What is agricultural biogas production?
What is agricultural biogas production?
Biogas production is part of the energy transition. It enables the production of renewable energy. But what exactly is “biogas”?
Biogas is produced from organic material. So-called feedstock can be, for example, organic residues from food production (e.g., onion and potato peelings), food waste (overstored, expired, leftovers …), renewable raw materials, liquid manure / slurry as well as landscape preservation material. After the digestion process, the digestate is reused as fertiliser for the crops. This represents a natural cycle: what was previously taken from the soil in nutrients via the plants is returned.
The process:
The various feedstocks are placed in an airtight vessel called a ” digester”. The principle is theanaerobic (without oxygen) microbial degradation (digestion) of the input materials. Special microorganisms break down the organic substances in the absence of oxygen, producing methane, carbon dioxide and small amounts of other gases. The gas mixture produced by digestion, biogas, consists of about 50 % methane, a combustible gas that can be utilised for energetic purposes in various ways.
Two possibilities of utilisation:
- Cogeneration: with an engine driving a generator, the biogas is converted into electricity and heat.
- Upgrading: with pre-treatment and subsequent separation of the gases, the biogas produced becomes biomethane or renewable natural gas (RNG), which can be fed directly into the gas grid. This is because biomethane is chemically identical to natural gas. The only difference between the two is their origin.
agricultural biogas production
Agricultural biogas production enables the use of agricultural residues such as manure and slurry to produce green energy. It also secures additional income for the farmer, decreases his expenditure on chemical fertilisers and reduces the production of greenhouse gases … So many advantages!