Turning digestate into organo-mineral fertiliser – the process

The process is based on chemical hydrolysis under controlled aerobic conditions and includes:

1. Feedstock preparation
Digestate from AD is used as the main input material.

2. Hydrolysis and mixing
The digestate is treated with a combination of substances such as:

• • Acids (sulfuric and phosphoric acid)
  • Alkaline compounds (potassium hydroxide)
  • Additives (e.g. haemoglobin, copper sulfate, lignosulphonate, peat, ash, micronutrients)
  • water

This step stabilises the material and enhances its nutrient content. The process is currently non-automated, operating under controlled temperature (below 60°C) and pH conditions.

3. Granulation and neutralisation
The treated material is processed into a granulated fertiliser, making it easier to store, transport and apply.

The final product

The output is a granulated organo-mineral fertiliser, combining organic matter with added nutrients.

Field trials (e.g. on maize) have demonstrated its effectiveness when applied at different nutrient rates.