THE “LE CORTINE” PLANT IN ASCIANO, IN THE PROVINCE OF SIENA, IS A KEY WASTE MANAGEMENT HUB IN SOUTHERN TUSCANY. ENTSORGA CONTRIBUTED TO ITS TECHNOLOGICAL REVAMPING PROJECT, THANKS TO THE ADDITION OF THE ANAEROBIC DIGESTION SECTION. THE ENTIRE REVAMPING HAS MADE THE SYSTEM AMONG THE MOST ADVANCED AND VIRTUOUS NATIONWIDE, INCREASING RECYCLING BY 15 PERCENT, FURTHER REDUCING WASTE AND THUS THE USE OF LANDFILLS, AS WELL AS SAVING THE ENVIRONMENT MORE THAN 100,000 TONS OF CO2EQ PER YEAR, EQUAL TO THE ABSORPTION OF A 40-HECTARE FOREST.
THE PLAYER
The “Le Cortine” plant in Asciano, in the province of Siena, owned by Sienambiente S.p.A., is a key waste management hub in southern Tuscany.
THE PROJECT
Its revamping project, worth about 40 million euros, was contracted in 2022 to the association of companies composed of Entsorga Spa, Secit Impianti Srl and Tecnostrade Srl, and involved all production lines, from the treatment of organic waste to the valorization of separated waste collection, from paper recovery to the treatment of unsorted municipal waste.
THE ENTSORGA’S SOLUTION
Entsorga provided 4 proprietary technologies essential to the new biomethane production line: the Spider™ robotic bridge cranes, the pretreatment systems, Cow™ semi-dry plug flow anaerobic digesters, and Eagle Cloud™ plant control and management systems.
THE ANAEROBIC DIGESTION LINE
Anaerobic Digestion complements composting as its natural counterpart. The two processes are organized in series: in the first phase, the organic fraction undergoes mechanical pre-treatment and hot biological degradation in the absence of oxygen in a plug-flow (piston-flow) horizontal digester. The section is set up in a fully enclosed environment, ensuring improved effectiveness of the process and reducing its climate-altering and odor emissions.
From the process, biogas and an intermediate product, digestate, are obtained; the latter, mixed with a structuring substance consisting mainly of clippings and prunings, is then treated until it is transformed into compost, completing the waste recovery cycle.
From the biogas, through an upgrade system, 2,500,000 Nm3/year of biomethane will be extracted to be fed into the grid, enough to cover the annual needs of 1,800 households. This also prevents the emission of 9,000 tons of CO2 into the environment each year.
Sienambiente’s Le Cortine anaerobic digestion line also marks a historic milestone for Entsorga. It is in fact the first to be built entirely by Entsorga and fully in Italy. We are responsible for the design of the biodigester, including the agitator shaft, as well as the quality controls on incoming materials.
STRENGTHS OF THE ANAEROBIC SECTION
- Total safety and minimal environmental and health impact: no odor or dust is released into the outdoor environment. All operations take place in an enclosed environment with a slight vacuum.
- reduced operating and labor costs: full plant automation reduces access to waste treatment areas, protecting the health and ensuring the safety of operators.
- low energy consumption due to the use of high-efficiency equipment (Spider overhead crane).
- maximum yield in biogas production
- no need for a water cleaning plant
- minimum amount of waste to be sent to landfill (depending on the quality of the incoming waste)
- high industry 4.0 automation
- limited area commitment
