Optimization-driven anaerobic digestion of rice straw and potato peel waste for enhanced Biohythane production: A synergistic approach towards lignocellulosic biomass conversion to clean energy

Biohythane production from lignocellulosic biomass such as rice straw (RS) and potato peel waste (PPW) via anaerobic digestion (AD) stands as a viable biotechnological management fostering bioeconomic strategies benefiting the environment. It contributes to Sustainable Development Goals (SDG 7) concerning affordable, clean and renewable energy challenges. This study explores biomass conversion of two lignocellulosic wastes to Biohythane through “Optimization-Driven” AD. RS, a recalcitrant substrate having particle size (<0.425 mm), was co-digested with nutrient-rich co-substrate PPW in four different ratios based on weight/weight of (dry VSsubstrate), along with mixed inoculum anaerobic sludge (AS) and cow dung slurry (CDS) via AD at 11% TS. Batch experiments revealed that the [RSI-PP] ratio [(2:1):1/2] significantly improved yields of cumulative hydrogen (H2) and methane (CH4), viz., 36.98 ± 1.22 mL/g VS and 390.12 ± 3.45 mL/g VS, respectively. The S Gompertz equation exhibited excellent fit (>0.90), underscoring a positive synergy between substrate and co-substrate. The result signifies that RS in combination with PPW with homogenous particle size, mixed inoculum at 11% TS, confirms process stability and positive synergistic effects by providing essential buffer capacity, micronutrients and hydration, thereby enhancing the AD and Biohythane production. The findings of the results support the process's synergistic potential for waste biomass conversion to biofuel.