Biogas to Energy from the MSW organic fraction Solid State Anaerobic Digestion: a real case experimental evluation and process optimization procedure

Waste management consist of many different activities with the aim of pursuing an economical, environmental and social sustainable system. Among the different possible strategies, the achieving of high fractions of differentiate collection, represent an important aspect for reducing the impact that wastes can have on the environment. Anyway this goal can be successfully pursued only if adequate systems or technologies are available for allowing a correct treatment of the wastes arising from the differentiate collection. As known, an important fraction of the differentiate, as non differentiate, waste is represented by the organic biodegradable fraction. A diffused way of treating this fraction is represented by the biological treatments. Generally the preferred solution is represent by the aerobic stabilization process, that can lead to the production of high quality natural fertilizer, exploitable for agricultural needs. The anaerobic biological treatment, even if can lead to energy production, is less diffused due to different problems like an higher investment and management cost and, mainly, to the production of a large amount of leachate, due to the need of high moisture content, required by the most diffused technologies available for such process. This large leachate production, in many different case, represent the main drawback to its exploitation. In this paper are represented the preliminary results regarding the experimental analysis procedure for the evaluation of the main parameters affecting the performances of a low moisture content, batch, anaerobic solid state process, exploiting the MSW organic fraction produced in an Italian region. A technical and economical analysis of a real scale solid state anaerobic plant, have also been performed.