The airline industry does seem to be trying to tackle their greenhouse-gas emission problems in a number of ways. Apart from reducing aircraft weight by not carrying heavy cutlery and duty-free offerings, leaving behind newspapers and charging people more for their excess baggage – which hopefully has made people think a bit about what they drag around with them, now they are experimenting with bio-fuel alternatives.
Earlier this year Virgin Airlines flew a 747 on babassu and coconut oil but some quarters dismissed it as a publicity stunt as the flight consumed the equivalent of 150,000 coconuts and that was only for 20% of the fuel mix in one of four fuel tanks, in the Heathrow to Amsterdam flight. The babassu tree makes about 250 gallons of oil per acre. Richard Branson later revealed plans to use algae to produce bio-fuels as this would not necessarily involve using food-producing acreage to grow the algae.
Next up is Air New Zealand (ANZ) who have announced that on Dec 3rd, a 747-400 jumbo-jet will fly with one of the four RB211 Rolls-Royce engines fuelled by a blended mix of aviation gasoline and refined jatropha oil. "This flight strongly supports our efforts to be the world's most environmentally responsible airline," said Air New Zealand Chief Executive Officer Rob Fyfe in a recent press release.
Working together, ANZ Terasol Energy, Rolls-Royce and Boeing, have proposed the jatropha plant as being a possible sustainable source of aviation bio-fuel. This is the first large capacity processing of a bio-product into jet fuel that is being touted as being commercially feasible. ANZ are trying to fly green as they can, as they swap out less efficient aircraft for Rolls-Royce Trent engined, Boeing 787 Dreamliners that are 20% more fuel-efficient.
To make sure the flight is safe, and to establish the jatropha bio-fuel as a qualified aviation gas, Rolls-Royce conducted stringent engine tests. Boeing seem pretty happy with the potential too, as Boeing Commercial Airplane's Managing Director of Environmental Strategy Billy Glover pointed out, “In preparation for Air New Zealand's test flight we achieved our near-term goal - identifying and sourcing the first large-scale run of sustainable bio-fuel for commercial aviation,"
If the flight is a success, then they say it could prove the validity of the jatropha oil-processing technology and show that high-octane fuel can be made from the jatropha plant without the problems of the fuel freezing at high altitude and cold temperatures. Maybe this is true but there are some serious drawbacks to the proposed use of bio-fuel, especially for aircraft which demand high octane (highly refined, high energy density) fuel; and large quantities of it.
The jatropha plant is a tropical plant that grows on non-arable land. The plants produce seeds that have about 40% oil content but even so it only would give about 70 gallons of fuel an acre (according to Wikipedia). The ANZ flight will be powered by oil from plants in India and Southeastern Africa (Malawi, Mozambique and Tanzania).
The pursuit of alternative, second generation, sustainable bio-fuels for the airline industry is driven in part by the Sustainable Aviation Fuel Users Group. The members include BOEING, Air France, Air New Zealand, ANA (All Nippon Airways), Cargolux, Gulf Air, Japan Airlines, KLM, SAS, Virgin Atlantic Airways and environmental non-government organizations (NGO) such as the Natural Resources Defense Council and the World Wide Fund for Nature. Interesting group of bed-fellows, especially with the NGOs included.
Air France, KLM and Continental Airlines have also said they will introduce bio-fuels into their aviation gas, some as early as the end of this year. Their hope is that they will save money on the fuel (about US$43 a gallon versus about US$120 for aviation gas) and we all hope they will end up polluting less. Bio-fuels reduce the greenhouse gas products coming out of the engine exhaust, but overall you still have to account for all the emissions that go into growing, collection, transporting and processing the bio-fuel feed stock.
It is tricky to estimate exactly how much aviation fuel a 747 uses but it seems to be about 16 gallons of fuel to throttle down the runway and take-off, about 120 gallons to get to cruising altitude and about 3.5 gallons per km when cruising (26,250 gallons to fly the 7500kms from London to Vancouver). This means that one 20% bio-fuel flight would need about 75 acres of jatropha plant seed, a year to grow the actual seed and all the energy needed to process it.
Some of the algae options seem to be a lot more viable as they produce anything ranging from 5000 to 20000 gallons per acre each year but even that seems grossly inadequate given all the planes flying around the planet on a daily basis.
It still seems like we have a lot of hard work ahead of us to find a truly eco-friendly way to fly. So, while the experts are busy working on it, why not stay at home, live in the community you were born in, cruise the world on the internet and chat to distant relatives with Skype or I-Chat, you will save a lot of money, time, aggravation at the airports, reduce greenhouse gases and help save the planet, not to mention all those bushes and trees the airlines want to harvest for bio-fuel.
Trevor Williams is a University of Victoria Mechanical Engineering PhD candidate specialising in renewable energy, power grid modelling and plug-in hybrid electric vehicles. He has a bachelors in Aeronautical Engineering, a Masters in Management Science and over 23 years international experience in the space industry, having worked on Earth observation and telecommunications satellites.
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