Solutions of a Selection of Partial Differential Equations with Application to Micropore Diffusion and Fixed-bed Adsorption
(P Haynes, J Aarao, B Benjamin, P Howlett, L White with P Pendleton and J-H Kim)
The process of adsorption is one in which one or more solutes are removed
from a fluid passing through an insoluble porous solid, called an adsorbent,
and accumulate on the walls of the adsorbent pores. Commercially viable
adsorbents have a large ratio of surface area to volume where the walls to
the pores provide the surface area. Activated carbon, having a low affinity
for water, is the most important adsorbent used in water treatment.
Activated carbons have different pore structures depending upon the raw
material used, activation conditions and activation techniques employed.
Although the pore-size distributions for adsorbents are known, existing mathematical models for the adsorption process do not consider that the rate of adsorption may be different in pores of different sizes. We, in collaboration with chemists, have developed a mathematical model for adsorption in a fixed-bed of activated carbon that incorporates a partitioning of the pore-size distribution. The model can be used for activated carbon adsorbents with their slit-shaped pores, or for other adsorbents with cylindrical pores. We have used the extended model to show that the results can differ if the adsorption rate (or the desorption rate) is different for different pore-sizes, and to explain a bump in the breakthrough curve.
Publications
P.D. Haynes and S.K. Lucas. Extension of a short-time solution of the diffusion equation with application to micropore diffusion in a finite system. ANZIAM J., 48:503-521, 2007.
External Collaborators
Phillip Pendleton (Center for Molecular and Materials Sciences,
University of South Australia)
Jung-Hee Kim (Department of Chemical Engineering, Pukyong National
University, Busan 680-739, Korea)
Funding
APA