Determination of Equilibrium Parameters and Effective Pore Diffusion Coefficient of Light and Liquid N-Paraffins on SA Molecular Sieves.

The molecular sieves are selective adsorbents. They can
adsorb some kind of molecules that are different in size
or shape from the others. In separation of n-paraffins
from iso-paraffins and aromatics, SA molecular sieve is
the suitable adsorbent, and can adsorb n-paraffins to
separate them from other hydrocarbons.
In this paper equilibrium isotherms of n-CS, n-C6 and
n-C7 from an inert solvent, benzen (non adsorbed), on
SA molecular sieves, was determined, for single
component adsorption. The experimental data was
conducted on the Langmuir Isotherm and the parameters
of this model were determined.
On the other hand , the kinetics of adsorption of n-C6
and n-C7 have been determined in the finite bath
experiments; and the concentration profile of each
component versus time was determined.
The batch adsorption model based on pore diffusion
model had been written and calculated numerically. There
were film and pore diffusion resistances against the
n-parrfin adsorption, and also there was local equilibrium
between the pore fluid and the solid phase. The
equilibrium model was based on the Langmuir Isotherm.
By super position of batch adsorption model onto
finite bath experiments, the tortousity factor of adsorbent
structure and the film mass transfer were estimated.
By determination of tortousity factor , the pore
diffusion coefficient of each component was calculated.
This procedure is a general method to determine the
effective pore diffusion coefficient of any component into
the adsorbents.