A novel gas chromatographic method for high-resolution analysis of gasoline fuels that enables the calculation of CHO ratio, higher and lower heating value, density and energy density

As the share of renewable gasoline fuels is likely to increase in the next decades to reduce greenhouse gas emissions, efforts to better understand the relationship between fuel composition and fuel properties need to be intensified to ensure the compatibility of alternative fuels with the existing engine fleet. Therefore, a gas chromatographic method with high resolution is presented here, with which it is possible to determine the chemical composition of renewable and conventional gasoline fuels with high accuracy and to calculate the properties CHO ratio, higher heating value (HHV), lower heating value (LHV), density, and energy density. Using a flame ionization detector and a very simple data evaluation algorithm, quantification is carried out via normalization, which avoids the need for complex calibration series. Identification is carried out using a mass spectrometer. The accuracy of the method was checked both internally using standard solutions and a certified reference material and externally by comparison with a measurement of a renewable gasoline sample consisting of 10 % [v/v] EtOH, 22 % [v/v] EtBE, 30 % [v/v] isooctane, and 38 % [v/v] renewable synthetic gasoline (e-fuel) in accordance with EN ISO 22854. All components of the certified reference material could be correctly determined within the mean value ± uncertainty stated in the certificate of analysis. The comparison of the sum parameters with an external analysis according to ISO 22854 and the comparison with external measurements of the CHO ratio and the density were also within the deviations from the mean value of the respective methods given by the reproducibility. However, the HHV and LHV were no longer within the range of the value measured externally using DIN 51900 ± the reproducibility of the method, but were slightly overestimated. The novelty of this method is that it can quickly provide both the chemical composition and some very relevant fuel properties with high accuracy, reliability, and precision, using equipment that is available in almost every chemistry laboratory. This method can therefore be particularly useful for the development of future sustainable gasoline fuels.