The Metrohm Application Note AN-NIR-025 describes the determination of various indices (mainly with ASTM and ISO conformance) for the characterisation of kerosene as aviation turbine fuel using Metrohm near-infrared spectroscopy.
Determination of various indices for the characterisation of jet fuel using Metrohm near-infrared spectroscopy
The following parameters were determined with the aid of an NIRS XDS Process Analyser: degree of density in accordance with the American Petroleum Institute (API), aromatics content, Cetane Index, distillation characteristics pursuant to ASTM D86, flash point, freezing point, viscosity and hydrogen content.
All of these parameters are determined quickly and easily with just a single measurement.
The quality and grade of jet fuel is characterised by a variety of physical and chemical properties that affect the performance and use of fuel. These properties are quantified and reported by a variety of time consuming and sometimes elaborate and expensive lab methods.
Most often the methods are based on standardised methods published by the ASTM or ISO. Variations in the characteristic physical properties of jet fuel (freezing point, viscosity, etc.) are known to change based on differences in the chemical composition of the fuel. This link between chemical composition and physical properties permits accurate predictions of these physical properties by correlation with results from direct chemical analysis. Near- infrared (NIR) spectroscopy can do this.
This technique uses NIR light to record a spectrum of many chemical characteristics such as the presence and abundance of different types of chemical components or chemical bonds.
The chemical measurements taken with NIR spectroscopy can be correlated to the defining physical properties of jet fuel. Scattering effects correlate directly to physical properties.