Electric energy generation and technical–economic viability of a biodigester in the hospital sector

Abstract

The construction of hospitals has transformed and evolved sensibly in the last decades, being seen as an industrialized process, with increase in scale, which generates large amounts of waste, causing great environmental problems. Within this context, a new provision is needed for the waste produced (biomass) and its reuse. Following the appropriate techniques, the use of the biodigester, which allows hospital waste to be treated, can generate electricity and/or natural gas through the biogas and allows the use of the residual effluent as a soil fertilizer. The present study aimed to evaluate the potential of energy generation and the economic and environmental viability of the adoption of a biodigester at the General Hospital of the State of Alagoas (HGE). For this, a study of the residual biomass produced in the HGE, consumption, and costs, electric power oscillation was carried out, and equations were used to obtain the valuesof energy production, economic and environmental viability. The results show that the hospital generates 20,914.40 Kg / year-1 of food waste, with a potential of 840 m3 / year-1 of biogas, producing electricity of 5,352 kWh / year-1. This results in a cost of equipment that was R$ 80,598.00. From an economic point of view, the adoption of the biodigester in the HGE was not feasible, since the electric energy generated by this system would present the cost of R$ / KWh 1.45, while the amount paid to Eletrobrás is R$ / KWh 0.24.