Energy pathway for transitioning to a circular economy within wastewater services

Abstract This case study assessed the role of an emerging waste to energy technology in transitioning wastewater services to a circular economy. The technology processed about 1.5 tonnes of dry wastewater sludge to about 1 tonne of hydrochar with additional energy recovered in support of the circular economy energy pathway. A preliminary assessment of potential retrofit into existing wastewater treatment infrastructure processing wastewater sludge for use of hydrochar as source of energy was conducted. The potential benefits of the technology as an accelerator for adopting circular economy within wastewater services are highlighted using the proposed closed-loop concept.