Renewable energy from municipal waste composting in Cesena, Italy: a case study

摘要

Managing solid waste in urban areas remains a major challenge for achieving sustainability in the city. Our work presents the experience gained during the last decade in treating organic waste to produce electricity and compost in Cesena, Italy. Cesena is a city of about 100,000 inhabitants, located in the southeast corner of the Emilia-Romagna region (northern Italy). Since 2001 Romagna Compost Sri. has been disposing of organic waste from Cesena, with the aim of producing electricity and viable compost for local nurseries, city parks, gardens and other green spaces. The pre-existing composting plant (located in S. Carlo), which is 8 Km southwest of the city, was renovated between 2008 and 2009 to eliminate bad odours, improve the quality of its effluent water and to reduce the overall environmental impact of the facility on the surrounding landscape. Through the process of anaerobic digestion, similar to that occurring in a cow's stomach, each ton of organic waste is now being converted into about 90 cubic meters of biogas of which 60% is methane and 180 kWh. The introduction of dry fermentation as a new treatment process allowed for a conversion of biomass with a dry matter content of up to 50% into compost and renewable energy. This system supplies about 10% of the electricity for domestic use in Cesena and it is the first dry anaerobic digestion plant in Italy. More data will be presented together with the ongoing effort to employ this facility also as an education centre and a demonstration site, to inspire other municipalities to achieve more sustainable methods and approaches of managing and recycling organic, municipal waste.