Testing of next-generation biofuels is ahead of schedule, says the US Defense Advanced Research Projects Agency, which is increasingly confident it can demonstrate a surrogate JP-8 jet fuel 100% produced from biological feedstock.
Two of three contractors working under DARPA's BioFuels project are through the first stage of laboratory testing, says programme manager Doug Kirkpatrick.
The third should complete testing soon and one is already through the second stage. "We should have several hundred litres into engine stand testing by early summer," he says.
Industry is closely watching the DARPA project, which is viewed as the effort most likely to produce viable next-generation bio-jet fuels.
"We will demonstrate the ability to produce 100% spec-compliant JP-8 with bio feedstock," says Kirkpatrick. Results so far indicate the production price goal of less than $3/USgal can be met, he says.
One of the programme goals is to develop processes able to use diverse feedstocks that do not compete with food production.
The initial contracts are looking at crop and non-crop oils like soy and camelina, but DARPA is close to awarding contracts to develop processes using cellulosic feedstock, such as landfill, as well as algae.
"Cellulosic will take another two-and-a-half to three years", while the challenge with algae will be reducing the feedstock cost, says Kirkpatrick.
While they are identical to JP-8, the cost of qualifying biofuels from different sources is another concern. "Every time we change the feed we need 250,000-500,000 gallons to qualify it," he says.
Qualification and commercial production of the biofuels is beyond the scope of the DARPA programme, says Kirkpatrick, who is looking to the US Air Force take the initiative.
But the USAF is currently qualifying a 50% blend of synthetic JP-8 across its fleet and plans to meet 50% of its domestic needs with coal-to-liquid fuel by 2016.