Thermal energy recovery from municipal wastewater treatment by an innovative hybrid energy recovering system

Civil buildings air conditioning systems comprise a massive source of energy consumption and greenhouse gas emissions. The experimental study we present is a full-scale demonstration of a "nearly zero energy facility" provided with a water-based air conditioning system and domestic hot water production unit, both supplied with thermal energy produced by a water sourced solar heat pump, whose hot and cold sources are partially fed by the leftover thermal bio-energy available in an innovative wastewater treatment system, whereas energy excess produced by solar heat pump is stored in phase change material units. Preliminary results showed that the innovative system, thanks to its particular features, allows wastewater heat extraction within the treatment process, and demonstrated its ability to exchange energy and, at the same time, to operate a thermal regulation of the treatment reactors, integrating the optimization of thermo-dependent biological processes with energy recovery systems.