3' min read
3' min read
In Olbia, the focus is on biomethane. A biodigester will produce it from the treatment of Gallura's organic waste, starting in 2026. Work on the construction of the new plant, which benefits from NRP funding, is to start by 2024 on a 4-hectare area in Spiritu Santu. "The total investment is 20 million euro," emphasise Cipnes, the public body for the economic growth of Gallura and North-East Sardinia, "and will be covered by a capital contribution of 40% and the Gse incentives for the production of biomethane: the two measures will bring Cipnes Gallura resources of 32.7 million in 15 years. The call for tenders for the assignment of the works has begun. Work on the facility will be carried out in a 4-hectare area in the Spiritu Santu locality and will start within the year.
The hypothesised production is three million cubic metres per year (40 per cent more than the current requirement), and will be destined for the city of Olbia, although for the future it is also hypothesised that it will be used by companies in the consortium's production district, which would become one of the first in Italy to be supplied with this type of energy.
As for how it works, it is quickly explained: the waste produced by the inhabitants of Olbia and then disposed of, will be processed in the biodigester through a 'odour-free' system. This system, completely free of odorous emissions, transforms the waste into biomethane, which is distributed in the city's gas network. Thus, citizens not only dispose of their waste in an environmentally friendly way, but also contribute to the production of clean energy, while also benefiting from cost savings,' explain Cipnes.
The anaerobic digestion plant (biodigester) in Olbia - which already has an Integrated Environmental Authorisation (IEA) for its implementation - will be of the wet, continuous and mesophilic two-stage type; downstream of the digester, a digestate separation system is planned by means of helical separators and a dehydrator.
The Spiritu Santu biodigester will process organic waste (Forsu, green, Soa) from the municipalities of Olbia, Arzachena, Berchidda, Budoni, Golfo Aranci, Loiri Porto San Paolo, Padru and San Teodoro. The plant will transform organic waste from agricultural, agro-industrial, urban and zootechnical activities into resources, producing biomethane. Specifically, 5 thousand tonnes of green waste, 20 thousand tonnes of Forsu and 15 thousand tonnes per year of animal by-products will be treated. "The overall potential in terms of treatable organic matrices (waste and by-products) is therefore 40,000 tonnes per year," reads the project. "The plant will be fed with about 110 tonnes per day of organic matter, with an average of 24 per cent dry matter. But during peak summer periods, the feed will be able to reach up to 150-160 tonnes per day'. In addition to the biodigester, there will be the revamping of the composting plant: two measures that will eliminate odorous emissions.
