Page 225 - Gas Adsorption Equilibria
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4. Volumetric – Gravimetric Measurements 211
values in an EOS one gets and hence from eqs.
(4.49) new values Repeating this procedure i. e. calculating
n = 0,1,2..., i = l,2) from eqs. (4.49) by using
one will arrive in the limit of iterations at the
true sorptive masses
which via eqs. (4.50) will lead to the Gibbs excess masses adsorbed
i = l,2). A similar procedure can be used to calculate the absolute
masses adsorbed i = 1,2), in this case using the model equation (2.9) for
in eq. (4.43) instead of the helium approximation (2.7).
In case the two sorptive gas components (1,2) are mixed with a carrier gas
of molecular weight which practically is not adsorbed on the sorbent
material considered, densimetric – gravimetric measurements still can be used
to determine binary coadsorption equilibria of the (non-isomeric) components
(1, 2). However, the basic equations (4.41, 4.44, 4.47) have to be modified as
follows:
Sorptive gas density:
Thermal equation of state of sorptive gas mixture:
Total mass of gas supplied the adsorption chamber:
Mass concentrations of gas originally supplied to the adsorption chamber:
