Anaerobic Digestion Process
The anaerobic digestion process
Anaerobic digestion consists in the organic substance by methanogenic and hydrogenotrophic bacteria degradation in conditions of anaerobiosis in the absence of free oxygen.
Biomasses are composed of organic materials that can be degraded anaerobically to allow the biogas production (methane and carbon dioxide).
How does the anaerobic process work?
The anaerobic decomposition process is structured in three phases:
- Hydrolysis: the action of hydrolytic and fermentative bacteria transforms present in organic materials carbohydrates, proteins and lipids into simpler substances such as fatty acids, monosaccharides, amino acids and alcohols;
- Acidogenesis: in this phase of the process the substances produced in hydrolysis is transformed, by acid-forming bacteria, into volatile fatty acids with the anhydride carbonic, ammonia and hydrogen sulphide production;
- Acetogenesis: these molecules are digested producing hydrogen, carbon dioxide and acetic acid.
These substances are then transformed into biogas from which can be obtained electricity, heat, through cogeneration, and/or biomethane by means of Upgrading plants.
Thanks to the special technologies and applied plant engineering choices, the anaerobic digestion’s natural biological process maximizes both energy recovery and the solid residues of the process stabilization.
Biowaste, thanks to its technology, provides the best tailormade configuration for every project.
Our anaerobic digesters are designed to obtain optimal mixing conditions and a constant temperature during all the process.
The anaerobic digestion’s sdvantages, in summary, are:
Energy recovery (electricity and thermal energy);
Benefits deriving from the biomethane's sale;
Stabilization of digestate for agricultural use, replacing the one of chemical fertilizers;
The waste and organic waste valorisation with reduction of disposal costs;
The greenhouse gas emissions reduction;
Benefits deriving from the tariff for the electricity produced and fed into the network;
Incentives generated by the exploitation of thermal energy not in self-consumption;
Partial reduction of the nitrogen concentration in the digestate produced, compared to the incoming biomass;