Steel product process-level process modeling carbon footprint evaluation system and analysis method thereof

Abstract

The invention provides a steel product process-level process modeling carbon footprint evaluation system and an analysis method thereof, and relates to the technical field of carbon emission data analysis. The steel product process-level flow carbon footprint evaluation system comprises a material management module, an emission factor management module, a process module and a carbon footprint calculation module. The material management module is used for configuring material codes, material classification, transportation types and material consumption; the emission factor management module is used for managing attributes of production process emission factors and hidden emission factors of materials; and the process module is used for adding input and output related information and setting emission factor related information. By adopting process-level process modeling, the problem of coarse granularity of a carbon footprint accounting result in a traditional black box calculation mode is effectively solved, the calculation process is transparent through process-level process modeling, and the life cycle carbon footprint value of each intermediate product in the steel production process can be traced.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon emission data analysis, and in particular to a carbon footprint assessment system for process level flow modeling of steel products and an analysis method thereof. Background Art

[0002] As a key carbon emission industry, the steel industry accounts for a large proportion in the supply chain of downstream customers. Therefore, typical steel-using industries such as automobiles, home appliances, and shipbuilding are facing the problems of carbon peak and carbon reduction. Downstream high-end customers regard green supply chain procurement as an important part of their carbon reduction path planning, that is, the carbon footprint of steel products will be included in procurement evaluation indicators.

[0003] When evaluating the carbon footprint of steel materials, the traditional black box calculation model cannot trace back the carbon emission footprint of each process, and cannot know the carbon footprint value of each intermediate product. Process-level flow modeling can make the calculation transparent, but the production process of steel products is complex, and there are complex circular references and cross-relationships between public and auxiliary processes in process-level modeling. Therefore, for process-level flow modeling, how to solve the problem of the calculation results of public and auxiliary processes being referenced by the main process, as well as the circular reference problem between public and auxiliary processes, has not yet been effectively solved. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a carbon footprint assessment system for process-level flow modeling of steel products and an analysis method thereof, which solves the problem of black-box carbon footprint calculation of steel products in the prior art, resulting in the untraceability of carbon footprint values ​​of intermediate products, the problem of circular cross-reference of emission factor values ​​calculated by public and auxiliary processes in process-level flow modeling, and the key issue of how carbon footprint results can effectively guide low-carbon product production, product ecological design and green procurement.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: an assessment system for the carbon footprint of a steel product process level, characterized in that it includes:

[0006] Material management module, emission factor management module, process module and carbon footprint calculation module;

[0007] The material management module is used to configure material coding, material classification, transportation type, and material consumption; the emission factor management module is used to manage the properties of the production process emission factor and the material implicit emission factor;

[0008] The process module is used to add input and output related information and set emission factor related information;

[0009] The carbon footprint calculation module is used to complete the carbon footprint value of the main product life cycle of each process.

[0010] The analytical method for process-level carbon footprint modeling of steel products includes the following steps:

[0011] S11. Build a steel product process model based on the steel production process, and add input and output material types, material codes, material consumption, and transportation related information;

[0012] S12. Based on the constructed process model, connect the upper and lower process models according to the production process, and build a carbon footprint accounting model for steel products;

[0013] S13. Determine the production process emission factors and material implicit emission factors for the input and output of the carbon footprint accounting model for steel products respectively;

[0014] S14. The emission factor value is calculated for the public and auxiliary processes, which is referenced by multiple public and auxiliary processes and the main process based on the material code to calculate the life cycle carbon footprint value of the final product.

[0015] Preferably, the modeling process in S12 is to connect the main processes, and when connecting, the relationship between the materials of the upper and lower processes is specified, that is, the main product of the upper process is the main raw material of the lower process.

