Gasoline volatility index

In Fig. 23, spectra of two different grades of U.S. gasoline are shown, de Bakker and Fredericks [90] demonstrated that it was possible to perform a variety of petroleum property measurements, including research octane number (RON), motor octane number (MON), density, benzene content, and flexible volatile index (FVI), using fiber-optical FT-Raman spectroscopy coupled with partial least-squares analysis to reduce sample fluorescence. The potential for on-line measurement of these properties was mentioned by both Cooper et al. [89] and de Bakker and Fredericks [90], Cooper et al. [89,92,93] compared Raman spectroscopy to both mid-IR and near-IR for the measurement of several parameters in fuel mixtures including aromatic concentrations, octane number, and vapor pressures. Cooper et al. similarly utilized partial least squares to accomplish the data analysis. In this series of articles. Cooper et al. described their attempts to quantify mid-IR, near-... 

The TPHCWG correlated chemical-specific leaching factors and volatilization factors for hydrocarbon compounds present in gasoline and crude oil with the Carbon Number Index, which is defined as the boiling point normalized to the n-alkancs. The correlation to Carbon Number Index was used because it closely follows chemical behavior in the boiling point gas chromatograph column and because the literature indicates that the various properties should be well correlated to this index (Gustafson 1995). 

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