Page 76 - Gas Adsorption Equilibria

62 Chapter 1

This is in contradiction with the requirement for thermodynamic stability

which itself is a consequence of the Second Law of thermodynamics
[1.64, 1.68]. Hence this model proposition (P1) should not be used for
high pressure gas adsorption data.

The solid line next to data (1) is the best fit we could get for correlating
the data to a somewhat generalized Langmuir adsorption isotherm (AI) in
the –space,

with asymptotic mass and the exponent being
related to energetic heterogeneity of the sorbent surface, cp. Chap. 7, Sect.
2.1. Obviously the correlation is poor and unacceptable. For data
dispersions cp. Table 1.7.

2) Data present absolute masses adsorbed calculated from Eq. (1.34),
i. e. assuming and with having
been determined via the optimization procedure (1.33) using the
Langmuirian adsorption isotherm (AI)

parameters having a similar meaning as in (1.48). Though
reasonably could be correlated by the adsorption isotherm (1.49), it should
be noted that again for gas densities we have