This guy lives on an island in Nicaragua and gathers plastic waste on the beach. He puts the plastic into a metal tank that is sealed, and builds a fire under it. The plastic pyrolyzes and the fumes are piped through a few condensers where the liquids are drawn off. Some liquids are like diesel and some are like gasoline. He runs his electric generator engine with the gasoline.
In an industrial setting the heat could be what is left over from a gas turbine exhaust. Or some of the plastic could be used to make the fire.
Other similar
Waste plastic to oil/fuel improved pyrolysis reactor
I watched the 1st one and YouTube showed more videos with similar pyrolysis systems. What is mysterious is we have millions of tons of plastic waste that is polluting the environment yet no one seems to have used this pyrolysis process on an industrial scale to eliminate much of it. The plastic waste stays in the environment until it is pyrolyzed when it turns into fuel and ends up creating CO2 in the atmosphere, but which is worse? Plastic waste or CO2? But the CO2 could be captured and sequestered.