Animal Wastes Become Oil
Turkey and pig slaughterhouse wastes are daily trucked into the world’s first biorefinery, a thermal conversion processing plant in Carthage, Missouri.1 On peak production days, 500 barrels of high-quality fuel oil better than crude oil are made from 270 tons of turkey guts and 20 tons of pig fat.
From the loading bay hopper, a pressurized pipe pushes the animal wastes into a brawny grinder that chews them into pea-size bits. A first-stage reactor breaks down the wastes with heat and pressure, until the pressure then rapidly drops in order to flash off the excess water and minerals. These are shunted off to dry into a high-calcium powdered fertilizer.
The remaining concentrated organic soup is poured into a second reaction tank, where it is heated to 500°F (260°C) and pressurized to 600 pounds per square inch (42 kilograms per square centimeter). Within 20 minutes the process replicates what happens to dead plants and animals buried deep in the earth’s sedimentary rock layers, chopping long, complex molecular chains of hydrogen and carbon into the short-chain molecules of oil. Next, the pressure and temperature are dropped, and the soup swirls through a centrifuge that separates any remaining water from the oil. That water, because slaughterhouse waste is laden with nitrogen and amino acids, is stored to be sold as a potent liquid fertilizer.
The oil produced can be blended with heavier fossil-fuel oils to upgrade them or simply used to power electrical utility generators. The good news is that it appears this thermal conversion technology can also be adapted to process sewage, old tires, and mixed plastics. And it is also energy efficient. Only 15 percent of the potential energy in the feedstock is used to power the operation, leaving 85 percent in the output of oil and fertilizer products.