Synthesis Of Several Kinds Of Zr-MOFs And Their C1?C3 Hydrocarbon Adsorptive Performance

The separation and recovery of C2/C3 from natural gas and the separation of propene and propylene at normal temperatures and pressures are challenging issues for the petrochemical industry.In this work,three kinds of zirconium-based MOFs were prepared and their adsorption separation performances for light hydrocarbons C1/C2/C3 and C₃H₈/C₃H₆ mixtures were examined by experiments and molecular simulations.The findings of this work has theoretical significance and practical application value.UiO-67 materials were synthesized and its separation performances for C1/C2/C3 were examined by using static and dynamic adsorption experiments.Three models?IAST model,DIH equation and adsorptive transmission curve method?were used to calculate the adsorption selectivity of UiO-67 for C1/C2/C3 and then were evaluated for the first time.The adsorption selectivity of UiO-67 toward C₃H₈/CH₄ and C₂H₆/CH₄ binary mixtures were in range of 69-73and 7.3-8.1,respectively.The complete separation of C1-C3 components can be achieved at room temperature.Calculation simulations revealed that the density of these three molecules adsorbed in the tetrahedral sites and octahedral sites of UiO-67 materials followed the order:propane>ethane>methane.NU-1000 materials were synthesized and their adsorption isotherms and the heats of adsorption for C1,C2 and C3 were determined.The performance of dynamic separation of NU-1000 for C1,C2 and C3 was determined using a fixed bed.The adsorption selectivity of NU-1000 toward ethane/methane and propane/methane binary mixtures reached as high as 11.8 and46.1,respectively.Fixed bed experiments confirmed that the use of NU-1000 as an adsorbent can achieve complete separation of C1,C2 and C3 components under normal temperature and pressure conditions,and its separation performance was in the advanced level.Calculation simulations revealed that adsorption mechanism of C1,C2 and C3 in NU-1000.UiO-67-bpy was synthesized and its separation performance for C₃H₈/C₃H₆ was examined by experiments and molecular simulations.The resulting UiO-67-bpy exhibited characteristics of significantly preferential adsorption of propane over propylene.Its adsorption capacity for propane and propylene reached as high as 7.32 and 6.82 mmol/g,respectively,which was currently one of the best materials with super-high adsorption capacities of propane and propylene.Its propane/propylene adsorption selectivity was in the range of 5.2–1.5.Fixed bed experiments confirmed that use of UiO-67-bpy as an adsorbent can achieve complete separation of the propane-propylene mixture at ambient temperature and pressure with the help of a simple adsorption process.