“High confidence level” as alcohol-to-jet fuel closes in on historic ASTM approval

As ASTM technical balloting is underway and as experts sift through and request revised submissions of technical data, insiders are pointing to an early 2016 approval for Gevo’s renewable alcohol-to-jet fuel. 

In Washington, CAAFI Executive Director Steve Csonka declared a “high confidence level” in the approval of a key fuel standard, for alcohol-to-jet fuels, by ASTM, the international technical standards organization.

Csonka said that the fuel pathway, which is critical to Gevo’s expansion of its renewable jet fuel production capacity, could be approved as soon as the first quarter of next year, but cautioned that a final technical committee ASTM ballot and a full ASTM ballot stood between the fuel and the marketplace. ASTM plans to hold those two ballots concurrently, after Gevo provides additional technical data that was requested following a first technical ballot in recent weeks.

Gevo has been working through the rigorous ASTM process for six years, which includes extensive engine testing and data analysis by all of the major original equipment manufacturers to establish the specification for this drop in fuel. Once approved, this fuel can be seamlessly integrated into the existing distribution infrastructure and onto commercial aircraft.

The primary concerns that remain?

Snecma has raised a question regarding a time interval relation to distillation temperatures, and Gevo, which had relied to an extent in the first ballot of work done previously in other fuel approval cases, was asked to provide additional data of its own.

In addition, Airbus raised a concern regarding the dielectric curve data — in this case, primarily relating to the way that the application presented the data for conventional fuels, and how the slope of the new fuels compares to conventional fuels was left in some doubt.

Over in military circles

A third concern raised was from the military sector. Although this is a commercial fuel spec, military buyers are now obtaining commercial-spec fuels (instead of a separate military spec), which is saving the Department of Defense “millions of dollars per year,” according to one source.  In this case, important testing that was supposed to be completed by the US Air Force by this time relating to afterburner performance in F-35 fighters is not yet done — and is now not expected to be completed until the second half of 2016.

The military has in other cases of new fuels not completed testing, but has been able to obtain “NTO” letters (“no technical objection”) from key engine and airframe partners, and military-related delays have not held up approval of a commercial fuel spec, to date. However, in this case, while GE and Rolls-Royce provided NTO letters, one manufacturer felt unable to do so until completion of the F-35 testing.

The resolution?

In this case, Gevo will not have expanded production capacity to compete on new military contracts until after the testing is completed, so the military concerns have been laid to rest commercially by an assurance that these fuels will not be sold to the military in the interim.

“This is what ASTM is all about. Negative ballots at this stage are a normal part of the technical validation process, and we would have expected one more ballot at the committee level anyway.” Csonka told the Digest. “At the end of the day, there’s going to be no significant delay.”

Do these issues represent technical failures? “It’s not a technical failure,” said Csonka. “These are technical concerns that originate from the way the data is organized. But we can’t slough this off completely, because the approval process is not complete, and there’s always some possibility, even if slim, that there could be some difference between this fuel and the fuel we know and love. But my expectation, based of what I know and see, is that there are pathways to solving the issues, and we are not impacted on timeline.”

Csonka expressed confidence that Gevo was experiencing some of the same concerns that have come up previously with new renewable fuels — for example, Amyris — and that the resolution of concerns would follow a similar pathway to ultimate success.

The Bottom Line

A “high confidence level” in approval. “No impact on timeline.” “No technical failures” seen to date. What does that add up to? This train is heading for the station, barring new complications. Alcohol-to-jet, here it comes.

More on ASTM’s latest activities

ASTM sets standard D7862 for three types of butanol

Neste and Boeing team up to accelerate ASTM approval of aviation biofuels

ASTM revises jet fuel standard to allow biodiesel blends

Amyris and Total to begin marketing drop-in jet fuel following ASTM revision

Joule renewable diesel and jet fuel meet ASTM standards

Gevo and aviation fuels

Gevo’s ATJ is produced at its demo biorefinery in Silsbee, TX, using isobutanol produced at its Luverne, MN, fermentation facility. Gevo is currently operating its Luverne plant in Side-by-Side operational mode, whereby isobutanol is being produced in one of the facility’s four fermenters, while the other three fermenters are dedicated to ethanol production. The isobutanol that Gevo is producing is meeting product specifications for direct drop-in applications, as well as for use as a feedstock for the Silsbee biorefinery to produce hydrocarbons such as ATJ.

In May, Gevo and Alaska Airlines announced a strategic alliance to purchase Gevo’s renewable jet fuel and fly the first-ever commercial flight on alcohol-to-jet fuel (ATJ).

The demonstration flight is expected to occur after Gevo receives ASTM International certification for its fuel.

In March, NASA purchased volumes Gevo’s renewable alcohol-to-jet fuel (ATJ) for aviation use at the NASA Glenn Research Center in Cleveland, Ohio. Gevo’s ATJ is manufactured at its demonstration biorefinery located in Silsbee, Texas, using renewable isobutanol produced at its Luverne, Minnesota, isobutanol plant. The biorefinery, where Gevo also produces bioparaxylene and bioisooctane, is operated in conjunction with South Hampton Resources.

In December 2014, the US Navy’s Naval Air Systems Command announced its first successful alcohol-to-jet supersonic flight, fueled by Gevo’s renewable isobutanol. This was the first aviation test program to comprehensively test and evaluate the performance of a 50/50 ATJ blend in supersonic (above Mach 1) afterburner operations – a critical test to successfully clear the F/A-18 for ATJ operations through its entire flight envelope. This military specification would allow for commercial supply of ATJ fuel to the Navy and Marines Corps.

In April 2014, Gevo announced tan agreement with Lufthansa to evaluate Gevo’s renewable jet fuel with the goal of approving Gevo’s alcohol-to-jet fuel for commercial aviation use. Lufthansa’s testing is being supported through work with the European Commission.