Economic viability to generate electricity from the biogas produced in the wastewater treatment plant

Objective of the study: to present the analysis of the collected data referring to the characteristics of affluent sewage of the Serraria Sewage Treatment Station, in Porto Alegre/RS. Methodology / approach: descriptive research with a quantitative approach and centralized in the case study of the biogas exploration generated for the production of electric energy. Originality / relevance: this study focuses on the technical and economic feasibility for generating electricity from biogas effluent for use at the station itself, serving most of the local loads, as well as the energy conversion technology used from of the internal combustion Cycle Otto, with its accessories. Main results: installation, operation and maintenance costs for five years are estimated at around R$ 4.500.000,00. In addition, the return on invested capital occurs, at most, in 4 years and 7 months. Theoretical / methodological contributions: there is a tendency to increase electricity from the network tariff and the flow of inputs in the UASBs, making self-generation even more viable. Currently, biogas is flared and the sludge generated is deposited in landfills, which makes it possible to produce electricity and supply it to the distribution network. Conclusion: sewage treatment plants consisting of an upstream flow anaerobic sludge deposit followed by active sludge aims to treat effluents, that is, to promote the separation of gases, solids and liquids as a form of sustainable treatment and, in addition, to provide sustainable benefits and resources for society.