Dive Brief:
- Electricity consumption is a primary driver of environmental impacts across polyester production, according to a new lifecycle assessment by global nonprofit Textile Exchange and SCS Consulting Services. That means even recycled polyester, if produced with energy from a coal-fueled national grid, can have elevated emissions, the report found.
- Thermomechanical recycling — a method in which plastic is cleaned, shredded, and melted down — generally results in higher carbon dioxide emissions than chemical recycling, which breaks polyester down into its chemical constituents, the assessment found. But thermomechanical recycling also requires clean, high-quality input materials, and with about 98% of recycled polyester produced using post-consumer bottles, it doesn’t help reduce the textile industry’s enormous waste problem.
- For recycled polyester, how far waste had to be transported to get to the plant in the first place had a strong impact on the overall emissions associated with the products, even more than the emissions intensity of the trucks being used, the report found.
Dive Insight:
Virgin polyester is widely used in the fashion industry, making up 57% of global fiber production, but spurs a myriad of negative environmental impacts. Polyester is derived from fossil fuels and its production generates increased greenhouse gas emissions, water pollution and air pollution. Even once discarded, it can persist in the environment for at least decades, if not millennia, according to recent research.
Life cycle assessments, which take into account every step of how a material is produced, provides an estimate of the total carbon dioxide emissions and other environmental impacts associated with that material. But until now, there was no publicly available data for virgin polyester produced in Asia, despite it being the world’s most important producer.
“This study helped to close those data gaps,” SCS Technical Manager Ilan MacAdam-Somer told ESG Dive in an email. LCAs “are a powerful tool for understanding the environmental impacts of manufacturing a product, but they are only as useful as the data on which they’re based,” he added.
The June report evaluated one virgin polyester producer in Southeast Asia — the first known publicly available data from Asia — as well six recycled polyester producers in China, Europe, Southeast Asia, and the United States.
Producing virgin polyester yarn or staple fiber — a wool-like fluff that can be spun into yarn — resulted in between 3.96 and 4.76 kilograms of carbon dioxide emissions, the report found. Meanwhile, producing thermomechanically-recycled staple fiber resulted in 3.04 kg of CO2 emissions. Chemically recycled chips — which can be melted and drawn into polyester yarn—emit 1.77 to 2.24 kg of CO2, compared to 0.959-1.31 kg for thermomechanically recycled chips. But a non-commercial producer in Europe, using a proprietary chemical recycling method, was able to keep emissions as low as 0.683-0.885 kg.
However, two of the three chemical recyclers only recycled post-industrial waste, such as fabric trimmings and scraps from garment assembly, which are cleaner and more uniform.
“The recycling industry needs support in order to mature, especially related to the complexity of sorting and separating polyester post-consumer waste,” MacAdam-Somer said.
By modeling different scenarios, the report authors showed that whether a plant depends on coal or renewable energy greatly changes the emissions picture. “Companies looking to set up new recycling facilities should look for regions with large amounts of renewable energy in the grid mix, consider entering into contracts with renewable energy producers, or install on-site renewable energy to see lower environmental impacts,” the report said.
The report also highlighted social impacts associated with virgin and recycled polyester production. Because virgin polyester begins with fossil fuel extraction, it inevitably is intertwined with potential land-grabs, violence, pollution, and poor working conditions. Meanwhile, gathering plastic bottles for recycling is often done by informal laborers, even children, in unsanitary and unsafe conditions.
“While not the focus of this study, the advent of fast fashion and our economy’s focus on growth leads to over production and consumption of textile products, which then cause major environmental and social issues,” MacAdam-Somer said. “If we want to seriously reduce these impacts, we have to consider our relationship to consumption and make sure we design textile products that can be easily reused, repaired, and recycled.”
