Codigestão anaeróbia do resíduo da produção de cogumelos Agaricus bisporus e soro de leite para a produção de biogás

Abstract

Recent global transformations, driven by rapid population growth and geopolitical conflicts, have reinforced the need to invest in renewable and sustainable energy sources as alternatives to fossil fuels. In this context, optimizing production processes and utilizing waste, in line with the concept of a circular economy, have gained prominence in biofuel production and energy generation. This study evaluated the biochemical methane potential (BMP) from the anaerobic digestion of spent mushroom substrate and its co-digestion with whey. To ensure an optimal substrate/inoculum ratio (0.5), in accordance with VDI 4630 (2016), total solids (TS) and volatile solids (VS) analyses were performed. Additionally, the substrates underwent alkaline pretreatment with 1% NaOH (v/v) at a 1:9 ratio (substrate/sodium hydroxide, w/w). The experiments were conducted over 25 days under mesophilic conditions. The results showed that the highest biogas production was obtained in the mono-digestion of pretreated mushroom residue, with a cumulative volume of 76.2 LN.(kg.VS)⁻¹, followed by the codigestion of mushroom residue with whey (67.6 LN.(kg.VS)⁻¹), mono-digestion of microcrystalline cellulose (51.7 LN.(kg.VS)⁻¹), mono-digestion of raw mushroom residue (46.6 LN.(kg.VS)⁻¹), and, finally, the inoculum-only system (25.6 LN.(kg.VS)⁻¹). The kinetic modeling of biogas production using the modified Gompertz model showed a good fit to the experimental data (R²≥0.96). Although the digestion of pretreated mushroom residue yielded the highest biogas volume, co-digestion with whey demonstrated promising potential, highlighting the need for adjustments in experimental conditions to optimize the process and guide future research.