“The technology works on polyolefin waste, the sort of plastic used for grocery bags, toys, and shrink wrap. This sort of plastic accounts for about 23% of plastic waste, according to researchers who describe the process in a paper published in Sustainable Chemistry and Engineering. The new technique uses a process called hydrothermal liquefaction, in which very high temperatures melt pellets of polyolefin and then dissolve them in water…”
Paper: https://pubs.acs.org/doi/10.1021/acssuschemeng.8b03841