Properties, Characteristics, and Combustion Performance of Sasol Fully Synthetic Jet Fuel

Abstract

In 1999, as the only inland petroleum refinery in South Africa was reaching capacity, Sasol gained approval of a semisynthetic jet fuel (SSJF) for civil aviation to augment production and meet the growing demand for jet fuel at the airport in Johannesburg. Prior to this, all jet fuel had to be refined from petroleum sources. SSJF consists of up to 50% of an isoparaffinic kerosene produced from coal using Fischer–Tropsch processes. The production of SSJF remains vulnerable to the production capacity of conventional jet fuel, however. To ensure supply, Sasol has proposed producing a fully synthetic jet fuel (FSJF) using synthetic kerosene streams that contain aromatics and satisfy all the property requirements of international specifications for jet fuel. Being fully synthetic, it was necessary to demonstrate that the fuel is “fit-for-purpose” as jet fuel, i.e., behaves like conventional jet fuel in all aspects of storage and handling as well as air worthiness and flight safety. Four sample blends were developed, covering the practical range of production. Extensive tests on chemistry and physical properties and characteristics demonstrated that Sasol FSJF will be typical of conventional jet fuel. As a final demonstration, the engine manufacturers requested a series of engine and combustor tests to evaluate combustion characteristics, emissions, engine durability, and performance. The performance of the synthetic test fuel was typical of conventional jet fuel. This paper identifies the tests and presents the results demonstrating that Sasol fully synthetic jet fuel is fit-for-purpose as jet fuel for civilian aviation. Sasol FSJF is the first fully synthetic jet fuel approved for unrestricted use.