With airlines now starting scheduled flights using biofuel blends, Bill Read summarises this progress in sustainable aviation. [caption id="attachment_4561" align="alignnone" width="300" caption="Lufthansa will be using biofuels on one engine of an A321. (Lufthansa)"][/caption] This month Lufthansa became the first carrier to start using biofuels on commercial flights as part of a six month trial to see the longer term effects of such fuels on aero engine performance and emissions. From 15 July, the airline is operating daily biofuel flights between Frankfurt and Hamburg using an Airbus A321. However, upon reading the small print, it transpires that the aircraft will not be totally powered by non oil sources, as the fuel in question (sourced from a combination of jatropha, camelina and animal fats by Neste Oil in Finland) will be blended 50/50 with regular fuel and only used in one engine. The trial, which the airline claims will reduce CO2 emissions by up to 1,500 tonnes, is reported to be costing Lufthansa around $9.5m, of which $3.5m has been contributed by the German Ministry of Economics and Technology. Biofuels have been much in the headlines recently. On 20th June Boeing flew a 15% biofuel blend-powered 747-8 freighter across the Atlantic to the Paris Air Show, although they were pipped at the post for the title of first Atlantic biofuel flight by Honeywell which flew a Gulfstream G450 business jet to Paris on 18 June using a 50/50 blend of camelina-based fuel. On the military side, the US Air Force is working on long term plans that it will eventually see its entire fleet flying on alternative fuels. [caption id="attachment_4562" align="alignnone" width="300" caption="Following trials using a 747, AF-KLM has started revenue biofuel flights. "][/caption] Several other airlines are following Lufthansa’s lead. Finnair has begun regular biofuel flights between Amsterdam and Helsinki while Thomson has announced that it will begin flights using biofuel from September. On 18 July Air France-KLM which trialled a commercial Boeing 737-800 flight in June using a blend of recycled cooking oil, announced a new initiative in conjunction with the European Commission, Airbus, other airlines and European biofuel producers. Called Biofuel Flightpath, the initiative aims to produce up to 2m tonnes of aviation biofuels (4% of Europe’s current consumption) by 2020. While the Lufthansa flights mark the end of the beginning, as the use of biofuels moves into a new phase, there is still a long way to go before such alternative fuels could be use to power the world’s airline fleet. On the technical aide, there has been steady progress with more and more immediately usable ‘drop in’ fuels becoming available for aero engines while certification approval of 50% fuel blends for flight from standards bodies, such as ASTM International in the US, is continuing - with certification of 100% biofuels as the ultimate goal.

Next steps

[caption id="attachment_4563" align="alignnone" width="300" caption="An EQ2 future forecast predicts that biofuel production in 2025 will only satisfy 2% of global jet fuel consumption. (Greener By Design)"][/caption] However, much work still needs to be done, firstly on researching different potential sources of biofuels (sources currently being looked at include plants, biomass, algae, animal fat and municipal waste), and secondly on tackling the problem of how such fuel sources can be produced sustainably, cheaply and in bulk. Currently, biofuels do not yet have the potential to satisfy more than a fraction of the world’s future fuel demand – a situation that will not improve rapidly in the future. At the RAeS Greener by Design Conference in 2010, speakers estimated that enough biofuels could be produced by 2050 to only supply 10%-35% of global jet fuel demand. Biofuel manufacturers and regulators are currently keen to stress that the sources they are working on do not - and should not - conflict with sources of food, water, rain forests or human populations. In this initial experimental phase when the world can still rely on oil to fuel its demands for power and transport, this is all well and good but the worry remains that, once the oil starts to run dry and biofuels become the only game in town, these laudable ideals may no longer remain intact. Already, there have been concerns voiced by organisations such as Friends of the Earth that certain biofuel sources, such as palm oil, could compete for land used to grow food crops. Also, to produce enough biofuels to keep the world’s aircraft flying, a large amount of land would need to be dedicated to feedstock generation. An OPEC forecast estimated that to grow enough jatropha to satisfy demands for fuel in 2030 would take up 35% of the world’s current arable area. When looking at the future supply and demand for biofuels, it must be born in mind that aviation is not the only consumer. Once sources of oil and solid fuels start to dry up in the future, there will be huge additional demands from other fuel users, such as road or sea transport and power generation. [caption id="attachment_4564" align="alignnone" width="300" caption="Storm clouds ahead for biofuel? Has Honeywell's transatlantic biofuel flight opened the door to sustainable aviation? "][/caption] There is also the environment to be considered. There is currently some debate over whether certain biofuels produce more or less CO2 than conventional fuels but, whatever they produce, it will still further contribute to the problem of global warming. Are biofuels the ultimate solution to replacing oil-based products or just a further stepping-stone on the way to a more sustainable goal?

21 July 2011