Modelling of the fixed-bed adsorption of methane/nitrogen mixtures on silicalite pellets

In this work, the adsorption of methane and nitrogen on silicalite pellets packed in a fixed-bed has been studied. Equilibrium and kinetic measurements of the adsorption of methane and nitrogen on this adsorbent have been carried out. A model using the LDF approximation for the adsorption kinetics has been used to simulate the breakthrough curves of nitrogen and methane. The model predicted well the breakthrough curves obtained with methane/nitrogen mixtures. A PSA cycle was proposed to increase the methane content of a methane/nitrogen mixture (85/15), and its performance has been analyzed. With this cycle, a methane purity of 96% can be reached with a recovery of 74%, and with a productivity of 0.048 kgmethane kgadsorbent−1 h−1.