Zeolitic imidazolate frameworks for kinetic separation of propane and propene.

Propane/propene separation by cryogenic distillation is one of the most energy and cost intensive industrial processes. Adsorptive separation is a more energy-efficient alternative. Three isostructural zinc imidazolate zeolitic framework materials are found, for the first time, to be very promising in the separation of propene and propane based on their different diffusion rates. Fine-tuning of the pore opening size is critical for this type of separation.