Purpose Recycled polyester, derived from waste plastic bottles, is known for its eco-friendliness, but its specific environmental benefits remain undisclosed. In this study, the life cycle assessment methodology was employed to quantitatively evaluate the comprehensive environmental impacts of three varieties of recycled polyester: pre-oriented yarn, draw textured yarn, and fully drawn yarn. This analysis aims to shed light on the sustainability claims associated with these materials, providing a more nuanced understanding of their ecological footprint. Methods Sixteen midpoint indicators and three endpoint categories were calculated using the SimaPro software, employing the Ecoinvent database and the ReCiPe methodological framework. Subsequently, key emission sources were pinpointed through the application of the area allocation method, which allocates emissions to different products or services based on their contribution to the overall environmental impact. The most significant impact categories were then identified using the standardized and weighted approaches outlined in the Product Environmental Footprint Category Rules, ensuring a consistent and comparable assessment. Finally, a sensitivity analysis was conducted to examine the robustness of the calculated results, providing insights into how changes in input data or assumptions might affect the overall conclusions drawn from the life cycle assessment. Results and discussion The study reveals that 1 ton of draw textured yarn has an environmental footprint of 111.5040 Pt, higher than fully drawn yarn with 67.6762 Pt and pre-oriented yarn with 36.5132 Pt. The study highlights global warming potential, fossil resource scarcity, and freshwater eutrophication in midpoints, as well as human health in endpoints, are the most relevant impact categories. The energy and natural resources sector, particularly the consumption of electricity and heat, is identified as a key emission source. The single most relevant impact category is in good agreement with the results of the comprehensive environmental impact assessment. The sensitivity analysis shows that the input of electricity is highly sensitive to the life cycle assessment results. Conclusions Among the three kinds of recycled polyester, pre-oriented yarn exhibits superior sustainability performance, followed by fully drawn yarn, while draw textured yarn demonstrates a greater environment impact. The study identifies the most relevant impact categories and key emission sources. It underscores the utility of the most relevant impact categories as an environmental impact assessment indicator and prompts manufacturers to consider strategies such as increasing clean energy usage and streamlining processes to reduce environmental footprints.

Life cycle assessment of recycled polyester and analysis of key emission sources

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发表日期：

2025年3月17日

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Saiyu Zhao,
Nannan Hou,
Rong Li

摘要

Purpose

Recycled polyester, derived from waste plastic bottles, is known for its eco-friendliness, but its specific environmental benefits remain undisclosed. In this study, the life cycle assessment methodology was employed to quantitatively evaluate the comprehensive environmental impacts of three varieties of recycled polyester: pre-oriented yarn, draw textured yarn, and fully drawn yarn. This analysis aims to shed light on the sustainability claims associated with these materials, providing a more nuanced understanding of their ecological footprint.

Methods

Sixteen midpoint indicators and three endpoint categories were calculated using the SimaPro software, employing the Ecoinvent database and the ReCiPe methodological framework. Subsequently, key emission sources were pinpointed through the application of the area allocation method, which allocates emissions to different products or services based on their contribution to the overall environmental impact. The most significant impact categories were then identified using the standardized and weighted approaches outlined in the Product Environmental Footprint Category Rules, ensuring a consistent and comparable assessment. Finally, a sensitivity analysis was conducted to examine the robustness of the calculated results, providing insights into how changes in input data or assumptions might affect the overall conclusions drawn from the life cycle assessment.

Results and discussion

The study reveals that 1 ton of draw textured yarn has an environmental footprint of 111.5040 Pt, higher than fully drawn yarn with 67.6762 Pt and pre-oriented yarn with 36.5132 Pt. The study highlights global warming potential, fossil resource scarcity, and freshwater eutrophication in midpoints, as well as human health in endpoints, are the most relevant impact categories. The energy and natural resources sector, particularly the consumption of electricity and heat, is identified as a key emission source. The single most relevant impact category is in good agreement with the results of the comprehensive environmental impact assessment. The sensitivity analysis shows that the input of electricity is highly sensitive to the life cycle assessment results.

Conclusions

Among the three kinds of recycled polyester, pre-oriented yarn exhibits superior sustainability performance, followed by fully drawn yarn, while draw textured yarn demonstrates a greater environment impact. The study identifies the most relevant impact categories and key emission sources. It underscores the utility of the most relevant impact categories as an environmental impact assessment indicator and prompts manufacturers to consider strategies such as increasing clean energy usage and streamlining processes to reduce environmental footprints.