Biogas Digester for Power Generation using Rabbit Manure as Feedstock: Design, Fabrication, and Evaluation

Assessing rabbit manure’s potential as a biofuel source for small-scale internal combustion engines was the primary objective of this study. The research utilized rabbit manure as feedstock, which was inoculated with carabao manure. A total of 60 kilograms of rabbit manure was subjected to treatment using a 1:1 water-to-manure ratio with a retention time of 25 days. Additionally, a microbial inoculant comprising 10% carabao manure was incorporated into the digestion process. The design consists of a split-type biogas digester with gasholder storage and a three-stage gas cleaning system, an internal combustion engine connected to a DC generator, and a simple lighting circuit. Findings indicated that the pH level recorded at 7.75 resulted in alkalinity which helped the biogas production by preventing the slurry from acidity. The total dissolved solids (TDS) were recorded at 3137 ppm, and it increased to 6980 ppm. For the performance evaluation in fueling the engine using biogas, the engine operated for 80 seconds and generates an average power of 31.66 watts.