NPK

Herstellung wasserlöslicher NK, PK oder NPK-Dünger auf Basis von Biogas Gärrest und Gülle

Energy-intensive production, rising costs, and increasing dependence on imports are key challenges in the use of nitrogen- and phosphorus-containing artificial fertilizers. The use of fermentation residues from biogas plants is one way to limit the use of synthetic fertilizers. However, direct fertilization has disadvantages. The typically high ammonium content in fermentation residues often results in undesirable emissions and fertilization that does not meet requirements. Therefore, this joint project aims to develop a new process for producing water-soluble potassium phosphate and nitrate fertilizers from fermentation residues. Water-soluble fertilizers enable crop fertilization tailored to requirements and are also high-priced. This considerably reduces the above-mentioned ecological problems and increases added value. The economic chances of success are also supported by the fact that biogas plants are often unable to fully utilize the heat released, which means that energy reserves are available at low cost for the concentration steps required for the crystallization of the fertilizer salts.

Within the joint project, PFI focused on developing processes for separating ammonium and phosphate from fermentation residues and on the biological oxidation of NH4 to nitrate. Project partner BTN is concentrating on developing processes for the direct oxidation of ammonium in fermentation residues. The partner K-UTEC converts the nitrate and phosphate concentrates obtained into marketable fertilizers.

The project with the funding code FKZ 2224NR023Ais financially supported by the Federal Ministry of Food and Agriculture (BMLEH) as part of the “Sustainable Renewable Resources” funding program via the project management agency FNR.