NOVELTY - A carbonaceous material is processed in a reactor by contacting the material with an inorganic particulate material in a riser section, at an elevated temperature and in the absence of oxygen. This produces a dense suspension containing 7x10E8 - 3x10E11 particles/m3. The mass ratio between the particulate matter bringing heat into the reactor and the carbonaceous material is 1:1-10:1.    USE - For processing carbonaceous material, e.g. saw dust, plant residues from forestry or agricultural processes, municipal solid waste or refuse derived fuel, in a reactor.    ADVANTAGE - The inventive method provides high pyrolysis liquid yield with enhanced product quality based on very low concentrations of solid contaminants in the liquid fuel. It eliminates the problems of pyrolysis systems in the prior art, thus achieving benefits not previously obtained by pyrolysis of carbonaceous feedstock. It also reduces the heat demand to the pyrolysis reactor.    DETAILED DESCRIPTION - Processing of carbonaceous material in a reactor involves feeding the material into a riser section (10) of the reactor, where it is contacted with inorganic particulate material and reactor walls at an elevated temperature in the absence of oxygen, thus converting the material into gaseous processed products. The products contain fluidization gas and processed products. The method also involves separating the material from the gas phase in a separation unit (12, 16), recirculating the inorganic particulate into the riser space, recovering the processed products, and condensing part of the processed products into liquid products. A dense suspension is formed into the riser space of the reactor. It contains 7x10E8 - 3x10E11 particles/m3. The mass ratio of between the particulate matter bringing heat into the reactor and the carbonaceous material is 1:1-10:1.    DESCRIPTION OF DRAWING(S) - The figure shows a process diagram of the above method.    Riser section (10)    Separation unit (12, 16)    Bed material (15)    Material fed (18)    Boiler unit (20)    Fluidized reactor (33)