[0016] Preferably, each process in S14 will calculate the life cycle carbon footprint value of the main product of this process, and the corresponding public and auxiliary processes will also calculate the life cycle carbon footprint value of the main product of this process, that is, the material implicit emission factor of the material of the main process, and identify it according to the material code. If the material code is the same, it is considered to be the same material. The material implicit emission factor calculated by the public and auxiliary process will be automatically referenced by multiple public and auxiliary processes and the main process through the material code to calculate the life cycle carbon footprint value of the intermediate product and the final product. The material of each process is expressed in unit consumption, and then the life cycle value of the main product of this process is calculated as the carbon dioxide emissions generated by one unit of the main product, that is, the material implicit emission factor value. When the public and auxiliary process contains multiple main products, the mass distribution or volume distribution method is used to calculate the life cycle carbon footprint value of the main product of this process. The unit consumption is defined as:

[0017] Unit consumption = consumption of a certain material / output of main product of this process.

[0018] Preferably, CO2 emissions during the life cycle of steel products = carbon emissions during the production process + carbon emissions embodied in materials - carbon emission rights deduction, which is specifically calculated according to the following formula:

[0019]

[0020] Where:

[0021] CFT – total emissions based on LCA, t CO2;

[0022] CF α——Carbon emissions in the production process (i.e. carbon emissions generated in the process of producing steel products), t CO2;

[0023] CF β ——Carbon emissions embodied in the material (i.e. carbon emissions from upstream production of the material), t CO2;

[0024] CF γ ——Carbon emission rights offset, t CO2;

[0025] V i ——Unit consumption of the i-th fuel, raw material, power medium, etc. in the production process, t, kWh or km3;

[0026] EF i ——Indicates the CO2 emission factor of the i-th fuel, raw material, power medium, etc., and is divided into direct and indirect emission factors for accumulation, t CO2 / t;

[0027] W j - the output of the jth product, by-product or waste;

[0028] EF j ——Emission factors of the jth product, by-product and waste, including emission factors of the production process of carbon-containing substances, as well as deductions in the form of material implicit emission factors for by-products such as power medium export and tar slag, t CO2 / t.

[0029] Preferably, the carbon footprint results of the accounting products are analyzed from a combination of the life cycle dimension and the production process dimension to guide low-carbon product development, low-carbon ecological design and green procurement.

[0030] Preferably, the carbon footprint result analysis divides the carbon footprint life cycle of steel products into seven stages from the life cycle dimension, including: direct load, self-produced energy load, transportation load, upstream load, internal benefits of by-products and external benefits of by-products. Thus, the carbon emissions generated in different stages and their contribution to the life cycle carbon footprint value can be clearly obtained.

[0031] Preferably, the carbon footprint life cycle value = direct load + energy load + intermediate product load + transportation load + upstream load + by-product internal benefits + by-product external benefits.

[0032] Preferably, the carbon footprint result analysis is based on the production process dimension. According to the process-level modeling function logic, the carbon footprint values ​​of the intermediate products and final products of each process, that is, the carbon footprint life cycle value of the main product of each process, can be obtained. Then, the contribution of each process to the carbon footprint of the calculated product can be further calculated, and it can be analyzed which process has a greater impact on the product life cycle value, which process needs to be focused on, and carbon emissions can be managed in a refined manner.

[0033] The present invention provides a carbon footprint assessment system for process level flow modeling of steel products and an analysis method thereof.

[0034] It has the following beneficial effects:

[0035] 1. The present invention effectively solves the problem of coarse-grained carbon footprint calculation results in the traditional black box calculation mode by adopting process-level flow modeling. Process-level flow modeling makes the calculation process transparent and can trace the carbon footprint value of each intermediate product in the steel production process during its life cycle. Steel products, as raw materials, usually have intermediate products such as continuous casting billets, hot-rolled coils, and cold-rolled coils that are taken out. Manufacturers can provide different downstream customers with the carbon footprint value of the taken-out products through a single calculation.

[0036] 2. The present invention automatically matches the material code with the main process material, so that the main process can reference the public and auxiliary process factors, and can realize the circular cross-reference of the public and auxiliary processes.

