Sewage sludge

Sewage sludge is the solid product of the wastewater treatment in terms of sewage sludge plants. It contains concentrates of all useful substances and pollutants significantly in an organically bound form. 

Due to new legal regulations in Germany, phosphor bounded in german sewage sludge needs to be recovered from the sewage sludge which contains phosphorus on a large scale. Moreover, phosphor does have a central impact on energy metabolism as well as the genetic material of all higher organisms. Without the constant provision of the essential component phosphorus by the nutrition cycle, the survival of humans, flora and fauna would not be possible. 

Thermal utilisation of sewage sludge gains more and more awareness and meaning since the incineration ashes contain phosphorus in a concentrated form.

With WEHRLE's fluidised-bed combustion technology sewage sludge of a mono incineration can be used energetically. This offers the possibility to ease the use of valuable raw materials like phosphorus from the incineration ashes.  By raising the phosphorus concentration in terms of the ashes, the recovery of phosphorus can be facilitated. 

Sewage sludge can be used as a direct combustilbe without further measures when reaching a dry residue of > 40% and a calorific value of >4,5 MJ/kg. 

WEHRLE's plant engineering has proven its reliability at various reference plants throughout the years. 

Our portfolio offers a wide range of complete sewage sludge mono-incineration plants from mechanically drained sewage sludge to chimneys. The sizes 1 MWth for decentralised versions up to 10 MWth can be delivered as standardised plants. Plants on a larger scale are customer-specifically designed and realised with WEHRLE partners.  

Decentralised plants from approx. 100.000 EW are available in combination with customer-specifically chosen dryers and downstramed electricity generation (steam turbine, ORC-plant).

Advantages of sewage sludge incineration plants:

  • phosphor-recycling by incineration, compliance of the new sewage sludge regulation
  • plant sizes from 1 MWth (approx. 1600 tTS, approx. 100.000 EW)
  • specifically low disposal costs
  • approval procedures according to 4. BImSchV standards for a fuel quantity of < 3 to/h 
  • low  NOx-emissions due to controlled firing temperature 
  • compliance of the emission values and the prescribed dwell times according to 17.BImSchV regulations
  • elimination or worm eggs, germs, hormones and drug residues
  • separation of heavy metals and other harmful substances from the recyclable ashes

our competences: plant engineering for thermal treatment of sewage sludge

  • mono-incineration of sewage sludge via a stationary atmospherical fluidised-bed combustion
  •  optional use of additional fuels
  • production of energy and heat in the form of process steam generation 
  • enrichment of phosphorus in terms of the ashes, meaning eased phosphorus recycling with further procedures

Contact us! We are happy to analyse your specific requirements with you and well-advice you accordingly!