Carbon footprint calculation method of film product

Abstract

The invention discloses a method for calculating a carbon footprint of a film product. The method comprises the following steps of: 1, determining a system boundary of the carbon footprint in a life cycle of the film product; 2, dividing the carbon footprint into a raw material acquisition stage, a transportation stage and a synthesis stage in the system boundary; 3, greenhouse gas emission factors in the raw material obtaining stage, the transportation stage and the synthesis stage are determined respectively, and a carbon emission formula is constructed; step 4, obtaining the carbon footprint of the membrane product through the carbon emission formula of each stage; the method can comprehensively quantify greenhouse gas emission generated in the whole life cycle of the membrane product, and is very suitable for carbon footprint calculation of small-scale membrane products in college laboratories.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conservation and emission reduction measurement and evaluation methods, in particular to the technical field of carbon footprint calculation. Background Art

[0002] Faced with the excessive global greenhouse gas emissions and the serious problems they bring (such as climate change and global warming), the international community has proposed a variety of solutions. Currently, many countries have passed the Paris Agreement on Climate Change and pledged to achieve carbon neutrality by 2050. my country also formally proposed the "dual carbon" goal at the 75th United Nations General Assembly.

[0003] The membrane industry is an industrial field that uses membrane technology to separate, purify and concentrate substances. The core of the membrane industry is to use the selective separation function of the membrane to separate different components in liquids or gases through physical barriers (this technology does not require phase changes or the addition of additives). However, industrial membrane production not only consumes a lot of energy and toxic chemicals, but also emits a lot of greenhouse gases, which puts tremendous pressure on the environment and sustainable development.

[0004] With the development of the membrane industry, more and more researchers have used different methods to study the environmental issues in the membrane synthesis process; for example, Flavie Prézélus (Modeling equations and dataset of model parameters for ultrafiltration membrane fabrication [J]. Data in Brief, 2020, 33.) conducted a systematic environmental evaluation of the carbon emissions of NMP (solvent) and glycerol (pretreatment liquid) in the production process of cellulose acetate ultrafiltration membranes, and developed a decision-making tool for green membrane manufacturing; Teow (Integrated assessment of environmental and economic performance of chemical products using analytic hierarchy process approach [J]. Chinese Journal of Chemical Engineering, 2007, 15 (1): 81-87.) analyzed the current environmental load status of integrated membrane treatment systems through electricity consumption, process water utilization and NaOH use, and evaluated four major life cycle impact categories (climate change, terrestrial acidification, eutrophication and human toxicity); Li (Carbon Emission Calculations and Reductions in Membrane Water Treatment: A Review [J]. Acs Es&T Water, 2023, 4(1): 20-32.) et al. proposed an effective way to reduce emissions from membrane technology by clarifying the greenhouse gas emission boundaries and accounting methods of membrane technology; however, traditional accounting methods basically do not determine the operating conditions of membrane production and the possible impact of raw materials on the environment, and lack quantification of carbon emissions from the composite membrane production process from a full life cycle perspective, resulting in accounting results that are not comprehensive and rigorous.

[0005] In addition, with the superposition of the "dual carbon" goals and the "border carbon tariff" policy, the concept of low carbon has gradually spread from the industrial field to the academic field; how to reduce greenhouse gas emissions caused by scientific research activities (and the broader product carbon footprint) has gradually become the moral responsibility of the scientific community (in fact, the academic community plays an important role in generating and disseminating knowledge on the topic of "dual carbon"); however, few scholars currently study the greenhouse gas emissions generated by academic research activities on membranes. Summary of the invention

[0006] The purpose of the present invention is to solve the problems in the prior art and propose a method for calculating the carbon footprint of membrane products, which can comprehensively quantify the greenhouse gas emissions generated by membrane products throughout their entire life cycle and is very suitable for the carbon footprint calculation of small-scale membrane products in university laboratories.