[0037] 3. The present invention analyzes the carbon footprint results from the perspective of both the life cycle dimension and the production process dimension, which has strong guiding significance for low-carbon products, product ecological design and green procurement. The carbon footprint calculation results are displayed in stages according to the different stages of the life cycle. From the product level, it helps manufacturers understand the current status of carbon emissions of their products, helps them purchase green energy and raw materials, build a green supply chain, and effectively guides the research and development of green and low-carbon products. From the enterprise level, it provides data support for low-carbon optimization and scheduling of production processes, effectively controls emissions and takes emission reduction measures to achieve effective carbon emission management of enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the process level process modeling process of the present invention;

[0039] Figure 2 It is a functional module schematic diagram of the carbon footprint calculation device of the present invention;

[0040] Figure 3 A schematic diagram showing the carbon footprint emission contribution ratio of each process of the present invention;

[0041] Figure 4 This is a schematic diagram of an example of process-level product modeling of the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Example:

[0044] like Figure 2 As shown, the embodiment of the present invention provides a carbon footprint assessment system for a steel product process level, which is characterized by comprising:

[0045] Material management module, emission factor management module, process module and carbon footprint calculation module;

[0046] The material management module is used for configuration of material coding, material classification, transportation type, and material consumption;

[0047] The emission factor management module is used to manage the properties of production process emission factors and material implicit emission factors;

[0048] The process module is used to add input and output related information and set emission factor related information;

[0049] The carbon footprint calculation module is used to complete the carbon footprint value of the main product life cycle of each process.

[0050] Embodiment 1, as Figure 1 and Figure 3 The analytical method for carbon footprint modeling of steel product process level includes the following steps:

[0051] S11. Build a steel product process model based on the steel production process, and add input and output material types, material codes, material consumption, and transportation related information;

[0052] S12. Based on the constructed process model, connect the upper and lower process models according to the production process, and build a carbon footprint accounting model for steel products;

[0053] S13. Determine the production process emission factors and material implicit emission factors for the input and output of the carbon footprint accounting model for steel products respectively;

[0054] S14. The emission factor value is calculated from the auxiliary process, which is referenced by multiple auxiliary processes and the main process based on the material code to calculate the life cycle carbon footprint value of the final product;

[0055] The main process refers to the key production process of steel, the main production technology, generally including: sintering process, pelletizing process, premixing process, blast furnace process, converter process, electric furnace process, refining process, hot rolling process, cold rolling process, continuous annealing process, galvanizing process, etc.

[0056] Public auxiliary processes refer to auxiliary processes in the steel production process, generally including: self-generation process, steam treatment process, compressed air production process, water treatment process, gas production process (oxygen, nitrogen, argon), etc.

[0057] The calculation result of the public and auxiliary process is the emission factor value of its main product. The steel production process is extremely complex. There may be a situation where the calculation result of a public and auxiliary process is referenced by multiple main processes, and there may also be a situation where the calculation result of a public and auxiliary process is referenced by one or more other public and auxiliary processes. For example, the public and auxiliary process is a self-generating process, and there may be a situation where the factor value of self-generating power needs to be referenced by each main process. There may be a situation where the factor of self-generating power will be cyclically referenced by this process and referenced by multiple other public and auxiliary processes such as steam treatment process and water treatment process. By setting a unified material code, the circular cross-reference problem between public and auxiliary processes and main processes can be solved.

[0058] The modeling process in S12 is to connect the main processes, and specify the relationship between the materials of the upper and lower processes when connecting, that is, the main product of the upper process is the main raw material of the lower process.

[0059] Each process in S14 will calculate the life cycle carbon footprint value of the main product of this process, and the corresponding public and auxiliary processes will also calculate the life cycle carbon footprint value of the main product of this process, that is, the material implicit emission factor of the main process material, which will be identified according to the material code. If the material code is the same, it is considered to be the same material. The material implicit emission factor calculated by the public and auxiliary process will be automatically referenced by multiple public and auxiliary processes and the main process through the material code to calculate the life cycle carbon footprint value of the intermediate product and the final product. The material of each process is expressed in unit consumption, and then the life cycle value of the main product of this process is calculated as the carbon dioxide emissions generated by one unit of the main product, that is, the material implicit emission factor value. When the public and auxiliary process contains multiple main products, the mass distribution or volume distribution method is used to calculate the life cycle carbon footprint value of the main product of this process. The definition of unit consumption is:

[0060] Unit consumption = consumption of a certain material / output of main product of this process.

