Volumetric properties of normal fluids at low temperatures: An extension of Pitzer's generalized correlation



The three-parameter tabular correlation of Pitzer et al. for calculating the compressibility factor of pure components has been extended to lower temperatures in the region where Tr is from 0.5 to 0.80 and Pr is from 0 to 9. The compressibility-factor is expressed linearly in the acentric factor Z = Z(0) + ωZ(1) with values of Z(0) and Z(1) tabulated in terms of Tr and Pr. The generalized correlation has been tested for 21 compounds with a total number of 463 data points. The average deviations in the calculated compressibility factors are 1.63% for the compressed liquids and 0.67% for the gases.