[0007] To achieve the above object, the present invention proposes a method for calculating the carbon footprint of a membrane product, comprising the following steps: Step 1, determine the system boundary of carbon footprint during the life cycle of membrane products; Step 2: Divide the carbon footprint into raw material acquisition stage, transportation stage and synthesis stage within the system boundary; Step 3, determine the greenhouse gas emission factors in the raw material acquisition stage, transportation stage and synthesis stage respectively and construct a carbon emission formula; Step 4: Obtain the carbon footprint of the membrane product through the carbon emission formula of each stage.

[0008] Preferably, the carbon footprint of the raw material acquisition stage is quantified using formula (1); (1); In formula (1), C m Greenhouse gas emissions for all raw material inputs; M i is the consumption of the i-th raw material; EF i1 is the greenhouse gas emission factor of the i-th raw material; in addition, C m The unit is kilograms of carbon dioxide equivalent , M i The unit is kilogram (kg), EF i1 The unit is kg CO2 equivalent / kg .

[0009] Preferably, the carbon footprint of the transportation stage is quantified using formula (2); (2); In formula (2), C t T is the greenhouse gas emissions generated by energy consumption during transportation; i D is the average energy consumption per kilometer of the i-th type of transportation; i is the transport distance of the i-th type of transport; EF i,2 is the greenhouse gas emission factor of the i-th type of transportation; in addition, C t The unit is , T i The unit is kg, D i The unit is kilometer (km), EF i,2 The unit is kg CO2 equivalent / kg km .

[0010] Preferably, the carbon footprint of the synthesis stage is quantified using formula (3); (3); In formula (3), C p is the greenhouse gas emissions generated by energy consumption during the synthesis process; E i is the consumption of the i-th type of energy; EF i3 is the greenhouse gas emission factor of the i-th energy source; in addition, C p The unit is , E i The unit is kg, EF i3 The unit is .

[0011] Preferably, the raw material acquisition stage includes a chemical main material supply link and a chemical auxiliary material supply link, the transportation stage includes a chemical main material and chemical auxiliary material transportation link and an instrument and equipment transportation link, and the synthesis stage includes a water consumption link and a power consumption link.

[0012] Preferably, the greenhouse gas emission factors of the water consumption link are selected from the Ecoinvent 3.0 ultrapure water market average upstream database, and the greenhouse gas emission factors of the electricity consumption link are selected from the Ecoinvent 3.0 joint power generation average database.

[0013] Beneficial effects of the present invention: In view of the incomplete division of system boundaries (insufficient inventory completeness) in the existing membrane product carbon footprint calculation process, the lack of carbon footprint quantification models for each stage of membrane products, and the lack of carbon footprint research methods for laboratory academic research activities, the present invention, based on the LCA method, has established a full life cycle carbon footprint model calculation method for membrane product synthesis according to the full life cycle process of membrane product synthesis. The carbon footprints of the raw material acquisition stage, transportation stage and synthesis stage in the membrane product synthesis process can be quantified respectively, so as to standardize the calculation method of the carbon footprint of each stage; this method can be used for environmental carbon emission analysis of small-scale trial synthesis processes of membrane products in university laboratories, so as to accurately evaluate the contribution of inputs of chemicals, energy and water consumption in the synthesis process to environmental emissions, in order to provide data reference for chemical laboratories undergoing low-carbon research transformation, ultimately improve environmental strategies, and take action on the operating conditions of composite membrane synthesis, so that the improved technical and economic feasibility studies can be incorporated into the comprehensive ecological design of membrane processes.

[0014] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1is a system boundary diagram of membrane product life cycle adjustment in Example 1; Figure 2 This is a comparison chart of the impact of different production scales on carbon emissions at each stage of membrane production; Figure 3 This is a comparison chart of the impact of different production scales on the carbon emissions of a single composite membrane; Figure 4 This is a comparison chart of the impact of different calculation methods on carbon emissions at each stage of membrane production. DETAILED DESCRIPTION

