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?