Science and the circular economy close the gaps

While biogas energy from organic waste often suffers in terms of quantity and purity, the Frauenhofer Institute has now succeeded in processing sewage sludge into biogenic crude oil and ultimately petrol, diesel and paraffin.

The disposal guidelines and the comparatively simple pre-treatment make it possible to provide a relatively pure starting product for which there were previously few ideal solutions. The agricultural use of sewage sludge has been increasingly restricted for health reasons - a complete phase-out is already being planned. Sewage sludge was increasingly contaminated with medicines, heavy metals and other hazardous substances. Pure landfilling was already abolished in 2015. The euphonious humification of sewage sludge only served to dewater it for the most common procedure - thermal disposal in mono- and co-incineration plants.

In the current EU research project, 50,000 litres of oil could be converted from 500 tonnes of sewage sludge, from which 40,000 litres of fuel could be obtained. The new fuel could be processed in conventional refineries - the vehicles did not require any conversion measures or restrictions and even mixing with conventional fuels did not result in any losses.

The industry of sewage sludge extraction and removal, which is ailing due to modern construction, is thus facing a new significance and challenge.