Exergoeconomic analysis of a municipal solid waste fired power plant with biological filters for emissions

In the last few decades, the energy demand has vastly increased, and the generation of municipal solid wastes (MSW) in the cities represents extraordinary challenges for sustainable economic growth. Aiming to mitigate these problems, this work verifies an MSW fired power plant's technical and economic viability that uses biological filters for carbon dioxide fixation and microalgae biomass production. An exergoeconomic analysis is undergone in a southern Brazil waste-to-energy (WtE) plant with an incineration capacity of 50 kg/h, providing hot flue gases for a set of heat exchangers that operate as the system boiler for a 15-kW water Rankine cycle. The system sums six 10 m³ tubular Photobioreactor (PBR) producing up to 30,000 kg/year of microalgae biomass with the southern Brazil solar conditions of 1.732 kWh/m² per year. Considering a payment for the incineration services, this integrated power plant could reach a payback as low as 3.39 years, with biomass costing as low as 0.39 US$/kg and emissions factor that could reach 22.3 gCO2/kWh. Therefore, this system shows a capacity to produce clean electricity treating the MSW and provide microalgae biomass that can be processed into animal food and bio-fuels.