Abstract

Aviation history was made on 21 September 2010, when four aircraft, a Hawker 4000 corporate jet, a Beechcraft King Air 350i, a Beechcraft King Air P750, as well as a Boeing 737-200 with some 90 passengers aboard, flew from Johannesburg and Nelspruit to the African Aerospace & Defence Exhibition in Cape Town (AAD 2010), South Africa using a unique, Sasol developed, 100% synthetic Jet A-1 fuel in all their engines. This was the culmination of a sustained effort over the last two decades during which Sasol, together will all the international stakeholders, developed and followed a comprehensive process for the qualification of firstly semi-synthetic jet fuel and later fully synthetic jet fuel. During the course of this prolonged effort, the protocol for the approval of any alternative jet fuel was also developed, as no precedents existed for this. Sasol has subsequently received widespread recognition from the aviation fuels community for this pioneering work.

For the past eleven years, Sasol has supplied a semi-synthetic jet fuel mixture comprised of a synthetic, coal derived kerosene component blended with crude oil derived kerosene to local and international airlines operating from O.R. Tambo International Airport in Johannesburg. Based on the success of this first alternative fuel blend and following an extended period of rigorous testing and evaluation, the British Ministry of Defence, that administers the DEFSTAN 91-91 jet fuel specification, approved Sasol's fully synthetic jet fuel for commercial use in all types of turbine aircraft in April 2008. This was followed in September 2009, when Sasol's gas to liquid (GTL) kerosene was also approved for use as a synthetic blend component in mixtures with conventional jet fuel, according to the new ASTM D7566 specification.

Sanctioned by these global aviation fuel specification authorities, Sasol's synthetic Jet A-1 has become the first (and at present, still the only) alternative jet fuel to be approved for commercial use. The successful flights of the four aircraft at AAD 2010 is a real life demonstration of the feasibility of a drop-in replacement for conventional jet fuel, thus marking a significant contribution to the adoption of clean burning alternative fuels for the aviation industry. This paper gives an overview of the process that Sasol followed to gain approval for its semi- and fully synthetic jet fuel and describes some of the research activities that were undertaken to achieve this milestone in jet fuel technology. Current and future jet fuel research activities are also covered in the paper.

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