Plastics recycling by pyrolysis for polyethylene and polypropylene. C&EN has detailed article indicating the plastics and chemical industry seem to be adopting this technology. Exxon-Mobil in Baytown, TX has a plant due soon that can feed by-products into the refinery there for processing.
“Nearly every large chemical company—Dow, BASF, Shell, ExxonMobil, LyondellBasell Industries, Sabic, Ineos, Braskem, and TotalEnergies, to name some—either has joined hands with a smaller firm developing a process or is creating its own.”
“These firms argue that pyrolysis can make up for the shortcomings of mechanical recycling, the familiar process of washing and repelletizing the plastics that consumers drop into blue bins. Only two polymers—the polyethylene terephthalate (PET) found in soda and water bottles and the high-density polyethylene in milk [bottles] and other such containers—are widely recycled at an appreciable scale. And it is difficult to get even these relatively homogeneous materials up to the contamination specifications needed for food-contact use. In all, mechanical recycling manages to capture only about 9% of plastics in the US, according to the US Environmental Protection Agency.”