What you need to consider for a moment is the fact that zeolites and many other solids have large surface areas. Gases can bind to the surface of a zeolite, commonly the Langmuir isotherm is used to explain or consider this binding. The amount of gas on a solid (moles of gas per gram of solid) can be expressed using the following equation.
$q = kP/(1+kP)$
Where $q$ is the moles of gas per gram of solid, $k$ is a constant and $P$ is the pressure of the gas.
This equation relates to a model which has three assumptions.
- The solid has an array of identical sites
- A site can either have one gas molecule on it or none
- There is no communication between the sites.
If we have two gases present then for gas a we can write
$$
\begin{align}
q(a) &= \frac{kP(a)}{(1 + (kP(a)) + (k'P(b)))}\\
q(b) &= \frac{k'P(b)}{(1 + (kP(a)) + (k'P(b)))}
\end{align}
$$
If the values of k and k' are different then it is possible to use a bed of the solid to make a separation of the two gases. The plant you show uses a cyclic process in which one gas is absorbed onto a column and occasionally desorbed from the column. There are other applications of similar ideas in chemistry.
If we consider for a moment the classic Tc cow, this is Mo-99 which is adsorbed onto alumina. The binding of $\ce{Mo}$ as molybdate onto alumina is much stronger than that of pertectinate. I am sure that if one was to do experiments with very small amounts of Mo or Tc as the anions then it would be possible to measure the values of K for these anionic metal complexes onto alumina. Then we could use the same Langmuir equation to model and understand a Tc cow (Tc-99m generator).
Another use of the same maths is in soil chemistry, for the adsorption of a small amount of a metal onto the surface of soil minerals it is common to use Kd values to predict what happens. Consider for a moment a soil which contains a very small trace of uranium or zinc.
Under these conditions the concentration in the soil water is directly proportional to the concentration of the metal in the soil. This is at the low concentration set of conditions where
$[\ce{M}]_\text{aq} = k[\ce{M}]_\text{soil}$
The way to get this is to write
$[\ce{M}]_\text{soil} = k'\frac{[\ce{M}]_\text{aq}}{1 + (k'[\ce{M}]_\text{aq})}$
Where $k'[\ce{M}]_\text{aq}$ is much less than one then we can write
$[\ce{M}]_\text{soil} = k'[\ce{M}]_\text{aq}$
So $k = 1 / k'$
Under some conditions in soils (and zeolites) when the concentration of either the gas or the metal is high then we can deviate from the simple conditions. In a soil we can reach a situation where all the binding sites for a metal are occupied, under these conditions the Langmuir equation will be a better way of modelling the metal concentration in the soil rather than assuming that the metal content of the soil water is directly proportional to that metal concentration in the solid particles in the soil.
As an alternative in soil we can reach solubility limits, for example if I add lime to my garden soil then we can reach the solubility limit for calcium carbonate. Again the soil will deviate from the simple model of
$[\ce{M}]_\text{aq} = k[\ce{M}]_\text{soil}$
In a zeolite we can at high coverage of gas we can get adsorption of gas molecules onto other gas molecules (see the BET isotherm for more detail) we can also get other effects such as liquid gases condensing into pores of silicas and zeolites.
I think that to understand the zeolite system then you would need to make a lot of measurements of isotherms for the adsorption of both nitrogen and oxygen onto the zeolite. Doing this at different temperatures would also help you understand the system better as well.
Another thing you need to consider is how quickly does diffusion in and out of a zeolite particle occur, this will make the system more complex. If you want to understand this kinetics issue then I suggest that you read about the maths of GC columns. The resolution of a GC column goes down both at low and high flow rates. A good mathematical model exists for HPLC and GC columns, I recall it was published years ago by a Dutch chemist.
I will warn you that many systems do deviate from the Langmuir isotherm model.