Model-Based Evaluation of Hydrothermal Treatment for the Energy Efficient Dewatering and Drying of Sewage Sludge

This research paper evaluates hydrothermal carbonization (HTC) as a possible treatment for sewage sludge, including phosphorus recycling. German governmental requirements force high number of wastewater plants (WWTP) to recover from sludge above limits 20 g kgTS?1 before further disposal (e.g., co-incineration). The results show that pH reduction has positive effect on shifting the liquid phase during HTC. Although experimental this do not yet achieve necessary reduction, various calculations are made goal in future studies. In order be able assess energy benefits HTC, Aspen Plus modeling was used impact implementing technology WWTP. It is shown mechanical dewaterability (SS) increases after HTC enabling savings by means subsequent thermal drying. A heat optimized cut expenses half, providing phosphorus-depleted hydrochar extensive energetic use.