Super digestate fertilizer for organic crop production

Purpose and goal

The project has, in laboratory- and pilot scale tests, successfully verified co-digestion of farmyard manure where phosphorus and nitrogen-rich poultry manure is the main substrate followed by digestate processing with solid-liquid separation and nutrient concentration of the liquid with evaporation enabling cost effective long distance transport. The results have contributed to planning the plans for a full-scale plant by develop the basis of design but also credibility for implementation, resulting in investment grant and formation of a new economically stronger Company.

Expected results and effects

A successful project will, in the short term, results in building a plant that produces about 70 GWh biogas/year for renewable automotive fuels. Produced solid and liquid digestate are valuable fertilizers that can nitrogen fertilize 12 000 ha/year of organic cultivation and phosphorus fertilize 20 000 up to ha/year. In the long term, the potential in Sweden is estimated to 5 to 10 large-scale manure digestion plants of this size with poultry manure as the main raw material. This will lead to reduced climate impact and redistribution of nutrients, which will reduce the eutrophication.

Planned approach and implementation

The project contained the following components i) 6 month pilot digestion tests with the prospective substrates, ii) applied trials of separating and concentrating the digestate, iii) laboratory tests to determine biogas potential for feedstocks, and to determine the potential for increased gas production by post-digestion, iv) calculation of the nutrient value and the function of the concentrated fertilizer in organic farming, v) demonstration of the concepts and results through presentations in 4 seminars where in total 220 persons participated.