Among the renewable energy sources European Commission already in the" Action Plan for Biomass " on December 2005 has placed as a central point the need to encourage the production of energy from biomass like plant or animal waste and biodegradable garbage.
This biomass offers many advantages like:
it is completely renewable,
it can be collected at short distance, with lower costs of transportation and therefore greater security for human being and environment
it is the only one that can be converted into a liquid or gaseous product.
The transformation of biomass into energy is considered one of the actions available to achieve the sustainability objectives set out in the Kyoto Protocol because it allows to reduce the use of fossil fuels due to greenhouse gas emissions, energy dependence, environmental pollution and damage to human health .
The countries that signed the Kyoto Protocol, including Italy, have pledged to reduce by 2012 (later extended to 2015) the emissions of greenhouse gases by 8 %, including natural gas. Agricultural activities in this regard represent a significant source of emissions of methane and nitrous oxide, derived from the digestive processes of the animals with enteric emissions or from both the anaerobic decomposition of manure ( pig, poultry, etc.). The anaerobic digestion of manure and slurry in a plant allows the capture of biogas that is produced by such substances, reducing harmful emissions while getting usable energy for the farm/company or for the public grid . reducing odours released into the surrounding environment, reducing ammonia emissions.
Many European countries are facing problems associated with an over-production of industrial organic waste, agricultural and urban and the recycle of these products into biogas plants can contribute to reduce the volume of waste and consequently waste disposal costs for the all community and to obtain a storable substrate to be used as fertilizer instead of chemical products.