Air New Zealand says it has successfully carried out the first airliner flight test using "second generation" biofuel, manufactured from plants which don't require good farmland to grow. Such biofuels-2.0 potentially have no ill effects on food prices or deforestation, yet could seriously lower airlines' carbon numbers.
Flight International reports that the flight was made by a Kiwi Boeing 747-400 fitted with Rolls-Royce RB211 engines. One of the four big jets was fuelled up 50-50 with ordinary jetfuel and biofuel sourced from jatropha nuts. Various manoeuvres including engine stops and restarts in mid-air were carried out without incident, and full power was apparently available from the half-biofuelled engine.
Jatropha nuts are tolerant of being grown in arid climes, and their advocates suggest that they could be viably grown in deserts and other unused regions. This would avoid the use of scarce arable land, or deforestation to create more.
Air New Zealand believes it would need plantations totalling 1.25 million hectares to run entirely on jatropha. That would equate to about 85 per cent of New Zealand's arable land, but hardy jatropha might, for instance, be grown in the deserts of Australia. There are 1.4 million square kilometres of deserts in Oz, enough to fuel a hundred airlines the size of ANZ if they were all covered in jatropha plants.
That said, many are sceptical that the oily nuts can really be grown en masse in deserts, harvested and processed into fuel at a reasonable cost in money, energy and water. Some believe that true gen-2.0 biofuel can only be raised from algae blooms, perhaps even grown on salt water. Others consider that in fact a variety of different feedstocks will be used to produce fuels to a common standard in future.
The airline industry tends to focus especially hard on bio or other synthetic hydrocarbon fuels, as - unlike the car industry - it has few other alternatives. Options such as hydrogen and electric power are much harder to use in aircraft, which are low weight, high power technology. ®