Method for quantifying the environmental impact of a semi-steel radial tire over its entire life cycle

Abstract

The present application belongs to the technical field of life cycle assessment method, and relates to a method for quantifying environmental influence of semi-steel radial tire in whole life cycle, which comprises target and range determination, inventory analysis, influence assessment method and result analysis. The present application quantifies environmental influence of semi-steel radial tire from the perspective of life cycle, provides basis for reasonable planning of energy and resource use and pollutant emission in whole life cycle of tire, can analyze contribution rate of each stage in life cycle from two perspectives of each link and each material input, and provides specific scientific basis for improving technical level and developing new products while reducing environmental influence.

Description

Technical Field

[0001] This invention belongs to the technical field of life cycle assessment methods, and relates to a method for quantifying the environmental impact of semi-steel radial tires throughout their entire life cycle. Background Technology

[0002] In recent years, with the popularization of new energy vehicles, the rapid development of the automotive industry has greatly promoted the expansion of the tire industry. The production, transportation, use, and recycling of a semi-steel radial tire involves a large amount of resources and energy, resulting in a huge environmental burden and greenhouse effect, as well as threats to human health and ecosystems. Furthermore, because the tire industry is a high-energy-consuming, high-polluting, and high-emission industry, achieving a green transformation of the tire industry has become an inevitable trend.

[0003] Life Cycle Assessment (LCA), as an environmental management tool, is used to assess the environmental impact of products, facilities, or services throughout their entire life cycle, "from cradle to grave." Currently, scholars both domestically and internationally widely utilize LCA methods to conduct research on the environmental impact of tires. From the perspective of research boundaries, compared to international research, domestic studies focus more on the environmental impact of the "cradle to gate" and disposal stages, while research on the environmental impact of tires throughout their entire life cycle is relatively limited. From the perspective of indicator selection, domestic analyses of tire environmental impacts tend to be simplistic, thus requiring a more systematic and comprehensive quantitative analysis of the environmental impact generated throughout the tire's life cycle. Summary of the Invention

[0004] To address the above issues, this invention provides a method for quantifying the environmental impact of semi-steel radial tires throughout their entire life cycle. This invention uses a 1-ton semi-steel radial tire as the research object, combining the Ecoindicator 99 method (an ecoindicator 99 method for life cycle assessment, involving a series of indicators to help assess the impact of a product or activity on the environment, human health, and resource utilization) and the carbon-energy-water environmental footprint to comprehensively analyze the environmental impact generated throughout the tire's entire life cycle.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for quantifying the environmental impact of semi-steel radial tires throughout their entire life cycle includes the following steps:

[0007] (1) Target and scope definition: The research boundary is all life cycle stages from the production, transportation, use to disposal of semi-steel radial tires; considering the resource and energy input of each unit process within the system boundary, as well as the emission of gas and hazardous waste generated during operation, the functional unit is defined as 1 ton of semi-steel radial tire.

[0008] (2) Inventory analysis: Collect input data for each stage of the entire life cycle of semi-steel radial tires; the data includes resources, energy consumption, pollutant emissions and pollutant treatment;

[0009] (3) Impact Assessment Method: Based on the actual data from the field survey and combined with the background data from the Ecoinvent 3.1 database (ecoinvent database, a life cycle inventory database developed by the Swiss Ecoinvent Center, with data mainly sourced from statistical data and technical literature) built into GaBi software, an LCA assessment software developed by PE International in Germany, we modeled each stage of the entire life cycle of a 1.5-ton steel radial tire. We used the Ecoindicator 99 method to comprehensively quantify the environmental impact, selecting 8 midpoint environmental impact indicators and 3 endpoint environmental impact indicators to quantify the environmental impact of the tire's entire life cycle. The calculation formula is shown in formula (1):

[0010]

[0011]

[0012] In the formula,

[0013] M i This represents the midpoint environmental impact index of the i-th category;

[0014] a i The characteristic factor representing the midpoint environmental impact index of the i-th class;

[0015] A j The value of the midpoint environmental impact index after the j-th characteristic is given.

[0016] E k For the k-th category of environmental impact indicators;

[0017] The eight midpoint environmental impact indicators are fresh water consumption, fresh water ecotoxicity, fresh water eutrophication, water acidification, climate change, fossil fuel consumption, human toxicity-carcinogenicity and human toxicity-non-carcinogenicity indicators. After characterizing and classifying the eight midpoint environmental impact indicators, they are transformed into three endpoint environmental impact indicators, namely human health, ecosystem quality and resource consumption.

