Implementation at full scale of demand-driven biogas production from anaerobic digestion of sewage sludge

Abstract

In a net-zero emissions scenario, a secure supply of electricity involves renewable generators that can flexibly increase their production when needed. Currently, electricity generation from biogas in the water industry is most commonly at a steady level, given Anaerobic Digestion (AD) is traditionally operated in steady state. This research demonstrated at different scales that demand-driven biogas production from AD of sewage sludge is feasible. Performance parameters are not negatively affected by a flexible feeding schedule and stability parameters show transitional imbalances that do not threaten the overall process. This paper presents the trial implementation in digesters of volume 3800 m3, which became permanent. Economic and environmental benefits exist; however, in order to unlock the full potential of flexible electricity generation from sewage sludge, synergies between technical, operational and political factors in the water and energy sectors need to be developed. HIGHLIGHTS Full-scale trials confirm the pilot- and demonstration-scale results.; Successful implementation at full scale of dynamic feeding of anaerobic digestion.; Dynamic feeding and flexible electricity generation have financial and carbon benefits.;

Keywords

• demand-driven anaerobic digestion
• energy recovery
• operational performance improvement