Sludge plants

Sludge types that can be treated:

How a sewage sludge biogas plant works

At the core of the plant is the CSTR reactor, where sewage sludge undergoes anaerobic digestion to produce biogas.

The process includes four stages:

• Thickening: reduces sludge volume by increasing the dry solids content
• Anaerobic digestion (CSTR): degrades organic content in the absence of oxygen, producing biogas and stabilising the sludge
• Dewatering: removes water to achieve a dry solids content of up to 22%, using technologies such as centrifuges, filter presses or belt presses
• Drying: further reduces the moisture content using thermal energy.

Sludge types suitable for anaerobic digestion include:

• Primary sludge: generated during primary sedimentation and characterised by a high biogas yield (300–400 Nm³/tODS)
• Secondary sludge: generated by aerobic treatment processes and characterised by a lower methane potential (200–300 Nm³/tODS), while remaining suitable for co-digestion.

Environmental benefits of a sewage sludge biogas plant

Integrating an anaerobic digester into a sludge treatment system makes enables to:

• Generate renewable energy for on-site use or sale
• Reduce dependence on fossil fuels and the associated costs
• Cut sludge disposal costs
• Improve sludge stabilisation and reduce odour emissions
• Reduce the bacterial load and the final sludge volume

A sewage sludge biogas plant enables companies to turn waste into a resource while reducing operating costs.

Economic benefits of a sewage sludge biogas plant

An anaerobic digestion plant can be readily integrated with existing wastewater treatment facilities and does not require major structural works.

We provide modular, scalable solutions designed to:

• Reduce wastewater treatment plant operating costs
• Optimise the management of primary and secondary sludge
• Maximise renewable energy production
• Simplify long-term sludge management