Production and Utilization Stage Analysis of Biogas: Case of IZAYDAS Plant

This study investigates size and operating condition effects on energy production efficiency, greenhouse gas (GHG) mitigation and economic potentials in production and utilization stages of a biogas system. In IZAYDAS plant, efficiencies of biogas production and electricity generation are found to be 28 % and 20 % independently from operating scheme, respectively. When these results are compared to a small capacity plant without an automatic control keeping the biogas system at or close to favorable conditions for fermentation and a lower quality electricity generator, both biogas and electricity production efficiencies are found to be lower showing the importance of operating conditions and size on energy production efficiency. Organic waste processing is the major contributor to the GHG mitigation potential followed by fossil electricity and then chemical fertilizer replacement. Economically, liquid fertilizer is the major source of income due to its high amount followed by solid organic fertilizer and electricity sold to the grid. When different utilization paths are investigated for biogas, it is found that direct utilization of biogas has a higher GHG mitigation potential and favorable energetically