Synergistic sorbent separation for one-step ethylene purification from a four-component mixture.

Purification of ethylene (CH), the largest-volume product of the chemical industry, currently involves energy-intensive processes such as chemisorption (CO removal), catalytic hydrogenation (CH conversion), and cryogenic distillation (CH separation). Although advanced physisorbent or membrane separation could lower the energy input, one-step removal of multiple impurities, especially trace impurities, has not been feasible. We introduce a synergistic sorbent separation method for the one-step production of polymer-grade CH from ternary (CH/CH/CH) or quaternary (CO/CH/CH/CH) gas mixtures with a series of physisorbents in a packed-bed geometry. We synthesized ultraselective microporous metal-organic materials that were readily regenerated, including one that was selective for CH over CO, CH, and CH.