[0061] CO2 emissions during the life cycle of steel products = carbon emissions during the production process + carbon emissions embodied in materials - carbon emission rights deduction, which is calculated according to the following formula:

[0062]

[0063] Where:

[0064] CFT – total emissions based on LCA, tCO2;

[0065] CF α ——Carbon emissions from the production process (i.e. carbon emissions generated during the production of steel products), tCO2;

[0066] CF β ——Embedded carbon emissions of materials (i.e. carbon emissions from upstream production of the materials), tCO2;

[0067] CF γ ——Carbon emission rights offset, tCO2;

[0068] V i ——Unit consumption of the i-th fuel, raw material, power medium, etc. in the production process, t, kWh or km3;

[0069] EF i ——Indicates the CO2 emission factor of the i-th fuel, raw material, power medium, etc., and is divided into direct and indirect emission factors for accumulation, tCO2 / t;

[0070] W j - the output of the jth product, by-product or waste;

[0071] EF j ——Emission factors of the jth product, by-product and waste, including emission factors of the production process of carbon-containing substances, as well as deductions in the form of material implicit emission factors for by-products such as power medium export and tar slag, tCO2 / t.

[0072] The public and auxiliary processes calculate the carbon footprint value of this process, that is, the emission factor value of the main product. According to the material code, it is determined whether it is the same material. If the material code is the same, it is considered to be the same material. The emission factor value of the main product is automatically referenced by the material. In this way, the circular cross-reference of the public and auxiliary processes and the reference between the public and auxiliary processes and the main process are realized. The life cycle carbon footprint value of each process and the final product is calculated according to formula (1).

[0073] Embodiment 1, as Figure 4 , the product model of galvanized steel coil constructed based on the above functional logic is listed.

[0074] As shown in Table 1, Figure 4 The constructed process-level product model calculates the carbon footprint values ​​of each process and the final unit of declaration, which is 1t of galvanized steel coil. The next process is the accumulation of the previous process. Therefore, the calculated carbon emissions of the galvanizing process are the carbon footprint value of the final product, galvanized steel coil, 2.76tCO2. The carbon footprint value of each process (i.e. the carbon footprint value of the intermediate product) is clearly obtained through Table 1. As raw materials, steel products usually have takeaway situations such as intermediate products such as continuous casting billets, hot-rolled coils, and cold-rolled coils in this case. Manufacturers provide takeaway product carbon footprint values ​​to different downstream customers through a single calculation.

[0075]

[0076] Table 1

[0077] Embodiment 2: Based on the calculated carbon footprint values ​​of each process, the present invention provides a carbon footprint contribution analysis method, such as Figure 3, which comprises the following steps:

[0078] Step S31, determine the process coefficient, which is a special unit consumption. The previous process is defined as process A, and the current process is process B. Process coefficient = process A main product consumption / B main product output, that is, defined as the process coefficient between process A and process B. In actual production, there may be multiple previous processes in this process.

[0079] Step S32, calculating the relative carbon emissions of this process.

[0080] Furthermore, the relative carbon emissions of this process are calculated as shown in formula (2):

[0081]

[0082] CF 相对 is the relative carbon emission of this process.

[0083] CFT 本工序 is the carbon footprint value of this process;

[0084] Q 绝对k is the kth absolute process coefficient;

[0085] Q 上道工序 It is the process coefficient between the previous process associated with this process.

[0086] j is the number of previous processes directly associated with this process.

[0087] Furthermore, the process coefficient between process A and process B (A is the previous process, B is the current process):

[0088] Q A-B =C A本道工序 / P 本道工序 (3)

[0089] Q A-B is the process coefficient between process A and process B;

[0090] C A本道工序 The consumption of the main product of process A in this process;

[0091] P B本道工序 is the output of the main product of process B.

