Life cycle assessment of polycarbonate production: Proposed optimization toward sustainability

• A life cycle assessment of two polycarbonate production processes was conducted. • Bisphenol A production and coal mining and burning were identified as key factors. • The leading-level polycarbonate green factories can reduce carbon emissions by 10%. • Mechanically recycled polycarbonate could yield environmental benefits of over 82%. • Green mines and bio-based plastics were suggested to optimize the environment. The global plastics industry urgently requires a shift to sustainable manufacturing, but only a mere fraction of these plastics have been explored for their life cycle environmental impacts. Polycarbonate (PC), the top consumer of engineering plastics, lacks due attention. This study quantified the industrial-level environmental impacts of two mainstream PC production processes in China, the world's largest PC producer, via an integrated and regionalized life cycle impact assessment model. The fossil depletion category contributed dominant environmental impacts, accounting for approximately 60% in both scenarios. Bisphenol A production and coal mining and combustion were identified as crucial processes, specifying optimal directions toward sustainability. The PC green factories showed eco-effectiveness, with roughly 10% reductions in both non-carcinogens and global warming categories at the leading level. The mechanically recycled PC production could yield 82.3%–99.6% benefits in key categories. Moreover, green mines, ultra-low emission, bio-based plastics, and extended producer responsibility are highly recommended.