Are Green Jet Fuels Finally Ready for Takeoff?

When United Airlines test pilot Ryan Smith took off from Houston earlier this month for a 90-minute flight over the Gulf of Mexico, he wasn’t carrying any passengers, but he did have a special fuel powering the Boeing 737. One engine was burning standard petroleum-based aviation fuel from a Texas refinery, while the other was running on gas produced entirely from leftover cooking oil and grease from a factory in Los Angeles. But because the sustainable fuel is made from plant-based sources instead of petroleum, and because plants consume carbon dioxide during photosynthesis, it has a carbon footprint that’s about 70 percent smaller. This is a true step in the path of decarbonization.” Imagine sustainable aviation fuel, or SAF, as part of a big plant-fuel-engine carbon recycling loop, rather than a one-way ticket that sends carbon from a subterranean oil patch directly to the atmosphere. Only two plants in the United States make SAF: the World Energy waste oil plant in Paramount, California, and the Gevo facility in Silsbee, Texas, which takes an alcohol-based compound made from corn called isobutanol and distills it into aviation fuel.