Highly selective adsorption separation of light hydrocarbons with a porphyrinic zirconium metal-organic framework PCN-224

Light hydrocarbons are important raw materials in the petrochemical industry, mainly achieved by a cost intensive and energy-consuming cryogenic distillation. In this work, we reported a porphyrinic zirconium metal organic framework material, PCN-224, for the adsorption separation of C2 (ethane, C2H6) and C3 (propane, C3H8) hydrocarbons over C1 (methane, CH4). The Brunauer-Emmett-Teller (BET) surface area of the synthesized PCN-224 was 2704m(3).g(-1) and the pores were mainly centered at 12 and 16 angstrom. Gas adsorption experiments revealed that PCN-224 exhibited much higher adsorption capacities of C2H6 and C3H8 (2.94 and 8.25 mmol.g(-1) than that of CH4 (0.47 mmol.g(-1)) at 298 K and 100 kPa. The corresponding adsorption selectivity of C2H6/CH4 predicted by the ideal adsorbed solution theory (LAST) was 12. Particularly, the C3H8/CH4 selectivity reached up to 609 at the same conditions. Furthermore, the breakthrough experiments results showed favorable dynamic performance of PCN-224 for efficient separation of C2/C1 and C3/C1 mixtures. Additionally, PCN-224 exhibited excellent water stability after retaining its framework in water for 48 h. Therefore, PCN-224 is a promising material for the separation of C1-C3 hydrocarbons.