A new commercially viable recycling process for polyethylene and polypropylene?

I was pleased to read that researchers at the University of California, Berkley, have recently developed a new process for breaking down polyethylene (PE) and polypropylene (PP) waste into its individual monomers.¹

While there are currently large scale efforts to reduce the production of single-use plastics, and bioplastics have recently been forecast to grow with a CAGR of 18.4% during 2024-2031,² large volumes of PE and PP waste still end up in landfills, incinerators, or in aquatic environments every year. It it is therefore great to see the development of new methods for breaking down these existing plastics and provide some circularity to the plastics economy. 

The newly developed process relies on the catalytic breakdown of the polymers using tungsten oxide and sodium. This is particularly exciting as these catalysts are relatively cheap and abundant compared to commonly used heavy metal catalysts such as ruthenium.  The process also does not require dehydrogenation of the starting polymers. It therefore appears that it has potential to be industrially scalable.

The route has also shown to work on a mixed feed of PE and PP, however, the presence of other polymers, such as PET and PVC, significantly reduced the efficiency. As a result, there will still be a need to comprehensively separate plastics ahead of the process. Fortunately, this area is quite well developed.

The research was recently published in Science³ and we look forward to seeing how it develops over the next few years.

References:

1. https://packagingeurope.com/news/researchers-break-down-and-rebuild-pet-and-pp-packs-in-new-chemical-process/11867.article
2. https://www.openpr.com/news/3656566/bioplastics-market-size-share-growth-and-trends-forecast
3. https://www.science.org/doi/10.1126/science.adq7316