Page 226 - Gas Adsorption Equilibria

212 Chapter 4

As the molar concentrations of the gas mixture originally
supplied to the adsorption chamber are assumed to be known, the total masses
of all components of the gas supplied can be calculated from (4.54, 4.55) by

From these quantities and eqs. (4.52, 4.53) the Gibbs excess of the
adsorbed components (1, 2) can be calculated via eqs. (4.45) as

with

Equations (4.57) include the compressibility factor

and hence need an iterative procedure for solution similar to that described
above, cp. eqs. (4.49, 4.51). For low initial concentrations of the sorptive
components (1,2), i. e. i = 1,2 , Z can be approximated by the real
gas factor of the pure sorptive gas, i. e.

thus avoiding any numerical iteration procedure.