Ethylene Purification by Pressure Swing Adsorption with the Paraffin Selective Metal–Organic FrameworkDUT‑8

Finding ways to separate olefins and paraffin more efficiently has motivated the development of improved adsorbents for adsorption-based separations. Recently, metal–organic frameworks have emerged as a promising alternative. Thus, this work focuses on the potential application of DUT-8 for separating ethane and ethylene mixtures by pressure swing adsorption (PSA). To this end, a model-based PSA design strategy was employed. The adsorption equilibrium model was identified by fitting single equilibrium adsorption data of ethane and ethylene on DUT-8 at three temperatures and pressures of up to 10 bar to a quadratic Langmuir (QL) model. Multicomponent equilibrium results were predicted by ideal adsorbed solution theory and validated with binary breakthrough experiments. The identified model was used in an optimization problem that maximized ethylene recovery under two scenarios: 98 and 99.5% ethylene minimum purity. The particle swarm optimization method was employed to solve the optimization problem. The first scenario obtained a maximum ethylene recovery of 94.6%. In the second, a maximum ethylene recovery of 80% was obtained. Finally, data from particle swarm optimization history were reused to build the process feasible operating regionsa tool that allowed robustly characterizing various conditions at which the designed PSA can be operated at optimal performance