DIPPR Project 851 – Thirty Years of Vapor–Liquid Critical Point Measurements and Experimental Technique Development

Abstract

Experimentally determined critical temperatures (T c ) and critical pressures (P c ) are reported for 64 compounds. In addition, the critical volume (V c ) has been experimentally determined for 14 of these compounds. The compounds in this study are of industrial interest in process design, simulation, and safety. These data also extend our understanding of and ability to predict these properties from group contribution methods.

Estimation of the critical properties of compounds using volume‐based thermodynamics

“…As stated, the global applicability of the proposed model for both polar and nonpolar compounds suggests the feasibility of interpolation and extrapolation within a particular compound‐family, alongside serving as a screening tool of GC methods to assess their adequacy for reproducing the general ratio trends. It should also be emphasized that although the critical property values used in the current study for the development of the proposed inter‐relationships have been carefully reviewed and revised over the course of four decades, 37‐41 nonetheless, no unanimous agreement currently exists between the reported critical properties of heavier compounds. In other cases, the available sources are rather limited.…”

“…In other cases, the available sources are rather limited. This being the case, care should be exercised when dealing with such instances, where experimental references are limited for comparative purposes and independent verification 41,74 …”

“…It should be reiterated that for the case of heavier hydrocarbons, independent verifications of the critical properties are yet to be accomplished and certain disagreements exist between the literature data, especially for the reported critical pressures 79,80 . As such, new insights are expected for such cases as ever more accurate data become available 41 …”

“…To develop predictive models to estimate the critical properties of compounds having low to high molecular weights, the data of 1,589 compounds belonging to 83 different compound‐classes have been collected 35,36 . All the pure component constants, as well as the temperature‐dependent data utilized in the current study, are critically‐evaluated data published by the steering committee of the Design Institute for Physical Property Data®, a subsidiary of AIChE, since the late 1970s as a joint‐industry cooperative physical property data endeavor 37‐41 . Nonetheless, care should be exercised in interpreting the results obtained, since a portion of the data are well‐educated estimates, as opposed to being purely‐experimental data, so that future updates may introduce meaningful alterations.…”

“…In order for the models not to be limited to the usual restriction of applicability to only homologous series, the databank collected consists of a wide range of compounds comprised of polar and nonpolar organics, as well as a number of inorganics. It is also worth pointing out that in the case of temperature‐dependent properties, linearly‐spaced estimated data have been employed 37‐41 …”