Avaliação da eficiência e viabilidade da biodigestão anaeróbica em escala agrícola: estudo de caso da instalação e monitoramento de um biodigestor para produção de biogás

Abstract

The present work addresses three stages: physical-chemical characterization of manure chicken, assembly of the biodigester and monitoring of the biodigestion process. About fresh biomass the following parameters were determined: BOD (2.3mg/L), protein (11.46%), fats (1.71%) and density (956kg/m³). The second stage refers to the assembly of the biodigester, which was prefabricated in China and installed on a farm in Moamba, the daily food flow (1:1) was additionally calculated based on in the dimensions of the biodigester (15m³). The last step consisted of monitoring the biodigestion process, in which the substrate sample was collected daily, in 500 ml plastic bottles for analysis ensuring the following operating conditions: mesophilic temperature range (25-40°C), acceptable pH (6.2-7.4), total solids (5%) and volatile solids removed (63%). As a result of anaerobic biodigestion, we obtained: biogas production of 6.28𝑚3 daily, calorific value of biogas of 6264 kJ/m³, composition of biogas (measured with the BIOGAS 5000 from GeoTech) indicating 44% methane, 40% carbon dioxide and the remaining residues (water vapor and hydrogen sulfide gas). The biogas produced was used at Quinta Mothassy Investimentos itself as cooking and agricultural fertilizer (TRADUÇÃO NOSSA).