Mesoporous separation layers are commonly in the transient - regime among Knudsen diffusion and molecular diffusion, with large effects on the selectivity (

separation factor).

Current membranes are required to exceed 1000 gas permeation units (GPUs), and have a 'CO2/N2

separation factor' above 20 - a measure of their carbon-capturing specificity.

To investigate the process efficiency, the

separation factor ([alpha]) was also calculated, as exposed by Eq.

In addition, the ideal gas

separation factor or the [O.sub.2]/[N.sub.2] selectivity was estimated by (2) [3,10,14].

Calculation of Suitability of Adsorbent to Adsorbate/ Constant

Separation Factor. To determine the characteristic behavior of the adsorption, constant

separation factor (R) was used.

A dimensionless constant,

separation factor, RL was applied to given data to find the favorability of adsorption isotherm [32].

The technique of DFDS design offered earlier allows calculating its constructive and production characteristics, but does not provide the determination of flow

separation factor value, that is optimum from the point of view of cleaning efficiency.

Based on these values, retention factors [k.sub.1] and [k.sub.2], and

separation factor a are obtained as follows: [k.sub.1] = ([t.sub.1] - [t.sub.0])/ [t.sub.0] = 0.50, [k.sub.2] = ([t.sub.2] - [t.sub.0])/ [t.sub.0] = 1.17 and [alpha] = [k.sub.2]/[k.sub.1] = 2.34.

The essential characteristics of Langmuir isotherm can be expressed by the constant dimensionless number,

separation factor or equilibrium parameter ([R.sub.L]), which indicates the curvature of the sorption isotherm: if [R.sub.L] > 1, the isotherm is not favorable; if [R.sub.L] = 1, it is linear; 0 < [R.sub.L] < 1, favorable; [R.sup.L] = 0, irreversible.

It was found that the

separation factor of d-tryptophan in affinity ultrafiltration was increased with the increase in the BSA concentration and the decrease of the racemic tryptophan concentration due to preferentially permeation of unbound d-tryptophan through the membrane at pH 7 [9].

In order to determine whether the adsorption is favorable or unfavorable, the

separation factor, [R.sub.L] has been calculated using the following equation (6):