[0092] Furthermore, the absolute process coefficient is defined as the product of the process coefficients of the next process connected to the current process. When there are multiple next processes, there will be multiple absolute process coefficients. Assuming that process D is the final process, process B is the current process, and C and E are the next processes directly related to the current process, then the absolute process coefficient is expressed as:

[0093] Q B-C绝对 =QB-C Q C-D (4)

[0094] Q B-E绝对 =Q B-E Q E-D (5)

[0095] Step S33, calculate the carbon emission contribution of each process, as shown in formula (6):

[0096] CN=CF 相对 / CFT (6)

[0097] CF 相对 is the relative carbon emission of this process.

[0098] CFT is the total emission based on LCA, i.e. the carbon footprint value of the accounting product, tCO2;

[0099] CN is the carbon footprint contribution rate.

[0100] As shown in Table 2, Figure 4 The process-level product model constructed uses the above logic to calculate the carbon footprint contribution of each process:

[0101] Process Name Coking process Sintering process Blast furnace process Converter process Refining process Continuous Casting Process Hot rolling process Pickling process Galvanizing process Carbon emission contribution 11％ 24％ 22％ 7％ 4％ 3％ 16％ 4％ 10％

[0102] Table 2

[0103] Furthermore, from Table 2, the carbon emission contribution of each process can accurately discover the impact of resource and energy consumption of each process in product production on the carbon footprint. It is analyzed that the carbon emissions caused by the sintering process and blast furnace process are relatively large. Enterprises can conduct targeted analysis on how to reduce carbon emissions for key emission processes, providing decision-making basis for steel enterprises to save energy and reduce consumption, and develop green and low-carbon.

[0104] Example 3: Analyze the carbon footprint results of the accounting products from the perspective of both the life cycle dimension and the production process dimension to guide low-carbon product development, low-carbon ecological design and green procurement. It can intuitively determine which stage of the life cycle causes the high carbon footprint value. Combined with process-level flow modeling, it can clearly trace the carbon footprint values ​​of different processes, thereby analyzing which process contributes the most to the carbon footprint value.

[0105] The carbon footprint analysis results divide the carbon footprint life cycle of steel products into seven stages from the life cycle dimension, including: direct load, self-produced energy load, transportation load, upstream load, internal benefits of by-products and external benefits of by-products. This clearly derives the carbon emissions generated at different stages and their contribution to the life cycle carbon footprint value.

[0106] Carbon footprint life cycle value = direct load + energy load + intermediate product load + transportation load + upstream load + by-product internal benefits + by-product external benefits.

[0107] Direct load is defined as the carbon emissions generated during the production process. The calculation logic is as shown in formula (6):

[0108]

[0109] Among them, M i It is the unit consumption of various energy and power media, and various raw and auxiliary materials.

[0110] EF 生产过程排放i is the emission factor of the production process of the ith material or product.

[0111] P i Unit consumption of main products and by-products.

[0112] W i It is waste with no utilization value.

[0113] CF α It is the direct load, i.e. the carbon emissions in the production process of this process.

[0114] Self-produced energy load generally refers to the energy produced by the public and auxiliary processes of the steel plant, such as hydrogen, compressed air, electricity, etc. The calculation logic is as shown in formula (7):

[0115]

[0116] Among them, E i It is the unit consumption of energy and power medium;

[0117] EF 材料隐含排放i is the implicit emission factor of the ith energy source power medium material.

[0118] U j The unit consumption value of the main product of the previous process consumed by this process.

[0119] CF ε上道工序 It is the energy load produced by the previous process.

[0120] In this application, intermediate products refer to the main products of each main process. The calculation logic of intermediate product load is as shown in formula (8):

[0121]

[0122] Among them, CF θ is the intermediate product load;

[0123] CF θ上道工序i It is the load of the i-th intermediate product of the previous process. If this process is the first process, the load of the intermediate product is 0.

[0124] CF α上道工序i Directly load the previous process;

[0125] U i The unit consumption value of the main product of the previous process consumed by this process.

[0126] By-product internal benefits refer to the recycling and reuse of by-products of steel enterprises. In this case, carbon emissions must be offset for by-products used for self-use. The calculation logic of by-product internal benefits is as shown in formula (9):

[0127]

[0128] Among them, U i Unit consumption of by-products produced by this process for self-use.

