Anaerobic digestion digestate: a valuable fertilizing resource 

Digestate is a product resulting from the anaerobic digestion process, a technology that mimics the digestive system of cows by converting organic matter into biogas and digestate. After processing, it comes in two forms: solid and liquid digestate.

The liquid digestate is rich in nitrogen (N), phosphorus (P), and potassium (K), which are essential for the growth of crops such as maize, cereals, or vegetables.

The solid digestate, which contains more stable organic matter, improves soil structure and fertility over the long term. These qualities make digestate a valuable resource for more sustainable fertilization. It also enables a more circular and production of fertilizer. 

Challenges and limitations of biogas digestate 

Currently, digestate from centralized anaerobic digesters faces several challenges: 

● The equipment required for spreading the digestate is expensive. 

● The ammoniacal nitrogen present in the liquid digestate can volatilize during field application, leading to a loss of fertilizing value and a potential environmental risk. 

● The presence of trace metals (TMs) or organic micropollutants, often linked to unwanted materials in the waste (plastics, glass, metals, etc.), raises both health and environmental concerns. 

Digestates from the BioCapsule®

The BioCapsule® integrating micro-methanization processes produces both a solid digestate and a liquid digestate, which can be used as a fertilizer to support plant growth. These digestates are tailored to farmers’ needs while minimizing usual drawbacks: 

● The liquid digestate from the BioCapsule® is compatible with drip irrigation systems, enabling targeted and efficient application both outdoors and in greenhouses – without extra cost for adapting material. 

● A key innovation of the BioCapsule® is the process developed in partnership with INRAE (The French National Research Institute for Agriculture, Food and the Environment). This process helps significantly reduce nitrogen volatilization during spreading, thereby improving agronomic efficiency and lowering greenhouse gas emissions. 

● Thanks to the semi-automated sorting line in the BioCapsule®, no unwanted plastics or metals are present in the produced digestates. 

● Its mesophilic digestion process (at 40°C) can eliminate up to 99% of pathogenic germs, according to ADEME (French Agency for Ecological Transition, 2014), ensuring the digestates are safe for use on soil. 

Thanks to all this innovative process, the BioCapsule® is also an efficient, safe, and environmentally friendly fertilization solution, suitable for both quick crop nutrition and long-term soil health improvement.