A continuous converter for pyrolyzing or otherwise processing biomass or other solid organic feed materials includes a reaction chamber (5) for producing a solid carbon-containing product and a gas product and optionally a liquid water product via pyrolysis or other reaction mechanisms from a solid organic feed material. The chamber has an inlet (41) for supplying a solid organic feed material to the chamber and separate outlets (15, 35) for the solid carbon-containing product and the gas product produced in the reaction chamber. The inlet and the solid carbon-containing product outlet are configured so that the solid materials in the inlet and in the outlet form respective gas seals in the inlet and the outlet.