Drying Sludge

drying sludge Drying Sludge


Cost savings. Resource recovery.

Energy efficient sludge drying technologies from Stronga are capable of drying dewatered sludges.

Such drying decreases the weight and volume of sludge, significantly reducing your disposal costs. Dried sludge provides a high calorific alternative fuel with carbon neutral properties for use in cement production facilities, CHP via fluidised bed combustion, or pyrolysis.

Stronga sludge drying solutions use residual waste heat (e.g. from electricity generation) throughout the year. Drying sewage sludge is a sustainable and cost-effective way of recycling sewage sludge into substitute fuel or fertiliser.

stronga slug drying solution Drying Sludge

Waste to valuable output

Stronga is a leading global supplier of waste to value systems. Sewage sludge as a final product of wastewater treatment is upgraded to a valuable substance (dried granulate) by drying.

This dried sludge granulate contains the following properties:


Dry substance content >90% DS correct icon 3 Drying Sludge

Ultra-low sludge dust content correct icon 3 Drying Sludge

Excellent handling properties correct icon 3 Drying Sludge

Biologically stable (hygienised) correct icon 3 Drying Sludge


Consequently, both the material and energy contained in the dried granulate can be used in various, highly valuable ways. Read on to find out more.

waste to valulable stronga Drying Sludge

Journey from waste to value

Thermal drying systems for drying sewage sludge represent a real challenge given the high moisture content.

Sewage sludge is dewatered, dried, and subsequently sieved. It can ultimately be sold as a high grade bio-granulate which is suitable as an alternative fuel or nutrient-rich fertiliser. The journey from sludge being a waste by-product to one that can produce both useful material and energy provides the following features:


Reduced weight of sludge to be disposed of correct icon 3 Drying Sludge

Natural nutrient reserves correct icon 3 Drying Sludge

Renewable alternative fuel generation* correct icon 3 Drying Sludge
* Calorific fuel comparable to lignite

Substitute fuel with carbon neutral properties correct icon 3 Drying Sludge


Dried granulate can either be sold as a valuable resource to coal-fired power plants, waste incineration plants and cement factories, or be used on farm as a nutrient-rich fertiliser.

stronga thermal drying systems Drying Sludge

Sustainable solutions. Intelligent equipment.

The most sustainable method…

Drying sludge using exhaust waste heat from processes like power generation from sewage gas or other green gas sources optimises thermal heat recovery and reduces CO₂ emissions. Dry granulate produced by Stronga drying technologies can be used both as fuel and soil improver.

Using the most intelligent drying equipment…

Drying sewage sludge using leading technology from Stronga ensures maximum energy efficiency, full automation, flexible use of exhaust heat, and the lowest operating costs. Stronga sludge dryers can be easily integrated into existing installations and process plants.

stronga drying equipments Drying Sludge

Utilising waste heat

There are many sources of residual heat that are currently being wasted such as:

Green gas engine thermal output from landfill sites & AD plants correct icon 3 Drying Sludge

Process air from cooling ORC units correct icon 3 Drying Sludge

Other industrials processes such as cement works correct icon 3 Drying Sludge

Steam turbine cooling correct icon 3 Drying Sludge


Stronga FlowDrya enables a thermal and material link between sewage sludge plants and residual heat sources, enabling effective energy conservation. Thermal energy for drying sewage sludge comes entirely from waste heat. The dry granulate produced serves as carbon neutral auxiliary fuel. The sludge ash is used as an additive in cement production, reducing the amount of minerals used.

  • 100% of the sewage sludge heating value and ash are used.
  • Operating costs are significantly reduced by substituting primary energy and minerals.
  • Substitute carbon-neutral fuel is produced.

stronga flowdrya waste heat Drying Sludge