An apparatus for treating solid waste material comprising a first cylinder 10 rotatable about a first axis with waste inlet, treated waste outlet and steam inlets for introducing steam into the first cylinder, a heated jacket 18 surrounding the first cylinder, and a second cylinder 22 which is extends from and is rotatable about the first axis and comprises an inlet for receiving waste from the first cylinder outlet and an outlet. The second cylinder surrounds the first cylinder so that the cylinders are concentric with waste travelling in one direction in the first cylinder or drum and travelling in the other direction through the second cylinder. Both cylinders contain Archimedes or conveying screws 16, 30. The method comprises subjecting the waste to steam at 150°C — 200° in the apparatus with separation of the resultant material into constituent parts. Biomass and/or plastics are subjected to further treatment. The further treatment preferably produces bioethanol from the biomass and diesel from the plastics. Alternatively, biomass may be gasified to produce hydrogen.
