Pretreatment of roadside grass clippings
ProNatura and Innec have been investigating how to improve the quality of roadside grass clippings for materials applications. They are investigating the impact of sun drying, milling and sieving on the quality of the grass clippings. The challenge at the moment is to reduce the amount of dust formed after milling the grass fibers for size reduction.
Dry anaerobic digestion of roadside grass clippings
Vanheede, UGhent, HoGent and Millvision have been investigating how to best create value from the digested grass clippings resulting from the bulk anaerobic digestion conducted at Vanheede. To better understand the impact of digestion time on fiber quality, a pilot-scale experiment has been started and the fresh fibers quality will be compared to that of semi-digested and fully digested fibers.
Liquid fraction of grass as fertilizer
In 2019, Canterbury Christ Church University, with the help of UGhent, cultivated tomatoes using the liquid fraction of grass as fertilizer. Even though tomatoes were produced, this fraction negatively affected the plants health. These partners are now investigating pretreatments, like anaerobic digestion, to improve the use of the nutrients present in the liquid fraction as a plant fertilizer.
Production of board planks from roadside grass clippings
Avans has produced a prototype board plank in 2020 to be used as a nature path instead of wood, which was just one of several prototypes produced by Grassification. Now, they are further upgrading their process to have a final product that will be installed in a nature path as a real-life demonstration of the potential of the Grassification project!
Heavy metal content of roadside grass clippings
Even though previous projects have indicated that the heavy metal content of roadside grass clippings should not be a great cause of concern, this is still a sensitive topic for regulatory agencies. We are currently analyzing the heavy metal content of samples from Belgium, the Netherlands and the UK and also checking how the distance from highway exits affect this content in Belgium.