[0129] U j The unit consumption value of the main product of the previous process consumed by this process.

[0130] CF γ内上道工序 It is the internal revenue of the by-product of the previous process.

[0131] CF γ内 It is the internal benefit of the by-product.

[0132] By-product external benefits refer to the environmental benefits brought by the by-product sales of steel enterprises. In this case, carbon emissions must be offset for the by-product sales. The calculation logic of by-product external benefits is as follows:

[0133]

[0134] U i Unit consumption of by-products produced in this process for sale.

[0135] U j The unit consumption value of the main product of the previous process consumed by this process.

[0136] CF γ外上道工序 It is the external benefit of the by-product of the previous process.

[0137] CF γ外 It is the external benefit of by-product.

[0138] The carbon emissions generated by transporting materials or intermediate products. The calculation logic of transportation emissions is as follows:

[0139]

[0140] L i is the transportation distance of the ith material or intermediate product.

[0141] M i The unit consumption of materials in this process.

[0142] U j The unit consumption value of the main product of the previous process consumed by this process.

[0143] CF μ上道工序 Emissions from transportation to the previous process.

[0144] Upstream load generally refers to the load generated by raw material mining. The calculation logic of upstream load is as shown in formula (12):

[0145]

[0146] Among them, CF σ is the upstream load.

[0147] CF σ上道工序 It is the upstream load of the previous process.

[0148] U j The unit consumption value of the main product of the previous process consumed by this process.

[0149] EF 材料隐含排放j It is the material implicit emission factor of the jth intermediate product (i.e. the main product of the previous process).

[0150] M i It is the unit consumption of various energy and power media, and various raw and auxiliary materials.

[0151] EF 材料隐含排放i It is the implicit emission factor of each energy medium and each raw and auxiliary material.

[0152] As shown in Table 3, the Figure 4 The process-level product model constructed uses the above logic to calculate the carbon emissions caused by different stages of the life cycle, that is, the different contributions to the product carbon footprint:

[0153]

[0154] Table 3

[0155] Furthermore, the load brought by the steel production process = direct load + self-produced energy load + intermediate product load + by-product internal benefits, upstream load = raw material mining load + transportation load + by-product external benefits. According to Table 3, the carbon emissions of producing galvanized steel coils are 1.6tCO2e, accounting for 57.39%, and 1.188tCO2e, accounting for 42.61%. This can guide enterprises to reduce carbon emissions in a targeted manner in steps, for example, considering green supply chain management, adopting green energy, etc., and on the other hand, taking energy-saving and consumption-reducing measures from the steel production process or adopting CCUS carbon capture technology to reduce carbon emissions.

[0156] From the perspective of the production process, the carbon footprint results analysis can obtain the carbon footprint values ​​of the intermediate products and final products of each process, that is, the carbon footprint life cycle value of the main product of each process, based on the process-level modeling function logic. Then, the contribution of each process to the carbon footprint of the calculated product can be further calculated, and it can be analyzed which process has a greater impact on the product life cycle value, which process needs to be focused on, and carbon emissions can be managed in a refined manner.

[0157] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations may be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. The carbon footprint assessment system for steel product process level is characterized by: include: Material management module, emission factor management module, process module and carbon footprint calculation module; The material management module is used for configuration of material coding, material classification, transportation type, and material consumption; The emission factor management module is used to manage the properties of the production process emission factors and the material implicit emission factors; The process module is used to add input and output related information and set emission factor related information; The carbon footprint calculation module is used to complete the carbon footprint value of the main product life cycle of each process.

2. An analysis method for modeling the carbon footprint of a steel product process level flow, according to claim 1, characterized in that: The following steps are involved: S11. Build a steel product process model based on the steel production process, and add input and output material types, material codes, material consumption, and transportation related information; S12. Based on the constructed process model, connect the upper and lower process models according to the production process, and build a carbon footprint accounting model for steel products; S13. Determine the production process emission factors and material implicit emission factors for the input and output of the carbon footprint accounting model for steel products respectively; S14. The emission factor value is calculated for the public and auxiliary processes, which is referenced by multiple public and auxiliary processes and the main process based on the material code to calculate the life cycle carbon footprint value of the final product.

