NOVELTY - A method of pyrolysis (thermal decomposition) of solid bulk organic waste, especially sewage sludge and sludge from biogas station in a reactor (1), where the solid bulk organic waste is fed to the reaction space (320) of the reactor (1), around which a heated hollow casing (32) of the reaction space (320) is arranged, which forms the duct (3) of the heat transfer medium, separated from the inner space of the reactor (1), and during passage of the solid bulk organic waste through this reaction space (320) its pyrolysis takes place.    USE - The method and reactor are for use in pyrolysis (claimed).    ADVANTAGE - The method and reactor provide economical and cost efficient way of treating waste including solid bulk organic waste, especially sewage sludge from municipal sewerage plants, and sludge from biogas plants.    DETAILED DESCRIPTION - A method of pyrolysis (thermal decomposition) of solid bulk organic waste, especially sewage sludge and sludge from biogas station in a reactor (1), where the solid bulk organic waste is fed to the reaction space (320) of the reactor (1), around which a heated hollow casing (32) of the reaction space (320) is arranged, which forms the duct (3) of the heat transfer medium, separated from the inner space of the reactor (1), and during passage of the solid bulk organic waste through this reaction space (320) its pyrolysis takes place, where the movement of the subsequently supplied solid bulk organic waste is in this reaction space (320) decelerated by a counter flow of steam and gas products formed by the pyrolysis of the previous solid bulk organic waste. An INDEPENDENT CLAIM is included for a reactor (1) for pyrolysis of solid bulk organic waste, especially sewage sludge and sludge from biogas plant, where in its inner space a reaction space is created (320), around which is arranged a heated hollow casing (32) of the reaction space (320), which is connected with the inlet (30) of the heat transfer medium to the reactor (1) and with the outlet (34) of the heat transfer medium from the reactor (1), and which is separated from the inner space of the reactor (1).    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a reactor for performing pyrolysis.    Reactor (1)    Duct (3)    Feeder (6)    Inlet (30, 34)    Hollow casing (32)    Upper chamber (33)