A product carbon footprint accounting method based on a multi-generation cycle model

Abstract

The application discloses a product carbon footprint accounting method based on a multi-generation cycle model, which comprises the following steps: S1, determining an accounting object and a space-time range, defining a unit process and defining a system boundary; S2, collecting required data and processing the data; S3, determining resource quality and corresponding carbon emissions of each generation life cycle through step-by-step deduction of different resource materials of the product, and adding up to obtain total carbon emissions of the product; S4, calculating product service quantity of each generation life cycle, and constructing distribution weights to complete intergenerational distribution of carbon emissions; and S5, re-accounting product carbon emissions according to the distribution result. The time parameter is introduced, the system boundary is expanded to infinite life cycles, and the quantification of long-term environmental loss and gain is realized. Through the allocation of product carbon footprint and service quantity to resources and the addition of products, the ILCA model originally considering only single resource flow is expanded to a model considering multiple parallel resources, so that the model can be applied to the carbon footprint accounting of multi-resource products.

Description

Technical Field

[0001] This invention relates to the technical field of resource recycling and carbon footprint accounting, and in particular to a product carbon footprint accounting method based on a multi-generation model. Background Technology

[0002] The booming development of the circular economy has driven the widespread application of recycling technologies. This has led to increasingly blurred product lifecycle boundaries, thus affecting the validity of Life Cycle Assessment (LCA) results. To address this, scholars have begun developing algorithms to recalculate product carbon footprints. However, while existing algorithms allocate environmental impacts from different perspectives, they lack a unified standard, making it difficult for companies to choose appropriate methods for their assessments. Practice shows that using different algorithms significantly impacts carbon footprint calculation results, raising a dual risk: firstly, upstream and downstream companies may selectively use calculation methods based on their own interests, leading to an underestimation of overall industry carbon emissions; secondly, the inaccuracy and incomparability of the calculation results can easily trigger a crisis of trust among the public and investors, thereby hindering the process of sustainable development. Therefore, it is urgent to establish a scientific and unified carbon footprint calculation method to ensure that LCA results are more scientifically sound in the context of the circular economy.

[0003] To address the challenge of ambiguous product lifecycle boundaries, academia has improved the LCA method through a "system extension" approach: Multi-generational Life Cycle Assessment (MLCA) extends the system boundary to two or more lifecycles and uses various algorithms such as The Circular Footprint Formula (CFF) to rationally allocate the environmental impact of the recycling process to each generation, making it suitable for scenarios with a limited number of cycles and a clear product iteration cycle; Dynamic Life Cycle Assessment (DLCA) introduces the time dimension and dynamic changing factors, using time series data and system dynamics models to track changes in the environmental impact of factors such as technology and policy in real time, making it suitable for fields with rapid technology iteration and significant changes in environmental load over time; Infinite Generation Life Cycle Assessment (ILCA) extends the model boundary to infinite generations. For example, the spiral infinite generation life cycle assessment algorithm combines polar coordinates and time parameters to construct a dynamic framework to assess resource efficiency and environmental impact under infinite cycles, making it suitable for single-resource systems with high cycle rates.

[0004] While multiple MLCA, DLCA, and ILCA offer new approaches to circular economy accounting, limitations remain in practical applications. MLCA, by extending to a finite number of generations, initially addresses the allocation of environmental impacts in the recycling process, but its "finite perspective" makes it difficult to quantify long-term environmental benefits and risks, leading to inaccurate long-term value judgments of the circular economy. DLCA introduces a time dimension to track dynamic changes in environmental impacts, but its reliance on large amounts of time-series data and complex models increases computational difficulty and interdisciplinary requirements, hindering its adoption by SMEs and grassroots organizations. ILCA, theoretically extending the system boundary to an infinite number of generations and simplifying time parameters, focuses on a single-resource perspective, making it difficult to adapt to the complex lifecycles of multi-resource composite products such as electronic products and new energy batteries. It also cannot handle the differences in recycling efficiency under multi-resource cycles, making it difficult to translate theoretical advantages into practical application value.

[0005] In summary, existing product carbon footprint accounting algorithms have shortcomings when applied to actual production processes, mainly due to the conflict between quantifying long-term environmental gains and losses and the practicality of the algorithms. This deficiency hinders the accurate calculation of product carbon footprints, thus necessitating a multi-generational circular model applicable to multi-resource products. Summary of the Invention

[0006] This invention proposes a product carbon footprint accounting method based on a multi-generation cycle model. It aims to address the problems of ambiguous product carbon footprint boundary definitions, inconsistent carbon emission allocation algorithms, and difficulty in quantifying long-term environmental benefits by constructing a Product Infinite Life Cycle (PILC) model algorithm to achieve a reasonable allocation of product carbon footprint from a multi-generation cycle perspective.

