NOVELTY - Biomass combustion for biomass conversion, comprises locating reactor vessel within an exterior vessel such that combustion of combustible feed material in the exterior vessel causes heating of the feed material in the reactor vessel to above 600degreesC; introducing combustion air into exterior chamber; causing breakdown products to exit the reactor vessel into the exterior vessel for combustion.    USE - For combusting biomass.    ADVANTAGE - The combustion method effectively disposes animal waste material including materials having a moisture content greater than 50% with random batches consisting of 100% water while maintaining the operation of the system and the required temperatures without the necessity for additional fossil fuels.    DETAILED DESCRIPTION - Biomass combustion for biomass conversion, comprises providing a combustible feed material; providing a reactor vessel (11) for initial heating of the feed material; locating the reactor vessel at least partly within an exterior vessel such that combustion of material in the exterior vessel causes heating of the feed material in the reactor vessel; feeding the feed material into the reactor vessel through an air lock feed system; causing the combustion in the exterior vessel to heat the feed material in the reactor vessel to a temperature above 600degreesC so as to cause the feed material in the reactor vessel to break down to breakdown products comprising solid materials including carbon and gaseous materials including water vapor and combustible gases; introducing combustion air into the exterior chamber for mixing with the breakdown products to effect combustion; causing the breakdown products to exit the reactor vessel into the exterior vessel for combustion to form solid combustion products and gaseous combustion products; providing a flue (30) for extraction of the gaseous combustion products from the exterior chamber and generating a flow of the gaseous combustion products from the exterior chamber into the flue; and providing an extraction system for the solid combustion products from a bottom of the exterior vessel.    DESCRIPTION OF DRAWING(S) - The figure is a schematic illustration of the whole system including the energy extraction systems.    Reactor vessel (11)    Flue (30)    Heat exchanger (31)    Exit system (32)    Draft fan (37)