FIXED-BED ADSORPTION OF N-PENTANE ISOPENTANE MIXTURES IN PELLETS OF 5A ZEOLITE/

Breakthrough curves were measured in fixed-bed adsorbers containing pe llets of 5A zeolite (Rhone-Poulenc) with feed mixtures of n-pentane, i sopentane, and nitrogen. The experiments covered a temperature range o f 448-548 K and partial pressure of n-pentane up to 0.2 bar in a nonis othermal, nonadiabatic system. The effects of the partial pressure of the sorbate, temperature, and total flow rate of the mixture on the be havior of the system are studied. Fixed-bed desorption with inert gas is also addressed; Experimental data clearly show that the shapes of t he breakthrough and desorption curves are practically influenced by th e adsorption equilibrium isotherm of n-pentane and the heat effects in the system. A mathematical model was developed to simulate the experi mental data. Model parameters were estimated from independent experime nts (adsorption equilibrium isotherm and diffusivity) and from correla tions available in the literature (axial mass and heat dispersion and film mass transfer). Good agreement was found between the model predic tions and experiments. The model developed is now being used for the d esign of cyclic VSA/PSA separation processes.