Reid vapour pressure as a route to calculating the flash points of petroleum fractions

The established method for calculating the flash point of a pure hydrocarbon compound such as benzene, which makes use of the Clausius-Clapeyron equation, is extended to petroleum fractions. This had not previously been thought possible, because of the fact that such fractions do not have a single normal boiling point for use as a limit in integrating the Clausius-Clapeyron equation. In this paper it is shown, with gasoline as an example, that the Reid vapour pressure can be used in place of the normal boiling point as a limit in the integration. Estimates of the latent heat of vaporisation and the lower flammability limit were also required, and these are explained completely.