Estimativa da geração de energia elétrica e redução da emissão de gases de efeito estufa a partir do uso do biogás gerado nas estações de tratamento de esgoto do estado do Ceará.

Abstract

Greenhouse gas (GHG) emissions and energy consumption are two of the main challenges currently faced by the sanitation sector. Due to this, this study aimed to assess the potential for biogas production in Wastewater Treatment Plants (WWTPs) in the state of Ceará, as well as to evaluate electricity generation and the reduction of greenhouse gas (GHG) emissions through the implementation of Upflow Anarebobic Sludge Blanket reaector for biogas recovery and utilization in WWTPs. Among the 289 WWTPs in the state, 97 had available flow data, of which 41 operate with compact systems using UASB technology, appart from an pre-conditioning station (PCS). The study evaluated the amount of biogas produced in WWTPs with this type of treatment and estimated the biogas potential associated with the implementation of such systems in other WWTPs in the state. As a result, a daily production of 8,809.96 Nm³/day of biogas was estimated, associated with 21,958.82 kWh/day of electricity generation by using the biogas produced in internal combustion engines (ICEs). In a scenario where compact systems are fully disseminated in WWTPs with available data, a daily production of 34,228.59 Nm³/day and a generation of 85,315.26 kWh/day are projected. This generation would not only result in an annual energy bill savings of R$ 5.4 million for the company but also contribute to an 81.2% reduction in greenhouse gas emissions due to the capture and utilization of the biogas generated at the WWTPs. This implementation, therefore, would not only reduce costs for the Company but also contribute to sustainable development in the sanitation sector.