The discovery of petroleum irreversibly changed the course of human history. Unfortunately, the party’s entering its final stages. Oil and gas are finite resources: Once they’re gone, they’re gone. And that means clever people around the world need to find solutions, and fast, to prevent serious disruption to our way of life.
Lots of progress has already been made on this front. Thanks to a long-overlooked byproduct of commercial cooking, more could be on tap. The key lies in used cooking oils, such as cottonseed oil, that restaurants typically throw away once they’re no longer suitable for use. Relatively recently, engineers devised a workaround that allows modified diesel engines to run on certain types of vegetable oil (or biodiesel, as the fuel is known when it’s used to power internal combustion vehicles). That has restaurateurs and chefs keen on reusing cottonseed oil and other high-energy cooking aids—and possibly profiting in the process.
The question of whether biodiesel can work on a large scale hinges on something called “energy density.” That’s a fancy way of expressing how much energy a given amount of fuel holds. Petroleum products like gasoline are so successful because they’re very energy dense. While vegetable oil isn’t quite as efficient, it packs a surprising punch.
Not all vegetable oils are equally energy dense, however. Due to its unique chemical composition, which features lots of energy-packed polyunsaturated fats, cottonseed oil may be a better biodiesel candidate than other cooking aids, such as olive oil. Since cottonseed oil is already used in lots of high-volume cooking operations—it’s a common medium for frying fish and french fries—there’s a lot of it to go around after hours. Instead of throwing it away, many restaurant owners now (literally) sell it out the back of their shops and pocket a cool profit.
More Work to Be Done
The case for cottonseed oil—or any other oil, for that matter—as biodiesel isn’t yet open-and-shut. While the technology is proven to work, more research is necessary to work out the kinks, reduce operational costs, and improve efficiency in road-ready engines. And a compelling marketing campaign may be necessary to convince truck owners to use cooking byproducts in their vehicles. Depending on how said research and marketing goes, though, drivers across America could be using cottonseed oil in biodiesel engines sooner than we think. One thing is certain: With chefs and restaurant owners clamoring for a new way to use old oil, there won’t be a supply problem anytime soon.