Biogas production using dry fermentation technology through co-digestion of manure and agricultural wastes

Abstract

Recently, dry anaerobic co-digestion is one of the mechanisms which have been increasingly used to improve the reactor’s performance for treating livestock manure with agricultural crop residues. Due to carbohydrate, protein and lipid existing in agricultural wastes, biogas yield decreased with higher reactor volume when using wet anaerobic digestion. In this regard, the aim of this work was to achieve the production of biogas using the dry anaerobic technology through livestock manure co-digestion with agricultural waste (AW) such as potato peels, lettuce leaves and peas peels. The manure and AW were mixed at a ratio of 2:1 for 15 min before being introduced into the batch anaerobic system. The results indicated that the co-digestion of lettuce leaves and manure yielded the highest production of methane and biogas which were 6610.2 and 12756.7 ml, respectively, compared to the control (manure) that yielded 4689.9 ml and 11606.7 ml, respectively. Additionally, the results indicated that the co-digestion of lettuce leaves and manure yielded the highest specific production of methane and biogas which were 405.5 ml CH₄ g⁻¹ VS and 782.6 ml biogas g⁻¹ VS, respectively, compared to the mono-digestion of manure (control) that yielded 328 ml CH₄ g⁻¹ VS and 633 ml biogas g⁻¹ VS, respectively. Eventually, dry anaerobic co-digestion process is an effective approach to waste treatment.