Method for preparing thin regenerated cellulose membranes of high flux and selectivity for organic liquids separations

摘要

A method is described for the production of regenerated cellulose membranes which method comprises the steps of: (a) dissolving a cellulose material to form a solution; (b) casting the cellulose solution into a film; (c) coagulating the cellulose solution film using an alkali alcoholic solution; (d) washing the coagulated cellulose film in an alcohol; (e) regenerating the cellulose film using acidic alcohol solution; (f) washing the regenerated cellulose membrane using an alcohol. The regenerated cellulose thus formed may be dried, if desired, preferably without a softener. The regenerated cellulose thus produced, when prepared in the form of a film or membrane, possesses higher flux and superior selectivity for organic liquid separation than regenerated cellulose membranes prepared employing aqueous solutions in steps b through e above and is most advantageously employed for the recovery of polar dewaxing solvents (e.g. ketones and mixed ketone/aromatic solvents) from dewaxed oil.