More than one billion gallons of hydroprocessed esters and fatty acids (HEFA) fuels—renewable, drop-in diesel and jet fuels such as Neste’s NEXBTL—were produced worldwide in 2014, according to the US Energy Information Administration (EIA).
HEFA fuels are hydrocarbons rather than alcohols or esters and are the most common drop-in biofuels; they can be used in diesel engines without the need for blending with petroleum diesel fuel. Currently, HEFA fuels are also approved by ASTM International for use in jet engines at up to a 50% blend rate with petroleum jet fuel.
HEFA fuels are produced by reacting vegetable oil or animal fat with hydrogen in the presence of a catalyst; the equipment and process are very similar to the hydrotreaters used to reduce diesel sulfur levels in petroleum refineries.
There are currently 10 plants worldwide that produce renewable diesel, one of which is ENI’s former petroleum refinery in Venice, Italy. Total is planning to convert its La Mede, France, refinery to HVO production, and there are four other renewable diesel projects also underway. Finnish Neste is the world’s largest producer of renewable diesel. Other major producers are Italy’s ENI, U.S.-based Diamond Green Diesel, and Swedish refiner Preem.
One potential consumer for HEFA biojet is the US Department of Defense, which intends to use biojet in its JP-8 jet fuel. JP-8 is a versatile fuel used in military vehicles, stationary diesel engines, and jet aircraft. This use of a common fuel simplifies logistics. There is also civilian interest in non-petroleum jet fuel. Alaska Airlines, KLM, and United Airlines have demonstrated the use of HEFA biojet fuel on commercial flights since 2011.