Complementary roles for mechanical and solvent-based recycling in low-carbon, circular polypropylene
Significance Polypropylene is a relatively low-cost polymer with useful material properties, making it one of the most widely produced plastics. Unfortunately, repeated mechanical recycling of polypropylene degrades its properties, performance, and aesthetics, so recycling infrastructure for polypropylene is underdeveloped and it often ends up in landfills. Solvent-assisted recycling processes like dissolution have emerged, offering near virgin-quality recycled polypropylene and the promise of greater circularity. To clarify the sustainability of circular polypropylene, we offer a detailed life-cycle evaluation of mechanical recycling, dissolution-based recycling, and virgin polypropylene production. We find that while dissolution-based recycling offers modest greenhouse gas savings relative to virgin polypropylene, it serves as an important upgrading step to broaden markets served by recycled polypropylene and displace demand for virgin resin.
Nordahl, Sarah L et al. “Complementary roles for mechanical and solvent-based recycling in low-carbon, circular polypropylene.” Proceedings of the National Academy of Sciences of the United States of America 120 (2023): n. pag.