Treatment of lower glycol-containing operative fluids
First Claim
1. A process comprising reclaiming lower glycol consisting essentially of one or more of monoethylene glycol, 1,2-propylene glycol and 1,3-propanediol, from fluid containing the lower glycol and at least one dissolved component by contacting the fluid with a feed side of a semi-permeable membrane under reverse osmosis conditions sufficient to permeate lower glycol to a permeate side of said membrane wherein the permeated lower glycol has a reduced concentration of said at least one dissolved component as compared to the concentration in the fluid contacted with the feed side of the membrane, said membrane(a) having properties for rejecting at least about 70 percent of sodium chloride contained in a 3.5 weight percent aqueous solution at Standard Conditions,(b) having properties for rejecting less than about 30 percent of monoethylene glycol contained in a 10 weight percent aqueous solution at Standard Conditions, and(c) having properties for rejecting at least about 90 weight percent of an eight mole ethoxylate of nonylphenol having an average molecular weight of about 570 contained in a 1.0 weight percent aqueous solution at Standard Conditions.
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Abstract
Operative fluids containing lower glycol are contacted with semi-permeable membranes under reverse osmosis conditions to permeate lower glycol to provide a reclaimed lower glycol product. Exemplary operative fluids include antifreeze solutions, heat transfer fluids, deicers, quenchants, hydraulic fluids, lubricants, solvents and absorbents.
43 Citations
20 Claims
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1. A process comprising reclaiming lower glycol consisting essentially of one or more of monoethylene glycol, 1,2-propylene glycol and 1,3-propanediol, from fluid containing the lower glycol and at least one dissolved component by contacting the fluid with a feed side of a semi-permeable membrane under reverse osmosis conditions sufficient to permeate lower glycol to a permeate side of said membrane wherein the permeated lower glycol has a reduced concentration of said at least one dissolved component as compared to the concentration in the fluid contacted with the feed side of the membrane, said membrane
(a) having properties for rejecting at least about 70 percent of sodium chloride contained in a 3.5 weight percent aqueous solution at Standard Conditions, (b) having properties for rejecting less than about 30 percent of monoethylene glycol contained in a 10 weight percent aqueous solution at Standard Conditions, and (c) having properties for rejecting at least about 90 weight percent of an eight mole ethoxylate of nonylphenol having an average molecular weight of about 570 contained in a 1.0 weight percent aqueous solution at Standard Conditions.
Specification