[0007] To achieve the above objectives, this invention proposes a product carbon footprint accounting method based on a multi-generational cycle model, comprising five steps:

[0008] S1. Determine the accounting object and its spatiotemporal scope, clarify the unit process, and define the system boundary:

[0009] The object is determined, such as product name, model, function, process technology, and the quantity and type of resources involved in the algorithm (determined by the resources that can be produced by the recycling process).

[0010] The scope is defined, and the time and geographical boundaries of the product's carbon footprint are specified with reference to ISO 14067;

[0011] The unit process can be clearly defined as follows: within a life cycle, the unit process can be divided into four life cycle stages: raw material mining, product manufacturing, product use, and recycling.

[0012] The definition of system boundaries refers to the entire process of various resources involved in the product, from raw material extraction to dissipation into the environment, which is referred to as "from cradle to environment".

[0013] S2. Collect and process the required data:

[0014] Data collection includes product functional units, emissions at each stage of the life cycle, waste product collection rate, service life, resource prices, the amount of resources consumed during production, resource recovery rate, and emissions generated during mining.

[0015] By constructing weights based on quality proportion and economic value proportion, product emissions and service volume are allocated to various resources to obtain resource emissions and service volume.

[0016] S3. By progressively extrapolating from the different resource materials used in the product, determine the resource quality and corresponding carbon emissions for each generation's life cycle, and then sum them up to obtain the total carbon emissions of the product:

[0017] By introducing a time parameter, parameters such as emission and recycling rates at each stage are constructed that vary over time. Furthermore, based on the characteristics of resource flow, the mass of each resource throughout its lifecycle is calculated under continuous recycling.

[0018] Using the carbon emissions from the resources allocated in S2, calculate the carbon emissions of each resource in each generation's life cycle under the infinite generation cycle scenario;

[0019] By summing up the resource carbon emissions across all generations of the product's lifecycle, we obtain the total resource carbon emissions for each resource in the product's circular system. Then, by summing up the total carbon emissions from all different resources, we obtain the total carbon emissions of the product within the circular system.

[0020] S4. Calculate the product and service volume for each generation's lifecycle and construct allocation weights to complete the intergenerational allocation of carbon emissions:

[0021] Using parameters such as resource service volume and resource recycling rate that change over time, calculate the service volume of each resource in each generation of lifecycles under the infinite generation cycle.

[0022] By summing up the resource service volume in each generation's life cycle, we can obtain the product service volume in each generation's life cycle. Then, by summing up the product service volume in each generation's life cycle, we can obtain the total product service volume in the cyclic system.

[0023] Weights are constructed based on the proportion of product and service volume in the primary life cycle to the total product and service volume, and the total carbon emissions of the product cycle system are allocated to the primary life cycle.

[0024] S5. Recalculate product carbon emissions based on the allocation results:

[0025] The carbon emissions of the products are recalculated based on the allocation results, including replacing the emissions from resource-related mining, recycling and disposal processes in the original product carbon footprint with the results allocated by the algorithm.

[0026] On the other hand, embodiments of the present invention also provide a computer program product, characterized in that the computer program product includes computer instructions, the computer instructions are stored in a computer-readable storage medium, the processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the computer device to perform the steps of a product carbon footprint accounting method based on a multi-generation cycle model in the foregoing embodiments.

[0027] Compared with existing technologies, the beneficial effects of this invention are: the introduction of a time parameter extends the system boundary to an infinite number of life cycles, enabling the quantification of long-term environmental gains and losses; by first allocating product carbon footprint and service volume to resources and then back to products, the original ILCA model, which only considered the flow of a single resource, is extended to the PILCA model, which considers the parallel flow of multiple resources, making it applicable to carbon footprint accounting for multi-resource products; in constructing the PILCA model, some parameters have been fine-tuned according to real-world conditions. For example, the original algorithm only considers resource recycling efficiency, while this algorithm breaks it down into waste product collection rate and resource recovery rate, making the accounting results more detailed and closer to actual emissions. Attached Figure Description

[0028] Figure 1 This is a flowchart of a product carbon footprint accounting method based on a multi-generation cycle model according to the present invention;

[0029] Figure 2 This is a framework diagram of the product cycle system constructed based on the multi-generation cycle model of this invention.

[0030] Figure 3 A comparison of the carbon emission distribution of the algorithm of this invention with three common algorithms.

