A reduced vapour pressure equation for use at low reduced temperatures

Abstract

Based on thermal and vapour pressure data for alkanes ranging from methane to n-hexadecane, a generalised vapour pressure correlation has been developed for reduced temperatures (T r) in the range 0.7 > T r > 0.4. The equation has the form: 1np 0 r = A r1nT r + B rT r − (D r/T r) + E r where the coefficients A r, B r, D r and E r are functions of acentric factor only. The accuracy of correlation achieved is better than given by the familiar Lee-Kesler correlation applied to alkanes in this range. Application to non-alkanes is discussed.