[0018] (4) Results Analysis: Combining the midpoint and endpoint environmental impact indicators of Ecoindicator 99, the environmental impact of semi-steel radial tires throughout their entire life cycle is comprehensively and quantitatively analyzed. Based on the carbon-energy-water environmental footprint, the contribution rate of the selected key factors to the environmental footprint is analyzed. According to the contribution rate, the key pollution links throughout the entire life cycle are analyzed, and effective improvement directions and corresponding measures to reduce pollutant emissions are proposed to reduce the carbon-energy-water environmental footprint of tires throughout their entire life cycle.

[0019] The beneficial effects of this invention are:

[0020] (1) Quantify the environmental impact of semi-steel radial tires from the perspective of life cycle, so as to provide a basis for the rational planning of energy and resource use and pollutant emissions throughout the tire life cycle.

[0021] (2) It can analyze the contribution rate of each stage of the life cycle from the perspectives of various links and material inputs, providing specific scientific basis for targeted improvement of technology level and development of new products while reducing environmental impact. Attached Figure Description

[0022] Figure 1 A schematic diagram illustrating the boundaries of the full life cycle study for semi-steel radial tires;

[0023] Figure 2 A research framework diagram for semi-steel radial tires;

[0024] Figure 3 A schematic diagram illustrating the contribution rate of each stage of the life cycle to the midpoint environmental impact indicators;

[0025] Figure 4 A diagram illustrating the contribution rate of each stage of the life cycle to the final environmental impact indicator;

[0026] Figure 5 This is a schematic diagram illustrating the contribution rate of midpoint environmental impact indicators to endpoint environmental impact indicators.

[0027] Figure 6a A schematic diagram illustrating the contribution of key factors from the perspective of "human health damage" to the "carbon-energy-water" footprint.

[0028] Figure 6b A schematic diagram illustrating the contribution rate of key factors to the carbon-water footprint from the perspective of "ecosystem quality damage";

[0029] Figure 6c A schematic diagram illustrating the contribution rate of key factors from the perspective of "resource consumption" to the "energy-water" footprint;

[0030] Figure 7 This is a schematic diagram of the sensitivity analysis of the selected key factors. Detailed Implementation Plan

[0031] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0032] The research object of this invention is semi-steel radial tires, and the functional unit is set as 1 ton of semi-steel radial tires. The research scope is defined as the energy and resource consumption and environmental impact generated at each stage of the product life cycle, from raw material mining, product production, product transportation, product use to product recycling and disposal.

[0033] The data in this invention is divided into real-world data and background data. The real-world data comes from literature and environmental impact assessment reports, while the background data comes from the Ecoinvent 3.1 database built into the GaBi software. After organizing the required data, it is input into the GaBi software according to the unit process conditions to complete the establishment of the full life cycle model of a 1.5-ton steel radial tire. The schematic diagram in the software is shown below. Figure 3 As shown.

[0034] Eight midpoint environmental impact indicators were selected: fresh water consumption, fresh water ecotoxicity, fresh water eutrophication, fresh water acidification, climate change, fossil fuel depletion, human toxicity (carcinogenicity), and human toxicity (non-carcinogenicity). Using characteristic factor transformation, these eight characteristic midpoint environmental impact indicators were classified into three endpoint environmental impact indicators according to their impact on ecosystem quality, human health, and resources. The results of quantifying the midpoint environmental impact indicators for the production, transportation, use, and disposal stages of semi-steel radial tires are shown in Table 1 below.

[0035] Table 1 Summary of Indicator Results

[0036]

[0037]

[0038] The various indicators derived from this invention are visualized as follows:

[0039] Figure 3 The contribution rate of each stage of the life cycle to the midpoint environmental impact indicators; such as Figure 3As shown, the usage phase contributes the most to the midpoint environmental impact, accounting for 73.1%, 39.9%, 76.5%, 83.6%, 76.3%, and 64.3% of the six midpoint environmental impact indicators: fossil fuel consumption, acidification, human toxicity / carcinogenicity, fresh water ecotoxicity, climate change, and human toxicity / non-carcinogenicity, respectively. This is because tires generate tiny rubber abrasion particles during friction with the ground. These particles enter the soil, atmosphere, or are washed into drainage systems, negatively impacting soil environment, air quality, and aquatic ecosystems. Simultaneously, the high rolling resistance of tires increases energy consumption and environmental burden during the usage phase. Secondly, the tire production phase contributes the most to fresh water consumption and eutrophication, accounting for 58% and 92.8% of the total, respectively. This is because tire manufacturing requires large amounts of water and chemicals such as solvents, coatings, adhesives, and cleaning agents. The use and disposal of these substances lead to water waste and pollution, adversely affecting aquatic ecosystems. The waste disposal stage uses pyrolysis to treat waste tires. This stage mainly results in the consumption of fresh water and the environmental impact of acidification. During the pyrolysis process, the cleaning and cooling of the equipment will introduce acidic substances, chemical additives and other pollutants into the water body and cause water acidification. At the same time, the gases and combustion products produced during the pyrolysis process may contain acidic substances, such as sulfur dioxide and nitrogen oxides, which will enter the atmosphere and form acid rain, causing water acidification.

