High utilization of the waste streams illustrated above
and proper sizing of the power plant can lead to total
system efficiencies that exceed 90%.
Biogas (a by-product of anaerobic digestion) is
delivered to the generator set as fuel.
The generator creates electricity for the plant’s onsite
needs or for export to the local grid.
Engine heat can be recovered via the engine’s
cooling circuit or exhaust gas and converted to
hot water or steam for the digester. This heat can
keep the digester at its optimal temperature for
increased biogas production.
Recovered generator heat can also be used to dry
the remaining digester solid for plant fertilizer, which
can be sold for additional revenue for the WWTP
To understand the power generation opportunities at a wastewater treatment plant, it is important to have a basic
understanding of its operations. This paper serves to give an overview of modern wastewater processing and discuss the benefits and opportunities of using a sparkignited engine generator to produce on-site heat and power.