A NEW CORRESPONDING-STATES GROUP-CONTRIBUTION METHOD (CSGC) FOR ESTIMATING VAPOR-PRESSURES OF PURE COMPOUNDS

A new method was proposed by combining the Corresponding-States Theore m with the Group-Contribution Method (CSGC) and a new vapor-pressure e quation was developed for estimating purpose. Group-contribution param eters of 117 functional groups were obtained by correlating 6540 datum points of experimental vapor pressures for 462 compounds, including a lkanes, alkenes, cyclohydrocarbons, aromatics, halogenated hydrocarbon s and compounds containing oxygen, sulfur and nitrogen etc. Predicted results for vapor pressures of 28 compounds show that the proposed equ ation with the normal boiling point temperature T(b) only is superior to the conventional Corresponding-States Methods. Furthermore, satisfa ctory results were also obtained by the proposed equation in estimatin g high vapor pressures of several compounds.