Innovative process for environmentally friendly manure treatment comes onto the market

The BioEcoSIM process supplies both mineral ammonium and phosphorus fertilizers, and humus-forming soil improvers. Fraunhofer IGB

Around 200 million cubic meters of liquid manure from livestock farming end up in fields and meadows in Germany every year. More than 90 percent of the “black gold” consists of water and contains considerable amounts of the important plant nutrients nitrogen and phosphorus.

However, if more liquid manure is applied to the fields than the soil can bind and plants can absorb, microorganisms convert the ammonium nitrogen in the soil into nitrate that seeps into the groundwater. The problem: Where large quantities of liquid manure are produced, there is often a lack of arable land that needs to be fertilized. For this reason, fattening farms use so-called slurry exchanges to order tankers to transport their slurry to areas requiring nutrients – often several hundred kilometers away.

With its BioEcoSIM process, the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB has developed an environmentally friendly solution. “We have combined various processing steps into an overall process and integrated them in a modular plant,” Dr. Iosif Mariakakis, the Fraunhofer IGB nutrient expert, explains.

This allows the valuable nutrients to be recovered as easily transportable and precisely metered phosphorus and ammonium fertilizer salts. The solid organic components are also recycled by drying and conditioning using an energy-efficient process. They are then available in the form of humus-forming soil improvers. Farm slurry is thus almost completely recycled and the recycled components are returned to the soil.

Large-scale implementation and operator model

With SUEZ Germany, Fraunhofer IGB has now gained a licensee for the patented technology. The globally operating waste recovery and recycling company will invest in processing plants as operator. “Gradually, large-scale technical facilities are to be built, on a nationwide basis, to take surplus manure from farmers, breeding and fattening farms. Especially the logistical aspects of delivery will be taken into account when selecting the plant locations,” says Kai Bastuck, Head of Recycling and Recovery Business Unit Development at SUEZ Germany, describing the business model.

“By recovering the finite raw material phosphorus, Germany's dependence on phosphorus imports is reduced. This conserves finite phosphorus resources and reduces pollutant inputs into soils. In this way, we contribute to a sustainable future and turn nutrients into valuable substances,” says Bastuck. Fraunhofer IGB supports SUEZ Germany in the further development of the process.

A first processing plant with a turnout of one cubic meter per hour is currently being built as a “Living Pilot Plant” at SUEZ’s Zorbau site in Saxony-Anhalt. The flexibly designed plant will process cattle and pig manure, but also fermentation residues from biogas plants, and thus serve as a blueprint for further large-scale plants.

“An average industrial-scale plant then produces about 100 kilograms of phosphate fertilizer, 100 kilograms of nitrogen fertilizer and 900 kilograms of organic, nutrient-poor solids per hour from ten cubic meters of raw slurry,” explains Siegfried Egner, Head of Department at Fraunhofer IGB.

The potential savings in synthetic fertilizers are enormous. With a capacity of one million cubic meters of liquid manure per year, which corresponds approximately to the quantity from around one hundred pig fattening farms, a plant can produce 10,000 metric tons of ammonium fertilizer and 10,000 metric tons of phosphate fertilizer. This corresponds to almost the annual requirements for the whole of Germany.

The BioEcoSIM process

Various process steps are necessary to completely process liquid manure. In a first step, the aqueous liquid manure is pretreated so that the phosphorus is completely dissolved. It is separated into a solid and a liquid phase by two-stage filtration.

The dewatered solid phase is dried using an energy-efficient process, also developed at Fraunhofer IGB, which operates with superheated steam in a closed system and is therefore particularly energy-efficient. The dried organic components can optionally be further converted to organic biochar at 450°C via a pyrolysis step – as in the drying step in an atmosphere of superheated water vapor.

The liquid manure fraction contains the dissolved inorganic nutrients. In a precipitation reactor, phosphorus is first recovered and precipitated and filtered off as calcium phosphate, magnesium phosphate or magnesium ammonium phosphate. Nitrogen is recovered in a second step. For this purpose, the aqueous fraction is separated as ammonium sulfate by means of membrane destillation, and crystallized. What remains is water that contains only traces of phosphorus and nitrogen but is rich in potassium; this can best be used for irrigation purposes.

In extensive investigations and field studies, the Fraunhofer researchers have shown that the mineral fertilizers and organic soil improvers prepared from farm slurry can be used directly as readily available fertilizers and humus-forming substrates in agriculture.

The BioEcoSIM processing method was developed within the BioEcoSIM project, which was funded by the 7th EU Research Framework Program from October 2012 to December 2016.

Presentation at IFAT

At IFAT 2018, the partners will be available in Munich from May 14–18 to provide further information and for discussions: Fraunhofer IGB at the Fraunhofer joint stand in Hall B2, Booth 215/314, SUEZ Germany in Hall A6, Booth 239.

https://www.igb.fraunhofer.de/en/press-media/press-releases/2018/innovative-proc…

Media Contact

Dr. Claudia Vorbeck Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

Alle Nachrichten aus der Kategorie: Process Engineering

This special field revolves around processes for modifying material properties (milling, cooling), composition (filtration, distillation) and type (oxidation, hydration).

Valuable information is available on a broad range of technologies including material separation, laser processes, measuring techniques and robot engineering in addition to testing methods and coating and materials analysis processes.

Zurück zur Startseite

Kommentare (0)

Schreib Kommentar

Neueste Beiträge

Scientists achieve higher precision weak force measurement between protons, neutrons

Through a one-of-a-kind experiment at the Department of Energy’s Oak Ridge National Laboratory, nuclear physicists have precisely measured the weak interaction between protons and neutrons. The result quantifies the weak…

High-performance single-atom catalysts for high-temperature fuel cells

Individual Pt atoms participate in catalytic reaction to faciitate the electrode process by up to 10 times. Single-atom Pt catalysts are stable at 700 degrees Celsius and expected to stimulate…

New method allows precise gene control by light

A novel optical switch makes it possible to precisely control the lifespan of genetic “copies”. These are used by the cell as building instructions for the production of proteins. The…

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close