Effect of gas imperfection on G.L.C. measurements : a refined method for determining activity coefficients and second virial coefficients

1965 ◽  
Vol 61 ◽  
pp. 1637 ◽  
Author(s):  
D. H. Everett
Keyword(s):  
Activity Coefficients ◽  
Virial Coefficients ◽  
Second Virial Coefficients ◽  
Refined Method

The use of gas-liquid chromatography to determine activity coefficients and second virial coefficients of mixtures II. Experimental studies on hydrocarbon solutes

1966 ◽  
Vol 295 (1442) ◽  
pp. 271-287 ◽  
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Activity Coefficients ◽  
Virial Coefficients ◽  
Injection System ◽  
Gas Liquid Chromatography ◽  
Molal Volume ◽  
Carrier Gas ◽  
Second Virial Coefficients ◽  
Experimental Values

This paper describes apparatus of a new design for measuring accurately gas-liquid retention volumes in packed columns under carrier gas pressures up to 25 atm. It includes a high pressure soap-film flowmeter, a high pressure vapour phase sample injection system and a pressure control system at the column outlet which enables a flame-ionization detector to be operated at atmospheric pressure. Results are reported for a series of hydrocarbon solutes in three different stationary liquids (squalane, dinonylphthalate and n -hexadecane), with nitrogen, hydrogen and argon as carrier gases. Solute activity coefficients at infinite dilution in the stationary liquids, and second virial coefficients ( B 12 ) for the solute + carrier gas mixtures have been obtained by analysing the retention volume data by the procedure established in part I. The activity coefficients are compared with values obtained from static vapour pressure measurements made by two widely different methods, and the agreement is satisfactory in both cases. The second virial coefficients ( B 12 ) are compared with those values predicted by the principle of corresponding states via the reduced equation of state of McGlashan & Potter (1962). The B 12 values given by using the ‘geometric mean’ combining rule for the mixed critical temperature in the reduced equation of state differ from our experimental values by as much as 75 cm 3 /mole. Using the combining rule of Hudson & McCoubrey (1960) or that of Munn (1961), both of which take account of differences in molal volume and ionization potential between the two components, however, gives B 12 values which agree with our experimental values.

The Bender Equation of State and Virial Coefficients

2000 ◽  
Vol 65 (9) ◽  
pp. 1464-1470 ◽  
Author(s):  
Anatol Malijevský ◽  
Tomáš Hujo
Keyword(s):  
Equation Of State ◽  
Virial Coefficient ◽  
Virial Coefficients ◽  
Low Density ◽  
Second Virial Coefficients ◽  
The Third ◽  
Temperature Dependences ◽  
Experimental Values

The second and third virial coefficients calculated from the Bender equation of state (BEOS) are tested against experimental virial coefficient data. It is shown that the temperature dependences of the second and third virial coefficients as predicted by the BEOS are sufficiently accurate. We conclude that experimental second virial coefficients should be used to determine independently five of twenty constants of the Bender equation. This would improve the performance of the equation in a region of low-density gas, and also suppress correlations among the BEOS constants, which is even more important. The third virial coefficients cannot be used for the same purpose because of large uncertainties in their experimental values.

Sign in / Sign up

Export Citation Format

Share Document