Análise da viabilidade técnica e econômica de geração de energia elétrica a partir do biogás produzido na Estação de Tratamento de Esgoto Serraria, em Porto Alegre (RS)

Abstract

This paper presents the analysis of data collected relating to the affluent sewage characteristics of the Sewage Treatment Plant Serraria, in Porto Alegre, Brazil, focused on the case study of biogas exploitation generated to produce electricity. The station plant processes the sewage in a tertiary treatment with anaerobic digestion step by Upflow Anaerobic Sludge Blanket - UASBs. Nowadays, biogas is burned and the sludge generated deposited in landfill. The consumed electricity is fully provided by the distribution network. With the case study verified the technical and economic feasibility for the generation of electricity from biogas effluent for use in the own station, in attendance to most loads. The maid energy conversion technology was the internal combustion engine Otto cycle, with their accessories. Installation costs, operation and maintenance for five years are estimated at R $ 4,437,989.28. The return on invested capital occurs in 4 years and 7 months. There is a tendency of increase of electricity from the network tariff and the input flow in UASBs, become the self-generation even more viable.