PRESS RELEASE OF THE TECHNICAL UNIVERSITY OF COLOGNE

PhD student Bastian Greisner presents innovative wastewater treatment technology at the Tech Tour NRW Green 2023

Press Release (in German)

So far, there is no legislation in the EU that addresses climate gases. This would change if the Green Deal is adopted.

The green transition is a top priority for Europe. EU member states want to reduce greenhouse gas emissions by 55% by 2030 compared to 1990 levels and become climate neutral by 2050. The staggered measures range from drastic emission reductions to investment in cutting-edge research and innovation, to preserving our natural environment. For the first time, the climate gases carbon dioxide, methane and nitrous oxide are to be severely restricted by law. For the time being, the Green Deal targets industry and large farms.

If the Green Deal is adopted, strong impacts are to be expected in agriculture, especially with regard to methane. Methane is 86x more harmful than carbon dioxide, and agriculture is considered the largest emitter of methane. The storage of manure and digestate alone is responsible for 15% of all methane emissions in Europe.

The liquid manure, pretreated by means of a separator and fine filtration, flows through the first osmosis stage, where most of the water is removed from the manure by selectively passing only water molecules through a special membrane into a saline solution. The Agrogreen process ensures that the critical ingredients of the manure, i.e. nitrogen, phosphorus, potassium and the whole organics, cannot pass through the membrane and are gently discharged as a concentrate without the addition of any external pressure.

This reliably protects the downstream reverse osmosis unit from the organic matter contained in the manure and digestate, so that the reverse osmosis unit only has to perform the simple task of a desalination unit, which greatly increases its service life and durability. The optional following polisher step refines the effluent water to drinking water quality, which can be discharged or stored on site for further use.

The saline from the salt cycle is treated in the second osmosis stage to produce clean water and brine. The brine is continuously returned to the first osmosis stage, while water is continuously discharged from the second osmosis stage.

The complete nutrients of the manure and digestate are retained in the separated solids and in the concentrate. The entire process runs without the addition of polymers or flocculants. There is no thermal or chemical product change. The manure concentrate is a valuable fertilizer that continues to fall under any fertilizer laws and regulations and can be spread on arable land and grassland within such scope.

The concentrate has significantly improved storability compared to untreated manure, as the biodegradation of the single-phase, solids-free liquid is stopped thanks to the Agrogreen process.

 The stop of the biodegradation leads to a strongly reduced outgassing of the greenhouse gases methane and carbon dioxide, as well as of ammonia and hydrogen sulfide. Thus, the Agrogreen process can contribute to a sustainable reduction of CO2 emissions from agriculture.

The clear manure or digestate concentrate, which is easy to store and handle, can be applied to fields as a valuable liquid organic fertilizer in accordance with respective fertilization legislation.

Due to the strong reduction of liquid manure and fermentation residues in the form of the liquid manure concentrate, needs-based fertilization can be carried out much more easily and in a more targeted manner. For livestock-heavy and landless farms, the costs of disposal via commercial manure discharges are significantly reduced.

The high-quality effluent water from the Agrogreen manure treatment is no longer subject to regulations on manure, which means that no manure or digestate storage capacities are required for it. Only the concentrate is still subject to manure regulations and must be able to be stored. However, manure and digestate storage capacities are now only required for the much smaller amount of manure concentrate generated. In relation to the initial amount of manure arising, the amount of concentrate is reduced by approx. 70%.

Even with sharply increasing regulations for increased manure storage, the existing storage capacities on most farms should be sufficient to avoid the expensive construction of additional manure storage facilities when an Agrogreen plant is acquired.

For farmers and biogas plant operators who are confronted with the legally required increase of their storage capacities, the investment in a manure treatment plant from Agrogreen is doubly worthwhile, as they can save themselves the high costs of increasing the storage capacity.

In large, centralized manure processing plants, the concentrate can additionally be evaporated and dried as granules, creating a marketable organic fertilizer that is easy to store and transport. Large farms considering a possible thermal processing of their manure or digestate can save a lot of money and effort by installing an Agrogreen plant before the process.

Thanks to the pre-treatment of manure with the Agrogreen technology, the amount of manure to be evaporated is reduced by about 70 percent, since instead of all the manure, only the remaining concentrate needs to be evaporated and dried. Thermal processing of manure and digestate is such an energy-consuming process that pretreatment prior to thermal processing by means of an Agrogreen plant is worthwhile in any case.

While plants for manure and digestate evaporation have to be regularly cleaned, as the solids from the manure can cause blockages, manual cleaning of such thermal evaporators after pre-treatment by an Agrogreen plant is not necessary. In the concentrate from the Agrogreen process there are almost only dissolved solids, which are automatically removed by the addition of acid in the evaporation plants, which is a requirement anyway.