McDonald's Frying Oil Might End Up Fueling The Plane On Your Next Flight

Fry cooks at the nearly 14,000 McDonald's restaurants around the United States go through a lot of oil. Employees say McDonald's changes its fry oil about once a week at most restaurants. Used fry oil can actually be repurposed into biofuel, and the leftovers from McDonald's are beginning to end up in jet plane engines.

It may not sound appetizing, but the McDonald's Corporation openly shares about how it has been recycling used cooking oil into jet fuel on certain flights at Dallas Fort Worth International Airport. The project has been running since 2019 in partnership with transportation fuel producer Neste. After oil is used to fry chicken nuggets or fries, oil at McDonald's and some other airport restaurants is processed to convert it into a fuel that can be used for jet planes. Companies like Airbus are also beginning to experiment with flights run entirely with recycled fuels like biodiesel made from cooking oil.

It's not just airplanes that are being run on fuel made from cooking oil. According to McDonald's Great Britain, used fry oil from its restaurants gets converted into biodiesel for its food delivery vehicles. McDonald's environmental footprint is far from perfect due to its enormous energy usage and the amount of waste it generates, but recycling oil is certainly a good step for any restaurant to take.

Oils used for deep frying are typically vegetable oils or animal fats, because these have fairly high smoke points (which means they won't burn at high frying temperatures). Originally, McDonald's frying oil contained beef tallow for flavoring, an ingredient that stopped these fast food fries from being vegetarian. That's not the case anymore – McDonald's now uses a canola oil blend for its fries — although natural beef flavoring still appears in the many, many ingredients packed into McDonald's fries.

Biodiesel is typically made from vegetable oils and animal fats, making used cooking oil like canola oil a great choice. You can't simply dump the used grease into the airplane, of course. The process involves taking that used oil and combining it with an alcohol like methanol and adding a catalyzing agent. The chemicals and oil react and transform into a usable fuel source, with glycerin as a byproduct. Considering how bad air travel is for global carbon dioxide emissions, it's nice that we're using oil for more than just a McNugget before we dispose of it.