Patent Number: 055368964
Section: description

The depicted apparatus comprises the following units and works in the following fashion. Solid waste is fed to a first pyrolysis reactor 1 of the gravity type via a feed 2. After pyrolysis of the solid waste in said reactor 1, the solid pyrolysis residue (ash) is drawn off via a screw 3 to a container 4, which optionally contains a compressing device for said residue. The gas formed during pyrolysis in reactor 1 is afterwards conducted via a ceramic filter 5 and a conduit 6 to a second pyrolysis reactor 7, where it is subjected to pyrolysis under the earlier stated conditions. In the depicted embodiment of the apparatus of the invention, a condenser 8 is additionally present, which is connected up as necessary if the gas contains tar products which need to be condensed out before pyrolysis reactor 7. In such a case, these tar products are drawn off from the condenser 8 via a withdrawal conduit 9. The gas pyrolysed in reactor 7 is conducted via conduit 10 to a reductant bed of carbon 11 where sulphur oxides present are reduced to hydrogen sulphide and carbon disulphide. The reduced gas from bed 11 is then transferred via conduit 12 to a bed 13 of sulphur-forming metal, e.g. iron. The metal sulphide formed can then be drawn off via conduit 14 from the bottom of said bed 13. If iron is used as a metal in the bed, this means that the withdrawn metal sulphide principally comprises pyrite. The depicted embodiment of the apparatus of the invention additionally comprises a burner 15 for the final oxidation or combustion of the exhaust gases and a pump 16, which in this embodiment is placed between bed 13 and burner 15 and which is intended to provide negative pressure in the apparatus.