Uncovering Pathways Toward Circular and Low-Carbon Development of PET Plastics for Bottled Water in China by Material Flow and Carbon Footprint Analyses

Polyethylene terephthalate (PET) plastics are widely
used in bottled
water packaging due to their lightweight and sealing properties, and
their additive-free composition significantly facilitates efficient
recycling. However, the life-cycle material metabolism and carbon
footprint of PET plastics for bottled water in China have not yet
been systematically quantified, limiting progress toward sustainable
management. In this study, we model the provincial production, consumption,
and waste management of PET plastics for bottled water, tracking material
flows and carbon footprint from 1997 to 2023. Furthermore, we assess
the circulation efficiency of different end-of-life treatment pathways
in 2023, along with the associated offsets provided by recycled materials.
Our results show that annual production rose from 0.036 to 2.18 million
tons (Mt) between 1997 and 2023, which represents a substantial increase
in quantity. In 2023, the end-of-life recycling rate reached 97%,
with 76% downcycled to chemical fiber and only 5% as the closed-loop
“bottle-to-bottle” cycle. In the same year, the life
cycle greenhouse gas (GHG) emissions were 6.48 Mt CO2-eq.
Under the low-carbon scenario, the life cycle GHG emissions in 2050
remain 59% above the 2024 levels. Therefore, achieving deeper decarbonization
will require coupling with additional technologies (adopting biobased
plastics and chemical recycling of plastic waste) to meet low-carbon
targets. Overall, our findings offer evidence and guidance to advance
circular resource use and coordinated carbon footprint reduction in
PET plastics for bottled water.