Although biogas production is efficient at reducing agricultural emission by converting the biomass into electricity and thermal energy (cogeneration), or biomethane, its major weakness is that it produces a digestate with a high concentration of nutrients (N, P, K) and a volume of around 90-95% of what was fed into the digester. This means that large agricultural areas are required for the application of the fermentation residues (because of nitrate regulations), which often results in long transport routes. 

In this project we set out to bring together all stakeholders for the installation of a new process to minimize spreading digestate flows and to economically valorise the minerals (nitrogen, phosphorus and potassium, among others). By using digestate instead of synthetic fertilizers, it is possible to save energy, limit consumption of fossil fuels and reduce our carbon footprint. 

DETRICON is proposing innovative low-cost solutions to produce green fertilizers with stripping technology and an optional module of solar drying. These nutrient recovery technologies allow for solutions adapted to the farmers needs in terms of capacity, available spreading surface and treatment costs. In the current context of problematic water and soil pollution in many parts of Europe, the DIGESMART project allows farmers to transform their waste into energy and fertilizer. 

DIGESMART solution aims to reduce the environmental impact of European farms by facilitating the market uptake of innovative solutions for the treatment, recycling and valorization of digestate. 


The DIGESMART solution consists of treating and recycling the digestate to produce green NPK fertilizers, hence reducing the environmental impact of the agricultural sector, as well as providing an economic incentive. 

The environmental benefits include: 

  • A reduction in the use of water resources and soil pollution

  • A reduction in the environmental impact notably CO2 and CH4 emissions associated with the manufacturing of organic fertilizers and to the treatment of agricultural wastes 

  • The preservation of natural resources through nutrient recovery (N, P, K, among others) from organic renewable sources

  • A reduction of fossil fuel consumption and transport emissions (due to the concentration of the effluents and volume to be transported)

  • An improvement in energy efficiency of biogas plants


The economical benefits include: 

  • Lower needs of digestate capacity storage, hence lower costs of storage facilities

  • An increase in the economic sustainability of small/middle size biogas plants due to the reduction of digestate treatment costs and, in some countries, additional income from the use of the heat generated by biogas production

  • The valorization of digestate into green fertilizers will lead to marketable products with a high value on the market


The general objective of the project is the complete valorization of agricultural waste through recycling digestate into green fertilizers. The general objectives of the project are:

  1. Reduction of the volume of liquid digestate fraction (concentration of nutrients), hence leading to a reduction of storage, transportation costs and pollutant emissions

  2. Reduction of energy consumption of digestate treatment process by reutilisation of the energy produced by cogeneration and solar power

  3. Development of a digestate treatment solution adapted to small/middle size farms and to the geographical and environmental situation

  4. Development of a low-cost digestate treatment solution, with lower costs than other solutions available on the market

  5. Development of green fertilizers with low carbon footprint and high agronomic value


The specific objectives of the project are: 

  1. To evaluate the regulatory context and energy costs relevant to the DIGESMART solution

  2. To test the digestate treatment solution at farm level

  3. To evaluate and compare the green fertilizer production system with existing technologies

  4. To develop the Life Cycle Analysis of the whole process

  5. To validate the solution developed and replicate it

  6. To facilitate the transfer of the results to European farmers


The DIGESMART project offers the solution of digestate valorization, contributing to reduce inorganic fertilizer amounts through recycling of nutrients (N, P, K) of digestate in an environmentally friendly way. 

The main results are: 

1. To bring to light the relevant issues from the regulatory context and costs that could influence the uptake of the DIGESMART solution in participating and targeted countries: Belgium, Denmark, France, Germany, Italy, Netherlands and Spain

2. First market implementation through installation, testing and validation at farm level of the DIGESMART solution (pilot plant of digestate treatment): a low-cost solution to produce green fertilizers with technologies for nutrient recovery from digestate (centrifuge, stripping and solar drying)

3. Field trials results from green fertilizers application: agronomic value (N, P, K, among others), crop yield response and optimal use of green fertilizers adapted to geographical and meteorological differences between northern and southern countries

4. Life Cycle Analysis study of the DIGESMART solution 

5. Development of a business plan to replicate the DIGESMART solution in the participating and targeted countries