[0031] Figure 4 A comparison of the results of the algorithm of this invention with those of two common algorithms under the impact of policy changes. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] To address the problem of unreasonable carbon emission allocation results caused by the ambiguity of boundaries in existing product carbon footprint accounting, this invention re-examines product carbon footprint allocation from the perspective of a multi-generational cycle model. Based on the life cycle inventory data that can be collected by traditional LCA (Life Cycle Assessment) methods, this invention combines time series data to construct an infinite-generation product life cycle model that can rationally allocate product carbon emissions. This model, by expanding the system boundaries and introducing time parameters, reflects the long-term benefits of factors such as policy shocks and technological advancements in product carbon emissions, thus achieving a rationalization of carbon emission allocation results.

[0034] Example 1

[0035] To help those skilled in the art to more thoroughly understand the present invention, the technical solutions in the embodiments will be clearly and comprehensively described below with reference to the accompanying drawings.

[0036] like Figure 1 As shown, the accounting method of the present invention comprises five steps.

[0037] S1. Determine the accounting object and its spatiotemporal scope, clarify the unit process, and define the system boundary:

[0038] In this embodiment, ternary lithium batteries in China's new energy vehicle industry in 2024 were selected as the research object. The carbon footprint of the products was calculated by considering the five metal materials: copper, lithium, nickel, cobalt, and manganese.

[0039] In this embodiment, ternary lithium batteries from the new energy vehicle industry are selected as the research object, with the production time set in 2024 and the geographical scope set within China.

[0040] To achieve accurate calculation of product carbon footprint from a multi-generational cycle perspective, this invention defines the system boundary as a product cycle system, the specific details of which are as follows: Figure 2 As shown, the product cycle system comprises a primary life cycle and several secondary life cycles. The primary life cycle includes four unit processes: raw material extraction, product manufacturing, product use, and recycling. The secondary life cycles include three unit processes: product manufacturing, product use, and recycling. The essence of the product cycle is the continuous recycling of extracted resources, accompanied by energy loss, carbon emissions, and resource depletion. The entire product cycle system begins with raw material extraction and continues until all materials are dissipated into the environment.

[0041] S2. Collect and process the required data:

[0042] In this embodiment, information including the following was collected and organized through environmental impact assessment reports and related literature searches: functional units of the product, emissions at each stage of its life cycle, waste product collection rate, product lifespan, resource price, amount of resources consumed during production, resource recovery rate, and emissions generated during the mining process.

[0043] Carbon emissions from a product are allocated to each resource based on its mass percentage, resulting in resource carbon emissions at each stage. Taking carbon emissions from the product recycling process as an example, the allocation method is as follows:

[0044] ,

[0045] in, The total carbon emissions during the product recycling process; Let be the quality of resource j contained in the product; m be the total number of resources considered by the algorithm.

[0046] The volume of products and services is allocated to each resource according to its economic value proportion, resulting in the service volume generated by each resource. The service volume allocation method is as follows:

[0047] ,

[0048] in, represent The service equivalent that a unit of product can provide per year; This represents the market price of j in year t, which can be calculated using the average annual price to ensure the relative stability of the weights.

[0049] S3. By progressively extrapolating from the different resource materials used in the product, determine the resource quality and corresponding carbon emissions for each generation's life cycle, and then sum them up to obtain the total carbon emissions of the product:

[0050] By summing up the emissions from resource extraction and recycling throughout each life cycle, we obtained the carbon emissions allocated to the j-th resource in the product cycle system. :

[0051] ,

[0052] in, This represents the carbon emissions from the primary extraction of 1 unit of resource j in year t. This represents the carbon emissions from disposing of 1 unit of resource j in year t; This represents the carbon emissions from producing 1 unit of recycled resource j in year t; This represents the product lifespan, assumed to be a constant. The product waste collection rate in year t; Indicates in The instantaneous lifecycle resource recovery rate of resource j in a given year.

[0053] The total environmental impact per unit product is obtained by summing the total emissions of each resource's recycling system. as follows:

[0054] ,

[0055] in This indicates the quality of resource j contained in a unit of product.

[0056] S4. Calculate the product and service volume for each generation's lifecycle and construct allocation weights to complete the intergenerational allocation of carbon emissions:

[0057] in, This represents the market price of resource j in year t, which can be calculated using the average annual price to ensure the relative stability of the weights. Using this weight, we can obtain the total ILC service volume allocated to resource j per unit of product during the production process. :

[0058] ,

[0059] in, represent The portion of the service equivalent that a unit of product can provide per year allocated to resource j. Therefore, the total service volume per unit of product. as follows:

[0060]

[0061] We can obtain the weight based on the ratio of total service volume to service volume in each period. Based on this weighting, the environmental impact of the cyclical process can be allocated back to each life cycle, resulting in the allocated product carbon footprint. :

[0062] ,

[0063] .

