Multi-Criteria Decision Analysis-Supported Evaluation of Biowaste Anaerobic Digestion Options in Slovakia

Slovakia’s biomethane production potential represents up to 10% of Slovakia’s natural gas consumption, which is largely unexploited. The aim of this paper is to develop a model of each available technology (continuous, dry batch, and wet batch) as well as that of a biogas treatment unit and evaluate the energetic, economic, and environmental potential of building a new anaerobic digestion plant in Slovakia, considering four plant locations with feedstock abundance within a 30 km perimeter. Feedstock composition and availability, energy integration, and product usability are evaluated. The applied multi-criteria decision analysis (MCDA) considers four evaluation criteria: return on investment (ROI), CO2 emissions production, potential industrial biowaste revenue, and municipal density within the operational region. Biogas plant deployment analysis yielded the Levice facility as top-ranked, primarily due to its minimal environmental impact and superior logistical performance, closely followed by the Žilina, Michalovce, and Prešov facilities. When comparing biomethane production facilities, the Levice plant was excluded due to economic infeasibility, and the Žilina facility emerged as the optimal choice, particularly due to its superior ROI performance and the largest biomethane production potential of over 1 million m3 biomethane per year. Thus, biomethane station deployment in Slovakia has proved feasible and can enhance the energy self-sustainability of the country and contribute to meeting the decarbonization goals.