[0040] Figure 4 The contribution rate of each stage of the life cycle to the final environmental impact indicator; such as Figure 4 As shown, from the perspective of ecosystem quality, the production, use, and waste disposal stages all have a certain impact, contributing 31.1%, 39.7%, and 26.1%, respectively. Tire production requires a large amount of raw materials such as rubber and chemical additives, as well as a large amount of energy input such as steam and electricity, leading to the destruction of natural resources and an increased demand for non-renewable resources, thus damaging ecosystem quality. From the perspective of human health damage and resource consumption, the use stage contributes the most to these two indicators, with contribution rates of 75.8% and 78.8%, respectively, followed by the production stage, with contribution rates of 19.7% and 20%, respectively. Specifically, the large amount of tire wear particles and chemicals generated during the tire use stage can be inhaled, adversely affecting the respiratory and cardiovascular health, thus causing human health damage; when vehicles are in motion, tires need to overcome rolling resistance, resulting in greater energy consumption and greenhouse gas emissions, thus causing resource consumption. Tire production requires large amounts of rubber, metal, water, and other materials, which may lead to over-exploitation and depletion of resources. At the same time, the use of a large number of chemical additives in tire manufacturing will release harmful gases and chemicals, thus affecting human health.

[0041] Figure 5 The contribution rate of the midpoint environmental impact indicator to the endpoint environmental impact indicator; such as Figure 5 As shown, the climate change impacts caused by greenhouse gases generated throughout the tire's life cycle contribute the most to human health damage, at 96.03%. This is because the greenhouse effect caused by greenhouse gases leads to an increased frequency of extreme heat, increasing the incidence of cardiovascular and respiratory diseases, and accelerating the spread of infectious diseases, thus directly threatening human health. The second largest contributor is non-carcinogenic effects on human health, contributing 3.71%. The acidification environmental impacts generated throughout the tire's life cycle contribute the most to the endpoint environmental impact indicator of ecosystem quality damage, at 99.34%. This is likely because tire production and use generate sulfur dioxide, nitrogen dioxide, and halogen gases such as chlorine, polluting the environment and acidifying water bodies, thus causing ecosystem damage.

[0042] Figure 6a To analyze the contribution rate of key factors from the perspective of "human health damage" to the "carbon-energy-water" footprint; such as... Figure 6a As shown, from the perspective of human health damage, the carbon footprint mainly originates from the climate change impacts caused by fuel use, raw material use, and electricity use. These three key factors contribute 77.45%, 15.00%, and 7.54% to climate change, respectively. The water footprint mainly stems from three midpoint environmental impact indicators: human health—non-carcinogenicity, human health—carcinogenicity, and fresh water consumption, with contribution rates of 93.57%, 4.44%, and 1.98%, respectively. Among these, human health—non-carcinogenicity has the largest contribution to the water footprint. This impact indicator is mainly composed of the three key factors of fuel use, raw material use, and electricity use, with contribution rates of 64.94%, 28.88%, and 5.95%, respectively.

[0043] Figure 6b To analyze the contribution rate of key factors to the carbon-water footprint from the perspective of "ecosystem quality damage"; such as... Figure 6b As shown, from the perspective of ecosystem quality, this category consists of water footprint and carbon footprint. However, the contribution of carbon footprint to ecosystem quality damage is very small, almost negligible. The water footprint comprises four midpoint environmental impact indicators: acidification, water ecotoxicity, fresh water consumption, and eutrophication. Among these, acidification contributes 99.30% to the water footprint. The acidification environmental impact indicators are mainly composed of fuel use, electricity use, and raw material use. These three key factors contribute 52.9%, 23.81%, and 23.28% to the acidification midpoint environmental impact indicators, respectively. This is because the large-scale use of fuel and coal releases acidic gases such as sulfur dioxide and nitrogen oxides into the atmosphere, forming acid rain and causing water acidification.

[0044] Figure 6c To analyze the contribution rate of key factors from the perspective of "resource consumption" to the "energy-water" footprint; such as... Figure 6c As shown, from the perspective of resource consumption, it consists of energy footprint and water footprint, with energy footprint contributing 99.66% and water footprint contributing 0.34%. The energy footprint originates from fossil fuel combustion, while the water footprint originates from water scarcity. Specifically, the three key factors—fuel use, raw material use, and electricity use—contribute 79.89%, 19.51%, and 0.6% to fossil fuel consumption, respectively.

