The anaerobic digestion or methane fermentation is a complex natural bio-chemical process, which consists of a bio-degradation of organic substances under anaerobic conditions (without oxygen) yielding the biogas: the biogas is a methane-rich gas that can be used as a fuel.
The anaerobic digestion is activated by various bacteria groups, which act sinergically in three subsequent phases:
– First phase: hydrolysis;
– Second phase: acid fermentation;
– Third phase: methane-genesis.
The process usually takes place in the temperature range of 10-60°C, and it allows to convert the inlet organic fraction into biogas (gaseous phase) and fertilisers (slurry phase). Temperature of the process needs to be monitored and controlled in order to optimise each phase, thus maximising the biogas yield.
The efficiency of the process, that is the production of biogas, is dependent on the level of bio-degradability of the inlet biomass nutrients; usually, the anaerobic digestion consumes 40-60% of the inlet organic fraction, this fraction being dependent on the residence time of the biomass into the digester.
The present project refers to a biomass anaerobic digestion plant (animal manure, silomais, agricultural residues) for power (about 1MWe) and heat generation, which is owned and operated by AgriEnergia Val Pesio Company (Societa’ Consortile a responsabilita’ limitata).
The whole initiative has been technically reviewed by the Thermochemical Power Group (TPG) of the University of Genoa (Dipartimento di Macchine, Sistemi Energetici e Trasporti – Facolta’ di Ingegneria), of which Luca Marigo is member as Renewables Area Manager.
Agrienergia Valle Pesio S.c. a r.l. has been constituted to build and operate the digestion plant, located in Chiusa di Pesio (CN), Italy, producing energy from renewable resources. The company is mainly participated by the following shareholders:
– Allevamento Baudovit di Baudino Livio e C. S.S.
– Sweet Milk, Cooperativa agricola
– Azienda agricola Baudino Pasquale e figlio Ezio
– Geo Consult di Pierangelo Pasqualin;
– Skyline Energy s.r.l. (Energy Service Company)
