A Local Multi-Criteria Assessment of Alternative Feeds for Biogas Plants in Calabria (Southern Italy)

Energy production by the anaerobic digestion of residual biomasses is strategic for the economic and environmental sustainability of the agricultural sector, provided that the most suitable digester feed is properly chosen. This option may be adopted by the use multi-criteria techniques, which are able to take into account a number of variability factors influencing the biomass supply chains. This study proposes a simple Multi-Criteria Assessment Model, integrating the Analytic Hierarchy Process and the Simple Additive Weighting methods. By the proposed model the biogas yield, economic efficiency and profitability of alternative substrates/blends to feed biogas plants were evaluated in an integrated way. The model was verified in a case study, identified in a 300-kW biogas plant operating in an agricultural district of Calabria (Southern Italy). By comparing the four alternative blends/substrates, the model showed the highest convenience of feeding a medium-sized biogas plant with self-produced residues of animal origin. The integration of the digester feed with external residues resulted in a slightly worst management option, if citrus peel is used. Feeding the biogas plant with a limited share of olive oil mill wastewater must be excluded, since this choice gave the worst synthetic performance index in the model. Copyright © 2018, AIDIC Servizi S.r.l.