Multi-stage facility and method for gasifying a feedstock including organic matter

Facility for producing synthesis gas from a solid feedstock including organic matter, said facility including means for circulating a heat-carrying solid providing at least some of the heat necessary for such production, a zone Z1 including pyrolysis and gasification means, a zone Z2 including separation means, a line for supplying gaseous and solid effluents from zone Z1 to zone Z2, a zone Z3 including gasification means, a zone Z4 including separation means, and a zone Z5 including combustion means, characterized in that zone Z1 has means for pyrolysis and gasification of said feedstock in a transported fluidized bed of the heat-carrying solid, in that zone Z2 has means for at least partial separation of the effluents from zone Z1 into an essentially gaseous phase and into an essentially solid phase comprising solid residue and heat-carrying solid, in that zone Z3 is supplied at least in part with said essentially solid phase and includes a dense fluidized bed of the heat-carrying solid for gasification of the solid residue of said essentially solid phase, in that zone Z4 includes means for separating the effluents coming from zone Z3 into a synthesis gas and an entrained solid phase, and in that zone Z5 includes means for combusting a solid phase comprising solid residue not converted into synthesis gas and spent heat-carrying solid coming from zone Z3 through a line directly connecting said zone Z3 to said zone Z5, and means for transferring the heat-carrying solid coming from zone Z5 into zone Z1.