Organic waste is probably what we’re most familiar with in our day-to day lives. The leaves you rake in your yard, the banana peel you throw out each morning, or what you clear off your dinner plates each evening. Organic waste encompasses any waste material that comes from plants or animals and is biodegradable.
According to the US Composting Council, organic waste is the largest trash component and makes up two-thirds of our solid waste stream. Until recently, the most sustainable solution for food waste and other organic waste was composting. Through composting, organic waste is decomposed to create fertilizer and other soil amendments. Composting can take place right in your backyard or on a much larger scale at local waste processing facilities.
What is Anaerobic Digestion?
Anaerobic digestion takes composting to the industrial level and has become very popular with food manufacturers as a way to handle food waste. Much like composting, the organic waste is decomposed to create a nutrient rich soil fertilizer. However, anaerobic digestion uses specialized sealed tanks that remove all oxygen while also speeding the process so that break-down takes as little as five days.
In addition to producing fertilizer, anaerobic digestion creates a second valuable by-product. As the waste breaks down, it creates a biogas, which can be used to to create power and heat energy.
Real Life Organic Waste Solutions
Here are a few innovative and surprising ways that companies are using anaerobic digestion to responsibly reduce the amount of organic waste disposed of each year, as well as produce renewable energy resources.
1. Potato Power
One of the UK’s biggest food manufacturing companies, 2 Sisters Foods, is using potato scraps from their mashed potatoes and pie product lines to create 3,500 megawatt hours of electricity and 5,000 megawatt hours of steam, through anaerobic digestion, to power their manufacturing facility. Their sustainability goals are to reduce carbon emissions, cut food waste, reduce water use and achieve zero landfill across their facilities.
2. Pumpkin Power
Over one billion pounds of pumpkins are produced in the U.S. each year, many of them decorating your front porch throughout the fall season. In Oakland, CA, discarded pumpkins and other organic waste is collected and put through anaerobic digesters. The resulting gas is used to generate electricity. It is estimated that digesting 100 tons of food waste for five days a week could generate the amount of electricity needed to power 1,000 homes.
3. Grocery Power
Several Kroger-owned grocery chains are beginning to use anaerobic digestion to process the 150 tons of food waste they create each day. The resulting energy is used to power their 49-acre campus, including a 650,000 square foot distribution center. Currently, the organic waste solution is off-setting more than 20% of their energy demand.