Researchers at UC Berkeley have developed a new catalytic process that can vaporize the polyethylene (single-use bags) and polypropylene (hard plastics) that dominate trash piles, converting them...
Plastics are only plastics when many separate (often gaseous) molecules called monomers form large chains or webs called polymers. If you vaporize a polymer, it gets reverted to being many monomers
"Researchers," meaning there's no reason to believe this is actually practical and there is no mention of the energy costs. The latter is especially important because as bad as microplastics are, climate change is just as bad, if not worse.