MOLECULAR SIMULATION OF CARBON CAPTURE AND SEPARATION IN A SERIES OF ISORETICULAR ZEOLITIC MATERIALS

摘要

In this work, adsorption and separation of CO2/CH4 were simulated by GCMC to study the effect of incorporating a different functionality in a series of zeolitic imidazolate frameworks (ZIFs) with the same topology. The magnitude of the contributions of electrostatic interactions in the adsorption of CO2 is found to correlate with the symmetry of the functionalization. Our calculations indicate that symmetry of the functionality and polarizability of functional groups increase CO2 uptake. The study of selectivity of CO2 in a representative natural gas CO2/CH4 mixture composition have showed the variation of the selectivity with pressure for ZIF-25 and ZIF-96. The simulation results in this work also revealed that gas adsorption and selectivity are not affected by the existence of humidity in ZIF-25 and ZIF-71 while the presence of humidity in ZIF-93, 96, and 97 affects gas adsorption and selectivity. The simulation results presented here could be used to guide future efforts to design ZIFs for carbon capture and separation and natural gas technologies.