Abstract: This invention relates to a hollow fiber membrane device which can accommodate large changes in fiber dimension due to fiber swelling or contraction during operation.

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.