AbstractThe separation of mixtures of helium and methane using a single column of activated carbon in a pressure swing adsorption process was studied experimentally. Process performace was predicted with an average error of 10% or less by a local‐equilibrium well‐stirred cell model in which dead volumes at the feed and product ends of the column were accounted for. Systematic differences between experiment and model were ascribed to omission from the model of flow resistance and heat rele