Potential and location of an anaerobic digestion plant using prickly pear biomass in semi-arid Mediterranean environment

Abstract

In recent years, prickly pear biomass has had a growing role in the area of agro-energy, aimed at the production of biogas and biomethane. However, technical validations of the use of prickly pears for energy purposes have not yet been carried out in Sicily, a region that accounts for more than 90% of Italian investment in cacti. A design idea was proposed in workshops to various stakeholders regarding building an anaerobic digestion plant to produce electricity from renewable sources (primarily but not exclusively prickly pear biomass). The BMP (biochemical methane potential) test was used to estimate the methanogenic potential of prickly pear biomass. Identification of the area in which to locate the investment [within the province of Catania and within the area governed by the production regulations of Ficodindia dell’Etna DOP (Etna Prickly Pear PDO)] was carried out using mainly AGEA data and a geographic information system (GIS). ISTAT and AGEA data were used to determine the individual variables, supplemented as necessary by information gathered through direct study and a face-to-face methodology. Existing relationships were studied using social network analysis (SNA). Results confirmed the benefits hoped for by interested stakeholders and also facilitated the identification of new alternative uses to that of fresh fruit sales. A biogas plant using prickly pears can, in this context, make a significant contribution – from the perspective of the circular economy – to supporting both the environment and producers.