(152p) Adsorption Behaviors of C2–C3 Olefin and Paraffin on Zeolite 13X

Olefins are one of the most important products in the petrochemical industry. Among them, ethylene and propylene are regarded as essential building blocks for polymer and plastic industries. Since olefins from cracking and dehydrogenation processes are produced with unreacted paraffin, additional separation processes for olefin production are required. At present, cryogenic distillation is widely used, but the development of high energy-efficient processes is challenging due to the highly energy-intensive characteristics of the cryogenic process.

Adsorption technologies are reported as promising alternatives, but powder-type adsorbents are not applicable to industrial processes. In addition, due to the similar physical properties of propane and propylene, the separation efficiency of adsorptive cyclic processes was highly affected by the small variance in the adsorption behavior of the gases on the adsorbent.

In this respect, this study aimed to precisely investigate the adsorption behaviors of C2–C3 olefin and paraffin on the pellet-type adsorbent. In particular, the data at low pressures below 1 atm were carefully measured to evaluate adsorption affinity and selectivity. Adsorption isotherms were obtained at pressures up to 6 bar and temperatures at 303, 323, and 343 K via a volumetric method and well correlated with the dual-site Langmuir isotherm model. In addition, the isosteric heats of adsorption were calculated. Adsorption kinetics for each gas were also evaluated by applying a non-isothermal sorption model to experimental uptake. Based on the results, the adsorption mechanism and kinetic resistances of the olefin and paraffin on zeolite 13X pellets were elucidated. The results can contribute to designing cyclic adsorption processes using zeolite 13X for olefin separation.