Analysis of energy return on investment of dry anaerobic digestion for low water alperujo with oxidative, thermal and alkaline pretreatments

ROCIO M GIL; MARIA CARLA GROFF; BENJAMIN KUCHEN; DAIANA G GIL; MARIA CECILIA FERNADEZ; FAVIO VAZQUEZ

Water and Environment Journal

John Wiley and Sons Inc

Lugar: San Juan Capital; Año: 2023

Anaerobic digestion processes for biogas generation using alperujo have been thesubject of intensive studies suggesting that phenolic compounds act as microbialinhibitors in anaerobic digestion. Pretreatments are needed to reduce the effects ofphenolic compounds and improve biogas production, especially for dry anaerobicdigestion. However, industrial-scale implementation of these pretreatments is challenging, and it is unclear whether the improvement in biogas production justifies theenergy expended on pretreatment. This study examines the energy analysis of dryanaerobic digestion and three alternative pretreatments: alkaline, oxidative and thermal. Results indicate that thermal pretreatment at 80C with added water reducesphenolic compounds in alperujo by 35.4%. Meanwhile, pretreated with hydrogen peroxide in alkaline medium had the highest methane productivity (205 mL CH4/gVS).Even so, thermal pretreatment was only one with an energy return on investmentgreater than 1, signifying the necessity for energy analysis to ensure the viability ofpretreatment processes.