The very idea of plastics being "waste" offends me..... It is a huge and valuable resource both for materials and for fuel. It is a hydrocarbon resource that breaks down largely into oils and olefins from which it is made. I've played with waste plastics and waste rubber in the past, doing destructive distillation, (pyrolysis), in which high temps are applied in an oxygen free environment. The resulting products are liquids, and vapors, some of which do not condense at room temps. All of which are flammable. I've actually run internal combustion engines on the (hot) vapors from waste rubber, waste plastic, and waste oil, in a controlled environment where I controlled the air fuel mixture manually.... This of course was very brief, just to demonstrate that it can be done.
The chemistry of all of this stuff is known, and it is possible in a refinery environment with the proper catalysts and other inputs to produce valuable chemicals for manufacturing products...... such as fuels, plastics, etc. Plastics are virtually all marked as to what they are these days, and even lacking the markings, simply heating / burning a tiny bit will give off odors that are a clue to what it is. Why are we creating this huge garbage stream instead of regarding it as a valuable resource?
Excuse my rant, but it does make me angry. Someday in the distant future, humans will be excavating garbage dumps for the resources they contain!
H.W.