CRITICAL PROPERTIES AND ACENTRIC FACTOR

To model the solubility of a solute in an SCF using an EOS, it is necessary to have critical properties and acentric factors of all components as well as molar volumes and sublimation pressures in the case of solid components. When some of these values are not available, as is often the case, estimation techniques must be employed. When neither critical properties nor acentric factors are available, it is desirable to have the normal boiling point of the compound, since some estimation techniques only require the boiling point together with the molecular structure. A customary approach to describing high-pressure phenomena like the solubility in SCFs is based on the Peng-Robinson EOS [48,49], but there are also several other EOS s [50]. 

Values of a-pj and bj for each component of the mixture are obtained with Equations 15-9 through 15-12 from a knowledge of the critical properties and acentric factors of the pure components. 

Coefficients for the vapor pressure equation are provided near the end of the book. Critical properties and acentric factor are given in the last section of the book. The tabulated values are especially arranged for quick usage with hand calculator or computer. Computer programs, containing data for all compounds, are available for a nominal fee. The programs are in ASCII which can be accessed by other software. Contact Carl L. Yaws, P.O. Box 10053, Lamar University, Beaumont, TX 77710, phone/FAX 409-880-8787. 

CRITICAL PROPERTIES AND ACENTRIC FACTOR - ORGANIC COMPOUNDS... 

In an engineering analysis, the critical properties and acentric factor are needed for ethylene (C2H4). Determine the critical properties and acentric factor for ethylene. 

Inspection of the tabulation for critical properties and acentric factor yields ... 

Table 1 Critical Properties and Acentric Factor - Organic Compounds... 

---