Although it may come as a surprise to many, wastewater can be a source of renewable energy. Indeed, as described elsewhere in this document, anaerobic treatment of wastewater converts the organic pollution into methane (CH4) gas, the main component of biogas.

The biogas produced during anaerobic treatment (BIOTIM®, LUCAS® anaerobic-aerobic) is collected and, if necessary, cleaned (BELGAS®). It can be stored for later use or imme diately transferred to the energy valorisation unit. This can be a gas engine, a steam boiler, ...

The energy of the biogas thus is converted into useful energy in the form of electricity, heat or a combination of both (cogeneration). The biogas typically has a heating value of 20 to 25 MJ/Nm³. Per kg of incoming COD an electricity production of approx. 1 kWh can be expected.