Emily Kwong

Ryan Spies, the managing director of sustainability for Alaska Airlines, is definitely feeling the pinch.

Oh, really?

Yeah.

Well, honestly, that is an airline company's worst nightmare.

They need our butts in those seats to meet their bottom line.

So in a strange way, this global crisis has kicked down the door for a new kind of conversation about alternatives to jet fuel.

And someone who pointed this out to me is Annie Petsonk, the former assistant secretary of transportation for aviation and international affairs under the Biden administration.

Today on the show, greener flights.

We explore a bunch of alternatives to jet fuel.

Their chemistry, their cost, and what it would actually take to decarbonize the aviation industry for good.

Yeah, so the most commonly used SAF is made from cooking oils, fats, and greases.

I love those.

Yeah, at a molecular level, they're similar to jet fuel.

These long chains of hydrocarbons go through a chemical glow-up to be something that airplanes can fly on.

Cool.

This process is known as HEFA.

which stands for hydroprocess esters and fatty acids.

And by the way, that Virgin Atlantic flight we mentioned earlier was mostly powered by HEFA fuel.

And this fuel is chemically similar to renewable diesels, which are already used in land and aquatic vehicles.

And this fuel works for planes.