Análise de viabilidade técnica, econômica e ambiental da geração de energia elétrica a partir do biogás em uma estação de tratamento de efluentes sanitários

Abstract

Considering the growing demand for energy and the consequent environmental problems associated with the use of fossil fuels, there is a need to search for renewable and sustainable sources. Biogas emerges as an alternative and a potential source of renewable energy, since it is composed basically of methane, has calorific potential and is formed through the decomposition of organic matter, also collaborating with the treatment of these. Within this context, this study aimed to analyze the technical, economic and environmental feasibility of generating electricity from biogas originating from a sanitary Effluent Treatment Plant (ETE). To this end, the energy generation potential was determined based on primary data collected at the ETE of Cachoeira do Sul/RS, after a systematic review of the literature was carried out, where it was defined that the most appropriate economic methodologies were Simple and Discounted Payback, Net Present Value (NPV), Internal Rate of Return (IRR) and Levelized Cost of Energy (LCOE). Next, the population ranges that would be suitable were defined, opting to work with four scenarios (from 50 to 450 thousand inhabitants), calculations were made and finally the avoided quantity of equivalent carbon emitted into the atmosphere was estimated. The anaerobic digestion process of the effluents demonstrated efficiency since the quantity of biogas produced is sufficient to generate electricity, thus demonstrating the technical feasibility of the project. Financial feasibility is achievable mainly in scenarios that serve larger populations, from 200 thousand inhabitants. Finally, it was found that the use of biogas contributes significantly to the reduction of greenhouse gas emissions, avoiding emissions between 3,356.24 tCO2eq for scenario 1 and 30,206.12 tCO2eq for scenario 4. The generation of electricity from biogas in sewage treatment plants is a sustainable and economically viable solution, which can contribute significantly to the Brazilian energy matrix and to environmental preservation. [resumo fornecido pelo autor]