Determination of Ethanol Content in Gasoline Fuel Using Raman Spectroscopy

The ability to detect the ethanol rapidly and sensitively in ethanol–gasoline blends has become important in recent times, both for engine performance and for fuel economy. In order to achieve this, a deterministic methodology based on Raman spectroscopy is employed for quantitative estimation of ethanol in commercial ethanol–gasoline blends of fuel. The different concentrations of anhydrous ethanol were mixed with pure gasoline to calibrate the Raman spectroscopy measurement setup. The variation in the ratio of the heights of Raman peaks at wavenumbers ∼885 and 1005 cm –1 is found to be linear with the fractional volumes of ethanol and gasoline in the blends. Using this methodology, the volume percentage of ethanol in commercial gasoline is determined to be ∼10%. This methodology can also be adopted for detection of other additives/adulterants in commercial gasoline.