The rotating cone reactor is a novel reactor type for fast pyrolysis of biomass with negli­gible char formation, in which rapid heating and short residence time of the solids can be realized. Particles fed into the reactor first enter an impeller which is mounted in the base of the heated cone. After leaving the impeller, the particles flow outward over the conical surface and experience a high heat transfer rate due to their small distance from the heated surface. Biomass materials like wood, rice husks, or even olive stones can be pulverized and fed to the rotating cone reactor. Flash heating of the biomass will suppress coke-forming cracking reactions. Since no carrier gas is needed (cost reducing), the pyrolysis products will be formed at high concentrations. If additional thermal quenching of the gas outlet flow is applied, the amount of secondary tar decomposition reactions can be suppressed. In the rotating cone reactor, wood particles fed to the bottom of the rotating cone, together with an excess of inert heat carrier particles, are converted while being transported spirally upward along the cone wall. The cone geometry is specified by a top angle of p/2 radians and a max­imum diameter of 650 mm. Products obtained from the flash pyrolysis of wood dust in a rotating cone reactor are noncondensable gases, bio-oil, and char. The biomass decomposes into 70% condensable gases with 15% noncondensable gases and 15% char.