Sludge thermal drying and cogeneration
The need to seek how to finally dispose of the bio-solids generated in the sewage treatment plants has led to a process of thermal drying consisting of heat application for evaporation of a major part of the interstitial water content of these bio-solids from sewage plants.
Through this process, by reducing the volume, a better final disposal of sludge generated is obtained, moreover, in many cases, it may be used as fertilizer to improve ground quality and as fuel in certain industrial processes.
Cogeneration in a municipal sewage plant produces mechanical and thermal power from the digestion gas that may, in turn, be used as fuel for internal combustion engines or gas turbines. Thus, the cogeneration process fulfils two basic objectives: one economic and another environmental.
This process produces electric power, reducing the operating costs and producing heat, which allows to obtain, through thermal drying, a dry granulated biosolid, with a very reduced volume, highly hygienic and with a potential subsequent use.
Among its references, Cadagua counts with the largest Sludge Thermal Drying Plant in Europe (South, Madrid 300,000 tn/year) as a DBOO contract; a total of nine contracts and three of which are in Poland.