|Sasol’s synthetic jet fuel is derived from four synthetic streams: Iso-paraffinic kerosene, Heavy naptha kerosene, Light distillate #1 and Naptha #2. Click to enlarge.|
Sasol’s synthetic jet fuel, produced by its proprietary Coal to Liquids (CTL) process, has received approval for full, unblended use in international commercial aviation. Sasol’s fully synthetic jet fuel (FSJF) is the first such fuel to be approved.
For the past nine years, Sasol has supplied a semi-synthetic jet fuel—a mixture of CTL components with petroleum-derived kerosene—to international airlines operating from OR Tambo International Airport in Johannesburg. Based on the success of the alternative fuel blend and following a several-year period of testing and evaluation, international aviation fuel authorities including the UK Ministry of Defence (UK MoD), governing the Defence Standard DEFSTAN 91-91, approved Sasol’s fully synthetic jet fuel as Jet A-1 fuel for commercial use in all types of turbine aircraft.
ASTM International, originally known as the American Society for Testing and Materials, has also been working closely with the UK MoD and is expected to include Sasol CTL synthetic jet fuel in its ASTM D1655 specification following the publication of the UK’s DEFSTAN 91-91. Jet A-1 according to the DEFSTAN 91-91 specification is very similar to Jet A-1 defined by the ASTM D1655 except for a small number of areas where DEFSTAN 91-91 is more stringent.
Aviation industry stakeholders, including airframe, engine and ancillary equipment manufacturers; airlines and aviation authorities such as the International Air Transport Association (IATA); and relevant oil companies have all participated in the approval process.
The fuel is a drop-in replacement for petroleum jet fuel; it is fully fungible and aligned with the current aviation infrastructure through its compatibility with the existing engine requirements and can be used with conventional crude oil-derived jet fuelling systems.
Sasol produces its synthetic jet fuel from four primary synthetic streams from its high-temperature Fischer-Tropsch (HTFT) process:
Iso-paraffinic kerosene, with a few percent n-paraffins and no aromatics;
Heavy naptha kerosene, with about 10% aromatics;
Light distillate #1, with about 24% aromatics; and
Naptha #2, with about 39% aromatics.
The full synthetic jet fuel is ultra-low sulfur (< 5 ppm) and with 8-25% aromatics. Engine-out emissions of Sasol’s jet fuel are lower than those from jet fuel derived from crude oil due to its limited sulfur content.
The current approval covers jet fuel produced at Sasol’s Synfuels facility in Secunda, South Africa. Sasol jet fuel products that will also be submitted for sanction include Oryx GTL plant in Qatar, the joint venture GTL plant in Nigeria and the potential CTL ventures in the USA, China and India.
Research is also underway to find an effective process to produce synthetic fuel from biomass to further improve environmental sustainability.