The role of adsorbent microstructure and itspacking arrangement in optimising theperformance of an adsorption column

Abstract

Physical adsorption takes place inside narrow pores where the attractive interac-tion between the surface of the adsorbent and the contaminant molecules is strongenough to retain the molecules. Adsorption columns involve a range of mass-transport mechanisms: advection through the free spaces between the adsorbentpellets, diffusion through the wider pores of the adsorbent, and adsorption at thesurface, where the narrower pores exist. The adsorbent specifications along withits assembly within the sorption column are key factors when optimizing the fil-tration of pollutants. In this work we present a mathematical model based onadvection–diffusion equations coupled with Langmuir kinetics that accounts fora geometrical approach to the porosity structure inside the adsorbent and thechannels through which the fluid flows. The model is tested using typical lab-scalevalues, and we use it to identify potential design optimisation of the adsorbentmass and its assembly.