A method and apparatus for converting a process material such as powdered plastic to usable fossil fuel. A hollow cylinder having a piston slidably mounted therein is externally hea
2.The process of claim 1 wherein the downward transport of the off-gas liquid dispersion generates a static pressure head at least equal to the static pressure head generated by the fermentation liquid at the discharge point. 3.The process of claim 1 wherein the gas separation tank is locate...