Optimism over the use of biofuels in the aviation sector appeared to be increasing among attendees at this year's Farnborough air show, with the possibility of scaling up production to the levels needed to make them a viable option starting to look like a more attainable goal than it did even just a year or two ago.
The International Air Transport Association's target of attaining carbon neutral growth in the airline industry in the medium term is achievable according to representatives of the United Alternative Aviation Fuels Display, which exhibited at Farnborough for the first time to publicise the progress that biofuels have made towards meeting that goal.
"We have a very important message. We're dealing with technologies that can contribute on a significant level to achieving carbon neutral growth - it's happening and it's happening now," says Richard Altman, executive director of the Commercial Aviation Fuels Initiative (CAAFI) and co-ordinator of the alternative fuels display.
The exhibitors behind the display - algae-derived oil producer Solazyme, bioenergy company Solena and Honeywell unit UOP - spent the week "trying to ensure the aviation community gives visibility" to biofuel producers, says Altman.
Solazyme does not rely on sunlight to grow its algae. Instead the San Francisco-based company produces jet fuel derived from microalgae, which is grown in the dark and fed with carbohydrate feedstocks. The company's work is "well beyond the laboratory or pilot phase" and it already has a product that is "ready to be scaled up at a commercial level", says the company's senior vice-president of government relations, David Isaacs. He points out that the technique employed by Solazyme to produce oil from algae by means of indirect photosynthesis turns a "multi-million year process into a couple of days".
While the jet fuel produced by Solazyme is not carbon neutral Isaacs says that, based on the lifecycle theory, it emits 85% less carbon dioxide than kerosene. "The reduction could be greater than 100% because the process avoids releasing methane into the atmosphere," he adds.
Companies such as Solazyme may be confident in their ability to scale up production to commercially viable levels, but the challenges lie in attracting the investment needed to make it happen. "The issue for large investors is that they need to see success models," says CAAFI's Altman. "Solazyme and Solena are sticking their necks out on this, but if the market dynamic comes into play the industry has a shot at being carbon neutral. The idea of carbon neutral growth has real legs. It's not unrealistic, it's just a matter of getting additional investment capital and doing more feedstock research."
François Gayet, secretary general of the Aerospace and Defence Industries Association of Europe (ASD), is confident that investment for making large-scale biofuels use a reality will come from companies outside the crude oil business. "We will see new emerging companies that are not oil companies [providing funding]. It is clear that the market will change in the future."
Boeing, which is participating in various regional biofuel projects around the world, is seeing "very strong investment and activity" in this field, says Boeing Commercial Airplanes managing director of environmental strategy Billy Glover. The level of global activity on the biofuels front "gives us a lot of confidence", he adds.
While Glover believes it will take "many, many years" for biofuels to be in a position to completely replace kerosene in the commercial airline industry, he says "a few percent" of the fuel used to power aircraft will come from alternative sources to crude oil by 2020, and "a large amount" will be in use by 2050. This "depends on investment", but he is confident that "as we emerge from the financial crisis" investment should increase.
Glover says the best type of biofuel depends on the region in which it is being produced. "What's best for one location is not necessarily best for another," he notes, adding that there are "going to be a lot more choices" in the future as new feedstocks and new processing techniques emerge.
"Five years ago, drop-in biofuel for aviation was impossible," says Glover. "Four years ago it was unlikely. Three years ago we thought 'maybe there's something here', but now we've got through most of the technical barriers. We are really ahead of where anybody could have predicted."
Aside from its work on biofuels, Boeing used the Farnborough air show to unveil its ecoDemonstrator programme, which is designed to increase the pace with which emerging green technologies for aviation come to the fore.
Boeing is delivering the flight test portion of the programme and will begin testing emerging environmental technologies on board a 737 in 2012. Further tests will be carried out on board a twin-aisle aircraft in 2013. Technologies will be tested in the areas of fuel efficiency, noise reduction and operational efficiency.
The programme is being partly funded by the US Federal Aviation Administration's continuous lower energy emissions noise (CLEEN) programme. Glover says the manufacturer will "select collaborations over the next year or so", adding that some of the technology used on the test flights "will be used in the development of new aircraft over the next few years".
Airlines themselves are increasingly putting their money where their mouths are by committing to trial biofuels. The latest addition to the list is British Airways, which has entered into a partnership with US bioenergy group Solena.
BA and Solena are evaluating potential sites in east London on which to build a sustainable jet fuel plant aimed at providing at least half of the airline's fuel needs for aircraft based at one of its London airports from 2014.
BA manager of environmental affairs Leigh Hudson says there are "some prominent sites in the East End that would be convenient to our operations at London City". She adds that while "if we could make the fuel in the East End it would be a neat solution for our London City operations", the carrier has not yet decided which of its London bases the new fuel will be destined for.
BA has not invested financially in the project but has given a "long-term commitment to buying the fuel", says Hudson. At the moment the fuel is certificated for 50/50 blends, but by the time the plant becomes operational in 2014 Hudson believes it is feasible that it could provide all of the fuel for aircraft based at one of BA's London airports.
The fuel will be derived from waste that would otherwise have gone to landfill. Solena converts the waste material into a gas which is then turned into liquid biofuel through the Fischer Tropsch process. BA will be the first airline to test jet fuel derived in this way. Hudson says the carrier expects the fuel to be "commercially competitive with the price of regular jet kerosene over the lifetime of the agreement".
The fuel will also be eligible for credits under the European Union's emissions trading system, which Hudson adds "helps the financial viability of the project as we will not have to buy any carbon credits for the Solena fuel".
BA has also teamed up with Rolls-Royce under the FAA's CLEEN programme to make a joint call to fuel suppliers to take part in a study to evaluate alternative aviation fuels. The two companies have put out a joint request for information inviting suppliers to send in alternative fuel samples to undergo a series of tests.
Hudson says these tests will include lab tests and rig tests. Eventually full engine tests will be carried out on up to two fuels on a BA 747 RB211-524GT powerplant. The tests will be carried out at Rolls-Royce's testing facility in Derby, UK and will assess performance parameters, handling and emissions.
The programme will test both neat fuel samples and samples that need to be blended, but the fuel "must not unduly compete with food production, cause land or water stress, nor have potential adverse effects on ecosystems", says BA.