A company called Vadxx in Ohio is taking the "picked-over" scraps of plastic and converting into a low-sulfur crude oil. I don't know how feasible this would be large scale but its nice to see this stuff out of the landfills and being put to use.
This article talks about KiOR's plans to use "non-food biomass" and convert it into gasoline and diesel through biocrude technology. KiOR plans to use both wood chips and crude oil to create gasoline. This procedure, KiOR claims, will reduce "direct lifecycle greenhouse gas emissions by over 80% compared to the petroleum-based fuels they displace."