NOVELTY - The feedstock (1) is heated at 100-150degreesC, removing its stoichiometrically-defined water content, which is used subsequently in gasification and cracking processes. In a second zone, the solids are heated to 500degreesC, producing pyrolysis gas. The residue, largely a soft coke, is transferred down to a further, indirectly-heated zone at 800degreesC, where it is endothermically gasified with steam. The product gas is extracted co-currently with the solids. In a fourth, lower reaction zone this gas is heated to more than 1000degreesC. Condensable hydrocarbons (CmHn) are converted in the presence of water vapor, by cracking processes, largely to non-condensibles (CO and H2). In a fifth zone, near-stoichiometric additions of oxygen ash the carbonaceous residues.    USE - Plant for energy recovery from e.g. biomass, supplying e.g. fuel cells or gas engines. Wastes treated include insulation, carpets, rubber, tires, light shredded materials, organic sludges, screened residues, meat refuse, scrap- and weak timber, high calorific value domestic waste, similar trade wastes, and DSD (a German collection system) wastes (all claimed)    ADVANTAGE - The process assures a high quality of product gas. Especially when ceramic radiant tubes are employed for indirect heating. Separation and definition of the reaction zones, enables optimization in each. There is no requirement for a separate boiler to produce steam, with costly water treatments. Instead water vapor evolved is recycled, and similarly all heat required is recycled in the process. A key novel feature, is water content adjustment in the feedstock, to assure maximum possible process efficiency. Destruction of all condensibles, facilitates energy from the product gases in heat engines or fuel cells.    DETAILED DESCRIPTION - The cascade reactor employed, is a staged- or grid reactor. The fifth zone is in a subsequent unit; it takes account of the melting behavior of inorganic substances (slagging is recognized). Indirect heating employs steel tubes fired with the recycled process gas as fuel. In addition, some direct heating takes place, by supplying hot process gas directly into the reactor. A heating jacket is used for indirect heating. Processes at up to 500degreesC are limited to one reactor, cracking and higher temperature process take place in others, outside the cascade reactor. Air or oxygen is supplied. Further details of operation in accordance with the foregoing principles are provided.    DESCRIPTION OF DRAWING(S) - A schematic diagram of a cascade reactor is presented.(Drawing includes non-English language text)    feedstock (1)    feed screw (gas lock) (2)    clearing arms (3)    motor drive (5) axis (4)