Organic fertiliser, a byproduct of biomethane
Organic fertiliser is a by-product of biomethane. In the process of making the biogas, we’re left with a digestate which we use to make valuable organic fertiliser that is rich in Nitrogen, Phosphorus and Potassium (NPK).
What is organic fertiliser?
Organic fertilisers are plant or animal-based substances that are used to provide essential nutrients to soil and plants. Unlike synthetic fertilisers, which are made from chemicals and minerals, organic fertilisers are derived from natural materials and are considered to be more environmentally friendly. These can include compost, manure, bone meal, and other materials that are high in nitrogen, phosphorus, and potassium, which are essential for healthy plant growth. These fertilisers help to improve soil structure, increase the availability of nutrients to plants, and enhance the overall health and productivity of the soil.
How do we make organic fertilisers?
We make biogas in anaerobic digester tanks (reactors). After the process, we’re left with biogas and a digestate. This material from the reactors is separated into a solid and liquid fraction through a decanter centrifuge.
The solid fraction from this separation process is referred to as ‘dried digestate’ and is a valuable organic fertiliser rich in NPK. The solid digestate from the decanter centrifuge has a moisture content of approximately 72 per cent, so it’s still considerably wet.
To make the fertiliser easier to transport, we dry it further. A fertiliser with a moisture content of approximately 20 per cent remains. We can put it in a bag so it’s more accessible to a wider range of customers who may not have the necessary farm equipment to handle the bulk solids.
How do you use organic fertilisers?
The solid fertiliser of 72 per cent moisture can be used in its bulk form and spread on cropland as a fertiliser. The 20 per cent fertiliser can be processed into pellets, providing a more gradual release of nutrients into the soil. In addition, it’s less likely to be blown away by the wind.