The Commercial Aviation Alternative Fuels Initiative

Richard Altman, who spent 39 years as a propulsion engineer at Pratt & Whitney, is executive director of the Commercial Aviation Alternative Fuels Initiative. The industry-government alliance was formed in 2006 to push development of alternative fuels in an effort to reduce aviation’s carbon footprint. Altman spoke with Air & Space Executive Editor Paul Hoversten in October.

Air & Space: What’s the most promising alternative fuel for commercial airliners?

Altman: There is no single silver bullet. We view this as silver buckshot. One of the advantages of biofuel is that it can be generated and manufactured locally. We’re presently certifying from seed oil crops, and many of those crops such as jatropha are grown plus or minus 20 degrees from the equator. So it grows in places like India, parts of Latin America, Africa, but not the United States. Here the crop would be something like camellina, a rotation crop for wheat. Later on, we’ll be getting into technology that breaks down sugars out of grass and other cellulosic materials. But the fuels will vary by region. Our goal is to make sure we have all the processes that are required to be able to use those seed stocks as jet fuels.

A&S: Is there a challenge in getting airlines to use it?

Altman: It’s no problem in getting the airlines to use it. The airlines are ready. The understanding of the long-term economic and environmental consequences [of oil fuel] has really blossomed in the last few years. The airline industry does not usually have a long-term focus; it’s usually how do I get to next month without going bankrupt? That has changed. They clearly do have a long-term view now.

A&S: What’s the outlook on the technical side?

Altman: A process that’s based on gasification of solids [known as the Fischer-Tropsch process] has already been qualified, and the seed oil process we hope to have qualified in December. That leaves us with at least three other processes we want to seriously take a look at. One is based on a fermentation process that uses insects to consume the crop and then excrete it into the hydrocarbon molecules that are used in jet fuel. We also have a high-temperature pressure process that is important because it provides the needed complex hydrocarbons called aeromatics. The third is to convert [fuel] from alcohol using cellulosic materials. Those are coming down the pike.

A&S: How is your group working to promote alternative fuels?

Altman: CAAFI is a coalition of people from the airlines, airports, aerospace industry, and the federal government. We sit at the top of the supply pyramid. On R&D, we depend on the manufacturing sector such as Pratt & Whitney, Boeing, and General Electric. That brings in the university partnerships. We’ve done a good job of bringing the aviation people and the academic people together in alliances that wouldn’t have formed in other circumstances.

A&S: How does alternative fuel affect engine performance?

Altman: The whole idea of the certification is that it won’t affect engine performance. Our fuels are a 50-50 blend of alternative fuel with petroleum fuel. The certification ensures that the engine doesn’t know the difference. All of the primary qualities [of jet fuel] such as freeze point or flash point have what we call purpose properties, of which there are dozens. That includes things like lubricity or how slippery it is; does it provide the same wear; does it have the same electrical conductivity. So when we say “drop-in,” that’s what we mean: It’s the same. And by the way, the infrastructure doesn’t know the difference either. So the pipelines, the fuel tanks, and everything else at an airport really is totally indifferent as to whether it has these fuels or conventional jet fuel.

A&S: Is 50-50 the limit for jet fuel?

Altman: No, we can go further. There are certain technical issues, including a specific issue with aeromatic content and complex hydrocarbons. We need a certain percentage of those molecules in order for the airplane engine seals to swell in order to prevent leakage. It’s possible [someday] that we could be 100 percent bio [for jet fuel] but it’s down the road a bit. The limitation is not the fuel itself. There is one fuel from South Africa that is fully synthetic and it’s used by an airline that flies out of Johannesburg. We’re not ready to certify 100 percent fuel. Nor do we have the supply. If you don’t have the supply, to some degree having 100 percent biofuel is almost academic.

A&S: What’s the goal for the airline industry?

Altman: Probably the most significant goal is to have carbon neutral growth by 2020. That goal was set very carefully because it accounts for new products coming into play and continuous improvement in fuel consumption in our industry. We’ve already improved fuel consumption by some 70 percent over a 40-year period. We also account for the new air traffic control system Next Gen that’s going to create efficiencies.

A&S: What do you mean by carbon neutrality?

Altman: The aviation industry will continue to grow, but when you bring in fuels that have a better carbon lifecycle outcome than oil, it allows the industry to generate no more carbon even with growth. The goals most embraced by the industry are those associated with what the actual data tells you about carbon and the carbon lifecycle. It starts from the ground and goes all the way through the exhaust of the airplane, not just what the airplane burns. That’s the important part. When you calculate carbon lifecycle, it depends on the nature of the feedstocks and the crops, not just the burning of the fuel. Because quite frankly there’s very little difference between oil fuel and bio-jet fuel in terms of emissions measured out the back of the airplane. That’s going to be purely a function of fuel consumption.

A&S: Synthetic fuels have been around since World War II. Why has it taken so long for them to be pushed for aviation?

Altman: Cheap oil. The economics are the reason it didn’t happen earlier. Now you’ve got oil that isn’t so cheap, concerns about what will happen in the future, and the environmental element which is much stronger today. When I took this on in 2006, I was under the impression that if the price of oil dropped a bit, the whole thing would go away. It looked like a nice retirement job for me. But clearly it hasn’t happened that way. 

A&S: Is getting investors a problem for the bio-fuel industry?

Altman: I don’t think we have a problem that everyone else doesn’t have. The question is, will we find solutions before others do? And that’s going to require some policy changes in the government. Things like, do you do crop insurance? We have those for food crops, but not energy crops. Are you going to have a [federal] subsidy for these fuels, say, $1 a gallon? Most of the producers say you need it on a three-year basis to justify investment. The good news is, we know where the problems are. The U.S. Department of Agriculture and the aviation sector are engaged in a very intense dialogue in those and other areas. I think within the next six months to a year, we’ll see some very significant breakthroughs on the investment side.

A&S: What’s ahead for alternative fuel research?

Altman: One is qualification of the fuel; we can’t go anywhere without that. Another is finding practical solutions on the investment front, which are in the works. And finally, ensuring that the feedstocks come along as quickly as could be used in engines. We could be in a position where you could actually fly the stuff and qualify more crops than could be grown. Those are the three challenges.