From the tobacco fields of South Africa to the deserts of Abu Dhabi and arid lands in Australia, the aviation industry is piecing together a comprehensive puzzle of sustainable biofuel candidates in order to reach its goal of becoming carbon-neutral by 2020.

The airline industry contributes about 2 percent of all carbon dioxide emissions globally, according to the International Air Transport Association (IATA), an industry trade group. Since 2009 the industry has been working to cap carbon emissions and improve fuel efficiency by 1.5 percent a year to 2020 and to cut CO2 emissions by 50 percent relative to 2005 levels by 2050.

Key to that carbon neutral strategy is the use of sustainable aviation biofuels, which have the potential to reduce the industry’s carbon footprint by 80 percent, according to the IATA. These fuels are derived from various feedstocks such as plants or waste materials. “We need options and we need to start now,” said James Kinder, a Boeing chemist, in a video interview. “You don’t wait until all the petroleum runs out, you have to start now.”

Three of the most recent feedstock developments include a tobacco plant hybrid, agave, the plant from which tequila is made and plants grown with waste seawater.

The tobacco tie-in comes in the form a partnership that includes South African Airways, Dutch aviation biofuels company SkyNRG and Boeing to create jet fuel from Solaris, a nicotine-free tobacco plant.  “By using hybrid tobacco, we can leverage knowledge of tobacco growers in South Africa to grow a marketable biofuel crop without encouraging smoking,” said Ian Cruickshank, South African Airways Group environmental affairs specialist in a statement. At first just the oil from the plant’s seeds will be used for fuel; however, in coming years Boeing expects new technology will allow biofuel to be made from the whole plant.

Agave may be best known as the plant from which we get tequila, but it can produce extraordinary high per acre yields, has a propensity for growing on marginal lands and is capable of producing a sugar content twice that of sugarcane, which makes it a prime biofuel candidate.  That’s the word coming out of Byogy Renewables, which has teamed with AusAgave Australia to produce jet fuel from the plant. AusAgave has developed a drought resistant strain of the plant over the last ten years.  Recent tests by Byogy, using its proprietary technology, have produced a cost competitive jet fuel “at or below that of petroleum products without infrastructure modification, blending or government subsidies,” the company said in a statement. “Because of its ability to grow in dry climates and poor soil conditions, with very low water and fertilizer demands, agave can be a new global feedstock without displacing any existing food crops, or provoking deforestation,” the company said.

Seawater is an integral part of a five-year biofuel research project from the Sustainable Bioenergy Research Consortium (SBRC), affiliated with the Masdar Institute of Science and Technology in Abu Dhabi. Dubbed ISEAS, for Integrated Seawater Energy and Agriculture System, the program uses plants known as halophytes, grown in desert soil and irrigated by waste saltwater from fish and shrimp ponds. The halophytes clean the water as they grow. That water will then be used to irrigate a field of mangroves before returning to the ocean. The project will turn both plants into aviation biofuels using SBRC research. “This project can have a global impact, since 97 percent of the earth’s water is ocean and 20 percent of the earth’s land is desert,” said Alejandro Rios, director of the SBRC in a statement.

Sustainable Bioenergy Research Consortium

A Sustainable Second Generation

Biofuels have a jaded history. First generation biofuels, derived from edible feedstock such as corn and sugarcane, and are at the heart of the “food vs. fuel” debate.  Other criticism takes aim at the aviation industry’s drive toward biofuels as a means to combat climate change calling it “ill-conceived at best or hypocritical at worst.”

“When you talk about biofuels, they have to be done right,” Kinder said. “We’re actually trying to figure out how much energy it takes to take this biomass to grow it, to harvest it, to process it, turn it into jet fuel,” he said. “That’s what we call the whole life cycle.”

