Patent ID: 8747501

Claim:
A fuel gasification system comprising: a gasification furnace which has a fluidized bed formed by fluidizing reactant gas to gasify charged fuel into gasification gas and flammable solid content; a combustion furnace into which the flammable solid content generated in the gasification furnace is introduced together with bed material and which has a fluidized bed formed by fluidizing reactant gas to burn the flammable solid content; a material separator for separating bed material from the exhaust gas introduced from the combustion furnace to feed the separated bed material to said gasification furnace; and tar decomposing means for heating the gasification gas produced in the gasification furnace to decompose tar contained in the gasification gas, wherein the tar decomposing means is constituted by a heat exchanger comprising a gasification gas passage formed on an outer surface of a downcomer for guiding bed material separated in a material separator to the gasification furnace, the gasification gas being introduced into the gasification gas passage and heated by heat of the downcomer, and wherein, on an outer surface of the heat exchanger comprising the gasification gas passage, an exhaust gas passage is formed into which introduced is the exhaust gas from the combustion furnace and elevated in temperature by additional heating means.