing gaseous components. This refers to the total volumetric flow rate of the exhaust gas. For the first g The volume concentration of the components, Here are the correction factors for temperature T and pressure P, where T is the pressure P. o =273.15K, P0=101.325kPa, For the first g The number of carbon atoms in a component molecule.

6. The method according to claim 2, characterized in that, The calculation of the carbon content of the waste includes: ， In the formula, For process i Mass flow rate of produced scrap materials This represents the carbon mass fraction of the waste.

7. The method according to claim 2, characterized in that, The method also includes verifying the reliability of the monitoring data through carbon balance closure verification; The carbon balance closure check includes: ， In the formula, For process i The relative deviation of the balance closure degree; when If the data is less than the set threshold, it indicates that the monitoring data is reliable; otherwise, it is unreliable, and the monitoring plan should be adjusted.

8. The method according to claim 1, characterized in that, The real-time monitoring data obtained, including information on solid carbonaceous materials, gaseous carbonaceous emissions, process parameters, and energy consumption, includes: At the raw material feeding port or conveyor belt, deploy a high-precision electronic belt scale or loss-in-weight feed scale and equip it with a near-infrared spectrometer or rapid carbon analyzer to continuously measure the mass flow rate of solid material feed and periodically detect the total organic carbon mass fraction. At the inlet and outlet nodes of exhaust pipes and waste gas treatment facilities in each process, high-temperature infrared gas analyzers are deployed to measure the concentrations of CO, CO2, and CH4; flame ionization detectors are deployed to measure the concentration of total volatile organic carbon (TVOC); and thermal or Pitot tube mass flow meters and temperature and pressure integrated instruments are deployed to measure the volumetric flow rate of waste gas, the concentration of each carbon component in the exhaust gas, as well as the temperature and pressure, in real time, and calculate the actual density and mass flow rate of each component accordingly. The consumption of natural gas, biomass gas, and fuel oil in each process is measured by a mass flow meter, while the hot pressing temperature, curing time, and holding pressure are collected in real time by the equipment control system.

9. The method according to claim 1, characterized in that, The carbon input list includes carbon from resins, carbon carbonates in fillers, carbon from auxiliary materials, and carbon from fuels; the carbon output list includes carbon from CO2 emissions, carbon from CO emissions, carbon from CH4 and other VOCs, carbon from product solidification, carbon from waste recovery, and carbon carried over by waste heat.

10. The method according to any one of claims 1-9, characterized in that, The method further includes: Based on the total carbon emissions, the carbon emission intensity per unit product and the carbon emission intensity per unit output value are calculated, and a carbon flow Sankey diagram, a process carbon emission ratio diagram, and a carbon emission trend diagram are generated for visualization output.

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