Regeneration of liquid desiccants and acid gas absorbing liquid desiccants
AssigneeThe Dow Chemical Company
InventorsGeorge W. Lyon, Roscoe L. Pearce
Life of this patent
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Abstract
This invention relates to the low temperature regeneration of liquid desiccants and acid gas absorbing liquid desiccants. Both classes of desiccants can be regenerated to separate water and/or water and acid gases to a satifactory degree under the pressure conditions employed at temperatures substantially below the normal boiling point of the dry desiccant or desiccant-water mixture by countercurrently contacting the desiccant to be regenerated in conventional distillation equipment with the vapors of an easily condensable hydrocarbon or hydrocarbon mixture which is substantially immiscible with the regenerated desiccant at the boiling temperature of the hydrocarbon or hydrocarbon mixture employed as a stripping agent.
Claims25
In a method of regenerating liquid desiccants or acid gas absorbing liquid desiccants or mixtures thereof, the steps comprising, feeding a rich liquid absorbent into an upper portion of a regeneration column, vaporizing by heat a normally liquid hydrocarbon or mixture of hydrocarbons substantially insoluble in the dried desiccant and in water, which hydrocarbon has a boiling temperature below the upper and above the lower critical solution temperatures of the mixture of the desiccant and the said hydrocarbon under the pressure conditions employed, passing the vapors upwardly through the rich liquid absorbent, said vapors being the sole source of heat added for regeneration of the desiccant, condensing overhead vapors from the regenerator out of direct contact with the rich liquid absorbent, separating liquid hydrocarbon from water, and returning at least a portion of the overhead hydrocarbon condensate to the regeneration column as reflux, passing a two phase liquid mixture from the regenerator into a separator to form a lean desiccant phase and a liquid hydrocarbon phase, passing the hydrocarbon phase into a vaporizer wherein the hydrocarbon phase is heated and vaporized for recycle to the regenerator, and removing the lean desiccant phase from the separator.
Dependencies are inferred from the claim text.