Cycling zone separation is a method of operating conventional separation devices that can be applied to a wide variety of separations such as adsorption, chromatography, and extraction. The basic technique developed by Pigford et al. (1) consists of cycling some thermodynamic variable in such a way that a continuously fed mixture is separated. The original work removed all solutes at once and has since been extended to multi-component fractionation by Wankat (2). A tutorial review of cycling zone separation was recently presented by Wankat et al. (3) and includes theoretical analyses and a description of experimental results.