Sustainable biofuels technically near take-off

May 21, 2009 | 00:00

Sustainable biofuels technically near take-off

Boeing says it has proven the ‘technical viability’ of biofuels for use in commercial aircraft. Now the company wants to ‘accelerate’ the process of making biofuels available on a commercial scale.

After four test flights by four major airlines – carrying engines of the four major manufacturers – the facts are clear to Bill Glover, Boeing’s commercial planes’ managing director of environmental strategy. ‘We haven proven the technical viability of biofuels as a “drop-in” for the traditional Jet-A fuel without any modification to engines or airframe,’ he says. ‘As tests have shown that the biofuels even have a higher energy content and emit, for example, less sulphur, we consider the outcome as a performance breakthrough for the whole industry.’

Boeing has only recently become involved in the promotion of second-generation biofuels, following its customers’ drive to reducing their CO2 emissions, the environmental director explains. ‘The road to this goal is through burning less fuel as well as using clean fuel. Therefore, we want to accelerate the process of getting new sustainable aviation fuel available at a commercial scale. After all, it is also in our interest to keep the industry viable.’

Since Boeing has become convinced of the viability of biofuels, it has initiated the Sustainable Aviation Fuel Users Group (SAFUG) in 2008. Its eight member-airlines – together they account for approximately 15% of commercially burned jet fuel – focus on developing the criteria for the second-generation green fuel, whose cultivation is not allowed to impact food crops or water resources, nor require deforestation.

The SAFUG has commissioned Yale University to look into the socio-economic impact of  jatropha cultivation as well as the jatropha-related CO2 lifecycle. At the same time, the large US environmental action group National Resources Defence Council is researching the sustainability of algae as feedstock for jet fuel for SAFUG.

In addition, last year Boeing was among the founders of the Algal Biomass Organization (ABO), a not-for-profit trade association “dedicated to the advancement of the production of oil from algal biomass”.

‘Since both airlines and engine manufacturers are now convinced that biofuels work well, the next step is certification,’ according to Glover. He optimistically expects that the influential US American Society for Testing and Materials (ASTM) and the UK Defence Standards Committee could already have approved the various specifications by 2010, and that the respective national civil aviation authorities will follow in their wake soon. ‘If the biofuels have been certified, the producers know that the aviation industry will accept their products.’

Glover’s optimism is shared by the International Air Transport Association (IATA). ‘Although the present timeline sees certification in 2013, we are challenging governments to deliver even faster, by 2010 or 2011,’ said IATA’s general director and CEO, Giavanni Bisingani, recently. As part of its broad climate change plan, the lobbying organization – representing 230 airlines – wants 10% of aviation fuel to come from biofuels in 2017. IATA estimates the worldwide fuel consumption by civil aviation at 266.3 million tons in 2008, slightly lower than in 2007. This is more than 6% of total world oil consumption and more than twice as much as for example the oil consumption of Germany.

Supply chain

The next step –  commercial-scale production against competitive prices – is slightly farther away, but could be set within three to five years, the Boeing director reckons.
‘After the fuel has been certified, the biggest challenge we face will be setting up an entire new supply chain. Mass production of the feedstock must be followed up by sufficient refinery capacity, and airlines must subsequently connect with commitments to refineries,’ he points out.

Although the price of traditional aviation fuel needs to rise to at least $70 a barrel before the average biofuel – depending on the feedstock – starts becoming competitive, Glover is convinced that the oil price will overtake the price of green fuel in the not too far future. ‘Moreover, we expect biofuels to become cheaper once the benefits of large-scale production kick in,’ he argues.

In Glover’s opinion, biofuels could not only play a significant role as a clean aviation fuel, they could even fully take over the role of the present day mineral oil-based Jet-A fuel in the long term. ‘Technically it is feasible and there is potential for sufficient production capacity. However, I am talking about at least thirty years from now, while assuming the growth of supply can keep up with demand.’

At the moment, officials at Boeing believe that jatropha is the most promising green fuel for the near future, given the prospects for availability so far, with camelina as runner-up. They consider switch grass and saltwater-tolerant plants (halophytes) as potential feedstock for the mid-term. Recently, IATA spokesman Anthony Concil also called jatropha ‘one of the very promising’ jet fuels.

Biofuel from algae is hardly showing on the company’s radar yet. Glover: ‘We can’t see it becoming available on a commercial scale within ten and maybe even fifteen years.’


A central role in Boeing’s efforts to kick-start the use of biofuels is being played by UOP – a Honeywell subsidiary – which focuses on refining technology for bio-feedstock. The company claims to have developed a process that meets all the critical specifications for jet fuel for civil aviation, after having been awarded a contract from the US Defence Department for the creation of technology to produce renewable JP-8 fuel for military aircraft. According to UOP, it has extended its technology to generating fuel from feedstock like jatropha, camelina and algae.