Sustainable aviation biofuels are derived from so-called “second generation” or “advanced biofuels.” According to the Sustainable Aviation Fuel Users Group, these are feedstocks that:

  • Exhibit minimal impact on biodiversity
  • Meet a sustainability standard with respect to land, water, and energy use
  • Do not displace or compete with food crops
  • Provide a positive socioeconomic impact
  • Do not require any special fuel handling equipment, distribution systems, or changes to engine design

These biofuels are known as “drop-ins” because they can be added to (or substituted for) traditional jet fuels without modification. This is important because it means manufacturers don’t have to redesign engines or aircraft and that fuel suppliers don’t have to develop new delivery systems.

Price is Pain Point in March to Commercialization

More than 1,500 trial flights have been flown using some blend of jet fuel and biofuel, typically a 50/50 split (the most allowed by current industry standards). However, no commercially viable aviation biofuels currently exist. Jet fuel accounts for about 30 percent of the industry’s operating costs.

In the U.S., the Federal Aviation Administration is aiming for the aviation industry (both commercial and military) to use one billion gallons of sustainable jet biofuel starting from 2018, “with the intent of encouraging commercial production,” according to a recent GAO report. That’s about 5 percent of the predicted fuel consumption for military and domestic airlines in 2018, the FAA told GAO investigators.

“Achieving price competitiveness for alternative jet fuels is the overarching challenge to developing a viable market,” the GAO report says. The report said the most frequently cited impediments to competitive pricing were “high development costs and the uncertainty of federal regulations and policies” and that “federal activities are needed to help advance the alternative jet-fuels industry.”

The GAO report also states that alternative jet fuels would need a subsidy ranging from 35 cents to $2.86 per gallon to be price competitive with conventional jet fuels in 2020.

There are more than 20 biofuel development projects in the U.S. alone, according to a U.S. Agriculture Department report. “These projects utilize a variety of feedstock and process technologies to produce renewable fuels, and several have the potential to produce aviation biofuel,” the report says. “However, these projects need additional funding to support biofuel development in the near term.”

Research shows that so-called “green diesel,” made from recycled animal fat, used cooking oil and inedible corn oil, and already used in for ground transportation, can power aircraft, too. Unlike other biofuels, green diesel is available today in commercial quantities, about 800 million gallons a year, from the U.S., Europe and Singapore, but that’s still little more 1 percent of the total needed by the thirsty global aviation industry. Another huge selling point: green diesel, at about $3 per gallon with government subsidies, is cost competitive with jet fuel. Green diesel is an important step in the evolution of viable sustainable aviation biofuels, Julie Felgar, managing director of Boeing Commercial Airplanes Environmental Strategy and Integration, told the Chicago Tribune. “A few years ago, people said this was a complete longshot," she said. "We still have a lot of work to do, but it will be an easier road to travel."

Despite the challenges, “the race is on to develop viable and cost-competitive supply chains using sustainably sourced feedstocks that can be readily processed into finished fuels on an industrial scale” for aviation and maritime biofuels, according to Navigant Research.

Led by North America, production capacity of aviation and maritime biofuels is expected to reach 3.3 billion gallons by 2024, representing 1.5 percent of total aviation and maritime consumption, the Navigant Research report says. The report forecasts that a cumulative total of 18.2 billion to 19.6 billion gallons of renewable aviation and maritime biofuel could be produced between 2014 and 2024.

All that advancement won’t come cheap. It’ll cost—conservatively—an estimated $30 billion to $40 billion by 2020 to reach the IATA’s “aspirational target” of 6 percent of global jet fuel supply met by advanced biofuels,” says the Navigant report.

“[B]iofuels will account for a low proportion of global aviation consumption before 2020, but could make a significant contribution over a longer time horizon,” says an FAA Center of Excellence report. The report says that a high price on carbon, combined with some “optimistic assumptions” could result in 100 percent biofuel usage by airlines globally by the early 2040s. “With no carbon price and slow development of biofuel technologies, biofuels account for 3% of aviation fuel use in 2030 and 37% in 2050,” the report says.


This is one in a series of posts related to the event What's Next: Navigating Global Challenges with the Innovation Generation.

An Arabic translation of this article is provided here.