Vegetable oils as additives to improve the lubricity of low-sulphur fuels

The aim of the study was to determine the sulphur content in 33 samples of oils pressed from different species of vegetable. The unconventional oil samples were purchased from commercial store. Oils was analysed in terms of sulphur content according to the method using X-ray fluorescence spectrometry with wave dispersion, that is described in the PN-EN ISO 20884, 2012 standard. Obtained results of sulphur analysis were presented as the arithmetic mean ± standard deviation (from three replicates) and statistically analysed using the Statistica 13.0 PL program. In order to indicate significance of differences between oils analysis of variance (ANOVA) with Tukey’s test of p ≤ 0.05 significance level was used. The statistical analysis indicated significant differences in the content of sulphur content in the analysed vegetable oils, which could affect the lubricity of prepared fuel blends and in some cases significantly, increase the sulphur content above acceptable value 10 ppm. It was concluded that vegetable oils could be a suitable raw material improving the lubricating properties of low-sulphur diesel oils. However, due to significant differences in the sulphur content in the analysed samples, the content of this element should be analysed beforehand in order to eliminate the possibility of exceeding the permissible level of sulphur in transport fuels.