Biomethane from fish waste as a source of renewable energy for artisanal fishing communities

The potential of biogas production from fish waste as source of renewable energy for fishermen communities was evaluated. Four different fish waste concentrations (1%, 1.5%, 2% and 2.5% total solids (TS)) were digested during 28 days at mesophilic conditions. Biochemical Methane Potential (BMP), volatile fatty acids (VFA) concentration and ammonia concentration were analysed during the experiment. Energy production and economic projections were performed to estimate the number of families that can benefit from the biogas production in Tumaco, Colombia. The 1% TS had the highest BMP (464.5 mL CH4/g VS) and the lowest VFA production (2515 mg/L); in contrast, the 2.5% TS had the highest VFA production (11302 mg/L) and the lowest methane production (206.86 mL CH4/g VS). The treatments with 1.5%, 2% and 2.5% TS exhibited diauxic growth as result of different solubilisation rates in the fish waste components. The energetic and economic analyses estimated a yearly energy production of 489 MWh, which can satisfy the electric energy consumption or the cooking energy demand of 230 fishermen families. The results showed that biogas production from fish waste is a viable and sustainable alternative to adequately manage this material and provide renewable energy to fishermen communities.