| abstract |
The invention relates to a method and a device for drying and gasifying sludge, in particular excess sludge from biological treatment processes, which takes place in a converter (1) and without the sewage sludge being cooled in the meantime. As a result, the converter (1) according to the invention is very compact, the output is very high and, moreover, the converter (1) can be operated almost autonomously in terms of energy. The method provides for the thermal drying of the sludge with superheated steam, the heating of the sludge by microwave or high-frequency radiation and the gasification of the sludge in the absence of oxygen in a first gasification step and in a water vapor atmosphere in a second gasification step. |