Turn food waste into clean and renewable fuel

　　When we eat, our body converts food into energy to provide power for our lives. But what about the energy stored in the 80 billion pounds of food that the United States throws away each year? As part of advancing sustainable energy solutions, scientists at the Department of Energy’s Pacific Northwest National Laboratory are turning food waste into clean, renewable fuels to power our planes, trains and cars.
　　For decades, PNNL researchers have supported the Department of Energy’s goal of producing fuel derived from plant or animal waste in a cost-effective manner, rather than petroleum. They have developed technologies to produce these biofuels from raw materials such as agricultural residues, forest by-products, algae, and even sewage sludge and manure.
　　In their recent efforts, the researchers successfully converted the food waste from the Lewis-McChord Joint Base and the Wild Wolf Ridge Correction Center into an energy-intensive biofuel, which helps replace today’s fossil fuels. Early results indicate that food waste may bring benefits in efficiency, economy and environment.
　　PNNL researchers are exploring how to convert such waste into biofuels in a cost-effective manner. They have tested a variety of potential raw materials, including waste grains from local breweries, as well as canteen waste and kitchen scraps. First, from the perspective of efficiency, compared with other raw materials, food waste has a higher fat content and lower mineral content, so more gallons of biofuel can be produced per ton of food waste. Kitchen waste can easily be made into pumpable slurry, which simplifies production and minimizes the cost of pretreatment required for other raw materials.
　　Second, compared with other raw materials with higher planting and harvesting costs, food waste may be obtained at a lower cost. Food waste has been produced in large quantities, and people are willing to pay for it. Using food waste instead of planting crops such as corn or soybeans to produce biofuels can also avoid using arable land for fuel instead of food.
　　Finally, converting this waste into fuel can avoid sending it to landfills, which is important given the recent ban on food waste. As the garbage decomposes, it produces methane, which is a strong greenhouse gas, and if it is not captured, it will be released into the environment.
　　PNNL scientists pursue this win-win-win approach, starting with mixing waste, usually with the help of custom-made equipment called “muffin monsters,” which will go from bones and abrasives to seeds, wrapping paper and packaging. Everything is ground to produce a slurry that can be pumped into the reactor and converted into an energy-rich biofuel that can be used to replace traditional fossil fuel fuel mixtures.