"Let me guess, the cost of sorting the plastic?"
Post# of 43064
That would be the right answer. For whatever reason, PTOI investors can't believe it would cost $800/ton to sort plastics by type out of a waste stream...and they're unwilling to do any basic DD on the subject because that doesn't support the hypothesis they're absolutely sure is correct.
There's a fragmented, but very real market out there for scrap plastics sorted by type. It's available to anyone who wants to recycle plastics. If someone wants a quick $800, they can simply collect 16,000 empty gallon milk jugs and collect that cold, hard cash.
I suppose it's much easier and pleasant to chase the carrot around the calendar for years than it is to think about the value proposition.