Productivity of biogas production from dragon fruit branches co-digested with pig dung

This research aimed to appraise the promising biogas generation from dragon fruit branches co-digested with pig dung. Biochemical methane potential assay was employed for effective biogas production via the optimized ratio between branches and pig dung, the ratio between feedstock and inoculum, the ratio between solid mixture and water, the percentage of added seedings, and incubating temperatures. Each batch was operated for 17 to 22 days, depending on the quantities of branches, dung, inoculum, water, added seedings, and incubating temperature. The biogas productivity was substantially intensified in the first eight to fourteen working days before decreasing in the following days. The maximized accumulated biogas capacity (2,628 mL), and biogas yield (63.71 mL/g volatile solid) were achieved under the optimal conditions of 50% branches and 50% pig dung (w/w), 1 g feedstock/ 2 mL inoculum, 1 g solid mixture/ 5 mL water, 20% added seedings, and 27oC incubating temperature. Furthermore, this output (63.71 mL/g volatile solid) was boosted by 128.18% as compared to the biogas yield from sole dragon fruit branches at the anaerobic conditions of 1 g feedstock/ 1 mL inoculum, 1 g solid mixture/ 4 mL water, 10% added seedings, and 35oC incubating temperature (27.92 mL/g volatile solid). Based on these outputs, dragon fruit branches are a promising material for biogas production, which gains economic profits for this plant and benefits sustainable development in green energy and waste valorization.