BIOMASS: ENVIRONMENTAL COMPATIBILITY AND STRATEGIES FOR ENERGY PLANNING

1 ABSTRACT Authorities and agencies in many nations are discussing ambitious targets in order to mitigate the most dangerous impact of human activity (climate change) on the environment; by considering health of human society, and also concerns about economics aspects, some regions have already set reduction targets. The European Union has set itself the ambitious target to increase the share of renewable sources in final energy consumption to 20 % by 2020, in order to reduce both GHGs emissions and reliance on fossil fuels from foreign markets. In the framework of this productive change, biomass (one of the major sources of renewable energy) plants are getting a lot of attention, but it is necessary to determine whether, in comparison with individuated climate and resource benefits, the use of this type of energy is also environmentally beneficial. A complete assessment of the impact of a biomass energy plant requires the evaluation of many different aspects at local and global scales. From one side there are important positive aspect such as limitation of greenhouse gas (GHG) emission, use of secondary materials, improvement of local activities, right destination of organic sludges, absence of toxicity, and limited cost; from the other side, the effects on land use, need of chemicals and imported resources, expansion and/or intensification of agriculture in other locations, and, chiefly, formation of secondary pollutants (dust, nitrogen oxides, and VOC) must be carefully considered. The present thesis has the aim to evaluate all these aspects, by providing a methodological approach and a scheme, to be applied for practical application in real situations and in order to perform a quantitative analysis of the environmental impacts. The proposed methodology permits to evaluate the environmental compatibility of a specific biomass plant and the potential energy production from biomass at regional level. Some specific numerical applications, referred to structure of plants and local impact assessment, and also to planning considerations utilized to define the bioenergy potentials and environmental consequences in Italian regions of different structure. The overall description of technological schemes and process and territorial acceptability of bioenergy plants has been completed with considerations about production of biogas and biomethane, and fermentation of low-cost natural materials to produce second generation biofuels. The obtained conclusions, that with their numerical definition can be considered very useful for the specific studied situations, can also be considered fairly representative as a methodological approach, with the general purpose to study with a global approach the effects of biomass energy plants.