Abstract: Preferred and modified forms of a method and apparatus for converting waste into useful energy in which solid waste materials are fed through a single or parallel feed lines under constant pressure to a gasifier, at least partially combusted under pressure in the gasifier while constantly removing the ash from the gasifier, advancing the gases through a combuster stage for complete combustion, followed by delivering the combusted gases under pressure to a gas turbine and the like in order to generate power or perform other useful work.