[0016] The carbon footprint calculation method of the membrane product of the present invention comprises the following steps: Step 1: Determine the system boundary of the carbon footprint within the life cycle of the membrane product; for the research scope of membrane products, its boundary is defined as the entire production process (i.e., the system boundary of membrane products is defined as the entire cycle from "cradle" to "gate"); Step 2, within the system boundary, the carbon footprint is divided into the raw material acquisition stage, the transportation stage and the synthesis stage; the raw material acquisition stage includes the chemical main material supply link and the chemical auxiliary material supply link, the transportation stage includes the chemical main material and chemical auxiliary material transportation link and the instrument and equipment transportation link, and the synthesis stage includes the water consumption link and the electricity consumption link; the greenhouse gas emission factor of the water consumption link is selected from the Ecoinvent 3.0 ultrapure water market average upstream database, and the greenhouse gas emission factor of the electricity consumption link is selected from the Ecoinvent 3.0 joint power generation average database; Step 3, determine the greenhouse gas emission factors in the raw material acquisition stage, transportation stage and synthesis stage respectively and construct a carbon emission formula; Step 4: Obtain the carbon footprint of the membrane product through the carbon emission formula of each stage.

[0017] For step 4, the carbon footprint of the raw material acquisition stage is quantified using formula (1); (1); In formula (1), C m Greenhouse gas emissions for all raw material inputs; M i is the consumption of the i-th raw material; EF i1 is the greenhouse gas emission factor of the i-th raw material; in addition, C m The unit is , M i The unit is kg, EF i1 The unit is .

[0018] For step 4, the carbon footprint of the transportation stage is quantified using formula (2); (2); In formula (2), C t T is the greenhouse gas emissions generated by energy consumption during transportation; i D is the average energy consumption per kilometer of the i-th type of transportation; i is the transport distance of the i-th type of transport; EF i,2 is the greenhouse gas emission factor of the i-th type of transportation; in addition, C t The unit is , T i The unit is kg, D i The unit is km, EF i,2 The unit is .

[0019] For step 4, the carbon footprint of the synthesis stage is quantified using formula (3); (3); In formula (3), C p is the greenhouse gas emissions generated by energy consumption during the synthesis process; E i is the consumption of the i-th type of energy; EF i3 is the greenhouse gas emission factor of the i-th energy source; in addition, C p The unit is , E i The unit is kg, EF i3 The unit is .

[0020] Embodiment 1: The carbon footprint calculation method of the membrane product of the present invention is further supplemented by combining actual data. Specifically, the area of ​​15 synthetic membranes is calculated to be 19.61 cm 2 Carbon footprint of the composite membrane.

[0021] See also Figure 1 As shown in Table 1 below, the main chemical materials consumed by the composite membrane are urea, N,N-dimethylformamide, ferric nitrate nonahydrate and polyacrylonitrile, while the auxiliary chemical materials consumed are anhydrous ethanol and sulfuric acid. The carbon emissions of each material are calculated using formula (1) and the principle of conservation of materials.

[0022] Table 1 Data list of chemical raw materials and auxiliary materials acquisition stage

[0023]

[0024] (1); In formula (1), C mGreenhouse gas emissions for all raw material inputs; M i is the consumption of the i-th raw material; EF i1 is the greenhouse gas emission factor of the i-th raw material; in addition, C m The unit is , M i The unit is kg, EF i1 The unit is .

[0025] The calculation process is as follows:

[0026] As shown in Table 2 below, considering that the gross weight of the chemical raw materials and chemical auxiliary materials of the composite membrane is relatively small and the various drugs are transported separately, a one-way distance of 439 km is used as the transportation mileage during the transportation stage (starting from Shanghai Aladdin Biochemical Co., Ltd. and ending at the composite membrane synthesis laboratory); in addition, since the instruments and equipment have been stored for a long time and the equipment depreciation rate is almost zero during a single synthesis of the composite membrane, the carbon emissions from the transportation of the instruments and equipment are not included in this process.

[0027] Table 2 Data list of transportation stage

[0028]

[0029] (2); In formula (2), C t T is the greenhouse gas emissions generated by energy consumption during transportation; i D is the average energy consumption per kilometer of the i-th type of transportation; i is the transport distance of the i-th type of transport; EF i,2 is the greenhouse gas emission factor of the i-th type of transportation; in addition, C t The unit is , T i The unit is kg, D i The unit is km, EF i,2 The unit is .

