Biodigester & Composting Plant

The biodigester based in Nera Montoro,

reduces the amount of waste sent to landfill, recovers energy through the process of anaerobic biodigestion for the production of biogas and recycles material through the aerobic treatment process for the production of compost. The plant is located on a total area of about 10,000 square meters, 7,000 square meters of which are roofed.

The plant GreenAsm based in Nera Montoro has been authorized by the Integrated Environmental Authorisation (AIA) and can handle up to 43,500 tons / year of organic fraction of municipal solid waste and / or other organic matrices. The expected energy recovery from biogas production is equal to 4.8 GWh / year, while from the aerobic treatment will result quality compost to be used in agriculture and gray compost.
The activity started in October 2012, with a treated amount of approximately 15,000 tons in the first year of operation. The construction of the biodigestion plant contributes to limit the cost of treatment of municipal solid waste in the entire integrated territory “ATI4 Terni” and have a positive impact on reducing emissions through reduced transport of materials treated.

The integrated GreenAsm plant recovers energy through the process of anaerobic biodigestion for the production of biogas and recycle material through the composting process. The organic fraction of municipal solid waste, transported by appointed companies which are also responsible for the plant, will be crushed and sieved in a closed location. Subsequently waste will be sent to an horizontal biodigester, for a period from 12 to 15 days. The biogas generated in the process feeds the cogenerator GE Jembacher that produces electricity and heat, which reduces the use of fossil fuels and limit the emission of greenhouse gases. The heat and electricity exceeding the required consumption amount will be delivered into the grid.

The digested product – with the innovative cycle optimization – is mixed with fresh and green waste and sent to the composting section. The second phase of the process takes place in sealed containers with no emissions into the atmosphere, the biotunnel. The exhausted air output is then cleansed of potentially polluting agents and odors through the use of a “scrubber” (washing tower) and a biofilter (filtering surface consists of wood chips of 750 square meters)

At the end of the whole process, that does not cause any emission into the environment and that replicate under controlled conditions the same process occurred naturally, is obtained a radical transformation of the starting material, realizing ” a quality Compost.” It is a material that can be used as a soil conditioner of agricultural land, to improve its physical-mechanical constitution and fertility thanks to the contribution of organic substance. The compost takes the smell and appearance of the fertile soil and is sanitized and stabilized. In addition, the compost is less heavy, takes up less volume, has a lower water content and thus does not release slurry. it is, a product that can be handled, transported, stored.