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A system and method for removing water from a liquid desiccant such as a glycol used to dry cooled air in order to restore the desiccant to a purity up to around 97% in a closed continuous flow process. Liquid desiccant can be sprayed into cooled air in a conditioner where it gains moisture. The wet or gained desiccant can be optionally preheated in an economizing heat exchanger and then routed into a concentrator. Desiccant pure to around 97% can be removed from the concentrator, passed through an economizing heat exchanger to provide the preheating and returned to the conditioner holding area. The concentrator can be heated by steam or other means such as natural gas to boil the wet desiccant causing mixed vapor to enter a vertical distillation column where most of the glycol condenses out on the column packing or plates and returns to the concentrator. Almost pure water vapor normally passes out of the top of the column and can be condensed in a water-cooled (or otherwise cooled) condenser and collected or discarded as liquid water. A portion of the water can be piped back into the top of the column as a reflux stream that scrubs the column packing or plates of desiccant. In this way, the desiccant can be purified to around 97%.
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