Ultramicroporous Hydrogen-Bonded Organic Framework Material with a Thermoregulatory Gating Effect for Record Propylene Separation

Abstract

Propane/propylene separation is one of the most challenging and energy-consuming but most important tasks in the petrochemical industry. Herein, a stable hydrogen-bonded organic framework (HOF-FJU-1) was tailor-made for highly efficient propylene separation from binary C₃H₆/C₃H₈ and even seven component CH₄/C₂H₄/C₂H₆/C₃H₆/C₃H₈/CO₂/H₂ mixtures. The temperature-controllable diffusion channels in HOF-FJU-1 have enabled the porous material to completely exclude propane to reach high-performance propylene purification under energy-efficient operation conditions. Single-crystal structural analysis revealed that the well-matched pore aperture of HOF-FJU-1 can exactly accommodate propylene molecules via multiple intermolecular interactions, exhibiting a very high propylene/propane selectivity of 616 at 333 K. The propylene purity and productivity are over 99.5% and 30.2 L kg^-1 from the binary C₃H₆/C₃H₈ (50/50) mixture at 333 K. Through a follow-up column separation of C₃H₆/C₂H₄ at 353 K, not only high-purity propylene (99.5%) but also ethylene (98.3%) can be readily collected from the seven component CH₄/C₂H₄/C₂H₆/C₃H₆/C₃H₈/CO₂/H₂ (31/10/25/10/10/1/13) cracking gas mixtures. The great potential of HOF-FJU-1 for the industrial propylene separation process has been further supported by the high stability of this porous material under different environments and straightforward processibility and regeneration feasibility.