Page 108 - Gas Adsorption Equilibria
P. 108
94 Chapter 2
This is a system of N linear equations from which the absolute adsorbed
masses of all components k = 1...N can be calculated. The symbol
for and for i = 1...N is the Kronecker Symbol. For the reference
density of the adsorbed phase an approximate value
with – according to experience – roughly estimated values of the expected
concentrations is used. Of course results can be improved by iteration, i.
e. using numerical solutions of (2.31) to get a new approximation for (2.32)
etc.
From either the set (2.30) or (2.31) the concentrations of
masses in the adsorbed phase i = 1…N and of mole
numbers i = l...N can be calculated. Hence the
selectivities of any two components i, k of the gas-adsorption-system
can be determined. These are key quantities for adsorption separation
processes.
4.3 Uncertainties or Errors of Measurements
We restrict this discussion to dispersions or mean square deviations
(MSD) of the Gibbs excess masses of component i = 1...N of a
multicomponent adsorbate as given by Eqs. (2.30). Applying the Gauss law of
propagation of error or uncertainty we have in view of (2.28), (2,24), (2.27):
