A Generalized Correlation for Henry's Constants in Nonpolar Systems

Abstract

A generalized thermodynamic expression for Henry's constants is derived. The derivation is based on the statistical mechanics of dilute liquid solutions in conjunction with Scott's two-fluid theory and a reduced empirical equation of state; it is applicable to solid as well as fluid solutes. When Henry's constants are plotted against temperature, the correlation correctly predicts the maximum observed for some systems. The correlation is applied successfully to experimentally obtained Henry's constants covering seven orders of magnitude for 60 nonpolar binary systems.

Corresponding states. III. Henry's constants for nonpolar binary mixtures

“…This particular system is unusual because accurate data are available for it over a very wide temperature range, 180 to 510 K. The maximum deviation shown in Table 3 is 5%, and the average deviation is 0.8%. For this same system and for the same temperature range, Preston and Prausnitz (1971) report an average deviation of 23% for their method. Table 4 summarizes calculated results for a number of other binary mixtures.…”

“…Unfortunately such methods involve approximations which place serious restrictions on their applicability to mixtures and conditions of engineering interest. Preston and Prausnitz (1971) have developed one of the most widely applicable methods in which they successfully circumvented some of the less accurate statistical mechanical approximations.…”

“…Nakahara and Hirata (1969) have developed a solution model with some success for predicting Henry's constants in hydrogen-hydrocarbon mixtures. Miller and Prausnitz ( 1969), Funk and Prausnitz (1971), and Preston and Prausnitz ( 1971) have developed additional theoretical methods. Preston and Prausnitz in particular present one of the most accurate and most widely applicable methods available.…”

A generalized correlation for Henry's constants in nonpolar binary systems

“…Table 1 summarizes calculated results for a number of the binary mixtures. For comparative purposes, Table 1 also includes calculated results reported by Preston and Prausnitz (1971) and by Gunn et al (1974). As shown in Table 1, our procedure is more accurate than Preston and Prausnitz's procedure and gives similar accuracy to the procedure of Gunn et al which uses three interaction parameters, whereas our procedure requires two characteristic parameters, The overall average deviations for calculated Henry's constants from the proposed method.…”

“…Although the method of Sagara et al gives good results for hydrocarbon systems, the deviation is large for the calculation of Henry's constants containing hydrogen or nitrogen. Preston and Prausnitz (1971) have proposed one of the most widely applicable methods using statistical mechanical procedure. Gunn et al (1974) have developed a Henry's constant correlation from a macroscopic corresponding states theory for mixtures.…”