Symbiotic product carbon footprint allocation method and system based on full life cycle assessment

Abstract

This invention relates to the field of carbon footprint assessment technology, and discloses a method and system for allocating the carbon footprint of co-products based on life cycle assessment. The method includes: determining the chemical reaction equation based on the chemical reaction process of the process to be assessed; identifying all reactants and all co-products, and the corresponding balancing coefficient for each; calculating the sum of the balancing coefficients of all co-products as the total molarity baseline; calculating the carbon footprint allocation ratio for each co-product based on the ratio of the balancing coefficient of each co-product to the total molarity baseline; obtaining the total carbon footprint of the chemical reaction unit process; and allocating the total carbon footprint to each co-product according to the carbon footprint allocation ratio. This invention solves the technical problems of distorted results from existing mass allocation methods and the narrow applicability and computational complexity of energy allocation methods, achieving a scientific, accurate, and universally applicable allocation of carbon footprints.

Description

Technical Field

[0001] This invention relates to the field of carbon footprint assessment technology, and in particular to a method and system for allocating the carbon footprint of symbiotic products based on life cycle assessment. Background Technology

[0002] Life Cycle Assessment (LCA) is an internationally recognized core standard for identifying green and eco-friendly products. Through quantitative analysis of the entire process "from cradle to grave," it accurately assesses a product's resource and energy consumption and environmental emissions impact, making it a crucial tool for corporate carbon management, green certification, and carbon disclosure. In industrial production, many processes simultaneously generate multiple co-products within the same unit. For example, blast furnace ironmaking produces molten iron, blast furnace slag, and blast furnace gas, while chlor-alkali electrolysis produces chlorine, hydrogen, and sodium hydroxide. In such cases, the total carbon load of the process must be reasonably allocated to each product; otherwise, the carbon footprint calculation results will be severely distorted.

[0003] Existing technologies prioritize avoiding allocation by dividing processes into sub-processes, expanding system boundaries, and decomposing closed-loop cycles. However, these methods are only applicable to specific scenarios and cannot fundamentally solve the allocation problem. When allocation cannot be avoided, the mainstream approach is mass allocation, but this method is extremely unsuitable for coexisting products with significantly different physicochemical properties (such as gaseous, liquid, and solid coexistence, or significant differences in molecular weight). For example, hydrogen has a very low mass percentage, and mass allocation hardly contributes to the carbon load, completely contradicting the nature of the reaction. While energy allocation methods based on the heat of combustion, which have emerged in recent years, have improved the allocation bias of byproduct hydrogen, they are only applicable to endothermic reactions containing hydrogen, highly dependent on energy data, computationally complex, and lack versatility. Therefore, there is a need to improve existing methods for allocating the carbon footprint of symbiotic products. Summary of the Invention

[0004] In view of this, the purpose of this invention is to propose a method and system for allocating the carbon footprint of symbiotic products based on life cycle assessment, to solve the technical problems of distorted results from existing mass allocation methods and narrow applicability and computational complexity of energy allocation methods, and to achieve scientific, accurate and universal allocation of carbon footprint.

[0005] To achieve the above objectives, embodiments of the present invention provide a method for allocating the carbon footprint of co-existing products based on full life cycle assessment, including: S1 determines the chemical reaction equation based on the chemical reaction process of the process to be accounted for, and identifies all reactants and all symbiotic products and the corresponding balancing coefficient for each item; S2 calculates the sum of the balancing coefficients of all symbiotic products as the total mass basis, and calculates the carbon footprint allocation ratio of each symbiotic product based on the ratio of the balancing coefficient of each symbiotic product to the total mass basis. S3 obtains the total carbon footprint of the chemical reaction unit process and distributes the total carbon footprint to each symbiotic product according to the carbon footprint allocation ratio.

[0006] In some implementations, S3 further includes: when the symbiotic product contains multiple derivatives of the same chemical substance at different concentrations and / or in different forms, the total carbon footprint allocation ratio is subdivided into each derivative product based on the mass percentage of the effective component of the chemical substance in each derivative product.

