Bags into Gas

This sounds like a toxic mess and it doesn't say how much energy must be expended to get a liter of gasoline back out of the plastic bags, but at least it is moving toward closing the loop:

Gasoline from old plastic bags
Russia

A litre of gasoline can be obtained from a kilogram of old plastic sachets by appying a technology being developed by the specialists of the D.I. Mendeleev Russian Chemical-Engineering University. This is one of unique examples how the scientists can use a material initially made of petroleum to get if not oil per se again but the product of petroleum refining - engine fuel...