Sludge to Resource Process

 In Germany, sludge from municipal wastewater treatment is still partly used as a fertilser in soil. This will change for plants of a size of 100.000 population equivalents (PE) in 2029 and for plants of a size of 50.000 PE in 2032, when sludge has to be incinerated. This is not only the case for Germany. Worldwide, tremendous incineration capacities for sewage sludge are required. 

The StR-process (Sludge to Resources) does not only solve this issue in a very energy efficient way, but also produces valuabel resources: The ash has a phoshorous content of more than 10%, recovering more than 97% of the initial ash. Applying ORC-turbines or gasification additional electric energy can be produced.

The StR-process combines approved technologies: Sludge hydrolysis, digestion, dewatering, low temperature drying, and fluidized bed incineration. The challenge is the right conduction of the orchestra!

T E C H N I C A L  D A T A

  • Size from 10 t/d to 300 t/d dry substance.

  • Perfect dewatered sludge after digestion, disintegration and dewatering at 32% DM.

  • Granulate with 90%DM.

  • Total Volume reduction by more than 90%.

  • Specific electrical energy production of 130 Wh/m waste water.


  • Safe treatment of municipal sludge.

  • Recovery of valuable resources to be used as fertilizer.

  • Energy positive process.