Fraunhofer Institute for Electron BeamThe ELBION project aimed to combine the phytosanitary treatment of seeds with electrons and biological agents, and to make the methods economically attractive also for seed producers with smaller annual volumes. To this end, Fraunhofer FEP developed a compact and cost-effective cylindrical electron source, while RAUSSENDORF GmbH designed a mobile, modular small-container system and investigated the effects of various bioactive substances.
The phytosanitary treatment of seeds with accelerated electrons offers a purely physical, environmentally friendly alternative to chemical dressing. While pathogens on and within the seed coat are reliably inactivated by this method, the embryo remains unaffected. This is possible because the penetration range of the electrons can be precisely tuned by the acceleration voltage of the beam generator. Depending on the seed variety, tailored recipes make sure that the recommended amount of energy is applied with appropriate surface uniformity and depth distribution. The ecological advantages as well as the phytosanitary efficacy of the electron treatment have been proven in long term studies together with German Federal Authorities and by decades of field experience in practical farming. To integrate the electron treatment into seed production workflows, Fraunhofer FEP has developed and transferred several container-based units (called “ISABEL”) over the past years. They are being operated as stationary installations in large-scale facilities or as mobile plants at various locations of smaller enterprises. These existing units are highly productive and can treat (depending on the seed type) up to 25 metric tons per hour, but they also require significant investment.
Therefore, the main objective of the ELBION project was to make the electron treatment economically appealing even for customers with smaller annual volumes (below 5,000 tons) thereby increasing its market share. In close collaboration with RAUSSENDORF GmbH, a mobile and modular small-scale container system was designed for
this purpose, which, following electron treatment, also allows for the application of bioactive substances. These typically contain organic fertilizers or beneficial bacteria and fungi that promote plant growth, enhance nutrient uptake or protect against soil-borne pests and diseases.
As a key component for this concept, Fraunhofer FEP has developed a novel cylindrical electron source which emits electrons into atmosphere radially outwards to treat the surrounding curtain of falling seed, facilitating a throughput of about 10 metric tons per hour, which fits the typical productivity of upstream and downstream processes in commercial seed processing plants well. Like the linear sources previously available, this source is designed for acceleration voltages up to 150 kV and a rated power of 30 kW. However, by housing all the components of electron generation and acceleration inside the cylinder, significant savings are achieved in terms of space requirements and manufacturing costs. A prototype of this new, patented source was successfully commissioned on a test rig of Fraunhofer FEP and used to treat seed samples for field trials. It shall be integrated with controls and supplies and installed into a mobile, production-ready container in the next development phase.