[0030] The calculation process is as follows:

[0031] As shown in Table 3 below, in the synthesis stage, resource consumption is divided into two categories: water consumption and electricity consumption; among them, water consumption is mainly used for solution configuration, pickling and composite membrane phase transformation (the water consumption for instrument washing is obtained by estimation method), while electricity consumption is mainly used for the operation of equipment such as ovens, muffle furnaces, stirrers and scraping machines; specifically, the water consumption taken in this embodiment is selected from the Ecoinvent 3.0 ultrapure water market average upstream database, and the electricity consumption is selected from the Ecoinvent 3.0 joint power generation average database.

[0032] Table 3 Data list of synthesis stage

[0033]

[0034] (3); In formula (3), C p is the greenhouse gas emissions generated by energy consumption during the synthesis process; E i is the consumption of the i-th type of energy; EF i3 is the greenhouse gas emission factor of the i-th energy source; in addition, C p The unit is , E i The unit is kg, EF i3 The unit is .

[0035] The calculation process is as follows:

[0036] Finally, the carbon emissions of each stage can be added together to obtain the total greenhouse gas emissions.

[0037] The calculation process is as follows:

[0038] Comparative Example 1: Simapro computer software was used to calculate the production of 15 composite membranes in the laboratory (each composite membrane has an area of ​​19.61 cm 2 ) for comparison.

[0039] Depend on Figure 2 Part (a) and Figure 3 It can be seen that the area of ​​15 synthetic membranes is 19.61 cm 2 During the composite film production process, the carbon emissions over the entire life cycle are 20.3 ; Carbon emissions in the synthesis stage account for the largest proportion (reaching 98.203%), which indicates that the carbon emissions caused by electricity consumption of instruments and equipment (such as ovens, muffle furnaces, agitators and scrapers) in the synthesis stage contribute the most (related to the release of power generation types in southern my country, and the high carbon emissions of traditional power generation industry will bring high carbon emission burden to downstream products); in the synthesis stage, the carbon emissions caused by water consumption are only 0.0168% (the smallest ratio of carbon emissions in the entire life cycle); in the transportation stage, the carbon emissions caused by one-way transportation by medium-sized trucks account for 1.39%; the chemical acquisition stage (i.e. the raw material acquisition stage) includes the mining and synthesis process of each required raw material, and carbon emissions account for 0.39% of the total emissions, and the carbon emissions of NN dimethylformamide account for 0.157% (the highest emission among all types of chemicals), and the lower carbon emission ratio in the chemical acquisition stage is related to the use of chemical raw materials and auxiliary materials.

[0040] Comparative Example 2: The production scale of the composite film was expanded from 15 sheets to 150 sheets, and the other conditions were the same as those of Comparative Example 1.

[0041] like Figure 2 Part (b) and Figure 3 It can be seen that when the production scale is expanded by 10 times, the carbon emissions over the entire life cycle are 21.11 , only 0.81 higher than that of comparative example 1 (The increased carbon emissions are caused by the increased use of chemical raw materials and auxiliary materials during the expansion of production); the overall carbon emissions in the chemical acquisition stage increased from 0.39% to 3.7% (carbon emissions increased from 0.078 Improved to 0.78 The carbon emissions increased at a rate that matched the rate of production expansion. The carbon emissions due to energy consumption in the synthesis phase dropped from 98.2% to 94.8% (the decrease in emissions was caused by the increase in emissions in other phases), while the electricity emissions in the synthesis phase did not change significantly and remained at 19.9. The carbon emissions caused by water consumption in the transportation and synthesis stages did not change significantly. In addition, when synthesizing 150 membranes with an area of ​​19.61 cm 2 In the composite membrane process, the emission of a single composite membrane is only 0.141 (In comparison, the area of ​​the synthesized 15 membranes was 19.61 cm 2 During the composite membrane production process, the carbon emissions of a single composite membrane reached 1.353 ), which indicates that scaling up the production process of composite membranes has guiding significance for emission reductions during the synthesis process.

