Comprehensive environmental performance of bottle-to-bottle recycling of PET bottles based on deposit-refund system in China

Polyethylene terephthalate (PET) is a widely used packaging material and has high value in recycling. However, under China's dominant informal recycling system, most PET bottles are downcycled into fibers. The deposit-refund system (DRS) is considered a feasible mechanism to facilitate the high-value recycling of PET bottles. To comparatively evaluate the environmental performance [reduction of greenhouse gas (GHG) and pollutant emissions] under different scenarios using life cycle assessments, including the current system based on informal recycling, an improved system with a larger contribution from the source separation of municipal solid waste, and evolving systems with DRS application, five scenarios were set up. The DRS can reduce GHG emissions and the comprehensive environmental impact by 0.538 kg CO2 /kg PET bottles and 1.73 × 10-3 PE/kg PET bottles, respectively, compared to informal recycling. It can be concluded that the DRS-based recycling approach and the bottle-to-bottle recycling provide the substantial emission reduction potential of GHGs and pollutants.