Effect of ionic liquids in carbon nanotube bundles on CO2, H2S, and N2separation from CH4: A computational study

Abstract

Carbon nanotube (CNT) bundles are being explored as a support structure for four ionic liquids (ILs) in gas separation. Grand canonical Monte Carlo simulations were performed to investigate the CO2/CH4, H2S/CH4, and N2/CH4 separation performance in CNT bundles and CNT-supported ILs (CNT-ILs) as a function of pressure and IL loading. The results show that by adding ILs to the CNT bundles, the gas separation performance can be significantly increased. Increasing the number of IL molecules in the composites increases the separation performance. Such a phenomenon is more evident for the CO2/CH4 mixture in comparison to H2S/CH4 and N2/CH4. Calculations of isosteric heat of adsorption and selectivities in gas mixtures as a function of pressure show promising gas separation performance for CNT-ILs. Due to the excellent mechanical properties of CNTs, it has been shown that this structure may be used as a strong mechanical support for structures containing ILs with excellent CO2/CH4 separation performance.