Recent progress of biogas produced from the waste of natural indigo dyes for electricity generation

Biogas is an attractive renewable fuel because it can be produced from abundant organic wastes via anaerobic digestion. This study reports the recent progress of the biogas produced from the waste of natural Indigofera wastes co- digested with cow dungs. The substrate flow rate of 50 kg/day and 100 kg/day was digested in the digestion reactor 1 and reactor 2 of 3000 L and 1000 L, respectively. The biogas production was measured daily and used as fuel in an internal combustion engine for electricity generation. The results show that the higher the flow rate of the substrate, the higher the biogas was produced. The average biogas production from reactor one and two were 313.8 and 1503.9 L/day. Meanwhile, the engine efficiency is up to 30% at 350 W load and 25% at 700 W load when using biogas digested from reactor 1 and 2, respectively. It is interesting to further improve the anaerobic digestion reactor to obtain higher biogas production and to produce a higher power generation.