I came across this a week or so ago,. It seemed a bit hair brained to me,like how much energy was being put into producing the energy returned.
Most of the people doing it where in India subcontinent using wood to produce the fuel or similar it appears, Some had more sophisticated techniques but seemed very expensive for the return.
Anyway have a look at some of these videos.
Maybe it could be a good way to simply rid the land fill of plastic even if it does cost more to produce the fuel, it could create some jobs along the way too.