The synthetic fuels produced from the Gas to Liquid (GTL) process are ultra-clean as they lack aromatics and sulfur. Many international airlines have already started using blends of conventional jet fuel and synthetic jet fuel to compensate the increase in jet fuel price and their dwindling availability. The rapid growth of the aviation industry and the stringent environmental regulations, in addition to the increase of fuel prices, have encouraged the industry to explore alternative jet fuels for turbine jet engines. Since emissions from aircraft occur at very high altitudes, therefore their effect in terms of Greenhouse Gas (GHG) contribution is compounded, especially for NO x and SO x emissions however, these emissions have a significant negative impact on the airport’s neighbourhood environment. Currently, CO 2 emissions from the aviation industry is about 2% and is expected to grow to 3% in 2050. Therefore, the consumption of aviation fuel will be doubled in 2040 compared to the consumption in 2015. The projected annual growth for the next 30 years for passenger traffic and airline fleets is expected to be 4.7 and 3.5%, respectively. The aviation industry is expanding with an annual growth rate of ~ 6.2% over the last 5 years. The dual nature of this study facilitated the optimization of the physicochemical properties of the fuel samples. Linoleic acid sample showed the best improvement in lubricity of SPK with wear scar diameter of 417 μm well below the ASTM D7566 maximum limit of 850 μm. The lubricity model was successfully introduced into the mathematical model in order to improve the capabilities of the model. In parallel to the experimental campaign, a pre-existing mathematical modelling tool was utilized to predict the properties of interest. Quinoline, at high concentrations, elevated the blend’s freezing point above the acceptable limits. Ethyl oleate also demonstrated significant improvement in lubricity at low concentrations but had a negative impact on the fuel’s freezing point at high concentrations. Linoleic acid was found to be an excellent lubricity improver even at a very low concentration and its negative impact on the other physicochemical properties was found to be insignificant. The effect of the additives on the physicochemical properties, such as, density, flash point, freezing point, viscosity, and heat content, were investigated. The lubricity of the samples was determined experimentally and the samples that meet the industry specifications have been studied further. To improve the lubricity of SPK, three selected additives have been mixed with SPK at different concentrations. One of them is the low lubricity compared to its conventional counterpart Jet A-1.
Although, SPK has a good potential to replace the conventional fuel Jet A-1, it also has some deficiencies. Synthetic paraffinic kerosene (SPK) is an ultra-clean fuel with low aromatic content and negligible quantities of sulfur compounds.