Biogas from anaerobic digestion of fruit and vegetable wastes: Experimental results on pilot-scale and preliminary performance evaluation of a full-scale power plant

The results of the experimental investigation were used for a preliminary performance evaluation of a full-scale anaerobic digestion power plant for treating all the fruit and vegetable wastes produced by the Wholesale Market of Sardinia (9 t/d). The estimate of daily methane production (290 Nm3/d) leads to a CHP unit with a power output of about 42 kW and an annual electrical production of about 300 MW h/year (about 25% of the wholesale market electrical consumption). The AD power plant also shows interesting economic features, since its energy production cost (about 150 €/MW h) is slightly lower than the energy purchase cost of the wholesale market (about 200 €/MW h) and a Pay-Back Time of about 7.25 years can be achieved in the case of dispatching the electrical energy to the national grid. The PBT decreases to about 5.4 years if 50% of the available thermal energy is used to substitute heat production from fossil fuel boilers.