[0064] S5. Recalculate product carbon emissions based on the allocation results:

[0065] Based on the existing product carbon footprint, emissions related to the extraction, recycling, and disposal of relevant resources are replaced with the results allocated by the algorithm. Through this revised resource carbon emissions, a reassessment of carbon emissions is completed. :

[0066] ,

[0067] in, This refers to the carbon emissions of a product throughout its entire life cycle under traditional LCA calculations (including all emissions from raw material acquisition, product manufacturing, product use, recycling and disposal, where raw materials are obtained from natural sources).

[0068] Furthermore, this study also compared the algorithm results with common single-generation model algorithms such as GB / T 24067 (GB / T), Cyclic Footprint Formula (CFF), and multi-generation model algorithms such as Spiral Infinite Generation Algorithm (SILCA):

[0069] Figure 3 A comparison of carbon emission distribution in the algorithms shows that the SILCA model only considers one resource, and its carbon emission allocation range is too one-sided. In contrast to the GB / T and CFF single-generation algorithms, PILCA can consider the benefits of long-term recycling. For products with complete recycling systems and advanced recycling technologies, its calculation results are lower than those of the other algorithms.

[0070] Figure 4 Further comparison was made between this algorithm and GB / T and CFF in the face of long-term impacts: when the policy impact is rapid, all three algorithms can react normally; however, when the policy impact is long-term, PILCA can reflect its impact normally, while GB / T and CFF cannot.

[0071] In summary, this invention achieves a reasonable allocation of product carbon footprint based on a multi-generational cycle model through steps S1 to S5.

[0072] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A product carbon footprint accounting method based on a multi-generational circular model, characterized in that, include: S1: Determine the accounting object and its spatiotemporal scope, clarify the unit process and define the system boundary; Specifically, it refers to the entire process of various resources involved in the product, from raw material extraction to dissipation into the environment; S2: Collect and process the required data; The collected data includes: product functional units, emissions at each stage of the life cycle, waste product collection rate, product lifespan, resource prices, the amount of resources consumed during production, resource recovery rate, and emissions generated during the mining process; The carbon emissions of a product are allocated to each resource based on its mass proportion, resulting in resource carbon emissions at each stage. Taking the carbon emissions during the product recycling process as an example, the allocation method is as follows: ， in, The total carbon emissions during the product recycling process; Resources included in the product The quality; Total number of resources considered for the algorithm; The service volume is allocated to each resource according to its economic value proportion, resulting in the service volume generated by each resource. The allocation method for service volume is as follows: ， in, represent The service equivalent that a unit of product can provide per year; Indicates in Annual Resources The market price is calculated using the annual average price. S3: By tracing the different resource materials of the product step by step, determine the resource quality and corresponding carbon emissions of each generation's life cycle, and sum them up to obtain the total carbon emissions of the product; By using the product collection rate and resource recycling rate, the quality of each resource in each generation's life cycle is calculated under continuous recycling. Using the carbon emissions of the resources allocated in S2, calculate the carbon emissions of each resource in each generation's life cycle under a multi-generation cycle. By summing up the resource carbon emissions of each generation's life cycle, we obtain the total resource carbon emissions of each resource in the product recycling system. Then, by summing up the total resource carbon emissions of different resources, we obtain the total carbon emissions of the product in the recycling system. S4: Calculate the product and service volume for each generation's life cycle and construct allocation weights to complete the intergenerational allocation of carbon emissions; Using the resource service volume allocated in S2 and the quality of each resource in each generation's lifecycle in S3, calculate the service volume of each resource in each generation's lifecycle under multi-generation cycles. By summing up the resource service volume in each generation's life cycle, we can obtain the product service volume in each generation's life cycle. Then, by summing up the product service volume in each generation's life cycle, we can obtain the total product service volume in the cyclic system. Weights are constructed based on the proportion of product and service volume in each life cycle to the total product and service volume, and the total carbon emissions of the product cycle system are allocated to each life cycle. S5: Recalculate product carbon emissions based on the allocation results; The specific process involves recalculating the carbon emissions of the product based on the allocation results, including replacing the emissions from resource-related raw material mining and end-of-pipe disposal processes in the original product carbon footprint with the results allocated by the algorithm.

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