Method and device for separating polar from non-polar liquids using membranes

[54] METHOD AND DEVICE FOR SEPARATING POLAR FROM NON-POLAR LIQUIDS USING MEMBRANES

[75] Inventors: Robert DeVellis, Pleasant Hill;

Lawrence R. Schroeder, Danville; H.
Hunter Paalman, Walnut Creek;
Curtis M. Tong, Antioch; Terrence L.
Caskey, Concord, all of Calif.;
Charles W. Martin, Lake Jackson,
Tex.

[73] Assignee: The Dow Chemical Company,
Midland, Mich.

[21] Appl. No.: 921,940

[22] Filed: Oct. 21, 1986

[51] Int. C1.+ B01D 13/00

[52] U.S. CI. 210/640; 210/644;

210/651; 210/21.74

[58] Field of Search 210/640, 321.1, 651,

210/652, 500.23, 644, 321.74, 321.83

[56] References Cited

U.S. PATENT DOCUMENTS

FOREIGN PATENT DOCUMENTS

180204 10/1983 Japan .
206006 11/1984 Japan .
2139110A 11/1984 United Kingdom .

OTHER PUBLICATIONS

Charles T. Blaisdell and Karl Kammermeyer, "Counter-Current and Co-Current Gas Separation," Chemical Engineering Science, 1973, vol. 28, pp. 1249-1255.

Primary Examiner—Frank Spear
Attorney, Agent, or Firm—Norman L. Sims

[57] ABSTRACT

The invention is a method for separating one or more polar liquids from one or more non-polar liquids which comprises the following steps. First, contacting a mixture comprising one or more polar liquids and one or more non-polar liquids with one side of a membrane comprising a polymer of a perfluorosulfonic acid, or metal salt thereof, which is adapted for selective permeation of the polar liquids over the non-polar liquids under conditions such that the polar liquids selectively permeate through the membrane. Second, passing a desiccant fluid by, pulling a vacuum on, or a combination thereof, the other side of the membrane, under conditions such that the polar liquids which have permeated through the membrane are carried away from the membrane. Third, removing the fluid desiccant containing the permeated polar liquids or the permeated polar liquids wherein a vacuum is used, from the vicinity of the membrane. Fourth, removing the non-polar liquids from the vicinity of the membrane.

Another aspect of this invention is a novel hollow fiber membrane device useful for performing a preferred mode of the above-described method.

This method allows the removal of one or more polar liquids which are dissolved in or entrained in one or more non-polar liquids in a continuous manner which no shoft-term changeout required.

21 Claims, 3 Drawing Sheets