‘We believe that, with our technology, we could reach production levels of a million tons a year by 2012,’ says Jennifer Holmgren, UOP’s general manager. The company says it provided most of the biofuels for the four test flights during the world’s first large-scale production run in its pilot plant. Spokeswoman Susan Gross declines give details on the scale of the operation, ‘for commercial reasons’. Although she indicates that no contracts have been signed yet for the sale of UOP technology, the first commercial refinery, with a daily capacity of almost 14,000 tons, can be operational within two years and a half, according to Gross.

Near the start of the supply chain is US-based Terasol Energy, a project developer focusing on sourcing sufficient sustainable and responsible feedstock. The company expects to be able to supply approximately 30,000 tons in 2012, its spokesman indicates, adding that Terasol is growing new oil seed crops in Brazil at present. However, he declined to provide details on the crops, ‘as the project is still in its study phase’.

‘If customer demand warrants it, jatropha will come from India, as well as other nations in South East Asia and East Africa,’ he says. ‘However, jatropha is still a wild growth and not yet suited for commercial cultivation. In its present form, the plant is suited for small social enterprises or rural employment projects.’ On its website, the company states that an oil yield of up to five tons a hectare is possible.

‘The jatropha secor is still in a very early stage of development,’ stresses Arjen Brinkmann, a Dutch bio-energy consultant, who has been involved in developing criteria for sustainable cultivation of the energy crop. ‘Large-scale cultivation hasn’t proved itself yet, because it hardly exists. Worldwide, there are no more than a few major production units, generally not exceeding 10,000 or 20,000 hectare. What’s more, one hectare of jatropha will only yield a few tons of oil a year under optimal conditions. It is no miracle crop. It needs fertiliser, water and a better soil for an optimal production. Although it tolerates marginal conditions, the oil yield there will be marginal as well.’

Brinkmann believes it could take well up to twenty years before jatropha can play a significant role for aviation fuel. ‘Trees that are planted now, won’t yield sufficient oil for the next five years,’ he stresses, adding that jatropha might become much more important as local fuel in Africa.


Elsewhere, Sam Huttenbauer III, ceo of the US company Great Plains, is convinced that camelina has the best prospects of developing into the main source of aviation fuel. Great Plains, which calls itself “the camelina company” has been pioneering the crop during the past fourteen years. It has contracted out the cultivation of camelina to farmers in the US and Canada since 2006 for biodiesel, Huttenbauer says.

In cooperation with the University of Dakota, Great Plains is developing a  refinery for jet fuel – with an initial capacity of 50,000 tons – which must become operational within three years, according to the ceo. ‘Depending on the increase of demand, we could be producing 400,000 tons of camelina oil at price which is competitive with petroleum within four years,’ he claims.

To Huttenbauer, the potential for growing camelina is tremendous. ‘Our four-year forecast is based on camelina as a rotation crop on less than 3% on the total wheat acreage in the US and Canada. And because camelina offers a good return, there is a lot of interest among farmers.’ The ceo of Great Plains expects that improvements in seed and cultivation could double the oil yield of camelina to 1.1 to 1.4 tons a hectare within the next four years.

Most promising

In the opinion of Dennis Bushnell, chief scientist at NASA’s Langley Research Centre, salt-water plants are the most promising option for second-generation biofuel. ‘They could be grown on wasteland and seawater, and yield as much as conventional fresh-water plants. Because halophytes agriculture saves arable land, fresh water and energy and don’t come at the expense of food production, it is a potential revolution of massive impact,’ he argues.

According to Bushnell, there are already 25 experimental halophytes farms worldwide and they could be quite rapidly be ramped up. ‘If we really took the gloves off, oil from salt-water plants could replace all petrol in approximately fifteen years,’ he suggests.

A plant like Salicornia has so far produced an oil yield of 1.8 tons a hectare, but there is a potential for improvement through bio-engineered versions of over 2,000 halophytes, the NASA scientist makes clear. ‘The main challenge is to increase knowledge about the agriculture of salt-water plants and to convince farmers that salt is not bad.’

Potential feedstocks

There are at least seven sources for biofuels being looked at, although not all are considered sustainable, as some are grown on plantations on arable land.

  • Jatropha, a scrub, which was until recently mainly used as cattle fence, mainly on marginal lands in semi-arid areas in Africa and India. Oil is derived from its inedible seeds.
  • Camelina, a member of the mustard family, also known as false flax or gold-of-pleasure. It is common in the US and can be used on fallow land as part of crop rotation. Its seeds provide oil.
  • Halophytes: salt-tolerant plants, such as seashore mallow and euphorbia, which can be grown in harsh environments, such as coastal and arid areas.
  • Switch grass, a tall fast-growing prairie grass, once common on the Great Plains of North America. According to Auburn University, it could provide 6.2 tons of ethanol per hectare per year.
  • Some species of algae – tiny single-cell plants growing in fresh of salt water -  contain large amounts of lipids.
  • Oil from coconut palms, grown on plantations on arable land.
  • Babassu is a native palm in the Amazon rainforest. Its seeds contain edible oil.

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