Method of converting carbonaceous material into synthesis gas with a low tar content

摘要

In a continuous multi-stage vertical process for converting solid carbonaceous material to low tar synthesis gas, the carbonaceous material is passed down a pyrolysis zone where the carbonaceous fuel is pyrolyzed to pyrolysis vapours (26) leading to a partial oxidation zone separated from the pyrolysis zone by a separating member (32). The separating member (32) also directs the pyrolysis residue (24) from the pyrolysis zone to the reduction zone, where a pyrolysis residue bed (28) with a uniform depth (d) and uniform width (d) is formed on the inclined perforated bottom (42) with a declination (θ) with a uniform depth (d) and uniform width (h) of the crude pyrolysis residue. The angle of inclination of the perforated bottom (42) is within ± 30° of the natural angle of inclination of the pyrolysis residue. The perforated bottom (42) is at a distance (D) from the separating member (32). A deflector (48) is located in the middle of the reduction zone. As the synthesis gas passes through the pyrolysis residue bed (28), an endothermic reaction takes place and the pressure drop of the reduction zone, the residence time and the space velocity of the synthesis gas flow are regulated. A substantially tar-free synthesis gas (49) is formed, which is passed in a counter current flow upwards to indirectly heat the pyrolysis zone. The decarbonized pyrolysis residue (52) is discharged from the lower bed (54) through the outlet port (56). The solution also includes a device for carrying out this method.