ISSN:
0001-1541
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
The Frost-Kalkwarf vapor-pressure equation has been modified to include as variables the reduced temperature and pressure of the substance. The resulting relationship was found to contain a universal constant δ = 0.1832 and three other constants α, β, and γ, which are characteristic of the substance. Relationships between α, β, and γ were found to exist, and thus a vapor-pressure equation was produced which contains only one characteristic contant β and which is capable of predicting vapor pressures of pure substances up to the critical point.This vapor-pressure relationship has been applied to hydrocarbons of all types, including normal paraffins, isoparaffins, olefins, diolefins, acetylenes, naphthenes, and aromatics. In these calculations values of β were estimated from the molecular structure of the hydrocarbons. For hydrocarbons the approach developed in this study was found to reproduce experimental vapor pressures with an average deviation of 2.7% for 456 experimental points representing fifty four hydrocarbons.This study indicates that if reliable vapor-pressure data, however meager, are available for a hydrocarbon, these data can be used to obtain constants which enable the prediction of the critical temperature and the critical pressure of the substance.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aic.690080318
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