Novel gas adsorption properties by room-temperature ionic liquids (ILs) confined in carbon nanotube (CNT) bundles were ascertained using grand canonical ensemble Monte Carlo (GCMC) simulations in which the adsorption and separation of CO(2 )from CO2/N-2 mixtures. The introduction of ILs into the CNT channels significantly enhances the adsorption of CO2, while it is not sensitive to N-2 adsorption. This is due to the strong interaction between specific ILs in the CNTs and CO2 molecules. The presence of water showed a significant impact on the adsorption capacity of CO2 as well. (C) 2018 Elsevier Ltd. All rights reserved.