Fri 18 Apr 2008 – Speaking at the ‘Future Fuels Aviation’ conference in London this week, Sebastian Remy, Head of Business & Program Support Engineering, Airbus, said plans were underway to conduct the first biofuel-powered flight by an Airbus aircraft in 2009. Although preparations are at an early stage, Airbus says it is keen to test a second-generation biofuel.
Airbus used a Rolls-Royce Trent 900-powered A380 for carrying out the early February in-flight test of a Gas-To-Liquid (GTL) synthetic fuel blended 40/60 with standard Jet-A1 fuel. Remy said the test results had been entirely positive and the aircraft had operated perfectly. “There are no unknown unknowns,” he stated.
Remy said additional testing and investigation would take place within the Qatar consortium that was set up late last year (see story) in partnership with, amongst others, Qatar Airways, Rolls-Royce and Shell (who supplied the GTL fuel for the test flight). This would look at potential environmental benefits, such as on local air quality, and aircraft performance. Airbus, he said, would now actively support generic synthetic fuels approvals for commercial aviation through the ASTM (US) and Def Stan (UK) industry protocols.
Remy told delegates GTL fuel had similar characteristics to future Biomass-To-Liquid (BTL) carbon neutral fuels and was a “good precursor” to second-generation biofuels. He believed Qatar Airways could be using GTL in-service by as early as next year.
In the longer term, Airbus estimates second-generation, high-yield biomass stocks like algae should reach maturity by 2015. Approvals for flying airliners using second-generation, high-yield biomass HVO (hydrogenated vegetable oil) biojet fuel could be in place by 2020, and up to 25% of jet fuel could be alternative fuel by 2025, and possibly up to 30% by 2030.
Remy concluded by saying: “As far as alternative fuels for commercial aviation are concerned, Airbus believes in an extended international and cross-industry collaboration, and will support such initiatives.”
Sian Foster, Corporate Sustainability and Responsibility Manager for Virgin Atlantic, said pilots and observers onboard Virgin’s Boeing 747 biofuel demo flight last month had noticed no difference in performance between the engine containing the 20/80 biofuel blend and the other three, and no issues had been identified during post-flight maintenance.
She said the next steps in the process towards achieving a sustainable market for aviation biofuels were:
· Guaranteeing availability of sustainable (socially, environmentally, economically) fuel in viable quantities;
· Gaining acceptance from all relevant stakeholders (airlines, airports, manufacturers, fuellers, NGOs, governments); and
· Ensuring approval of biofuels and certification by manufacturers, military and other relevant bodies.
Chris Lewis, Fuels Specialist at Rolls-Royce, told delegates that plans for the Air New Zealand Rolls-Royce-powered Boeing 747 test flight were still in progress for later in the year but could not confirm what type of biofuel would be used. “We are still looking around for a suitable biofuel that is technically viable, has long-term sustainability and can be scaled out to the industry.” Lewis said his company was working with the University of Sheffield in testing potential fuels.
Despite the airline enthusiasm for emission-reducing biofuels, identifying a suitable ‘drop-in’, sustainable replacement biofuel that meets both the exacting performance standards of current Jet-A kerosene and was available in sufficient quantities for testing is proving difficult. Dr Tim Held of GE Aviation said a number of interested biofuel suppliers had approached the aero-engine manufacturer but the requirements were an obstacle. Although only a small amount of biofuel was required for initial lab testing, Held said around 200,000 gallons were needed for full durability testing.
Representatives from the US Air Force reported a commitment to certify the use of a 50/50 blend of Fischer-Tropsch (FT) synthetic fuel (synfuel) and standard military JP-8 (similar to Jet-A) fuel in all types of its aircraft by 2011 was on course. Jeff Braun of the USAF Alternative Fuels Certification Office confirmed a B-1B bomber had recently achieved the first supersonic flight using synfuel.
By 2016, spurred on by energy security concerns, the goal is for 50% of Air Force consumption to come from domestically produced synfuel blends from sources using CO2 capture and reuse technology. Currently, however, FT synfuels are only produced in large-scale quantities in South Africa, Malaysia and Qatar.
Alternative fuels have so far largely been limited to FT Coal-to-Liquid fuels which, without carbon capture and storage, have limited environmental benefits. However, the USAF has been looking at ‘greener’ BTL synfuels and biofuels, which have a greater potential for significant CO2 reduction potential, said Dr Tim Edwards of the USAF Research Laboratory. He said there was a requirement under section 526 of the US Energy Dependence and Security Act 2007 that any alternative fuel must have a smaller carbon footprint than traditional fuels.
The size of a large airline, Braun said the USAF used about 2.6 billion gallons of fuel in 2006, down from a peak of 3.1 billion in 2003. However, its fuel bill in 2006 was in the region of $5.9 billion compared to $2.6 billion in 2003. “Every $10 increase in a barrel of oil leads to a $600 million increase in costs to the Air Force,” he said. The Air Force estimates that FT synfuels could be $20 to $40 cheaper per barrel than the current price of oil.
Robert Midgley, Technology Manager, Aviation Fuels for Shell Aviation, said BTL promised a number of benefits as a jet fuel. Its properties suggested a potential for hotter, more efficient engines, reduced soot emissions, longer engine life and a 94% reduction in the CO2 footprint. Midgley said it was “probably the first route to greener skies.”
However, a number of factors mitigated against its viability, not least the amounts of biomass required (15 million tonnes of biomass were required to produce 30,000 barrels per day of BTL fuel) and the cost of transporting it, plus the very high costs of building production plants.
Another option being looked at by Shell is Hydrotreating Vegetable Oil, which through existing technology removes oxygen and hence provides a good energy density, unlike most first-generation biofuels such as ethanol, which are unsuitable for jet fuel. The kerosene it produces is very similar to GTL in that it has low sulphur and aromatics properties. The production process is also cheaper than BTL but the feedstock is more expensive and there were potential availability problems.
Algae is widely seen as having the greatest potential as a biojet fuel, said Midgley, but commercial scale availability is some years away. Through a collaborative partnership in Hawaii, Shell is constructing a pilot plant to grow marine algae in saline ponds. Microalgae produce at least 15 times more oil per hectare than alternatives such as rape, palm, soy and jatropha.
He saw three main challenges facing the oil and biofuel industries over biojet fuels:
o high capital investment requirement
o competition with biodiesel
o economics of feedstock costs
o potential carryover into final properties
o narrow carbon spread
o wide ranging feedstock and process approvals needed
o land usage, monoculture and biodiversity
o finding biomaterial that has a high growth rate, low production and cultivation costs, and has the right natural carbon chain length.
Midgley said high capital and product costs and an unclear business case had so far led to few players entering the alternative fuels market. Legislation in Europe and the US had also meant there were better returns to be made from biodiesel production, which aviation would have to compete with.
This was a theme echoed by Tim Bingham, Technical Director of Air BP. The ‘carrot and stick’ approach by governments in Europe to increase the use of biofuels in ground transportation would see demand quadruple by 2020, he said. “This will be the main focus of the oil and biofuel industries as there are significant economic drivers.”
Current annual global jet demand is around 300 billion litres, he told delegates, therefore a 5% biojet blend with conventional jet fuel implies a biojet demand of 15 billion litres. In Europe alone, the existing biodiesel demand is 11 billion litres and is already equivalent to total rapeseed oil production.
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