Life Cycle Assessment comparativo tra il processo diudco-digestione della frazione organica dei rifiuti solidiudurbani e dei fanghi di depurazione disidratati e iludsistema di gestione attuale. Il caso di Bagnacavallo (RA)

摘要

Waste management is becoming, year after year, always moreudimportant both for the costs associated with it and for the ever increasing volumes of waste generated.udThe discussion on the fate of organic fraction of municipal solid waste (OFMSW) leads everyday to new solutions. Many alternatives are proposed, ranging from incineration to composting passing through anaerobic digestion.ud“For Biogas” is a collaborative effort, between C.I.R.S.A. and R.E.S. cooperative, whose main goal is to generate “green” energy from both biowaste and sludge anaerobic co-digestion. Specifically, the project include a pilot plant receiving dewatered sludge from both urban and agro-industrial sewage (DS) and the organic fraction of MSW (in 2/1 ratio) which is digested in absence of oxygen to produce biogas and digestate.udBiogas is piped to a co-generation system producing power and heat reused in the digestion process itself, making it independent from the national grid.udDigestate undergoes a process of mechanical separation giving a liquid fraction, introduced in the treatment plant, and a solid fraction disposed in landfill (in future it will be further processed to obtain compost).udThis work analyzed and estimated the impacts generated by the pilot plant in its operative phase. Once the model was been characterized, on the basis of the CML2001 methodology, a comparison is made with the presentudscenario assumed for OFMSW and DS.udActual scenario treats separately the two fractions: the organic one is sent to a composting plant, while sludge is sent to landfill.udResults show that the most significant difference between the two scenarios is in the GWP category as the project "For Biogas" is able to generate “zero emission” power and heat.udIt also generates a smaller volume of waste for disposal.udIn conclusion, the analysis evaluated the performance of twoudalternative methods of management of OFMSW and DS, highlighting that "For Biogas" project is to be preferred to the actual scenario.