Fri 15 Apr 2016 – Fuel standards body ASTM International has approved for commercial aviation use a new alternative aviation fuel created from an alcohol called isobutanol that in turn is derived from renewable feedstocks such as sugar, corn or forest wastes. ASTM has published a revision of its ASTM D7566 specification for aviation fuel containing synthesised hydrocarbons to include the new fuel, to be known as alcohol to jet synthetic paraffinic kerosene (ATJ-SPK). The annex to the specification is initially limited to ATJ fuels produced from isobutanol and in blends restricted to a maximum level of 30%. Currently, the only producer of isobutanol-derived ATJ-SPK is Colorado-based Gevo, which has been awaiting the ASTM decision in preparation for shipping its fuel to launch customer Alaska Airlines. ATJ-SPK becomes the fifth alternative aviation fuel pathway to be approved by ASTM.
“With this significant milestone achieved, we look forward to making the first test flight with Alaska a reality,” said Gevo CEO Dr Patrick Gruber. “We fundamentally believe that our ATJ is one of the most cost-competitive bio-based jet alternatives in the market place, and we anticipate being able to announce further partnerships across the aviation industry in the near future.
“Jet fuel is one of Gevo’s core market segments and this ASTM revision represents the next step in building a profitable business from this market vertical.”
Alaska Airlines will work with the Federal Aviation Administration to schedule the flight using Gevo’s fuel. The FAA has collaborated with the aviation industry in the approval process, which included development and testing, through its Continuous Lower Energy, Emissions and Noise (CLEEN) programme. In addition to CLEEN, the FAA says it is working with industry, other government agencies and academia through the Commercial Aviation Alternative Fuels Initiative (CAAFI) and the agency’s Aviation Sustainability Center (ASCENT), a consortium of research universities.
It estimates the use of ATJ-SPK fuels could reduce greenhouse gas emissions on a life-cycle basis by up to 85% compared to its fossil equivalent.
“I believe the industry will be pleased to see this additional approval,” Steve Csonka, Executive Director of CAAFI, told GreenAir. “We congratulate Gevo on their fortitude and success, and we look forward to pending demonstration activities and subsequent commercial production announcements.”
No other sustainable alternative jet fuel processes were qualified for use in this latest specification update. “The ASTM and aviation communities are typically advancing approval one pathway at a time, although several others are currently at various stages of the review process, having working task forces within ASTM,” reported Csonka.
“It is the ultimate objective of the two communities to permit use of all C2 to C5 alcohols as feedstocks for production of ATJ-SPK once sufficient test data is available for each and the addition has been commercially pursued.”
Previously approved pathways include Fischer-Tropsch Synthetic Paraffinic Kerosene (FT-SPK) and Fischer-Tropsch Synthetic Kerosene with Aromatics (FT-SKA), which both use various sources of renewable biomass such as municipal solid waste, agricultural and forest wastes, wood and energy crops. Other approvals include Hydro-processed Esters and Fatty Acids Synthetic Paraffinic Kerosene (HEFA-SPK) fuels, which use fats, oils and greases, and Synthesized Iso-paraffins (SIP), which convert sugars into jet fuel.
ASTM International – ASTM D7566 ATJ-SPK revision document
Commercial Aviation Alternative Fuels Initiative (CAAFI)
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