The International Air Transport Association (IATA) has set itself the goal to reduce the climate impact of the aviation industry by 50 percent by 2050, using 2005 as a base. To improve the fuel efficiency of aircraft is an important, but the objective also includes a clear commitment to renewable fuels. “The idea of bio-based jet fuels was around already ten years ago but were met mostly with skepticism,” says Professor Angelica Hull, Managing Director of Swedish BioFuels.

“We have long researched alternative fuels, but it was the former U.S. Ambassador Michael Woods who found us in search of Swedish energy and environmental technology companies. He helped that we had a significant funding from the U.S. Defense Department’s DARPA research,” continues Hull.

The development of jet fuel has been successful and Sweden’s Biofuels is now taking the next step with plans to lead a consortium on a semi-industrial scale to produce 10,000 tonnes of fuel per year from biomass. Half of this will consist of jet fuel and the rest of gasoline and diesel. The environmental benefit is the reduction of emissions of carbon dioxide and particulate matter from aircraft and tests have shown that the fuel meets or exceeds the quality and specifications of the military jet fuel JP-8 and because the raw materials are obtained from waste products from the timber industry, domestic waste or biogas will not compete with food production and land use.

From biomass to jet fuel

Jet fuel is a complex product composed of a mixture of hundreds of hydrocarbons. It is therefore a challenge to use biomass to produce a product that has the same technical characteristics as fossil fuel. The core of the Swedish BioFuels technology is based on using cellulose, lignocellulose, or other carbon sources as a raw material in a patented process to produce fully synthetic paraffinic oil. The technological progress is in the development of catalysts and equipment involved in the synthesis of the complex final product, i.e., branched paraffinic oils, single aromas and cyclic compounds.

The manufacturing process consists of two steps where the first is called “biomass-to-alcohol” (BTA) and the other “alcohol-to-jet” (ATJ). In the first step, alcohols are produced with carbon chains consisting of 2 to 5 carbon atoms and where ethanol is an important product. Here, Swedish BioFuels can choose different ways to produce alcohol, such as from wood pellets to synthesis and fermentation of synthesis gas or a similar route that uses biogas. Even roads uses fermented household garbage or wood. The advantage of the process is that the final product will be a well-defined mixture of short chain alcohols. In the following chemical synthesis alcohols are converted to hydrocarbons by the addition of hydrogen (hydrogenation). After a cleaning process, jet fuel, gasoline and diesel are separated.

The Royal Institute of Technology in Stockholm has a pilot plant that has been in continuous operation for two years. The plant can produce a total of 10 tonnes of product per year, equivalent to 4.8 tonnes of jet fuel, 3.5 tonnes of gasoline and 1.7 tonnes of diesel.

Process plant for the production of bio-based jet fuel.

“The process of using alcohols as intermediate steps is a flexible method of producing advanced hydrocarbon fuels. Therefore, we see great potential in the use of “alcohol-to-jet” in the large scale production of jet fuel,” says Angelica Hull. “We call this jet fuel SB JP- 8, and it is currently being tested by the U.S. Air Force in their programs to introduce and certify alternative fuels. Data have been forwarded to the U.S. testing organization ASTM and we hope for certification in 2014 of our fuel for commercial use.”

Leading international consortium

Swedish BioFuels has in 2013 formed an international consortium of companies and universities that together can provide raw materials, process development, design of process equipment and the construction of a production plant on a semi-industrial scale. The five-year project, supported by the EU, applies a broad perspective of sustainability, and in particular, a life cycle assessment will be performed of the environmental impact from raw material to finished product. One aim of the project amongst others:

  • To show that in the semi-industrial scale can fully synthetic paraffinic oil can be produced that meets the specifications for jet fuels of type Jet A, Jet A-1 and JP- 8.
  • To show that it is possible to use different types of raw materials in the process.
  • To evaluate the environmental, economic and commercial implications of the bio-based jet fuel.

The article was published in November 2013