THERMAL EXCHANGES IN A COVERED LAGOON BIODIGESTER TREATING PIG FARM EFFLUENT HEATED BY SOLAR ENERGY

Covered lagoon biodigesters are widely used in Brazil for treatment of agro-industrial effluents; however, under natural conditions, they operate at temperatures below the ideal. Thus, external sources heating effluent can enhance reactor performance and optimize thermal exchanges between biodigester environment. This study aimed to evaluate internal environments a covered from influence through solar energy. Mathematical modeling (EnergyPlus software) was as tool simulate obtain heat transfer rates. To do so, two scenarios were considered: with without heated effluent. The results showed that radiation is primary source anaerobic reactors high inertia soil contributes small variation temperature resident biomass over course day, even scenario reached stabilized 30°C, after biogas soil, both hot cold periods when applied.