Experimental and Full-scale Plant Assessment of Biogas Production via Anaerobic Co-digestion

Biogas production from anaerobic digestion of organic waste is an important renewable energy source with great potential of replacing fossil fuels for heat and electricity generation. However, efficient anaerobic digestion process and energy conversion technology must be ensured for better biogas yield and energy generation. The present study involves experimental assessment of biogas production from anaerobic co-digestion of biomass feedstock. The experimental stage involves the co-digestion of livestock manure with slaughterhouse waste and vegetable waste, different sets of experiments were conducted at mesophilic condition of 37o C, 25 days of retention time and utilizing water displacement experimental setup. The biogas yields obtained for the co-digestion of Cow dung + Poultry manure (S1), Cow dung + Sheep manure (S2), Slaughterhouse waste + Poultry manure (S3), Sheep dung + Poultry manure (S4), Poultry manure + Whey (S5) and Vegetable waste + Cow (S6) are 0.0236m3/kg, 0.0231m3/kg, 0.0264m3/kg, 0.0234m3/kg, 0.0266m3/kg and 0.0191m3/kg respectively. These values are acceptable values of biogas yields for livestock manure co-digestion. However the co-digestion revealed that the biogas yields obtained are slightly above the minimum reported value for co-digestion of manure slurry, this is due to the nature of the experimental setup used. According to the simulation conducted with engineering equation solver software on the modeled biogas plant, energy efficiency of 42.55% was achieved by integrating the digestion process to the steam cycle which provides better heat utilization.