The University of Notre Dame has made several moves toward becoming more sustainable in the past couple of years. The Office of Sustainability has created the University Comprehensive Sustainability Strategy which includes several waste diversion goals for the University. One way Notre Dame is working to reduce waste on campus has been inspired directly by the research on food waste on campus at ND by a junior Chemical Engineer major, Matthew Magiera. As a result of this student’s research, Notre Dame has invested in three Grind2Energy machines by Emerson Electric. Notre Dame is only the second university in the nation to invest in this machine. Altogether, Notre Dame has three Grind2Energy machines, and it’s predicted that they will help reduce non-consumable food waste on campus by more than 2,000 pounds per day. These Grind2Energy machines will allow ND to turn food waste into clean, renewable energy for local farmers and reduce total campus waste by 10% per year!
The Grind2Energy machine is a system that recycles food waste into clean water and renewable energy such as electricity, heat or compressed natural gas. It works via a cyclic process. First, organic food waste is collected and put into the grind chamber. Then, the Grind2Energy grinds the food waste. The resulting slurry goes into the holding tank outside through a pipe. This liquid waste is transported by a septic tank to a local anaerobic digestion facility. There, the food slurry is recycled by recovering water and converting captured methane into renewable energy. The remaining nutrient-rich organic material can be used as a natural fertilizer that promotes more food growth.
At Notre Dame, this new method of food disposal is fairly easy, especially considering the huge benefits it creates. There is a Grind2Energy system at the Center for Culinary Excellence, North Dining Hall and South Dining Hall on campus. In the dining halls, dishwashers and bussers sort out food to be put in the system. The system then grinds and stores the waste which is later transported 30 miles south of campus to a farm called Homestead Dairy in Plymouth, IN. Besides transportation, the entire process is only 20 minutes long. Furthermore, ND donates the energy to local farms, but money is actually saved through lower trash costs. The anaerobic digestion of food waste will turn this waste into a gas product, liquid product and soil product. The gas product formed from the waste collected from ND, local farms and other companies in the area is burned for energy and sold to the Northern Indiana Public Services Company (NIPSCO). The energy from this gas alone creates enough power for approximately 1,000 homes in Plymouth, IN. The liquid product is sold to farmers as fertilizer, and the soil product can be recycled as cattle bedding.
So what do ND students have to do? It’s simple: sort out napkins before putting your plates onto the conveyor belt in the dining hall! Remember, paper napkins (along with paper towels, paper plates and tissues) are never recyclable. Because these products usually come into contact with food wastes and grease, they are unable to be “cleaned” during the recycling process. However, magazines, copy paper, tissue boxes and paper towel cores can still be recycled! It is important to always throw away paper napkins when sorting them out of your food waste, even if they are unused! Of course, recycling everything possible is important. However, it is also important to not contaminate recycling bins, so that everything that is correctly sorted is not thrown out due to contamination!