[0007] In some implementations, determining the chemical reaction equation based on the chemical reaction process of the step to be accounted for includes: The chemical reaction processes for the procedures to be accounted for include reactants such as A1, A2, A3...A n ; The chemical reaction processes involved in the steps to be accounted for include the following co-products: B1, B2, B3...B i ; Based on the chemical reaction process of the procedure to be accounted for, the chemical reaction equation is determined as follows:

[0008] Where n is a natural number, i is a natural number, and a1, a2, a3...a n b1, b2, b3...b i These are the balancing coefficients for the reactants and symbiotic products.

[0009] In some implementations, the step of calculating the carbon footprint allocation of each symbiotic product includes: Calculate the sum of the balancing factors for all symbiotic products:

[0010] b 总 Using the total amount of matter as the baseline, the ratio of the balancing coefficient of each symbiotic product to the total amount of matter is used to calculate symbiotic product B. i carbon footprint allocation ratio

[0011]

[0012] In the formula, Product B i The proportion of carbon footprint allocation.

[0013] In some implementations, the carbon footprint allocation ratio satisfies: =1.

[0014] In some implementations, the symbiotic products are at least two products generated simultaneously in the same chemical reaction process.

[0015] In some implementations, the physical state of the symbiotic product includes gaseous, liquid, and solid states. In some implementations, the balancing coefficients are determined based on the law of conservation of elements.

[0016] In some embodiments, the chemical reaction process includes chlor-alkali electrolysis, propane dehydrogenation, ethylbenzene dehydrogenation, catalytic reforming, steam cracking, ammonia synthesis, and methanol synthesis.

[0017] In another aspect, the present invention provides a carbon footprint allocation system for co-existing products based on life cycle assessment, the system being used in the above-described method, comprising: The identification module is configured to determine the chemical reaction equation based on the chemical reaction process of the process to be accounted for, and to identify all reactants and all symbiotic products and the corresponding balancing coefficient for each item. The calculation module is configured to calculate the sum of the balancing coefficients of all symbiotic products as the total mass basis, and to calculate the carbon footprint allocation ratio of each symbiotic product based on the ratio of the balancing coefficient of each symbiotic product to the total mass basis. The allocation module is configured to obtain the total carbon footprint of the chemical reaction unit process and allocate the total carbon footprint to each symbiotic product according to the carbon footprint allocation ratio.

[0018] The present invention has at least the following beneficial technical effects: (1) Based on the law of conservation of matter, the chemical reaction balancing coefficient is used as the sole basis for allocation, which is in line with the nature of the reaction and fundamentally solves the distortion problem that the carbon footprint of light products (such as hydrogen) is underestimated and the carbon footprint of heavy products is overestimated. (2) Applicable to all chemical reaction-type symbiotic product systems, without being limited by product physical state, reaction type, or whether it contains hydrogen, covering most industrial scenarios such as chemical engineering and metallurgy; (3) It does not require any additional data such as heat of combustion, heat of reaction, or economic value. The allocation can be completed solely through the balanced chemical reaction equation. The steps are standardized, highly reproducible, and significantly reduce accounting costs. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0020] Figure 1This is a flowchart illustrating an embodiment of the carbon footprint allocation method for symbiotic products based on life cycle assessment provided by the present invention.

[0021] Figure 2 This is a schematic diagram of an embodiment of the coexisting product carbon footprint allocation system based on life cycle assessment provided by the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0023] The terms "comprising" and "having," and any variations thereof, used in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., used in the specification, claims, and accompanying drawings are used to distinguish different objects, not to describe a particular order. "A plurality of" means two or more, unless otherwise explicitly specified.

[0024] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] like Figure 1 The figure shows a method for allocating the carbon footprint of co-existing products based on life cycle assessment provided by the present invention, which includes the following steps: S1 determines the chemical reaction equation based on the chemical reaction process of the process to be accounted for, and identifies all reactants and all symbiotic products and the corresponding balancing coefficient for each item; S2 calculates the sum of the balancing coefficients of all symbiotic products as the total mass basis, and calculates the carbon footprint allocation ratio of each symbiotic product based on the ratio of the balancing coefficient of each symbiotic product to the total mass basis. S3 obtains the total carbon footprint of the chemical reaction unit process and distributes the total carbon footprint to each symbiotic product according to the carbon footprint allocation ratio.

