Currently, the digestate produced by biogas plants is usually spread by farmers on agricultural lands. The digestate has a high concentration of NPK but in some European regions the amount of digestate is too important and contributes to soil and water pollution. Indeed an overdose of ammonium nitrate produces an excess of non-use by plants and thus the leaching of it and subsequent environmental consequences such as eutrophication.
The DIGESMART solution consists of treating and recycling the digestate to produce green NPK fertilizers, hence reducing the environmental impact of agricultural sector.
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.
- 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.
DIGESMART PROJECT - DIGESTATE FROM MANURE RECYCLING TECHNOLOGIES
Co-funded by the Eco-innovation Initiative of the European Union