HTF costs $1.00 per gallon. If you blend a gallon of HTF (that’s a cost of 1 dollar) with free plastic to make 2 gallons of fuel, that gives them a feedstock cost of 50 cents per gallon. That sounds pretty reasonable. The ratio of HTF vs. plastic may not be exact but I think I’m close. I’m not a mathematician but I think I’m correct. Please correct me if I’m wrong.
It would appear the the 'ideal' feedstock is a combination of clean plastic and heating fluid. Crayola may have a large quantity of the former, but they'd still have to pay for the latter.