Abstract

The process disclosed includes treating settled sludge and/or organic debris recovered from a wastewater treatment system and thermally converting the treated material and/or comminuted organic solid wastes separately or in combination into steam, combustible gas, residual tars and oils and other energy by-products which are recycled as heat for increasing the thermodynamic efficiency of the process. In one embodiment of the invention the process includes cleaning the combustible gas which is provided during the thermal conversion, with the clean gas driving a heat engine such as a gas engine or gas turbine generator or the like. In another embodiment of the invention the gas drives the heat engine without the above described benefit of the aforenoted cleaning. In either case, the high temperature exhaust from the described heat engine is fed back for supporting the thermal conversion of the organic materials in a boiler/pyrolyzer, refractory furnace or a separate retort having its own heat chamber, connected directly to the exhaust manifold of the heat engine.