[0026] Furthermore, S3 also includes: when the symbiotic product contains multiple derivatives of the same chemical substance at different concentrations and / or in different forms, the total carbon footprint allocation ratio is subdivided into each derivative product based on the mass percentage of the effective component of the chemical substance in each derivative product.

[0027] Furthermore, determining the chemical reaction equation based on the chemical reaction process of the process to be accounted for includes: The chemical reaction processes for the procedures to be accounted for include reactants such as A1, A2, A3...A n ; The chemical reaction processes involved in the steps to be accounted for include the following co-products: B1, B2, B3...B i ; Based on the chemical reaction process of the procedure to be accounted for, the chemical reaction equation is determined as follows:

[0028] Where n is a natural number, i is a natural number, and a1, a2, a3...a n b1, b2, b3...b i These are the balancing coefficients for the reactants and symbiotic products.

[0029] Furthermore, the steps for calculating the carbon footprint allocation of each symbiotic product include: Calculate the sum of the balancing factors for all symbiotic products:

[0030] b 总 Using the total amount of matter as the baseline, the ratio of the balancing coefficient of each symbiotic product to the total amount of matter is used to calculate symbiotic product B. i carbon footprint allocation ratio

[0031]

[0032] In the formula, Product B i The proportion of carbon footprint allocation.

[0033] Furthermore, the carbon footprint allocation ratio satisfies: =1.

[0034] Specifically, the carbon footprint is allocated among the symbiotic products based on the molar ratio of the chemical reaction symbiotic products, where the carbon footprint allocation coefficient corresponding to product B1 is: The carbon footprint allocation factor for product B2 is The carbon footprint allocation factor for product B3 is , ..., B i The carbon footprint allocation factor for the product is: ,but

[0035] Furthermore, symbiotic products are at least two products generated simultaneously in the same chemical reaction process.

[0036] Furthermore, the physical states of symbiotic products include gaseous, liquid, and solid states. Furthermore, the balancing coefficients are confirmed based on the law of conservation of elements.

[0037] Furthermore, the chemical reaction processes include chlor-alkali electrolysis, propane dehydrogenation, ethylbenzene dehydrogenation, catalytic reforming, steam cracking, ammonia synthesis, and methanol synthesis.

[0038] like Figure 2 As shown, another aspect of the present invention provides a carbon footprint allocation system for co-existing products based on life cycle assessment, the system being used in the above-described method, comprising: The identification module 011 is configured to determine the chemical reaction equation based on the chemical reaction process of the process to be accounted for, and to identify all reactants and all symbiotic products and the corresponding balancing coefficient for each item. The calculation module 012 is configured to calculate the sum of the balancing coefficients of all symbiotic products as the total mass basis, and to calculate the carbon footprint allocation ratio of each symbiotic product based on the ratio of the balancing coefficient of each symbiotic product to the total mass basis. The allocation module 013 is configured to obtain the total carbon footprint of the chemical reaction unit process and allocate the total carbon footprint to each symbiotic product according to the carbon footprint allocation ratio.

[0039] The present invention will be further explained below with reference to specific embodiments.

[0040] Taking the chlor-alkali process as an example, the implementation methods of the present invention will be described in detail.

[0041] The chlor-alkali process is a basic chemical process that produces sodium hydroxide, chlorine, and hydrogen through the electrolysis of saturated brine. Its products are widely used in chemical, light industry, textile, metallurgical, petrochemical, and public utilities sectors. The production principle involves the electrolysis of a saturated sodium chloride solution, where ions (Na+, Sodium chloride, and Sodium hydroxide) in the brine... + H + Cl - OH - Under the influence of an electric field, the particles move directionally and undergo redox reactions at the anode and cathode, respectively. At the anode, the oxidation of chloride ions mainly produces chlorine gas, while at the cathode, the reduction of hydrogen ions mainly produces hydrogen gas. Sodium hydroxide solution is also produced.

[0042] The relevant parameters of the chlor-alkali process in a certain factory are shown in Table 1-1.

