The Australian airline Qantas

The Australian airline Qantas will this month announce a deal to build the world's second commercial-scale plant to produce green biojet fuel made from waste for its fleet of aircraft.

Its proposed partner, the US-based fuel producer Solena, is also in negotiations with easyJet, Ryanair and Aer Lingus about building a plant in Dublin, although this project is less advanced.

Airlines are trying to reduce their reliance on fossil fuels ahead of their entry into the EU's carbon emissions trading scheme in January 2012 and the introduction of other new environmental legislation. Under the scheme, any airline flying in or out of the EU must cut emissions or pay a penalty.

Solena's joint venture with Qantas – which could be announced within the next fortnight – follows a tie-up with British Airways, signed in February last year, to build the world's first commercial-scale biojet fuel plant in London, creating up to 1,200 jobs.

Once operational in 2014, the London plant, costing £200m to build, will convert up to 500,000 tonnes of waste a year into 16m gallons of green jet fuel, which BA said would be enough to power 2% of its aircraft at its main base at Heathrow. The waste will come from food scraps and other household material such as grass and tree cuttings, agricultural and industrial waste. It is thought the Qantas plant, to be built in Australia, will be similar.
Solena uses technology based on the Fischer-Tropsch process, which manufactures synthetic liquid fuel using oil substitutes. Germany relied on this technology during the second world war to make fuel for its tanks and planes because it did not have access to oil supplies.
Airlines have been using synthetic fuel made in this way from coal for years, but this results in high carbon emissions.
The use of biomass – which does not produce any extra emissions – as an oil substitute has more recently been pioneered by Solena. The privately owned company says that planes can run on this green synthetic fuel, without it having to be mixed with kerosene-based jet fuel. In the UK and US, regulators allow only a maximum 50% blend, and the fuel was only recently certified for use by the UK authorities. BA is understood to be exploring the possibility of using 100% biojet fuel, once it is approved as expected.

Airlines including Virgin Atlantic have also been testing biofuels – made mostly from crops, which are converted into fuel – by blending them with kerosene-based jet fuel. But experts say these blends have to have a low level of biofuels to ensure that engine safety and performance are maintained. In February 2008, Virgin became the first airline in the world to operate a commercial aircraft on a biofuel blend, but this was only 20% and through just one of the plane's four engines.

The use of conventional, crop-based biofuels is controversial. Some environmentalists are concerned that an increase in the farming of crops and trees for biofuels could take up too much agricultural land and hit food production. But Solena plans to make its biojet fuel using waste, not crops.
Industry experts say that, in the future, biojet fuel will work out cheaper than kerosene-based fuel as oil prices rise. Producers such as Solena could also earn subsidies by using waste materials that may otherwise have to be sent to landfill. The Germany airline Lufthansa is also understood to be interested in a joint venture with Solena. But with each plant costing £200m to build, it will take time to roll out the technology.
One challenge faced by Solena is securing a supply of biomass waste for its new plants. Ideally, facilities will be located in or near cities, where most of the waste will be sourced, and near airlines' bases. The bioenergy producer will face competition from other companies planning to build incinerators, which also need to use waste to generate subsidised electricity.