Biofertiliser

The biofertiliser (often referred to as digestate) is one of two end products produced by anaerobic digestion (the other being biogas).  

The biofertiliser can be a liquid and solid product or mechanically separated into liquid only and solid only, the quantity of which is dependent on the feedstock.

The liquid fraction, which has a similar consistency to slurry, can be used as a biofertilser; and the solid fraction, a compost like material, can be used as a soil conditioner on agricultural land.

There are few losses in nutrients within the process; the nutrients that enter as part of the feedstock will be present in the biofertiliser.   The concentrations of nutrients are again dependant on that within the feedstock.   Examples of the nutrient ranges are;

Nitrogen - 2.3 -4.2 kg/tonne

Phosphorous - 0.2 - 1.5 kg/tonne

Potassium - 1.3 - 5.2 kg/tonne