[0043] Table 1-1 Relevant parameters of products from the chlor-alkali process in a certain factory

[0044] The present invention allocates carbon footprint among co-existing products.

[0045] The reaction feedstock for the chlor-alkali process is refined brine, which is a mixture of sodium chloride (A1) and water (A2).

[0046] The symbiotic products of the chlor-alkali process are chlorine (B1), hydrogen (B2), and sodium hydroxide (B3). Sodium hydroxide further includes products with varying concentrations: liquid alkali (30%) (B3...). 3-1 ), liquid alkali (50%) (B) 3-2 ) and caustic soda (B 3-3 ).

[0047] The chemical reactions in the chlor-alkali process are as follows: (1-1) Calculate the total amount of substance of the symbiotic products (sum of balancing coefficients) based on chemical reaction equation (1-1). 总 : (1-2) Computational symbiotic product B i carbon footprint allocation ratio : ① Carbon footprint allocation ratio of Cl2

[0048]

[0049] ② Carbon footprint allocation ratio of H2

[0050]

[0051] ③ Distribution ratio of sodium hydroxide products When a symbiotic product comprises multiple derivatives of the same chemical substance at different concentrations / forms, a two-tiered logic of total pure product allocation and active ingredient subdivision is employed: first, the total carbon footprint allocation ratio of the pure substance is calculated based on the chemical reaction balancing coefficient; then, the total pure product ratio is subdivided into each derivative based on the mass percentage of the active ingredient in each derivative. For example, if the chemical reaction only produces a 100% sodium hydroxide product, but in reality, three products with sodium hydroxide contents of 30%, 50%, and 98% are produced, the carbon footprint allocation coefficient for the 100% sodium hydroxide product is calculated first, followed by the carbon footprint allocation ratio of the three products based on the sodium hydroxide content.

[0052] Carbon footprint allocation of 100% sodium hydroxide products :

[0053] Calculate the distribution ratio of sodium hydroxide products with different contents. First, calculate the mass of sodium hydroxide in liquid caustic soda (30%), liquid caustic soda (50%), and caustic soda flakes according to the data in Table 1-1: The mass of sodium hydroxide in the 30% alkali solution: 138638.364 × 30% = 41591.509 t The mass of sodium hydroxide in 50% caustic soda solution: 35852.7 × 50% = 17926.350 t The mass of sodium hydroxide in caustic soda flakes: 1785.92 × 98% = 1750.202 t Next, calculate the total mass of sodium hydroxide in the liquid caustic soda (30%), liquid caustic soda (50%), and caustic soda flakes: 41591.509+17926.350+1750.202=61268.061t Third, calculate the proportion of sodium hydroxide mass in the total mass of sodium hydroxide in liquid caustic soda (30%), liquid caustic soda (50%), and caustic soda flakes: The percentage of sodium hydroxide in the 30% caustic soda solution is: 41591.509 / 61268.061 = 68% The mass of sodium hydroxide in the 50% caustic soda solution is: 17926.350 / 61268.061 = 29%. The mass of sodium hydroxide in caustic soda flakes: 1750.202 / 61268.061 = 3% Fourth, calculate the carbon footprint allocation ratio of liquid alkali (30%).

[0054]

[0055] Calculate the carbon footprint allocation of liquid alkali (50%).

[0056]

[0057] Calculate the carbon footprint allocation ratio of caustic soda flakes

[0058]

[0059] Among them, c 液碱（100%） It is 50%.

[0060] The carbon footprint is allocated among the co-products based on the molar ratio of the chemical reaction products. The carbon footprint allocation ratios are as follows: chlorine (25%), hydrogen (25%), liquid caustic soda (30%) (34%), liquid caustic soda (50%) (15%), and caustic soda flakes (1%).

[0061] If the carbon footprint of the chlor-alkali process is q, then the carbon footprint allocation ratio for chlorine products is q×25%, the carbon footprint allocation ratio for hydrogen products is q×25%, the carbon footprint allocation coefficient for liquid alkali (30%) products is q×34%, the carbon footprint allocation ratio for liquid alkali (50%) products is q×15%, and the carbon footprint allocation ratio for caustic soda flakes products is q×1.

