Wilken, C., de Goede, S., and Viljoen, C., "A Comparison of the Properties and Cold Flow Performance of ‘Summer’ and ‘Winter’ GTL Diesel," SAE Int. J. Fuels Lubr. 9(2):430-442, 2016, doi:10.4271/2016-01-9074.
Gas to Liquids (GTL) diesel has been produced commercially for several years. GTL diesel is known for its excellent properties, including zero aromatics, near zero sulphur and a high cetane number. Most of the GTL diesel produced by commercial plants is utilised as a blend component, especially in blends up to 20%. In these applications, the cold flow properties are potentially less critical, as the cold flow properties of the blend will mostly be determined by the petroleum-derived component. In certain markets, however, it is possible that GTL diesel can be used as a neat diesel, therefore requiring good cold flow properties.An advantage of GTL technology is that the cold flow properties of GTL diesel can be tailored to meet the climatic requirements of a specific geographical area. In the current study, GTL diesel samples with cold flow properties ranging from ‘summer type’ to ‘winter type’ and varying intermediate cold flow qualities were evaluated. In line with expectations, it was shown that increasing the degree of isomerisation will improve the cold flow properties of the GTL diesel, whilst the other bulk properties such as density, cetane and viscosity of the fuels are not significantly altered. It is also shown that the excellent cold flow properties of these ‘winter type’ GTL fuels translate into excellent operability performance.