Fluidized-bed gasification method and facility therefor

A fluidized-bed gasification method comprising:

• arranging a fluidized-bed combustion furnace where char is burned to heat a bed material;
• separating hot fluid from said fluidized-bed combustion furnace by a separator into the bed material and an exhaust gas;
• introducing the separated bed material through a downcomer into a dispersion section having a length extending substantially along a width of a bed-material-introduction-side wall of a fluidized-bed gasification furnace;
• blowing a fluidizing gas via a plurality of fluidizing-gas introduction pipes arranged along the length of the dispersion section into the dispersion section to fluidize the bed material;
• supplying the bed material in the dispersion section into the fluidized-bed gasification furnace substantially evenly throughout the width of a bed-material-introduction side;
• introducing a raw material into said fluidized-bed gasification furnace where the raw material is gasified in a fluidized bed fed with a gasification agent and a resultant produced gas is taken out;
• and
• circulating char produced upon the gasification of the raw material and the bed material to said fluidized-bed combustion furnace to burn the char.

A fluidized-bed gasification method comprising:

• arranging a fluidized-bed combustion furnace where char is burned to heat a bed material;
• separating hot fluid from said fluidized-bed combustion furnace by a separator into the bed material and an exhaust gas;
• introducing the separated bed material through a downcomer into a dispersion section extending substantially along a width of a bed-material-introduction-side wall of a fluidized-bed gasification furnace;
• blowing a fluidizing gas into the dispersion section to fluidize the bed material;
• supplying the bed material in the dispersion section into the fluidized-bed gasification furnace substantially evenly throughout the width on a bed-material-introduction side;
• introducing a raw material into said fluidized-bed gasification furnace where the raw material is gasified in a fluidized bed fed with a gasification agent and a resultant produced gas is taken out;
• and
• circulating char produced upon the gasification of the raw material and the bed material to said fluidized-bed combustion furnace to burn the char,
• wherein the downcomer comprises an intermediate portion which accumulates the bed material for formation of a sealing zone for pressure and an outlet portion leading from the intermediate portion to the dispersion section to supply the bed material overflowed from the intermediate portion to the dispersion section, the sealing zone being configured to prevent burnt gas from flowing back from the dispersion section to over the downcomer.