Benchmark Performance of One-Step Ethylene Separation: From Optimized Crystal Synthesis to Quantitative Mixture...

As highlighted by the development of C₂H₆-selective adsorbents for one-step separation of C₂H₄, adsorption is promising for chemical separation; however, the field still suffers from the lack of benchmark adsorbents and quantitative evaluation protocols. In this work, an amorphous-recrystallization method is developed to control the crystal size and morphology of the pioneering C₂H₆-selective adsorbent MAF-49. At the optimal crystal size, the C₂H₄ kinetic selectivity is negligible, enabling the highest productivity of 3.1 mmol cm^-3 for one-step C₂H₄ purification from the 15:1 C₂H₄/C₂H₆ mixture. Larger crystals exhibit higher C₂H₄ kinetic selectivity, which sharply decrease the C₂H₄ purification performance and can even lead to apparent C₂H₄ selectivity. Switching the column breakthrough experiment from the conventional outlet concentration mode to the outlet flow-rate mode and modifying the RUPTURA simulation code enable the quantitative evaluation and prediction of key parameters for gas mixture adsorption and separation, such as purification productivity, adsorption amount, and selectivity.