How biogas is created
Anaerobic digestion is a biological process of organic substance transformation, which produces the production of biogas. This one, composed mainly of methane and carbon dioxide, is developed by bacteria that operate in conditions of absence of oxygen. This process enables a recovery of large amounts of scraps, which would otherwise would be disposed of, worsening both environmental and economic aspects. The thermal energy that is obtained is used for the same digesters and for the production of hot water intended for agricultural or industrial use. In environmental terms, this recovery process is worth the equivalent of several thousand tonnes of petrol and CO2, that every year is not released into the atmosphere.
We don’t use resources destined for human nutrition
It is important to clarify that the farms and agri-food companies exploit this technology only to recover their production waste and increase the energy efficiency of their plants. Other types of biomass are not used, such as cereal flours, in conflict with the food or animal feed sectors. The use for energy purposes of food matrixes may in fact cause supply problems in major chains and market distortions.
From biogas: fertilisers, thermal and electric energy
The starting matrix are brought to liquid state, grinded and introduced into the system. In the first stage of the process they are mixed and heated to about 37° C to create the optimal environment for growth of the so-called microbial methanogenic flora. This is followed by the real biological digestion, which involves a biomass stationing time in the system for about 30 days. From this controlled anaerobic digestion process are obtained: biogas, which after being recovered, is purified and used for the production of electricity; the “digestate”, the residue of the digestion process and a perfect organic substance that allows a significant reduction in the use of chemical fertilisers; thermal energy (heat), used internally for the energy needs of the company and the drying of digestate.
Italy is the third largest producer of biogas in the world, after Germany and China
Biogas is an important technology for improving environmental sustainability, both in agriculture and in the food industry. However, it must be used for effective recovery activities of waste not otherwise exploitable. Italy is now the third largest producer of biogas in the world, after Germany and China. The main contribution to the production of this clean energy happens to come from the zootechnical sector. In the production of biogas, the agricultural sectors, in just the last five years have made investments of over 4.5 billion Euro, which created 12,000 new and highly skilled permanent jobs. To date, about 1,300 plants, with an installed capacity of 1000 MWe, produce 7,400 GWh of electricity.