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 T r is from 0.5 to 0.80 and P r is from 0 to 9. The compressibility‐factor is expressed linearly in the acentric factor Z = Z (0) + ω Z (1) with values of Z (0) and Z (1) tabulated in terms of T r and P r . 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.