Potential of layer excreta as a substrate for sustainable production of green energy

The increasing demand for energy and the gradual depletion of fossil fuels necessitate an urgent expansion of renewable green energy sources. Utilization of poultry waste for the production of green energy can address the problem of handling waste as well as fulfilling the demands of producing green energy. With this consideration, the present study was taken to analyze the potential use of layer excreta as a substrate for biogas production (green energy). Three treatments were given to layer excreta, which includes L₀ with dilution rate of 1:10; L₁ with dilution rate of 1:8; and L₂ with dilution rate of 1:6. The loading of the digester was done with an initial organic loading rates (OLRs) calculated as per dilutions for different treatments and then digesters were sealed properly. After that, they were left undisturbed for 20 days and then regular feeding was started with daily OLRs for specific treatments as per dilution. Results showed that the hydraulic retention time (HRT) of biogas production from layer excreta was found least in the L₀ (33 days) treatment followed by L₂ (41 days) treatment and highest in L₁ treatment (43 days). The daily amount of biogas produced differs significantly (P<0.01) between treatments, and it was found to be highest in L₀ (0.0144 m³) treatment followed by L₁ (0.0074 m³) and then L₂ (0.0068 m³). The composition of biogas, methane yield, and calorific values of the biogas produced was also analyzed and compared between treatments. Along with biogas, bioslurry was also produced and it also showed significant (P<0.01) differences in physicochemical properties, proximate composition, and manurial value. It was concluded from the study that layer excreta had a good potential to act as a substrate for biogas production.