A procedure to draw membrane cascade schemes to separate an n-component gaseous mixture into n product streams, each enriched in one of the components, is presented. These n-component membrane cascade schemes are drawn by simple analogy with multicomponent distillation schemes for ideal mixtures. This procedure yields some interesting membrane cascade schemes with two-way communication between various subcascades present within the cascade structure. It also leads to n-component gas separation membrane cascade superstructures which have several n-component cascade schemes embedded within as substructures.