The effects of water residues on solvent adsorption cycles are investigated with a mathematical model which has been experimentally verified for steam regeneration. Adsorbers for recovering hexane vapors from humid air streams are simulated in cycles during which they are alternately loaded to 5% breakthrough and regenerated with a fixed amount of steam. The temperature of the feed determines whether a cycle is stable or unstable. An unstable cycle accumulates water, leading to flooding of the adsorber. Rapid changes in outlet temperature, flow rate, and solvent concentration occur immediately after steam regeneration, when the feed of solvent-laden air is reintroduced.