Analysis of heavy fuel oils by near infrared spectroscopy using a new diffusing support

The characterization of heavy fuel oils (HFO), used as fuel for boats, requires the analysis of various properties which are essential for engine optimization and pollution control. For some time, Near Infrared (NIR) spectroscopy combined with chemometric treatment of the spectra was used for on-line analysis. This preliminary study included 61 heavy fuels from Europe, America, and Asia with different specifications according to their geographical origin, their refining process, and their physicochemical properties, including density, flash point, viscosity, and sulfur content. We have developed a new method for sampling heavy fuels on a fiber glass cell support. The use of such support presents advantages such as that it is fast, easy to implement, gives repeatable results, and allows freeing itself from problems of tank cleaning. . Two sample presentations, an integrating sphere and an optical fiber, were used to collect the NIR spectra. A theoretical study of the choice of the value of resolution, scan number and spectral region was conducted. The best conditions were chosen as a function of the quality of quantitative analysis results on viscosity, sulfur content, flash point, and density. The two collecting methods were compared on the same criteria.