Biogas Sardinia

Biogas are a mixture of various types of gases, mainly composed of methane, produced by bacterial fermentation in anaerobic (absence of oxygen) organic residues from plant or animal residues. Useful residues can have multiple origins: agro-industry waste (chopped corn, sorghum or other crops), food industry (waste meal or expired products), livestock industry (animal waste or carcasses); it is also possible to use specially cultivated crops in order to be harvested and chopped to produce “biomass”, such as corn, sugary sorghum, wheat, common cane, beets; research is currently underway for the use of algae. The whole process sees the decomposition of organic material by some types of bacteria, producing carbon dioxide, hydrogen and methane (methanization of organic compounds). Biogas is formed spontaneously from the fermentation of organic matter. Landfills of municipal waste can become major producers, since normally 30–40% of waste is precisely organic material, other main sources could be the agricultural or livestock industry; in order to be usable and obtain an economic value, this gas must first be captured and accumulated in special structures, avoiding its dispersion into the environment, to be subsequently burned to produce heat and electricity. The CO2 produced by the combustion of the methane thus obtained makes it possible to equalize the balance of the carbon dioxide emitted into the atmosphere: in fact the CO2 emitted by the combustion of biogas is the same CO2 fixed by plants (or assumed by animals indirectly through plants), contrary to what happens for the CO2 emitted from scratch by the combustion of fossil fuels.