[0062] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0063] It should be understood that, as used herein, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" means any and all possible combinations of one or more of the associated listed items.

[0064] The embodiment numbers disclosed in the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0065] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for allocating the carbon footprint of co-existing products based on life cycle assessment, characterized in that, include: S1 determines the chemical reaction equation based on the chemical reaction process of the process to be accounted for, and identifies all reactants and all symbiotic products and the corresponding balancing coefficient for each item; S2 calculates the sum of the balancing coefficients of all symbiotic products as the total mass basis, and calculates the carbon footprint allocation ratio of each symbiotic product based on the ratio of the balancing coefficient of each symbiotic product to the total mass basis. S3 obtains the total carbon footprint of the chemical reaction unit process and allocates the total carbon footprint to each symbiotic product according to the carbon footprint allocation ratio.

2. The method for allocating the carbon footprint of co-existing products based on life cycle assessment according to claim 1, characterized in that, S3 further includes: when the symbiotic product contains multiple derivatives of the same chemical substance at different concentrations and / or in different forms, the total carbon footprint allocation ratio is subdivided into each derivative product according to the mass percentage of the effective component of the chemical substance in each derivative product.

3. The method for allocating the carbon footprint of co-existing products based on life cycle assessment according to claim 1, characterized in that, Determining the chemical reaction equations based on the chemical reaction process of the process to be accounted for includes: The chemical reaction processes for the procedures to be accounted for include reactants such as A1, A2, A3...A n ; The chemical reaction processes involved in the steps to be accounted for include the following co-products: B1, B2, B3...B i ; Based on the chemical reaction process of the procedure to be accounted for, the chemical reaction equation is determined as follows: Where n is a natural number, i is a natural number, and a1, a2, a3...a n b1, b2, b3...b i These are the balancing coefficients for the reactants and symbiotic products.

4. The method for allocating the carbon footprint of co-existing products based on life cycle assessment according to claim 3, characterized in that, The steps for calculating the carbon footprint allocation of each symbiotic product include: Calculate the sum of the balance factors for all symbiotic products: b 总 Using the total amount of matter as a baseline, the ratio of the balancing coefficient of each symbiotic product to the total amount of matter is used to calculate symbiotic product B. i carbon footprint allocation ratio In the formula, Product B i The proportion of carbon footprint allocation.

5. The method for allocating the carbon footprint of co-existing products based on life cycle assessment according to claim 4, characterized in that, The carbon footprint allocation ratio satisfies: =1。 6. The method for allocating the carbon footprint of co-existing products based on life cycle assessment according to claim 1, characterized in that, The symbiotic products are at least two products generated simultaneously in the same chemical reaction process.

7. The method for allocating the carbon footprint of co-existing products based on life cycle assessment according to claim 7, characterized in that, The physical states of the symbiotic products include gaseous, liquid, and solid states.

8. The method for allocating the carbon footprint of co-existing products based on life cycle assessment according to claim 1, characterized in that, The balancing coefficients are determined based on the law of conservation of elements.

9. The method for allocating the carbon footprint of co-existing products based on life cycle assessment according to claim 1, characterized in that, The chemical reaction processes include chlor-alkali electrolysis, propane dehydrogenation, ethylbenzene dehydrogenation, catalytic reforming, steam cracking, ammonia synthesis, and methanol synthesis.

10. A carbon footprint allocation system for co-existing products based on life cycle assessment, the system being used to implement the method as described in any one of claims 1 to 9, characterized in that, include: The identification module is configured to determine the chemical reaction equation based on the chemical reaction process of the process to be accounted for, and to identify all reactants and all symbiotic products and the corresponding balancing coefficient for each item. The calculation module is configured to calculate the sum of the balancing coefficients of all symbiotic products as the total mass basis, and to calculate the carbon footprint allocation ratio of each symbiotic product based on the ratio of the balancing coefficient of each symbiotic product to the total mass basis. The allocation module is configured to obtain the total carbon footprint of the chemical reaction unit process and allocate the total carbon footprint to each symbiotic product according to the carbon footprint allocation ratio.

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