[0042] See also Figure 4 The carbon footprint of the composite membrane synthesis process obtained by the emission factor method and the carbon footprint evaluation result obtained by Simapro modeling (i.e., this method) are highly consistent. The electricity consumption in the synthesis process provides the main contribution, but there are still differences in the details of the emission results in each stage; there is no significant difference in the carbon emissions in the chemical acquisition stage and transportation stage obtained by the emission factor method and Simapro modeling. The carbon emissions in the chemical acquisition stage obtained by the emission factor method account for 0.89%, which is only 0.5% higher than Simapro's 0.39%, and the emissions are only increased by 0.0821 The carbon emission percentage obtained by the emission factor method in the transportation stage is only 0.84% ​​higher than that in the Simapro analysis, and the emission is increased by 0.13 This is due to the lower activity level in the chemical acquisition and transportation process; however, as the activity level data increases, the carbon emission differences caused by database differences will show obvious changes. For example, when analyzing the carbon emission of electricity consumption in the synthesis stage, Simapro calculated the result to be 19.93 (accounting for 98.27%), the calculated emission factor is 17.04 (accounting for 92.32%), the large difference in carbon emissions comes from the selection of different databases (Simapro Power selected the Ecoinvent 3.0 database China-Zhejiang conventional power generation value (2012), and the emission factor selected the Ecoinvent3.0 Zhejiang Province Power Emission Factor 17100H2122020A (2020). The selection of databases of different years and production capacity processes will directly affect the carbon emission intensity of the downstream); in addition, the carbon emissions of water consumption in the synthesis process obtained by the emission factor method increased sharply from 0.00343 (0.017%) increased to 0.86 (4.61%), which is also the emission difference caused by database selection; since different carbon footprint databases may lead to different carbon emission assessment results for the same product or activity based on different data sources and accounting methods, choosing an accurate and reliable database and accounting method is the key to ensuring the accuracy of carbon emission assessment.

[0043] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention belongs to the protection scope of the present invention.

Claims

1. A method for calculating the carbon footprint of a membrane product, characterized in that: The steps include: Step 1, determine the system boundary of carbon footprint during the life cycle of membrane products; Step 2: Divide the carbon footprint into raw material acquisition stage, transportation stage and synthesis stage within the system boundary; Step 3, determine the greenhouse gas emission factors in the raw material acquisition stage, transportation stage and synthesis stage respectively and construct a carbon emission formula; Step 4: Obtain the carbon footprint of the membrane product through the carbon emission formula of each stage.

2. The method for calculating the carbon footprint of a membrane product according to claim 1, characterized in that: Formula (1) is used to quantify the carbon footprint of the raw material acquisition stage; （1）； In formula (1), C m Greenhouse gas emissions for all raw material inputs; M i is the consumption of the i-th raw material; EF i1 is the greenhouse gas emission factor of the ith raw material.

3. The method for calculating the carbon footprint of a membrane product according to claim 1, characterized in that: Formula (2) is used to quantify the carbon footprint of the transportation stage; （2）； In formula (2), C t T is the greenhouse gas emissions generated by energy consumption during transportation; i is the average energy consumption per kilometer of the i-th type of transportation; D i is the transport distance of the i-th type of transport; EF i,2 is the greenhouse gas emission factor of the i-th type of transport.

4. The method for calculating the carbon footprint of a membrane product according to claim 1, characterized in that: The carbon footprint of the synthesis stage is quantified using formula (3); （3）； In formula (3), C p is the greenhouse gas emissions generated by energy consumption during the synthesis process; E i is the consumption of energy of type i; EF i3 is the greenhouse gas emission factor of the i-th energy source.

5. The method for calculating the carbon footprint of a membrane product according to any one of claims 1 to 4, characterized in that: The raw material acquisition stage includes the chemical main material supply link and the chemical auxiliary material supply link, the transportation stage includes the chemical main material and chemical auxiliary material transportation link and the instrument and equipment transportation link, and the synthesis stage includes the water consumption link and the electricity consumption link.

6. The method for calculating the carbon footprint of a membrane product according to claim 5, characterized in that: The greenhouse gas emission factors for the water consumption link are selected from the Ecoinvent 3.0 ultrapure water market average upstream database, and the greenhouse gas emission factors for the electricity consumption link are selected from the Ecoinvent 3.0 combined power generation average database.

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