Light olefins/paraffins separation with 13X zeolite binderless beads

In this work 13X zeolite binderless beads were tested as a new promising material for polymer-grade olefin production from olefin/paraffin mixtures by VPSA technology. In order to characterize the adsorbent and its potential for the target separations, the equilibrium isotherms of propane, propylene, ethane and ethylene were measured gravimetrically on a 13X zeolite binderless sample, in a temperature range from 50 °C to 150 °C and pressure up to 5 bar. Dynamic studies were performed at 100 °C and 1.5 bar in a fixed-bed single-column unit. The adsorbent under evaluation presented high olefin selectivity, with values between 7 and 9 for the C2 pair and about 8 for the C3 pair. A mathematical model was proposed and validated by the breakthrough experiments. With this model, pilot scale 5-step VPSA cycles were successfully designed and tested experimentally to produce polymer-grade olefins.