Computer simulations for the adsorption and separation of CH4/H2/CO2/N2 gases by hybrid ultramicroporous materials

Abstract

The adsorption isotherms of two types of hybrid ultra-microporous materials SIFSIX-3-M (M = Fe, Cu, Zn) and M′FSIX-2-Cu-i (M′ = Si, Ti, Ge) for H2, CH4, CO2 and N2 are comparatively studied by grand canonical Monte Carlo simulation (GCMC), and their differences are explained from pore structure and isosteric heat of adsorption. Natural gas and biogas upgrading (CO2/CH4), synthesis gas separation (CO2/H2), flue gas separation (CO2/N2), and steam methane reforming hydrogen production (CH4/H2) are simulated equimolar binary mixture system. The related separation factors are elucidated from the adsorption selectivity and the difference of isosteric heat of adsorption. The microscopic adsorption mechanism of the material is further analyzed by the preferential adsorption sites of the gas on the framework. Our works provide new insights into the adsorption and separation mechanism of HUMs for the energy-related gas, as well as in industrial application.