Assessment of Biogas Potential of Pineapple Waste in Mono and Co- Digestion with Cow Dung at Ambient Temperature

Pineapple (Ananas comosus (L.) Meril) processing in Benin's agri-food industries generates waste with high potential for energy production. The present study assessed the biogas production potential of pineapple cakes and crowns in mono and co-digestion with cow dung. The methodology used is based essentially on the Simplex-Centroid Designs mixing scheme designed in Minitab.19. Anaerobic digestion tests were carried out with seven formulations in triplicate. Temperature, pH and biogas volume were monitored. A predictive model of biogas production according to mixing ratios was developed. Results indicate that digesters operating at mesophilic temperatures ranged from 23°C to 33°C, with an average of 26.5°C±0.33. The best-performing mixture in terms of biogas volume generated contained 50 g cake:50 g cow dung. This resulted in the production of 9.62 liters of biogas/kg of waste. Therefore, it has been established that pineapple waste and cow dung can be used efficiently for biogas production. The results also reveal the importance of maintaining some physico-chemical parameters of the waste mixtures in order to optimize biogas production. The model approximates average biogas production, with an R² correlation coefficient over 80%. In total, pineapple waste can be used to produce biogas. The exploitation of this energy resource in agri-food industries can contribute to the use reduction of conventional energy and fossil fuels.