Fermented sugar-based jet fuel has been approved by the standards-development organisation ASTM International for its blending with conventional jet fuel, at up to 10 per cent of its volume.
The sugar based alternative fuel, with the technical name Synthesized Iso-Paraffini, or SIP, is produced from hydroprocessed fermented sugars. The Commercial Aviation Alternative Fuels Initiative (CAAFI) support the SIP work. CAAFI was created by Airlines for America (A4A) in 2006.
The A4A vice president for environmental affairs, Nancy Young, says: “This standard provides another pathway for alternative jet fuel production, and will enable increased commercial production.
“We commend ASTM International, the US [government’s] Federal Aviation Administration, the airframe and engine manufacturers, the US military, fuel producers and our entire CAAFI team for continuing to drive toward commercially viable alternative jet fuels that meet the rigorous criteria set forth under the jet fuel specification.”
With the approval of SIP, it becomes the third approved option for alternative jet fuel production. The other approved alternative fuels are the conversion of triacylglycerides from plant oils and animal processing waste, referred to as Hydroprocessed Esters and Fatty Acids, or HEFA, and the conversion of a variety of biomass and fossil fuel feedstocks through the Fischer-Tropsch process.
According to Boeing more than 1,500 passenger flights have taken place using biofuel. The US aircraft manufacturer has biofuel projects (see picture above) ongoing in Brazil and South Africa. In Brazil it is working with Sao Jose dos Campos Technology Park to analyse what the company calls “gaps” in feedstock production and processing technologies. The South Africa effort involves South African Airways to create a biofuel supply chain. Flight tests have shown that plant or algae derived biofuel performs like petroleum-based jet fuel. A mix of 50/50 plant or algae based biofuel and conventional fuel, has been approved. Algae is viewed as sustainable by Boeing and its collaborators because it takes carbon dioxide out of the atmosphere.