Abstract: Municipal solid waste is classified as to density as well as size in a perforated inclined trommel through which a gas stream is flowed inwardly through the perforations and downwardly to entrain and remove paper and plastics through the lower end. Ferrous and non-ferrous metals are removed from the residue which is digested anaerobically in two stages with an intermediate steam explosion treatment to expose cellulose fibers coated with lignin. Mercury may be removed as a vapor phase in an initial stage of the steam heating and condensed and collected. An aqueous phase of the anaerobic digestate may be treated to remove heavy metals and may be discarded or reused to slurry solid phase incoming to a digester. The solids phase of the anaerobic digestate may be acidified to solubilize heavy metals which are recovered by electrodeposition from the solution. The depleted residue can be neutralized and disposed of.

Abstract: Municipal solid waste is classified as to density as well as size in a perforated inclined trommel through which a gas stream is flowed inwardly through the perforations and downwardly to entrain aid remove paper and plastics through the lower end. Ferrous and non-ferrous metals are removed from the residue which is digested anaerobically in two stages with an intermediate steam explosion treatment to expose cellulose fibers coated with lignin. Mercury may be removed as a vapor phase in an initial stage of the steam heating and condensed and collected. An aqueous phase of the anaerobic digestate may be treated to remove heavy metals and may be discarded or reused to slurry solid phase incoming to a digester. The solids phase of the anaerobic digestate may be acidified to solubilize heavy metals which are recovered by electrodeposition from the solution. The depleted residue can be neutralized and disposed of.

Abstract: Municipal solid waste is classified as to density as well as size in a perforated inclined trommel through which a gas stream is flowed inwardly through the perforations and downwardly to entrain and remove paper and plastics through the lower end. Ferrous and non-ferrous metals are removed from the residue which is digested anaerobically in two stages with an intermediate steam explosion treatment to expose cellulose fibers coated with lignin. Mercury is removed as a vapor phase in an initial stage of the steam heating and is condensed and collected. The solids phase of the anaerobic digestate is acidified to solubilize heavy metals which are recovered by electrodeposition from the solution. The depleted residue is neutralized and disposed of.

Abstract: Garbage and other incinerable waste is treated with hot air and steam in a rotary furnace, under conditions inhibiting free and complete combustion, so as to produce a gaseous phase and a solid phase consisting of non-combustible solids. The gaseous phase is mixed with excess air and recirculated combustion gases and passed to a cyclone chamber in which further combustion takes place at a temperature controlled so as to destroy toxic organic compounds and to melt solids such as glass but insufficient to promote excessive nitrogen oxide formation. The gases are then passed through a ceramic heat exchanger, tempered with ambient air to cause any residual molten glass still entrained in the gases to solidify, and passed through a second heat exchanger, clean compressed air being passed through the second and then the first heat exchanger so as to raise its temperature sufficiently to drive a gas turbine.