The National Aeronautics and Space Administration (NASA) has purchased Gevo’s renewable Alcohol-to-Jet fuel (ATJ) (earlier post) for aviation use at the NASA Glenn Research Center in Cleveland, OH. Gevo’s ATJ is manufactured at its demonstration biorefinery located in Silsbee, TX, using renewable isobutanol produced at its Luverne, MN, isobutanol plant.
The biorefinery, where Gevo also produces bio-paraxylene and bio-isooctane, is operated in conjunction with South Hampton Resources.
Over the past several years, NASA has been studying the effects of alternate biofuels on engine performance, emissions and aircraft-generated contrails at altitudes typically flown by commercial airliners. Results from recent tests showed that a blend of renewable jet fuel and standard jet fuel significantly reduced emissions, as compared to using standard jet fuel alone, while not affecting flight operations.
Gevo has developed and demonstrated the technology to convert isobutanol into aliphatic and aromatic hydrocarbons using known chemistry and existing refinery infrastructure:
Isobutanol produced from starch or biomass is dehydrated over an acidic catalyst to produce isobutylene, which is then further reacted to product mixtures of longer chain aliphatic hydrocarbons.
A portion of this material is reacted separately to form high density aromatic compounds./p>
Hydrogen gas, a byproduct of the aromatization reaction, is used to remove unsaturated bonds in the aliphatic material.
The hydrocarbons then are blended in proportions that can meet all ASTM standards for fuels: isooctane is a dimer of dehydrated isobutanol and is a major component of the premium value alkylates, a key gasoline component; a trimer of the isobutylene (dehydrated isobutanol) is a jet fuel blend stock; a polymer of four and five isobutylenes can make a diesel blend stock.
Gevo’s patented ATJ fuel is a true drop-in fuel, designed to be fully compliant with aviation fuel specifications and provide equal performance, including fit-for-purpose properties and engine compatibility. Through testing initiatives, partners such as Lufthansa and the U.S. military are looking to certify our ATJ and accelerate its full-scale commercialization.—Patrick Gruber, CEO