Separation of ethylene and ethane by adsorption on titanosilicate

The energy costs associated with ethane-ethylene separation could be significantly reduced by the development of alternatives to cryodistillation. This work examined ethylene recovery by equilibrium adsorption on two types of titanosilicate molecular sieve adsorbents, Na-ETS-10 and Zn-RPZ. A practical adsorptive separation of industrial process gas, with a measured binary bed selectivity for ethylene over ethane of approximately 5 at 25°C and 1 atm, was demonstrated using Na-ETS-10 as the adsorbent. The effects of different binder systems and separation flow rates on the mass transfer properties of Na-ETS-10 were examined in order to optimize the separation. High pressure and low temperature, similar to the working conditions in ethylene production plants, were found to increase the separation factor for these materials. Thermal, steam and microwave desorption methods were compared, and microwave desorption was determined to be the most efficient option for ethylene/ethane desorption and Na-ETS-10 regeneration.