NOVELTY - The device comprises a zone for pyrolyzing solid fuel, a combustion zone including combustion units, a path for the passage of the pyrolysis gas towards the combustion zone, a reduction zone having a passage of contact with the pyrolysis zone for the collection of coke obtained from the pyrolysis of solid fuel, a location for receiving the coke, a passage for contact with the combustion zone for the arrival of the gas, which is obtained from the combustion of the pyrolysis gas, in the reduction zone, and an outlet for the solid residue derived from the pyrolysis of solid fuel.    USE - The device is useful for the transformation of a fuel comprising solid components or solid fuel into a gaseous fuel such as a syngas, which is useful for boiler application, internal combustion engine operation and fuel cell application.    ADVANTAGE - The compact device ensures economical, energy-efficient, simple and reliable transformation of the fuel comprising solid components or solid fuel into the gaseous fuel without the emission of polluting gases such as dioxins into the atmosphere.    DETAILED DESCRIPTION - The device comprises a zone for pyrolyzing solid fuel, a combustion zone including combustion units, a path for the passage of the pyrolysis gas towards the combustion zone, a reduction zone having a passage of contact with the pyrolysis zone for the collection of coke obtained from the pyrolysis of solid fuel, a location for receiving the coke, a passage for contact with the combustion zone for the arrival of the gas, which is obtained from the combustion of the pyrolysis gas, in the reduction zone, an outlet for the solid residue derived from the pyrolysis of solid fuel, a filtration unit for filtering the gas and injecting solid particles such as dust and ashes contained in the gas within the reduction zone, a zone for circulating the gas, which is resulting from the reduction of coke, around the pyrolysis zone for transmitting a portion of its heat to the pyrolysis zone by conduction with an external peripheral wall of the pyrolysis zone, a unit for injecting water vapor in the reduction zone, and a unit for drying the solid fuel contacting with inlet of the pyrolysis zone for drying solid fuel prior to its introduction in the pyrolysis zone. The pyrolyzing zone comprises a pyrolysis unit to decompose the solid fuel into a pyrolysis gas and into a residue of solid pyrolysis such as coke. The combustion zone is surrounded by the pyrolysis zone or is mounted coaxially in the pyrolysis zone. The passage of contact has a downward slope from the pyrolysis zone to the reduction zone for collecting the coke in receiving location by gravity. The pyrolysis zone has an annular shape, and is delimited between an outer peripheral wall and an inner peripheral wall of the device. The reduction zone is located partially in the combustion zone and/or in the pyrolysis zone. The combustion zone and the pyrolysis zone comprise a common partition wall. The combustion unit comprises an inlet for air, and an initiation unit for the reaction between the air and the pyrolysis gas. A portion of the external wall of the device comprises heat insulation unit.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a transformation device.    Pyrolysis zone (2)    Combustion zone (3)    Reaction zone (4)    Circulation zone (5)    External wall. (10)