Interesting, I never knew this.

dd74 posted a link to a guy in Eastern Europe who made a furnace/kiln to do the same thing. He said a metric ton of processed plastic is around $50 and makes about 1000 liters of diesel. Accounting for cost of electricity and plastic, the fuel cost under $0.50/gallon. I think it was around $0.20 gallon.

I was planning to build a kiln later this year. With higher fuel prices, I don't know how much longer I can get waste vegetable oil to make biodiesel. If I can make fuel from vegetable oil or plastic, I will be set for a long time.

The ideal scenario would be using an oil burner, instead of electricity, to heat the kiln. You might use 25 gallons of processed fuel to process 250 gallons of new fuel. The advantage to electricity is control, despite it's high relative cost.

Take a boat like they use to harvest Kelp and a freighter set up for this out to the plastic island in the Pacific, harvest the trash, make oil.

Acetylene is a gas, polyacetylene is a solid (an electrically conducting polymer, by the way)
Ethylene is a gas, polyethylene is the most common plastic.
Butadiene is another gaseous monomer, out of which rubber is made.

Gases are light, but if you hook the molecules together, you can make heavy solids (aka polymers). Then, if you depolymerize, you get oligomers which can be liquid, like oil.