Can biofuel help clean up airline emissions?

An estimated 80,000 people have descended on Dubai for COP28.

This latest gathering, meant to expand multilateral cooperation on climate change, has record attendance and a massive carbon footprint to match. Some world leaders and corporate executives arriving in private jets — we’ve been assured — got there using sustainable aviation fuel, also known as SAF.

Just last week, a Virgin Atlantic passenger jet traveled from London to New York powered 100% by SAF. It came from “feedstock” that included used cooking oil, waste animal fats and what the company called a “small amount of synthetic aromatic kerosene.”

Critics call this a gimmick. And to be clear, right now SAF makes up a tiny slice of fuels that airlines use to fly us around.

Marketplace’s Lily Jamali spoke with Louise Burke, an energy analyst and vice president of business development at Argus Media, who said that could change.

The following is an edited transcript of their conversation.

Louise Burke: The big difference between sustainable aviation fuel and conventional jet fuel is that there is a very specific difference in the amount of greenhouse gas emissions that are released into the atmosphere. So these companies are essentially trying to reduce the greenhouse gas emissions. The aviation sector in general is kind of one of the last remaining industry sectors to really take a good look at this and see how they can actually reduce their carbon emissions.

Lily Jamali: Which is a big problem for them, right?

Burke: I mean, aviation overall accounts for 2 to 3% of the global greenhouse gas emissions. That was a report that was released by the [United Nations’] Intergovernmental Panel on Climate Change. So, the big issue with the aviation industry is what are the methods? How can we reduce greenhouse gas emissions? So, there’s a couple of different ways, but SAF is one of the most significant ways to reduce for that sector.

Jamali: We’re describing sustainable aviation fuel as a sustainable fuel source, but it does release carbon dioxide when it’s burned just as other fuels do. I wonder if you can set the record straight for us. Is it actually accurate to use phrases like “carbon-free” as a label here?

Burke: That’s a good question. I think each type of sustainable aviation fuel has a different level of carbon intensity. In some instances, the processes that are being worked on will be carbon-free, and you’ll actually see this net-zero type of technology. At this point, we’re seeing that the current sustainable aviation fuel, which is the HEFA-based process [for hydroprocessed esters and fatty acids]. That’s that chemical process of taking that animal waste and that used cooking oil and manufacturing a SAF molecule. The maximum we’ve seen is it reduces carbon intensity by 80%. However, everyone’s working very hard on this, and we will see net zero and potentially even more positive ways of ensuring that there are no carbons being released into the atmosphere. So yeah, we’re on that path, but we’re not there yet.

Jamali: In practical terms, we have to talk about price. How much more does SAF cost as compared to traditional aviation fuel?

Burke: It costs anywhere from 2½ to 5 times more than conventional jet fuel. Keep in mind, conventional jet fuel has fully scalable plants right now. We’ve been using conventional fuels for many, many years. So now you need new technology as well as the scalability of some of these plants. Right now, for example, jet fuel is around $3 a gallon and if you were to look at how much SAF costs, it’s about $7.50 to $8 a gallon. So, in order to actually produce more SAF, we need more government incentives. So, government policy is definitely very key.

Here in the U.S. we have a type of policy that promotes the potential production of biofuels in general. So, it’s renewable diesel as well as SAF. In Europe, they have a different way of handling it. In Europe, they say, “We’re putting in a blend mandate” and, in other words, you must use SAF in the process. So, each region handles it differently. But policy is key, and all the other shareholders are very key, private investment, etc., to really ensuring that we will have sufficient SAF to help with the decarbonization initiatives.

Jamali: Can SAF then be something that’s used with regularity? Can it be scaled up at the level that the proponents of this technology want to see?

Burke: That’s a great question. One of the biggest issues that we have on the current production pathway process, which is called the HEFA based pathway, is feedstocks. So, think about used cooking oil as the new crude oil. We always hear about crude oil in the traditional conventional markets. We hear questions about whether there is going to be enough crude oil. In some instances, there is pressure on this market to ensure that the feedstocks that we have that are used in the current technology pathway will be sufficient, so that we will be able to scale up.

Jamali: I’m always interested in ways we can make this stuff feel more real and less abstract, and one question that comes to mind is what does sustainable aviation fuel look like? And given that it’s coming from the fat of dead animals, does it smell different than traditional aviation fuel?

Burke: What’s important about this product is that the final product is a drop-in fuel, which means it completely replaces and has identical characteristics to conventional jet fuel.

Jamali: So it looks and smells the same?

Burke: Absolutely. I don’t know about smell, I haven’t smelled it directly, so I don’t know about that. But the idea is that it’s chemically exactly the same and identical to what you’d see with conventional fuel. The benefit is that it’s a lower-carbon fuel.

Jamali: If this push to scalability continues, are we as consumers going to be asked to do things differently? Maybe be more careful about discarding the oils that we use to cook, the waste that we would otherwise throw away?

Burke: I think when you look at this market, you have different participants in it. And one of the most interesting ones that I’ve encountered is what we call the feedstock aggregators. They’re the ones that go to McDonald’s and pick up the used cooking oil and that go to the tallow facilities and pick it up. It is valuable. And I think that you may be able to see the other point, which I think if anyone looks at their airline ticket these days, you can actually measure your carbon footprint. The airlines will tell you how much carbon you’re actually using by taking that flight and they may even ask you to pay in for a green premium, and that could be your way of contributing as well.

More on this

Louise Burke made the point that government policy is helping to drive a lot of SAF adoption in the aviation industry. This past year, as it implemented the Inflation Reduction Act, the Treasury Department established a sustainable aviation fuel credit for producers.

Now, the energy and airline industries are trying to make it easier for corn-based ethanol to qualify for that credit. They sent the Joe Biden administration a letter pushing for that just last week.

Many environmentalists oppose allowing ethanol to qualify, saying production can involve removing trees and wetlands to plant the corn it’s made from. And that can raise the carbon footprint of the land where it’s grown. They say only “waste” products from corn, like leaves and stalks, should qualify.

In Gary, Indiana, plans for a plant that turns Chicago trash into jet fuel has the support of the mayor, but those plans have received pushback from a group of self-described “badass women.” They note that the process of converting trash to fuel is itself extremely energy-intensive.

The leader of an environmental group tells Inside Climate News that he refuses to use the term “sustainable aviation fuel” because of the implication that it’s beneficial, which he doesn’t think it is. He calls it “alternative aviation fuel” instead.

And U.K. economist Josh Moos tells the BBC that the science would suggest there “really is no such thing as sustainable aviation.” The only real solution to bring aviation emissions down, he said, is to fly less and reduce global demand for flights.