Analysis of energy sustainability of byproducts from thermal drying in wastewater treatment

The objective of this article is to analyze the energy, economic -financial and operational sustainability of the installation of a thermal dryer in a sewage treatment plant in Curitiba. The methodology was based on the estimation of biogas generation, sludge production and available energy, considering 2 evaluation scenarios: 1) reducing the total solids (TS) content in the sludge; 2) supplement biogas with energy from dry sludge. In alternative 1, 40.1% of ST was obtained. Alternative 2 meets the equipment demand (36.1 MWh) and supplies surplus (14.2 MWh). Both alternatives guarantee energy sustainability. The dry sludge can be sold (R$ 165.00 ton(-1)). As a conclusion: the recovery of biogas and sludge generates surplus energy (2,672.6% in processing and 200% in storage), reduces 85% of the amount of sludge without burner and 96% with burner.