The simulated moving bed (SMB) is now a well-established adsorption process for obtaining high-purity products at a similarly high recovery. In principle, the SMB process can be, and has been, applied to gases, but application has been limited. Here, we reexamine the SMB process for separation of gaseous components in the light of recent developments in novel cyclic operating schemes for liquid-phase operation, with focus on cyclic modulation of the internal flow rates. A novel experimental single-column setup is employed to demonstrate the feasibility of the process, explore the effect of its major operating parameters, and illustrate the performance enhancements that are obtained by modulating the internal flows. The experimental feasibility and effectiveness of time-variable flow-rate operation for gas-phase SMB are assessed by optimizing and comparing classical, zone-modulated, and flow-modulated configurations for the separation of CH4CO2 over activated carbon using nitrogen as the carrier gas.