Study on interchangeability of seed based feedstocks for biogas production in multi-feeding mode

Biogas is an excellent renewable fuel providing gas for clean energy applications and fertilizers for organic farming. In the present study, seeds from four tree species of Acacia nilotica, Albizia lebbeck, Prosopis juliflora, and Leucaena leucocephala have been utilized for biogas production as alternative feedstocks. They have been investigated in a mixed-feeding mode in a single digester to tackle the feedstock availability and seasonality challenges. The investigations were conducted in a 300 ​L anaerobic digester for 120 days under daily feeding mode. The average specific biogas yield and specific methane yield was found to be 0.425 ​m3/kg of volatile solids and 0.228 ​m3/kg of volatile solids, respectively. The average volumetric methane content in biogas was 54.7%. This paper presents a unique study on anaerobic digestion of selected seeds in a mixed-feeding mode to provide broad opportunities for their efficient and sustainable utilization. [Display omitted] •Interchangeability of tree species seeds explored for 120 days in the mixed-feeding mode for biogas production.•Anaerobic digestion parameters for the utilization of these seeds are investigated in detail.•An amount of 3.0–3.5 ​kg of seeds is required to produce one cubic metre of biogas.•Specific biogas yield of 0.425 ​m3/kg VS with methane of 54.7% and TVSMRE as 46.0% were found.