Methane generation potential through anaerobic digestion of fruit waste

Abstract

In fruit juice and pulp production, around 40–50% of waste generated is related to industrially processed fruit gross amount. Brazil is responsible for 57% of world market production, having the waste generation lost or being undervalued. Anaerobic digestion is an alternative for energetic valorization of this waste. The aim of this work is to evaluate methane generation potential of fruit waste (passion fruit peel, orange and cashew bagasse) and determine kinetic parameters for scale up. Biochemical methane potential (BMP) was evaluated in 250 mL batch reactors in mesophilic conditions for 60 days, using industrial and sewage anaerobic sludge as inocula. Kinetic parameters were determined from methane production curves, adjusting in first-order and modified Gompertz kinetic models. The best observed maximum generation potential (BMP) was 348 NmL.g−1 VS, in biogas, and 128 NmL.g−1 VS in methane, for orange bagasse with industrial sludge. Configuration methane accumulated volume presented better fit in modified Gompertz kinetic model. Fruit waste anaerobic digestion is a promising alternative for valorization and utilization of its energy potential, providing gains to productive chain.