耐２‐プロパノン（アセトン）性逆浸透膜の開発研究

Abstract

Reverse osmotic concentration of aqueous 2-propanone (acetone) solutions was carried out, using cellulose acetate membranes and composite membranes (PEC-1000, FT-30 and NS-100). Separation of acetone and flux through the membranes were measured within the following ranges : concentration of acetone (C1) = 1 to 10wt% and operating pressure (ΔP) = 4-7MPa.PEC-1000 gave the best acetone separation. Its separation was above 90%. However, pure water permeation flux after experiment was reduced to the one-tenth of the initial value, remaining the same salt rejection, because of the degradation of support membrane.The acetone-proof composite RO membranes (ON membranes) of which support membrane was polyimide OF membrane were prepared. Separation of acetone and flux through the ON membranes were measured at the following conditions : C1 = 1 and 2wt% and ΔP = 1.96MPa.The permeation fluxes after experimemt remained unchanged for ON membranes.Membrane constants were calculated by Spiegler-Kedem's membrane transport model. The deviation from their model was corrected by the compaction coefficients.The estimated acetone separation for ON membrane was almost the same as the experimental value obtained for NS-100 P3500 membrane. The estimated flux was about 6 times larger than that for PEC-1000.Its separation and flux through the ON membrane (1wt% aqueous acetone solution RO concentration at 5.5MPa) was 92%, 0.25mol·m-2, s-1, respectively.