4500Nm3/d biogas

Case History

An innovative and efficient Made in Italy biogas plant in South Korea, perfectly integrated in the production cycle of the company. Realised by IES Biogas, it is able to produce 4500 Nm3 of biogas per day, also producing thermal energy for the operation of the digester and quality natural fertilizer. The plant is fed by squeezed OFMSW and pig manure.

TECHNICAL DATA SHEET // 4500 Nm3/day biogas

BIOGAS PRODUCTION 4,648.80 Nm3/day

BIOGAS PRODUCTION 4,648.80 Nm3/day
Pre-tank: n.1 Ø 10 m h=8m
Food waste leachate: n.1 Ø 10 m h=8m
Digesters: n.2 Ø 22 m h=6m
Post-digester: n.1 Ø 22 m h=6m
Ventilation tank: n.1
Pig manure: 78 ton/day
Squeezed OFMSW: 52 ton
Annual biogas production: 1.696.812 Nm3
Average concentration of methane (CH4) in biogas: 60 %

Biogas is one of the most widely used alternative sources of renewable energy production.

Biogas is the product of microbial degradation of organic substances in the absence of oxygen, a process commonly called anaerobic digestion. It is a mixture of gases, mainly composed of methane (CH4) and carbon dioxide (CO2).

Slurry from the barn, together with corn and triticale silage, is daily put into the two mainly digesters. Here they remain for about 100 days and then pass into the covered storage tank. The process is therefore of “double-stage” type and takes place at a temperature of 38-42 degrees (mesophilia). The “double-stage” technology allows a safe and elastic fermentation process but, above all, guarantees adequate retention times.

The covering of the storage ensures a complete degradation and therefore an efficient exploitation of the biomass used. Moreover, it also allows a greater reserve of biogas and a better desulphurisation (removal of H2S). Desulphurisation is biological, by injection of very small amounts of oxygen. The internal structure and a desulphurisation network offer an excellent surface for the colonisation of the desulphuriser bacteria. The biogas produced is conveyed to the cogenerator, which produces electricity and thermal energy.

The electricity is transferred to the public grid, the heat is reused partly for the fermentation process, partly for the district heating of barns and offices. At the end of the fermentation process the digestate is obtained: a liquid material, completely odourless, with very high agronomic value, with improved characteristics compared to the raw material.

The digestate undergoes a process of solid/liquid separation: the solid that has the consistency, appearance and smell of a “soil-humus”, is distributed in the fields with a manure spreader or sold to specific users such as flower-gardeners.