Enhancement of biogas production from cow manure through a higher dilution ratio and supplemental additives

Although biogas holds significant promise as a renewable energy resource worldwide, its development is limited by suboptimal yields from single biomass sources. This study examined the effects of combining dilution and supplemental additives on increasing biogas production. Two sets of experiments were conducted with varying substrate-to-water dilution ratios and the addition of different organic and inorganic matter, including fish waste, sugarcane bagasse, flaxseed, bamboo biochar, nanoparticles, vitamin C, sodium bicarbonate (NaHCO₃), and the weed (Wedelia trilobata). Supplementing with small amounts of fish waste, nanoparticles, and flaxseed raised the yield to 49 440 ml/kg, representing a 1.7-fold increase in biogas volume. The highest production of 70 880 ml/kg was observed when a 1:3 dilution was combined with a mixture of fish waste, bamboo biochar, and NaHCO₃, resulting in a 2.36-fold increase compared to the 1:1 control. These results suggest that optimizing dilution and utilizing synergistic additives can enhance biogas production from cow manure.