When Thomas learned that the waste from the Mankiewicz canteen was also being converted into energy, he took a closer look: For some time now, the Mankiewicz Canteen has been cooperating with ReFood GmbH, which, among other things, offers the service of collecting food waste and converting it into sustainable energy. "To reduce the negative impact of food waste, we start with waste separation," explained Bianca from the canteen team. "All the food that is not eaten and ends up in organic waste is processed to produce energy and fertilizer." But to avoid waste, adjustments are also made to the amount of food prepared. With this system, the canteen managed to minimize food waste per person to just 6 g per table guest in August 2021, and only fill one of the two 240l garbage cans halfway by the collection date.
The large garbage cans will be collected twice a week by ReFood. The biomass is then refined in a hydrocyclone that separates lead and glass chips from the biomass. The oil that comes out is filtered and shipped to biodiesel producers with other collected oil residue. This creates a biomass that is converted to biogas in a biogas plant. The remaining fermentation product contains nutrients such as phosphorus and nitrogen, which are used as organic fertilizer in agriculture, thus closing the nutrient cycle again. So, as with the Ex_Kurs project, "Think inside the circle" applies here. Although the Mankiewicz canteen does not yet produce the energy itself, who knows what will be possible in the future.