[0045] Figure 7 Sensitivity analysis for the selected key factors; such as Figure 7 As shown, the midpoint environmental impact indicator of climate change is most sensitive to changes in raw material consumption. When raw material consumption changes by -10%, -5%, 5%, and 10%, the midpoint environmental impact indicator of climate change changes by -1.31%, -0.66%, 0.66%, and 1.31%, respectively. The midpoint environmental impact indicator of fossil fuel consumption is most sensitive to changes in fuel consumption. When fuel consumption changes by -10%, -5%, 5%, and 10%, the midpoint environmental impact indicator of fossil fuel consumption changes by -7.22%, -3.61%, 3.61%, and 7.22%, respectively. The midpoint environmental impact indicator of fresh water consumption is most sensitive to changes in raw material consumption. When raw material consumption changes by -10%, -5%, 5%, and 10%, the midpoint environmental impact indicator of fresh water consumption changes by -5.64%, -2.82%, 2.82%, and 5.64%, respectively. The midpoint environmental impact indicator, fresh water ecotoxicity, is most sensitive to changes in raw material usage. When raw material usage changes by -10%, -5%, 5%, and 10%, the midpoint environmental impact indicator of fresh water ecotoxicity changes by -1.24%, -0.62%, 0.62%, and 1.24%, respectively. The midpoint environmental impact indicator of fresh water eutrophication is also most sensitive to changes in raw material usage. When raw material usage changes by -10%, -5%, 5%, and 10%, the midpoint environmental impact indicator of fresh water eutrophication changes by -7.41%, -3.7%, 3.7%, and 7.41%, respectively. The midpoint environmental impact indicator of human toxicity—carcinogenicity—is most sensitive to changes in fuel use. When the key factor fuel usage changes by -10%, -5%, 5%, and 10%, the midpoint environmental impact indicator of human toxicity—carcinogenicity changes by -7.65%, -3.83%, 3.83%, and 7.65%, respectively. The midpoint environmental impact indicator of water acidification is most sensitive to the key factor of electricity consumption. When electricity consumption changes by -10%, -5%, 5%, and 10%, the midpoint environmental impact indicator of water acidification changes by -1.93%, -0.94%, 0.94%, and 1.87%, respectively.

[0046] By quantifying the environmental impact of semi-steel radial tires throughout their entire life cycle, we can identify which key factors or important processes contribute more significantly to the environmental impact. This allows for a more comprehensive analysis of the main sources of pollution, enabling corresponding optimization based on the identified key contributing factors. It also promotes the rational allocation of resources and improves the utilization rate of various resources.

Claims

1. A method for quantifying the environmental impact of semi-steel radial tires throughout their entire life cycle, characterized in that, Includes the following steps: (1) Target and scope definition: The research boundary is all life cycle stages from the production, transportation, use to disposal of semi-steel radial tires; considering the resource and energy input of each unit process within the system boundary and the emission of gas and hazardous waste generated during operation, the functional unit is defined as 1 ton of semi-steel radial tire; (2) Inventory analysis: Collect input data for each stage of the entire life cycle of semi-steel radial tires; the data includes resources, energy consumption, pollutant emissions and pollutant treatment; (3) Impact assessment method: Based on the actual data from the field survey and the background data from the Ecoinvent 3.1 database built into GaBi software, the entire life cycle of the 1.5-ton steel radial tire was modeled. The Ecoindicator 99 method was used to comprehensively quantify the environmental impact. Eight midpoint environmental impact indicators and three endpoint environmental impact indicators were selected to quantify the environmental impact of the tire throughout its entire life cycle. The eight midpoint environmental impact indicators are fresh water consumption, fresh water ecotoxicity, fresh water eutrophication, water acidification, climate change, fossil fuel consumption, human toxicity-carcinogenicity and human toxicity-non-carcinogenicity indicators. After characterizing and classifying the eight midpoint environmental impact indicators, they are transformed into three endpoint environmental impact indicators, namely human health, ecosystem quality and resource consumption. (4) Results analysis: Combining the midpoint and endpoint environmental impact indicators of Ecoindicator 99, the environmental impact of semi-steel radial tires throughout their entire life cycle is comprehensively and quantitatively analyzed; combined with the "carbon-energy-water" environmental footprint, the contribution rate of the selected key factors to the environmental footprint is analyzed, and the key pollution links throughout the entire life cycle are analyzed based on the contribution rate, and effective improvement directions and corresponding measures to reduce pollutant emissions are proposed to reduce the "carbon-energy-water" environmental footprint of tires throughout their entire life cycle.

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