Turning old into new
Students and company cafeteria work on energy recovery
At Mankiewicz, we look for sustainable solutions not only when developing new products, but also in many other areas of the company. An exciting example can be found in our company canteen.
Our dual students Thomas and Bjarne became aware of the use of bio-waste from our canteen for sustainable energy production during the Ex_Kurs Summer School project. True to the motto "Think inside the circle", they planned and built a biogas plant together with 30 other students from other universities. "The goal of the project was to model the recyclability of biowaste for commercial kitchens - because biowaste is great for cooking," says Thomas. Thomas and Bjarne mainly worked on the technical team, which took care of the entire process, starting with the collection of food scraps and ending with their recycling into biogas.
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.
Thomas looks back on the Ex_Kurs Summer School project with enthusiasm: "I really enjoyed working on a joint project with other students from completely different disciplines: "I learned how to communicate my ideas in such a way that they make sense even to someone with a different way of thinking. And I had a chance to look at problems from a different perspective and find new ways to approach them. It was a great feeling to work with a group that has a common goal of advocating for sustainable living and thus a better future."
Mankiewicz has supported this special project from the very beginning with material and monetary allowances and regularly participates in the SummerSchool with students. The Ex_Kurs has been taking place on the Wilhelmsburger Zinnwerke site since 2019 and offers young people the chance to work creatively and independently on forward-looking projects.