3. The analysis method for process-level carbon footprint modeling of steel products according to claim 2, characterized in that: The modeling process in S12 is to connect the main processes, and when connecting, the relationship between the materials of the upper and lower processes is specified, that is, the main product of the upper process is the main raw material of the lower process.

4. The analysis method for carbon footprint modeling of steel product process level according to claim 2, characterized in that: Each process in S14 will calculate the life cycle carbon footprint value of the main product of this process, and the corresponding public and auxiliary processes will also calculate the life cycle carbon footprint value of the main product of this process, that is, the material implicit emission factor of the main process material, which will be identified according to the material code. If the material code is the same, it is considered to be the same material. The material implicit emission factor calculated by the public and auxiliary process will be automatically referenced by multiple public and auxiliary processes and the main process through the material code to calculate the life cycle carbon footprint value of the intermediate product and the final product. The material of each process is expressed in unit consumption, and then the life cycle value of the main product of this process is calculated as the carbon dioxide emissions generated by one unit of the main product, that is, the material implicit emission factor value. When the public and auxiliary process contains multiple main products, the mass distribution or volume distribution method is used to calculate the life cycle carbon footprint value of the main product of this process. The unit consumption is defined as: Unit consumption = consumption of a certain material / output of main product of this process.

5. The analysis method for process-level carbon footprint modeling of steel products according to claim 4, characterized in that: CO2 emissions during the life cycle of steel products = carbon emissions during the production process + carbon emissions embodied in materials - carbon emission rights deduction, which is calculated according to the following formula: Where: CFT – total emissions based on LCA, t CO2; CF α ——Carbon emissions in the production process (i.e. carbon emissions generated in the process of producing steel products), t CO2; CF β ——Carbon emissions embodied in the material (i.e. carbon emissions from upstream production of the material), t CO2; CF γ ——Carbon emission rights offset, t CO2; V i ——Unit consumption of fuel, raw material, power medium, etc. in the production process, t, kWh or km3; EF i ——Indicates the CO2 emission factor of the i-th fuel, raw material, power medium, etc., and is divided into direct and indirect emission factors for accumulation, t CO2 / t; W j - the output of the jth product, by-product or waste; EF j ——Emission factors of the jth product, by-product and waste, including emission factors of the production process of carbon-containing substances, as well as deductions in the form of material implicit emission factors for by-products such as power medium export and tar slag, t CO2 / t.

6. The analysis method for process-level carbon footprint modeling of steel products according to any one of claims 2 to 5, characterized in that: The carbon footprint results of accounting products are analyzed from the perspectives of life cycle and production process to guide low-carbon product development, low-carbon ecological design and green procurement.

7. The analysis method for carbon footprint modeling of steel product process level according to claim 6, characterized in that: The carbon footprint analysis results divide the carbon footprint life cycle of steel products into seven stages from the life cycle dimension, including: direct load, self-produced energy load, transportation load, upstream load, by-product internal benefits and by-product external benefits. Therefore, the carbon emissions generated in different stages and their contribution to the life cycle carbon footprint value can be clearly obtained.

8. The analysis method for carbon footprint modeling of steel product process level according to claim 7, characterized in that: The carbon footprint life cycle value = direct load + energy load + intermediate product load + transportation load + upstream load + by-product internal benefits + by-product external benefits.

9. The analysis method for process-level carbon footprint modeling of steel products according to claim 6, characterized in that: The carbon footprint result analysis can obtain the carbon footprint values ​​of the intermediate products and final products of each process from the production process dimension according to the process-level modeling function logic, that is, the carbon footprint life cycle value of the main product of each process, and then further calculate the contribution of each process to the carbon footprint of the calculated product, analyze which process has a greater impact on the product life cycle value, and which process needs to be focused on, so as to manage carbon emissions in a refined manner.

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