Recent Advances in the Development of Metal–Organic Frameworks for Propylene and Propane Separation

Abstract

Separation of propylene (C3H6) and propane (C3H8) is a vital step for the manufacture of high-purity C3H6 as an important energy source and critical raw material in the petrochemical industry. Due to their similar sizes and properties, the separation of C3H6 and C3H6 is challenging and currently relies on energy-intensive cryogenic distillation. Metal–organic framework (MOF)-assisted adsorptive separation and membrane-based separation are revolutionary energy-saving technologies that can enable efficient gas purification under mild conditions. This review presents the current progress in C3H6/C3H8 separation achieved with MOFs and MOF-based membranes. The different separation mechanisms (including equilibrium separation, kinetic separation, gate-opening effect, molecular sieving, and combination of them) along with the materials design principles that contribute to benchmark C3H6/C3H8 separation are discussed. Diverse creative strategies for the fabrication of high-quality MOF membranes (both continuous membranes and mixed-matrix membranes) to surpass the tradeoff between selectivity and gas permeability are summarized. Lastly, this review also outlines the major challenges and opportunities of MOFs to be used for practical C3H6/C3H8 separation.

Remarkably Selective Propylene–Propane Separation Using a Copper Scorpionate

“…[9][10][11] Among the nondistillation methods, adsorptive and membrane-based C 3 H 6 /C 3 H 8 separation processes are gaining attention as they are relatively energy-efficient and afford high-purity propylene. [6,7,11,12] For example, several MOFs have recently been successfully demonstrated for size-selective sieving of C 3 H 6 from C 3 H 8 . [2,7,13,14] Furthermore, several high-performance porous metal-organic frameworks (MOFs) and hydrogen-bonded organic frameworks (HOFs) based adsorbents have also been successfully realized by us and our collaborators for propylene purification.…”

“…[6,7,11,12] For example, several MOFs have recently been successfully demonstrated for size-selective sieving of C 3 H 6 from C 3 H 8 . [2,7,13,14] Furthermore, several high-performance porous metal-organic frameworks (MOFs) and hydrogen-bonded organic frameworks (HOFs) based adsorbents have also been successfully realized by us and our collaborators for propylene purification. [8,[15][16][17][18] However, designing porous adsorbents with optimal pore size to produce the complete sieving effect and preparation of ultrathin MOF membranes are quite challenging.…”

“…[8,[15][16][17][18] However, designing porous adsorbents with optimal pore size to produce the complete sieving effect and preparation of ultrathin MOF membranes are quite challenging. [6,7] Some of these methods also suffer from low selectivity, limited uptake capacity, and slow adsorption kinetics. [7] Here, we report the use of a nonporous material based on a molecular copper complex in propylene-propane separation with remarkably high selectivity.…”

“…[6,7] Some of these methods also suffer from low selectivity, limited uptake capacity, and slow adsorption kinetics. [7] Here, we report the use of a nonporous material based on a molecular copper complex in propylene-propane separation with remarkably high selectivity.…”

“…[3,5,6] The industrial separation and purification of C 3 H 6 are mainly accomplished by capital and energy-intensive, distillation process which requires very tall towers containing over 100 trays and large reflux ratios. [3,7] The C 3 H 6 /C 3 H 8 separation process is in fact, even more energy-consuming than that utilized for ethylene-ethane separation. [8] Consequently, there is a great of 1 in CDCl 3 appear as broad signals at δ 103.5 and 84.4 ppm, compared with the corresponding resonance of the free C 3 H 6 , δ 133.9 and 115.7 ppm.…”