Thermo-valorisation in integrated waste management

In 2002, approximately 25 million tons of Municipal Solid Waste (MSW) were produced in Italy, but no more than 5.5 million were collected separately. Data analysis shows that despite the progress in differentiated waste collection and in the process of quality recovery, dumps are still the most common means of disposal. With reference to thermo-valorisation, although the number of active thermal plants and the amount of thermo-valorised waste has increased (by over 10% from 1999 to 2000), total processed waste appears to be excessively low compared to the amount of waste produced. Moreover, it is below the EU average. Our objective was to analyse three different scenarios for the quantity of thermally valorisable waste through to 2005. We have also evaluated the incineration of MSW taking into account the technological, environmental and economic factors in different plant types (with and without energy and heat recovery) considering emission quantity and quality with possible CO2 recovery. The most economical and environmental solution might be the transformation of waste to synthetic gas for use as an energy and heat source in a conventional power plant in the future. From current information we understand that today thermo-destruction with energy recovery and a combined energy–heat cycle could be an option with great benefits for the environment, and could even be competitive compared to other solutions for replacing some energy sources.